Automatic gauge for paper cutting machines and the like

Claim 1

IN A PAPER CUTTING MACHINE HAVING A TABLE ADAPTED TO SUPPORT A STACK OF SHEETS THEREON, A KNIFE MOUNTED FOR RECIPROCATION IN A VERTICAL PLANE TO CUT SUCH STACK, MEANS ADAPTED TO RECIPROCATE SAID KNIFE, AND A BACK GAUGE MOUNTED ON SAID TABLE FOR RECIPROCATION THEREALONG TOWARD AND AWAY FROM SAID KNIFE TO ADVANCE SUCH STACK INTO SELECTED CUTTING POSITION; A BAR MOUNTED FOR PRECISELY LIMITED AXIAL RECIPROCATION IN A DIRECTION NORMAL TO THE PLANE OF SAID KNIFE, RESILIENT MEANS URGING SAID BAR AWAY FROM SAID KNIFE, A STOP MOUNTED ON SAID BAR AND ADJUSTABLE THEREALONG, MEANS FOR SECURING SAID STOP IN SELECTED POSITION, A PLUNGER MOUNTED ON SAID GAUGE BENEATH SAID BAR FOR VERTICAL RECIPROCATION, RESILIENT MEANS NORMALLY EFFECTIVE TO HOLD SAID PLUNGER IN UPWARDLY EXTENDED POSITION TO ENGAGE SAID STOP WHEN SAID GAUGE IS SHIFTED TOWARD SAID KNIFE, WHEREBY SAID BAR MAY BE RECIPROCATED TOWARD SAID KNIFE AND FURTHER ADVANCE OF SAID GAUGE THEREUPON HALTED, SOLENOID MEANS CONNECTED WITH SAID PLUNGER ADAPTED WHEN ENERGIZED TO RETRACT THE LATTER DOWNWARDLY OUT OF STOP-ENGAGING POSITION, WHEREUPON SAID FIRST RESILIENT MEANS BECOMES EFFECTIVE TO RETURN SAID BAR AWAY FROM SAID KNIFE TO DISPLACE SAID STOP FROM PLUNGERENGAGING POSITION, A NORMALLY OPEN LIMIT SWITCH OPERATIVE WHEN CLOSED TO ENERGIZE SAID SOLENOID, AND SWITCHENGAGING MEANS MOVABLE IN SYNCHRONISM WITH SAID CLAMP AND KNIFE TO CLOSE SAID SWITCH UPON COMPLETION OF DOWNWARD RECIPROCATION OF SAID KNIFE AND TO RELEASE SAID SWITCH UPON UPWARD RETURN MOVEMENT OF SAID KNIFE; REVERSIBLE ELECTRIC MOTOR DRIVE MEANS FOR SAID GAUGE, REVERSING SWITCHES FOR SAID MOTOR LOCATED FOR ACTUATION BY SAID GAUGE AT THE FOREMOST AND REARMOST POSITIONS OF THE LATTER, A MOTOR CONTROL SWITCH ARRANGED FOR ACTUATION BY REARWARD RECIPROCATION OF SAID BAR TO ENERGIZE SAID MOTOR TO DRIVE SAID GAUGE IN A FORWARD DIRECTION AND ARRANGED FOR ACTUATION BY FORWARD RECIPROCATION OF SAID BAR WHEN SAID PLUNGER ENGAGES A STOP TO DEENERGIZE SAID MOTOR, AND CONTROL MEANS FOR SAID MOTOR EFFECTIVE TO BRING SAID DEENERGIZED MOTOR TO A FULL STOP JUST AS SAID BAR IS FIRMLY PRESSED AGAINST THE FORWARD LIMIT OF ITS RECIPROCATION.