A resistance welding apparatus includes: a cleaning system that, before a welding electrode contacts a welding target, supplies a fluid to clean, of a contact portion of the welding electrode and a contact portion of the welding target, at least the contact portion of the welding target, the contact portion of the welding target being to contact the welding electrode, the contact portion of the welding electrode being to contact the welding target; and a cooling system that, during and/or after welding the welding target by the welding electrode, supplies the fluid to cool the welding electrode and a portion near the contact portion of the welding target.

An apparatus includes a welding electrode and a holder with a primary electrical connection for carrying a welding current. The electrode and the holder may separate easily due to a weak interference fit of the primary electrical connection. Bare hands may provide sufficient force for separation. The electrode and the holder may be configured for self-alignment. A quick-release mechanism may prevent unintentional dislodgement of the electrode from the holder and include a rotation-resistant device for preventing electrode rotation. A secondary electrical connection may be included to supplement or replace the primary electrical connection. A workpiece clamping force, traditionally intended for clamping the electrode to a workpiece, may also be utilized to enable the secondary electrical connection.

A method of joining a multiple member work-piece includes providing a first steel work-piece having a first thickness and a second steel work-piece having a second thickness. The first thickness is at least twice the second thickness. A third material is disposed in contact with the second steel work-piece. For example, the third material may be in the form of a rivet, a plurality of pins, or a coating material. The method includes resistance welding the first and second work-pieces together. A bonded assembly includes the first and second steel members and the third material being bonded together, where the thickness of the first member is at least twice the thickness of the second member.

A method of joining a multiple member work-piece includes providing a first steel work-piece having a first thickness and a second steel work-piece having a second thickness. The first thickness is at least twice the second thickness. A third material is disposed in contact with the second steel work-piece. For example, the third material may be in the form of a rivet, a plurality of pins, or a coating material. The method includes resistance welding the first and second work-pieces together. A bonded assembly includes the first and second steel members and the third material being bonded together, where the thickness of the first member is at least twice the thickness of the second member.

A swing arm assembly is provided for a spot welding machine. The swing arm assembly can accommodate a tip dresser or a tip exchanger and can include a lift assembly that can translate the tip dresser from a first position to a second position along a lateral axis.

A swing arm assembly includes a tip dresser, a flange, and a swing arm. The flange is coupled with the tip dresser. The swing arm includes a mounting base and an arm assembly. The arm assembly includes an arm, an extendible arm mount, and a head. The arm is coupled with the mounting base. The extendible arm mount is disposed within the arm and is slidable with respect to the arm along a first axis between a retracted position and an extended position. The head is mounted to the extendible arm mount and includes a support plate and an actuator. The actuator is coupled with the support plate. The tip dresser is coupled with the support plate. The actuator is operably coupled with the flange to facilitate selective sliding of the tip dresser with respect to the support plate.

A welder having first and second electrodes configured to clamp and weld a fastener to a workpiece at an opening in the workpiece, wherein the first electrode is configured to move in a direction transverse to a clamping direction to center the fastener with the opening. The welder can carry out a method of aligning and welding an internally-threaded nut to a panel at an opening in the panel. The method includes the steps of: centering the opening in the panel relative to a first electrode using a tapered guide pin that extends into the opening; centering the nut relative to the opening using the tapered guide pin; clamping the nut and panel between the first electrode and a second electrode; and welding the nut to the panel by passing current through the nut and panel from one of the electrodes to the other electrode.

A weld wheel cleaning system is provided to clean or remove a layer of embedded material and other debris produced from welding from the working surface of a weld wheel. Such a weld wheel cleaning system includes a cleaner with an abrasive material positioned on an outer surface of the cleaner. The cleaner is positionable adjacent to the weld wheel such that the abrasive material is aligned with the working surface of the weld wheel. An actuator can be used to selectively actuate the cleaner with a force sufficient to remove the layer of embedded material from the working surface of the weld wheel with the abrasive material. The debris from the cleaner can be removed by a vacuum.

A cap dispenser for a welding gun includes a sleeve that slidably receives a drawer that is configured to house a column of weld caps. The cap dispenser also includes a spring that cooperates with a slide block that is arranged in the drawer. The spring urges the slide block toward an aperture in the drawer that is configured to receive a welding gun electrode.

A device for twisting-off and stripping an electrode cap from an electrode cap receptacle of an end of a welding gun of a welding robot, the device comprising a cap twisting-off unit and further comprising a stripping device. The stripping device is arranged along an insertion path for an electrode cap receptacle with an electrode cap as seen in front of the cap twisting-off unit and along a discharge path for an electrode cap receptacle without or with electrode cap as seen from behind the cap twisting-off unit. The stripping device can be for use in combination with the cap twisting-off unit.