GB2027822A - Friction clutch driven plates - Google Patents

Abstract

A friction clutch driven plate is made by securing annular friction facings (12) onto an annular support plate (14) by the use of a heat curable adhesive which is distributed in numerous discrete spots between the contact surfaces of each facing and the support plate. <IMAGE>

Description

SPECIFICATION Friction clutch driven plates This invention relates to friction clutch driven plates.

A motor vehicle clutch driven plate may typically include a pair of opposed annular friction facings mounted onto an annular sheet metal support. The sheet metal support is then utilised for attaching the facings to a hub member. One method of securing the facings to the support is by the use of adhesives.

Problems are associated with the use of adhesives in that if the adhesive has to be heat cured then when the adhesive is applied in large areas between a facing and its support then: (i) because of the large areas of adhesive it may not be thoroughly cured in the driven plate manufacturing process, (ii) gases formed by the chemical action that cures the adhesive may not be able to escape and there may be a build up of such gases that strain the friction facing, (iii) the adhesive bond formed is so strong that when, after removal of the driven plate from the curing ovens, differential thermal contraction takes place between the lining and the support plate then the driven plate may become distorted.

The object of the present invention is to provide an improved method of securing by use of a heat and adhesive annular friction facing to a support plate.

According to this invention there is provided a method of manufacture of a friction clutch driven plate in which an annular friction facing is secured onto an annular support plate which supports the full radial width of the facing, said method comprising: placing contact surfaces of the facing and backing plate in opposition with an intervening heat curable adhesive applied over spaced areas of said surfaces, and applying heat to cure the adhesive.

The invention will be described by way of example and with reference to the accompanying drawings in which: Figure 1 shows an annular friction facing mounted onto a backing plate and the appropriate location of each adhesive spot is marked with an X; and Figure 2 is a section on the line ll-ll of Fig.

1.

A motor vehicle clutch driven plate 11 includes a pair of opposed annular friction facings 1 2 and 1 3 mounted onto an annular sheet metal support plate 1 4. The support plate 14 supports the whole annular width of the facings and extends radially inwards of the friction facings 1 2 and 1 3 and is used for attaching the facings 12 and 1 3 to a hub member (not shown).

The facings 1 2 and 1 3 are secured to the support plate 14 by use of an adhesive. A heat curable adhesive that has been found suitable for this application is Redux (Reg.

Trade Mark) 80 S adhesive manufactured by CIBA-GEIGY U.K. Ltd. The adhesive can be applied to one or other of the opposed contact surfaces oneach respective facing 1 2 or 1 3 and the support plate 14, and is distributed around each contact surface 1 6 or 1 7 of the facings 1 2 and 1 3 respectively, in discrete spots 1 5 which are evenly distributed around the facings when they are attached. The total area of each facing contact surfaces 1 6 and 17, covered by the spots of adhesive is approximately 1/3 of the total area of each contact surface.

The distribution of the adhesive in spots 1 5 as opposed to spreading the glue in large areas around the facings has an added advantage in that the individual spots of glue allow for a cushioning effect between the support plate 14 and the facings when the driven plate 11 is clamped between a flywheel and a pressure plate (not shown).

Also the use of discrete spots of adhesive allows any gases formed when the adhesive cures, to be easily released from between the friction linings and the support plate. Furthermore, the use of spots 1 5 of adhesive allows the differential contraction to be absorbed by the slight resilience in the friction facing 1 2 and 1 3 material relative to the plate 14.

After the adhesive has been applied to the facings 1 2 or 1 3 or the plate 14, the-facings and the plate are clamped together and placed into an oven to cure the adhesive at a temperature of 1 80-200 C.

1. A method of manufacture of a friction clutch driven plate in which an annular friction facing is secured onto an annular support plate which supports the full radial width of the facing, said method comprising: placing contact surfaces of the facing and backing plate in opposition with an intervening heat curable adhesive applied over spaced areas of said surfaces, and applying heat to cure the adhesive.

2. A method as claimed in Claim 1, wherein the total area of said spaced areas does not exceed 1/3 of the contact areas.

3. A method substantially as described herein.

4. A friction driven plate as manufactured by a method as claimed in any proceeding claim.

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

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Friction clutch driven plates This invention relates to friction clutch driven plates. A motor vehicle clutch driven plate may typically include a pair of opposed annular friction facings mounted onto an annular sheet metal support. The sheet metal support is then utilised for attaching the facings to a hub member. One method of securing the facings to the support is by the use of adhesives. Problems are associated with the use of adhesives in that if the adhesive has to be heat cured then when the adhesive is applied in large areas between a facing and its support then: (i) because of the large areas of adhesive it may not be thoroughly cured in the driven plate manufacturing process, (ii) gases formed by the chemical action that cures the adhesive may not be able to escape and there may be a build up of such gases that strain the friction facing, (iii) the adhesive bond formed is so strong that when, after removal of the driven plate from the curing ovens, differential thermal contraction takes place between the lining and the support plate then the driven plate may become distorted. The object of the present invention is to provide an improved method of securing by use of a heat and adhesive annular friction facing to a support plate. According to this invention there is provided a method of manufacture of a friction clutch driven plate in which an annular friction facing is secured onto an annular support plate which supports the full radial width of the facing, said method comprising: placing contact surfaces of the facing and backing plate in opposition with an intervening heat curable adhesive applied over spaced areas of said surfaces, and applying heat to cure the adhesive. The invention will be described by way of example and with reference to the accompanying drawings in which: Figure 1 shows an annular friction facing mounted onto a backing plate and the appropriate location of each adhesive spot is marked with an X; and Figure 2 is a section on the line ll-ll of Fig. 1. A motor vehicle clutch driven plate 11 includes a pair of opposed annular friction facings 1 2 and 1 3 mounted onto an annular sheet metal support plate 1 4. The support plate 14 supports the whole annular width of the facings and extends radially inwards of the friction facings 1 2 and 1 3 and is used for attaching the facings 12 and 1 3 to a hub member (not shown). The facings 1 2 and 1 3 are secured to the support plate 14 by use of an adhesive. A heat curable adhesive that has been found suitable for this application is Redux (Reg. Trade Mark) 80 S adhesive manufactured by CIBA-GEIGY U.K. Ltd. The adhesive can be applied to one or other of the opposed contact surfaces oneach respective facing 1 2 or 1 3 and the support plate 14, and is distributed around each contact surface 1 6 or 1 7 of the facings 1 2 and 1 3 respectively, in discrete spots 1 5 which are evenly distributed around the facings when they are attached. The total area of each facing contact surfaces 1 6 and 17, covered by the spots of adhesive is approximately 1/3 of the total area of each contact surface. The distribution of the adhesive in spots 1 5 as opposed to spreading the glue in large areas around the facings has an added advantage in that the individual spots of glue allow for a cushioning effect between the support plate 14 and the facings when the driven plate 11 is clamped between a flywheel and a pressure plate (not shown). Also the use of discrete spots of adhesive allows any gases formed when the adhesive cures, to be easily released from between the friction linings and the support plate. Furthermore, the use of spots 1 5 of adhesive allows the differential contraction to be absorbed by the slight resilience in the friction facing 1 2 and 1 3 material relative to the plate 14. After the adhesive has been applied to the facings 1 2 or 1 3 or the plate 14, the-facings and the plate are clamped together and placed into an oven to cure the adhesive at a temperature of 1 80-200 C. CLAIMS

1. A method of manufacture of a friction clutch driven plate in which an annular friction facing is secured onto an annular support plate which supports the full radial width of the facing, said method comprising: placing contact surfaces of the facing and backing plate in opposition with an intervening heat curable adhesive applied over spaced areas of said surfaces, and applying heat to cure the adhesive.

2. A method as claimed in Claim 1, wherein the total area of said spaced areas does not exceed 1/3 of the contact areas.

3. A method substantially as described herein.

4. A friction driven plate as manufactured by a method as claimed in any proceeding claim.