TODAY’S PATENT – HYDRAULIC DRIVE PUMP APPARATUS

The protective Hydraulic Pump Apparatus was invented by L. F. Perry (Olney, TX) on the 2^nd of October, 1984, bearing patent number US4474002A.

The present invention relates to the present invention relates to improvements in construction of a hydraulically driven pump jack wherein a mechanical servo linkage is connected directly to a variable volume hydraulic pump thereby to maintain pump pressure reciprocation, and therefore pump head movement, at proper speed. The pump is pivotally affixed on a stanchion and base assembly and is reciprocally driven by forward and rearward hydraulic cylinders which are pressurized in alternate sequence to oscillate the walking beam about a horizontal axis. A feedback control linkage is connected from the walking beam pivot point to a torque motor driven rotor which, in turn, is mechanically connected to a control lever of a variable volume pump as driven by a prime mover.