US2086818A - Alarm system - Google Patents

Description

D. E. NICHOLS ET AL ALARM SYSTEM Filed April 15, 1935 July 13, 1937.

2 Sheets-Sheet l July 13, 1937. D. E. NICHOLS ET AL ALARM SYSTEM Filed April 15, 1953' 2 Sheets-Sheet 2 Patented .lilly 13, 1937 PATENT oF'FlcE ALARM SYSTEM Dewey E. Nichols and Edward W. Glendinnng,

' Denver, Colo.

Application April 1.5, 1933, Serial No. 666,381

7 Claims.

l An important feature of our improved alarm i b-l system relates to the application or use of a closed protective circuit associated with the windows or doors or other means of access to a l building, which circuit is effective to sound an alarm in the event that the circuit is opened, or if the circuit is grounded in any manner or even contacted by the body of the burglar. This system contemplates the use of a grid glow tube relay which is operably responsive to an open circuit condition or to any grounded condition o f the closed protective circuit, whereby the tube relay becomes eiective to initiate operation of auxiliary relays that directly control the audible 7 or other alarm used. Such a system affords a double protection with a maximum of certainty of operation and eliminates any possibility of an attempt to bridge or otherwise tamper with the closed circuit as has been done with circuits in common use, and in any manner to render the circuit inoperative to' sound the alarm.

Our improved system provides one sequence of operation for night service and another sequence of operation for day service. By means of a double throw switch, the same may be set in one position atnight to aiord protection at windows or doors in a manner to initiate operation of a visible signal, in the present case the lighting system of the building; and, in addition, to sound an audible alarm. For day protection, this switch may be thrown to its other position to control relays and circuits, the operation of which will give a remote signal in the event that an unauthorized person makes body contact with a safe or till or otherdevice for containing valuables.

A particular object of the invention is to provide a means Wherebyanyone with proper authority may enter the premises Without initiating an audible alarm.

Another object is to provide a means comprising a time switch for opening a control circuit for permitting an authorized person to leave the premises without sounding an alarm,` but in a manner to condition the alarm system for normal operation a predetermined time later.

Another 'object is to provide an alarm that will become operative in the event the power line to the building is cut, or in case the power supply is cut oi.

Another object is to provide an alarm system vcontrol switch I2.

including electronic tube relays and in a manner that the alarm will become operative in case of failure of such tube relays. l

Another object is to provide an alarm system wherein every circuit may be supervised so that an automatic test of every circuit is obtained twice a day by either visual or audible means.

Another object is to provide a* combination of a burglar alarm and a re alarm, both of which are effective during night protection.

These and other objects will readily become apparent from the speciiication which follows when considered with the accompanying drawings which show a preferred form of our invention, and wherein Fig. 1 is an across-the-line diagram of the alarm systems; and

Fig. 2 is a schematic layout showing the various parts conditioned for night operation, with details not shown in Fig. 1.

The -alarm system disclosed comprises as its main elements a grid glow tube relay I, an electronic tube or capacity relay 2, a main alarm relay 3, power relay 4, auxiliary alarm relay 5, thermal relay 6, time switch 1, reset switch 53, closed circuit control relay 9, audible alarm bell l0, remote alarm buzzer II, and a four pole double throw Our improved system contemplates one mode or sequence of operation for protection at night and another sequence of operation for protection during the day. During the night or normal closed period of the building protected, the switch I2 will be thrown to render operative the relays 9, I,

3, 4, 2, and 6 in a manner to detect the presence 35 of a burglar by turning on the building lighting system and sounding an audible alarm. During the day or normal open business period of the building, the switch I2 will be moved to render operative the relays 2, 4 and 5 in a manner to 40 give protection against unauthorized contact by persons with a money till and safe, in which event a remote buzzer or signal is sounded. Such remote signal may be located, if desired, in a police station. l

The protection circuit for the one or more windows I3 is a closed circuit. At each window, a grounding switch I 4 is provided mounted on the frame I5. A pin I6 on the sash holds switch blade I4 out of contact with a grounded plate I'I. 5o A foil strip I 8 on each window contacts the pin I6. 'I'he relay coil I9 is in series circuit with conductor 2|, foil strip I8, pin I6, switch I4, Fig. 2, conduc- I tor 20, to post 22, conductor 23, across switch blade 24, through battery 25 and back'to coil I9. 55

opened by a break in foil I8 and the armature 26 is released whereby the armature is .grounded at 21. This operation connects ground 21 through a conductor28 to the grid 29 of` the tube 30 in a manner to initiate operation of this tube as a relay.

Wedesire to point out that the closed circuit shown is adapted to begrounded at the window either by body contact with a burglar or by his act in raising a window. Any upward movement of the window causes the pin I 6 to move up, and this pin normally maintains blade I4 away from grounded plate I1. When the pin I6 moves up, the switch blade I4 will spring up to contact the plate I1 in a manner to ground the entire circuit which is connected by conductor 28 to grid 29.v

This circuit is likewise grounded by opening of a door 3| which permits a plunger head 32 to move inwardly to force a contact 33 against a grounded plate 34. The contact 33 is connected by conductor 35 to the closed circuit conductor 20 whereby to ground the closed circuit at 34 when a door is opened.

The capacity of the closed protective circuit is superimposed upon the capacity of the variable condenser 36 and this capacity may become excessive in case the protective circuit includes a large number of windows in series. We, therefore, have found it desirable and effective to shunt the condenser 36 with a small xed condenser 31 of from .0001 to .0005 m. f. according to the length of the closed circuit. 'I'his shunt capacity is effective to increase the adjustable range of the variable condenser 36 by compensating for the l capacity of the closed. circuit.

The ilow of space current from cathode 38 to anode 39 is initiated by grounding of grid 29, and this space current passes in series through conductor 40, coil 4I of relay 3, transformer secondary 42 and back through resistance 43 to the cathode. Hence, opening or grounding of the closed protective circuit will cause relay tube 30 to operate to energize relay 3 in a manner to pull up its armature 44. The relay 3 provides a posi- -tive control ior the armature of the power relay 4 which has been so designated because it f unctions to first turn on the lights within the building and, a predetermined time thereafter upon actuation of a. delayed thermal relay 6, causes operation of an audible alarm. i v

When the armature 44 makes contact, the following 110 volt circuit is made, assuming the switch I2 is set for night operation; from line terminal 45 through conductor 46, armature 44, conductor 41, normally closed time switch 1, coil 48 of relay 4, and back over conductor 49 to line terminal 50. This closed circuit causes the armature 5I of power relay 4 to pull up to establish two shunt circuits as follows, one circuit through the lighting circuits and the other through the heating coil of thermal relay 6. The lighting circuit may be traced from line terminal 45'over conductor 52 through a normally closed reset switch 53, conductor 54, conductor 55, armature 5I and conductor 56 to the lighting load terminal 51, Fig. 2. 'I'he other load terminal 58 is connected to line terminal 50, whereby closure of the circuit just described will apply 110 volts to the lighting system to turn on all building lights upon operation of power relay 4. Closure of the aforesaid circuit will establish a shunt or heating circuit for relay 6 from armature 5I, through conductor 59, coil 68 of relay 6, conductor 6I, switch blade 82, and conductor 63 back to conductor 4 andline terminal 58.

The function of thermal relay 6, normally set to operate in about 30 seconds, is to delay operation of the alarm bell for a purpose to be described.'

When the bimetal strip 64 ilexes to contact a terminal 65, the following bell alarm circuit will be established; from local battery 66 overy line 61 to post 68 through bell I8, line 69, terminal 65, bimetal strip 64, line 10, blade 24 and back to battery 86. Closure of said alarm circuit about 30 seconds after energization of relay coil 60 will sound bell I and this bell may be located on the exterior wall of the building or anywhere desired.

When armatune I pulls up, a holding circuit for relay 4 will be established from terminal 45 over line52, through closed reset switch 53, line 54, line 55, armature 5I, up through coil 48, and back over line 49 to terminal 50. This holding circuit will maintain relay 4 closed to maintain bell I0 in operation until the reset switch is opened to permit armature 5I to open this circuit to de-energize or open all closed circuits above described.

A diierent type oi operation of our system is provided during normal business hours. To secure this, the switch I2 is thrown to permit alarm control by the capacity relay 2 and alarm relay 5. The binding post 1I is connected by a conductor 12 to a safe 13 or similar container for valuables such as a money till. A test circuit for detecting any break in line 12 may be traced from post 1 I, Fig. 2 through a battery 14, lamp 15, contact 16, push button contact 11 and to point of connection 18 of line 12 to the safe. To test the circuit over line 12, the push button 19 is pressed to make contacts 16-11.

'I'he electronic tube 80 of relay 2 is of the hot illament type and is shown as connected to continuously pass space current from its cathode to its anode. This current ows through the coil 8| of an auxiliary relay to maintain its armature 82 in open circuit position. In the event that an unauthorized person touches the safe 13, his added body capacity is applied to the grid of tube 80 to reduce the space current whereby to release the armature 82 which is released to establish a closed control circuit as follows: from line 52. through reset switch 53, line 83, armature 82, line 84, line 56, coil 48 of relay 4 and back over line 49 to line terminal 50, causing armature 5I to open up a closed holding circuit at its right contact 85.

The holding circuit for coil 86 of auxiliary alarm relay 5 serves as a means to test the system I by means of openingthis holding circuit at a manual switch 81. The opening of this holding circuit will operate a buzzer alarm if the switch I2 is in down position, which buzzer is located remote from the building, for example, at a police station. The holding circuit may be traced from line terminal 50, through coil 86 of relay 5, through test switch 81, through switch blade 88 in its position, over line 89, contact 85, armature 5I, over line 55, over line 54, through reset switch 53 and back over line 52 to line terminal 45.

When this holding circuit is broken at 85, the armature 90 will be released to establish a closed battery circuit from plus battery 66 up over line 9I, through armature 90, line 92, through switch blade 93 in its new position, over line 94 through the buzzer II to post 68 and back over line 61 to negative battery 66.

It will be noted that the buzzer I I will function as soon as the holding circuit is broken at 85 and that there is no delay in permitting the buzzer to function. Hence, operation of this buzzer immediately upon body contact on safe 13 will permit immediate dispatch of police to the building protected.

'I'he system disclosed lends itself readily to its use as a iire alarm for which purpose we provide a. snap thermostat 95 located in a desired position and operable by applied heat to flex reversely to make connection between ground at 91 and a contact 96 connected to line 28 in a manner to actuate tube relay 30, thereby setting in operation the audible alarm as above described.

The actual sequence of operation of all relays and alarms will be apparentY from the above description. It will be noted that movement of the pin I5 will not only break the circuit at switch I4, but also permit grounding of the circuit at plate I1. Any attempt to enter by breaking the glass will break the foil strip I8 and likewise break the circuit through coil I9.

An important feature of our invention is that it allows any one with proper authority to enter the premises without initiating the audible alarm and prevents any one else from doing so. To this end, the reset switch 53 is encased in a steel cabinet 8 positioned (Fig. 2) in a wall convenient to the access door so that the same may be reached and opened within about 30 to 60 seconds. This cabinet is under lock and key. When a. proper party enters at night or early morning, the lights are switched on by the alarm, but this party proceeds at once to open the, cabinet and open the switch 53. At this instant, thearmature 5| is pulled up, coil 48 being energized. Switch 53 is in the holding: circuit for coil 48, hence opening switch 53 will deenergize coil 48 to release armature 5| to open the circuit through thermal relay coil 60 and line 56 to the load terminal 51 and prevent operation of bell I0 and cut voi the lights.- If, however, at any later or other time, the switch 53 is opened, say, by breakage or if the wires to that switch are cut, the alarm is at once set off. 'I'his operation is due to the fact that switch 53 opens the holding circuit for coil 86 of relay 5 to permit its armature 90 to move to circuit closing position which permits battery current from 66 to flow over line 9|, armature 9D, line 92, blade 93 in its night position, line 69, through bell I8, line 61 and back to battery.

'I'his same operation is obtained if the test lswitch 81 is opened for test or in case the 110 volt supply is cut oi, in which latter case the coil 86 is deenergized to interrupt this holding circuit to sound the alarm.

In order to permit an authorized party to leav the premises at night or the last party to leave at closing time, the time switch 1 is provided. When this party departs, he will open that switch. 'Ihis switch will be timed to close in about three.l minutes. When this party opens the egress door, the relay 3 will pull up its armature 44, but the alarms will not be initiated because the circuit from line 46 through armature 44 to line v41 will be open at switch 1 until this party has had time to close the door. Switch 1 will close after the three minute period mentioned and permit normal operation of alarms as above set forth.

During daytime protection, it is necessary for normal access to the safe 13 without turning in an alarm. To permit this, a switch 98 in line 12 will be opened by a proper person to prevent capacity operation of the electronic relay 2.

It. should be noted that this system affords complete protection to the safe during night operation as well as by day. In the event that a burglar gains access at night in a manner to avoid an alarm set oir from a window or door and touches the safe'13, the tube relay 2 will function to permit armature 82 to make contact. This will close a circuit from line terminal 45 over line 52, reset switch 53, line 83, armature 82, line 84, to load terminal 51, line 56, through coil 48 of relay 4 and back over line 49 to terminal 50. This circuit will cause energization of coil 48 and will cause the building lights to come on and the bell III to sound as explained above for control by tube relay I.

In case the electronic tube relay 2 fails, current will fail to pass through its anode-cathode circuit and coil 8| and relay armature 82 will make Contact to establish a circuit as explained in the above paragraph to initiate both alarms.

The reset switch 8 is used to reset the system after an alarm has been initiated and while the alarms are in operation in the following manner: iirst the switch arm 53 is opened to cut oil the current through coil 48 of relay 4 to permit armature 5| to contact 85 and, second, arm 53 is then closed to place the entire system in normal operating condition.

It has been described that an automatic supervisory test of the system is made each morning and night when the main access door is opened. We have devised a separate means to insure a double automatic test each morning and evening when the switch I2 is thrown from night to day operation or vice versa. To this end, the main switch |2 as well as therelays I, 3, 4, 5, 6, 9 andl time switch 1 are installed in a steel cabinet, indicated by dotted lines at 99 (Fig. 2) which is located preferably in the rear of the building. When the door |08 of this cabinet is opened to throw the switch, the switch 81 will be automatically opened to open the holding circuit of coil 86 of relay 5. The switch arm of 81 is made of spring material and unless held down will spring upwardly to open its contact. 'I'he door |00, however, in closed position will contact a button |0I on this switch blade and hold the switch closed. If the switch I2 is set for night operation when the door opens, the alarm bell III will operate, but if the switch I2 is set forday operation when the door opens, the buzzer will operate to afford a test at the remote central station.

The capacity operated electronic relay 2 shown forms no part of our invention. This relay is a standard capacity relay which has been designed particularly for burglar alarm or like service. While we have shown and described a. preferred form of our invention, it is to be understood that various modiiications thereof are contemplated such as will be embraced within the scope of the appended claims. f

What we claim isz-- y l. In a burglar alarm system, a closed protective circuit associated with the building to be protected, a main alarm relay having an operating winding, a circuit for the alarmk relay, a main control relay having an energizing coil in series with the closed protective circuit, a capacity relay having a grid, said grid being connected to said protective circuit, a ground lead, means for connecting said grid to the ground lead upon de-energivzation of the control relay coil said control relay and capacity relay and being selectively operably responsiveveither to opening or grounding of the protective circuit and means for energizing the operating winding of said alarm relay upon grounding of said grid.

2. In a system as set forth in claim 1, a power relay having an operating winding, a switch operable by the alarm relay winding and in circuit with the winding oi' the power relay, a lighting circuit for the building, a gong circuitf a holding circuit for the winding of the power relay, means whereby each of said last three named circuits are closed upon energization of the power relay winding, a switch in the gong circuit, a delayed relay operable to close said switch, said delayed relay being operable upon energization oi.' the power relay and eiiective to prevent operation of the gong until a predetermined time after the lighting circuit is closed.

3. In a system as set forth in claim 1, a power relay having an operating winding, a switch operable by the alarm relay winding and in circuit with the winding of the power relay, a lighting circuit for the building, a gong circuit, a holding circuit for the winding of the power relay, and means whereby each of said last three named circuits are closed upon energization oi the power relay winding, a fth or holding relay having an operating winding, a test switch, said last named winding being in circuit with the test switch, said last named circuit being in shunt with the power supply leads used to energize the lighting circuit, meanswhereby de-energization of said last-named winding causes closure of the lighting and gong circuits, said winding being deenergizable either by interruption of the power supply or by opening of the test switch to sound the alarm.

4. In a burglar alarm system, a main alarm relay having an operating winding and a pair of contacts, a normally closed protective circuit, means operably responsive to opening of said circuit at any point for energizing the operating winding of said alarm relay, a capacity relay having a control grid connected to said protective circuit and being operable upon grounding oi' the protective circuit, means operably re-4 sponsive to operation of the capacity relay for energizing the operating winding of said alarm relay, to close said pair of contacts, a circuit includ- 'ng a gong, and means operably responsive to closure of said contacts for energizing the gong circuit.

5. In a burglar alarm system, a closed protective circuit associated with the building to be protected, a main alarm relay having an operating winding, a circuit for the alarm relay, a

main control relay having an energizing coil in series with the closed protective circuits capacity relay having a grid, said grid being cone nected to said protective circuit, means Wnsive to grounding .ot said protective circuit and connected grid for energizing the operating winding of said main alarm relay, and means responsive to de-energization or the coil of said control relay for grounding the grid of the capacity relay to cause energization of the. operating winding of said main alarm relay.

6. In an alarm system, a protective circuit associated with a building, a capacity relay having a grid connected to the protective circuit, a main alarm relay having an operating winding, means responsive t grolmding oi said circuit and grid for energizing said operating winding, a power relay having an operating winding, a

switch operable by the alarm relay winding and in circuit with the winding of the power relay, a lighting circuit for the building, a gong circuit, a holding circuit for the winding of the power relay, means whereby each of said last three named circuits are closed upon energization of the power relay winding, a switch in the gong circuit, a delayed relay operable to close said switch, said delayed relay being operable upon energization of the power relay and eilective to prevent operation of the gong until a predetermined time after the lighting circuit is closed.

7. In an alarm system, a protective circuit associated with a building, a capacity relay having a grid connected to the protective circuit.

' a main alarm relay having an operating winding, means responsive to grounding oi' said circuit and grid for energizing said operating winding, a power relay having an operating winding, a switch operable by the alarm relay winding and in circuit with the winding of the power relay, a lighting circuit forV the building, a gong circuit,` a holding circuit for the winding oi' the power relay, and means whereby each of the last three named circuits are closed upon energization of the power relay winding, a third or holding relay having an operating winding, a test switch, said last named winding being in circuit with the test switch, said last named circuit being in shunt with the power supplyleads used to energize the lighting circuit, and means

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