Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
152 words
An apparatus for hoisting a load comprising: a hoisting hook, a frame, at least two gripping arms mounted on the frame and each having a gripping jaw for gripping a load between them, means for mounting at least one said gripping arm on the frame for movement relative to the other gripping arm, means connecting the hoisting hook to said gripping arms for causing movement of said gripping jaws towards each other during hoisting movement of said hoisting hook comprising: a first hydraulic piston-cylinder assembly mounted on the frame and having resilient means for urging the piston thereof to a retracted position, a second hydraulic piston-cylinder assembly mounted on the frame and comprising means for actuating the movably mounted gripping arm, means connecting said hoisting hook and said first assembly for extending said first assembly upon hoisting movement of said hoisting hook, and hydraulic means for connecting said first and second assemblies.
Claim 2
Independent Claim
152 words
An apparatus for hoisting a load comprising: a hoisting hook, a frame, at least two gripping arms mounted on the frame and each having a gripping jaw for gripping a load between them, means for mounting at least one said gripping arm on the frame for movement relative to the other gripping arm, means connecting the hoisting hook to said gripping arms for causing movement of said gripping jaws towards each other during hoisting movement of said hoisting hook comprising: a first hydraulic piston-cylinder assembly mounted on the frame and having resilient means for urging the piston thereof to a retracted position, a second hydraulic piston-cylinder assembly mounted on the frame and comprising means for actuating the movably mounted gripping arm, means connecting said hoisting hook and said first assembly for extending said first assembly upon hoisting movement of said hoisting hook, and hydraulic means for connecting said first and second assemblies.
Claim 3
Dependent Claim
46 words
The apparatus of claim 1, and further comprising a third hydraulic piston-cylinder assembly mounted on the frame and having resilient means for urging the piston thereof to a retracted position, said hydraulic means comprising means for connecting said third assembly to said first and second assemblies.
Claim 4
Dependent Claim
33 words
The apparatus of claim 2, said hydraulic means comprising a three-way valve for connecting said second assembly to either said first or said third assemblies, or for closing communication to said second assembly.
Claim 5
Dependent Claim
24 words
The apparatus of claim 3, said hydraulic means further comprising a non-return valve permitting flow from said third assembly to said three way valve.
Claim 6
Dependent Claim
40 words
The apparatus of claim 3, said hydraulic means further comprising a by-pass line in parallel with said three way valve communicating said first and third assemblies, and a non-return valve in said by-pass line permitting flow from said first assembly.
Claim 7
Dependent Claim
55 words
The apparatus of claim 1, wherein each said gripping arm has a vertically depending portion, a pivoting arm horizontally pivotally connected at the lower end thereof, and the gripping jaw horizontally pivotally connected to the pivoting arm, at a level above the pivotal connection of the pivoting arm and the gripping arm during hoisting movement.
Claim 8
Dependent Claim
22 words
The apparatus of claim 6, and stop means for each said jaw to prevent excessive movement thereof relative to the pivoting arm.