4981 4985.output

* GB785388 (A)

Description: GB785388 (A) ? 1957-10-30

Improvements in or relating to pigment compositions

Description of GB785388 (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 7 f f i Date of Application and filing Complete Specification: Aug22, 1955. No 24168155. Application made in United States of America on Nov 16, 1954. Complete Specification Published: Oct 30, 1957. Index at acceptance:-Class 95, AS. International Classification:-CO 9 d. COMPLETE SPECIFICATION Improvements in or relating to Pigment Compositions We, ARMOUR AND COMPANY, a corporation organized under the laws of the State of Illinois, United States of America, of Union Stock Yards, City of Chicago, State of Illinois, United States of America, 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 and by the following statement:This invention relates to an improved pigment composition and to a process for its manufacture. Pigments are finely divided insoluble solids which are used in many various materials such as for example, coating compositions and rubber, for many different purposes In coating compositions they are mostly used to provide a colour or hue, but they may also be used to

perform an opacifying function In rubber, especially tyre rubber, carbon black is used to impart strength and abrasion resistance as well as colour It is hardly possible to look around and not see some article which contains a pigment material. In practically every application of pigmentary materials it is necessary that they be dispersed, generally in a liquid medium Pigment dispersion, as encountered in the field of coating compositions, involves generally transferring a dry pigmentary material existing really as a heterogeneous dispersion in air to a dispersion as uniform as possible in a liquid. The attainment of optimum dispersion usually results in the maximum practical development of such desirable properties as tinctorial strength, opacity, gloss and uniform pigment particle distribution. Pigment particles can be pictured as irregularly shaped solids surrounded by a bound envelope of air, gas or moisture which is to be considered distinctly different in its physical relationship to the pigment from the free air that separates the pigment particles. Both the free air and the surface-bound air constitute the initial obstacle to be overcome in converting the pigment from a dispersion _,,1 in the air to a dispersion in a liquid Pigments in the dry form are generally in the form of agglomerates which may be either in a relatively loose or in a compacted condition. In the dispersion process, a vehicle is added to the pigment mass in a mixing operation which is extended further by a so-called grinding operation The dispersion processes employed by the manufacturer of coating compositions are not really true grinding operations, but the tendency of the pigment to cluster or coalesce under the conditions of packing, shipment and storage, as well as a natural tendency of many pigments to agglomerate when initial wetting is attempted, are factors which might lead one to believe that real grinding does occur in the dispersion process Any attempt to truly grind the pigment, if actually accomplished, would probably result in mill scoring, contamination by abrasion, change in colour, quality and other possibly undesirable effects. As a result of the work done on a mixture of pigment and vehicle, a pigmented composition is obtained which may be represented by two extreme conditions, with, of course, the possibility of an actual composition which combines some of the characteristics of both. A poor dispersion is one in which the work done has failed to separate the pigment particles with the result that much of the original air is retained and the particles have become tightly packed into a hard aggregate as a consequence of the forces exerted The ideal result is one in which the pigment particles have been completely separated with an envelope of adsorbed vehicle replacing the original air envelope,

and free vehicle displacing the original free air. Wetting agents are well known in the field of dispersion, and are employed in emulsification as well as in dispersing solids Since most pigment manufacturing processes involve the formation of the pigment at some stage as a precipitate in an aqueous dispersion, it is known to coat the pigment with a wetting agent to render the pigment surface more oil85,388 acceptable However, most of the pigment wetting agents on the market today are potassium or sodium rosinates and petroleum sulphonates, which rely solely on the partial adsorption of the reagent upon the pigment in water, and are only 50 %' efficient These types of compounds generally remain watersoluble, and a large portion is washed away in the filtrate when filtering the pigment. We have discovered that if an aqueous precipitate of pigmentary material is treated in such a manner as to ultimately coat the pigment particle with a water-insoluble diacid salt of a N-aliphatic alkylene diamine, the coating will remain on the pigment during the filtration step and will act as a spacer between the pigment particles and prevent the formation of clusters of pigment particles or agglomerates Further, the amount of time required for grinding or dispersing these improved pigments into oil or resin-type vehicles is considerably diminished, and there is no adverse effect upon the properties of the resulting coating compositions. It is, therefore, an object of the present invention to provide an improved pigment composition. It is a further object of this invention to provide an improved process for the preparation of pigment materials. Still another object of this invention is to provide an improved process for transferring pigmentary material from an aqueous dispersion to an oil or resin type dispersion. This invention is applicable, generally, to hydrophilic or water-wettable pigments and involves treating the pigment in an aqueous system so as to ultimately coat the pigment particles with a strongly-adsorbed waterinsoluble salt of an N-aliphatic alkylene diamine According to a preferred modification of our invention, a small amount of a water-soluble salt of an N-aliphatic alkylene diamine is admixed with a slurry of water-wet pigment material, preferably at a stage in its manufacture prior to drying, and agitated for a time sufficient to adsorb the watersoluble salt on to the surface of the pigment particles, generally about 10 to 15 minutes. Next a stoichiometric quantity of a compound selected from the group consisting of RCOOZ and R-NHI-A-COOZ wherein R is an aliphatic hydrocarbon radical having from 12 to 22 carbon atoms, Z is an alkali metal, and A is a divalent aliphatic hydrocarbon radical having from 2 to 3 carbon atoms, is added and the agitation continued, whereby the

surface of the pigment particles is coated with a water-insoluble, oil-soluble diacid salt of the N-aliphatic alkylene diamine, which diamine has the general formula R-NH-(CGH 2),;-NH 2 and which acid has the general formula R'COOH or R'-NH A-COOH wherein R and RI are aliphatic hydrocarbon radicals or a mixture of radicals having from 12 to 22 carbon atoms, x is an integer of from 2 to 10 and A is a divalent aliphatic hydrocarbon radical having 2 to 3 carbon atoms in a quantity ranging from -l to 4 weight per cent, and the alkali metal salt reaction product is dissolved in the aqueous phase The coated pigment can then be collected in a filter and dried in an oven at about 95 to 110 ' C, while the clear filtrate containing the dissolved alkali metal salt is discarded The coated pigment is now ready for incorporation into an oil or oleoresinous vehicle and will disperse with much less effort than an uncoated pigment. It will be appreciated that the order of addition of the water-soluble diamine salt and the alkali metal salt can be reversed That is, the alkali metal salt or soap can first be admixed with the aqueous pigment system followed by the addition of the water-soluble salt of the diamine Our experience has been that the order of addition is not critical However, it is preferred to add the water-soluble salt of the diamine first because of the comparative ease and strength with which it is adsorbed upon the surface of the pigment particles. Among the diamine compounds which can be employed according to the present invention are the water-soluble salts, for example the acetate or hydrochloride, of an N-aliphatic alkylene diamine having the formula R-NH-(CH 2),-NH 2 wherein x is an integer of from 2 to 10, and R is an aliphatic hydrocarbon radical having from 12 to 22 carbon atoms R can also 100 represent mixtures of radicals as obtained from tallow, soybean oil, coconut oil, or other naturally-occurring oils The preferred class of diamines are those in which x is 3, that is the N-aliphatic trimethylene diamines The 105 preferred salts are the acetates and the preferred compound is N-tallow trimethylene diamine diacetate. The alkali metal salts or soaps which can be used in accordance with the present inven 110 tion are represented by the general formulae RCOOZ and R-NH-A-COOZ wherein Z is an alkali metal, A is a divalent aliphatic hydrocarbon radical having 2 or 3 carbon atoms, and R is an aliphatic hydro 115 carbon radical having from 12 to 22 carbon atoms R might also represent mixtures of radicals as obtained for example from tallow, soybean oil, coconut oil, or the like The class of compounds represented by the first general 120 formula are the soaps of long chain fatty acids, examples of which include sodium oleate, sodium stearate, sodium palmitate, potassium 785,388 our invention is applicable to such dry pigments when they are brought into an aqueous

dispersion Also within the scope of our invention are the above pigments as they are ultimately coated according to the process of this invention. By the term pigment is meant substances which are generally considered insoluble in the vehicle as distinguished from dyestuffs, which are generally considered soluble For example, pigments generally have the property of light refractivity, tending to give opacity to the system, whereas dyes generally only have the property of light absorption, tending to retain the transparency of the system. The following examples are intended to illustrate the underlying principles of our invention and are not to be construed as limiting the scope thereof. The fineness of grind of pigments was determined on the Hegman Grind Gauge The fundamental feature of the gauge is a wedgeshaped channel 42 inch wide and ranging in depth from zero to 0 005 inches, cut in a hardened tool steel block A linear scale beginning with 0 where the channel is 0 004 inches deep and ending with 8 where the channel is zero inches deep, is etched along-side the channel and reading expresses the "grind number " The method as described by Henry A. Gardner and G C Eward in "Physical and Chemical Examination of Paints, Varnishes, Lacquers, and Colors" was used to evaluate the fineness of the grind The gauge was laid flat and the deep end filled to slight overflowing with paint The scraper, held perpendicularly on the gauge, was drawn with a firm pressure towards the shallow end of the channel The drawdown at grazing incidence was viewed immediately and it was noted where the coarse particles appeared on the surface of the film The occasional particles in the deeper end were disregarded. When this method is used for viscous pastes, they should be reduced to flowing consistency. oleate, and the like The preferred compound of this class is sodium oleate The class of compounds represented by the second general formula are the alkali metal salts of Naliphatic aminoaliphatic carboxylic acids. These compounds are formed by the reaction between a long chain amine and an unsaturated acid or ester such as crotonic, acrylic, methacrylic, etc The preferred compound of this class is sodium N-Coco-fl-amino-butyrate, formed by the reaction between Coco amine and crotonic acid For purposes of simplicity, this compound has been designated as "A1300," and will be so referred to hereinafter. As an illustration of the calculations involved in determining quantities of reagents, the reaction between N-tallow trimethylene diamine diacetate and sodium oleate yields approximately 80 % of coating material and 20 % of sodium acetate as shown by the following reaction.

o o Ri-NH 2 C 920 H 2 Nn 3 + 2 a-0 R 2+,C-R 2,-G-R 2 + 2 NPO-C-CI 5 l RI-NR 2 C Hlell CIH 3 ll wherein R 1 represents a mixture of radicals as found in tallow and R 2 CO represents an oleyl radical If it was desired to coat 100 lbs of pigment with 3 0 weight per cent of N-tallow trimethylene diamine dioleate, the amount of reagents added to the pigment water slurry can be determined as follows: The molecular weights of N-tallow trimethylene diamine diacetate and N-tallow trimethylene dioleate are 440 and 884 respectively 3 % of 100 lbs requires 3 lbs of Ntallow trimethylene dioleate, which will require 3 0 x 440/884 or 1 49 lbs of N-tallow trimethylene diamine diacetate Since N-tallow trimethylene diamine diacetate is approximately 83 % active the corrected quantity of diacetate will amount to 1 79 lbs The molecular weight of sodium oleate is 304 Since 2 mols of oleate are required to replace the 2 mols of acetate, the quantity of sodium oleate will be 1 x 3 0 x 304/884 or 2 03 lbs. This invention includes the use of the above mentioned chemical agents for treatment of aqueous dispersions containing all pigments, preferably hydrophilic type pigments, including such materials well known commercially as iron blue, chrome yellow, chrome orange, chrome green, zinc chromate, red lead, azo type toners, aluminium hydrate, lakes, carbon black, iron oxide, zinc oxide, titaniumcontaining pigments, zinc sulphide-containing pigments, white lead and extenders Although it is realized that certain of these pigments, such as carbon black are not generally an aqueous mixture, it is to be understood that Ex AMPLE I 105 An iron blue pigment, either as a dry stock or a wet press cake, was coated with varying quantities of N-tallow trimethylene diamine dioleate or N-tallow trimethylene diamine di-A-1300, according to the preferred pro 110 cess of this invention as hereinbefore described. All of the coated pigments along with uncoated control samples were made into fairly highly pigmented roller mill pastes and passed over a laboratory roller mill A determination 115 was made of grinding time, the number of passes required to produce an enamel grind, and yield value These pastes were made into paints and checked further for rate of dry as indicated by dust free time, tack free time 120 (with Zapon (Registered Trade Mark) Tack tester), colour and gloss comparison, and pencil 785,388 785,388 hardness If the drying time exceeded the normal 8-hour day, the samples were checked the following morning and were found to be even It was found that the coating of the pigments did not impair the final film hardness. Table I summarizes some of the results of roller mill data obtained while Table II shows the effect of N-tallow trimethylene diamine dioleate and the corresponding di-A-1300 10 salt, on heat-cured and air-dried paint panels.

TABLE I Coating Material Wetting 1st Pass 2nd Pass Applied Aid Consis Total Pigment % Wt from Added in tency Grind Sample % of Aqueous Vehicle of Grind Time Grind Time Number Pigment Vehicle By Wt Vehicle Solution Portion Paste No Sec No Time on Mill Iron Blue Castor 1217 Dry Stock Oil 40 60 None None B 0 4.0 % 1218,, None D T D O S B 2 4.0 % 1219 D T D O None F 8 Iron Blue 1230 Press Cake None None B 1 42 5 2 38 9 81 4 Iron Blue 3 0 % 1231 Dry Stock None D T D O S B 2 37 5 8 42 4 79 9 Iron Blue 3 0 % 1232 Press Cake D T D O None <F 8 29 2 29 2 Iron Blue 3 0 % 1233 Dry Stock D T D O None <F 6 38 0 8 48 4 86 4 3.0 % 1234,, A-1300 None <F 1 37 7 7 52 2 89 9 Iron Blue 3 0 % 1235 Press Cake A-1300 None <F 8 31 0 31 0 Iron Blue Long Oil 35 1236 Dry Stock Alkyd 52-R-13 65 None None S B 1 15 7 3 17 1 32 8 Iron Blue 1237 Press Cake,, 35 65 None None S B 0 18 8 2 20 8 39 6 k^j TABLE I-continued. Coating Material Wetting 1st Pass 2nd Pass Applied Aid Consis Total Pigment % Wt from Added in tency Grind Sample % of Aqueous Vehicle of Grind Time Grind Time Number Pigment Vehicle By Wt Vehicle Solution Portion Paste No Sec No Time on Mill Iron Blue Long Oil 35 3 % 1238 Dry Stock Alkyd 52-R-13 65 D T D O None S B 2 16 6 6 28 0 34 1 Iron Blue 3 0 % 1239 Press Cake,, 35 65 D T D O None S B 6 20 2 20 2 Iron Blue 3 0 % 1241 Dry Stock,,,, ,, A-1300 None B 4 Slips on Rolls Iron Blue 2 0 % 1243 Press Cake,, a) D T D O S B 5 22 4 8 30 0 52 4 3.0 % 1244,, ,, D T D O S B 8 259 25 9 4.0 % 1245,,,,,, ,, D T D 1 O,, <F 8 25 8 25 8 2.0 % 1246,,,,,, ,, A-1300,, <F 5 21 2 8 29 5 50 7 3.0 % 1247,,,,,, ,, A-1300,, <F 8 26 4 26 4 4.0 % 1248,,,,,, A-1300,, <F 8 24 5 24 5 B Bodied MILL SETTING Ca 005 Front Roll S.B = Slightly Bodied 010 " Rear Roll F Fluid <F = Will Flow Slightly D.T D O _ N-tallow trimethylene diamine dioleate. 52-R-13 is a Federal Specification designation for an alkyd resin modified with vegetable oils, where the product is supplied as a liquid containing 68 to 72 % resin and 28 to 32 % petroleum solvent. 00 ui 785,388, TABLE II Humidity-(High) Sample No. 7/28/53 No No. 1243 1244 No No. 1245 1246 No. 1247 No No. 1248 1236 % Coating 2 0 % 3 0 % 4 0 % 2 0 % 3 0 % 4 0 % None D.T D O D T D O D T D O A 1300 A-1300 A-1300 Blank Starting Time 8:45 AM 8:49 AM 8:55 AM 8:58 AM 9:00 AM 9:01 AM 9:02 AM Dust Free 4:00 PM 4:00 PM 4:00 PM 4:00 PM 4:00 PM 4:00 PM 4:00 PM Time Tack Free OVER-NIGHT Time g /5 sec. Tack Free OVER-NIGHT Time g /5 sec. Tack Free BETWEEN 18-24 HOURS > Time g /5 sec.

24 Hour Pencil Hardness 48 Hour Pencil 3 B 3 B 3 B 3 B 3 B 3 B 3 B Hardness Heat Cured Panels 1 hour 2750 F Gloss Good Good Good Good Good Good Poor Pencil Hardness 2 B 2 B 2 B 2 B 2 B 2 B 2 B Settling Test No Set No No No No No Yes Skinning Some Some Some None None None Some The use of N-tallow trimethylene diamine dioleate in this formulation of Iron Blue CB-50, and Long-Oil alkyd resin did not prevent skinning, while the samples containing the Di-A 1300 salt of N-tallow trimethylene diamine showed no signs of skinning. Iron Blue CB-50 is an iron blue pigment supplied by the Standard Ultramarine and Color Company Iron Blues are complex ferric ferrocyanides containing an alkali metal or ammonia in the crystal lattice. "-g/5 secs " refers to the most weight in grams put on the Zapon Tack Tester for 5 seconds which will allow the foil to pull free from the film within 5 seconds. We have found that a paste consisting of blue pigmented paints on final pencil hardness, parts of iron blue and 60 parts castor oil, dust free time, tack free time, colour, gloss, when passed over a roller mill once will gel and hiding power Further, paints that conThe addition of more castor oil to the formu tain either of the tvo coated pigments showed lation can prevent this, but this is not desir no signs of hard settling, or caking on standing, able because an excess will overplasticize the while the pigments of the control samples final lacquer film Samples 1217, 1218 and formed a hard cake at the bottom of the 1219 in Table I are good examples of how container. the coating of N-tallow trimethylene diamine EXAMPLE II dioleate can correct this condition Referring Chrome green pigments are mixtures of to the table, it will be seen that Sample 1217 iron blue with a very fine particle size of 0 05 bodied so badly on one pass over the roller microns, and chrome yellow with a relatively mill it could not be passed over the mill again large particle size of 0 3 microns Upon Sample 1218 was prepared with N-tallow tri application of chrome green pigmented paints, methylene diamine dioleate added in the the heavy chrome yellow particles settle in the vehicle portion of the paste as a "wetting aid " paint film and the lighter and smaller iron This sample made a slightly better dispersion, blue particles are pushed to the surface of the but most important the paste consistency was film This causes the green paint film to turn sufficiently fluid to pass over -the mill a second blue upon drying We have found that floctime Sample 1219 is a pigment coated with culation in chrome green pigmented paints N-tallow trimethylene diamine dioleate from can be controlled if the chrome green pigment an aqueous solution, which has lowered inter is coated in accordance with the present facial tension between pigment and oil to a invention The pigment particles so coated

minimum, leaving a very fluid paint which can no longer act independently of one will disperse easily in one pass over the roller another, and they will not migrate in the paint mill to an enamel grind of 7-g to 8 (as per film to produce flooding and floating. Hegmanf Gauge) A first sample of a chrome green pigment It will be seen from Table I that pig was coated with N-tallow trimethylene diamine ments coated according to the present inven dioleate according to the process of the present tion will enable a paint manufacturer to invention A second sample of a chrome green formulate fluid pastes with high pigment pigment was coated with a petroleum sulratios, and further to obtain a decrease in phonate according to the conventional method. grinding time, as well as to cut down the These two samples along with a third control number of passes formerly required on the sample were formulated into a pigment paste roller mill and subsequently into a finished paint comThe data presented in Table II illustrates position Table III lists the dispersion and that the coating of the pigments according to roller mill data Table IV summarizes the the present invention has no effects in iron results of film characteristics. 785,388 785,388 TABLE III Roller Mill Data Sample No. Pigment Vehicle Pigment: Percent by Wt. Vehicle: Percent by Wt. Coating Material Applied from Aqueous Solution Consistency of Paste No 1270 No 1273 No 1274 Chrome Chrome Chrome Green Green Green 52-R-13 52-R-13 52-R-13 Alkyd Alkyd Alleyd 65 65 35 35 None Med. heavy 1st Pass on Mill: Grind No. Grind Time, Sec. 2nd Pass on Mill: Grind No. Grind Time, Sec. 3rd Pass on Mill: Grind No. Grind Time, Sec. Final Grind No. Total Time Consumed Passes Required 3 7.8 10.0 53 L 11.6 5:1 29.4 Pet. Sulph. Heavy 3 7.6 31 9.0 N-tallow trimethylene diamin& dioleate Thin 782 8.2 6 10.0 6 26.6 271, 8.2 TABLE IV Sample No. Heat Cured Panels 1 hour at 2750 F. Gloss Comparative Pencil Hardness Film Thickness No 1270 No 1273 No 1274 Poor 2 B 002 " Good 2 B 002 " Good 2 B 002 " Colour "Settling Test" Separation of Yellow and Blue Pigments Even Yes 24 hrs. Referring to Table III, the control sample No 1270 had a grind number of 3 (as per Hegman Gauge) on the first pass over the mill; 5 on the

second, and 511 f on the third. The total time consumed for all three passes was 294 seconds Sample No 1273 was Yes No 24 hrs Still Dispersed after 3 months treated with 3 0 % by weight of petroleum sulphonate from a water slurry, filtered and 10 dried This sample passed over the mill in the first pass to produce a grind of 3, 3 on the second pass, and 6 on the third pass The total grinding time for this sample was 266 seconds Sample No 1274 coated with 3 0 % by weight of N-tallow trimethylene diamine dioleate, reached a grind number of 7 T (enamel specifications) on the first pass over the mill in 8 2 seconds. Referring to Table IV, the data illustrates that coating chrome green pigments with Ntallow trimethylene diamine dioleate does not impair gloss, pencil hardness or colour and settling does not occur in chrome green paint. There is some indication in the literature that chrome yellow pigments have a tendency to react with certain organic coating materials at high temperatures, and thereby cause discolouration of the paint upon baking Because of this heat cured panels were prepared of the paints containing the coated pigments as well as the control It was found that chrome green pigments coated in accordance with the invention and made into a paint did not show any discolouration on heat curing Further, the coated pigments according to the invention produced a paint with a higher gloss, owing to a more uniform dispersion. EXAMPLE III Two samples of iron blue pigments in the form of a water slurry containing 4 28 and 3.1 weight per cent solid, respectively, and designated Iron Blue No 10 and Iron Blue No 10 A, were treated as follows: Four thousand ( 4000) parts by weight of Sample No 10 was divided into two equal parts of 2000 parts by weight each The control was vacuum filtered and dried at 110 C for 5 hours and 85 6 parts by weight of dry uncoated iron blue pulverized control was obtained To the other 2000 parts by weight, 1.42 parts by weight of N-tallow trimethylene diamine diacetate dissolved in hot water was added and mixed for 15 minutes To this 1.84 parts of sodium oleate dissolved in hot water was added and agitated for about 15 minutes The resulting slurry was vacuum filtered and dried at 1100 C for 5 hours. 85.6 parts by weight of pulverized 3 %' Ntallow trimethylene diamine dioleate coated iron blue was obtained. Sample No 10 A was treated exactly as Sample No 10. The coated and uncoated pigments were mixed with a linseed varnish and dispersed on a 3-roll mill The data obtained is recorded in Tables V and VI. TABLE V

Dispersion Data for Iron Blue No 10 3 Roll Mill Sample No. Vehicle Used No 10 Control Linseed Varnish No 10 Coated Linseed Varnish Vehicle by Wt. Pigment by Wt. Relative Viscosity 1st Grind No. Pass Grind Time 2nd Grind No. Pass Grind Time Roll Front Setting Back Oil Absorption Total Time Consumed on Mill parts parts Lowest 0 1 ' 43 O " < 5 1 '15 9 " 001 " 51.0 2 ' 58 9 parts parts 2 1 ' 20 6 6 1 '17 7 m Unchanged 41.0 2 ' 38 4 " Relative Viscosity means that one sample, namely that marked "lowest" was less viscous than the other sample. so 785,388 785,388 TABLE VI Roller Mill Data for Iron Blue No 10 A Sample No. Vehicle Used No 10 A Control Linseed Varnish No 10 A Coated Linseed Varnish Vehicle by Wt. Pigment by Wt. Relative Viscosity 1st Grind No. Pass Grind Time 2nd Grind No. Pass Grind Time 3rd Grind No. Pass Roll Front Setting Back Total Time Consumed on Mill Oil Absorption Results of iron blue samples No 10 and A coated pigment show a better dispersion and a decrease in the time consumed on the mill when compared to the uncoated controls. The actual time saving is much more pronounced on a large production basis Assuming that it is expected to obtain an enamel grind number of 6 with this blue pigment, it would be necessary to pass an uncoated pigment paste twice over a 5 roll mill On the other hand, it would be possible to obtain a grind number of 6 with one pass of a pigment coated in accordance with the invention. Therefore, the paint manufacturer can actually enjoy better than a 50 % saving of time.

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* GB785389 (A)

Description: GB785389 (A) ? 1957-10-30

Aralkyl carbinols and process for their preparation

Description of GB785389 (A) Translate this text into Tooltip



COMPLETE SPECIFICATION Aralkyl Carbinols and process for their preparation We, UNION CARBIDE CORPORATION (formerly Union Carbide and Carbon Corporation), of 30, East 42nd Street, New York, State of New York, United States of America, a Corporation organised under the laws of the State of New York, United States of America, (Assignee of JOSEPH AUGUSTINE LAMBRECH), 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 an improved process for making aralkyl carbinols. The aralkyl carbinols obtained by the process of this invention have the general formula: where R is either a carbonyl (-CO-) group or a hydrogenated carbonyl group (-HCOH-). These compounds may be named 2-benzoyl-2,2-dichloroethanol and 3phenyl-2,2-dichloropropanediol 3 respectively. Such compounds are useful for forming resins by reaction with formaldehyde. If desired, they may be esterified with acids to form plasticizers for synthetic resins. They may also be used as dye carriers for synthetic fibres such as polyethyleneterphthalate. According to one modification of the invention, 2-benzoyl-2,2-dichloroethanol may be prepared by condensing substantially equimolar amounts of formaldehyde and alpha-alpha-dichloroacetophenone in the presence of an alkaline catalyst and at a temperature between 0 C. and 40 C. The reaction may be represented as follows:

<img class="EMIRef" id="026445184-00010001" /> <img class="EMIRef" id="026445184-00010002" /> The condensation is conducted in the pre sence of an alkaline catalyst preferably in an amount between 1 per cent and 3 per cent by weight of the reactants. The alkaline catalyst may be an alkali metal hydroxide, an alkaline earth metal hydroxide or a tertiary amine and the reaction is carried out at a temperature of from 0 C. to 40 C. Preferably, the reaction is conducted at 20 C. and for a period of from two hours to twenty-four hours. After the reaction is complete, from one to three volumes of water may be added to the reaction mixture, whereby oil and water layers are formed. The oil layer is separated from the water layer and distilled to yield 2-benzoyl-2,2-dichloroethanol as a distillate. If desired, 2-benzoyl-252-dichloroethanol may be reduced by reaction with a low-boiling aliphatic secondary alcohol to form 3-phenyl2,2-dichloropropanediol- 1,3. Preferably the reduction reaction is conducted by reacting the ketoalcohol with an excess of a low-boiling aliphatic secondary alcohol, such as isopropanol, in the presence of an aluminum alcoholate, such as aluminum isopropoxide, as a catalyst at a temperature corresponding to the boiling point of the low-boiling alcohol until the lowerboiling ketone by-product of the reaction is no longer distilled from the reaction mixture. The reduction reaction can be graphically represented by the equation: <img class="EMIRef" id="026445184-00010003" /> wherein R is an alkyl group. The invention is more partlcularlrt described in the following examples: EXAMPLE I. 2-benzoyl-2, 2-dichloroetbanol was prepared by slowly adding a methanolic solution of sodium hydroxide (12 grams of sodium hydroxide in 150 cc. water and 300 cc. methanol) to a mixture of 567 grams of alpha-alpha-dichloro-acetophenone and 255 grams of 40 per cent formalin at 20 C. The reaction mixture was maintained at 20 C. for 24 hours and then added to two liters of water. The oil layer which formed was separated from the water and distilled. The fraction which boiled at 134 C. at an absolute pressure of 5 mm Hg. was recovered as the distilIate product. It had a specific gravity of 1.367 (20Q/20 C.). The yield was 90 per cent. This product is soluble in alcohols and ketones and is 2-benzoyl-2,3- dichloroethanol. EXAMPLE II. 3 -Phenyl-2,2-dichloropropanediol-1,3 was prepared by adding 300 grams of the product obtained in Example I to a mixture of 65 grams of aluminum isopropoxide and 1000 cc. of isopropanol at its boiling

point(70" C. to 85" C.). Heating was continued until acetone no longer distilled from the mixture. The isopropanol was removed by distillation and the catalyst neutralized with dilute sulfuric acid. The residue solidified. It was recrystallized from benzene in the form of a white crystalline solid melting at 107 C. It is soluble in alcohols and ketones and is 3-phenyl-2,2-dichloropropanediol. What we claim is: 1. As a new chemical compound an aralkyl carbinol having the general formula: <img class="EMIRef" id="026445184-00020001" /> where R is either a carbonyl group (-CO-) or a hydrogenated carbonyl group (-HCOH-). 2. A process for producing an aralkyl carbinol having the formula: <img class="EMIRef" id="026445184-00020002" /> which comprises condensing substantially equimolar amounts of alpha, alpha-dichloroacetophenone and formaldehyde in the presence of an alkaline catalyst at a temperature between 0 C. and 40 C. 3. A process for producing an aralkyl carbinol having the formula: <img class="EMIRef" id="026445184-00020003" />


* GB785390 (A)

Description: GB785390 (A) ? 1957-10-30

Improvements in methods of preparing cement raw slurry

Description of GB785390 (A)

P A Et N X S P a E C I F, I ATN PATENT SPE CIFICATION a 2 J,0 Inventor: JORGEN OLAF CLEEMAN 71 ( O W N Date of Application and filing Complete Specification: Sept 5,

1955. No 254521/55. Complete Specification Published: Oct 30, 1957. Index at acceptance:-Class 22, A 1 X International Classification:-CO 4 b. COMPLETE SPECIFICATION Improvements in methods of preparing Cement Raw Slurry ERRATUM SPECIFICATION N'O, 785,390 85,390 Page 4, line 50, fort "Centrlfugedn read ncentrifugal". TFIE PATENT OFFICE, 28th A/wit, al 8 DB 04462/2 ( 8)3604 150 4/58 R ferred method on account of its lower power requirements is closed-circuit grinding; in this method the raw materials after wet-grinding are passed to a separator which divides them into a fine and a coarse fraction; the coarse fraction is fed back to; the mill to be ground again and the fine fraction usually constitutes the raw slurry. The separator commonly used in closedcircuit grinding is a rake classifier or other apparatus in which the separation takes place under the action of gravity Now if separation is to take place at a suitable particle size by sedimentation the water content of the S 1 lurry must be as high as 70 or 80 %/ Qor even more On the other hand for efficient kiln operation the water content of the slurry should be as low as possible However if the raw slurry is too dry it cannot be pumped, and this obviously complicates its handling. Therefore for efficient kiln operation the raw slurry should be as dry as is consistent with pumping, and a water content of about 30 to 40/o meets these conflicting requirements. This water content is considerably lower than that required by the rake-classifier or the like and it is therefore usual to remove some of this water in a thickener, which is however costly to instal and operate and complicates the plant In some closed-circuit grinding plants gravity-action separators have somelPrice 3 s 6 d l able if efficient kiln operation is to be achieved. According to this invention a part of the raw materials is wvet-ground in a closed circuit that includes a centrifugal separator, thus removing from the circuit a fine fraction with a substantial water content Relatively dry raw materials are then mixed with the finet fraction to form a mixture which either as such or after further grinding constitutes the raw slurry. A centrifugal separator used in a cement works should be robust and simple and sve have found that it is advantageous to use a hydrocyclone. The proportions in which the m aterials may be used can be calculated in the manner set out below, these calculations being illustrated by

Figures 1 and 2 of the accompanying drawings. In Figure 1, the area I represents raw material of low water content (or containing no water at all, that is, the material is available as a dry powder), the area II the closedcircuit-ground material of comparatively high water content and the area III a slurry produced by mixing materials I and II T and V denote the absolute amounts of dry matter and water, respectively, contained in I, II and III. Then obviously I PATENT SPECIFICATION Inventor: JORGEN OLAF CLEEMAN 785,390 0 W t 3 Date of Application and filing Complete Specification: Sept 5, 1955. No 25452/55. ___ty Complete Specification Published: Oct 30, 1957. Index at acceptance:-Class 22, A 1 X International Classification:-CO 4 b. COMPLETE SPECI'F'ICATION Improvements, in methods of preparing Cement Raw Slurry We, F L SMIDTH & Co A/S, a Danish Company, of 33, Vestergade, Copenhagen K, Denmarki, 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 the production of cement raw slurry by grinding the raw materials. There are two methods of grinding in common use Straight grinding is the older method, and in this the raw materials are finish ground by a single passage through a grinding mill The newer and now the preferred method on account of its lower power requirements is closed-circuit grinding; in this method the raw materials after wet-grinding are passed toa separator which divides them into a fine and a coarse fraction; the coarse fraction is fed back to, the mill to be ground again and the fine fraction usually constitutes the raw slurry. The separator commonly used in closedcircuit grinding is a rake classifier or other apparatus in which the separation takes place under the action of gravity Now if separation is to take place at a suitable particle size by sedimentation the water content of the slurry must be as high as 70 or 80 % or even more On the other hand for efficient kiln operation the water content of the slurry should be as low as possible However if the raw slurry is too dry it cannot be pumped, and this obviously complicates its handling. Therefore for efficient kiln operation the raw slurry should be as dry as is consistent with pumping, and a water content of about 30 to /% meets these conflicting requirements. This water content is considerably lower than that required by the rake-classifier or the like and it is therefore usual to remove some of this water in a thickener, which is however costly to instail and

operate and complicates the plant In some closed-circuit grinding plants gravity-action separators have somelPrice 3 s 6 d l times of late been replaced by centrifugal separators such as hydrocyclones; the separation in the latter is effected by centrifugal force, which may he several thousand times greater than the force of gravity A snialeir water content in the closed-circuit can therefore be accepted However effective separation by hydrocyclones requires that the raw materials should have a water content slightly higher than that required for efficient kiln operation Thus a hydrocyclone either works inefficiently due to too low a water content or efficiently with the correct water content, but then the fine fraction forming the raw slurry has a water content larger than that desirable if effcient kiln operation is to be achieved. According to this invention a part of the raw materials is wet-ground in a closed circuit that indludes a centrifugal separator, thus removing from the circuit a fine fraction with a substantial water content Relatively dry raw materials are then mixed with the fine fraction to form a mixture which either as such or after further grinding constitutes the raw slurry. A centrifugal separator used in a cement works should be robust and sinple and we have found that it is advantageous to use a hydrocyclone. The proportions in which the materials may be used can be calculated in the manner set out below, these calculations being illustrated by Figures 1 and 2 of the accompanying drawings. In Figure 1, the area I represents raw material of 'low water content (or containing no water at all, that is, the matzrial is available as a dry powder), the area II the closedcircuit-ground material of comparatively high water content 'and the area III a slurry produced by mixing materials I and HI T and V denote the absolute amounts of dry matter and water, respectively, contained in I, II and III. Then obviously 785,390 T==T 1 +T 2 V.=V 1 +V 2 The percentages of water II and III are V 1 X 100 vi = T, + V, V 2 x 100 V 2 = T+ V 2 V 3 X 100 T, + V. From these the following V, and V, are obtained: v, X T V, 100-v 1 v x T V = _ 100-v. V 3 x T 3 V 3 = 100-v. On substituting ( 6), ( 7) and ( 8, sult is: v x T, v, x T v,,x _ = +__100-v 3 100-v, 100Assuming now T, to be= 1 tion ( 1) may be written: =t 1 tn t, and te being the distributio cf lry matter contained in I at t, = 100 t, On substituting from ( 10), -to ( 9) we have 100o v, ( 100 62 -v 100 -v, cort ( 1) and This equation contains four variables, viz.

v,, v 2, v, and t-. ( 2) If v, is fixed absolutely, for instance at ttained in I, 333-l, while v, is given different values in turn, for instance, 0, 10 % and 20 %I, curves may be drawn, showing the variation of to in f 2 \ accordance with v,. These curves are shown in Figure 2 at P, Q and R, the curve P corresponding to a water content of 0 %l in the raw materials of ( 4) and low water content, Q to a water content of % and R to a water content of 20 %,. Auxiliary lines show by way of example that, when manufacturing a cement rawv ( 5) slurry (III) containing 3310,% water, about % of the raw materials (II) mray be subjected to closed-circuit grinding at a water values for V 1, content of about 5 % higher (that is, 38 t33.1) than the water content in III if tha remaining 20 %Q of the raw materials I is entirely witheut water If on the other hand, ( 6) the water cont Lent of I is say 10 %, it is not possible to let more than about 75 % of the dry material pass through the closed-circuit grinding installation in order to obtain the ( 7) and desired 33-1 % water in the sluiry mix JII so long as the difference in swater content of III and II is to be maintained at 5 Under the same conditions the amount of drv ( 8) materi Al passing throurh closed circuit grindin R will be 68 % only if the water content in (), he e of I is 20 % 1. )mi ( 2), the re Figures 3 to 7 of the accompanying drawings are diagrams of different ways in which T Ccthe invention may be carried out. 2 ( 9) In the plant shown in Figure 3 raw v materials A and B are used, and, as also in the other examples, rnay be of the same or 00 ( 10), equa differ ent composition The material A is ground dry in a mi'i M, to produce the material I of the calculations Water 1 is ( 111 added to the material B, which is wet-ground in a mill M,, in closed-circuit with a hydron in p er cent cyclone H, more water being added at 2 to the 7 d II, or material entering the hydrocvclone and the coarse fraction from the hydrecyclone being ( 12) returned to the mill as shown at 3 = The fine fraction is the material II of the calculations, ( 11) and ( 12) and it is mixed with the ground material I in a mixer G and then fcmis the final slurry III. vt The compositions of suitable materials for ( 13) working by thi S method are shown in the folv lowing table: SO 785,390 TABLE 1 A = I B II III Parts of dry matter 22 78 78 100 Parts of water 0 0 to 52 52 52 % dry matter 100 100 to 60 60 66 % water 0 O to 40 40 34 Generally water is added at both 1 and 2 in Figure 3, but if the material B has a high enough water content it may be unnecessary to

add water at 1, and if the water content of the ground material is high enough for efficient separation in the hydrocyclone no water need be added at 2. The arrangement shown in Figure 4 nway be used when the material A is not dry Here the fine fraction II from the hydrocyclone H is fed to a mill M,p tin which the material A is wet-ground, and there is no need for a special mixer G Suitable compositions for carrying out the method shown in Figure 4 are given in Table 2. TABLE 2 A = 1 B II III Parts of dry matter 50 50 50 100 Parts of 5 0 to 45 45 50 water % dry matter 91 100 to 53 53 67 % water 9 0 to 47 47 33 When the raw materials contain both hard and soft particles they may be subjected to an initial grinding and then separated finto fine and coarse fractions, the coarse fraction constituting the part of the raw material that is ground in the closed circuit The fine fraction from the separation in the closed circuit is mixed either with the raw material before the initial grinding or with the first fine fraction. This method is illustrated by Figure 5. In Figure 5, the raw material A is mixed in a mill M 11 with a fine fraction II from a hydrocyclone H This mill grinds the mix selectively whereby the soft particles aren'iore finely ground than the hard particles; if the materials are of suitable composition they may be reduced in size in a wash drum instead of being ground The mixture III then passes to a screen S which divides the materials into a coarse fraction and a fine fraction Water 1 and a coarse fraction 3 tare added to the coarse fraction B before it passes into the closed circuit containing the mill MA, and the hydrocyclone H; more water may be added at 2 if required. The fine fraction from the screen S is ground in a mill M,, and then constitutes the finished cement raw slurry IV. The fine fraction coming from the closedcircuit grinding may be passed as II to the mill M,, as indicated by the dotted line, but usually the method shown in solid lines is preferred. Materials to be treated as shown in Figure may have the composition given in Table 3. 785,390 TABLE 3 A = I B II III IV Parts of dry matter 100 60 60 160 100 Parts of water 19 10 45 64 54 % dry matter 84 86 57 71 65 % water 16 14 43 29 35 Figures 6 and 7 are suitable when the raw materials A and B are different, A consisting of substantially dry materials whilst B consists of materials having a substantial water content In the two arrangements illustrated in these drawings only a fine fraction of the relatively dry raw material is mixed swith the fine fraction from the closed circuit to form the raw slurry, the remainder being fed into

the closed circuit. In the arrangement shown in Figure 6 the material A is first passed through a screen S, where they are divided into a fine fraction 5 and a coarse fraction 6 The coarse fraction 6 is passed through a mill M, to another screen 52 which divides this fraction into a fine fraction 9 and a coarse fraction 8 The materials B to which are added the fine fraction 5, the coarse fraction 8, another coarse fraction 3 and water 1 are passed into a closed circuit comprising the mill M,, and a hydrocyclone H; further water may be added to the materials at 2 if required The coarse fraction 3 from the hydrocyclone is fed bach into the circuit, whilst the fine fraction 1 I is fed to a mixer G The fine fraction 9 is passed through the mill M 1 ' to the mixer G where it combines with the fine fraction II to form the raw slurry III. The arrangement shown in Figure 7 is very similar to that shown in Figure 6 In it an air separator W replaces the screen 52, and as a result it is not necessary to carry out any further grinding of the fine fraction 9. It will be clear from these Figures and Tables that by the invention it is possible, to supply sufficient water to the rawv materials undergoing closed-circuit grinding to enable the hydrocyclone to work effectively, and at the same time without using a thickener to product a cement raw slurry having a water content say, 35 %, suitable for 'efficient kiln operation.


* GB785391 (A)

Description: GB785391 (A) ? 1957-10-30

Improvements in rotary thermal regenerators, particularly for gas turbines


PATENT SPECIFICATION Date of Application and filing Complete Specification: Sept 12, 1955. 785,391 No 26008/55. l v a g o DA Application made in Germany on Sept 10, 1954. Complete Specification Published: Oct 30, 1957. Index at acceptance:-Class 64 ( 1)5 L 4 (C:E). International Classification:-P 25 h. COMPLETE SPECIFICATION Improvements in Rotary Thermal Regenerators, Particularly for Gas Turbines We, HENSCHEL & SOHN GESELLSCHAFT MIT BESCHRANKTER HAFTUNG, of 2, Henschelstrasse, Kassel, Germany, a Joint-Stock Company organised under the Laws of Germany, 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 rotary thermal regenerators. Gas turbines for use as power units for driving lorries omnibuses and the like vehicles must answer the following requirements: they must be of low weight, inexpensive to manufacture, take up little room, and have a low fuel consumption The last requirement can only be satisfied by equipping the gas turbine with a heat exchanger For this purpose a thermal regenerator, or regenerative heat exchanger, is particularly suitable, that is to say a heat exchanger consisting of a plurality of chambers filled with a heat-absorbing filling material of steel, ceramic, or the like, which are traversed alternately by the hot waste gases from the turbine and by the air to be heated coming from the compressor in the opposite direction of flow. According to the present invention there is provided a rotary thermal regenerator having a plurality of chambers arranged in parallel with the axis of rotation and containing heattransfer material, characterised in that the individual chambers consist of cylindrical tubes filled with the heat-transfer filling material which extends wholly over the crosssection of the tube bore and through which the gases flow axially in their passage along the tube. The centres of the chambers are for preference arranged on a plurality of concentric circles around the axis of rotation and on radii extending from the axis of rotation, the number of chambers disposed on the different concentric circles being equal. lPrice 3/ 6 l As a further development of the invention, the diameters of the chambers disposed on the different concentric circles are so graduated that the tube-like chambers are tangent to the radii directed to the tubes of the outer 50 concentric circle on both sides. Shaped sheet metal strips are preferably used according to the

invention as filling material for the numerous tubular chambers, being simple to produce and offering only 55 slight resistance to flow Sheet metal strips of this kind can easily be inserted in a circular tube A tube-shaped chamber has furthermore the great advantage that it can be designed to have a lesser wall thickness than 60 chambers of any other shape with the same internal pressure. A preferred embodiment of the regenerator of the invention is shown diagrammatically and by way of example in the accompanying 65 drawings, in which:Fig 1 is a partial cross-section through an end chamber of the regenerator on the line I-I of Fig 2; Fig 2 is a partial longitudinal section of 70 the same; and Fig 3 shows a sheet metal strip forming the filling material. In the embodiment shown in Figs 1 and 2 only two concentric rows of tubular chambers 73 are provided The tubular chambers 1 are disposed on an outer circle 2 and the tubular chambers 3 on an inner concentric circle 4. The tubular chambers 3 have a smaller diameter corresponding to the smaller diameter 80 of the circle 4 All the tubular chambers disposed on one circle are of equal area. The diameters of the two rows of tubular chambers 1 and 3 are so selected that radii extending from the axis of rotation and 83 tangential to both sides of an outer chamber 1 are also tangential to both sides of the corresponding inner chamber 3 The tubular chambers 1 and 3 are filled with a filling material 5 and 6, indicated by cross-hatching 90 785,391 in the drawing At their ends the tubular chambers are secured in round ring-shaped chambers 7 and 8 by welding, soldering or other means The chambers 7 and 8 each consist of an inner circular bounding wall 9, an outer circular bounding wall 10, and each has a cover plate 11 receiving the ends of the tubular chambers 1 and 3, and a cover plate 12 having as many openings 13 of segmental cross-section as there are tubular chambers on a circle The chambers 7 and 8 are furthermore divided by radial ribs 14 into as many chambers as there are tubular chambers on a circle. The filling materials 5 and 6 consist of a continuous band composed of a straight sheet metal strip 15 of slight thickness and a sheet metal strip 16 likewise of slight thickness bent into semi-circular undulations The two sheet metal strips 15 and 16 are placed loosely upon one another and rolled up so that they can be easily inserted into the tubular chambers 1 and 2.

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* GB785392 (A)

Description: GB785392 (A) ? 1957-10-30

Differential


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DE1025279 (B) US2786367 (A) DE1025279 (B) US2786367 (A) less Translate this text into Tooltip



PATENT SPECIFICATION 78 f Date of Application and filing Complete If/ t Specification: Sept14, 1955 No 2 Application made in United States of America on Sept 28, 1954. Complete Specification Published: Oct 30, 1957. Index at acceptance:-Class 80 ( 2), D 1 A. International Classification:-F 06 h. COMPLETE SPECIFICATION Differential We, ALIAS-CHALMERS MANUFACTURING CO-m PANY, a Corporation organised under the laws of the State of Delaware, United States of America, of Post Box 512, Milwaukee 1, Wisconsin, United States of America, 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 power transmitting gearing and is concerned more particularly with a bevel gear differential, that is, a differential wherein a pair of bevel side gears and a set of planetary bevel pinions in mesh with the side gears are rotatably mounted within a rotary cage or housing structure. Bevel gear differentials are widely -used in motor vehicles and it is a primary object of the invention to provide an improved automotive type of bevel gear differential which permits removal of the side gears and planet pinions from the cage without the necessity of first removinn' the cage from its supporting structure, so that a substantial amount of time may be saved when component parts of the differential such as gears, bearings and thrust washers are to be inspected or replaced. Although it is possible to remove the bevel side gears and bevel planet pinions from some prior art differentials without removing the differential cage from its support, these previously suggested differential mechanisms are not entirely satisfactory, particularly those which employ only two planet pinions In a two pinion bevel gear differential it is difficult, for instance, to provide for even load distribution on the teeth of the pinions and side gears and to obtain satisfactory tooth life. More specifically, therefore, it is an object of this invention to provide an improved bevel gear differential of the type hereinbefore set forth in which the planet pinions are rotatably mounted in 50 registering relation, respectively, with peripheral apertures of the cage, and in which the peripheral cage apertures and the planet pinions are relatively proportioned so that the pinions may be moved 55 into and out of the cage through their respective cage apertures. It is a further object of this invention to provide an improved bevel gear differential of the torque proportioning 60 type. According to the invention, a bevel gear differential including a rotary cage structure, a pair of bevel side gears mounted therein and a plurality of bevel 65 planet pinions in mesh with the side gears, is characterised in that the cage structure has a peripheral aperture so proportioned and arranged with respect to the side gears as to accommodate move 70 ment of the side gears into and out of the cage structure through the aperture, and a releasably secured cover for said aperture serving, when secured, as a structure for mounting one 75 of the planet pinions in its operative position. The invention is illustrated by way of example in the accompanying drawings, in which: 80 Fig 1 is a sectional view taken on line I-I of Fig 2, of a differential gear installation for motor vehicles; Fig 2

is a plan view of the installation shown in Fig 1 with parts omitted for 85 purposes of exposure; Fig 3 is an end view taken in section on line III-III of Fig 1, the bevel ring gear at the right of Fig 1 being omitted in Fig 3; 90 ,392 6345/55. 785,392 Fig 4 is a sectional view corresponding to the lupper part of Fig 1, and showing a modification of the mounting structure for the planet pinions; and Fig 5 is a sectional view similar to Fig 4 and showing a further modification of the planet pinion mounting structure. Referring to Fig 1, a differential cage 11 is rotatably supported on stationary walls 12 and 13 through supporting tubes 14 and 16 and tapered roller bearings 17 and 18 A bevel ring gear 19 is secured to a circular flange 21 formed on cage 11 by a plurality of cap screws 22 which are threaded into drilled and tapped holes in flange 21 The ring gear 19 is driven by a driving pinion 23 formed on the end of a power shaft 24 connected to a power source, not shown. The cage 11 has a pair of inusardly extending hub portions 26 and 27 which present inwardly facing and radially' extending thrust transmitting surfaces 28 and 29, respectively Aligned bores 31 and 32 are formed in cage 11 and provide interior openings in hub portions 26 and 27, respectively A pair of bevel side gears 33 and 34 are positioned within the interior of the cage 11 and have their hubs 36 and 37 connected in splined, driving relation, respectively, to a pair of differential half shafts 38 and 39 The shafts 38 and 39 may be connected to vehicle traction wheels, not shown The splined connections between shafts 38 and 39 and their associated hubs 36 and 37 are axially loose so as to allow the shafts to be withdrawn from the side gears 33 and 34 Shaft 38 is withdrawable to the 401 eft and shaft 39 is withdrawable to the right as viewed in Fig 1 A cylindrical surface 41 is formed on the portion 42 of hub 36 which extends into bore 31 The cylindrical surface 41 is in radially confronting relation to bore 31 and the diameter of portion 42 of hub 36 is slightly less than the diameter of bore 31 so that there is clearance between surface 41 and bore 31 allowing gear 33 to float in bore 31 A similar relation exists between a cylindrical surface 43 formed on a portion 44 of hub 37 of side gear 34 and bore 32 of the cage 11. A thrust washer 46 surrounds hub portion 42 and is interposed between surface 28 of cage 11 and back side of bevel gear 33 Thus the axially outward thrust of gear 3-3 is transmitted to hub 26 of cage 11 through thrust washer 46. Similarly, a thrust washer 47 surrounds hub portion 44 and is interposed between the back side of bevel gear 34 and surface 29 of cage huh 27. When the side gears 33 and 34 are in 65their installed condition

within the cage structure 11 as shown in Fig 1, the distance between the axially innermost portions of their hubs 36 and 37 is greater than the distance which either hub portion 42 or 43 extends axially into 70 bores 31 and 32 respectively. Referring to Figs 1, 2 and:3, three cylindrical surfaces define three peripheral apertures 51 which communicate with the interior of cage 11 These apertures are 75 equally spaced circumferentially about the axis 52 of the side gears:33 and 34 this axis 52 also being the axis of shafts:3,8 and 39 and the axis of rotation of cage 11. A bevel planet pinion 53 is positioned 80 within each of the three apertures 51 and these pinions 53 are in mesh with the two side gears In Figs 1, 2 and:3, the planet pinions 53 each have a frusto-conical head portion 54 secured, as by welding, to an 85 outward extending stub portion 56 The frusto-conical head portions 54 each present a conical surface 57 which tapers radially outward, that is toward an apex at the outside of cage 11 As shown in go Fio' 3, the axes 38, 59 and 61 of pinions a radiate at right angles from axis 52 and like the axes of the conical surfaces 57 are spaced 120 degrees apart so as to coincide with the latter 95 Three annular retainers 62 are releasably secured to cage 11 by cap screws 63 wrhihel are threaded into tapped holes 64 in underlyinoa annular portions of the cage 11 As shown in Fig 1, each retainer 100 62 has a circular flange 66 extending radially relative to the axis of the associated aperture 51, the retainer 62 having drilled holes 67 through which cap screws 63 extend Each of the retainers 105 62 also has an inward extending collar 68 which has a cylindrical surface in thrust transmitting contact with the surrounding cylindrical surface of the associated aperture 51 Each of the 110 retainers 62 further has a conical surface 69 at its inner periphery and the retainers 62 are secured to the eage 11 in such positions that the conical retainer surfaces 69, like the conical head surfaces 57 taper 115 radially outward, that is, toward the ontside of cage 11 The annular retainers 62 surround the frusto-conical head portions 54, respectively, and the relatively contacting conical surfaces 57 and 69 are 120 complementary to each other Preferably, the same taper is used for all three heads 54 and for all three retainers 62 all having the same common taper The three planet pinions 53 which are disposed 125 within the three apertures 51 in the cage 11 are adjusted for coaction with the side gears 3, and 34 so as to radially center the latter relative to the axis of rotation of cage 11 The retainers 62 may be 130 785,392 radially adjusted relative to the cage 11 by a variable number of shims 71 which are interposed between each retainer 62 and the underlying annular portion of the 3 cage 11. From the forgoing description it is apparent that a mounting structure is provided for each planet pinion 53 which bridges the associated

aperture 51 in cage 11 Each of the planet pinion mounting structures includes a retainer element 62 releasably secured to the cage 11, and a bearing or head portion 54 formed on the respective pinion 53. Referring to Fig 2, the cap screws 63, retainer 62 and pinion 53 of Fig 1 have been removed to reveal the relative size of the peripheral cage apertures 31 and the side gears 33, 34 It is seen that the side gears and aperture 51 are so proportioned and arranged as to accommodate movement of the side gears 33 and 34 into and out of the cage 11 through the aperture 51 Although each of the apertures 51 is large enough to permit the side gears to be moved therethrouogh, it is evident that only one of the apertures need be so formed for the purposes of this invention. Before the side gears:33 and 34 can be removed from the interior of the cage 11, the cap screw 63 attaching the retainers 62 to the cage are unscrewed from cage 11 and the retainers and associated pinions are withdrawn outwardly from the cage. Also the half shafts 38, 39 are withdrawn from the hubs of the bevel gears 33 and 34 The dash dotted lines 72 in Fig 2 indicate, for instance, the position to which shaft 39 may be withdrawn preparatory to removal of side gear 34 from the cage 11 Before removing side gear 34 the shaft 38 must be withdrawn axially to the left in Figs 1 and 2 After the shafts have been properly withdrawn the gear 34 may be moved axially inwardly to the position shown by dash dotted lines 73, and thence the side gear 34 may be removed outwardly through the exposed aperture 51 in the cage 11 Side gear 33 may be removed from cage 11 in a like manner. Referring to Fig 1, the conical surfaces 57 and 69 co-operate to frictionally resist rotation of the planet pinions 53 and thus resist differential rotation of the shafts 38 and 39 The radial outward thrust transmitted in the direction of axis 58 from the side gears 33, 34 to the planet pinions 53 causes a wedging action to occur between the co-operating conical surfaces 57 and 69, thereby producing the desired friction to resist rotation of the planet pinions Differentials ineorporating this invention may be used in motor vehicles in which it is desirable to have differential action when the vehicle is in nonlinear travel, however, unobstructed differential action is not desired where slippage of one of the traction wheels occurs The frictional resistant to 70 differentiation afforded by the wedg-,ing, action between the conical surfaces is not so great as to prevent differential action when the vehicle is steered in a nonlinear course, yet it is great enough to propor 75 tion the torque between the half shafts 3)9. 39 so as to insure driving power to the wheel having good traction when the other driving wheel has little or no traction due to slippery

ground conditions, for instance 80 Fig 4 shows an alternative planet pinion mounting structure for rotatabljournaling the planet pinions on the eage 11 The planet member 76 shown in Fig. 4 corresponds to the planet pinion 53 in 85 Fig 1, and the means for mounting planet member 76 includes a disk like head. portion 77 of the pinion and an annular retainer or bearing member 78 The head portion 77 includes a disk 77 ' and a 90 removable ring 79 which is secured to the disk 77 ' by cap screws 81 extending through drilled holes 82 in ring 79 and threaded into drilled and tapped holes 83 in disk 77 ' A pair of relatively converg 95 ing conical surfaces 84 and 86 are formed on the disk head 77 on an axis 87 coineident with the axis on which the bevel teeth of pinion 76 are formed A pair of coaxial and relatively converging conical surfaces 100 88 and 89 are formed on retainer 78 in complementary thrust transmitting relation to conical surfaces 84 and 86. respectively The conical surfaces 84 and 86 are formed to converge relative to one 105 another in a radially inward direction relative to their common axis The removable ring 79 permits the pinion 76 together with the disk 77 ' to be separated from the retainer 78 The double conical 110 surface arrangement stablizes the pinion so-that its axis 87 will not deviate from a right angle relationship with the axis of side gears 33 and 34. A plurality of shims 90 are interposed 115 between ring 79 and disk 77 ' and when the conical surfaces 84, 86, 88 and 89 become worn through luse one or more ol the shims 90 may be removed to compensate for the wear Thus the ring 79 is 120 adjustably secured to the pinion member 76 so as to permit the establishment and maintainence of a close fit between the co-operating conical surfaces 84, 86, 98 and 89 125 In Fig 5 a further alternative planet pinion mounting structure is shown in which there is provided a two piece retainer or bearing member 93 for a planet member 92 Ring portions 94 and 130 785,392 96 of retainer 93 bear upon each other in the direction of pinion axis 91 and have relatively Converging conical surfaces 97 and 9 S, respectively, in coaxial relation to axis 91 The relative convergence of conical surface 97 formed on ring portion 94 and of conical surface 98 formed on ring poirtion 96 is radially outward relative to axis 91 The head portion 99 secured to planet pinion 92 has a pair of relatively converging coaxial conical surfaces 101 and 102 formed thereon in complementary relation to conical surfaces 97 and 98, respectively Thus, the planet pinion 92 is stabilized against movement relative to cage 11 except for rotation on axis 91 which is at right angles to the axis of rotation of cage 11. A plurality of shims 103 are interposed betveen ring portions 94 and 96 and by varying the number of shims the proper fit between the

co-operating conical bearing surfaces 97, 98, 101 and 102 man be provided For instance, if the conical surfaces become -worn in use one or more shims may be removed to compensate therefor. The co-operating conical surfaces of the pinion mountings shown in Figs 4 and 5 serve to proportion the torque to the differential half shafts in a manner similar to that previously described in regard to the pinion mounting shown in Fig 1. It will be noted that each of the herein disclosed planetary differentials has a pair of bevel side gears 33 and 34, bevel planet pinions in mesh with the side gears, a cage structure 11 and separable mounting means associated with the side gears, bevel pinions and cage structure 11 for operatively positioning the side gears and planet pinions within the cage structure, these mounting means including a head portion non-rotatably connected with one of the planet pinions, and a retainer rotatably and releasably securing the head portion within a peripheral aperture of the cage structure 11 In each of the illustrated embodiments of the invention the side gears 33 and 34 and a peripheral cage apertures are so proportioned and arranged as to accommodate movement of the side gears 33 and 34 into and out of the cage structure 11 through said aperture, the latter being bridged by the planet pinion mounting structure. The provision of a peripheral aperture ill the cage structure large enough to pass side gears 33 and 34 therethrough permits <o the cage 11 to be formed in one piece as )v casting The use of three planet pinions is desirable to balance the loads on the bevel teeth of the side gears 33 and 34 and planet pinions; also the use of three planet pinions is desirable to floatingly position the side oears 2, and 34 radially in relation to the axis of rotation of the cage 11. The differentials hereinbefore described permit the bevel pinions side gears and 70 thrust washers to be remox ed for repair or replacement without removing the cage from its support and this feature results in a saving of time and labour cost. Also, by providing shimis 71 between the 75 retainers and cage structure 11, it is possible to adjust the position of the pinions so that they centre the side gears radiallv relative to the axis of rotation of the cage By providing radial clearance 80 between the side gear hub portions 42 and 44 and cage bores 31 and 32 respectivelv, the loads on the teeth of the side gears and pinions will be substantially balanced Further, the radial thrust from 85 the side gears to the pinions will be equally distributed to the three pinions and this is particularly desirable in torque proportioning differentials of the type herein disclosed, in that the frictional resistances 90 afforded by the three pinion mounting structures are permitted to be simul taneously effective.


Date post:	15-Apr-2017
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