US2780671A

US2780671A - Telephonic alarm system

Info

Publication number: US2780671A
Application number: US269031A
Authority: US
Inventors: Thery Georges
Original assignee: Individual
Current assignee: Individual
Priority date: 1952-01-30
Filing date: 1952-01-30
Publication date: 1957-02-05
Anticipated expiration: 1974-02-05

Description

Feb. 5, 1957 ca. THERY 2,780,671

TELEPHONIC ALARM SYSTEM Filed Jan. so. 1953 L3 L1 to local subscriber set 1 "D to central office (llu.,|lb operaie 56 before He) before Hr-4e) INVENTOR. II GEORGES THERY TELEPHONIC ALARM SYSTEM Georges Thery, Paris, France Application January *30, 1952, Serial No. 269,031

7 Clai-s (Cl. 179-5) The present invention relates to a telephonic alarm system adapted to cooperate with conventional protective devices, such as fire or burglar alarms, for the purpose of automatically giving a long-distance alarm upon the occurrence of the emergency to be guarded against (e. g. the outbreak of a fire or an attempted breaking into the premises).

An object of the invention is to provide means for automatically alerting one or more stations, connected by way of the normal telephone .network with the protected premises, upon the happening of a specific one or any of several contemplated eventualities.

A more particular object of the invention is to provide means for selectively adapting an alarm system of this type for use with any of a variety .of conventional telephone systems, such as automatic dialing systems, centralbattery systems and local-battery systems.

Another object of the invention isto provide switch means for selectively placing an alarm system of this kind in a state of preparedness, in combination with control means preventing the transmission of a false alarm if, during installation or adjustment, a condition (e. g. an open circuit) simulating the existence of an emergency should occur.

A further object of the invention is to provide supervisory means for modifying (or suppressing) the operation of an alarm system of this type if an oif-normal condition should exist as a result of-some circuit trouble rather than by reason of the operation .of a'fire, burglar etc. detector associated therewith.

'In a preferred embodiment of the invention, the system operates in two successive stages, the first one alerting the proper authorities (police or fire department, according to the nature of the emergency), the second notifying the owner of the premises (orsome other interested party) of the existence of an alarm condition.

The above and other objects and features of the invention will become apparent from the following detailed description, reference being had to the accompanying drawing the sole figure of which shows, schematically and partly in block form, a representative embodiment of the invention.

In the drawing, the contact of the several relays and other switching devices are designatedby the reference number of the device (e. g. 4, 25) followed by a letter or, in some cases, a letter accompanied by a numeral (e. g. 4a, 25b2). Contacts difiering only by a letter should be understood to be gauged together.

-At the upper right of the figure, there is shown the power supply of the alarm system comprising, in this particular case, a low-voltage battery ,1 with grounded negative terminal. A sustaining charger, comprising a full-wave rectifier 2 connected across "the commercial alternating-current mains 100 bymeans of a transformer 101, is shown bridged across thebatterywhose positive terminal is'connected to the alarmcircuitatall points marked by an arrowhead and the v- -sign.

A commercial telephone line, v.wihose incoming .con-

nited States Patent ice ductors L1, L2 are normally connected to the conductors L3, L4 of an extension line leading to the local subscriber set, leads to the central ofiice (not shown) of a telephone network over which numerous other stations, including police headquarters, fire department and the residence of the owner of the protected premises, can be reached by dialing impulses transmitted over the line in the wellknown manner. A manually operable selector switch 25, whose three positions have been indicated at (1), 0.

(2) and (3), respectively, is shown placed in position (1) to close its contacts 25111, 25b1 and 2501, thereby adapting the alarm circuit for use with a telephone network of this character. If the network were of the central-battery or local-battery type, then the switch 25 would have to be rotated to its second position (contacts 254:2, 25b2, 25c2, 25d2 closed) or to its third position (contacts 25a3, 25b3, 2503, 25d3, 25:23 closed), respectively.

The connection normally established between conductors L1, L2 on the one hand and conductors L3, L4 on the other leads over the back contacts of armatures 11a, 11b of a relay 11 Whose armature makes after the two first-mentioned armatures have engaged their front contacts. Bridged across relay 11 is a voltage divider comprising two resistance-shunted

indicator lamps

57, 53 to the junction of which a bus bar 102 is connected. Another bus bar 103 is normally grounded over a back contact and armature 5th; of a general-release relay 50. Two conditioning switches 3 and 4 are designed to place the system in a state of preparedness when operated to close their

contacts

3a, 3b, 3c, 3d, and 3e and 4a, 4b, 4c, 4d, 4e, respectively. Two relays .8 and It? are then energized. The circuit for relay S extends from positive battery over contacts 3b, resistance-shunted indicator lamp 59, winding of relay 8 to grounded bus bar 103 by way of the various circuit breakers, such as 5', 5", of a fire detector circuit 5; that for relay It) extends from positive battery over contacts 4b, resistance-shunted indicator lamp 6%, Winding of relay 1b to the same groundby wayof the various circuit breakers, such as 6', 6", .of a burglar detector circuit 6. Similar energizing circuits extend from battery over contacts 30 and lamp 55 through the Winding of a relay 7 to ground at 103 by wayof a back contact and armature 9b of a relay 9, and from battery over contacts 4c and lamp 56 through the winding of relay 9 to the same ground by way of a back contact and armature 7b of relay 7. Operation of relays 7 and 9 is, however, normally prevented by respective shunt circuits whichmay be traced for the relay 7 from the Winding of that relay .over front contact and armature 8a of relay 8, back contact and armature 7a of relay 7, detectors 5 5" to ground at 163 and for the relay 9 from the winding of the latter relay over front contact and armature 10a of relay 10, back contact and armature 9a of relay 9, detectors 6 6 to the same ground. It will be apparent that release of the relays 8 and-1t by the shunting effect of

lamps

55 and 56 will be prevented so long as the resistance of these lamps (taking into account the associatedshunting resistors) is high compared with that of lamps 59 and 6%. Armatures 7b and 9bhave front contacts connected across the winding of relay 11.

Switches 3 and 4 are controlled by respective blocking devices 53 and 5d, device SSbeing connected between ground bus bar 163 and battery in series with switch contact 3a and detector circuit 5 While device 54 is similarly connected between this bus bar and battery in series with switch contact 411 and detector circuit 6. When the switches 3 and 4 are set to operative position,

contacts

3a and 4a thereof are first to close; if, at this time, any break should exist in the associated detector circuit 5 or 6 (as by one of the circuit breakers 5" or 6, 6" being accidentally left open), the corresponding blocking device will be deenergized and in this condition will prevent the respective switch from being operated further to close its remaining contacts 3b Be or ab 40, whereby the system will be prevented from giving a false alarm as will become apparent hereinafter.

An energizing circuit for a relay 12 extends from ground bus bar 103 over front contact and armature 110 of relay 11, a resistor 104, the winding of relay 12 and, a thermal cut-out 13 to the bus bar 102; the Winding of relay 12 is, however, initially short-circuited by its own back contact and armature 12a in series with the break contacts 13a of cut-out 13, whereby the operation of the relay will be delayed until after the cut-out has responded. Bus bar 102 is normally maintained at positive potential from battery over closed switch contacts 3d and 4d in parallel, back contact and armature 50b of release relay 50, and a circuit which includes the winding of a relay 20 in series with front contacts and armatures 8c, 100 of relays 8, and a resistor 105 which lies in parallel with a back contact and armature 28a of relay 28, the said circuit being shunted by break contacts 29a of a thermal cut-out 20. An energizing circuit for a motor 14 extends between the

bus bars

102, 103 and is controlled by front contact and armature 12b of start relay 12. The winding of relay 28 is also connected via a resistor 116 to ground on conductor 103.

The armatures 11a and 11b of relay 11 are provided with front contacts connected, respectively, to two

conductors

106 and 107. With the energization of relay 11, the line loop is completed from conductor 106 through normally closed contacts 19, interrupter contacts of three serially connected

impulse generators

16, 17, 18, back contact and armature 27b of a switch-over relay 27, winding 26' of a dual-winding, polarized relay 26 and winding of a relay 23 to conductor 107, the latter winding being shunted by a condenser 115.

The

impulse generators

16, 17 and 18 are three disks each adapted to emit, during each rotation, a predetermined train of dialing impulses corresponding, respectively, to the call numbers of the fire department, the police station and the residence of the proprietor. Each of these disks is individually shunted, respectively, by back contact and armature 7c of relay 7, back contact and armature 0c of relay 9 and back contact and armature 28b of relay 28, the latter armature having a front con tact which places a shunt across

generators

16 and 17 when the relay 28 is energized. All three generators are also bridged by contacts 103 which are controlled by a cam 109 in such manner as to be open during one out of several revolutions of each disk, whereby the transmission of dialing pulses will be followed by an interval during which the called party has an opportunity to answer. A earn 110, synchronized with cam 109, operates contacts 19 to open the line loop prior to renewed transmission of the dialing pulses if the called party has not answered.

Armature 27b has a front contact connected directly to conductor 106, thereby short-circuiting the impulse generators when the relay 27 is operated. In that condition, the secondary of a transformer 52 is connected across

loop conductors

106 and 107 in series with a blocking condenser 111. The primary of transformer 52 is connected via a line to a message transmitter 112 which, when energized from a generator 113, reproduces and amplifies a recorded message to be transmitted over the line L1, L2. The message may be worded, for example, as follows: This is John Does shop at 123 Main Street. Assistance is urgently needed.

Cams 100 and 110,

disks

16, 17 and 18 and generator 113 are driven from the motor 14 as schematically indicated in the drawing.

Also connected across

conductors

106 and 107 is the secondary 21 of a transformer 21 in series with a blocking condenser 114. The primary 21 of this transformer,

which assumes significance only in the case of local-battery telephone systems (switch 25 in its third position), is bridged across the resistor 104 in series with a vibrator 20 and with a thermal cut-out 22 whose contacts 22a normally shunt the contacts of the vibrator, connected between the latter and conductor 102. A shunt circuit around vibrator 20 and its contacts includes contacts 25e3 of switch 25 and a back contact and armature 23a of relay 23, which short-circuit the vibrator as Well as relay 12 in the third position of switch 25.

The winding of relay 27 is connected in series with resistor normally shunted by armature 28a and with a front contact and armature 12b of starting relay 12 between the

bus bars

102 and 103. This winding is bridged by a lock-out circuit including the armature 26a of polarized relay 26, one of two parallel-connected contacts alternately engageable by said armature, contacts 25111 and 25112 in parallel, and a back contact and armature 27a of relay 27. In the third position of switch 25, this lockout circuit is broken and a connection exists, instead, between the front contact of armature 12b and the armature 27a over contacts 2503 (in parallel with a front contact and armature 23b of relay 23) and contacts 25b3. A circuit having two parallel branches extends between a front contact associated with armature 27a and the back contact of armature 28a; one branch includes the thermal cut-out 29 in series with contacts 25:11, the other branch includes a thermal cut-in 51 in series with the parallel combination of contacts 25:12 and 25113. Cut-in 51 is also directly connected to a front contact of armature 28a. From the latter armature, a circuit also extends through an audible alarm device 24 and parallel contacts 2501, 2502 to a back contact associated with armature 23b.

The second winding 26 of polarized relay 26 is energizable in a circuit extending from grounded bus bar 103 over a front contact and armature of relay 11 through said winding to battery at the back contact of armature 50b. Make contacts 51a of thermal cut-in 51 extend this battery, applied to armature 50b through switch contacts 3d and 4a, to the grounded winding of release relay 50, this relay being provided with a locking circuit by virtue of a connection between its winding and a front contact associated with its armature 50b. The relay is also energizable over two parallel circuits comprising, respectively, switch contacts Se in series with a back contact and armature 8b of relay 8 and switch contacts 4e in series with a back contact and armature 10b of relay 10, each of these circuits being connected to the winding of relay 50 over contacts 25d2 and 25033 in parallel.

The operation of the system just described is as follows:

Since the arrangements of the two

detector circuits

5 and 6 are symmetrical, it will be suflicient to describe the operations resulting from the response of one of the circuit breakers of either of these detectors, e. g. of the circuit breaker 5' of fire detector 5. The resistor connected across the open circuit breaker enables the passage of suflicient current to maintain relay 8 operated; at the same time, however, the short circuit around relay 7 is broken so that this relay energizes and at 7a further opens said short circuit, at 7b opens the operating circuit of relay 9 and at 7c removes the short circuit from digital disk 16. Relay 11 energizes in parallel with lamp 58 in a circuit extending from ground at 103 through front contact and armature 7b, winding of relay 11, lamp 57 to conductor 102; the current passing through lamp 57 in series with the relay winding is insufiicient to light this lamp so that only lamp 58 functions, thereby indicating that the break had occurred in the fire detector circuit 5.

Relay 11, by first reversing its armatures 11a and 11b, disconnects the telephone line L1, L2 from the local subscriber set and connects it, instead, across the impulse and message transmitting circuit 15-18 via

leads

106, 107. The operating winding 26 of relay 26 is energized, in series with relay 23, by the line current; armature 26a thereupon engages one of its contacts to close the short circuit around the winding of relay 27, while armature 23b opens the circuit or" audible alarm device 24. (If, for some reason, the telephone line L1, L2 had been dead, relay 23 would not have operated and the audible alarm would have sounded upon the subsequent operation of relay 12.) Relay 11 then attracts its armature 11c to energize the biasing winding 26" of relay 26; this also energizes the thermal cut-out 13 in series with the winding of start relay 12, the latter relay operating after the cutout has opened the shunt tliereacross at 13a. The disengagement of armature 12a from its back contact insures continued operation of the relay.

Relay 12, in attracting its armature 12b, energizes the motor 14 which rotates the impulse generators 16-18 as well as the current generator 113 feeding the message transmitter 312, only the impulse generator 16 being effective at this time. During the first rotation of disk re, the line current is interrupted a number of times to produce a train of digital impulses corresponding to the call number of the fire department. Thereafter the cam 109 closes the contacts 108 to await the response of the called station. If no answer is received before the cams 1&9 and ill have completed their revolution, the latter cam momentarily opens the line loop at 19 whereupon another train of digital impulses is sent out by the disk 16. As soon as the called station answers, the polarity of the line current is reversed and overcomes the biasing current in winding 26" to move armature 26a into engagement with its alternate contact; during the changeover, the lock-out circuit of relay 27 is momentarily broken, relay 27 energizes and by reversing its armature 27a avoids being shortcircuited again. Armature 27b engages its front contact, thereby short-circuiting the impulse generators, and the recorded message is sent over the line by the transmitter 112.

Armature 27a also closed the energizing ci'cuit for thermal cut-out 29 which, after a predetermined period, opens its contacts 29a to remove the short circuit from relay 28, the latter energizing in series with resistor 116 and reversing its

armatures

28a and 28b. Armature 28a by its reversal prevents reclosure of the short circuit across the winding of relay 28 and removes the shunt from across resistor 165 which is large enough to prevent relay 12 and motor 14'from remaining operative in series with it. Relay 12, in releasing, at 12b de-energizes relay 27 whose armature 27b, in turn, reconnects the impulse generating network 16-18 across the line. As soon as the thermal cut-out 29 has cooled sufliciently to rcclose its contacts 29a, a new'operating cycle is started by the re-energization of relay 12. With relay 28 operated, however, the digital impulses transmitted are those produced by the impulse generator 18 and correspond, in the assumed case, to the call number of the owner of the premises. When the connection has been established, relay 26 again reverses its armature and allows relay 27 to energize; the circuit established by armature 27a extends, however, through thermal cut-in 51 instead of thermal cut-out 29, in view of the altered position of armature 25a.

While the message from transmitter 112 is sent out a second time, thermal cut-in 51 heats up and finally closes its contacts 51a, thereby causing the operation of relay 54) which at 56a removes ground from bus bar 103, thus releasing all other relays. Indicator lamp 61 remains lit in parallel withrel'ay 50 to show that the system has functioned.

If the telephone systemserved by the line L1, L2 had been of the central-battery type, switch 25 would have been placed in its second position. Thermal cut-out 29 is thereby permanently"disconnected from the circuit, at 25a1,whereas the operation of thermal cut-in 51 is rendered independent of relay 23, by virtue of the closure of contacts 25a2. The transmission of digital impulses by

generator

16 or 17 over the line will have no eifect, yet the response of the operator summoned by the closure of the line loop will again cause a reversal in the polarity of the current passing through Winding 26', whereby a single cycle of message transmission, terminated by the operation of release relay 50, will be initiated. Audible alarm 24 functions as before in case the line should be in a no-current condition. It will be understood that with the line properly energized the condenser connected across relay 23 maintains the latter operated during impulsing, thereby preventing the alarm 24 from sounding when the line loop is broken by the operation of

impulse generator

16, 17 or 18. 7

in the third position of switch 25, the vibrator 26, which in the other two switch positions inefiectively attracts its armature, is initially short-circuited by theclosune of contacts 25a? which also short-circuit the relay l2. Energization of thermal cut-out 22 (which also occurs, incidentally, in the other positions of switch 25 but has no significance then) eventually opens the contacts 22a whereupon the vibrator 2d alternately energizes in series with cut-out 22 and releases, the resulting pulsating current being insulficient to maintain the cut-out operative so that contact 22a are eventually reclosed, again shoit-circuiting the vibrator contacts, and so on, whereby an intermittent ringing current is applied to the line Ll, L2 by way of transformer 21. When the operator answers, battery is applied to the line at the central ofiioe to energize the relay 23 which at 23a removes the short circuit from vibrator 20, thus inactivating the latter in energized position. Relay 12 operates instantly, the thermal cut-out 1 3 having meanwhile had time to warm up and to open the contacts 13a. Since the lock-out circuit of relay 27 is open at contacts 25121 and 25b2, relay .27 operates as soon as contacts 12b are closed, thereby establishing the circuit of cut-in 51 by way of

contacts

2503 and 23b in parallel, 25123 and 27a. As in the previous case, the message is now transmitted until contact 51a are closed to operate release relay 5!).

*If the operation of relay 7 had been due not to the opening of resistance-shunted circuit breaker 5 (or 5") but, instead, to some accidental break in the detector circuit 5, then the relay 8 would have released and, with switch 25 in its first position, would immediately have opened the short circuit around relay 28, thereby preventing the emission of an alarm to the authorities while merelycausing notice of the condition to be given to the proprietor by activating the disk 13 at the first (and only) cycle of operations. The efiect of a release of relay lli) for like causes would have been the same. After the system has been restored to normal by the release of relay 50 (e. g. through suitable manual means not shown), the location of the defect can be ascertained from the failure of lamps 59 and/ or so to light. If the telephone system had been of the centrahbattery or local-battery type, release of relays and/or 10 would merely have inactivated the system by energizing relay 50 over their corresponding back contacts and armatures 8b and/or lob.

If the defect had occurred during installation, inspection or readjustment, then, as previously noted, nonoperation of blocking device 53 or 54 would have prevented the corrcs'ponding conditioning switch 3 or 4 from being actuated far enough to close those of it contacts over which battery is applied to various conductors of the system. It will be observed, however, that in this case a failure of, say, detector circuit 5 :will not have disabled the system to the extent that it is controlled by detector circuit 6, or vice versa.

The system described and shown in the drawing may be modified in various ways. Thus it may be mentioned that a key or switch may be provided for isolating the apparatus from the telephone line for testing purposes; that the conditioning switches herein shown may be replaced by a simple, possibly remote-contnolled circuit breaker in series with the battery; that indicator lamps 59 and 60, for example, may be coupled with audible signaling devices in order to attract attention in the case of circuit failure; that the timing of various relays here shown as controlled by thermal switches may be brought about, instead, by other delay means, cams or the like; and that, finally, the functioning of the system and especially the pulse generating network may be improved by diverse expedients known per se, such as means to shortcircuit the line relays in order to reduce the inductivity of the line and condensers connected across the pulsing contacts in order to suppress arcing.

What is claimed is:

1. The combination with a telephone line, normally connecting a local subscriber set to an exchange forming part of a telephone network, of emergency detector means, electrical circuit means controlled by said detector means, call initiating means, normally inoperative message transmitter means adapted to send out an alarm over said line, connector means for connecting said transmitter means to said line preparatorily to a sending out of said alarm, switch means operable under the control of said circuit means for disconnecting said line from said subscriber set and connecting it to said call initiating means in response to operation of said detector means, mechanism controlled by said switch means for actuating said call initiating means, following connection thereof to said line, to summon a person capable of being reached over said line, starting means for rendering said message transmitter eans effective, line relay means connectable across said line by said switch means, along with said call initiating means, and responsive to a change in the current condition on said line, indicative of a response by the summoned person, for actuating said switch means to disconnect said call initiating means from said line, for operating said connector means to connect said message transmitter means to said line and for actuating said starting means to operate said message trans mitter means, saidnetwork being of a type in which a voltage is applied substantially continuously to said line by said exchange, and local alarm means controlled by said line relay means to operate in the absence of said voltage from said line.

2. An alarm system comprising emergency detector means, a subscriber line leading to an exchange of a telephone network, electrical circuit means controlled by said detector means, call initiating means including first and second impulse generator means, said first impulse generator means being adapted to produce digital impulses corresponding to the call number of a public safety service, said second impulse generator means being adapted to produce digital impulses corresponding to the call number of a predetermined station of said network other than said safety service, message transmitting means adapted to send out an alarm over said line, switch means operable under the control of said circuit means, in response to an emergency condition to which said detector means properly responds, to connect to said line and render operative, in succession, said first impulse generator means, followed by said transmitting means, in a first operative cycle and said second impulse generator means, followed by said transmitting means, in a second operative cycle, said switch means including line relay means ascertaining a change in the current condition of said line prior to establishing a connection to said transmitter means, said switch means further including timer means determining the length of the time during which said transmitter means is to be connected to said line, and control relay means responsive to faulty operation of said detector means for so modifying the operation of said switch means as to skip said first operative cycle.

3. A system according to claim 2, including a control switch settable to modify the operation of said switch means so as to skip said first operative cycle in case said network is of other than the fully automatic type, said call initiating means further including a source of ringing current, said control switch being further settable to modify the operation of said switch means so as to actuate said source in case said network is of the local-battery type.

4. A system according to claim 2, wherein said detector means include a fire detecting circuit and a burglar detecting circuit, said first impulse generator means including an impulse generator adapted to produce the call number of the fire department and another impulse generator adapted to produce the call number of the police station, said circuit means causing selection of either of said generators depending upon which of said detecting circuits has responded.

5. An alarm system for use in connection with a subscribers telephone station and line, comprising emergency detector means, electrical circuit means controlled by said detector means, normally inoperative signaling means adapted to send out an alarm over said line, connector means for connecting said signaling means to said line preparatorily to a sending out of said alarm, starting means for rendering said signaling means effective, switch means operable under the control of said circuit means for actuating said connector means and said starting means in response to operation of said detector means, conditioning means connected to said circuit means and adapted to place said circuit means in a state of preparedness, and blocking means connected to said conditioning means and to said detector means, said blocking means being responsive to a defective condition of said detector means for preventing full operation of said conditioning means.

6. An alarm system for use in connection with a subscribers telephone station and line, comprising emergency detector means, electrical circuit means controlled by said detector means, normally inoperative signaling means adapted to send out an alarm over said line, connector means for connecting said signaling means to said line preparatorily to a sending out of said alarm, starting means for rendering said signaling means effective, switch means operable under the control of said circuit means for actuating said connector means and said starting means in response to operation of said detector means, and relay means connected to said detector means and to said signaling means, said relay means being responsive to a defective condition of said detector means for at least partially preventing the operation of said signaling means.

7. An alarm system according to claim 6 wherein said detector means comprises a guard circuit including circuit breaker means and resistance means shunting said circuit breaker means, said relay means being energizable by way of said guard circuit in series with said resistance means but being inoperative in case of a break in a portion of said guard circuit not shunted by said resistance means.

References Cited in the file of this patent UNITED STATES PATENTS 1,974,551 Tuscher et a1. Sept. 25, 1934 2,062,822 Powell Dec. 1, 1936 2,099,913 Tuscher et al Nov. 23, 1937 2,121,282 Bradford June 21, 1938 2,195,627 Lornax et a1. Apr. 2, 1940 2,498,613 Talbot Feb. 21, 1950 2,555,714 Talbot June 5, 1951