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

Patent metadata

Field	Value
Publication number	US-9895740-B2
Application number	US-201514845344-A
Country	US
Kind code	B2
Filing date	Sep 4, 2015
Priority date	Oct 17, 2011
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

A pilot assembly and method has a cylindrical pilot body with a tapered outer end, a grooved inner end, and a central portion with at least one inwardly curved side wall relief, as well as internally mounted reciprocating ejector pins with outer ends that protrude through holes in the outer body end to strip stock from the pilot. A spring has its outer end mounted in the groove in the outer body end, and an inner end attached to the inner body end in a pre-tensed condition. A cap screw has an enlarged head that has at least a portion thereof fit into the pilot sidewall relief, and a threaded shank that anchors the pilot in an associated die member.

First claim

The invention claimed is:

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 pilot operably supported on one of said die members and having an outer end oriented toward the stock strip, an oppositely disposed inner end oriented away from the stock strip, and a medial portion disposed axially between said outer and inner ends, and including:
a generally cylindrically shaped body portion disposed at said medial portion of said pilot, having an outer end oriented toward the stock strip, an inner end oriented away from the stock strip, and an outer sidewall with a least one fastener relief therein, as well as at least one axially extending ejector pin aperture which opens through said outer end and into said inner end;
a generally tapered point portion disposed at said outer end of said pilot, having a circularly shaped innermost collar portion disposed adjacent said outer end of said body portion shaped for close reception in a pilot hole in the stock strip, and a generally frusto-conically shaped outer portion configured to engage the pilot hole in the stock strip and guide the same to a predetermined position in an associated die forming station;
a generally cylindrically shaped spring retainer rod portion disposed at said inner end of said pilot, having an outer end oriented toward the stock strip, an inner end oriented away from the stock strip, and an outer sidewall with a diameter that is less than the diameter of said outer sidewall of said body portion, thereby forming an annularly shaped spring groove adjacent said outer end of said spring retainer rod portion;

a spring member having a generally hollow interior that is received onto and over said spring retainer rod portion of said pilot, an outer end oriented toward the stock strip and received in said spring groove, and an opposite inner end oriented away from the stock strip and positioned adjacent to said retainer groove in said spring retainer rod portion;
at least one rigid ejector pin slidingly received and retained in said ejector pin aperture in said body portion, having an outer end that protrudes outwardly from said outer end of said body portion when urged to an extended condition to contact the stock strip and strip the same away from said pilot, and retracts toward the body portion when urged to a retracted position, and an inner end 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 ring detachably received on said spring retainer rod portion and engaging said inner end of said spring member in a pre-tensed condition to bias said ejector pin toward said extended condition; and
a mounting fastener having an enlarged head portion that is at least partially, closely received in said fastener relief in said body portion, and a shank portion anchored in said one die member to securely mount said pilot assembly on said one die member in a manner which causes said ejector pin to automatically reciprocate between said retracted and extended positions relative to said body portion of said pilot during operation of said metal forming die to insure that the stock strip is consistently stripped away from said pilot.

2. A metal forming die as set forth in claim 1 , including:
a retainer groove disposed adjacent said inner end of said spring retainer rod portion.

3. A metal forming die as set forth in claim 2 , wherein:
said retainer ring is detachably received in said retainer groove.

4. A metal forming die as set forth in claim 1 , wherein:
said pilot has a one-piece construction formed from a solid bar of rigid material.

5. A metal forming die as set forth in claim 4 , wherein:
said body portion of said pilot includes a plurality of said ejector pin apertures having a substantially identical configuration and arranged in a circumferentially spaced apart, mutually parallel, axially extending pattern through said body portion to insure effective stripping of the stock strip from said pilot; and including
a plurality of said ejector pins having a substantially identical configuration and slidingly received and retained in said ejector pin apertures in said body portion of said pilot.

6. A metal forming die as set forth in claim 5 , wherein:
said body portion of said pilot includes a plurality of said fastener reliefs having a substantially identical configuration and arranged in a circumferentially spaced apart pattern around said outer sidewall of said body portion to facilitate mounting said pilot assembly at various locations and orientations on said one die member.

7. A metal forming die as set forth in claim 1 , wherein:
said mounting fastener is a threaded screw.

8. A metal forming die as set forth in claim 7 , wherein:
said shank portion of said mounting fastener is anchored in said one die member to securely, yet detachably mount said pilot assembly.

9. 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 an associated die member, and having an outer end oriented toward the stock strip, an oppositely disposed inner end oriented away from the stock strip, and a medial portion disposed axially between said outer and inner ends, and including:
a generally cylindrically shaped body portion disposed at said medial portion of said pilot, having an outer end oriented toward the stock strip, an inner end oriented away from the stock strip, and an outer sidewall with a least one fastener relief therein, as well as at least one axially extending ejector pin aperture which opens through said outer end and into said inner end;
a generally tapered point portion disposed at said end of said pilot, having a circularly shaped innermost collar portion disposed adjacent said outer end of said body portion, shaped for close reception in a pilot hole in the stock strip, and a generally frusto-conically shaped outer portion configured to engage the pilot hole in the stock strip and guide the same to a predetermined position in an associated die forming station;
a generally cylindrically shaped spring retainer rod portion disposed at said inner end of said pilot, having an outer end oriented toward the stock strip, an inner end oriented away from the stock strip, and an outer sidewall with a diameter that is less than the diameter of said outer sidewall of said body portion, thereby forming an annularly shaped spring groove adjacent said outer end of said spring retainer rod portion;

a spring member having a generally hollow interior received on and over said spring retainer rod portion of said pilot, an outer end oriented toward the stock strip and received in said spring groove, and an opposite inner end oriented away from the stock strip and positioned adjacent to said retainer groove in said spring retainer rod portion;
at least one rigid ejector pin slidingly received and retained in said ejector pin aperture in said body portion, having an outer end that protrudes outwardly from said outer end of said body portion when urged to an extended condition to abut the stock strip and strip the same away from said pilot, and retracts toward the body portion when urged to a retracted position, and an inner end that operably engages said outer end of said sprin

Assignees

• Standard Lifters Inc

Inventors

• Breen Scott M
• Pyper Joel T

Classifications

• B23P15/24

  dies (B21C3/18, B21C25/10, B21D37/20 take precedence) · CPC title

• B21J13/02

  Dies or mountings therefor · CPC title

• B21D43/06 Primary

  by positive or negative engaging parts co-operating with corresponding parts of the sheet or the like to be processed, e.g. carrier bolts or grooved section in the carriers · CPC title

• B21D45/06

  Stripping-off devices · CPC title

• B21D43/05

  specially adapted for multi-stage presses {(B21D43/145 takes precedence)} · CPC title