| 摘要 |
1,022,013. Wall-plugs. W. REIN. Nov. 19, 1962 [Nov. 20, 1961], No. 43725/62. Heading F2H. A polyamide wall-plug has a tubular trailing end 4 and a leading portion 2 formed as a right- or left-hand helix with closely-spaced coils and a central space 3 forming the screw-receiving hole. The thread of polyamide forming the coil is of trangular section with the triangle base lying in the wall of the hole 3. The triangle apex is rounded and two filamentary webs 20, Figs. 5, 7 (not shown), of rectangular section, may extend longitudinally of the plug, connecting apices along two diametrically opposed lines. Midway between these webs, inner webs 21, of triangular section, may extend in two opposed lines adjacent the wall of the hole 3. The webs 21 shear in use. The tube end 4 may bear four ribs 8, two of which may be adjacent opposed inner ribs 9 at the edge of two slots 10. There may be a flange 22 at the end of the tube end, Figs. 3, 4 (not shown), extending to the edges of the ribs 8. The flange may be in two crescent halves 23, Figs. 7, 8 (not shown), extending only from two opposed sides of the tube end to the edges of two opposed ribs 8. |
