Vibrating and tamping devices

Claim 1

IN A VIBRATING AND TAMPING DEVICE FOR COMPACTING A MASS LOCATED BENEATH THE DEVICE, IN COMBINATION, FIRST SUPPORT MEANS; A PAIR OF ROTARY CRANK MEANS, EACH OF SAID ROTARY CRANK MEANS INCLUDING MEANS FOR SUPPORTING THE RESPECTIVE CRANK MEANS ON SAID FIRST SUPPORT MEANS; FOR ROTATION ABOUT A PREDETERMINED AXIS OF ROTATION AND FIRST AND SECOND CRANK PINS ANGULARLY DISPLACED FROM EACH OTHER BY 180* ABOUT SAID AXIS OF ROTATION AND THE AXES OF SAID FIRST AND SECOND CRANK PINS BEING RESPECTIVELY PARALLEL TO THE AXIS OF ROTATION, SAID PAIR OF ROTARY CRANK MEANS HAVING AT A GIVEN INSTANT THE SAME ANGULAR POSITIONS RELATIVE TO SAID SUPPORT MEANS, DURING OPERATION OF THE DEVICE, SO THAT AT ANY GIVEN INSTANT THE ANGULAR POSITION OF SAID FIRST CRANK PINS WITH REFERENCE TO THE AXES OF ROTATION OF THE PAIR OF CRANK MEANS ARE IDENTICAL AND SAID SECOND CRANK PINS OF SAID PAIR OF CRANK MEANS ALSO HAVE RESPECTIVELY WITH RESPECT TO SAID AXES OF ROTATION IDENTICAL ANGULAR POSITIONS DISPLACED BY 180* ABOUT SAID AXES OF ROTATION WITH RESPECT TO THE POSITIONS OF SAID FIRST CRANK PINS; WORKING PLATE MEANS OPERATIVELY CONNECTED TO SAID FIRST CRANK PINS FOR MOVEMENT THEREWITH AND LOCATED AT THE LOWEST PART OF THE DEVICE DURING OPERATION THEREOF, SAID WORKING PLATE MEANS BEING THE ONLY PART OF THE DEVICE WHICH ENGAGES THE MASS WHICH IS WORKED ON BY THE DEVICE AND SAID FIRST CRANK PINS ROTATABLY MOUNTED IN SAID WORKING PLATE MEANS WHICH LATTER CONSTITUTES A SECOND SUPPORT MEANS; AND BALANCING PLATE MEANS OPERATIVELY CONNECTED TO BOTH SAID SECOND CRANK PINS FOR MOVEMENT WITH THE LATTER FOR COUNTERBALANCING THE MOVEMENT OF SAID WORKING PLATE MEANS TO ELIMINATE INERTIA FORCES, SAID BALANCING PLATE MEANS REMAINING AT ALL TIMES OUT OF ENGAGEMENT WITH THE MASS WHICH IS WORKED ON BY THE DEVICE.