US2686576A

US2686576A - Brake shoe and head fastening means

Info

Publication number: US2686576A
Application number: US251292A
Authority: US
Inventors: Fred E Bachman; Jr Albert F Seelig
Original assignee: American Steel Foundries
Current assignee: American Steel Foundries
Priority date: 1951-10-15
Filing date: 1951-10-15
Publication date: 1954-08-17
Anticipated expiration: 1971-08-17

Description

Aug. 17, 1954 F. E. BACHMAN ET AL BRAKE SHOE AND HEAD FASTENING MEANS Filed Oct. 15, 1951 w m hy X I m5 e i {L 5 6 4 MW 3 0 O 3 2 3 2 5 III w w w 3 0 w. IHH 6 |l 9 w 2 w e fin liu l l l l l lflfl Q w w Q n. 6

Patented Aug. 17, 1954 BRAKE SHOE AND HEAD FASTENING MEANS Fred E. Bachman and Albert F. Seelig, Jr., St.

Louis, Mo., assignors to American Steel Foundries, Chicago, 111., a corporation of New Jersey Application October 15, 1951, Serial No. 251,292

15 Claims. (01. 188245) This invention relates to railway brakes and more particularly to a novel disk brake arrangement of the type disclosed in U. S. Letters Patent No. 2,363,453.

A primary object of the present invention is to devise an arrangement in which the brake shoe is readily detachable with respect to the brake head and may be discarded after becoming worn out in service.

A more specific object of the invention is to accommodate removal of the brake shoe without disassembling the brake head.

Another object of the invention is to positively restrain the brake head and shoe against rotation and to provide a novel rockable connection between the brake lever and head to aiford adjustment therebetween as the brake shoe wears in service.

A further object of the invention is to devise an arrangement such as above described wherein the parts are interconnected by a novel spring key formed and arranged to accommodate rockable movement of the lever with respect to the brake head.

The foregoin and other objects and advantages of the invention will become apparent from a consideration of the following specification and the accompanying drawing, wherein:

Figure 1 is a fragmentary top plan view of a disk brake arrangement embodying a preferred form of the invention;

Figure 2 is a side elevational view of the struc ture shown in Figure 1;

Figure 3 is a front edge elevational View of one of the brake levers and its associated brake head and shoe, and

Figure 4; is a fragmentary sectional view taken on the line 44 of Figure 3.

Describing the invention in detail, and referring first to Figure 1, the novel brake arrangement comprises a pair of brake levers 2, pivoted as at 4, on substantially vertical axes within a support or housing 6 containing conventional actuating means (not shown) for applying braking pressure to the levers between which is interposed a conventional disk or rotor 8 connected for rotation on a substantially horizontal axis X-X with a wheel (not shown) of an associated railway car truck (not shown) to which the support 6 is attached in any conventional manner.

Each lever 2, as best seen in Figures 2 and 3, comprises top and bottom jaws In and i2, having openings 14 and I6, respectively, partly defined by inner bearing surfaces 18 and 20, which converge inwardly toward each other, as best seen in Figure 3. Thus the opening 14 tapers upwardly and the opening l6 tapers downwardly, for a purpose hereinafter described.

A U-shaped strap 22 is positioned between the jaws I0 and I2 and is secured to a backing plate 23 of a brake shoe 24, which comprises one or a plurality of segments of any suitable friction material secured to the backing plate 23, in any desired manner as by a suitable cement. It may be noted, as best seen in Figure 2, that the shoe 24 is formed as a segment of an annulus corre sponding to a segment of the rotor 8, a fragmentary portion of which is shown in Figures 1 and 2.

The brake shoe comprises a radial forward edge 26 and a radial rear edge 28, as well as top and

bottom edges

30 and 32 converging forwardly toward the forward edge 26. The top and bottom edges of the backing plate 23 are formed with

outturned flanges

34 and 36, defining channels 38 and it receiving converging upper and

lower edges

42 and 44, respectively, of a brake head generally designated 46. As best seen in Figure 2, the brake head edges 42 and it are approximately of the same contour as the

brake head edges

30 and 32 whereby the brake shoe 26 and backing plate 23 may be moved forwardly to disengage the

flanges

34 and 36 from the brake head edges 42 and G l during removal of the brake shoe, as hereinafter described.

The brake head $6 is a substantially flat platelike member provided with a slot 48 interrupting its forward edge 56, which is complementary in form to that of the forward brake shoe edge 26, said slot t8 being adapted to accommodate passage of the strap 22 to and from the jaws it and 12, during assembly and disassembly of the brake shoe 24, as hereinafter described.

In the assembled position of the parts illustrated in the drawing, a spring key 52 extends through the jaw openings [4 and I6 and through the strap 22, to connect the jaws with the brake head and shoe. The key, as best seen in Figure 3, comprises

spaced legs

54 and 56, which are preferably substantinally flat and are provided intermediate their ends with

arcuate offset portions

58 and 59, respectively. The leg 56 is sprung into tight engagement, as at E2 and 64 with the upper and lower surfaces It and 20 of the jaw openings M and it. 'The other leg 5 is arranged with its offset portion 58 sprung against the strap 22 of the shoe 2:1 in complementary arcuate face engagement with said strap, whereby the head 45 is tightly engaged along its flat outer surface with inwardly tapered noses B0 of the jaws l0 and 12, each of said noses being defined by inwardly converging, substantially vertical surfaces accommodating rockable adjustment of the brake lever 2, with respect to the brake head 45, as the brake shoe 24 wears from a new condition, illustrated in the upper half of Figure 1, to the fully worn condition illustrated in the lower half of Figure 1.

The brake head 46 is guided for substantially linear movement toward and away from the rotor B by a guide channel 63 in an inverted U-shaped bracket 65, secured to the rear edge of the brake head 46 and the bracket is reinforced by a gusset plate 68, which is somewhat triangular in form, as illustrated in the top plan view of Figure 1. The channel 63 is approximately parallel to the rotational axis XX of the rotor 8 and is approx- 4 of the brake levers 2, whereby a guide bar or plate 69 of the support 2, received within the imately perpendicular to the vertical pivotal axes channel 83 and generally complementary thereto, is effective to guide the brake head 45 and shoe 24 in linear movement toward and away from the rotor and to positively prevent rotational move ment of the brake head and shoe thereby insuring even wear of the rotor engaging surface of the shoe from the forward to the rear edges thereof.

It may be noted, in this connection, that the radially outer edge of the annular rotor 8 inherently rotates faster than the radially inner edge thereof so that the rear edge 28 of the brake shoe normally tends to wear faster than the forward edge thereof. Thus if the brake head and shoe were permitted to pivot relative: to the brake lever on a substantially vertical axis, this uneven wear would continue until the rear edge of the brake shoe were worn out.

According to the present invention, however, the brake head and shoe are restrained from rotational movement by the above described means, and the brake lever noses Elli, as well as the arcuate bearing portion 58 of the spring key 52, are formed and arranged to accommodate rockable movement of the lever 2 relative to the brake head, as the brake shoe wears in service.

In the drawings, the parts are shown in assembled relationship and may be disassembled by removing the spring key 52, whereupon the brake shoe 24 may be moved forwardly with its strap 22 passing through the brake head slot 48 until the strap 22 has been removed from said slot, whereupon the brake shoe may be moved upwardly or downwardly to effect removal and replacement thereof. If desired, after the brake shoe has been removed, the braking head 46 may be lifted to effect removal and inspection thereof, although it will be understood that under normal service conditions the brake head @5 does not require replacement as does the brake shoe 24 which is subjected to wear due to frictional contact with the rotor 8 during braking.

In assembling the parts, the brake head 46 is lowered to engage its channel 63 with the bar 69, whereupon the strap 22 of the brake shoe 24 is inserted into the slot 48 and the brake shoe is moved rearwardly until the top and

bottom edges

42 and 44 of the brake head are tightly confined within the channels 38 and 40 of the brake shoe. Under these conditions, the strap opening is registered with openings [4 and lb of the brake lever jaws to accommodate insertion of the spring key 52 which holds the parts snugly in the assembled position shown in the drawing.

We claim:

1. In a brake arrangement for an annular rotor; the combination of a shoe in the form of a segment of an annulus, a brake head at the outer side of said shoe having a forward edge approximately complementary in form to that of said shoe, said brake head having a slot interrupting said edge and extending rearwardly therefrom, a lever having top and bottom members at the outer side of said head above and below said slot at the rear extremity thereof, and means securing said members to a portion of said shoe extending through said slot.

2. A brake arrangement, according to claim 1, wherein the means comprise a spring key extending through aligned openings of the brake lever members and shoe portion, and said key reacts against outwardly facing surfaces of the lever members and against an inwardly facing surface of the shoe portion to urge the outer side of the head tightly against said members.

3. A brake arrangement, according to claim 2, wherein the brake lever members bear against the brake head along tapered substantially vertical noses of said members, and wherein the engagement of the key and shoe portion are along complementary arcuate areas, as seen in top plan view.

4. A brake arrangement comprising a support, a lever pivoted thereto and having spaced portions with tapered noses, a brake head having a flat surface at one side thereof bearing against said noses, a brake shoe at the opposite side of said head having a portion extending through an opening thereof and extending between said lever portions, and a spring key with spaced legs extending through aligned apertures in said portions, one leg bearing against surfaces of the lever portions facing away from said head and the other leg being in complementary arcuate face engagement with a surface of the shoe portion facing said head, said legs being sprung apart from each other to thereby urge the head surface against said noses.

5. A brake arrangement, according to claim 4, wherein the opening of the head intersects the forward edge thereof between its upper and lower edges to accommodate removal of the brake shoe from said head upon removal of said key.

6. A brake arrangement, according to claim 5, wherein the upper and lower edges of the head converge forwardly thereof and the shoe is provided with forwardly converging channels within which said upper and lower edges are snugly fitted.

7. A brake arrangement comprising a support, a brake lever pivoted thereto, a brake head having an aperture, a brake shoe at one side of said head having a member extending through said aperture, aligned openings through said lever and member, and spring means in said openings reacting against said lever and member for urging said shoe against said head and thereby urging said head against said lever.

8. A brake arrangement, according to claim 7, wherein the spring means are in rockable contact with sai member in the opening thereof and the lever is in rockable contact with the head, and guide means are provided on said support for confining said head to substantially linear movement during pivoting of said lever.

9. A brake arrangement, according to claim 7, wherein the brake head aperture intersects the forward edge of the brake head to accommodate disassembly of the brake shoe from the head upon removal of the spring means.

10. In a brake arrangement for a rotor having an approximately horizontal rotational axis and having a friction surface extending radially outwardly from said axis; the combination of a brake lever pivotal on a substantially vertical axis, a brake head, means connecting the head to the lever on a substantially vertical axis, guide means for preventing rotation of said head, said connecting means comprising a brake shoe having a member projecting through an aperture of said head, registered openings, through said shoe member and lever, and securing means extending through said openings.

11. A brake arrangement, according to claim 10, wherein the brake lever engages the head along a tapered nose of said lever extending along a substantially vertical line to accommodate rockable adjustment of the lever with respect to the head as the shoe wears in service.

12. A brake arrangement, according to claim 10, wherein the aperture intersects the forward edge of the head, whereby upon removal of the securing means, the shoe may be moved forwardly out of engagement with the lever and head.

13. A brake arrangement, according to claim 12, wherein the upper and lower edges of the head and shoe converge forwardly and are in complementary tongue and groove engagement.

14. A brake arrangement comprising a lever, 0

a brake head carried thereby, a brake shoe at one side of the head having a portion extending through an aperture in the head interrupting its forward edge, complementary tongue and groove means interlocking the brake shoe with the upper and lower edges of the head, and means at the opposite side of said head securing said portion to said lever.

15. A brake arrangement comprising a brake lever, a brake head having an aperture interrupting its forward edge, a brake shoe having a portion extending through said aperture and removable by moving said portion forwardly of the brake head out of said aperture, and removable means extending through the lever and portion for securing the head to the lever and shoe portion, and for preventing such movement oi. said portion.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 130,734 McAlister Aug. 20, 1872 268,092 Gordon Mar. 28, 1882 369,736 Race Sept. 13, 1887 557,699 Pirch Apr. 7, 1896 743,794.- Adreon Mar. 10, 1903 1,465,975 Emery Aug. 28, 1923 2,228,818 Eksergian Jan. 14, 1941 2,504,668 Eksergian Apr. 18, 1950 FOREIGN PATENTS Number Country Date 407,722 France Jan. 6, 1910