Metallic cage structure and apparatus for manufacturing same

Claim 1

Apparatus for manufacturing a metallic cage structure for reinforcing concrete, comprising a support member carrying: i. a drive unit for receiving a plurality of bars and together propelling them horizontally forward in parallel spaced configuration through a vertical frame constituting part of said support member, said drive unit comprising a plurality of first support means carried on said frame and each being independently adjustable for position in a first direction perpendicular to the line of advancement of the bars, a plurality of second support means carried on said first support means and each independently adjustable for position relative to said first support means in a second direction perpendicular to the line of advancement of the bars and perpendicular to the said first direction, each of said second support means carrying location and forward drive means for a bar; ii. a wiring unit downstream of said drive unit and operative to tightly coil around all the bars a helix of wire in substantially straight runs between bars; iii. a welding unit downstream of and separated from said wiring unit operative to weld the wire to the bars at their mutual points of contact, said welding unit comprising a vertical frame constituting part of said support member carrying a plurality of carriages having mounted thereon weld guns adjustable for position across the line of advance of the bars, means for driving forward each carriage and associated weld gun in synchronism with the bars during each welding operation, and means for rapidly driving backward each carriage and associated weld gun after each welding operation in readiness for a subsequent operation.