Patent US3821544A successfully refreshed from Google Patents.
US3821544A
Expired / Lapsed
US
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Apparatus for sensing positions of vehicle along a track using voltage sensing in current track circuits
Assignee: Bombardier Transportation Holdings USA Inc
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Filing: 1972-07-24
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Granted: 1974-06-28
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Expires: 1992-07-24
Abstract
Abstract A vehicle control system in which a vehicle is operative on steel rails and in which a plurality of conductors are connected between the rails at predetermined locations. A track section between and including two such conductors forms a track circuit signalling block. At one end of the signalling block track current is introduced into the rails and a receiving antenna is positioned adjacent the conductor forming the other end of the track circuit signalling block. In the absence of a vehicle within the block, the receiving antenna senses a track current at a relatively high level and when a vehicle enters the track circuit signalling block the receiving means senses track current at a substantially reduced level. A plurality of voltage sensing means are located at predetermined locations across the track circuit signalling block for sensing the position of the vehicle within the signalling block. Each such voltage sensing means senses a voltage signal at a predetermined level in the absence of the vehicle being present adjacent the voltage sensing means. When the vehicle reaches a given voltage sensing means, the given voltage sensing means then senses voltage at a greatly reduced signal level which is indicative of the vehicle being present. Signal responsive means respond to the latter signal to provide an indication of vehicle presence at the given location.
Inventors
- 👤 T Matty
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:55
CPC Classifications
B; B61; B61L; B61L1/00; B61L1/18; B61L1/181; B61L1/187
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
250 words
In a system for determining the position of a vehicle within one of a plurality of signal conductive signalling blocks comprised of a conductive track including a pair of conductive continuous rails, the combination comprising: a plurality of conductors, with one such conductor being connected between said rails at each of a plurality of predetermined locations, each of said conductors providing a signal conductive path between said rails, with a track section between and including two such conductors forming one of said signalling blocks; means for introducing a signal current into each of said signalling blocks; at least one signal voltage responsive means connected between said rails at a predetermined location in a given one of said signalling blocks for sensing signal voltage between said rails at said predetermined location at a given level in the absence of a vehicle in said one signalling block and for sensing a decrease in signal voltage to a minimum voltage level as said vehicle approaches said predetermined location, with said one voltage responsive means having a high impedance relative to the impedance of said rails such that essentially all of said signal current flows through said rails and a negligible amount of said signal current flows through said one signal voltage responsive means, with said decrease in signal voltage to a minimum voltage level as said vehicle approaches said predetermined location being caused by the low impedance of the axles of said vehicle reducing the impedance between said rails at said predetermined location.
Claim 2
Dependent Claim
250 words
In a system for determining the position of a vehicle within one of a plurality of signal conductive signalling blocks comprised of a conductive track including a pair of conductive continuous rails, the combination comprising: a plurality of conductors, with one such conductor being connected between said rails at each of a plurality of predetermined locations, each of said conductors providing a signal conductive path between said rails, with a track section between and including two such conductors forming one of said signalling blocks; means for introducing a signal current into each of said signalling blocks; at least one signal voltage responsive means connected between said rails at a predetermined location in a given one of said signalling blocks for sensing signal voltage between said rails at said predetermined location at a given level in the absence of a vehicle in said one signalling block and for sensing a decrease in signal voltage to a minimum voltage level as said vehicle approaches said predetermined location, with said one voltage responsive means having a high impedance relative to the impedance of said rails such that essentially all of said signal current flows through said rails and a negligible amount of said signal current flows through said one signal voltage responsive means, with said decrease in signal voltage to a minimum voltage level as said vehicle approaches said predetermined location being caused by the low impedance of the axles of said vehicle reducing the impedance between said rails at said predetermined location.
Claim 3
Dependent Claim
226 words
In a system for determining the position of a vehicle within one of a plurality of signal conductive signalling blocks comprised of a conductive track including a pair of conductive continuous rails, the combination comprising: a plurality of conductors connected between said rails at selected locations for providing respective signal conduction paths between said rails, with a track section between and including two such conductors defining one of said signalling blocks; means for introducing current into a given signalling block; a plurality of voltage responsive means connected between said rails at predetermined locations within said given signalling block for sensing voltage between said rails at each of said predetermined locations, the voltage sensed at a given one of said predetermined locations decreasing from a maximum to a minimum voltage level as said vehicle approaches said given one of said predetermined locations, with each of said voltage responsive means having a high impedance relative to the impedance of said rails such that essentially of said signal current flows through said railS and a negligible amount of said signal current flows through any of said voltage responsive means, with the decrease in voltage sensed at said given one of said predetermined locations being caused by the low impedance of the axles of said vehicle reducing the impedance between said rails at said given one of said predetermined locations.
Claim 4
Dependent Claim
226 words
In a system for determining the position of a vehicle within one of a plurality of signal conductive signalling blocks comprised of a conductive track including a pair of conductive continuous rails, the combination comprising: a plurality of conductors connected between said rails at selected locations for providing respective signal conduction paths between said rails, with a track section between and including two such conductors defining one of said signalling blocks; means for introducing current into a given signalling block; a plurality of voltage responsive means connected between said rails at predetermined locations within said given signalling block for sensing voltage between said rails at each of said predetermined locations, the voltage sensed at a given one of said predetermined locations decreasing from a maximum to a minimum voltage level as said vehicle approaches said given one of said predetermined locations, with each of said voltage responsive means having a high impedance relative to the impedance of said rails such that essentially of said signal current flows through said railS and a negligible amount of said signal current flows through any of said voltage responsive means, with the decrease in voltage sensed at said given one of said predetermined locations being caused by the low impedance of the axles of said vehicle reducing the impedance between said rails at said given one of said predetermined locations.
Claim 5
Dependent Claim
30 words
The combination claimed in claim 2, wherein each of said voltage responsive means includes a transformer having a primary winding connected between said rails, and also having a secondary winding.
Claim 6
Dependent Claim
73 words
The combination claimed in claim 3 wherein said voltage responsive means further includes: a filter having an input connected to the secondary winding of said transformer, and also having an output; and a level detector having an input connected to the output of said filter, and also having an output at which an output signal is provided in response to a signal of at least a given value being applied to said input.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-27 | 1981-12-27 | 1982-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-27 | 1985-12-27 | 1986-06-28 | $7700.00 | Window Closed / Lapsed |