Abstract: A device for use in well pumping apparatus of the type having a bottom hole pump actuated by a vertically reciprocating operating rod, and in which the pump is of the kind in which a tendency to gas lock can be corrected by extending the downstroke of the pump plunger until this taps on the bottom pump parts. The device of this invention is capable of variably limiting the downstroke of the operating rod to allow the pump to be tapped on the downstroke or to be lifted clear of the bottom, as required. The device includes a cylinder carried by the pump bridle and arranged to be supplied with hydraulic fluid, a piston in the cylinder arranged to be lifted when fluid is pumped into the cylinder, means for holding the piston in its raised position relative to the cylinder, and means on the piston for engaging with a member fixed to the operating rod to raise and lower this relative to the pump bridle.

Abstract: A device for limiting leakage from a well head stuffing box assembly of the type which includes a vertically reciprocating polished rod. The device provides a chamber surrounding the rod, and a flap valve which is spring loaded to close against a valve seat which surrounds the aperture for the polished rod at the upper end of the chamber. The valve is normally held open by the rod but springs up to close the aperture if the rod breaks and leaves the chamber.