TODAY’S PATENT – HYDRAULIC DRIVE PUMP APPARATUS
The protective Hydraulic Pump Apparatus was invented by L. F. Perry (Olney, TX) on the 2nd 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.