Onboard Boat Lift Structure And Method

Abstract

An onboard lift for a pontoon boat has four legs pivotally attached underneath a platform and extending between the outer pontoons. Each leg terminates in a slide foot. The pivot pin for each leg is canted, such as at 13° relative to horizontal. In a stowed position, the legs and slide feet extend forward in the direction of travel and tight to the platform. When used to lift the boat, actuation of the legs pushes the slide feet outward due to the cant of the pivot axis, such that the slide feet are positioned underneath the outer pontoons when the boat is fully raised. The control allows separate powering of the front legs from the rear legs, and further has a display so the user can see the amount of extension of each set of legs.

1 . An onboard boat lift comprising:
 a plurality of support structures including at least a right support structure and a left support structure, wherein each support structure comprises:
 a mount attachable to an underside of a boat at a defined horizontal and at a defined direction of travel; 
 a pivot supported by the mount, the pivot defining a pivot axis which is canted relative to the defined horizontal and/or defined direction of travel; 
 a leg pivoting about the pivot axis between a generally horizontal stowed position and a relatively upright support position, the leg extending from the pivot to a slide foot; and 
 a power linkage for moving the leg between the generally horizontal stowed position and the relatively upright support position; 
 wherein the slide foot has a wider stance relative to a centerline of the boat when in the relatively upright support position than when in the generally horizontal stowed position. 
   
   
   
       2 . The onboard boat lift of  claim 1 , wherein the slide foot is movable relative to the leg via a foot pivot. 
   
   
       3 . The onboard boat lift of  claim 2 , wherein the foot gravitationally extends in line with the leg until a toe of the leg contacts the ground. 
   
   
       4 . The onboard boat lift of  claim 2 , wherein the foot is spring biased toward an extended position. 
   
   
       5 . The onboard boat lift of  claim 1 , comprising a front right support structure, a rear right support structure, a front left support structure and a rear left support structure, wherein the front support structures are independently powered relative to the rear support structures. 
   
   
       6 . The onboard boat lift of  claim 5 , wherein there is no mechanical coupling between legs or between feet other than the connection above the pivot pin through the boat. 
   
   
       7 . The onboard boat lift of  claim 6 , wherein the power linkage for each support structure comprises a hydraulic cylinder, and further comprising a separate hydraulic pump for each hydraulic cylinder. 
   
   
       8 . The onboard boat lift of  claim 5 , wherein the power linkage for each support structure comprises a hydraulic cylinder, wherein each leg comprises an opening for receiving the hydraulic cylinder when the leg is in the generally horizontal stowed position. 
   
   
       9 . The onboard boat lift of  claim 5 , wherein the power linkage for each support structure comprises a hydraulic cylinder, and wherein, when the leg is in the generally horizontal stowed position, the hydraulic cylinder is positioned beside the leg. 
   
   
       10 . The onboard boat lift of  claim 1 , wherein the support structures comprise a front support structure and a rear support structure, and further comprising:
 a first display mechanism indicating position of the front support structure; and   a second display mechanism indication position of the rear support structure.   
   
   
       11 . The onboard boat lift of  claim 10 , wherein the each display mechanism comprises at least two LEDs, and wherein the first and second display mechanisms are both provided on a control which allows control of the front support structure separate from control of the rear support structure. 
   
   
       12 . The onboard boat lift of  claim 10 , further comprising:
 a sensor for determining position of the front support structure; and   a sensor for determining position of the rear support structure.   
   
   
       13 . The onboard boat lift of  claim 1 , wherein the pivot axis is canted from 5 to 30° relative to the defined horizontal. 
   
   
       14 . The onboard boat lift of  claim 1 , wherein the mount of the right support structure and the mount of the left support structure are affixed to the underside of a deck of a pontoon boat, wherein the right and left support structures in the stowed position are each positioned within 26 inches of a centerline of the pontoon boat, and where the slide feet in the relatively upright support position are separated by 52 inches or more. 
   
   
       15 . A method of lifting a boat using an onboard boat lift, the method comprising:
 attaching a plurality of support structures including at least a right support structure and a left support structure to an underside of a boat, wherein each support structure comprises a leg extending to a slide foot;   lowering the slide foot of the right support structure and the slide foot of the left support structure until the slide feet make contact with the ground; and   after the slide feet contact the ground, widening the stance of the slide feet by pushing the contact of the slide feet outward while raising the boat.   
   
   
       16 . The method of  claim 15 , wherein the lowering and widening of the slide feet occur by pivoting the legs about canted pivot axes relative to horizontal. 
   
   
       17 . The method of  claim 15 , wherein the slide feet are tubular with ramped outward sides. 
   
   
       18 . An onboard boat lift comprising:
 a plurality of support structures including at least a front support structure and a rear support structure, each support structure being attachable to an underside of a boat;   a front power linkage for moving the front support structure between a generally horizontal stowed position and a relatively upright support position;   a rear power linkage for moving the rear support structure between a generally horizontal stowed position and a relatively upright support position;   a first display mechanism indicating position of the front support structure; and   a second display mechanism indication position of the rear support structure.   
   
   
       19 . The onboard boat lift of  claim 18 , wherein the each display mechanism comprises at least two LEDs, and wherein the first and second display mechanisms are both provided on a control which allows control of the front support structure separate from control of the rear support structure. 
   
   
       20 . The onboard boat lift of  claim 18 , further comprising:
 a sensor for determining position of the front support structure; and   a sensor for determining position of the rear support structure.