Actuator with wear compensating chamber
First Claim
1. A fluid-operated actuator for controlling the movement of a motor vehicle friction clutch having a diaphragm between an engaged position and a disengaged position, through a linkage coupling the actuator to the clutch diaphragm, said actuator comprising:
- a main cylinder;
a movable piston sub-assembly comprising;
a main piston mounted for movement in the main cylinder and having a cylindrical bore, said main piston and said main cylinder defining a control chamber;
a secondary piston movably mounted in said cylindrical bore to define therein a wear compensating chamber, said secondary piston adapted to be coupled to said linkage, wherein said secondary piston constitutes a coupling means for coupling said linkage to said main piston, said coupling means being in piston-and-cylinder relationship with said main piston;
wherein said actuator further comprises;
resilient booster means for resiliently applying a force to and connecting an outer sleeve with said piston sub-assembly, said outer sleeve fixed with respect to said main cylinder;
a resilient return means for applying a lighter force than the resilient booster means and engaging said piston sub-assembly;
loose coupled driving means for coupling said resilient booster means with said piston sub-assembly through said resilient return means, said loose coupled driving means being interposed between said resilient booster means and said resilient return means;
a stop element carried by the main cylinder for limiting the travel of the main piston;
a shut-off valve carried by said main piston for bringing said control chamber and said wear compensating chamber into communication with each other when said clutch is in said clutch engaged position;
whereby said return means bias said piston sub-assembly towards the stop element so as to open the shut-off valve in the engaged position of the diaphragm.
1 Assignment
0 Petitions
Accused Products
Abstract
An actuator for a friction clutch having a diaphragm includes coupling means comprising a first part associated with the clutch actuating linkage, and a second part associated with the actuator proper. The actuator, of the fluid operated type, comprises a main piston working in a main cylinder and defining with it a control chamber. A secondary piston works within the hollow bore of the main piston to define within the latter a wear compensating chamber. The main piston carries a shut-off valve for bringing the control chamber and the wear compensation chamber into communication with each other when the clutch is in its engaged position. The actuator also includes a booster spring for applying additional force to the diaphragm, such that the characteristic of the diaphragm has a positive gradient over the whole travel between the engaged and disengaged positions of the clutch. The booster spring is brought into operation by a loose coupled driving means between the booster spring and the sub-assembly of the two pistons.
6 Citations
9 Claims
-
1. A fluid-operated actuator for controlling the movement of a motor vehicle friction clutch having a diaphragm between an engaged position and a disengaged position, through a linkage coupling the actuator to the clutch diaphragm, said actuator comprising:
-
a main cylinder; a movable piston sub-assembly comprising; a main piston mounted for movement in the main cylinder and having a cylindrical bore, said main piston and said main cylinder defining a control chamber; a secondary piston movably mounted in said cylindrical bore to define therein a wear compensating chamber, said secondary piston adapted to be coupled to said linkage, wherein said secondary piston constitutes a coupling means for coupling said linkage to said main piston, said coupling means being in piston-and-cylinder relationship with said main piston; wherein said actuator further comprises; resilient booster means for resiliently applying a force to and connecting an outer sleeve with said piston sub-assembly, said outer sleeve fixed with respect to said main cylinder; a resilient return means for applying a lighter force than the resilient booster means and engaging said piston sub-assembly; loose coupled driving means for coupling said resilient booster means with said piston sub-assembly through said resilient return means, said loose coupled driving means being interposed between said resilient booster means and said resilient return means; a stop element carried by the main cylinder for limiting the travel of the main piston; a shut-off valve carried by said main piston for bringing said control chamber and said wear compensating chamber into communication with each other when said clutch is in said clutch engaged position; whereby said return means bias said piston sub-assembly towards the stop element so as to open the shut-off valve in the engaged position of the diaphragm. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
Specification