US3781540A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Jointless coded alternating current track circuits
Assignee: Trane US Inc
•
Filing: 1972-09-18
•
Granted: 1973-12-25
•
Expires: 1992-09-18
Abstract
Abstract Coded alternating current at the same low frequency is supplied at each location to the rails through a track transformer and transmitted in each direction into the adjoining track sections. The transformer secondary connected across the rails divides the track into sections without insulated joints. At each location, a separate phase sensitive unit is inductively coupled to the rails of each adjoining section to receive energy from the coded track currents. Each phase sensitive unit is also energized from the local alternating current source with the phase relationship so selected that the unit responds only to track current from the distant end and not to the locally transmitted track current. Each phase sensitive unit operates a code following track relay in response to the received distant end coded track current energy and the relay operation is decoded to determine section occupancy and/or advance traffic conditions. A timing logic means controls repeated cycles of alternate reception and transmission of track current at each location to eliminate interference between the local and distant end track currents in each section as received by the phase sensitive unit.
Inventors
- 👤 C Staples
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:28
CPC Classifications
B; B61; B61L; B61L1/00; B61L1/18; B61L1/181; B61L1/187
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
281 words
At each of selected locations along a stretch of railroad track having electrically continuous rails, jointless track circuit apparatus comprising in combination, a. a cross bond connected between rails to shunt current supplied by distant sources for dividing said stretch into two adjoining track sections extending to the next adjacent locations, b. a local source of alternating current having the same frequency as the corresponding source at each adjacent location, 1. said source coupled to the associated cross bond for supplying to said rails track current having a first predetermined phase relationship to the track currents supplied at each adjacent location, c. a separate track receiver means coupled to the rails on each side of the rail connections of said cross bond for receiving energy in accordance with the track current flowing in the rails at any instant, 1. each track receiver means also connected to said local source for receiving supplemental energy at another predetermined phase relationship with said track energy and jointly controlled thereby for responding only to track current supplied to the rails at the other end of the corresponding section, and d. a timing means controlled by each receiver means for periodically operating on a repeated cycle between a first and a second condition as a receiver means is responding or both receivers are not responding to track current, respectively, 1. said timing means having connections for inhibiting the supply of track current from said local source when in its first condition, e. each receiver means further operable for registering a nonoccupied and an occupied condition of the corresponding track section as track current is received and not received, respectively, from the other end of that section.
Claim 2
Dependent Claim
281 words
At each of selected locations along a stretch of railroad track having electrically continuous rails, jointless track circuit apparatus comprising in combination, a. a cross bond connected between rails to shunt current supplied by distant sources for dividing said stretch into two adjoining track sections extending to the next adjacent locations, b. a local source of alternating current having the same frequency as the corresponding source at each adjacent location, 1. said source coupled to the associated cross bond for supplying to said rails track current having a first predetermined phase relationship to the track currents supplied at each adjacent location, c. a separate track receiver means coupled to the rails on each side of the rail connections of said cross bond for receiving energy in accordance with the track current flowing in the rails at any instant, 1. each track receiver means also connected to said local source for receiving supplemental energy at another predetermined phase relationship with said track energy and jointly controlled thereby for responding only to track current supplied to the rails at the other end of the corresponding section, and d. a timing means controlled by each receiver means for periodically operating on a repeated cycle between a first and a second condition as a receiver means is responding or both receivers are not responding to track current, respectively, 1. said timing means having connections for inhibiting the supply of track current from said local source when in its first condition, e. each receiver means further operable for registering a nonoccupied and an occupied condition of the corresponding track section as track current is received and not received, respectively, from the other end of that section.
Claim 3
Dependent Claim
202 words
said second input signals having another predetermined phase relationship to the track currents such that each phase sensitive unit provides a first output signal only when said first input signal results from track current transmitted from the other end of the corresponding section and a second output signal at all other times, e. a separate track relay connected for receiving the output signals from each phase sensitive unit at each location and operable to a first and a second position as first and second output signals, respectively, are received, f. a decoding means at each location controlled by both track relays for registering a nonoccupied indication for an adjoining track section when the corresponding track relay operates alternately between its first and second positions, as coded track current from the other end of that section flows in the section rails, and an occupied indication as that relay remains in its second position, and g. timing logic means at each location connected to the associated alternating current source and controlled by both associated track relays for periodically alternating the supply of coded track current from that location with the reception of coded track currents transmitted from the outer ends of said adjoining sections.
Claim 4
Dependent Claim
202 words
said second input signals having another predetermined phase relationship to the track currents such that each phase sensitive unit provides a first output signal only when said first input signal results from track current transmitted from the other end of the corresponding section and a second output signal at all other times, e. a separate track relay connected for receiving the output signals from each phase sensitive unit at each location and operable to a first and a second position as first and second output signals, respectively, are received, f. a decoding means at each location controlled by both track relays for registering a nonoccupied indication for an adjoining track section when the corresponding track relay operates alternately between its first and second positions, as coded track current from the other end of that section flows in the section rails, and an occupied indication as that relay remains in its second position, and g. timing logic means at each location connected to the associated alternating current source and controlled by both associated track relays for periodically alternating the supply of coded track current from that location with the reception of coded track currents transmitted from the outer ends of said adjoining sections.
Claim 5
Dependent Claim
48 words
Track circuit apparatus as defined in claim 1 in which, a. said cross bond is the secondary winding of a track transformer, and b. said local source is connected to the primary winding of said track transformer for supplying said track current having said first predetermined phase relationship.
Claim 6
Dependent Claim
59 words
Track circuit apparatus as defined in claim 2 which further includes, a. a coding means connected for modulating the energy supplied from said local source to said track transformer primary winding, and b. a decoding means controlled by each receiver means for demodulating the energy received from the corresponding track section for registering the occupancy condition of that section.
Claim 7
Dependent Claim
122 words
Track circuit apparatus as defined in claim 3 in which each receiver means comprises, a. phase sensitive device coupled to said rails for receiving track energy and also connected to said local source for receiving said supplemental energy at said other predetermined phase relationship, and b. a track relay control by said phase sensitive device for alternately operating between a first and a second position in response to the reception of coded track energy only when said other predetermined phase relationship exists, c. said track relay controlling the associated decoding means to register a nonoccupied condition of the corresponding section only when said relay alternately operates between its two positions, and an occupied condition when said relay remains in its second position.
Claim 8
Dependent Claim
131 words
A jointless track circuit arrangement for a stretch of railroad track having electrically continuous rails, comprising in combination at each of selected locations, a. a track transformer means having a primary and a secondary winding, said secondary winding connected between the rails to divide said stretch into adjoining track sections, b. a source of alternating current having the same frequency as each adjacent location source, c. a code transmitter means connected between said source and said primary winding for supplying a coded track current having a predetermined phase relationship to the coded track current similarly supplied to the rails at each adjacent location, d. a separate receiver means coupled to said rails on each side of the secondary winding rail connections for receiving coded energy from the track current then flowing,
Claim 9
Dependent Claim
131 words
A jointless track circuit arrangement for a stretch of railroad track having electrically continuous rails, comprising in combination at each of selected locations, a. a track transformer means having a primary and a secondary winding, said secondary winding connected between the rails to divide said stretch into adjoining track sections, b. a source of alternating current having the same frequency as each adjacent location source, c. a code transmitter means connected between said source and said primary winding for supplying a coded track current having a predetermined phase relationship to the coded track current similarly supplied to the rails at each adjacent location, d. a separate receiver means coupled to said rails on each side of the secondary winding rail connections for receiving coded energy from the track current then flowing,
Claim 10
Dependent Claim
204 words
A track circuit arrangement as defined in claim 5 in which each receiver means comprises, a. phase sensitive apparatus operable to supply a first output signal only when local and track input signals have a predetermined phase relationship and a second output signal at other times, b. said phase sensitive apparatus connected to receive local input signals from said alternating current source and coupled to sAid rails in the vicinity of said secondary source winding rail connections to receive track input signals from the track current then flowing, said source selectively connected so that said predetermined phase relationship exists only when said track input signals result from track current transmitted from the other end of the corresponding track section, c. a track relay connected for receiving output signals from said phase sensitive apparatus and operable periodically between first and second positions, respectively, when said first and second output signals alternate periodically as coded track current is received through the rails from the other end of said corresponding section, d. said track relay further connected for registering a nonoccupied condition indication for the corresponding section when operating alternately between its first and second position and an occupied condition indication when remaining in its second position.
Claim 11
Dependent Claim
123 words
A track circuit arrangement as defined in claim 6 in which said timing logic means comprises, a. a slow acting relay having a preselected pickup time longer than a coded track current off time and a preselected release timing period longer than a selected plurality of coded track current cycles, and b. a control circuit for said slow acting relay including in series a second position contact of each track relay and a released position contact of said slow acting relay, c. the connections between said source and said track transformer primary winding further including a picked up position contact of said slow acting relay for interrupting the supply of coded track current from that location when said slow acting relay is released.
Claim 12
Dependent Claim
207 words
A track circuit arrangement as defined in claim 5 which further includes at each location, a. a track loop positioned in inductive relationship with the rails of each adjoining track section in the vicinity of the secondary winding rail connections for receiving induced energy in accordance with the track current flowing at any instant in the corresponding section, and in which each receiver means comprises, b. phase sensitive apparatus first connected to the corresponding track loop for receiving the energy induced therein by the existing track current and further selectively connected to said alternating current source to receive supplemental operating energy having a second predetermined phase relationship with the track currents such that said phase sensitive apparatus produces a coded output energy only when the energy received from the associated track loop is that induced by coded track current transmitted from the other end of the corresponding section, and c. a track relay controlled by said phase sensitive apparatus for operating between first and second positions to register a nonoccupied section indication only in response to coded output energy from the phase sensitive appparatus and for holding in its second position to register an occupied section indication when track current from said other end is not received.
Claim 13
Dependent Claim
121 words
A track circuit arrangement as defined in claim 8 in which, a. said timing logic means is operable to a first and a second condition to inhibit and enable, respectively, the supply of track current from the associated location, b. said timing logic means controlled by both associated track relays, when either follows a code output from the corresponding phase sensitive apparatus, for remaining in its first condition, c. said timing logic means operable to its second condition a preselected time period after said track relays cease code following operation, longer than a track code off time, and self-controlled to subsequently remain in said second condition for a second preselected time period longer than a selected plurality of track code cycles.
Claim 14
Dependent Claim
105 words
A jointless coded track circuit arrangement for a stretch of railroad track having electrically continuous rails, comprising in conbination, a. a track transformer at each location between track sections having a primary winding and a secondary winding connected across the rails to divide the track into sections without insulated joints, b. a source of alternating current at each location having the same frequency as each other source, c. a code transmitter means at each location connected to the associated primary winding and said location source for supplying coded alternating track current at a selected rate to the rails for transmission into each adjoining track section,
Claim 15
Dependent Claim
105 words
A jointless coded track circuit arrangement for a stretch of railroad track having electrically continuous rails, comprising in conbination, a. a track transformer at each location between track sections having a primary winding and a secondary winding connected across the rails to divide the track into sections without insulated joints, b. a source of alternating current at each location having the same frequency as each other source, c. a code transmitter means at each location connected to the associated primary winding and said location source for supplying coded alternating track current at a selected rate to the rails for transmission into each adjoining track section,
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) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |