| 摘要 |
A progressive die for producing collared holes in a sheet. The die includes a first station having a pattern of three punches producing three spaced apart holes in the sheet. A main punch at the second die station is extended into the three holes producing a single hole with portions of the sheet extending therein. The straightening punch mounted at the third station of the die has a diameter larger than the single main hole and is extended therethrough bending the portions extending into the hole outwardly forming a collar. The curling punch mounted at the fourth station of the die, curls the distal end of the collar outwardly.
|
