| 摘要 |
<p>A mechanical actuator (40) for a disc brake assembly (10) to effect a parking brake application. The mechanical actuator (40) includes a housing (62) for retaining an end plate (56) which is rotationally retained in a bore (60) and connected to an end plate (48) which is axially retained in the bore (60). End plate (56) is connected to end plate (48) by a plurality of pivotal connecting rods (50, 52, 54). The connecting rods (50, 52, 54) each have an end retained in indentations (74, 76, 78) in end plate (56) and indentations (75, 77, 79) in end plate (48). An input applied by lever (46) causes end plate (48) to rotate about an axis (70) of bore (60) and connecting rods (50, 52, 54) to pivot about indentations (74, 76, 78) and since end plate (56) is rotationally restrained the force from connecting rods (50, 52, 54) is translated into an axial force component which moves end plate (56). The force component varies as a function of angle of rotation of end plate (48). Initial rotation causes a large displacement of end plate (56) but as the connecting rods (50, 52, 54) approach planes which are parallel to the axis (70) of bore (60), a smaller displacement occurs however with smaller displacement more of the input force from the input lever (46) is transmitted to end plate (56). The three connecting rods (50, 52, 54) form a plane through which substantially equal forces are transmitted into end plate (56) to mechanically move friction pads (28, 30) into engagement with rotor (12) and effect a desired clamping force to retain the rotor (12) in a fixed position with respect to the vehicle.</p> |
