WO2008147415A1 - Commutateur optique - Google Patents

Commutateur optique Download PDF

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Publication number
WO2008147415A1
WO2008147415A1 PCT/US2007/070122 US2007070122W WO2008147415A1 WO 2008147415 A1 WO2008147415 A1 WO 2008147415A1 US 2007070122 W US2007070122 W US 2007070122W WO 2008147415 A1 WO2008147415 A1 WO 2008147415A1
Authority
WO
WIPO (PCT)
Prior art keywords
light
housing
switch
modify
distal ends
Prior art date
Application number
PCT/US2007/070122
Other languages
English (en)
Inventor
Raleigh L. Cox
Christopher E. Cox
Original Assignee
Cox Raleigh L
Cox Christopher E
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Cox Raleigh L, Cox Christopher E filed Critical Cox Raleigh L
Priority to CA002687514A priority Critical patent/CA2687514A1/fr
Priority to BRPI0721740-4A priority patent/BRPI0721740A2/pt
Priority to KR1020097027585A priority patent/KR101356592B1/ko
Priority to PCT/US2007/070122 priority patent/WO2008147415A1/fr
Priority to EP07797956A priority patent/EP2165115A4/fr
Priority to CN2007800531850A priority patent/CN101680646B/zh
Priority to MX2009012915A priority patent/MX2009012915A/es
Publication of WO2008147415A1 publication Critical patent/WO2008147415A1/fr
Priority to HK10108892.0A priority patent/HK1143628A1/xx

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H35/00—Switches operated by change of a physical condition
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D9/00—Level control, e.g. controlling quantity of material stored in vessel
    • G05D9/12—Level control, e.g. controlling quantity of material stored in vessel characterised by the use of electric means
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
    • G01F23/30—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by floats
    • G01F23/40—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by floats using bands or wires as transmission elements
    • G01F23/44—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by floats using bands or wires as transmission elements using electrically actuated indicating means
    • G01F23/446—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by floats using bands or wires as transmission elements using electrically actuated indicating means using opto-electrically actuated indicating means

Definitions

  • the invention relates to switches used primarily in hazardous environments, such as switches used in liquid level detection in tanks or switches to activate equipment within a hazardous environment.
  • Float switches are commonly used in applications of this sort to detect level for activation of a pump (see Figure 2), but float switches generally have electrical current that passes through wires and a switch housed within the float, such as a mercury switch located in the float. Wires from the float switch run to a control panel (or other device) located external to the tank or pit and are located outside the hazardous area.
  • control panel or other device located external to the tank or pit and are located outside the hazardous area.
  • Some tanks containing flammable liquids or gases use ultrasonic level detection which sends a sonic burst to the surface of the liquid and then back.
  • the transit time of the beam is used to determine the liquid level (some alternative devices use radar or microwave radiation as an energy packet instead of a sound wave, and other sensing technologies are used in level detection, e.g. magnetostrictive, submersible pressure transducers, bubblers, capacitance, etc.).
  • level detection e.g. magnetostrictive, submersible pressure transducers, bubblers, capacitance, etc.
  • This technique is not generally used to remotely signal a device, such as a signal to engage/disengage a pump (such as a dosing pump) at discrete levels, as these level detectors will detect all fluid levels requiring additional logic circuits to select a predetermined height or level for operation of a pump, thereby raising the complexity and expense of such as system.
  • explosion proof containers are used to contain equipment or devices that may present a possible sparking hazard, such as controls, pumps, motors, etc. While pumps or other devices located in a hazardous environment may be contained in an explosion proof housing, these devices must be activated or deactivated by electrical signals (e.g. providing power to the device). Activation is done remotely from the hazardous environment to reduce the possibility of explosion. Hence, when an operator is onsite, the operator cannot manually activate/deactivate the device within the hazardous area unless the activation device is in an explosion proof housing. It would be desirable to have a switch located within the hazardous environment that could be used to manually activate/deactivate the powered device, and have the switch not present an arcing hazard, and would not have to be located in an explosion proof housing.
  • the invention is an optically activated switch for use in a hazardous environment, (non- hazardous environments also are contemplated) and in one embodiment, the switch activation components are contained in a floatable housing and used to signal the need to operate a pump or other device.
  • a switch is a device having a status (on/off, make/break, open/closed or other status indicator) that can be used to control an electrical device.
  • the switch invention uses a light beam from a transmitter located outside of the hazardous atmosphere ("outside the hazardous environment” includes a location within an explosion proof container or housing) which travels through a light carrying cable, fiber, tube or light guide (all considered a "light guide”) to a switch means located in a hazardous area.
  • the light can travel to a powered light detector or receiver located outside the hazardous area, which detects the status of the switch, and circuitry can act on the status to activate or deactivate a powered device, such as a pump or motor.
  • a powered device such as a pump or motor.
  • the controller to which the switch is connected can be configured to activate a pump or device upon detection of the light or detection of the lack of the light.
  • Figure 1 depicts an optically activated float.
  • Figure IA is a detail of the float of figure 1
  • Figure 2 depicts a conventional float.
  • Figure 3 depicts an optically activated float having a damped switch.
  • Figure 4 is a cross sectional view of the float of figure 3.
  • Figure 4A is a detail of the separator assembly of the float of figure 4.
  • Figure 5 depicts a switch operated mechanically or manually.
  • Figure 6 depicts another embodiment of a float switch.
  • Figure 7 depicts another embodiment of a float switch with a delay ring.
  • Figure 8 depicts a tether cable for a float embodied switch.
  • Figure 9 depicts a light and a limit optical switch located in a hazardous environment.
  • Figure 10 is a representative circuit diagram incorporating the switch, and used to power a device.
  • Figure 1 1 depicts a top view of an ampoule with two parallel same side optical fibers where the two fibers are optically aligned by position of the reflective bar at position A and where the two fibers are optically non-aligned (or optically interrupted) by position of the reflective bar at position B.
  • Figure 12 is a cartoon showing a magnet used to delay operation of the switch through a preselected range of motion.
  • Figure 13 A depicts the operation of a wide angle float as the pump chamber fills.
  • Figure 13B depicts the operation of a wide angle float as the pump chamber is pumped down.
  • Figure 14 depicts a float embodiment of the switch using a paddle insert separator assembly.
  • FIG 1 Shown in figure 1 is an embodiment of the invention in a float.
  • the invention includes a housing 1, two light guides 2 (hereafter described as fiber optic cables), a light source 3, and a means to interrupt or modify the alignment, here by interposing an object between the distal ends.
  • the housing shown has an interior section.
  • the two cables 2 are positioned into the housing 1. Each cable terminates at or within the floating housing 1.
  • the terminal (or distal) ends of the cables are positioned in the housing near each other, but separated by a gap 10 (see figure 1, detail A).
  • the gap 10 is generally positioned in the separator assembly 6 within the housing 1.
  • the separator assembly fixes the relationship of the cable terminal ends and maintains the gap, although this relationship can be fixed through use of the housing alone.
  • the gap can vary in size, with 0.01 - 0.5 inch suitable for most applications, but could be larger.
  • Some light detectors can sense the presence of light radiation across a gap of up to four inches.
  • the ends of the two fiber optic cables should be "optically aligned," that is, light emitted from one terminal end will travel though the gap (possibly along a zig-zag path if reflective material, such as mirrors, are employed to bounce the emitted beam appropriately) and a portion of the transmitted light will enter the terminal end of the second cable. The portion that enters must be sufficient to be able to detect the presence of light radiation by the light detector.
  • the two cables may be parallel with a 45 degree reflective surface positioned at the fiber ends, so the two fibers, while parallel, are "optically aligned.”
  • the two cable ends can be offset a distance and still be optically aligned if sufficient light is captured and transmitted through the cable connected to the light detector to activate the light receptor.
  • the degree of offset will depend upon the sensitivity of the light detector and the strength of the source. Suitable sources and detectors can be found at www.fiberopticproducts.com: with sources such as E97 (red 660 nanometers, bright) and detector D92. Using these sources and detectors, the light source can still be detected with an offset of one inch over a gap of about 1 inch.
  • the separator assembly 6 generally includes an internal chamber 6A with one fiber cable 2 terminal end positioned adjacent to, in or on the wall of the interior chamber and the other fiber optic cable 2 terminal end positioned on an opposite wall of the internal chamber 6A, with the two ends optically aligned.
  • the separator assembly is generally an assembly removable from the interior of the float with the cables positioned on the assembly. Applicant believes it is more efficient to build the separator assembly with attached cables and inserted into the float, than using only a hollow interior with the cables inserted into or attached to the interior walls of the float, although such a design is workable and within the scope of the invention.
  • the separator assembly is not required, but is preferred.
  • a separator assembly 6 comprising a glass or clear plastic ampoule 5.
  • Ampoule contains a slidable bar, ball, or cylinder (or other shape) 1OA, and has the two light guides coupled on opposing sides of the ampoule exterior through use of a yoke or collar 1 1.
  • Separator assembly 6 would be positioned in the interior of the float, usually the separator assembly will be fixedly positioned in the float interior such as with epoxy or a friction fit.
  • a collar 12 is used to fix the ampoule in position in the interior of the float, and in some cases collar 12 functions as additional weight to modify the buoyancy and center of gravity of the float as needed.
  • the weight can be lead or other dense material, for instance, steel particles encased in a corrosion resistant (preferably an environmental friendly) material.
  • Yoke 1 1 and collar 12 could be combined (not shown).
  • a detail of yoke 1 1 is shown in Figure 4, detail A.
  • the separator assembly may not be preferred.
  • the separator is a flat paddle 60, constructed of flexible plastic. Formed in the paddle are clips 61 to hold the ampoule and optical cables.
  • the paddle 60 is inserted in the bottom 1 ⁇ of the housing IA and fixed into position. The paddle may be fixed by potting the bottom of the paddle to the housing portion IA, leaving the top portion of the paddle free to flex.
  • the top of the housing IB is then attached to the bottom IA, such as by RF welding.
  • the top of the paddle 60 is not form fitting to the top of the float housing I B, to allow the top of the paddle (where the ampoule is located) to flex in response to shock forces. For instance, operators have been known to "clean" floats by swinging the float by the tether and slamming the float into a wall.
  • the housing 1 is floatable, and the cables "tether" the housing 1 to a fixed point, allowing the float to rise and fall with the media for a range of elevations.
  • the two fiber cables 2 are contained in a single cable structure, later described.
  • One of the fiber optic cables is connected to a light source 3, and the other cable is connected to a light detector 5.
  • the light source 3 can be any suitable source, such as a laser, incandescent light bulb, sunlight, a light emitting diode, and light generally refers to any electromagnetic radiation, but for fiber optics, preferably the light source will consists of visible light, infrared light, sunlight, and ultraviolet light; more preferably, light from about 300 nanometers to about 30,000 nanometers in frequency.
  • the light source 3 and light receiver or detector 5 will be located external to the hazardous area in a control panel or other device (they do not have to be located together), and only the fiber optic cables will travel into the hazardous area to the housing 1.
  • the internal chamber 6A of the separator assembly 6 creates the needed gap between the fiber optic cables 2 terminal ends.
  • a means to interrupt optical alignment 10 such as a rollable or slidable ball or bar or cylinder, or an opaque fluid positioned within the internal chamber partially filling the chamber. If the housing floats, at a certain level the floating housing will tilt (as it is tethered by action of the cable that is tied to an internal or external fixed weight, or the housing is attached to another stationary device with a cable or tether) and as it tilts, the means to interrupt optical alignment will move within the internal chamber due to gravitational forces.
  • the means to interrupt optical alignment will block (or unblock) the light path between the two terminal ends of the fiber optic cables 2.
  • the means to interrupt optical alignment can be a floating arm or floating barrier positioned in the internal chamber 6A of the housing. As the water level rises up to the level of the housing, the floating arm or barrier will rise (much like a floating limit switch) to block the light beam (or unblock the light beam).
  • the switch will have a means to fix the elevation of the housing, such as a clamp, to attach the housing to a structure in the hazardous environment, such as a dosing pump or to the container storing the hazardous material.
  • a structure in the hazardous environment such as a dosing pump or to the container storing the hazardous material.
  • the housing is a cylindrical shell 100 with an center hollow interior 101 that is open on both ends to the external environment.
  • the housing would be fixed in position in the hazardous environment. Trapped in the interior is an opaque float body 102.
  • the two ends of hollow interior 101 may have a mesh filter covering the openings that retains the float body in the hollow interior.
  • Positioned on opposing sides of the interior 101 are the two optic cable 104A and B.
  • the float body 102 rises and will block the optical path between the two cables 104 A and B.
  • the cables do not have to be on opposing sides, but must either be optically aligned, or be optically alignable.
  • the twin fiber optic cables 150 (here shown as lmm diameter sheathed with a polyvinylchloride (PVC) coating 100) are positioned in the interior of an outer sheath member 300, here a 0.020 inch thick PVC extruded watertight jacket, used for strength. More than two optic fibers may be located in the cable.
  • PVC polyvinylchloride
  • the fiber-optic cables or light guides are deployed in a filler material 160 in the interior of the extruded sheath 300.
  • the filler material is very fine hair-like polypropylene fibers, all contained in a paper wrap 200.
  • the interior of the tether cable 250 is substantially filled, leaving very little freedom of movement for the optical fibers within the interior.
  • both optic fibers be sheathed to prevent shorting of the switch in the cable (particularly for the use of side glow cables (not preferred), for end glow cables, this may not be necessary).
  • a strong reinforcing cable such as a steel, Kevlar, carbon fiber, etc cable within or attached to, the tether cable structure.
  • a strong reinforcing cable such as a steel, Kevlar, carbon fiber, etc cable
  • Shown in Figure 8 is a cable that houses two optic fibers. The cable may contain more than two fibers.
  • the float may reach a position where the switch will "flutter" between an optical path open or “blocked” position or optical path closed or “complete” position due to inherent instabilities in a float embodiment. For instance, the float's position may jitter due to surface waves in the fluid environment. This float jitter may cause the slidable or reliable means to interrupt optical alignment (or the switch activator) located in the float interior to move back and forth, causing the switch status to rapidly move between open and closed (note, switch "open” can be interpreted as path blocked or path complete, depending on how the device connected to the switch circuitry is configured to respond to the status of the switch).
  • a damped switch can be employed by including a means to dampen the switch activator or the means to interrupt optical alignment.
  • the optical switch may be damped through a variety of means.
  • the ampoule may be filled or partially filled with a damping fluid 1 10, such as mineral oil or other clear or light transmissive fluid.
  • the fluid in the ampoule serves two purposes, lubrication (to help prevent the Tollable or slidable means to interrupt from scratching the walls of the ampoule and possibly modifying the optical characteristics of the ampoule walls) and acts as a damping force, creating a drag on the bar or ball reducing sudden movements of the bar or ball.
  • a damping fluid When a damping fluid is used, it is preferred to separate the fluid from the light guides (such as by having the fluid contained in an ampoule) to avoid contamination of the light guide distal ends by the damping fluid.
  • the amount of fluid in the ampoule can vary from a few drops to fully filled.
  • a slidable bar, ball, cylinder or other structure could be used with the sides of the structure roughened (or the interior walls of the ampoule could be roughened or have added ridges) to create additional surface area resulting in additional frictional forces opposing a sudden movement of the bar.
  • a ring or annulus positioned in the separator assembly chamber 6.
  • a rollable ball is used as the slidable member. The ring in the housing chamber insures that a ball positioned in the chamber will not move from position A (unblocked) to position B (blocked) without a sufficiently large enough movement of the housing to allow the ball to roll over the ridge created by the ring. The ending position of the ball would not be altered by minor fluctuations in the float position.
  • an hourglass shaped vessel may be used, where the neck of the hourglass can pass the slidable ball, specially designed segmented cylinders, other movable structure, or other light blocking device (e.g. opaque liquid).
  • the shape of the chamber is used to control switch flutter.
  • Another means to deal with switch flutter is to allow the light to blink, flash or pulse periodically, and a change in status of the switch is detected by the presence or absence of a suitable number of pulses. For instance, if the light path is initially blocked, and the status changes, the change will be noted after detection of so many consecutive light pulses (detection of, say 5, consecutive flashes, detecting the presence or absence of a predetermined number of flashes over a predetermine time interval helps reduce switch flutter); if the light path is not blocked, then a change in status would be detected after detection of the absence of a certain number of pulses or flashes of light over a predetermined time interval. This is generally not preferred as it increases the complexity of the circuitry tied to the switch, but may be useful where the lifetime of the light source is an issue.
  • switch flutter Another means to deal with switch flutter is not to use a constantly "on” light source. Instead, the source can remain off until the switch is "polled” for its status.
  • the electronics tied to the switch such as a controller (e.g. PLC or microcontroller), may interrogate the status of the switch every second, and turn the light source on once per second for a designated time, and "look" for the return status, e.g either light blocked or light present on the return optical fiber.
  • the light may stay on, and the status of the switch polled at the light detector. Again, this is not preferred, as it increases the complexity of the circuitry tied to the switch. To reduce switch flutter, the change in switch status should be consistent for a selected period of time.
  • FIG. 12 Another method to reduce switch flutter is to use magnets suitably positioned in the separator assembly in conjunction with a cylinder or slidable bar or structure composed of magnetably interactive material.
  • Shown in figure 12 is a cartoon depicting the movement of a slidable magnetic interactive cylinder or slug (here an 18-8 cold formed 3/16" D x 1/2" L stainless steel cylinder (sometimes denoted 300 series stainless steel having approximately 18% chromium and 8% nickel)) in an ampoule, and a "horseshoe” magnet positioned in the interior of the float where the two ends of the horseshoe near the sides or ends of the ampoule.
  • the horseshoe magnet is shown for purposes of explanation and is not preferred.
  • a weak magnetic interaction means that for a given magnet and slug or moveable structure (or vice versa, where the magnet moves), the magnetic force exerted between the slug or device and magnet is insufficient to overcome the gravitational force acting on the slug, thereby allowing the slug to be released at some point as the position of the slug approaches vertical, as shown in figure 12.
  • the actual release point of the slug can vary by modifying the strength of the magnet, the weight of the slug, or the magnetizability of the slug's material.
  • the location of the magnets can vary. For instance, in figure 12, detail A, two magnets Ml and M2 can be positioned at or near each end of the ampoule or chamber (either internal or external to the chamber) (by using two different strength magnets, the release point of the slug on an upward rotation can be different for the release point on a downward rotation).
  • FIG. 13 Shown in figure 13 is a typical wide angle pump switch operation.
  • the pump chamber fills with fluid and the pump remains “off” until the float reaches position B.
  • the pump turns on.
  • the pump remains "on” as fluid is pumped out until position A is reached, at which time the pump turns off.
  • the switch as described uses optically aligned light guides and a means to interrupt optical alignment by interposing an object.
  • the light guides may be optically aligned by a light path that bounces off a reflective moveable member, such as a reflective bar. Sufficient movement of the slidable object destroys the bounce path, and hence, results in non-alignment of the distal ends of the light guides.
  • the switch activator (the sliding bar, cylinder, ball, etc) is the means to interrupt optical alignment upon suitable movement.
  • the fibers may be parallel, but offset, positioned on the exterior of the ampoule, as shown in figure 1 1.
  • a slidable reflective bar Positioned in the ampoule is a slidable reflective bar (the ampoule may have a track for the bar to slide in, or be suitably shaped (e.g. rectangular prism), to maintain the orientation of the bar in the ampoule, however, if the receptor is sensitive, a reflective cylinder or ball may be used in a cylindrical ampoule, as some scattered light will be detected by a sensitive detector, such as the D92 detector).
  • a sensitive detector such as the D92 detector
  • one end (or both ends) of the fibers could be movable between a first position of optical alignment of the distal ends and a second position of optical non- alignment, such as by moving one end (e.g. having that end mounted on a sliding bar) to move sufficiently so that the optical alignment is interrupted, or having both ends move to either align the distal ends or interrupt the optical alignment , such as by moving both fibers in unison until a fixed object is interposed between the two fiber ends.
  • a floating housing 1 can be constructed in any number of ways. One such way would be to use foam in a two part mold, encasing the separator assembly within (or by welding two half floats together).
  • the housing can also could be constructed of two halves fused together by glue or heat, with the separator assembly located within the housing. Any object that floats could be drilled or carved out and the separator assembly (if employed) could be inserted inside and then sealed using any number of means, including plastic injection molding methods
  • the receiver or detector 5 can be located external to the hazardous area in a control panel or other device and is not required to be located with the light source. Any number of commercially available devices that are sensitive to light energy, such as devices containing a photo eye or photo transistor, are suitable as a light detector or receiver. The presence or absence of light, through the switch, detected at the receiver, is indicative of the position of the floating housing in the environment. The status of the switch can be utilized as a signal means to perform a specific task such as starting or stopping a pump.
  • the switch components can be used as any type of switch.
  • FIG 5 shown in figure 5 is a device switch.
  • the switch has a housing 200 (here a plate with two upstanding flanges) into which a first 201 and second 202 light guide are mounted and separated by a gap, but optically aligned.
  • One of the light guides is connected to a light source, another to a light detector.
  • Slidably mounted to the plate is slide 210. Slide is movable between positions (e.g. position A, blocking transmission, and position B, allowing transmission) between the light guides 202 and 201.
  • Figure 5 depicts a "slide" switch type, but any type switch device can employ the optical components, including a toggle type switch, push button type switch, rotary type switch, rocker type switch, key activated switch, limit switch, proximity switch or other type of manually or mechanically operated switch where the operation of the switch occults or blocks the light path or otherwise interrupts optical alignment (or as later described, modifies the transmitted characteristics of the source light) between the two light guides, through manual or mechanical activation (e.g. relay operation of the switch activator) as opposed to gravity operation by a float switch.
  • a toggle type switch e.g. push button type switch, rotary type switch, rocker type switch, key activated switch, limit switch, proximity switch or other type of manually or mechanically operated switch where the operation of the switch occults or blocks the light path or otherwise interrupts optical alignment (or as later described, modifies the transmitted characteristics of the source light) between the two light guides, through manual or mechanical activation (e.g. relay operation of the switch activator) as opposed
  • the optical switch may incorporate a means to modify the received characteristics of a light beam, allowing the switch have multiple "statuses," instead of simply on or off.
  • a switch could be used to control devices with selectable settings (such as selecting the speed of a motor) or if the allowed variation is an analog variation, the switch can operate as a "dimmer switch” or continuously variable switch.
  • the slidable bar could be a stepped density filter or a stepped transmission filter, such as available from Edmund Optics fwww.edmundoptics.com) as model numbers 147-524, 147-525, 147-526 or 147-527.
  • the slidable bar does not totally block the light path at all positions on the bar, but generally allows partial transmission through the bar.
  • the relative position of the bar with respect to the cable ends within the float interior or separator assembly can be determined based upon a the amount of light received by the light receptor after passage through the bar.
  • the amount of light transmitted through the bar can be used to allow the device to function as a multiple position switch, to control devices having selectable positions.
  • the bar instead of modifying the degree of light transmission though the bar, other parameters could be used to modify the received characteristics of the source light, such as polarization or frequency. For instance, if the bar had four regions of different color, the light transmitted through the bar will vary in color or frequency based upon the position of the bar with respect to the source of light. The relative position of the bar (as detected by reception of a different color or frequency of light) can then be used to perform different functions (e.g, start pump 1, start pump 2, etc). A continuous or analog gradation in transmission characteristics could also be used instead of a stepped bar as a "dimmer" type of switch to control a variable speed motor.
  • polarization or frequency For instance, if the bar had four regions of different color, the light transmitted through the bar will vary in color or frequency based upon the position of the bar with respect to the source of light. The relative position of the bar (as detected by reception of a different color or frequency of light) can then be used to perform different functions (e.g, start pump 1, start pump 2, etc).
  • Another type of dimmer or continuously variable type switch would two polarization filters, one fixed and one rotatable, with the distal ends of the fibers aligned through the polarized lenses.
  • rotation of one of the polarization filters (such as by mechanical or manual activation of the switch activator), the amplitude of the transmitted light can be varied in a continuous manner. All of the above are considered a means to modify the received characteristics of a light beam.
  • the "means to interrupt optical alignment" is also a "means to modify the received characteristics of a light beam” as the modification is the non-transmission or non-reception of the light beam by operation of non- alignment of the distal ends or by interposing a light opaque object between the distal ends.
  • the optical switch can accommodate "three way switches" or multiple pole, multiple throw type switches. Additional light fibers or light sources/receivers may be needed for a particular application. For instance, for a three way switch, each switch has three distal fiber ends (here denoted the source, the common, and the traveler). The "traveler" optical fiber is to run between the two switches. Each three way switch contains a mirror or other reflective surface that provides optical alignment within the switch between the "source wire” and either the traveler or the common within each switch, and interrupts optical alignment with the non-selected path. That is, the light beam in a three way switch has two possible routes through the switch, and the route through the switch selects the path (by movement of the switch activator). Again, instead of moving a reflective surface, the optical fiber could be moved by operation of the switch.
  • the housing (or at least that portion containing the distal ends of the light guides and the gap therebetween (such as the separator assembly) will be substantially lightproof, and it is preferred that the housing itself be substantially lightproof with the switch activator or actuator (the slide, pushbutton, toggle, etc), for manual operation, extending through the housing.
  • the distal ends of the light guides are located in the interior of the housing in order to keep the optical switch components isolated from external light sources (such as ambient light) which might provide a false reading.
  • the housing does not need to be light proof, and simply is used to define a gap between the distal ends of the light guides, such as shown in figure 5.
  • the switch as described could be positioned within the hazardous environment, such as adjacent to (or attached to) an explosive proof housing containing a device (e.g. a motor or pump within the interior of the explosive proof housing).
  • a device e.g. a motor or pump within the interior of the explosive proof housing.
  • the light source and light detector utilized by the switch can be located in a remote switch panel or other remote device, and located separately if desired.
  • the source and detector can be located in the interior of the explosive proof housing, and the light guides from the switch (within the hazardous environment) routed into the interior of the explosive proof housing through an explosive proof connector (the interior of an explosive proof container is considered to be remote from the hazardous environment). See figure 9, showing an optical toggle light switch 1000 operating a light fixture
  • the light fixture 1002 located in a hazardous environment, and is wired 1004, through an explosion proof conduit or using explosion proof wire), to a panel 1003 located outside the hazardous environment (the light may be wired to an explosion proof panel in the hazardous environment).
  • the light fixture 1002 is in an explosion proof housing, but the optical switch 1000 is not.
  • the optical switch light guides 1005 proximal ends are located in the panel 1003 and connected to the light source and light detector. The status of the switch is detected in the panel 1003, such as through use of a circuit (one suitable circuit is shown in figure 10), which circuit will power or de-power the light fixture based upon the detected switch status.
  • Figure 9 also shows an optical limit switch 1010. This optical switch can be connected to panel
  • This limit switch is activated by a level arm 1100 of a valve or other device that activates or deactivates the optical limit switch 1010.
  • the circuit in figure 10 shows the light source (E97) and light detector (D92) with the corresponding optical fibers connected to a float embodiment of the optical switch.
  • the circuit is designed to have the relay de-energized when the return optical fiber is dark, that is, when the detector fails to detect light on the return optical fiber. If light is detected, the relay is energized, closing switch 90, which is used to connect power to the light fixture located in the hazardous region.
  • the powered components of the optical switch are electrically isolated from the hazardous environment, and the only energy present within the hazardous environment is a light beam.
  • such an optical switch presents a safe and economic alternative to conventional switches using an electrical contact in the hazardous environment that present a potential source of electric spark and ignition within the hazardous environment.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Automation & Control Theory (AREA)
  • Fluid Mechanics (AREA)
  • Geophysics And Detection Of Objects (AREA)
  • Mechanical Light Control Or Optical Switches (AREA)
  • Switches Operated By Changes In Physical Conditions (AREA)

Abstract

L'invention concerne un interrupteur optique ayant un boîtier [1], une source de lumière [3] et un détecteur de lumière [5]. La source de lumière [3] et le détecteur de lumière [5] sont situés à distance du boîtier. La source de lumière [5] est reliée au boîtier au moyen d'un premier guide de lumière [2] et le détecteur de lumière [5] est relié au boîtier au moyen d'un second guide de lumière [2]. Les premier et second câbles de guidage de lumière ont des extrémités distales positionnées à travers le boîtier et sont alignés optiquement mais séparés par un espace. L'interrupteur comprend un dispositif permettant d'interrompre le faisceau de lumière.
PCT/US2007/070122 2007-05-31 2007-05-31 Commutateur optique WO2008147415A1 (fr)

Priority Applications (8)

Application Number Priority Date Filing Date Title
CA002687514A CA2687514A1 (fr) 2007-05-31 2007-05-31 Commutateur optique
BRPI0721740-4A BRPI0721740A2 (pt) 2007-05-31 2007-05-31 comutador àtico
KR1020097027585A KR101356592B1 (ko) 2007-05-31 2007-05-31 광학 스위치
PCT/US2007/070122 WO2008147415A1 (fr) 2007-05-31 2007-05-31 Commutateur optique
EP07797956A EP2165115A4 (fr) 2007-05-31 2007-05-31 Commutateur optique
CN2007800531850A CN101680646B (zh) 2007-05-31 2007-05-31 一种光学开关
MX2009012915A MX2009012915A (es) 2007-05-31 2007-05-31 Un interruptor optico.
HK10108892.0A HK1143628A1 (en) 2007-05-31 2010-09-19 An optical switch

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US2007/070122 WO2008147415A1 (fr) 2007-05-31 2007-05-31 Commutateur optique

Publications (1)

Publication Number Publication Date
WO2008147415A1 true WO2008147415A1 (fr) 2008-12-04

Family

ID=40075414

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2007/070122 WO2008147415A1 (fr) 2007-05-31 2007-05-31 Commutateur optique

Country Status (8)

Country Link
EP (1) EP2165115A4 (fr)
KR (1) KR101356592B1 (fr)
CN (1) CN101680646B (fr)
BR (1) BRPI0721740A2 (fr)
CA (1) CA2687514A1 (fr)
HK (1) HK1143628A1 (fr)
MX (1) MX2009012915A (fr)
WO (1) WO2008147415A1 (fr)

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8658962B2 (en) 2008-10-16 2014-02-25 Christopher E. Cox Optical switch with glowable activator portion
US9383518B2 (en) 2012-12-14 2016-07-05 Christopher E. Cox Optical switch activator
US9502192B2 (en) 2014-02-14 2016-11-22 Covidien Lp Surgical instruments with non-contact switch assemblies
US9991069B2 (en) 2014-10-22 2018-06-05 Covidien Lp Surgical instruments and switch assemblies thereof
US10285690B2 (en) 2015-12-22 2019-05-14 Covidien Lp Surgical instruments and switch assemblies thereof
WO2020150744A1 (fr) * 2019-01-18 2020-07-23 Soraa Laser Diode, Inc. Système de lumière blanche couplé à un guide d'ondes basé sur un laser destiné à une application d'éclairage
US10840045B1 (en) 2019-06-04 2020-11-17 Christopher E. Cox Invertible optical float switch
US11272948B2 (en) 2018-07-10 2022-03-15 Covidien Lp Hand-held surgical instruments
US11395655B2 (en) 2019-12-06 2022-07-26 Covidien Lp Hand-held surgical instruments
US11493695B2 (en) 2019-06-25 2022-11-08 Thomas C. Stewart Sustained continuity non-powered optomechanical position switch utilizing self-testing multiplexed optocontrolling transceiver in a fiber-optic circuit
US11504117B2 (en) 2020-04-02 2022-11-22 Covidien Lp Hand-held surgical instruments
US11540827B2 (en) 2019-12-13 2023-01-03 Covidien Lp Hand-held electromechanical surgical instruments
US11594862B2 (en) 2018-12-21 2023-02-28 Kyocera Sld Laser, Inc. Fiber delivered laser induced white light system
US11737747B2 (en) 2019-12-17 2023-08-29 Covidien Lp Hand-held surgical instruments
US11788699B2 (en) 2018-12-21 2023-10-17 Kyocera Sld Laser, Inc. Fiber-delivered laser-induced dynamic light system
US11871924B2 (en) 2018-09-21 2024-01-16 Covidien Lp Hand-held surgical instruments
US11884202B2 (en) 2019-01-18 2024-01-30 Kyocera Sld Laser, Inc. Laser-based fiber-coupled white light system

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11067559B2 (en) 2016-02-26 2021-07-20 Honeywell International Inc. Optical switch with reflection disk in explosion-proof gas detector

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3863067A (en) * 1972-07-24 1975-01-28 Cornelius Leonard Gooley Orientation indicating apparatus
US4773265A (en) 1980-11-20 1988-09-27 Atlantic Richfield Company Method for detecting leaks
US5373153A (en) * 1993-01-04 1994-12-13 Motorola, Inc. Optoelectronic tilt detector having tapered floors extending in same direction

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4836632A (en) * 1988-05-16 1989-06-06 National Magnetic Sensors Inc. Fiber optic liquid level sensor
US5017748A (en) * 1988-08-02 1991-05-21 Sapiro Andrew J Float switch with buoyant housing and switch operating means within the housing
US5743135A (en) * 1993-08-27 1998-04-28 Vlsi Technology, Inc. Optical-fiber liquid-level monitor
US5684296A (en) * 1996-06-17 1997-11-04 Optical Systems Industries, Inc. Fiber optic liquid sensing system
US6973247B2 (en) * 2001-07-02 2005-12-06 Acreo Ab Method and device for controlling the refractive index in an optical fiber
AUPS267202A0 (en) * 2002-05-30 2002-06-20 Dunbar, Neil James A sensor and method for measuring the level of a medium

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3863067A (en) * 1972-07-24 1975-01-28 Cornelius Leonard Gooley Orientation indicating apparatus
US4773265A (en) 1980-11-20 1988-09-27 Atlantic Richfield Company Method for detecting leaks
US5373153A (en) * 1993-01-04 1994-12-13 Motorola, Inc. Optoelectronic tilt detector having tapered floors extending in same direction

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP2165115A4 *

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8658962B2 (en) 2008-10-16 2014-02-25 Christopher E. Cox Optical switch with glowable activator portion
US9383518B2 (en) 2012-12-14 2016-07-05 Christopher E. Cox Optical switch activator
US10236144B2 (en) 2014-02-14 2019-03-19 Covidien Lp Surgical instruments with non-contact switch assemblies
US9502192B2 (en) 2014-02-14 2016-11-22 Covidien Lp Surgical instruments with non-contact switch assemblies
US10446342B2 (en) 2014-10-22 2019-10-15 Covidien Lp Surgical instruments and switch assemblies thereof
US9991069B2 (en) 2014-10-22 2018-06-05 Covidien Lp Surgical instruments and switch assemblies thereof
US10285690B2 (en) 2015-12-22 2019-05-14 Covidien Lp Surgical instruments and switch assemblies thereof
US11272948B2 (en) 2018-07-10 2022-03-15 Covidien Lp Hand-held surgical instruments
US11871924B2 (en) 2018-09-21 2024-01-16 Covidien Lp Hand-held surgical instruments
US11594862B2 (en) 2018-12-21 2023-02-28 Kyocera Sld Laser, Inc. Fiber delivered laser induced white light system
US11788699B2 (en) 2018-12-21 2023-10-17 Kyocera Sld Laser, Inc. Fiber-delivered laser-induced dynamic light system
WO2020150744A1 (fr) * 2019-01-18 2020-07-23 Soraa Laser Diode, Inc. Système de lumière blanche couplé à un guide d'ondes basé sur un laser destiné à une application d'éclairage
US11884202B2 (en) 2019-01-18 2024-01-30 Kyocera Sld Laser, Inc. Laser-based fiber-coupled white light system
US10840045B1 (en) 2019-06-04 2020-11-17 Christopher E. Cox Invertible optical float switch
US11493695B2 (en) 2019-06-25 2022-11-08 Thomas C. Stewart Sustained continuity non-powered optomechanical position switch utilizing self-testing multiplexed optocontrolling transceiver in a fiber-optic circuit
US11395655B2 (en) 2019-12-06 2022-07-26 Covidien Lp Hand-held surgical instruments
US11540827B2 (en) 2019-12-13 2023-01-03 Covidien Lp Hand-held electromechanical surgical instruments
US11737747B2 (en) 2019-12-17 2023-08-29 Covidien Lp Hand-held surgical instruments
US11504117B2 (en) 2020-04-02 2022-11-22 Covidien Lp Hand-held surgical instruments

Also Published As

Publication number Publication date
EP2165115A4 (fr) 2011-07-27
EP2165115A1 (fr) 2010-03-24
CN101680646B (zh) 2013-08-14
CA2687514A1 (fr) 2008-12-04
HK1143628A1 (en) 2011-01-07
KR20100030636A (ko) 2010-03-18
MX2009012915A (es) 2010-03-03
BRPI0721740A2 (pt) 2013-02-13
KR101356592B1 (ko) 2014-02-03
CN101680646A (zh) 2010-03-24

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