GB1354456A - Acoustical sensing systems - Google Patents

Acoustical sensing systems

Info

Publication number
GB1354456A
GB1354456A GB1354456DA GB1354456A GB 1354456 A GB1354456 A GB 1354456A GB 1354456D A GB1354456D A GB 1354456DA GB 1354456 A GB1354456 A GB 1354456A
Authority
GB
United Kingdom
Prior art keywords
curtain
acoustic
receiver
detected
parabolic reflector
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
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.)
Automatic Switch Co
Original Assignee
Automatic Switch Co
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 Automatic Switch Co filed Critical Automatic Switch Co
Publication of GB1354456A publication Critical patent/GB1354456A/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
    • G08B13/16—Actuation by interference with mechanical vibrations in air or other fluid
    • G08B13/1609—Actuation by interference with mechanical vibrations in air or other fluid using active vibration detection systems
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/18—Methods or devices for transmitting, conducting or directing sound
    • G10K11/26—Sound-focusing or directing, e.g. scanning
    • G10K11/28—Sound-focusing or directing, e.g. scanning using reflection, e.g. parabolic reflectors

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
  • Burglar Alarm Systems (AREA)

Abstract

1354456 Acoustic sensing of object presence AUTOMATIC SWITCH CO 20 Jan 1973 3070/73 Heading H4D [Also in Division G4] A substantially continuous acoustic curtain is established by multiple reflection of a collimated acoustic beam 14 between sets 16, 17 of reflectors, whereby penetration of the curtain at any point by an object bigger than, e.g. half the beam cross-sectional area can be detected by the resulting drop in the energy reaching a receiver 12. The beam generator may be a whistle with a parabolic reflector 13, the receiver 12 being at the focus of a parabolic reflector 15 and comprising a fluidic device which switches from one state to a second state when the curtain is penetrated. The invention is useful in a safety system to prevent operation of a machine when an operator's hand &c. is in a dangerous place, or in a security system to initiate an alarm when intrusion of a restricted area is detected.
GB1354456D 1973-01-20 1973-01-20 Acoustical sensing systems Expired GB1354456A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB307073 1973-01-20

Publications (1)

Publication Number Publication Date
GB1354456A true GB1354456A (en) 1974-06-05

Family

ID=9751435

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1354456D Expired GB1354456A (en) 1973-01-20 1973-01-20 Acoustical sensing systems

Country Status (1)

Country Link
GB (1) GB1354456A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1986005837A1 (en) * 1985-04-02 1986-10-09 Joensson Bert Ove Device for indicating a pressure or force
GB2207999A (en) * 1987-08-13 1989-02-15 Memco Med Ltd Safety systems

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1986005837A1 (en) * 1985-04-02 1986-10-09 Joensson Bert Ove Device for indicating a pressure or force
GB2207999A (en) * 1987-08-13 1989-02-15 Memco Med Ltd Safety systems
GB2207999B (en) * 1987-08-13 1992-04-22 Memco Med Ltd Safety systems

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Legal Events

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