GB750437A - Improvements in electrical alarms - Google Patents
Improvements in electrical alarmsInfo
- Publication number
- GB750437A GB750437A GB2340953A GB2340953A GB750437A GB 750437 A GB750437 A GB 750437A GB 2340953 A GB2340953 A GB 2340953A GB 2340953 A GB2340953 A GB 2340953A GB 750437 A GB750437 A GB 750437A
- Authority
- GB
- United Kingdom
- Prior art keywords
- housing
- alarm
- circuit
- plunger
- rod
- 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
- G08B13/22—Electrical actuation
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Burglar Alarm Systems (AREA)
Abstract
750,437. Theft alarms. BYRNE, J. N. April 30, 1954 [Aug. 25, 1953], No. 23409/53. Class 118(1) A theft alarm comprises a housing, such as a case, through which a spring-loaded plunger 7 can protrude thereby completing an electric circuit which may be within the housing or at a separate location, the plunger being depressed within the housing and the circuit opened when the housing is placed on an object, so that on lifting the housing the electric circuit is completed thereby energizing a selfholding relay controlling the operation of an alarm device, such as an electric buzzer, bell or other visual or audible signal device. The alarm is so constructed that movement of the housing on the object also causes the completion of the circuit so that the alarm is operated. Once the alarm has been operated it continues in operation whatever the position of the plunger until the circuit is broken by means of a key-operated control switch within the housing. The plunger comprises a rod 7 carrying a conical protuberance 8 which is urged downwardly by means of a compression spring 10. The rod passes through the wall of the housing so that on lifting the housing the protuberance 8 is free to move downwardly and complete a circuit through the rod 7 and a contact plate 12. If the housing is moved without being lifted from the object on which it rests, the rod 7 will move with respect to the plate 12 and complete the circuit by making contact with the edge of the aperture in the plate through which it passes. A number of alarms may be interconnected, so that operation of any one causes the operation of all of them. Instead, the alarm may be connected to one or more slave devices which also give an alarm signal when the housing for the alarm is moved. In the preferred embodiment, the alarm circuit is arranged within the housing; in an alternative arrangement the housing comprises the plunger and associated contacts only, and is connected to one or more slave alarm devices.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2340953A GB750437A (en) | 1953-08-25 | 1953-08-25 | Improvements in electrical alarms |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2340953A GB750437A (en) | 1953-08-25 | 1953-08-25 | Improvements in electrical alarms |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB750437A true GB750437A (en) | 1956-06-13 |
Family
ID=10195153
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB2340953A Expired GB750437A (en) | 1953-08-25 | 1953-08-25 | Improvements in electrical alarms |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB750437A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2197516A (en) * | 1986-11-15 | 1988-05-18 | John Bryan Clough | Security device |
-
1953
- 1953-08-25 GB GB2340953A patent/GB750437A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2197516A (en) * | 1986-11-15 | 1988-05-18 | John Bryan Clough | Security device |
| GB2197516B (en) * | 1986-11-15 | 1990-10-03 | John Bryan Clough | Security device |
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