US3247502A - System for signalling unauthorized displacement of an article - Google Patents

System for signalling unauthorized displacement of an article Download PDF

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Publication number
US3247502A
US3247502A US317618A US31761863A US3247502A US 3247502 A US3247502 A US 3247502A US 317618 A US317618 A US 317618A US 31761863 A US31761863 A US 31761863A US 3247502 A US3247502 A US 3247502A
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US
United States
Prior art keywords
wall
switches
unit
signalling
magnets
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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US317618A
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English (en)
Inventor
Eberts Klaus
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Accumulatorenfabrik Sonnenschein GmbH
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Accumulatorenfabrik Sonnenschein GmbH
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H36/00—Switches actuated by change of magnetic field or of electric field, e.g. by change of relative position of magnet and switch, by shielding
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B13/00—Burglar, theft or intruder alarms
    • G08B13/02—Mechanical actuation
    • G08B13/08—Mechanical actuation by opening, e.g. of door, of window, of drawer, of shutter, of curtain, of blind
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B13/00—Burglar, theft or intruder alarms
    • G08B13/02—Mechanical actuation
    • G08B13/14—Mechanical actuation by lifting or attempted removal of hand-portable articles
    • G08B13/149—Mechanical actuation by lifting or attempted removal of hand-portable articles with electric, magnetic, capacitive switch actuation

Definitions

  • My invention relates to a system for signalling unauthorized displacement of an article positioned on a surface, such as a picture suspended on a wall, to thereby protect the article from theft.
  • FIG. 1 is a perspective view of a self-contained signalemitting unit forming part of my novel system, this unit being disposed in a sheltered position between a wall shown in cross section and a picture suspended thereon, the picture being likewise shown in perspective, partly broken away,
  • FIG. 2 is a circuit diagram of the emitter unit shown in FIG. 1,
  • FIG. 3 represents a receiver forming part of my novel system, the receiver being disposed at a remote alarm station,
  • FIG. 4 is a modified circuit diagram of the emitter unit shown in FIG. 1,
  • FIG. 5 is a circuit diagram of the receiver shown in FIG. 3, and
  • FIG. 6 is a sectional view of one of the switches included in the emitter unit of FIG. 1 and shown in FIGS. 2 and 4.
  • a picture or painting 10 consisting of a canvas 11 held by a frame 12 is suspended on a wall 13, such as the wall of a hall in a museum, and a self-contained signalling unit 14 is disposed in a sheltered or hidden position between the substantially plane back-face of the picture 10 and the plane surface of the Wall 13 confronting the back-face of the painting.
  • the housing of unit 14 has a front Wall 15 and a back wall 16 both extending parallel to each other and to the wall surface and consisting of steel or another suitable ferromagnetic material. Moreover, the
  • 3,247,502 Patented Apr. 19, 1966 housing has side walls 17, 18, 19 and 20 which extend at right angles to the wall surface and project beyond the front wall 15 and the back wall 16 a certain distance towards and into contact with the back-face of the painting and the wall surface.
  • the unit 14 and the wall 13 are illustrated as being spaced apart for the purpose of exposing the housing to view. In fact, however, the edges of the side walls 17-20 contact the painting and the wall surface.
  • the unit 14 is so far spaced from the frame 12 as to be invisible and practically inaccessible. It is fixed to the wall by suitable detachable means. In the embodiment illustrated in FIG.
  • this means comprises a cup-shaped shield member 21 of steel or of another ferromagnetic material fixed to the wall 13 and a permanent magnet 22 inserted in the cup-shaped member 21 and in contact with the plane bottom 23 thereof and with the back wall 16 of the housing.
  • the cup-shaped member 21 has a pin 24projecting from the bottom 23 thereof and the pin 24 is inserted in a bore 25 of a socket member 26 inserted in the wall 13 and suitably fixed thereto. In this manner the cup-shaped member 21 is securely held on the wall 13 and the permanent magnet 22 firmly adheres to the cup-shaped member and to the back wall 16 of the housing, whereby this housing is held in position on the wall 13.
  • Another cup-shaped shield member 27 having a plane bottom 28 encloses a second permanent magnet 29 which adheres to the front face of the front Wall 15 'of the housing and to the bottom 28 of member 27.
  • the bottom wall 28 is suitably fixed to the painting 10, for instance adhesively attached to the back of the canvas 11.
  • Each of the walls 15 and 16 has an aperture 30, or 31 respectively, whose diameter is smaller than the length of the permanent magnet 29, or 22 respectively, so that this magnet may extend across the aperture having its end portions firmly adhering to portions of the housing wall adjacent to the aperture.
  • the housing of unit 14 is diagrammatically indicated by broken lines. It encases a signalling circuit which includes a signalling device E, a source of current, such as an accumulator battery 32, and a pair of magnetically operable switches 33 and 34 each being of the type which tends to assume its connecting position but will stay in its disconnecting position, when subjected to a magnetic field.
  • The'switches 33 and 34 are preferably of the well known type shown in FIG. 6 which comprises an evacuated glass bulb 35 mounted in a socket 36 and enclosing a relatively stationary contact leaf 37 and a relatively movable contact leaf 38 carrying a small armature 39 of a suitable ferromagnetic material, such as steel, for attraction by one of the magnets 22, 29.
  • each of the switches 33, 34 is located adjacent to the aperture 30, or 31 respectively, as Will appear from FIG. 1.
  • the sockets 36 of the bulbs 35 of the switches constitute a support suitably fixed to the housing wall 15 in such a position that armature 39 of switch 33 is confronted with magnet 29, whereas armature 39 of switch 34 is confronted with magnet 22.
  • both of the switches 33 and 34 are maintained in the open condition illustrated in FIGS. 2 and 6 by the magnetic attracting forces produced by the magnetic field lines extending from the magnets 22, 29 through the apertures 31, 30 to the armatures 39.
  • the shield members 21, 27 have their edges disposed in substantial engagement with the housing walls 16, and- 15 respectively, and these edges are spaced from the wall surface and from the canvas of the painting a distance corresponding substantially to the distance by which the side walls 1720 project beyond the front and back walls 15 and 16 of the housing.
  • the permanent magnets 22 and 29 inserted in the cups 21 and 27 have a coercitive force of such strength as to be operative to do both (a) Attract the shield members 21 and 27 and the housing 14 for holding the latter in its normal position and (b) Cause their magnetic fields to extend through the apertures 31 and 30 of the opposed housing walls and to hold the switches 33, 34 in their disconnecting positions in which the signalling device E is disconnected from the battery 32.
  • the armature 39 of the switch 33 or 34 mounted behind the armature will 'cease to be attracted and permits its contact leaf 38 to engage the contact leaf 37 whereby an electrical circuit will be closed extending from one terminal of the battery 32 through the closed switch 33, or 34, the signalling device E and back to the other terminal of the battery 32.
  • the signalling device E will be energized and will emit a suitable acoustic or electromagnetic signal.
  • Suitable receiving means such as shown in FIG. 3, are disposed outside of and at a distance from the housing 14, for instance in a remote alarm station.
  • This receiving means may comprise a receiver 40 equipped with a microphone 41 where the signal-ling device E is an alarmbell emitting sound, or an antenna 42, where the signalling device E is a radio transmitter, or a loop antenna 43, where the signalling device E in housing 14 is so constructed as to transmit inductive low frequency impulses.
  • cup-shaped shield members 21 and 27 in cooperation with the housing walls and 16 consisting of iron or the like will effectively shield the armatures 39 of the switches 33 and 34 from any magnetic field which a thief may produce in an attempt of maintaining the switches 33 and 34 in their disconnecting positions while removing the painting '10 from the wall.
  • the embodiment of my invention described hereinabove with reference to FIG. 1 is capable of numerous modifications.
  • the cup-shaped shield member 21, the permanent magnet 22 therein and the switch 34 may be omitted, if the housing 14 is fixed to the wall 13 by other suitable means.
  • the embodiment shown in FIG. 1 has the advantage of a reliable response of the sel fcontained unit 14 to any attempt of tampering therewith. If the unit 14 is immovably fixed to the wall 13, a thief may try to drill a hole into the housing to thereby destroy the battery. With the embodiment shown in FIG. 1, however, any such attempt will inevitably result in a slight displacement of the housing 14 relative to the cup-shaped member 21 and in a consequent sounding of the alarm by switch 34.
  • a thief may silence the signalling device E within a few seconds after starting the alarm by destroying the self-contained unit 14 upon removal of the painting from the wall
  • means are preferably provided for keeping the alarm device in the receiver 40 in operation after the receipt of signals from the signal transmitting device E will have stopped.
  • the alarm device in the receiver 40 cannot be put out of function by wilful destruction of the self-contained unit 14.
  • FIG. 5 shows the circuit diagram of a receiver equipped with an alarm bell 50 and with a battery 51 for the operation thereof.
  • the receiver shown in FIG. 5 comprises a self contained unit 52 indicated by a broken line and disposed in a remote central alarm station in the museum building and a microphone 53 mounted in the same hall of the building in which paintings safeguarded by units 14 are accommodated.
  • the input of a scrambling or voice distorting unit 54 of well known conventional design is connected by a suitable cable to the microphone 53, whereas the output of the unit 54 which is supplied with electrical energy by the battery 51 is connected with the input of an amplifier 55 whose output is connected with the winding of a relay 56 having a normally open contact 57.
  • a second relay 60 is shunted across the alarm bell 50 by connection to wires 58 and 59.
  • This second relay has a normally open contact 61 which represents a holding contact which is placed parallel to the contact 57 and maintains both relay winding 60 and alarm hell 5% in energized condition after contact 57 may have opened as a result of a discontinuation of the emission of sound by the signalling device E or as a result of a destruction of the microphone 53.
  • the alarm bell may be silenced by opening press button switch 65.
  • Suitable means may be provided to make the alarm bell 50 responsive to a deenergization of the receiver such as exhaustion of the battery 51.
  • a third relay 62 may have a normally closed contact 63 and a winding connected to the battery 51 via the scrambling unit 54. When the battery 51 runs low but is still capable of sounding the bell 50, the relay contact 63 will close and will establish a circuit through the alarm hell 5%) and through the battery 51.
  • the scrambling unit 54 It is the purpose of the scrambling unit 54 to prevent misuse of the microphone 53 by connection to the output of amplifier 55 of a telephone permitting a person in the central alarm station to overhear conversation held in the hall in which microphone 53 is installed.
  • the battery 51 constitutes a source of energy which is individually coordinated to the alarm station and supplies energy to the receiver 52, my system is independent of the supply of electrical power from a power station.
  • the batteries 51 and 52 may be of the non-spillable transportable type which can be re-charged upon exhaustion.
  • leads 70 and 71 may lead from the terminals of battery 32 through suitable holes in the walls of unit 14 to a socket disposed in an easily accessible position for connection to a source of a re-charging voltage.
  • At least one of the wires 70 and 71 includes the blocking diode '72, such as a rectifier, which prevents the battery from being shortcircuited by a person tampering with the conductors 7t), 71.
  • FIG. 4 I have illustrated an embodiment of my invention in which the switches 33 and 34' are mounted in reversed position in which the contact leaf 37 rather than the contact leaf 38 is confronted with the permanent magnet, whereby this magnet keeps the switch in its closed position by magnetic attraction.
  • a relay 80 is mounted within the housing 40 and has a normally closed contact 81.
  • the winding of relay 80 has one terminal directly connected with one terminal of the battery 32' and has its other terminal connected with the other terminal of the battery 32 via the switches 33, 34' arranged in series. As long as the switches are kept in closed condition by magnetic attraction, the relay winding 80 is energized. Its resistance is so high that the energizing current is quite feeble but just sufiicient to attract armature 81.
  • the switch 33' or the switch 34 or both will be opened thereby interrupting the circuit through the winding of relay 80 permitting contact 81 to close and to thereby connect battery 3-2 to the signalling device E thus causing the alarm to be sounded.
  • the alarm will be also sounded, if the voltage of battery 32 owing to partial exhaustion has dropped below the limit required to keep contact 81 open. This limit voltage, however, will still suffice to operate the signalling device E.
  • System for signalling unauthorized displacement of an article positioned on a surface such as a picture suspended on a wall comprising a signalling circuit including a signalling device, a source of current and a pair of magnetically operable switches for connecting said device to said source for current, each of said switches being of the type which tends to assume its connecting position but will stay in its disconnecting position when subjected to a magnetic field, a housing encasing said device, said source of current and said switches and therewith constituting a self-contained unit disposed in a normal position between said surface and said article and hidden by the latter, and a plurality of magnets, at least one of said magnets being fixed to said picture for maintaining one of said switches in its disconnecting condition as long as said article is left undisplaced relative to said unit, another one of said magnets being fixed to said wall for maintaining the other one of said switches in its disconnecting condition as long as said unit is left undisplaced relative to said wall, said unit having portions of ferromagnetic material for attraction by one of said magnets fixed
  • System for signalling unauthorized displacement of an article having a substantially plane face and being positioned on a substantially plane surface confronting said plane face, such as a painting suspended on a wall said system comprising a housing disposed in a normal position on said surface behind said article so as to be hidden thereby, said housing having parallel front and back walls consisting of a ferromagnetic material and extending parallel to and spaced from said face and said surface, each of said walls having an aperture, and side walls projecting beyond said front and back walls a certain distance towards and into contact with said article face and said surface, a signalling circuit confined within said housing and including a signalling device, a source of electrical current and a pair of magnetically operable switches for connecting said device to said source for operation, each of said switches being located adjacent to an aperture and being of the type which tends to assume its connecting position but will stay in its disconnecting position when subjected to magnetic attraction, a pair of cup-shaped shield members of ferromagnetic material one having its bottom fixed to said plane face of the article and the other
  • System as claimed in claim 6 further comprising receiving means disposed outside of and at a distance from said housing for receiving signals emitted by said signalling device.
  • System as claimed in claim 6 further comprising means for normally energizing said receiving means so as to enable it to receive said signals, and an alarm device responsive to a de-energization of said receiving means.
  • System as claimed in claim 6 further comprising receiving means disposed outside of and at an alarm station distant from said housing for receiving signals emitted by said signalling device and an alarm device in said station connected to said receiving means to be responsive to the receipt of said signals, and means for keeping said alarm device in operation after the reception of said signals so that said alarm device cannot be put out of function by a willful destruction of said self-contained unit or of said receiving means.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Burglar Alarm Systems (AREA)
US317618A 1963-04-17 1963-10-21 System for signalling unauthorized displacement of an article Expired - Lifetime US3247502A (en)

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Application Number Priority Date Filing Date Title
DEA0042907 1963-04-17

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US (1) US3247502A (ko)
BE (1) BE640835A (ko)
CH (1) CH428503A (ko)
GB (1) GB1002295A (ko)
NL (1) NL300473A (ko)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3463491A (en) * 1966-01-26 1969-08-26 Albert E Shaw Pin detection system with radially symmetrical pattern of magnetic reed switches
US3484775A (en) * 1965-10-20 1969-12-16 Wallace Dean Cline Theft prevention system
US3530451A (en) * 1967-01-20 1970-09-22 Security Systems Inc Holster radio alarm
US3544987A (en) * 1967-02-24 1970-12-01 Renville H Mcmann Jr Property protection alarm system
US3569644A (en) * 1969-07-14 1971-03-09 Elgin Electronics Bill trap
US3582931A (en) * 1967-10-18 1971-06-01 Daniel Nawrocki Pilferage-prevention system
US3618067A (en) * 1969-11-04 1971-11-02 Donald P Devale Movement detector
US3618059A (en) * 1968-06-19 1971-11-02 Milton F Allen Electronic detection and tracing means
US3641425A (en) * 1969-08-07 1972-02-08 Transalarm Electronics Inc Alarm system
US3641540A (en) * 1970-03-30 1972-02-08 Joel L Cutler Wireless alarm system
US3665448A (en) * 1970-08-03 1972-05-23 Hugh A Mcglinchey Electronic shoplifting prevention system
US3710371A (en) * 1970-02-18 1973-01-09 G Whalen Portable security alarm and alarm system
US3725887A (en) * 1968-06-10 1973-04-03 Sneider Electronic Sys Inc Radio transmitting alarm system
US4023176A (en) * 1975-04-02 1977-05-10 Texas Instruments Incorporated Beacon tracking display system
EP0111948A1 (en) * 1982-11-19 1984-06-27 CASTELIJN & BEERENS LEDERWAREN B.V. Portable alarm device
US4638307A (en) * 1985-10-15 1987-01-20 Swartout Willson C Patient position monitoring system
WO1988003689A1 (en) * 1986-11-15 1988-05-19 John Bryan Clough Security device
US5512877A (en) * 1995-05-09 1996-04-30 Mosler, Inc. Currency removal sensor system
US20070040674A1 (en) * 2005-08-16 2007-02-22 Honeywell International, Inc. Conductive tamper switch for security devices
IT201900012729A1 (it) * 2019-07-24 2021-01-24 Petersen Fabio Rocco Valentini Dispositivo antifurto per oggetti da parete

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61201454U (ko) * 1985-06-07 1986-12-17
NO168394C (no) * 1986-05-21 1992-02-12 Securiton Ag Innretning til sikring mot tyveri av gjenstander
GB2197516B (en) * 1986-11-15 1990-10-03 John Bryan Clough Security device

Citations (15)

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Publication number Priority date Publication date Assignee Title
GB669820A (en) * 1948-03-06 1952-04-09 John Westaway Improvements in electric alarm devices
US2754498A (en) * 1954-04-29 1956-07-10 Louise K Lavelle Alarm device for suspended articles
US2766358A (en) * 1950-12-13 1956-10-09 Davidson Signal Co Ltd Hold-up alarm signal system
GB770958A (en) * 1954-06-22 1957-03-27 Bonochord Ltd Improvements relating to burglar alarms
US2877361A (en) * 1957-04-12 1959-03-10 Holmes Electric Protective Com Burglar alarm system
US2899674A (en) * 1959-08-11 Sierer
US2905762A (en) * 1957-04-10 1959-09-22 George W Rettie Fire and burglar alarm system
US2943308A (en) * 1956-03-15 1960-06-28 Everett A Westphal Protective alarm system
DE1108111B (de) * 1960-05-20 1961-05-31 Siemens Ag Anordnung zur Sicherung gegen Diebstahl
US3056951A (en) * 1958-05-06 1962-10-02 Doris H Tooni Safe alarm system
US3114905A (en) * 1962-08-13 1963-12-17 Michael T Sliman Alarm system
US3135953A (en) * 1961-11-06 1964-06-02 Samuel M Bagno Lamp illuminating network
US3155954A (en) * 1962-06-15 1964-11-03 Howard M Larrick Automatic sensitivity control for sound actuated detection and alarm systems
US3161742A (en) * 1961-08-24 1964-12-15 Specialties Dev Corp Magnetic intruder and fire deterctor
US3192517A (en) * 1962-05-11 1965-06-29 Bay State Security Corp Burglar alarm

Patent Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2899674A (en) * 1959-08-11 Sierer
GB669820A (en) * 1948-03-06 1952-04-09 John Westaway Improvements in electric alarm devices
US2766358A (en) * 1950-12-13 1956-10-09 Davidson Signal Co Ltd Hold-up alarm signal system
US2754498A (en) * 1954-04-29 1956-07-10 Louise K Lavelle Alarm device for suspended articles
GB770958A (en) * 1954-06-22 1957-03-27 Bonochord Ltd Improvements relating to burglar alarms
US2943308A (en) * 1956-03-15 1960-06-28 Everett A Westphal Protective alarm system
US2905762A (en) * 1957-04-10 1959-09-22 George W Rettie Fire and burglar alarm system
US2877361A (en) * 1957-04-12 1959-03-10 Holmes Electric Protective Com Burglar alarm system
US3056951A (en) * 1958-05-06 1962-10-02 Doris H Tooni Safe alarm system
DE1108111B (de) * 1960-05-20 1961-05-31 Siemens Ag Anordnung zur Sicherung gegen Diebstahl
US3161742A (en) * 1961-08-24 1964-12-15 Specialties Dev Corp Magnetic intruder and fire deterctor
US3135953A (en) * 1961-11-06 1964-06-02 Samuel M Bagno Lamp illuminating network
US3192517A (en) * 1962-05-11 1965-06-29 Bay State Security Corp Burglar alarm
US3155954A (en) * 1962-06-15 1964-11-03 Howard M Larrick Automatic sensitivity control for sound actuated detection and alarm systems
US3114905A (en) * 1962-08-13 1963-12-17 Michael T Sliman Alarm system

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3484775A (en) * 1965-10-20 1969-12-16 Wallace Dean Cline Theft prevention system
US3463491A (en) * 1966-01-26 1969-08-26 Albert E Shaw Pin detection system with radially symmetrical pattern of magnetic reed switches
US3530451A (en) * 1967-01-20 1970-09-22 Security Systems Inc Holster radio alarm
US3544987A (en) * 1967-02-24 1970-12-01 Renville H Mcmann Jr Property protection alarm system
US3582931A (en) * 1967-10-18 1971-06-01 Daniel Nawrocki Pilferage-prevention system
US3725887A (en) * 1968-06-10 1973-04-03 Sneider Electronic Sys Inc Radio transmitting alarm system
US3618059A (en) * 1968-06-19 1971-11-02 Milton F Allen Electronic detection and tracing means
US3569644A (en) * 1969-07-14 1971-03-09 Elgin Electronics Bill trap
US3641425A (en) * 1969-08-07 1972-02-08 Transalarm Electronics Inc Alarm system
US3618067A (en) * 1969-11-04 1971-11-02 Donald P Devale Movement detector
US3710371A (en) * 1970-02-18 1973-01-09 G Whalen Portable security alarm and alarm system
US3641540A (en) * 1970-03-30 1972-02-08 Joel L Cutler Wireless alarm system
US3665448A (en) * 1970-08-03 1972-05-23 Hugh A Mcglinchey Electronic shoplifting prevention system
US4023176A (en) * 1975-04-02 1977-05-10 Texas Instruments Incorporated Beacon tracking display system
EP0111948A1 (en) * 1982-11-19 1984-06-27 CASTELIJN & BEERENS LEDERWAREN B.V. Portable alarm device
US4584571A (en) * 1982-11-19 1986-04-22 Castelijn & Beerens Lederwaren B.V. Magnetic article theft alarm
US4638307A (en) * 1985-10-15 1987-01-20 Swartout Willson C Patient position monitoring system
WO1988003689A1 (en) * 1986-11-15 1988-05-19 John Bryan Clough Security device
US5512877A (en) * 1995-05-09 1996-04-30 Mosler, Inc. Currency removal sensor system
US20070040674A1 (en) * 2005-08-16 2007-02-22 Honeywell International, Inc. Conductive tamper switch for security devices
US7388484B2 (en) * 2005-08-16 2008-06-17 Honeywell International Inc. Conductive tamper switch for security devices
IT201900012729A1 (it) * 2019-07-24 2021-01-24 Petersen Fabio Rocco Valentini Dispositivo antifurto per oggetti da parete
WO2021014341A1 (en) * 2019-07-24 2021-01-28 Valentini Petersen Fabio Rocco Anti-theft device for wall-mounted objects

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Publication number Publication date
CH428503A (de) 1967-01-15
GB1002295A (en) 1965-08-25
BE640835A (ko) 1964-04-01
NL300473A (ko)

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