MANUALLY RELEASABLE PARKING BRAKE DEVICE

摘要

SURE A manually releasable, spring-a-plied, air-released parking brake device has a hollow guide rod and a non-rotatable spindle connectable to the brake rigging extending through a portion of a cylindrical housing. On one end of the guide rod is secured a portion of a clutch arrangement, and on the opposite end is secured a spline member having a plurality of externally disposed spline grooves. The connection between the guide rod and clutch portion provides coincident movement by such two members. The spline member, being similarly secured on the opposite end of the guide rod, moves coincidentally with the guide rod and clutch portion. A latching member having an extending surface engages the spline grooves of the spline member, thus preventing rotational movement of the spline member, guide rod, and clutch portion. A release lever, connected to the latching member, provides a means for engaging and disengaging the latching member and spline member. When the latching member has been disengaged from the spline member, as corresponds to a manual release of the parking brake device, a retractable blocking member is urged against the end surface of the spline member. The blocking member prevents engagement of the latching member and spline member, thus no longer preventing rotational movement of the spline member. With the spline member, guide rod and clutch collar now rotationally movable, the brake-applying spring force is dissipated away from the forceapplying spindle. To reset the parking brake device air is introduced to piston chambers, moving a plurality of pistons in a direction to compress a plurality of brake-applying springs. The guide rod then moves to a position whereby said blocking element is moved out of blocking position between the latching member and spline member. A return spring contacts the release lever, urging the release lever to a position corresponding to engagement between the spline member and latching member.