Automatic machine tool control mechanism

Claim 1

A HYDRAULIC DEVICE FOR MOVING A MACHINE PART AT DIFFEREN SELECTABLE SPEEDS WHICH COMPRISES: A PAIR OF ADJACENT, CLOSED, PARALLEL CYLINDERS CARRIED BY SAID MACHINE PART AND EACH HAVING AN OPENING AT ONE END THEREOF, A PAIR OF FLUID CONDUITS CONNECTING THE INTERIORS OF SAID CYLINDERS, ONE CONDUIT CONNECTING ONE END OF SAID CYLINDERS TOGETHER, THE OTHER CONDUIT CONNECTING THE OPPOSITE ENDS, A RECIPROCABLE PISTON IN EACH OF SAID CYLINDERS, ONE OF SAID PISTONS HAVING A PASSAGE FROM FACE TO FACE, A HOLLOW PISTON ROD CARRIED BY SAID ONE PISTON COMMUNICATING WITH SAID PASSAGE AND EXTENDNG OUT OF SAID CYLINDER THROUGH SAID OPENING, ANOTHER HOLLOW PISTON ROD CARRTIED BY THE OTHER OF SAID PISTONS HAVING A HOLE PROXIMATE SAID OTHER PISTON INTO SAID CYLINDER AND EXTENDING OUT OF SAID CYLINDER THROUGH SAID OPENING, SAID PISTON RODS HAVING THEIR FREE ENDS RIGIDLY AFFIXED AGAINST MOVEMENT, A SOURCE OF MOTIVE FLUID, MEANS FOR SELECTIVELY ADMITTING SAID MOTIVE FLUID THROUGH ONE OF SAID PISTON RODS WHEREBY WHEN SAID FLUID IS ADMITTED INTO ONE OF SAID HOLLOW RODS SAID MACHINE PART WILL BE MOVED IN ONE DIRECTION WHILE FLUID IS DISCHARGED FROM SAID ANOTHER PISTON ROD, AND WHEN ADMITTED INTO SAID ANOTHER PISTON ROD AND DISCHARGE FROM SAID ONE PISTON ROD SAID MACHINE PART WILL BE MOVED IN THE OPPOSITE DIRECTION, MEANS FOR CONTROLLING THE RATE OF DISCHARGE OF SAID MOTIVE FLUID.