US5374015A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Railroad telemetry and control systems
Assignee: Westinghouse Air Brake Co
•
Filing: 1993-09-16
•
Granted: 1994-12-20
•
Expires: 2013-09-16
Abstract
Abstract Improvements relating to railroad telemetry and control system address problems in compatibility between HOT and EOT units, implement an automatic UDE location procedure, and automate calibration of EOT units. An improved two way protocol that allows EOT units having different code formats to be used with a HOT unit. A method is implemented by a HOT unit, cooperating with an EOT unit, for locating a fault which causes a UDE brake operation. An automatic calibration procedure for the EOT unit that does not require the operator to have access to the electronic circuitry.
Inventors
- 👤 Angel P. Bezos
- 👤 Clive Wright
- 👤 Emilio A. Fernandez
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:53
CPC Classifications
B; B61; B61L; B61L15/00; B61L15/0018; B61L15/0027; B61L15/0054
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
149 words
An End of Train (EOT) and Head of Train (HOT) railroad telemetry system wherein an EOT unit includes means for transmitting a signal to a HOT unit when an Undesired Emergency (UDE) brake event due to venting of air in a train brake pipe to atmosphere is detected at the EOT unit, and further comprising at the HOT unit: means for storing different propagation constants representing differences in propagation rates in directions from a front to a rear of the train and from the rear to the front of the train due to air flow in said brake pipe; means for detecting the UDE at the HOT unit; means for measuring a time differential between times when the UDE is detected at the EOT and HOT units; means, using the measured time differential and the stored different propagation constants, for automatically calculating an approximate location where the UDE originated.
Claim 2
Dependent Claim
149 words
An End of Train (EOT) and Head of Train (HOT) railroad telemetry system wherein an EOT unit includes means for transmitting a signal to a HOT unit when an Undesired Emergency (UDE) brake event due to venting of air in a train brake pipe to atmosphere is detected at the EOT unit, and further comprising at the HOT unit: means for storing different propagation constants representing differences in propagation rates in directions from a front to a rear of the train and from the rear to the front of the train due to air flow in said brake pipe; means for detecting the UDE at the HOT unit; means for measuring a time differential between times when the UDE is detected at the EOT and HOT units; means, using the measured time differential and the stored different propagation constants, for automatically calculating an approximate location where the UDE originated.
Claim 3
Dependent Claim
94 words
The End of Train (EOT) and Head of train (HOT) railroad telemetry system recited in claim 1 wherein said EOT unit includes means for generating a first time stamp when a UDE brake event is detected by the EOT unit, said time stamp being transmitted to the HOT unit as part of said signal, and said HOT unit further including means for generating and temporarily storing a second time stamp when the UDE brake event is detected by the HOT unit, said first and second time stamps being used to measure said time differential.
Claim 4
Dependent Claim
88 words
The End of Train (EOT) and Head of Train (HOT) railroad telemetry system recited in claim 2 wherein the HOT and EOT units communicate with a protocol including discretionary bits which are used in normal transmissions from the EOT unit to the HOT unit for status or condition information, said EOT unit including means for alternatively using said discretionary bits in a Rear-to-Front transmission as said first time stamp to be transmitted from the EOT unit to the HOT unit in the event of an Undesired Emergency (UDE)event.
Claim 5
Independent Claim
149 words
A method used in End of Train (EOT) and Head of Train (HOT) railroad telemetry systems in which an EOT unit includes means for transmitting a signal to a HOT unit in the event of an Undesired Emergency (UDE) brake event due to venting of air in a train brake pipe to atmosphere, said method performed by said HOT unit and comprising the steps of: storing different propagation constants representing differences in propagation rates in directions from a front to a rear of the train and from the rear to the front of the train due to air flow in said brake pipe; detecting at said HOT unit a UDE brake event; measuring a time differential between times when the UDE is detected at the EOT and HOT units; and computing from the measured time differential and the stored different propagation constants an approximate location where the UDE originated.
Claim 6
Independent Claim
149 words
A method used in End of Train (EOT) and Head of Train (HOT) railroad telemetry systems in which an EOT unit includes means for transmitting a signal to a HOT unit in the event of an Undesired Emergency (UDE) brake event due to venting of air in a train brake pipe to atmosphere, said method performed by said HOT unit and comprising the steps of: storing different propagation constants representing differences in propagation rates in directions from a front to a rear of the train and from the rear to the front of the train due to air flow in said brake pipe; detecting at said HOT unit a UDE brake event; measuring a time differential between times when the UDE is detected at the EOT and HOT units; and computing from the measured time differential and the stored different propagation constants an approximate location where the UDE originated.
Claim 7
Dependent Claim
94 words
The method recited in claim 4 further comprising the steps of: time stamping at the EOT unit a time of detection of a UDE brake event to generate a first time stamp; transmitting said first time stamp from the EOT unit to the HOT unit; time stamping at the HOT unit a time of detection of a UDE brake event to generate a second time stamp; and temporarily storing said second time stamp; wherein said step of measuring the time differential is performed by calculating a difference between said first and second time stamps.
Claim 8
Dependent Claim
83 words
The method recited in claim 5 wherein the HOT and EOT units communicate with a protocol including discretionary bits which are used in normal transmissions from the EOT unit to the HOT unit for status or condition information, said method further comprising the step at the EOT unit of alternatively using said discretionary bits in Rear-to-Front transmission as said first time stamp to be transmitted from the EOT unit to the HOT unit in the event of an Undesired Emergency (UDE) brake event.
References Cited (Backward Citations)
US3699522A
Cited
US3588186A
Cited
US3696758A
Cited
US4066299A
Cited
US4041470A
Cited
US4574376A
Cited
US4582280A
Cited
US5039038A
Cited
US4692867A
Cited
US4723737A
Cited
US4652057A
Cited
FR2587959A1
Cited
US4773001A
Cited
US4718271A
Cited
US4835693A
Cited
US4885689A
Cited
US5016840A
Cited
US5028918A
Cited
WO1991011791A1
Cited
US5142277A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-12-19 | 1998-06-20 | 1998-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-12-19 | 2002-06-20 | 2002-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-12-19 | 2006-06-20 | 2006-12-20 | $7700.00 | Window Closed / Lapsed |