Detecting contact or pressure on curved surfaces once required several multipart switches.
A new Sensor Ring switch from Tapeswitch Corp., Farmingdale, N.Y. (www.tapeswitch.com), does the same job with a simple, one-piece curved device inside a seamless, flexible housing. It mounts on the circumference of a hollow arc or ring and can handle diameters of 1.5 to 5 ft, covering angular ranges of 10 to 360°. The hollow-ring design permits pass-through of wires, components, or personnel.
Inside the flexible housing, which can be made of a variety of materials, is a simple pressure-activated ribbon switch. It has two strips of a proprietary metal alloy separated by a layer of compressible insulation. Pressing the switch makes contact between the two strips and activates the switch. The device's design life is 3 million actuations at any point.
The switches, which operate in temperatures ranging from -10 to 140°F, have earned IP67 Protection Classification and CE approval, and are protected against dust and immersion (to one meter). They can be mounted using factory-installed adhesive backing or foam tapes. For more permanent installations, the company provides PVC channels and mounting screws. The switches can be used to detect human contact or stop limits in safety applications or provide feedback for aligning machines.