US2729312A - Air cooled brake shoe - Google Patents

Description

Jan- 3, 1955 R. w. FOSTER 2,729,312

AIR ACOOLEJD BRAKE SHOE Filed Oct. 19, 1950 `.Fl- 3 4 {z INVENTOR. .iiaffr I4( FaS/16W.

1,719,312 AitCoLj Btli siren' :notiert W'. Foefer, snuiven, tml'. Application october 19, 1950,-- serral No. 190,970

` Claims. (c'i. isszdi This invention relates to an air cooled brake shoe,- andy more particularly to clamp anchoring means therefor adapted te provide secure, durable connection. between the shoe and its holder.

This invention is an improvement over my co-pending application serial No. 150,079' niet; en March rs, 195o, iv, abfandiid, and entitled Air Cl ed Brake Sl.

it n ttte primary @bien of this invention te provide rc'lioring r'iarls for the brake" sh clamp, f sch eliarctr that it not only tieners the eterne but as weltsertfes as a canopy' fe difesi an through an passages inthe shoe. l,

Heretfo'r' it has liee'i th' practice in the art to provide cflaii'ip nlio'rin'g' il 'the' frfr'i of a longitudinally disposed, cat iie'tl iilt. Thishpla't'e hasnorrnaily been o'illi stp'er'lic'illy ilddd i' upper face of uthe shoe, and lia's lerivf length siich that it spansbut sb'sfaitially th space 4 between the opposed holder sockets. As a res'lt of this construction and the stresses upon t-heu plate, the clamp Vanchored thereto has freuently beeqme loosened. As aAv consequence tli brake s oe has either been impaired in its function or has at United States Patent O times been completely detached from its mounting. It

is obvious that there are many disadvantages and dangers that flow from the conventional construction. With applicants construction, on the other hand, the plate is firmly and relatively deeply imbedded in the upper face of the shoe. Furthermore, its length is so increased that it not only spans the space between the opposed holder sockets but extends therebeyond to a point outwardly of the shoe endsthemselves. The projecting plate ends are then formed into a type of scoop or canopy which serves to direct the air through the air passages in the shoe It is a still further object of this invention to provide improved air passages over those disclosed in my aforementioned pending application. The importance and significance of such passages can not be over emphasized. As is well known, the friction of the brake shoe against the wheel generates a great amount of heat. As a result, the shoe tends to develop ilaws in spots, and small slivers form on the braking surface. Since the slivers will fuse together, it follows that there will be a reduction of the contact area between the shoe and the wheel.

In addition, the heat generated by friction in the conventional brake shoe is such that the aforementioned metal plate is softened thereby. As a result, it tends to bend. Furthermore, the heat causes the plate to expand. As it cools it naturally contracts. WithY the bending, expanding and contracting of the plate there is a series of varying stresses and strains upon the cast brake shoe. As a result the casting ultimately cracks or breaks. Not only does this impair the effectiveness of the shoes but frequently renders them useless. Furthermore, there are known instances where a train or a car has been derailed by the falling of a portion of the brake shoe.

With applicants invention, the heat generated by the friction is dissipated so rapidly and to such an extent that the aforementioned diiculties and dangers are eliminated.

n2,729,312 Patented Jan. 3, 1956 This is accomplished through the provision of not' only longitudinally but transversely extending air passages'. Furthermore, the passages are provided with such'- a cone tour and configuration that the air is acceleratedY during passage therethrough. As a result of the rapid rush therethroughf a constant supply of cooling air, the heat is' effectively dissipated.-

It is a still further object of this invention to provide means in addition to the aforementioned platev to anchor the elarnp which isf connected to the brake shoe holder. This neafns is inthe form of riesh' which is fol-med iiil one or horizontal layers both above' and below theV air' pasJ sages.V The layers disposed above the pssage's have ceritralI cutout portions complementary to the ctnoutpr'` tions in the plate. As a result it is possible to east the clamp in the shoe in such manner' that tlie' of the clamp envelop not only the plate but tnelayers of ineen as iv'ell.l This results in the' clamp' beingl n'hl more' securely and durably anchored to' the Slide.

rnadd-itien to thev layers er horizontally disposed insh (the upper ones being utilized as mentioned above), there are prefemuly provided a plurality er vente ly disposed mesh elements. These are disposed on ei-tl sfi'de of fll' longitudinal air passages. As a co'riseqe, the cas/ting is substantially' fortified.

A Tlte fell nature' of. the invention will be' understood from the accompanying drawing and the following dscrip tion and claims.

In the drawing?,

Fig. t is a side elevation view' ofthe invention strewn in braking ass'efitien with t wheel or' a railway car.

Fig. 2 is a rep plan new of the Brake shoe.

Fig. 3 is a sectio View thereof taken n lilies er Eig. 2in die; direction of the arrows. L

Fig. 4 is a section new ftfereef taken on Beesd-'4"4 of Fig. 3 in the direction of the arrows.

In the drawing, the truck of a railway car is indicated at 10. Pivotally secured to the truck at 11 and depending therefrom on opposite sides of the car wheel 12 are the links or hangers 13. Pivotally carried by the links adjacent their lower extremities are the brake shoe holders 14.

The brake shoe is shown generally at 15 in Fig. 1 in braking engagement with the wheel riding on the track 16. The shoe is of conventional contour, i. e. arcuate, and has a pair of opposed lugs 17 projecting upwardly at its extremities. Sockets are formed in the lugs to receive therewithin the ends 18 of the holders.

It is, of course, essential that the shoe be securely connected to the holder. For that purpose there is provided the clamp 19 through which a pin 20 of the holder extends. This clamp is transversely disposed relative to the shoe and is located in the center thereof. This much is conventional. However, in order to assure that the clamp is rmly anchored to the shoe, applicant provides not only the arcuate metal vplate member 21 having central cutout portions 22, but as well the expanded metal elements or mesh 23. The mesh also has central cutout portions complementary to those formed in the plate.

As will be observed particularly in Figs. 2, 3 and 4, at least two layers of the mesh are disposed immediately below the plate. The free ends 24 of the clamp extend downwardly through the cutout portions of the plate and mesh and turn inwardly adjacent their extremities. When the shoe is cast, the clamp will consequently be securely anchored therewithin. It is to be noted that the upper face of the plate and the side portions of the clamp projecting above the upper face of the shoe are covered by a substantial layer of the substance of which the shoe is cast. This fact also adds to the secure and durable anchoring of the clamp within the shoe.

In order that the shoe may be air cooled, there are provided a plurality of longitudinally extending air passages 25 which open through the end walls of the shoe. These passages preferably have a narrowed medial bore portion 26 in order that the air will be accelerated in its movement therethrough. Extending transversely of the shoe are a series of passages 27 which also may have a centrally narrowed portion.

In order to direct and channel air through the passages, an air canopy or scoop 28 is formed at either end of the shoe in a plane above the longitudinal passages. The scoops are preferably although not necessarily the projecting ends of the plate 21 which is of such a length that said ends extend beyond the end walls of the shoe. As shown particularly in Fig. 3, the projecting ends may be bent downwardly in order to better guide the air into the passages although this is not necessary. It is, of course, possible to provide similar air scoops for the transverse passages.

The brake shoe is fortied by the addition of expanded metal or mesh which may be disposed in layers 29 below the longitudinal passages and in one or more vertical layers 30 between and outside of said passages.

While the invention has been illustrated and described in great detail in the drawing and foregoing description, the same is to be considered as illustrative and not restrictive in character.

The invention claimed is:

1. A brake shoe for railroad cars, and the like, including an elongated generally arcuate brake shoe body adapted to conform generally to the contour of the wheel with an engaging surface adapted to oppose the wheel, at least one longitudinal air passage formed therein, extending from end to end and terminating in openings on the ends of the shoe, and air scoops connected to and extending beyond both ends of the shoe to direct air into the end of each passage.

2. The structure of clairn 1 characterized by and including a plurality of transverse air passages formed in the shoe in communication with the longitudinal air passages.

3. A brake shoe for railroad cars, and the like, including an elongated generally arcuate brake shoe body adapted to conform generally to the contour of a wheel with an engaging surface adapted to oppose the Wheel, at least one longitudinal generally open uid passage formed therein, extending from one end of the body to the other with a venturi in each passage positioned approximately intermediate the ends of the shoe.

4. The structure of claim 3 in which each passage is confined within the body of the shoe.

5. The structure of claim 3 characterized by and including a plurality of transverse fluid passages in the shoe.

6. The structure of claim 3 in which the passages are air passages and terminated in openings on the body of the shoe.

References Cited inthe tile of this patent UNITED STATES PATENTS 548,939 Whitcomb Oct. 29, 1895 785,355 Gallagher Mar. 21, 1905 886,694 Gibbs May 5, 1908 943,995 Reid Dec. 2l, 1909 984,253 Adriance Feb. 14, 1911 995,013 Jones June 13, 1911 1,369,497 Thompson Feb. 22, 1921 1,498,983 Schmidt June 24, 1924 1,510,825 Bousquet Oct. 7, 1924 1,715,806 Wersall June 4, 1929 1,921,836 Pogue Aug. 8, 1933 2,368,621 Tack Feb. 6, 1945 2,406,067 Eurit Aug. 20, 1946 FOREIGN PATENTS 19,951 Great Britain Sept. 2, 1912 488,382 Great Britain July 6. 1938

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