GB1570438A

GB1570438A - Method of producing a brake band

Info

Publication number: GB1570438A
Application number: GB2981877A
Authority: GB
Original assignee: Daimler Benz AG
Current assignee: Daimler Benz AG
Priority date: 1976-07-21
Filing date: 1977-07-15
Publication date: 1980-07-02
Also published as: FR2359319A1; JPS5313068A; DE2632796A1

Description

(54) A METHOD OF PRODUCING A BRAKE BAND (71) We, DAIMLER-BENZ AKTIENGESELLSCHAFT, of Stuttgart Unterturkheim, Germany, a Company organised under the laws of the Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the follow mg statement:- The invention relates to a method of producing a double-wrap brake band, that is a band for substantially double encirclement of a brake drum, for use in an automatic gearbox, particularly but not exclusively for a motor vehicle. Double-wrap brake bands are disclosed, for example, in United States Patent Specifications Nos. 2,975,870 and 2,867,898. These specifications disclose a method of production which starts from an open annular blank into which arcuate parts, including brake-band anchorages, are welded, requislte slots being milled in the blank in a subsequent operation. The band thus produced is brought to its final shape by a subsequent stretching or drawing operation. Another known method of production starts from an annulus in which slots are milled and to which brake-band anchorages are welded, the band being then brought to its final shape by a stretching operation.

Such methods are time-wasting and costly and the present invention seeks to effect a reduction in production costs.

According to the invention, in a method of producing a double-wrap brake band for a brake drum in an automatic gearbox, a bifurcated band blank is first produced, as a clean stamping with smooth surfaces and edges, in extended form from a supply of continuous flat material, the said stamping is then brought to a circular shape and brakeband anchorages are attached to it.

By thus stamping a bifurcate band blank from flat material, bringing the blank to circular form by shaping apparatus and then providing it with brake-band anchorages, simple inexpensive production can be achieved. Inter alia, milling operations for producing necessary slots can be obviated.

One manner of carrying the invention into effect will now be more fully described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a plan view of a stamped brake-band blank in extended form, and Figure 2 is an axial view of the brake band brought to a circular shape and provided with anchorages and a lining.

Fig. 1 shows a blank for a double-wrap brake band 1 for a brake drum for providing a reaction torque in forward speeds in an automatic gearbox. As will be seen from Fig. 1, the blank comprises a bifurcate portion (on the right-hand side in the figure) of a length to afford one encirclement of the drum and an unbifurcated portion of a length to afford another encirclement of the drum and of a width which can be accommodated between the limbs of the bifurcate portion. For convenience of compact illustration only, both portions are shown with parts of their length omitted. The blank is cleanly stamped, i.e. with smooth surfaces and edges, in extended flat condition from continuous flat material in sheet or, preferably, strip form. After this stamping, the blank is brought to a circular form corresponding to that of the drum (Fig. 2), brake-band anchorages 2, 3 are then secured to it by soldering or welding, with inert-gas protection, and the brake lining 4 is attached by adhesive.

WHAT WE CLAIM IS: 1. A method of producing a doublewrap brake band for a brake drum in an automatic gearbox, wherein a bifurcated band blank is first produced, as a clean stamping with smooth surfaces and edges, in extended form from a supply of continuous

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. (54) A METHOD OF PRODUCING A BRAKE BAND (71) We, DAIMLER-BENZ AKTIENGESELLSCHAFT, of Stuttgart Unterturkheim, Germany, a Company organised under the laws of the Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the follow mg statement:- The invention relates to a method of producing a double-wrap brake band, that is a band for substantially double encirclement of a brake drum, for use in an automatic gearbox, particularly but not exclusively for a motor vehicle. Double-wrap brake bands are disclosed, for example, in United States Patent Specifications Nos. 2,975,870 and 2,867,898. These specifications disclose a method of production which starts from an open annular blank into which arcuate parts, including brake-band anchorages, are welded, requislte slots being milled in the blank in a subsequent operation. The band thus produced is brought to its final shape by a subsequent stretching or drawing operation. Another known method of production starts from an annulus in which slots are milled and to which brake-band anchorages are welded, the band being then brought to its final shape by a stretching operation. Such methods are time-wasting and costly and the present invention seeks to effect a reduction in production costs. According to the invention, in a method of producing a double-wrap brake band for a brake drum in an automatic gearbox, a bifurcated band blank is first produced, as a clean stamping with smooth surfaces and edges, in extended form from a supply of continuous flat material, the said stamping is then brought to a circular shape and brakeband anchorages are attached to it. By thus stamping a bifurcate band blank from flat material, bringing the blank to circular form by shaping apparatus and then providing it with brake-band anchorages, simple inexpensive production can be achieved. Inter alia, milling operations for producing necessary slots can be obviated. One manner of carrying the invention into effect will now be more fully described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a plan view of a stamped brake-band blank in extended form, and Figure 2 is an axial view of the brake band brought to a circular shape and provided with anchorages and a lining. Fig. 1 shows a blank for a double-wrap brake band 1 for a brake drum for providing a reaction torque in forward speeds in an automatic gearbox. As will be seen from Fig. 1, the blank comprises a bifurcate portion (on the right-hand side in the figure) of a length to afford one encirclement of the drum and an unbifurcated portion of a length to afford another encirclement of the drum and of a width which can be accommodated between the limbs of the bifurcate portion. For convenience of compact illustration only, both portions are shown with parts of their length omitted. The blank is cleanly stamped, i.e. with smooth surfaces and edges, in extended flat condition from continuous flat material in sheet or, preferably, strip form. After this stamping, the blank is brought to a circular form corresponding to that of the drum (Fig. 2), brake-band anchorages 2, 3 are then secured to it by soldering or welding, with inert-gas protection, and the brake lining 4 is attached by adhesive. WHAT WE CLAIM IS:

1. A method of producing a doublewrap brake band for a brake drum in an automatic gearbox, wherein a bifurcated band blank is first produced, as a clean stamping with smooth surfaces and edges, in extended form from a supply of continuous flat material, the said stamping is then brought to a circular shape and brake-band anchorages are attached to it.

2. A method of producing a brake band substantially as hereinbefore described.

3. A brake band produced by the method of claim 1 or 2.

4. A brake band as claimed in claim 3 and substantially as hereinbefore described with reference to the accompanying drawings.