4341 4345.output

* GB784748 (A)

Description: GB784748 (A) ? 1957-10-16

Improvements in or relating to hair curlers

Description of GB784748 (A)

PATENT SPECIFICATION Date of filing Complete Specification: Jan 10, 1956. Application Date: Oct 20, 1954 No 21058/54. Complete Specification Published: Oct 16, 1957. Index at Acceptance:-Class 131, B 4 (A 3: A 4: D). International Classification:-A 45 d. COMPLETE SPECIFICATION. Improvements in or relating to Hair Curlers. We, GABRIELLE DINGER, of 84 Hallwylstrasse, Zurich 4, Switzerland, and ALBERT EDWARD LANGLEY, of 33 The Kingsway, Swansea, Glamorgan, both British Subjects, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention concerns improvements in or relating to hair curlers. It is an object of the present invention to provide an improved hair curler suitable for use in permanent waving or curling, 13 setting or temporary waving or curling of the hair, which, whilst being simple and cheap to manufacture, is particularly easy and quick to manipulate. Thus according to the present invention there is provided a hair curler comprising a body around which the hair is to be wound, a rod disposed within and extending longitudinally of the body and being both slidable and rotatable relative thereto, said rod having rigidly secured thereto or integral therewith at one end thereof a hair retaining finger which when the rod is disposed to the fullest extent within the body overlies the body and is spaced therefrom, the other end of the rod being suitably shaned so as to prevent complete withdrawal of the rod from the body and co-operating locking means on

said rod and body which when the rod is disposed within the body to the fullest extent serve to Drevent relative rotation between the rod and body. In order to wind the hair upon the curler the rod is first withdrawn to its fullest extent so that the hair retaining finger no longer overlies the body After the hair has been wound on the body, in either direction of winding, the rod is returned to the fullest extent within the body in which position it is locked against rotation with respect to the body and hence the hair retaining finger which now overlies the hair, prevents it unwinding. It will be appreciated that it is unnecessary for the hair retaining finger to grip the hair in order to prevent it unwinding and hence the hair is not kinked or dented as commonly occurs with existing curlers e g. curlers using elastic bands to retain the hair. The hair retaining finger can if desired be so shaped that its ends will be closer to the body than the intermediate portion thereof. Preferably the surface of the body of the curler is roughened to provide a better grip on the hair when winding it thereon Thus we may provide roughening projections on the surface such as, for example, longitudinally extending ribs Alternatively or in addition we may cover the surface of the body with gauze or other like material If desired the ends of the body may be knurled or serrated to assist in manipulation. It will be understood that the curler may be made in different sizes in order to produce curls or waves of different shapes and of any suitable material or materials e g. wood, metal or plastic e g nylon Furthermore the body of the curler may be solid with a longitudinal bore therethrough or may be of composite structure A preferred form of composite structure suitable for use in the permanent waving or curling of hair comprises a tubular hair contacting part and an inner tubular member mounted therewithin which serves to receive the rod The tubular hair contacting part is preferably perforated and covered with gauze. Various forms of locking means may be provided to prevent relative rotation between the rod and body when the rod is 7849748 within the body to the fullest extent We prefer however to provide a locking member either mounted on or integral with the rod adjacent either end thereof and a corresponding shaped recess or aperture suitably disposed in the body to receive the locking member when the rod is disposed to the fullest extent within the body Preferably we provide the locking member and recess or aperture with corresponding longitudinally extending serrations around the circumference thereof. We prefer to form the rod and hair retaining finger integrally of a

metal rod or wire suitably bent to the required shape although it will be understood that the rod and hair retaining finger may be formed separately and of different materials and then rigidly secured together in any suitable manner When however the rod and retaining finger are formed integrally of metal rod or wire we prefer to cover the hair retaining finger with a sheath of rubber, plastic or other material. In order that the invention may be well understood, there will now be described, two preferred embodiment thereof by way of example only, with reference to the accompanying drawings, in which: Fig 1 is a longitudinal section through one preferred form of curler according to the invention; and Fig 2 is a similar view of another preferred form of curler. Referring to Fig 1 of the drawings the curler comprises a body including a tubular hair contacting part 1 and an inner tubular member 2 which is mounted on the part 1 by means of two collars 3, 4 mounted one at each end of the member 2 which fit tightly within the part 1 and are secured in position The part 1 is provided with numerous perforations 5 and is covered by gauze 6 A plug 7 is also partly within one end of the part 1 and abutting against the collar 4 The plug 7 is provided with a recess 8 having longitudinally extending serrations 9 around the circumference thereof which recess communicates with the member 2 through an aperture 10 in the base thereof The aperture 10 is of smaller cross-section than the member 2. A rod 11 and hair retaining finger 12 are formed from a single length of a wire bent to the required shape Mounted on the rod 11 is a tapered locking member 12 of complementary shape to the recess 8 and also having serrations 13 around its circumference which are adapted to engage the 6 o serrations 9 of the recess 8 to prevent relative rotation between the rod and body The hair retaining finger 12 is covered by a rubber sheath 14. The end 15 of the rod 11 is swaged to a diameter greater than that of the aperture to prevent the complete withdrawal of the rod 11 from the body of the curler. Referring to Fig 2 of the drawings there is shown a curler which comprises a solid body 16 which tapers from each end to a 70 minimum cross-section at the centre, having an axial bore 17 extending from one end of the body and communicating with a recess 18 formed in the other end of the body through an aperture 19 of reduced 7 5 r diameter A rod 20 disposed within the bore has an abutment 21 at one end thereof which will not pass through the aperture 19 and thus prevents complete withdrawal of the rod from the body A locking member So 22 is mounted on the rod at its other end and both it and the recess 18 are provided with longitudinally extending serrations 23, 24 in similar

manner to the locking member 12 and recess 8 of the curler shown in Fig 85 1 A hair retaining finger 25 forms an extension of the rod 20 and is covered by a rubber sheath 26. The operation of the curlers of Figs 1 and 2 is identical In order to wind the 90 hair on the bodies thereof the rod 11 or 20 and hence the finger 12 or 25 are withdrawn as far as possible to the left as shown in the drawings but in each case are prevented from complete withdrawal by the swaged hi end 15 and abutment 21 respectively After winding the hair on the body in either direction the rod 11 or 20 is returned to the fullest extent within the body so that the locking member 12 or 22 engages the recess 100 8 or 18 and the mating serrations thereof interlock to prevent relative rotation -of the rod and body so that the finger 12 or 25 which now overlies the hair wound on the body Prevents the hair from unwinding It 105 will thus be seen that both the construction and utilisation of these curlers is particularly simple and effective. Although two preferred embodiments of the invention have been described in detail 110 by way of example only, it will be understood that alterations and modifications thereto may be made without departing from the scope of the invention as defined in the appended claims 115

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* GB784749 (A)

Description: GB784749 (A) ? 1957-10-16

Improvements relating to lamp standards and the like


PATENT SPECIFICATION

Inventor:-THOMAS CROPPER RYLEY SHEPHERD. i Date of fllingj Complete Specification: Nov 29, 1955. Application Date: Dec 13, 1954 No 36038/54. Complete Specification Published: Oct 16, 1957. Index at Acceptance Class 45, F. International Classification:-E 02 d. COMPLETE SPECIFICATION. Improvements relating to Lamp Standards and the like. We, THE EDISON Sw AN ELECTRIC COMP At AY LI Mn TED, a British Company, having its registered office at 155 Charing Cross Road, London, W C 2, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:This invention relates to lamp posts or standards and to other posts or standards such as are used for example in mounting traffic lights or signs, and for supporting overhead power supply lines for trolley buses. Hitherto it has been common practice for such lamp, or other posts or standards to be erected in one piece with a length thereof buried below ground and supported usually in concrete poured into a hole in the ground at the time the post or standard was erected. The present invention provides an improved construction which facilitates erection, reduces transport costs and affords other material advantages as will hereinafter appear. According to the present invention a lamp or other post or standard comprises a precast or preformed plinth and a hollow column, wherein the plinth is in the form of a substantially solid block wholly or substantially buried below ground level or adapted to be so buried, and includes an upwardly extending spigot co-operating with the lower end of the hollow column to provide support of said column in directions longitudinally and transversely thereof, said block being provided with a through passage for an electrical cable between an opening located below ground level and an opening in the upper face of said spigot within the bore of the hollow column Conveniently, the hollow column may be constructed of an aluminium or other _gkigtalloy The cables or leads lPr l will enter the plinth at a level which will be below ground and pass directly through it into the interior of the column for connection 45 to the lamp or sign or wiring system at the upper end of the column. In addition to the support of the column afforded by engagement of the spigot in the open end of the column, it is also contem 50 plated to seat the end of the column in a groove in the face of the plinth extending round the spigot This groove may advantageously be tapered in cross-section With this arrangement, it is envisaged that, after 55

the column is mounted in position on the plinth, the channel will be filled with sealing material, conveniently a thermo-setting material such as bitumen whereby to prevent corrosion and erosion at the bottom of the 60 column. One embodiment of the invention will now be described by way of example with reference to the accompanying drawing, the single Figure of which is a sectional side view 65 of the lower part of the lamp post or lamp standard. The post or standard comprises a precast concrete plinth 1 having a generally rectangular cross-section and a hollow aluminium alloy 70 column 2 The plinth is provided at the top thereof with a spigot 3 preferably tapered inwardly in the direction of the column A channel 4 of tapered crosssection extends peripherally round the lower 75 end of the spigot Said plinth is cast with a substantially L-shaped electrical conduit extending through it from the end face of said spigot to emerge at a side of said plinth. In erecting the lamp post or standard the SO plinth is submerged in the ground with the spigot projecting vertically upwardly above pavement level ( 6) Thereafter an enlarged end 7 of the aluminium alloy column is 784,749 784,749 placed over the spigot so as to seat in the channel 4 The channel is filled with bitumen 8 whereby to provide a waterproof seal between the column and the plinth at or substantially at pavement level While the bitumen is still fluid the column is finally set in the desired vertical position by means of tapered wedges 9 engaging between the tapered spigot and the adjacent 1 fs inner surface 10 of the enlarged end of the column The wedges which may be inserted through a door or panel (not shown) in the side of the column enable small adjustments of the vertical position of the column to be effected.


* GB784750 (A)

Description: GB784750 (A) ? 1957-10-16

Process for the treatment of boiler feed water

Description of GB784750 (A) Translate this text into Tooltip

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The EPO does not accept any responsibility for the accuracy of data and information originating from other authorities than the EPO; in particular, the EPO does not guarantee that they are complete, up-to-date or fit for specific purposes.

PATENT SPECIFICATION Inventor: JOHN ALAN GRAY 784,75 O Date of filing Complete Specification (under Section 3 ( 3) of the Patents Act, 1949): Dec 2, 1955. Application Date: Dec 20, 1954. Application Date: Oct 11, 1955. No 36832/54. No 28935/55. ' Complete Specification Published: Oct 16, 1957. Index at acceptance:-Classes 46, B 11 B, C; and 123 ( 1), D 2 B. International Classification:-C 02 b F 061. COMPLETE SPECIFICATION Process for the Treatment of Boiler Feed Water ERRATA SPECIFICATION No 784,750 Page 1, line 92, for " 20 " read " 200 " Page 2, line 108, the formula "( 3 Mg O 2 T Si O 2 H,O)" should read "( 3 Mg O 2 Si O 2 H,O) THE PATENT OFFICE, 12th December, 1957. z ERRATA SPECIFICATION NO 784, 750 Page 2, line 92, for " 20 " read " 200,". 3 Page 2, line 108, the formula ( 3 g O T 22 H) sh O Uld read "( 3 Mgo 28102 2)H 20) THE PATENT OFFICE, 31st Decemnber, 19 f 7 intervalo l be done is generally governed by the maxiniurn content of dissolved and suspended solids the boiler water can carry without foaming Sometimes the sludges are less free-flowing and resist removal by blowing-down but can still DB 01820/2 ( 9)/3624 150 12/57 R magnesium content of te IC wa UL Lo advantageous to raise it by additions of suit 90 able magnesium compounds Starch and tannins are known to modify the types of prePATENT SPECIFICATION Inventor: JOHN ALAN GRAY 7849750 Date of filing Complete Specification

(under Section 3 ( 3) of the Patents II S 17 9 Act, 1949): Dec 2, 1955. Application Date: Dec20, 1954 No 36832/54. Application Date: Oct11, 1955 No 28935/55. w W / Complete Specification Published: Oct16, 1957. Index at acceptance:-Classes 46, Bli B, C; and 123 ( 1), D 2 B. International Classification:-CO 2 b F 061. COMPLETE SPECIFICATION Process for the Treatment of Boiler Feed Water We, IMPERIAL CHEMICAL INDUSTRIES LIMITED, of Imperial Chemical House, Millbank, London, S W 1, a British Company, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention relates to a process for the treatment of water for steam generation in boilers, and more particularly to those boilers and waters with which operating pressures and other conditions are such that calcium carbonate is precipitated inside the boiler. When boiler feed water is softened and conditioned before it enters the boiler system any compounds precipitated as a result of the treatment may be removed by settling or filtering and consequently find their way into the boiler only in such small amounts as cause little trouble during steam generation It is different when the water treatment is applied to water already in the boiler or in a feed vessel not arranged for settling for then nearly all precipitation of compounds takes place in the boiler and causes sludges to be formed. Such sludges consist to a large extent of calcium carbonate since waters used for steam generation often contain in the raw state more calcium compounds than any others, for example magnesium compounds; some contain silicon compounds and a few contain aluminium compounds, but the amounts of the former are usually small in relation to the calcium compounds, and the amounts of aluminium compounds usually do not exceed one or two parts per million expressed as A 120, Sometimes these sludges are freeflowing and may be prevented from accumulating by blowing-down the boiler at intervals The frequency with which this has to be done is generally governed by the maximum content of dissolved and suspended solids the boiler water can carry without foaming Sometimes the sludges are less free-flowing and resist removal b lwing-down but can still be removed from the empty boiler by means of a jet of water Sometimes they form deposits that cement together insoluble particles formed elsewhere and then they are too compacted to be removed except by mechanical means such as chipping or scraping It follows that sludges that are not free-flowing enough to be removed by blowingdown are a cause of increased cleaning and maintenance costs

and can, if not removed, lead in the end to failure of the boiler through overheating of metal heat-transfer surfaces and through other causes. It is an object of this -invention to provide a process for treating boiler feed water whereby all precipitated solids in the boiler are in the form of a sludge that is free-flowing and non-adherent and consequently able to be removed by blowing-down. A further object of the invention is to provide a process for treating boiler feed water that in addition to rendering boiler sludges free-flowing will prevent or reduce to negligible amount the formation of calcium carbonate scale on surfaces inside the boiler. It is known that to be free-flowing and easily removed by blowing-down a sludge should in general be highly flocculent It then has a high water content, of the order of 80 % calculated on the settled sludge, is readily maintained in suspension by circulating water and if allowed to settle does not compact to a dense deposit but is taken up into suspension again when circulation is resumed, or flows towards a blow-down outlet. Various chemicals are commonly used to improve the mobility of sludges, for example tannins, starch and sodium aluminate The latter is sometimes useful in combination with starch or tannin when the magnesium hardness of the feed water is more than 15 % of the total hardness; in some such cases where the magnesium content of the water is low it is advantageous to raise it by additions of suitable magnesium compounds Starch and tannins are known to modify the types of pre_ <<<CHAR-SET=99>>> ipitates produced in the boiler and it has usually been considered that the presence of a flocculent magnesium aluminate gel in a sludge was the essential factor in making the sludge free-flowing, though as far as is known the use of sodium aluminate, starch, tannin and other materials has been on an empirical basis and not related in any recognisably regular way to feed water composition. We have now discovered that contrary to the commonly held belief that behaviour of a sludge is mainly dependent on the amount of aluminium compounds present in the environment it is in fact the concentration of magnesium compounds that is decisive We have also discovered how to relate numerically the concentration of magnesium compounds required to make a sludge free-flowing to the concentrations of other substances present in a feed water. Accordingly the present invention provides in the known alkaline treatment processes as hereinafter defined given to boiler feed waters and boiler waters, a method for rendering the resulting boiler sludges free-flowing characterised in that a readily-soluble magnesium compound is added to the boiler feed water in such amount that the

value of the expression Mg O 2 l Si O 2 Ca O 3 3 in which Ga O, Mg O and Si O 2 are respectively the equivalents in moles of the calcium, magnesium and silicon compounds in the boiler feed water, is greater than 4 and preferably greater than 7. It should be emphasised that any adjustment of the concentration of magnesium compounds in a feed water in accordance with the above expression of our invention is supplementary to, and in no way replaces, the known customary alkaline treatment given to waters to condition them for steam generation, and it should be accordingly understood that the operation of our invention is dependent on the maintenance in the water of that degree of alkalinity which normally follows from such alkaline treatment, for example the addition of sodium carbonate or caustic soda, together, if desired, with other substances such as antifoam agents, deoxygenating agents This degree of alkalinity is usually equivalent to several hundred parts per million of sodium carbonate In this known alkaline treatment it is customary to inject a solution of the alkali and any other desired additives into the boiler, or into the feed water before it enters the boiler, or to allow the feed water, or part of it, before it enters the boiler to flow through a vessel containing the alkali and any other desired additives in solid soluble form. Common to all these alternatives is the fact that the water-conditioning reactions occur inside the boiler and not in some external settling vessel. The process of our invention is applicable to all feed waters generally used for industrial 65 purposes Such waters may conveniently be classified as (i) waters of lakes and streams in moorland country, (ii) waters of lakes, reservoirs, rivers and canals in lowland country, (iii) water from wells, springs and 70 lower measures of coal mines In the first of these classes the water is soft; the combined concentration of dissolved calcium and magnesium compounds is in general in the range of about 0-50 parts per million (ex 75 pressed as Ca CO,), and the concentration of silicon compounds is from 0-10 parts per million (expressed as Si O 2) Waters of the second and third classes stretch from those moderately soft to those that are very hard; 80 the concentrations of dissolved calcium and magnesium compounds falling roughly within the range 50-300 and 10-75 parts per million (expressed as Ca C Ou) respectively, the concentration of silicon compounds being 85 about 10-15 parts per million (expressed as Si O 2) as a rule. As discussed above, most boiler sludges consist of calcium carbonate This comes about because the treatment applied in the large 90 numbers of boilers operating at pressures less than about 20 lb /sq inch or at any pressure at which calcium carbonate can be precipitated usually

takes the form of additions of sodium carbonate or caustic soda, along with various 95 other auxiliary materials such as sodium aluminate, phosphates, tannins, starch The sodium carbonate or caustic soda reacts with the soluble calcium compounds responsible for most of the hardness of the feed water and 100 precipitates calcium carbonate as a result. We have found from an examination of numerous boiler sludges that the least mobile are composed almost entirely of calcium carbonate in the form of calcite Free-flowing 105 sludges we find on the other hand to contain proportions of one or more of serpentine ( 3 Mg O 2 T Si O 2 2 H 0), kaolinite (AL-0, 2 Si O 2 21120) and magnesium hydroxide In general non 110 mobile sludges are not flocculent whereas free-flowing sludges are highly so, and in fact the most desirable property to induce in a boiler sludge is high degree of flocculation, which comes about when a magnesia or 115 magnesia/alumina gel is present in it though the dominant factor in the latter is the part played by the magnesia Another desirable objective is for the crystal shape of the compounds constituting the sludge to be that of 120 long needles, since these do not readily compact once they have settled. We have discovered further that in all cases where the amount of magnesium compounds in a feed water has been adjusted to comply with 125 the expression of our invention, the formation of calcium carbonate scale on surfaces inside the boiler is prevented or at least reduced to a 784,750 aluminium compounds may be ignored calculating the value of the expression Mg O 2 negligible amount It is not clear how this comes about since absence of scale makes it impossible to discover by analysis what part magnesium compounds play It is known that some magnesium compounds can remove silica from water, and in so far as a calcium carbonate scale may have its tenacity increased by the presence of silicon compounds, removal of silica would weaken such scale but could not account for its not being formed at all It may be that many examples of socalled calcium carbonate scale are in fact adherent deposits of compacted calcium carbonate sludge, and if that were so one would not expect to find evidence of scale whenever sludge was free-flowing. In calculating the value of the expression Mg O 2 l Si O 2 l Ca O 3 3 one requires analytical data for the calcium, magnesium and silicon compounds present in the raw water Thus the accuracy of the value depends on the accuracy with which these data are determined and on the experimental errors involved In fixing a minimum value for the expression one ought therefore to take these things into account if the invention is to be practised successfully Basing our calculations on analytical data of the highest accuracy we have found that if the value is less than 4 the chance of a sludge being free-flowing is so

small as to be negligible; if between 4 and 7 some sludges are likely to be free-flowing, and if greater than 7 the probability of a sludge not being free-flowing is virtually zero Likewise with regard to the formation of calcium carbonate scale: below a value of 4 scaling occurs readily, between 4 and 7 it is diminished in degree and above 7 it is substantially prevented altogether To allow for large errors in analysis of the water and for inaccurate control of the process, one might recommend the minimum to be set at a higher value, for example 10, since in general the higher the value the more free-flowing the sludge, though beyond values of about 25 no significant improvement is obtained But to set the minimum as high as 10 merely for such reasons would be to deny the force of the observations that it can be safely as low as 7 always, and in some cases as low as 4. As discussed above, we now have found that it is not necessary, as far as sludge control and calcium carbonate scale prevention are concerned, to add aluminium compounds to the water but it is necessary to consider the circumstances that arise when the water already contains aluminium compounds. There are examples of feed waters that contain small amounts of alumina, and it may sometimes be desirable to add aluminium compounds, for example sodium aluminate, to the water for other reasons We have found that in such aluminium-containing waters the in l a Si O 2 l Ca O 3 3 and provided the value is greater than 4 and preferably greater than 7 sludge formed in boilers fed with the waters will be free-flowing and calcium carbonate scale formation 70 negligible It has been stated that adjustment of the magnesium content of a water is supplementary to and in no way replaces the normal alkaline conditioning treatment given to boiler waters by known methods In the same way it 75 is supplementary to other treatments given to some waters from time to time for other purposes, for example the addition of antifoaming agents, or de-oxygenating agents including tannins Among antifoaming agents 80 compatible with the process of the invention are certain polyoxyalkylene glycols having a molecular weight greater than 1000, for example polyoxyethylene glycols and polyoxypropylene glycols; certain mono and 85 diethers of polyoxyalkylene glycols having molecular weights greater than 500, for example the mono-butyl ether of a polyoxypropylene glycol and the dicetyl ether of polyoxyethylene glycol; certain polyacyl poly 90 amines, for example di-palmityl ethylene diamine Among de-oxygenating agents sodium sulphite and sodium nitrite, tannins, hydrazine may be mentioned. A convenient way of adjusting the concen 95 tration of magnesium compounds is by adding magnesium sulphate to the feed water Preferably a solution of magnesium sulphate is continuously fed into a boiler

feed water vessel, which may be supplied with entirely 100 raw water or with a mixture of raw water and boiler condensate, whilst the alkalies required for the normal alkaline treatment may be introduced directly into the boiler or into the feed water before it enters the boiler, so that in 105 either case precipitation of sludge occurs in the boiler The solution of magnesium sulphate may be supplied as such from a stock tank previously prepared, or on the other hand briquettes of, -or containing, magnesium 110 sulphate may be packed into a by-pass feeder and dissolved gradually as feed water passes over them If desired other substances such for example as antifoaming agents and de-oxygenating agents may be incorporated with the 115 magnesium sulphate in a briquette Other magnesium compounds may be used, for example the nitrate, carbonate, chloride. Since under all ordinary working conditions within the scope of this invention substantially 120 all the lime, magnesia, silica and alumina in a feed water appear in the boiler sludge, it is of interest to examine in the light of the invention the compositions of some actual boiler sludges. It has been possible to analyse the sludges from 125 26 working boilers of which 7 were free-flow784,750 ing and 19 non-mobile For the free-flowing 7 9, 6 9, 5 6 and 4 1 For the non-mobile sludges the values of the expression sludges the values were 5 0, 4 7, 4 3, 4 2, 4 1, Mg O 2 3 3, 1 3, 0 8, 0 5, 0 4, 0 4, 0 0, -0 8, -0 8, -0 4, l Si O 2 l -1 1, -1 7, -1 8 and -6 1Actual analytical data Ca O 3 3 for the highest and lowest values in each group worked out to be respectively 18 9, 15 1, 13 3, are given in the table below 1 % moles per 100 moles Ca O Value Ca O Mg O A 1203 P 205 Si O 2 Mg O Si O 2 A 1203 free-flowing 33 60 16 86 nil 18 40 2 36 69 8 6 6 nil 18 9 free-flowing 47 75 4 94 2 89 nil 0 58 14 4 1 1 3 3 4 1 non-mobile 49 56 5 63 0 06 1 42 0 16 15 8 0 3 0 1 5 0 non-mobile 44 33 5 05 0 86 2 00 8 10 15 8 17 1 1 1 -6 1 I In the following examples, which further illustrate but do not restrict the invention, the expression Mg O 2 l Si O 2 l Ga O 3 3 is for convenience referred to as "the formula index " EXAMPLE 1. An 'Economic' boiler working at a pressure of 100-120 p s i and evaporating 60009000 gallons of water per 24 hours was being fed with a water which had in the raw state high calcium and low magnesium hardnesses respectively of 232 and 14 parts per million expressed as Ca CO, and a medium silica content of 7 parts per million, and which was being treated with sodium carbonate and an anionic surface-active agent with dispersing properties This boiler had a long history of intractable non-mobile sludge and had always showed a considerable degree of scale formation The formula index for the feed water worked out to be approximately minus 1. The existing treatment was terminated and replaced by additions of

caustic soda sufficient to maintain the total alkalinity equivalent to 500 parts per million of sodium carbonate In addition magnesium sulphate solution was continuously fed in such amount as to raise the magnesium content of the feed to approximately 90 parts per million (as Ca CO,) With these proportions the formula index was just below 10 After four months under these conditions the boiler was examined and found to be virtually free from sludge, what there was being free-flowing Test plates in the boiler were completely free of scale and a test area had deposit estimated at less than 0 001 inch in thickness. EXAMPLE 2. This is an example of a feed water of high calcium hardness and low magnesium hardness, namely respectively 288 and 16 parts per million expressed as Ca CO,, and of high silica content namely 21 parts per million This water had been treated with various alkaline tannin mixtures and fed to a locomotive-type boiler working at 150 p s i Non-mobile sludge formation had been considerable, and it had been necessary to wash out the boiler every six weeks The formula index was approximately minus 5 5 The existing treatment was replaced by one based on caustic soda as in Example 1, and magnesium sulphate was added to bring the magnesium content to approximately 135 parts per million (as Ca COQ) The corresponding formula index was now approximately 8 3. After three months working under the new conditions the boiler was completely clean. This boiler was one of a pair of the same kind working side by side The second one was operated concurrently in the same way and with the same treatment as the first except for an addition to the feed of sodium aluminate equivalent to 5 parts per million of AI 20,. Substantially equivalent results were obtained, the boiler after three months being completely clean. EXAMPLE 3. This is an example of a feed water of medium to high calcium hardness and fairly high magnesium hardness namely respectively and 50 parts per million expressed as Ga CO,, and of medium silica content namely parts per million The formula index of this was approximately 3 7 The treatment had been based on sodium aluminate, sodium carbonate and starch, and sodium sulphite. The boiler was an 'Economic' working at 80-100 p s i evaporating 6000-9000 gallons per 24 hours with a raw water make-up of to 60 % It contained a considerable amount of scale and had a long record of non-mobile sludge The existing treatment was replaced by one based on sodium carbonate equivalent 784,750 and in addition two cleaned areas on the smoke tubes and two scaling plates which had been installed in

the boiler were found to be free from deposit Such satisfactory conditions had never formerly been achieved with the phosphate treatment, and the example illustrates the usefulness of the process of the invention in replacing phosphate treatment, which is not always effective.


* GB784751 (A)

Description: GB784751 (A) ? 1957-10-16

Check circuit for electronic ciphering arrangement for teleprinter signals


A high quality text as facsimile in your desired language may be available amongst the following family members:

DE1017646 (B) FR1124016 (A) DE1018452 (B) FR68606 (E) FR69910 (E) FR70167 (E) FR76696 (E) DE1017646 (B) FR1124016 (A) DE1018452 (B) FR68606 (E) FR69910 (E) FR70167 (E) FR76696 (E) less Translate this text into Tooltip

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PATENT SPECIFICATION

m- Date of Application end filing Complete Specification: Jan18, 1955. Application made in Norway on Jan 18, 1954. Patent of Addition to No 784,530, dated Jan 18, 1955). Complete Specification Published: Oct 16, 1957. Index at acceptance: -Class 40 ( 3), H( 15 K:ISX:31). International Classification:-HO 41. COMPLETE SPECIFICATION Check Circuit for Electronic Ciphering Arrangement for Teleprinter Signals We, STANDARD TELEPHONES AND CABLES LIMITED, a British Company, of Connaught House, 63, Aldwych, London, W C 2, England, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to an electronic arrangement for ciphering and deciphering teleprinter signals. The invention constitutes an improvement in or modification of, the invention described and claimed in the specification of co-pending Application No 1557/55 (Serial No. 784,530) In what follows, the Specification just mentioned will for convenience be referred to as the " parent specification " The object of the present invention is to provide testing means for indicating faults due to missing pulses in the operation of the arrangement of the parent specification. This object is achieved according to the invention by providing an electronic arrangement for ciphering or deciphering teleprinter character signals according to claim 1 of the parent specification further comprising testing means controlled by the input or output character signals, and by pulses produced in the said arrangement, for indicating the absence of pulses whose presence is necessary for the proper operation of the arrangement. By a "teleprinter character signal" is meant a ggroup of marking or spacing code elements comprisinff a start element followed by a train of code elements (usually five) and terminated by a stop element The start element is generally a spacing element and the stop element a marking element. The invention will be described with reference to the accompanying drawings, in which:Fig 1 shows a block schematic circuit diagram of one form of the invention This figure is substantially the same as Fig 3 of the parets ecification with the addition of lPri As the testing arrangements according to the present invention; Fig 2 shows graphical diagrams of pulses used in explaining the invention; 50 Fig 3 shows a simplified form of Fig 1 providing less complete testing facilities; Figs 4 to 7 show circuit details of the ciphering and deciphering arrangement and are the same as Figs 4 to 7 of the parent 55

specification; Fig 8 shows how Figs 4 to 7 should be put together to form a complete circuit; Fig 9 shows waveform diagrams used in explaining the operation of the ciphering 60 arrangement; and Fig 10 shows details of the testing circuit according to the present invention It should be placed to the right-hand side of Fig 7, the terminals A, B, C, D and E of Fig 7 65 being respectively connected to the correspondingly designated terminals of Fig 10. Referring to Fig 1, input teleprinter character signals are supplied over conductor 11 to an electronic distributor circuit com 70 prising the blocks 1 to 4, and to an electronic gate circuit 6 in which the signals are combined by " false addition " (as understood from the parent specification) with corresponding key character signals supplied over 75 conductor 16 The electronic distributor comprises a start-stop circuit 1 which controls a source 2 of timing pulses over a conductor 12 The timing pulses are supplied over conductor 13 to control a scale-of-two counting 80 circuit 3 which is connected over a group of conductors 14 to a rectifier matrix 4 which supplies reading pulses in succession respectively over a group of conductors, indicated at 15, to a tape transmitter 5 or like device 85 which is fed with tape (not shown) on which are punched in known manner successive key character signals corresponding to, but generally different from successive teleprinter character signals supplied over conductor 11 90 The tape is stepped forward after the transmission of each character signal by a readin g pulse supplied over one of the conductors 15. The key character signals are produced by appropriate selection of the reading pulses by the tape transmitter 5 and are supplied over conductor 16 The ciphered or deciphered character signals are supplied from the combining gate circuit 6 over conductors 17 to a two-condition multivibrator device 7 which acts to amplify and shape the output character signals which are delivered to conductor 71. If desired, timing pulse X from the source 2 may be supplied over conductor 26 to the gate circuit 6 for regenerating the combined character signals The conductor 26, and the multivibrator 7 are, however not essential and can be omitted. The testing arrangements according to the present invention comprise a gate circuit 8 (called the "first test gate ") having three control conductors 18, 28 and 48 connected to the tape transmitter 5, and a fourth control conductor 38 connected to the rectifier matrix 4 The gate circuit 8 has an output conductor 19 connected to a second gate circuit 9 (cabled the "second test gate ") which controls an alarm relay (not shown) over conductor 91. The gate 8 is such that a positive potential appears on conductor 19

so long as there is a positive pulse or potential on at least one of the four control conductors. The output character signal from the multivibrator 7 (or from the gate circuit 6 if the multivibrator is omitted) is also supplied to the gate circuit 9 which is of the kind which will release the alarm relay (not shown) to given an alarm if positive potential is missing from both input conductors simultaneously As will be made clear later if a positive pulse which should appear on one of the input conductors 18, 28, 38 and 48 during the period of a character signal is missing at a time when the output character signal has a spacing element (which will be & nopotential condition), then the gate 9 fill have no potential applied to either input conductor, and the alarm will be given. As will be explained later, the conductor 26 is only required when regeneration is used in the gate circuit 6. The operation of Fig 1 will be more clearly understood by reference to Fig 2. Assuming a five-element teleprinter code, and a telegraph speed of 50 bauds, graph a represents a positive pulse of duration 20 milliseconds which corresponds to the startelement of a character signal, and which should be produced by the rectifier matrix 4 and should appear on conductor 38, Fig 1. Graphs b to f represent similar positive pulses corresponding respectively to the five code elements, and which should appear on five corresponding ones of the conductors 15, and which are distributed by the tape transmitter 5 to conductor 18 or conductor 48, according to the key character signal Graph g indicates a positive pulse produced by combining the pulses of graphs a to f Assuming that regeneration is not used, and that the 70 conductor 26 is omitted, the pulses of graphs a to f will be applied to the gate circuit 8 over conductors 38, 18 and 48 so that on the assumption that no pulses are missing, a positive potential will be applied to the gate 75 circuit 8 for the whole period of the pulse shown in graph g, and a positive output will be supplied over conductor 19 to the gate 9. Graph I, Fig 2 shows an example of an output signal applied over conductor 71 to gate 80 9 In this example, spacing elements (nopotential condition) occur during the start period, and during code element periods 2 and 4 If one of the pulses of graphs a, c or e (which normally occur at the times of these 85 spacing elements) should be missing, the gate 9 will have no potential supplied over either input conductor 19 or 71, a Rtd the alarm will be given It will be clear that in a succession of g very few output signals, a space element 9 Q will occur sometime in every one of the periods start, 1, 2, 3, 4, 5 and an alarm will be given in response to the loss of any

of the pulses shown in graphs a to f. When regeneration is used, a slightly dif 95 ferent procedure is adopted In this case the regenerated character signal is delayed by half an element period ( 10 milliseconds) The additional conductor 26 (Fig 1) is now used. Referring to Fig 2, graph j shows a pulse of 100 milliseconds duration and corresponding to the second half of the pulse, graph a which is supplied over conductor 38 (Fig 1) in circumstances which will be explained later on Graph k shows a pulse of 20 milliseconds 105 duration which follows the graph f pulse and is used to step forward the tape (not shown) in the transmitter 5 This pulse is supplied over one of the conductors 15 and over conductor 28 to the gate circuit 8 Graph m rep 110 resents a pulse corresponding to the combination of the pulses shown in graphs j, b to f and k Graph N shows an example of a regenerated output character signal which is half an element period later than the signal 115 shown in graph h. Under normal conditions, positive potential is supplied to the gate 8 over one of the conductors 18, 28, 38 and 48 for the whole period of the pulse shown in graph m As be 120 fore, if one of the pulses of graph j, b to f or k is missing, it will be detected by a space element of one of the output signals which overlaps by 10 milliseconds the normal period of the missing pulse, and so the relay con 125 trolled by the gate 9 will give the alarm in the manner previously described. -Fig 3 shows a simpler arrangement in which only the conductors 18 and 48 are used This only checks the pulses shown in 130 784,751 is shunted by the anode-cathode circuit of a stop valve V 9 which is normally conducting, so that the oscillation circuit is heavily loaded and no oscillations can be generated The control grid of the valve V 9 is connected to 70 the anode of the valve V 15 through a reversing valve V 8, so that V 15 being normally conducting, V 8 will be blocked and V 9 conducting As already explained, on receipt of the start element, V 15 becomes blocked, and so 75 V 9 also becomes blocked and oscillations of the valve V 10 A can start If the stopping current through the valve V 9 is suitably chosen, it can be arranged so that the oscillations start without transients, and so that the first 80 half-cycle of oscillation at the grid of the valve V 10 A is positive whereby the first timing pulse supplied to conductor 13 occupies the first half of the start element period and is negative Graphs A and B, Fig 85 9 show the oscillations and timing pulses, respectively When the multivibrator V 14, V 15 returns to the stable condition, valve V 9 is unblocked again and no more timing pulses are generated 90 In Fig 6 are shown three double valves Vii, V 12 and V 13 each of which is arranged as a conventional binary counting stage.

These valves comprise the counting circuits 3 of Fig 1 Eight groups of rectifiers SR 7 to 95 SR 14 comprise the matrix 4 During the initial stop period before the receipt of a character signal, the right-hand section of each of the double valves Vii, V 12 and V 13 is conducting and the left-hand section is 100 blocked The anode of a section which is conducting is at a potential near zero, and that of a section which is blocked is at a relatively high positive potential The conductor 13 from the valve V 1 OB (Fig 4) is connected 105 symmetrically to both the control grids of the valve V 11; the right-hand anode of the valve Vii is connected to both the control grids of the valve V 12, and the right hand anode of the valve V 12 is connected to both 110 the control grids of the valve V 13 Thus any counting stage receiving a negative pulse from the preceding stage or from conductor 13 is switched over to the opposite condition in the conventional way The arrangement 115 thus counts up to 8 timing pulses. The arrangement operates in the following well known manner. The first negative timing pulse which arrives over conductor 13 at the end of a stop 120 period cuts off the conducting right-hand section of the valve V 11 and switches the valve over to the opposite condition with the right-hand section blocked and the left-hand section conducting The negative timing pulse 125 has no effect on the left-hand section because it is initially already blocked A positive pulse is thereupon supplied from the right-hand anode of the valve Vil to the control grids of the valve V 12, but the grids are so biased 130 graphs b to f, corresponding to the code elements 1 to 5, under the control of the input character signal which is applied direct to the gate 9 The combining gate circuit 6 and the multivibrator 7 of Fig 1 are not shown in Fig 3 The gate 9 operates in the same way as in Fig 1, except that it is controlled by the input character signal instead of by the output ciphered character signal. Reference will now be made to the detailed circuit diagrams, Figs 4 to 7, put together as shown in Fig 8 In Fig 4, the start-stop circuit 1 of Fig 1 comprises the valves V 14, V 15, V 8 and V 9, and the timing pulse source 2 comprises the valves V 1 OA and V 1 OB The incoming teleprinter character signals are supplied to the control grid of a valve Vi A, and it will be assumed that the potential applied to this grid is about zero, or slightly positive, during marking periods, and negative during spacing periods The conductor 11 connected to the anode of the valve Vi A will thus be a a potential near zero for mnarking periods (since the valve Vi A is then conducting) and at a positive potential during spacing periods, (since the valve Vi A is then blocked). The two valves V 14 and V 15 are connected to form a single-stable multivibrator, and thzt valve V 15 is conducting and the valve V 14 is

blocked in the stable condition The conductor 11 is connected through a rectifier SR 6 to the control grid of the valve V 14, and when the start element of a character signal arrives, a positive potential is fed through the rectifier SR 6 and switches the multivibrator over so that the valve V 15 becomes blocked A positive potential is thereby applied from the anode of valve V 15 to block the rectifier SR 6 so that the multivibrator is unaffected by the following code elements of the character signal The multivibrator is timed to return to the stable condition after 8 timing pulses have been generated by the valves V 10 A and V 1 OB This is done by suitable choice of the time constant of the coupling circuit in the well known manner. The valve Vi 1 A is arranged as a conventional Hartley oscillator, the anode being effectively connected to ground through the high tension source (not shown) This oscillator should be arranged to generate a frequency whose period is equal to one code element period For example, if the code element period is 20 milliseconds, the Gscillator frequency will be 50 cycles per second. The anode of the valve V 10 A being effectively at ground potential, the output is taken from the control grid which is connected to the control grid of an amplifier valve V 1 OB. which is biassed to act as a limiter, so that substantially rectangular negative pulses of duration 10 milliseconds are supplied to conductor 13. e 5 The oscillation circuit of the valve V 1 OA 784,751 784,751 that only negative pulses can have any effect. The second negative timing pulse switches the valve V 11 back to the original condition with the right-hand section conducting A negative pulse is now transmitted from the right-hand anode of the valve V 11 to the control grids of the valve V 12, and switches it over to the condition with the right-hand section cut off The corresponding positive pulse transmitted to the control grids of the valve V 13 has no effect. The third negative timing pulse switches the valve V 11 again to the condition with the right-hand section blocked No effect is produced on the valve V 12. The fourth negative timing pulse switches the valve V 11 again back to the original condition The negative pulse thereby generated at the right-hand anode of valve V 11 switches the valve V 12 back to its original condition The negative pulse thereby generated at the right-hand anode of the valve V 12 switches the valve V 13 over to the condition in which the right-hand section is blocked. Succeeding timing pulses continue the operation in the same way The following Table Lgives the potential of the left-hand anode of each of the three valves V 11, V 12 and V 13 after the application of each of

eight successive timing pulses:TABLE I Each of the groups of rectifiers SR 7 to SR 13 comprises four separate rectifiers arranged in a vertical column Group SR 14is similar to the others except that the uppermost rectifier of the column is omitted The three rectifiers of each group other than the uppermost rectifier in the column will be referred to as the " three lower rectifiers " This term will also be applied to the three rectifiers of group SR 14. The three lower rectifiers of each of the eight groups are respectively connected over three of the conductors 14 a to 14 f to one of the anodes of the three valves Vil to V 13, there being a different selection of anodes for each group The connections are shown in the following Table II, the number of the conductor over which the connection to an anode is made being entered in the column corresponding to the anode. 784,751 TABLE II V 1 i anode V 12 anode V 13 anode Rectifier Group L H R H L H R H L H R H. SR 7 14 a 14 d 14 f SR 8 14 b 14 c 14 f SR 9 14 a 14 c 14 f SRIO 14 b 14 d 14 e S Rll 14 a 14 d 14 e SR 12 14 b 14 c 14 e SR 13 14 a 14 c 14 e SR 14 14 b 14 d 14 f 11 1 1 1 The three lower rectifiers of each group form a conventional coincidence gate such that a positive output voltage is only produced from the gate if all the anodes to which it is connected are at a relatively high positive voltage This can be understood by considering the group SR 14 An output terminal 30 is connected to the anodes of the three rectifiers of the group, and to a positive source + through a load resistor In the stop condition (that is after the eighth timing pulse) all three rectifiers of the group SR 14 are connected to positive valve anodes (see Tables I and II) All three rectifiers are then blocked, and the source + supplies a positive output to terminal 30 If the potential of any one or more of the valve anodes, to which the rectifiers of group SR 14 are connected, falls to zero, the corresponding rectifier or rectifiers of the group will be unblocked and the potential of the terminal 30 is then prevented from rising above zero, so no output is obtained Such a condition occurs, for example, after the first timing pulse, when the left-hand anode of the valve Vil is at zero potential (see Table I), so the lowest rectifier of group SR 14 is unblocked, and no output can be obtained at terminal 30. The other rectifier groups SR 7 and SR 13 operate in the same way, but each of them is provided with an isolating rectifier (the uppermost rectifier) through which the output potential from the source + reaches the corresponding one of seven outputs conductors 15 a to 15 f and 15 h These seven outputs are designated 0, 1, 2, 3, 4, 5 and M. The output of the eighth group SR 14 is taken directly to the terminal

30 and is designated H The group SR 14 is only used in a slight modification of the embodiment to be de. scribed later, and may be omitted if the modification is not adopted An additional output conductor 15 g connected directly to the three gate rectifiers of the group SR 13 is provided for the M output. It has already been stated that in the stop condition, the right-hand sections of all the valves V 11 to V 13 are conducting, and it will be found that the connections to the anodes are such that only the rectifier group SRI 4 is( connected to tliree posifive anodes (see Tables I and II), and so this group is the only one which gives a positive output, at terminal 30. On the arrival of a character signal on conduc. tor 11 (Fig 4), the timing pulses (graph B, Fig 9) are supplied to conductor 13 and step the counter stages Vii to V 13 on in the known way In response to the first timing pulse it will be found that a positive output is obtained from SR 7, and then successively, in turn, from SR 8 to SR 13, as the counter is stepped on Finally, the eighth timing pulse restores the counter to the initial condition, and a positive output again appears at terminal 30 Just after the appearance of the eighth timing pulse, the multivibrator V 14, V 15, Fig 4, restores itself and stops the oscillator V 10 A. Thus positive reading pulses of duration substantially equal to one code element period ( 20 milliseconds) are supplied in turn respectively to conductors 15 a to 15 g The first is used for test purposes, and the next five are the reading pulses corresponding respectively to the five code elements 1 to 5, and the last reading pulse M is used to step forward the tape 25 in the tape transmitter 5 (Figs 1 and 3), as will be explained later The six positive pulses 1 to 5 and M are shown graphically in Fig, 7. 784,751 In Fig 7 there is shown the net SM of the tape transmitte This is controlled by the M which is supplied over condu normally blocked valve V 7 hav ping magnet SM in series wit circuit When the M reading after the five reading pulses 1 t ping magnet SM is operated to forward by one step On this tal in Fig 7) are punched a series ( character signals The punched by means of peckers (not shown of change-over contacts K 1 to the lower part of Fig 7, those responding to spacing element character signal being changed thus be evident that the key ch will be supplied to conductor 1 code elements being represente pulses In the case of the incon signals supplied over conducto and 5) the spacing code eleme represented by positive pulses. Referring now to the combinin shown in Fig 5, which is the of Fig 1, an incoming telegra signal arrives over conductor 11 that spacing elements are represe tive pulses A corresponding -I signal derived from a punched over conductor 16 Only the sig elements are punched on

the t resulting key character signal spacing code elements are rel positive pulses There being nc in the start and stop periods, th ter signal effectively provid elements in both these periods. The combination of the tw "false addition" is carried out b fier groups SR 1, SR 2, and SR 3 ness, a particular example o elements of fliese two signals wit according to the following Tab TABLE IN. St 1 2 3 Input Signal S M S S Key Signal (M) S M S Ciphered S S S M St = start; Sp = stop; M =marl The groups of four rectifiers S together form four coincidence g group of rectifiers SR 3 form two lating output rectifiers The con connected directly to the lower 1 fiers SR 1, and through a reversi to the upper pair The conduct( nected through a reversing valve lower pair of rectifiers SR 2, and stepping mag reversing valves V 2 A and V 2 B connected in er 5 (Fig 1) cascade to the upper pair, so that no reversal reading pulse is produced The upper pair of rectifiers of ctor 15 g to a the group SR 3 are connected over conductor ing the step 31 to a first amplifying valve V 3 A, and the 65 h the anode lower pair over conductor 32 to a second pulse appears similar amplifying valve V 3 B The valves to 5, the step V 3 A and V 3 B are each blocked unless a posishift the tape tive potential is applied to the control grid pe (not shown over the corresponding conductor 31 or 32 70 )f random key The rectifiers are interconnected in groups tape controls of three by four conductors 33 to 36, and the ) the five sets arrangement is such that a positive output is K 5 shown in only obtained on that particular one of these contacts cor four conductors 33 to 36 for which both the 75 s in the key rectifiers of groups SR 1 and SR 2 to which it over It will is connected are simultaneously blocked. aracter signal Ihen this positive output is supplied to that 6, the spacing one of the conductors 31 or 32 which is cond by positive nected to the said particular one of the con 80 aing character ductors 33 to 36 through one of the rectifiers r 11 (Figs 4 of group SR 3. rnts are also To make this clear, suppose the input signal and the key signal both have a mark ng gate circuit element (e g code element period 4 of Table 85 gate circuit 6 III) Substantially zero potential is supplied aph character over both the conductors 11 and 16 ThereL, and is such fore positive potential will be applied from ented by posi the anode of valve V 1 B to the upper two key character rectifiers of SR 1, and from the anode of valve 90 l tape arrives V 2 A to the lower two rectifiers of SR 2 All gnificant code these four rectifiers will therefore be blocked. tape, and the At the same time substantially zero potential is such that will be applied to the remaining four rectifiers presented by of groups SR 1 and SR 2 so that all of these 95 o such pulses rectifiers will be unblocked It will be found e key charac that the only one of

the four conductors 33 Les marking to 36 which is connected to two blocked rectifiers is conductor 34, and so a positive o signals by potential is supplied from this conductor 100 y three recti through the uppermost rectifier of group SR 3 3 For clear to conductor 31 Because conductor 35 is f the code substantially at zero potential on account of 1 be assumed, the unblocking of the lower rectifiers of group le MIII: SR 1 and the upper rectifiers of SR 2, the 105 other rectifier of group SR 3 connected to conductor 31 is blocked, so that conductor 4 5 Sp 35 is effectively disconnected from conductor 31. M S M It will be found that if both the character 110 M M (M) signals have a space element (eg code element period 3 of Table III), then conducM S M tor 35 is the only one of the four which has a positive potential applied to it, and again a k; S=space positive output is supplied to conductor 31, 115 but this time through the lower rectifier of R 1 and SR 2 the upper pair of SR 3 In accordance with ates, and the Table III, conductor 31 will be called the I pairs of iso "mark conductor" because the ciphered ductor 11 is signal has a mark element under both condi 120 pair of recti tions just set out. ng valve VIB If now the input signal has a space element or 16 is con and the key signal a mark element (e g code V 2 A to the elements period 2 of Table III), it will be through two seen that positive potential is applied to the 125 character signals from conductor 71 a will be delayed by half an element period, namely 10 milliseconds. If regeneration is employed, the multivibrator 4 cannot be omitted 70 When regeneration is employed, a slightly different method of starting the counters V 11 to V 13 (Fig 6) may be used In this case the limiting amplifier V 1 OB is differently biased so that a train of positive timing pulses shown 75 in graph C, Fig 9 is obtained The first of these timing pulses corresponds to the first negative loop of the oscillations of graph A, and occurs during the second half of the start period, from 10 to 20 milliseconds 80 There is then no negative-going pulse edge at zero time (that is at the beginning of the start period) and the counting circuit will thus count only 7 instead of 8 during the whole character period To remedy this, a 85 negative pulse is taker from the anode of the valve V 3 B (Fig 5) which, as already explained, goes negative at 10 milliseconds when regeneration is used This negative pulse is supplied through an appropriate gate 90 circuit (not shown) to the control grids of the valve VII (Fig 6) and triggers it at 10 milliseconds It will be triggered back again at 20 milliseconds by the trailing edge of the first timing pulse (graph C, Fig 9), and so the 95 first or " O " pulse supplied over conductor a has a duration of 10 milliseconds instead of 20 milliseconds, and occupies the second half of the start period The counting circuit thereafter counts at 20 millisecond

intervals, 100 as already explained. According to another minor modification of the circuits described, the rectifier SR 6 and the valves V 14 and V 15 in Fig 4 may be omitted, and a connection taken from terminal 105 of Fig 6 through a reversing valve (not shown) to the control grid of the valve V 8, Fig 4 Then in the stop condition, the positive potential which appears on terminal 30 (and which appears reversed on the grid of 110 V 8) will hold the valve V 9 in the conducting condition As soon as the start signal is received, the valve V 8 will be unblocked by the positive pulse applied over conductor 11, and the valve V 9 is thereby blocked, thus per 115 mitting the oscillator V 10 A to start The first timing pulse supplied from the oscillator over conductor 13 removes the positive potential from terminal 30, so that the valve V 8 remains unblocked After 8 timing pulses have 120 been counted by the counting stages V 11 to V 13, positive potential again appears on terminal 30 and the oscillator is stopped. The testing arrangements according to the present invention are shown in Fig 10, 125 terminals A, B, C, D and E of which are intended to be connected respectively to the correspondingly designated terminals of Fig. 7 The arrangement is then that described with reference to the block schematic circuit of 130 lower rectifiers of SRI directly from conductor 11, and to the lower rectifiers of SR 2 from the anode of valve V 2 A, and these are the only rectifiers to be blocked Thus conductor 36 is now the only one which has positive potential, which is supplied through the lowest rectifier of SR 3 to conductor 32, called the " space conductor " Similarly if, as in period 4 of Table III, the input signal has a mark element and the key signal a space element, conductor 33 is the only one which has positive potential, which is again supplied to conductor 32. The anodes of the valves V 3 A and V 3 B are respectively connected -over conductors 17 a and 17 b to the left-hand and right-hand control grids of a double valve V 4 arranged as a double-stable multivibrator The valve V 4 corresponds to the device 7 of Fig 1 In the stop condition, there will be positive potential on the mark conductor 31 and substantially zero potential on the space conductor 32, and the right-hand section of the valve V 4 is conducting On receipt of the start element, which is a space, conductor 32 becomes positive, so that a negative pulse is transmitted to the right-hand control grid of the valve V 4, changing it over to the opposite condition Positive potential is thus supplied to the output conductor 71 a connected to the anode of the valve V 4 During code element period 3 (see Table III) the output signal has a mark element and so a positive potential now appears on conductor 31, and the multivibrator V 4 is changed back

to the original condition with the right-hand side conducting Substantially zero potential now appears on the output conductor 71 a Thus the output signal is delivered to conductor 71 a in such manner that spacing elements are represented by positive pulses. The multivibrator V 4 acts to amplify and shape the output pulses, but is not essential. and can be omitted In that case the output character signal can be obtained from conductor 17 a, or its inverse from conductor 17 b. According to a slight modification of Fig 5, a conductor 26, shown dotted, connects conductor 13 of Fig 4 through capacitors Cl and C 2 to the control grids of the valves V 3 A and V 3 B The capacitors differentiate the timing pulses shown in graph B, Fig 9, so that short positive differential pulses are superimposed on the code element pulses supplied over conductors 31 and 32 to the valves V 3 A and V 3 B These valves are in this case biased so, that they can only be unbllo Iked when the differential pulses and the code element pulses coincide With this arrangement the valve V 4 is triggered at the times determined by the short differential pulses which thereby effectively regenerate the signals Since these differential pulses coincide with the positive-going edges of the timing pulses, it will be evident that the output -7 784,751 Fig 1 The gate 8 comprises a group SR 5 of four rectifiers, of which the two innermost rectifiers 44, 45 are connected to the output conductor 19 Conductor 38 is a continuation of conductor 15 a (Fig 7); conductor 18 is connected to the five upper switch contacts (Fig 7) controlled by the peckers of the tape transmitter (not shown); conductor 48 is connected to a switch S (Fig 7) and thence to conductor 16 when the switch is in position 1 as shown; conductor 28 is connected to a combining device 40 (Fig 7) to which also the conductor 15 h is connected Conductors 18 and 38 are connected through a capacitor 42 to rectifier 44 and thence to conductor 19. Conductor 48 is connected through an isolating rectifier SR 4 b to capacitor 42 Conductor 28 is connected through a second capacitor 43 to the rectifier 45 and thence to conductor 19 The rectifiers 46 and 47 act as dischargers for the capacitors 42 and 43. The conductor 19 is connected to a valve V 6 which comprises the gate 9 of Fig 1, and has an alarm relay not shown, connected to the anode output conductor 91 The conductor 71 b connected to the left-hand control grid of valve V 4 (Fig 5) is connected through Fig 7 and through an isolating rectifier SR 4 a to the control grid of the valve V 6. Under normal conditions, positive potential is applied to the control grid of the valve V 6 either over conductor 19, or over conductor 71 b, or over both conductors In this condition the anode current holds

the alarm relay (not shown) operated During spacing periods of the ciphered character signal, there is no potential applied over conductor 71 b, and if during one of these spacing periods some pulse is missing so that no positive potential reaches the rectifier group SR 5 over any of the conductors 18, 28, 38 or 48, no positive potential will be applied to the valve V 6 over conductor 19 Thus the anode current will breduced and the alarm relay (not shown) will be released, thereby giving the alarm T-is the loss of a pulse will not be detected during the period vnhen a marking element is transmitted, and the detection must wait for a spacing element, which will generally be available at the right time during normal transmission after a very small delay. The pulse of graph a (or j) Fig 2 is supplied to the rectified SR 5, Fig 10, from the rectifier group SR 7 (Fig 6) over conductors 15 a and 38 The pulses b to f, Fig 2, are also shown in the lower part of Fig 7, and reacz SR 5 from the rectifier groups SR 8 to SR 12 (Fig 6) over conductors 15 b to 15 f and conductor 18 or 48 according to the setting of the five switches The M pulse shownvm in graph k (Fig 2) is suppled from fthe rec Ltfir group SR 13 (Fig 6) over conductor 15 h to the device 40 (Fig 7) This device is controlled by the contacts 41 operated by the stepping magnet SM in such a way that the M pulse is delivered to conductor 28 if the tape stepping machanism is operating properly Thus the absence of the M pulse can be used to indicate a failure of the stepping mechanism 70 It should be made clear that the loss of the M pulse can only be detected if regeneration is used whereby the ciphered character signal is delayed by 10 milliseconds This is because the pulse M corresponds to, and occurs 75 at the time of, the stop element, which must be a mark, and during the mark period a positive potential is applied to the conductor 71 b Witi-the 10 milliseconds' delay, the fifth code element overlaps the M pulse, and if 80 the fifth code element is a space and the M pulse is missing, positive potential is withdrawn from conductors 71 b and 28, so that the alarm relay is released. If regeneration is not used the conductors 85 k and 28, and the device 40, may be omitted. If the switch S (Fig 7) be operated to position 2, the pulses from the lower contacts of the five switches are taken from the anode 90 of the valve V 2 B over conductor 72, and in this way failure of one or both of the valves V 2 A, V 2 B will be detected by the loss ot the spacing pulses of the key character signal. It will be evident to those skilled in the 95 art that the release of the alarm relay in response to the loss of one or more of the pulses generated by the distributor and associated circuits may be arranged to stop the transmission by suitable arrangements 193


* GB784752 (A)

Description: GB784752 (A) ? 1957-10-16

Improvements in and relating to electric lamp fittings for panelillumination and the like purposes


PATENT SPECIFICATION 7 Inventors:-BERTRAM STEVENS, MAJOR SQUIRE and CHARLES WINTON TURNER. Date of filing Complete Specification: Jan 10, 1956. Application Date: Jan 26, 1955 No 2391/55. Complete Specification Published: Oct 16,1957. Index at Acceptance:-Classes 75 ( 3), D 4 P; and '75 ( 4), O( 8 Ht 3: 13). International Classification: -Flb. COMPLETE SPECIFICATION. Improvements in and relating to Electric Lamp Fittings for Panel Illumination and the like Purposes. We, THORN ELECTRICAL INDUSTRIES LIMITED, a British Company, of 105-109 Judd Street, London, W C 1, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to electric lamp fittings for illuminating panels and for like purposes. A requirement exists for an electric lamp fitting which can be mounted in an aperture in a panel and which, when so mounted, provides a substantially hermetic seal of the two sides of the panel from one

another through the aperture, and with which the electric lamp can be changed without breaking the aforesaid seal, and it is the principal object of this invention to provide a lamp fitting meeting these requirements. According to the present invention, an electric lamp fitting comprises a hollow cylindrical casing having an outwardlyprojecting flange adapted to be sealed by means of a washer around an aperture in a panel or the like, means being provided for fixing the casing in the said aperture and compressing the washer between the flange and a surface of the panel or the like, the casing being adapted for the insertion of a lamp through one end thereof 2 to engage electric contacts within the casing, one or more electrical connecting means for making connection with one or more of the contacts passing out through the other end of the casing, and the latter end, including the aperture or apertures through which the connecting means pass being sealed by means lPrice 3 s 6 d l of a member of rubber or similarly compressible material. The invention will be described by way of example with reference to the drawings accompanying the Provisional Specification in which:Fig 1 is an exploded view of one embodiment of the invention; Fig 2 is a view in section of the embodiment of Fig 1 mounted in an aperture in a panel; Fig 3 is a view in section on the line 3-3 of Fig 2; Figs 4 and 5 are views similar to that of Fig 2, showing modified forms of the invention; and Fig 6 is an enlarged sectional view on the line 6-6 of Fig 5. Referring to Figs 1 to 3, the embodiment there illustrated is for use for so-called transillumination of a transparent panel 10 (Fig. 2), the fitting including a lamp 11 being passed through an aperture 12 in the panel Light from the lamp is transmitted through the panel 10 by repeated internal reflection and can be made available in known manner at desired points in the surface of the panel 10 The transparent panel is mounted behind a main panel 13 of the equipment Devices such as instruments containing dials to be illuminated by light from the panel 10 are mounted in the panel 13, although such devices are not illustrated. The panel 13 is assumed to be a part of one wall of a closed container and it is one of the purposes of the embodiment to provide a lamp fitting such that the inside of the container, that is to say the part to the left of the panel 13 in Fig 2, is substantially her84,752 metically sealed from the outside air, that is to say the space to the right of the panel 13 in Fig 2. The fitting comprises a cylindrical casing a 14 having a flange 15 at one end thereof The casing 14 is of a suitable plastic which is light-transmitting and may have any desired colour such for example as

signal red The flange 15 is located within a boss 16 projecting outwardly from the panel 13 and is sealed to the panel by means of a rubber washer 17 The flange 15 is firmly clamped to maintain the washer 17 in compression by means of an annular ring 18 threaded internally and externally the external thread engaging in a corresponding thread in the boss 16 Within the casing 14 are two contact members 19 and 20 in the form of suitably bent strip metal Extensions 21 and 22 respectively of the contact members pass through slots 23 and 24 formed in the bottom of the casing 14 In order to seal the base of the casing 14 and prevent leakage through the slots 23 and 24 there is provided a cylindrical rubber sealing member having projecting lugs 26 and 27 The strips 21 and 22 project through slots formed in the lugs 26, 27 of the member 25 The rubber sealing member 25 is provided with an annular ridge 251 (Fig 1). In order to retain the rubber sealing member 25 and compress and deform it in such a way as to provide the required seal, there is provided a metal cap 28 of generally cylindrical shape having its upper edge inwardly turned as indicated at 29 The edge 29 is crimped over to engage in a groove 30 (Fig 1) in the casing 14 after the cap 28 has been pressed on to the end of the casing 14. The base of the cap 28 is apertured to pass the two lugs 26 and 27 and is inwardly dished as shown in Fig 2 Thus when the cap 28 is pressed into position, pressure is exerted upon the member 25 in a region around the lugs 26 and 27 and close to these lugs The lugged surface of the member 25 which was previously flat is thus deformed as shown in Fig 2, thereby achieving the desired compression of the sealing member around the strips 21 and 22 The ridge 25 ' also becomes flattened and provides a seal around the strips 21 and 22 against the base of the casing 14. The lampholder comprises an opaque knob 31 having a screw-thread 32 which engages in the internal thread of the annular ring 18 To the knob 31 is fixed a metal shell 33 the central part of which is cut away to form windows and leaving portions 34 Rio which are of only sufficient width to give the structure sufficient strength In this way the windows Drovided are as large as possible The free end part of the member 33 is slotted at 36 in order to produce 635 tongues 37 which can engage firmly the conducting side of a lamp, the conducting side constituting one terminal of the lamp. When the lamp is to be inserted it is placed in position in the slotted part 35 of the lampholder and the knob 31 is screwed 70 into position The part 35 then engages within and makes contact with the contact member 20 while the central contact of the lamp makes contact with the contact member 19 It is arranged that when the lamp 7 a is in position its filament is located opposite the centres of the windows

in the shell 33 and in line with the medial plane of the transparent panel 10 in Fig 2. It will be evident that with the arrange 50 ment described the inside of the casing 14 is hermetically sealed from the inside of the container bounded by the panel 13 and moreover that the lampholder with its lamp can be removed without breaking the seal 55 With a pressure difference between the two sides of the panel 13 of 20 lb per square inch it has been found that leakages not exceeding 1 c c per hour are obtainable. In Figs 4 to 6 like parts are given the go same references as in Figs 1 to 3 The arrangement shown in Fig 4 is intended to emit light from a lamp 11 through a cupshaped translucent member 38 which may be coloured as desired The casing in this case 145 is also of insulating material and is indicated by the reference 39 The arrangements for sealing the base of the casing are the same as described in Figs 1 to 3 The contacts 19 and 20 are also as previously described 100 The cas'ne 39 is externally threaded to engage a threaded aperture in the panel 13 and has a flange 40 which engages the front face of the panel 13 and is sealed with respect thereto by a washer 41 The casing is locked 1 o 5 in position by means of a lock nut 42 The lampholder 43 has a flange 44 and a portion of similar construction to the slotted portion 35 in Fig 1, this portion serving to make contact with the outer cylindrical contact 110 surface of the lamp 11 and also with the contact member 20 A knurled ring 46 having an inwardly-projecting flange 47 serves to clamp the flange 44 against the end of the casing 39, a washer 48 being interposed for 115 sealing purposes The translucent cover 38 is a push fit on the portion 49 of the member 43. The arrangement of Figs 5 and 6 differs from that of Fig 4 in the following respects 120 The flange 40 of the casing 39 is provided, in addition to the washer 41, with a further inset washer 50 which is engaged by and sealed against a knurled ring 51 screwed on to the end of the casing 39 A metal mem 125 ber 52 corresponding to the lampholder 43 in Fig 4 is fixed as by welding to the knurled ring 51 The member 52 has an end wall provided with apertures 53 which co-operate with further apertures 54 formed in the end 134) 784,752 784,752 of a metal thimble 55 which is disposed within a translucent cover 56 corresponding to the member 38 in Fig 4 A pin 57 is fixedly mounted by screwing into the cover 56 and 3 works in a slot 58 (Fig 6) in the member 52, limited rotary movement of the cap 56 being thus permitted In this way the degree of overlap of the apertures 53 and 54 can be adjusted and hence the light transmitted through the cover 56 can be adjusted by rotating the cover 56.

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