TRAIN LENGTH MEASURING DEVICE

• US 3,581,071 A
• Filed: 04/10/1969
• Issued: 05/25/1971
• Est. Priority Date: 04/10/1969
• Status: Expired due to Term

• Current Assignee: Lawrence A. Payseure
• Original Assignee: Lawrence A. Payseure
• Inventors: Payseure, Lawrence A.
• Application Number:
  US04/815,075
• Time in Patent Office: 775 Days
• US Class Current: 702/158
• CPC Class Codes: G01B 11/043 for measuring length

Abstract

An apparatus and method for measuring the overall length of a series of connected and moving articles each of which may be of indeterminate length. The example to be described comprises interconnected railroad cars forming a train. The total length of the train is determined by employing two separated photocells and two light sources, each source normally shining on a respective photocell, so that each car of the moving train sequentially breaks the lightbeams to the photocells causing the photocells to produce electrical outputs. Since the distance between the two photocells is known and the time which each car takes to travel from one to the other is easily determined from the occurrences of output signals from the photocells, the distance from the beginning of one car to the beginning of the next is computed, the computations being accumulated to indicate the total train length.

Claims

1. A method of determining the total length of a plurality of moving articles, said method comprising the steps of:

detecting the leading edge of an article as it passes a first sensing device to produce a first electrical signal, detecting the leading edge of said article as it passes a second sensing device separated from said first device by a given distance to produce a second electrical signal, determining a first time interval between the time when said first signal is produced and the time when said second signal is produced, detecting the leading edge of the next article as it passes said first sensing device to produce a third electrical signal, determining a second time interval between the time when said second signal is produced and the time when said third signal is produced, utilizing said first and second time intervals and said given distance to calculate the distance from the leading edge of said one article to the leading edge of the next article, and summing all of the distances from the leading edge of one article to the leading edge of the next article to determine the approximate total length of said plurality of moving articles.

2. A system for measuring the total length of a chain of moving articles, said system comprising:

first detecting means for detecting the leading edge of each said article and for producing a first signal at the time said edge is detected, second detecting means separated from said first detecting means by a given distance for detecting the leading edge of each said article, after said edge is detected by said first detecting means, and for producing a second signal at the time said edge is so detected, means operatively connected to said first and second detecting means for determining a first time interval between the time when said first signal is produced and the time when said second signal is produced for any given article, means operatively connected to said first and second detecting means for determining a second time interval between the time when said second signal is produced for said given article and the time when said first signal is produced for the next succeeding article, computing means operatively connected to said means for determining a first time interval and to said means for determining a second time interval, said computing means being adapted to utilize said first and second time intervals and said given distance to calculate the distance from the leading edge of one article to the leading edge of the next article, and accumulator means for summing the distances from the leading edge of one article to the leading edge of the next article to determine the total length of said chain.

3. Apparatus as in claim 2 wherein each detecting means includes a photocell and a source of light positioned so that a beam of light is normally directed onto said photocell but is interrupted by said article to cause the photocell to produce an output signal.

4. Apparatus as in claim 2, wherein:

said means for determining a first time interval comprises means for producing a first number of pulses representing the time between the leading edge of one article being detected by said first detecting means and being detected by said second detecting means, said means for determining a second time interval comprises means for producing a second number of pulses representing the time between the leading edge of said one article being detected by the second detecting means and the leading edge of the next article being detected by said first detecting means, said computing means comprising means for developing a given pulse count representative of said given distance and means for effectively dividing said second number by said first number and for effectively multiplying the quotient by said given pulse count to result in an additional count representing the distance between leading article edges that is in excess of said given distance, and said accumulator means comprises means for adding said given pulse counts and said additional counts for successive articles in said chain.

5. Apparatus for measuring the length of a moving railroad train made up of a plurality of connected cars comprising:

first means for detecting a given portion of each railroad car, second means for detecting said portion of each railroad car after that car is detected by said first detecting means, said first and second means being separated by a given distance, means for determining a first time interval between the detection of the given portion of one car by said first detecting means and by said second detecting means and for determining a second time interval between the detection of the given portion of said one car by the second detecting means and the given portion of the next car by said first detecting means, means responsive to said given distance and said first and second time intervals for calculating the distance between the given portion of said one car and the given portion of the next car.

6. Apparatus as in claim 5, wherein said given portion is the leading edge of said car.

7. Apparatus as in claim 5, further including means for adding all of the distances between said given portions to produce a result approximating the total length of the train.

8. Apparatus as in claim 5, wherein said determining means includes:

a source of clock pulses, a first register, a second register, means for routing said pulses to said firSt register during said first time interval so that said first register accumulates a number of pulses which is a function of said given distance and the duration of said first time interval, means for routing said pulses to said second register during said second time interval so that said second register accumulates a number of pulses which is a function of the duration of said second time interval, and means for comparing the numbers accumulated in first and second registers.

9. Apparatus as in claim 8, wherein said first detecting means produces an electrical pulse when the given portion of a car is detected to permit said routing means to route said clock pulses to said first register and said second detecting means produces an electrical pulse when said given portion is detected to route said clock pulses to said second register.

10. Apparatus as in claim 8, wherein said first register accumulates the total number of clock pulses produced during said first time interval by said clock pulse source divided by said given distance, said second register accumulates clock pulses produced during said second time interval, and said comparing means, during the second interval, divides the number accumulated in said second register by the number accumulated in said first register.

11. Apparatus as in claim 5, wherein said first and second detecting means each comprises a photocell and a source of light disposed in relation to said photocell such that said source produces a lightbeam which shines on said photocell except when interrupted by said cars.

12. Apparatus as in claim 5, including additional detecting means for sensing the presence of said train to actuate said first and second detecting means, said determining means, and said calculating means.

13. A method of determining the length of a moving railroad train made up of a plurality of cars comprising the steps of:

detecting the leading edge of a railroad car as it passes a first sensing device to produce a first electrical signal, detecting the leading edge of said railroad car as it passes a second sensing device separated from said first device by a given distance to produce a second electrical signal, determining a first time interval between the time when said first signal is produced and the time when said second signal is produced, detecting the leading edge of the next railroad car as it passes said first sensing device to produce a third electrical signal, determining a second time interval between the time when said second signal is produced and the time when said third signal is produced, utilizing said first and second time intervals and said given distance to calculate the distance from the leading edge of said one car to the leading edge of the next car, and summing all of the distances from the leading edge of one car to the leading edge of the next car to determine the approximate total length of said train.

14. A method as in claim 13, wherein said utilizing step includes the further steps of :

dividing said first time interval by said given distance, dividing said second time interval by said divided first time interval, and adding said second time interval divided by said divided first time interval to said given distance to produce the approximate distance from the leading edge of each car to the leading edge of the next.