Track circuit principle wheel detector
First Claim
1. A system for detecting the presence and position of wheel-axles on railroad cars comprising:
- a pair of rails;
a transmitter or signal source having a high frequency output;
a pair of current carrying loops, the first loop including said pair of rails and a pair of boundary shunts connecting said rails so as to define a detection zone;
the second loop extending in close proximity to and inside said first loop, said first and second loops being subdivided for current flow into two substantially equal portions with respect to a center line of said detection zone;
said transmitter being coupled to said pair of loops, and being connected to said first loop on said center line; and
,sensing means oriented for sensing field changes due substantially only to the direction of wheel-axle shunt current flow when a wheel-axle contacts said rails in said detection zone, said sensing means being insensitive to the fields produced by the currents flowing in said loops.
1 Assignment
0 Petitions
Accused Products
Abstract
Apparatus for detecting the presence and position of individual wheels or wheel-axles of railroad cars. The apparatus involves no moving parts and basically senses the presence of a car wheel by sensing a shunt current flowing through the car wheel-axle set. The apparatus or system includes a transmitter which develops a high frequency AC signal which is impressed across the rails, and a sense or pick-up coil which is sensitive to the fields produced by currents flowing up through the radius of the wheel, whereas it is substantially unaffected by fields produced by the currents flowing in the rails. A pair of current-carrying loops is provided, the first loop including a pair of rails and a pair of boundary shunts connecting said rails; the first loop being subdivided for current flow into two substantially equal portions with respect to a detection zone center line; the second loop extending in close proximity to and inside said first loop, said second loop likewise being subdivided for current flow.
13 Citations
7 Claims
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1. A system for detecting the presence and position of wheel-axles on railroad cars comprising:
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a pair of rails; a transmitter or signal source having a high frequency output; a pair of current carrying loops, the first loop including said pair of rails and a pair of boundary shunts connecting said rails so as to define a detection zone; the second loop extending in close proximity to and inside said first loop, said first and second loops being subdivided for current flow into two substantially equal portions with respect to a center line of said detection zone; said transmitter being coupled to said pair of loops, and being connected to said first loop on said center line; and
,sensing means oriented for sensing field changes due substantially only to the direction of wheel-axle shunt current flow when a wheel-axle contacts said rails in said detection zone, said sensing means being insensitive to the fields produced by the currents flowing in said loops. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification