Abstract: A protective device (14) for the drive unit (10) of a watercraft such as a sport motor boat, a fishing vessel or the like, especially having a Z-drive. In order to prevent barnacle infestation and fouling of the drive unit (10) while the watercraft lies in the water, the protective device (14) is configured as a housing (16) with at least two dimensionally stable housing shell parts (18), which, in the mutually connected closed state, for the seal-tight enclosure of the drive unit (10) to be protected, bear in a seal-tight manner one against the other with their closing edges (22), which correspond to one another in shape, and with an opening edge (24) against the hull of the watercraft, the housing shell parts (18) consisting of a lightproof material.

Abstract: Disclosed is a unilaterally alternating torque backlash lock mechanism that overcomes the disadvantages of prior art single part loop spring braking parts. The invention comprises a control element having a hub member and a housing member surrounding the hub member. The hub member is equipped with a sleeve curving at a distance around a bearing member (or inner hub member). The sleeve does not completely surround the bearing member, but rather displays a slot-like area running its entire length, thus forming a drive slot. A spring is wound around the bearing member and is so designed that each of the spring ends form a peg-like member bent down radially in the outward direction. Each of these peg-like members abut with some clearance against one of the edges of the slot in the sleeve on one side and against a cam-like member on the other side. The cam-like member is formed on the inside surface of the housing and is of sufficient dimensions to extend into the slot-like area of the sleeve.

Abstract: Disclosed is a unilaterally alternating backlash torque locking mechanism which comprises a frame member, a control member having a longitudinally extending tubular portion, a longitudinally extending torque transmission member in rotational engagement about its axis with the control member, a sleeve member fixedly mounted on the frame member and extending radially adjacent the tubular portion of the control member and two loop springs embracing said control element in a loosely sliding arrangement against the sleeve member and extending at their inner and outer ends into recesses in the control member.