GB886819A - Improvements in and relating to the production of prestressed concrete sleepers and like bodies - Google Patents

Abstract

886,819. Moulding prestressed concrete sleepers. STANTON IRONWORKS CO. Ltd. Sept. 21, 1960 [Dec. 3, 1959], No. 41129/59. Class 87(2). In a method of forming pre-stressed concrete and like bodies according to which reinforcing wires are made to traverse a plurality of moulds arranged in rows on a mould bed, the wires 21, Fig. 1, are fed from reels (not shown) through a distributer head 20 and through holes in a pair of clamped anchor plates 12, 13 and the ends are held by wire grips. The plates are moved forward until plate 12 is arrested by beams 11 which are abutted by hydraulic rams 10 carried by a buttress 2. The plate 13 is then unclamped and is moved forwards and upwards by a trolley 15 mounted on rails 16 and pulled by a cable 33 by means of a winch 17 at the distant end of the bed, Fig. 1a. The wires 21 are carried by rollers 35, Fig. 6, and spaced apart by guide fingers 28 above moulds 25 positioned at intervals along the bed, the moulds being supported by arms 23 and columns 22. The arms 27 carrying the guide fingers 28 are lowered and the wires 21 guided into vertical slots in the mould end plates (not shown). Meanwhile the winch 17 maintains the tension in cable 33 and hence in the wires, and the end of the cable is aligned with the wires 21 by the vertical adjustment of rollers 29 on a carriage 30. The plate 13 is then fixed to the buttress 4 and the wires 21 severed just beyond the distributer head 20, the severed ends being pulled backwards at the feed end of the bed to tension the wires, and concrete or like substance is introduced into the mould.