This mechanical assembly is a welding jig. It allows the welding of sleeves and reinforcement/support bars in a repeatable and dedicated manner on Ø340 coils with sleeve centres distance of 240 mm, 555 mm and 735 mm.
The rotating frame placed on the chassis by means of a slewing ring offers a 180° rotation (reversible) of the coils in position (to facilitate welding operations). The rotation is locked in the 0° and 180° positions by a lock.
The coils are positioned using three combs to ensure the correct spacing of the coils. One of the three combs is attached to a retractable flap on the rotating frame to free the field for loading.
When a coil is loaded, the flap is folded down and clamped in place by means of clamps.
The positioning and holding of the sleeves on the coil is carried out by two centring devices equipped with clamps. They can be moved to the positions defined by the sleeve centre distance of each coil.
Two protective caps are placed at the locations not occupied by the centring devices to protect the reference surfaces of the sleeves.
The jaws of these centring devices, which are exposed to welding, are reversible, which considerably increases their service life.
On the flap carrying the coil holding comb is placed a support allowing the positioning of one of the reinforcing bars to be welded on the coils at 45°.
Opposite the first flap, a second flap, which can be retracted by means of a pivot link, allows the other bars to be positioned at -45°.
The chassis has a ground connection to the rotating frame which short-circuits the slewing ring, thus avoiding any possible weld start at the level of the balls of this one.