Abstract: A flat plate drive system for controlling the axial rotational motion of a drive shaft for raising and lowering a load, that optimizes frictional engagement while maximizing heat dissipation away from the moving parts of the drive system. The drive system can be generally used for raising and lowering many types of heavy loads, and is particularly suited for loads that are supported by a cable attached to one end of the drive shaft, with the cable extending through a cradle beam which supports a heavy object, such as a boat. The drive system comprises a worm connected to a source of rotational power. The worm frictionally engages a worm gear wheel that axially rotates a drive shaft. The worm and worm gear wheel are connected to a backplate support. The system maximizes the friction between the worm and worm gear wheel.

Abstract: An adaptable boat lift for use in raising and lowering boats having a weight of up to about sixty thousand pounds. The boat lift is able to safely support heavy boats with an upgradeable design that is adaptable to boats of varying weights and sizes by adding or changing the components of the boat lift. The boat lift has a plurality of support pilings, one piece extruded support beams, a drive shaft enclosed within the support beams, bearings attached to the support beam and surrounding the drive shaft, a mechanism for rotating the drive shaft, cradle beams to support the boat, and lifting members attached to the support beam, cradle beam and drive shaft so that when the drive shaft is rotated the boat is raised or lowered. In one embodiment, the support beams are formed as a one piece extrusion of an aluminum alloy suitable for marine use.