| 摘要 |
1,239,409. Releasable fastenings. F. T. PRODUCTS Ltd. 15 Oct., 1968 [16 Oct., 1967], No. 47128/67. Heading E2B. A fastener comprises a pin 13 having a head 11 at its upper end, a foot 13a at its lower end and, between its head and foot, a neck 17 and an annular abutment surface 18 facing the head, and a socket 14 which comprises a tubular shank 20 having an external flange 21 at its upper end, the respective external and internal dimensions of the pin and shank being such that the shank is expanded when the pin is driven into it, characterized in that the shape of the neck, at its junction with the abutment surface, is oblong in cross-section and of dimensions such that when the pin has been driven home in the shank the oblong shape of the neck serves to draw inwardly a portion of the lower end of the shank into locking engagement with the abutment surface 18 of the pin. The external periphery of the abutment surface 18 is approximately oval and the neck 17 is generally conical except for two bosses 19 and 19a which are located at opposite ends on the minor axis of the periphery of the surface 18; the periphery of the neck 17 at its junction with the surface 18 is thus approximately oval with its major axis perpendicular to the major axis of the periphery of the surface 18. When the pin is inserted into the socket a rib 23 binds on the neck 17 and is distorted by the bosses 19 and 19a which deform and stretch the wall of the shank around one axis thereby contracting it along the other axis so that the wall of the shank is drawn inwardly along the major axis of the surface 18 and provides a positive and secure abutment for the rib 23 at the tip of the shank to resist withdrawal of the pin from the socket. The pin is moulded integrally with the socket and during insertion of the pin in the socket it breaks away from the socket. The head 15 as shown is formed with a part cylindrical channel 16 into which a cable can be manually snap engaged but in a modification the head can have two integral channels which are of different diameters and will accept cables of different dimensions. The pin 13 is hollow so that it can collapse temporarily as it enters the socket. |
