US2275981A - Alarm system - Google Patents

Description

March 1o, 1942. M. w. MUEHTER ALARM SYSTEM Filed March 4, 1958 INVENTOR M.W. MUEHTER ATTORN EY www@ n PNIO Patented Mar. 10, 1942 UNITE ALARM SYSTEM Fries Application March 4, 1938, Serial No. 193,896

9 Claims.

This invention relates to a compulsory delinquency indicating watchmans tour system wherein the failure of a watchman to complete a predetermined tour -of transmitting stations will cause a delinquency signal to be actuated and of the general type disclosed in the co-pending application of G. G. N. Purcell, Ser. No. 193,873, filed March 4, 1938. Each station must be visited at a particular time and the stations must be visited in a particular sequence so that failure to operate a certain station within a certain grace period will be known at a supervisory point and investigation can be instituted. Such a system is very diicult to defeat and wilful failure of a watchman or attempted operation of the system l5 by an intruder will be evident to a supervisor.

The principal object of this invention is to provide an improved compulsory delinquency indicating watchmans tour system wherein all of the tour stations are directly connected to a central oilice.

Another object of this invention is to provide a watchmans tour system wherein failure to visit the tour stations in a given order is indicated at a central station and wherein failure of the electrical connections of the system is indicated at the central o'ice.

In general the system comprises a series of watchmans tour stations distributed through the premises to be protected and control equipment located preferably in the protected premises and connected to the watchmans tour stations by a loop connection of three conductors. The control equipment comprises relays responsive to thel combination signals of the tour stations and said relays operate one or more selector switches to in turn operate an indicator reset device which may be located in a central station and is normally reset to avoid a delinquency signal, but if the watchman fails to operate the proper station within the given grace period, the delinquency signal will be operated to start investigation of any trouble on the watchmans tour.

Referring to the drawing, the system shown is adapted to accommodate twelve tour stations on the series line conductors I, 2 and 3, two stations A and B being shown as examples. Station A comprises two jacks and 20 and a Watchmans double plug register containing rectier elements I4 and 26, indicated as portable in the drawing. The other stations to a total of twelve are similar to station A with the exceptions that the connections of the jacks to lines I, 2 and 3 are varied as shown in the following table:

Station Connect 7 to Connect 19 to Connect 20 to A still further object of the invention is to 4o provide a watohmans tour system wherein noncoding transmitters are connected to a receiving oce by few wires and wherein failure of said wires can be corrected by bridging them to again receive the proper signals.

A further object of this invention is to provide a non-coding watchmans tour system wherein McCulloh operation is possible.

Further objects and advantages will appear from the following description of the preferred embodiment of this invention in connection with the accompanying drawing wherein the single figure of the drawing is a circuit diagram of the preferred embodiment of the watchmans compulsory tour system.

For example, at station A spring 5 of jack 1 is connected to line 2, spring 6 is connected to line 3, and the sleeve is connected to line I, while in jack 20, spring I9 is connected to line I and the sleeve is connected to line 3 while spring I8 remains unconnected. Therefore, when the watchman inserts his plug rectier, a connection is established from line 3 through springs 5 and 6 to line 2, another connection being established from line 3 through connection I0, spring tip I contact I3, rectifier I4, sleeve contact I5, conductor 8 to line I. Another connection is established from line 3 through sleeve 20, sleeve connection 25, rectier 26 and tip 24, spring I9 and conductor 2| to line I. The other stations B to L are connected in accordance with the above table.

The stations are connected to the control equipment through conductors I, 2 and 3 which may be arranged in the form of a loop. Conductor I is connected to relays 34 and 58 through rectiers 32 and 62, respectively, while conductor 2 is connected to relays 33 and 59 through rectiers 3| and 64, respectively. The other sides of the relays 33, 34, 58 and 59| are connected to the alternating current source and to rectier 18, relay 19, through conductor 11 to ground. The other end of the tour station loop comprises conductors I', 2f and 3', I and 2' being connected through rectiers and 38, respectively, to conductor 39, contact 41, contact 48 to conductor 3 which in turn is connected to the alternating current source 30. The relays 33 and 34 establish operating connections through other contacts to a selector switch comprising switch wipers and 54, which is in turn connected to the contacts of the relays 58 and 59 to control an indicator reset device 10. Wipers 50 and 54 are driven by stepping relay 'Z2 through the p-awl 15, ratchet 16 and shaft 49.

In order to re-establish the tour circuit in the event of a break or ground, a switch |00 and its accompanying circuit has been provided. Switch |00 establishes a connection from line I through line I0| to conductor |01 and line I' while a connection is also established from line 2 through conductor |92, switch |00 and line |06 to line 2. The switch also establishes a connection from alternating current source 30 and line 3 to line 3 and thus it is seen that in the event of a break I in one part of the loop circuit the tour stations may still operate over lines IBI, |02 and |03 to operate the control equipment. A signal bell 81 and lamp 98 are provided for indicating breaks in the loop circuit. Thus, when a break occurs in the loop circuit, relays 58 or 59 or both drop their armatures to start a trouble circuit in operation. If one of the relays 58 and 59 drops its armature, a circuit is established from positive battery through armature 94 or 95 or both, conductor 99, contact 96 and lamp 98 to negative battery and also through switch |00, conductor IIO, switch |I2, conductor I8, contact 86, bell 81 to negative battery. Therefore, the trouble lamp 98 and bell 81 will operate to notify the control equipment operator that trouble has occurred in the loop circuits. A ground in the loop circuit is indicated by the lamp 82 andrelay 19 which becomes energized through the circuit from the alternating current source 39, through a conductor 11, rectifier 18, relay 1'9, to ground and back to the source 30 through the grounded line of the loop. Relay 19 operates and closes the circuit from battery to the lamp 82 and back to battery.

In operating the system in its proper manner the watchman is required to make a tour through the protected premises and consequently to operate the stations, for example twelve stations such as those shown, in a particular sequence and within a particular grace period so that the delinquency signal will not give a delinquency indication.. However, if the watchman negligently fails to' operate the stations in their proper sequence or if an intruder unfamiliar with the proper sequence should attempt to operate the stations it is evident that the indicator reset device 10 would fail to reset and therefore a delinquency signal would be' operated.

' According to the objects of this invention it is desired to transmit signals from the tour stations to the control equipment without the use of coding transmitters. Therefore, I provide the peculiar arrangement of rectiers and relays. When the watchman desires to operate a station he inserts his twin plug rectifier in the jacks, for instance jacks 1 and 20 of station A. In so doing he completes a connection from line 3 through the sleeve of jack 20, rectifier 26, tip 24 of the plug spring I9 to line I and in so doing he polarizes line I negatively since only the negative half wave from alternate current source 30 will be passed by rectifier 28. At the same time the watchman establishes a circuit from line 3 through connection I0, springs 5 and 8, connection 9 to line 2, and thus polarizes line 2 plus and minus since there is a direct connection between said line and line 3. A further connection is established from line 3 through spring 6, tip I3, rectifier I4, sleeve I5 to line I, to thereby polarize line I positively. Thus we iind that lines I and 2 both have positive and negative polarity as set forth in the table mentioned before. Because of the positive polarization of lines l and 2, rectifiers 62 and 64 pass the positive half wave from source 30 and relays 58 and 59 are energized from the alternating current source 30 and they therefore pull up all their armatures. Due to the negative polarization of lines and 2, rectiers 3| and 32 pass the negative half wave from alternate current source 30 so that relays 33 and 34 also pull up all their armatures. Normally relay 61 is energized from positive battery through contacts 31 and 53 of relays 33 and 34, respectively, and conductor 5I but the operation of relays 33 and 34 de-energizes the circuit so that relay 61 drops its armature to close contact 68. 'I'he operation of the above mentioned relays establishes a circuit from positive battery through contact 36 of relay 33, contact 40 of relay 34, line 42, contact 43 of the selector switch, switch-arm 50, conductor 52 through switch-arm 54, contact 55 to line 56, contact 51 of relay 58, contact 60 of relay 59, line 65, contact 68 of relay 61 to the indicator reset relay 10 and the stepping relay 12.

The indicator reset device may be one of the type shown by the patent to R. M. Hopkins No. 1,942,814 issued Jan. 9, 1934. Operation of relay 10 prevents a delinquency signal. Of course the watchmanwill then Withdraw his plug resistor and in so doing de-energize relay 12 and step switches 50 and 54 to the next succeeding contacts. When the watchman operates the next station, for example station B, it can be seen from the drawing that he will polarize line I negatively and line 2 both positively and negatively and will therefore operate the relays 59, 33 and 34, relay 58 being de-energized to drop its armature. Therefore, a circuit can be traced from positive battery through contacts 36 and 40 through conductor 42, contact 44 and switch-arm 50, line 52 and switch-arm 54, Contact 55 through contact of relay 58, contact 60 of relay 59, line 65 through contact 88 of relay 61 to relays 10 and 12, relay 10 preventing a delinquency signal and relay 12 preparing the switches for the next stepping operation. When the watchman withdraws his plug from this station, the switch- arms 50 and 54 will againstep to the next succeeding contacts. Let it be assumed that the watchman or an intruder attempts to operate the system from the wrong station, for instance the fourth station on the tour instead of the third, in so doing, according to the table 2,275,981 given above, he will polarize lines I and 2 negatively in each case, thus only relays 33 and 34 will be operated. As before indicated, relay 6l will be de-energizedand drop its armature. 'lhis operation of the fourth station will fail to set the indicator reset device since a circuit cannot be traced from positive battery to relays 'l0 and 12. For example, the circuit starts as normally at positive battery and continues through contacts 36 and 40, through conductor 42, through the contact 45, switch-arm U, through conductor 52 to the switch-arm 54, and contact 9i of relay 58. At this point the circuit is found to be open since neither line I nor line 2 is polarized positively. Therefore, the indicator reset relay I0 will not reset the delinquency indicator and the central station operator will receive a delinquency signal indicating trouble of some sort in the guarded premises.

As described above, the watchman must operate the transmitting station in a particular sequence and therefore the selector switch is wired as shown so that its various contacts are in circuit with the proper relay contacts at the time when the watchman -polarizes the line in the proper manner and sequence. Thus, if the proper transmitting station is operated within a predetermined time, a delinquency signal will not be given. The watchman must operate the different transmitting stations within certain time limits since failure to do so will allow the delinquency signal to operate, said signal being time controlled as well as watchman controlled. Therefore, if the watchman is prevented from completing his tour, a delinquency signal will be given.

From the above description it is evident that the system uses non-coding transmitters, few wires are necessary, and McCulloh operation is obtained. No matter which lines break or become grounded it is still possible to signal from the watchmans stations.

Various modifications of this system are possible. For instance, the number of stations may be increased by increasing the number of wires polarized by each station and of course the number of selector banks may be increased to provide for the increased number of stations. Furthermore, it may be desirable to operate annunciators or recording devices either separately or in combination with the selector and indicator reset. l

I claim:

1. In a watchmans tour system, a plurality of stations, each station comprising one or more rectifiers, conductors connected to said stations and arranged in a loop, a source of alternating current connected in the loop connections between said rectiiiers and said conductors arranged to polarize the conductors differently at each station, relays connected to said conductors, rectiers in series with said relays and arranged in such a manner that said relays respond to loop polarities in diiferent combinations, a selector connected to contacts of said relays whereby proper sequential operation of said stations steps said selector through a complete cycle, an indicator reset device connected to said selector through contacts of said relays and energized at each successive step of the selector, means connected to at least two of said relays for indicating a loop break, a conductor loop connected to each end of the station loop and a switch therein, said switch arranged to bridge said rst loop in the event said rst loop breaks whereby stations on either side of said break can still operate the indicator reset device.

2; In a watchmans tour system, a transmission line comprising a pair of signalling conductors and a common return conductor, a source of alternating current connected between the common return conductor and the signalling conductors, a plurality of tour stations connected between the common return conductor and the signalling conductors and arranged to establish a watchmans tour, rectifiers in at least onestation, rectifier connections `at each station between the common conductor and the signalling conductors lfor polarizing the signalling conductors differently at each station, a central station, a pair of switchingrelays at the central station connected between the source of alternating current and the signalling conductors and energized by currents of a given polarity, a second pair of switching relays at the central station connected between the signalling conductors and the source of alternating current and energized by currents of a different polarity, a selector switch for preparing circuits between the contacts ofeach pair of relays, and

an indicator reset device connected between the` contacts of said relays and adapted to be energized when currents of proper polarity energize the relays to com-plete the circuit through the selector switch whereby operation of the tour stations in a predetermined order completes circuits through the selector switch to reset the indicator device.

3. In a watchmans tour system, a transmission line comprising a pair of signalling conductors and a common return conductor, a

`source of alternating current connected between the common return conductor and the signalling conductors, a plurality of tour stations connected between the common return conductor and the signalling conductors and arranged to establish a watchmans tour, rectiers in at least one station, rectifier connections at each station between the common conductor and the signalling conductors for polarizing the signalling conductors differently at each station, a central station, switching means at the central station energized by currents of a given polarity in the signalling conductors, a second switching means at the central station energized by currents of a different polarity, a selector for preparing circuits between each of the switching means, and an indicator reset device connected with the selector andthe switching means and energized when currents of proper polarity operate the switching means to complete the circuit through the selector whereby operation of the tour stations in a -predetermined order completes circuits to reset the indicator device.

4. In a watchmans tour system, a transmission line comprising a pair of signalling conductors and a common return conductor, a source of alternating current connected between the common return conductor and the signalling conductors, a plurality of tour stations connected between the common return conductor and the signalling conductors and arranged to establish a watchmans tour, rectiers in at least one station, rectifier connections at each station for polarizing the signalling conductors differently at each station, switching means connected to the signalling conductors and energized by currents of a given polaritya second switching means connected to the signalling conductors yand energized by currents of a diierent polarity,

a selector for preparing a circuit between the switching means, and an indicator reset device energized by the switching means and the selector whereby operation'of the tourstations in a predetermined order resets the indicator device.

5. In combination, a tour station comprising two jacks, a loop circuit connected to said jacks,

a source of alternating current connected tothe loop rectiers connected to said jacks for polaryizing said loop circuit in a particular manner, relays connected to said loop circuit, means for passing current to said relays in accordance with the particular polarizationof the loop at said jacks, an indicator reset, a selector means responsive to said relays for energizing said in- 'dicator reset, means for indicating a break in the loop and means whereby said loop may be bridged in the event of a break in said conductors to reestablish a connection from the tour station to said relays whereby operation of the indicator reset continues in spite of breaks in the loop circuit.

6. In a watchmans tour system, a plurality of tour stations arranged to define a watchmans cessively energizing said indicator reset device,

means responsive to a break in said lop for indicating the same and switch means arranged in said central station for rearranging said loop whereby stations on either side of a break in said loop may still operate said indicator reset device.

vil() 7. In a watchmans tour system, a plurality 'of tour stations arranged `to define a watchmans tour, a control equipment, a line comprising a plurality-of signalling conductors and a common return conductor for connecting the tour stations to the control equipment, a source of alternating current connected to said conductors, means at each tour station for polarizing at least 'two of the signalling conductors differently at each station, switching means in the control equipment for responding to each particular polarization -of said polarized signalling conductors, an indicator reset device and a second switching means responsive to the first switching means for successively energizing the indi'- cator reset device in a predetermined sequence.

8. In a watchmans tour system, a line in the form of a loop having at least two watchmans tour stations therein, a source of alternating current connected to the loop, means at each tour station for polarizing the loop in a -particular manner, switching means responsive to each polarized condition of the loop, an indicator reset device energized by the switching means, means for indicating a fault in the loop and switching means for rearranging the loop circuit whereby the tour stations may still operate the indicator reset device.

9. In a signalling system, a plurality of transmitting stations, a line in the form of a loop connecting said stations, a source of alternating current connected to said line, means in each transmitting station for polarizing the line differently at each station, switching means connected to said line for responding to each particular polarization of the line, a signalling device and a second switching means responsive to the first switching means for successively energizing vthe signalling device.

MANFRED W. MUEHTER.

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