Mounting for a screw jack
OwnerJerry W. Pittmaninventor
Life of this patent
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Abstract
A screw jack incorporating a quick retract mechanism to permit movement of the jack into engagement with the ground such that only limited rotation of the screw is necessary for elevating the tongue of a trailer for disengaging a coupler on the trailer from a trailer hitch. The screw-type jack incorporates an improved handle which is rotatable about a horizontal axis between an active position for rotating the screw about a vehicle axis and a stowed position wherein the handle engages the body of the jack to prevent rotation of the screw. A support for the screw jack which incorporates improved versatility such that it can be interchangeably used on other jacks and can be used in applications involving uneven and/or non-level surface conditions.
Claims18
A jack comprising:
- tubular mounting means having a longitudinally extending passage;
- an outer tube slidably disposed in said passage, said outer tube having an outer wall surface and an inner wall surface, said inner wall surface extending around the periphery of a cylindrical opening;
- an inner tube slidably disposed in said cylindrical opening, said inner tube having an outer wall surface in which a longitudinally extending guide way is formed and an inner wall surface having a longitudinally extending rib formed thereon;
- said outer tube being deformed to provide spaced projections on the inner wall surface of said outer tube and spaced recesses in the outer wall surfaces of said outer tube, said projections on said inner wall surface of said outer tube extending into said guide way formed in the outer wall surface of said inner tube preventing rotation of said inner tube relative to said outer tube;
- locking means movably secured to said tubular mounting means, said locking means being movable to selectively engage spaced recesses in the outer wall surface of said outer tube to limit movement of said outer tube through said passage in said mounting means;
- and elevating means secured between said outer tube and said inner tube for moving said inner tube relative to said outer tube.
A top wind screw jack comprising:
- a hollow tubular jack body having a longitudinal axis, first and second ends, inner and outer wall surfaces, and a longitudinally extending bore, said inner and outer wall surfaces and said bore being concentric to said longitudinal axis of said jack body;
- threaded screw means extending through said bore, said screw means having a first end projecting beyond said first end of said hollow tubular jack body;
- threaded ram means in said bore, said threaded ram means engaging said threaded screw means;
- crank means;
- means movably securing said crank means to said first end of said threaded screw means such that said crank means is movable between:
- (a) an extended position wherein said crank means is movable to rotate said screw means to move said ram means and
- (b) a retracted position wherein said crank means frictionally engages said outer wall of said tubular jack body to prevent rotation of said threaded screw means.
Dependencies are inferred from the claim text.