Hydraulic boat lift

Abstract

The present invention relates to a hydraulically operated boat lift capable of raising a boat vertically from the water in a linear fashion using a single hydraulic ram having its piston integral to the stationary frame and its cylinder integral to the non-stationary lifting portion of the apparatus. The ram raises a supporting crossbars under the front and rear of the boat. This single ram eliminates the critical problem of power distribution, binding, and levelness during raising and lowering. This simplified linear lift enables greater lift distances and also reduces and limits the extreme stresses that non-linear radius swing arm mechanisms experience thereby enabling construction with lightweight metals or plastics.

1 . A hydraulic boat lift for linearly raising and storing a boat above water using a single hydraulic ram having its piston integral to the stationary frame and its cylinder integral to the non-stationary lifting portion of the apparatus, or, having its cylinder integral to the stationary frame and its piston integral to the non-stationary lifting portion of the apparatus. comprising: 
 a lightweight PVC plastic or metal pvc four post pipe frame, for supporting the overall apparatus and the raised boat;    a lightweight PVC plastic or metal front of boat supporting crossbar, for supporting the front of the boat, concentrically retained to said PVC four post pipe frame;    a lightweight PVC plastic or metal rear of boat supporting crossbar, for supporting the rear of the boat, concentrically retained to said PVC four post pipe frame;    a hydraulic ram cylinder, for retaining the hydraulic pressure during operation;    a hydraulic ram piston, for transferring the hydraulic pressure from the ram to the load, rigidly fused to said PVC four post pipe frame;    a soft, flexible, and compressive hydraulic ram rubber seal, for retaining the hydraulic pressure and yet allowing he piston to move up and down within the cylinder, concentrically positioned to said Hydraulic ram piston, and concentrically positioned to said Hydraulic ram cylinder;    a flexible hydraulic ram water entry hose, for supplying pressurized water to the hydraulic ram, hydraulically coupled to said Hydraulic ram cylinder;    a flexible hydraulic ram water exit hose, for removing water or air from the hydraulic ram, hydraulically coupled to said Hydraulic ram cylinder;    a lift point for cables one, two, and three, for providing a strong tie point to attach the three load cables to the hydraulic ram, rigidly connected to said Hydraulic ram cylinder;    a load lift area for cable one, for attaching cable one to the front crossbar, internally connected to said Lift point for cables one, two, and three, and vertically attached to said Front of boat supporting crossbar;    a load lift area for cable two, for attaching cable two to the rear crossbar, internally connected to said Lift point for cables one, two, and three, and vertically attached to said Rear of boat supporting crossbar; and    a load lift area for cable three, for attaching cable three to the rear crossbar, internally connected to said Lift point for cables one, two, and three, and vertically attached to said Rear of boat supporting crossbar.    
   
   
       2 . A hydraulic boat lift for linearly raising and storing a boat above water using a single hydraulic ram having its piston integral to the stationary frame and its cylinder integral to the non-stationary lifting portion of the apparatus, or, having its cylinder integral to the stationary frame and its piston integral to the non-stationary lifting portion of the apparatus. comprising: 
 a lightweight PVC plastic or metal pvc four post pipe frame, for supporting the overall apparatus and the raised boat;    a lightweight PVC plastic or metal front of boat supporting crossbar, for supporting the front of the boat, concentrically retained to said PVC four post pipe frame;    a lightweight PVC plastic or metal rear of boat supporting crossbar, for supporting the rear of the boat, concentrically retained to said PVC four post pipe frame;    a hydraulic ram cylinder, for retaining the hydraulic pressure during operation;    a hydraulic ram piston, for transferring the hydraulic pressure from the ram to the load, rigidly fused to said PVC four post pipe frame;    a soft, flexible, and compressive hydraulic ram rubber seal, for retaining the hydraulic pressure and yet allowing the piston to move up and down within the cylinder, concentrically positioned to said Hydraulic ram piston, and concentrically positioned to said Hydraulic ram cylinder;    a flexible hydraulic ram water entry hose, for supplying pressurized water to the hydraulic ram, hydraulically coupled to said Hydraulic ram cylinder;    a flexible hydraulic ram water exit hose, for removing water or air from the hydraulic ram, hydraulically coupled to said Hydraulic ram cylinder;    a lift point for cables one, two, and three, for providing a strong tie point to attach the three load cables to the hydraulic ram, rigidly connected to said Hydraulic ram cylinder;    an entry point to pulleys for cables one, two, and three, for routing the three load cables to the simple pulleys within the tubular frame;    a load lift area for cable one, for attaching cable one to the front crossbar, internally connected to said Lift point for cables one, two, and three, and vertically attached to said Front of boat supporting crossbar;    a load lift area for cable two, for attaching cable two to the rear crossbar, internally connected to said Lift point for cables one, two, and three, and vertically attached to said Rear of boat supporting crossbar; and    a load lift area for cable three, for attaching cable three to the rear crossbar, internally connected to said Lift point for cables one, two, and three, and vertically attached to said Rear of boat supporting crossbar.