Patent ID: 6848290
Filing Date: 2005-02-01
Classification: B21D,Y10T

Abstract:
1. In a progressive metal forming die of the type having multiple stations, the improvement of a self-contained stock lifter, comprising: a base plate having first and second vertically oriented, mutually parallel mounting apertures extending completely through said base plate adjacent opposite sides thereof, at least one fastener mechanism for connecting said stock lifter assembly to said metal forming die, and at least one vertically oriented spring unit aperture extending completely through said base plate at a location generally intermediate said first and second mounting apertures and including an internal thread; a lifter bar having third and fourth vertically oriented, mutually parallel mounting apertures extending completely through said lifter bar adjacent opposite sides thereof in vertical registry with said first and second mounting apertures, and including a central portion disposed generally intermediate of said third and fourth mounting apertures; at least two rigid guide shafts extending between said base plate and said lifter bar, and having first ends thereof received in said first and second mounting apertures to permit said lifter bar to reciprocate between extended and retracted positions in a manner which selectively lifts stock in said metal forming die to permit shifting the stock longitudinally along said multiple stations of said metal forming die; a spring unit having a base portion thereof received and retained in said spring unit aperture in said base plate, and a reciprocating rod portion extending outwardly from said base portion and being biased outwardly to an extended position; said rod portion having a free end thereof which abuts said central portion of said lifter bar to shift said lifter bar to the extended position, whereby said stock lifter defines a fully self-contained unit that can be readily mounted in and removed from said metal forming die to reduce the cost of manufacturing and repairing said metal forming die; and wherein said spring unit base portion includes an external thread which mates with the internal thread of said spring unit aperture, such that rotation of said spring unit base relative to said base plate varies the axial position of said rod portion relative to said lifter bar to permit making stock lifters having different vertical lifts.