AU646174B1

AU646174B1 - Stop squeal shim

Info

Publication number: AU646174B1
Application number: AU20606/92A
Authority: AU
Inventors: M.J. Cusick
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-07-27
Filing date: 1992-07-27
Publication date: 1994-02-10
Anticipated expiration: 2012-07-27

Description

P100/011 281W Regulation 3.2

AUSTRALIA

Patents Act 1990 646174

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT nvention Title: TOPSQUEAL S The following statement is a full description of this invention, including the best method of performing it known to me:- I I I I I I -2- STOP SQUEAL SHIM This invention relates to improvements in preventing squeal of disc brake pads on machinery, motor vehicles, electric trains and any application that has a disc brake system.

Squealing of disc brakes can cause lack of concentration and frustration to drivers and or passengers whom travel on our roads and rail systems. Not disregarding noise pollution.

There have been few proposals preventing disc brakes squealing. As found no suitable product can withstand the temperatures or friction produced between disc brake piston and disc brake pad, in a disc brake system. One previous application proposes a rubber glue mixture painted to the backing of the disc brake pad, forming a thin layer or coat. As experienced this has the disadvantage of eventual errosion of the rubber glue mixture, when under friction and temperature changes, in the disc brake system within several weeks.

*•oo 20 These problems are overcome by the present invention, which provides a stop squeal shim fitted between the disc brake piston and back of the disc brake pad. Comprising 1.50mm thick aluminium oxide resin bond polyester fibre, which is a coated abrasive. This can be cut to the size and 25 configuration of the disc brake pad, to suit fastening into an existing disc brake system, without being a permanent too.

part of the disc brake system.

a a Aluminium oxide resin bond polyester fibre is non flammable to heat produced from the brake disc, water and oil resistant. The coated abrasive can be temporarily fitted between the disc brake piston and disc brake pad by using existing disc brake caliper guide pins and guide clips and or bonded to the back of the disc brake pad, with the abrasive side faced toward the disc brake piston and the polyester fibre side faced toward back of the disc brake pad. Due to flexability and durability of the coated abrasive, expansion and contraction can take place whilst under friction and temperature changes, in the disc brake system. Also to exclude erosion and composition of the coated abrasive.

The coated abrasive is replaced in the disc brake system as required and in the same manner as you would fit disc brake pads. It is recommended that at the time of the new disc brake pads fitted, stop squeal shims be fitted.

In one assessment of the invention aluminium oxide resin bond polyester fibre is a shim. Comprising a polyester fibre backing 1.12mm thick with coated abrasive minerals (aluminium oxide) resin bonded 0.38mm thick thereon, one side only. Forming a 1.50mm thick coated abrasive, with vulcanised fibre appearance.

*.0o dee.

:Coated abrasives have two layers of adhesives. A "make" 25 coat to anchor the aluminium oxide mineral and a "size" S. on coat to lock the aluminium oxide mineral to the polyester SSfibre backing.

S

S The grade or grit of the coated abrasive used depends on the size of the aluminium oxide minerals resin bonded to the polyester fibre backing, also to suit the application used.

However, the stop squeal shim will not damage the disc brake piston as it is designed to eventually breakdown the aluminium oxide abrasive side of the coated abrasive, over a long period. The material of the stop squeal shim is currently used in the metal industry as aluminium oxide resin fibre discs. These discs are recommended for use on mild steel grinding of welds and in mild steel fabrication or on non ferrous metals excluding hard alloys.

In another form of the invention, the coated abrasive may be described as an insulator 1.50mm thick. Cut to size and configuration of a disc brake pad and fitted between the disc brake piston and the back of the disc brake pad. This is to minimise vibration and friction in the disc brake system causing squeal of the disc brakes to diminish.

The coated abrasive may be made of a polyester fibre backing 1.12mm thick with aluminium oxide minerals resin bonded thereon, 20 one side only. The resin bond 0.38mm thick is glue, urea o formaldehyde over glue, phenolic resin over glue, phenolic resin "make" and "size" and waterproof resin forming a •0 flexible and durable coated abrasive 1.50mm in thickness.

00 •0 o• see* $see 6 00 0 To assist with understanding the invention, reference will now be made to the accompanying drawirgs which show one example of the invention.

In the drawings: FIG. 1 shows one example of a stop squeal shim according to this invention.

FIG. 2 shows the application of such a stop squeal shim fitted to a disc brake system.

Referring to FIG. I it can be seen that a stop squeal shim 1 according to this invention comprises. A 1.12mm thick polyester fibre backing 2 with aluminium oxide abrasive minerals resin bonded 0.38mm thick, thereon one side only 3 forming a 1.50mm thick coated abrasive 1.

The coated abrasive 1 can be cut to the size and configuration 5 of the disc brake pad 8 used. Suitable holes are drilled 4 in the coated abrasive 1 to suit diameter of holes in the disc brake pad, for ease of fitting to a disc brake system.

FIG. 2 shows a stop squeal shim in operation. It can be 20 seen that a disc brake system 6 has a stop squeal shim 1 fitted between the disc brake piston 9 and the back of the disc brake pad, 10 by using existing disc brake caliper 7 guide pins 11 and clips 12 and or bonded to the back of the disc brake pad 8 with the abrasive side of the shim 3 faced toward the disc brake piston 9.

*se p 1 tL -6- By the use of one stop squeal shim of this type, fitted between each of the disc brake pistons and the back of each disc brake pad, it is necessary that two stop squeal shims be required per one disc brake caliper.

No further fixing of a stop squeal shim is required unless bonding of the coated abrasive to the back of the disc brake pad, optional as existing disc brake caliper guide pins and guide clips will hold the coated abrasive firmly in position. This is for ease of removal and for installation of new shims.

It will be realised that a stop squeal shim according to this invention is not restricted to heat or friction produced in the disc brake system to the form of a rubber glue mixture shown in the example. Therefore, longer life can be expected from a stop squeal shim.

e.

ee** a i a a a

Claims

1. A stop squeal brake device fitted between a disc brake piston and back of a disc brake pad comprising 1.50mm thick aluminium oxide resin bond polyester fibre, which is a coated abrasive, said aluminium oxide resin bond polyester fibre cut to the size and configeration of said disc brake pad, to suit fastening into an existing disc brake system without being a permanent part of said disc brake system, said aluminium oxide resin bond polyester fibre being non flammable to heat produced from brake disc in said disc brake system also being water and oil resistant, said aluminium oxide resin bond polyester fibre being temporarily fitted between said disc brake piston and said disc brake pad by using existing disc brake caliper guide pins and guide clips or by bonding to said back of said disc brake pad, said aluminium oxide resin bond polyester fibre having an abrasive side and a polyester fibre side, with said abrasive side faced toward said disc brake piston and said polyester fibre side faced toward said back of said disc brake pad.

2. The stop squeal brake device of claim 1 wherein said aluminium I: oxide resin bond polyester fibre is a said coated abrasive, comprising a polyester fibre backing 1.12mm thick with coated abrasive minerals (aluminium oxide) resin bonded 0.38mm thick, thereon one side only, forming a said 1.50mm thick coated abrasive, with vulcanised fibre appearance.

3. A stop squeal brake device substantially as herein described with reference to the accompanying drawings. M. J. CUSICK 23 NOVEMBER 1993 (NAME OF APPLICANT) (DATE) ABSTRACT A stop squeal shim is disclosed. The device is a 1.50mm thick coated abrasive with aluminium oxide abrasive minerals resin bonded 0.38mm thick to one side of a 1.12mm thIck polyester fibre backing complete with suitable holes (4) drilled in the coated abrasive and cut to size and configuration of a disc brake pad Then fitted into the disc brake system between the disc brake piston (9) and back of the disc brake pad (10) wiith the abrasive side of the coated abrasive facing the disc brake piston and using existing disc brake caliper guide pins (11) and caliper guide clips (12) to fix the coated abrasive in position. Coated abrasive can also be bonded to the back of the disc brake pad (10) using a suitable adhesive. Two coated abrasives of this type are used for each disc brake caliper to reduce friction and squeal in a disc brake system. oboe oo *0 00