Shoulder pilot assembly with self-contained stripper and method for metal forming dies

摘要

A pilot assembly with a self-contained stripper and method for metal forming dies has a cylindrical pilot with internally mounted reciprocating ejector pins with outer ends that protrude through holes in the body of the pilot to strip stock from the pilot. The pilot assembly is secured to the die by a window mount such that one or more surfaces of the pilot abut surfaces on the window mount and die to secure the pilot to the die and window mount when the window mount is secured, via a fastener, to the die. A spring within the pilot assembly contacts an end of the ejector pins to force the pins to reciprocate when the dies are pulled apart. The assembly can be made without the locating pilot surface to provide a stripper assembly for stripping the stock from the associated die.

主权项

1. In 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, the improvement of a modular pilot assembly with self-contained stripper, comprising:
a generally cylindrically shaped pilot operably supported on one of said 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 has 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 greater than said first outside diameter of said first sidewall of said outer collar portion and defines an annularly shaped, radially oriented shoulder therebetween for securing said pilot in an associated pilot mounting aperture in said one die member, and at least one axially oriented ejector pin aperture which extends through said outer end surface and opens generally to said inner end surface;said outer end portion has a generally tapered nose protruding outwardly from said outer end surface of said outer collar portion, with a circularly shaped innermost portion disposed adjacent said outer end surface of said outer collar portion configured for close reception in a pilot hole in the stock strip, and a generally conically shaped outermost portion configured to engage the pilot hole in the stock strip and guide the stock strip to a predetermined position in an associated die forming station;said inner end portion has a generally cylindrically shaped spring retainer rod protruding inwardly from said inner end surface of said inner collar portion, with an inner end surface of the spring retainer rod oriented away from the stock strip and an outer sidewall with an outside diameter that is less than said second outside diameter of said second sidewall of said inner collar portion; a spring member having a generally hollow interior that is received onto and over said spring retainer rod, an outer end oriented toward the stock strip, and an opposite inner end oriented away from the stock strip and positioned adjacent to said inner end surface of said spring retainer rod; at least one rigid ejector pin slidingly received and retained in said ejector pin aperture in said medial portion of said pilot, the rigid ejector pin having an outer end that protrudes outwardly from said outer end surface of said outer collar portion of said medial portion when urged to an extended position to contact the stock strip and strip the stock strip away from said outer end portion of said pilot, and retracts toward said medial portion of said pilot when urged to a retracted position, and an inner end of the rigid ejector pin that operably engages said outer end of said spring member and is thereby biased outwardly by said spring member toward said extended condition; a retainer operably connecting said inner end portion of said spring retainer rod with said inner end of said spring member in a pre-tensed condition to define a fully assembled pilot condition wherein said ejector pin is biased toward said extended condition; and a window mount operably supporting said pilot in said fully assembled pilot condition in said pilot mounting aperture in said one die member to define an installed condition, and having:
a marginal portion with at least one fastener aperture extending laterally therethrough;at least one fastener positioned in said fastener aperture of said window mount and having a threaded shank portion anchored in said one die member to securely, yet detachably retain said window mount on said one die member;a central portion with a through mounting aperture for receiving said pilot, whereby said ejector pin automatically reciprocates between said retracted and extended positions relative to said pilot during operation of said metal forming die to insure that the stock strip is consistently stripped away from said outer end portion of said pilot.