Achieving correct clamp force is critical in fastener assembly. Among other things, proper clamp force prevents joint failure due either to fatigue or to loosening caused by vibration.
To help designers address the variables that affect a fastened joint on the assembly line, engineers at Camcar Textron, Rockford, IL, teamed with Force Imaging Technologies, Chicago, to develop a system that accurately monitors clamp force during assembly.
The ClampRight(TM) fastening system incorporates a 0.003-inch-thick force sensor, custom-designed to fit the joint. Made of conductive material, each sensor has a strategically placed "button" to sense clamp force. The sensor is installed as part of the joint, and attaches to the drive gun.
As the fastener is installed, the button on the sensor monitors clamp force. Once the button senses a predetermined force, the sensor and included software send a signal to automatically shut off the drive gun.
Accurate to plus or minus 1.5%, ClampRight provides repeatability, so that installation variables such as friction will not affect results. The system is compatible with almost any type of fastener, according to Camcar engineers. Engineers analyze individual application and assembly parameters to design new systems, or incorporate Clamp-Right into existing assembly and driving equipment.
Applications include gasketed joints, joints susceptible to cross-talk during assembly, and safety-related or structurally critical joints.