Stock lifter for metal forming dies and method for making the same

A self-contained, modular stock lifter assembly for progressive metal forming dies of the type having multiple stations, comprising:

• a modular base plate having first and second vertically oriented, mutually parallel mounting apertures extending completely through said modular base plate adjacent opposite sides thereof, at least one fastener mechanism for connecting said stock lifter assembly to an associated 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 modular lifter bar having third and fourth vertically oriented, mutually parallel mounting apertures extending completely through said modular 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 modular base plate and said modular lifter bar, and having first ends thereof received in said first and second mounting apertures to permit said modular lifter bar to reciprocate between extended and retracted positions in a manner which selectively lifts stock in the metal forming die to permit shifting the stock along the multiple stations of the metal forming die;
• a spring unit having a base portion thereof received and retained in said spring unit aperture in said modular 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 modular lifter bar to shift said modular lifter bar to the extended position, whereby said stock lifter assembly defines a fully self-contained unit that can be readily mounted in and removed from the metal forming die to reduce the cost of manufacturing and repairing the 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 modular base plate varies the axial position of said rod portion relative to said modular lifter bar to permit making modular stock lifter assemblies having different vertical lifts.

In a metal forming die, the improvement of a self-contained stock lifter, comprising:

• a first member having first and second vertically oriented, mutually parallel guide shaft mounting apertures extending completely through said first member 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 first member at a location generally intermediate said first and second mounting apertures, and including an internal thread;
• a second member having third and fourth vertically oriented, mutually parallel mounting apertures extending completely through said second member 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 first member and said second member, and having first ends thereof received in said first and second mounting apertures to permit said second member to reciprocate between extended and retracted positions in a manner which selectively lifts stock in said metal forming die;
• a spring unit having a base portion thereof received and retained in said spring unit aperture in said first member, 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 second member to shift said second member 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 varies the axial position of said rod portion relative to said lifter bar to permit making stock lifters having different vertical lifts.

A stock lifter for metal forming dies and the like, 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 to an associated 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 and retained 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 the metal forming die;
• a self-contained 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;
• 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.

In a method for making progressive metal forming dies of the type having a lower die block, multiple metal forming stations, and a stock lifter which selectively lifts stock to permit shifting the stock along the multiple stations, the improvement comprising:

• providing a stock lifter base plate having opposite sides;
• forming first and second vertically oriented, mutually parallel mounting apertures completely through the stock lifter base plate adjacent the opposite sides thereof;
• forming at least one fastener mechanism in the stock lifter for connecting the stock lifter to the lower die block of the metal forming die;
• forming at least one vertically oriented spring unit aperture extending completely through the stock lifter base plate at a location generally intermediate the first and second mounting apertures;
• forming internal threads in the spring unit aperture of the base plate;
• providing a lifter bar having opposite sides and a central portion;
• forming third and fourth vertically oriented, mutually parallel mounting apertures completely through the lifter bar adjacent the opposite sides thereof for vertical registry with the first and second mounting apertures;
• providing at least two rigid guide shafts having first and second ends;
• positioning the guide shafts between the base plate and the lifter bar, so that the first ends thereof are received in the first and second mounting apertures to permit the lifter bar to reciprocate between extended and retracted positions to selectively lift the stock in the metal forming die and permit shifting the stock along the multiple stations of the metal forming die;
• providing a self-contained spring unit having a base portion, and a reciprocating rod portion extending outwardly from the base portion and being biased outwardly to an extended position;
• forming external threads in the spring unit base portion which mate with the internal threads of the spring unit aperture;
• positioning the self-contained spring unit between the base plate and the lifter bar, such that the free end of the rod portion abuts the central portion of the lifter bar to shift the lifter bar to the extended position, and the base portion of the spring unit is threadedly received and retained in the spring unit aperture in the base plate, such that rotation of the spring unit base relative to the base plate varies the axial position of the rod portion relative to the lifter bar to permit making stock lifters having different vertical lifts
• positioning the stock lifter on the lower die block of the metal forming die;
• and
• detachably connecting the stock lifter with the metal forming die, whereby the stock lifter can be readily mounted in and removed from the metal forming die to reduce the cost of manufacturing and repairing the metal forming die.

A method for making a stock lifter for progressive metal forming dies of the type having multiple stations, comprising:

• providing a base plate having opposite sides;
• forming first and second vertically oriented, mutually parallel guide shaft mounting apertures completely through the base plate adjacent the opposite sides thereof;
• forming at least one fastener mechanism in the base plate for connecting the stock lifter to an associated metal forming die;
• forming at least one vertically oriented spring unit aperture extending completely through the base plate at a location generally intermediate the first and second guide shaft mounting apertures;
• forming internal threads in the spring unit aperture of the base plate;
• providing a lifter bar having opposite sides and a central portion;
• forming third and fourth vertically oriented, mutually parallel mounting apertures completely through the lifter bar adjacent the opposite sides thereof for vertical registry with the first and second mounting apertures;
• providing at least two rigid guide shafts having first and second ends;
• positioning the guide shafts between the base plate and the lifter bar, so that the first ends thereof are received in the first and second mounting apertures to permit the lifter bar to reciprocate between extended and retracted positions in a manner which selectively lifts stock in the metal forming die to permit shifting the stock along the multiple stations of the metal forming die;
• providing a self-contained spring unit having a base portion, and a reciprocating rod portion extending outwardly from the base portion and being biased outwardly to an extended position;
• forming external threads in the spring unit base portion which mate with the internal threads of the spring unit aperture;
• and
• positioning the self-contained spring unit between the base plate and the lifter bar, such that the free end of the rod portion abuts the central portion of the lifter bar to shift the lifter bar to the extended position, and the base portion of the spring unit is threadedly received and retained in the spring unit aperture in the base plate, such that rotation of the spring unit base relative to the base plate varies the axial position of the rod portion relative to the lifter bar to permit making stock lifters having different axial lifts.