US20130019531A1 - Optical pressure switch, door operating system and method - Google Patents
Optical pressure switch, door operating system and method Download PDFInfo
- Publication number
- US20130019531A1 US20130019531A1 US13/470,561 US201213470561A US2013019531A1 US 20130019531 A1 US20130019531 A1 US 20130019531A1 US 201213470561 A US201213470561 A US 201213470561A US 2013019531 A1 US2013019531 A1 US 2013019531A1
- Authority
- US
- United States
- Prior art keywords
- switch
- door
- membrane
- pressure
- edge
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H35/00—Switches operated by change of a physical condition
- H01H35/24—Switches operated by change of fluid pressure, by fluid pressure waves, or by change of fluid flow
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H2239/00—Miscellaneous
- H01H2239/022—Miscellaneous with opto-electronic switch
Definitions
- Automatic door operating systems are commonly used in vehicles such as passenger transit buses and rail cars, for example.
- the door or doors of such systems have a pneumatic sensing edge connected by a gas conduit or hose to a pressure wave switch included in an electrical control circuit for the door operating system.
- a pressure pulse or wave is produced that propagates through the gas conduit to actuate the switch.
- the switch then provides a control signal energizing an operator of a door opening mechanism to open the door automatically.
- Mechanical pressure wave switches are currently being used for passenger door obstruction sensing.
- Such conventional mechanical pressure wave switches typically use two mechanical metallic contacts that are subject to oxidation and other environmental contamination that can reduce the reliability or sensitivity of the switches, as well as creating a failure condition.
- the mechanical contact components of mechanical pressure wave switches have no self-cleaning capabilities such as contact wiping.
- the mechanical contacts pass very low current (approximately 12-18 milliamps) which is not enough to keep these mechanical contacts clean.
- This invention has one or more features as discussed subsequently herein. After reading the following section entitled “DETAILED DESCRIPTION OF SOME EMBODIMENTS OF THIS INVENTION,” one will understand how the features of this invention provide its benefits.
- the benefits of this invention include, but are not limited to providing: an optical pressure wave switch having greater stability and reliability under environmental contaminating conditions; an optical pressure wave switch that is easy to calibrate or re-calibrate; an optical pressure wave switch that is less sensitive to environmental contamination, and therefore, will remain calibrated longer creating a longer life; and an optical pressure wave switch that is electronic rather than a mechanical type, and optionally, may have the ability for self annunciation for purposes of diagnostic testing.
- the optical pressure switch of this invention includes a body having a passageway therein, a flexible membrane in fluid communication with the passageway, and an optically activated control device having a light beam projected along an optical path within the body. The light beam is interrupted upon the membrane flexing.
- the membrane may comprise an elastic diaphragm having a perimeter in a fixed position and a central portion from which an elongated portion extends that moves into the path of the light beam when the membrane flexes.
- the elastic diaphragm may be a rubbery sheet material and be circular and disk shaped.
- the elongated portion may be integral with the membrane and comprise a stem element projecting outward from a side of the membrane substantially at a right angle prior to the membrane flexing.
- the guide member may comprise a tubular structure in which the stem element is seated.
- the body may comprises a plurality of components.
- the components may be molded of plastic.
- one component may include the passageway which has an inlet into which enters the pressure wave. This wave, being at a pressure above ambient pressure to flex the membrane, propagates along the passageway, exiting at an outlet of the passageway.
- the inlet and outlet function as ports that allow air to flow in both directions. As discussed subsequently in greater detail, this enables the door operating system of this invention to be self-equilibrating.
- the components are assembled to create at least two chambers with the membrane providing a common wall for the chambers.
- the chambers normally are each at ambient pressure, however, the membrane flexes when there is a differential in pressure across the membrane as a pressure wave propagates through the switch. The membrane returns to an un-flexed condition when the differential in pressure is removed as the pressure wave dissipates. In other words, the pressure across the membrane is equalized.
- one chamber may include a port normally in communication with ambient pressure but also in fluid communication with a pneumatic sensing edge.
- one chamber includes the optically activated control device and is 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.
- This chamber is substantially closed to the atmosphere and houses or encloses essentially the entire optically activated control device, or at least the optical elements of the device. This protects the optical elements to reduce significantly environmental contamination.
- the components may be connected together in a manner that enables one component to be moved relative to the other component to adjust the distance the elongated portion must move before it interrupts the light beam. This feature enables the pressure switch to be calibrated. After calibration the components are fixedly connected together, for example, using a removable adhesive that is applied in a manner to maintain the two components fixedly connected together until the adhesive is removed.
- the switch may have a control circuit and a first light-emitting device mounted on the exterior of the body that indicates when power is applied to the control circuit and a second light-emitting device mounted on the exterior of the body that indicates when pressurized gas flows into the switch. These light-emitting devices are used for testing of the switch as discussed subsequently.
- the body has a longitudinal reference line has first, second, and third housing components.
- the first housing component includes a threaded surface
- the second housing component includes a threaded surface.
- the third housing component includes the optically activated control device.
- the optical path intersects the longitudinal reference line.
- the first housing component is disposed between the second and third housing components.
- the membrane is a flexible and resilient circular disk having a circular perimeter and a center that the longitudinal reference line intersects.
- the disk is positioned between the 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. A portion of the disk moves a predetermined distance into the optical path when the membrane flexes.
- Opposed sides of the membrane are each normally at ambient pressure so the membrane is in an un-flexed condition prior to the pressure wave entering one chamber.
- This invention also includes a door operating system.
- This system includes a door mounted to open and close and having a pneumatic sensing edge holding a gas and the optical pressure switch discussed above in fluid communication with the gas so the switch is activated when it receives a pressure wave from the edge. Activation of the switch provides an operational control signal to operate a door opener mechanism.
- the pneumatic sensing edge upon connection to the switch is placed in fluid communication with ambient pressure and concurrently one side of the membrane, which normally has both its sides at ambient pressure. When the pressure wave propagates through the switch, the membrane flexes, but only momentarily.
- both the pressure within the edge and the pressures on both sides of the membrane are at ambient pressure because they are always in fluid communication with the atmosphere.
- Ambient pressure however, constantly changes due to changing weather and the vehicle traveling to different elevations. Nevertheless, the door operating system of this invention self-equilibrates to readjust continually and compensate for changing ambient pressure. Consequently, the edge and the switch are always at ambient pressure except when the edge contacts an object or is squeezed during testing as discussed subsequently.
- This invention also includes a method of diagnosing problems with a door operating system.
- the embodiment of this invention that employs a light-emitting device is especially designed to be self-annunciating because it provides light signals indicating problems. A technician squeezes and holds the door sensing edge and the light-emitting device is illuminated. After a brief time period the light is automatically discontinued when the pressure differential across the membrane equalizes.
- FIG. 1 is a perspective view looking at the front side of the optical pressure switch of this invention.
- FIG. 1A is a schematic diagram of a door operating system of this invention using the optical pressure switch shown in FIG. 1 .
- FIG. 1B is a schematic diagram of optical pressure switch shown in FIG. 1 .
- FIG. 2 is a perspective view looking at an outlet side of the optical pressure switch shown in FIG. 1 .
- FIG. 3 is a perspective view looking at an inlet side of the optical pressure switch shown in FIG. 1 .
- FIG. 4 is an exploded perspective view of the optical pressure switch shown in FIG. 1 looking at the top of the switch.
- FIG. 5 is an exploded perspective view of the optical pressure switch shown in FIG. 1 looking at the bottom of the switch.
- FIG. 6 is a cross-sectional view taken along line 6 - 6 of FIG. 1 .
- FIG. 7 is a perspective view of the optical pressure switch shown in FIG. 1 with its the bottom side removed.
- FIG. 8 is a cross-sectional view of an alternate embodiment of the optical pressure switch of this invention.
- FIG. 9 is a cross-sectional view of another alternate embodiment of the optical pressure switch of this invention.
- one embodiment of the optical pressure switch of this invention designated by the numeral 10 comprises a body 12 , an optically activated control device 14 ( FIG. 7 ), and a membrane 16 ( FIGS. 4 , 5 and 6 ) within the body.
- a suitable optically activated control device 14 may be purchased from Bircher, distributed through JMT Automation and Controls, Inc., of Gastonia, N.C.
- the membrane 16 flexes.
- An elongated portion 16 a extending from one side S 1 ( FIG.
- the optical pressure switch 10 is calibrated to respond to gas pressures substantially from 0.01 to 0.16 pounds per square inch (psi).
- the optical pressure switch 10 may be utilized advantageously in a door operating system 20 such as depicted in FIG. 1A .
- the door operating system 20 is commonly employed in vehicles or other structures that require a door or doors 22 to open automatically when, for example, a passenger's hand, or other object, contacts the door, thereby avoiding accidents and injuries.
- the door 22 is mounted to open and close and has a pneumatic sensing edge 22 a holding a gas, typically air at ambient pressure.
- the pneumatic sensing edge 22 a is a well-known device comprising a balloon like, resilient vessel 23 having a hose 22 b with one end E 1 in fluid communication with the gas in the vessel and its other end E 2 ( FIGS. 1 and 6 ) connected to an inlet 24 of the optical pressure switch 10 .
- the resilient vessel 23 upon being compressed when the edge 22 a contacts an object, forces gas to flow at a predetermined pressure to flow as a pressure wave from the vessel 23 through the hose 22 b and into the switch 10 to flex the membrane 16 and move the elongated portion 16 a into the optical path of the light beam LB.
- This actuates the switch 10 that provides a control signal CS ( FIG. 1B ) to a conventional door opener mechanism 28 .
- the door opener mechanism 28 opens in response to the control signal CS.
- the membrane 16 is an elastic diaphragm made of rubber or other suitable material and may be a circular disk having a recessed central portion 16 b ( FIG. 5 ) and a center 16 c that a longitudinal reference line X intersects at a right angle upon mounting the disk in the body 12 .
- the central portion 16 b is substantially flat and planar when not flexed. Although it is flexible and resilient, the central portion 16 b maintains a substantially flat condition until a greater pressure is applied to the side S 2 ( FIG. 6 ) than to the side S 1 .
- the perimeter 16 d of the membrane 16 may include a stiffening ring 17 .
- the elongated portion 16 a is formed during molding of the membrane 16 and is integral therewith. It may be in the form of a substantially rigid, elongated stem of sufficient length to extend through a tubular guide member 19 into the optical path of the light beam LB when the membrane 16 is flexed.
- the elongated portion 16 a is substantially at a right angle to the side S 1 prior to the membrane 16 flexing.
- the membrane 16 is designed so the elongated portion 16 a moves only a short distance to interrupt the light beam LB ( FIG. 1B ). Typically, this distance ranges substantially from 0.02 to 0.12 inch and is adjusted during calibration as discussed subsequently.
- the body 12 includes a plurality of housing components 30 , 32 , and 34 .
- the housing component 30 is disposed between the housing components 32 and 34 .
- These housing components 30 , 32 and 34 each have a generally hollow cylindrical portion with predetermined diameters enabling them to be nested together with the longitudinal reference line X being co-extensive with the axes of these cylindrical portions.
- the housing components 30 , 32 , and 34 may be molded from a plastic material such as, for example, ABS resin, and are connected together upon assembly to form three chambers C 1 , C 2 , and C 3 as depicted in FIG. 6 .
- the membrane 16 provides a common wall for the chambers C 1 and C 2 .
- the housing component 30 has a cylindrical wall 30 a open at opposed ends with a threaded interior surface and an annular rim 30 b at a right angle to the wall. A pair of spaced apart cut-a-way sections 30 c ( FIG. 5 ) are formed in the rim 30 b. There are a number of openings 31 passing through the rim 30 b that, upon assembly of the components 30 , 32 and 34 , place the chambers C 2 and C 3 in communication with ambient air pressure as discussed subsequently in greater detail.
- the housing component 32 has an upper block segment 32 a that includes an outlet 25 .
- Opposed to the inlet 24 is an enlarged, stepped, cylindrical recess created by aligned bores B 3 and B 4 as depicted in FIG. 6 .
- the bore B 4 has a diameter slightly larger than the bore B 3 and its internal surface S 3 is threaded.
- a flow control member 42 and a threaded tubular cap 44 are seated in the stepped recess with the flow control member in the bore B 3 and the cap threaded into the bore B 4 to hold the flow control member in position.
- the flow control member 42 impedes gas flow through the passageway 18 so back pressure is created within the passageway when the pressure wave enters the passageway.
- the flow control member 42 may comprise a porous plug with a plurality of torturous paths therein. This flow control member 42 also serves as a filter to eliminate particulate contaminates from air flowing into the chamber C 1 through this flow control member.
- a suitable flow control member 42 in the form of a porous plug may be purchased from Applied Porous Technologies, Inc.
- the threaded tubular cap 44 is hollow to provide the outlet 25 .
- the inlet 24 which is integral with the block segment 32 a, is in the form of a tubular member projecting from the block segment 32 a and may be directly opposite and aligned with the outlet 25 .
- the passageway 18 connects the inlet 24 and the outlet 25 so gas may flow into the inlet, through the passageway, and out the outlet 25 . Under some conditions as discussed subsequently, gas may flow into the chamber C 1 through the outlet 25 .
- a branch passageway 18 a extending along the longitudinal reference line X. This branch passageway 18 a has an open end E 3 ( FIG. 6 ) terminating in the chamber C 1 .
- the branch passageway 18 a merges at another end E 4 about mid-way between the inlet 24 and the outlet 25 to provide a generally T-shape configuration. Pressurized gas will flow from the open end E 3 when the pneumatic sensing edge 22 a contacts an object to produce a pressure wave that is at a pressure above ambient pressure.
- a cylindrical wall 40 projects from an underside of the block segment 32 a that has a threaded exterior surface 40 a.
- a stepped cavity 33 ( FIG. 6 ) within the housing component 32 is formed by cylindrical bores B 1 and B 2 , aligned so their axes are coextensive with the longitudinal reference line X.
- the bore B 1 has a diameter smaller than the bore B 2 , thereby forming a landing L 1 on which rests the perimeter 16 d of the membrane 16 .
- Along the wall of the bore B 2 is an annular groove 35 at a right angle to the longitudinal reference line X. The distance between the top of the groove 35 and the landing L 1 is approximately equal to the thickness of the perimeter 16 d of the membrane 16 .
- the diameter of the groove 35 is greater than the diameter of the membrane 16 and a C-ring 38 is snapped into the groove 35 to hold the perimeter 16 d of the membrane 16 snug against the landing L 1 in a fixed position, maintaining the membrane within the chamber C 2 with the elongated stem portion 16 a aligned with the longitudinal reference line X and extending into the chamber C 3 .
- the housing component 34 holds a substantially flat circuit board 36 on which is mounted the optically activated control device 14 and other electrical and electronic devices of a control circuit 46 ( FIG. 1A ).
- a pair of cut-a-away sections 36 b of the circuit board 36 are aligned with the openings 31 to place the chambers C 2 and C 3 in fluid communication with ambient air pressure.
- an inner portion of each of the cut-a-away sections 36 b extends inward to create access openings placing the chamber C 3 in fluid communication with chamber C 2 .
- the housing component 34 includes a cylindrical wall 48 open at its circular topside TS and preferably closed at its bottom side BS. (The closed bottom side is shown removed in FIG. 7 ).
- the cylindrical wall 48 has a pair of slits 49 therein ( FIG. 4 ) and a pair of spaced apart indentations 50 , each terminating as a base landing 51 integral with the wall's bottom side BS.
- Each base landing 51 includes a hole 53 through which a screw (not shown) passes when mounting the switch 10 .
- the interior of the cylindrical wall has an annular ledge 54 ( FIG. 4 ) near the open topside TS upon which the circuit board 36 rests when the housing components 30 , 32 and 34 are assembled.
- Conductive metal prongs 52 extend outward from an edge of the circuit board 36 .
- the circuit board 36 provides a common wall for the chambers C 2 and C 3 .
- the tubular guide member 19 has a reduced diameter end 19 a ( FIG. 6 ) that fits snugly into a central hole 36 a in the circuit board 36 .
- the optical pressure switch 10 may have visual indicators such as light emitting diodes (LED), for example, a green light emitting diode LED G and a red light emitting diode LED R used to diagnose problems with the switch 10 or the door operating system 20 .
- LED light emitting diodes
- the indicator LED R when lit indicates that power is being applied to the switch, and the indicator LED G when lit indicates that pressurized gas is flowing into the switch 10 .
- the indicators LED G and LED R are mounted on the exterior of the body 12 .
- the parts of the optical pressure switch 10 are assembled in a conventional manner.
- the circuit board 36 with its components mounted thereon may first be positioned in the housing component 34 with the prongs 52 extending through the slits 49 and the circuit board resting on the ledge 54 .
- the surface of the circuit board 36 to which the electrical and electronic components are mounted faces the chamber C 3 so these electrical and electronic components, including the optically activated control device 14 , are in the chamber C 3 .
- the diameter of the rim 30 b is substantially equal to the diameter of the topside TS of the housing component 34 .
- the housing component 30 is next placed on top of the circuit board 36 with its rim 30 b resting on the top of the circuit board.
- the diameter of the rim 30 b is substantially equal to the inside diameter of the housing component 34 .
- the housing component 30 is connected to the housing component 32 with membrane 16 and the flow control member 42 and threaded cap 44 attached thereto as discussed above.
- the membrane 16 is in an un-flexed condition, and the pressure on both sides S 1 and S 2 of the membrane is the same, i.e., ambient pressure. This is a state of equilibrium.
- air is forced to propagate along the passageway 18 and the branch passageway 18 a as a pressure wave above ambient pressure, causing the membrane 16 to flex to move the elongated portion 16 a a selected distance to interrupt the light beam LB of the optically activated control device 14 .
- This provides the control signal CS to which the door opener mechanism 28 responds to open the door 22 .
- the optical pressure switch 10 is calibrated prior to being used in the door operating system 20 by adjusting the distance the elongated portion 16 a moves in order to interrupt the light beam LB.
- This adjustment is made by screwing the threaded surfaces of the housing components 30 and 32 together, rotating these housing components until the outer tip of the elongated portion 16 a passes through the tubular guide member 19 and is positioned next to the light beam LB at the selected distance.
- This distance depends on whether the user desires the membrane 16 to flex greatly before the light beam LB is interrupted or only to flex slightly. A slight flexing of the membrane 16 moves the elongated portion 16 a only a short distance, making the switch 10 very sensitive. In other words, only a slight pressure increase in the passageway 18 and the branch passageway 18 a will cause the elongated portion 16 a to interrupt the light beam LB.
- the housing components 30 and 32 are fixedly connected together after calibration. This may be accomplished by applying to adjacent exterior portions of the housing components 30 and 32 an adhesive after adjusting the relative positions of these components.
- a silicone type of adhesive may be used, which may be removable, to allow re-calibration.
- a suitable adhesive is sold by Dow-Corning under the identifying number 832 .
- FIG. 8 An alternate embodiment of the switch of this invention is generally designed by the numeral 10 a in FIG. 8 .
- This switch 10 a is essentially identical to the switch 10 , except an orifice plate 60 with a central aperture 60 a therein is used instead of the porous flow control member 42 .
- the aperture 60 a has a diameter substantially from 0.008 to 0.016 inches.
- the orifice plate 60 is seated in the bore B 4 on a ledge between the bores B 3 (shallower than in the switch 10 ) and B 4 and the aperture 60 a is aligned with the outlet 25 provided in the threaded tubular cap 44 .
- the cap 44 is screwed in position to hold the plate 60 in position in the bore B 3 .
- the optical pressure switch 10 b uses a membrane 15 that includes a tiny orifice 15 a therein to establish initially ambient pressure on each side S 1 and S 2 of the membrane 15 .
- the passageway 18 is also different in that it has a generally L-shape, with its one leg 18 c having an outlet end E 5 terminating adjacent the side S 2 of the membrane 15 . This end E 5 serves as the only outlet of the passageway 15 .
- a back pressure is sufficient so that most of the pressurized gas flows through the branched passageway 18 a to flex the membrane 16 .
- the switch 10 b there is only a single outlet, namely, the end E 5 in the one leg 18 c.
- the pressurized gas flowing into the optical pressure switches 10 , 10 a, and 10 b is above ambient pressure and is a transitory phenomenon occurring only momentarily when the pneumatic sensing edge 22 a makes initial contact with an object.
- the switches 10 , 10 a, and 10 b each essentially immediately provides the control signal CS on contact of the edge 22 a with an object so the door 22 is opened automatically.
- the door 22 and object disengage to discontinue forcing gas at an elevated pressure to flow into the operable switch 10 , 10 a, or 10 b, as the case may be.
- both sides S 1 and S 2 of the membrane 16 are initially subjected to ambient pressure and are again, essentially immediately, subjected to ambient pressure when the pressure wave dissipates, returning the membrane 16 to its normal un-flexed, equilibrated condition.
- the optical pressure switch 10 has the ability for self-annunciation for purposes of diagnosing or testing its operability. This is achieved by the means of the light indicators LED R and LED G.
- the indicator LED R when lit, is indicating that the switch 10 is electrically connected to a 12V or 24V power source P.S. ( FIGS. 1A and 1B ) from an electrical system of, for example, a vehicle such as a bus employing the doors 22 .
- the indicator LED G when lit, is indicating that the switch 10 has been activated by the pneumatic sensing edge 22 a making contact with an object as the door is being closed.
- This illuminated indicator LED G provides to, for example, a technician trouble shooting a visual “Door Obstruction” signal.
- a typical diagnostic test procedure is as follows:
- the technician While observing the indicator LED G, the technician conducts a test using his or her hand to squeeze and hold the pneumatic sensing edge 22 a. The indicator LED G should be illuminated each time the technician squeezes the pneumatic sensing edge 22 a and go out after releasing this pneumatic sensing edge. If the technician squeezes the pneumatic sensing edge 22 a and holds it, the indicator LED G will go out within a short time interval, for example about 30 seconds, because the air pressure in the chambers C 1 and C 2 equalizes.
- the illumination of the indicator LED G when the pneumatic sensing edge 22 a is squeezed and held by the technician is an indication that the switch 10 is operating correctly and that it is receiving a signal from the logic circuit LC, indicating that the pneumatic sensing edge 22 a and the switch are working properly. If the indicator LED G does not light up at all when the technician squeezes and holds the pneumatic sensing edge 22 a, this is an indication that there may be a problem with the door edge 22 a and that it is not sending a pressure pulse wave to the switch 10 . It would then be necessary to troubleshoot the door edge 22 a or the hose 22 b connecting the edge to the switch 10 .
- the stem 16 a replaces metallic contacts and improves the switch's operating characteristics when subjected to shock and vibration. This is because the stem 16 a is lighter in weight than metallic contacts. In addition, the stem 16 a is less affected by its mounting orientation, vertically or horizontal or otherwise.
- the prior art mechanical switch requires pressure between the two metallic contacts for the necessary electrical continuity. This makes calibration more difficult. This is not the case with the switches 10 , 10 a or 10 b. Calibration adjustments of these switches are much easier to make and they also has the capability of working at a very low air pressure (down to 2 millimeters of water column, or 0.003 psi).
- the switch 10 may use the porous flow control member 42 for an ambient air orifice which acts as a filter.
- Removing the cap 44 allows for replacement of the flow control member 42 if it becomes contaminated. This is a cost savings to the vehicle operators.
- the calibration adjustment allows for a visual tamper proof indicator, because the removal of the adhesive from the exterior of the housing components 30 and 32 is readily observable. This feature is desired by the vehicle manufactures to insure that unauthorized individuals have not changed the pressure setting.
Landscapes
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Measuring Fluid Pressure (AREA)
- Switches Operated By Changes In Physical Conditions (AREA)
- Power-Operated Mechanisms For Wings (AREA)
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.
Description
- This application is divisional patent application of U.S. utility patent application Ser. No. 12/224,025, now U.S. Pat. No. 8,178,830, filed pursuant to 35 U.S.C. 371 and which claims priority based on international patent application PCT/US06/05650, filed Feb. 17, 2006. This related utility patent application is incorporated herein by reference and made a part of this application. Moreover, any and all U.S. patents, U.S. patent applications, and other documents, hard copy or electronic, cited or referred to in this application are incorporated herein by reference and made a part of this application.
- The words “comprising,” “having,” “containing,” and “including,” and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items.
- Automatic door operating systems are commonly used in vehicles such as passenger transit buses and rail cars, for example. The door or doors of such systems have a pneumatic sensing edge connected by a gas conduit or hose to a pressure wave switch included in an electrical control circuit for the door operating system. When the sensing edge makes momentary contact with an object on closure of the door, a pressure pulse or wave is produced that propagates through the gas conduit to actuate the switch. The switch then provides a control signal energizing an operator of a door opening mechanism to open the door automatically. Mechanical pressure wave switches are currently being used for passenger door obstruction sensing. Such conventional mechanical pressure wave switches typically use two mechanical metallic contacts that are subject to oxidation and other environmental contamination that can reduce the reliability or sensitivity of the switches, as well as creating a failure condition. The mechanical contact components of mechanical pressure wave switches have no self-cleaning capabilities such as contact wiping. Moreover, the mechanical contacts pass very low current (approximately 12-18 milliamps) which is not enough to keep these mechanical contacts clean.
- This invention has one or more features as discussed subsequently herein. After reading the following section entitled “DETAILED DESCRIPTION OF SOME EMBODIMENTS OF THIS INVENTION,” one will understand how the features of this invention provide its benefits. The benefits of this invention include, but are not limited to providing: an optical pressure wave switch having greater stability and reliability under environmental contaminating conditions; an optical pressure wave switch that is easy to calibrate or re-calibrate; an optical pressure wave switch that is less sensitive to environmental contamination, and therefore, will remain calibrated longer creating a longer life; and an optical pressure wave switch that is electronic rather than a mechanical type, and optionally, may have the ability for self annunciation for purposes of diagnostic testing.
- Without limiting the scope of this invention as expressed by the claims that follow, some, but not necessarily all, of its features are:
- One, the optical pressure switch of this invention includes a body having a passageway therein, a flexible membrane in fluid communication with the passageway, and an optically activated control device having a light beam projected along an optical path within the body. The light beam is interrupted upon the membrane flexing.
- Two, the membrane may comprise an elastic diaphragm having a perimeter in a fixed position and a central portion from which an elongated portion extends that moves into the path of the light beam when the membrane flexes. The elastic diaphragm may be a rubbery sheet material and be circular and disk shaped. The elongated portion may be integral with the membrane and comprise a stem element projecting outward from a side of the membrane substantially at a right angle prior to the membrane flexing. There may be a guide member within the body aligned with the stem element to guide the stem element as it moves in response to the flexing of the membrane. For example, the guide member may comprise a tubular structure in which the stem element is seated.
- Three, the body may comprises a plurality of components. For example, the components may be molded of plastic. In one embodiment of this invention, one component may include the passageway which has an inlet into which enters the pressure wave. This wave, being at a pressure above ambient pressure to flex the membrane, propagates along the passageway, exiting at an outlet of the passageway. Although referred to as an inlet and outlet, the inlet and outlet function as ports that allow air to flow in both directions. As discussed subsequently in greater detail, this enables the door operating system of this invention to be self-equilibrating.
- Four, the components are assembled to create at least two chambers with the membrane providing a common wall for the chambers. The chambers normally are each at ambient pressure, however, the membrane flexes when there is a differential in pressure across the membrane as a pressure wave propagates through the switch. The membrane returns to an un-flexed condition when the differential in pressure is removed as the pressure wave dissipates. In other words, the pressure across the membrane is equalized. For example, one chamber may include a port normally in communication with ambient pressure but also in fluid communication with a pneumatic sensing edge.
- Five, in one embodiment of this invention, one chamber includes the optically activated control device and is 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. This chamber is substantially closed to the atmosphere and houses or encloses essentially the entire optically activated control device, or at least the optical elements of the device. This protects the optical elements to reduce significantly environmental contamination.
- Six, the components may be connected together in a manner that enables one component to be moved relative to the other component to adjust the distance the elongated portion must move before it interrupts the light beam. This feature enables the pressure switch to be calibrated. After calibration the components are fixedly connected together, for example, using a removable adhesive that is applied in a manner to maintain the two components fixedly connected together until the adhesive is removed.
- Seven, the switch may have a control circuit and a first light-emitting device mounted on the exterior of the body that indicates when power is applied to the control circuit and a second light-emitting device mounted on the exterior of the body that indicates when pressurized gas flows into the switch. These light-emitting devices are used for testing of the switch as discussed subsequently.
- In one embodiment, the body has a longitudinal reference line has first, second, and third housing components. The first housing component includes a threaded surface, and the second housing component includes a threaded surface. The third housing component includes the optically activated control device. The optical path intersects the longitudinal reference line. The first housing component is disposed between the second and third housing components. The membrane is a flexible and resilient circular disk having a circular perimeter and a center that the longitudinal reference line intersects. The disk is positioned between the 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. A portion of the disk moves a predetermined distance into the optical path when the membrane flexes. Opposed sides of the membrane are each normally at ambient pressure so the membrane is in an un-flexed condition prior to the pressure wave entering one chamber.
- This invention also includes a door operating system. This system includes a door mounted to open and close and having a pneumatic sensing edge holding a gas and the optical pressure switch discussed above in fluid communication with the gas so the switch is activated when it receives a pressure wave from the edge. Activation of the switch provides an operational control signal to operate a door opener mechanism. According to this feature, the pneumatic sensing edge upon connection to the switch is placed in fluid communication with ambient pressure and concurrently one side of the membrane, which normally has both its sides at ambient pressure. When the pressure wave propagates through the switch, the membrane flexes, but only momentarily. Shortly after the pressure wave dissipates, both the pressure within the edge and the pressures on both sides of the membrane are at ambient pressure because they are always in fluid communication with the atmosphere. Ambient pressure, however, constantly changes due to changing weather and the vehicle traveling to different elevations. Nevertheless, the door operating system of this invention self-equilibrates to readjust continually and compensate for changing ambient pressure. Consequently, the edge and the switch are always at ambient pressure except when the edge contacts an object or is squeezed during testing as discussed subsequently.
- These features are not listed in any rank order nor is this list intended to be exhaustive.
- This invention also includes a method of diagnosing problems with a door operating system. The embodiment of this invention that employs a light-emitting device is especially designed to be self-annunciating because it provides light signals indicating problems. A technician squeezes and holds the door sensing edge and the light-emitting device is illuminated. After a brief time period the light is automatically discontinued when the pressure differential across the membrane equalizes.
- Some embodiments of this invention, illustrating all its features, will now be discussed in detail. These embodiments depict the novel and non-obvious optical pressure switch, door operating system, and method of this invention as shown in the accompanying drawing, which is for illustrative purposes only. This drawing includes the following figures (Figs.), with like numerals indicating like parts:
-
FIG. 1 is a perspective view looking at the front side of the optical pressure switch of this invention. -
FIG. 1A is a schematic diagram of a door operating system of this invention using the optical pressure switch shown inFIG. 1 . -
FIG. 1B is a schematic diagram of optical pressure switch shown inFIG. 1 . -
FIG. 2 is a perspective view looking at an outlet side of the optical pressure switch shown inFIG. 1 . -
FIG. 3 is a perspective view looking at an inlet side of the optical pressure switch shown inFIG. 1 . -
FIG. 4 is an exploded perspective view of the optical pressure switch shown inFIG. 1 looking at the top of the switch. -
FIG. 5 is an exploded perspective view of the optical pressure switch shown inFIG. 1 looking at the bottom of the switch. -
FIG. 6 is a cross-sectional view taken along line 6-6 ofFIG. 1 . -
FIG. 7 is a perspective view of the optical pressure switch shown inFIG. 1 with its the bottom side removed. -
FIG. 8 is a cross-sectional view of an alternate embodiment of the optical pressure switch of this invention. -
FIG. 9 is a cross-sectional view of another alternate embodiment of the optical pressure switch of this invention. -
FIG. 1 through 7 - As illustrated in
FIGS. 1 through 7 , one embodiment of the optical pressure switch of this invention designated by the numeral 10 comprises abody 12, an optically activated control device 14 (FIG. 7 ), and a membrane 16 (FIGS. 4 , 5 and 6) within the body. A suitable optically activatedcontrol device 14 may be purchased from Bircher, distributed through JMT Automation and Controls, Inc., of Gastonia, N.C. When pressurized gas flows as a pressure wave though a passageway 18 (FIG. 6 ) in thebody 12, themembrane 16 flexes. Anelongated portion 16 a extending from one side S1 (FIG. 5 ) of themembrane 16 moves a predetermined distance, typically substantially from 0.02 to 0.12 inch, to interrupt a light beam LB (FIG. 1B ) in the optically activatedcontrol device 14 when themembrane 16 flexes in response to the pressure wave. As discussed subsequently in greater detail, theoptical pressure switch 10 is calibrated to respond to gas pressures substantially from 0.01 to 0.16 pounds per square inch (psi). - The
optical pressure switch 10 may be utilized advantageously in adoor operating system 20 such as depicted inFIG. 1A . Thedoor operating system 20 is commonly employed in vehicles or other structures that require a door ordoors 22 to open automatically when, for example, a passenger's hand, or other object, contacts the door, thereby avoiding accidents and injuries. Thedoor 22 is mounted to open and close and has apneumatic sensing edge 22 a holding a gas, typically air at ambient pressure. Thepneumatic sensing edge 22 a is a well-known device comprising a balloon like,resilient vessel 23 having a hose 22 b with one end E1 in fluid communication with the gas in the vessel and its other end E2 (FIGS. 1 and 6 ) connected to aninlet 24 of theoptical pressure switch 10. Theresilient vessel 23, upon being compressed when theedge 22 a contacts an object, forces gas to flow at a predetermined pressure to flow as a pressure wave from thevessel 23 through the hose 22 b and into theswitch 10 to flex themembrane 16 and move theelongated portion 16 a into the optical path of the light beam LB. This actuates theswitch 10 that provides a control signal CS (FIG. 1B ) to a conventionaldoor opener mechanism 28. Thedoor opener mechanism 28 opens in response to the control signal CS. - As best shown in
FIGS. 4 , 5 and 6, themembrane 16 is an elastic diaphragm made of rubber or other suitable material and may be a circular disk having a recessedcentral portion 16 b (FIG. 5 ) and acenter 16 c that a longitudinal reference line X intersects at a right angle upon mounting the disk in thebody 12. Thecentral portion 16 b is substantially flat and planar when not flexed. Although it is flexible and resilient, thecentral portion 16 b maintains a substantially flat condition until a greater pressure is applied to the side S2 (FIG. 6 ) than to the side S1. Theperimeter 16 d of themembrane 16 may include astiffening ring 17. Theelongated portion 16 a is formed during molding of themembrane 16 and is integral therewith. It may be in the form of a substantially rigid, elongated stem of sufficient length to extend through atubular guide member 19 into the optical path of the light beam LB when themembrane 16 is flexed. Theelongated portion 16 a is substantially at a right angle to the side S1 prior to themembrane 16 flexing. For most applications themembrane 16 is designed so theelongated portion 16 a moves only a short distance to interrupt the light beam LB (FIG. 1B ). Typically, this distance ranges substantially from 0.02 to 0.12 inch and is adjusted during calibration as discussed subsequently. - As depicted in
FIGS. 4 , 5 and 6, thebody 12 includes a plurality ofhousing components housing component 30 is disposed between thehousing components housing components housing components FIG. 6 . Themembrane 16 provides a common wall for the chambers C1 and C2. - The
housing component 30 has acylindrical wall 30 a open at opposed ends with a threaded interior surface and anannular rim 30 b at a right angle to the wall. A pair of spaced apart cut-a-way sections 30 c (FIG. 5 ) are formed in therim 30 b. There are a number ofopenings 31 passing through therim 30 b that, upon assembly of thecomponents - The
housing component 32 has anupper block segment 32 a that includes anoutlet 25. Opposed to theinlet 24 is an enlarged, stepped, cylindrical recess created by aligned bores B3 and B4 as depicted inFIG. 6 . The bore B4 has a diameter slightly larger than the bore B3 and its internal surface S3 is threaded. Aflow control member 42 and a threadedtubular cap 44 are seated in the stepped recess with the flow control member in the bore B3 and the cap threaded into the bore B4 to hold the flow control member in position. Theflow control member 42 impedes gas flow through thepassageway 18 so back pressure is created within the passageway when the pressure wave enters the passageway. Theflow control member 42 may comprise a porous plug with a plurality of torturous paths therein. Thisflow control member 42 also serves as a filter to eliminate particulate contaminates from air flowing into the chamber C1 through this flow control member. A suitableflow control member 42 in the form of a porous plug may be purchased from Applied Porous Technologies, Inc. The threadedtubular cap 44 is hollow to provide theoutlet 25. - The
inlet 24, which is integral with theblock segment 32 a, is in the form of a tubular member projecting from theblock segment 32 a and may be directly opposite and aligned with theoutlet 25. Thepassageway 18 connects theinlet 24 and theoutlet 25 so gas may flow into the inlet, through the passageway, and out theoutlet 25. Under some conditions as discussed subsequently, gas may flow into the chamber C1 through theoutlet 25. Between theinlet 24 andoutlet 25 is abranch passageway 18 a extending along the longitudinal reference line X. Thisbranch passageway 18 a has an open end E3 (FIG. 6 ) terminating in the chamber C1. Thebranch passageway 18 a merges at another end E4 about mid-way between theinlet 24 and theoutlet 25 to provide a generally T-shape configuration. Pressurized gas will flow from the open end E3 when thepneumatic sensing edge 22 a contacts an object to produce a pressure wave that is at a pressure above ambient pressure. - A
cylindrical wall 40 projects from an underside of theblock segment 32 a that has a threadedexterior surface 40 a. A stepped cavity 33 (FIG. 6 ) within thehousing component 32 is formed by cylindrical bores B1 and B2, aligned so their axes are coextensive with the longitudinal reference line X. The bore B1 has a diameter smaller than the bore B2, thereby forming a landing L1 on which rests theperimeter 16 d of themembrane 16. Along the wall of the bore B2 is anannular groove 35 at a right angle to the longitudinal reference line X. The distance between the top of thegroove 35 and the landing L1 is approximately equal to the thickness of theperimeter 16 d of themembrane 16. The diameter of thegroove 35 is greater than the diameter of themembrane 16 and a C-ring 38 is snapped into thegroove 35 to hold theperimeter 16 d of themembrane 16 snug against the landing L1 in a fixed position, maintaining the membrane within the chamber C2 with theelongated stem portion 16 a aligned with the longitudinal reference line X and extending into the chamber C3. - As best shown in
FIG. 7 , thehousing component 34 holds a substantiallyflat circuit board 36 on which is mounted the optically activatedcontrol device 14 and other electrical and electronic devices of a control circuit 46 (FIG. 1A ). As best shown inFIG. 7 , a pair of cut-a-away sections 36 b of thecircuit board 36 are aligned with theopenings 31 to place the chambers C2 and C3 in fluid communication with ambient air pressure. Note, an inner portion of each of the cut-a-away sections 36 b extends inward to create access openings placing the chamber C3 in fluid communication with chamber C2. Thehousing component 34 includes acylindrical wall 48 open at its circular topside TS and preferably closed at its bottom side BS. (The closed bottom side is shown removed inFIG. 7 ). Thecylindrical wall 48 has a pair ofslits 49 therein (FIG. 4 ) and a pair of spaced apart indentations 50, each terminating as a base landing 51 integral with the wall's bottom side BS. Each base landing 51 includes ahole 53 through which a screw (not shown) passes when mounting theswitch 10. The interior of the cylindrical wall has an annular ledge 54 (FIG. 4 ) near the open topside TS upon which thecircuit board 36 rests when thehousing components Conductive metal prongs 52 extend outward from an edge of thecircuit board 36. Thecircuit board 36 provides a common wall for the chambers C2 and C3. Thetubular guide member 19 has a reduced diameter end 19 a (FIG. 6 ) that fits snugly into acentral hole 36 a in thecircuit board 36. - As depicted in
FIGS. 1 and 1B , theoptical pressure switch 10 may have visual indicators such as light emitting diodes (LED), for example, a green light emitting diode LED G and a red light emitting diode LED R used to diagnose problems with theswitch 10 or thedoor operating system 20. The indicator LED R when lit indicates that power is being applied to the switch, and the indicator LED G when lit indicates that pressurized gas is flowing into theswitch 10. The indicators LED G and LED R are mounted on the exterior of thebody 12. - The parts of the
optical pressure switch 10 are assembled in a conventional manner. Thecircuit board 36 with its components mounted thereon may first be positioned in thehousing component 34 with theprongs 52 extending through theslits 49 and the circuit board resting on theledge 54. The surface of thecircuit board 36 to which the electrical and electronic components are mounted faces the chamber C3 so these electrical and electronic components, including the optically activatedcontrol device 14, are in the chamber C3. The diameter of therim 30 b is substantially equal to the diameter of the topside TS of thehousing component 34. Thehousing component 30 is next placed on top of thecircuit board 36 with itsrim 30 b resting on the top of the circuit board. The diameter of therim 30 b is substantially equal to the inside diameter of thehousing component 34. Next, thehousing component 30 is connected to thehousing component 32 withmembrane 16 and theflow control member 42 and threadedcap 44 attached thereto as discussed above. - Initially the
membrane 16 is in an un-flexed condition, and the pressure on both sides S1 and S2 of the membrane is the same, i.e., ambient pressure. This is a state of equilibrium. When thepneumatic sensing edge 22 a contacts an object, air is forced to propagate along thepassageway 18 and thebranch passageway 18 a as a pressure wave above ambient pressure, causing themembrane 16 to flex to move theelongated portion 16 a a selected distance to interrupt the light beam LB of the optically activatedcontrol device 14. This provides the control signal CS to which thedoor opener mechanism 28 responds to open thedoor 22. The air pressure across themembrane 16 subsequently rapidly equalizes because the pressure wave dissipates due to air escaping from chamber C1 through theoutlet 25. Consequently, theelastic membrane 16 again returns to its un-flexed condition almost immediately after the pressure wave actuates theswitch 10, thereby withdrawing theelongated portion 16 a from thecontrol device 14, moving the same selected distance it moved to interrupt the light beam LB but in the opposite direction. The light beam is now uninterrupted by theelongated portion 16 a. In the un-flexed condition themembrane 16 is substantially at a right angle to the longitudinal reference line X. - As mentioned above, the
optical pressure switch 10 is calibrated prior to being used in thedoor operating system 20 by adjusting the distance theelongated portion 16 a moves in order to interrupt the light beam LB. This adjustment is made by screwing the threaded surfaces of thehousing components elongated portion 16 a passes through thetubular guide member 19 and is positioned next to the light beam LB at the selected distance. This distance depends on whether the user desires themembrane 16 to flex greatly before the light beam LB is interrupted or only to flex slightly. A slight flexing of themembrane 16 moves theelongated portion 16 a only a short distance, making theswitch 10 very sensitive. In other words, only a slight pressure increase in thepassageway 18 and thebranch passageway 18 a will cause theelongated portion 16 a to interrupt the light beam LB. - The
housing components housing components - An alternate embodiment of the switch of this invention is generally designed by the numeral 10 a in
FIG. 8 . Thisswitch 10 a is essentially identical to theswitch 10, except anorifice plate 60 with acentral aperture 60 a therein is used instead of the porousflow control member 42. Typically, theaperture 60 a has a diameter substantially from 0.008 to 0.016 inches. Theorifice plate 60 is seated in the bore B4 on a ledge between the bores B3 (shallower than in the switch 10) and B4 and theaperture 60 a is aligned with theoutlet 25 provided in the threadedtubular cap 44. Thecap 44 is screwed in position to hold theplate 60 in position in the bore B3. - Another alternate embodiment of the switch of this invention is generally designed by the numeral 10 b in
FIG. 9 . Theoptical pressure switch 10 b uses amembrane 15 that includes a tiny orifice 15 a therein to establish initially ambient pressure on each side S1 and S2 of themembrane 15. Thepassageway 18 is also different in that it has a generally L-shape, with its oneleg 18 c having an outlet end E5 terminating adjacent the side S2 of themembrane 15. This end E5 serves as the only outlet of thepassageway 15. In theswitch 10, there are in effect two outlets: theoutlet 25 provided in the threadedtubular cap 44 and the end E3 in the branchedpassageway 18 a. In both theswitches flow control member 42 and theorifice plate 60, is sufficient so that most of the pressurized gas flows through the branchedpassageway 18 a to flex themembrane 16. In theswitch 10 b, there is only a single outlet, namely, the end E5 in the oneleg 18 c. - In all the embodiments, the pressurized gas flowing into the optical pressure switches 10, 10 a, and 10 b is above ambient pressure and is a transitory phenomenon occurring only momentarily when the
pneumatic sensing edge 22 a makes initial contact with an object. Theswitches edge 22 a with an object so thedoor 22 is opened automatically. Thus, thedoor 22 and object disengage to discontinue forcing gas at an elevated pressure to flow into theoperable switch openings 31 in therim 30 b of the housing component, the inner portion of the cut-a-away sections 36 b creating access openings in thecircuit board 36, and theoutlet 25 placing the chambers C1, C2 and C3 in fluid communication with the atmosphere, both sides S1 and S2 of themembrane 16 are initially subjected to ambient pressure and are again, essentially immediately, subjected to ambient pressure when the pressure wave dissipates, returning themembrane 16 to its normal un-flexed, equilibrated condition. - Because of the tiny orifice 15 a in the
membrane 15 both its sides S1 and S2 are initially at ambient pressure. The diameter of the orifice 15 a only about 0.012 inch. Consequently, a pressure wave entering theswitch 10 still flexes themembrane 15 since only a very small faction of pressurized gas is forced through the tiny orifice 15 a. As soon as pressure wave dissipates, themembrane 15 returns to its normal un-flexed condition. - The
optical pressure switch 10 has the ability for self-annunciation for purposes of diagnosing or testing its operability. This is achieved by the means of the light indicators LED R and LED G. For example, the indicator LED R, when lit, is indicating that theswitch 10 is electrically connected to a 12V or 24V power source P.S. (FIGS. 1A and 1B ) from an electrical system of, for example, a vehicle such as a bus employing thedoors 22. The indicator LED G, when lit, is indicating that theswitch 10 has been activated by thepneumatic sensing edge 22 a making contact with an object as the door is being closed. This illuminated indicator LED G provides to, for example, a technician trouble shooting a visual “Door Obstruction” signal. A typical diagnostic test procedure is as follows: - 1. Open an access panel over the door opening to access a compartment holding the
switch 10. - 2. Activate the vehicle's run/key switch to provide power to the vehicle's onboard electronics including the
switch 10. - 3. Visually check the indicator LED R to confirm it is lit.
-
- An illuminated indicator LED R shows that the
switch 10 is connected to the vehicle's wiring and that power and ground is present. This will eliminate further diagnosing of the vehicle's power circuit to theswitch 10 and the technician may proceed to Step 4 below. - If the indicator LED R is OFF (not illuminated), this is an indication that:
- 1. There is a problem with vehicle's wiring to the
switch 10, or. - 2. There is a problem with the vehicle's power circuit, or.
- 3. The
switch 10 has failed
There is no need to further diagnose the rest of the components that comprise of thedoor operating system 20 until this problem is resolved. This will eliminate unnecessary troubleshooting of the remaining components such as thepneumatic sensing edge 22 a and the hose 22 b connected to theinlet 24.
- 1. There is a problem with vehicle's wiring to the
- An illuminated indicator LED R shows that the
- 4. Observe the indicator LED G: While observing the indicator LED G, the technician conducts a test using his or her hand to squeeze and hold the
pneumatic sensing edge 22 a. The indicator LED G should be illuminated each time the technician squeezes thepneumatic sensing edge 22 a and go out after releasing this pneumatic sensing edge. If the technician squeezes thepneumatic sensing edge 22 a and holds it, the indicator LED G will go out within a short time interval, for example about 30 seconds, because the air pressure in the chambers C1 and C2 equalizes. - The illumination of the indicator LED G when the
pneumatic sensing edge 22 a is squeezed and held by the technician is an indication that theswitch 10 is operating correctly and that it is receiving a signal from the logic circuit LC, indicating that thepneumatic sensing edge 22 a and the switch are working properly. If the indicator LED G does not light up at all when the technician squeezes and holds thepneumatic sensing edge 22 a, this is an indication that there may be a problem with thedoor edge 22 a and that it is not sending a pressure pulse wave to theswitch 10. It would then be necessary to troubleshoot thedoor edge 22 a or the hose 22 b connecting the edge to theswitch 10. If the indicator LED G does not go out after the technician squeezes and holds thepneumatic sensing edge 22 a, this is an indication that theswitch 10 is plugged and the pressure on the opposite sides S1 and S2 of themembrane 16 is not equalizing. If this cannot be remedied then theswitch 10 should be replaced or repaired. - The
stem 16 a replaces metallic contacts and improves the switch's operating characteristics when subjected to shock and vibration. This is because thestem 16 a is lighter in weight than metallic contacts. In addition, thestem 16 a is less affected by its mounting orientation, vertically or horizontal or otherwise. The prior art mechanical switch requires pressure between the two metallic contacts for the necessary electrical continuity. This makes calibration more difficult. This is not the case with theswitches switch 10 may use the porousflow control member 42 for an ambient air orifice which acts as a filter. Removing thecap 44 allows for replacement of theflow control member 42 if it becomes contaminated. This is a cost savings to the vehicle operators. The calibration adjustment allows for a visual tamper proof indicator, because the removal of the adhesive from the exterior of thehousing components - The above presents a description of the best mode contemplated of carrying out the present invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains to make and use this invention. This invention is, however, susceptible to modifications and alternate constructions from that discussed above which are fully equivalent. Consequently, it is not the intention to limit this invention to the particular embodiments disclosed. On the contrary, the intention is to cover all modifications and alternate constructions coming within the spirit and scope of the invention as generally expressed by the following claims, which particularly point out and distinctly claim the subject matter of the invention:
Claims (4)
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.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/470,561 US20130019531A1 (en) | 2006-02-17 | 2012-05-14 | Optical pressure switch, door operating system and method |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/US2006/005650 WO2007106061A2 (en) | 2006-02-17 | 2006-02-17 | Optical pressure switch, door operating system & method |
US22402508A | 2008-08-14 | 2008-08-14 | |
US13/470,561 US20130019531A1 (en) | 2006-02-17 | 2012-05-14 | Optical pressure switch, door operating system and method |
Related Parent Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2006/005650 Division WO2007106061A2 (en) | 2006-02-17 | 2006-02-17 | Optical pressure switch, door operating system & method |
US22402508A Division | 2006-02-17 | 2008-08-14 |
Publications (1)
Publication Number | Publication Date |
---|---|
US20130019531A1 true US20130019531A1 (en) | 2013-01-24 |
Family
ID=38509904
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/224,025 Active 2028-04-02 US8178830B2 (en) | 2006-02-17 | 2006-02-17 | Optical pressure switch, door operating system and method |
US13/470,561 Abandoned US20130019531A1 (en) | 2006-02-17 | 2012-05-14 | Optical pressure switch, door operating system and method |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/224,025 Active 2028-04-02 US8178830B2 (en) | 2006-02-17 | 2006-02-17 | Optical pressure switch, door operating system and method |
Country Status (2)
Country | Link |
---|---|
US (2) | US8178830B2 (en) |
WO (1) | WO2007106061A2 (en) |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2007106061A2 (en) * | 2006-02-17 | 2007-09-20 | Jec Optics, Inc. | Optical pressure switch, door operating system & method |
CN102473015B (en) * | 2009-07-09 | 2016-01-13 | 诺格伦有限责任公司 | Comprise the pressure monitor system of multiple pressure switch |
US8901940B2 (en) * | 2010-10-05 | 2014-12-02 | Miller Edge, Inc. | Resistor storage cavity in plug of sensing edge |
US10246927B2 (en) | 2010-10-05 | 2019-04-02 | Miller Edge, Inc. | Sensing edge |
US8832996B2 (en) | 2010-10-05 | 2014-09-16 | Miller Edge, Inc. | Sensing edge |
US10637470B2 (en) * | 2018-01-05 | 2020-04-28 | Darfon Electronics Corp. | Optical keyswitch |
Family Cites Families (38)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3491246A (en) * | 1966-12-05 | 1970-01-20 | American Atomics Corp | Pressure transducer varying position of radiant energy source in accordance with pressure change |
US3916567A (en) | 1974-08-26 | 1975-11-04 | Vapor Corp | Obstruction sensor for pneumatic door operator |
US4004272A (en) * | 1975-07-21 | 1977-01-18 | The Firestone Tire & Rubber Company | Optical pressure switch |
US4035637A (en) | 1975-12-23 | 1977-07-12 | Zot Manufacturing Company | Fluid actuated light switch |
US4122337A (en) | 1976-02-26 | 1978-10-24 | Matsushita Electric Industrial Co., Ltd. | Pressure-electrical signal conversion means |
US4049964A (en) | 1976-04-01 | 1977-09-20 | Cavitron Corporation | Optical switching device |
US4133345A (en) | 1977-06-08 | 1979-01-09 | Clarence Mitchell | Attitude insensitive valve |
US4211901A (en) | 1977-12-29 | 1980-07-08 | Bridgestone Tire Company Limited | Pressure sensing switch with conductive deflectable diaphragm |
US4369344A (en) | 1979-07-26 | 1983-01-18 | Vapor Corporation | Sensitive door edge Wiegand module switch assembly |
US4371762A (en) | 1979-07-26 | 1983-02-01 | Vapor Corporation | Contactless pressure sensitive switch |
DE2937484A1 (en) | 1979-09-17 | 1981-05-14 | Siemens AG, 1000 Berlin und 8000 München | OPTICAL DEVICE FOR MEASURING PRESSURE DIFFERENCES BY LIGHT INTENSITY CHANGE |
US4320294A (en) | 1979-09-17 | 1982-03-16 | Robertshaw Controls Company | Control device and method of making the same |
US4521683A (en) * | 1981-03-20 | 1985-06-04 | The Boeing Company | Pressure-actuated optical switch |
US4479111A (en) * | 1982-02-09 | 1984-10-23 | Burroughs Corporation | Photo-optical switch apparatus |
US4604633A (en) | 1982-12-08 | 1986-08-05 | Konishiroku Photo Industry Co., Ltd | Ink-jet recording apparatus |
DE3307964A1 (en) | 1983-03-07 | 1984-09-13 | Philips Patentverwaltung Gmbh, 2000 Hamburg | PRESSURE SENSOR |
JPS60111129A (en) * | 1983-11-21 | 1985-06-17 | Yokogawa Hokushin Electric Corp | Pressure sensor |
US4626681A (en) | 1984-09-14 | 1986-12-02 | Johnson Service Company | Differential pressure control apparatus |
US4620072A (en) | 1985-04-12 | 1986-10-28 | Miller Norman K | Hollow non-occluding pressure sensor |
EP0227556A1 (en) | 1985-12-24 | 1987-07-01 | Schlumberger Industries | Optical sensor for physical magnitudes |
US4698967A (en) | 1986-05-05 | 1987-10-13 | F. L. Saino Manufacturing Co. | Supervising apparatus |
US4745925A (en) | 1986-10-06 | 1988-05-24 | Dietz Henry G | Optoelectronic inhalation sensor for monitoring inhalation and for inhalation therapy |
EP0287098B1 (en) | 1987-04-15 | 1996-07-31 | Canon Kabushiki Kaisha | Residual-ink detector and a liquid injection recording apparatus comprising the detector |
DE3725777C1 (en) | 1987-08-04 | 1988-12-22 | Josef 4040 Neuss De Franken | |
US5148631A (en) | 1988-03-11 | 1992-09-22 | Mark Iv Transportation Products Corporation | Pneumatic door operator having pneumatic actuator and lock |
US4911015A (en) | 1988-11-14 | 1990-03-27 | Asea Brown Boveri Inc. | Non-electrical monitoring of a physical condition |
DE3921641A1 (en) | 1989-06-30 | 1991-01-24 | Hoermann Kg Antrieb Steuertec | SECURING DEVICE FOR THE CLOSING EDGE OF A DOOR LEAF |
US5130502A (en) | 1990-10-22 | 1992-07-14 | Chen Teh Chih | Vacuum-controlled switch means responsive to engine load |
CA2067594C (en) | 1991-05-10 | 1997-02-25 | Daniel J. Flanagan | Transit car power door obstruction sensing system and device |
US5130503A (en) | 1991-06-24 | 1992-07-14 | Mark Iv Transportation Products Corporation | Pressure wave switch having improved contact structure and pressure equilization |
US5262641A (en) * | 1991-12-30 | 1993-11-16 | Honeywell Inc. | Compensation mechanism for a pressure sensor having counterweight mechanism |
US5252826A (en) * | 1991-12-30 | 1993-10-12 | Honeywell Inc. | Differential pressure utilizing opto-reflective sensor |
US5426293A (en) | 1993-04-29 | 1995-06-20 | Miller Edge | Sensing edge having a photoelectric switch positioned therein |
US5725359A (en) | 1996-10-16 | 1998-03-10 | B&S Plastics, Inc. | Pool pump controller |
US6040536A (en) | 1998-01-26 | 2000-03-21 | Miller Edge, Inc. | Pressure responsive switch and method of making same |
US6904192B2 (en) * | 2002-10-07 | 2005-06-07 | Agilent Technologies, Inc | Latching bubble for fluid-based optical switch |
US7225676B2 (en) * | 2004-05-18 | 2007-06-05 | Jennings Technology | Method and apparatus for the detection of high pressure conditions in a vacuum switching device |
WO2007106061A2 (en) * | 2006-02-17 | 2007-09-20 | Jec Optics, Inc. | Optical pressure switch, door operating system & method |
-
2006
- 2006-02-17 WO PCT/US2006/005650 patent/WO2007106061A2/en active Application Filing
- 2006-02-17 US US12/224,025 patent/US8178830B2/en active Active
-
2012
- 2012-05-14 US US13/470,561 patent/US20130019531A1/en not_active Abandoned
Also Published As
Publication number | Publication date |
---|---|
US8178830B2 (en) | 2012-05-15 |
WO2007106061A2 (en) | 2007-09-20 |
US20100154311A1 (en) | 2010-06-24 |
WO2007106061A3 (en) | 2008-10-23 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US20130019531A1 (en) | Optical pressure switch, door operating system and method | |
US4805739A (en) | Elevator control switch and position indicator assembly | |
EP0660092B1 (en) | A remain detector and a liquid injection recording apparatus having the detector | |
CN101071087B (en) | Automobile tyre prewarning system | |
US5709358A (en) | Installing structure of cluster module | |
US5557256A (en) | Tire pressure loss indicating device | |
JPH03190029A (en) | Pressure sensor | |
US5729256A (en) | Ink remain detector having a biased flexible film member with limited deformation | |
US8085141B2 (en) | Self-diagnostic switch | |
US7656279B2 (en) | Glass breakage detecting sensor | |
KR20220062543A (en) | Pressure relief device and battery housing comprising such pressure relief device | |
US5334090A (en) | Integrated cabin pressure controller | |
KR20020005499A (en) | Two-Way Valve | |
US6223769B1 (en) | Gas pressure sensor and indicator apparatus for recreational vehicles and the like | |
US6307466B1 (en) | Two stage gauge with electrical signal output | |
US6011462A (en) | Tire pressure monitor | |
US3209721A (en) | Pressure-responsive devices | |
US4788525A (en) | Electric pneumatic pressure sensor | |
US5101754A (en) | Device for surveillance of a pressure in a vehicle tire | |
US2797407A (en) | Indicator light | |
JP3982971B2 (en) | Air conditioning equipment | |
US3411533A (en) | Controlling and indicating unit and system | |
GB2255850A (en) | Low tyre pressure indicating device | |
US7134448B2 (en) | Transducer for monitoring the position of a movable body | |
US5493900A (en) | Indicator for compressed air bottles |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: JEC OPTICS, INC., CALIFORNIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:CONDON, JAMES E;BECK, GREGORY S;SIGNING DATES FROM 20060811 TO 20060819;REEL/FRAME:028389/0118 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |