GB1482567A - Presence detecting system with self-checking - Google Patents

Presence detecting system with self-checking

Info

Publication number
GB1482567A
GB1482567A GB46547/74A GB4654774A GB1482567A GB 1482567 A GB1482567 A GB 1482567A GB 46547/74 A GB46547/74 A GB 46547/74A GB 4654774 A GB4654774 A GB 4654774A GB 1482567 A GB1482567 A GB 1482567A
Authority
GB
United Kingdom
Prior art keywords
detector
pulse
photodetector
energized
missing
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.)
Expired
Application number
GB46547/74A
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.)
Xenex Corp
Original Assignee
Xenex Corp
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 Xenex Corp filed Critical Xenex Corp
Publication of GB1482567A publication Critical patent/GB1482567A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B13/00—Burglar, theft or intruder alarms
    • G08B13/18—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength
    • G08B13/181—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength using active radiation detection systems
    • G08B13/183—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength using active radiation detection systems by interruption of a radiation beam or barrier
    • 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
    • F16P—SAFETY DEVICES IN GENERAL; SAFETY DEVICES FOR PRESSES
    • F16P3/00—Safety devices acting in conjunction with the control or operation of a machine; Control arrangements requiring the simultaneous use of two or more parts of the body
    • F16P3/12—Safety devices acting in conjunction with the control or operation of a machine; Control arrangements requiring the simultaneous use of two or more parts of the body with means, e.g. feelers, which in case of the presence of a body part of a person in or near the danger zone influence the control or operation of the machine
    • F16P3/14—Safety devices acting in conjunction with the control or operation of a machine; Control arrangements requiring the simultaneous use of two or more parts of the body with means, e.g. feelers, which in case of the presence of a body part of a person in or near the danger zone influence the control or operation of the machine the means being photocells or other devices sensitive without mechanical contact
    • F16P3/144—Safety devices acting in conjunction with the control or operation of a machine; Control arrangements requiring the simultaneous use of two or more parts of the body with means, e.g. feelers, which in case of the presence of a body part of a person in or near the danger zone influence the control or operation of the machine the means being photocells or other devices sensitive without mechanical contact using light grids

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Electronic Switches (AREA)
  • Geophysics And Detection Of Objects (AREA)
  • Photometry And Measurement Of Optical Pulse Characteristics (AREA)

Abstract

1482567 Machinery safety devices XENEX CORP 28 Oct 1974 [29 Oct 1973] 46547/74 Heading F2J [Also in Division G1] A presence detection system comprising a plurality of sets of a light source and phototransistor 20a and 22a, 20b and 22b,..., each defining a channel, each photodetector receiving light from its source unless its channel is obstructed, multiplexers 26 and 28 with clock 30 connected to their channel address inputs 62 and 64 for sequentially and synchronously connecting the light sources to pulse generator 32 and the photodetector to detection means 34 respectively, means 34 including missing pulse detector 40. Each photodetector has a biasing system (Fig. 4a, not shown) which controls the electrical output for a given light pulse, a feedback amplifier 48 adapted to produce an output such that its input is equal to a predetermined level and switching field effect transistor 50 for disconnecting amplifier 48 from the bias means only when the source is energized, whereby the photodetector is compensated for changes in ambient conditions. Detector 40 detects if a pulse is missing and causes relay 44 to be de-energized, thereby to stop a machine. Self-checking means includes masterchecker 51, with inputs from pulse generator 32 and multiplexers 52 and 54 and includes plural selected test points some in missing pulse detector 40 and includes a binary comparator in missing pulse detector 56, so that if pulses from any of the test points are low, the output of detector 56 remains low and relay 44 is de-energized. The circuits are shown and described in detail.
GB46547/74A 1973-10-29 1974-10-28 Presence detecting system with self-checking Expired GB1482567A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US41086173A 1973-10-29 1973-10-29

Publications (1)

Publication Number Publication Date
GB1482567A true GB1482567A (en) 1977-08-10

Family

ID=23626540

Family Applications (1)

Application Number Title Priority Date Filing Date
GB46547/74A Expired GB1482567A (en) 1973-10-29 1974-10-28 Presence detecting system with self-checking

Country Status (3)

Country Link
CA (1) CA1036686A (en)
DE (1) DE2451100C2 (en)
GB (1) GB1482567A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2177216A (en) * 1985-07-05 1987-01-14 Baumer Electric Ag Proximity switch
GB2177503A (en) * 1985-06-12 1987-01-21 John Peter Hughes Guard system
GB2206662A (en) * 1987-07-08 1989-01-11 Truro School A safety system for machinery having exposed moving parts
US5038488A (en) * 1988-10-04 1991-08-13 Carl-Zeiss-Stiftung Protective arrangement for a longitudinally extendible machine component

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES495038A0 (en) * 1979-09-10 1981-12-16 Gordon Ambler Kenneth A METHOD AND A DETECTION DEVICE FOR OPAQUE MEMBERS WHICH ARE FOUND WITHIN A DETECTION SPACE.
JPS59140994A (en) * 1983-01-31 1984-08-13 株式会社小松製作所 Ray type safety device
DE3603940A1 (en) * 1986-02-07 1987-08-13 Efaflex Transport Lager DEVICE FOR CONTROLLING THE OPENING AND / OR CLOSING PROCESS OF HIGH-SPEED GATES
DE3603927A1 (en) * 1986-02-07 1987-08-13 Efaflex Transport Lager DEVICE FOR DETECTING A SHADOW OF A SIGNAL SENDED BY AT LEAST ONE TRANSMITTER IN AN INTERMEDIATE SPACE BETWEEN THE TRANSMITTER AND RECEIVER
WO1988000745A1 (en) * 1986-07-24 1988-01-28 Keith Jeffrey Gate Detection system
DE3803033A1 (en) * 1988-02-02 1989-08-10 Sick Erwin Gmbh LIGHT BARRIER GRID
DE69317231T2 (en) * 1992-12-03 1998-08-27 Reer Spa Comparator device with intrinsic safety, especially for opto-electronic barriers
DE102004022812B4 (en) * 2004-05-08 2007-03-01 Leuze Lumiflex Gmbh + Co. Kg Method for detecting objects in a surveillance area by means of a light grid

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3543260A (en) * 1968-07-24 1970-11-24 Honeywell Inc Self checking interuder and fire detector units and system
US3556235A (en) * 1969-09-15 1971-01-19 Hobart Mfg Co Photocell checking circuit for optical weighing scale
FR2135819A5 (en) * 1971-04-30 1972-12-22 Cometa Sa
US3704396A (en) * 1971-05-12 1972-11-28 Cincinnati Inc Safety device for machines
US3764813A (en) * 1972-04-12 1973-10-09 Bell Telephone Labor Inc Coordinate detection system

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2177503A (en) * 1985-06-12 1987-01-21 John Peter Hughes Guard system
GB2177216A (en) * 1985-07-05 1987-01-14 Baumer Electric Ag Proximity switch
GB2177216B (en) * 1985-07-05 1989-07-19 Baumer Electric Ag Proximity switch
GB2206662A (en) * 1987-07-08 1989-01-11 Truro School A safety system for machinery having exposed moving parts
US5038488A (en) * 1988-10-04 1991-08-13 Carl-Zeiss-Stiftung Protective arrangement for a longitudinally extendible machine component
US5111591A (en) * 1988-10-04 1992-05-12 Carl-Zeiss-Stiftung Protective arrangement for a longitudinally extendible machine component
GB2255810A (en) * 1988-10-04 1992-11-18 Zeiss Stiftung A protective arrangement for a longitudinally-extendible machine component
GB2255810B (en) * 1988-10-04 1993-02-03 Zeiss Stiftung Protective arrangement for longitudinally extended machine components
GB2223557B (en) * 1988-10-04 1993-02-03 Zeiss Stiftung Protective arrangement for longitudinally extended machine components

Also Published As

Publication number Publication date
DE2451100A1 (en) 1975-05-22
CA1036686A (en) 1978-08-15
DE2451100C2 (en) 1983-01-13

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Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee