A plasma arc welding system includes at least two wire delivery mechanisms and at least two wires. Each of the two wires is delivered by one of the at least two wire delivery mechanisms.

A consumable electrode gas shield arc welding torch (20) includes a torch body (21), a tip body (22) mounted to a front end of the torch body, a tip holder (23) mounted to a front end of the tip body, a spring (26) provided in the tip body (22) in contact with the front end of the torch body (21), a pressing shaft (27) provided in the tip body (22) in contact with a front end of the spring 26) and a power feed tip (28) pressed by the pressing shaft (27) and the tip holder (23). The tip (28) includes a side surface having a projection contacting with a base end (23a) of the holder (23), with a space (29) defined between an inner surface of the holder (23) and a front end (28a) of the tip (28) when the front end (28a) of the tip (28) is inserted into the holder (23).

A welding torch system includes a receiving assembly to receive a contact tip and a welding nozzle. The welding torch system also includes a locking element that retains the contact tip in a partially secure position. Further, the welding torch system includes the welding nozzle configured to couple to the receiving assembly to retain the contact tip in a fully secure position.

A contact tip for welding includes: a tip case; a power supply tip that is housed in the tip case and supplies power to a welding wire supplied from a side close to one end of the power supply tip while holding the welding wire at another end opposite to the one end; and a guide that presses the power supply tip from the side close to the one end and houses the power supply tip in the tip case, in which the power supply tip has a shape in which an outer diameter from a press point pressed by the guide to a fulcrum in contact with the tip case increases from the press point toward the fulcrum, and the power supply tip is rotated about the fulcrum by pressing of the guide to hold the welding wire at the other end.

A welding torch system includes a receiving assembly to receive a contact tip and a welding nozzle. The welding torch system also includes a locking element that retains the contact tip in a partially secure position. Further, the welding torch system includes the welding nozzle configured to couple to the receiving assembly to retain the contact tip in a fully secure position.

A welding torch system includes a diffuser assembly that includes a locking mechanism to receive a contact tip. Additionally, the welding torch system includes the contact tip, which includes locking elements configured to interact with the locking mechanism of the diffuser assembly to secure the contact tip within the diffuser assembly. Further, the contact tip is rotated within the diffuser assembly to securely align the locking elements with the locking mechanism.

A welding torch system includes a nozzle, a contact tip retainer assembly, and a diffuser assembly. The diffuser assembly couples to the neck of a welding torch. Additionally, the welding torch system includes a contact tip axially secured between the contact tip retainer assembly and the diffuser assembly. Further, the nozzle axially secures the contact tip retainer assembly and the contact tip to the diffuser assembly.

Disclosed herein is a rotary changer including a rotator rotatable on a rotational axis extending vertically. An interlocking member is arranged to rotate integrally with the rotator and be movable in a direction intersecting with the rotational axis. The interlocking member has an interlocking groove interlockable with an outer peripheral surface of a nozzle inserted into the hollow of the rotator. Rotating the rotator with the interlocking member interlocked with the nozzle makes the nozzle replaceable.

A welding torch system includes a receiving assembly to receive a contact tip and a welding nozzle. The welding torch system also includes a locking element that retains the contact tip in a partially secure position. Further, the welding torch system includes the welding nozzle configured to couple to the receiving assembly to retain the contact tip in a fully secure position.

A welding torch system includes a diffuser assembly that includes a locking mechanism to receive a contact tip. Additionally, the welding torch system includes the contact tip, which includes locking elements configured to interact with the locking mechanism of the diffuser assembly to secure the contact tip within the diffuser assembly. Further, the contact tip is rotated within the diffuser assembly to securely align the locking elements with the locking mechanism.