Failsafe watercraft lift with convertible leveling system

Abstract

A watercraft lift for raising and lowering a watercraft in water, including a buoyant pontoon, a lifting cradle and at least one pivot arm. The lifting cradle includes at least one air tank and a support bunk configured to receive and support the watercraft. The air tank has an internal chamber configured to receive and release pressurized air. The internal chamber has sufficient internal volume that when sufficient pressurized air is received therein the air tank has sufficient buoyancy to lift the lifting cradle to a raised position with the watercraft out of the water when positioned on the support bunk and that when sufficient pressurized air is released from the internal chamber the air tank loses sufficient buoyancy to sink the lifting cradle to a lowered position sufficiently submerged to receive and deploy the watercraft. The pivot arm is pivotally connected to the pontoon and pivotally connected to the lifting cradle to guide movement of the lifting cradle between the lowered position and the raised position.

Description

FIELD OF THE INVENTION [0001] The invention generally relates to an apparatus and method for lifting watercraft out of the water. DESCRIPTION OF THE RELATED ART [0002] The use of watercraft lifting devices is well known. Out-of-water storage prevents damage resulting from boat contact with docks, other craft or floating debris. It reduces the possibility of the boat breaking free from its moorage and floating adrift or running aground. Out-of-water storage also lessens boat damage associated with long-term exposure to water and water-based pollutants and the attachment of barnacles or other marine growth to the boat's hull. Once a boat is lifted it can be maintained in its position for extended periods of time, relieving the user of maintenance concerns. In certain situations where the water fluctuation is high, water depth is too deep, or permanent mounting is undesired, floating watercraft lifting devices are used. A number of floating lift designs are currently known that provide...

AI Technical Summary

Benefits of technology

[0017] The watercraft lift may further include a lock operable to lock the pivot arm relative to the pontoon when the lifting cradle is in the raised position to prevent downward movement of the pivot arm and thereby movement of the lifting cradle to the lowered position. The lock includes a selectively rotatable upright member having an engagement member attached thereto, the rotatable member being rotatable between a locked position and an unlocked position. In the locked position the engagement member is

Problems solved by technology

It reduces the possibility of the boat breaking free from its moorage and floating adrift or running aground.

In certain situations where the water fluctuation is high, water depth is too deep, or permanent mounting is undesired, floating watercraft lifting devices are used.

This device, however, is limited in that the watercraft will not be raised or lowered in a horizontal position which is undesirable to many users.

While this device raises the boat out of the water, it has many disadvantages including a complicated rope tying configuration for stabilizing, non-horizontal lifting by raising the bow of the watercraft before the stern, and incompatibility with all boats by only fitting boats with outboard and inboard/outboard motors.

While addressing these stability issues, the lift suffers from a number of disadvantages including the lack of a means for keeping the lift stable if air pressure is lost i

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