Boat lift operated by boat's propulsive force

摘要

A boat lift includes a lift frame rotatably mounted to a boat dock. A lower trolley with a buoyant body slides on the frame. An upper trolley slides on the frame and is engaged by the boat as it propels itself forward onto the frame when the latter is in a boat receiving position. A linkage connected between the trolleys causes the lower trolley and the buoyant body to slide rearwardly underneath the boat to rotate the lift frame into a final docking position in which the boat is out of the water. The upper trolley is locked into position, thus holding the lower trolley in position through the linkage. The boat is launched by releasing the upper trolley lock, which permits the upper trolley to slide rearwardly, with concomitant forward sliding movement of the lower trolley that permits the frame to rotate and launch the boat from the frame.