US2559743A

US2559743A - Shock absorbing mechanisms for railway draft riggings

Info

Publication number: US2559743A
Application number: US688860A
Authority: US
Inventors: Williams Keith
Original assignee: Individual
Current assignee: Individual
Priority date: 1946-08-07
Filing date: 1946-08-07
Publication date: 1951-07-10
Anticipated expiration: 1968-07-10

Description

July 10, 1951 Filed Aug. '7, 1946 K. WILLIAMS 2,559,743

SHOCK ABSORBING MECHANISMS FOR RAILWAY DRAFT RIGGINGS 7 Sheets-Sheet l 7 Sheets-Sheet 2 v In V6 72/02";

July 10, 1951 K. WILLIAMS SHOCK ABSORBING MECHANISMS FOR RAILWAY DRAFT RIGGINGS Filed Aug. 7, 1946 Jig/Z72 MZZzLams.

fli ly.

y 10, 1951 K. WILLIAMS 2,559,743

snocx ABSORBING MECHANISMS FOR RAILWAY DRAFT RIGGINGS Filed Aug. 7, 1946 '7 Sheets-Sheet 3 Infra n/for:

Jfepik Wlllha'ms.

y 1951 K. WILLIAMS 2,559,743

SHOCK ABSORBING MECHANISMS FOR RAILWAY DRAFT RIGGINGS Filed Aug. 7, 1946 7 Sheets-Sheet 4 Inven/or: Raj/{71 hQLZZ ia'ms.

Juiy W, 1951 K. WILLIAMS 2,559,743

SHOCK ABSORBING MECHANISMS FOR RAILWAY DRAFT RIGGINGS Filed Aug. v, 1946 7 Sheets-Sheet 5 I 9 I E. 17 2! l I l I I I9 I I6 JnVen /or: Xe 572; 74 );ZZjams.

.Fufiy 10, 1951 K. WILLIAMS 2,559,743

SHOCK ABSORBING MECHANISMS FOR RAILWAY DRAFT RIGGINGS Filed Aug. 7, 1946 7 Sheets-Sheet 6 InVen r:

jte aLi fi MZZja/ms.

SHOCK ABSORBING MECHANISMS FOR RAILWAY DRAFT RIGGINGS Filed Au 7, 1946 WILLIAMS July M, 1951 .7 Sheets-Sheet 7 Inrenj or Kai/l3 WEI/jams.

Patented July 10, 1 951 UNITED STATES PATENT OFFICE SHOCK ABSOB'BING MECHANISMS FOR RAILWAY DRAFT RIGGINGS 12 Claims. 1

This invention relate to improvements in shock absorbing mechanisms, and more particularly to shock absorbing mechanisms for railway draft riggings.

While my improved shock absorbing mechanism is adapted for use with both freight and passenger equipment, it has been particularly designed for use on locomotives and cars of modern passenger trains operated at high speeds and wherein a large number of passenger cars are used per train.

The main object of my invention is to produce such soft initial action in shock absorbing mechanisms having only springs or other similar cushioning means by the employment of a pair of springs or cushioning elements, which are compressed in series during the first part of the compression stroke of the mechanism, whereby the compression force is distributed equally to both members of the pair with resultant soft action, and compressed in parallel during further compression of the mechanism to absorb the heavier shocks.

A further object of the invention is to provide a shock absorbing mechanism of the character set forth in th preceding paragraph, wherein the cushioning element are composed of rubber mats or pads.

A more specific object of the invention to provide a shock absorbing mechanism comprising a pair of front and rear outer follower member-s, a pair of front and rear intermediate follower members, a cushioning element interposed between said outer front follower member and front intermediate follower member, and a second cushioning element interposed between said rear intermediate follower member and outer rear follower member, wherein the intermediate followers are in contact with each other to transmit the force from one cushionin element to the other during the first part of the compression stroke, to produce soft cushioning action, and wherein the two cushioning elements are compressed in parallel between the outer front follower and the front intermediate follower and the outer rear follower and the rear intermediate follower to provide high capacity during the remainder of the compressionstroke for absorbing the heavier shocks.

Another object .of the invention is to provide a shock absorbin mechanism of highcapacity having free spring action throughout the compression stroke and soft initial resistance to take care of :the lighter shocks, wherein the high capacity .is produced by two sets of twin arranged springs which are compressed in parallel, and the sof initial action is produced by compression in Series of the two sets .of springs.

Still another object of the invention is to pro? vide a shock absorbing mechanism comprising front and rear casings having inwardly prejecting arms, intermediate followers respectively engageable by the arms, and cushionin elemen s within the casings compressible by said followers respectively, wherein the intermediate follOwers have flanges embracing the arms of the casings to hold said arms against being spread apart.

Other objects of the invention will more clearly appear from the description and claims hereinafter following.

In the accompanying drawings, forming a part of this specification, Figure 1 is a horizontal, longitudinal, sectional view of a portion of a railway draft rigging, showing my improved shock abs rb.- ing mechanism in connection therewith, the improved mechanism being shown partly in plan and partly in horizontal section. Figure 2 is a side elevational view of the shock absorbing mechanism shown in Figure 1, partly in longir tudinal vertical section, illustrating the position assumed by the part thereof when the mechanism has been partly compressed. Figure 3 is a sectional view of a paneshaped spacing member employed in my improved mechanism, said view corresponding substantially to the line 3,-.3 of Figure 4. Figure 4 is an elevational view of Fig.- ure '3, looking from right .to left in said figure. Figure 5 is a side elevational view of the mechanism shown in Figure 1, illustrating the same compressed beyond the stage .of compression shown in Figure 2. Figure 6 is .a view similar to Figure 5, showing the mechanism fully 0. .1.1 pressed. Figure '7 is ,a top plan iew of the front casing employed in my improved mechanism. Figure 8 is an elevational View of Figure 7, lookingfrom right to left in said figure. Figure 9 is a side elevational view of Figure 8. Figure 10 is a transverse sectional view, corresponding substantially to the line 3-40 of Figure 1. Figure 1.1 is a plan view of one of the rubber units of my improved mech ism nd e sp i member t which it is attached. Figure 12 is an elevational view of on of the intermediate follower members. Figure 13 is a top edge view of Figure 12. Figure '14 is a side edge view of Figure 12, looking from right to 'left in said figure. Figure 15 is a view similar to Figure '1, with the parts of the draft rigging omitted, illustrating another embodiment of the invention. Figure 16 is a rear end elevational view of the-front casing and the associated front intermediate follower of my improved mechanism, as illustrated in Figure 15. Figure 17 is a View similar to Figure 16, with the front intermediate follower omitted.

In said drawings, referring to Figure 1, H3H3 indicate channel-shaped center or draft sills of a railway car underframe provided with the usual front and rear stop lugs H and I2. The inner end of the drawbar is indicated by 13, to which is operatively connected a hooded yoke it of well known form. The shock absorbing mechanism proper, as well as a front main follower I5, is disposed within the yoke. The yoke and the parts therewithin are supported in operative position by a detachable saddle plate l6.

Referring first to the embodiment of the invention illustrated in Figures 1 to 14 inclusive, the improved shock absorbing mechanism proper comprises broadly a front casing or column element A; a rear casing or column element 'B; a frontintermediate follower C; a rear intermediate follower D; a cushioning element E within the casing A; and a cushioning element F within the casing B.

The two casings A and B are preferably of identical construction. Each casing, as shown, comprises horizontally disposed top and bottom walls i'ii'l, curved side walls iB-lfi, and a transverse vertical end wall l9 closing the outer end thereof. Each casing is thus of broadly oval interior and exterior cross section. The end wall 59 of each casing is extended laterally outwardly of the casing proper, thus presenting flanges 23, which together with said wall form a substantially rectangular follower member integral with the casing. The side walls i8l8 of each casing are suitably reinforced by lengthwise extending upper and lower ribs 2 l2l, which extend to the flanges 28-223. Each casing is adapted to house one of the cushioning elements E or F. At its 3 inner or open end, the walls of each casing are cut away or recessed at diagonally opposite corners, as indicated at 22, providing a pair of longiand outer surfaces of the corresponding walls of the casing and are reinforced by the ribs 2l2i. At the inner end of each cut-away section 22, the casing is provided with a flat, transversely extending, limiting stop shoulder 25, for a purpose hereinafter described. As will be evident, each casing forms a rigid column element for trans- -mitting forces.

The front and rear intermediate followers C and D are of like construction. Each intermediate follower, as shown most clearly in Figures 12, 13, and 14, is in the form of a relatively heavy, substantially flat plate generally of oval outline, having extensions 25-25 at diagonally opposite side portions thereof adapted to be engaged by the ends of the corresponding arms 23-23 of the cooperating casing A or B. The indented portions of the plate between the extensions 25-25, which indented portions are indicated by 2626, provide clearance for the arms 23-23 of the other casing. At the outer edge thereof, each extension 25 is provided with a laterally projecting, curved flange 2'! adapted to overhang the corresponding arm 23 of the cooperating casing A or B. The flanges 27 -21 of each intermediate follower extend from the same side thereof and em- 4 brace the arms of the cooperating casing to prevent spreading of said arms.

In the assembled condition of the mechanism, the casings A and B are reversely arranged end for end, with the intermediate followers C and D therebetween, and the cushioning elements E and F within the casings. As clearly shown in Figure 1, the closed follower end of the casing A bears on the front follower l5, and the closed follower end of the casing B cooperates with the rear stop lugs l2-l2 of the draft rigging and the inner end of the yoke I l. The arms 2323 of the casing A are staggered with respect to the arms 23--23 of the casing B, that is, the arms of the former engage between the arms of the latter. The front and rear intermediate followers 0 and D are in face-to-face contact with each other and bear respectively on the front and rear cushioning elements E and F, the arms 29-23 of the casing A embracing the follower C and being overlappedby the flanges 2l2a of the follower D, and the arms of the casing B embracing the follower D and being overlapped by the flanges 21-21 of the fol? lower C. In the full release position of the mechanism, the intermediate follower C is normally spaced from the inner ends of the arms 23-23 of the casing B, and the intermediate follower C is normally spaced from the inner ends of the arms 23-23 of the casing A, these followers thus, in effect, floating between the casings.

The cushioning elements E and F are identical, each comprising a plurality of rubber mats 28 and a plurality of metal spacing members 29, 38, and 3E. The rubber mats are alternated with the spacing members. These mats are all of the same design, each being in the form of an oval flat pad having projecting spaced ribs 32, preferably three in number, comprising a central elongated rib having rounded ends, a second rib of oval contour surrounding the first rib in spaced relation thereto, and a third rib of oval contour surrounding the second rib in spaced relation to the latter. The ribs 32 are preferably outwardly tapered in transverse section, as shown in Figure 1, and the spaces between the ribs serve to accommodate the flow of the rubber when the mats are compressed. The spacing members 29, which are preferably eight in number, are of pan-shaped oval form having peripheral, flaring flanges 33 provided with laterally outwardly offset outer portions 34, as shown in Figures 3 and 4. These spacing members are designed to be partially nested, as shown in Figure 1. A single spacing member 30 is employed, the same being similar to the spacing members 29 with the exception that the flange 35 thereof, which is similar to the flange 33 of the member 29, is not provided with the offset portion 34. The spacing member 31 is in the form of a flat plate of substantially oval outline. This spacing member is of slightly smaller size than the

spacing members

29 and 30. The spacin member 3| of each cushioning element is interposed between the adjacent intermediate follower and the first rubber mat 28 of said element, the rubber mat 28 having its fiat side bearing on the member 3!. The spacing member 30 is interposed between the first and second rubber mats, and the eight spacing members 29 are alternated with the remaining rubber mats, the end member 29 bearing on the end wall IQ of the corresponding casing. As will be seen upon reference to Figures 1 and 2, the peripheral flanges of the

spacing members

29 and 30 all extend in the same direction, that is, away from the end wall !9 of the corresponding casing A or B. The flange of each spacing meming pinching of the edges of the mat, which "would otherwise occur and result in serious damage to the same. The flange of the spacing member 38 also overliands the corresponding mat to protect the same. The fiat side of each mat is preferably vulcanized to the spacing member on which its flat side bears. The rubber-mats of the two cushioning elements are preferably under slight initial compression and hold the casings A and B in the position shown in Figure 1, with the end of the arms 2323 of the casing A spaced from the follower D and the ends of the arms 23-23 of the casing B spaced from the follower C, the two followers C and D being pressed against each other and held in centered position between the casings by the cushioning elements E and F.

The operation of my improved shock absorbing mechanism, shown in Figures 1 to 14 inclusive, is as follows: Upon a draft or bufiing force being applied to the drawbar [3, the mechanism is compressed, the yoke being pulled forwardly in draft, forcing the casing B forwardly, thereby compressing the mechanism against the front follower I5, which at this time is held stationary by engagement with the front stop lugs ll-l I, and the follower l5 being forced rearwardly in buff by the drawbar as the latter is forced inwardly, thereby forcin the casing A rearwardly 1 toward the casing B, which at this time is held stationary by engagement with the rear stop lugs l2--l2. During the first part of the compressing action of the mechanism, the two rubber cushionin elements E and F are compressed in series between the end walls [9-19 of the casing A and B, which end walls act as followers, the pressure being transmitted from one cushioning element to the other through the floating intermediate followers C and D. Thus, rel-atively'soft cushioning action is provided, which takes care of the lighter shocks, which are numerous in service. As will be evident, during this action the forces are distributed between the two cushioning elements, each element being compressed to an extent corresponding to half of the total lengthwise movement of the drawbar during this part of the compression stroke. This soft cushioning action continues until the parts reach the position shown in Figure 2, whereupon the rear intermediate follower D and the arms 23-23 of the front casing A come into engagement as 'well as the front intermediate follower C and the arms 23 23 of the rear casin B. During the remainder of the compression stroke, the intermediate follower D and the casing B are moved lengthwise toward each other, and the intermediate follower C and the casin A are also moved lengthwise toward each other, thus effecting compression of the cushioning elements E and Fin parallel, with resultant high shock absorbing capacity to take care of the heavier shocks. Figure-6 shows the mechanism fully compressed and Figure 5 shows an intermediate stage of the parallel action. When the mechanism has been compressed to the extent shown in Figure 6, the intermediate follower C is engaged with the stop shoulders 24-24 of the casing A and the rear intermediate follower D is engaged with the stop shoulders 24'24 of the casing EB, thecasings 'A and 3 together with the intermediate followers 0 and D acting as a solid column totransmit the load and prevent undue or over-compression of the rubber mat 28 of the cushioning elements E and F. The rubber mats are thus protected from damage, adding greatly to the life of the same.

When the actuating pressure is reduced, the tendency of the rubber mats of the elements E and F to return to their original shape acts to expand the mechanism and return the casings A and B and the followers C and D to the position shown in Figure l.

Assuming that the shock absorbing mechanism illustrated has a total travel of 2 inches, and during 1 inch of said total travel, the cushioning elements are being compressed in series, the mechanism is thus compressed 1 inch during movement of the parts from the position shown in Figure 1 to that shown in Figure 2. Figure '5 shows the mechanism compressed 1% inches, in other words, shows the position of the parts after compression of the cushioning elements E and F in parallel to an extent of of an inch. As willbe evident, during the first inch of compression, each cushioning element has been compressed inch but during the next inch of compression of the mechanism, which is in parallel, each cushioning element is compressed an additional inch. Thus the total compression of each element, as shown in Figure 5, amounts to 1 /4 inches while the total compression of the mechanism has reached 1% inches. When the mechanism has" been fully compressed, as shown in Figure 6, that is, the total 2 /2 inches, which is of an inch beyond the compression shown in Figure 5, each cushioning element will have been compressed a total of 2 inches, inch in series and 1 inches in parallel. fhis series and tandem compression gives a decided advantage over prior mechanisms of the series type wherein the entire compression of 2 inches is in series with the result that each cushioning element is compressed to an extent of 2 /2 inches. Softer cushioning action is thus provided during the first inch of the compression stroke.

In this connection, it is pointed out that during the entire action of the mechanism, that is, at all sta es of operation thereof, spreading of the arms 23-23 of the casings A and B is efiectively prevented by the flanges Z-i-Z'l of the intermediate followers, which flanges at all times overlap and embrace the arms of the cooperating casings.

Referring next to the embodiment of the invention illustrated in Figures 15, 16, and 17, the construction and design are the same as that of the mechanism described in connection with Figures 1 to 14: inclusive, with the exception that the cushioning elements are composed of springs instead of rubber mats. The casings and intermediate followers shown in Figures l5, l6, and

17, are identical with the casings A and B and the intermediate followers C and D hereinbefore described, and the same and all parts thereof are indicated by the same reference characters as employed in Figures 1 to 14 inclusive.

As shown in Figures 15, 16 and 17, four double coil springs GG and HH are employed in this embodiment of the invention. Each double coil spring G'r or H comprises a relatively light inner coil and a heavier outer coil. The springs G-'G are twin-arranged, that is, side by side in the casing A, and the springs H-H are also twinarranged in the casing B. The springs G-G have their front and rear ends bearing respectively on the end wall it] of the casing Aand the front intermediate follower C, and the springs HH have their front and rear ends bearing respectively on the intermediate follower D and the end wall 19 of the casing B. The springs GG and HIl are under initial compression and function in a manner similar to thecushioning elements E and F hereinbefore described. The operation of the mechanism shown in Figures 15, 16, and 17, is substantially the same as that hereinbefore described, the springs 6-6: and H-I-I being compressed in series during the first inch of the compression stroke of the mechanism and in parallel during the remaining 1 /2 inches of said stroke.

From the preceding description taken in connection with the drawings, it will be evident that I have provided an exceedingly flexible shock absorbing mechanism, which has the desired light cushioning action so important in passenger equipment to absorb the lighter shocks to which the rigging is subjected and also effectively takes care of all excessively heavy shocks, the action being blended throughout.

I claim:

1. In a shock absorbing mechanism, the combination with a set of cushioning elements; of means for compressing the elements of said set in series; and means cooperating with said first named means operative after compression to a predetermined extent of aid elements in series by said first named means for compressing said elements of said set in parallel.

2. In a shock absorbing mechanism, the combination with a pair of front and rear cushioning elements; of means for compressing said elements in series; and means cooperating with said first named means operative after compression to a predetermined extent of said pair of elements in series for compressing said pair of elements in parallel.

3. In a shock absorbing mechanism, the combination with two longitudinally aligned end followers movable lengthwise of the mechanism toward and away from each other; of a pair of longitudinally aligned cushioning elements be.- tween said followers; a pair of centrally disposed, longitudinally aligned followers interposed between said cushioning elements; and pressuretransmitting column means between each end follower and the centrally disposed followerremote therefrom and having lost motion with respect to one of said followers last named during the first part of the compression stroke of the mechanism to permit compression of said pair of elements in series between said end followers, and engageable during the remainder of the compression stroke with said follower with respect to which it has lost motion to effect parallel compression of said elements.

4. In a shock absorbing mechanism, the combination with longitudinally aligned front and rear end followers movable lengthwise toward and away from each other; of a pair of front and rear longitudinally aligned intermediate followers normally engaged with each other; front and rear longitudinally aligned cushioning elements, said front element being interposed between the front end follower and the front intermediate follower, and said rear element being interposed between said rearintermediate follower and said rear end follower; and pressuretransmitting column means cooperating with said end followers and intermediate followers to compress said elements in parallel after predeterm ne omp e s n Qi. i. =l..e mem$,.m ser es between said end followers, said column means comprising a. column member interposed between each of said end followers and the intermediate .said casings being relatively movable toward and away from each other lengthwise of the mechanism; of front and rear intermediate followers, said front intermediate follower being lengthwise movable with respect to the front casing, and

said rear intermediate follower being lengthwise movable with respect to said rear casing; a cushioning element in each casing, one of said elements being interposed between said follower means of the front casing and the front intermediate follower, and the other of said elements being interposed between said rear intermediate follower and the follower means of the rear casing, said intermediate followers being in engagement with each other to transmit the actuating force from one cushioning element to the other to effect compression thereof in series; a rearwardly projecting arm on said front casing spaced from said rear intermediate follower; and a forwardly projecting arm on said rear casing spaced from said front intermediate follower, said arms of said front and rear casings being engageable with said rear and front intermediate followers respectively to compress said elements in parallel after a predetermined compression of the mechanism.

6. In a shock absorbing mechanism, the combination with front and rear follower means relatively movable toward and away from each other;

of front and rear intermediate followers engaging each other; a cushioning means interposed between said front foliower means and front intermediate follwer; a second cushioning means interposed between said rear follower means and rear intermediate follower, said first and second 50 named cushioning means being compressed in from with the outer ends thereof spaced from 's'aid'rear intermediate follower, said rear column member having arms extending forwardly therefrom with the outer ends thereof spaced from said front intermediate follower, said first and last named arms being respectively engageable with said rear and front intermediate followers to actuate said intermediate followers and compress said cushioning means in parallel after the mechanism has been compressed said predetermined portion of the stroke.

'7. In a shock absorbing mechanism, the cornjbination with front and rear longitudinally aligned casings closed at their outer ends; of a cushioning element in each casing bearing at its outer end on the closed end of the casing; a pair of front and rear intermediate followers between said cushioning elements, said front intermediate cushioning element, and said rear intermediate follower bearing on the inner end of said rear cushioning element; rearwardly extendin arms on said front casing engageable with said rear intermediate follower to actuate the same after the mechanism has been compressed to a predetermined extent; and forwardly extendin arms on said rear casing engageable with said front intermediate follower to actuate the same after compression of the mechanism to said predetermined extent, said cushioning elements holding said intermediate followers spaced from the engaging ends of the arms of said front and rear casings.

8. In a shock absorbing mechanism, the combination with two longitudinally aligned end followers movable lengthwise of the mechanism toward and away from each other; of a pair of longitudinally aligned rubber cushioning elements between said followers, each cushioning element comprising a plurality of rubber mats alternated with metal spacin members; a pair of centrally disposed, longitudinally aligned followers interposed between said cushioning elements; and pressure-transmitting column means between each end follower and the centrally disposed follower remote therefrom and having lost motion with respect to one of said followers last named during the first part of the compression stroke of the mechanism to permit compression of said pair of elements in series between said end followers, and engageable during the remainder of the compression stroke with said follower with respect to which it has lost motion to effect parallel compression of said elements.

9. In a shock absorbing mechanism, the combination with two longitudinally aligned end followers movable lengthwise of the mechanism toward and away from each other; of a pair of longitudinally aligned spring cushioning elements between said followers; a pair of centrally disposed, longitudinally aligned followers interposed between said cushioning elements; and pressure-transmitting column means between each end follower and the centrally disposed follower remote therefrom and having lost motion with respect to one of said followers last named during the first part of the compression stroke of the mechanism to permit compression of said pair of elements in series between said end followers, and engageable during the remainder of the compression stroke with said follower with respect to which it has lost motion to effect parallel compression of said elements.

10. In a shock absorbing mechanism, the combination with front and rear follower casings having follower means at the outer ends thereof, said casings being relatively movable toward and away from each other lengthwise of the mechanism; of front and rear intermediate followers, said front intermediate follower being movable lengthwise with respect to the front casing, and

said rear intermediate follower being movable lengthwise with respect to said rear casing; a pair of twin springs in each casing, one of said pair of twin springs being interposed between said follower means of the front casing and the front intermediate follower, and the other pair of said twin springs being interposed between said rear intermediate follower and the follower means of the rear casing, said intermediate followers being in engagement with each other to transmit the actuating force from one of said twin springs to the other to effect compression thereof in series; a rearwardly projecting arm on said front casing spaced from said intermediate follower; and a forwardly projecting arm on said rear casing spaced from said front intermediate follower, said arms of said front and rear casings bein engageable with said rear and front intermediate followers respectively to compress said front and rear springs in parallel after a predetermined compression of the mechanism.

11. In a shock absorbing mechanism, the combination with two longitudinally aligned casings relatively movable toward and away from each other; of a cushioning element in each casing; a pair of centrally disposed followers interposed between said cushioning elements; spaced arms on each casing engageable with one of said followers; and means on each follower overhanging the arms of the cooperating casing to hold said arms against spreading.

12. In a shock absorbin mechanism, the combination with front and rear casings, each casing having laterally spaced arms at the inner end thereof; of front and rear cushioning elements within the casings; front and rear intermediate followers, said front intermediate follower being engageable by the arms of said rear casing, and said rear intermediate follower being engageable by the arms of the front casing; and guide flanges on each intermediate follower embracing the arms of the cooperating casing to hold said arms against spreading.

KEITH WILLIAMS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,674,826 Haseltine June 26, 1928 1,876,019 Priebe Sept. 6, 1932 2,165,383 Johnson et al. July 11, 1939 2,187,156 Johnson Jan. 16, 1940 2,277,881 Olander Mar. 31, 1942 2,395,972 Olander Mar. 5, 1946 FOREIGN PATENTS Number Country Date 587,498 Germany Nov. 3, 1933 733,478 France July 11, 1932