Abstract: The walking beam of a pumping unit is suspended from an oscillating hanger arm. It is pivoted at one end to a crank and to a link, the other end of the latter being pivoted to a fixed position shaft. At the other end of the walking beam is a point which follows a virtually rectilinear path between a bottom dead center position and a top dead center position. This point may therefore be coupled through a rigid member to an oil well pump sucker rod line.

Abstract: A pair of pumps which are joined by a flexible connection passing over spaced rotatable devices positioned for rotation in a substantially vertical plane. The rotatable devices are driven alternately in clockwise and counterclockwise directions whereby the lifting of one pump occurs as the other pump is lowered. To facilitate the pumping operation, a counterweight is operatively associated with the flexible connection intermediate the pair of rotatable devices.

Abstract: A pair of pumps which are joined by a flexible connection passing over a rotatable device positioned for rotation in a substantially vertical plane. The rotatable means is driven alternately in clockwise and counterclockwise directions whereby the lifting of one pump occurs as the other pump is lowered.

Abstract: The invention concerns pumping apparatus for wells, such as oil wells, coising a framework constituted by a tubular mast, a driving plant, a linkage connectable to a force pump immersed in the well, a flexible connection between the said plant and the said linkage for transmitting and imparting a reciprocating lifting and lowering movement to the rod linkage to actuate the force pump, the tubular mast including, for the connection to the rod linkage, guide pulleys with horizontal axes of rotation, and a lockable arm for carrying the guide pulleys and mounted for pivoting on the tubular mast about a vertical axis.

Abstract: A system is provided for maintaining a permanent reciprocatory movement of a mechanical arrangement, particularly a pump unit. A main driving wheel is coupled to the mechanical arrangement and fastened on the shaft of a hydraulic motor which is supplied by a variable delivery pump provided with control means. The control means is coupled to the wheel by a drive mechanism which comprises a rocking lever coupled to the control means and a cam carrier wheel rotationally fixed to the wheel. As the mechanical arrangement moves in one direction, the rotation of the driving wheel causes the cam wheel to change the position of the rocking lever thus permitting the control means to direct the flow of fluid from the variable delivery pump to the hydraulic motor to reverse the direction of travel of the mechanical arrangement.