Patent ID: 7251980
Filing Date: 2007-08-07
Classification: B25B

Abstract:
1. A hydraulically powered and operated tool comprising: a body, a trigger mounted for movement between first and second positions with respect to the body, a pair of jaws mounted with respect to the body so that at least one of the jaws is movable between an opened jaw position and a closed jaw position so as to engage work between the jaws, jaw actuating structure associated with the at least one jaw to cause movement of the at least one jaw, a ram assembly having first and second ends and including a valve actuating structure and a ram piston, the valve actuating structure having first and second ends, the first end of the ram assembly being coupled with the jaw actuating structure, a first check valve associated with the ram piston, a second check valve associated with the ram piston and with the second end of the valve actuating structure, a lever associated with the first end of the valve actuating structure and with the ram assembly, surfaces defining a cavity in the body, the cavity having hydraulic fluid therein, the ram piston being disposed in the cavity separating the cavity to define a ram chamber and a reservoir chamber, spring structure engaging a second end of the ram assembly, and a pump assembly operatively associated with the trigger to be movable between a first position, when the trigger is in the first position, and a second position when the trigger is in a second position, the pump assembly having a pump chamber in selective fluid communication with the ram chamber and the reservoir chamber, whereby, 1) when the lever is moved to an activated position, the valve actuating structure unseats the second check valve permitting fluid to flow from the ram chamber to the reservoir chamber, with the ram assembly displacing fluid as it compresses the spring structure and causes the jaw actuating structure to move the at least one jaw so work can be placed between the jaws, and 2) when the lever is released from the activated position, the second check valve is seated and the spring structure drives the ram assembly to an extended position causing the jaw actuating structure to move the at least one jaw so the jaws engage the work, with the first check valve being unseated by fluid pressure in the reservoir chamber, permitting fluid to flow from the reservoir chamber to the ram chamber, and 3) when the trigger is moved from the first position to the second position, the pump assembly moves to the second position thereof and forces fluid from the pump chamber into the ram chamber causing the first check valve to seat, with the forced fluid being exerted on the ram piston, increasing force of the jaws on the work.