Patent ID: 7628248
Filing Date: 2009-12-08
Classification: G01V

Abstract:
1. A seismic vibrator comprising: a hydraulic piston; a mass disposed on the hydraulic piston and movable thereon; a servo valve coupled to the mass and connected to first and second hydraulic flow lines, the servo valve controlling communication of hydraulic fluid between the first and second hydraulic flow lines and the hydraulic piston; first accumulators carried by the mass, one of the first accumulators in hydraulic communication with the hydraulic fluid of the first hydraulic flow line, another of the first accumulators in hydraulic communication with the hydraulic fluid of the second hydraulic flow line; and second accumulators carried by the mass, one of the second accumulators in hydraulic communication with the hydraulic fluid of the first hydraulic flow line, another of the second accumulators in hydraulic communication with the hydraulic fluid of the second hydraulic flow line, the second accumulators each having an internal volume smaller than an internal volume of the first accumulators.