Weld gun lug resurfacing tool

The present invention relates generally to a resurfacing tool for welding equipment.

For particular welding systems, weld gun arms may include cable lugs that attached to jumper cables. The face of the lug adjacent to the jumper cable must be kept perpendicular to a cable bolt attachment hole for proper electrical alignment—that is, in order to avoid arcing during operation of the weld gun. If a jumper cable loosens-up during operation of the weld gun, the arcing that occurs at the joint between the cable lug and the jumper cable (gun arm cable) can cause the cable lug to become arced (burned).

Once damaged, the weld gun arm cable lug must be repaired or replaced. Replacement is undesirable because of the down time for disassembly and reassembly of the weld gun components, as well as the relatively high cost of the replacement gun arms. Grinding or sanding the lug face of the cable lug is undesirable because of the environmental considerations involved with dust from the copper beryllium alloy that the cable lugs are typically cast from. Providing for an environmentally-controlled area for machining the lug face has the drawbacks of having to set up an environmentally-controlled area, and also the downtime required for disassembly and reassembly of the gun in order to be able to take the cable lug to this area for processing.

An embodiment contemplates a resurfacing tool for a weld gun lug having a lug face and a cable bolt attachment hole extending through the face. The resurfacing tool may comprise a hollow chip retention housing having a lug entrance, a bushing opening in opposed relation to the lug entrance, and a chip retention area. A rotary attachment shaft extends through the lug entrance and can rotate relative to the retention housing, and includes a rotary tool attachment portion configured to be couple to a rotary power tool. A cutting head assembly is mounted to the rotary attachment shaft in the retention housing for rotation with the rotary attachment shaft, with the cutting head assembly having at least one cutting head facing toward the lug entrance. A member defines an alignment bore oriented coaxially relative to the rotary attachment shaft. Also, a guide pin has a lug attachment portion configured to attach to the weld gun lug normal to the cable bolt attachment hole, and a pilot shaft telescopically receivable in the alignment bore.

An embodiment contemplates a resurfacing tool for a weld gun lug having a lug face and a cable bolt attachment hole extending through the face. The resurfacing tool may comprise a hollow chip retention housing having a lug entrance, a bushing opening in opposed relation to the lug entrance, and a chip retention area. A rotary attachment shaft extends through the lug entrance and can rotate relative to the retention housing, and includes a rotary tool attachment portion configured to be coupled to a rotary power tool. A cutting head assembly is mounted to the rotary attachment shaft in the retention housing for rotation with the rotary attachment shaft, with the cutting head assembly having a cutting head facing toward the lug entrance and having a central bore coaxial with the rotary attachment shaft.

An embodiment contemplates a method of resurfacing a lug face of a cable lug on a weld gun arm, the method comprising the steps of: mounting a cutting head assembly in a hollow chip retention housing; rotationally coupling the cutting head assembly to a source of rotary power; mounting a lug attachment portion of a guide pin in a cable bolt attachment hole on the lug face such that a pilot shaft portion of the guide pin extends from the lug face; telescopically sliding the pilot shaft portion into an alignment bore in the chip retention housing that is normal to a face of the cutting head; sliding the cutting head into engagement with the lug face; and catching chips cut off the lug face by the cutting head in a chip retention area of the chip retention housing.

An advantage of an embodiment is that a quick and environmentally-friendly tool and method for resurfacing the lug face on a cable lug of weld gun arms is provided. Disassembly and reassembly of the weld gun is not required since the resurfacing tool is small enough to be used without disassembling the gun, thus minimizing downtime. Also, grinding and sanding is avoided in order to eliminate dust from the copper beryllium alloy, and the copper beryllium chips taken from the lug face are captured for proper disposal. Moreover, the cost of a new weld gun arm and downtime for disassembly and replacement is avoided. And, the resurfacing tool can be driven by a common source of rotary power, such as, for example, a common drill.