US1667375A - Method of making brake shoes - Google Patents

Description

April 24, 1928.

A. Y. DODGE METHOD OF MAKING BRAKE SHOES' 2 Sheets-Sheet Fild July 27. 1925 'y ENVENTOR Anm. Y; DODGE 4 er su) Patented Apr. 24, 1928.

UNITED STATES PATENT OFFICE.

ADIEL Y. DODGE, SOUTH BEND, INDIANA, ASSIGNOR TO BENDIX BRAKE COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

METHOD OF MAKING BRAKE SHOES.

Application filed July 27, 1925. Serial No. 46,242.

This invention relates to the manufacture of brake shoes, and will be described as carried out in making shoes of pressed' metal blanks.

'5 Heretofore, in the manufacture of brake shoes of sheet metal, most earlier shoes having been channel-shaped in cross-section, it has been the practice -to have the face of the forming member engage the cylindrical l lining-supporting part, or friction face, of the shoe, which cylindrical face therefore bottoms in the die. When the pressure is relieved, and the formed blank is removed,

'there is invariably more or less return' spring ofthe curved pressed friction face, andthis -spring is variable and injects an uncontrollable factor which makes exact results dilicult, many rejections being necessary to secure accurate interchangeability ,of the shoes.

According to the present invention, the blanks and shoes are formed by a novel process includingas a very important Step, the pressing of the blanks with the material of the flat shoe web in engagement with the face of the forming member and with the cylindrical flange formed by a drawing action between the` side of the forming meniber and the side of the die. As is well known, great accuracy can be secured, in such a drawing action, whilethe web which bottoms in the die, being fiat, has no uncon- A trollable springto be considered, and

moreover the accuracy of the stilfeningjweb is not very important. t

The above and other objects and novel steps contemplated by the invention, together with novel features of the formed blanks, will be understood from the following description of one application of the invention as illustrated by the accompanyingdrawings, in which:

Fig. 1 is a vertical section through' they brake, just linside the wheel, showing the shoes in side elevation;

' Fig. 2 is an outside elevation of one of the end shoes, before the brake lining isI attached; t

Fig. 3 Ais a side elevation of the same shoe; Fig. 4 is a section through the shoe on the line 4,-4 of Fig. 3; i

Fig. 5 is an inside elevation ofv the shoe; Fig. 6v is a section through one `Vof the blanks andbthe forming member and die;

Fig. 7 is a similar view showing the use of a different die; and

Fig. 8 1s a plan View of one of the blanks.

In the arrangement of Fig. l, the brake 24. -The shoes are expanded against the drum 10 by means such as a double cam 26, y against the resistance of springs 28 and 30.

The shoe 14 is illustrated in Figs. 245, 'and the method of making it in Figs. 6-8; the construction and method of manufacture of the other shoes being substantially the same. As best appears in Fig; 4, the shoe is built up of two pressed parts or stampings, made from blanks such as B in Fig. 8, and each generally L-shaped in cross-section. Thus the two stampings have substantially fiat radial web portions 32, spread apart at the anchored end of the shoe to form parallel arms 34 straddling the end of shoe 16 (Fig. 1) and provided with openings 36 to give ample clearance for anchor 22.

Around the edge of each stamping runs a continuous flange 38, Wide enough on the outside of the shoe so that the aligned flanges of the two stampings form Ythe friction. face of the shoe and directly support the brake lining 40 (Fig. 1). The two stampings are' arranged back to back and fastened together, e. g. by means of rivets 42 passing through the two web portions 32. A plate 44 may bridge the arms 34 to lengthen the friction surface and strengthen forming member 60 and a die 62v (Fig. 6)

or 64 (Fig. 7), with the web material 32 in engagement with the face of the forming member. Thus the material bottoming -in the die 62, or pushed into the open die 64,

' is the flat web of the blank, which has no Aas tendency to spring back, whereas the flange 38, the accuracy of which is highly important, is drawn between the' side of the forming member 60 and the side of the die 62 or 64. Web 32 is depressed dierent distances into the die, to form the offset arm 34.

While one particular shoe, and one particular way oit' making it, have y.been described in detail, it is not my intention to limit the scope of the invention by that description, or otherwise than by the terms of the appended claims.

claim: l. That method of forming pressed meta-l brake shoes which includes the steps of cutting integral blanks, each including web material and flange material, and (b) pressing each blank by a forming member into a die, with the face of the forming member engaging the fiat web of the shoe and with the opposite sides of the forming member cooperating with the opposite sides of the die to draw out two ianges alono the inner an'd outer edges of said web, he iange along the outer edge being cylindrical.

2. That method of forming pressed metal brake shoes which includes the steps ,of (a) cutting integral blanks, each including web material and flange material, and (b) pressing each blank by a forming member into a die, with the `face of the forming member engaging the fiat web of the shoe and with the sides of the forming member co-operating With the sidesof the die'to draw out a continuous flange extending entirely around the edge of the Web, the parts of said flange along the inner and outer edges of the web beingcurved, and the outer part having a true cylindrical surface.

3. That method of forming pressed metal brake shoes which includes the steps of (a) cutting integral blanks, each including Web material and angematerial, and (b) pressing each blank by a forming member into a die, with the face of the forming member engaging the flat web of the shoe and With the sides of the forming member co-operating with the sides of the die to draw out a cylindrical flange extending along the outer edge of the web and a substantially radial flange at the end of the shoe, and (c) assembling two of the formed blanks back to back and arranging a wear plate across the joint at the end of the shoe and fastening it to said radial flanges.

4. That method of making brake shoe sections Which comprises the operations of drawing two-reversely contoured sheet metal' parts each having a curved web and a laterally-extending arcuate flange thereon, assemL bling the said parts with the webs back to back at one portion of their length and separated at another and with the arcuate flanges in axial alinement to present a widened support for a brake lining, and connecting the abutting portions of the 'web to form a unitary structure.

In testimony whereof l have hereunto signed my name.

ADIEL DODGE.

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