Abstract: A free fall stroker for raising and dropping a drop hammer for soils bearing testing or the like includes a housing through which a drop hammer cable extends from one side to the bottom thereof. A pair of guide pulleys guide the cable through the housing and a movable sheave operates within a parallelogram-shaped track with four legs, and is attached to a telescoping arm of a hydraulic stroking cylinder. When the arm is retracted, the sheave is moved in a first leg of the track and engages the cable, pulling it between the guide pulleys. When the sheave reaches the end of the first leg, it moves in a second leg in a second direction away from the guide pulleys. This causes the cable to be released, thus dropping the drop hammer and letting it free fall. Extension of the telescoping arm then returns the sheave to the point of origin via the third and fourth legs of the track. A winch is provided on top of the housing to adjust the cable length and a stroke counter counts the number of hammer strokes.

Abstract: A vibrator baseplate for use in a seismic signal transducer system has a bottom plate with a dome centrally located thereon. A pair of partial domes overlap the central dome on opposite sides thereof. Top plates are attached to the partial domes, which are also attached to the bottom plate. Internal rib stiffeners are provided within each dome and gusset members extend between the partial domes and the top plates. Means are provided to connect the baseplate to the seismic signal transducer system. Alternatively, the baseplate comprises a bottom plate with an elongate eccentric dome attached thereto.

Abstract: A reinforced valve member including a body having upstream and downstream sides and an annular rim forming a first sealing surface. A frusto-conical portion of the body extends upstream from the first sealing surface and displays a second sealing surface. A substantially conical flow diverter extends upstream from the frusto-conical portion and a plurality of guide fins extend upstream from the flow diverter. The annular rim, frusto-conical portion and flow diverter are all coaxially aligned on the longitudinal axis of translation of the valve member. A dish-shaped reinforcing washer is embedded in the valve member body and includes a concave side oriented upstream and a convex side oriented downstream.