GB2103311A - Friction clutch driven plates - Google Patents

Abstract

A friction clutch driven plate having friction facings (11) and (12) secured onto a support (13) by fastening means (14) that project into holes (15) in the support, each of which has a surrounding collar (16) on the side of the support away from the friction facing. The fastening means (14) extend into the respective collars (16) and may be formed as either pre-moulded inserts of wearable material eg. phenolic moulding compound or integral projections of the respective facing. <IMAGE>

Description

SPECIFICATION Friction clutch driven plates This invention relates to friction clutch driven plates for but exclusively for automobile clutches.

Typical friction clutch driven plates have one or more friction facings rivetted onto a supporting plate. The rivets are generally manufactured from steel, but could be brass or copper, and are countersunk into the surface of the friction facing so that the amount of. usable facing is that which projects above the head of the rivet.

It has been proposed in British Patent Specification No. 326 147 to manufacture rivets out of an asbestos filled polymerisable material having similar properties to the friction material. This allows the rivets to be flush with the surface of the friction material and to wear down with friction facing without causing damage to the opposed rubbing surface, The advantage of this construction is that for a given life of the facing its thickness can be reduced because the life of the facing its thickness can be reduced because the life of the facing is not now related to the amount of wearable material above the rivet head. A disadvantage of the construction shown in this patent specification is that as the rivets wear down with the facing there is a tendancy for the rivet to break out of its retaining hole.

The object of the present invention is to produce a friction clutch driven plate having wearable fastening means securing the facing to a support and in which the above problem is alleviated.

Accordingly there is provided a friction clutch driven plate in which a friction facing is secured onto a support plate by mechanism fastening means that project into holes in the support plate characterised in that each hole in the support plate is surrounded by a roller extending away from the facing and the fastening means extend into and are held in said collar.

Preferably the fastening means are rivets formed from a material having similar properties to the friction facing. The invention will be described by way of example and with reference to the accompanying drawings in which: Figure 1 is a circumferential section through a friction clutch driven plate according to this invention.

Figure 2 shows a modified raised collar; Figure 3 is a section through an alternative driven plate according to this invention.

With reference to Fig. 1 a friction clutch driven plate has a pair of annular friction facings 11 and 1 2 which are mounted on opposite sides of an array of cushioning segments 13, only one of which is shown. This type of constructior is well known and is shown in published British Patent Specification No. 1 541 213.

The facings 11 and 1 2 are attached on opposite sides of the cushioning segment by rivets 1 4. The rivets 14 are tapered and are formed from a wearable material of similar composition to the facing material. They could either be made from facing material itself or phenolic moulding compound eg. Bakelite (Reg. Trade Mark).

The facing 11 and 1 2 also have apertures 1 8 therein that are located opposite the rivets 14 in the other of the two facings 11 or 12.

These apertures 1 8 accommodate the axial movement of the rivets when the cushioning segments are compressed.

The rivets 14 engage in pierced holes 1 5 in the cushioning segment, which each have a respective raised collar 1 6 on the side of the segment away from the adjacent facing. The collars 1 6 are formed when the holes 1 5 are pierced, and may be split as shown in Fig. 2 to give some resilience to allow the rivets to be pushed home. The taper on the rivets extends into the collar so that the undercut between the rivet and friction facing exists until the lining is fully worn.

The facings may be moulded around the rivets and then the cushioning segments attached to the facings, or alternatively the rivets can be inserted through co-operating matched holes in the facing.

Fig. 3 shows an alternative arrangement in which the annular facing is moulded with integral projections 24 on the projections 24 on the back surface thereof, which are inserted through holes 25 in a flat support plate 27. The holes 27 are surrounded by a collar 26 which may be resilient.

Whilst the invention has been described with respect to annular friction facings, it is equally applicable to single segmental facings mounted on a backing plate.

1. A friction clutch driven plate in which a friction facing is secured onto a support plate by mechanical fastening means, that project into holes in the support plate characterised in that each hole in the support plate is surrounded by a collar extending away from the facing and the fastening means extend into and are held in said collar.

2. A friction clutch driven plate as claimed in Claim 1, characterised in that the fastening means are rivets of a hard synthetic material having similar wear properties to the material of the facing.

3. A driven plate as claimed in Claim 2, characterised in that each rivet is tapered from the head thereof to a diameter at some point within the collar.

4. A friction clutch driven plate substantially as described herein and as illustrated in the accompanying drawings.

**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 for but exclusively for automobile clutches. Typical friction clutch driven plates have one or more friction facings rivetted onto a supporting plate. The rivets are generally manufactured from steel, but could be brass or copper, and are countersunk into the surface of the friction facing so that the amount of. usable facing is that which projects above the head of the rivet. It has been proposed in British Patent Specification No. 326 147 to manufacture rivets out of an asbestos filled polymerisable material having similar properties to the friction material. This allows the rivets to be flush with the surface of the friction material and to wear down with friction facing without causing damage to the opposed rubbing surface, The advantage of this construction is that for a given life of the facing its thickness can be reduced because the life of the facing its thickness can be reduced because the life of the facing is not now related to the amount of wearable material above the rivet head. A disadvantage of the construction shown in this patent specification is that as the rivets wear down with the facing there is a tendancy for the rivet to break out of its retaining hole. The object of the present invention is to produce a friction clutch driven plate having wearable fastening means securing the facing to a support and in which the above problem is alleviated. Accordingly there is provided a friction clutch driven plate in which a friction facing is secured onto a support plate by mechanism fastening means that project into holes in the support plate characterised in that each hole in the support plate is surrounded by a roller extending away from the facing and the fastening means extend into and are held in said collar. Preferably the fastening means are rivets formed from a material having similar properties to the friction facing. The invention will be described by way of example and with reference to the accompanying drawings in which: Figure 1 is a circumferential section through a friction clutch driven plate according to this invention. Figure 2 shows a modified raised collar; Figure 3 is a section through an alternative driven plate according to this invention. With reference to Fig. 1 a friction clutch driven plate has a pair of annular friction facings 11 and 1 2 which are mounted on opposite sides of an array of cushioning segments 13, only one of which is shown. This type of constructior is well known and is shown in published British Patent Specification No. 1 541 213. The facings 11 and 1 2 are attached on opposite sides of the cushioning segment by rivets 1 4. The rivets 14 are tapered and are formed from a wearable material of similar composition to the facing material. They could either be made from facing material itself or phenolic moulding compound eg. Bakelite (Reg. Trade Mark). The facing 11 and 1 2 also have apertures 1 8 therein that are located opposite the rivets 14 in the other of the two facings 11 or 12. These apertures 1 8 accommodate the axial movement of the rivets when the cushioning segments are compressed. The rivets 14 engage in pierced holes 1 5 in the cushioning segment, which each have a respective raised collar 1 6 on the side of the segment away from the adjacent facing. The collars 1 6 are formed when the holes 1 5 are pierced, and may be split as shown in Fig. 2 to give some resilience to allow the rivets to be pushed home. The taper on the rivets extends into the collar so that the undercut between the rivet and friction facing exists until the lining is fully worn. The facings may be moulded around the rivets and then the cushioning segments attached to the facings, or alternatively the rivets can be inserted through co-operating matched holes in the facing. Fig. 3 shows an alternative arrangement in which the annular facing is moulded with integral projections 24 on the projections 24 on the back surface thereof, which are inserted through holes 25 in a flat support plate 27. The holes 27 are surrounded by a collar 26 which may be resilient. Whilst the invention has been described with respect to annular friction facings, it is equally applicable to single segmental facings mounted on a backing plate. CLAIMS

1. A friction clutch driven plate in which a friction facing is secured onto a support plate by mechanical fastening means, that project into holes in the support plate characterised in that each hole in the support plate is surrounded by a collar extending away from the facing and the fastening means extend into and are held in said collar.

2. A friction clutch driven plate as claimed in Claim 1, characterised in that the fastening means are rivets of a hard synthetic material having similar wear properties to the material of the facing.

3. A driven plate as claimed in Claim 2, characterised in that each rivet is tapered from the head thereof to a diameter at some point within the collar.

4. A friction clutch driven plate substantially as described herein and as illustrated in the accompanying drawings.