Patent ID: 6725521
Filing Date: 2004-04-27
Classification: B21J,Y10T

Abstract:
A method for inserting a fastener (1) into sheet material (5, 6) comprising inserting the fastener (1) into at least one sheet without full penetration such that a deformed end of the fastener remains encapsulated by an upset annulus of the sheet material, the sheet material (5, 6) being disposed between a nose (17) and a die (16) of fastening apparatus (18) and the fastener (1) being inserted into the sheet material by means of a punch that is reciprocal relative to the nose (17), characterized in that a first clamping force is applied to the sheet material during fastener insertion between the nose and die in the region around the fastener insertion location, and in that after the fastener is inserted the punch is retracted and then a second clamping force is applied to the sheet material (2, 3) between the nose (17) and die (16) in the region around the fastener insertion location so as to reduce deformation of the sheet out of its plane in the region around the fastener insertion location.