Hydraulic positioning system for gripping heads of forging machines

Claim 1

A HYDRAULIC POSITIONING SYSTEM WHICH COMPRISES A POSITIONING MEMBER WHICH IS MOVABLE IN TWO MUTUALLY OPPOSITE, PREDETERMINED DIRECTIONS, A HYDRAULIC MOTOR WHICH IS OPERATIVELY CONNECTED TO SAID MEMBER AND ADAPTED TO BE ENERGIZED BY PRESSURE FLUID SELECTIVELY IN EITHER OF TWO MUTUALLY OPPOSITE SENSES TO MOVE SAID MEMBER IN EITHER OF SAID DIRECTIONS, A HYDRAULIC CIRCUIT FOR ENERGIZING SAID HYDRAULIC MOTOR, SAID CIRCUIT COMPRISING VALVE MEANS ELECTRICALLY OPERABLE TO CONTROL THE ENERGIZATION OF SAID MOTOR AND THE SENSE IN WHICH IT IS ENERGIZED, SAID SYSTEM FURTHER COMPRISING ELECTRICALLY ENERGIZABLE MEANS FOR OPERATING SAID VALVE MEANS, LIMIT SWITCH MEANS FOR CONTROLLING THE ENERGIZATION OF SAID ELECTRICALLY OPERABLE MEANS, A PLURALITY OF ADJUSTABLE CAM MEANS, EACH OF WHICH IS ARRANGED TO OPERATE SAID LIMIT SWITCH MEANS IN A PREDETERMINED POSITION OF SAID MEMBER, A FEELER-CONTROLLED SLIDE VALVE ADAPTED TO BE CONNECTED IN SAID CIRCUIT, A FEELER ARRANGED TO CONTROL SAID SLIDE VALVE BY A MOVEMENT IN A FIRST DIRECTION, AND A PLURALITY OF ADJUSTABLE RUN-UP MEMBERS, EACH OF WHICH IS ASSOCIATED WITH ONE OF SAID CAM MEANS AND HAS AN OBLIQUE SURFACE, SAID FEELER AND RUN-UP MEMBERS BEING ARRANGED TO BE RELATIVELY MOVED IN A SECOND DIRECTION, WHICH IS TRANSVERSE TO SAID FIRST DIRECTION, IN RESPONSE TO A MOVEMENT OF SAID POSITIONING MEMBER IN EITHER OF SAID PREDETRMINED DIRECTIONS, EACH OF SAID RUN-UP MEMBERS BEING ARRANGED TO ENGAGE SAID FEELER WITH A PREDETERMINED POINT OF ITS OBLIQUE SURFACE WHEN SAID POSITIONING MEMBER IS IN THE PREDETERMINED POSITION IN WHICH THE CAM MEANS ASSOCIATED WITH THE RESPECTIVE RUNUP MEMBER OPERATES SAID LIMIT SWITCH MEANS, RESILIENT MEANS BIASING SAID FEELER IN SAID FIRST DIRECTION TOWARD SAID RUN-UP MEMBERS, SAID SLIDE VALVE BEING ARRANGED TO ASSUME A NEUTRAL POSITION WHEN SAID FEELER IS ENGAGED BY SAID PREDETERMINED POINT OF SAID OBLIQUE SURFACE, SAID HYDRAULIC CIRCUIT BEING ARRANGED TO ENERGIZE SAID MOTOR SO AS TO MOVE SAID POSITIONING MEMBER TO SAID PREDETERMINED POSITION IN RESPONSE TO A MOVEMENT OF SAID SLIDE VALVE OUT OF SAID NEUTRAL POSITION WHEN SAID SLIDE VALVE IS CONNECTED IN SAID CIRCUIT.