A method of making tennis bracelets includes coupling together collet elements (2) in a repetitive series, wherein an L-shaped lateral appendage (3) of a collet element is inserted into a through hole (6) of an immediately adjacent collet element and then bent against a face (7) of the collet element to which it belongs. The collet elements are inserted according to the repetitive series into an assembly template (10) implemented as a self-supporting unit provided with fasteners (16) for fastening the unit to first and second carriage supports (22, 36) of first and second machines (18, 19), which cause the assembly template to translate under a die block (26) of a press device (24) of the first machine. The lateral appendages (3) of the collet elements are bent in succession under a laser welding head (38) of the second machine, for welding the appendages (3) to their respective collet elements.

A method of making tennis bracelets includes coupling together collet elements (2) in a repetitive series, wherein an L-shaped lateral appendage (3) of a collet element is inserted into a through hole (6) of an immediately adjacent collet element and then bent against a face (7) of the collet element to which it belongs. The collet elements are inserted according to the repetitive series into an assembly template (10) implemented as a self-supporting unit provided with fasteners (16) for fastening the unit to first and second carriage supports (22, 36) of first and second machines (18, 19), which cause the assembly template to translate under a die block (26) of a press device (24) of the first machine. The lateral appendages (3) of the collet elements are bent in succession under a laser welding head (38) of the second machine, for welding the appendages (3) to their respective collet elements.

In a chain belt having: plurality of link plates each provided with a pin hole; plurality of connecting pins to connect a part of the plurality of link plates in an endless annular form by being inserted into the pin holes across the part of the plurality of link plates in a state where the part of the plurality of link plates are overlapped; and a retainer pin welded to an end portion of the connecting pin and engaged with the link plate to prevent the link plate from coming off the connecting pin, the retainer pin is disposed in a posture in which an outer circumferential surface is in contact with an outer circumferential surface of the connecting pin, and a plurality of points on the outer circumferential surface of the retainer pin separated from each other in the circumferential direction are welded to the connecting pin.

A description is given of a method for the production of gourmette jewellery articles comprising the steps consisting of: forming by cutting a series of links (10) starting from a metal plate; creating a reinforcing edge around said links; pressing in a mould said reinforced links to confer thereto an undulated shape; making a cut (41) which develops from the outer perimeter to the inner perimeter on some of said reinforced links (30), obtaining in this way a series of reinforced links provided with cut (40); attaching in sequence two reinforced links provided with cut (40) to an intact reinforced link (30), or two intact links to a link provided with cut, obtaining a chain wherein a reinforced link (30) alternates with a reinforced link provided with cut (40); and closing the cuts (41) previously formed in the reinforced links provided with cut (40).

A method and an apparatus for chain welding a chain starting from a chain composed of open C-shaped chain links uses a conveying wheel which receives one or more chain links of the chain and positions them for welding. The conveying wheel is a double chain wheel, the two pocket wheels of which receive a respective chain link of two chain strands of the chain. In each sequence of welding of a chain link, the conveying wheel is displaced relative to a welding device transversely with respect to the longitudinal direction of the chain and then occupies a welding position in which a chain link to be welded, as chain link that is vertical in the conveying wheel, faces the welding device and the open ends thereof are welded. This sequence is repeated, allowing that chain links of the two chain strands are alternately welded in the chain wheel.

A method and an apparatus for chain welding a chain starting from a chain composed of open C-shaped chain links uses a conveying wheel which receives one or more chain links of the chain and positions them for welding. The conveying wheel is a double chain wheel, the two pocket wheels of which receive a respective chain link of two chain strands of the chain. In each sequence of welding of a chain link, the conveying wheel is displaced relative to a welding device transversely with respect to the longitudinal direction of the chain and then occupies a welding position in which a chain link to be welded, as chain link that is vertical in the conveying wheel, faces the welding device and the open ends thereof are welded. This sequence is repeated, allowing that chain links of the two chain strands are alternately welded in the chain wheel.