| 摘要 |
A self-captivating screw becomes captive in a metal sheet, yet is freely rotatable after a simple pressing of the two parts. The screw is applied to the sheet by pressing against an anvil having a circular cavity in alignment with the panel aperture. The screw has an elongate shank with a head at one end and a threaded portion at the opposite end. The head and threaded portion are greater in diameter than the shank. The screw includes a displacer collar just beneath the head which, under pressure, deforms the metal sheet causing the cold flow of panel metal inward about the screw shank without gripping it tightly. The anvil cavity has a diameter greater than the major diameter of the screw threads, but less than the diameter of either the displacer collar or the minor diameter of the threads.
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