Combination crane and jack unit

Claim 2

A combination crane and jack unit including a base having a plurality of floor-engaging wheels, a mast extending upwardly from said base, a parallelogram structure including a pair of parallel arms pivotally mounted at one of their ends and one above the other to the upper end of said mast, a generally horizontal support pivotally connected to the opposite ends of the arms, means for raising and lowering said arms to raise and lower said support, with said arms having a lower position extending at an angle of approximately 45* to the mast to place said support just above said base, a first means on said support for holding a supporting chain or the like for a depending article when the unit is to function as a crane, second means on said support for holding a fixture to engage under an article when the unit is to function as a jack, said parallel arms lying one above the other, and shield means depending from the upper one of said arms and overlapping the lower one of said arms to prevent positioning of an operator''s fingers between said arms.

Claim 3

A combination crane and jack unit as defined in claim 1 wherein said first means on said support includes a hook and said second means includes a plate holding a socket, and means for adjustably tipping said plate and for providing play therEof relative to the support whereby an article may be aligned while carried by the unit.

Claim 4

A combination crane and jack unit as defined in claim 1 wherein said means for raising and lowering said arms includes a generally vertically extending rod and cylinder connected between the mast and one of said arms, a hand pump operatively connected to said cylinder and having a release valve associated therewith, and means pivotally mounting said hand pump at an end thereof to one side of the mast whereby the pump may extend outwardly generally parallel to the plane of the parallel arms when an operator is using the unit as a jack and extend normal to the plane of the parallel arms when the unit is used as a crane.

Claim 5

A combination crane and jack unit as defined in claim 1 wherein said pivot mounting for one of the parallel arms to the mast is defined by a rod fixed to the mast and having exposed ends to serve as handles for guiding movement of the unit along the floor.

Claim 6

A combination crane and jack unit comprising a base with a plurality of floor-engaging wheels to render the unit portable, a vertical mast extending upwardly from one end of the base, a parallelogram structure including a pair of parallel arms each having an upper end pivotally connected one above the other to the upper end of the mast whereby said arms may move between a lowermost position at an acute angle to the mast and a raised position at an obtuse angle to the base, a generally horizontal support pivotally connected to the lower ends of said parallel arms and positionable immediately above saId base when said parallel arms are in their lowermost position, means on said support for holding a fixture to engage under an article when the unit is to function as a jack including a plate movably mounted on said support, means on said support for engaging a chain or the like when the unit is to function as a crane, a fluid piston and cylinder operatively connected to one of said arms for causing movement and positioning thereof, a hydraulic hand pump connected to said piston and cylinder, and means mounting said hand pump for movement to different positions whereby the hand pump may be positioned adjacent an operator in both crane and jack uses of the unit.

Claim 7

A combination crane and jack unit comprising a base with a plurality of floor-engaging wheels to render the unit portable, a vertical mast extending upwardly from one end of the base, a parallelogram structure including a pair of parallel arms each having an upper end pivotally connected one above the other to the upper end of the mast whereby said arms may move between a lowermost position at an acute angle to the mast and a raised position at an obtuse angle to the base, a generally horizontal support pivotally connected to the lower ends of said parallel arms and positionable immediately above saId base when said parallel arms are in their lowermost position, means on said support for holding a fixture to engage under an article when the unit is to function as a jack including a plate movably mounted on said support, means on said support for engaging a chain or the like when the unit is to function as a crane, a fluid piston and cylinder operatively connected to one of said arms for causing movement and positioning thereof, a hydraulic hand pump connected to said piston and cylinder, and means mounting said hand pump for movement to different positions whereby the hand pump may be positioned adjacent an operator in both crane and jack uses of the unit.

Claim 8

A combination crane and jack unit as defined in claim 5 wherein said plate is pivotally mounted on said support, and a pair of adjustable bolts engageable with saId plate one at each side of the pivot and adjustable to either engage and hold the plate in a pivoted position or backed off a small amount to permit a slight pivotal play of said plate relative to said support.

Claim 9

A combination crane and jack unit as defined in claim 5 wherein said parallel arms lying one above the other, and shield means depending from the upper one of said arms and overlapping the lower one of said arms to prevent positioning of an operator''s fingers between said arms.