US3819933A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Detector track circuit for railroad crossings
Assignee: Trane US Inc
•
Filing: 1972-12-08
•
Granted: 1974-06-25
•
Expires: 1992-12-08
Abstract
Abstract A separate transmitter source of periodic high voltage pulses is coupled to each approach section rails at the end distant from the permanent shunt across the rails at a railroad crossing. Each pulse transmits a high level oscillating current pulse through the rail loop including the intersecting rail shunt so that similar track currents flow in both approach sections. A single receiver means is coupled to each rail shunt by a separate pickup coil, the output of which is rectified to charge a storage capacitor at an averaged voltage level representative of the amplitude of the current pulses in the corresponding shunt. The voltages stored in both capacitors are applied to the dual inputs of a two channel, vital level detector and logic AND circuit element. An output signal is produced by the level detector and AND circuits only when both inputs are at or above a level representative of an unoccupied section. The output is then applied, through a relay driver circuit, to a vital type track relay to jointly register the occupancy condition of both crossing approaches.
Inventors
- 👤 R Grundy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:13
CPC Classifications
B; B61; B61L; B61L1/00; B61L1/18; B61L1/181; B61L1/185
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
329 words
A detector track circuit arrangement, for detecting the presence of any part of a train occupying a railroad track section having a permanent rail shunt formed by an intersecting rail connected between the section rails at one end, comprising in combination, a. a transmitter means coupled to the section rails at a point distant from said permanent shunt and comprising, 1. a direct current energy source having a preselected high voltage, 2. a capacitor connected in series with said source across said section rails at the distant point for receiving an energy charge at a predetermined charging rate, 3. a circuit switch normally in an open circuit condition and operable to a closed circuit condition while a gating signal is applied thereto, 4. a source of periodic gating signals having a preselected repetition rate connected for applying such gating signals to said circuit switch, 5. said circuit switch connected between said source and said capacitor for periodically completing, when in its closed circuit condition, an initial discharge circuit path of a predetermined polarity for said capacitor including said section rails, said capacitor and rails forming an oscillatory circuit for discharging the energy stored in said capacitor, and 6. a unidirectional circuit element connected in multiple with said circuit switch for providing a second circuit path of opposite polarity for said oscillating current during discharge of said capacitor while a gating signal is applied, and b. receiver means coupled to said section rails in the vicinity of said permanent shunt and responsive to the flow of said oscillating track current for registering a non-occupied indication for said section when and only when said oscillating current pulses flow in said permanent shunt at or above a preselected amplitude level, 1. said receiver means registering an occupied section indication when the amplitude of current pulses flowing in said permanent shunt is reduced below said preselected level by a rail shunt at any other location in said section or by any other cause.
Claim 2
Dependent Claim
329 words
A detector track circuit arrangement, for detecting the presence of any part of a train occupying a railroad track section having a permanent rail shunt formed by an intersecting rail connected between the section rails at one end, comprising in combination, a. a transmitter means coupled to the section rails at a point distant from said permanent shunt and comprising, 1. a direct current energy source having a preselected high voltage, 2. a capacitor connected in series with said source across said section rails at the distant point for receiving an energy charge at a predetermined charging rate, 3. a circuit switch normally in an open circuit condition and operable to a closed circuit condition while a gating signal is applied thereto, 4. a source of periodic gating signals having a preselected repetition rate connected for applying such gating signals to said circuit switch, 5. said circuit switch connected between said source and said capacitor for periodically completing, when in its closed circuit condition, an initial discharge circuit path of a predetermined polarity for said capacitor including said section rails, said capacitor and rails forming an oscillatory circuit for discharging the energy stored in said capacitor, and 6. a unidirectional circuit element connected in multiple with said circuit switch for providing a second circuit path of opposite polarity for said oscillating current during discharge of said capacitor while a gating signal is applied, and b. receiver means coupled to said section rails in the vicinity of said permanent shunt and responsive to the flow of said oscillating track current for registering a non-occupied indication for said section when and only when said oscillating current pulses flow in said permanent shunt at or above a preselected amplitude level, 1. said receiver means registering an occupied section indication when the amplitude of current pulses flowing in said permanent shunt is reduced below said preselected level by a rail shunt at any other location in said section or by any other cause.
Claim 3
Dependent Claim
33 words
a relay driver means coupled between said level detector means and said relay for receiving said output signal and responsive thereto for energizing said relay winding only when an output signal is present.
Claim 4
Dependent Claim
33 words
a relay driver means coupled between said level detector means and said relay for receiving said output signal and responsive thereto for energizing said relay winding only when an output signal is present.
Claim 5
Dependent Claim
33 words
a relay driver means coupled between said level detector means and said relay for receiving said output signal and responsive thereto for energizing said relay winding only when an output signal is present.
Claim 6
Dependent Claim
33 words
a relay driver means coupled between said level detector means and said relay for receiving said output signal and responsive thereto for energizing said relay winding only when an output signal is present.
Claim 7
Dependent Claim
33 words
a relay driver means coupled between said level detector means and said relay for receiving said output signal and responsive thereto for energizing said relay winding only when an output signal is present.
Claim 8
Dependent Claim
33 words
a relay driver means coupled between said level detector means and said relay for receiving said output signal and responsive thereto for energizing said relay winding only when an output signal is present.
Claim 9
Dependent Claim
168 words
A track circuit arrangement as defined in claim 1 in which said receiver means comprises, a. a receiver coil inductively coupled to said permanent rail shunt and tuned to respond to the oscillating current in said rail shunt for producing voltage pulses at the periodic gating rate, b. a full wave rectifier arrangement, c. a capacitor connected by said rectifier arrangement to said receiver coil for storing a voltage signal proportional to the amplitude level of the current pulses flowing in said rail shunt, d. a vital level detector means connected to receive the voltage signal stored by said storage capacitor and responsive thereto for producing an output signal when and only when the voltage signal represents a track current pulse amplitude equal to or greater than said preselected amplitude level, and e. an indication registry means coupled for receiving the output signal from said detector means and operable for registering a nonoccupied or occupied condition of said section as an output signal is received or absent, respectively.
Claim 10
Dependent Claim
26 words
a capacitor connected in series with said source across said section rails at the distant point for receiving an energy charge at a predetermined charging rate,
Claim 11
Dependent Claim
26 words
a capacitor connected in series with said source across said section rails at the distant point for receiving an energy charge at a predetermined charging rate,
Claim 12
Dependent Claim
23 words
a circuit switch normally in an open circuit condition and operable to a closed circuit condition while a gating signal is applied thereto,
Claim 13
Dependent Claim
23 words
a circuit switch normally in an open circuit condition and operable to a closed circuit condition while a gating signal is applied thereto,
Claim 14
Dependent Claim
111 words
A track circuit arrangement as defined in claim 2 in which, a. said circuit switch is a controlled rectifier device having a normally open anode to cathode circuit path and a gate electrode to which gating signals are applied to enable current to flow through said anode to cathode circuit path when a voltage of proper polarity is applied thereto, b. said unidirectional circuit element is a diode device through which current flows only when the positive potential of an applied voltage is at the anode electrode, c. said receiver coil is tuned by another capacitor connected across the full winding of the coil, and d. said indication registry means includes,
Claim 15
Dependent Claim
21 words
a source of periodic gating signals having a preselected repetition rate connected for applying such gating signals to said circuit switch,
Claim 16
Dependent Claim
21 words
a source of periodic gating signals having a preselected repetition rate connected for applying such gating signals to said circuit switch,
Claim 17
Dependent Claim
179 words
A track circuit arrangement as defined in claim 1 in which, a. said track section is one approach section to a railroad grade crossing and said permanent shunt is formed by one rail of the intersecting track, and which further includes, b. a second transmitter means coupled to the rails at the distant end of the other opposite direction approach track section having a permanent shunt at its crossing end formed by the other rail of said intersecting track, and operable for applying to said other section rails periodic pulses of high voltage energy to transmit through said other section rails oscillating current pulses having the same characteristics as those flowing in said one seCtion rails, c. said receiver means coupled also to said other section rails in the vicinity of the corresponding permanent shunt and jointly responsive to the current pulses flowing in both permanent shunts for registering a joint nonoccupied indication for both approach sections when and only when the amplitude of oscillating current pulses flowing in each permanent shunt is at or above said preselected level,
Claim 18
Dependent Claim
195 words
A track circuit arrangement as defined in claim 4 in which said receiver means comprises, a. a separate receiver coil inductively coupled to each permanent rail shunt and tuned to respond to oscillating current flowing in the associated rail shunt for producing voltage pulses at the periodic gating rate of the corresponding transmitter gating signal source, b. a full wave rectifier arrangement associated with each receiver coil, c. a separate capacitor connected to each receiver coil by the associated rectifier arrangement for storing a voltage signal proportional to the amplitude level of the current pulses flowing in the associated rail shunt, d. a vital level detector and logic means connected to receive the voltage signals stored by both said storage capacitors and jointly responsive to both input signals for producing an output signal when and only when each input signal represents a track current amplitude equal to or larger than said preselected amplitude level, and e. an indication registry means connected for receiving the output signal from said level detector and logic means and operable for registering a nonoccupied or occupied condition of said approach section as an output signal is present or absent, respectively.
Claim 19
Dependent Claim
52 words
said circuit switch connected between said source and said capacitor for periodically completing, when in its closed circuit condition, an initial discharge circuit path of a predetermined polarity for said capacitor including said section rails, said capacitor and rails forming an oscillatory circuit for discharging the energy stored in said capacitor, and
Claim 20
Dependent Claim
52 words
said circuit switch connected between said source and said capacitor for periodically completing, when in its closed circuit condition, an initial discharge circuit path of a predetermined polarity for said capacitor including said section rails, said capacitor and rails forming an oscillatory circuit for discharging the energy stored in said capacitor, and
Claim 21
Dependent Claim
89 words
a unidirectional circuit element connected in multiple with said circuit switch for providing a second circuit path of opposite polarity for said oscillating current during discharge of said capacitor while a gating signal is applied, and b. receiver means coupled to said section rails in the vicinity of said permanent shunt and responsive to the flow of said oscillating track current for registering a non-occupied indication for said section when and only when said oscillating current pulses flow in said permanent shunt at or above a preselected amplitude level,
Claim 22
Dependent Claim
89 words
a unidirectional circuit element connected in multiple with said circuit switch for providing a second circuit path of opposite polarity for said oscillating current during discharge of said capacitor while a gating signal is applied, and b. receiver means coupled to said section rails in the vicinity of said permanent shunt and responsive to the flow of said oscillating track current for registering a non-occupied indication for said section when and only when said oscillating current pulses flow in said permanent shunt at or above a preselected amplitude level,
Claim 23
Dependent Claim
111 words
A track circuit arrangement as defined in claim 5 in which, a. each circuit switch is a controlled rectifier device having a normally open anode to cathode circuit path and a gate electrode to which gating signals are applied to enable current to flow through said anode to cathode circuit path when a voltage of proper polarity is applied thereto, b. each unidirectional circuit element is a diode device through which current flows only when the positive potential of an applied voltage is at the anode electrode, c. each receiver coil is tuned by another capacitor connected across the full winding of that coil, and d. said indication registry means includes,
Claim 24
Dependent Claim
56 words
A track circuit arrangement as defined in claim 1 in which, a. said track section extends beyond the point of coupling of said transmitter means to said rails to another permanent rail shunt, formed by another intersecting rail, both rail shunts being substantially equidistant from said coupling point of said transmitter means to said section rails,
Claim 25
Dependent Claim
192 words
A track circuit arrangement as defined in claim 7 in which said receiver means comprises, a. a separate receiver coil inductively coupled to each permanent rail shunt and tuned to respond to oscillating current flowing in the associated rail shunt for producing voltage pulses at the periodic gating rate of the gating signal source, b. a full wave rectifier arrangement associated with each receiver coil, c. a separate capacitor connected to each receiver coil by the associated rectifier arrangement for storing a voltage signal proportional to the amplitude level of the current pulses flowing in the associated rail shunt, d. a vital level detector and logic means connected to receive the voltage signals stored by both said storage capacitors and jointly responsive to both input signals for producing an output signal when and only when each input signal represents a track current amplitude equal to or larger than said preselected amplitude level, and e. an indication registry means connected for receiving the output signal from said level detector and logic means and operable for registering a nonoccupied or occupied condition of said section as an output signal is present or absent, respectively.
Claim 26
Dependent Claim
111 words
A track circuit arrangement as defined in claim 8 in which, a. said circuit switch is a controlled rectifier device having a normally open anode to cathode circuit path and a gate electrode to which gating signals are applied to enable current to flow through said anode to cathode circuit path when a voltage of proper polarity is applied thereto, b. said unidirectional circuit element is a diode device through which current flows only when the positive potential of an applied voltage is at the anode electrode, c. each receiver coil is tuned by another capacitor connected across the full winding of that coil, and d. said indication registry means includes,
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) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |