Abstract: A linear compressor has a hollow piston with crown and sidewall. The piston reciprocates in a cylinder. A piston rod connects the piston to a spring. A connection between the piston rod and the piston transmits axial forces directly to the piston crown. The connection transmits lateral forces to the piston at an axial location away from the piston crown. The connection allows rotational flexibility between the piston and the piston rod transverse to and uniformly around the piston reciprocation axis. Other improvements in or relating to linear compressors are disclosed.

Abstract: A micropump has two chambers separated by an actuator for causing fluid to flow in the chambers. Each chamber is equipped with a ball that acts as a valve for allowing flow in a desired direction. The balls are heavier than the fluid being pumped, and reside at an interface between the chambers and passages feeding fluid into the chambers and provide a tight seal between the chambers and passages feeding the chambers when fluid pressure forces the fluid back toward the feeding passages.

Abstract: A modular check valve system includes a plurality of modular check valves all having a common stack height. The common stack height allows for a substitution of individual valve modules. The substitution capability provides an economical way to increase or decrease the flow area through the valve assembly by varying size of the ball within the check valve. Thus, the specifications of the pump can be relatively easily changed, either at the factory or in the field. The modular construction also permits the use of different types of valves (e.g. flap valves, poppets, duckbills, or trihedrals) without having to change any additional pump fittings. In one embodiment, the modular valve system of the present invention is described in conjunction with a pump having at least one fluid communication fitting adapted to receive a check valve assembly.

Abstract: Inlet valve assembly for a paint prayer and the like includes an adjustable inlet valve stop movable toward and away from an inlet valve seat to reduce or increase the amount of free movement of the inlet valve for obtaining optimum volumetric efficiency by reducing the back flow through the inlet valve. The adjustable stop includes a rebound spring and a holder therefor which is threadedly mounted, whereby rotation of the holder in opposite directions varies the initial clearance space between the spring and inlet valve when the inlet valve is closed. The holder has a non-circular opening in the center to enable the user to insert a turning wrench or the like therein to turn the holder to the desired adjusted position. Access to the adjustable stop for turning the holder may be obtained by inserting the tool through an outlet valve opening in the sprayer pump upon removal of an outlet valve assembly therefrom. A conical lock spring may be used to frictionally lock the holder in the desired adjusted position.

Abstract: Submergible pumping apparatus for use in an oil or other well comprises, in a self-contained downhole unit, a double-acting reciprocating positive displacement pump for pumping well fluid, a reservoir containing power fluid for operating the double-acting pump, a rotary motor-driven positive displacement pump for supplying power fluid under pressure from the reservoir to operate the reciprocating pump, and a control valve for properly directing high pressure power fluid from the rotary pump to the reciprocating pump and from the reciprocating pump back to the reservoir so as to provide stroke reversal of the reciprocating pump.

Abstract: A double acting hydraulically actuated pump and engine valve assembly for use downhole in a borehole for producing fossil fuel therefrom. High pressure hydraulic power fluid is forced downhole to a special control valve means located between opposed engine pistons. The valve means causes the power fluid to apply an alternating force to confronting faces of the pistons, while the opposed faces of the spaced apart pistons serve to pump and force production fluid to flow from a production zone, upward to the surface. The pump assembly can be used in combination with existing bottom hole assemblies, fixed or free type, already installed downhole in the wellbore.