Self-propelled seismic signal generator

Claim 1

In combination, a seismic vibrator having a base plate movable in a vertical direction and being adapted to engage the earth''s surface; and a self-propelled vehicle for transporting and for adding inertia mass to said base plate when vibrating, said vehicle comprising a first bed frame defining a central open area adapted to movably receive therein said vibrator, a driver''s cab on said first frame; a second bed frame, a primary power source and two hydraulic pumps mounted on said second fRame, said pumps being driven by said primary power source; a pair of axles on each bed frame, a wheel mounted on each axle, drive means, including a differential transmission and a hydraulic motor for supplying power to each pair of axles, said hydraulic pumps supplying hydraulic power to drive the motor on each bed frame whereby each motor is independently powered; horizontal pivot means for pivotally interconnecting said bed frames for relative rotation about said horizontal pivot means, vertical pivot means for pivotally interconnecting said frames for relative rotation about said vertical pivot means; a pair of hydraulic lifting cylinders on said first bed frame for raising and lowering said vibrator; steering means, including two hydraulic steering cylinders interconnecting said bed frames on opposite sides of said horizontal pivot means for rotating said frames relative to each other about said vertical pivot means; said hydraulic pumps supplying power to said lifting cylinders and said steering cylinders; operating controls inside said driver''s cab for controlling said: primary power source, hydraulic pumps, hydraulic motors, steering cylinders and lifting cylinders; said base plate when lowered by said lifting cylinders to engage the earth''s surface causing said first bed frame to become raised by a preselected height to supply static loading to said base plate, and means for vibrating said base plate to thereby inject a seismic signal into the ground.