TRAIN WHEEL DEFECT DETECTOR

• US 3,558,876 A
• Filed: 10/16/1968
• Issued: 01/26/1971
• Est. Priority Date: 10/16/1968
• Status: Expired due to Term

• Current Assignee: Arthur J. Glazar, Leonard Tillman
• Original Assignee: Arthur J. Glazar, Leonard Tillman
• Inventors: Tillman, Leonard, Glazar, Arthur J.
• Application Number:
  US04/777,957
• Time in Patent Office: 832 Days
• US Class Current: 246/169.00S
• CPC Class Codes: G01N 2291/2696 Wheels, Gears, Bearings
• CPC Class Codes: G01N 29/12 by measuring frequency or resonance of acoustic waves measuring frequency or resonant frequency of mechanical vibrations or acoustic waves in general G01H1/06, G01H3/04, G01H13/00; acoustic resonators G10K11/04; vibration or shock testing of structures G01M7/00

Abstract

A railroad wheel defect-detecting device is described. An accelerometer senses the vibrations induced in a test rail by a railroad wheel traveling thereon. The test rail is vibrationally isolated from adjacent train tracks and ground vibrations to permit sensing of train wheel defects such as flat spots on wheels, loose couplings, dragging equipment and the like. Defects are recognized when the sensed vibrations exceed preselected maximum tolerable levels, said levels being fixed or automatically regulated to compensate for varying train conditions. Identification of each wheel having a defect is provided as well as optional car identification.

Claims

1. A wheel carriage defect detector for a railroad car moving on support rails comprising in combination:

a first test rail mounted in spaced alignment with a supporting rail and vibrationally isolated therefrom;

means for sensing the vibrations induced by a railroad wheel traveling on said first test rail and producing a first vibration signal indicative thereof;

a second test rail mounted in spaced alignment with the first test rail on the side opposite to the direction of movement of the wheel and vibrationally isolated from the first test rail and the supporting rail;

means for sensing the vibrations induced by said traveling railroad wheel in said second test rail and producing a signal indicative of the average thereof; and

means responsive to said selected vibration signal and the first vibration signal for producing a defect signal when said first vibration signal exceeds said selected vibration signal by a preselected amount.

2. A device as received in claim 1, wherein said average signal-producing means comprises:

an accelerometer mounted on said second test rail;

a filter driven by the accelerometer output; and

a sampling and hold circuit detecting and storing the filtered accelerometer signal at a predetermined time.

3. A device as recited in claim 2, and further comprising:

means mounted adjacent the spacing between the first test rail and the second test rail for detecting when said railroad wheel is about to travel over said second test rail and producing a wheel signal indicative thereof;

said wheel signal actuating the sampling and hold circuit; and

a fixed threshold circuit biased by the sampled and stored signal to produce a preselected defect reference signal and wherein the defect signal producing means comprises a differential amplifier coupled to the defect reference signal and the first vibration signal.

4. A wheel carriage defect deTector for a railroad car moving on support rails comprising in combination:

a plurality of spaced test rails mounted in spaced alignment with one another and with a supporting rail and vibrationally isolated therefrom and from one another;

a separator rail spaced between and in alignment with said test rails;

means sensing vibrations induced in individual test rails by moving railroad wheels and producing electrical signals individually indicative thereof;

a plurality of wheel detectors mounted adjacent the spaces between the rails and producing electrical wheel signals indicative of the presence of a wheel;

means controlled by the wheel signals and responsive to the vibration signals for producing a plurality of wheel defect signals when said vibration signals exceed predetermined levels, and said spaced test rails and separator rails having preselected lengths, where the total length of said test rails is greater than the maximum common railroad wheel circumferential length and where the separator rail has a length commensurate with that necessary to bring the entire circumference of the common railroad wheel in contact with a test rail.

5. A device as recited in claim 4 wherein said wheel detectors includes a first wheel detector adjacent the spacing between the supporting rails and test rail;

a wheel counter driven by the electrical signal from said first wheel detector for counting the number of wheels.

6. A device as recited in claim 4 wherein the wheel defect-producing means further comprises:

a threshold circuit, driven by the vibration signal;

an AND gate having its input coupled to the vibration signal and the wheel detector signals, said gate being temporarily blocked by the wheel detector signal.

7. A device as recited in claim 5 and further including;

a storage circuit coupled to the output of the gate for storing the detection of a defect by the threshold circuit.

8. A device as recited in claim 5 wherein the wheel counter produced a car count signal indicative of a preselected number of counted wheels, said preselected number being commensurate with an assumed number of wheels per car, and;

a car counter responsive to the car count signal for counting the number of cars.

9. A wheel carriage defect detector for a railroad car moving on support rails comprising in combination:

first and second test rails mounted in spaced alignment with one another and a supporting rail and vibrationally isolated therefrom and from one another;

means for sensing the vibrations induced by a railroad wheel traveling on said first test rail and producing a signal indicative thereof;

means responsive to the sensed vibrations in said first test rail and producing a signal indicative of an average vibration level of the wheel traveling over said test rail;

means sensing the vibrations induced by said railroad wheel traveling on said second test rail and producing a second vibration signal indicative thereof; and

means responsive to said selected vibration signal and the second vibration signal for producing a defect signal when said second vibration signal exceeds said average vibration signal by a predetermined amount.

10. A wheel carriage defect detector for a railroad car moving on support rails comprising in combination:

first and second test rails mounted in spaced alignment with one another and vibrationally isolated from the supporting rail;

means for sensing the vibrations induced by a railroad wheel traveling on said first and second test rails and producing first and second signals representative thereof;

means responsive to the first vibration signal for producing a first wheel defect signal when said first vibration signal exceeds a preselected level;

means responsive to the second vibration signal for producing a second wheel defect signal when said second vibration signal exceeds a preselected level and wherein said second wheel defect signal is representative of the same defect represented by said first wheel defect signal; and

means actuated by said first wheel defect signal for producing an alarm signal upon the occurrence of said second wheel defect signal.