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
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.
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)
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 |
-
1968
- 1968-11-08 GB GB1250803D patent/GB1250803A/en not_active Expired
Cited By (7)
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 |