Normally Closed Track Circuit Patents (Class 246/130)
  • Patent number: 11285980
    Abstract: The present invention relates to methods of improving the reliability and accuracy of level crossing warning systems. The invention is comprised of an axle counter based system that detects the presence and calculates the speed of a train approaching a level crossing and adjusts the activation time for any warning system using a pre-defined period.
    Type: Grant
    Filed: November 21, 2017
    Date of Patent: March 29, 2022
    Assignee: RAIL CONTROL SYSTEMS AUSTRALIA PTY LTD
    Inventor: Neil Popplewell
  • Patent number: 10883705
    Abstract: The present disclosure provides a new gate lamp system and method. The system and method is configured to facilitate the installation of a gate lamp onto a gate arm, and to facilitate the replacement of one or more of the gate lamps. The present disclosure provides a system and method of installing gate lamps on a gate arm in the field in a robust manner with ease.
    Type: Grant
    Filed: January 16, 2018
    Date of Patent: January 5, 2021
    Assignee: Railway Equipment Company
    Inventors: David K. Fox, Benjamin Moulton, Randall G. Honneck, Greggory C. Phelps
  • Patent number: 10752273
    Abstract: System and methods for determining train direction and speed using laser measurements. The speed and direction determinations can be used to monitor, diagnose, and/or report the operational performance of a crossing warning system.
    Type: Grant
    Filed: July 17, 2017
    Date of Patent: August 25, 2020
    Assignee: Siemens Mobility, Inc.
    Inventor: Nathan Clanney
  • Patent number: 9067609
    Abstract: A vital programmable logic device (VPD) is provided having at least two microprocessors. The VPD is configured to provide failsafe operation of a vital control system while operating in a closed circuit environment. In at least one embodiment of the present invention, railroad grade crossing signals are controlled by the VPD.
    Type: Grant
    Filed: June 19, 2013
    Date of Patent: June 30, 2015
    Assignee: Central Signal, LLC
    Inventors: David Baldwin, Ahtasham Ashraf
  • Patent number: 8888052
    Abstract: A vehicle detection system is provided for tracking, detecting, and monitoring vehicles. The system and methods of the present invention are suitable for on-track and roadway vehicles. In particular the present invention provides an improved and cost effective system and methods for tracking, detecting and monitoring locomotives and on-track vehicles.
    Type: Grant
    Filed: August 20, 2013
    Date of Patent: November 18, 2014
    Assignee: Central Signal, LLC
    Inventors: David Baldwin, Ahtasham Ashraf
  • Publication number: 20130341468
    Abstract: A vehicle detection system is provided for tracking, detecting, and monitoring vehicles. The system and methods of the present invention are suitable for on-track and roadway vehicles. In particular the present invention provides an improved and cost effective system and methods for tracking, detecting and monitoring locomotives and on-track vehicles.
    Type: Application
    Filed: August 20, 2013
    Publication date: December 26, 2013
    Applicant: Central Signal, LLC
    Inventors: David Baldwin, Ahtasham Ashraf
  • Patent number: 8517316
    Abstract: A vehicle detection system is provided for tracking, detecting, and monitoring vehicles. The system and methods of the present invention are suitable for on-track and roadway vehicles. In particular the present invention provides an improved and cost effective system and methods for tracking, detecting and monitoring locomotives and on-track vehicles.
    Type: Grant
    Filed: March 27, 2012
    Date of Patent: August 27, 2013
    Assignee: Central Signal, LLC
    Inventors: David Baldwin, Ahtasham Ashraf
  • Patent number: 8469320
    Abstract: A vital programmable logic device (VPD) is provided having at least two microprocessors. The VPD is configured to provide failsafe operation of a vital control system while operating in a closed circuit environment. In at least one embodiment of the present invention, railroad grade crossing signals are controlled by the VPD.
    Type: Grant
    Filed: September 30, 2011
    Date of Patent: June 25, 2013
    Assignee: Central Signal, LLC
    Inventors: David Baldwin, Ahtasham Ashraf
  • Patent number: 8157219
    Abstract: An vehicle detection system is provided for tracking, detecting, and monitoring vehicles. The system and methods of the present invention are suitable for on track and roadway vehicles. In particular the present invention provides an improved and cost effective system and methods for tracking, detecting and monitoring locomotives and on track vehicles.
    Type: Grant
    Filed: January 15, 2008
    Date of Patent: April 17, 2012
    Assignee: Central Signal, LLC
    Inventors: Ahtasham Ashraf, David Baldwin
  • Publication number: 20080169385
    Abstract: An vehicle detection system is provided for tracking, detecting, and monitoring vehicles. The system and methods of the present invention are suitable for on track and roadway vehicles. In particular the present invention provides an improved and cost effective system and methods for tracking, detecting and monitoring locomotives and on track vehicles.
    Type: Application
    Filed: January 15, 2008
    Publication date: July 17, 2008
    Inventors: Ahtasham ASHRAF, David Baldwin
  • Patent number: 7296770
    Abstract: A railroad signaling method includes measuring a track current on a first track section, measuring a local voltage on the railroad line wires, determining whether a magnitude of the track current meets or exceeds a threshold value independent of the local voltage, and determining whether the track current and the local voltage are nominally in phase with one another in a manner that is independent of the track current measuring step. A first signal is provided only if the magnitude is determined to meet or exceed the threshold and the track current and local voltage are determined to be nominally in phase. The first signal is an indication that a train is not present in the track section, that the track section does not have a broken rail, and that the insulated joints that bound the track section do not include a fault condition. An associated relay arrangement is also provided.
    Type: Grant
    Filed: May 24, 2005
    Date of Patent: November 20, 2007
    Assignee: Union Switch & Signal, Inc.
    Inventor: Raymond C. Franke
  • Patent number: 4581700
    Abstract: A railroad train moving along an approach to a grade crossing (or other location of interest) is detected by apparatus that is responsive to the change in effective track impedance caused by the moving shunt. A constant current AC signal is applied to the track adjacent the crossing, and the resulting voltage changed in amplitude and phase is picked off by a receiver on the opposite side of the crossing. Voltage and current information derived from these signals is inputted to a microcomputer which calculates the track impedance and determines whether or not a warning device or devices at the crossing should be activated. Such determination is made on a repetitive basis in accordance with a repeating program loop and stored in memory.
    Type: Grant
    Filed: August 6, 1984
    Date of Patent: April 8, 1986
    Assignee: SAB Harmon Industries, Inc.
    Inventors: Wilfred L. Farnham, Lynn R. Garrison, Wayne N. Wheeler, Forrest H. Ballinger
  • Patent number: 4365777
    Abstract: A train approach detector uses frequencies in the audio spectrum to activate grade crossing protection devices in advance of and during the presence of railroad trains at grade crossings. The detector is completely solid state, and includes one transmitter and one receiver each connected to the tracks so that transmitted and received track signals, which are partially pulse modulated for optimum filtering and signal coupling and minimum third harmonic radiation, appear on opposite sides of the crossing. The section of track between the transmitter and receiver is designated as a crossing island and sections of rail outside of the island are known as approaches.
    Type: Grant
    Filed: August 17, 1979
    Date of Patent: December 28, 1982
    Assignee: Modern Industries Signal Equipment, Inc.
    Inventor: Willard L. Geiger
  • Patent number: 4251041
    Abstract: At a railroad crossing, a single motion detection unit is selectively coupled to an occupied track in such manner that safe, effective and efficient control is obtained over the crossing alarm device. The means for coupling the motion detection unit includes means for terminating the activation of the crossing alarm device when a train stops on the approach track, but short of the actual intersection. Techniques for multiplexing a motion detection unit with plural tracks at the grade crossing or with multiple track circuits on a single track are provided. Safe operation is assured with multiple track occupancy irrespective of the sequence of occupancy and which is the last to remain occupied or if one of the trains stops or reverses direction of motion.
    Type: Grant
    Filed: July 12, 1978
    Date of Patent: February 17, 1981
    Assignee: General Signal Corporation
    Inventor: Frank A. Svet
  • Patent number: 4120471
    Abstract: A highway crossing warning system includes a motion detector transmitter and receiver respectively coupled to the track rails adjacent the highway crossing for detecting motion of an approaching train. Wrap-around approach sections initiate operation of the highway crossing warning, but once motion is detected, the motion detector can serve to inhibit the highway crossing warning, after a predetermined delay, if motion indication ceases. To increase the effectiveness of the motion detection, the motion detector transmitter impresses a modulated carrier onto the track rails, wherein the modulation is phase locked to the carrier. The receiver, tuned to the carrier frequency, detects the modulation, and then determines from the level of demodulated signal whether or not approaching motion is detected. The transmitter employs solid state circuits switched between saturated and off conditions to prevent circuit component failures from masking approach motion.
    Type: Grant
    Filed: June 21, 1977
    Date of Patent: October 17, 1978
    Assignee: General Signal Corporation
    Inventor: John H. Auer, Jr.
  • Patent number: 4067523
    Abstract: An adjustable adapter bracket for a railroad-highway crossing gate and signal installation for permitting the elongated gate arm to be shifted laterally to avoid interference with overhead obstacles. The adapter bracket is fixedly attached to the ends of a pair of gate supporting arms and includes upper and lower U-shaped strut members each of which is provided with at least two longitudinal rows or lines of apertures. A breakaway gate arm connector including a pair of apertured mounting plates is selectively positioned along the length of the U-shaped strut member and is securely fastened thereto by a plurality of bolts and nuts. A plurality of reinforcing spacer members are positioned between and are bolted to the upper and lower U-shaped strut members to reinforce and strengthen the adapter bracket.
    Type: Grant
    Filed: February 22, 1977
    Date of Patent: January 10, 1978
    Assignee: Westinghouse Air Brake Company
    Inventors: John M. Kenny, Spiro J. Pappas