Sensor for railcar wheels
First Claim
1. A detector for the presence of a train wheel on a train track comprising:
- a) at least one electromagnetic field generator sensor comprising;
an inductance-capacitance (L/C) loop tank circuit that develops an alternating current at a natural resonance frequency to provide an electromagnetic field when the L/C tank circuit is electrically charged;
a charging circuit that provides an electrical charge to the tank circuit when amplitude of the frequency drops below a predetermined level; and
a feed back from the tank circuit to the charging circuit at the resonance frequency permitting the charging circuit to determine when the amplitude of the frequency has dropped below the predetermined level;
said L/C tank circuit and charging circuit being incapable of maintaining the predetermined amplitude of the frequency when a ferromagnetic material of the mass of a train wheel is located in a center of the field;
b) at least one means for holding the electromagnetic field generator proximate a train rail so that the electromagnetic field extends through a spatial area through which a train wheel travels and so that the field is affected to cause a drop in the frequency amplitude below a second threshold level that is below the predetermined level when a train wheel is located on the rail so that it partially affects the field, and so that there is a further drop in frequency amplitude below a third threshold level below the second threshold level when the train wheel is located so that it filly affects the field;
c) at least one means for detecting an increase in frequency amplitude above a first threshold level above the predetermined level indicating that the electromagnetic field generator is no longer in a proper position relative to the train rail, for detecting the drop in frequency amplitude below the second threshold level to indicate approach of the train wheel, and for detecting the drop in frequency amplitude below the third threshold level to indicate the presence of the train wheel; and
d) a means for compensating for drift of frequency amplitude from the predetermined level when the drift is between the first and third threshold levels and for ceasing such compensating when the frequency amplitude is above the first threshold level or below the second threshold level.
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Accused Products
Abstract
Method and apparatus for detection of the presence of a train wheel on a train track that overcomes problems associated with previously known detectors. The invention includes a method for detecting the presence of a train wheel on a train track. The method includes the steps of: a) generating an electromagnetic field using at least one electromagnetic field generator sensor including a resonance tank circuit; b) providing an electrical charge to the tank circuit when amplitude of the frequency drops below a predetermined level by using a charging circuit; c) providing a feed back from the tank circuit permitting the charging circuit to determine when the amplitude of the frequency has dropped below the predetermined level; d) holding the electromagnetic field generator proximate a train rail so that a train wheel causes a drop in the frequency amplitude below a second threshold level when a train wheel partially affects the field, and so that there frequency amplitude below a third threshold level below the second threshold level when the train wheel is located so that it fully affects the field; e) detecting when there is an increase in frequency amplitude above a first threshold level indicating that the electromagnetic field generator is no longer in a proper position relative to the train rail; f) detecting when there is a change in frequency amplitude relative to the threshold levels; and g) compensating for drift of frequency amplitude between the first and second threshold levels and ceasing such compensating when the frequency amplitude is above the first threshold level or below the second threshold level. The method includes all uses of the detector and apparatus as previously described. The invention further includes apparatus for practicing the method of the invention.
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Citations
47 Claims
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1. A detector for the presence of a train wheel on a train track comprising:
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a) at least one electromagnetic field generator sensor comprising;
an inductance-capacitance (L/C) loop tank circuit that develops an alternating current at a natural resonance frequency to provide an electromagnetic field when the L/C tank circuit is electrically charged;
a charging circuit that provides an electrical charge to the tank circuit when amplitude of the frequency drops below a predetermined level; and
a feed back from the tank circuit to the charging circuit at the resonance frequency permitting the charging circuit to determine when the amplitude of the frequency has dropped below the predetermined level;
said L/C tank circuit and charging circuit being incapable of maintaining the predetermined amplitude of the frequency when a ferromagnetic material of the mass of a train wheel is located in a center of the field;
b) at least one means for holding the electromagnetic field generator proximate a train rail so that the electromagnetic field extends through a spatial area through which a train wheel travels and so that the field is affected to cause a drop in the frequency amplitude below a second threshold level that is below the predetermined level when a train wheel is located on the rail so that it partially affects the field, and so that there is a further drop in frequency amplitude below a third threshold level below the second threshold level when the train wheel is located so that it filly affects the field;
c) at least one means for detecting an increase in frequency amplitude above a first threshold level above the predetermined level indicating that the electromagnetic field generator is no longer in a proper position relative to the train rail, for detecting the drop in frequency amplitude below the second threshold level to indicate approach of the train wheel, and for detecting the drop in frequency amplitude below the third threshold level to indicate the presence of the train wheel; and
d) a means for compensating for drift of frequency amplitude from the predetermined level when the drift is between the first and third threshold levels and for ceasing such compensating when the frequency amplitude is above the first threshold level or below the second threshold level. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 44, 45, 46, 47)
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26. A method for detecting the presence of a train wheel on a train track comprising:
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a) generating an electromagnetic field by means of at least one electromagnetic field generator sensor comprising;
an inductance-capacitance (L/C) loop tank circuit that develops an alternating current at a natural resonance frequency to provide an electromagnetic field when the L/C tank circuit is electrically charged;
b) providing an electrical charge to the tank circuit when amplitude of the frequency drops below a predetermined level by means of a charging circuit;
c) providing a feed back from the tank circuit to the charging circuit at the resonance frequency permitting the charging circuit to determine when the amplitude of the frequency has dropped below the predetermined level where the L/C tank circuit and charging circuit are incapable of maintaining the predetermined amplitude of the frequency when a ferromagnetic material of the mass of a train wheel is located in a center of the field;
d) holding the electromagnetic field generator proximate a train rail so that the electromagnetic field extends through a spatial area through which a train wheel travels and so that the field is affected to cause a drop in the frequency amplitude below a second threshold level that is below the predetermined level when a train wheel is located on the rail so that it partially affects the field, and so that there is a further drop in frequency amplitude below a third threshold level below the second threshold level when the train wheel is located so that it fully affects the field;
e) detecting when there is an increase in frequency amplitude above a first threshold level above the predetermined level indicating that the electromagnetic field generator is no longer in a proper position relative to the train rail;
f) detecting when there is a drop in frequency amplitude below the second threshold level to indicate approach of the train wheel;
g) detecting when there is a drop in frequency amplitude below the third threshold level to indicate the presence of the train wheel; and
h) compensating for drift of frequency amplitude from the predetermined level when the drift is between the first and second threshold levels and ceasing such compensating when the frequency amplitude is above the first threshold level or below the second threshold level. - View Dependent Claims (27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43)
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Specification