Abstract: A welding gun for wire spring relays has jaws designed to clamp the wire contact arm with the end of the wire on which the contact is to be welded projecting a predetermined amount through the jaws. Mechanism on the gun brings the contact against the clamped wire (to which it is to be welded) with a predetermined spring pressure, the mechanism increases the pressure between contact and wire by a consistent amount before initiating the welding operation.

Abstract: A welding gun for replacing the movable contacts of wire spring relays is provided with a pair of jaws relatively movable toward each other to clamp the contact material to the relay arm for welding them together. A manual control member is movable to cause the relative movement over a resilient connection which provides the clamping pressure. The manual control member moves past the point in its travel where clamping is achieved stressing the resilient connection to actuate a switch to initiate the welding cycle. The clamping pressure is thus controlled at the time that welding commences.