Patent ID: 7377720
Filing Date: 2008-05-27
Classification: B63B,B63C

Abstract:
1. A boat lift comprising: a base member adapted to be secured to land adjacent to the water; a boat supporting frame having a boat supporting platform with a forward portion adjacent to the water and a rear portion spaced from the water; a lift frame having opposite ends pivotally connected to said base member at a first axis and to said boat supporting frame at a second axis; a tie bar having a length substantially equal to said lift frame with one end connected to said base member at a third axis and the other end connected to said lift frame at a fourth axis, said four axes forming the corners of a parallelogram linkage for guided movement of said boat supporting frame relative to said base member between a boat launching position in which said platform is submerged in the water and a boat storage position in which said platform is above water and adjacent to said base member; a support arm pivoted to said base member and extending upwardly; and first and second fluid pressure actuators each having a cylinder end and an extendable rod end, said first fluid pressure actuator having one of its said ends connected to said base member and the other of its said ends connected to said support arm, said second fluid pressure actuator having one of its said ends connected to said support arm and the other of its said ends to said lift frame to move said parallelogram linkage and said platform between said boat launching position in which both of said actuators are fully extended and a boat storage position adjacent to said base member in which both of said actuators are collapsed.