Patent GB-1251111-A (GB)
IPC: E04C5/06
Filed: 1969-02-19
Abstract: 1,251,111. Making reinforcements; coiling helices; stretching. NIPPON CONCRETE INDUSTRIES CO. Ltd. 19 Feb., 1969 [26 Feb., 1968], No. 8878/69. Headings B3A and B3E. [Also in Division F2] A reinforcement for a pre-cast concrete pipe, pole &c., comprises a cage-shaped body C formed of non-tension reinforcements 2, 1 respectively which extend generally longitudinally and transversely of the cage C, metal end fittings T, T and a plurality of tension reinforcements 3 having their ends connected to, and supported by the end fittings so that they are freely supported in the cage C and can be tensioned by moving the end fittings T, T apart. As shown, a central cage C and end pieces E, E, of slightly larger diameter, are formed in a spiral-forming-welding device (A), Figs. 1A, 1B, not shown, which has a cutter (B) for cutting off required lengths of welded-together longitudinal and spiral reinforcements 2, 1 respectively. An end piece E is telescoped over each end of a cage C, and tension reinforcements 3, having hooks on the left hand ends, are inserted from, the left side through corresponding holes formed in the peripheries of the end fittings T, T around a pitch circle having a diameter equal to that of the cage C, the right hand ends of the reinforcements 3 being upset. To prevent the ends of the reinforcements 3 from intermingling with the helical reinforcement 1 they are passed through the cage a guide (G), Fig. 3, not shown, can be employed. In a modification, Figs. 5, 6, for forming a cage a disc 18, having chucks 19, 20, 21 for securing the ends respectively of the tension, longitudinal, and helical reinforcements 3, 2, 1, is carried by a traction device 17 which is movable in the direction of the arrow, by a motor 13, operating through reduction mechanism 14 and gears 14. The latter also rotate a bobbin 11 which supplies, from a guide at its centre, the reinforcements 2, 3 and which winds the helical reinforcement 1 on to the longitudinal reinforcement 2. The bobbin also carries an electric welding device 12 to intermittently weld the reinforcements 1, 2. In a further modification, Figs. 7-10, not shown, the tension and non-tension longitudinal reinforcements (3, 2) are shifted axially while being rotated to take-up a helical reinforcement from a stationary bobbin having an electric welding device. In another embodiment for forming a concrete pole, Fig. 11(F), not shown, a helical reinforcement (1) is wound around, and welded at intervals, to longitudinal reinforcements (2) which are pulled, by a traction device (53), over a bunch of parallel tension reinforcements (3) located between a fitting base (50) and a tensioning applying plate (47). As the traction device (53) moves to the left a guide device (54) on the fitting base (50) moves to the right and contracts radially inwardly so that a tapered cage is formed. A device is also described for continuously forming a cage by apparatus which axially feeds and rotates longitudinal reinforcements which receive the helical reinforcement from a stationary bobbin and welding station. A somewhat similar device, Figs. 14(A)-14(E), not shown, is also described which continuously supplies the longitudinal reinforcement as it is wound by the helical reinforcement, the tension reinforcement also being inserted symultaneously with the fabrication of the reinforced cage.