Manufacture of wire binding elements

A machine for transforming zig-zag wire to slotted tubular form ready for use as a binding element comprising means for feeding a strip of zig-zag wire longitudinally, means for momentarily arresting the feed of each prong of the wire strip as it reaches a shaping station, means for clamping each prong at that station and means for shaping each clamped prong into the desired configuration characterised in that the clamp is operated by clamp actuation means at least twice for each revolution of rotary feed means. This has the advantage that the clamping means may be operated at much lower speeds than the feed means and the shaping means thus allowing the output to be increased by at least fifty percent over known machines with no danger of overheating.