US3886534A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Security system
Assignee: POLAR CORP
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Filing: 1973-01-08
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Granted: 1975-05-27
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Expires: 1993-01-08
Abstract
Abstract A security system for monitoring predetermined alarm conditions at multiple locations. Security units are provided at each monitored location with each unit including an emergency d.c. power source for providing power during a.c. power line failure. In the event of an alarm condition, an amplitude modulated radio frequency carrier signal having a modulation frequency indicating the location of an alarm condition is superimposed on an a.c. power line for detection at a remote monitoring location. A method is provided for checking the operability of the individual security units by the user of the unit without indicating an alarm condition at the monitoring location. A two modulation frequency method and system is provided for two alarm conditions.
Inventors
- 👤 Norwood Rosen
- 👤 Anthony J Nicolini
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:38
CPC Classifications
G; G08; G08B; G08B25/00; G08B25/01; G08B25/06; G08B29/00; G08B29/12; G08B29/14
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
412 words
A security system for use with an a.c. power line connected between a plurality of locations comprising: a plurality of security units, each including a sensor for detecting the opening of a portal and a sending unit responsive to said sensOr for coupling to the a.c. power line an amplitude modulated radio frequency signal identifying the location of the security unit at which said predetermined condition exists, each of said sending units including: a radio frequency oscillator for generating a carrier signal having a predetermined frequency common to a plurality of said sending units, and means for amplitude modulating said carrier signal, the combination of the predetermined frequency and the amplitude modulation being unique to each of said security units, one of said sending units includes switch means biased to couple said amplitude modulated radio frequency signal to said a.c. power line and manually operable against said bias to uncouple said amplitude modulated signal to said a.c. power line, said one sending unit being disposed in sufficient proximity to the portal to permit the manual operation of said switch means simultaneously with the manual opening of the portal to permit the opening of the portal without the coupling of said amplitude modulated signal to said a.c. power line, the bias of said switch means being sufficient to couple said amplitude modulated signal to said a.c. power line in the event that the open condition of the portal persists beyond the manual operation of said switch means so that the natural act of stepping away from the portal upon the forceable entrance of an intruder through the portal couples said condition responsive signal to said a.c. power line; and, a monitor unit coupled to said a.c. power line at a location remote from said plurality of security units and responsive to the coupling of amplitude modulated radio frequency signals on the a.c. power line for indicating at which of said security units said sensed predetermined condition exists; said monitor unit including a plurality of modules, each of said modules associated with a predetermined group of said security units having a common carrier frequency different from the carrier frequency of all of the remaining ones of said security units, each of said modules having means for indicating at which of the security units in an associated group said predetermined condition exists, and each of said modules including a plurality of switch means responsive to a different frequency of modulation to actuate said indicating means.
Claim 2
Dependent Claim
412 words
A security system for use with an a.c. power line connected between a plurality of locations comprising: a plurality of security units, each including a sensor for detecting the opening of a portal and a sending unit responsive to said sensOr for coupling to the a.c. power line an amplitude modulated radio frequency signal identifying the location of the security unit at which said predetermined condition exists, each of said sending units including: a radio frequency oscillator for generating a carrier signal having a predetermined frequency common to a plurality of said sending units, and means for amplitude modulating said carrier signal, the combination of the predetermined frequency and the amplitude modulation being unique to each of said security units, one of said sending units includes switch means biased to couple said amplitude modulated radio frequency signal to said a.c. power line and manually operable against said bias to uncouple said amplitude modulated signal to said a.c. power line, said one sending unit being disposed in sufficient proximity to the portal to permit the manual operation of said switch means simultaneously with the manual opening of the portal to permit the opening of the portal without the coupling of said amplitude modulated signal to said a.c. power line, the bias of said switch means being sufficient to couple said amplitude modulated signal to said a.c. power line in the event that the open condition of the portal persists beyond the manual operation of said switch means so that the natural act of stepping away from the portal upon the forceable entrance of an intruder through the portal couples said condition responsive signal to said a.c. power line; and, a monitor unit coupled to said a.c. power line at a location remote from said plurality of security units and responsive to the coupling of amplitude modulated radio frequency signals on the a.c. power line for indicating at which of said security units said sensed predetermined condition exists; said monitor unit including a plurality of modules, each of said modules associated with a predetermined group of said security units having a common carrier frequency different from the carrier frequency of all of the remaining ones of said security units, each of said modules having means for indicating at which of the security units in an associated group said predetermined condition exists, and each of said modules including a plurality of switch means responsive to a different frequency of modulation to actuate said indicating means.
Claim 3
Dependent Claim
69 words
The security system of claim 1 wherein power from the a.c. power line is utilized for the normal operation of the system, and including: an independent source of power for each of said security units and for said monitor unit; and, means responsive to a loss of power on said a.c. power line for connecting said independent sources of power to said security units and to said monitor unit.
Claim 4
Dependent Claim
26 words
The security system of claim 1 wherein said sending unit further includes tuning fork means for establishing the modulation frequency for each of said security units.
Claim 5
Dependent Claim
155 words
The security system of claim 1 wherein each of said modules includes means for demodulating an amplitude modulated radio frequency carrier signal coupled to the a.c. power line comprising: crystal controlled radio frequency amplifying means including crystal controlled filter means tuned to the frequency of said carrier signal; transformer means coupled to said a.c. power line for applying signals to said crystal controlled radio frequency amplifying means, said transformer means being tuned to the frequency of said carrier signal for removing a.c. power line signals from the signal applied to said crystal controlled radio frequency amplifying means; means for amplifying the output signal from said radio frequency amplifying means; and, crystal controlled detector means for generating an output signal having a frequency corresponding to that of said carrier modulation, said detector means including crystal controlled filter means tuned to said carrier frequency for removing carrier frequency signal components from signals applied to said deTector means.
Claim 6
Dependent Claim
54 words
The security system of claim 1 wherein each of said security units includes a plurality of sensors; and, wherein said sending unit is responsive to each of said plurality of sensors to couple to the a.c. power line an amplitude modulated signal having a predetermined frequency identifiable with one of said plurality of sensors.
References Cited (Backward Citations)
US3029420A
Cited
US3204245A
Cited
US3201592A
Cited
US3200393A
Cited
US3388389A
Cited
US3460121A
Cited
US3530450A
Cited
US3487397A
Cited
US3534350A
Cited
US3603973A
Cited
US3705401A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-26 | 1978-11-25 | 1979-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-26 | 1982-11-25 | 1983-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-26 | 1986-11-25 | 1987-05-27 | $7700.00 | Window Closed / Lapsed |