1,837,912 Dec. 22, 1931. R. E. MANN ' ELLIPSOGRAPH

Filed Ju1y~ 11, 1929 1 2 Sheets-Sheet

Dec. 22, 1931. R E_ MANN 1,837,912 ELLIPSOGRAPH

Filed July 11, 1929 2 Sheets-Sheet 2

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Patented Dec. 22, 1931

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PATENT orrics ROBERT E. MANN, 0F VENICE, CALIFORNIA

ELLIPSOGRAPH Application v?led July 11, 1929. Serial No. 377,552.

My invention is an improvement in geo metrical instruments and relates more es pecially to devices" of this nature for the pur pose of describing an ellipse andknown as 'ellipsographs. , The primary object of my invention is to

provide a mechanical device or improved trammel for the purpose of drawing ellipses of various dimensions and contemplating an arrangement of the parts whereby the device different diameters. A further object of my invention is to pro

vide a mechanical device of this general char acter which can be easily and conveniently manipulated in connection with either pencil or pen and a wide range of adjustments made for drawing ellipses of small and large di ameters without requiring a trammel frame of large dimensions, and including an at tachment for the pen or pencil usable in con nection with both rods and a bearing block traveling on-the rim of the frame for use in connection with the device when used for drawing circles. _ With these principal objects in view my

invention consists in the particular construc tion of the parts including a frame having a circular rim and crossed slots therebetween

' with shiftable supporting legs for said frame, together with blocks slidable in the slots with respect to one another and rods of different lengths attachable to said blocks above and below the frame for carrying the scriber, one of the blocks being provided with a swivelled cap for adapting the device in drawing cir cles; all as hereinafter fully described and particularly set forth in the appended claims.

In the drawings : . Figure l is a perspective view of my

improved mechanical device for drawing ellipses and circles. v

Fig. 2 is a top plan view of the device. Fig. 3 is a side elevation. ' Fig. 4 is a transverse sectional view on a

line with one of the diametral slots. Fig. 5 is a detail sectional view of one of the

blocks adapting the device for drawing cir cles.

vfor drawing circles of,

Fig. 6 is a similar view of the companion block, and '

Fig. 7 is a detail view of the holder for con necting the scriber to either one of the rods. Like numerals of reference indicate like

parts in the several views of the drawings. , In carrying out my invention the main

frame of the device is similar to that of an ordinary trammel and consists of a circular f-t rim 10 with bars 11 extending inwardly from said rim in spaced pairs joined near the center'of the frame as shown in the drawings to provide two diametral slots .12 and 13

to

which cross each other at the center of the .. .. frame, and for supporting the frame at the ' desired height above the drawing board three legs 14 are employed in. the present instance and connected to the rim by set screws 15 and 16 (Fig. 3) the set screw 15 passing through - r. the rim from above into the offset portion of the leg at the underside of the rim while the screw 16 extends upwardly through said off set portion into the rim whereby the legs may be disposed at any required angle with re spect to the frame in the operation of the de- _ vice as hereinafter explained, and more rigid ly secured by screw 16 when disposed radial ly. The lower ends of the legs are turned outwardly to form feet 17 the device in place on'the drawing board a pointed screw 18 is threaded through each foot, said screws also providing for adjusting the height of the frame. For drawing ellipses blocks 19 and 20 are

slidable in the respective slots and provided in the upper part thereof withtransverse apertures or openings, 19a20a, through which a rod 21 passes from one to the other of said blocks and carries a scribereither1 pencil or penfor drawing large ellipses, said blocks being also extended below the frame to receive an additional rod 22 for drawing small ellipses within the zone of the supporting legs, the rod 22 passing through transverse apertures 19?) and 20b in the blocks. By reference to Figs. 5 and 6 it will be seen that these blocks are made in two parts or members for connection to the frame, one

and for holding . ; 30

of said members being provided with a rec; _ - tangular projection 23 extending through the '

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slot in the frame and the companion member having an integral screw 24 threaded into said other member, with outwardly project ing ?anges 25 on both of the members for sliding engagement with the upper and lower edges of the bars forming the slots, and in order to adapt the device for drawing circles the block 19 is provided at its upper end with a swivelled cap 26 having a transverse open ing 27 to receive the aforementioned rod 21 which is secured to the swivelled cap bymeans of a set screw 28, said swivelled cap being rotatably connected to the block by means of a peripherally grooved stem 29 extending into said block and engaged by a set' screw 30 (see Fig- 5). Rod 21 extending through the upper portions of the blocks 19 and 20 is. adjustably. connected thereto by set screws 31 and 32V (Fig. 1) and rod 22. which extends through, the lower portionsof. said blocks is likewise adjustably connected by set screw

' 33. threaded in block19 and knurled nut 84

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threaded on the rod against the outer side of block 20.

It will be. understood that when a small ellipse isbeing drawn within the supporting legs by the use.~.of. rod 22 the other rod 21 is used as the operating lever, but when the longer rod. is being used for drawing ellipses beyond the supporting frame rod 22 may be removed, and in drawing ellipses of such a size, that thelegs in normal position (Fig. 1) would interferesaid legs may be shifted, as indicated in dotted lines Fig. 2, in. which case the longer rod of course will be used; conse quently ellipses of various sizes as to longi tudinal and transverse diameters may be drawn by simply adjusting the blocks with respect to each other, as for instance the dis tancebetween block 19 and the scriber is set tioequal theradius of the minor diameter of theellipse and the distance between block 20 and the scriber is set to equal the radius of themajor diameter, and should it be desired toidraw two ellipses-across each other at'right angles this is accomplished by placing a scriber on each projecting end portion of the rod being used and sliding the rod through so that the pencil points are at the same dis tance from blocks 19 and 20 at, each end, as will, be obvious. Furthermore, when the device is used for drawing circles block .19is positioned at the center of the frame and held in place by rod 22 (Fig. 4-) which'is passed through. the block' 19 and through block 20 at one side and througha similar block 85 at the other side, said supplemental block. being secured to the rod by a set screw 36 whileknurled- nut 84 is threaded against the opposite block 20, whereby a ?xed ful crum for the rod: 21. is provided so that the scriber carried by said rod may be manipu lated in describing a- circle. Rod 21is gradu ated for the accurate. spacing of the blocks

65 andscriberswith respect to the longitudinal

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and transverse diameters of the ellipses, and of course rod 22 may be also graduated. Any preferred form of scriber or drawing

instrument may be used, as pencil 37 or pen 38, and for convenience in connecting the scriber to either of said rods I employ a holder 39 consisting of a member having a longitudi nal opening 40 (Fig. 7) at one end and a transverse opening 41 at the other end to re ceive a rod and drawing instrument according to theme of said holder with respect to said rods-the rod 22 being passed through the longitudinal opening and the shank of the drawing instrument through the other in one instance (Fig; 3) and the positions reversed in the other instance or whenthe holder is usedinconnection withrod 21 (Fig. 4) with

' set screws, 42 and 43 for connectingthe holder to the respective parts; this holder thereby compensating for the distance of said rods from the drawing board. respectively for use in connection with the drawing instruments. Howevena modified, form ofvholder 44 may be used, in connect-ion'with rod>21 as shown inFig. 1 of thedrawings and connected there to by set screw 45, and in order to steady the rod 21 in describing a circle ablock 46 is ad justable o-nsaidrod by set. screw 47. and pro vided with a ball'bearing- 48 at its lower end adapted to travel around the rim of the frame, asshown in Fig. 4. From thev foregoingdescription in connec

tion with the accompanying drawings the construction and operation of my improved device for drawing ellipses and circles will be readily understood, the rods being, guided by the blocks traveling in the crossed slots after themanner of atrammehin the present instance the shorter rod 22 being used for small ellipses within the zone of the legs and the longer rod 21 for drawing ellipses beyond the zone of the legs, the latter being shifted so asto not interfere with ellipses in the intermediate zone, and ' for drawing circles the blocks 19, 20,.and35 are connected so that the block 19 will be held at the center of the frame with the attachment 46 adjusted so that, the ball- bearing at the lower end

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thereof will travel around the circular rim of said frame, it. being understood that for the purpose of drawing smaller circles with the rod 22'bl'ock 19 can bereversed and inter mediate circles drawn. by shifting the legs as explained with reference to drawing ellipses. . The device is light in construction and

provides simple and effective means for ac curately drawing true ellipses of any desired size as to longitudinal and transverse diam eters, the holder which is used in connection with the rods permitting the use of pen or pencil of the kind used in connection with other mechanical instruments, as compasses, etc., it being understood that the form of blocks and cooperating attachments herein

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shown and described may be varied in detail and other modi?cations resorted to in carry ing out my invention within the spirit and scope of the claims.

I claim : 1. An ellipsograph comprising a frame

having supporting legs and crossed diam etral slots, blocks slidable in the slots and having portions thereof projecting above and below the frame, a rod detachably connected to the upperportion of the blocks and extend ing beyond the frame for drawing large ellipses, a rod detachably connected to the lower portions of the blocks, for drawing small ellipses within the legs of the frame and 21V scriber carried by said rods.

2. A device for drawing ellipses and cir~v cles comprising a frame having crossed diametral slots and supporting legs at the outer edges of said frame, a pair of blocks reversible and slidable in the slots and hav ing portions thereof projecting above and below the frame, a long rod connected to the upper portions of the blocks and adjust able longitudinally therein for drawing el lipses beyond the supporting legs of the frame, a shorter rod longitudinally adjust able in the lower portions of said blocks for drawing smaller ellipses within said support ing legs, a swivelled cap at the upper end of one of the blocks for using the device in draw ing circles, and means for connecting each pair of blocks together.

3. A device for drawing ellipses and cir cles comprising a circular frame having crossed diametral slots and supporting legs at the outer edges of said frame, a pair of

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ellipses beyond the supporting legs of the frame, a shorter rod detachably connected to the lower portions of the aforesaid blocks and on which said blocks are adjustable longi tudinally with respect to each other for draw ing ellipses within said supporting legs, a swivelled cap at the outer end of one of the blocks for using the device in drawing cir cles, and means for connecting each pair of blocks to hold the block with the swivelled cap at the center of the frame; together with a block adjustable on one of the rods for traveling on the rim of the circular frame when the device is used in drawing circles.

ROBERT E. MANN.

blocks reversible and slidable in the slots and , having portions thereof projecting above and below the frame, a long rod connected to the upper portions of the blocks and adjust able longitudinally therein for drawing el lipses beyond the supporting legs of the frame. and a shorter rod longitudinally ad justable in the lower portions of said blocks for drawirnr smaller ellipses within said sup porting legs, a swivelled cap at the upper end of one of the blocks for using the device in drawing circles, means for connecting each pair of blocks together, and a block adjustable on the rod in the upper portions of the blocks and having a bearing at the lower end thereof to travel around the circular rim of the frame for supporting said rod in drawing circles.

4. A device for drawing ellipses and circles comprising a circular frame having crossed diametral slots, legs pivotally secured to the outer edges of the frame for supporting the same above the work, a pair of blocks re versible and slidable in the slots and having portions thereof projecting above and below the frame, a long rod detachably connected to the upper portions of the blocks and on which said blocks are adjustable longitudi nally with respect to each other for drawing

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