Vibratory pile hammer

Claim 1

A VIBRATORY PILE HAMMER COMPRISING THE COMBINATION OF A CASING, STATIONARY TUBULAR SHAFTS RIGIDLY SECURED AT THEIR ENDS TO OPPOSITE WALLS OF SAID CASING, ROTORS JOURNALLED ON SAID STATIONARY SHAFTS, WEIGHTS MOUNTED IN READILY REMOVABLE RELATION IN SAID ROTORS, A MOTOR MOUNTED IN SAID CASING, DRIVE GEARING FROM SAID MOTOR TO THE RESPECTIVE ROTORS, A PILE CLAMP AT THE BOTTOM OF THE CASING IN RIGID CONNECTION WITH SAID OPPOSITE WALLS OF THE CASING TO RECEIVE THE FULL FORCE OF VIBRATIONS IMPARTED TO THE CASING, SAID ROTORS BEING OF ANNULAR FORMATION IN SURROUNDING RELATION ABOUT THE SHAFTS AND HAVING CELLS IN THE PERIPHERAL PORTIONS OF THE SAME OPEN AT ONE END, SAID CASING HAVING SERVICING OPENINGS PROVIDING ACCESS TO SAID OPEN ENDS OF THE CELLS, SAID WEIGHTS BEING INSERTABLE THROUGH SAID SERVICING OPENINGS INTO SEATED ENGAGEMENT IN SAID CELLS AND RELEASABLE MEANS ON THE ENDS OF SAID ROTORS FOR CLOSING THE OPEN END OF SAID CELLS OVER THE WEIGHTS INSERTED THEREIN.