GB375450A - Improvements in or relating to electric signalling systems and apparatus - Google Patents
Improvements in or relating to electric signalling systems and apparatusInfo
- Publication number
- GB375450A GB375450A GB987131A GB987131A GB375450A GB 375450 A GB375450 A GB 375450A GB 987131 A GB987131 A GB 987131A GB 987131 A GB987131 A GB 987131A GB 375450 A GB375450 A GB 375450A
- Authority
- GB
- United Kingdom
- Prior art keywords
- relay
- frequency
- signal
- circuit
- relays
- 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
- G08B25/00—Alarm systems in which the location of the alarm condition is signalled to a central station, e.g. fire or police telegraphic systems
- G08B25/01—Alarm systems in which the location of the alarm condition is signalled to a central station, e.g. fire or police telegraphic systems characterised by the transmission medium
- G08B25/08—Alarm systems in which the location of the alarm condition is signalled to a central station, e.g. fire or police telegraphic systems characterised by the transmission medium using communication transmission lines
Abstract
375,450. Electric signalling systems and road-traffic signals. GRASEBY, R. C. and MATTHEWS, S. J., Kingston By-Pass Road, New Malden, Surrey. April 1, 1931, No. 9871. [Classes 40 (i) and 118 (ii).] In an electric signalling system a signalling apparatus, e.g. an audible signal apparatus, is connected to a local source of power by a relay responsive to a particular frequency, the frequency being applied to the system at predetermined intervals to actuate the signal a number of times. In addition a second signalling apparatus, e.g. a visual signal apparatus, is connected to the local source of power in response to receipt of current of this frequency and is disconnected on the receipt of current of a second frequency, the connection being maintained by a mechanical locking device. As described, the invention is applied to a system in which signals are given to indicate, to police and traffic, that fire engines are to be expected, the audible signal indicating the number of engines, and if illuminated traffic control signals are used, all the controls are altered to the " stop " indication. Referring to Fig. 1, the apparatus 4 is situated at the fire station and controls signals over routes 19, 20, and 21. A motor 1 drives generators 2 and 3, which generate current of 16.7 and 100 cycles respectively, and also drives discs 14 .. 17 which carry teeth 18. The wheels 14 .. 17 control contacts 9 .. 12, the contacts being made respectively one, two, three or four times in succession and are used to indicate the number of engines to be expected. If, for example, two engines are to pass over route 19, switch 5 is moved into its upper position and switch 13 is connected to contact 10. Current of frequency 16À7 cycles is repeatedly connected to route 19 twice in quick succession. Relays 24 and 31 at the distant point respond, relay 31 locking to connect current to visual signal 23 and relay 24 ringing alarm 22 at each pulse. To remove the signal, switch 5 is moved into its lower position to connect generator 3 to the circuit. Relay 41 responds to this frequency and unlocks relay 31. Relay groups 56, which are similar to relay groups 31 and 41, provide, through lamps 55, a local check on the route over which the signals are being transmitted. The route 21 connects with an illuminated traffic control signal and the relays 31 and 41 control relays 54 which, when energized, alter all controls to the " stop indication. As illustrated in Fig. 1 the construction of the apparatus fitted at the signal points is that described in Specification 367,433 but the alternative construction illustrated in Fig. 2 may be used. The relay 24 controls springs 30 which are in the circuit of the audible alarm. The visual alarm is controlled by relays 31 and 41. When the operating pulse is received relays 24 and 31 respond, relay 24 releasing when the pulse ceases. Relay 31 closes the visual alarm circuit at 36, 37 and also closes contacts 50 in the circuit of release relay 41. The projection 40 on the armature 32 slips under the notch 46 on bell crank 45, which is pulled to the right by spring 44 when relay 31 operates and the armature 32 is locked in operated position. The movement of 45 to the right allows springs 52, in the circuit of 31, to open. When the releasing frequency is received, relay 41 pulls up and allows 32 to move back under action of spring 34. Springs 50 break the circuit of 41 and 45 returns to its normal position. Condenser 47 is connected in series with relay 41.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB987131A GB375450A (en) | 1931-04-01 | 1931-04-01 | Improvements in or relating to electric signalling systems and apparatus |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB987131A GB375450A (en) | 1931-04-01 | 1931-04-01 | Improvements in or relating to electric signalling systems and apparatus |
Publications (1)
Publication Number | Publication Date |
---|---|
GB375450A true GB375450A (en) | 1932-06-30 |
Family
ID=9880307
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB987131A Expired GB375450A (en) | 1931-04-01 | 1931-04-01 | Improvements in or relating to electric signalling systems and apparatus |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB375450A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5470859A (en) * | 1989-08-05 | 1995-11-28 | Beecham Group P.L.C. | Azabicyclic compounds with muscarinic activity useful for treating dementia |
-
1931
- 1931-04-01 GB GB987131A patent/GB375450A/en not_active Expired
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5470859A (en) * | 1989-08-05 | 1995-11-28 | Beecham Group P.L.C. | Azabicyclic compounds with muscarinic activity useful for treating dementia |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
GB375450A (en) | Improvements in or relating to electric signalling systems and apparatus | |
US1536192A (en) | Self-supervised electric system | |
US1613802A (en) | Signaling system | |
US2492043A (en) | Fire alarm system | |
US1620107A (en) | Fire-alarm system | |
US477712A (en) | Alfred stromberg | |
US1945989A (en) | Electrically controlled clock | |
US2006975A (en) | Supervisory indication of carrier current transmitter | |
US2040691A (en) | Selective code receiver | |
US1411112A (en) | Electric alarm system | |
US372865A (en) | pearce | |
US966897A (en) | Central-energy alarm system. | |
US563474A (en) | frost | |
US472359A (en) | Electric indicator for railroad-blocks | |
US291360A (en) | Railway block signal | |
US1120995A (en) | Signaling system. | |
US1375059A (en) | Signal system | |
US1073335A (en) | Signaling system. | |
US357960A (en) | Electric fire-alarm | |
GB453699A (en) | Improvements in or relating to electric signalling systems | |
US1870988A (en) | Fire alarm system and repeater | |
US1274367A (en) | Signal system. | |
US2055979A (en) | Railway traffic controlling system | |
US1008960A (en) | Fire-alarm system. | |
US435482A (en) | conly |