Optical pressure switch, door operating system and method
First Claim
1. An optical pressure switch comprisinga body including a passageway having an outlet and an inlet into which flows a gas at a pressure above ambient pressure,an optically activated control device having a light beam projected along an optical path within said body, andan elastic membrane within the body including a first side in communication with the passageway and a second side having an elongated portion that moves a predetermined distance into the optical path when the membrane flexes,said first and second sides of the membrane each normally being at ambient pressure so the membrane is in an un-flexed condition prior to the pressurized gas flowing into the passageway through the inlet and, in response to said pressurized gas flowing into the passageway, flexing the membrane to move the elongated portion said predetermined distance, with the membrane returning to the un-flexed condition as the gas escapes through the outlet.
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Accused Products
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 (10) 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 (10) includes a membrane (16) having a portion that interrupts a light beam (LB) when the membrane (16) flexes due to the increase gas pressure over ambient pressure as gas is forced from the edge.
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Citations
15 Claims
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1. An optical pressure switch comprising
a body including a passageway having an outlet and an inlet into which flows a gas at a pressure above ambient pressure, an optically activated control device having a light beam projected along an optical path within said body, and an elastic membrane within the body including a first side in communication with the passageway and a second side having an elongated portion that moves a predetermined distance into the optical path when the membrane flexes, said first and second sides of the membrane each normally being at ambient pressure so the membrane is in an un-flexed condition prior to the pressurized gas flowing into the passageway through the inlet and, in response to said pressurized gas flowing into the passageway, flexing the membrane to move the elongated portion said predetermined distance, with the membrane returning to the un-flexed condition as the gas escapes through the outlet.
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2. An optical pressure switch comprising
a body including a first chamber and a second chamber, an elastic membrane providing a common wall between the chambers and flexing when there is a differential in pressure across the membrane, the first chamber including a port normally in communication with ambient pressure and adapted to be placed in communication with a pressure wave above ambient pressure that momentarily flows through the first chamber, the second chamber including an optically activated control device having a light beam projected along an optical path within said second chamber, said membrane having a portion that interrupts the light beam so an electronic signal is generated upon flexing of the membrane, said second chamber being open to ambient pressure through a restricted opening that substantially reduces contamination of the optically activated control device that would interfere with the functioning of the light beam.
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4. An optical pressure switch comprising
a body including a passageway having an inlet end and an outlet end and through which a pressurized gas flows between the inlet and outlet ends, a control circuit including an optically activated control device where a light beam is projected along an optical path within said body, a first light-emitting device that indicates when power is applied to the circuit, and a second light-emitting device that indicates when pressurized gas flows into the passageway, and a flexible and resilient membrane positioned within the body and including a first side in communication with the passageway and a second side having an elongated portion that moves a predetermined distance into the optical path when the membrane flexes in response to a predetermined pressure of said pressurized gas, said body having an opening therein accessing ambient pressure so the membrane is initially subjected to ambient pressure on each side of the membrane prior to the pressurized gas flowing into the passageway and a first chamber and a second chamber with the membrane providing a common wall for the chambers, said passageway being in the first chamber and said elongated portion extending into the second chamber, said body including two components with the membrane being attached to one of said components, said components having been moved relative to each other to adjust said predetermined distance to thereby calibrate the pressure switch, said components being fixedly connected after calibration.
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5. An optical pressure switch comprising
a body having a longitudinal reference line and including a first housing component including a threaded surface, a second housing component including a threaded surface and a passageway having an inlet end and an outlet end and through which a pressurized gas flows into the inlet end through the passageway and out the outlet end, and a third housing component including an optically activated control device where a light beam is projected along an optical path within said third housing, said optical path intersecting the longitudinal reference line, said first housing component being disposed between the second and third housing components, a flexible and resilient circular disk membrane having a circular perimeter and a center which the longitudinal reference line intersects, said disk membrane positioned between said first and second housing components to form within the first housing component a first chamber and within the second housing component a second chamber with the membrane providing a common wall for the chambers, said membrane including a first side in communication with the passageway and a second side having an elongated portion extending from said center of the disk membrane along said longitudinal reference line, said elongated portion moving a predetermined distance into the optical path when the membrane flexes in response to a predetermined pressure of said pressurized gas, said second side being substantially at a right angle to the longitudinal reference line prior to the membrane flexing, and said membrane initially being in communication with ambient pressure on each side of the membrane prior to the pressurized gas flowing into the passageway, said membrane being attached to one of said housing components having a threaded surface, said threaded housing components having been moved relative to each other by engaging the threaded surfaces to adjust said predetermined distance to thereby calibrate the pressure switch, said first and second housing components being fixedly connected after calibration.
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9. An optical pressure switch comprising
a body including first and second chambers with a flexible elastic diaphragm providing a common wall for the chambers, said first chamber providing a passageway having an outlet and an inlet into which flows a pressurized gas at a pressure above ambient pressure, and said second chamber providing an enclosure for optical elements of an optically activated control device that projects a light beam along an optical path within said second chamber, said elastic diaphragm having a central portion, a perimeter in a fixed position, a first side in communication with the passageway and a second side having an elongated stem element projecting outward therefrom into the second chamber that moves a predetermined distance into the optical path when the diaphragm flexes, an accessing opening enabling both sides of the diaphragm to be initially subjected to ambient pressure prior to pressurized gas flowing into the passageway, and a flow control member at or near the outlet of the passageway that impedes gas flow through the passageway so back pressure is created within the passageway when a pressure wave enters the passageway.
Specification