Apparatus for blow molding plastic articles

Claim 1

IN A BLOW MOLDING MACHINE HAVING A FRAME, FIRST AND SECOND HORIZONTALLY SPACED MOLD CARRYING PLATENS SLIDABLY MOUNTED ON SAID FRAME FOR SUBSTANTIAL HORIZONTAL RECIPROCAL MOVEMENT TOWARD EACH OTHER TO "MOLD CLOSED" POSITIONS AND AWAY FROM EACH OTHER TO "MOLD OPEN" POSITIONS, A MEMBER SLIDABLY MOUNTED ON SAID FRAME IN A SPACED RELATION WITH SAID PLATENS SUCH THAT SAID SECOND PLATEN IS BETWEEN SAID FIRST PLATEN AND SAID SLIDABLE MEMBER, MEANS RIGIDLY CONNECTING SAID FIRST PLATEN AND SAID SLIDABLE MEMBER, SHAFT MEANS DISPOSED BETWEEN SAID SECOND PLATEN AND SAID SLIDABLE MEMBER, REVERSIBLE HYDRAULIC MOTOR MEANS CONNECTED IN A DRIVING RELATION TO SAID SHAFT MEANS, TOGGLE MEANS CONNECTED INTERMEDIATE THE ENDS THEREOF TO SAID SHAFT MEANS AND AT THE ENDS THEREOF TO SAID SECOND PLATEN AND SAID SLIDABLE MEMBER, SAID SHAFT BEING OPERABLE ON ROTATION IN ONE DIRECTION TO SUBSTANTIALLY STRAIGHTEN SAID TOGGLE MECHANISM SO AS TO MOVE SAID SECOND PLATEN AND SAID SLIDABLE MEMBER AWAY FROM EACH OTHER AND THEREBY MOVE SAID PLATENS TO MOLD CLOSED POSITIONS, AND SAID SHAFT BEING OPERABLE ON ROTATION IN AN OPPOSITE DIRECTION TO MOVE SAID TOGGLE MECHANISM OUT OF A SUBSTANTIALLY STRAIGHT POSITION TO THEREBY MOVE SAID PLATENS TOWARD "MOLD OPEN" POSITIONS, A HYDRAULIC CIRCUIT FOR SUPPLYING FLUID TO SAID MOTOR MEANS, VALVE MEANS IN SAID CIRCUIT OPERABLE IN ONE POSITION TO LIMIT THE PRESSURE OF FLUID SUPPLIED TO SAID MOTOR MEANS TO A PREDETERMINED LOW PRESSURE, CONTROL MEANS FOR SAID VALVE MEANS OPERABLE TO MOVE SAID VALVE MEANS TO SAID ONE POSITION DURING MOVEMENT OF SAID PLATENS TOWARD "MOLD CLOSED" POSITIONS, SWITCH MEANS, SWITCH ACTUATING MEANS ON SAID SHAFT MEANS OPERABLE IN A PREDETERMINED POSITION OF SAID SHAFT MEANS CORRESPONDING TO A POSITION OF SAID PLATENS BETWEEN SAID "MOLD OPEN" AND "MOLD CLOSED" POSITIONS, AND MEANS RESPONSIVE TO ACTUATION OF SAID SWITCH MEANS FOR OPERATING SAID CONTROL MEANS TO MOVE SAID VALVE MEANS OUT OF SAID ONE POSITION.