US3558874A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signals at highway crossings for high speed trains
Assignee: SPX Technologies Inc
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Filing: 1968-10-18
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Granted: 1971-01-26
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Expires: 1988-10-18
Abstract
Abstract The system differentiates between high speed trains and regular trains by having inductive means partly on the car and partly on the wayside for the high speed trains, while the regular speed trains cooperate with detector track circuit apparatus on the wayside for initiating the warning signals at the highway crossing. The inductive means on the wayside is located considerably in advance of the detector track circuit apparatus, but acts through such apparatus for initiating the warning signals. The warning signals given at the crossing continue their operation until the train has passed the highway. In one form of the invention, the car-carried equipment includes a radio transmitter which is initiated when the train passes the wayside inductive means. The transmission of such radio signal initiates the warning at the highway crossing and also causes the transmission of a return radio signal. If such return radio signal is promptly received, the train can continue in the usual fashion; but, if such return signal is not received within a predetermined length of time, the apparatus then causes an automatic application of the train brakes. This form also withholds the return radio signal for stopping the train if a vehicle is stalled on the railroad track at the crossing.
Inventors
- 👤 John E Freehafer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:35
CPC Classifications
B; B61; B61L; B61L29/00; B61L29/24; B61L29/28; B61L29/32
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
130 words
A railroad highwAy-crossing protection system for activating a signal means at the crossing for warning vehicles of an approaching train, approach apparatus including track circuit means for detecting the presence of a train in approach of said crossing and causing the operation of said signal means at said crossing wherein the improvement comprises: coupling means including; inductive means on the wayside, located at a distance beyond each end of the track circuit and only on certain trains, said wayside inductive means responsive to the train carried inductive means for detecting the passage of only those certain trains regardless of speed, and means responsive to said coupling means for acting upon said track circuit means the same as if any train were present to affect the operation of said signal means.
Claim 2
Dependent Claim
130 words
A railroad highwAy-crossing protection system for activating a signal means at the crossing for warning vehicles of an approaching train, approach apparatus including track circuit means for detecting the presence of a train in approach of said crossing and causing the operation of said signal means at said crossing wherein the improvement comprises: coupling means including; inductive means on the wayside, located at a distance beyond each end of the track circuit and only on certain trains, said wayside inductive means responsive to the train carried inductive means for detecting the passage of only those certain trains regardless of speed, and means responsive to said coupling means for acting upon said track circuit means the same as if any train were present to affect the operation of said signal means.
Claim 3
Dependent Claim
44 words
A system as specified in claim 1 wherein said means responsive to said coupling means remains responsive thereto until reset for acting upon said track circuit and reset means responsive to the rear end of the train passing said crossing for resetting said means.
Claim 4
Dependent Claim
171 words
A protective system for vehicles at a grade crossing between a railroad track and a highway, a warning signal means at the crossing for warning vehicles of an approaching train, a track circuit means for detecting the presence of a train in approach of said crossing and causing the operation of said warning signal means at said crossing, wherein the improvement comprises: inductive approach means located at a substantial distance beyond the range of said track circuit for detecting the approach of certain trains, inductive actuating means carried only on the certain trains and operative for actuating said approach means, and electrical means responsive to said approach means in response to the passage of a train carrying said operative actuating means for acting upon said track circuit the same as if any train were present on it, whereby the warning signal means at the crossing is initiated by said certain trains and by those trains not equipped with said inductive actuating means at two different distances in approach to the crossing.
Claim 5
Dependent Claim
171 words
A protective system for vehicles at a grade crossing between a railroad track and a highway, a warning signal means at the crossing for warning vehicles of an approaching train, a track circuit means for detecting the presence of a train in approach of said crossing and causing the operation of said warning signal means at said crossing, wherein the improvement comprises: inductive approach means located at a substantial distance beyond the range of said track circuit for detecting the approach of certain trains, inductive actuating means carried only on the certain trains and operative for actuating said approach means, and electrical means responsive to said approach means in response to the passage of a train carrying said operative actuating means for acting upon said track circuit the same as if any train were present on it, whereby the warning signal means at the crossing is initiated by said certain trains and by those trains not equipped with said inductive actuating means at two different distances in approach to the crossing.
Claim 6
Dependent Claim
21 words
A protective system as specified in claim 3 wherein said track circuit means is of the overlay relatively high frequency type.
Claim 7
Dependent Claim
23 words
A protective system as specified in claim 3 wherein said approach means is an inductive receiver distinctively responsive to a high speed train.
Claim 8
Dependent Claim
145 words
A protective system for vehicles at a grade crossing between a railroad track and a highway comprising, a warning signal means at the crossing for warning vehicles of an approaching train, a wayside inductor located at a suitable approach distance from the crossing, means on the train responsive to the passage of the train past said inductor, radio-transmitting means on the train initiated by said means responsive to the passage of a wayside inductor and acting to transmit a radio signal, means at the wayside responsive to said radio signal for initiating operation of said warning signal means, wayside located radio-transmitting means associated with said warning signal means when it is initiated to transmit a return radio signal to said train-carried apparatus, and means on the train for stopping the movement of said train if said return signal is delayed longer than a predetermined time.
Claim 9
Dependent Claim
145 words
A protective system for vehicles at a grade crossing between a railroad track and a highway comprising, a warning signal means at the crossing for warning vehicles of an approaching train, a wayside inductor located at a suitable approach distance from the crossing, means on the train responsive to the passage of the train past said inductor, radio-transmitting means on the train initiated by said means responsive to the passage of a wayside inductor and acting to transmit a radio signal, means at the wayside responsive to said radio signal for initiating operation of said warning signal means, wayside located radio-transmitting means associated with said warning signal means when it is initiated to transmit a return radio signal to said train-carried apparatus, and means on the train for stopping the movement of said train if said return signal is delayed longer than a predetermined time.
Claim 10
Dependent Claim
147 words
A protective system for vehicles at a grade crossing between a railroad track and a highway comprising, a warning signal means at the crossing for warning vehicles of an approaching train when rendered active, a wayside location identifier located at a suitable approach distance from the grade crossing, control means on a train including means responsive to said location identifier for indicating the passage of the train past said location identifier and, means for transmitting a radio signal to said grade crossing for rendering said warning signal means active, return transmission means rendered active by the reception of said radio signal at said highway crossing to transmit a return radio signal to said tRain, and means on the train for applying its brakes if a return radio signal fails to be received a predetermined time following the receipt of the initial signal from the wayside location identifier.
Claim 11
Dependent Claim
147 words
A protective system for vehicles at a grade crossing between a railroad track and a highway comprising, a warning signal means at the crossing for warning vehicles of an approaching train when rendered active, a wayside location identifier located at a suitable approach distance from the grade crossing, control means on a train including means responsive to said location identifier for indicating the passage of the train past said location identifier and, means for transmitting a radio signal to said grade crossing for rendering said warning signal means active, return transmission means rendered active by the reception of said radio signal at said highway crossing to transmit a return radio signal to said tRain, and means on the train for applying its brakes if a return radio signal fails to be received a predetermined time following the receipt of the initial signal from the wayside location identifier.
Claim 12
Dependent Claim
31 words
A system as defined in claim 7 wherein said control means on the train is restored to normal a predetermined time following the reception of a control from said wayside-identifying means.
Claim 13
Dependent Claim
47 words
A system as specified in the preceding claim 8 wherein said restoration of said control means after said predetermined time causes the warning signal means to be rendered inactive unless said train has approached to within a predetermined distance of said grade crossing within said predetermined time.
Claim 14
Dependent Claim
82 words
A system as specified in claim 8 wherein there is approach track circuit means adjacent said grade crossing and a predetermined distance in advance of the crossing for detecting the presence of a train and rendering said warning signal means active, whereby said warning signal means is continuously rendered active from the time of a train passing said wayside location identifier until it passes said grade crossing if said train occupies said approach track circuit means before said control means is restored.
Claim 15
Dependent Claim
73 words
A system as defined in claim 7 wherein there is means at the crossing for detecting the presence of a stalled vehicle, said means being effective to prevent the operation of said return transmission means to transmit a return radio signal to the train when a vehicle is stalled on the tracks, whereby said train is automatically caused to immediately apply the brakes and remove power upon the presence of a dangerous condition.
Claim 16
Dependent Claim
142 words
A railroad highway crossing protection system for activating warning signal means at the crossing for warning vehicles of an approaching train, comprising: approach apparatus means at a preselected distance on each side of the crossing for at least momentarily detecting the presence of a train as it passes, control means responsive to said approach apparatus means for initiating the operation of the warning signal means when said train engages said approach apparatus means in a direction approaching the crossing, means at the crossing responsive to the last car for restoring said control means when the train passes the crossing, and storage means for registering the passage of said train by said approach apparatus, including a capacitor repeatedly charged by the repeated operation of the approach means by the train leaving the crossing to thereby maintain the control means in a restored condition.
Claim 17
Dependent Claim
142 words
A railroad highway crossing protection system for activating warning signal means at the crossing for warning vehicles of an approaching train, comprising: approach apparatus means at a preselected distance on each side of the crossing for at least momentarily detecting the presence of a train as it passes, control means responsive to said approach apparatus means for initiating the operation of the warning signal means when said train engages said approach apparatus means in a direction approaching the crossing, means at the crossing responsive to the last car for restoring said control means when the train passes the crossing, and storage means for registering the passage of said train by said approach apparatus, including a capacitor repeatedly charged by the repeated operation of the approach means by the train leaving the crossing to thereby maintain the control means in a restored condition.
Claim 18
Dependent Claim
38 words
A system as defined in claim 12 wherein said storage means includes a capacitor repeatedly charged by the repeated operation of said approach means by said leaving train to thereby maintain said control means in its restored condition.
References Cited (Backward Citations)
US2027188A
Cited
US3268723A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-25 | 1974-07-27 | 1975-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-25 | 1978-07-27 | 1979-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-25 | 1982-07-27 | 1983-01-26 | $7700.00 | Window Closed / Lapsed |