Directional wheel detector

• US 3,941,338 A
• Filed: 09/25/1974
• Issued: 03/02/1976
• Est. Priority Date: 09/25/1974
• Status: Expired due to Term

• Current Assignee: Servo Corporation of America
• Original Assignee: Servo Corporation of America
• Inventors: Knudsen, Will B.
• Primary Examiner(s): Blix, Trygve M.
• Assistant Examiner(s): Eisenzopf, Reinhard J.
• Application Number:
  US05/509,095
• Time in Patent Office: 524 Days
• Field of Search: 246/34 R, 246/77, 246/247, 246/255
• US Class Current: 246/77
• CPC Class Codes: B61L 1/16 Devices for counting axles; Devices for counting vehicles
• CPC Class Codes: B61L 25/021 Measuring and recording of train speed

Abstract

A system is provided for determining the passage of a railroad car wheel along a section of track and the direction of movement of the wheel. The system includes a first wheel sensor mounted adjacent the track and adapted to generate a signal upon the passage of a wheel past the first sensor and while the wheel remains within a length of track associated with the first sensor. The system further includes a second wheel sensor closely spaced along the track from the first sensor and adapted to generate a second signal on the passage of the wheel past the second sensor and while the wheel remains within a length of track associated with the second sensor. The first and second sensors are sufficiently closely spaced to each other so as to provide an overlap between the first and second signals as a wheel passes. Logic means are connected to the outputs of the first and second sensors for determining the direction of travel of the wheel by the sequence of output signals from the sensors.

Claims

1. A detecting system for determining the passage of a railroad car wheel along a section of track and the direction of movement of said wheel, said system comprising:

a first wheel sensor mounted adjacent said track to generate a first signal upon the passage of a wheel past said first sensor and while said wheel remains within a length of track associated with said first sensor;

a second wheel sensor closely spaced along said track from said first sensor to generate a second signal upon the passage of said wheel past said second sensor and while said wheel remains within a length of track associated with said second sensor;

said first and second sensors being sufficiently closely spaced to each other so as to provide an overlap between said first and second signals as a wheel passes said first sensor toward said second sensor;

logic circuit means connected to the outputs of said first and second sensors for determining the direction of travel of the wheel by sequence of outputs from said sensors, and first analog to digital converter means interposed between said first sensor and said logic means and a second analog to digital converter means interposed between said second sensor and said logic means.

2. The detecting system in accordance with claim 1 wherein said first and second sensors are spaced along the track so that said overlap will occur when a wheel travels a minimum distance of 2 inches.

3. The detecting system in accordance with claim 1 wherein said logic circuit means comprises a first differential amplifier connected to the output of said first analog to digital converter and a second differential amplifier connected to the output of said second analog to digital converter.