PRESSURE OPERATED ELECTRIC SWITCH AND AN ALARM SYSTEM USING SUCH SWITCH

摘要

The present invention provides a pressure operated electrical switch and an alarm system using the switch. The switch is constructed such that a force is applied to a pressure plate in the switch and once the load is reduced below a predetermined value the pressure plate will move under spring influence to close/open a microswitch or electrical contact means. The invention has particular application as an alarm system for use in hospitals and nursing homes. The normal force applied to the pressure plate is the load on the leg of a hospital bed when occupied. If the bed occupant gets out of the bed the load on the pressure plate is reduced below the predetermined value and the consequent movement of the pressure plate opens/closes the switch means to actuate the alarm.