Abstract: A vibration reducing structure of pneumatic hammer includes a handle having a concave room with a bottom wall and an air inlet channel communicating with the concave room. A control valve is disposed in the air inlet channel. A movable inner tube shell is accommodated in an outer tube shell coupled with the concave room and extends a rear bucket portion into the concave room. A movable hammer member, an air inlet valve for activating the hammer member and a hole communicating the air inlet channel to the air inlet valve are disposed in the inner tube shell. An air room is formed between the bottom wall and an end wall of the inner tube shell. A communicating channel communicates the air inlet channel to the air room for air with high pressure entering the air room.

Abstract: A pneumatic cushion for a wheel chair and the like is disclosed which comprises an air plenum box, a plurality of air openings in the air plenum box, and a plurality of air channels communicating with an air supply. The air channels communicate with the air openings to deflate and inflate individual air sacks carried over the air openings. The air sacks are unattached so that they act individually. An air distribution manifold includes a rotating blocking member to periodically block air distribution to the air sacks allowing them to deflate. The air sacks are constructed from a fabric having a low air permeability. The blocked air sacks thus allow air to escape through the sacks for deflation which cools the portion of the occupant seated on the cushion while allowing temporary pressure relief during deflation. The air sack inflation system is open so that, in addition, pressure may be relieved by a backward flow of air through the system.

Abstract: A hydraulic pump jack is disclosed which utilizes a hydraulic cylinder to provide pumping force to an oil well sucker rod. The hydraulic pump jack may be directly mounted on an oil well casing either above or below ground. A tubular piston rod which may be connected to a sucker rod in telescoping relation for transmitting vertical force without side loading is also disclosed. Apparatus for mounting the piston rod within a cylindrical housing is described. The use of a counter weight system for balancing the pump load is also described.

Abstract: The invention relates to an oil well jack having a walking beam mounted on a frame for motion in a vertical plane; and a plurality of hydraulic actuators connected to move the walking beam. The amplitude of movement of the beam as well as the frequency of the stroke are adjustable through regulation and control of the hydraulic system.

Abstract: This invention relates to an improved pump jack characterized by a hollow piston rod which telescopes down over the sucker rod to which it is clamped for reciprocating motion. The cylinder, in turn, is fastened in fixed position directly to the upper exposed end of the well casing. As fluid is introduced into the lower end of the cylinder it raises the piston into engagement with a pushrod housed in the upper cylinder head that lifts switch-actuating means associated therewith into a position operative to actuate a switch located adjacent thereto thereby causing the latter to change state and actuate a multi-function solenoid valve so as to cut off fluid flow to the cylinder. As gravity lowers the sucker rod and piston exhausting the hydraulic fluid therebeneath, an adjustable stop engages the pushrod from above so as to return it together with the switch-actuating means associated therewith to their original positions thereby resetting the switch to complete the operating cycle.

Abstract: This hydromechanical automatic reversing device for linear hydraulic rams operates by inertia and comprises a support block mounted to the ram body, a pendular arm pivoted at one end to the spool of the reversing valve associated with the ram, and, at the opposite end, to an eccentric pin trunnioned in the support block. A shaft rigid with and parallel to the ram piston rod is provided with a pair of adjustable stops adapted to engage by turns the eccentric pin of the pendular arm for shifting the spool of the reversing valve, for reversing the direction of movement of the ram.