Grapple

Claim 2

A grapple comprising a pair of relatively movable arms having load-gripping portions which are movable toward and away from each other to grip and release a load, a generally upright fluid-operated ram, having a cylinder and a piston including a rod, operatively connected to said arms, operable on extension to move said load-gripping portions toward one another, said ram being disposed whereby it carries, axially and in tension, at least a portion of the weight of any load gripped by said load-gripping portions, check valve means operatively interposed between the opposite ends of said cylinder, operable, with said load-gripping portions gripping a load, to accommodate extension of the ram while preventing contraction of the ram, and rotator means operatively interposed between said cylinder and piston operable to produce relative rotation therebetween about said axis.

Claim 3

A grapple comprising a pair of relatively movable arms having load-gripping portions which are movable relatively toward and away from each other to grip and release a load, a generally upright fluid-operated ram having a cylinder and a piston including a rod, means mounting said arms on said ram whereby changes in different directions in the rams effective length cause said load-gripping portions to move toward and away from one another, and whereby the weight of any load gripped by the load-gripping portions is carried through said arms and said ram, and tends to change the effective length of the ram in a direction tending to tighten the grip of the load-gripping portions on the load, means defining first and second fluid passages communicating with opposite ends of said cylinder for supplying fluid to and exhausting it from said ends, with the supply of fluid through said first fluid passage to one of said ends producing a change in the ram''s effective length that moves said load-gripping portions toward one another, and with the supply of fluid through said second fluid passage to the other end producing the reverse operation, means defining a third fluid passage interconnecting said opposite ends of said cylinder, and check valve means in said third fluid passage which accommodates fluid flow therethrough from said other end to said one end of said cylinder and blocks such flow in the reverse direction.

Claim 4

A grapple comprising a pair of relatively movable arms having load-gripping portions which are movable relatively toward and away from each other to grip and release a load, a generally upright fluid-operated ram having a cylinder and a piston including a rod, means mounting said arms on said ram whereby changes in different directions in the rams effective length cause said load-gripping portions to move toward and away from one another, and whereby the weight of any load gripped by the load-gripping portions is carried through said arms and said ram, and tends to change the effective length of the ram in a direction tending to tighten the grip of the load-gripping portions on the load, means defining first and second fluid passages communicating with opposite ends of said cylinder for supplying fluid to and exhausting it from said ends, with the supply of fluid through said first fluid passage to one of said ends producing a change in the ram''s effective length that moves said load-gripping portions toward one another, and with the supply of fluid through said second fluid passage to the other end producing the reverse operation, means defining a third fluid passage interconnecting said opposite ends of said cylinder, and check valve means in said third fluid passage which accommodates fluid flow therethrough from said other end to said one end of said cylinder and blocks such flow in the reverse direction.

Claim 5

The grapple of claim 2, wherein said first, second and third fluid passages are formed within said piston.

Claim 6

The grapple of claim 2, wherein, said arms are pivoted intermediate their ends to said cylinder, and there is means operatively interconnecting the upper end portions of said arms and said rod.

Claim 7

The grapple of claim 2, wherein said cylinder and piston are relatively rotatable about the longitudinal axis of the ram, and which further comprises rotator means operatively interposed between said cylinder and said piston operable to produce relative rotation therebetween about said axis.

Claim 8

A grapple comprising a pair of relatively movable arms having load-gripping portions which are movable toward and away from each other to grip and release a load, a generally upright, fluid-operated ram having a cylinder at the base thereof and a piston including a piston rod extending upwardly from said cylinder, said cylinder and piston rod being relatively Rotatable about the axis of the piston rod, means mounting said arms on said ram whereby with elongation said ram causes said load-gripping portions to come together and with the weight of any load carried by said arms tending to elongate said ram, said means including pivot means pivotally mounting the arms intermediate their ends on said cylinder and means operatively connecting upper ends of said arms to said rod, first and second fluid passages extending through said rod opening to the interior of said cylinder for the supply and exhaust of pressure fluid to opposite ends of said ram, and rotator means operatively interposed between said cylinder and said rod operable to produce relative rotation of the cylinder with respect to said rod about said axis.

Claim 9

A grapple comprising a pair of relatively movable arms having load-gripping portions which are movable toward and away from each other to grip and release a load, a generally upright, fluid-operated ram having a cylinder at the base thereof and a piston including a piston rod extending upwardly from said cylinder, said cylinder and piston rod being relatively Rotatable about the axis of the piston rod, means mounting said arms on said ram whereby with elongation said ram causes said load-gripping portions to come together and with the weight of any load carried by said arms tending to elongate said ram, said means including pivot means pivotally mounting the arms intermediate their ends on said cylinder and means operatively connecting upper ends of said arms to said rod, first and second fluid passages extending through said rod opening to the interior of said cylinder for the supply and exhaust of pressure fluid to opposite ends of said ram, and rotator means operatively interposed between said cylinder and said rod operable to produce relative rotation of the cylinder with respect to said rod about said axis.