CPC B23P 19/064 (2013.01) [B21D 39/031 (2013.01); B21J 15/04 (2013.01); F16B 37/068 (2013.01)] | 7 Claims |
1. A method of clinch-in fastening a fastener into a blind hole of workpiece, comprising the steps of:
a. providing a workpiece;
b. providing a fastener having an internal bore with threads;
c. inserting the fastener into a blind hole in the workpiece; and,
d. displacing workpiece material surrounding the blind hole against the fastener by:
i. applying a localized force to a segment of the workpiece material proximate the perimeter of the hole, said localized force having force components in both the parallel and perpendicular direction relative to the plane of the workpiece;
ii. increasing the localized force until it induces the yield stress in the workpiece and workpiece material deforms radially toward the fastener;
iii. radially advancing the localized force around the hole perimeter to a new segment;
iv. repeating steps (i)-(iii) until the localized force has been applied to the entire perimeter of the blind hole; and
e. deforming workpiece material into at least one of the threads of said internal bore.
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