| 摘要 |
A panel fastener includes a metallic screw insert with an overmolded plastic cap. The screw insert is preferably manufactured by means of cold forming process which allows fabrication of the internal drive recesses and dog point ends for easy location of the mating threads while providing increased thread strength. The plastic cap is in the form of a knob which has large flutes on its outer diameter for ergonomic finger operation. In addition the knob may have a slot molded into its top to allow screwdriver or coin operation. The metallic insert may also be accessed by a drive through a central cavity in the knob. Assembly of the screw to the ferrule is achieved by passing the screw threads through the ferrule body which includes an internal annular retaining ring. The ring is very narrow and dimensioned to allow the screw to be easily pressed through the annular opening since the ring elastically expands as the thread portion of the screw passes through it. The screw is thus captivated in the ferrule however may be removed by applying a light axial force in a direction away from the panel and simultaneously applying a counterclockwise rotation to the screw head to "unthread" the screw through the annular retaining ring. The ferrule includes a plurality of resilient fingers on its leading edge which provide low installation force snap-in panel attachment.
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