US2110574A

US2110574A - Brake shoe and key wedge means

Info

Publication number: US2110574A
Application number: US550392A
Authority: US
Inventors: Victor H Harbert; Malcolm S Johnson
Original assignee: Illinois Railway Equipment Co
Current assignee: Illinois Railway Equipment Co
Priority date: 1931-07-13
Filing date: 1931-07-13
Publication date: 1938-03-08
Anticipated expiration: 1955-03-08

Description

\ Mardm 8, 1938. v. H. HARBERT El AL 2,110,574

BRAKE SHOE AND KEY WEDGE MEANS F'i 111111 11111 s1 March 8, 1938. v. H. HARBERT ET AL 2,110,574

BRAKE SHOE AND KEY WEDGE MEANS Filed July 15, 19s] s Sheets-Sheet 2 7h Jud March 8, 1938. I v. H. HARBERT ET AL 2,110,574

KE s EY WED r Patented Mar. 8, 1938 UNITED STATES PATENT OFFICE 2,110,574 BRAKE SHOE AND KEY WEDGE MEANS poration of Illinois Application July 13, 1931, Serial No. 550,392

19 Claims.

Our invention relates to means adapted to the present day M.'C. B. standard type of brake head and brake shoe for removing undue play between the brake head and the brake shoe; our improved means causing the brakeshoe to be firmly anchored to the brake head against the vibration and wear producing movement normally encountered between the head and shoe during train operation.

Our invention has for its object the provision of means of the character defined which may be easily and quickly applied to brake heads in use, even though the latter is in more or less worn condition, thereby enabling the brake head to be if continued in service for a considerablelength of time and further wear on the brake head thereby discontinued.

The objects and advantages of our invention will be readily comprehended from the following detailed description of the accompanying drawings, wherein: v

Figure 1 is a side elevation of a brake head and shoe with one form of our improved wedge means shown applied.

Figure 2 is a. vertical sectional view of the assembled structure.

Figure 3 is a perspective view of the form of means employed in Figures 1 and 2.

Figure 4 is a vertical sectional view of assembled brake head and shoe with a modified form of our invention applied.

Figure 5 is a rear face view of the intermediate portion of the shoe and the form of means disclosed in Figure 4.

Figure 6 is a perspective view of the type of wedge means shown in Figures 4 and 5.

Figure '7 is a perspective view of another modified form of our improved wedge means.

Figure 8 is a vertical sectional view of an assembled brake head and shoe with the modified form of Figure '7 shown applied.

Our improved means is especially intended for the standard type of brake heads and shoes at present in use on the railroads of this country without necessitating any alterations or changes in the constructions.

For purposes of economy in operation and interchange, the railroads of this country many years ago adopted and put into practice a stand- 55 into a recess in the brake head or between two ard brake head and brake shoe insofar asthe genlugs on the head; and as the head and shoe consist of two rough castings, certain tolerances in manufacture are allowed. As a result, it is never possible under such conditions to obtain a tight fit between the brake shoe and the brake-head; in fact, the tolerances in manufacture are such that there is sufilcient clearance between the lug on the brake shoe and the cooperating part of the brake head to which the shoe is attached, to permit of an excess play between the two members.

Brake shoes are of hard cast iron while the brake heads are of malleable iron and therefore softer material. The weight of the brake shoe is carried on the supporting lugs of the brake head and theexcess play between the brake head and the shoe permits the shoe to vibrate in an up and down movement when the train is in motion. This constant action or vibration causes the shoe lug to out into and wear away the supporting lugs and particularly the lower intermediate lug on the brake head.

This excess play between the shoe and head increases as wear occurs and to such an extent that the shoe soon has an excess travel independently of the head during brake application. This excess travel also causes the shoe to dig into and wear the supporting lugs on the brake head and to also wear the contact points between the back of the shoe and the forward face of the lugs on the brake head. The excess play thus occurring between the shoe and head causes so much wear that the life of the brake head is greatly shortened, thus requiring more frequent expense-incident to a more frequent renewal of the entire brake head than is desirable and hence greatly more frequent than would be the case if the shoe was firmly anchored to the brakehead, a condition, however, not obtainable with the cast heads and shoes as now employed.

An ideal braking condition is one where the brake shoe is firmly anchored to the head, with the two elements moving together as one unit.

As it is impossible to have such an arrangement or condition, owing to the present construction and methods of manufacture, we have devised our improved wedge means adapted to fill the space between the lug on the shoe and the lugs on the head, eliminating the play and vibration mentioned, and firmly wedging the shoe to the brake head.

Our improved means have been designed not only for application to new brake heads, but also I to the brake heads and shoes when the supporting lugs are in a worn condition thereby increasing the usefulness of the brake head adapting it to continue in service for a greater period of time and hence obviating the necessity of removing and discarding the heads because their further use would be unsafe. With our improved means, further wear on the brake head will cease and the wear transferred to our less expensive and more easily applied wedge means.

In the particular embodiment of the invention as disclosed in the first three figures of the draw ings, our improved means, shown at IS in Figure 3, comprises a steel plate formed to provide the fiat top portion IS with the opposite ends bent downwardly at substantially right angles, as shown at l1, II. The length and width of the top portion I6 is substantially equal to the width and transverse length of one of the supporting lugs l8, l8 on the brake head i 9, which are spaced apart longitudinally of the head to receive the supporting lug 20 on the rear face of the brake shoe 2|.

The supporting lugs 18, i8 of the head and lug 20 of the shoe are provided with vertical openings therethrough adapted td' partially register with each other to receive the usual wedge or locking key 22, which is substantially of the same length as the shoe and given approximately the same arcuate formation as the forward side of the head l9 and adapted to be inserted from the top or upper end, of the head while the shoe is held in place with its lug 20 disposed between the lugs l8, l8 of the head.

As practically all of the wear, due to vibration, is encountered by the lower lug [8 of the head, our improved wedge means is shown applied to the lower lug l8.

The ends I1, I! of our wedge means I5 are intended to depend on opposite sides of the lower head lug [8, as shown in Figure 1, the rear or head opposing marginal edges of the ends H, I! being shown cut or formed at an inclination at 23 because of the forward curvature of the forward face of the head.

The ends l1, I! are preferably of length greater than the vertical depth of the lower lug l8, so as to permit the bottoms of the ends l1, I! to be bent around the bottom of the head lug I8 after the wedge means has been positioned on the lug IS.

The intermediate portion of the top portion I 6 is slit at properly spaced apart points from one longitudinal side namely the longitudinal side or edge disposed toward the forward face of the head, and this slit or partially severed portion is then bent downwardly to provide the depending tongue 24. This tongue 2i is intended to be inserted in the vertical opening or slot in the supporting lug H of the brake head as can more readily be seen in Figure 2. The tongue 24 is normally bent downwardly substantially at right angles to the top portion l6 and depends sufliciently forward of the rear edge of the means so as to engage the forward side of the opening through lug l8, see Figure 2, and hence will be disposed intermediate of the forward side of the vertical-slot in lug l8 and the forward side of the key member 22 as shown.

As the top face of the head lug l8 slopes downwardly toward its free or shoe engaging end, itis apparent that the top plate portion l6 will likewise be in a slight forwardly declining position, with theresult that the free or lower end of the tongue 24 (which normally is disposed substantially at right angles to the body of the plate) will extend into the path of the locking key 22. It is therefore apparent that when the locking key 22 is driven into place, its forward face will cause the tongue to bend forwardly into the position shown in the sectional view Figure 2 and continue to have frictional and snug relation with the forward face of the wedge key 22; the tongue 24 being disposed between the key 22 and the forward wall of the lower lug l8 and hence firmly holding the key 22 against accidental movement.

With our improved means positioned as shown and described, it is apparent that the space between the shoe lug 20 and the lower head lug I8 is not only filled, but that the space between the forward face of the key 22 and the forward wall of the head lug I8 is also partially filled. As a result, the up and down play between the shoe lug 20 and the head lugs l8, l8 will be eliminated and the pounding action and wear caused by the shoe lug 20 absorbed or taken care of by the steel plate; but the tongue 24 will force the key 22 rearwardly and hence, by reason of key 22 engaging the rear wall of the slot in the shoe lug 20, induce the shoe 2| to be drawn backward against the head l9 into snug relation therewith.

In Figures 4 to 6, we illustrate a modified form of our improved wedge means adapted to be supported from or applied to the lug of the shoe instead of being supported on or applied to a lug on the head as in the preceding figures.

This modified wedge means consists of a suitably sized rectangular steel plate 25 of width and length commensurate with the transverse length and width of the lug 20 of the shoe 2| and the lower lug l8 of the brake head is; the lugs being similar to those heretofore shown and described and apertured vertically to receive the usual wedge or locking key 22.

One longitudinal edge of the plate 25, namely the edge which is to be disposed toward the brake head I9, is provided with an upstanding leg 26, which is adapted to fit into a recess usually formed in the outer end of the shoe lug 2'0; and the upper end of this leg 26 is bent forwardly and thence downwardly into the hook portion indicated at 21.

The vertical length of the upstanding leg 26 is suflicient to permit the hook portion or lip 21 to enter the upper end of the vertical slot or opening through the shoe lug 20', as shown in Figure 4, with the leg 26 disposed along the rear side of the shoe lug, while the plate portion is bent forwardly beneath the shoe lug 20 and across the face of the head lug i8, thus filling the space between these two lugs and receiving any frictional wear or action that may occur.

In order to permit the wedge key 22 to be inserted through the apertures in the head and shoe lugs in the usual manner, the plate portion 25 is-provided intermediate of its ends and the longitudinal edges with a slot 28 which will register with the opening in the head lug I! when our improved wedge means is in proper position.

With the hook portion or depending lip 2'! arranged in the key receiving slot in the shoe lug 20, the lip will engage with the rear side of the key 22 and as a result will exert rearward pressure on the shoe lug 20, thereby causing the shoe to be drawn rearwardly into firm relation with the head and hence prevent play between the various elements.

In Figures '7 and 8, we illustrate another form of our wedge means, namely a type like the one shown in Figure 3, which is supported on the lug it of the brake head ID. This construction also consists of a rectangular steel plate portion 29'prcvided with the integral depending leg 30 depending from the plate adjacent to one longitudinal edge thereof with the plate cut away toward the opposite longitudinal edge as shown at 3| in order to provide a passage for the usual locking key 22. The lower end of the depending leg 30 is bent forwardly to engage beneath the lower face of the head lug Ii.

As in the previous constructions, the plate portion 29 fills the space between the head and shoe lugs and prevents the vibration or up and down movement of the shoe relative to the head and hence also prevents wear on the softer head me.

The leg 30 is disposed through the vertical slot or opening in the head lug l8 and will be disposed forward of the locking key 22, causing the latter to be forced rearwardly and likewise drawing the shoe toward the head into firm relation therewith.

With our improved means of steel, the shoes are wedged into firm relation with the heads, removing all lost motion at present encountered, and at the same time eliminates the wear on the shoe and the head; while the lips and legs of our wedge means, normally extending at right angles to the plate portions and capable of slight flexing, will induce a. firm binding relation with the locking keys and will also compensate for slight variations in the keys.

We have shown what are believed to be some of the simplest embodiments of the invention which have been described in terms employed merely for purposes of description and not as terms of limitation, as modifications may be made without, however, departing from the spirit of our invention.

What we claim is:

1. Brake shoe and key wedge means of the character described comprising a plate portion adapted to be disposed between the opposing faces of the slotted supporting lugsof a brake head and brake shoe and provided with a passage for a brake shoe locking key, said plate portion coincident with said passage having an angularly disposed portion adapted to extend into the slot of one of the lugs.

2. Brake shoe and key wedge means of the character described adapted to be disposed between the interengaging lugs on the head and shoe and comprising a plate portion adapted to be interposed between the opposing faces of the slotted lugs of a brake/head and brake shoe, and a vertically disposed portion integral with an intermediate part of the plate portion adapted to extend into a slot of a lug to be disposed lengthwise of and in wedging'contact with the shoe locking key.

3. Brake shoe and key wedge means of the character described comprising a horizontally disposed plate portion, adapted to be interposed between a lug of the brake head and a lug of the shoe, provided intermediate of its ends with a key receiving passage and intermediate of its ends with a vertically disposed portion adapted to constitute a key wedging tongue arranged to extend into a vertical plane intermediate of the longitudinal sides of the plate portion 4. Brake shoe and key wedge means of the character described comprising a single piece member involving a horizontally disposed portion formed intermediate of its ends with a passage therethrough, a vertically disposed portion intermediate of the ends of the plate portion adjacent to one side of said passage and coincident therewith to constitute a key wedging portion, and angularly disposed lug engaging portions 5. Means of the character described comprising, in combination with the apertured supporting lugs of a brake head and a brake shoe and the shoe locking key, a plate portion adapted to extend intermediate of the opposing faces of the lugs on the brake head and the brake shoe and provided with a key-receiving passage therethrough intermediate of its ends, and a key engaging portion intermediate of the ends of the plate portion disposed vertically therefrom adjacent one side of said passage adapted to enter an aperture of one of the lugs and have wedging engagement with the side of the locking key.

6. Brake shoe and key wedge means of the character described comprising a plate portion adapted to be interposed between the slotted supporting lugs of a brake head and a brake shoe, said portion being formed. to provide passage for a shoe lo'ckingkey, a portion of the plate coincident with the passage being adapted to extend into a slot of one of the lugs in wedging relation with the key, and means whereby said plate portion is secured to one of the lugs.

'7. Brake shoe and key wedge means of the character described comprising a horizontal portion provided with a key receiving passage and a perpendicular portion formed to constitute a lug engaging and key wedging element.

8. Brake shoe and key wedge means of the character described comprising a plate portion provided with a key receiving passage intermediate of its ends and a portion disposed angularly from one longitudinal side of the plate portion, with the outer end of said angularly disposed portion bent laterally and thence downwardly to provide a holding and key wedging element.

' 9. The combination with a brake head and shoe having a pair of apertured lugs attached respectively thereto and arranged in overlapped relation, and a key extending longitudinally between the head and shoe and through the apertures in the lugs and serving in conjunction with the lugs to hold the shoe and head in connected relation, of an elongated wear plate extending transversely of the head and shoe and between opposing faces of the lugs and embodying means at the ends thereof for holding it against displacement and in connected relation with one of the lugs.

10. The combination with a brake head and shoe having a pair of apertured lugs attached respectively thereto and arranged in overlapped relation, and a key extending longitudinally be-' tween the head and shoe and through the apertures in the lugs and serving in conjunction with the lugs to hold the shoe and head in connected relation, of an elongated wear plate'extending transversely of the head and shoe and between opposing faces of the lugs and embodying fingers at the ends thereof engaging the ends of one of the lugs and serving to hold the plate against displacement and in connected relation with respect to said ing.

11. A brake head wear receiving element adapted to be disposed on the upper face of a brake-head lug and comprising a plate provided with a downwardly flexible portion whereby the plate is secured to the head lug against displacement. 12. A brake head wear receiving element adapted to be disposed on the upper face of a brake head ing and comprising a fiat plate having downwardly disposed ends and a downwardly bendable tongue intermediate of the front and rear longitudinal sides of the plate.

13. The combination with a brake head and shoe having a pair of apertured lugs attached respectively thereto and arranged in overlapped relation, and a key extending longitudinally between the head and shoe and through the apertures in the lugs and serving in conjunction with the lugs to hold the shoe and head in connected relation, of a wear plate fitting between opposite faces of the lugs, and means associated with the plate for holdingthe key against longitudinal displacement.

14. The combination with a brake head and shoe having a pair of apertured lugs attached respectively thereto and arranged in overlapped relation, and a key extending longitudinally between the head and shoe and through the apertures in the lugs and serving in conjunction with the lugs to hold the shoe and head in connected relation, of a wear plate fitting between opposing faces of the lugs and having means attached thereto for holding the key against longitudinal displacement.

15. The combination with a brake head and shoe having a pair of apertured lugs attached respectively thereto and arranged in overlapped relation, and a key extending longitudinally between the head and shoe and through the apertures in the lugs and serving in conjunction with the lugs to hold the shoe and head in connected relation, of a wear plate fitting between opposing faces of the lugs and embodying a tongue engaging frictionally the key and operating to hold the latter against longitudinal displacement.

16. The combination with a brake head and shoe having a pair of apertured lugs attached respectively thereto and arranged in overlapped relation, and a key extending longitudinally between the head and shoe and through the apertures in the lugs and serving in conjunction with the lugs to hold the shoe and head in connected relation, of a wear plate fitting between opposing faces of the lugs and embodying in the central portion thereof a tongue extending into the aperture in the lug attached to the head and engaging frictionally the key in order to hold the latter against longitudinal displacement.

17. The combination with a brake head and shoe having a, pair of apertured lugs attached respectively thereto and arranged in overlapped relation, and a key extending longitudinally between the head and shoe and through the apertures in the lugs and serving in conjunction with the lugs to hold the shoe and head in connected relation, of a wear plate fitting between opposing faces of the lugs and embodying means for holding the key against longitudinal displacement and additional means for holding the plate in place.

18. Brake shoe and key wedge means comprising, in combination with the apertured supporting lugs of a brake head and a brake shoe and the shoe locking-key, a plate member provided with a downwardly bent portion intermediate of the ends of the plate whereby the latter is secured to a head lug against displacement.

19. Brake shoe and key wedge means comprising, in combination with the apertured supporting- VICTOR H. HARBERT. MALCOLM S. JOHNSON.