公开(公告)号：US3611765A

公开(公告)日：1971-10-12

申请号：US3611765D

申请日：1969-09-08

Applicant: UNITED AIRCRAFT CORP

Inventor： HARVEY JOHN WILLIAM

IPC: B21D28/18 ,  B21D31/02

CPC classification number: B21D28/18 ,  B21D31/02

Abstract: A TWO-STEP METHOD IS PROVIDED FOR PRODUCING LOUVERS BY THE GUERIN PROCESS IN WHICH A FORM BLOCK HAVING A CLOSEDEND RECESS WITH AN ERECT SHEAR RULE THEREIN AND A RESILIENT FORMING BLOCK ARE MOVED RELATIVE TO EACH OTHER WITH A SHEET METAL BLANK THEREBETWEEN, INCLUDING A FIRST PREFORMING STEP IN WHICH A PLASTIC INSERT IS PLACED IN THE RECESS ALONGSIDE THE SHEARS RULE WHICH PREVENTS SHEARING OF THE BLANK WHILE EFFECTING CONTROLLED STRETCHING OF THE METAL OVERLYING THE RECESS AS THE BLANK IS FORCED INTO THE RECESS BY THE FORMING BLOCK, AND A SECOND SHEARING AND FORMING STEP PERFORMED IN THE SAME MANNER IN THE SAME APPARATUS WITH THE PLASTIC INSERT REMOVED.