Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66D—CAPSTANS; WINCHES; TACKLES, e.g. PULLEY BLOCKS; HOISTS
  • B66D5/00—Braking or detent devices characterised by application to lifting or hoisting gear, e.g. for controlling the lowering of loads
  • B66D5/02—Crane, lift hoist, or winch brakes operating on drums, barrels, or ropes
  • B66D5/06—Crane, lift hoist, or winch brakes operating on drums, barrels, or ropes with radial effect
  • B66D5/08—Crane, lift hoist, or winch brakes operating on drums, barrels, or ropes with radial effect embodying blocks or shoes
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D49/00—Brakes with a braking member co-operating with the periphery of a drum, wheel-rim, or the like
  • F16D49/16—Brakes with two brake-blocks
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D66/00—Arrangements for monitoring working conditions, e.g. wear, temperature
  • F16D66/02—Apparatus for indicating wear
  • F16D66/021—Apparatus for indicating wear using electrical detection or indication means
  • F16D66/026—Apparatus for indicating wear using electrical detection or indication means indicating different degrees of lining wear
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D66/00—Arrangements for monitoring working conditions, e.g. wear, temperature
  • F16D2066/003—Position, angle or speed

Definitions

• the present invention relates to a device for brake monitoring, and in particular to a device for monitoring of an elevator brake, and more particularly to a brake monitoring device for retrofitting of already existing elevator constructions.
• Elevators are commonly used constmctions, in particular for high buildings. In recent times, elevators became more and more popular also for smaller buildings. At the same time the security requirements became higher and higher. Elevators need a periodical check-up for maintaining the security devices. As elevators have a long lifetime, some elevator constructions are a couple of decades old, some more than 50 or 60 years. Nevertheless, the security of even the old elevator constructions is an important issue.
• One of the most relevant parts of an elevator is the brake of the elevator. Owing to the vertical construction of the elevator, a failure of the brake will result in a serious damage for passengers as well as the elevator construction. The brake of an elevator often is a mechanical device having a significant abrasion.
• the present invention provides for a brake monitoring device, in particular for elevators and escalators, allowing a reliable determination of the current state of a brake, in particular of an elevator or escalator brake, according to the independent claims, wherein further embodiments are incorporated in the dependent claims.
• the following aspects refer to a brake monitoring device as well as an elevator and escalator, each being equipped with a brake monitoring device.
• a brake monitoring device for distance monitoring a brake process between a brake medium and a moving object
• the brake monitoring device comprising an interface for a first distance sensor unit, a controlling unit for controlling the first distance sensor unit, and an evaluation unit
• the controlling unit comprises a driver for driving the first distance sensor unit
• the evaluation unit is adapted for determining a distance between the first distance sensor unit to be connected to the interface to a moving object based on the distance signal, and for evaluating the distance so as to determine correct operation of the brake process.
• the brake monitoring device may determine the distance between the moving object, e.g. a brake drum, and a brake medium, like e.g. a brake leaver.
• the distance between those both elements may be an indicative for the thickness of e.g. a brake pad.
• the monitoring device may give information on the capability of the brake and further may distinguish between serious fail states of high security relevance, and less serious states, sooner or later requiring maintenance.
• the moving object may also be a brake disk and the brake medium may be a moving part of a brake caliper.
• the brake monitoring device further comprises a first distance sensor unit being connected to the interface.
• the evaluation unit is adapted for evaluating a determined distance based on a first predetermined distance range within which the distance is evaluated as duly.
• a proper braking condition may be a distance indicating that the distance between e.g. a brake drum and a brake leaver is within a first predetermined distance range.
• This predetermined distance range may be defined by a maximum distance between e.g. the brake drum and the brake leaver at a minimum abrasion of brake pads, when the brake pads are in contact with the brake drum, and a minimum distance between e.g. the brake drum and the brake leaver at a maximum abrasion of brake pads, when the brake pads are in contact with the brake drum. It should be noted that it is not excluded that further devices may be provided to ensure that the leaver side brake pads are in contact with the brake drum. It should also be noted that the brake pads may be provided at the brake drum and a contact surface may be provided at the leaver side.
• the evaluation unit is adapted for evaluating a determined distance larger than the first distance range as a fail state.
• the brake monitoring device may detect that the leaver is in a too large distance away from the brake drum, i.e. that the brake pads are not in contact with the braking surface.
• the braking surface may be in the drum side or in the leaver side.
• the brake monitoring device may also indicate whether the brake shoes are in contact with the brake disk.
• the evaluation unit is adapted for evaluating a determined distance based on a second predetermined distance range being smaller than the first predetermined distance range within the second distance range the distance is evaluated as a maintenance requiring state.
• the monitoring device may indicate a state in which the brake pads are almost fully worn out, and should be replaced soon. This state is not mandatorily an emergency state, as the brake pads may have a remaining thickness.
• the second distance range may be divided into a couple of sub-ranges being representative for an increasing urgency state for maintenance.
• the evaluation unit is adapted for evaluating a determined distance smaller than the second distance range as fail state.
• the monitoring device may indicate a state, in which e.g. the brake pads are fully worn out or even fully lost owing to break down of the fixing bolts or the like fixing the brake pat to a carrier of the brake pad, e.g. the brake leaver.
• the brake monitoring device is adapted for a self learning process with respect to the first distance range based on the quantified determined distance.
• the self learning process may be a manually set up min-max position, for each of which the monitoring system receives a set signal.
• the brake monitoring device may also include a fully automated self learning system automatically detecting the respective end-positions at first use. It should be noted that also further assistance systems may be provided for supporting a self learning procedure.
• controlling unit and the evaluating unit are integral with each other.
• the entire electronics may be formed integral and e.g. encapsulated for dust and dirt protection. Further some additional wiring may be saved owing to saving parallel lines as well as saving line length at all due to short distances. An encapsulated total electronics may also avoid unintended manipulations. Further the entire electronic including controlling unit and evaluation unit may be located on one single printed circuit board.
• the brake monitoring device further comprising a power supply line sensor, wherein the power supply line sensor is adapted for monitoring a brake activation power signal, wherein the evaluating unit is adapted for detecting a duly operation state of the brake to be monitored based on a signal of the power supply line sensor and a signal of the first distance sensor unit.
• the brake monitoring device is capable of detecting a duly operation state of the brake to be monitored based on a signal of the power supply line sensor and a signal of the first distance sensor unit.
• the line sensor may detect the correct controlling signal, as an indicative that the activation of the brake was intended.
• the power supply line sensor is a contactless sensor, which may be attached to a line without contacting the conductor of the line.
• the power supply sensor may be installed without intervening or interrupting an already existing installation. This may avoid the risk for unintended over voltages or breakage of particularly older elevator installations. Thus measure allows for installation of the monitoring device without any intervention into the existing installation.
• the first distance sensor unit is operated with an AC signal for distance measurement and a DC offset signal for overheat detection.
• the distance sensor unit may not only be used for determining a distance, bus also for determining a temperature.
• the DC-voltage may be used for determining the temperature when using a wire for the sensor unit having a known temperature characteristic.
• the evaluation unit may also provide for the evaluation of the DC signal for determining a temperature.
• the brake monitoring device is adapted for being mounted to a drum brake, wherein the first distance sensor unit is mounted so as to monitor a distance between a first brake leaver of a drum brake and the brake drum.
• the distance sensor may detect the distance in order to evaluate whether this distance is in a distance range of proper operation.
• the determined distance between a brake drum and a brake leaver may indicate the remaining thickness of a brake pad, so that the distance may indicate the proper operation of the brake as well as the upcoming need for maintenance, like e.g. change of brake pads.
• the brake monitoring device is adapted for being mounted to a first brake leaver of a drum brake, wherein the first distance sensor unit faces the brake drum.
• the sensor unit may be provided at a part with only a limited movement, like the brake leaver.
• the distance sensor may also be positioned on the brake drum, mounting of the sensor on the leaver may avoid complicated contacting of the sensor with the sensor electronics, like the driver, generator or oscillator on the one hand and the evaluation unit on the other hand.
• the brake monitoring device further comprising a second interface for a second distance sensor unit.
• the brake monitoring device further comprising a second distance sensor unit being connected to the second interface, wherein the second distance sensor unit is adapted for being mounted to a second brake leaver of the drum brake.
• the entire brake system may be monitored, in particular when having two brake leavers for each drum.
• the distance of one of the leavers may not fully represent the state of the brake.
• the combined determination of both distances of each of both leavers and the brake drum may provide a more complete information on the brake state or brake condition.
• the brake monitoring device may also be provided with respective interfaces for connecting and changing respective sensors, including the first and second distance sensor unit, temperature sensors or brake activation sensors.
• the evaluating unit is adapted for determining a total state of the brake based on a logic operation of a first determined distance of the first distance sensor unit and a second determined distance of the second distance sensor unit.
• both determined distances between both leavers and the brake drum may be logically combined to arrive at a more complete information on the brake condition and the brake state, in particular on the moving mechanical parts of the brake or the condition of the brake pads, when using a drum brake.
• more than two leavers may be used per brake drum.
• more than two distance sensors may be provided as well as a logic combining more than two distance signals.
• the brake monitoring device is adapted for being mounted to an elevator brake, wherein the evaluation unit comprises an emergency brake signal output.
• the brake monitoring system may directly trigger an emergency brake process, by e.g. a secondary emergency brake, like a pyrotechnical brake or a clutch brake.
• the secondary brake may directly connected to the emergency brake signal output, so that the brake monitoring device may immediately trigger the emergency brake when detecting a serious fail state of the brake.
• the brake monitoring system is adapted for being mounted retroactively to existing elevator brakes.
• existing elevation constructions may be updated and equipped with a security providing brake monitoring device.
• the brake monitoring device may be a clip on system, where the sensor unit as well as a possible power supply line sensor may be clipped onto the existing brake without the need for interruption any existion line of the elevator brake.
• an elevator comprising a brake with a brake drum and at least one brake pad, and an above described brake monitoring device, wherein at least the first distance sensor unit faces a surface of the brake dram, which is cleaned by at least one brake pad.
• an entire elevator including a brake monitoring device may be provided.
• an escalator comprising a brake with a brake drum and at least one brake pad, and an above described brake monitoring device, wherein at least the first distance sensor unit faces a surface of the brake drum, which is cleaned by at least one brake pad.
• an entire escalator including a brake monitoring device may be provided. It should be noted that also escalator may bear a significant risk to arrive at an uncontrolled state, in particular long escalators having a plurality of passengers on top.
• Fig. 1 illustrates an exemplary drum brake system.
• Fig. 2 illustrates an exemplary drum brake system having mounted thereon a brake monitoring device according to an exemplary embodiment of the invention.
• Fig. 3 illustrates a brake monitoring device having a distance sensor unit according to an exemplary embodiment of the invention.
• Fig. 4 illustrates a brake monitoring device having a two distance sensor units according to an exemplary embodiment of the invention.
• Fig. 5 illustrates possible distance ranges of a brake monitoring device according to an exemplary embodiment of the invention.
• Fig. 6 illustrates a possible driving current of a distance sensor of a brake monitoring device according to an exemplary embodiment of the invention.
• Fig. 7 illustrates a distance sensor of a brake monitoring device according to an exemplary embodiment of the invention.
• Fig. 8 illustrates a first alternative of a controlling unit of a brake monitoring device according to an exemplary embodiment of the invention.
• Fig. 9 illustrates a second alternative of a controlling unit of a brake monitoring device according to an exemplary embodiment of the invention. Detailed Description of exemplary Embodiments
• the invention provides for a brake monitoring device including one or more sensors including some electronics that allows measuring the distance or spacing between two objects in a brake system, in particular in a brake system of an elevator or escalator.
• a brake monitoring sensor system In order to meet and exceed the new safety standards in the elevator market, it may be necessary to install a brake monitoring sensor system in already existing and into newly produced elevators and escalators, respectively.
• One of the tasks of the here described brake monitoring sensor system is to measure the distance between two specific surfaces that move proportionally in relation to the brake action.
• Fig. 1 illustrates an exemplary drum brake system for e.g. an elevator or escalator.
• the brake system 50 comprises a brake drum 55 being mounted to a driving shaft for driving the movement of the elevator 2 or escalator 3.
• the brake drum 55 is to be braked by one or more brake pads 53, 54, being mounted to one or more brake leavers 51, 52.
• the brake leavers 51 , 52 may be rotary mounted to the fixed structure of the elevator 2 or escalator 3.
• the leavers 51 , 52 may rotate so as to bring the brake pads 53, 54 into contact with the brake drum or to bring the brake pads into a distance to the brake drum when releasing the brake.
• Fig. 2 illustrates an exemplary drum brake system 50 having mounted thereon a brake monitoring device 1 according to an exemplary embodiment of the invention.
• the structure of the brake system is somewhat similar to that shown in Fig. 1.
• the brake monitoring device 1 may be mounted onto one of the brake leavers 51 , 52.
• a location at the inside and at the top end of the brake leaver may be used for mounting the monitoring device 1.
• the brake monitoring sensor 1 may be permanently mounted to the leaver 51 , 52 and may move with the leaver 51 , 52.
• the brake monitoring module may include all of the functions required, including the sensors 10, 15, the sensor electronics 30, and a controller 20 with e.g. a user interface (not shown). It should be noted that the sensor or the entire brake monitoring device may also be mounted on the drum side. This however may increase the contacting efforts.
• the brake pads 53, 54 may be made or tooled from different materials that either "include” metallic particles or “do not include” metallic particles, e.g. if made from synthetic materials.
• the brake pads 53, 54 may not be used as the sensor system reference or the sensor system target, in particular when the sensor is sensitive to metallic mass.
• the building- concrete used to erect structures like office blocks and houses has strong magnetic properties because of the high iron mineral content in the sand used to mix the concrete.
• Great care has to be taken about the fact that concrete dust may fall down the elevator shaft and will come to rest on-top of the elevator brake system.
• the installation location for the here described sensor solution may be of significant relevance. It may be desirable finding a location that is self-cleaning at all times. This location may be the contacting surface of the brake drum 55, receiving the corresponding contact surface of the brake pads 53, 54.
• the sensor system design may be of such design that it may be easily fixed or mounted onto a wide range of older brake systems that have been produced by several manufacturers over the last 40 to 60 years or more.
• the brake monitoring device may be adapted to function reliably when different metal alloys will be used. Some of these metal alloys have magnetic properties and others do not.
• the brake systems produced over the last 40 to 60 years will have been produced and maintained by different sights and facilities. Consequently it may be difficult of getting a guarantee about what the exact metal composition will be for all of the elevators produced. Nevertheless, the brake monitoring device 1 functions with the largest number of elevator brake models possible.
• Fig. 3 illustrates a brake monitoring device having a distance sensor unit according to an exemplary embodiment of the invention.
• Fig. 3 illustrates a more detailed buildup of the brake monitoring device 1 including a distance sensor unit 10, sensor electronics 30, and a controller 20.
• the highlighted functions are the brake monitoring device 1 having a sensor unit 10, the sensor electronics 31, 34 with an application specific electronics, a digital signal processor with the output interface 34, and a e.g. non-contact electric current sensor 40 with the accompanying driving electronics 28 and sensor electronics 38.
• the brake monitoring device may need to receive information from the brake actuator.
• Such a signal can be a change in voltage, electric current, pneumatic or hydraulic pressure, magnetic field, acoustic signal, or optical signal.
• the optional electric current sensor 40 including the respective electronics 28, 38, may be needed to identify by when the electric command has been given to activate / deactivate the brakes.
• a non-contact sensor solution may be used to avoid having to tab into unknown or elderly elevator control functions with potentially risky consequences.
• the here shown additional sensor unit 40 has the task to measure non-contact the electric current running through an isolated wire or line 56. This sensor may be tooled as a "clip-on” version and may be placed at the wire 56 that passes-through the activation current for the elevator brake system.
• the distance signal from distance sensor 10 and the current signal from the current sensor 40 may be fed to a multiplexer 35 and an analogue-digital converter 36, before being processed in a micro controller 37.
• the device may have an emergency output 33 for outputting an emergency signal. This allows an automatic activation of a secondary emergency brake (not shown).
• the sensor electronics 30 and the application specific controller 20 may fit into the same housing where the brake monitoring device is placed, providing that the housing is large enough.
• the sensor unit 10 may be coupled to the electronics 20, 30 via a first interface 17, so that the sensor unit may be changed. Nevertheless, the interface also allows a fixed connection of the sensor unit to the brake monitoring device 1.
• the distance sensor unit may be a linear distance sensor.
• the following description is based on the assumption that a distance sensor is used that is based on magnetic principles. In general it is possible to use a distance sensor that is activated at one specific distance, e.g. between the target object and the sensor unit. Some of the features of the sensor may be only possible when using a so called linear position sensor. The output information of such a linear position sensor will change, e.g. proportionally or semi-proportionally, in relation to the distance between the target object and the sensor unit with a high level of repeatability.
• the distance sensor proposed for the targeted application may use a low-level of magnetic field to prevent magnetic-attracted materials from sticking to the sensor itself. Otherwise this may interfere with the sensor performance over time.
• a low-level magnetic field may be applied, which may be anything below around 30 Gauss (below 3 mT). Permanent magnets generally may also be used, but may be too strong in such application as the emanating magnetic field strength most likely exceeds 100 Gauss (10 mT) or may be much much higher.
• the AC powered actuator field may provide for that the sensor signal response can be found by using an signal filter that is matching the actuator frequency or the filter specification assures that the AC actuator field will be able to pass-through.
• One suitable sensor principle may be using Eddy Current principle.
• Another potential sensor technology may be a magnetic field absorption.
• Lastly mentioned here should be the principle of measuring the angular magnetic field change when the target object is changing the distance to the sensor unit.
• Fig. 4 illustrates a brake monitoring device having a two distance sensor units according to an exemplary embodiment of the invention.
• Fig. 4 illustrates an alternative build-op of a brake monitoring device 1 , including inter alia the distance sensor units 10, 15, the sensor electronics 31, 32 for each of the sensor units 10, 15, and a respective controller 21, 22.
• the highlighted functions are inter alia the distance sensors 10, 15 and the sensor electronics 20, 30 with the application specific electronics, a digital signal processor 37 with output interfaces 34, and a non-contact electric current sensor 40 and separate temperature sensors 16 with the
• the temperature detection may also be implemented in the distance sensor, in particular when using a coiled wiring having a known temperature characteristic, as will be described later with reference to Fig. 6.
• the alternative shown in Fig. 4 may also include combined temperature detection within the distance sensor units 10, 15, wherein the alternative shown in Fig. 3 may also have separate temperature detection (not shown, but equivalent to 16 and 39 in Fig. 4).
• the optional additional sensor device of the electric current sensor 40togeter with the electronics 28, 38 may be needed to identify by when the electric command has been given to activate / deactivate the brakes.
• the sensor 40 may be of a non-contact sensor type for the reason given above.
• the second additional sensor devices of temperature sensors 16 are needed to detect the temperature difference between brake drum 55 and surrounding to detect potential dragging of the brake.
• the temperature difference may be measured between temperature sensor 16 close to the brake drum 55 and an internal temperature sensor (not shown) of the microcontroller 37, for example. In other applications it could be, that only one temperature sensor 16 is needed close to the brake drum 55.
• the additional sensor unit 40 may have the task to measure non-contact the electric current running through an isolated wire 56. Also this sensor 40 may be tooled as a "clip-on" version and will be placed at the wire 56 that passes-through the activation current for the elevator brake system 50.
• the sensor electronics, and the application specific controller may fit later into the same housing where the brake monitoring device is placed, providing that the housing is large enough. It should be noted that the sensor units 10 and 15 may also be coupled to the electronics 20, 30 via a first interface 17 and a second interface 18, so that the sensor units may be changed.
• Fig. 5 illustrates possible distance ranges of a brake monitoring device according to an exemplary embodiment of the invention.
• the following table will illustrate in more detail the benefit of the distinction of different distance ranges:
• the above table illustrates that particular distances do not correspond to the state of the activation signal detected by sensor 40 in line 56.
• the range A is between distance dA and distance dB.
• the range B is between distance dB and distance dC.
• the range C is between distance dC and distance dD.
• the range D is between distance dD and distance 0.
• Distance dA between the brake drum 55 and the brake leaver represents a resting state of the brake leaver 51 , 52.
• the normal operation range should be range B, which is defined between the maximum and minimum nominal abrasion of the brake pads 53, 54. If the detected distance is not in range B, something does not properly work.
• the brake pads 53, 54 are not in proper contact with the drum 55, i.e. the brake does not brake.
• the consequence should be activation an emergency brake, given that no other priority allowing condition is present.
• range C which is defined between maximum nominal abrasion and maximum safety abrasion
• a maintenance warning should be given out.
• the consequence may be change of the brake pads with the next time.
• no proper brake effect can be expected, so that again activation of an emergency brake should be carried out.
• the normal position should be in range A, in particular the detected distance should be dA, i.e. the resting position.
• the detected distance allowing a certain tolerance, is uneven dA, or allowing no tolerance is outside range A, a blocking or any other failure can be assumed. This may lead to either activation of an emergency brake or to switch of the elevator in a save state.
• the above mentioned distances 0, dD, dC, dB, dA may have an offset value, without departing from the above table.
• the sensor may distinguish between several distances and further may determine a quantity of a distance, a simple proximity sensor will not fulfill the requirements.
• Fig. 6 illustrates a possible driving current of a distance sensor of a brake monitoring device according to an exemplary embodiment of the invention.
• This driving current is particularly relevant for temperature detection in the distance sensor unit 10, 15.
• the AC current serves for driving the distance sensor, i.e. for generating a magnetic field in the coil 14 shown in Fig. 7.
• the DC current is without relevance for the magnetic field generation.
• the DC current may be used for determining the conductivity of the wire 14, which conductivity depends on the temperature of the sensor or the environment. The temperature may be determined when knowing the current and the temperature characteristic of the wire 14. - I I
• Fig. 7 illustrates a distance sensor of a brake monitoring device according to an exemplary embodiment of the invention.
• the distance sensor may comprise terminal or connection lines 1 1 for connection the coil or wound wire 14 to the electronics 20, 30, as will be illustrated in Figs 8 and 9.
• the core 12 may be used for mechanically supporting the wire 14.
• the core may be of synthetic materials, in particular non metallic or non magnetic or non ferromagnetic materials.
• the distance sensor may have a shielding 13, which shielding may be of a metal, in particular of copper Cu.
• the facing orientation of the distance sensor 10 in Fig. 7 is the left side.
• Fig. 8 illustrates a first alternative of a controlling unit of a brake monitoring device according to an exemplary embodiment of the invention.
• the distance sensor 10 may be coupled via a resistor to an oscillator 20, which oscillator may be a driver or generator unit.
• the signal between one terminal of the sensor 10 and the resistor may be fed with the receiver or evaluation unit 30, in particular unit 31 in Figs. 3 and 4.
• Fig. 9 illustrates a second alternative of a controlling unit of a brake monitoring device according to an exemplary embodiment of the invention.
• the sensor 10 is parallel to a capacitive divider.
• a terminal between the sensor 10 and the capacitive divider is fed to the receiver or evaluation unit 30, as described with respect to Fig. 8.
• the sensor may be driven by an oscillator or driver 20 or generator, which oscillator is connected with its first terminal between the capacitive divider and the other terminal of the sensor 10, and with its second terminal between the both capacities of the capacitive driver.
• an oscillator or driver 20 or generator which oscillator is connected with its first terminal between the capacitive divider and the other terminal of the sensor 10, and with its second terminal between the both capacities of the capacitive driver.
• a pressure sensor (of any kind) will be used to retrieve the "brake" instruction command signal.
• the brake instruction signal can be retrieved by using an optical sensor (by looking at a light that will switch on or off when the brake signal is sent), or through a microphone, by listening to a distinct sound or a distinct audible signal like when a noisy relay or "Schuetz" is activated, or even the temperature changes of the power line that actuates the brake.
• a brake monitoring device and system may be that it o monitors the thickness of the remaining brake-pad material and/or assures that the brake-pads are not used-up and have sufficient surface to execute
• o identifies potential or actual failure situation and provide feedback to another supervising system, such system may prohibit the further use of the elevator or escalator, or activates warning systems, for example: blinking light, audible sound etc.
• o provides data logging functions that are optimized for a certain application or a certain situation similar to a black-box in aero planes.
• the output signals of the brake monitoring system may be any combination of the following:
• a digital "yes / no" answer indicating that the brake system specifications are still met, e.g. brake system is ready and safe to use, and / or a quantifying signal in analogue or digital format, that allows identifying at what condition the brakes system actually are, like percentage of actual remaining brake surface, for example.
• a digital "yes / no” information indicating that maintenance work at the brake system / or the brakes is required, and / or a quantifiable analogue or digital signal that indicates by when the next maintenance cycle is required.
• a digital "yes / no” information about a "fault” in the system has been identified, i.e. any type of fault or a specific fault, and / or a quantifying analogue or digital signal that provides details about what nature the fault is and how serious the identified fault actually is.
• the brake monitoring system may comprise of several components / modules:
• Sensor Environment Requirements may be the following:
• the target object (brake drum or beam) may be tooled from a conductive
• the target object may be either static (like a beam) or moving / rotating (like a rotating drum)
• the targeted measurement range may be between 0 mm (minimum value) to several mm (maximum value) or much more. For some specific applications it may be from a few mm distance (min value) to a few cm (max value) or much more.
• the target object and the sensor unit may be nothing that may interfere with the magnetic distance measurement principle in an unpredicted / uncontrollable way or that can reduce the senor efficiency below a manageable level. It should be noted that compensation measures can be taken for compensating magnetic effects of material between the sensor and the target.
• the sensor may be operated under atmospheric air gas between the target surface and the magnetic operating sensor unit (in an elevator application, for example).
• a liquid like water or oil
• a non-magnetic material like plastic, wood, or fiber of any kind
• such a sensor system can be used to monitor the condition and operation of a clutch system, as used in cars, vehicles of any kind, or any type of mechanical power transferring setups.
• dB distance value representing minimum nominal abrasion of brake pad
• dC distance value representing maximum nominal abrasion of brake pad
• dD distance value representing full abrasion of brake pad

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Braking Arrangements (AREA)
• Cage And Drive Apparatuses For Elevators (AREA)

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Citations (5)

• 2012
  • 2012-01-23 DE DE112012000585.6T patent/DE112012000585T5/de not_active Ceased
  • 2012-01-23 WO PCT/EP2012/050972 patent/WO2012101091A1/en active Application Filing

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