US2298840A - Alarm system - Google Patents

Description

1942. G. G. N. PURCELL v 2,298,840

ALARM SYSTEM Filed March 4, 1938 2 Sh eets-Sheet l INVENTOR c. e. N. PURCELL ATTORNEY G. G. N, PURCELL 2,298,840

ALARMISYSTEM v Filed March 4, 1938 2 Sheets-Sheet 2 s2 FIG.2 4

SIG-NA L5 INDICATOR RESET INVENTOR (3.6. N? PURCELL ATTORNEY Patente d Oct. 13, 1942 ALARM SYSTEM Gerald G. N. Purcell, East Orange; N. J., assignor to American District Telegraph Company; New York, N. Y., a corporation of New Jersey Application March 4, 1938-, Serial N 0. 193,873

4 Claims.

This invention relates to a watchmans tour system wherein a factory or other premises is equipped with a number of signal transmitting stations so arranged that a watchman will make a predetermined tour of the premises and will operate the stations in a, predetermined order within a given. grace period whereby failure of the watchman to so operate thestations will be indicated at a remote control ofiice- The principal object of this invention is to simplify the watchmans compulsory tour system and yet increase the safety of the system by providing a, number of different annunciation or control functions in a signal receiver from a number of non-coding transmitting stations using only a few conductors.

A further object of the invention is to provide in a watchmans tour system a plurality ofitour transmitting stations, each station being directly supervised by a central station, as animprove ment over prior systems wherein only certain stations are connected to the central station and intermediate stations merely perform a mechanical operation on the watchmans register to enable operation of the connected stations,

Another, object of this invention is to provide a watchmans tour system wherein the transmitting stations do not transmit a code but merely polarize the transmission lines in such a manner that an indication is received at the central station.

A still further object of this invention is to provide a compulsory watchmans tour system wherein the proper sequentialoperation of the transmitting stations will polarize the transmis- 2 sion lines to produce signals individual to each transmitting station.

Another object of this invention is to provide an improved compulsory tour system wherein the Watchman must visit the transmitting stations' the preferred embodiment shown in the drawings, I

in which ting an individual signal.

Fig. 1 shows the transmitting stations andpart of the control equipment of the watchmans tour system;

Fig. 2 shows selectors and an indicating device to be used in connection with Fig. 1;

Fig. 3 shows a watchmans transmitter device and the jacks for receiving the transmitter; and

Fig. 4 shows a modified form of receiver.v

The preferred embodiment. of this invention comprises a watchmans compulsory sequence delinquency system wherein the transmitting stations are all connected by wires to the control equipment as distinguished from prior systems of this nature in which some of the route stations are not actually connected to the control equipment but merely condition a watchmans register for operating other route stations which are electrically connected to the control equipment. This system provides a watchmans tour which is less vulnerable to attack than the prior mechanical tour systems.

, Referring to the drawings, Fig. 1 shows transmitting stations I to XII which areconnected by three wires to the control equipment; but, if desired, a system of more stations can be provided by using more wires, each station transmit- For instance, 24 stations require four wires, 40 stations require five wires,.and 60 stations require six wires, or the stations can be further increased by increasing the number of wires polarized by each station. A one-wire alternating current supply is also necessary and therefore increases the'number of wires in each case by one unless the powersupply is picked up at or beyond the transmitting point. Each transmitting station comprises two sets of contacts and the watchmans transmitter comprises two dry plate rectifiers 4 and 5 with which he transmits the signals characteristic of each station. Numeral I of the drawings indicates one complete transmitting station. Station I, for example, is connected to a grounded alternating current supply In through conductor H and to the control. equipment comprising relays l6, ll, 23 and 24 and rectifiers' l4, l5 I9, and 20 by conductors l3 and [8 respectively. Station III is connected in a different manner to the control equipment through conductor l3, as mentioned above in connection with station I, and through conductor 25, rectifiers 26 and 28 to relays 2'! and 29 respectively. Relays [6, ll, 23, 24, 21 and 29 are all normally energized and slow to release so that normally the armatures are pulled up and do not drop during the suppressed half wave. The armature 32 of relay I6 is connected from battery through its contact to conductor 36, contacts 62, 63, 64 and 65 of selector switch I08, Fig. 2, which is in turn connected to an indicator reset device such as shown in Patent No. 1,942,814 issued January 9, 1934, to R. M. Hopkins and which is located at a central ofiice. The indicator reset device is a timing circuit which will produce a delinquency signal unless it is reset to its starting position as a result of the proper operation by the watchman of the route stations. Armature 48 of relay I1 completes a connection from battery through contact M and conductor 38 to contacts 66, 61, 68 and 69 of selector switch I80. Armature 45 of relay 23 is connected through contact 46 and conductor 48 to contacts I8 and II of selector switch I88, while armature of relay 23 is connected through contact 52 and conductor 53 to contacts I5 and I9 of selector switch I89. The armature 56 of relay 24 is connected through contact 51 and conductor 58 to contacts I2 and I3 of selector switch I88, while armature 58 of relay 24 is connected through contact 59 and conductor 68 to contacts I6 and 80 of selector switch I88. Armature 95 of relay 21 is connected through contact 66 and conductor. 91 to contacts 11, 8|, 83 and 85 of selector switch I 88 and armature 98 of relay 29 is connected through contact 99 and conductor I22 to contacts I8, 82, 84 and 86 of selector switch I88. The selector switch arms 6| and I4 are each connected to stepping relay 98 and interrupter contacts 9| as shown in the drawings. Relays I6, I1, 23, 24, 2! and. 29 each operate armatures 38, 3|, 42, 43, 55 and 55', which are connected in a trouble circuit 34.

It may be desirable to use in this system annunciators or recorders instead of the selector switch and indicator reset device for indicating the whereabouts of a watchman. As shown in Fig. 4 of the drawings, the annunciator or recorder coils I8I to I I2 may be connected to the conductors 36, 38, 48, 58, 53, 68, 91 and I82. Thus, in a proprietary system, for instance, a chief watchman may observe the annunciator drops or the recorder tapes and thereby check the whereabouts of each watchman under his supervision.

The operation of the compulsory tour circuit is started when the Watchman inserts his transmitting device I, shown in Fig. 3, in the jacks I and 2 which are shown at station I, for instance. The watchmans transmitter device contains rectifiers 4 and 5 shown in station I. Insertion of the transmitting device connects the rectifier devices in series in-each of the conductors I3 and I8 in order to operate the selector switch arms 6| and I4 in the proper sequence. Signals of particular polarity must be transmitted from each transmitting station. Therefore, the watchmans transmitter I is connected to the lines I3 and I8 in such amanner that the rectifiers contained therein will polarize both of the lines I3 and I8 positively. Since these lines are so polarized, relays I6 and 23 will release because of the fact that rectifiers I4 and I9 do not pass the positive half of the alternating current wave. The armatures 32 and 5| will therefore drop, closing a circuit from positive battery through conductor 36 and contact 62 toselector switch arm 6|, through the stepping relay 98 and the indicator reset device in parallel through selector arm I4, contact T5,. conductor 53 and armature 5!, back to battery. The indicator reset device Will be operated to preventv a delinquency alarm and the selector coil 98 will become energized, pull up its armature and break its own circuit at contacts 9 I, thus completing its stopping function even while the transmitter I remains in the first station. Switch arms 6| and I4 advance to contacts 63 and I6 respectively. The circuit to coil 98 and to the indicator reset device is now open at contact 59 and the reset device starts a new timing cycle. As stated above, it is desirable and necessary that the watchman operate the tour stations in a predetermined sequence in order to prevent intruders or burglars from trying to operate the watchmans system. Thus the watchman must next operate station No. II. This station in effect sends a different signal by polarizing wire I3 positively and wire I8 negatively, whereas station I polarized both wires positively. Relay I6 will release its armature as before in connection with station I but since wire I8 is now polarized negatively relay 24 will drop its armature since rectiiier 28 will not pass the negative half of the alternating current cycle. Thus a circuit is set up from armature 32 of relay I6 to conductor 36, contact 63 of switch I88, indicator reset device and relay 96 in parallel, switch arm I4, contact I6, conductor 68 and the armature 58 of relay 24. Thus the indicator reset device again prevents the delinquency alarm from operating and switch arms 6| and I4 are stepped to the next contacts. As the watchman progresses from station to station in the prescribed sequence, the switch arms 6| and I4 are stepped around to prevent a delinquency alarm, but if an intruder had attempted to operate the system, he would in all probability select the wrong sequence of stations. For example, if he attempted to operate the system and operated station VI instead of station III, lines I3 and I8 would be polarized negatively and relays I and 24 would drop their armatures since rectifiers I5 and 28 will not pass the negative half wave. However, it is found that the indicator reset device will not reset the alarm system because of the fact that armature 48 closes a circuit from battery through conductor 38 to contacts 66 to 89. However, the circuit is open at this point since switch arm 6| has not been stepped to these contacts by the proper sequence of transmission from the tour stations. Therefore, the indicator reset device has not been reset by the control equipment and will continue its operation to cause an alarm which will indicate to the central station operator that trouble of some sort has occurred in the protected premises. The indicator reset device will also operate if the signals from the respective transmitting stations are not sent within a predetermined time which would occur if the watchman is prevented from completing his tour.

The annunciator or recordsr coils I8| to H2 are operated in a manner similar to the selector switch I86. For instance, when the watchman operates station I, he polarizes the lines I3 and I8 shown. in Fig. 1 in such a manner that the relays I6 and 23 both drop their armatures. This sets up a circuit from positive battery through contact 33, line 36, annunciator or recorder I 8|, line 53, contact 52, to negative battery, thereby operating the annunciator I8I. The remaining annunciators I82 to H2 are operated in the obvious manner as the watchman progresses from station to station of his prescribed tour. Obviously, the selector and indicator reset, the annunciators and the recorder coils may all be operated simultaneously or each of the elements may be used alone in the system.

In the event that a break or ground occurs on lines I3, I6 and 25, the trouble circuit 34 will give an indication. Taking line l3, for example, a break or ground will release both relays l6 and H to close through their armatures 30 and 3| respectively the trouble circuit 34. The other lines l8 and 25 will operate their respective relays in a similar manner in the event that any break or ground occurs. The trouble circuit 34 may be adapted to operate a bell or any other indicating device.

This system is found to be the acme of simplicity in that it does not require coding devices; it provides individual supervision at a receiver of a plurality of tour stations, only a few wires are necessary and it is less vulnerable to attack than the conventional mechanical tour systems.

Various modifications of the system are possible, one of which may be to increase the number of stations by increasing the number of wires as indicated previously, or to increase the number of stations by increasing the number of wires polarized by each station, or the polarizing feature of the system may be used separately; each station polarizing only one wire.

I claim:

1. A signal system comprising a source of potential, a transmitting station and a plurality of lines connected thereto, said transmitting station including jacks and a portable key member comprising rectifier members adapted to be connected to said jacks for signaling over said lines.

2. In a signal system, a source of alternating,

current, a plurality of conductors connected thereto, jacks connected to said conductors, a plug member adapted to be inserted in any group of said jacks, said plug member including a plurality of rectifiers adapted to be connected to said jacks for signaling over said conductors.

3. A watchmans signal system comprising a plurality of transmission lines, a source of alternating current common to said lines, a plurality of transmitting stations, each station being connected to at least two of said lines, a plurality of rectifiers adapted to be connected to said lines at each station, at least two pairs of contacts at each station, said rectifiers being connected to said contacts at each station in such a manner that the lines are polarized differently at each station, a receiving station, a pair of normally energized polarized relays connected to each transmission line, contacts operated by each relay and one or more selector switches connected to said contacts and adapted to be operated upon operation of said contacts.

4. A watchmans signal system comprising a plurality of transmission lines, a source of alternating current common to said lines, a plurality of transmitting stations, each station being connected to at least two of said lines, a plurality of rectifiers adapted to be connected to said lines at each station, at least two pairs of contacts at each station, said rectifiers being connected to said contacts at each station in such manner that the lines are polarized differently at each station, a receiving station, a pair of normally energized polarized relays connected to each transmission line, contacts operated by each relay and one or more selector switches connected to said contacts and adapted to be operated upon operation of said contacts and an indicator reset device connected to and operated by said selector switch.

G, G. N. PURCELL,

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