Patent FR565888A successfully refreshed from Google Patents.
US5115224A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Personal security system network
Assignee: Denka Co Ltd
•
Filing: 1991-07-05
•
Granted: 1992-05-19
•
Expires: 2011-07-05
Abstract
Abstract A personal security system includes at least one movable transmitter adapted to produce an emergency signal transmission when activated and a plurality of transceivers adapted to receive emergency signal transmissions from the movable transmitter. The received strength of an emergency signal received by one of the transceivers is compared with the received signal strength of an emergency signal received by other of the transceivers, and an alarm signal is produced by a transceiver in response to receipt of a transmission whose signal strength is stronger than any other transmission signal strength to which it has been compared. The alarm signal may include a code identifying both the activated movable transmitter and the transceiver producing the alarm signal.
Inventors
- 👤 Karl H. Kostusiak
- 👤 Daniel F. Pedtke
- 👤 Todd E. Heckleman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 23:27
CPC Classifications
G; G08; G08B; G08B25/00; G08B25/009
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
103 words
A personal security system comprising: at least one movable transmitter adapted to produce an emergency signal transmission when activated; a plurality of transceivers adapted to receive emergency signal transmissions from the movable transmitter; means for comparing the received strength of an emergency signal received by one of said transceivers with the received signal strength of an emergency signal received by others of said transceivers; and means for causing a transceiver to produce an alarm signal only in response to receipt of a transmission whose signal strength is at least as strong as any other received signal strength to which it has been compared.
Claim 2
Dependent Claim
103 words
A personal security system comprising: at least one movable transmitter adapted to produce an emergency signal transmission when activated; a plurality of transceivers adapted to receive emergency signal transmissions from the movable transmitter; means for comparing the received strength of an emergency signal received by one of said transceivers with the received signal strength of an emergency signal received by others of said transceivers; and means for causing a transceiver to produce an alarm signal only in response to receipt of a transmission whose signal strength is at least as strong as any other received signal strength to which it has been compared.
Claim 3
Dependent Claim
24 words
A personal security system as set forth in claim 1 wherein said alarm signal includes a code identifying the transceiver producing the alarm signal.
Claim 4
Dependent Claim
29 words
A personal security system as set forth in claim 1 wherein said alarm signal includes a code identifying the activated movable transmitter and the transceiver producing the alarm signal.
Claim 5
Dependent Claim
33 words
A personal security system as set forth in claim 1 wherein: said transceivers are fixed in a predetermined pattern within a geographic area; and said movable transmitters are portable within said geographic area.
Claim 6
Dependent Claim
38 words
A personal security system as set forth in claim 4 wherein said emergency signal transmissions of the portable transmitters are radio frequency signals to be received by all transceivers that are within radio range of an activated transmitter.
Claim 7
Dependent Claim
27 words
A personal security system as set forth in claim 5 wherein said transceivers include a receiver adapted to produce a coded data signal and a received-signal-strength indication.
Claim 8
Dependent Claim
31 words
A personal security system as set forth in claim 6 wherein said transceivers include a transmitter adapted to produce a relay signal including said coded data signal and said received-signal-strength indication.
Claim 9
Dependent Claim
34 words
A personal security system as set forth in claim 7 wherein said relay signal producing transmitter is adapted to produce the relay signal having the approximate same frequency as that of said movable transmitter.
Claim 10
Dependent Claim
39 words
A personal security system as set forth in claim 8 wherein said relay signal is identical to the transmission from the movable transmitter in terms of format, frequency, and power level, with the addition of the received-signal-strength indication information.
Claim 11
Dependent Claim
40 words
A personal security system as set forth in claim 3 further comprising a central station, and wherein said transceivers are adapted to re-transmit alarm signals received from other transceivers so as to propagate the alarm signal to said central station.
Claim 12
Dependent Claim
47 words
A personal security system as set forth in claim 3 further comprising a central station, and wherein said transceiver further includes a second transmitter having a longer transmitting range than the other transmitter in the transceiver so as to broadcast an alarm signal to the central station.
Claim 13
Dependent Claim
29 words
A personal security system as set forth in claim 3 wherein said transceiver transmitter is adapted to randomly space multiple transmissions to avoid collisions between transmissions from other transmitters.
Claim 14
Dependent Claim
87 words
A personal security system as set forth in claim 1 wherein said means for comparing the received strength of an emergency signal comprises: means for causing each transceiver to transmit an alarm signal at the end of a respective time period following receipt of an emergency signal, said respective time period for each transceiver being inversely related to the strength of an emergency signal as received by the transceiver; and means for preventing transmission of an alarm signal by any but the first transceiver to do so.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-05-19 | 1995-11-18 | 1996-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-05-19 | 1999-11-18 | 2000-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-05-19 | 2003-11-18 | 2004-05-19 | $7700.00 | Window Closed / Lapsed |