GB2133541A - Movement detecting apparatus - Google Patents

Movement detecting apparatus Download PDF

Info

Publication number
GB2133541A
GB2133541A GB08334142A GB8334142A GB2133541A GB 2133541 A GB2133541 A GB 2133541A GB 08334142 A GB08334142 A GB 08334142A GB 8334142 A GB8334142 A GB 8334142A GB 2133541 A GB2133541 A GB 2133541A
Authority
GB
United Kingdom
Prior art keywords
light
detectors
movement
detecting apparatus
movement detecting
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.)
Withdrawn
Application number
GB08334142A
Other versions
GB8334142D0 (en
Inventor
D A Straw
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Plessey Co Ltd
Original Assignee
Plessey Co Ltd
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
Priority claimed from GB838300431A external-priority patent/GB8300431D0/en
Application filed by Plessey Co Ltd filed Critical Plessey Co Ltd
Priority to GB08334142A priority Critical patent/GB2133541A/en
Publication of GB8334142D0 publication Critical patent/GB8334142D0/en
Publication of GB2133541A publication Critical patent/GB2133541A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B66HOISTING; LIFTING; HAULING
    • B66BELEVATORS; ESCALATORS OR MOVING WALKWAYS
    • B66B1/00Control systems of elevators in general
    • B66B1/34Details, e.g. call counting devices, data transmission from car to control system, devices giving information to the control system
    • B66B1/3492Position or motion detectors or driving means for the detector
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01DMEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D3/00Indicating or recording apparatus with provision for the special purposes referred to in the subgroups
    • G01D3/08Indicating or recording apparatus with provision for the special purposes referred to in the subgroups with provision for safeguarding the apparatus, e.g. against abnormal operation, against breakdown

Landscapes

  • Engineering & Computer Science (AREA)
  • Automation & Control Theory (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Length Measuring Devices With Unspecified Measuring Means (AREA)

Abstract

A very sensitive indicator for a winding drum used at collieries consists of a toothed wheel rotating between a light emitter and a light detector. The pulses of light received by the detector are counted until a preprogrammed count is reached when the speed of the winding drum is reduced prior to stopping it with the lift at a certain level. Two detectors 10, 12 located side by side are used and positioned so that one of the detectors is always fully off or on whenever the other is in an intermediate state. The detector circuit looks for a change in state of both detectors to protect against vibrations causing a count, and determines the sense of movement by detecting which of the detectors changes state before the other. <IMAGE>

Description

SPECIFICATION Movement detecting apparatus This invention relates to movement detecting apparatus and more particularly but not exclusively to apparatus for detecting rotational movement of a member such as the winding engine drum for lift cages used in mines. The direction of movement of a lift cage in a mine is required to be known and its position needs to be accurately determined for stopping it at predetermined positions.
It is an object of the present invention therefore to provide movement detecting apparatus which will indicate movement of a member, its direction of movement and which is able to accurately determine its relative position.
According to the present invention movement detecting apparatus comprises a movable member having a plurality of equally spaced windows formed therein, a light source located on one side of the member and two light detectors located on the opposite side of the member to receive light from the light source through the windows, the light detectors being spaced such that when the member is stationary one of the detectors receives either full light or no light from the light source, and the other detector receives a partial amount of light from the light source, an electrical circuit for receiving signals from the light detectors and adapted to detect changes in state of the light detectors to detect movement of the member, which of the light detectors change state before the other to determine the direction of movement of the member, the electrical circuit also including counter means for counting the number of windows which have traversed the light detectors for determining the distance moved by the member.
In this specification the term "light" also includes light invisible to the human eye such as infra-red and ultra-violet rays.
Preferably the electrical circuit includes clock means to determine the speed of movement of the member.
The electrical circuit may also determine when a predetermined speed of the member has been exceeded.
The movable member preferably comprises a rotatable wheel.
The windows preferably comprise a series of slots formed in the periphery of the wheel.
An embodiment of the invention will now be described with reference to the accompanying drawings in which Figure 1 is a scrap view of a slotted wheel for use in a rotation sensor constructed in accordance with the present invention and Figure 2 is an electrical circuit for the rotation sensor The rotation sensor is designed to give indication and direction of movement of the lift winding engine drum used at colleries. It was designed as a direct replacement for a mechanical device currently in use. The main advantage over the mechanical device is the sensitivity, the new device being capable of detecting down to 3" of rope movement on the winding drum, whereas its mechanical counterpart has nothing like this performance.
The sensor is adapted to detect the position of the drum, whether the drum is stationary or rotating, the direction of rotation of the drum and also detects when a predetermined rate of rotation of the drum has been exceeded. The system can be used merely to indicate these conditions or signals can be produced to affect the actual mine signalling system or the drum operating control system itself.
It is not limited to colliery use, since a belt drive to a pulley may be driven from any available shaft where detection of any movement is required.
Electronic pulses are generated by the rotation of a wheel 14 having a plurality of teeth 1 6 in its periphery between a light source (not shown) and two detectors 10, 1 2 mounted side by side. The teeth 1 6 of the wheel prevent light from passing between the light source and the light detectors 10 and 1 2 while the slots permit passage of light, thus creating on-off states in the light detectors.
As the wheel 1 4 rotates at a fairly high speed the detectors 10, 1 2 switch on and off, and the pulses produced are counted by a high speed electronic circuit. If the number of pulses in a preset scan time exceeds a preprogrammed count the sensor indicates that the drum is operating normally. When the wheel slows down to a speed below the preprogrammed count a slow speed circuit activates and slow speed is indicated by the sensor.
Both circuits are reset when the wheel comes to rest.
By monitoring which of the two light detectors 10, 12 changes state before the other, then the direction of rotation is detected.
The spacing of the two opto devices is such that when the wheel is stationary, one of the detectors is guaranteed to be fully off or fully on (e.g. detector 12), whereas the other detector can be in an intermediate state i.e. just on the verge of being on or off (e.g. detector 10). The input circuitry is arranged to look for a change in state of both detectors thus protecting against vibrations causing a 'count' (slow movement) from being detected.
Fig. 1 shows part of the toothed wheel 14 which has twenty four teeth and the relative positions of the optical detectors 10, 1 2.
From this it can be seen that irrespective of which position the wheel comes to rest it is guaranteed that one of the detectors is either completely off or completely on. The spacing of the detectors is controlled very strictly by accurate P.W.B. layout and the toothed wheel is precisely machined.
The outputs from the detectors 10, 1 2 are taken via test switches 18, 20 to clock D type flipflops ML1 and ML2. Before an output can appear at an AND gate ML3 both D types have to be clocked which means that a positive going edge has to be received from both detectors thus preventing false pulses, due to vibrations causing a detector which is at the threshold of being just on (as is detector 10 in Fig. 1) from causing incorrect operation.
Once the wheel 14 has travelled a distance of 1 pitch both detector outputs will have gone from a low to high state and so both D type flip-flops ML1, ML2 will be set, and the AND gate ML3 will be enabled, so that as the wheel continues to rotate, pulses appearing at the AND gate ML3 output are injected into a mono stable ML4. The monostable ML4 gives output pulses of 1 ms into a second monostable ML5, which operates in the retriggerable mode and has an output duration of 1 second. This means that once the wheel has started to rotate the output from the monostable ML5 will stay low until rotation has stopped, when after 1 second of stopping the monostable ML5 output returns to the high state. This output is differentiated by a differentiator D12 to give a narrow reset pulse to both of the D type flip-flops ML1 and ML2.
Output pulses from the monostable ML5 are used to clock a counter ML6 once the reset from the counter ML6 is removed by the monostable ML5. The setting of switches A3 determines the number of pulses required to enable AND gate ML7. Once an output at the AND gate ML7 appears a J/K flipflop ML8 is set, the information being clocked into the flipflop by a free running clock ML11. The flip-flop ML8 output is used to operate a relay SC via a driver ML10. The relay SC remains operated until the flip-flop ML8 is reset when rotation ceases and the stop output from the monostable ML5 goes high.It follows that the relay SC may be operated by 1-1 5 pulses which on the 24 tooth wheel 14 corresponds to between 1 5 and 225 degrees of angular movement. On the most sensitive setting i.e.
position 1 of A3, providing the wheel is rotated at greater than 2.5rum slow speed detection will be achieved.
The relay SC is used to operate a slow speed indicator.
The master clock ML1 1 output is divided down by counters ML12 and ML13 and passed to a monostable ML14 which gives a 1 mSec output every 1.3 seconds. This output is used to apply a reset pulse to counters ML15, ML16 and ML17. The counter outputs ML16 and ML17 are counted via switches A5 and AND gates ML18 and ML19. Pulses from the monostable ML4 are used to clock the counter ML15 and when the pulses are received at a rate equal to or higher than that required to cause an output from the AND gate ML18 within the 1.3 second scan time a flip4lop ML9 will be set. In turn a relay FC will operate via the driver ML1O and will remain operated until rotation has ceased and a stop signal from the monostable ML5 resets the flip-flop ML9.
The relay FC is used to operate a high speed indicator.
By selection of switches A5 the detection speed may be governed between approximately 30RPM and 20û0RPM.
Test switches 18, 20 are included which when operated disconnect the detectors 10, 1 2 from the circuit and connect the D type flip-fiops ML1, ML2 to the master clock output ML1 1. This may be used to determine the health of the main circuit for maintenance purposes and, by elimination, the state of the detector circuit may be also determined.

Claims (6)

1. Movement detecting apparatus comprising a movable member having a plurality of equally spaced windows formed therein, a light source located on one side of the member and two light detectors located on the opposite side of the member to receive light from the light source through the windows, the light detectors being spaced such that when the member is stationary one of the detectors receives either full light or no light from the light source, and the other detector receives a partial amount of light from the light source, an electrical circuit for receiving signals from the light detectors and adapted to detect changes in state of the light detectors to detect movement of the member, which of the light detectors changes state before the other to determine the direction of movement of the member, the electrical circuit also including counter means for counting the number of windows which have traversed the light detectors for determining the distance moved by the member.
2. Movement detecting apparatus as claimed in claim 1 in which the electrical circuit includes clock means to determine the speed of movement of the member.
3. Movement detecting apparatus as claimed in claim 2 in which the electrical circuit determines when a predetermined speed of the member has been exceeded.
4. Movement detecting apparatus as claimed in any preceding claim in which the movable member comprises a rotatable wheel.
5. Movement detecting apparatus as claimed in claim 4 in which the windows comprise a series of slots formed in the periphery of the wheel.
6. Movement detecting apparatus constructed and adapted to operate substantially as hereinbefore described with reference to the accompanying drawings.
GB08334142A 1983-01-07 1983-12-22 Movement detecting apparatus Withdrawn GB2133541A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB08334142A GB2133541A (en) 1983-01-07 1983-12-22 Movement detecting apparatus

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB838300431A GB8300431D0 (en) 1983-01-07 1983-01-07 Movement detecting apparatus
GB08334142A GB2133541A (en) 1983-01-07 1983-12-22 Movement detecting apparatus

Publications (2)

Publication Number Publication Date
GB8334142D0 GB8334142D0 (en) 1984-02-01
GB2133541A true GB2133541A (en) 1984-07-25

Family

ID=26284860

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08334142A Withdrawn GB2133541A (en) 1983-01-07 1983-12-22 Movement detecting apparatus

Country Status (1)

Country Link
GB (1) GB2133541A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2720178A1 (en) * 1994-05-17 1995-11-24 Bdms Theft protection system for electronic and electrical appliances
US8757328B2 (en) 2010-03-15 2014-06-24 Kone Corporation Method and device for the startup of an electric drive of an elevator

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1375679A (en) * 1972-03-03 1974-11-27
GB1437272A (en) * 1972-05-31 1976-05-26 Sauter August Gmbh Method of indicating a balance reading error
GB1513306A (en) * 1974-08-14 1978-06-07 Dickey John Corp Controlled seed population monitor
GB2009397A (en) * 1977-11-25 1979-06-13 Stanley Works Measurning device
GB2046896A (en) * 1979-04-11 1980-11-19 Marconi Co Ltd Apparatus for testing the braking efficiency of industrial machines
GB2048494A (en) * 1979-04-04 1980-12-10 Sps Technologies Impact wrench
GB2057119A (en) * 1979-08-21 1981-03-25 Standard Telephones Cables Ltd Fibre optic digital positional encoder
GB2090655A (en) * 1980-12-11 1982-07-14 Sfena Incremental Encoder

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1375679A (en) * 1972-03-03 1974-11-27
GB1437272A (en) * 1972-05-31 1976-05-26 Sauter August Gmbh Method of indicating a balance reading error
GB1513306A (en) * 1974-08-14 1978-06-07 Dickey John Corp Controlled seed population monitor
GB2009397A (en) * 1977-11-25 1979-06-13 Stanley Works Measurning device
GB2048494A (en) * 1979-04-04 1980-12-10 Sps Technologies Impact wrench
GB2046896A (en) * 1979-04-11 1980-11-19 Marconi Co Ltd Apparatus for testing the braking efficiency of industrial machines
GB2057119A (en) * 1979-08-21 1981-03-25 Standard Telephones Cables Ltd Fibre optic digital positional encoder
GB2090655A (en) * 1980-12-11 1982-07-14 Sfena Incremental Encoder

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2720178A1 (en) * 1994-05-17 1995-11-24 Bdms Theft protection system for electronic and electrical appliances
US8757328B2 (en) 2010-03-15 2014-06-24 Kone Corporation Method and device for the startup of an electric drive of an elevator

Also Published As

Publication number Publication date
GB8334142D0 (en) 1984-02-01

Similar Documents

Publication Publication Date Title
JP2550097Y2 (en) System for determining maximum safe speed of rotor, system for reading maximum safe speed coding element on rotor and centrifuge system
EP0095319B1 (en) Games machine
GB2133541A (en) Movement detecting apparatus
EP0144321B1 (en) Electronic speed sensor
US7283887B2 (en) Method for determining a change in direction of rotation of a motor
US4429407A (en) Counting circuit for coin counting device
JPH06325233A (en) Ball counter
US3819998A (en) Dynamic braking control system
JP2583642B2 (en) Elevator door control device
JPS61134801A (en) Positioning control device
EP0650059A1 (en) Sensing motor speed and rotation direction
EP0179121B1 (en) Device for accurate time control of a locking means in a vehicle safety belt
US3932752A (en) Gamma counter shutter assembly
JPS57163868A (en) Detector for turning speed of internal combustion engine
JPS6413255A (en) Disk discriminating method
JPS6280514A (en) Pulse counting device
JPH0425597B2 (en)
JPH0260691A (en) Braking control device for industrial sewing machine
JPH0810374Y2 (en) Centrifuge
SU399346A1 (en) SIGNALIZER FOR DETERMINATION OF THE SYNCHRONICITY OF ROTATION OF MAGNETIC-ASSOCIATED SHAFTS
KR830005561A (en) Diagnosis method of symptom in axial vibration monitoring of rotating machine
JPH024750B2 (en)
JPH10269389A (en) Method for detecting passage of plural persons in gate device
JPH052817Y2 (en)
JPS5827432Y2 (en) Tape amount display device

Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)