Description:Field of Invention
[001] The present invention relates to a friction lining and in particular for the clutch of motor vehicles such as passenger vehicles or industrial vehicles.
Background of the invention
[002] A motor vehicle clutch comprises, in general, a friction or friction disc carrying on each of its faces friction linings fixed to a possibly common support, the support being fixed to a splined hub in engagement with an input shaft of a gearbox. The transmission can also take place using a wet clutch (single or double for example).
[003] Generally, friction linings are made from a compression mold. A friction lining comprises a friction material with a fixing face facing the support, and a flat friction face opposite the fixing face and capable of contacting a counter-material, such as a reaction plate or a pressure from the clutch, to transmit the engine torque.
[004] Each friction lining, conventionally in the form of a full flat ring-type fixed to a common support. Theoretically, a full flat ring-type is not necessary for a torque transfer from the engine.
[005] The present invention focus on this scope to use few segments of friction lining instead of full flat ring-type.

Objective of the invention
[006] Primary objective of the invention is to use segmented friction lining, in more particular one full flat ring friction lining is segmented into plurality of parts.
[007] Further objective of the present invention is to mount each friction-lining segments with the clutch disc using atleast two rivets.
[008] Other objects, features and advantages will become apparent from detail description and appended claims to those skilled in the art.
Summary of the Invention
[009] The invention relates to the friction device for a clutch in particular for a motor vehicle, comprising: a clutch disc with a first side and second side opposite to the first one and friction lining segments riveted to the first and second side of the clutch disc wherein each of the friction lining segments comprises atleast four holes intended for riveting the clutch disc.
[010] Preferably in each friction lining two holes in the friction lining segment comprises partially counter bore or partially counter sink to accommodate rivet head and the remaining part of the hole is intended for the passage of the rivet pin without counter bore or counter sink; the other two holes are through holes for the passage of the rivet ends.
[011] Preferably in each friction lining segment two holes are through holes to accommodate rivet head; the other two holes are through holes for the passage of rivet pins.
[012] Preferably, each friction lining segment is mounted on first side of the clutch disc opposite to another friction lining segment mounted on the second side of the clutch disc.
[013] Preferably, the clutch disc comprises plurality of rivet forming holes to mount the friction segments using rivets.
[014] Preferably, the rivets axially pass through the holes in the friction lining segments and the said rivet forming holes wherein atleast two rivet heads and atleast two rivet ends are housed in each friction-lining segment.
[015] Preferably, each rivets carry a friction lining segment in first side of the clutch disc pass through the said rivet forming holes and carries another friction-lining segment mounted on the second side of the clutch.
[016] Method of manufacturing a friction device for a clutch comprising the following steps:
a. the following components are obtained : a clutch disk and atleast one circular friction lining.
b. cutting said circular friction ling into a plurality of segments wherein each of the friction lining segments comprises at least four holes intended for riveting with the clutch disk.
c. assembling by rivet the friction lining segments on the clutch disk
[017] In the method of manufacturing of friction device as above in step a. only one full flat ring friction lining is used.
Brief Description of Drawings
[018] Figure 1 is the exploded view of the vehicle clutch.
[019] Figure 2 shows the section view of the vehicle clutch.
[020] Figure 3 is the section view showing rivet slots in the friction lining segments.
[021] Figure 4 shows the damper assembly with friction lining segment.
[022] Figure 5 shows a friction ling segment.
[023] Figure 6 is the block diagram of manufacturing process of friction lining segment.
[024] List of reference numbers
1 - Friction segment mounted on first side of the clutch disc
2 - Friction segment mounted on second side of the clutch disc
3 – Cushion segment of the clutch disc
4 – First side of the cushion segment in clutch disc
5 – Second side of the cushion segment in clutch disc
6 – Holes for the rivet
7 – Holes for the rivet
8 – Rivet forming holes in the cushion segment of the clutch disc
9 – Cushion segment rivet
10 – Rivet for mounting friction segments
11 – Drive plate
12 – Hub
13 – Hysteresis washer
14 - Damping spring
15 – Elastic washer
16 – Retainer plate
17 – Flat washer
18 – Snap ring
19 – Holes in the friction segment for rivet heads
20 – Holes in the friction segment for rivet pin
21 Holes in the friction segment for the rivet ends
22 – Three friction lining segments mounted of first side of the clutch disc
Brief Description of the preferred embodiments
[025] The embodiments of the present invention are useful in vehicles that utilize friction clutch for engaging and disengaging with engine flywheel.
[026] For example, a motor vehicle clutch comprises, in general, a friction or friction lining segment carrying on each of its faces friction linings fixed to a possibly common support, the support being fixed to a splined hub in engagement with an input shaft of a gearbox. The transmission can also take place using a wet clutch (single or double for example).
[027] In the present invention, the friction linings are the plurality of friction lining segments. Each friction-lining segment has four holes to mount with the common support using rivets. The common support has first side and second side opposite to first one. The friction lining segments riveted to the first and second side of the common support. In one aspect the friction lining segments mounted on first side of the common support are opposite to the friction lining segments mounted on second side of the common support.
[028] One of the possible application of the invention is embodied in figure1 to 5. Figure 1 is the exploded view of a vehicle clutch. It comprises friction lining segments (1) (2), common support (5) (for the explanation herein after common support is called as cushion segment of the clutch disc (3), drive plate (11), damper spring (14), retainer plate (16) and hub (12).
[029] The clutch disc (5) is mounted with friction lining segments (1) (2). The cushion segment in the clutch disc (3) has first side (4) and the second side (5) opposite to first side. Plurality of friction lining segments (1) (2) mounted on either side of the cushion segments in the clutch disc (3) using rivets (10). For riveting each friction lining segment has atleast four holes (6) (7). Atleast two rivets (10) are used to connect a friction segment (1) (2) with the clutch disc (3). As shown in figure 3 the riveting holes in the friction segment are of partially counter bore or counter sink (19) for the rivet head. The remaining portion of the holes is through hole for the rivet pin (20). Friction lining segment has through holes (21) for the rivet ends. In another aspect, the friction lining segment holes are through holes for both rivet heads (not shown in figures), rivet pin (20) and rivet ends (21).
[030] As shown in figure 4 three friction lining segments (22) are mounted on first side (4) of the clutch disc (3) and another three friction lining segments (not shown) are mounted on second side (5) of the clutch disc (3). The friction lining segments in the first side (4) and second side (5) of the clutch disc are mounted axially opposite to each other. For the mounting, each friction lining segments contains four holes two holes for rivet head (6) and two holes for the rivet ends (7).
[031] For example, any friction lining segment has four rivets (10) in which two rivets pass through holes for the rivet head (19) in friction lining segment in first side of the clutch disc (3) (cushion segment), holes (20) in the cushion segment and holes for the rivet end (21) in second side of the friction lining segment. The heads of the said rivet reside in the slot (19) of the friction-lining segment in first side (1) of the clutch disc and the rivet ends are in the slot (21) of the friction-lining segment in second side (2) of the clutch disc. Similarly other two rivets pass through friction lining segment in second side of the clutch disc, holes in clutch disc (3) (cushion segment) and holes in the first side of the friction lining segment. The heads of the said rivet reside in the friction lining segment in second side of the clutch disc and the rivet ends are in the friction lining segment in first side of the clutch disc.
[032] Figure 6 shows a block diagram of a manufacturing process of the friction lining segments for friction lining. Following steps are the key manufacturing process of the friction lining segment.
a) Preparation of raw materials wherein powders of resin, fillers and latex are mixed. Powders were loaded in the hopper and mixed as a batch.
b) Mixing the said powders with water and cement to form a wet mixture;
c) Yarn procured and stored as a spool.
d) Yarn Impregnation: Preparing yarn by texturizing and twisting. Said yarn passed through the wet mixture.
e) The said impregnated yarn formed as a cylindrical shape. Cylindrical pack was formed in the required size of friction lining.
f) Heat treatment: Back the cylindrical friction lining to make the rigid.
g) The said treated yarn disc undergone heat press, curing, deburring, deflash and baking in an oven;
h) Grinding of the baked member to maintain a smooth surface;
i) The yield product is a friction lining;
j) Drilling plurality of holes on the friction-facing intended for riveting/attaching with the clutch disc;
k) Undergone anti-dust treatment at the end of step i);
l) Cutting of the said friction facing into plurality of segments;
Wherein each of the friction facing segments contains atleast, four holes intended for riveting with the cushion segment of the clutch disc (3).
[033] Based the above manufacturing process the step h is the one full flat ring friction lining. The friction lining obtained from step h is divided into six friction lining segments as in step k. All the friction-lining segments obtained in step k are riveted to one clutch disc to form as a friction lining.
[034] For example six friction lining segments are divided from one full flat ring friction lining obtained in step k. As shown in figure 4, three friction-lining segments are mounted on the first side (22) of the clutch disc and the other three friction lining segments are mounted in second side (not shown) of the clutch disc opposite to each friction-lining segment of the first side of the clutch disc.
[035] Above description is one of the possible embodiment of the present invention. The scope of the invention may be obtained in many of the other possible embodiments as known to the person skilled in the art.
, Claims:We claim,
1. Friction device for a clutch, in particular for a motor vehicle, comprising :
- a clutch disc (3) with a first side and second side opposite to the first one, and
- friction lining segments (1) (2) riveted to the first and second side of the clutch disc (3)
Wherein each of the friction lining segments (1) (2) comprises at least four holes (6) (7) intended for riveting with the clutch disc (3).

2. The clutch disc as claimed in claim 1 wherein,
two holes comprises partially a counter bore (19) or partially a counter sink to accommodate rivet head and the remaining part of the hole (20) is intended for the passage of the rivet pin without counter bore or counter sink;
the other two holes (21) are through holes for the passage of the rivet ends.
3. The clutch disc as claimed in claim 1 wherein, each friction lining segment comprises atleast four holes:
two holes are through holes to accommodate rivet head;
the other two holes are through holes for the passage of rivet pins and rivet ends.
4. The clutch disc as claimed in claim 1 wherein, each friction lining segment (1) is mounted on a first side of the clutch disc opposite to another friction lining segment (2) mounted on a second side of the clutch disc (3).
5. The clutch disc as claimed in claim 1 wherein, the clutch disc comprises plurality of rivet forming holes (20) to mount the friction segments (1) (2) using rivets (10).
6. The clutch disc as claimed in claim 1 wherein, the rivets axially pass through the holes (19) (21) in the friction lining segments and the rivet forming holes (20) wherein atleast two rivet heads and atleast two rivet ends are housed in each of the holes (19) (21) of the friction-lining segment.
7. The clutch disc as claimed in claim 1 wherein, each rivets (10) carry the friction lining segment (1) in first side of the clutch disc (4) pass through the said rivet forming holes (20) and carries another friction-lining segment (2) mounted on the second side of the clutch disc (2).
8. Method of manufacturing a friction device for a clutch comprising the following steps:
a. the following components are obtained : a clutch disk and atleast one circular friction lining.
b. cutting said circular friction ling into a plurality of segments
wherein each of the friction lining segments comprises at least four holes intended for riveting with the clutch disk
c. assembling by rivet the friction lining segments on the clutch disk.
9. Method of manufacturing a friction device according to claim 8 wherein in step a. only one circular full flat ring friction lining is used.
10. A clutch disc obtained using the method according to any one of the preceding claims.
11. A clutch disc according to preceding claim, being a dry friction or a wet friction clutch disc.