AU600173B2

AU600173B2 - Brake shoe ribs and method of making same

Info

Publication number: AU600173B2
Application number: AU22878/88A
Authority: AU
Inventors: Geoffrey F. Paton; James H. Sheets
Original assignee: Dana Inc
Current assignee: Dana Inc
Priority date: 1987-11-02
Filing date: 1988-09-27
Publication date: 1990-08-02
Anticipated expiration: 2008-09-27
Also published as: GB2211776B; FR2622657A1; GB8823084D0; BR8805421A; IT1224288B; CA1306959C; FR2622657B1; DE3834768A1; AU2287888A; JPH066967B2; KR970006856B1; KR890007886A; GB2211776A; IT8848504A0; MX172475B; JPH01158236A

Description

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FOR OFFICE USE: Class Int Class o C 0 o u, o on 0 00n (0 no 00 00 o on o on o ou o o 00 0 0 0 00 Complete Specification Lodged: Accepted: Published: Priority: This document contains the namendments made under SLction 49 and is correct for printing.

0abt..tt m~~tM* Related Art: Name and Address of Applicant: Dana Corporation 4500 Dorr Street Toledo Ohio 43615 UNITED STATES OF AMERICA Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Address for Service: Complete Specification for the invention entitled: Brake Shoe Ribs and Method of Making Same The following statement is a full description best method of performing it known to me/us of this invention, including the i 4 5845/4 ALLOWED 5845/3 f" L I- L L i

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ABSTRACT

Brake shoe ribs are formed in a continuous strip stock utilizing a method to decrease the amount of trim stock. The strip stock is selected to have a width substantially equal to the maximum dimension between the ends of a rib to eliminate trim stock along the edges of the strip. Each rib is formed with a pair of notches in an outer radius and the ends of an adjacent rib extend into the notches to reduce the amount of trim stock between the ribs.

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TITLE

BRAKE SHOE RIBS AND METHOD OF MAKING SAME BACKGROUND OF THE INVENTION The invention relates generally to a method of forming a plurality of identical brake shoe ribs for vehicles and, in particular, to brake shoe ribs formed to be nested together to reduce the amount of material required in the manufacturing process.

In the prior art, brake shoe ribs were formed from a continuous strip of material which allowed for trim stock around each rib. The trim stock represented both additional S, material costs to the brake rib manufacturer, and additional processes for the trimming of the excess material from the 15 brake shoe rib. Each rib was welded to a brake shoe table to 0o' o which lining would be attached.

I o One prior art method for manufacturing a drum brake shoe is by forming a plurality of connected blanks from a strip of material. The plurality of blanks are each bent to form an So 20 arcuate outer surface with adjoining sides, and are cut 00 individually from the remaining plurality of blanks. The 0 a blanks are trimmed to remove the excess material, and .io friction lining material is attached.

In another prior art method, a strip of shoe rim steel has holes punched into it, and a lining is molded to it in segments with a flat or curved top. The strip is then bent j at locations between the.-lining segments so as to remain flat SI' and not destroy the bond between the rim and the lining material. The assembly is trimmed to length, a web or rib is attached and the lining pads ground to a final dimension.

SUMMARY OF THE INVENTION The invention described herein provides a method for forming a plurality of brake shoe ribs which have been designed to use a minimum amount of material in the manufacturing process. In particular, the present invention eliminates trim stock at the top and bottom of the brake shoe 1 -2eliminates trim stock at the top and bottom of the brake shoe rib and relief notches are added on the outside radius of the rib to accommodate the nesting of the next stamped rib.

In accordance with one aspect of the present invention there is disclosed a method of forming a plurality of brake shoe ribs comprising the steps of: 10 o -,r ou 9 a CO i a 0 0000 a. providing a strip of continuous metal stock; b. feeding said strip stock into a forming machine; c. forming a first brake shoe rib in said strip stock with at least two notches at predetermined positions in an outer periphery of said rib; and d. forming a second brake shoe rib adjacent the outline of said first brake shoe rib with opposite ends of one of the said brake shoe ribs extending into respecti',e notches of said other brake shoe rib.

In accordance with another aspect of the present invention there is disclosed a method of forming a plurality of brake shoe ribs comprising the steps of: a.

b.

notches at rib; providing a strip of continuous metal stock; forming a first brake shoe rib in said strip having a pair of predetermined positions along an outer periphery of said first c. forming a second brake shoe rib in said strip nested with the outline of said first rib and having a pair of notches at said predetermined positions along an outer periphery of said second rib, °Q opposite ends of one of said ribs extending into respective notches of said other rib; and d. repeating step c. to form a plurality of brake shoe ribs with adjacent ones of said ribs nested together.

In accordance with another aspect of the present invention there is disclosed a brake shoe rib comprising a substantially planar piece of metal strip stock defined by an outer radius and an inner radius connected by opposed end portions, and a pair of notches formed in said outer radius at predetermined postions adjacent said respective end portions.

During the process, a first brake shoe rib is formed in the continuous flat metal stock with at least two notches in the outer radius 2A of the rib. A second brake shoe rib is formed adjacent the outer radius of the first brake shoe rib with the ends of the second brake shoe rib extending into the notched out areas of the first brake shoe rib. The flat metal stock is continuously fed through the forming machine in steps so as to form a plurality of brake shoe ribs in which each adjacent rib nests into the notched out areas of the preceding rib.

It is an advantage of the present invention that a brake shoe rib is provided without the excess trim stock material required in current brake shoe rib forming methods. Furthermore, the need for trimming the brake 0 I0 shoe ribs of the excess trim stock, and the associated processes for trimming the trim stock can be eliminated. The advantages of the present invention result in an estimated ten percent to twenty percent reduction in S° the material previously required to manufacture brake ribs, and a further economic benefit can be realized as a result of eliminating the associated trimming process.

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3 1-7253 i BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a front elevation schematic view of an apparatus for performing the method of forming brake shoe Sribs according to the present invention; Fig. 2 is a plan view of a piece of strip stock having brake shoe ribs formed therein according to the present invention; Fig. 3 is a plan view of a finished brake shoe rib according to the present invention; and Fig. 4 is a plan view of a piece of strip stock having Sbrake shoe ribs formed therein according to the prior art methods.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, Fig. 1 shows a coil of strip stock material 10 being unrolled to provide a strip of metal stock 12 which is continuously fed into a forming machine 14.

The width of the metal stock 12, which is mild steel such as SAE 950 and 1035 for example, is approximately equal to the longest dimensions between ends of individual brake shoes.

The metal stock 12 enters the forming machine 14, which can be a metal stamping press, and is positioned between a pair of cooperating metal forming dies 16. The die members are closed under pressure forming a first brake shoe rib 18, as shown in Fig. 2, in the metal strip 12. The strip 12 is advanced to a position whereby enough stock is provided to form a second brake shoe rib 20 identical to and adjacent the first rib 18.

As best shown in Fig. 2, the second brake shoe rib 20 is formed adjacent an outer radius 22 of the first brake shoe rib 18. The outer radius 22 has a pair of notches 24 and 26 formed therein adjacent an upper end 28 and a lower end respectively of the rib 18. The upper end 28 and the lower end 30 of the second brake shoe rib 20 extend into the notches 24 and 26 respectively of the first brake shoe rib 18, thereby minimizing the amount of stock material used for i Ih 1-7253 j 0 .o ii- 0 0 0~0 i I i 4 4o

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i forming the ribs. The process continues as the strip 12 is advanced in the direction of an arrow 32 through the forming machine 14 to form a plurality of substantially identical brake shoe ribs.

The minimization of the strip stock material 12 used in the forming of the brake shoe rib in the present invention is also a result of the elimination of trim stock at the top and the bottom of the rib, as well as by the ability to nest the ends of the next stamped rib within the notches 24 and 26 of the preceeding rib. The present invention is estimated to save between ten percent and twenty percent of the material previously required to manufacture brake ribs. The width of the strip 12 is equal to the distance between an upper edge surface 34 defining a junction point 36 of the outer radius 15 22 and the upper end 28, and a lower edge surface 38 defining a junction point 40 of the outer radius 22 and the lower end of the ribs. The distance between the points 36 and represents the longest dimension between the ends of the rib.

The trim stock is thus an area of metal 42 between the outer radius 22 of the rib 18, and an inner radius 44 and the ends 28 and 30 of the rib A plurality of brake ribs using minimal amounts of the metal stock 12 can be formed by continuously advancing the metal stock 12 in steps in the direction of the arrow 32 within the forming machine 14 so as to allow the ends of each subsequent rib formed to nest within the notches 24 and 26 of the preceeding rib formed. The plurality of ribs are exited into a receiving tub 46 as shown in Fig. 1 for transfer to additional operations used in the formation of a brake shoe assembly.

Turning now to Fig. 3, a finished brake shoe rib 18 is shown with the notches 24 and 26 formed along the outer radius 22 of the rib. The rib 18 is configured so that the depth of the notches 24 and 26 is limited, thereby preventing any adverse effect on the structural strength of the final brake shoe assembly. The rib ends 28 and 30 are designed to 1-7253 be the upper and lower edges respectively of the metal stock material 12 from which the rib 18 is formed in order to eliminate the trim stock previously required to manufacture brake ribs. The rib ends 28 and 30 are further configured with notches 48 and 50 respectively, which locate the brake shoes in their proper positions when installed on a 'otor vehicle. The rib 18 is also provided with a pair of apertures 52 and 54 which are used to attach return springs oo (not shown) which are required for the proper functioning of LO the braking system. The aperture 52 is formed adjacent the o. notch 24 and the aperture 54 is formed adjacent the notch 26.

In addition, an aperture 56 can be formed in the rib 18 S adjacent the notch 48 for retaining a cam spring (not shown) oo should one be required.

There is shown in Fig. 4 a portion of a strip of stock material 60 which was utilized in a prior art method of o 0t, forming brake shoe ribs. A plurality of ribs 62, 64 and 66 are formed in the strip 60 by stamping leaving substantial trim stock as an area of metal 68 between each adjacent pair So 0 of ribs as well as an upper edge area 70 and a lower edge area 72 adjacent the edges of the strip 60. The present invention provides a method and a brake shoe rib configuration for reducing the amount of trim material in the areas 68 and for eliminating the trim material in the areas i 70 and 72.

In accordance with the provisions of the patent statutes, the principle and mode of operation of the present invention have been described in what is considered to represent the preferred embodiment. However, it should be understood that the invention may be practiced other than as j specifically illustrated and described without parting from its spirit or scope.

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Claims

1. A method of forming a plurality of brake shoe ribs comprising the steps of: a. providing a strip of continuous metal stock; b. feeding said strip stock into a foring machine; c. forming a first brake shoe rib in said strip stock with at least two notches at predetermined positions in an outer periphery of said rib; and d. forming a second brake shoe rib adjacent the outline of said first brake shoe rib with opposite ends of one of the said brake shoe ribs extending into respective notches of said other brake shoe rib.

2. A method as claimed in claim 1 wherein said metal stock is mild steel.

3. A method as claimed in claim 1 or 2 wherein said forming machine is a stamping press.

4. A method as claimed in claim 3 wherein said stamping press contains cooperating die members for forming said ribs.

5. A method of forming a plurality of brake shoe ribs comprising o the steps of: o, a. providing a strip of continuous metal stock; b. forming a first brake shoe rib in said strip having a pair of notches at predetermined positions along an outer periphery of said first S rib; c. forming a second brake shoe rib in said strip nested with the outline of said first rib and having a pair of notches at said predetermined positions along an outer periphery of said second rib, opposite ends of one of said ribs extending into respective notche; of said other rib; and d. repeating step c. to form a plurality of brake shoe ribs with adjacent ones of said ribs nested together.

6. A brake shoe rib comprising a substantially planar piece of metal strip stock defined by an outer radius and an inner radius connected by opposed end portions, and a pair of notches formed in said outer radius at predetermined postions adjacent said respective end portions.

7. A brake shoe rib as claimed in claim 6 including a pair of return spring apertures formed in said strip stock. CO AD 3o: ULi k -7-

8. A brake shoe rib as claimed in claim 6 or 7 including a locating notch formed in each of said end portions.

9. A brake shoe rib as claimed in claim 6, 7 or 8 including a cam spring aperture formed in said strip stock.

A method of forming a plurality of brake shoe ribs substantially as described herein with reference to Figs. 1 to 3 of the drawings.

11. A brake shoe rib substantially as described herein with reference to Fig. 3 of the drawings. a DATED this TWENTY-SECOND day of MAY 1990 o00 oDana Corporation 0 0 0 Patent Attorneys for the Applicant SPRUSON FERGUSON o0 4 ri0o0 00 0 0 I T