FIELD OF THE INVENTION:
The present invention relates to automobile clutches in general and more particularly relates
to an improved clutch design employing an extra Belleville washer.
BACKGROUND OF THE INVENTION:
Clutches are well known mechanisms used in automobiles, which are devices adapted to typically connect a driven means and a rotational power source. The clutches generally includes a clutch cover assembly and one or more clutch disc. The clutch disc wears as the clutch is used in the vehicle and thereby the clutch characteristics changes and after some interval, it becomes necessary to adjust the clutch and/or clutch actuating mechanism. The torque-transmitting capacity of the clutches is reduced as the clutch disc wears, since the clamp load exerted by a biasing member on the clutch disc is reduced. Generally the biasing member placed inside the clutch is a diaphragm type spring. However the diaphragm spring can only provide a limited adjustment for wear.
US 5862901 disclose a friction clutch, wherein the pressure force is obtained from the interaction of two different types of springs. A plate spring, which is unable by itself to apply pressure force for transmitting torque, is used, and at least one additional spring, which produces a force effect in the same direction and the force of which is added to the force of the diaphragm spring, is also used.
Typically, such a clutch arrangement uses a steel diaphragm spring, which initially (in rest position) is formed in a cone shape. It becomes nearly flat in the clutch engaged position and
energy is stored. As the clutch wears, this flat diaphragm spring tends to be conical again and hence, the position of clamp load changes on its load deflection characteristics. But such a friction clutch suffers from shortcomings that associated wear allowance due to transmitting of torque cannot be increased to an optimum\requisite value because of high stresses in the diaphragm spring material. Further, any friction material below the metallic rivet head goes as a waste. Thus there is a requirement of providing approximate constant clamp load for greater amount of wear.
The subject matter claimed herein is not limited to embodiments that solve any disadvantages or that operate only in environments such as those described above. Rather, this background is only provided to illustrate one exemplary technology area where some embodiments described herein may be practiced.
SUMMARY OF THE INVENTION:
It is a principal object of the present invention to provide a clutch with an increased wear life
without losing the torque capacity.
It is another object of the present invention to provide an extra Belleville washer in between the existing diaphragm spring and cover in such a way that as the clamp load of main diaphragm spring start decreasing after going through flat, another Belleville washer start providing extra clamp load to kept it constant for longer time.
It is another object of the present invention to provide a simple, quick, foolproof clutch with a Twin Diaphragm Spring, which can stand greater amount of wear and that is easy to manufacture.
It is another object of the present invention to provide a mechanism for providing approximate constant clamp load for greater amount of wear.
It is yet another object of the present invention to provide a clutch assembly with a Belleville washer in between a diaphragm spring and cover in such a way that under high stress in the diaphragm spring and high release loads, the clutch assembly will not slip.
Additional features of the invention will be set forth in the description that follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The features and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS:
To further clarify the above and other advantages and features of the present invention, a more particular description of the invention will be rendered by references to specific embodiments thereof, which are illustrated in the appended drawings. It is appreciated that
these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
Fig. 1 illustrates plan view of the clutch according to one embodiment of the present
invention; and
Fig 2 illustrate clamp load curve of the clutch disclosed in the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS:
Fig. 1 illustrates an improved clutch, wherein a Belleville washer 10 with lesser stiffness is provided in between the diaphragm spring 15 and cover plate 20 in such a way that as the clamp load of the diaphragm spring 15 decreases, the Belleville washer 10 start providing extra clamp load to kept the clamp load constant for longer time. Further a clip 25 may be provided to hold the Belleville washer 10 and keep it in place. The clutch assembly further may have other conventional components such as pressure plate, friction plate, etc.
Fig.2 depicts the clamp load curve of the clutch disclosed in the present invention. The point A represents clutch clamp load when the clutch is in new condition. The point B represents clutch clamp load when the clutch is completely worn out. The larger horizontal distance between points A & B, the larger is the wear life of the clutch.
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all
respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes, which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

We Claim:
1. A clutch assembly comprising a cover plate 20 and a diaphragm spring 15, characterized
in that a Belleville washer 10 is provided between the cover plate 20 and the diaphragm
spring 15.
2. The clutch assembly as claimed in claim 1 wherein a clip 25 is provided for retaining the Belleville washer 10 in place.