GASKET AND METHOD FOR MAKING THE SAME

Abstract: A gasket for use in an aggressive environment, e.g. as a vibration and noise damping spacer in vehicle brakes, has a body (1) of fibre cloth, at least one side of which is coated with a rubber layer (2) penetrating into the cloth. The gasket is made in that a rubber solution is applied to at least one side of a body (1), the rubber solution being dried and vulcanised, so as to result in a thin inner rubber layer (2a). A rubber sheeting (2b) is applied to the inner layer (2a) by calendering, whereupon the applied rubber sheeting (2b) is vulcanised to the inner layer (2a).

Description: GASKET AND METHOD FOR MAKING THE SAME The present invention relates to a gasket for use in an aggressive environment, e.g. as a vibration and noise damping spacer in vehicle brakes, as well as to a method for making such a gasket. In disc brakes for vehicles, friction pads are pressed against a rotating disc by means of hydraulic cylinders. Many of today's disc brakes use vibration and noise damping spacers which are mounted on the friction pads, between the pads and the cylinders. Usually, the spacers are thin steel plates which on both sides are coated with a layer of rubber. Although such spacers func¬ tion satisfactorily and give no grinding of brakes, they are unfortunately complicated to make as well as difficul to handle. One object of the present invention is, therefore, to provide a vehicle brake spacer which is much easier to make and handle. A more general object of the invention is to provide a gasket for use in an aggressive environment, e.g. in engines, compressors, pumps and vehicle brakes. The gaske should be resistant to oil and solvents as well as to hig pressures and temperatures. It should also be easy to mak and handle. According to the present invention, these objects ar achieved by a gasket for use in an aggressive environment e.g. as a vibration and noise damping spacer in vehicle brakes, characterised in that it has a body of fibre cloth, at least one side of which is coated with a rubber layer penetrating into said cloth and consisting of an inner layer which is applied to said body in the form of rubber solution, and an outer layer which, in the form of a rubber sheeting, is applied by calendering and is vul- canised to the inner layer. Suitably, the body is made of glass fibre cloth, and the rubber layer consists of nitrile rubber. A further object of the invention is to provide a simple method for making such a gasket. According to the present invention, this object is achieved by a method characterised in that a rubber solu- . tion is applied to at least one side of a body of fibre cloth, that the rubber solution is dried and vulcanised, resulting in a thin inner rubber layer, that a rubber sheeting is applied to the inner layer by calendering, and that the applied rubber sheeting is vulcanised. Suitably, the rubber solution used is a solution of nitrile rubber in alcohol. The invention will now be described in more detail, with reference to the accompanying drawing which is a section of a gasket according to the present invention. The gasket shown in the drawing has a body 1 of glass fibre cloth. A suitable glass fibre cloth is, for instance, the one sold by MITEX GLASFIBER AB as article number 1581-136. This cloth has a thickness of 0.21 mm. Cloths made of other fibres, such as ceramic fibres or Kevlar fibres, may also be used. Both sides of the body 1 are coated with a layer 2 of nitrile rubber penetrating into the glass fibre cloth. In the making of the gasket, the two layers 2 are applied by pulling a web of glass fibre cloth through a solution of nitrile rubber in ethyl alcohol. The applied rubber solu¬ tion is dried and hot-vulcanised so that a thin inner layer 2a which penetrates into the glass fibre cloth is obtained on both sides thereof. Then, a sheeting 2b of nitrile rubber is applied to both of the inner layers 2a by calendering, whereupon the nitrile rubber sheetings 2b are vulcanised to the inner layers 2a in a Rotocure machine to produce, on both sides of the glass fibre cloth, a nitrile rubber layer 2 made up of an inner layer 2a and an outer layer 2b.

Claims: CLAIMS 1. A gasket for use in an aggressive environment, e.g. as a vibration and noise damping spacer in vehicle brakes, c h a r a c t e r i s e d in that it has a body (1) of fibre cloth, at least one side of which is coated with a rubber layer (2) penetrating into said cloth and consisting of an inner layer (2a) which is applied to said body (1) in the form of a rubber solution, and an outer layer (2b) which, in the form of a rubber sheeting, is applied by calendering and is vulcanised to the inner layer. 2. Gasket as claimed in claim 1, c h a r a c - t e r i s e d in that the body (1) is made of glass fibre cloth. 3. Gasket as claimed in claim 1 or 2, c h a r a c ¬ t e r i s e d in that the rubber layer (2) consists of nitrile rubber. 4. A method for making the gasket of claim 1, c h a r a c t e r i s e d in that a rubber solution is applied to at least one side of a body (1) of fibre cloth, that the rubber solution is dried and vulcanised, resulting in a thin inner rubber layer (2a), that a rub- ber sheeting (2b) is applied to the inner layer (2a) by calendering, and that the applied rubber sheeting (2b) is vulcanised. 5. Method as claimed in claim 4, c h a r a c ¬ t e r i s e d in that the rubber solution used is a solution of nitrile rubber in alcohol.

Inventors: JOSEFSSON PERCY, JOSEFSSON, PERCY
Applicants: RUBORE MATERIALS SWEDEN AB
Application year: 1990
Main classification: F16D69
IPC codes: B29C43, B29C70, B32B25, F16D65, F16D69