Watercraft lift

Abstract

A watercraft lift with rearward and forward lateral beams, left and right side longitudinal side beams, a pair of left side lifting arms, a pair of right side lifting arms supporting at their upper ends left and right side watercraft supports, and left and right side actuators pivotally attached to the left and right side rearward lifting arms. In one embodiment the left side rearward lifting arm and the left side actuator rotate about their pivotal attachments to the longitudinal left side beam in a left side plane, and the right side rearward lifting arm and the right side actuator rotate about their pivotal attachments to the longitudinal right side beam in a right side plane.

The invention claimed is: 
     
         1 . A watercraft lift apparatus for lifting and lowering a watercraft, comprising:
 a rearward lateral beam;   a forward lateral beam;   a longitudinal left side beam having a rearward end portion and a forward end portion, the rearward end portion being supported by the rearward lateral beam and the forward end portion being supported by the forward lateral beam;   a longitudinal right side beam having a rearward end portion and a forward end portion, the rearward end portion being supported by the rearward lateral beam and the forward end portion being supported by the forward lateral beam;   a left side rearward lifting arm having a lower end portion pivotally attached to the rearward end portion of the longitudinal left side beam and an upper end portion;   a right side rearward lifting arm having a lower end portion pivotally attached to the rearward end portion of the longitudinal right side beam and an upper end portion;   a left side forward lifting arm having a lower end portion pivotally attached to the forward end portion of the longitudinal left side beam and an upper end portion;   a right side forward lifting arm having a lower end portion pivotally attached to the forward end portion of the longitudinal right side beam and an upper end portion;   a left side watercraft support having a rearward end portion pivotally connected to the upper end portion of the left side rearward lifting arm, and a forward end portion pivotally connected to the upper end portion of the left side forward lifting arm;   a right side watercraft support having a rearward end portion pivotally connected to the upper end portion of the right side rearward lifting arm, and a forward end portion pivotally connected to the upper end portion of the right side forward lifting arm;   a left side actuator having a lower end portion pivotally attached to the rearward end portion of the longitudinal left side beam and an upper end portion pivotally attached to the left side rearward lifting arm; and   a right side actuator having a lower end portion pivotally attached to the rearward end portion of the longitudinal right side beam and an upper end portion pivotally attached to the right side rearward lifting arm;   wherein the left side rearward lifting arm is pivotally rotatable about the longitudinal left side beam in a first left side plane and the left side actuator is pivotally rotatable about the longitudinal left side beam in a second left side plane, the first and second left side planes being substantially coplanar, and the right side rearward lifting arm is pivotally rotatable about the longitudinal right side beam in a first right side plane and the right side actuator is pivotally rotatable about the longitudinal right side beam in a second right side plane, the first and second right side planes being substantially coplanar.   
     
     
         2 . The watercraft lift apparatus of  claim 1 , wherein the left side rearward lifting arm is pivotally rotatable about the longitudinal left side beam in a left side plane and the left side actuator is pivotally rotatable about the longitudinal left side beam in the left side plane, and the right side rearward lifting arm is pivotally rotatable about the longitudinal right side beam in a right side plane and the right side actuator is pivotally rotatable about the longitudinal right side beam in the right side plane. 
     
     
         3 . A watercraft lift apparatus for lifting and lowering a watercraft, comprising:
 a rearward lateral beam;   a forward lateral beam;   a longitudinal left side beam having a rearward end portion and a forward the forward end portion being supported by the forward lateral beam;   a longitudinal right side beam having a rearward end portion and a forward end portion, the rearward end portion being supported by the rearward lateral beam and the forward end portion being supported by the forward lateral beam, at least one of the longitudinal left and right side beams being adjustably, selectively laterally movable relative to the other of the longitudinal left and right side beams;   a left side rearward lifting arm having a lower end portion pivotally attached to the rearward end portion of the longitudinal left side beam and an upper end portion;   a right side rearward lifting arm having a lower end portion pivotally attached to the rearward end portion of the longitudinal right side beam and an upper end portion;   a left side forward lifting arm having a lower end portion pivotally attached to the forward end portion of the longitudinal left side beam and an upper end portion;   a right side forward lifting arm having a lower end portion pivotally attached to the forward end portion of the longitudinal right side beam and an upper end portion;   a left side watercraft support having a rearward end portion pivotally connected to the upper end portion of the left side rearward lifting arm, and a forward end portion pivotally connected to the upper end portion of the left side forward lifting arm;   a right side watercraft support having a rearward end portion pivotally connected to the upper end portion of the right side rearward lifting arm, and a forward end portion pivotally connected to the upper end portion of the right side forward lifting arm;   a left side actuator having a lower end portion pivotally attached to the rearward end portion of the longitudinal left side beam and an upper end portion pivotally attached to the left side rearward lifting arm; and   a right side actuator having a lower end portion pivotally attached to the rearward end portion of the longitudinal right side beam and an upper end portion pivotally attached to the right side rearward lifting arm;   wherein the left side rearward lifting arm is pivotally rotatable about the longitudinal left side beam in a first left side plane and the left side actuator is pivotally rotatable about the longitudinal left side beam in a second left side plane, the first and second left side planes being substantially coplanar, and the right side rearward lifting arm is pivotally rotatable about the longitudinal right side beam in a first right side plane and the right side actuator is pivotally rotatable about the longitudinal right side beam in a second right side plane, the first and second right side planes being substantially coplanar.   
     
     
         4 . The watercraft lift apparatus of  claim 3 , wherein the left side rearward lifting arm is pivotally rotatable about the longitudinal left side beam in a left side plane and the left side actuator is pivotally rotatable about the longitudinal left side beam in the left side plane, and the right side rearward lifting arm is pivotally rotatable about the longitudinal right side beam in a right side plane and the right side actuator is pivotally rotatable about the longitudinal right side beam in the right side plane. 
     
     
         5 . The watercraft lift apparatus of  claim 3 , further including a laterally extending rearward connector member extending between the left side rearward lifting arm and the right side rearward lifting arm to selectively lock the longitudinal left and right side beams in selected lateral positions. 
     
     
         6 . A watercraft lift apparatus for lifting and lowering a watercraft, comprising:
 a rearward lateral beam;   a forward lateral beam;   a longitudinal left side beam having a rearward end portion and a forward the forward end portion being supported by the forward lateral beam;   a longitudinal right side beam having a rearward end portion and a forward end portion, the rearward end portion being supported by the rearward lateral beam and the forward end portion being supported by the forward lateral beam;   a left side rearward lifting arm having a lower end portion pivotally attached to the rearward end portion of the longitudinal left side beam and an upper end portion;   a right side rearward lifting arm having a lower end portion pivotally attached to the rearward end portion of the longitudinal right side beam and an upper end portion;   a left side forward lifting arm having a lower end portion pivotally attached to the forward end portion of the longitudinal left side beam and an upper end portion;   a right side forward lifting arm having a lower end portion pivotally attached to the forward end portion of the longitudinal right side beam and an upper end portion;   a left side watercraft support having a rearward end portion pivotally connected to the upper end portion of the left side rearward lifting arm, and a forward end portion pivotally connected to the upper end portion of the left side forward lifting arm;   a right side watercraft support having a rearward end portion pivotally connected to the upper end portion of the right side rearward lifting arm, and a forward end portion pivotally connected to the upper end portion of the right side forward lifting arm;   a left side actuator having a lower end portion pivotally attached to the rearward end portion of the longitudinal left side beam and an upper end portion pivotally attached to the left side rearward lifting arm; and   a right side actuator having a lower end portion pivotally attached to the rearward end portion of the longitudinal right side beam and an upper end portion pivotally attached to the right side rearward lifting arm;   wherein the left side actuator is extendable to rotate the left side rearward lifting arm from a rotational position rearward of a top dead center position of the left side rearward lifting arm to a rotational end position forward of the top dead center position, and the right side actuator is extendable to rotate the right side rearward lifting arm from a rotational position rearward of a top dead center position of the right side rearward lifting arm to a rotational end position forward of the top dead center position.   
     
     
         7 . The watercraft lift apparatus of  claim 6 , wherein the pivot connection of the rearward end portion of the left side watercraft support to the upper end portion of the left side rearward lifting arm is forward of a center line of the left side rearward lifting arm at a location such that when the left side actuator rotates the left side rearward lifting arm to a rotational end position forward of the top dead center position, the left side rearward lifting arm is vertically oriented, and the pivot connection of the rearward end portion of the right side watercraft support to the upper end portion of the right side rearward lifting arm is forward of a center line of the right side rearward lifting arm at a position such that when the right side actuator rotates the right side rearward lifting arm to a rotational end position forward of the top dead center position, the right side rearward lifting arm is vertically oriented. 
     
     
         8 . The watercraft lift apparatus of  claim 6 , wherein the left side rearward lifting arm is pivotally rotatable about the longitudinal left side beam in a left side plane and the left side actuator is pivotally rotatable about their the longitudinal left side beam in the left side plane, and the right side rearward lifting arm is pivotally rotatable about the longitudinal right side beam in a right side plane and the right side actuator is pivotally rotatable about the longitudinal right side beam in the right side plane. 
     
     
         9 . The watercraft lift apparatus of  claim 6 , wherein the left side rearward lifting arm is pivotally rotatable about the longitudinal left side beam in a first left side plane and the left side actuator is pivotally rotatable about the longitudinal left side beam in a second left side plane, the first and second left side planes being substantially coplanar, and the right side rearward lifting arm is pivotally rotatable about the longitudinal right side beam in a first right side plane and the right side actuator is pivotally rotatable about the longitudinal right side beam in a second right side plane, the first and second right side planes being substantially coplanar. 
     
     
         10 . A watercraft lift apparatus for lifting and lowering a watercraft, comprising:
 a rearward lateral beam;   a forward lateral beam;   a longitudinal left side beam having a rearward end portion and a forward end portion, the rearward end portion being supported by the rearward lateral beam and the forward end portion being supported by the forward lateral beam;   a longitudinal right side beam having a rearward end portion and a forward end portion, the rearward end portion being supported by the rearward lateral beam and the forward end portion being supported by the forward lateral beam, at least one of the longitudinal left and right side beams being adjustably, selectively laterally movable relative to the other of the longitudinal left and right side beams;   a left side rearward lifting arm having a lower end portion pivotally attached to the rearward end portion of the longitudinal left side beam and an upper end portion;   a right side rearward lifting arm having a lower end portion pivotally attached to the rearward end portion of the longitudinal right side beam and an upper end portion;   a left side forward lifting arm having a lower end portion pivotally attached to the forward end portion of the longitudinal left side beam and an upper end portion;   a right side forward lifting arm having a lower end portion pivotally attached to the forward end portion of the longitudinal right side beam and an upper end portion;   a left side watercraft support having a rearward end portion pivotally connected to the upper end portion of the left side rearward lifting arm, and a forward end portion pivotally connected to the upper end portion of the left side forward lifting arm;   a right side watercraft support having a rearward end portion pivotally connected to the upper end portion of the right side rearward lifting arm, and a forward end portion pivotally connected to the upper end portion of the right side forward lifting arm;   a left side actuator having a lower end portion pivotally attached to the rearward end portion of the longitudinal left side beam and an upper end portion pivotally attached to the left side rearward lifting arm; and   a right side actuator having a lower end portion pivotally attached to the rearward end portion of the longitudinal right side beam and an upper end portion pivotally attached to the right side rearward lifting arm;   wherein the left side actuator is extendable to rotate the left side rearward lifting arm from a rotational position rearward of a top dead center position of the left side rearward lifting arm to a rotational end position forward of the top dead center position, and the right side actuator is extendable to rotate the right side rearward lifting arm from a rotational position rearward of a top dead center position of the right side rearward lifting arm to a rotational end position forward of the top dead center position.   
     
     
         11 . The watercraft lift apparatus of  claim 10 , wherein the pivot connection of the rearward end portion of the left side watercraft support to the upper end portion of the left side rearward lifting arm is forward of a center line of the left side rearward lifting arm at a location such that when the left side actuator rotates the left side rearward lifting arm to a rotational end position forward of the top dead center position, the left side rearward lifting arm is vertically oriented, and the pivot connection of the rearward end portion of the right side watercraft support to the upper end portion of the right side rearward lifting arm is forward of a center line of the right side rearward lifting arm at a position such that when the right side actuator rotates the right side rearward lifting arm to a rotational end position forward of the top dead center position, the right side rearward lifting arm is vertically oriented. 
     
     
         12 . The watercraft lift apparatus of  claim 10 , wherein the left side rearward lifting arm is pivotally rotatable about the longitudinal left side beam in a left side plane and the left side actuator is pivotally rotatable about their the longitudinal left side beam in the left side plane, and the right side rearward lifting arm is pivotally rotatable about the longitudinal right side beam in a right side plane and the right side actuator is pivotally rotatable about the longitudinal right side beam in the right side plane. 
     
     
         13 . The watercraft lift apparatus of  claim 10 , wherein the left side rearward lifting arm is pivotally rotatable about the longitudinal left side beam in a first left side plane and the left side actuator is pivotally rotatable about the longitudinal left side beam in a second left side plane, the first and second left side planes being substantially coplanar, and the right side rearward lifting arm is pivotally rotatable about the longitudinal right side beam in a first right side plane and the right side actuator is pivotally rotatable about the longitudinal right side beam in a second right side plane, the first and second right side planes being substantially coplanar. 
     
     
         14 . The watercraft lift apparatus of  claim 10 , further including a laterally extending rearward connector member extending between the left side rearward lifting arm and the right side rearward lifting arm to selectively lock the longitudinal left and right side beams in selected lateral positions. 
     
     
         15 . A watercraft lift apparatus for lifting and lowering a watercraft, comprising:
 a rearward lateral beam;   a forward lateral beam;   a longitudinal left side beam having a rearward end portion and a forward end portion, the rearward end portion being supported by the rearward lateral beam and the forward end portion being supported by the forward lateral beam;   a longitudinal right side beam having a rearward end portion and a forward the forward end portion being supported by the forward lateral beam;   a left side rearward lifting arm having a lower end portion pivotally attached to the rearward end portion of the longitudinal left side beam and an upper end portion;   a right side rearward lifting arm having a lower end portion pivotally attached to the rearward end portion of the longitudinal right side beam and an upper end portion;   a left side forward lifting arm having a lower end portion pivotally attached to the forward end portion of the longitudinal left side beam and an upper end portion;   a right side forward lifting arm having a lower end portion pivotally attached to the forward end portion of the longitudinal right side beam and an upper end portion;   a left side watercraft support having a rearward end portion pivotally connected to the upper end portion of the left side rearward lifting arm, and a forward end portion pivotally connected to the upper end portion of the left side forward lifting arm;   a right side watercraft support having a rearward end portion pivotally connected to the upper end portion of the right side rearward lifting arm, and a forward end portion pivotally connected to the upper end portion of the right side forward lifting arm;   a left side actuator having a lower end portion pivotally attached to the rearward end portion of the longitudinal left side beam and an upper end portion pivotally attached to the left side rearward lifting arm; and   a right side actuator having a lower end portion pivotally attached to the rearward end portion of the longitudinal right side beam and an upper end portion pivotally attached to the right side rearward lifting arm;   wherein the left side actuator is extendable to rotate the left side rearward lifting arm from a rotational position rearward of a top dead center position of the left side rearward lifting arm to a rotational end position forward of the top dead center position, and to rotate the left side forward lifting arm from a rotational position rearward of a top dead center position of the left side forward lifting arm to a rotational end position forward of the top dead center position; and the right side actuator is extendable to rotate the right side rearward lifting arm from a rotational position rearward of a top dead center position of the right side rearward lifting arm to a rotational end position forward of the top dead center position, and to rotate the right side forward lifting arm from a rotational position rearward of a top dead center position of the right side forward lifting arm to a rotational end position forward of the top dead center position.   
     
     
         16 . A watercraft lift apparatus for lifting and lowering a watercraft, comprising:
 a rearward lateral beam;   a forward lateral beam;   a longitudinal left side beam having a rearward end portion and a forward end portion, the rearward end portion being supported by the rearward lateral beam and the forward end portion being supported by the forward lateral beam;   a longitudinal right side beam having a rearward end portion and a forward end portion, the rearward end portion being supported by the rearward lateral beam and the forward end portion being supported by the forward lateral beam, at least one of the longitudinal left and right side beams being adjustably, selectively laterally movable relative to the other of the longitudinal left and right side beams;   a left side rearward lifting arm having a lower end portion pivotally attached to the rearward end portion of the longitudinal left side beam and an upper end portion;   a right side rearward lifting arm having a lower end portion pivotally attached to the rearward end portion of the longitudinal right side beam and an upper end portion;   a left side forward lifting arm having a lower end portion pivotally attached to the forward end portion of the longitudinal left side beam and an upper end portion;   a right side forward lifting arm having a lower end portion pivotally attached to the forward end portion of the longitudinal right side beam and an upper end portion;   a left side watercraft support having a rearward end portion pivotally connected to the upper end portion of the left side rearward lifting arm, and a forward end portion pivotally connected to the upper end portion of the left side forward lifting arm;   a right side watercraft support having a rearward end portion pivotally connected to the upper end portion of the right side rearward lifting arm, and a forward end portion pivotally connected to the upper end portion of the right side forward lifting arm;   a left side actuator having a lower end portion pivotally attached to the rearward end portion of the longitudinal left side beam and an upper end portion pivotally attached to the left side rearward lifting arm; and   a right side actuator having a lower end portion pivotally attached to the rearward end portion of the longitudinal right side beam and an upper end portion pivotally attached to the right side rearward lifting arm;   wherein the left side actuator is extendable to rotate the left side rearward lifting arm from a rotational position rearward of a top dead center position of the left side rearward lifting arm to a rotational end position forward of the top dead center position, and to rotate the left side forward lifting arm from a rotational position rearward of a top dead center position of the left side forward lifting arm to a rotational end position forward of the top dead center position; and the right side actuator is extendable to rotate the right side rearward lifting arm from a rotational position rearward of a top dead center position of the right side rearward lifting arm to a rotational end position forward of the top dead center position, and to rotate the right side forward lifting arm from a rotational position rearward of a top dead center position of the right side forward lifting arm to a rotational end position forward of the top dead center position.   
     
     
         17 . The watercraft lift apparatus of  claim 16 , further including a laterally extending rearward connector member extending between the left side rearward lifting arm and the right side rearward lifting arm to selectively lock the longitudinal left and right side beams in selected lateral positions. 
     
     
         18 . A watercraft lift apparatus for lifting and lowering a watercraft, comprising:
 a rearward lateral beam;   a forward lateral beam;   a longitudinal left side beam having a rearward end portion and a forward end portion, the rearward end portion being supported by the rearward lateral beam and the forward end portion being supported by the forward lateral beam;   a longitudinal right side beam having a rearward end portion and a forward end portion, the rearward end portion being supported by the rearward lateral beam and the forward end portion being supported by the forward lateral beam;   a left side rearward lifting arm having a lower end portion pivotally attached to the rearward end portion of the longitudinal left side beam and an upper end portion, the left side rearward lifting arm being rotatable about the longitudinal left side beam in a first left side plane;   a right side rearward lifting arm having a lower end portion pivotally attached to the rearward end portion of the longitudinal right side beam and an upper end portion, the right side rearward lifting arm being rotatable about the longitudinal right side beam in a first right side plane;   a left side forward lifting arm having a lower end portion pivotally attached to the forward end portion of the longitudinal left side beam and an upper end portion;   a right side forward lifting arm having a lower end portion pivotally attached to the forward end portion of the longitudinal right side beam and an upper end portion;   a left side watercraft support having a rearward end portion pivotally connected to the upper end portion of the left side rearward lifting arm, and a forward end portion pivotally connected to the upper end portion of the left side forward lifting arm;   a right side watercraft support having a rearward end portion pivotally connected to the upper end portion of the right side rearward lifting arm, and a forward end portion pivotally connected to the upper end portion of the right side forward lifting arm;   a left side actuator having a lower end portion pivotally attached to the rearward end portion of the longitudinal left side beam and an upper end portion pivotally attached to the left side rearward lifting arm, the left side actuator being rotatable about the longitudinal left side beam in a second left side plane, the first and second left side planes being substantially coplanar; and   a right side actuator having a lower end portion pivotally attached to the rearward end portion of the longitudinal right side beam and an upper end portion pivotally attached to the right side rearward lifting arm, the right side actuator being rotatable about the longitudinal right side beam in a second right side plane, the first and second right side planes being substantially coplanar;   wherein the longitudinal left side beam comprises a left side forward beam portion and a left side rearward support member having a forward end portion and a rearward end portion, the left side rearward support member having an upright, laterally outward side plate and an upright, laterally inward side plate, in spaced apart relation, with the lower end portion of the left side rearward lifting arm pivotally attached to the rearward end portion of the longitudinal left side beam in position between the outward and inward side plates of the left side rearward support member and the lower end portion of the left side actuator pivotally attached to the rearward end portion of the longitudinal left side beam in position between the outward and inward side plates of the left side rearward support member, and the longitudinal right side beam comprises a right side forward beam portion and a right side rearward support member having a forward end portion and a rearward end portion, the right side rearward support member having an upright, laterally outward side plate and an upright, laterally inward side plate, in spaced apart relation, with the lower end portion of the right side rearward lifting arm pivotally attached to the rearward end portion of the longitudinal right side beam in position between the outward and inward side plates of the right side rearward support member and the lower end portion of the right side actuator pivotally attached to the rearward end portion of the longitudinal right side beam in position between the outward and inward side plates of the right side rearward support member.   
     
     
         19 . The watercraft lift apparatus of  claim 18 , further including a left side floor member extending between the laterally outward side plate and the laterally inward side plate of the left side rearward support member, the laterally outward side plate and the laterally inward side plate of the left side rearward support member being spaced apart to permit passage of the left side actuator therebetween and allow the left side actuator to engage and be supported by the left side floor member during pivotal attachment of the lower end portion of the left side actuator to the rearward end portion of the longitudinal left side beam, and a right side floor member extending between the laterally outward side plate and the laterally inward side plate of the right side rearward support member, the laterally outward side plate and the laterally inward side plate of the right side rearward support member being spaced apart to permit passage of the right side actuator therebetween and allow the right side actuator to engage and be supported by the right side floor member during pivotal attachment of the lower end portion of the right side actuator to the rearward end portion of the longitudinal right side beam. 
     
     
         20 . A watercraft lift apparatus for lifting and lowering a watercraft, comprising:
 a rearward lateral beam;   a forward lateral beam;   a longitudinal first side beam having a rearward end portion and a forward the forward end portion being supported by the forward lateral beam;   a longitudinal second side beam, spaced apart from the first side beam, and having a rearward end portion and a forward end portion, the rearward end portion being supported by the rearward lateral beam and the forward end portion being supported by the forward lateral beam;   a first side rearward lifting arm having a lower end portion pivotally attached to the rearward end portion of the longitudinal first side beam and an upper end portion;   a second side rearward lifting arm having a lower end portion pivotally attached to the rearward end portion of the longitudinal second side beam and an upper end portion;   a first side forward lifting arm having a lower end portion pivotally attached to the forward end portion of the longitudinal first side beam and an upper end portion;   a second side forward lifting arm having a lower end portion pivotally attached to the forward end portion of the longitudinal second side beam and an upper end portion;   a first side watercraft support having a rearward end portion pivotally connected to the upper end portion of the first side rearward lifting arm, and a forward end portion pivotally connected to the upper end portion of the first side forward lifting arm;   a second side watercraft support having a rearward end portion pivotally connected to the upper end portion of the second side rearward lifting arm, and a forward end portion pivotally connected to the upper end portion of the second side forward lifting arm; and   at least one actuator having a lower end portion pivotally attached to the rearward end portion of the longitudinal first side beam and an upper end portion pivotally attached to the first side rearward lifting arm;   wherein the first side rearward lifting arm is pivotally rotatable about the longitudinal first side beam in a first side plane and the first side actuator is pivotally rotatable about the longitudinal first side beam in a plane substantially coplanar with the first side plane.   
     
     
         21 . The watercraft lift apparatus of  claim 20 , wherein at least one of the longitudinal first and second side beams are selectively laterally movable relative to the other of the longitudinal first and second side beams between a plurality of lateral positions, and selectively lockable in a selected one of the plurality of lateral positions.