US2241353A

US2241353A - Draft connection

Info

Publication number: US2241353A
Application number: US263616A
Authority: US
Inventors: Edmund P Kinne; Frank H Kayler
Original assignee: American Steel Foundries
Current assignee: American Steel Foundries
Priority date: 1939-03-23
Filing date: 1939-03-23
Publication date: 1941-05-06
Anticipated expiration: 1958-05-06

Description

May 6 @4L E. F.r KINNE ETAL' 2,244,353

DRAFT CONNECTION Filed March 23, 1939 `4 Sheecs--Sheefl l ATTORNEY.

4 Sheets-Shee'fI 2 1NVENTOR5 ZIN-7K fara/4 f/ czgZc.

ATTORNEY E. P. KINNE ETAL DRAFT CONNECTION Filed March 25, 1959 Sgm@ Q wm am May 6 i941.,

May 6, 1941. E. P. KINNE ET A1.

DRAFT CONNECTION Filed March 25, 1939 4 Sheets-Sheet C5 mmm ATTORNEY.

May 6, 1941. E.`P. KINNE ET Al.

DRAFT CONNECTION Filed March 2s, 1959 4 Sheets-Sheet 4 www zg/v;

ATTORNEY.

Patented May 6, 1941 DRAFT CONNECTION Edmund P. Kinne and Frank H. Kayler, Alliance, Ohio, assignors to American Steel Foundries, Chicago, Ill., a. corporation of New Jersey Application March 23, 1939, Serial No. 263,616

23 Claims.

Our invention relates to draft rigging for railway cars and more particularly to a novel arrangement of connection-between a yoke and associatedparts such as a coupler and a draft gear.

A"In the development of modern passenger equipment it has been found desirable to eliminate all free slack in the connections between cars. Couplers, now commonly designated tight lock couplers and controlled slack couplers, have been developed for this purpose and such couplers eliminate all free slack in the contour of the mated coupler heads.

In the elimination of free slack between cars, it is just as important that the connections between the coupler shank and the draft arrangement or between the draft arrangement and the car sills be free of slack in order to accomplish the desired results. A number of devices have been developed to provide slack 'free connections between the yoke and the coupler, and experience has demonstrated that these devices are either too heavy and unwieldy or too expensive for practical operation. None of these devices have provided for closing all free slack between the draft connection and the car sills. In order to do this, it isnecessary to have an adjustable length of the gear pocket in the yoke in order that it may conform to the length of the enclosed gear and the space afforded between the car sills.

An object of our invention is -to provide a draft connection for a railway car which will overcome the above disadvantages and provide an arrangement affording an entirely slack free connection.

Our invention contemplates an arrangement which is adjustable and affords the possibility of adapting the length of the gear pocket to accommodate manufacturing variations in gear lengths and, likewise, to accommodate the manufacturing tolerances which must be provided in all parts.

A further object of our invention is a novel form of arrangement between a coupler shank and a yoke therefor which will afford at all times a tight engagement between the yoke, the coupler shank and the associated draft gear.

A different object of our invention is a novel form of connection between a coupler shank, a draft gear and a yoke which is adjustable to take up any free slack that may develop between the parts. l

Another object of our invention is a yoke designed to be associated with a coupler and a draft gear and having a novel arrangement adaptable for use at either end of said pocket for adjusting the length of said pocket to eliminate all free slack between the said parts.

Our invention also comprehends such an arrangement as that just described wherein resilient means may be used to prevent loose play between the parts, said resilient means being associated with said adjustable parts to eliminate 'play therebetween. l0

Our novel device affords an arrangement in a new car assembly which will permit an accurate adjustment of the parts involved in the draft arrangement to allow the angling of the rigid shank coupler, thus avoiding excessive side force which might otherwise cause derailment. It also permits the take-upor reduction to a minimum of any slack developed after the new car parts have been worn in. L

Whereas, under present standard arrangements, the various manufacturing tolerances permitted may, and sometimes do, result in assembled conditions varying from a considerable increase in slack over that desired to a condition of actual interference, sometimes resulting in initial compression of the draft gear, our arrangement permits adjustments of the gear pocket length in the draft connection to the same y,length as that of the gear pocket in the car regardless of manufacturing tolerances.

The manner in which the above objects are accomplished is more clearly brought out in the following description of the embodiments thereof shown in the accompanying drawings and referred to in the appended claims.

Figure l is a side elevation, partly in section, of a draft connection embodying our invention, the section being taken substantially in a vertical plane bisecting the coupler connecting end of the yoke and substantially as indicatedby the line `l-l of Figure 2;

Figure 2 is a top plan view of the device shown in Figure 1, partly in section, the section being taken substantially in the horizontal plane bisecting the coupler connecting end of the device and as indicated by the line 2-2 of Figure l;

Figure 3 is a fragmentary View corresponding to Figure 2, but showing the provision for horzontal angling between the coupler and the yoke; I

vFigure 4 is a front view of the device, partly in section, showing the manner in which a pro- 'vision is made for torsional movement of the coupler with relation to the yoke structure;

Figure 5 is a fragmentary top plan view of the yoke structure shown in Figures 1 to 4, partly in stantially in the vertical planes indicated by the line 8-8 of Figure 6;

Figure 9 is a sectional view through the yoke structure, the top half of said view being taken in the transverse vertical plane substantially as indicated by the line 9-9 of Figure 7 and the bottom half thereof being taken substantially in the transverse vertical plane indicated by the line A-A of Figure 7; i

Figure 10 is a top plan view of the pin bearing block, and Figure 11 is a side elevation thereof;

Figure 12 is a front elevation of the adjusting wedge used in the structure shown in Figures 1 to 4, Figure 13 is a side elevation thereof, and Figure 14 a top plan view;

Figure 15 is a front elevation of the follower bearing block used in conjunction with the adjusting wedge shown in Figures 12 to 14, Figure 16 is a side elevation thereof, and Figure 17 is a 'top plan view;

Figure 18 is a top plan view of the coupler bearing block used in the structure shown in Figures 1 to 4, and Figure 19 is aside elevation thereof;

Figure 20 Ais a fragmentary side elevation, partly in section, showing a. modified form of our invention, the section being taken substantially in the vertical plane bisecting the device longitudinally and as indicated by the line 20-20 of Figure 21;

Figure 21 is a fragmentary top plan View, partly in section, of the structure shown in Figure 20, the section being taken substantially in the horizontal plane indicated by the line 2I-2I of Figure 20;

Figure 22 is a view corresponding in general to Figure 20, but showing the parts arranged in full take-up position affording the minimum length of gear pocket; A

Figures 23, 24 and 25 show the wedge block y structure used in the modification shown in Figures 2() to 22, Figure 23 being a front elevation, Figure 24 a side elevation and Figure 25 a top plan view.

Describing in greater detail the modification generally shown in Figures 1 to 4, the yoke 2 comprises the top member 4 and the bottom member 6 withv a standard type of rear end 8 and a draft gear pocket I Il, the forward end of which is defined by the front follower bearing block I2 which is adjustably arranged Within the open head of the yoke I4 to vary the length of said pocket. The side walls of the head are cored out as at I5, I5 to lighten the casting, and the bottom wall thereof has the centrally formed opening I3 (Figure 7) slotted at the rear vfor reception of an adjustable screw, hereafter more fully described.

The forward end of the yoke comprises the top and bottom jaws I6 and I8 with centrally formed aligned pin holes I'I, II for reception of the connecting pivot pin 20, said pin being supported against gravity by the retainer bolt and nut assembly 2l, the ends of which bolt extend through aligned openings in the

ears

23, 23

formed at opposite sides of the pin cpeningin the bottom wall of the yoke head. Within the jawsA I6 and I8 is received the coupler shank 22 having the pin hole 24 aligned with the bcfore mentioned pin holes in the top and bottom jaws of the yoke and receiving the pin 2l which serves as a connecting means. The pin hole in the coupler shank is flared at the top and bottom as indicated at 26 and 28 to accommodate the required vertical angling and also as at 3l and 32 (Figure 4) to accommodate torsional movement of the coupler shank.

The rear end of the coupler shank 22 is made with a spherical surface for universal engagement as at 34 with the front surface of the bufng bearing block 36 against which it is seated. The bearing block 36 has relatively close fit as at 35, 35 (Figure 3) at its lateral edges with the side walls of the yoke head, and the rear portions of said lateral edges are chamfered. In the rear of the pin hole 24 the coupler shank is formed with a cavity 38, the rear surface of which is also spherical in form and has abutment as at 40 with the complementary spherical surface on the pin bearing block 42,

the front of said block having at 4I a. cylindrical face complementary to the pin 20 for engagement therewith, thus providing universal action under draft forces as follows: Horizontal angling is afforded through movement of the bearing block 42 on the connecting pin 20; vertical angling is afforded through movement of the coupler shank 22 at the surface 40 on the bearing block 42; torsional movement is provided for by the clearance in the shank cavity 38 at the sides thereof as at 44 and 46 respectively (Figure 2), permitting the coupler to rotate as required upon the bearing block 42; and the upper and

lower faces

48 and 50 of the coupler shank are relieved to provide the necessary clearances for universal action of the shank between the yoke jaws I6 and I8.

All necessary adjustment, both to vary the length of the draft gear pocket III to match the length of the associated draft gear and follower block vdiagrammatically indicated at 52 as well as to take up any slack in the connection between the coupler shank 22 and the yoke 2, is secured by vertical movement of the wedge 54. The rear surface of the wedge 54 is tapered in offset planes to cooperate as at 56 and 5l with similar offset tapered surfaces formed on the front face of the follower block. Centrally formed in the wedge face 58 of the follower bearing block I2 is the shallow channel 55 (Figure 15) extending along the greater portion of the length thereof, and a similar channel 51' is centrally formed inthe front face of the adjusting wedge 54 (Figure 13) said shallow channels preventing concentration of load on the respective members adjacent the threaded opening for the adjusting screw. The vertical adjustment of the wedge 54 is secured through the screw 62 which has threaded engagement as at 64 with the bottom portion of the wedge 54, the said screw 62 being formed with the bearing collar 66 which may seat as at 61 (Figure 6) in the elongated channel 69 formed on the bottom wall of the yoke head. The screw 62 has also the head El and the locking device 'III in the form of a rectangular strap formed with aligned openings to receive the securing cotter 'I2 which extends through the bolt head 68, said strap having the tail piece 'I4 extending within an accommodating slot formed in the bottom wall of the yoke head I4.

The front follower block |2 is channeled as at 16 throughout its length to receive the plate spring ,18 which may be composed of one or a plurality of flat plate springs. The said spring is inserted at the top through the opening 80 and seated at the bottom in the pocket 82, said spring acting to retain the follower bearing block |2 in a forward position when the yoke may be pulled forward away from the draft gear follower. The various parts in the head of the yoke are thus always retained in rm engagement with each other eliminating loose play and rattling. i

In the event of the failure of the plate spring '|8, displacement of the parts is prevented in that rearward movement of the follower block |2 is limited by a cooperation of the lugs 84, 84 (Figure l) on the top of the yoke with the

slots

86, 86 formed in the follower block as Well as by the fitting of the lug 88 on the bottom of the follower |2 into the notch 90 in the bottom strap 6 of the yoke.

associated adjusting screw 62 is applied through the rear opening of the hooded portion of the yoke and, thereafter, the follower block |2 is inserted in a manner to secure interlocking of the retainer lugs 84 and 88 with their respective slots. The spring 18 is next 'inserted through the opening 80 while suflicient play is still permitted between the parts to allow entrance of said spring without flexing. After flexing, the upper end of the spring has abutment as at 8| with the lug 83 on the top wall of the yoke head. 'Ihe bufl'lng bearing block 36 is next inserted from the front of the yoke followed by the coupler shank 9 with the associated draft bearing block 42. When the can not be combined with means for tightening vthe coupler with the yoke as was the case in the first modication described, but ythe method for varying the length of the gear pocket as shown in the modification of Figures 20 to 25, inclusive, is generally similar to that already described.

Referring in detail to the modification of Figures 20 to 25, inclusive, the yoke |02 comprises the top and bottom straps |04 and |06 integrally joined by the rear end portion |08 forming therewith the usual gear pocket |09, said rear portion |08 being of channel shape as best seen from the view of Figure 21, said end portion comprising the side walls |05 and |01 and the web of said channel forming the sloping wall ||0 offset adjacent the middle thereof as at ||2, said sloping wall presenting on its forward face a plurality of offset wedge surfaces indicated respectively at ||4 and ||`6. An adjusting wedge block ||8 is assembled into the rear end of the yoke, the said wedge block having the rear wedge faces |20 and 22 for engagement with the before mentioned surfaces ||4 and ||6. The adjusting wedge ||8 is retained in position by engagement of the top interlocking lugs 24, |24 in the sloping grooves |26, |26 formed in the side walls of the yoke and by the bottom interlocking lugs |28, |28 engaging in similar grooves |30 in the side walls of the yoke, as well as by the nonthreaded upper endA |32 of the adjusting screw |34, said screw having threaded engagement as at |36 in the bottom wall or strap |06. The upper unthreaded portion of the screw |34 extends into the accommodating opening |38 in the bottom of the adjusting wedge block ||8 whereby said adjusting screw |34 may be moved up or down by the threaded engagement at 36 to adjust the position of the wedge block |8.

coupler shank is forced rearwardly into position to receive the connecting pivot pin 20 the parts to the rear of the shank will have been moved rearwardly, flexing the spring '|8 and placing the parts in tight engagement with each other.

It will be apparent that manipulation of the adjusting screw 62 in the wedge block 54 will be effective to move said block upwardly or downwardly as required, upward movement thereof forcing the follower block |2 rearwardly, thus reducing the length of the gear pocket |0 to accommodate the gear and the associated follower block normally seated therein.

The forward end or head of the yoke incorporated in the modification just described is shown in detail in Figures 5 to 9, inclusive, wherein certain details, above referred to, may be more clearly observed.

The pin bearing block 42 is shown in detail in Figures lo and 11, the adjusting wedge in Figures 12 to 14, the follower bearing block in y Figures 15 to 17, inclusive, and the coupler bearing block in Figures 18 and 19.

The modification shown in Figures 20 to 25, inclusive, provides for adjustment of the gear pocket. length from the rear of said pocket instead of the front thereof as shown in the previous modification. Adjustment of the length of The adjusting screw |34 is secured in any desired position by means of the heavy wire |40 which is threaded through the opening |42 at the bottom of said screw and extended through the opening |44 in the rib |46 formed on the bottom wall of the-yoke. 'Ihe opening |42 serves as a means for insertion of a rod to turn the adjusting screw, and the rib |46 also forms a protection preventing marring of the adjusting screw |34.

Along the forward edges of the wedge block ||8 are formed the vertical flanges or guide ribs |48 having guiding engagement with the adjacent ribs |50 formed on the side walls of the yoke.

The adjusting wedge` block ||8 is shown in detail in Figures 23 to 25, inclusive. It may be noted that the wedge surfaces |20 and |22 are offset adjacent each other as at |52 thus accomthe gear pocket at the rear of the yoke naturally 75 modating the` offset ||2 in the wall they abut.

Rotation of the adjusting screw |34 is operative to move the wedge block upwardly or to permit it to move downwardly under the force of gravity as desired and the manner in which the movement of the wedge block operates to reduce the length of the gear pocket |09 is made clear by a comparison of the views of Figures 20 and 22, Figure 20 showing the wedge block |8 seated in its lowermost position and Figure 22 showing it seated in its uppermost position. In the lowermost position the adjusting block ||8 is seated on thebottom wall or strap |06 whereas in its uppermost position it abuts the top wall or strap |04. It will be apparent that the operation of this adjusting means is similar to that of the modification previously described, but operates to reduce the length of the gear pocket from the rear thereof instead of at the forward end. In

certain applications it is more practical to make Ythe adjustment from the rear of the yoke inthose skilled in the art without departing from the spirit of the invention or the scope of the claims.

We claim:

1. In a draft rigging for a railway car, a coupier, a yoke having a gear pocket, a pivotal connecton between said coupler and yoke, and adjustable means mounted in said yoke between said pivot point and said pocket, said adjustable means being operable to tighten said pivotal connection and to'vary the length of said pocket and comprising a follower bearing block movable longitudinally of said yoke and having a plurality of wedge faces, an adjusting wedge renewed between said coup1er and said block and having wedge faces in engagement with said first mentioned wedge faces, and means for moving said wedge longitudinally along said wedge faces.

2. In a draft connection for a railway car, ya

coupler, a. yoke pivoted thereto, a gear pocket in said yoke, and means mounted in said yoke and operable to adjust the tightness of fit at said pivotal connection and to modify the length of said pocket, said means being operable to eliminate slack between said coupler, said yoke and an associated draft gear, said means com-V prising a wedge face follower having limited movement longitudinally of said yoke, a coupler `bearing block, and an adjustable wedge member between said follower and bearing block.

3. In a draft connection for a railway car, a

said yoke, and means mounted in said yoke and operable to adjust the tightness of fit at said pivotal connection andto modify the length of coupler, a. yoke pivoted thereto, a gear pocket in said pocket. said means being operable to eliminate slack between said parts including said coupler, said yoke and an associated draft gear, said means comprising a follower having limited longitudinal movement with respect to said yoke, a coupler bearingrblock, a movable wedge meml ber between said follower and bearing block, and

means for adjusting the position of said wedge member to alter the relative position of said follower and block.

4. In a draft connection, a coupler, a. yoke l pivoted thereto, a draft gear pocket in said yoke,

and means inthe head of said yoke operable to tighten said pivotal connection and4 to adjust the length of said gear pocket, said means comprising a movable follower block having a wedge face, an adjusting wedge in abutment with said face, a coupler bearing block between said wedge and said coupler, and means associated with said wedge and yoke and operable to raise and lower said wedge and effect said adjustments.

5. In a draft connection for a railway car, a coupler, a yoke pivoted thereto, a gear pocket in said yoke, and means mounted in said yoke adjacent said pivot point, said means comprising a follower block movable longitudinally of lsaid yoke, a coupler bearing block, and a wedge between said follower block and bearingblock, said aains having a wedge face, an adjusting wedge in abutment with said face, a coupler bearing block between said wedge and said coupler, and means for adjusting the position of said wedge between said follower block and said bearing block to alter their relative positions.

7. In a draft connection, a coupler, a yoke pivoted thereto and comprising a draft gear pocket, and means mounted in said yoke and 0perable to. tighten said pivotal connection and to modify the length of said pocket, said means comprising a movable follower block defining one end of said pocket, resilient means restraining the movement of said block, means on said follower block and said yoke operable to limit said movement in the absence of said resilient means, wedge means supported in said yoke between said follower vblock and said coupler,l and means mounted on said yoke and operable to raise and lower said wedge means and vary the relative position of said follower block and said coupler.

8. In a draft connection for a railway car, a coupler, a yoke pivoted thereto, a gear pocket in said yoke, and means mounted in said yoke adjacent said pivot point, said means comprising a movable follower block defining an end of said pocket, a coupler bearing block, and a wedge inserted between said follower block and bearing block, said wedge being operable to urge said bearing block and follower block apart.

9. In a draft connection for a railway car, a. coupler, a yoke pivoted thereto, a gear pocket in said yoke, and means mounted in said yoke and operable to adjust the tightness of fit at said pivotal connection and to modify the length of said pocket, said means being operable to eliminate slack between said parts including said coupler, said yoke and an associated draft gear, said means comprising a follower block having a face defining an end of said socket and an opposite face of wedge form, and a wedge member mounted in said yoke between said block and said coupler in engagement with said wedge face and movable therealong to vary the lrelative position of said follower block and said coupler.

10. In a draft connection, a coupler, a yoke pivoted thereto, a gear pocket in said yoke, and means in said yoke operable to tighten said pivotal connection and to vary the length of said pocket, said means comprising a follower block having limited movement longitudinally of said yoke and having a face defining one end of said pocket, a coupler vbearer closely fitted Within the walls of said yoke. and wedge means between said bearer and said follower operable to vary their relative positions.

1l. In a draft rigging for a railway car. a coupler, a yoke having a gear pocket, a pivotal connection between said coupler and yoke, and adjustable means mounted in said yoke between said pivot point. and said pocket, said adjustable means being operable to tighten said pivotal connection and to vary the length of said pocket, and comprising an adjustable follower block having a face defining one end of said pocket and an opposite wedge face, a wedge member inserted between said wedge face and said coupler, and means mounted in said yoke operable to move said wedge member to alter the relative position of said follower block and said coupler.

12. In a draft connection for a railway car, a

` coupler, a yoke pivoted thereto, a gear pocket in said yoke, and means mounted in said yoke adjacent said pivot point and operable to tighten the connection at said pivot point and eliminate slack therein, said means being also operable to adjust the length of said draft gear pocket and comprising a wedge follower movable longitudinallyof said gear and having a face dening one end of said pocket, wedge means inserted between said wedge follower and said coupler, and means mounted in said yoke operable to vary the position of said wedge member and alter the relative position of said follower block and said coupler.

13. In a draft connection for a railway car, a coupler, a yoke pivoted thereto, a gear pocket in said yoke, and means mounted in said yoke adjacent said pivot point and operable to tighten the connection at said pivot point and eliminate slack therein, said means comprising a wedge follower having limited movement longitudinally of said yoke, an adjustable wedge member between said wedge follower and said coupler, and means mounted on said yoke operable to maintain said wedge member in tight engagement between said follower and said coupler, said lastmentioned means comprising resilient means associated with said follower, and a screw associated with said wedge member 14. In a draft connection for a railway car, a coupler, a yoke pivoted thereto, a gear pocket in said yoke, and means mounted in said yoke adjacent said-pivot point, said means comprising a follower block movable longitudinally of said yoke and having a face defining an end of said pocket and an opposite wedge face, a wedge in abutment with said wedge face and slidable therealong, a coupler bearing block abutting said wedge, and means for moving said wedge along said wedge face to vary the relative position of said bearing block with respect to said follower block.

15. In a draft connection for a railway car, a coupler, a yoke pivoted thereto, said yoke having a draft gear pocket, a follower wedge mounted in said yoke and longitudinally movable therein, and means secured to said yoke and operable to adjust said wedge to vary the length of said pocket, said means comprising a wedge member mounted in said yoke between said follower able to move said wedge member and flex said resilient means.

17. In a draft connection, a coupler, a yoke pivoted thereto, and means in said yoke operable to vary the tightness of said pivotal connection and comprising a follower having limited longitudinal movement with respect to said yoke, a coupler bearer, adjustable wedge means between said bearer and follower, and actuating means mounted on said yoke in threaded engagement with said wedge means for operation thereof.

18. In a draft connection, a coupler, a yoke pivoted thereto, a draft gear pocket in said yoke, and means in the head of said yoke operable to tighten said pivotal connection and to adjust the length of said gear pocket, said means comprising a follower block having a face defining one end of said pocket and an opposite wedge face, a. wedge member mounted in said yoke between said coupler and said follower block and having slidable engagement with said wedge face, and means for moving said wedge member.

19. In a dfaft connection, a coupler, a yoke pivoted thereto, a gear pocket in said yoke, and means mounted in said yoke operable to tighten said pivotal connection and comprising a movable follower block defining an end of said pocket, and a wedge received between said follower block and coupler, said wedge being operable to urge said followerd block and coupler apart.

20.I In a draft connection for a railway car, a coupler, a yoke pivoted thereto, a gear pocket in said yoke, a follower wedge mounted in said yoke and having limited longitudinal movement therewedge and said coupler, and means mounted in said yoke and said wedge member operable to slide said wedge member along said follower wedge to vary the position of said follower wedge with respect to said coupler.

16. In'a draft connection for a railway car, a coupler, va yoke connected thereto and comprising a draft gear pocket, an adjustable block mounted in said yoke and having a face defining one end of said pocket, resilient means associated with saidblock, and means for operating said `block to vary the length of said pocket, said means comprising a wedge face on said block, a wedge member slidable therealong, and means mounted in said yoke and wedge member operin, a wedge member between said coupler and said follower Wedge, and means securing said wedge member to said yoke and operable to slide said member along said follower wedge for adjusting the length of said pocket.

21. In a draft connection for a railway car, a coupler, a yoke having a gear p ocket, a pivotal connection between said coupler and said yoke, and means mounted in said yoke between said pocket and said connection for elimination of slack, said means comprising a hollow follower block resiliently mounted in said yoke and having a face defining one end of said pocket and opposite tapering faces, a wedge member between said tapering faces and said coupler, and adjustable means mounted in said yoke and operable to move said wedge member to alter the relative position of said follower block and said coupler.

22. In a yoke, a draft gear pocket and a hollow wedge-shaped follower having limited movement longitudinally of said yoke, said follower comprising a fiat Wall defining one end of said pocket, a diagonally disposed wall having a plurality of tapering faces for engagement with associated wedge means, and a fulcrum centrally formed on the inner surface of said diagonal Wall for abutment with an associated spring.

23. In a yoke, a draft gear pocket and a follower member yieldingly mounted therein and comprising a flat wall defining one end of said pocket, a tapering wall for engagement with associated wedge means, an opening extending through said member for reception of associated spring means, and a fulcrum on said tapering wall within said member for engagement with said spring means.

EDMUND P. KINNE. FRANK H. KAYLER.