EP0206664A3 - Guard system - Google Patents

Guard system Download PDF

Info

Publication number
EP0206664A3
EP0206664A3 EP86304518A EP86304518A EP0206664A3 EP 0206664 A3 EP0206664 A3 EP 0206664A3 EP 86304518 A EP86304518 A EP 86304518A EP 86304518 A EP86304518 A EP 86304518A EP 0206664 A3 EP0206664 A3 EP 0206664A3
Authority
EP
European Patent Office
Prior art keywords
multiplexer
receivers
cycle
energised
intrusion
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Withdrawn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
EP86304518A
Other languages
German (de)
French (fr)
Other versions
EP0206664A2 (en
Inventor
John Peter Hughes
Brian Dows Fletcher
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Publication of EP0206664A2 publication Critical patent/EP0206664A2/en
Publication of EP0206664A3 publication Critical patent/EP0206664A3/en
Withdrawn legal-status Critical Current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

Abstract

Guard system for protecting some space against un­ detected intrusion uses a plurality of wave beam paths (from transmitter T1 -Tn to receivers R1 -Rn) selectively energised in cycles (multiplexer Tx-Mx) so that each beam (transmitters T1 -Tn) is energised for part only of each cycle. Pressure or absence of beam energy indicative of intrusion is monitored (receivers R1 -Rn and multiplexer Rx-Mx). Signal level discrimination (46) of received signals operates both logic circuitry (flipflop 55) to give effectively continuous output (56, 58) except for beam interruption (52) even through a quiescent state of each cycle, and fault indication logic cir­ cuitry (100 via 70, 72) that is shown duplicated.
EP86304518A 1985-06-12 1986-06-12 Guard system Withdrawn EP0206664A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8514862 1985-06-12
GB8514862 1985-06-12

Publications (2)

Publication Number Publication Date
EP0206664A2 EP0206664A2 (en) 1986-12-30
EP0206664A3 true EP0206664A3 (en) 1989-03-01

Family

ID=10580624

Family Applications (1)

Application Number Title Priority Date Filing Date
EP86304518A Withdrawn EP0206664A3 (en) 1985-06-12 1986-06-12 Guard system

Country Status (2)

Country Link
EP (1) EP0206664A3 (en)
GB (1) GB2177503A (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5015840B1 (en) * 1990-01-09 1995-04-11 Scient Technologies Inc Self-checking light curtain system and method of operation.
GB2266143A (en) * 1992-04-16 1993-10-20 Ind Tech Res Inst Palm-triggered photo switch

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3970846A (en) * 1973-10-29 1976-07-20 Xenex Corporation Presence detecting system with self-checking
WO1981000750A1 (en) * 1979-09-10 1981-03-19 Ambler K Improvements relating to safety mechanisms for industrial machinery

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2247053C3 (en) * 1972-09-26 1979-08-09 Erwin Sick Gmbh Optik-Elektronik, 7808 Waldkirch Light barrier
GB1482567A (en) * 1973-10-29 1977-08-10 Xenex Corp Presence detecting system with self-checking
SE385746B (en) * 1974-09-20 1976-07-19 Telub Ab DEVICE FOR DETECTING AN INFORTABLE OBTAIN IN A CANDLEHOLDER
GB1579020A (en) * 1977-02-21 1980-11-12 Pull D V Machine guards
GB1603197A (en) * 1978-03-09 1981-11-18 Rigby Electronics Ltd Electronic machine guard
SE418426B (en) * 1978-04-10 1981-05-25 Telub Ab Light Curtain
DE3013967C2 (en) * 1980-04-11 1984-08-09 Erwin Sick Gmbh Optik-Elektronik, 7808 Waldkirch Adjustment arrangement for light grids

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3970846A (en) * 1973-10-29 1976-07-20 Xenex Corporation Presence detecting system with self-checking
WO1981000750A1 (en) * 1979-09-10 1981-03-19 Ambler K Improvements relating to safety mechanisms for industrial machinery

Also Published As

Publication number Publication date
GB8614303D0 (en) 1986-07-16
EP0206664A2 (en) 1986-12-30
GB2177503A (en) 1987-01-21

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