US4370020A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transportable fibre optic apparatus for use in a security system
Assignee: Individual
•
Filing: 1980-06-25
•
Granted: 1983-01-25
•
Expires: 2000-06-25
Abstract
Abstract Apparatus which comprises at least one length of flexible optic fibre, storage means for receiving the length of optic fibre, means for transmitting an optical signal along the length of optic fibre, and means for detecting an optical signal in the length of optic fibre. There is also provided a communication or security system which comprises at least one loop of flexible optic fibre, a reel on which the optic fibre is coilable, means for transmitting an optical signal along the loop of optic fibre, and means for detecting an optical signal in the length of optic fibre.
Inventors
- 👤 James W. Davey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:04
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/02; G08B13/12; G08B13/122; G08B13/124; G08B13/18; G08B13/181; G08B13/183; G08B13/186
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
74 words
A transportable unit for use in a security system, the unit comprising an axle and a handle for supporting the axle, a reel, rotatably mounted on the axle, on which a length of optic fibre is coiled and from which the optic fibre can be drawn as required, a transmitter for transmitting an optical signal along the length of optic fibre, and detecting means connectable to the optic fibre to detect said optical signal.
Claim 2
Dependent Claim
74 words
A transportable unit for use in a security system, the unit comprising an axle and a handle for supporting the axle, a reel, rotatably mounted on the axle, on which a length of optic fibre is coiled and from which the optic fibre can be drawn as required, a transmitter for transmitting an optical signal along the length of optic fibre, and detecting means connectable to the optic fibre to detect said optical signal.
Claim 3
Dependent Claim
12 words
A unit according to claim 1 which incorporates an independent power source.
Claim 4
Dependent Claim
29 words
A unit according to claim 1 wherein the detecting means is responsive to variations, including cessation, in the intensity of the optical signal in the length of optic fibre.
Claim 5
Dependent Claim
17 words
A unit according to claim 1 wherein the transmitter includes means for modulating the transmitting optical signal.
Claim 6
Dependent Claim
71 words
A security system comprising a unit according to claim 1 in which the optic fibre is drawn at least partially from the unit to form a loop around the perimeter of an area and the end of the optic fibre is brought back to and connected to the unit, and interruption of signals passing along the optic fibre is detected by the detecting means to indicate an intrusion into the area.
References Cited (Backward Citations)
US3943021A
Cited
GB1497995A
Cited
GB1488409A
Cited
US4095872A
Cited
US4275294A
Cited
US4307386A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-01-24 | 1986-07-26 | 1987-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-01-24 | 1990-07-26 | 1991-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-01-24 | 1994-07-26 | 1995-01-25 | $7700.00 | Window Closed / Lapsed |