System prevents finger injury on spot welders

February 8, 2005

Unitrol Electronics Inc. has introduced Soft Touch, a passive process to its Solution series controls designed to protect fingers from electrode pinch points on spot welding machines.

The system lets electrodes close under low force and then electronically checks to see if metal is between the electrodes. If no metal is detected, the electrodes automatically release. If metal is detected, the full electrode force is applied and the weld is completed.

The process uses no external operator adjustments or mechanical detection arms and operates always, even if electrode spacing or welding force has been adjusted. The process can reduce a press welding machine's heavy ram weight to about 40 lbs. or less through use of the supplied pneumatic scheme and available pneumatic kit.

The low-force electrode pressure setting is locked in a NEMA 4 enclosure. Changing a machine's welding force regulator does not affect the initial low electrode force.

A control with this function can be installed on any type of press or rocker arm spot welding machine without modifying the machine's air cylinder. Kits also are available to update older controls for this feature.