US1972212A - Method of making brake shoes - Google Patents

Description

Sept. 4, 1934. s. WHITWORTH 1,972,212

METHOD OF MAKING BRAKE SHOES Filed March 5, 1930 mmvroz sTlplLEY WHITWORTH A TTORNEY Patented Sept. 4, 1934 "PATENT OFFICE- METHOD OF MAKING BRAKE SHOES Stanley Whitworth, South Bend, Ind., assignor to Bendix Brake Company, South Bend, Ind., a

corporation of Illinois Application March 5, 1930, Serial No. 433,201

Claim.

This invention relates to brakes in general and more particularly to a method of fabricating the most essential part of an internal expanding automotive brake, namely, the friction element 5 thereof.

Heretofore, the manufacture of both the band and shoe elements of this type of brake has been effected by any one of several processes, such as die casting or welding, which processes can be improved upon by simplification with a consequent cost reduction.

To the end, therefore, that the production of the friction element be simplified. there is sug-,

gested the process elaborated in more detail below, preferably comprising the shaping, by either a hot or cold rolling process, of suitably dimensioned and sectioned stock into a helix or spiral form and subsequently cutting, from the helix so formed, either brake shoe segments or annular 2o band brake segments as desired. The segments may then be straightened, perforated and otherwise shaped to effect the finished product.

Further details and novel features of the invention will become'apparent from the following detailed description of a preferred mode of practicing my invention exemplified in the .drawing forming a part of this specification, in which:

Figure 1 is a view partly in elevation and partly. in section showing a T- section type of stock rolled to the helix form;

Figure 2 discloses a brake shoe member in its final state, the same having been cut as a segment from-the helix of Figure 1; and

Figure 3 discloses a band or annular type of friction element employed in internal expanding brakes which may also be cut from the stock of Figure 1.

In practicing the preferred embodiment of my invention, I suggest first that a straight length 40 of relatively narrow gauge flat sheet steel stock be folded to provide a double thickness rim and web of T shape in cross section. The straight length of this T section stock so folded may then be sufliciently heated to render the same pliable, and bent into a coil or helix, as shown in Figure 1. From this stock, which is readily portable and also readily packed and stored, the segments necessary to effect the brake shoe of Figure 2 or the hand brake element of Figure 3 are cut. To finally form the brake shoe product of Figure 2, it is necessary to straighten the stock so that the web portion 10 thereof lies in a single plane. The web portion may also be cut away intermediate the ends of the shoe to provide reinforcing or .as by riveting.

thickened end and intermediate portions 12 and 14, respectively.

The web portion may also be provided with suitable openings at the aforementioned reinforced portions to accommodate certain of the m usual remaining elements of the brake assembly with which it co-operates. The rim 16 of the shoe segment may also be provided with the conventional brake lining 18, rigidly secured thereto I From the same diametered stock of Figure 1, the continuous or annular band friction element of Figure 3 may be formed, the web of which may subsequently be cutaway intermediate its ends to provide the tapered web portions 20 to increase the flexibility of the band. I prefer that all of the web be deleted throughout a substantial sector of the centerof the band. The ends of the rim of the band may'also be turned inwardly friction elements by an extremely simple sequence of operations. While I have described a preferred mode of practicing my invention, it is to be understood that the same is merely an examplification of many possible ways of carrying out the same and it is to be understood that the invention is limited only by the scope of the appended claims.

I claim:

1. That method of fabricating a brake friction element or the like comprising forming a flat length of formable metal into two substantially perpendicular flanges rolling the thus sectioned stock into a helix, cutting to length, from said helix-shaped stock, discontinuous cylindrical brake friction elements, and thereafter shaping by permanently inherently deforming said elemanently deforming said shoe elements to their final operative form.

3. That method of fabricating a brake friction element or the like comprising rolling, from a no length of flat, relatively narrow sheet stock, double 7 thickness rim and web T-section stock, rolling said stock so formed into a helix, cutting to length from said helix cylindrically shaped brake fric- 8 tion elements and thereafter permanently deforming said friction elements to their final operative form.

4. That method of fabricating a brake shoe friction element or the like, comprising rolling, from a length of flat, relatively narrow sheet stock, double thickness web and rim T-section stock, rolling stock so formed into a helix, cutting to length from said helix split annular bandlik friction elements, bending said elements so that their STANLEY WHITWORTH.

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