Lifting device

Abstract

A lifting device for platforms carrying a load is disclosed. A winch or piston is engaged with two vertical arms connected to two horizontal arms configured for attaching to a load carrying assembly such that exerting an upward force on the two vertical arms causes the horizontal arms to pivot upward to lift the load carrying assembly which enables transporting the platform and the load on it to another location. The lifting device is configured to quickly attach to and detach from the load carrying platform and for maintaining a level position during transportation. The horizontal arms are configured for retracting and expending which enables the tilting of the load carrying assembly backward or forward as needed for improved transportation stability and load discharge.

I claim: 
     
         1 . A lifting device adapted for releasable connection to a powered vehicle equipped with a winch via a receiver tube on the vehicle, comprising a unitary integrated combination of:
 (a) a support structure that includes a vertically extending stanchion with a pulley rotatably mounted proximate an apex of the stanchion,   (b) a horizontal set of pivot arms including at least,
 (1) a first horizontal arm pivotally attached at a first end to the support structure at a first pivot point, 
 (2) a second horizontal arm pivotally attached at a first end to the support structure at a second pivot point wherein the first and second pivot points are disposed in substantially the same first horizontal plane, and 
 (3) a third horizontal arm pivotally attached at a first end to the support structure at a third pivot point wherein the third pivot point is horizontally disposed above the first horizontal plane, 
   (c) a lift member having (i) a first appendage pivotally attached to the first horizontal arm at a fourth pivot point spaced from the first pivot point, (ii) a second appendage pivotally attached to the second horizontal arm at a fifth pivot point spaced from the second pivot point, and (iii) an interconnect member vertically positioned below the pulley and above the third horizontal arm and interconnecting the first and second appendages; and   (d) a coupler tube mateable with the receiver tube,   (e) wherein the third horizontal arm is not attached to the lift member nor either of the first and second horizontal arms.   
     
     
         2 . The lifting device of  claim 1  wherein the interconnect member is operable for engagement by a distal end of a cable supported upon the pulley wherein (i) tensioned pulling of the cable away from the interconnect member is operable for effecting a lifting of the first and second vertical arms and an upward pivoting of the first and second horizontal arms about the first and second pivot points against the force of gravity respectively, and (ii) releasing a length of the tensioned cable effects a gravitational lowering of the first and second vertical arms and downward pivoting of the first and second horizontal arms about the first and second pivot points. 
     
     
         3 . The lifting device of  claim 1  wherein the first and second horizontal arms are horizontally extendable and retractable. 
     
     
         4 . The lifting device of  claim 1  wherein the third horizontal arm is horizontally extendable and retractable. 
     
     
         5 . The lifting device of  claim 1  wherein the first and second appendages are vertically extendable and retractable. 
     
     
         6 . The lifting device of  claim 4  further comprising a pair of powered actuators selected from a hydraulic cylinder, a pneumatic cylinder, and an electric linear actuator, each operable for selectively extending and retracting one of the first and second horizontal arms. 
     
     
         7 . The lifting device of  claim 5  further comprising a powered actuator selected from a hydraulic cylinder, a pneumatic cylinder, and an electric linear actuator, operable for selectively extending and retracting the third horizontal arm. 
     
     
         8 . The lifting device of  claim 1  further comprising a coupling member attached to a second end of each of the first, second and third horizontal arms. 
     
     
         9 . The lifting device of  claim 8  wherein the first, second and third horizontal arms are pivotally pinned to the coupling member at sixth, seventh and eighth pivot points respectively, wherein the sixth and seventh pivot points are disposed in substantially the same second horizontal plane and the eighth pivot point is horizontally disposed above the second horizontal plane. 
     
     
         10 . The lifting device of  claim 9  further comprising a load carrying assembly releasably attached to the coupling member, the load carrying assembly having a horizontal platform, a vertical support member attached to the horizontal platform and a containment member attached to the vertical support member, the coupling member being configured for tightly wedging in the containment member. 
     
     
         11 . A lifting device adapted for releasable connection to a powered vehicle equipped with a winch via a receiver tube on the vehicle, comprising a unitary integrated combination of:
 (a) a support structure that includes a stanchion projecting in a first transverse direction with a pulley rotatably mounted proximate an apex of the stanchion;   (b) a pair of laterally spaced lower arms each (i) pivotally attached at a first end to the support structure at first pivot points for pivoting about a first lateral axis, (ii) extending in a first longitudinal direction from the support structure, and (iii) disposed in substantially the same horizontal plane;   (c) an upper arm pivotally attached at a first end to the support structure at a second pivot point for pivoting about a second lateral axis wherein the second lateral axis is transversely spaced in the first transverse direction from the first lateral axis;   (d) a laterally extending yoke (i) conjoining the pair of lower arms, (ii) transversely positioned in a second transverse direction opposite the first transverse direction from the pully, and (iii) operable for effecting joint pivoting of the pair of lower arms about the first pivot points when the yoke is transversely displaced without concomitant pivoting of the at least one upper arm about the second pivot point; and   (e) a coupler tube adapted for coupling with the receiver tube and extending in a second longitudinal direction opposite the first longitudinal direction from the support structure.   
     
     
         12 . The lifting device of  claim 11  wherein the at least one arm is extendable and retractable. 
     
     
         13 . The lifting device of  claim 11  further comprising a load carrying assembly, the load carrying assembly including at least a vertical support and a platform, with the load carrying assembly attached to a second end of each of the pair of lower arms and a second end of the upper arm. 
     
     
         14 . A lifting device adapted for releasable connection to a powered vehicle equipped with a winch via a trailer hitch receiver on the vehicle, comprising a unitary integrated combination of:
 (a) a support structure that includes a stanchion projecting in a first transverse direction with a pulley rotatably mounted proximate an apex of the stanchion;   (b) a pair of laterally spaced lower arms each (i) pivotally attached at a first end to the support structure at first pivot points for pivoting about a first lateral axis, (ii) extending in a first longitudinal direction from the support structure, and (iii) disposed in substantially the same horizontal plane;   (c) a means for stabilizing a load carrying assembly when the load carrying assembly is pivotally attached to a second end of each of the pair of lower arms, the stabilizing means (i) pivotally attached at a first end to the support structure for pivoting about a second lateral axis wherein the second lateral axis is transversely spaced in the first transverse direction from the first lateral axis, and (ii) configured and arranged at a second end for pivotable attachment to the load carrying assembly;   (d) a laterally extending yoke (i) conjoining the pair of lower arms, (ii) transversely positioned in a second transverse direction opposite the first transverse direction from the pully, and (iii) operable for effecting joint pivoting of the pair of lower arms about the first pivot points when the yoke is transversely displaced; and   (e) a trailer hitch coupler tube extending in a second longitudinal direction opposite the first longitudinal direction from the support structure.