A new series of hinges from Banner Engineering Corp., Minneapolis (www.bannerengineering.com), has built-in safety switches concealed in them. Once a hinge opens to a user-set point in its 180* range, the switch opens to turn machinery off for safety reasons. The hinge supports axial loads of 165 lb and radial loads of more than 220 lb. They provide physical protection rated as IEC IP67. Two of these positive-opening switches and a controller can provide Category 4 protection.

Operating temperatures range from -25 to 70*C and they have a maximum switching speed of 20 operations/min. Their mechanical life is 1 million operations. A simple hinge-only version is available to match the hinge switch unit. Applications include doors, gates, and fences.