Patent GB-380564-A (GB)
Title: Improved means for manufacturing concrete pipe reinforcements and the like
IPC: B21F27/12
Filed: 1931-08-10
Abstract: 380,564. Making concrete reinforcements. HALKYARD, C. C., Kinnear House, King Street, Melbourne, COSGRAVE, C., Norford Grove, Malvern, and HUME STEEL, Ltd., Kinnear House, King Street, Melbourne, both in Victoria, Australia. Aug. 10, 1931, No. 22622. [Class 83 (iv).] Coiling; winding; welding.-Tubular reinforcements for concrete piles, poles, pipes, &c. of circular, elliptical or rectangular section and consisting of longitudinal wires or rods welded at their points of intersection to one or more helical wires or rods, are made by continuously feeding the longitudinal wires through an annular rotary head, which winds the helical wire thereon and has one or more electrodes for welding each joint in succession, the longitudinal wires passing through guides which act also as supports for the wires at the welding points. The welding drum 2 is supported and rotated by pairs of rollers 3, one pair of which is driven from the main shaft 4, preferably through variable speed gearing. The drum carries one or more transformers or pairs thereof 9a, 9b, the primaries of which are connected in parallel and supplied with current from slip rings 7 and the secondaries of which are connected in series to one or more divided rings 11, one part being provided with electrodes 13 engaging the flange 26 of a detachable guide ring 22 or with spring-pressed pivoted brushes 13a engaging the periphery 53 of a wheel 34, the ring 22 or wheel being fixed to a stationary beam 23 secured in brackets 24. A copper electrode 12, which is grooved to engage the helical wire 30, is carried by a cranked rod 74 angularly and also longitudinally adjustable in a spring-pressed pivoted holder 76 mounted on the ring 11. In one form, one half of the ring 11 may consist of two overlapping sections 11a, 11b insulated from each other and containing conical members 77 on which the holders 76 for the electrodes 12, 13 are secured by an insulated bolt 81. When using a guide ring 22 the longitudinal wires 28 are drawn through guides 33 adjustable on rods 32 secured to the beam 23 and then through holes 25 in the flange 26. The flange 27 is provided with angular brackets 29 on which the wires are pressed by the electrode 12 during welding. Insulated bowed members 31 of tapered section are placed on the flange between each pair of brackets so as to prevent sagging of the helical wire. When using the wheel 34, the longitudinal wires are drawn through apertures 44 in guides 37, which are adjustable on and clamped to spokes 36, the wires then passing over wearing strips 46 inserted in recesses in the tapered parts 43 of the guides to serve as supports during welding. The helical wire is engaged by pins 52 on members 38 adjustable on and clamped to spokes 36a. The hub of the wheel may also have a guide ring 22a for use in making fabrics of small diameter. The joints are preheated by the electrodes prior to the electrode 12 engaging the crossing points. The helical wire is fed through a tube 61 from a spool 59 rotatably mounted on rollers 64 on the drum. The spool is provided with a pulley 67 so that it may be driven by a belt from a shaft 69 in order to replenish it with wire. The fabric is drawn through the machine by metallic brushes 84 on four chain conveyers 83, which are mounted on bars 88 connected by parallel links 89 pivoted at 98 so that they may be bodily adjusted to suit the size of fabric without disturbing the drive by screwed rods 93, pivoted to one pair of links and engaging trunnioned nuts 95. The drive is effected by chains 112 on shafts 86, 109, the chains being tensioned by jockey pulleys 116 on bell cranks 117 connected by bars 118 attached to the parallel links. The shafts 109 are geared together by mitre gears and are driven by gearing 108, 107, chain gear, worm reduction gear 103 and spur gear 101 from the shaft 4. In welding two helical wires simultaneously, two transformers or pairs thereof are used, the secondaries in the first case being in parallel, and in the second case the secondaries of one pair being in parallel with those of the other pair, a divided ring 11 and electrode 12 being used for each helical wire. A single ring 22 or wheel 34 is used and one or more electrodes 13. In welding three helical wires simultaneously three transformers may be used with a three-phase circuit, the primaries being connected in delta and the secondaries in star. A divided ring 11 and electrode 12 are also in this case used for each helical wire, and only one ring 22 or wheel 34 and a single electrode 13 provided. The guides are adjustable to vary the spacing. Specification 302,662, [Class 83 (iv), Metals, Working], is referred to.