Grinding machine

Claim 1

A GRINDER COMPRISING A TABLE HAVING CLAMPING MEANS FOR CLAMPING A WORK PIECE IN FIXED POSITION THEREON, MEANS OPERABLE TO EFFECT RECIPROCATION OF SAID TABLE OVER A PATH IN A DIRECTION LENGTHWISE OF THE WORK PIECE, A CARRIAGE MOUNTED FOR HORIZONTAL MOVEMENT TOWARD AND FROM SAID TABLE IN A DIRECTION TRANSVERSELY OF SAID PATH, A VERTICALLY DISPOSED COLUMN STRUCTURE ON SAID CARRIAGE, A SUPPORT SLIDABLY MOUNTED ON SAID COLUMN STRUCTURE FOR VERTICAL MOVEMENT TOWARD AND FROM THE PLANE OF SAID TABLE, A GRINDING MOUNT CARRIED BY SAID SUPPORT ABOVE SAID TABLE AND INCLUDING AN ARBOR JOURNALLED FOR ROTATION AND A GRINDING WHEEL MOUNTED ON SAID ARBOR, A MOTOR OPERATIVELY CONNECTED TO SAID ARBOR FOR EFFECTING ROTATION THEREOF, SAID MOUNT HAVING LIMITED VERTICAL MOVEMENT RELATIVE TO SAID SUPPORT, MEANS YIELDINGLY URGING SAID MOUNT DOWNWARDLY A REVERSIBLE MOTOR CONNECTED TO SAID SUPPORT AND OPERABLE IN FORWARD DIRECTION TO MOVE SAID SUPPORT DOWNWARDLY FOR ENGAGEMENT OF SAID GRINDING WHEEL WITH A WORK PIECE CLAMPED ON SAID TABLE, AND SAID REVERSIBLE MOTOR BEING OPERABLE IN REVERSE DIRECTION TO MOVE SAID SUPPORT UPWARDLY, SAID MOUNT ASSUMING A PREDETERMINED POSITION RELATIVE TO SAID SUPPORT UPON THE PRESSURE BETWEEN SAID GRINDING WHEEL AND WORK PIECE REACHING A PREDETERMINED VALUE, CONTROL MEANS CONNECTED TO SAID MOUNT FOR ACTUATION THEREBY UPON THE PRESSURE BETWEEN SAID WHEEL AND WORK PIECE EXCEEDING SAID PREDETERMINED VALUE TO ENERGIZE A POWER CIRCUIT FOR OPERATION OF SAID REVERSIBLE MOTOR IN REVERSE DIRECTION AND, UPON SAID PRESSURE FALLING BELOW SAID PREDETERMINED VALUE, TO ENERGIZE SAID POWER CIRCUIT FOR FORWARD OPERATION OF SAID REVERSIBLE MOTOR.