Patent ID: 7000446

Claim:
In a press for stamping sheet material between an upper die assembly and a lower die assembly wherein the lower die assembly includes a lower die, a lower ring supported on the lower die for vertical movement relative to the lower die and cooperable with the upper die assembly in the shaping of the sheet material, and air cushion pins projecting through holes in the lower die and exerting upward pressure on the ring, the improvement comprising: guide means for guiding the vertical movement of the ring, said guide means including a guide pin, said guide pin being secured to the lower die in alignment with one of the holes therein, said guide pin having a tubular lower end portion adapted to receive one of the air cushion pins projecting upwardly from the lower die, a retainer and lockdown block, an attachment for securing said block to said guide pin selectively in a ring retainer position or in a ring lockdown position, the ring having a retainer abutment and a lockdown abutment, said block being engageable with said retainer abutment when said block is in the ring retainer position to prevent the ring from separating from the lower die without interfering with the relative vertical movement of the ring during a stamping operation, said block being engageable with the lockdown abutment when said block is in the ring lockdown position to lock the ring down on the lower die for machining and spotting of the ring.