摘要 |
A single-acting, clearance sensing slack adjuster for brakes is provided. The slack adjuster includes a displaceable brake actuation assembly (28), a rotatable driving member (52), a rotatable intermediate member (60) and a rotatable driven member (56). The driven member is in driving relationship with a rotatable adjustment member (50) which is rotatable in a given direction to advance a brake friction member (32) to maintain the running clearance (38) within predetermined limits. A linear to rotational motion assembly (76-80) is provided to rotate the driving member in the slack decreasing direction of rotation in response to greater than predetermined movement (82) of the brake actuation assembly. A first coil clutch (20) couples the driving and intermediate members while a second coil clutch (72) couples the intermediate and driven members. One clutch (72) delivers torque in the given direction in its low torque transmitting capacity direction of rotation and that torque capacity is less than is required to rotate the rotatable actuation members when the brake friction members are engaged. |