Abstract: A method and an apparatus for mass retrieval for an acoustic pulse generator are disclosed herein. In an impulse type seismic generating apparatus an air spring, mechanical spring, controlled pressurization of an air spring or other energy storage medium is employed to use potential energy to raise the impact mass to a resting position above an earth contacting baseplate as quickly as possible after the impact mass strikes the baseplate.

Abstract: Apparatus for generating seismic waves including an upstanding hollow cylindrical housing within which an impact piston latched in a cocked position is adapted to be propelled downwardly by high pressure expanding gas in the confined chamber above it within the housing so as to strike a target plate resting on the ground adjacent the lower end of the housing. After each blow against the target, the piston is retracted upwardly by means of hydraulic cylinders which recompress the gas in the chamber to its original pressure. Since there is no need for recharging the pressure chamber after each shot, economical rapid cycle operation is facilitated.

Abstract: The weight of a transport vehicle and the actuator of an impact type seismic source carried thereby is partially transferred by means of hydraulic lift cylinders to a freely movable earth contacting baseplate positioned beneath the actuator. In operation a mass is propelled by the actuator along a prescribed slant path to strike the baseplate. Shear strain is induced in elastomeric pads sandwiched between the hydraulic lift cylinders and the baseplate if the baseplate shifts sideways under such a slanting blow. The pads then exert a force to restore the vehicle and the actuator to a correct perpendicular alignment over the baseplate. Upper and lower position locator means fixed respectively to the hydraulic lift cylinders and to the baseplate interface with the elastomeric pads and fit slidably within each other so as to transmit vertical force from vehicle to baseplate.