US3257654A - Alarm system and clock therefor - Google Patents

Description

June 21, 1966 R H. ROGERS ETAL ALARM SYSTEM AND CLOCK THEREFOR 5 Sheets-Sheet l Filed Deo. 30, 1963 June 21, 1966 R H. ROGRS ETAL ALARM SYSTEM AND @Loox THEREFGR (5 Sheets-Sheet 2 vFiled Dec. 30, 1965 INVENTORS JOHN A. SADLER RICHARD H. ROGERS Bw y, i, ATTORNEYS June 21, 1966 R. H. RCGERS ETAL. 3,257,554

ALARM SYSTEM AND CLOCK THEREFOR Filed Deo. 30, 1963 5 Sheets-Sheet 5 FlG. 3

FIG. 4

FlG. 5

INVENTORS JOHN A SADLER RICHARD H. ROGERS ATTORNEYS 4 is cold and its resistance is low.

United States Patent O 3,257,654 ALARM SYSTEM AND vCLOCK THEREFGR Richard H. Rogers, Toronto, Ontario, and .lohn A. Sadler,

Rexdale, Ontario, Canada, assignors, by mesne assignments, to Chubb-Mosler and Taylor Safes Ltd., Brampton, Untario, Canada Filed Dec. 30, 1963, Ser. No. 334,296 25 Claims. (Cl. 340-276) This invention relates to an alarm system clock and to an alarm system incorporating the clock.

IIt is an object of the invention to provide reliable and simple timing means for an alarm system. The invention provides a clock for putting the system into its on Iguard condition at desired times, and for timing the duration of -an alarm condition.

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

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

FIG. 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. 1;

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

FIG. 4 is a partly sectional side View of the clock; and

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

The alarm Iunit of FIG. 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 la pair of -wires and 11. The wires 10 and I11 normally carry an oscillatory signal trom the vault unit. As will presently be explained, when this signal is present a bell 13 (or other annunciator) in the alarm unit is prevented from ringing.

The wiresrltl and 11 also conduct'DC. charging current vto a six-volt battery V14 in the alarm unit. The DE.' flows to the battery through a choke d5, which impedes the oscillatory signal, and through a lamp 16. 4The lamp 16 is notemployed to give a visual indication; rather it is a convenient electrical resistive means. Under normal con ditions `there is a D.C. voltage across the wires 10 and 11 substantially equal to the voltage of battery 14, so that only a small current ows through the lamp 16, the lamp l-f, however, a short should occur across the wires 10 and l11, the lamp would have substantially full battery voltage connected across it, causing the lamp to heat rapidly. The lamp has a hi-gh temperature coetlcient of resistance, and therefore its resistance quickly rises to place only a small load on the battery and prevent its rapid discharge. Consequently if a burglar should attempt to defeat the system by shorting the wires 10 and y11 he would not succeed in quickly discharging the battery to deprive the system of a power source for ringing the bell 13. 'If a high voltage were placed across the wires 10 and 11 with the object of destroying the battery, the lamp 16 would burn out and thereby protect the battery.

The oscillatory signal normally supplied over the wires 10 and 11 passes through a 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 'filtered by a capacitor 20 and resistor 2.1 and applied across an emitter-base resistor 22 of a transistor amplier A23. This signal holds the transistor 23 on. A turther transistor 24, biased by a resistor 25 and diode 26, is held off by the. potential drop across resistor 27 when the transistor 23 is on. If the oscillatory signal supplied over the wires 10 and 11 disappears, the reed contacts 19 remain open, the transistor 23 goes off, the transistorvalve 124 turns on, and current flows through ice a relay coil 28 to close relay contacts 29 and energize the bell 13 rfrom the battery 111i.

lNow 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 includes a rectier and lter (not shown) for supplying six-volts DC. across the wires lil and 11 which run to the alarm unit of FIG. 2. A capacitor 32 is the nal smoothing capacitor of the iilter. The power supply 30 furnishes charging current for the battery .14 of the alarm funit and also supplies power for the vault unit, the sole battery in the system being the one in the `alarm Iunit. This battery 14 supplies power for the whole system if the A.C. supply on line 3.1 should tail. Because charging current is supplied to the battery 14 over the wires 10 and 11, the battery can be relatively small and yet have a long life.

The oscillatory signal for the wires 10 and 11 is supplied by a tuning fork oscillator 33. Power lfor the oscillatoris supplied by the power supply 3i) through a choke 34 (which keeps the oscilla-tory signal out of the power supply) and 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 from the oscillator passes through a capacitor 137 to the wire |10. It also passes through a capacitor 33, is rectiiied by diodes 39, 40 and ltered by a capacitor -41 and resistor `4-2, and applied across an emitter-base resistor 43 of a transistor amplifier `411i. The signal holds the transistor 44 on. A further transistor 45, biased by a resistor 46 and diode 47, is held inopera-tive by the potential drop across resistor Sii when the transistor 44 is on. If the signal `from the oscillator .should momentarily fail (causing the bell 13 to ring), transistor 44. would turn ofi, causing transistor valve 45 to turn on. This shunts the oscillator 33 so that its signal remains off The D.C. current through the coil 35 is increased. As will be more fully explained, the coil 35 is part of a timer of the clock of this invention, 4and when actuated by the increased D.C. current the timer requires a predetermined time to elapse (for example, tifteen minutes, during which the bell 13 continues to ring) and then momentarily closes a switch 49. This supplies suilicient voltage to the -oscillator 33 to resume its operation, so that the oscillatory signal can reappear .to turn off the bell 13 and the transistor 45 and thus remove the D C. which actua-tes the timer coil 35. The oscillatory signal thus normally holds the coil 35 inoperative. A choke 50 prevents the oscillatory signal from being shunted through the oscillator when the switch 49 is closed.

If the line lll, 11 is momentarily opened, the oscillatory signal to the alarm unit is lost and the bell rings. The power supply 30 loses part of its load, and it is deliberately given .poor voltage regulation so that its D.C. output voltage rises. This rise in voltage causes a Zener diode 51 to conduct, causing a voltage drop across a resistor 52 and thereby biasing the oscillator oit. This causes the 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 10, 11 is open circuited, and this change in the operation of the power supply could, instead of its rise in voltage, be sensed to render the oscillator inoperative.

The Vault unit has - several switches 53a, 53h, 53C, and 53d which are ganged together and which are moved to the position shown in FIG. 1 at times 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 3@ and the oscillatory signal, and the bell in the alarm unit rings as long as the switch 54 remains closed. When the switch 54is Patented June 21, 1966 reopened, the time delay required to charge the capacitor 41 prevents the transistor valve 44 from turning on before the transistor valve 45, so that inA response to the resumption of power the latter transistor 45 turns on, actuates the timer coil 35, and holds the oscillator off until the timer closes the switch 49.

Another switch 53b connects a microphone 55 to the input of an audio amplifier 56. The amplier is supplied with DC. from the supply 30 through a choke 57 which blocks the oscillator output signal. A Zener diode 58, resistor 59 and capacitor 60 maintain a constant DC. Voltage supply to the amplifier so that the gain of the amplifier does not vary. The output of the amplifier passes through a capacitor 61 and is rectified by diodes 62 and 63 to 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 off the oscillator 33 until the predetermined time has elapsed. If desired the audio amplifier can include a short term memory circuit which requires a microphone noise signal that exceeds a given level or duration before turning off the transistor 4d.

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 an alarm in the police station to alert the police when the system is disturbed. Anti-tamper switches can be provided in parallel withthe switch 54 to close if unauthorized persons seek access to the vault or alarm units.

FIGS. 3, 4 and 5 show a clock for operating the Vswitches 53a, 53h, 53C and 53d. The clock has, within a casing 69 a conventional mechanically wound spring driven mechanism that will operate for at least fourteen days without rewinding. by means of a shaft 70. A rotatable spindle 71 of the clock mechanism 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. Between a shoulder 73 near the lower end of the sleeve and a metal washer 74 near its upper end is a stack of metal discs numbered from 75 to S1. The washer 74 is held against the stack of discs by a clip 32 sprung into a groove of the sleeve. The discs '77 and 79 are not keyed to the sleeve, but the sleeve has a fiat 72b to which the discs, other than 77 and 79, conform so that they must rotate with the sleeve. 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 and spindle. Thus the stack of discs forms part of the constantly driven mechanism of the clock. This mechanism rotates once every twentyfour hours in the direction of the arrow 84 in FIG. 3, and the top disc 81 has a dial 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 9:00 a.m. If this time indicated should happen to be incorrect, knobs 86 on the disc 81 can be used to rotate the clock mechanism manually and set .the correct time opposite the pointer S5. The disc 79'has an arm labelled D and the disc 77 has an arm labelled N. In FlG. 3 the arm labelled N (for night) is set at 6:00 pm. and the arm labelled D (for day) at 6:00 am. For these settings the switches 53a to 55d are to be moved to the on guard position of FIG. 1 at 6:00 p.m. and are to be moved to their other, or olf guard position, at 6:00 am. Thus, as the clock mechanism rotates from the time of day indicated in FIG. 3 (9:00 am.) to 6:00 pm. and the arm N comes opposite the pointer S and at the underside of the arm N a lug 87 `cornes into contact with a switch arm 88, forcing the arm 88 to pivot to the right about its Vaxle 88a and moving the ganged switches 53a to 53d to the on guard position. At 6:00 am. the following morning (which will be Thursday morning for the arrangement shown) the arm D comes opposite the pointer 85. The arm D is sufficiently long to Contact a Vertical pin S9,

The mechanism can be wound designated THUR. (for Thursday), 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 the 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. As the pin THUR. is moved by the arm D past the switch arm 8S (at 6:00 a.m.)l it encounters the arm 8S and moves it to the left (ie. to the position illustrated in FIG. 3), switching the system to the o guard condition. The pin SUN. is shown pulled up relatively to the t other day pins on the wheel 90 so that when it is the V6:00 am. Sunday), itwould be encounter the arm turn of the SUN. pin to be moved by the arm D past the switch arm 8S the SUN. pin fails to strike the `arm S8 and the system remains on guard, Sunday being 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 the switch arm 8S (under the influence of the arm D at 33 and push it to the left, switching the system to the off guard condition. Thus, whether on a given day the system is to be oi guard from 6:00 a.m. to 6:00 pm. depends on whether the pin for that day is pushed down. The arm N ensures that the system is on guard every night from 6:00 pm. to 6:00 am. The hours for which the arms D and N are set can be changed by loosening the nut S3 and rotating the arms to new positions relative tothe dial markings Sie.

To ensure that the wheel is properly positioned after the arm D disengages a pin, there is provided at the underside of the wheel 90 a detent 92 which is spring pressed upwardly to center in one of seven conical recesses 93 located radially inwardly from the pins. The

Vdetent 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 a 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 detent 92 by seating in a conical rece-ss 93 pulls the wheel back to the correct position for the next engagement. Thus each day the wheel 90 is turned one seventh of a revolution by the clock mechanism. The pins are not easily removed from the day wheel, and spring pressed detents 94 which seat in necks 89a of the pins facilitate positive location of the pins in their pushed downV or pulled up position-s.

VBelow the lowermost disc 75 of the clock mechanism, and resting on a fiber washer 95, is a cup 96 having an inner hub 96a journalled on the spindle 71 and sleeve 72. Fixed within the cup, and coaxial with the disc 75, is the timer coil 35 which is connected into the circuit of FIG. l by iexible leads 97 (FIG. 3). When the coil 35 is in its normal condition, i.e., not energized by current owing through the transistor 45, the cup 96 rests on the washer 95, and an arm 96b xed to the cup is held by a spring 98 against a stop 99 so that the cup is held stationary as the clock mechanism rotates. The cup 96 and the discs 75 and 76 are of magnetizable material, whereas the washer is of non-magnetizable material. When the timer coil 35 is actuated by the transistor 45, Ithe 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 cup 96 and coil 35 constitute an electromagnetic clutch that is engageable with the driven mechanism of the clock, the coil 35 being an electromagnetic means that is actuable to engage the clutch. After this clutch has rotated through an are corresponding to a predetermined time of, say, fifteen minutes on the dial 81a, a contact 49a on the clutch arm 96b encounters a stationary contact 49b, closing the switch 49 of FIG. 1. As previously explained, this causes the coil 35 to be deactuated, so that the clutch disengages and the spring 98 restores the clutch to its initial position where the arm 96b is held against Athe stop 99. Therefore whenever a disturbance puts the system into an alarm condition, that condition is maintained for at least fifteen minutes by the operation of the clutch. The contact 49h 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 exible and slightly distorted so that it does not lie perfectly iiat against the disc 76. The disc 75 is also resilient, so that it presses Ithe clutch downwardly to assist its disengagement. Part of the disc 75 is always touching the 'cup 96 to facilitate establishment of a good magnetic -flux path through the cup 96 and discs 75 and 76 Whenthe coil 35 is again energized; 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 supplied 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 the normal on guard condition to the normal off guard condition and to move the clutch during an alarm condition, so that the clutch and clock mechanism serve as a timer and no separately driven timer'is required.

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 being transmitted by the wires and 11 to prevent an alarm. He can readily measure the six volts D.C. across the Wires 10 and 11 but if he connects a six volt battery across the wires 10 andy 11, expecting that this will hold the bell inoperative, he will short 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 and without knowledge of the alarm system circuitry. His task can be rendered still more difficult by using a signal device 33 and a receiver 18 capable of working at ultrasonic frequencies which cannot be heard by tapping earphones across the wires 10 and 11.

What we claim is:

1. An alarm system having a first normal condition, a second normal condition, and an alarm condition, comprising a clock having a constantly driven mechanism for changing the alarm system from one normal condition to the -other at predetermined times, a clutch, means responsive to an alarm condition to engage the clutch with the driven mechanism to move therewith from an initial position, and means operable when the clutch reaches a second position to terminate the alarm condition and disenlgage the clutch from the driven mechanism.

2. An alarm system as claimed in claim 1, including restoring means for returning the disengaged clutch to its initial position.

3. An alarm system as claimed in claim 1, wherein said means operable when the clutch reaches the second position comprise switch means operable by the clutch.

4. An alarm system as claimed in claim 3, wherein the clutch is an electromagnetic clutch that is deenergized by operation of the switch means by the clutch on reaching the second position.

5. An alarm system as claimed in claim 1, wherein the clutch is an electromagnetic clutch.

6. An alarm system as claimed in claim 5, including a thin, flexible, resilient and distorted disc of magnetizable material for pressing the clutch and driven mechanism apart.

7. An `alarm system as claimed in claim 6, wherein the driven mechanism is mechanically wound.

8. An alarm system as claimed in claim 1, wherein the first normal condition is day time operation and the second normal condition is night time operation, and including switch means .actuable by the driven mechanism at a predetermined position each day to change the alarm system from the' rst to the second normal condition.

9. An alarm system as claimed in claim 8, wherein the clock has a day wheel engaged by the driven mechanism at another predetermined position each day to move the day wheel one-seventh of a revolution, the day wheel having day pins positionable to actuate the switch means, as the day wheel is moved, to change the alarm system from the second to the first normal condition.

10. An alarm system as claimed in claim 9, wherein the day pins `are also positionable to fail to actuate the switch means thus leaving the alarm system in the second normal condition.

11. An alarm system as claimed in claim 10, wherein the driven mechanism moves the day wheel by engaging the day' pins.

12. An alarm system having at least a first normal condition, a second normal condition, and an alarm condition, comprising a clock having a movable mechanism for changing the .alarm system from any one normal condition to another normal condition at predetermined times, means responsive to a disturbance of the system to change the system from a normal condition to an alarm condition, and means for maintaining the alarm condition until the clock mechanism has moved a predetermined amount after the disturbance, thus maintaining the alarm condition for at least a predetermined time, the last mentioned means comprising a clutch actuable t-o engage the clock mechanism andmove therewith. l

13. An alarm system as claimed in claim 12, includ ing means for deactuating the clutch after said predetermined amount of movement.

14. An alarm system having a normal on guard condition, a normal off guard condition, and an alarm condition, comprising a clock having a constantly driven mechanism for changing the system alternately from one normal condition to the other, electrical means responsive to a disturbance of the system to change the system from at least the on guard condition to an alarm condition, and means for maintaining the alarm condition for at least a predetermined time and comprising a clutch having a normal condiition in which it is disengaged from the clock mechanism, electromagnetic means for actuating the clutch to engage the clock mechanism and move therewith from an initial position, and restoring means operable when the clutch reaches a second position to restore the clutch to its normal condition.

15. An alarm system as claimed in claim 14 having a rectifier power supply, an alarm having a battery charged from the power supply, the battery of the alarm being the sole battery in the system, the driven mechanism of the clock being mechanically wound.

16. An alarm system as claimed in claim 14, wherein the electrical means comprise a signal device for normally supplying a signal to an alarm -to render the alarm inoperative, and means for rendering the signal device inoperative in response to the disturbance, the means for maintaining the alarm condition comprising means for actuating said electromagnetic means and means for maintaining the signal device inoperative while the clutch moves from its initial to its second position, the last mentioned actuating means being normally held inoperative by the signal.

17. An alarm system as claimed in claim 16, wherein thev means for rendering the signal device inoperative comprise means for shunting a power supply of the signal device during the disturbance, the actuating means being responsive to resumption of power at the end of the disturbance.

18. An alarm system as claimed in claim 14, wherein the electrical means comprise a signal device for normally supplying a signal to an alarm to render the alarm inoperative, and means for interrupting said signal in response to the disturbance.

19. An alarm system as claimed in claim 18, wherein the restoring means comprise means for restoring said signal after the clock mechanism has moved the clutch from the initial to the second position.

20. An alarm system as claimed in claim 18, wherein the electrical means further comprise an electronic valve rendered operative -after the disturbance to actuate the electromagnetic means. v

21. An alarm system as claimed in claim 20,'including means responsive to the signal for normally rendering the electronic valve inoperative.

22. An alarm system as claimed in claim 18, wherein a line connects the signal device to the alarm, a power supply for the signal device is connected to the line, and the alarm normally provides a load on the line for the power supply wherebyan open circuit disturb-ance of the line changes the operation of the power supply, the signal interrupting means comprising means responsive to such change to render the signal device inoperative.

tion 'before theA signal device is again rendered operative.v

24. An alarm system as claimed in claim 23, wherein the signal interrupting means comprise means for shunting the signal device and valve.

25. An alarm system as claimed in claim 19, wherein the signal device comprisesan oscillator rendered inoperative in response to the disturbance and maintained inoperative until the lclutch reaches its second position.A

References Cited bythe Examiner UNITED STATES PATENTS 2,177,102 10/1939 Glover 340-323 X 2,436,824 3/1948 Potter 340--164 X 2,493,576 1/1950 Foss 340-276 2,963,628 12/1960 Ostland 20G- 38.1 X 3,136,985 6/1964 Robinson 20G-38 X 3,152,232 10/1964 Pardee 340--3091 NEILv c. READ, Primary Examiner. R. M. GOLDMAN, Assistant Examiner.

Claims (1)

14. AN ALARM SYSTEM HAVING A NORMAL ON GUARD CONDITION, A NORMAL OFF GUARD CONDITION, AND AN ALARM CONDITION, COMPRISING A CLOCK HAVING A CONSTANTLY DRIVEN MECHANISM FOR CHANGING THE SYSTEM ALTERNATELY FROM ONE NORMAL CONDITION TO THE OTHER, ELECTRICAL MEANS RESPONSIVE TO A DISTURBANCE OF THE SYSTEM TO CHANGE THE SYSTEM FROM AT LEAST THE ON GUARD CONDITION TO AN ALARM CONDITION, AND MEANS FOR MAINTAINING THE ALARM CONDITION FOR AT LEAST A PREDETERMINED TIME AND COMPRISING A CLUTCH HAVING A NORMAL CONDITION IN WHICH IT IS DISEN-

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