1. Field of the Invention
This invention relates generally to a clutch wherein a reinforcement mechanism is provided in a force flow zone between a pressure element and a second clutch part, which mechanism has ramps to transmit a biasing force for pressing the pressure element against the second clutch part.
2. Description of the Prior Art
Such clutches with reinforcement mechanisms are described in EP 1 882 862 A2 and EP 1 801 441 B1. The reinforcement mechanisms have ramps that can here be described as force transmission surfaces. The ramps are arranged at an angle of greater than zero to the drive shaft and at which a circumferential force is partly deflected into a biasing force. A problem with such clutches is that on a load change, i.e. on a change from an acceleration of the output shaft to a braking of the output shaft, metallic knocking noises known as clonking noises can occur due to the mutual impacts of the ramps. As well as the noise nuisance, this leads to increased wear on the clutch. The pressure element and the second clutch part usually each have a flat friction surface for their mutual friction connection, so the pressure element is also often called a pressure plate and the second clutch part a friction disc.