Metal working – Method of mechanical manufacture – Combined manufacture including applying or shaping of fluent...
Reexamination Certificate
1999-07-06
2001-08-28
Rosenbaum, I Cuda (Department: 3726)
Metal working
Method of mechanical manufacture
Combined manufacture including applying or shaping of fluent...
C164S011000, C164S044000, C164S245000, C188S25000B, C188S25000B
Reexamination Certificate
active
06279222
ABSTRACT:
This invention is concerned with a method of manufacturing a brake pad, for example a brake pad suitable for use in a disc brake of a vehicle.
A conventional brake pad comprises a pad of friction material adhered to a back plate. The pad contains a mixture of various friction-enhancing and wear-promoting materials and is bonded together by a cured material which is often phenolic resin. Such a pad is conventionally formed by pressing a mixture containing friction material and curable material against the back plate so that a block of curable material is formed adhered to the back plate, and curing said curable material. The block of friction material may subsequently be machined to its final shape.
In order to adhere the block to the back plate, adhesive is commonly used and the back plate, which is usually made of rolled steel, may define a small number of cylindrical holes or depressions which are entered by friction material. The friction material in these holes or depressions acts to resist the removal of the friction material from the back plate by forces caused by contact with the disc. It is also known (see GB 2 245 667 A) to provide the back plate with projections which enter the friction material and serve the same purpose as the above-mentioned holes or depressions. However, these holes or depressions or projections do not materially assist in preventing the friction material from becoming detached from the back plate as a result of failure of the adhesive. Such a failure of the adhesive, which may occur because of high temperatures created by brake operation, can result in complete loss of the block of friction material.
Various attempts have been made to key the block of friction material to the back plate to prevent loss of the block in the event of adhesive failure or, indeed, to avoid the necessity for the use of adhesive. For example, it is known (EP 0 084 591 A) to apply metal powder to the back plate and sinter the powder to form a porous layer into the interstices of which the friction material can enter. Another known possibility (EP 0 387 182 B) is to weld a piece of expanded metal mesh to the back plate so that the mesh becomes embedded in the friction material. These possibilities, although they improve the keying, are complex to manufacture.
DE 26 29 793 A describes a back plate which is made from cast iron instead of rolled steel. One advantage claimed for the use of this material is that the friction material adheres well to the rough cast surface. However, this publication does not suggest that the keying can be improved by casting any features into the back plate. GB 1 160 503 describes a back plate which may be made of cast metal and which has anchoring recesses to receive the friction material. It is mentioned that these recesses may be undercut but no method for achieving this is disclosed.
It is an object of the present invention to provide a method of manufacturing a brake pad which provides a brake pad with improved keying.
The invention provides a method of manufacturing a brake pad, the method comprising forming a back plate by a casting operation in a mould, the back plate being formed with at least one integral projection which overhangs and adjacent surface portion of the back plate, the mould being formed from frangible material and having a recess therein in the shape of the projection, the mould being formed by compressing particulate material against a surface from which there is a projection made of resilient material, the compression causing the resilient material to deform to the shape of the required projection of the back plate, solidifying said particulate material, and withdrawing said resilient material to form the recess, the method also comprising casting metal in the mould including said recess, the metal in said recess forming said projection, and, after solidification of the metal, breaking the mould away from the projection, the method also comprising pressing a mixture containing friction material and curable material against the back plate including pressing said mixture around said projection so that it extends beneath said overhang, and curing said curable material to form a block of friction material adhered to the back plate.
In a method according to the invention, the overhang of the projection provides the required keying in a simple manner. In most cases, the keying is additional to the use of adhesive of conventional type for bonding the block to the back plate.
Preferably, the back plate is formed with a plurality of the projections distributed over at least part of the surface of the back plate which is engaged by the block. For example, there may be projections in the form of ribs with overturned portions running transversely, or longitudinally, or both transversely and longitudinally forming a lattice. Alternatively, said projection or projections may be generally cylindrical with an overturned top lip. Numerous other shapes are possible.
Preferably, the or each projection is formed within a recess in the back plate.
The invention also provides a brake pad manufactured by a method in accordance with the invention.
There now follows a detailed description, to be read with reference to the accompanying drawings, of a method of manufacturing a brake pad which is illustrative of the invention.
REFERENCES:
patent: 684559 (1901-10-01), Vair
patent: 787092 (1905-04-01), Gallagher
patent: 1559146 (1925-10-01), Andrews
patent: 1950260 (1934-03-01), Nelson
patent: 3624758 (1971-11-01), Harris
patent: 3738418 (1973-06-01), Harris
patent: 3986585 (1976-10-01), Toplis et al.
patent: 4023613 (1977-05-01), Uebayashi et al.
patent: 4569424 (1986-02-01), Taylor, Jr.
patent: 4599772 (1986-07-01), Graham
patent: 4799579 (1989-01-01), Myers et al.
patent: 5141083 (1992-08-01), Burgoon
patent: 5429216 (1995-07-01), Kahr
patent: 5732800 (1998-03-01), Spigener
patent: 758303 (1953-07-01), None
patent: 871077 (1942-04-01), None
patent: 1160503 (1969-08-01), None
patent: 58-212837 (1983-12-01), None
Bunker Kenneth James
Denton Peter Gareth
Fischer Hans
Holme John David
Phillips Alan Jeffory
Compton Eric
Cuda Rosenbaum I
Federal-Mogul Technology Limited
Synnestvedt & Lechner LLP
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