Optical pressure switch, door operating system and method

Abstract

A door having a pneumatic sensing edge is operated automatically to open when an object and the edge make contact. An optical pressure switch in fluid communication with gas forced from the edge on contact with the object initiates the operation of a door opener. The optical pressure switch includes a membrane having a portion that interrupts a light beam when the membrane flexes due to the increase gas pressure over ambient pressure as gas is forced from the edge.

1 . The combination of an optical pressure switch and a pneumatic sensing edge in fluid communication with the switch so that a pressure wave produced by compressing the edge actuates the switch,
 said switch comprising   a body and a flexible and resilient membrane positioned within the body and having opposed sides,   said body including a passageway having an inlet end and an outlet end and through which the pressure wave propagates upon compressing the edge,   means for accessing ambient pressure so the membrane is initially subjected to ambient pressure on each side of the membrane prior to the pressure wave propagating along the passageway,   means for providing a stem portion extending from one side of the membrane that moves a predetermined distance into the optical path when the membrane flexes in response to the pressure wave, and   means for calibrating the switch.   
     
     
         2 . A door operating system comprising
 a door mounted to open and close and having a pneumatic sensing edge holding a gas,   an optical pressure switch in fluid communication with said gas, said gas flowing into the optical pressure switch when the edge makes contact with an object upon closure of the door to force gas from the pneumatic sensing edge,   said optical pressure switch including a light beam that is interrupted when the gas is forced to flow into said switch thereby generating a control signal, and   a door opener mechanism,   said door opener mechanism being responsive to said control signal to open said door upon receiving said control signal.   
     
     
         3 . A door operating system of  claim 2  where the optical pressure switch comprises
 a body including a passageway in communication with the gas flowing from the pneumatic sensing edge, 
 an optically activated control device in which said light beam is projected along an optical path within said body, and 
 a membrane within the body including a first side in communication with the passageway and a second side having an elongated portion that moves into the optical path when the membrane flexes in response to a predetermined pressure of said pressurized gas, interrupting said light beam to generate the control signal. 
 
     
     
         4 . A door operating system comprising
 a door opener mechanism,   a door mounted to open and close and operably connected to door opener mechanism, said door having a pneumatic sensing edge,   a pressure switch in fluid communication with said sensing edge that is momentarily actuated by a pressure wave when an object contacts the sensing edge, said switch upon actuation signaling the door opener mechanism to open said door,   said pressure switch including a light source that is illuminated for a predetermined period when the pressure wave actuates the switch.