Method and apparatus for performing secondary operations in a press
OwnerGene Pitzerinventor
Life of this patent
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Abstract
A method and apparatus for conducting a secondary operation on a workpiece such as punching or flanging, after a primary forming operation has been completed while the workpiece is still in the press. The secondary operation is performed by discharging a volume of hydraulic fluid to a working cylinder at a selectively controlled point in the press cycle, the hydraulic fluid pressurized by compression of a volume of gas by the press during the primary operation, and thereafter released by a solenoid valve at the time the secondary operation is to be performed. A discharge cylinder is mounted to one of the dies and is engaged to cause the hydraulic fluid to be pressurized by compression of the gas during the downstroke of the press.
Claims16
A method of carrying out a secondary operation on a workpiece which has been formed in a primary operation by a press having movable platens and respective forming dies attached to each platen, said primary operation carried out by stroking of said press platens, said method comprising the steps of:
- generating a pressurized volume of operating fluid by movement of said press platens during said primary forming operation;
- progressively compressing a confined volume of a compressible fluid by continued movement of said press platens during said primary forming operation;
- exerting the pressure of said compressed volume of compressible fluid on said pressurized volume of operating fluid;
- after completion of said primary operation but before removal of said workpieces from said press, driving secondary tooling located within the press to perform said secondary operation with said pressurized volume of operating fluid using the stored energy of said compressed volume of fluid.
Apparatus for performing a secondary operation in a forming press having upper and lower platens moved towards each other by operation of the press to bring respective upper and lower dies located on said upper and lower platens into contact with a workpiece to perform a primary forming operation, the apparatus comprising:
- a discharge cylinder mounted to move with one of said platens to extend towards the other platen, said cylinder including a piston and piston rod, a chamber beneath said piston containing an operating fluid;
- means engaging said piston rod upon operation of said press and movement of said platens, said engagement of said discharge cylinder piston rod acting on said discharge cylinder piston to pressurize said operating fluid in said chamber;
- accumulator means including a confined volume of a compressible fluid and means for progressively compressing said volume of fluid responsive to the continued engagement of said discharge cylinder piston rod to thereby create stored energy by operation of said press during said primary forming operation;
- means for exerting said stored energy of said compressed confined volume of compressible fluid of said accumulator means on said pressurized operating fluid in said discharge cylinder chamber;
- a working cylinder mounted within said forming press, said working cylinder having a piston rod, and tooling for conducting said secondary operation mounted on said working cylinder piston rod, said tooling located within said press to be engageable with said workpiece after primary forming thereof in said upper and lower dies but before removal of said workpiece from said press;
- said working cylinder including a piston attached to said working cylinder piston rod and defining a working chamber in said working cylinder;
- and,
- valve means for selectively allowing discharge of operating fluid under pressure in said discharge cylinder to be exerted in said working chamber of said working cylinder after forming of said workpiece in said upper and lower dies, timed, operation of said valve means causing said working cylinder piston to advance through a working stroke and to thereby cause said secondary operation to be conducted on said workpiece after primary forming of said workpiece in said upper and lower dies, said workpiece still located in said press during performance of said secondary operation thereon.
Dependencies are inferred from the claim text.