GB2222439A

GB2222439A - Clutch cover assembly

Info

Publication number: GB2222439A
Application number: GB8919092A
Authority: GB
Inventors: Ian Commander Maycock; Robert Jolyon Ball; Denzil John William Symonds
Original assignee: Automotive Products PLC
Current assignee: Automotive Products PLC
Priority date: 1988-08-31
Filing date: 1989-08-22
Publication date: 1990-03-07
Anticipated expiration: 2009-08-22
Also published as: GB8919092D0; GB8820538D0; GB2222439B

Abstract

A friction clutch cover assembly for a pull type clutch has a diaphragm spring 5 pivoted on a fulcrum ring 2 carried on the clutch cover 4. Also fitted to the clutch cover is location means 2A in the form of a wear resistant ring insert whose radially inner surface acts to locate the outer peripheral edge 11 of the diaphragm spring 5. The insert 2A may be located in a recess 3A in the cover 4. The ring insert 2A may abut a pivot for the spring 5 or be formed integrally with said pivot (Figs 2 and 3). <IMAGE>

Description

CLUTOLt COVF.R ASSE,MBI.Y This invention relates to the clutch cover assemblies of null type clutches.

When a diaphragm spring is located by its outer diameter in, for example, a cast aluminium clutch cover, there is a possibility that excessive wear may occur to the softer material used in clutch cover manufacture. Pull type clutches of vehicles used, in particular, in commerce and heavy haulage industry receive frequent and prolonged use. The clutch components of clutches in such vehicles have to resist rapid wear which would necessitate frequent servicing and/or replacement of major clutch components.

It is an objet of this invention to provide a means of preventing the excessive wear of the cover of a pull tyne clutch as referred to above.

According to the invention there is provided a pull type clutch cover assembly comprising 3 diaphragm spring, a pressure plate having a circumferential fulcrum bearing on one face of the diaphragm spring, and a clutch cover having a circumferential fulcrum bearing on the other face of the diaphragm spring and having location means for locating the diaphragm spring radially, wherein said location means comprises a wear resistant ring carried by the cover and so that its radially inner surface serves to locate the diaphragm spring at its peripheral edge.

In order that the invention may be more easily understood reference is made to the drawings.

Fig 1 is a sectional view of one embodiment of a clutch cover assembly made in accordance with the invention; Fig 2 is a similar sectional view to Fig 1 showing a further embodiment of the invention.

Fig 3 is a similar section view to Fig 1 showing another embodiment of the invention.

Referring specifically to the drawings, Fig 1 shows a clutch cover assembly comprising a pressure plate 7, a diaphragm spring 5 and a clutch cover 4. The clutch cover carries a fulcrum ring 2 located in a channel 3 of the clutch cover 4. Insert 2 bears on the diaphragm spring 5 near its outer diameter. The pressure plate 7 has a circllmferential fulcrum 6 which is shown bearing on the face of the diaphragm spring opposite the face on which the fulcrum carried by the clutch cover bears, and at a point 8 displaced centrally from th outer diameter of the diaphragm spring 5.

Location means for locating the diaphragm spring radially comprises a wear resistant ring or insert 2A of rectangular cross section. This is positioned to locate the diaphragm spring at its , si I peripheral edge. The insert 2A is of spring steel and may be slit longitudinally or diagonally to permit 'snap in' insertion into a groove 3A in the radially inner face of the cover. The ring may be an undulating ring of resilient material with undulations in the plane of the ring so that the radially inner peaks of the wavy ring abut the outer edge 11 of the diaphragm spring 5 and act as a resilient centring mechanism.

Fig 2 shows a clutch cover assembly in which a clutch cover 4A carries a wear resistant ring or insert 10 of rectangular cross-section. Abutting the diaphragm spring 5 is a fulcrum ring 9 of hemispherical or D-shaped cross-section. Both rings 9 and 10 are carried by the clutch cover in a 'L' shaped sectioned recess 15in the face of the clutch cover and may be made of a glass reinforced plastics material which may be moulded or extruded. Fulcrum ring 9 abuts the inner diameter of the ring 10 to retain it in the recess.

The pressure plate 7 is provided in its annular boss 12 with a fulcrum ring 8A of a section and material similar to those of fulcrum ring 9. This may be retained by an adhesive, eg silicone rubber, having cushioning properties.

Fig 3 shows a clutch cover assembly in which a clutch cover 4B carries a one-piece wear resistant insert and fulcrum ring 13. The one-piece ring 13 combines the cross-section of rings 9 and 10 shown in Fig 2 and may be of similar material. The fulcrum 14 of the ring 13 bears on the diaphragm spring 5 and the ring 13 is carried in recess 15 of clutch cover 4B. The pressure plate fulcrum 6 bears on diaphragm spring 5 as in Fig 1.

The invention has the advantage of preventing excessive wear in the clutch components constructed of softer material and it enables quick and inexpensive servicing of vehicle clutches via replacement or repair of the wear inserts.

The wear resistant inserts are made of any suitable wear resistant material including the examples of glass reinforced plastic or spring steel. Where the cover is cast or moulded the insert may be placed in situ in the mould before casting or moulding. Instead of or in addition to being held in a recess the inserts may be retained by adhesive or by interference fit.

Claims

1. A pull type clutch cover assembly comprising a diaphragm spring, a pressure plate having a circumferential fulcrum which bears on one face of the diaphragm spring, and a clutch cover having a circumferential fulcrum bearing on the other face of the diaphragm spring and having location means for locating the diaphragm spring radially, wherein said location means comprises a wear resistant ring carried by the cover so that its radially inner surface serve to locate the diaphragm spring at its peripheral edge.

2. A clutch cover assembly according to Claim 1 wherein the wear resistant ring carried by the clutch cover is affixed directly to the cover in a recess in the clutch cover.

3. A clutch cover assembly according to any preceding Claim in which the wear resistant ring abuts on its inner diameter a circumferential fulcrum ring bearing on the diaphragm spring.

4. A clutch cover assembly according to Claim 3 in which the wear resistant ring and the fulcrum ring are formed integrally.

5. A pull type clutch cover assembly according to any preceding Claim wherein the wear resistant ring is made of spring steel or glass reinforced plastic.

6. A clutch cover as claimed in any one of Claim 1, Claim 2, or Claim 3 wherein the wear resistant ring is an undulating ring having undulations in the plane of the ring so that the ring can act as a resilient centring mechanism for the diaphragm spring.

7. A pull type clutch cover assembly substantially as hereinbefore described with reference to Figs 1, 2 or 3 of the accompanying drawings.