| 摘要 |
1,240,202. Laying pipes. HEPWORTH IRON CO. Ltd. 21 July, 1970 [5 Aug., 1969; 20 Oct., 1969; 22 May, 1970], Nos. 39261/69, 51282/69 and 24860/70. Heading F2P. In mole-ploughing piping into the ground a deflated inflatable bag is inserted into the piping and inflated into gripping contact along its length with the inside of the length of piping and the bag is pulled by a mole-plough so as to pull the piping into and through the ground. The bag is then deflated and withdrawn. The bag itself may be connected to the mole-plough in which case it may have reinforcing wires incorporated, or a separate wire may be inserted with the deflated bag so that when the bag is inflated the wire is gripped between the bag and the wall of the piping and the wire connected to the mole-plough. In another arrangement a wire extends inside the bag and is secured to the ends thereof. Whilst one length of piping is being laid into the ground a further length is prepared ready for laying. |
