US1537911A - Brake shoe - Google Patents

Description

May 12, 1925 1,537,911

0. B. WUNSCHOW 1 BRAKE 5110111 Filed Dec. 31, 1925 1 [N VISNTOA (72% Z. l Vzwckozz/ Patented May 12, 1925.

PATENT OFFICE.

OTTO B. WUNSCHQW, OF CHATTANOOGA, TENNESSEE BRAKE SHOE.

Application filed December 31, 1923. Serial No. 683,675.

To all whom it may concern:

Be it known that I, O'rro B. W'uNscrrow, a citizen of the United States, residing at Chattanooga, in the county of Hamilton and State of Tennessee, have invented certain new and useful Improvements in Brake Shoes; and I do hereby declare the follow ing to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in brake shoes and re-inforcements therefor, and has for its primary object the production of a shoe of maximum stability which will remain true and hang accurately relative to the wheel and be effective even when worn down to the reinforcing means.

With this and further objects in view as will in part hereinafter become apparent and in part be stated, the invention coinprises certain novel constructions, combinations and arrangements of parts as subse quently specified and claimed.

In the accompanying drawings,-

Figure 1 is a view in side elevation of a brake shoe embodying the features of the present invention.

Figure 2 is a top plan view thereof.

Figure3 is a perspective view of the back and key loop detached.

Figure 4 is a transverse section taken approximately midway of the length of the structure as seen in Figures 1 and 2.

Figure 5 is a fragmentary section through the back and loop detached, the parts being seen on an enlarged scale.

a Figure 6 is a view similar to Figure 5 of a slightly modified embodiment.

Figure 7 is afragmentary, inverted plan of the central portion of the back and loop,

part being broken out for showing structure below.

Referring to the drawing by numerals, 1 indicates a wrought plate, preferably of malleable steel, formed with its edges beveled, at 2, 2, for bonding purposes, and also formed with longitudinal slots 3, 3, each of which is surrounded by beveled edges 4 for increasing the effectiveness of the bond. Approximately midway of the length of the plate 1, the same is formed with a l0n-' gitudinal slot 5 through whic'h'extends a loo 6 of material similar to plate 1, and designed to provide an accurate key-way for the attaching lug hereinafter mentioned.

The loop 6 is formed of a strip of material bent into U-shapewith the legs bent outward beneath the plate 1, and the plate 1 is formed with notches or recesses 7, 7,

openinginto the slot 5 for accommodating the vertical or leg portions of the loop 6.

The recesses 7 insure accurate assemblage of the loop within the plate 1 in the first instance, and also serve to prevent any edgewise movement of the loop during subsequent operations. The said notches, therefore, in initially locating and subsequently retaining the loop in place during casting, prevent distortion or oblique location of the loop 6, which insures an accurate key-way and a consequent true and accurate hanging of the brake shoe.

The plate 1 is formed by any of the well known methods, and the slot 5 with therecesses 7 is preferably stamped through the plate 1, or otherwise formed in a quick and inexpensive manner, so that there may at times appear a slight looseness between the loop 6 and engaged recesses. To avoid any possible dislocation of the loop 6 during the subsequent casting operation. the underlap'ping, outwardly-turned portions 8, 8, of the loop are preferably anchored to the plate 1 after the loop has been located in any ofvarious acceptable ways. as, for example, by the spot welding indicated at 9 in Figure 5. A rivet or like connecting member,.'such as seen at 10 in Figure 6, may be employed when preferred in lieu of the spot welding. As the balance of Figure 6 shows a structure identical with Figure 5. the reference numerals above used and-the foregoing description will apply.-

When the parts have been assembled, as seen in Figure 3, and the loop 6 anchored to the plate 1, the plate is inverted'to the position seen in Figure 7, and in this posi-' tion is introduced into a mold which is closed and the molten iron is then poured in to form the completed brake .shoe 11, as seen in Figures 1, 2 and 4. Thisbrake shoe may be of various sizes, contours and dimensions, but always preferably conforming with the requirements of the .Master Car Builders Association so as' to fit the standard brake heads. The cast metal, as clearly seen in Figures 1,2 and 4,-covers the end portions of platel and effectively bonds through the slots 3, overlapping the beveled edges 4 and also overlapping the beveled edges 2. The cast metal also fills in the space between the legs of the loop 6 and rises through the slot 5, forming a solid filler above the plane of the adjacent upper surfaces of plate 1, leaving only a key-way 12, and, outside of the loop 6, the cast metal extends above the loop and overlies a part of the cross plate thereof, leaving'only the requisite portion of such plate exposed for effective engagement with the brake hanger. Thus the attaching lug 13 is formed of maximum stability with the key-way 12 formed with that precision and accuracy assuring the hanging of the brake shoe in exactly the proper relation to be most effective in engaging the wheel. In structures heretofore produced, the malleable loops employed have not been accurately maintained in place, and an angularly or oblique relation of the shoe relative to the wheel has followed, which has been especially detrimental to the effective brake action and production of rapid wear and early necessity for discarding such shoes;

Also it has been suggested heretofore that a brake shoe back of malleable material be employed with a central slot for the introduction of a hanger loop, which slot should be ofa, length equal to or. greater than the length of the core employed for preserving the key-way in the loop during the casting operation. Such an enlarged, central slot in the backing plate has,- of course, facilitated introduction of the said .core, but in most instances the result was a failure to obtain effective bonding about the central area of the back and the production of objectionable sand holes. The present invention provides a slot 5, of a length less than the actual length of the core to be introduced which must .at least be as long or longer than the thickness of the hanger lug 13. The slot 5 is, therefore, made, as best seen in Figure 7, slightly longer than the width of the material of loop 6, so that the core may be introduced after the plate 1 and loop 6 has been placed in the mold by havingjthe end of the core inserted between the loop, down through the slot 5 to a point with the lower end beyond the adjacent end of the slot, then lowering the upper end of the core and moving the core ack until it res'tscentered. upon the surface of, the cross bar of loop 6.- Thus the slot 5 while of greater length than the width of the material of-loo 6 is of less length than the thickness oft 0 base of the hanger lug 13, that is, in other words, the slot 5 is of lesslength than the core to be introduced and insures a conditiomwhen the molding operation isbegumwhich guarantees the production of an efiecting bonding between the cast portions of the shoe and the plate 'as high as ten per cent of the production Such loss is total-- incident to such defects. ly eliminated by the present invention. Furthermore, in types of shoes already in use, the key-ways have been found in instances to be too large, allowing the shoes to assume an angular relationship and ride' diagonally on the periphery of the wheel. Such a condition is'impossihle with a brake shoe embodying the features of the present invention. In other constructions of brake shoes wherein a backing plate and malleable loop for the hanger lug have been employed, the fitting in of thecore employed to produce the key-way'has resulted in the crushing of the sand of the core, leaving floating sand producing defective shoes. Such constructions have also been found objectionable, from the presence of fins which i have to be clipped and ground after the tumbling operation. The revision for the efl'ective core insertion in t e present invention both eliminates danger of floating sand, and enables such precision of fit of the parts of the mold as to obviate fins, and assures the constant and uniform production of shoes which are ready for service as they come from the tumbler.

What I claim is I L'A brake shoe back comprising a re inforcing plate having a centrally located slot, and a hanger lug loop extendin through the slot, the plate being formed withv recesses opening into the slot for accommodating the legs of the loop.

2' In a brake shoe, the combination of a re-inforcingplate having a longitudinal slot, a hanger lug" loop extending through the slot, a brake shoe body bonded with the plate-and a brake shoe lug embedding parts of the -loop,.the slot being of greater length than the width of the material of the 100 and of less llejngth'than the width of the lug. 3. In a brake shoe, the combination of a re-infor'cing plate having a V longitudinal slot, a hanger lug loop extending through the slot, a brake shoe body bonded .with and a brake shoe lug embedding parts of the loop, the slot being of greater length than the width ofthe material of the loop and of less lengththan'the width of the lug, the material of the body of the shoe, extending into the loop beyond the said recesses, each recess being of a depth plane of the back face of the body and formas great as the width of the respective leg ing an integral part of the lug. of the loop for leaving the slot open and 4. A brake shoe comprising a re-inforcfree throughout its length.v

5 ing plate having a centrally located slot extestimony Wher Of I affix my signature 15 tending longitudinally of the plate, the in p n e of WO Witn ses.

plate being formed at each side of the slot OTTO B. WUNSCHOW. with recesses extending along the slot and Wit e of a length less than the length of the slot, LOUISE BERGER,

9 and a loophaving its legs extending through VERA' L. J OHNSON.

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