Abstract: A piston cylinder is formed inside a ram and is fitted with a piston attached to a stationary hollow piston rod, creating a upper piston chamber for receiving pressurized hydraulic fluid, which causes the ram to rise as the volume of the upper piston chamber is expanded due to the hydraulic pressure and increasing volume of hydraulic fluid. When the ram reaches predetermined desired height, hydraulic pressure is released by opening a directional valve, allowing the ram to drop. A lower piston chamber is sealed and filled with gas. A moveable shuttle member that reciprocates up and down inside a hollow piston rod in response to the changing volume of the lower piston cylinder, facilitating the evacuation of hydraulic fluid from the upper piston chamber. An alternative embodiment uses a single fluid and has no shuttle member.

Abstract: Small wells cut into the upper interior surface of the head plate collect oil that is sprayed forcefully upward by the rotating gears and eccentric weights and channels that oil through a throughbore across the width of the head plate, routing the oil into a hose or bored channel at each end of the throughbore, with oil in the hoses or bored channels flowing through bearing access ports into the bearings on the rotating eccentric weights. A separate oil collection well, throughbore and hose arrangement is provided for each of the eccentric weight and gear sets and may be provided for pinion gears connected to hydraulic drive motors.

Abstract: A vibratory hammer for use in driving a work piece such as a pile, pipe, caisson or plate into the earth includes a support frame 10 adapted to be suspended from a crane or the like, and a vibrator assembly 12 that is suspended from the frame. The vibrator assembly includes at least one pair of laterally spaced, parallel rotary shafts 40 that are rotatable in opposite directions to one another, and a weight 46 is supported on each shaft. Each weight is shiftable radially relative to the corresponding shaft between a balanced position in which the center of mass of the weight is collinear with the longitudinal axis of the shaft, and an eccentric position in which the center of mass of the weight is offset radially from the longitudinal axis of the shaft. Preferably, a fluid-actuated piston-and-cylinder assembly 54 is supported between each weight and the corresponding shaft for selectively carrying out the shifting movement of the weights. However, other types of shifting mechanisms could also be employed.