US3266030A - Alarm system - Google Patents

Description

RI/EYSAd 3 Sheets-Sheet 1 J j N .n m m ln In INVENIOR JOHN A SADLER Bhf/07% ATTO no mv Tlv om. W\Nm mSx m/.m f,

ALARM SYSTEM J A SADLER' Aug. 9, 1966 Aug.9,1966 J.A.SADLER I 6,266,030"

ALARM SYSTEM Filed Des.v so, 19:55 s sneets-sheet Vv2 A118" 9 1956 J. A. SADLER k f- 3,266,030

' ALARMsYsTEM jl Filed Deo. so; 196s s 4sheets-sheet a FIG.;

K l 72b 1 I y Y Y g" u i 7a' y d FlG. 5^ 73- I -4 LL INVENTOR i W 1 JOHNASADLE swf/Ky l n A, ATTORNEYS i l l signal holds the transistor 23.0n. v 24, biased-by a resistor 25 and diode 26, is held ofi by 3,266,030 ALARM SYSTEM` John A. Sadler, Rexdale,-Ontario, Canada, assigner, by mcsne assignments, to Chubb-Mosler and Taylor Safes Ltd., Brampton, Ontario, Canada, -a corporation of Canada Filed Dec. 30, 1963, Ser. No. 334,290

4 Claims. (Cl. 340-276) This' invention `relates to an alarm system, primarily to a system for protecting a vault having an alarm bell outside the vault.

It is an object of the invention to provide a'highly reliable alarm system. In carrying out the invention it ispossible to achieve a stable system free of conventom al balanced relays. The system can employ an oscillatory signal that is not easily measured.

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

FIG. 1 is` an electrical circuit diagram of apparatus that is located inavault;

FIG.v 2 is an electrical circuit diagram of a bell or alarm unit that is located outside the vault but is electrically connected to the unit of FIG. 1f

FIG. 3` is a plan view of a clockffor the vault unit; FIG. 4 is a partly sectional side view ofthe clock; and

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

The alarm unit of FIG. 2 can be mounted on an outside wall of a bank, preferably-.at a relatively inaccessible location. Allparts of the unit are housed in a sealed box, from which a transmissionlnejuns to -the vault unit of FIG. 1, the line consisting of a pair of wires 10 and 11. The wires 10 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 bell 13 (orother annunciator) in the alarm unit is prevented from ringing.

The wires' 10 and 11 also conduct D.C. charging current to to a six-volt battery 14 Vinthe alarm unit. The D.C. flows to the battery through a choke 15, which impedes the oscillatory signal, and through a lamp 16. The

lamp 16 is not employed to give a visual indication; rather it vis a. convenient electrical resistive means.

knormal conditions there is a D.C. voltage across the wires 10 and 11 substantially equal to the voltage of Under battery 1 4, so that only'a small current liows through the lamp '16, thelatnp is cold and its resistance is low. 1f,

succeed i'n quickly 'discharging the battery to deprive the system of a power source for ringing'the bell 13. lf a high voltage were-placed across the wires'10 and 11 with the objecty of destroying thebattery, the. lamp 16' would burn out'nnd thereby protect thc battery.

The oscillatory signal normallyi'supplied over thewires-10 and llpasses through n capacitor 17 to'a resonant reed receiver 18. The signal causes reed contacts 19 to make and break alternately,` thus supplying a pulsating D.C\. output signal which is `iiltered by a capacitor 2O and resistor 21 andapplied across an emitter-base -rcsistor 22 of a transistoramplficr23- This A further transistor the potential drop across resistor 27 vwhen the transistor azsaosu Patented August 9, 1966 2 Y 23 is on. If the oscillatory signal supplied over the Wires 10 and 11 disappearsfthe reed contacts 19 remain open, the transistor 23 goes om, theV transistor valve 24 turns on, and current flows through a relay coil 23 to closev relay contacts 29 and energize the bell 13 from the battery 14.

Now referring to the vault unit shown in FIG. 1, a power supply 30 is supplied from an A.C. line 31. The power supply 30 vincludes a rectifier and filter (not shown) for supplying sixwolts. D.C. across the wires 10 and lhwhich run to the alarm unit of FIG. 2. A capacitor 32 is the tinal smoothing capacitor of the filter. The power supply 30 furnishes charging current for the battery 14 of the alarm unit andl also supplies power foi 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 AC". supplyon line 31 should fail. Because charging current is supplied to lthe battery 14 over the wires 10 and 11, the battery can be relatively smalland yet have a long life. i

The oscillatory signal for the, wires 10 and 11 is supplied by a tuning fork oscillator l33. Power for the oscillator is supplied by the powersupply 30 throughy a choke 34 (which keeps the oscillatory signal out of the power supply) and Vthrough 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 froml theV sistor 52 and thereby biasing the yoscillator ott.v This' oscillator passes through a capacitor 37 tothe wiref'10. It also passes through a capacitor 38, is rectified by diodes 39, 40 and filtered by a capacitor 41 and resistor 42, and applied across an einitter-baseresistor 43 offa transistor amplifier 44. The signal holds :the transistor 44 on. A further transistor 45 biased by a resistor 46- and diode 47, is held inoperative by the potential drop acrossiresistor 4S when the transistor' 44 is on. If the signal from the oscillator should momentarily fail (causing the bell 13 to ring),ftransistor' 4'4` Wouldvturn olf, causing transistor valve 45 to turn o n. This shunts the oscillator 33 .so that its signal remains; off'. The D.C. current through the coil 35is increased.. As will be more fully explained,

sistor 45 and thus remove the DC. which actuated the timer coil 35. A .choke 5t) prevents the oscillatory signal from beingshunted through the oscillator when the .switch 49 is closed.-

`If thel line 10, 11 is momentarily opened, the oscillatory The. power supply 30 loses part yof its load, and it is de? signal lto the alarmnsnit is lost/and the bell rings.

Vlibcrately given po'or voltage regulation 'so thatits D.C. -output voltagehrises. This -rise in voltage causesa Zener .diode 51 to conduct, causing a voltage drop across Ya re-l -ca usesthe transistor valve 45 to be turned on, shunting the oscillator, so that the aforementioned predetermined time must again elapse before the oscillator-can come on again. The amount of hum in the power supply 30 also changes if the line l'tl, 11 is open circuitcd, andiths change inthe operation ofthe power supply could, instead of its.` rise in voltage, be sensed to renderthe oscillator inoperative;

`The vault unit has several switchesiSSmSBb, 53e and dewhich al@ gauged together and which are moved to the position shown in FIG. l at ltimes when the system is to be on guard against intruders. In series with the switch. 53a is a door switch 54 which closes if an intruder enters.- This shunts the power supply 30 and the oscilla- -tory signal, and the bell in the alarm -unit rings as 4long as the switchl 54 remains closed. When the switch 54 is reopened, the time delay required to charge the capacitor 41 prevents the transistor valve'44 -from turning on before the transistor valve45, so that in response to the resumption of power the latter transistor 45 turns on, actuates the timer coil 35, and holds the oscillator oft until the timer closes the switch 49.

Anotherswitch 53b` connects a microphone 55 to the input of an audio amplifier 56. The amplifier is supplied with D C. from the supply 30 through a choke 57 which blocks the oscillator output signal. rA Zener diode 58,

resistor 59 and capacitor 60 maintain a constant D. C. voltage supply to the amplifier so that the gain ofthe amplier does not vary. The output of the/amplifier passes through a capacitor 61 and is rectified by diodes 62 and picked up by the microphone 55. This turns on the transsistor 45, which actuates the timer coil 35 and turns off the oscillator 33 until the predetermined time 4has elapsed. If desired the audio amplifier can include a short term nal that exceeds a given level or duration before turning olf the transistor 44.

It will be apparent that the usual teller buttons, indicator lights and the like can be connected into the system by the switches 53e` and 53d. A line `can also be run to 63 to turn off the transistor 44 in response to a noise 'memory circuit which requires a -microphone noise sig-V 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 unauthorized persons seek access to the vault or alarm units.

FIGS. 3, 4 and 5 showrarclock for operating the casing 69 a conventional mechanically wound spring driven mechanism that will operate for at least fourteen i `switches 53b, 53b, 53e and 53:17. The clock has, within a M days without rewinding. The mechanism can be wound by means of a shaft 70. A rotatable spindle 71 of the clockmechanism protrudes upwardly from the casing around the shaft 70. .Around the spindle is a sleeve 72 keyed at 72a with the spindle to rotate therewith. Be-

tween a shoulder 73 near the lower end of the sleeve and with the sleeve.

a -metal Washer 74 near its upper end is a stack of metal discs numbered from 75 to,. 8 1. The washer 74 is held against the stack of discs by a clip 82 sprung into a groove of the sleeve.

other than 77 and 79, conform so that they must rotate A nut 83, threaded onto the end of the spindle, is normally tightened down against the washer 74 to compress the stack `and force the discs 77 and 79 to rotate with the sleeve"V and spindle. Thus the stack of discs forms part of the constantly driven mechanism of fthe clock. This mechanism rotates once every twentyfour hours in the direction of the arrow 84in FIG-3, and

-the top disc 81 has adial 81a to show the time of day opposite a stationary pointer represented in FIG. 3 by an arrow 85, the time indicated in FIG. 3 being 9:00am. If

this time indicated should happen tox'be incorrect, knobs 86 on the disc 81 can be yused to rotate the clock mecha- ``53a to 53d are to be moved tothe on guard position ofv FIG. 1 at 6:00 pm. and are to be moved to their other, or off guard position, at 6:00 a.m. Thus, as the clock nismmanually andfset the correct time opposite theV vpainter 85.` The dise 79 has 'an arm labelled D and the disc 77 has an arm labelled N. In FIG. 3 the arm labelled N (for night) vis set at'6:00 pm. and the arm labelled D (for day)'at 6:00 a.m. For these settings the switches fmechanism rotates from the time of day indicated in FIG. 3.(9z00 am.) to 6:00pm. the arm N comes oppov site the pointer and at the underside of the arm N a lug 87 comes into contact with a switch arm 88, forcing the arm 88 to pivot toA ht h e right about its axle 38a and moving the ganged switches A53rzto 53d-to the on guard position. At 6:00 a.m. the following morning (which y The discs 77 and 79 are not keyed to the sleeve, but the sleeve ,has a flat 72b -to which the discs,

.will berThursday morning forthe arrangement shown) the arm D comes-:opposite the pointer 85. The arm D is sufficiently long to contact a vertical pin 89, designated THUR. (for Thhrsday), mounted on an adjacent rotatable day wheel 90. The arm D by engaging the pin THUR. rotates the wheel 90 until the pin THUR. reaches approximately 4the position formerly occupied by the pin WED.,

i.e., a position opposite a stationary pointer 91, when the arm D is no longer long enough to continue engaging the pin THUR.` and the wheel 90 ceases its movement. the pin THUR.` is moved by the arm -D past the switch arm 88 (at 6:00 am.) it encounters the arm 88 and moves it-to the left (Le. to the position illustrated in FIG. 3), switching thesystem to the oft' guard condition. 'The pin SUN. is shown pulled up relativelyto the other day pinsr on the wheel 90 so that when itis the turn ofthe SUN.4

pin to bemoved by the'arm D past the switch arm 88 'the SUN. pin fails tof-strike the arm 88 and the system remains on guard, SundayY beb'gig a holiday. If however authorized persons planned to work in the bank'on Sunday, the SUN. pin would be pushed -down to a position like that shown for the' other pins, and .in its down position, as the SUN. pin was moved past thenswitch arm 88 y(under the influence of the arm D at 6:00 a.m. Sunday), it would encounter the arm 88 and'push it;v to the left,

vswitching vthe system to the voiir-gifrd condition. Thus,

whether on a givenday thesystem is to be otf guard from 6:00 a.m. te 6:00 p.m. 'dpends on whether the pin for that day is pushed down. The arm N ensures that the system is on guardjgg'yhnight from 6:00 p.m. .to 6:00 am. The hours for which thFFms Dpnd N are set can be changed by loosening the nut SSf-xdrotating the arms tdnew positions relative to the dial markings 81a.

' To ensure that the wheel`f90`is properly positioned after the arm D disengages a pin, there is provided at the underside of the wheel A90 a detent 92 which is spring pressed 'upwardly to center in neof seven conical recesses 93- located radially inwardly from the pins. The detent 92,

when centered in a recess'93, positions the wheel 90 correctly for the next engagement of the arm D with a day pin; when the arm D disengages aV pin, it has pushed the wheel 90 slightly beyond this correct position so that next time around the arm D might jam or bind on the next pin,

but the det'nt 92 vby seatinggina conical recess 93 pulls the wheel back to the correct position for thenext engage.-

l ment. Thus each day thevvheel 90is turned one seventh -of a revolutionby the clock mechanism. Thepins are f 1 not easily removed from the day wheel, and spring pressed detents 94 which seatA in necks 89a of the pins facilitate positive location of the pins in their pushed down or f pulled up positions.

Below the lowermost disc 75 of the clock mechanism,

. and resting on a liber washer 95, isa c'up 96 having an Binner hub 96a journalled on the spindle 71 and sleeve 72.

Fixed within the cup, and coaxial-'with the disc'75, is thel v timer coil 35 which is connected into the circuit of FIG. 1v 1 by fiexible leads-97 (FIG. 3). When the coil 35 is not .'energiedfbyeciirrent flowing through the transistor 45,

l the cup 96 restson the washer 95, and an arm 96b lixed to" v the cup is held by a spring 98 against a stop 99 so that thev `cup isheld stationary as -the clock mechanism .rotates4 4rI "he cup 96 and the discs 75 and 7'6 are of magnetizable *.ntaterial, whereas thc washer is of non-magnetizablc'.

When the timer coil 35 is actuated by the j `f material. 'transistor 45, the cup 96 and coil 35 are attracted to the discs 75 and 76 and move upwardly into close engagement with the disc 75 and begin to rotate therewith. Thus the 2 cup 96 and coil 35 constitute an electromagnetic clutch 'that is engageable with the driven mechanism of the encountersa stationary contact49b. closing' the switch 49,

of FIG. l. As previously explainedfthis causes the coil]l 35th be deactuated, so that the clutch disengages andthe' clock.` After this clutch has rotated through an'arc corresponding to a predeterminedtime of, say, `fifteen minutes on the dial 81a, a Contact 49a on-t-he clutch arm 96b AsA spring 98 restoresthe clutch to its initial position where the arm 96b is held against the stop 99. Therefore whenever a disturbance puts the system into an alarm state, that state is maintained for at least fifteen minutes by the operation of the clutch. The vcontact 49D arrests the movement of the clutch, so that if for any reason the coil 35 fails to be deactuated when the switch 49 is closed, the clutch simply slips relative to the clock mechanism.

The disc 75 is thin and flexible and slightly distorted so that it does not lie perfectly at against the disc 76. The disc 75 is also resilient, so that it presses the clutch downwardly to assist its disengagement. Part of the disc 75 is always touching the cup 96 to facilitate establishment v of a good magnetic flux path through the cup 96 and discs 75 and 76 when the coil 35 is againenergized; thus only a small amount of power is required to engage the clutch.

The electrical power requirements of the alarm system are not heavy, since the system is devoid of electromagnetic relays save for the relay 28 in the alarm unit, and this relay is not normally energized. Thus the single battery 14 can operate the system in the event of a failure of the power source that supplies the line 31. The transistorized circuits of FIGS. 1 and 2 are highly reliable, and the system is more stable and less costly than conventional alarm systems that employ balanced relays. The mechanically wound clock serves both to change the condition of the system from on guard to off guard and to move the clutch, so that the clutch and clock mechanism serve as a timer and no Aseparately driven timer iserequired. l

The oscillator 33 provides a signal of, say, 2500 cycles per second. Thus a burglar who does not have rather complex equipment cannot ascertain what type of signal is beingtransrnittedjy the wire s .10 and 11 to prevent an al'ain. He caeadilyMrne-:isie the six volts D.C, across the wires 10 and 11 but if he connects a six volt battery across the wires 10 and 11, expecting that this will hold the bell inoperative, he willshort out the oscillatory signal and cause the bell to ring. Even if he can measure the oscillatory signal he cannot easily replace it without special equipment andN without knowledge of the alarm system circuitry. His task can be rendered still more diflicult by using a signa l ,device 33 and a receiver 18 capable of working at ultrasonic frquencieswhich cannot be heard 'by tapping earphones across the wires 10 and 11.

What I claim is:

1. An alarm system comprising an. oscillator for supplying an oscillatory signal,

an alarm at a location remote from the oscillator, Q a transmission line between the oscillator and the alarm N' mating the oscillatory signal to the alarm,

. lit," 6 abattery at 'said remote location for operating the alarm, ,f

a direct curent power suppiy located at thesamc endl v of the transmission line as the oscillator for provid-l ing a directcurrent voltage on the line,

means connecting the battery to the power supply through the line 'for charging the battery by the power supply,

the receiver including means for rendering the alarm operative by the battery 'if the oscillatory signal is not received over the line and despite the presence of direct current voltage on the line, and

disturbance responsive means for interrupting the supply of oscillatory signal to the line whereby the alarmis operated. 4

2'. Analarm system as' claimed in claim 1,- wherein the oscillator'has a direc-t current input normally supplied from the power stipplymlutgogonnected to the line for supply frorn the battery if the power supply fails.

3. An alarm system as claimed in claim 1, includingy x i the timer being operative to restore said interrupted signal at the end interval.

the disturbance responsive means include means responv 30 sive to a change of load orrt-he power supply to render the oscillator inoperative.

`rleferences Gitedby the Examiner UNITED STATES PATENTS 704,779 3/1954 Great Britain.

NEIL C. READ, Primary Examiner.

kR.- M. GOLD'MAN, AsssialIixanzner.

. 4. An'alarm system as claimed in claim 3, wherein

Claims (1)

1. AN ALARM SYSTEM COMPRISING AN OSCILLATOR OF FOR SUPPLYING AN OSCILLATORY SIGNAL, AN ALARM AT A LOCATION REMOTE FROM THE OSCILLATOR, A TRANSMISSION LINE BETWEEN THE OSCILLATOR AND THE ALARM FOR TRANSMITTING THE OSCILLATORY SIGNAL TO THE ALARM, THE ALARM INCLUDING A SIGNAL RECEIVER RESPONSIVE TO THE OSCILLATORY SIGNAL TO HOLD THE ALARM INOPERATIVE WHEN SUPPLIED WITH THE OSCILLATORY SIGNAL BY THE LINE, A BATERY AT SAID REMOTE LOCATION FOR OPERATING THE ALARM, A DIRECT CURRENT POWER SUPPLY LOCATED AT THE SAME END OF THE TRANSMISSION LINE AS THE OSCILLATOR FOR PROVIDING A DIRECT CURRENT VOLTAGE ON THE LINE, MEANS CONNECTING THE BATTERY TO THE POWER SUPPLY THROUGH THE LINE FOR CHARGING THE BATTERY BY THE POWER SUPPLY,

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