US3647974A

US3647974A - Sound-type detection system

Info

Publication number: US3647974A
Application number: US868086A
Authority: US
Inventors: Raymond E Geisler; Leroy E Hull; Michael E Kirschbaum
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-10-21
Filing date: 1969-10-21
Publication date: 1972-03-07
Anticipated expiration: 1989-03-07

Abstract

A sound-type intrusion and mechanical disturbance detection system includes a plurality of monitors located at a control station and individually connected detector-transducer units located in the various areas to be protected. A common AC and DC supply is used for the monitors as well as a common speaker and amplifier. Multiple mechanical disturbance detectors may be used, each producing a characteristic output sound so as that the attendant may determine the appropriate action to be taken.

Description

States Patent Geisler et a1.

[ 5] Mar.7,19'72 SOUND-TYPE DETECTION SYSTEM Inventors: Raymond E. Geisler, RFD 02 Araby Road, Frederick, Md. 21701; Leroy E. Bull, 2701 Weissman Road, Silver Spring, Md. 20902; Michael E. Kirschbaum, 4419 Brookfield Drive, Kensington, Md. 20795 Filed: 06:. 21, 1969 Appl. No.1 868,086

US. Cl. ..179/5 R Int. Cl. ..H04m 11/04 Field of Search ..179/5 R; 340/253 Y References Cited UNITED STATES PATENTS 1/1936 Hand ..340/253 Y Brennon. ..179/5 X Bristol ..348/261 A. C, SUPPLY Dv C. 6214,93

t AUDIO AU DIO MONITOR as I LIMITER I 34 10 3,452,345 6/1969 Kinsey ..179/5 X 3,475,751 10/1969 Sontag et a1. ...179/5 X 3,492,426 1/1970 Foreman et a1... ..179/5 3,523,162 8/1970 Streit ..l79/5 Primary Examiner-Kathleen Claffy Assistant ExaminerWilliaJn A. Helvestine AttorneyLarson, Taylor and Hinds [57] ABSTRACT 4 Claims, 4 Drawing Figures SENDING UNIT I Liz POWER l l SUPPLY SENDING SOUND-TYPE DETECTION SYSTEM FIELD OF THE INVENTION The present invention relates to detection systems and more particularly to a sound-type detection system for detecting.

BACKGROUND OF THE INVENTION A large number of systems have been developed for intruder detection as well as for detecting certain mechanical disturbances for maintenance purposes or so that the proper authorities can be alerted such as in the case of fire. The systems have various strengths and weaknesses although, in general, the greatest disadvantage of most systems is the prohibitive expense of these systems. Other serious disadvantages include lack of adaptability to existing communication setups; the complexity of such systems, which is reflected in both high initial investment costs and high maintenance costs; and the relative great amount of floor space required by some systems.

SUMMARY OF THE INVENTION In accordance with the present invention a system is provided for detecting intrusion into a protected area as well as mechanical disturbances or failures such as fires, power failures, boiler failures and the like. The system of the present invention is relatively inexpensive, compact and simple in design yet is both effective and efficient.

In accordance with a presently preferred embodiment of the invention a sound-type system is provided which includes a plurality of sending units located in the areas to be protected and including a detector-transducer for converting detected sounds into electrical signals which are transmitted to individual monitors. According to an important feature of the present invention a common power supply is provided for the monitors as well as a common output speaker. This arrangement permits stacking of the monitors and storage of the monitors within a relatively small area in a single cabinet. The system preferably includes common AC and DC power supplies as well as a common alarm circuit such as buzzer circuit.

Preferably, at least one of the sending units includes at least two mechanical disturbance detectors, the detectors sensing different types of mechanical disturbances and each producing a predetermined characteristic sound corresponding to that disturbance which is transmitted to the output speaker so that appropriate action may be taken. One such detector may comprise a power failure detector for a three-phase system which provides connection of a sound producing alarm device to the corresponding monitor in response to a power failure. A second such detector may comprise a heat sensor for detecting fires and a sound producing alarm responsive to the heat sensor.

The present invention may be incorporated in both audio and direct type systems. As incorporated in an audio system, preexisting telephone lines may be used in coupling the sending units to the monitors, the sending units preferably including a telephone unit and a switching system for switching the inputto the telephone lines between the detector-transducer and the telephone unit. A line monitor in the telephone unit is connected to the telephone line input when the telephone is not in use to indicate that the unit is in working condition and that the control switch is in the position for which the detector-transducer is disconnected. The audio monitors preferably include a sensing relay which is actuated by an amplified signal received over the telephone lines, the relay controlling energization of a holding relay. The holding relay preferably includes three sets of contacts, one set for actuating an indicator light individual to the monitors, a second set for energizing the common buzzer circuit referred to above and a third set which forms a holding circuit. A manually actuated reset switch breaks the holding circuit and connects the output of the associated telephone lines to the common speaker. A telephone jack provides a connection for plugging in a tape recorder or an auxiliary telephone unit for communicating with the various protected areas prior to activating the system.

Other features and advantages of the invention will be set forth in or apparent from the detailed description of presently preferred embodiments thereof found hereinbelow.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic block diagram of a detection-monitoring arrangement in accordance with the invention as incorporated in an audio-type system;

FIG. 2 is a schematic circuit diagram of one embodiment of sending unit in accordance with the invention;

FIG. 3 is a schematic circuit diagram of one embodiment of an audio monitor in accordance with the present invention; and.

FIG. 4 is a schematic circuit diagram of matching unit used where the invention is incorporated in an intercom system having its own amplifier.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a specific embodiment of an intruder and mechanical failure detection system in accordance with the present invention, as incorporated in an audio-type system, is shown. The system includes a plurality of audio monitoring units 10 located at the control station of the system and a corresponding plurality of sending units 12 located at various areas protected by system. One monitor 10 and one sending unit 12 with the associated detectors comprise one installation, the detectors all feeding the common sending unit 12. In general the sending units 12 are switching and matching devices and when set couple the sound system to a telephone line. If the sound system is an intercom system, the output thereof is disconnected and is switched to the telephone line through, if required, a matching transformer as described hereinbelow.

The audio monitors 10 are each connected to an amplifier 14 which powers an output speaker 16. An auxiliary amplifier 18, which is normally loaded by a resistor (not shown), may be connected to monitors l0 and speaker 16 by

switches

19 and 20 of a two-pole switch.

Amplifiers

14 and 18 are preferably transistor amplifiers and thus switches 14 and 18 are preferably of the shorting type. In accordance with an important feature of the invention audio monitors 10 are each poweredfrom the same AC and DC power supplies. Thus, referring to FIG. 1, monitors 10 each are connected to the existing AC bus 22 and to the existing DC bus 24. The DC power supply 24 is a standard DC regulated supply with an output adjustable between 6 volts and 10 volts at about I ampere maximum. This rating will handle more than monitors corresponding to monitor 10. The AC power supply 22 is a 24 v. AC supply provided by any standard signal transformer. Monitors 10 are also connectedtogether through a common cable 26 to amplifier 14, each of the connections between cable 26 and a monitor 10 being made through a switch 28. It is noted that

busses

22 and 24 and cable 26 each include two conductors, only one conductor being shown for purposes of illustration. One output of each of the monitors 10 is connected through a common conductor 30 to an alarm device 32 such as a buzzer. A switch (not shown) may be used to disconnect the buzzer alarm 32 if desired, the buzzer 32 being used to produce an alarm signal when the attendant is away from the monitoring station. The common power supplies, amplifier and speaker permit the monitors to be housed together in a single cabinet.

Audio monitors are connected to sending units 12 through existing telephone lines 34. Telephone lines 34 each include limiting devices 36 as required by the telephone companies.

Each sending unit 12 includes an individual power supply 38 and is connected to associated pickup speakers 40 for detecting noise within a protected area. Power supply 38 is used to power an optional line monitor described hereinbelow which is housed with the switching unit described hereinafter or, if an optional telephone unit is used, housed with this unit so that connection of the line monitor is controlled by the cradle switch. If a builtin amplifier such as shown in FIG. 3 discussed below is used, the power supply 38 is used as the power supply thereof.

In addition to pickup speakers 40, further detection devices are preferably provided to indicate the occurrence of power failures, fires and the like. For example, considering the uppermost sending unit shown in FIG. 1, a power failure detector generally denoted 42 includes a first relay 44 connected between one phase to neutral of a three-phase system and a second relay 46 connected across the other two phases as indicated.

Relay contacts

44a and 46a normally complete the connection between sending unit 12 and monitor 10. With

relays

44 and 46 deenergized,

relay contacts

44a and 46a connect a sounding device 48 across telephone lines 34. Sounding device 48, which is connected in series with a battery 50, is preferably an interruptor type device or a solid state noisemaker". Considering the operation of power failure detector 42, when a power failure occurs, one or both of

relays

44 and 46 will be deenergized and thus a circuit will be completed between sounding device 48 and audio monitor 10.

An indication of the occurrence of a fire may be provided by a fire or heat sensor 52 of conventional construction, connected in series with a further sounding device or alarm 54. Of course, other sensing devices and associated sounding alarms may also be used. Each such alarm used in the protected area should have a distinctive sound so that a person monitoring the protected area will know immediately what has occurred.

Referring to FIG. 2, one embodiment of the sending units 12 of FIG. 1 is shown. In the embodiment shown, the device of the invention is incorporated into a system having an intercommunication or intercom setup indicated at 56. The intercom speakers 58 are used as the sensing transducers for the system and are connected to the two inputs of an amplifier 60. Amplifier 60 may take a number of forms and any suitable amplifier arrangement may, of course, be utilized. In the embodiment shown in FIG. 2, amplifier 60 is housed with a switching unit 62 which includes a series of terminals 62 to 62 A power supply 64 for amplifier 60 is connected across

terminals

62 and 62 of switching unit 62. Power supply 64 may be a simple DC battery.

A telephone unit 66 for communicating with the control station at which monitors are located, is connected to terminals 62 62 and 62,, of switching unit 62. Connection of telephone unit 66 to telephone lines 34 is controlled by a fourpole, double-throw switch indicated at 67. In the first position thereof, switch 67 connects amplifier 60 to the positive side of power supply 64 through switch terminal 67A,; connects one output of amplifier 60 to terminal 62 through contact terminal 678,, terminal 62 being connected to one of the telephone lines 34; and connects the outputs of intercom 56 to the inputs of amplifier 60 through terminals 67C and 67D, so that the output of intercom 56 is connected to telephone line 34 through amplifier 60. In the second position thereof, switch 67 connects telephone unit 66 to telephone lines 34 as described hereinbelow. Telephone unit 66 includes a conventional receiver 68 and a conventional transmitter 70. Unit 66 also includes a pushbutton switch 72 which controls connection of receiver 68 and transmitter 70 to input

terminals

62 and 62 respectively and a line monitor 74 which is connected between power supply 64 and a first terminal 760 of a conventional cradle switch 76. The switching terminal 76c of cradle switch 76 is connected to terminal 62 of switching unit 62 whereas the telephone lines 34 of FIG. 1 are connected to switching

unit terminals

62 and 62 Thus, line monitor 74, which comprises a conventional free running multivibrator or flip-flop, provides, with cradle switch 76 in the normal position thereof, a continuous signal such as a clicking sound over the telephone lines 34. The circuit is completed through power supply 64, switch unit terminal 62,, and control switch terminals 67A; and 678 to output terminal 62 and through switch 76 and terminal 62., to output terminal 62 Connection of the telephone receiver 68 and transmitter 70 is also controlled by switch 67. Thus with cradle switch 76 open, and hence with switch contact terminal 760 connected to contact terminal 76b, for the first position of pushbutton switch 72, receiver 68 is connected to telephone line output terminal 62 through terminal 62 and control switch contact terminal 678:, and to telephone line output terminal 62 through cradle switch 76 and switching unit terminal 62 With pushbutton switch in the second position thereof, transmitter 70 is connected through power supply 64, switching unit terminal 62,, and control switch contact terminals 67A and 67B to telephone line output terminal 62 and through cradle switch 76 and switching unit input terminal 62., to telephone line output terminal 62 similarly to line monitor 74.

The sending arrangement described hereinabove permits detection of any noises within the protected areas through the pickup speakers 58 of intercom 56 as well as provides for communication with the protected area through telephone unit 66 as is described in somewhat more detail hereinbelow.

Referring to FIG. 3, a schematic circuit diagram of one embodiment of the audio monitors 10 of FIG. 1 is shown.

Input terminals

80 and 82 of the monitor are connected to telephone line 34 and to switch 28 which, when actuated, as described hereinabove, provides a connection to amplifier 14. Switch 28 is mechanically interlocked with a reset switch 84 as indicated by dashed lines 86. Switch 28 and switch 84 may be part of a conventional three'pole, double-throw switch.

Input terminals

80 and 82 are also connected through a telephone jack 88 to the primary winding 90 of a transformer 92. One side of the secondary winding 94 of transformer 92 is connected to base of a PNP transistor 96 through a resistor 98 whereas the other side of winding 94 is connected to the emitter of transistor 96 through a resistor I00 and capacitor 102 connected in parallel. Transistor 96 drives a sensing relay 104 connected in the collector-to-base circuit thereof, a diode 106 being connected across relay 104. Biasing for the basecollector junction of transistor 96 and sensitivity control for relay 104 is furnished from a negative supply terminal 108 through a variable resistor 110 and a fixed resistor 112. A positive supply terminal for the base-emitter junction is indicated at 114.

Sensing relay 104 controls actuation of normally open contacts 1040 which, when closed, complete the energization circuit for a 24-volt AC holding relay 116. Relay 116, when energized from input supply terminals 118, causes three sets of normally

open contacts

116a, 116b and 116C to close. Contacts 116a, when closed, provide a holding circuit for relay 116 whereas contacts 116b and 116s control energization of a pilot or indicator light 120 and buzzer alarm 32 (not shown in FIG. 3), respectively. A pilot light corresponding to light 120 is provided for each monitor 10 whereas, as set forth hereinabove, buzzer alarm 32 is common to all monitors.

Reset switch 84, when opened, breaks the holding circuit forrelay 116 and thus returns the relay circuit to the normal condition or state thereof.

Telephone jack 88 permits a telephone unit 122 to be plugged in so that communication can be maintained between the control station and the protected areas. The telephone unit 122 includes a transmitter 124 and cradle switch 126 connected in series with DC supply terminals 128 and the primary winding of a transformer 130, A receiver 132 and pushbutton switch 134 are connected across the secondary winding of transformer and to a coiled output cord 136 which terminates in a telephone plug 138.

A tape recorder 140 may also be plugged into jack 88 to provide a recording of the activity taking place in a particular area. Telephoncjack 88 is preferably of the switch type so that when tape recorder 140 is plugged in the sensing relay 104 is disconnected although the telephone lines 34 may be audibly monitored while recording if desired.

Referring to FIG. 4, a sending unit matching circuit is shown which may be used when the intercom system 56 of FIG. 2 includes its own amplifier. The circuit of FIG. 4 includes a telephone transmitter 142 connected in series with the primary winding of a transformer 144, power supply terminals 146 and a cradle switch 148. Cradle switch 148, in the second position thereof, connects a line monitor 150 of the type described hereinabove to power supply terminals 146. A telephone receiver 152 is connected in series with a pushbutton switch 154 across the secondary winding of transformer 144. A switch 156 controls connection of telephone lines 34 either to the sending unit terminals 158 or to the intercom terminals 160.

For preexisting installations where a sound system is required, a solid-state system is preferably used which is housed in switching unit 62 or connected externally to the sending unit. The pickup devices used are preferably speakers as described hereinabove and thus the amplifier used should properly match the number of speakers connected across the output thereof. The voltage output of such a speaker for relatively faint sounds, such as made by an intruder attempting to avoid making noise, is quite small and hence the amplifier used should be able to amplify a signal of between about 75 or 80 db. to about a 0 db. level.

Although the operation of the system described hereinabove is believed to be generally apparent from the above description, this operation will be briefly summarized here. Referring particularly to FIG. 1, any sounds detected by the sending unit transducers (speakers 40 of FIG. 1 and speakers 58 of FIG. 2) in a particular area are transmitted over the corresponding telephone lines 34 to the respective audio monitor 10. The electrical signal corresponding to the detected sound is, after amplification by transistor 96, sensed by sensing relay 104 (see FIG. 3) which causes relay contacts 104a to close and holding relay 106 to be energized. Energization of holding relay 106 causes contacts 116a to close to form a holding circuit and in addition causes activation of a pilot or indicator light 120 individual to the particular monitor as well as of the common buzzer alarm 32. The attendant, upon noting the lighting of light 120, then manually actuates reset switch 84 which is mechanically interlocked to switch 28. Closing of switch 28 causes telephone line 34 to be connected to common speaker 16 through amplifier 14 so that the attendant may listen to the reproduction of the sound and determine the significance thereof so that appropriate action may be taken. The tape recorder 140 may be plugged into telephone jack 88 at this time if desired. The buzzer alarm 32 is used to warn the attendant when he is away from the control station. The reset switch 84 may be returned to the normal position thereof while other sending units are being monitored or while an appropriate action is taken in response to the received signal.

Telephone unit 122 of the audio monitors 10 and the telephone unit 66 at each protected area permit communication with the various areas prior to activating the detection system. For example, when a building is being secured for the day, last minute information may be transmitted by picking up the telephone and speaking with the pushbutton 72 depressed so that transmitter 70 is connected to power supply 64. Before leaving the building the operator throws switch 67 to the first or detection" position thereof wherein amplifier 60 is connected to the speakers 58 of the intercom unit 56. The line monitor 74, as stated hereinabove, is used to produce a characteristic noise, such as a low level click, over the associated telephone line 34 while the building is occupied, the click indicating that the telephone unit 66 is in good order. Thus if the click is heard when the building should be secured an indication is provided that the switch 67 was not set to the "detection" position and the attendant can be contacted by telephone to rectify this.

As stated hereinabove, although detection apparatus of the invention has been shown as incorporated in an audio system, the apparatus may also comprise part of a direct" type system wherein a direct connection is provided between the sending units and the monitors. A direct line system would be substantially the same as the audio system disclosed but would be even less involved. For example, the DC supply for the direct line monitors would not have to be regulated as must the DC supply for audio monitors described hereinabove. The direct system would be particularly suited for use for protecting a single piece of property such as a modern shopping center wherein anywhere from six to 60 or more stores are housed essentially under one roof.

Although the invention has been described in detail with respect to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that variations and modifications may be effected within the scope and spirit of the invention.

Iclaim:

1. An intrusion and mechanical disturbance detection system comprising a plurality of sending units, one said sending unit being located in each area to be monitored and each of said sending units including detecting means for detecting acoustical energy generated within a protected area and for converting detected acoustical energy into electrical energy, at least one of said detecting means comprising a means for sensing sounds such as made by intruders entering a protected area and a means for detecting mechanical disturbances and producing a corresponding audio output, said sending units further comprising amplifier means for converting said electrical energy into an amplified electrical signal; a monitoring station comprising electrical monitoring means for monitoring said plurality of sending units; and transmitting means for transmitting a said electrical signal from a protected area to said monitoring station, said monitoring means comprising a plurality of audio monitors individual to said sending units and an indicator device common to said plurality of monitors, a common power supply for said plurality of monitors, and a common output transducer for said plurality of monitors for converting a said electrical signal into an acoustical signal and a common amplifier for amplifying the input to said common output transducer, said transmitting means comprising telephone lines connected between said sending units and said monitors and said sending means including means for connecting the associated detecting means to the corresponding telephone line, said mechanical disturbance detecting means comprises a first means for detecting mechanical disturbances of a first type and a second means for detecting mechanical disturbances of a second type, said first means causing actuation of a first device for producing a characteristic sound and said second means causing actuation of a second device for producing a characteristic sound different from the sound produced by said first device, said first mechanical disturbance detecting means comprising power failure detecting means for detecting a power failure for a three-phase system, said power failure detecting means including first and second relays, first and second sets of relay contacts and an independent source of power for said first sound producing device, said first relay being connected between neutral and a first phase conductor of the three-phase system and said second relay being connected between the remaining two phase conductors of the three-phase system and the first and second sets of relay contacts controlled by said first and second relays completing, in the actuated state thereof, a circuit between a said sending unit and the transmitting means connecting said sending unit to a corresponding monitor, and completing, in the unactuated state thereof, a circuit including said first sound producing device, said independent source of power, and said transmitting means.

2. A system as claimed in claim 1 wherein said second mechanical disturbance detecting means comprising means for detecting a fire within the area to be protected, said fire detection means comprising a heat sensor and said second sound producing device being responsive to said heat sensor.

3. A system as claimed in claim 1 wherein each said audio monitor comprises transformer means connected to the corresponding telephone line, means for amplifying the electrical signal received over said telephone line, a sensing relay connected to the output of said amplifier means, a holding relay responsive to the energization of said sensing relay and a manually actuated reset switch for, when actuated, breaking the holding circuit of said holding relay, said system including a plurality of further switches individual to said audio monitors for controlling the connection of the outputs of said telephone lines to said common amplifier, each said reset switch being mechanically interlocked with a corresponding said further switch to cause actuation thereof when said reset switch is actuated so as to cause connection of the associated telephone line to said common amplifier.

4. A system as claimed in claim 3 wherein said common transducer comprises a buzzer and wherein said holding relay controls actuation of a first set of contacts for controlling actuation of said buzzer, said system further comprising an indicator light individual to each monitor and said holding relay controlling a second set of contacts for controlling actuation of said indicator light, a third set of contacts controlled by said holding relay providing a holding circuit for said holding relay and being connected in series with said reset switch.