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A boatlift leg and frame structure utilizing a ball screw lifting mechanism driven by a reversible electric motor to raise and loser a boat support carriage. The raising and lowering operation of the ball screw mechanism is controlled by electronic circuitry that includes wired and remote direction

A boatlift leg and frame structure utilizing a ball screw lifting mechanism driven by a reversible electric motor to raise and loser a boat support carriage. The raising and lowering operation of the ball screw mechanism is controlled by electronic circuitry that includes wired and remote direction selection; lifting logic with conflict detection and direction reversal delay; lighting control logic; motor power control; and overload detection logic to detect lifting overload and disable power to the motor power control. A drive train mechanism converts high-speed low torque rotation of the motor drive shaft to low-speed high-torque rotation drive of the ball screw. A boatlift leveling mechanism associated with one or more legs of the boatlift includes a ground engaging footpad, an extendible leg, a height adjusting screw mechanism and a height adjusting actuator with mating bevel gears coupled to the height adjusting screw for allowing adjustment through the side of a boatlift leg.

대표청구항 ▼

The invention claimed is: 1. A powered boatlift comprising: a plurality of support legs; a boat lifting structure moveably mounted to said plurality of support legs; a cable assembly having a connecting end and a lifting end connected in cooperation with said boat lifting structure for causing said

The invention claimed is: 1. A powered boatlift comprising: a plurality of support legs; a boat lifting structure moveably mounted to said plurality of support legs; a cable assembly having a connecting end and a lifting end connected in cooperation with said boat lifting structure for causing said boat lifting structure to be raised or lowered; an electric drive unit having a drive shaft capable of rotating in a first direction in response to a first input signal or rotating in a second direction in response to a second input signal; a drive coupling structure coupled to said drive shaft; a ball screw assembly having a first portion coupled to said coupling structure and a second portion coupled to said connecting end; wherein said first portion of said ball screw assembly includes an elongated ball screw having a driving end coupled to said coupling structure wherein said coupling structure rotatably supports said driving end; and said second portion of said ball screw assembly includes a ball nut associated with said elongated ball screw, said ball screw having a cable connection coupled to said connecting end of said cable assembly; and wherein said drive coupling structure includes: a drive train assembly having an input drive coupled to said drive shaft for receiving high-speed low-torque input from said electric drive unit; a torque conversion mechanism coupled to said input drive for converting said high-speed low-torque input to a low-speed high-torque output at an output drive; and an output coupling intermediate said output drive of said torque conversion mechanism and said driving end of said elongated ball screw. 2. A powered boatlift as in claim 1, wherein said torque conversion mechanism includes: a speed-reducing structure driven by said input drive and having an output drive shaft; and a torque-increasing structure driven by said output drive shaft and coupled to said output coupling. 3. A powered boatlift as in claim 2, wherein said speed-reducing structure is a pulley assembly and is belt driven; and said torque-increasing structure is a gear assembly and is chain driven. 4. A powered boatlift as in claim 1, wherein said torque conversion mechanism includes: a first drive pulley having a first predetermined diameter coupled to said input drive; a pulley drive shaft having a driven end and a driving end; a second drive pulley having a second predetermined diameter larger than said first predetermined diameter, said second drive pulley rotatably supported by said pulley drive shaft at said driven end; a belt intercoupling said first drive pulley and said second drive pulley; a first drive gear having a third predetermined diameter mounted on said driving end of said pulley drive shaft; a gear drive shaft having a driven end and a driving end; a second drive gear having a fourth predetermined diameter larger than said third predetermined diameter, said first drive gear rotatably supported by said gear drive shaft at said driven end; a chain intercoupling said first drive gear and said second drive gear; and an output coupling intercoupling said driving end of said gear drive shaft and said driving end of said elongated ball screw. 5. A boatlift structure as in claim 4, wherein a first ratio of said first predetermined diameter to said second predetermined diameter establishes a predetermined speed reduction at said pulley drive shaft; and a second ratio of said third predetermined diameter to said fourth predetermined diameter establishes a predetermined torque increase at said output coupling. 6. A powered boatlift structure as in claim 1, and further including a lift movement limiting mechanism comprising: a lift measuring mechanism capable of determining the extent of upward and downward movement of said lifting structure; a first disabling structure coupled to said lift measuring mechanism to disable power to said electric drive unit when said lift measuring mechanism determines that a predetermined permissible upward movement of said lifting structure has been achieved; and a second disabling structure coupled to said lift measuring mechanism to disable power to said electric drive unit when said lift measuring mechanism determines that a predetermined permissible downward movement of said lifting structure has been achieved. 7. A powered boatlift structure as in claim 1, wherein said electric drive unit includes: a reversible electric motor; and a control circuit coupled to said electric motor to selectively control the direction of rotation or said electric motor in response to said first signal and said second signal. 8. A powered boatlift structure as in claim 7, wherein said control circuit includes: a load limit detecting circuit to provide a disabling signal to disable application of power to said reversible electric motor when electrical current flow to said reversible electric motor is detected to be in excess of a predetermined permissible level. 9. A power boatlift structure as in claim 8, and further including: a manual reset actuator coupled to said control circuit to enable operation of said control circuit after a said disabling signal has been provided by said load circuit detecting circuit. 10. A powered boatlift structure as in claim 7, wherein said control circuit includes: a first manually operable switch to provide said first signal to apply electrical circuit to said reversible electric motor to cause rotation in a first direction; and a second manually operable switch to provide said second signal to apply electrical current to said reversible electric motor to cause rotation in a second direction. 11. A powered boatlift structure as in claim 7, wherein said control circuit includes a receiver circuit responsive to a first remote signal to provide said first signal to apply electrical current to said reversible electric motor to cause rotation in a first direction; and responsive to a second remote signal to provide said second signal to apply electrical current to said reversible electric motor to cause rotation in a second direction. 12. A powered boatlift structure as in claim 7, wherein said control circuit includes: a first switch to provide said first signal; a second switch to provide said second signal; a receiver responsive to a first remote signal to protect said first signal and responsive to a second remote signal to provide said second signal. 13. A powered boatlift structure as in claim 7, wherein said control circuit includes: a reversal delay circuit to delay application of said first signal or said second signal by a predetermined delay time interval to delay reversal of rotation of said reversible electric motor. 14. A powered boatlift structure as in claim 1, and further including: a brake mechanism for holding said boat lifting structure in place when said electric device unit does not have electrical current applied. 15. A powered boatlift structure as in claim 1, wherein one or more of said plurality of support legs includes a boatlift leveling mechanism. 16. A powered boatlift structure as in claim 15, wherein said boatlift leveling mechanism includes: a footpad; a height adjustment mechanism for use in colinear alignment with an associated boatlift leg and having a first end portion coupled to said footpad and having a second end portion; and a height adjustment actuator accessible along an associated one of said plurality of boatlift legs and coupled to said second end portion at a predetermined angle with respect to said alignment, whereby the relationship of said footpad with respect to an associated one of said plurality boatlift legs can be controlled. 17. A boatlift leveling mechanism as in claim 16, wherein said height adjustment mechanism includes: a leg extension member having said first end portion and said second end portion; a height adjusting screw mechanism in cooperation with said leg extension member, said height adjusting screw mechanism including an elongated screw having an activating end and having a screw nut coupled to said leg extension member; and an affixed bevel gear coupled to said activating end, whereby said leg extension member is caused to move with respect to an associated boatlift leg when said height adjusting screw mechanism is activated by rotation of said affixed bevel gear. 18. A boatlift leveling mechanism as in claim 17, wherein said height adjustment mechanism further includes: a height adjustment actuator having a mating bevel gear in cooperation with said affixed bevel gear and having a height adjustment actuator for causing said mating bevel gear to impart rotational movement to said affixed bevel gear, whereby said screw is caused to rotate and move said screw nut long the length of said screw. 19. For use with a boatlift having at least one boatlift leg, a boatlift leveling mechanism comprising: a footpad; a height adjustment mechanism for use in colinear alignment with an associated boatlift leg and having a first end portion coupled to said footpad and having a second end portion; and a height adjustment actuator accessible along an associated boatlift leg and coupled to said second end portion at a predetermined angle with respect to said alignment, wherein said height adjustment mechanism includes: a leg extension member having said first end portion and said second end portion; a height adjusting screw mechanism in cooperation with said leg extension member, said height adjusting screw mechanism including an elongated screw having an activating end and having a screw nut coupled to said leg extension member; and an affixed bevel gear coupled to said activating end, whereby said leg extension member is caused to move with respect to an associated boatlift leg when said screw mechanism is activated by rotation of said affixed bevel gear. 20. A boatlift leveling mechanism as in claim 19 wherein said leg extension member further comprises: an elongate structure having a predetermined length longer than the length of said screw mechanism, said elongated structure capable of slidable engagement with at least a portion of an associated boatlift leg, and said elongated structure having a predetermined tubular cross-section, wherein said screw mechanism is positioned within at least a portion of the tubular opening. 21. A boatlift leveling mechanism as in claim 19, wherein said height adjustment mechanism further includes: a height adjustment actuator having a mating bevel gear in cooperation with said affixed bevel gear and having a height adjustment actuator for causing said mating bevel gear to impart rotational movement to said affixed bevel gear, whereby said screw is caused to rotate and move said screw nut long the length of said screw. 22. A boatlift leveling mechanism as in claim 21, wherein said height adjustment actuator further includes: a shaped head that is accessible along a boatlift leg; and a shaft having a first shaft end coupled to said shaped head and a second shaft end coupled to said mating bevel gear, whereby said leg extension member is caused to be moved in a first direction when said mating bevel gear is rotated in a first direction and in a second direction when said mating bevel gear is rotated in a second direction be selective activation of rotation of said shaped head in a first rotation direction or in a second rotation direction, respectively. 23. A boatlift leveling mechanism as in claim 22, wherein said shaft is oriented substantially perpendicular to said elongated screw. 24. A boatlift leveling mechanism as in claim 22 and further including: a bracket having a first structure to hold said mating bevel gear in a rotatable cooperative relation with said affixed bevel gear and having a second structure for coupling said bracket to a boatlift leg.