| 摘要 |
1,270,236. Making fasteners; forging. E.G. ENG. (PTY.) Ltd. 26 Jan., 1970 [11 Feb., 1969; 8 May, 1969], No. 3675/70. Headings B3A and B3H. [Also in Division F2] A wood fastener comprises a shank divided longitudinally into two halves 3, 4 of semicylindrical cross-section, a head 6 being formed at one end with a hole 7 therethrough communicating with the axial passage 8 within the two halves, the other end of the shank being pointed and shaped to provide anchoring formations 11. The shaping simultaneously produces a constriction 12 of the passage 8 such that after the fastener has been driven into a piece of wood a nail 16 is driven down the axial passage 8 and spreads the two halves of the fastener apart to cause the anchoring formations to grip the wood. A washer 13 may act as a seal when the fastener is used to secure roof cladding material. The fastener may be formed by bending a length 1 of semi-cylindrical material on itself and then feeding it into a cold heading machine which simultaneously produces a pierced head, pointed end and anchoring formations, Fig. 1. Alternatively, the fastener may be in two separate halves 17, 18, the heading operation producing a shoulder 19, Fig. 3. A perforated cap 20 is bent round the periphery of the head to secure the two halves together. The fastener may also be formed from a length of pipe having a head formed at one end and a barbedlike point at the other. The wall of the pipe is split along at least that portion of the shank where the bore is constricted. |
