GB572385A - Improvements in the production of pre-stressed reinforced concrete sleepers and similar beams - Google Patents

Abstract

572,385. Moulding pre-stressed reinforced concrete sleepers, beams, &c. DOWSETT ENGINEERING CONSTRUCTION, Ltd., and BARBER, R. S. V. April 8, 1943, No. 5661. [Class 87 (ii)] A group of long reinforcing wires is stretched above a production line, and moulds, which run on a track in the line, are assembled in series around the wires and filled with concrete. Fig. 1 is a plan of part of an arrangement in which four groups of wires 18, in two pairs of groups, are stretched above tracks 16 having spaced mould-supporting rollers 17. Each mould comprises an open-ended trough 22 and end plates 23 which are slotted for the reception of the wires (see Specification 572,387). In operation, the empty troughs are fed in laterally in pairs along a runway 19 to a turntable 20 where they are turned into alignment with the production lines A, B. An elevator 21 then raises them to the level of the lines A, B, the end plates are bolted into position, bolt-pins are placed in position, and the completed empty moulds are slid to the right along the wires until they rest on a platform 12 beneath a concrete-containing hopper 15. Concrete is then fed into the moulds, which are simultaneously vibrated by means of a vibratory platform 14. The filled moulds are then slid along the wires, to the right or left, to their setting and hardening stations, the production lines being thus filled with charged moulds. When the concrete has hardened, the moulds are brought over an elevator 28, the wires are severed, and the moulds are lowered on to a lateral discharge track 26, which is stated to be a power-driven conveyer. The reinforcing wires themselves may form the haulage means for pulling the moulds into position over the elevator 28, and as shown a winch 25 is coupled by cable 29 and T -head 30 to one of the moulds, whereby the whole series can be pulled along as a train. Details.-The moulds may have rollers or wheels or skids, or each mould may be supported on a trolley having rollers, wheels or skids. The wires may be cleaned or etched, and are tensioned between standards. The final tension may be applied to the wires after the moulds have been assembled therearound. The production lines may be arranged in tiers, as described in Specification 572,388. The hopper 15, the vibratory platform 14 and the elevators 21 and 28 may move laterally between the production lines A, B and the production lines C, D. Specifications 338,864, [Class 87 (ii)], 364,621, 393,576 and 572,390 also are referred to.