Patent GB-270755-A (GB)
IPC: H04M11/04
Filed: 1927-05-07
Abstract: 270,755. Snyders, G. C., Gordyn, C., Kamp, J. van de, and Maitland, C. E. A. May 8, 1926, [Convention date]. Fire, police, and like alarm systems; order apparatus.-Central stations of fire and like alarm systems have means for repeating the number of an alarm-giving station to a third station, e.g. the fire watch nearest to the station giving the alarm. At the central station, hundreds, tens, and units keys H1, Z2, E3 are connected to the contacts of a motor-driven impulsesender ZG, the relay J1 repeating the impulses over the lines L to a relay X which causes stepby-step selectors VS, SS to select appropriate lamps, such as LH, LZ, LE, of a lamp indicator. Supervisory and progress lamps are provided at each station, and telephonic communication may be established between the central station and the fire watch. Transmission of selecting impulses. The operator at the central station HBW depresses the station selecting key ET and then keys H1, Z2, E3, say, in accordance with the number of the station giving the alarm, the units key starting the motor M which drives the sender ZG through a complete revolution, thereby closing a contact 9k in the circuit of relay J1 thirty times (three groups of ten). The impulses are repeated by relay J1 over contact 13 and lines L in parallel to relay X at the distant station, until the wiper B reaches the contact grounded by the depressed hundreds key H1, whereupon relay J2 disconnects relay J1 and locks up until the wiper B has passed the hundreds contacts. The tens and units impulses are transmitted similarly. Supervisory lamps at central station. The operator at the central station inserts her plug in the jack kl of the calling line, and moves a commutator, represented by contacts 71 - - 76, to connect up her telephone. This also energizes a relay S which lights lamp LII. The depression of the selecting key ET energizes relay I which lights lamp LI and prepares a cir-- cuit for lamp LII, which lights up when the transmission is complete. Control of indicator at distant station and establishment of telephone communication. The impulse relay X energizes a slow-release relay K and a self-locking relay K1, and repeats the first set of impulses to the magnet Dv of the selector VS, which closes the circuit of a lamp LA indicating the location of the call, and prepares a circuit for the hundreds lamp LH. At the end of the hundreds impulses, relay K closes the circuit of (1) a relay AL, which locks up and sounds an alarm VS, and (2) a relay VI which locks up and substitutes the vertical magnet H of a co-ordinate selector SS for the magnet Dv. The tens impulses are repeated to the relay K and magnet H, and when they cease relay V2 connects up the rotary magnet Dr which receives the units impulses. The relay V3 is then energized, locks up, closes the circuits of the selected lamps LH, LZ, LE, and connects the fire-station telephone leads ABA at contacts 27, 28, to the line L. A self-locking relay II at the central station is energized just before the impulse- Render completes its cycle and connects the central station telephone leads A<1>BA<1> to the line L. A high-resistance relay C energizes over the line Land lights the lamp LII. Restoration. The depression of the release key at AT unlocks relay I and energizes over line L a relay III at the central station and a relay U at the fire station. Relay III maintains relay I energized for a short time, and relay U locks up, unlocks the relays AL, K1, VI, V2, V3 and restores the selectors VS, SS.