Abstract: A shaft-locking device which locks rotation of a movable shaft by a clamping force of a coil spring closely surrounding a fixed shaft and a movable shaft. Both sides of the coil spring are inserted surrounding the fixed shaft and a central portion of the coil spring surrounds the movable shaft. In case of rotation of the movable shaft on both sides, the locking torque is applied. Further, the closed state of the coil spring to the movable shaft is maintained uniformly without any relation to operation by separating the end portions of the coil spring at the movable shaft side of the coil spring from an outer circumference of the movable shaft so that a constant locking torque may be always obtained.

Abstract: A brake shoe adjustment device for internally mounted shoe brakes is arranged between mutually neighboring ends of two brake shoes which are connected to each other via a tension spring. To minimize parts, size and cost the adjustment device has two mutually opposite spreading elements, each of which is held by one brake shoe end. One of the elements is equipped with a threaded shank that cooperates with a threaded bore of the other element. The elements are axially displaceable by a worm wheel gear which rotates the shank in response to turning by an adjusting tool.

Abstract: An elongated strip having spaced-apart air scoops formed thereon is adapted for installation within the brake drum of a truck for creating a flow of air across the braking surfaces of the drum in response to rotation of the drum. The strip is installed against the interior surface of the drum exterior wall adjacent the outer periphery thereof and is secured in place by the drum mounting studs or other threaded fasteners inserted through strip mounting holes in radially inward extensions of the strip upon alignment of those holes with the drum mounting holes. A second embodiment employs a plurality of strip sectors of arcuate configuration connected in end-to-end manner with a back sheet cooperating to define an air compression/flow cavity between it and the interior of each air scoop.