US2266984A

US2266984A - Railway brake structure

Info

Publication number: US2266984A
Application number: US339708A
Authority: US
Inventors: Ambrose C Moore
Original assignee: Chicago Railway Equipment Co
Current assignee: Chicago Railway Equipment Co
Priority date: 1940-06-10
Filing date: 1940-06-10
Publication date: 1941-12-23
Anticipated expiration: 1958-12-23

Description

' Dec. 23,1941. f A, Q MOQREl v l 2,266,984

" RAILWAY BRAKE STRUCTURE' y Filed AJune':`Lo, 1940y CAQQSE QMOORE ,ff mIVENToR y Patented Dec. 23, 1941 RAILWAY BRAKE STRUCTURE Ambrose C. Moore, Winnetka., Ill., assignor to Chicago Railway Equipment Company, Chicago, Ill., a corporation of Illinois Application June 10, 1940, Serial No. 339,708

9 Claims.

The invention relates to the assembly of brake Aheads and brake shoes of railway brake beams in vthe head and shoe in contact with each other so that these parts form a single rigid unit. As the parts consist of castings which are not machined, close and accurate lits are unlikely, and, irrespective of the initial assembly of the parts, the continuous jarring and vibration of the vehicle, together with the working of the parts on each other due to such vibration and to repeated application and release of braking forces, tend to develop play between the parts with resulting pounding and sliding which wears away the brake -head surfaces contacting with the brake shoe.

This is objectionable and may cause misapplication of the brakes and necessitate replacement of the heads which otherwise would have an indefinite useful life.

The main object of the present invention is to improve the mounting of the brake shoe upon the brake head by the use of yielding inserts lwhich will reduce or eliminate pounding between these parts.

Another object is to provide metal to metal contact between the shoe and the head when the braking force is applied, which may occur on an average of probably not over twenty-iive times a day, and thereby avoid subjecting the resilient elements to excessive pressure which would soon Adestroy their resilient characteristics, particularly if the resilient elements are formed of rubber.

Another object is to retain the shoe and head and assembling key against play and possible loss.

These and other detailed objects of the invention, as will appear from the following specification, are attained by the structure illustrated in the accompanying drawing in Which- Figure 1 is a side view and longitudinal section through a brake head and shoe assembly embodying one form of the invention, the section part being taken approximately on the line I-I of Figure 2.

Figure 2 is a front elevation of the structure shown in Figure 1 but with the shoe removed.

Figure 3 is a detail transverse section taken on the line 3-3 of Figure 1. V

Figure 4 is a similar section but showing the parts when subjected to braking forces.

Figure 5 is a view and section corresponding to Figure 1 but illustrating another form of the invention.

Figure 5a is an enlarged detail section illustrating the structure indicated in Figure.

Figures 6 and 7 are similar details illustrating other forms of the invention.

The brake head has a central body part I with a pocket 2, adapted to receive the ends of the compression and tension members (not shown) of a truss type brake beam,'and with recesses 3 and 4, either one of which may receive a brake hanger (not shown) by which the beam is suspended from the truck frame. The brake head includes the upper center lug 5, lower centerlug 6, which receive the shoe lug 'I between them, upper toe 3 and lower toe 9, which engage the end portions of the shoe.

Lugs

5 and 6 and toes 8 and 9 have the general contour and arrangement characteristic of this type of brake head.

Each lug and toe is shown recessed to receive a separately formed insert of rubber or rubber-like material. The insert IIl in the head upper center lug 5 has a body portion II, seated in the shoe opposing recess of the brake head, a neck I2, and a button I3, seated inthe key opposing recess of the head. `Normally the outer faces of elements II and I3 will project substantially beyond the planes of the adjacent surfaces ofthe head, as indicated in dotted lines at IIa and I3a (Fig. 3), but when the tapered key I5 is driven through the apertures I6 and I'I therefor in

lugs

5, 6 and I, the insert will be distorted as the shoe and key approach the head surfaces until the parts are substantially in the relative position indicated in Figure 3, the recesses in the head being large enough to accommodate this distortion of the insert.

The insert, when distorted as just described, tends to hold the shoe spaced away from the head during normal operation of the vehicle and thereby eliminate numerous wear producing contacts to which these parts otherwisewould be subjected. Also the high degree of friction between elements IIJ and key I5, and the shoe prevents these Darts from slipping over each other and prevents the key working upwardly and the corresponding loosening of the shoe and head, and this result will follow even if an old and badly worn key is used in which case the key may not lie close against the head as shown in Figure 3.

The brake head lower center lug 6 is shown with an insert 40 applied to its horizontal shoe lug opposing face and with a similar but separate insert 40 applied to its upright shoe back opposing face. The shoe upper center lug is shown with the single insert ID seated in its shoe back opposing face and having an angular extension I8 around its downwardly facing portion and opposing the upper face of lug 1. Either arrangement may be used on either or both shoe lugs.

The shoe toes 8 and 9 are shown provided with inserts I9 similar to inserts 40, although of smaller area, but the heads of inserts I9 do not engage the key and have no function except Vto retain the. inserts. in place. Y I

The density of the inserts and the sizeoi apertures. 2l extending through the lug walls will beso proportioned that. the heads. I3 and 20. may

be squeezed through the apertures, whereupon their normal expansion will `serve to retain the inserts. in the. head( Figure 5 illustrates. another form of the invention in which rubber-like inserts are received in recesses Zlin the brakeA shoe and function to absorb loose play between the shoe and the head and to resist pounding, and wear between these members, as do. the, inserts mounted in the. head `asi previously described, but when. the brakes are applied, the rubber elements may be compressed L and distorted until. the opposing elements of the shoe and head contact each other.

Figures 5 and 5d also illustrate another type `of, resilient insert in the shoe central lug and normally supporting. the same in the head. Springs 211 are seated in. upwardly and down- ,wardly facing recesses in the shoe lug. and bear :against blocks 29 slidable in the recesses. Blocks ,29- may be4 of rubber but preferably areof metal ywith facings 30 of rubber or other non-metallic materialbonded. to their outer surfaces and disposed to engage the opposing faces of the head lugs.

A shank 28 extends .throughY the shoe lug and blocks 29` and hasj its ends enlarged and slidableiin blocks 29. The shank functions to limit the outward movement of the blocks; Upon the application of the brakes, the friction between the shoe and the. wheel will cause the. shoe to move upwardly or downwardly, relativelyto the head, until the solid: portion of the shoe lug engagesv the upper or lower head1 center lug, thus relieving the yielding elements. of the load. The yieldingA elements are mounted at opposite sides of the key 3| asl are the elements 4i) on, the upper face of the head center lug shown in Figures, 1 and 2.

Applicant is aware that the usey of. rubber be- .tweerr a brake head and shoe. has been suggested previously, and in this connection ref-v erence is made to United States Durbin: Patent 1,939,296 issued- December 12, 1933,.but. the structure there disclosed is subjectY to objections in that all of: the thrusts between the brake head; and shoeA is transmitted through the rubber blocks with the resulting deterioration of the blocks. Furthermore, the, structure disclosed in ,saidpatent does notY prevent but vrather facilitates the working. loose ofthe key by the play between the` shoe and head.

rubber block may be bonded directly to the metal of the mounting part as indicated at 34 in Figure 7.

It is to be understood that any of the resilient elements referred to above may be used in lieu of any of the other resilient elements so far as the attainment of the main object of the invention is involved, and also that certain features described and illustrated may be omitted without departing from the spirit of the invention so far as the latter is embodied in the features retained.

The size, contour, location and other detailed construction of the: inserts may be modified otherwise than as indicated herein without departing from the spirit of the invention, and theexclusive use of such modifications as come within the scope of the claims is contemplated.

What is claimed is:

1. In a railway brake head having a brake shoe opposing face provided with a recess,l a rubber-like insert seated in said recess and. normally projecting there-from to yieldingly engage abrake shoe, the Volume of said recessY being substantially equal to the volume of said insert so as to completely receive said insert when braking forces are applied to the head and shoe.

2. In. a railway brake head, a lug having a brake shoe contacting, face provided with a recess, there being an aperture extending from the bottom of said recess toqthe opposite side of the: lug, and an. insert of rubber-like material seated in said recess and projecting outwardly therefrom to yieldingly engage a brake shoe and including a shank. extending through said aperturev and there flanged to engage said lugside to retainthe insert in' the. head.

Y3. In a railway brake head, a lug including a brake shoe opposing face and a key opposing face, each of said 'faces` having a recess, there being a cushion of resilient material seated in each of said. recesses and projecting outwardly therefrom to yieldingly engage a` shoe and key respectively, to absorb normal play between the head, shoe and key.

4. Ina railway brake head, a lug. including. a brake shoe opposing face and a key opposing face, each of said faces having a recess,. there.- being a relatively restricted aperture through saidV lug between said' recesses, andan insert of rubber-like material having portions seated in said recesses, and projectingA outwardly therefrom to seat a shoe and key respectively, and having a relatively narrow part connecting Asaid portions through said aperture, one of said portions-being distortable` to passv through said aperture to provide for assembly of the insert with the lug.

5; In' a railway brake head, a brake' shloe mounting lug having an aperture for a shoe retaining key, there being a recess in said lug ad'- jacent to-said' aperture, and aninsert of rubberlike material seated in saidrecess and' projecting therefrom toengage` a key passed therethrough andLV to' yieldinglyresist relative movethe aperture.

6. In combination with a railway brake head and shoe, cooperating lug members on the head and shoe having opposing, substantially horizontal faces by which the shoe is supported on the head, one of said members having a recess in its face, a spring seated in said recess, and a follower thrust from said recess by said spring to yieldingly engage the face of the other member to absorb play between the members.

'7. In combination with a railway brake head and shoe, cooperating lug members by which the shoe is supported on the head, there being upwardly and downwardly facing recesses in said shoe lug member and an aperture through said lug between the bottoms of said recesses, a shank piece extending through said recesses and apertures, a coil spring seated on the bottom of each aperture and surrounding said shank piece, and spring followers on said shank piece normally thrust from the faces of said lug member by said springs and arranged to contact the opposing lug member, whereby play between the head and shoe is yieldingly resisted.

8. In a railway brake head, a brake shoe mounting member with a shoe contacting surface, there being an element of rubber-like material secured to said member and arranged to project beyond said surface and to be compressed between the member and a shoe mounted thereon to prevent slippage of the shoe over said surface.

9. In combination, a railway brake head metallic member and a brake shoe metallic member mounted thereon, elements of yielding material supporting the shoe member on the head member when the head and shoe members are relieved of braking pressure but constructed to distort under adequate braking forces, said head and shoe metallic members having opposing faces normally spaced apart by the resiliency of said yielding elements but disposed to contact each other when said elements are distorted under adequate braking forces and thereby transmit thrust between the members directly through said faces.

AMBROSE C. MOORE.