US5257290A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transmission line termination of guide-communications wire for guided vehicles
Assignee: Comsource Systems Corp
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Filing: 1989-02-10
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Granted: 1993-10-26
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Expires: 2009-02-10
Abstract
Abstract A system for digital communication over a wire lain along the path of guided vehicles to a modem and a loop driver, the modem providing high frequency signals and the loop driver providing low frequency control signals. Instead, the modem and the loop driver are connected to one end of the wire and the other end of the wire is connected through an impedance matching network to earth ground. The impedance matching network provides an impedance approximately equal to the impedance of the wire at the frequency of the high frequency signals. The impedance matching network may conveniently comprise an inductor (choke) in parallel with a capacitor connected between the end of the wire and earth ground and a plurality of resistors connected in parallel with said inductor and capacitor. The resistors are selectively clipped to eliminate the echo bringing the impedance of the impedance matching network to approximate equality with the impedance of the wire at the frequency of the high frequency signals. Alternatively, a single loop connected in the ordinary way to the modem and loop driver, may be cut to form two separate wires and two separate impedance networks provided one at each end of the wires to earth ground.
Inventors
- 👤 Lawrence W. Hill
- 👤 Frederick W. Sarles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:46
CPC Classifications
H; H04; H04B; H04B5/00; H04B5/20; H04B5/22; G; G05; G05D; G05D1/00; G05D1/02; G05D1/021; G05D1/0259; G05D1/0265; H04B3/00; H04B3/54; H04B3/56; H04L; H04L12/00; H04L12/28; H04L12/40; H04B2203/00; H04B2203/54; H04B2203/5404; H04B2203/5425; H04B2203/5462; H04B2203/5483; H04B2203/5491; H04L2012/40267; H04L2012/40273
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
158 words
A system for digital communication along a wire for defining the path of wire guided vehicles comprising: A) a wire defining said path; B) a modem having two terminals for providing high frequency signals, one of said modem terminals connected to one end of said wire and the other of said modem terminals connected to a first earth ground; C) a loop driver having two terminals for providing low frequency control signals, one of said loop driver terminals connected to said one end of said wire and the other of said loop driver terminals connected to said first earth ground; and D) an impedance matching network having two terminals, one of said network terminals connected to the other end of said wire and the other of said network terminals connected to a second earth ground, said impedance matching network providing an impedance approximately equal to the impedance of said wire at the frequency of said high frequency signals.
Claim 2
Independent Claim
158 words
A system for digital communication along a wire for defining the path of wire guided vehicles comprising: A) a wire defining said path; B) a modem having two terminals for providing high frequency signals, one of said modem terminals connected to one end of said wire and the other of said modem terminals connected to a first earth ground; C) a loop driver having two terminals for providing low frequency control signals, one of said loop driver terminals connected to said one end of said wire and the other of said loop driver terminals connected to said first earth ground; and D) an impedance matching network having two terminals, one of said network terminals connected to the other end of said wire and the other of said network terminals connected to a second earth ground, said impedance matching network providing an impedance approximately equal to the impedance of said wire at the frequency of said high frequency signals.
Claim 3
Dependent Claim
20 words
The system as claimed in claim 1 wherein said network is located adjacent to said modem and said loop driver.
Claim 4
Dependent Claim
17 words
The system as claimed in claim 2 wherein said first and said second earth grounds are identical.
Claim 5
Dependent Claim
25 words
The system as claimed in claim 1 wherein said network and said second earth ground are located remote from said modem and said loop driver.
Claim 6
Dependent Claim
44 words
A system as claimed in claim 1 wherein said modem is adjusted to send a short signal at said high frequency signals on said wire such that echoes of said short signal may be minimized by adjusting the impedance of said impedance matching network.
Claim 7
Dependent Claim
35 words
A system as claimed in claim 1 wherein said high frequency signals are at a frequency greater than approximately 100 kilohertz and said low frequency signals are at a frequency substantially less than 100 kilohertz.
Claim 8
Dependent Claim
23 words
A system as claimed in claim 1 wherein said high frequency signals are within the range of frequencies between 100 and 500 kilohertz.
Claim 9
Independent Claim
142 words
A system for digital communication along a wire for defining the path of wire guided vehicles comprising: A) a wire (26) defining said path; B) a modem (74) providing high frequency signals at a first pair of terminals; C) a loop driver (28) providing low frequency control signals at a second pair of terminals; and D) an impedance matching network (164) connected between one end of said wire and a first earth ground; and a first one of said terminals of each of said pairs of terminals connected to a second earth ground (160), and the second one of said terminals of each of said pairs of terminals connected together and to the other end of said wire, said impedance matching network (164) providing an impedance approximately equal to the impedance of said wire at the frequency of said high frequency signals.
Claim 10
Independent Claim
142 words
A system for digital communication along a wire for defining the path of wire guided vehicles comprising: A) a wire (26) defining said path; B) a modem (74) providing high frequency signals at a first pair of terminals; C) a loop driver (28) providing low frequency control signals at a second pair of terminals; and D) an impedance matching network (164) connected between one end of said wire and a first earth ground; and a first one of said terminals of each of said pairs of terminals connected to a second earth ground (160), and the second one of said terminals of each of said pairs of terminals connected together and to the other end of said wire, said impedance matching network (164) providing an impedance approximately equal to the impedance of said wire at the frequency of said high frequency signals.
Claim 11
Dependent Claim
45 words
The system claimed in claim 8 wherein said impedance matching network comprises an inductor and a capacitor connected in parallel between said one end of said wire and said first earth ground, and a variable resistance means connected in parallel with said capacitor and inductor.
Claim 12
Dependent Claim
32 words
The system as claimed in claim 9 wherein said variable resistance means comprises a plurality of resistors connected in parallel whereby by disconnecting selected resistors the impedance of said network is changed.
Claim 13
Dependent Claim
44 words
A system as claimed in claim 8 wherein said modem is adjusted to send a short signal at said high frequency signals on said wire such that echoes of said short signal may be minimized by adjusting the impedance of said impedance matching network.
Claim 14
Dependent Claim
78 words
The system as claimed in claim 8; and, E) a coupling circuit connected to the other end of said wire that is not connected to said impedance matching network and to the second terminals of said modem and said loop driver, and said coupling circuit providing for transmission of said high frequency signals between said modem and said wire and for transmission of said low frequency control signals from said loop driver to said wire without mutual interference.
Claim 15
Dependent Claim
46 words
The system as claimed in claim 12 wherein said impedance matching network comprises an inductor and a capacitor connected in parallel between said one end of said wire and said first earth ground, and a variable resistance means connected in parallel with said capacitor and inductor.
Claim 16
Dependent Claim
32 words
The system as claimed in claim 13 wherein said variable resistance means comprises a plurality of resistors connected in parallel whereby by disconnecting selected resistors the impedance of said network is changed.
Claim 17
Dependent Claim
35 words
A system as claimed in claim 12 wherein said high frequency signals are at a frequency greater than approximately 100 kilohertz and said low frequency signals are at a frequency substantially less than 100 kilohertz.
Claim 18
Dependent Claim
23 words
A system as claimed in claim 12 wherein said high frequency signals are within the range of frequencies between 100 and 500 kilohertz.
Claim 19
Independent Claim
162 words
A system for digital communication along a wire for defining the path of wire guided vehicles comprising: A) first (26) and second (26') wires, each defining a different portion of the path of the vehicles; B) a modem (74) providing high frequency signals to one end of said first wire (26) and to one end of said second wire (26'); C) a loop driver (28) providing low frequency control signals to said one end of said first wire (26) and said one end of said second wire (26'); D) a first impedance matching network (164) connected between the other end of said first wire and a first earth ground (162); and E) a second impedance matching network (164') connected between the other end of said second wire and a second earth ground (162'); said impedance matching networks each providing an impedance approximately equal to the impedance of the wire to which it is connected at the frequency of said high frequency signals.
Claim 20
Independent Claim
162 words
A system for digital communication along a wire for defining the path of wire guided vehicles comprising: A) first (26) and second (26') wires, each defining a different portion of the path of the vehicles; B) a modem (74) providing high frequency signals to one end of said first wire (26) and to one end of said second wire (26'); C) a loop driver (28) providing low frequency control signals to said one end of said first wire (26) and said one end of said second wire (26'); D) a first impedance matching network (164) connected between the other end of said first wire and a first earth ground (162); and E) a second impedance matching network (164') connected between the other end of said second wire and a second earth ground (162'); said impedance matching networks each providing an impedance approximately equal to the impedance of the wire to which it is connected at the frequency of said high frequency signals.
Claim 21
Dependent Claim
35 words
A system as claimed in claim 17 wherein said high frequency signals are at a frequency greater than approximately 100 kilohertz and said low frequency signals are at a frequency substantially less than 100 kilohertz.
Claim 22
Dependent Claim
23 words
A system as claimed in claim 17 wherein said high frequency signals are within the range of frequencies between 100 and 500 kilohertz.
Claim 23
Dependent Claim
43 words
A system as claimed in claim 17 wherein said modem is adapted to send short signals at said high frequency signals on said wires such that echoes of said short signals may be minimized by adjusting the impedance of said impedance matching networks.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-10-25 | 1997-04-26 | 1997-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-10-25 | 2001-04-26 | 2001-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-10-25 | 2005-04-26 | 2005-10-26 | $7700.00 | Window Closed / Lapsed |