Multiple depth control for power press brakes

Claim 1

IN A POWER PRESS BRAKE HAVING A BED AND A CROSSHEAD RECIPROCABLE TOWARD AND AWAY FROM THE BED, A DRIVE SHAFT, ECCENTRIC MEANS THEREON AND MEANS CONNECTING THE SAME TO SAID CROSSHEAD FOR RECIPROCATING THE LATTER, SCREW ADJUSTMENT MEANS FOR VARYING THE EFFECTIVE LENGTH OF SAID CONNECTING MEANS, AND MOTOR MEANS FOR ROTATING SAID SCREW ADJUSTMENT IN OPPOSITE DIRECTIONS TO VARY THE DEPTH OF THE RECIPROCATING MOVEMENT OF SAID CROSSHEAD TOWARD SAID BED, A CAM SHAFT AND SPEED REDUCTION MEANS DRIVING THE SAME FROM SAID SCREW ADJUSTMENT MEANS, A PAIR OF ANGULARLY ADJUSTABLE CAMS ON SAID SHAFT, A PAIR OF CONTROL CIRCUITS OPERABLE TO ACTUATE SAID MOTOR MEANS IN OPPOSITE DIRECTIONS, A NORMALLY CLOSED SWITCH IN EACH OF SAID CIRCUITS, EACH OF SAID CAMS BEING ADAPTED TO OPEN ONE OF SAID SWITCHES WHEN SUCH CAM REACHES A PREDETERMINED ANGULAR POSITION AS DETERMINED BY THE ADJUSTED SETTING THEREOF ON SAID CAM SHAFT, AND MEANS FOR SELECTIVELY RENDERING EITHER OF SAID CONTROL CIRCUITS OPERATIVE FOR AUTOMATIC POSITIONAL ADJUSTMENT OF SAID CROSSHEAD.