GB1250803A - - Google Patents

Info

Publication number
GB1250803A
GB1250803A GB1250803DA GB1250803A GB 1250803 A GB1250803 A GB 1250803A GB 1250803D A GB1250803D A GB 1250803DA GB 1250803 A GB1250803 A GB 1250803A
Authority
GB
United Kingdom
Prior art keywords
reed
door
magnetic
magnet
screen
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
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 filed Critical
Publication of GB1250803A publication Critical patent/GB1250803A/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
    • G08B13/02—Mechanical actuation
    • G08B13/08—Mechanical actuation by opening, e.g. of door, of window, of drawer, of shutter, of curtain, of blind

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Burglar Alarm Systems (AREA)

Abstract

1,250,803. Burglar alarms. BRITISH RAILWAYS BOARD. 23 Jan., 1970 [8 Nov., 1968], No. 53088/68. Heading G4N. A burglar alarm comprises a first magnetic reed unit S1 mounted on a door (or window) frame and cooperating with a magnet mounted on the door (or window), a magnetic screen 10, shielding the reed unit S1 from magnetic fields other than that from the magnet and a further reed unit S3, parallel to S1 and mounted outside the screen 10 so as to become actuated by the application of an external magnetic field in an attempt to nullify the alarm system. Further reed units S2 ... S5 may be included for this purpose. The magnet (Fig. 3, not shown) may be let into the edge of the door and have its visible pole surrounded by a magnetic screen of drill resistant material. The contacts of reed units S1 ... S5 may be bridged by or connected in series with resistors R1 ... R3 so that an alarm may be operated by an attempt to short-circuit the contacts.
GB1250803D 1968-11-08 1968-11-08 Expired GB1250803A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB5308868 1968-11-08

Publications (1)

Publication Number Publication Date
GB1250803A true GB1250803A (en) 1971-10-20

Family

ID=10466587

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1250803D Expired GB1250803A (en) 1968-11-08 1968-11-08

Country Status (1)

Country Link
GB (1) GB1250803A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2176330A (en) * 1985-06-07 1986-12-17 Aica Kogyo Co Ltd Keysensor
FR2598005A1 (en) * 1986-04-25 1987-10-30 Const Elect Electro Cie Magnetic detection device, especially for protection against fraud
FR2611956A1 (en) * 1987-03-05 1988-09-09 Fichet Bauche MAGNETICALLY CONTROLLED DETECTOR FOR MOVING A MOBILE MEMBER TO A FIXED MEMBER FOR OPENING AN ENCLOSURE
GB2204169A (en) * 1987-04-28 1988-11-02 Arnold Walmer Key reminder apparatus

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2176330A (en) * 1985-06-07 1986-12-17 Aica Kogyo Co Ltd Keysensor
GB2176330B (en) * 1985-06-07 1989-07-05 Aica Kogyo Co Ltd Key sensing system
FR2598005A1 (en) * 1986-04-25 1987-10-30 Const Elect Electro Cie Magnetic detection device, especially for protection against fraud
FR2611956A1 (en) * 1987-03-05 1988-09-09 Fichet Bauche MAGNETICALLY CONTROLLED DETECTOR FOR MOVING A MOBILE MEMBER TO A FIXED MEMBER FOR OPENING AN ENCLOSURE
EP0283376A1 (en) * 1987-03-05 1988-09-21 FICHET-BAUCHE SociétÀ© dite: Magnetically controlled detector of the movement of a mobile part with respect to a fixed part for the opening of an enclosure
GB2204169A (en) * 1987-04-28 1988-11-02 Arnold Walmer Key reminder apparatus
GB2204169B (en) * 1987-04-28 1991-10-09 Arnold Walmer Key reminder apparatus

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Legal Events

Date Code Title Description
PS Patent sealed
PLNP Patent lapsed through nonpayment of renewal fees
PLNP Patent lapsed through nonpayment of renewal fees

Free format text: DELETE FROM JOURNAL 4618,PAGE 2702

PLE Entries relating assignments, transmissions, licences in the register of patents
732 Registration of transactions, instruments or events in the register (sect. 32/1977)
746 Register noted 'licences of right' (sect. 46/1977)
PE20 Patent expired after termination of 20 years