Abstract: A pumping method, principally for oil, allows the sucker rod to fall under gravity for the first part of the downward stroke, then decelerates the sucker rod to a slow rate of descent, so creating a pause in the sucker rod's motion. Shock-absorbing means are provided to eliminate the impulsive loadings imposed upon the sucker rod at either extremity of its motion in conventional pumping methods. Hydraulically and mechanically-driven apparatus is disclosed for carrying out the method.

Abstract: A pumping method, principally for oil, allows the sucker rod to fall under gravity for the first part of the downward stroke, then decelerates the sucker rod to a slow rate of descent, so creating a pause in the sucker rod's motion. Shock-absorbing means are provided to eliminate the impulsive loadings imposed upon the sucker rod at either extremity of its motion in conventional pumping methods. Hydraulically and mechanically-driven apparatus is disclosed for carrying out the method.

Abstract: A pump jack of the type comprising a rocker arm pivotably mounted intermediate its ends on a support member, said rocker arm being divided by said pivot mounting into a sucker-rod limb and a drive limb wherein the improvement comprises a pneumatic motor pivotably attached to the drive support member and further pivotably attached to the mounting base of the pump jack to provide the power to reciprocate the pump jack. The working fluid of said pneumatic motor being natural gas which is available from the well casing of the well without any interference with the flow of the oil in the oil tube of the well thereby making use of an energy source available at any oil well without having to provide gasoline to drive a rotating type gasoline engine or electricity to drive an electric motor usually of the rotating variety.

Abstract: A pumping method, principally for oil, allows the sucker rod to fall under gravity for the first part of the downward stroke, then decelerates the sucker rod to a slow rate of descent, so creating a pause in the sucker rod's motion. Shock-absorbing means are provided to eliminate the impulsive loadings imposed upon the sucker rod at either extremity of its motion in conventional pumping methods. Hydraulically and mechanically-driven apparatus is disclosed for carrying out the method.

Abstract: A pump jack comprises a rocker arm one end of which is fixed to the upper end of a sucker rod. The other limb of the rocker arm has rigidly affixed thereto a downwardly-extending drive support member and a large driven pinion is eccentrically and rotatably mounted at the lower end of this drive support member. The driven pinion is engaged by a chain, which also passes around a driving pinion fixed to the base of the pump jack. This drive arrangement reduces the acceleration and shock loadings imposed upon the sucker rod at the beginning of its upstroke and reduces the size and cost of the gearbox necessary to connect a prime mover to the driving pinion.

Abstract: A pumping method, principally for oil, allows the sucker rod to fall under gravity for the first part of the downward stroke, then decelerates the sucker rod to a slow rate of descent, so creating a pause in the sucker rod's motion. Shock-absorbing means are provided to eliminate the impulsive loadings imposed upon the sucker rod at either extremity of its motion in conventional pumping methods. Hydraulically and mechanically-driven apparatus is disclosed for carrying out the method.

Abstract: A pumping method, principally for oil, allows the sucker rod to fall under gravity for the first part of the downward stroke, then decelerates the sucker rod to a slow rate of descent, so creating a pause in the sucker rod's motion. Shock-absorbing means are provided to eliminate the impulsive loadings imposed upon the sucker rod at either extremity of its motion in conventional pumping methods. Hydraulically and mechanically-driven apparatus is disclosed for carrying out the method.

Abstract: Apparatus for pumping a liquid from a well comprises a drive unit on the surface, a well-bottom pump unit, two supply lines interconnecting the drive unit and the pump unit and a liquid discharge line extending from the pump unit to the surface for discharge of liquid. The pump unit has a drive piston which is reciprocated within a drive cylinder by applying pressure alternately by means of a changeover valve to the two supply lines. The drive piston drives a double acting driven piston which pumps oil from a well. The changeover valve is controlled by a logic unit which receives signals from sensors measuring the pressure and/or flow rate in a return line.

Abstract: Apparatus for pumping oil from a well includes a hydraulic pump for reciprocating a sucker rod string. A counterweight is connected to the sucker rod string by a chain strung over sprockets within a compact framework. The hydraulic pump applies a shock absorbing back pressure to the sucker rod.

Abstract: A cylindrical heat shield provided with circumferentially spaced apart axially extending drive members adapted to engage the wheel and a plurality of brake rotor friction discs interleaved with a plurality of brake stator friction discs which discs are adapted to be urged axially into engagement to retard rotation of the wheel. The shield surrounds the plurality of rotor and stator discs and reduces undesirable heat influx to the wheel from the plurality of friction discs radially inward therefrom.