Self-Leveling Hydraulic Motor Driven Boat Lift

Abstract

A self-leveling hydraulic motor driven boat lift includes proximal and distal support structures disposed on respective longitudinal sides of a lift platform. A pair of proximal and distal hydraulic motors are operably mounted to the proximal and distal support structures respectively. Each hydraulic motor is operably connected to a respective winder mechanism. A lift cable assembly is operably interconnected between the winder mechanism and a respective side of the lift platform. Each hydraulic motor is reversible and communicably connected to a respective hydraulic pump, which transmits hydraulic fluid between the pump and the connected motor for operating the motor and selectively driving the connected winder mechanism and cable assembly to selectively raise and lower the lift platform. A respective restrictor valve interconnects each hydraulic pump and that pump's corresponding hydraulic motor. An angle inclination sensor detects the lateral inclination of the lift platform and transmits a corresponding signal to a controller, which selectively directs at least one restrictor valve to adjust the flow rate of hydraulic fluid transmitted between at least one pump and its respective hydraulic motor such that the lift platform is laterally leveled.

1 . A hydraulic motor driven boat lift for selectively lifting a boat out of and lowering the boat into a body of water, said boat lift comprising:
 spaced apart proximal and distal support structures disposed on respective longitudinal sides of a lift platform, which lift platform is adapted for supporting the boat thereon;   proximal and distal hydraulic motors respectively mounted to the proximal and distal support structures, said proximal and distal hydraulic motors being operably connected to respective winder mechanisms;   a plurality of lift cable assemblies, each said lift cable assembly being operably interconnected between a respective winder mechanism and said lift platform; and   a plurality of hydraulic pumps, each said hydraulic pump being communicably connected to a respective one of said proximal and distal hydraulic motors for transmitting hydraulic fluid between said pump and said respective one of said proximal and distal hydraulic motors such that said hydraulic pumps operate said proximal and distal hydraulic motors and drive said respective winder mechanisms and operably interconnected cable assemblies to selectively lift and lower said lift platform.   
     
     
         2 . A self-leveling hydraulic motor driven boat lift for selectively lifting a boat out of and lowering the boat into a body of water, the boat lift comprising:
 spaced apart proximal and distal support structures disposed on respective proximal and distal longitudinal sides of a lift platform, which lift platform is adapted for supporting the boat thereon;   proximal and distal hydraulic motors respectively mounted to the proximal and distal support structures, said proximal and distal hydraulic motors being operably connected to respective winder mechanisms;   a plurality of lift cable assemblies, each said lift cable assembly being operably interconnected between a respective winder mechanism and said lift platform;   a plurality of hydraulic pumps, each said hydraulic pump being communicably connected to a respective one of said proximal and distal hydraulic motors for transmitting hydraulic fluid between said pump and said respective one of said proximal and distal hydraulic motors such that said hydraulic pumps operate said proximal and distal hydraulic motors and drive said respective winder mechanisms and operably interconnected cable assemblies to selectively lift and lower said lift platform;   a sensor for measuring lateral inclination between said proximal and distal longitudinal sides of said lift platform;   a plurality of hydraulic valves, each said hydraulic valve communicably interconnecting a respective hydraulic pump and said hydraulic motor connected to said pump; and   a controller responsive to signals form said sensor for selectively opening and closing at least one said valve a selected amount for adjusting the transmission of hydraulic fluid between at least one said hydraulic pump and a respective said hydraulic motor communicably connected to said hydraulic pump, whereby an operating speed of one or more of said proximal and distal hydraulic motors is adjusted to lateral level said lift platform.   
     
     
         3 . The boat lift of  claim 2  in which said angle measuring sensor includes an Inclinometer mounted on said lift platform. 
     
     
         4 . The boat lift of  claim 2  in which said valve includes a restrictor valve that is directed by said controller to constrict and reduce hydraulic fluid flow between said hydraulic pump and said connected hydraulic motor when a corresponding one of said proximal and distal longitudinal sides of said lift platform is laterally inclined at least two degrees relative to an opposite longitudinal side of said lift platform. 
     
     
         5 . A self-leveling system for a hydraulic motor driven boat lift, which boat lift includes spaced apart proximal and distal support structures disposed on respective proximal and distal longitudinal sides of a lift platform, which lift platform is adapted for supporting the boat thereon, the boat lift further including proximal and distal hydraulic motors respectively mounted to the proximal and distal support structures, the proximal and distal hydraulic motors being operably connected to respective winder mechanisms, the boat lift further having a plurality of lift cable assemblies, each lift cable assembly being operably interconnected between a respective winder mechanism and the lift platform, and the boat lift further having a plurality of hydraulic pumps, each hydraulic pump being communicably connected to a respective one of the proximal and distal hydraulic motors for transmitting hydraulic fluid between the pump and a respective one of said proximal and distal hydraulic motors such that the hydraulic pumps operate the proximal and distal hydraulic motors and drive the respective winder mechanisms and operably interconnected cable assemblies to selectively lift and lower the lift platform, the self-leveling system comprising:
 a sensor for measuring lateral inclination between said proximal and distal longitudinal sides of said lift platform; 
 a plurality of hydraulic valves, each said hydraulic valve communicably interconnecting a respective hydraulic pump and said hydraulic motor connected to said pump; and 
 a controller responsive to signals form said sensor for selectively opening and closing at least one said valve a selected amount for adjusting the transmission of hydraulic fluid between at least one one said hydraulic pump and a respective said hydraulic motor communicably connected to said hydraulic pump, whereby an operating speed of one or more of said proximal and distal hydraulic motors is adjusted to lateral level said lift platform. 
 
     
     
         6 . The self-leveling system of  claim 5  in which said angle measuring sensor includes an Inclinometer mounted on said lift platform. 
     
     
         7 . The self-leveling system of  claim 5  in which said valve includes a restrictor valve that is directed by said controller to constrict and reduce hydraulic fluid flow between said hydraulic pump and said connected hydraulic motor when a corresponding one of said proximal and distal longitudinal sides of said lift platform is laterally inclined at least two degrees relative to an opposite longitudinal side of said lift platform. 
     
     
         8 . The boat lift of  claim 2  in which said sensor includes an inclinometer. 
     
     
         9 . The self-leveling system of  claim 5  in which said sensor includes an inclinometer.