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US4176348A Expired / Lapsed US ⏱️ 0.0 years remaining

Electronic security device

Assignee: KYRN AND PATRICIA TEEUW 7005 DRY CREEK ROAD HEALDSBURG CA 95448
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Filing: 1978-03-30
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Granted: 1979-11-27
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Expires: 1998-03-30
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Abstract

Abstract An electronic security device includes an insulated loop shaped antenna which capacitively couples to any objects which intrude into a zone surrounding the antenna. The loop shape allows the antenna to be placed onto a doorknob of the room to be secured, and the insulation prevents electrical contact-bounce between the antenna and the doorknob. A detector circuit connects to the antennna and generates output signals indicating the amount of capacitive coupling. An alarm circuit connects to the detector circuit and sounds an audible alarm for a predetermined time interval when the coupling as indicated by the output signals implies that an object has intruded into the zone. A test circuit connects to the alarm circuit for temporarily decreasing the time interval of the alarm in response to a manually activated switch to allow the security device to be tested prior to being fully activated.

Inventors

  • 👤 Joseph J. Tobin
  • 👤 David B. Robinson
  • 👤 Robert L. Peay
  • 👤 Jerry R. Powell
  • 👤 Leslie W. Gay

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 21:14
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/22; G08B13/26

Claims Analysis

Total Claims: 16
Claim 1
Independent Claim 136 words
A portable electronic device for detecting the presence of absence of objects, said device being comprised of first circuit means for capacitively coupling to any objects within a zone surrounding said first circuit, second circuit means connected to said first circuit means for generating output signals indicating changes in said capacitive coupling, and third circuit means connected to said second circuit means for receiving said output signals and for taking predetermined action when said output signals indicate an intrusion of objects into or movement of objects within said zone, wherein said first circuit means is an antenna comprised of a wire in the shape of a loop for placement onto a doorknob and wherein said wire is covered with an insulator such that said antenna capacitively couples to said doorknob without being in physical contact therewith.
Claim 2
Dependent Claim 136 words
A portable electronic device for detecting the presence of absence of objects, said device being comprised of first circuit means for capacitively coupling to any objects within a zone surrounding said first circuit, second circuit means connected to said first circuit means for generating output signals indicating changes in said capacitive coupling, and third circuit means connected to said second circuit means for receiving said output signals and for taking predetermined action when said output signals indicate an intrusion of objects into or movement of objects within said zone, wherein said first circuit means is an antenna comprised of a wire in the shape of a loop for placement onto a doorknob and wherein said wire is covered with an insulator such that said antenna capacitively couples to said doorknob without being in physical contact therewith.
Claim 3
Dependent Claim 40 words
A device according to claim 1 wherein said wire and insulator are flexible and said antenna further includes a slip-ring around said antenna for increasing and decreasing the size of said loop to rigidly connect said device to said doorknob.
Claim 4
Dependent Claim 53 words
A device according to claim 1 wherein said second circuit means includes variable frequency oscillator means for generating oscillating signals having frequencies indicating the amount of said coupling, and filter means connected thereto for rejecting capacitive coupling changes between said antenna and objects within said zone which occur at above human movement rates.
Claim 5
Dependent Claim 61 words
A device according to claim 3 wherein said second circuit means further includes means for converting said oscillating signals to analog voltage levels representative of the frequency of oscillation coupled to said variable frequency oscillator, and means for generating said output signals in the form of logic levels in response to predetermined changes in the level of said analog voltage levels.
Claim 6
Dependent Claim 28 words
A device according to claim 4 wherein said means for generating includes means for rejecting said analog voltage changes when they occur at less than a predetermined rate.
Claim 7
Dependent Claim 26 words
A device according to claim 4, wherein said third circuit means includes feedback means for disabling said means for converting while said predetermined action is occurring.
Claim 8
Dependent Claim 26 words
A device according to claim 4, wherein said third circuit means includes feedback means for disabling said means for generating while said predetermined action is occurring.
Claim 9
Dependent Claim 116 words
A portable electronic device for detecting the presence or absence of objects, said device being comprised of first circuit means for capacitively coupling to any objects within a zone surrounding said first circuit, second circuit means connected to said first circuit means for generating output signals indicating changes in said capacitive coupling, third circuit means connected to said second circuit means for receiving said output signals and for sounding an alarm for a predetermined time interval when said output signals indicate an intrusion of objects into and movement of objects within said zone, and fourth circuit means connected to said third circuit means for temporarily shortening said time interval in response to a manually activated switch.
Claim 10
Dependent Claim 116 words
A portable electronic device for detecting the presence or absence of objects, said device being comprised of first circuit means for capacitively coupling to any objects within a zone surrounding said first circuit, second circuit means connected to said first circuit means for generating output signals indicating changes in said capacitive coupling, third circuit means connected to said second circuit means for receiving said output signals and for sounding an alarm for a predetermined time interval when said output signals indicate an intrusion of objects into and movement of objects within said zone, and fourth circuit means connected to said third circuit means for temporarily shortening said time interval in response to a manually activated switch.
Claim 11
Dependent Claim 53 words
A device according to claim 8 wherein said first circuit means is an antenna comprised of a wire in the shape of a loop for placement onto a doorknob and wherein said wire is covered with an insulator such that said antenna capacitively couples to said doorknob without being in physical contact therewith.
Claim 12
Dependent Claim 55 words
A device according to claim 8 wherein said second circuit means includes variable frequency oscillator means for generating oscillating signals having frequencies indicating the amount of said coupling, and filter means connected thereto for rejecting capacitive coupling changes between said first circuit means and objects within said zone which occur at above human movement rates.
Claim 13
Dependent Claim 61 words
A device according to claim 8 wherein said second circuit means further includes means for converting said oscillating signals to analog voltage levels representative of the frequency of oscillation coupled to said variable frequency oscillator, and means for generating said output signals in the form of logic levels in response to predetermined changes in the level of said analog voltage levels.
Claim 14
Dependent Claim 28 words
A device according to claim 11 wherein said means for generating includes means for rejecting said analog voltage changes when they occur at less than a predetermined rate.
Claim 15
Dependent Claim 28 words
A device according to claim 11 wherein said third circuit means includes means for rejecting said analog voltage changes when they occur at less than a predetermined rate.
Claim 16
Dependent Claim 25 words
A device according to claim 11, wherein said third circuit means includes feedback means for disabling said means for generating while said alarm is sounding.

References Cited (Backward Citations)

US3761912A Cited
US3784848A Cited
US4091371A Cited
US4083022A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1982-11-26 1983-05-28 1983-11-27 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1986-11-26 1987-05-28 1987-11-27 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1990-11-26 1991-05-28 1991-11-27 $7700.00 Window Closed / Lapsed

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