Vibratory pavement breaker

A pavement breaker comprising a resonant mass and pressurized hydraulic or pneumatic spring system having a resonant frequency, and a structure which supports said resonant mass-spring system for vibration towards and away from a pavement to be broken;

• an electrohydraulic driving and control system for driving said mass into vibration at the resonant frequency of said mass-spring system, said spring system comprising pressurized gas or liquid filled cavities, said cavities facing portions of said mass, said resonant frequency being determined by the stiffness of the fluid gas in said cavities and the mass of said system, and said cavities are defined by flexible boots surrounding at least a portion of said mass, and said cavities are filled with gas to provide the pneumatic spring system.

A pavement breaker comprising a resonant mass and pressurized hydraulic or pneumatic spring system, and a structure which supports said resonant mass-spring system for vibration towards and away from a pavement to be broken;

• an electrohydraulic driving and control system for driving said mass into vibration at the resonant frequency of said mass-spring system, said spring system comprising pressurized gas or liquid filled cavities, said cavities facing portions of said mass, said resonant frequency being determined by the stiffness of the fluid in said cavities and the mass of said system, and said control system comprising a displacement sensor coupled to said mass and responsive to the position and movement of said mass, and said control system further comprising servo means responsive to said sensor for controlling dynamic and static pressures applied to said mass to maintain said mass vibrating at said resonant frequency and biased against said pavement.