Site of the Month for September 2011 relates to Industry Directory. Industry 500 provides numerous links related to industrial supply, materials handling, safety products, paints, stains, and sealants, machinery & tools, fluid and gas control, lubricants, power transmissions and more.

“Controlled access” generally refers to a movable machine guard that is designed such that it can only be opened under specific conditions. Typically such movable guards restrict access to an area of a machine which continues to present a hazard to the operator immediately upon the removal of power. In these situations opening of the guard is prevented until the hazardous condition has abated.

This is usually achieved by a solenoid-latching interlock switch controlled by a motion detector, position sensor, time-delay or other machine-status monitor which releases the interlock (allowing the operator to open the guard) only after safe conditions exist.