Low profile pilot assembly and method for metal forming dies

A modular pilot assembly with self-contained stripper for multi-station progressive metal forming dies having at least two mutually converging and diverging die members between which an elongate stock strip is shifted longitudinally to form parts from the stock strip, comprising:

• a pilot configured for operable support on one of the die members and having an outer end portion oriented toward the stock strip, an oppositely disposed inner end portion oriented away from the stock strip, and a medial portion disposed axially between said outer and inner end portions, wherein:
• said medial portion having an annular groove;
• said outer end portion has a generally tapered nose to engage the pilot hole in the stock strip and guide the same to a predetermined position in an associated die forming station;
• said inner end portion has a generally cylindrical shape, with a flat surface for engaging a surface of the one die member;
• a spring member having a generally hollow interior that is received over said medial portion, an outer end oriented toward the stock strip, and an opposite inner end oriented away from the stock strip and positioned adjacent a surface on the pilot;
• a stripper with an outer collar portion with an outer end surface oriented toward the stock strip and a generally cylindrical first sidewall with a first outside diameter, an inner collar portion with an inner end surface oriented away from the stock strip and a generally cylindrical second sidewall with a second outside diameter which is less than said first outside diameter of said first sidewall of said outer collar portion and defines an annularly shaped, radially oriented shoulder there between for engaging the outer end of said spring member;
• wherein:
• said stripper is received over said medial portion of the pilot;
• said outer collar portion has a first inner diameter;
• said inner collar portion has a second inner diameter which is less than said first inner diameter of said outer collar portion and defines an annularly shaped, radially oriented inner shoulder there between;
• and
• a retainer operably connected on the annular groove of the medial portion of the pilot to maintain the stripper on the pilot assembly by engaging the inner shoulder of the stripper when the die members are diverged.

In a method for making a multi-station progressive metal forming die having at least two mutually converging and diverging die members between which an elongate stock strip is shifted longitudinally to form parts from the stock strip, with the improvement of at least one modular pilot assembly for precisely locating the stock strip in the die stations, comprising:

• forming a pilot for operable support on one of the die members with an outer end portion oriented toward the stock strip, an oppositely disposed inner end portion oriented away from the stock strip, and a medial portion disposed axially between the outer and inner end portions, and including:
• forming the medial portion with an annular groove;
• forming the outer end portion with a generally tapered nose to engage the pilot hole in the stock strip and guide the same to a predetermined position in an associated die forming station;
• forming the inner end portion with a generally cylindrically shape, with a flat surface for engaging a surface of the one die member;
• selecting a spring member with a generally hollow interior, an outer end oriented toward the stock strip, and an opposite inner end oriented away from the stock strip;
• positioning the hollow interior of the spring member onto and over the medial portion of the pilot;
• forming a stripper with an outer collar portion with an outer end surface oriented toward the stock strip and a generally cylindrical first sidewall with a first outside diameter, an inner collar portion with an inner end surface oriented away from the stock strip and a generally cylindrical second sidewall with a second outside diameter which is less than said first outside diameter of said first sidewall of said outer collar portion to define an annularly shaped, radially oriented shoulder there between for engaging the outer end of said spring member, including:
• forming the outer collar portion to have a first inner diameter;
• and
• forming the inner collar portion to have a second inner diameter which is less than said first inner diameter of said outer collar portion and defines an annularly shaped, radially oriented inner shoulder there between positioning the stripper over the pilot;
• selecting a retainer ring that fits securely onto the annular groove on the medial portion of the pilot;
• and
• positioning the retainer ring on the annular groove to maintain the stripper on the pilot assembly by engaging the inner shoulder of the stripper when the die members are diverged;
• forming a generally plate shaped window mount for operably retaining the pilot in the pilot mounting aperture in said one die member in an installed condition, and including:
• forming at least one fastener aperture in a marginal portion of the window mount which extends laterally therethrough;
• positioning at least one threaded fastener in the fastener aperture of the said window mount with the threaded shank portion thereof anchored in the fastener mounting aperture in the one die member to securely, yet detachably retain said window mount on the one die member;
• forming a pilot mounting pocket in a central portion of the window mount for receiving said pilot, whereby the stripper automatically reciprocates between the retracted and extended positions relative to the pilot during operation of the metal forming die to insure that the stock strip is consistently stripped away from the outer end portion of the pilot.