Apparatus and method for forming shaped articles

Abstract

A method and apparatus for forming shaped articles such as heat exchanger plates and fuel cell plates from a strip of material. The apparatus includes a feed mechanism for feeding the strip; one or more forming devices which form peripheral features and/or discontinuities in the strip; and an alignment device which maintains constant spacing between the discontinuities and thereby avoids accumulation of incremental feeding errors. Preferably, the strip is re-aligned once for each plate produced. The alignment device comprises a pilot pin and a pilot hole punch for forming index holes in the strip, and can be integral with or separate from the forming devices. One preferred apparatus utilizes a forming device comprising a plurality of punches mounted on a reciprocating frame or gantry structure.

1 . An apparatus for forming a plurality of shaped articles from a strip of material, the apparatus comprising: 
 a feed mechanism for incrementally feeding the strip of material in a forward direction along a strip feed axis;    a forming device which receives the strip of material from the feed mechanism and which forms discontinuities in the strip of material at axially-spaced intervals;    an alignment device for maintaining constant axial spacing between the discontinuities, the alignment device being located in fixed axial relation to both the forming device and the feed mechanism, the alignment device comprising a frame structure having a first portion and a second portion between which the strip is fed, the first and second portions being movable toward and away from one another, a pilot hole punch for forming pilot holes in the strip and a pilot pin rigidly mounted in axially-spaced relation to one another on the first portion of the frame structure, the pilot pin being spaced forward of the pilot hole punch so that the pilot pin is insertable into a pilot hole previously formed by the punch;    wherein the pilot pin and the pilot hole punch each have a length such that when the first and second portions of the frame structure are moved toward one another, the pilot pin passes through a pilot hole before the punch contacts the strip and aligns the strip relative to the pilot hole punch and the forming device.    
   
   
       2 . The apparatus of  claim 1 , wherein the pilot hole punch and the pilot pin are of substantially the same diameter.  
   
   
       3 . The apparatus of  claim 1 , wherein the alignment device is located between the feed mechanism and the forming device.  
   
   
       4 . The apparatus of  claim 1 , wherein the alignment device is located forward or rearward of the forming device.  
   
   
       5 . The apparatus of  claim 1 , wherein the second portion of the alignment device comprises a first recess for receiving the pilot hole punch and a second recess for receiving the pilot pin.  
   
   
       6 . The apparatus of  claim 1 , wherein each of the shaped articles has a periphery surrounding a central portion in which the discontinuities are formed, wherein the forming device comprises tooling to permit the formation of discontinuities selected from one or more members of the group consisting of ribs, dimples, apertures and raised apertured bosses.  
   
   
       7 . The apparatus of  claim 6 , further comprising a stamping apparatus having an upper die portion and a lower die portion, the stamping die forming the peripheries of the articles and separating the articles from the strip.  
   
   
       8 . The apparatus of  claim 7 , wherein the alignment device is located between the forming device and the stamping apparatus.  
   
   
       9 . The apparatus of  claim 7 , wherein the alignment device is associated with the stamping apparatus.  
   
   
       10 . The apparatus of  claim 7 , wherein the stamping apparatus comprises a progressive stamping die having a plurality of stamping stations, including a first stamping station where the strip is received from the forming device.  
   
   
       11 . The apparatus of  claim 10 , wherein the alignment device is located at the first stamping station.  
   
   
       12 . The apparatus of  claim 1 , wherein the feed mechanism engages the strip during said incremental feeding and is disengaged from the strip when the first and second portions of the frame structure move toward one another, thereby permitting the alignment device to adjust a position of the strip relative to the feed mechanism.  
   
   
       13 . The apparatus of  claim 1 , wherein the forming device comprises: 
 a forming frame structure having a first portion and a second portion, the forming frame structure being supported to reciprocate laterally of the strip feed axis;    a plurality of punches on the first portion of the forming frame structure;    a plurality of dies on the second portion of the forming frame structure, each of the dies being arranged to cooperate with a respective one of the punches and arranged so that the strip can be interposed between the punches and the dies;    a punch actuator for actuating each of said punches to form said discontinuities between the punch and its cooperating dies; and    a reciprocating drive for reciprocating said frame laterally of said strip feed axis.    
   
   
       14 . The apparatus of  claim 1 , wherein the pilot pin is longer than the pilot hole punch.  
   
   
       15 . A method for forming a plurality of shaped articles from a strip of material, comprising the following steps: 
 incrementally feeding the strip of material in a forward direction along a strip feed axis;    forming discontinuities in the strip of material at axially-spaced intervals;    periodically aligning the strip to maintain constant axial spacing between the discontinuities by use of an alignment device comprising a frame structure having a pair of dies between which the strip is fed, at least one of the dies being movable so as to open and close the dies, the alignment device including a pilot hole punch and a pilot pin rigidly mounted in axially-spaced relation to one another on one of the dies;    after each said incremental feeding step, closing the dies, thereby causing the pilot hole punch to punch a pilot hole in the strip and to simultaneously cause the pilot pin to pass through a pilot hole previously formed by the pilot hole punch;    wherein the pilot pin and the pilot hole punch each have a length such that, during closing of the dies, the pilot pin passes through a pilot hole before the punch contacts the strip, and the pilot pin thereby aligns the strip relative to the pilot hole punch.    
   
   
       16 . The method of  claim 15 , wherein the incremental feeding step is performed by a feed mechanism which engages the strip during each incremental feeding step and which is disengaged from the strip between the incremental feeding steps.  
   
   
       17 . The method of  claim 15 , wherein the discontinuities are formed by a forming device comprising a plurality of punches which are reciprocal laterally of the strip feed axis.  
   
   
       18 . The method of  claim 17 , wherein each of the discontinuities is formed after one of said incremental feeding steps and during engagement of the feed mechanism and the strip.