US3266031A

US3266031A - Alarm system

Info

Publication number: US3266031A
Application number: US334291A
Authority: US
Inventors: John A Sadler
Original assignee: Chubb Mosler and Taylor Safes Ltd
Current assignee: CSG Security Inc
Priority date: 1963-12-30
Filing date: 1963-12-30
Publication date: 1966-08-09
Anticipated expiration: 1983-08-09

Description

`E Sheets-Sheet 1 J. A. SADLER ALARM sYsT'EM rffff .U Y C .Nov y @RIMM Filed DeO 50,v 1963 6 6 9 l 9, uw u .A

Aug. 9, 1966" J. A. SADLER 3 Sheets-Sheet 2 med nem-'3o. `195s JOHN lA. SADLER- eve y ATTORNEYS '-INVENTOR Y ATTORNEYS" v Aug. 9.1966 .1.A. SADLER 3,265,031 l l ALARM SYSTEM Y Filed nec. so. 1965 s sheetssneet s FIG. 3

I A 4 v9 i j v 78 f H l Y 5. u

battery.- "W

The oscillatory signal normally supplied over thev wires- Patented August 9, 1966 "United States' Patent Ofcc 3,266,031 ALARM SYSTEM John A..Sadlcr, Rexdale, Gntario, Canada, assigner, by mcsne assignments, to Chubb-Musici' and Taylor Safes Ltd., Brampton, Ontario. Canada Filed Dec. 3l), 1963, Ser. No. 334,291 3 Claims. (Cl. S40-e276) This invention relates to an alarm system, and is concerned primarily with a bell unit that is supplied with signals-over a line leading to the unit.

It is an object of the invention to provide a reliable bell unit that will sound an alarm if attempts are made to defeat it, and that can if necessary supply power to a unit remote therefrom where disturbances are to be detected.

The invention is illustrated by way of example in the accompanying drawings in which:

FIG. 1 is an electrical circuit diagram of apparatu that is located in a vault;

FIG. 2 is an electrica-l circuit diagram of a bell or alarm unit that is located outside the vault but is electrically connected to the unit of FIG. l;

FIG. 3 is a plan view of a clock 'for the vault unit;

FIG. 4 is a partly sectional side view of theclock; and

FIG. 5 is an enlarged sectional view taken along the vertical plane indicated by the line 5-5 in FIG. 3.

The bell or alaim unit of FG. 2 can be'mounted on an outside wall of a bank, preferably at a relatively inaccessible location. .All parts of the unit are housed in a sealed box, from which a line runs to the vault unit` of FIG. 1, the line consisting of a pair of wires .1G and 11.

The wires and 11 normally carry an oscillatory signal from the vault unit to the remote alarm unit. As will presently be explained, when this signal is `present a bellV 13` (or other annunciator) in the alarm unit is prevented from ringing.

The wires 10 and 11 also conduct D.C. charging current to a six-volt battery 14 in the alarm unit.v The D.C.

`so that only asmall current flows through the lamp 16, the lamp is cold and its resistance is low. lf, howeyer,

a short should occur across the wires 1() and 11, the lampr would .have substantially full battery voltage connected across'it, 'causing the lamp `to heat rapidly. Thevlamp has a high positive temperature coeicicnt of resistance, and therefore Vits resistance quickly rises toplace only a small load on the batteryy and prevent its rapid discharge. Consequentlyif a burglar shouldattempt to `defeat the 'system by shorting the wires 10 and 11 hewould not succeed in'quicltly dischargingfthe battery to. deprive the system of a power source for ringing thebell 13.

'Although the lamp filament is nonffusible by current from the battery 14, if a high voltage wcre'placed across the wires 1t) andll -with the'object of destroying the bat- Itery, the lamp 16 would burn out and thereby protect the;

10 and 1l passem'hrough a 'capacitor-17 to a resonant reed receiver 18. The signal causes reed contacts 19 to maltel appears, the rc'ed` contacts 19 remain open, thel transistor 23 goes ofi, the transistor valve 24 turns on, and current flows through a' relay coil 28 to close relay contacts 29 and energize the bell 13 from the battery 14.

Now'referring to the vault unit (in the claims referred to as the rst unit) shown in FIG. 1, a power supply 30 is supplied from an A.C. line 31. The power supply 30 includes arectifier and lter (not shown)` for supplying six-volts D.C. across the wires 1G and 11 which run to the alarm unit of FIG. 2.. A capacitor 32 is the final smoothing capacitor of the lter. The power supply 30 furnishes charging current for the battery 14 of the alarm unit and also supplies power for the vault unit, the sole battery in the system being the one in the alarm unit. This battery 14 supplies power for the whole system if the A.C. supply on line`31 should f a hil the lamp 16 and choke 15 being non-rectifying andthus permitting flow of D.C. from the battery 14 to the vault unit. Because charging current is normally supplied to the battery 14 over the wires 10 and 11, the battery can be relatively small and yetl have a long life. v

The oscillatorysignal for the`wires 10 and 11 is supplied by a tuning fork oscillator ,33. Power for the oscillator is supplied by the power supply 30 through a choke 34. (which keeps the oscillatoryy signal out of the power supply) Aand through a coil 35 and diode 36. The oscillator is self starting, and thus `generates an oscillatory signal as soon as it receives power. The signal fronrthe oscillator passes through a capacitor 37 to the wire 10. It also passes through a capacitor 3S, is rectified by diodes 39, 4l) and lilteredby a capacitor 41 and resistor 42, and applied across an emitterbase resistor 43 of a transistor amplilier 44." The signal holds the transistor 44 on. A further transistor 45, biased by a resistor 46andkdiode 47, is held inoperative by the potential drop across resistor 4S when the transistor 44 is on. 1f the signal from the oscillator should momentarily fail (causing the bell v13 to ring),'transistor 44 would turn off, causing transistor valve 45 to turn on. This shunts the oscillator 33 so that its signal remains oil'. The` D C. currentithrough the coil 35 is increased. As will be more ful-ly explained, the coil 35 is part of a timer and when actuated by the increasedD.C. current it requires a predetermined time to elapse (forexample, fteen minutes, during which the bell 13 continues to ring) and then momentarily closes p from being shunted through` the oscillator when the switch 49 isclosed'. A

A further transistor 24,-biasedby a re-V i 'If the line 10, 11 is momentarily opened, the oscil latory signal lto the alarm unit is lost and the bell rings. The power supply 39 loses part of -its load, and itis deliberately lgiven poor voltage'regulalion so that itsD.C. l output voltage rises. This risc' in voltage ,causes a Zener v diode S1 to' conduct, causingv a voltage droplncrss a resistor 52 and thereby biasing the oscillator off.' This 'causes the transistor valve 45 to be turned;.`on, shunting 'the oscillator, so that the aforementioned predetermined time must again clapse before the oscillator canfcome on again. The amount of hum in the powersupply 5t) also changes if the line 10, 11 is open circuited, and this change in the operation of the power supply'could, instead of its rise in voitagc, be sensed to render the-oscil lator inoperative.

53d which areganged`togetlier and which are moved to the position shown in FlG. lat times whenfthe system is to be on guard against intruders. In sericswith the switch 53u is a door switch 5i which closesit anintruder The vault unit has several switches 53a, S3b, 53o and.

- blocks the oscillator output signal.

. o enters. This shunts the power supply and the oscilv latory signal, and the bell in the alarm unit rings as long as the switch 54 remains closed. When the switch 54 is reopenedthe time delay required to charge the cai' actuates the timer coil 3S, and holdsthe oscillator 0t`t`l until the timer closes the switch 49.

Another switch 531: connects a microphone 55 to the input of an audio amplifier 56. Tmn'rissupplied with DC. from the supply 39 through a choke 57 which A Zener diode 58, resistor 59 and capacitor 60 maintain a constant D.C. voltage supply to the amplier so that the/gain of the amplier doesnot vary. The output of the amplifier passes through a capacitor 61 and is rectified by diodes 62 and 63 Y vto turn off the transistor 44 in response to a noise picked up by the microphone 55. This turns on the transistor 45, which actuates the timer coil 35 and turns oft' the oscillator ,33 until th'predermined time has elapsed. If

desired the audio amplifier can include a short term i memory'circuit which requires a microphone noise signal that exceeds a given level or duration before turning off the transistor 44.

It will be apparent that the usual teller buttons, in"

dicator lights and the like can be connected into the systcm by the switches 53C and 53d. A line can also be runl to an alarm in the police station, to alert the police when the system is disturbed. Anti-tamper switches can be provided in parallel with the switch 54 to close if unau-V I `at,72a with the spindle to rotate therewith. Between a shoulder 73 near the lower end ofthe sleeve and a metal .washer 74 near its upper end -is a stack of metal discs numbered from 75 to 81. Thavasher 74 is held against the stackof discs by a clip S2 sprung into. a groove of the sleeve.A The

discs

77 and 79`are not keyed to the sleeve,` but the sleeve vhas a at 72b to which the discs, other than 77 andv 79, conform so that they must rotate CIK (which will be KThursday morning for the arrangement shown) the arm rD comes opposite the pointer 85. The arm D, is sntiicintly long to contact a vertical pin 8'), designated THUR. (for Thursday), mounted on an ad-l jacent rotatable day wheel 90. The arm D by engaging the pin THUR. rotates the. wheel 90 until the pin THUR.

reaches approxiamtely the position formerly occupied by the pin WED., i.e., a posilionopposite'a stationary pointerA 91, when the arm D is no longer `long enough to continue engaging the pin THUR. and the wheel 90 ceases its movement. As the pin THUR. is moved by the arm D past lthe switch arm S3 (at 600 am.) it encounters the arm 3S and moves 'itto the left (Le. to the position illustrated in FIG. 3), switching the system to the oit guard condition. vThe pin SUN. I 1is shown 'pulled lup relatively to the other day pins on the wheel 9d so that vwhen it is the turn of the SUN. pinto be moved bythe arm D past the switch arm 8S the SUN. gn fails tostrilze the arm SS and the system remains on guard, Sunday being a holiday; If however authorized persons planned to work inthe bank on Sunday, the: SUN. pin would be pushed down to a position like that shown for the other pins, and in its down positiomas the SUN. pin was moved past the switch arm S8 (under the intiuence of the arm D at 6:00 am. Sunday), it wouldeneeamter the arm SS and push it to the left, switching the system to the ofi guard condition. v Thus, whethein a given day the system is to be'off guard vfrom 6:05 am. to l6:00 p.1n. depends on whether the pin forjhuat day is pushed down. The arm N ensures that the system isvonguardevery night'from 6:00 p.m. to 6:00 am. The houtwhich the arms o pin; when the arm D disengag'es a pin, Ait has pushed the with the sleeve. A nut 83, threaded onto the end of the A' spindle, is normally tightened 'clown against the washer 74 to compress the stack .and force the

discs

77 and 79 to rotate with the sleeve and spindie. Thus the stack of discs forms part of the constantly driven mechanism of the clock. This mechanism rotates once every twentyfourhours in the direction of the arrow S-l`in FIG. 3, and

-the top disc 81 has adialfSla to show the time ofiday opposite a stationary pointer representedin FIG. 3 by labelled'D (for day) at 6:00 am.' For these settings thc switches 53h to 53d are to be moved to the on guard position of FIG. l at 6:00 pm. and are to be moved to their other, o'r off guard position, at 6:00 am. as theclock mechanism rotates from`thc time'of day indicated in PIG. l3 (9:00 am.) to-6:0O p.'ni. the arm-N Hcomes/opposite the pointer 85 and at the underside of the arm N a lng 87 comes into contactwitn-a .sv/itch arm ht about its axle 88,- t'orcingthc armtdivot to the r' 83a and moving thc ganged 'switches a to 53d to thc onl guard position. At 6:00 aan. the -follow ing morning GUS,

wheel 9i)l slightly beyond thispcorrect position so that next time around the arm D might jam or bind on theI lnext pin, but the'dtent 92-by seating in a conical recess Y93 pulls the wheel back to the correct position for the .next engagement; Thus each day the wheel is turned inner hub 96a journallcd onl the spindle 71 and sleeve .72. Y

. Fixed within the cup, and coaxial lwith the disc 75, is the .'timcPeeih-Z'rndtich Vis' connected into'the circuit of FIG.

v1.by flexible leads 97 (FIG. 3). When the coil 35 isnot energized` by current'lowing through the transistor 45,

`thecup-96 restsfon -thewasher 95, .andI an arm 9611 iix'ed to thecu'p is'held-.by a spring-9S againsta stop 99 so that the cup is held stationary' asjthe'clock mechanism rotates."` The cup 96 andthe discs 75 and 76 are of magnctizable material, whereas' the washer )5 is "of nonmagnctizable material. When the timer coil 35 is actuated i by the ,transistor 4S, the cup 96 and coil 35 are attracted clutch .that is c'nga'geablc with the driven mechanism of t-hc clock.' After this clutch has rotated through an arc corresponding to a predetermined time of, say, iiftecn` il? of'FlG.` 1. Asprcrt-'iously explained, this. causes the f 3,266,031 s 5 A 6 coil 3S to be deactuated,.so that the clutch disengages and current overv the line to the battery, non-rectifying resisthe spring 98 restores the Vclutch to its initial position tive means'connected in series between the line andthe where the arm 96b is held against the 'stop 99. Therebattery to conduct the charging current whereby the fore whenever a disturbance puts the system vinto an alarm charging current flows through the resistive means and, in

state, that state is maintained for at least fifteen minutes 5 the event of a failure of the power supply, current Hows by the operation of the clutch. The contact 49b arrests from the battery through the resistive means and the line the movement of the Clutch, So thatk if for any reason the to power the rst unit, the resistive means having normally Coil 35v failS t0 be deatllaed When the Switch 49 iS arelatively low resistance, being relatively unheatetl by s closed, the clutch simply slips relative to the clock mechthe charging current, being non-fusible by the current that anism. 10 ows through it from the battery in the event of a short The disc 75 is thin and flexible and slight-ly distorted circuit condition across theline but being rapidly heated so that 1t does not lie perfectly flat against the disc 76. by the last mentioned current and having a high positive The disc 75 S also resilient, 50 that lt PfoSses the clutch temperature coelicient of resistance whereby the resistdownwardly to assist lts dlseneftomeot- Part of the i ance of the resistive means rises rapidly inthe event' of dSC 75 S always touolllng the CUP 95 to facilitate @Stlb- 15 such a short circuit condition to prevent rapid discharge lShmerlt Of a good magnetic flux Path through the CUP 0f the battery, and Vvmeans responsive to a short circuit 96 and diSCS 75 l'dnd 76 When the Coil 35 iS again enefcondition across "tHe-line to operate the switching means l sized; thus only a Small. amount Of power is required t0 to connect the annunciata across the battery. Z engage thev clutch. 2. An alarm system as claimed in claim 1, whereinuthe The electrical power requirementsof 'the alarm system 20 resistive means is a lamp.

are not hoaVY, SHCC tho System l5 devoid 0f elootfomg- 3. An alarm system' as claimed in claim 2, wherein the neticw relays save for the relay 28 in the alarm unit, and first unit includes means for supplying a signal to. thcv this relay is not normally energized. Thus the single batline in addition to the charging current, the means rctery 14 can operate the system in the event 0f a failure 0f sponsive to a short circuit condition comprising a receiver the power source that supplies the line 31. The tran- 25 responsive to said signalprevent operation of the sistorized circuits of FIGS. 1 and 2 are highly reliable, switching means andsresponsive to loss of said signal, and the systemis more stable and -less costly than conthrough such a short circuit, to operate the switching ventional alarm systems 'that employ balanced relays. means, i l

lThe mecahnically wound clock serves both to change the mm u condition of the system from on guard to off guard and 30 References Cited bygtheExaminer t0 move the Clutch, S0. at the Clutch and 10k,mel}* Y J Y- UNITED STAT'Fis'.'lftrnNrs efrve as um and novsepafatly drive met 1S 755,669 3/19o'4^ Hutchison 320548 t per second. Thus a burglar who does not have rather 35 1'610205 12/ 1926 Fitfs i complex equipment cannot'ascertain what-type of signal 1,759,745 5/1930 Gnmfiltch' is being transmi-tted iby the wires 10 and 11 to preventv 11837338 12./1931 Vencim rr 32o-48 X an alarm. He can readilyme'asure the six volts D.C. f 2064'533 12/1936' Grant-L; across the wires 10 and 11 but if he connects a six volt:Y '2286101 6/1942 NQ-rd'berv-u 340-249 Abattery across the wires 10 and 11, expecting that this 40 2,419,957, 5/1947 Laforfl -L 340-276 will hold the bell inoperative, hewill short out the oScil- 21696524 12/1954 Huntington' "1"" 179-5 latory signal and cause the bell'to ring. Even if he can 23.01"' 874 2/1955 Mears 340-"276 -more dicult by using a signaldevice 33am a receiver 3,149,320- 9./1964 Deyme 340-276 kX 1`8y capable of working at ultrasonic frequencies which Y. s v o grntlbe heard by tapnms earphones MOSS the WlfeS 10 50 3,209,230 9/1965 Mas 32,) 48 X WhatIclairnisz v I 1. An alarm system comprising arst unit having Y FOREIGN PATENTS means for detecting a disturbance, an alarm. unit remote 347,761 4/1931 aEngland.

from the first unit, the alarmunit including a battery, f .704,779v 3/1954 England. an annunciator, andv switching means operable to connect '55 #542,295 Y 8?{1950 Great Britain.

the annunciator across thev battery in order to operate the v v annunci'ator, a line connecting the lirst unit and the alarm l NEL C- BEAD, Primary Examinerunit, adirect current power supply connected across the AN, ASSI-Smm ExammehV 1in`efor powering the first unit and supplying charging d y Y

Claims

1. AN ALARM SYSTEM COMPRISING A FIRST UNIT HAVING MEANS FOR DETECTING A DISTURBANCE, AN ALARM UNIT REMOTE FROM THE FIRST UNIT, THE ALARM UNIT INCLUDING A BATTERY, AN ANNUNCIATOR, AND SWITCHING MEANS OPERABLE TO CONNECT THE ANNUNCIATOR ACROSS THE BATTERY IN ORDER TO OPERATE THE ANUNCIATOR, A LINE CONNECTING THE FIRST UNIT AND THE ALARM UNIT, A DIRECT CURENT POWER SUPPLY CONNECTED ACROSS THE LINE FOR POWERING THE FIRST UNIT AND SUPPLYING CHARGING CURRENT OVER THE LINE TO THE BATTERY, NON-RECTIFYING RESISTIVE MEANS CONNECTED IN SERIES BETWEEN THE LINE AND THE BATTERY TO CONDUCT THE CHARGING CURRENT WHEREBY THE CHARGING CURRENT FLOWS THROUGH THE RESISTIVE MEANS AND, IN THE EVENT OF A FAILURE OF THE POWER SUPPLY, CURRENT FLOWS FROM THE BATTERY THROUGH THE RESISTIVE MEANS AND THE LINE TO POWER THE FIRST UNIT, THE RESISTIVE MEANS HAVING NORMALLY A RELATIVELY LOW RESISTANCE, BEING RELATIVELY UNHEATED BY THE CHARGING CURRENT, BEING NON-FUSIBLE BY THE CURRENT THAT FLOW THROUGH IT FROM THE BATTERY IN THE EVENT OF A SHORT CIRCUIT CONDITION ACROSS THE LINE BUT BEING RAPIDLY HEATED BY THE LAST MENTIONED CURRENT AND HAVING A HIGH POSITIVE TEMPERTURE COEFFICIENT OF RESISTANCE WHEREBY THE RESISTANCE OF THE RESISTIVE MEANS RISES RAPIDLY IN THE EVENT OF SUCH A SHORT CIRCUIT CONDITION TO PREVENT RAPID DISCHARGE OF THE BATTERY, AND MEANS RESPONSIVE TO A SHORT CIRCUIT CONDITION ACROSS THE LINE TO OPERATE THE SWITCHING MEANS TO CONNECT THE ANNUCIATOR ACROSS THE BATTERY.