초록 ▼

A fault-monitoring system for a large industrial conveyor belt to detect rips or other faults. There are fault-sensing units in the belt, each comprising a conductive loop extending across the belt and a sensing circuit. First and second frequency signals are directed to the fault sensor and the fau

A fault-monitoring system for a large industrial conveyor belt to detect rips or other faults. There are fault-sensing units in the belt, each comprising a conductive loop extending across the belt and a sensing circuit. First and second frequency signals are directed to the fault sensor and the fault-responsive circuit sends a response of a frequency to indicate either a fault condition or a no-fault condition. Thus, the response from the fault sensor is either an “I am here and I am okay” or “I am here, but there is a fault in the belt” signal.

대표청구항 ▼

1. A fault-monitoring and -sensing system to detect a fault condition in a conveyor belt having a longitudinal axis, a transverse axis, and first and second side portions, said monitoring system comprising:a) a fault-sensing system comprising a plurality of fault-sensing units at spaced fault-sensin

1. A fault-monitoring and -sensing system to detect a fault condition in a conveyor belt having a longitudinal axis, a transverse axis, and first and second side portions, said monitoring system comprising:a) a fault-sensing system comprising a plurality of fault-sensing units at spaced fault-sensing locations along the longitudinal axis of the belt, each of said fault-sensing units comprising:i. an electrically conductive fault-responsive component which extends between the side portions of the belt and which has an intact condition in a belt no-fault condition, and a non-intact condition in a belt fault condition;ii. a fault-sensing component comprising a fault-sensing circuit operatively connected to the fault-responsive component and arranged to provide no-fault or fault responses corresponding to the intact and non-intact conditions, respectively;b) a fault-monitoring section at a fault-detecting location arranged to transmit interrogating signals to said fault-sensing units and to receive the fault or no-fault responses from the sensing unit and to, in turn, generate a reporting signal corresponding to the response or responses from the sensing unit, whereby, as the belt travels and the fault-sensing units pass by the fault-monitoring section, the fault or no-fault condition of the belt at the location of the fault-sensing units is detected. 2. The system as recited in claim 1, wherein said electrically conductive fault-responsive component provides an electrically conductive path extending between first and second side portions of the belt and connecting to said fault-sensing circuit, said fault-sensing circuit having a first operating mode which functions with the conductive path of the fault-responsive component intact to provide said no-fault response, and having a second operating mode which functions with the conductive path of the fault-responsive component in a non-intact condition to provide said second fault response. 3. The system as recited in claim 2, wherein said electrically conductive fault-responsive component comprises a conductive loop having two end connecting portions connecting to the fault-sensing circuit to form a bypass connection, and with the fault-responsive component in its non-intact condition, said electrically conductive path is interrupted and the bypass path becomes nonfunctional. 4. The system as recited in claim 3, wherein said bypass connection is in parallel with at least one circuit component with said fault-sensing circuits. 5. The system as recited in claim 1, wherein said fault-sensing circuit comprises, at least in part, a resonant circuit portion which operates at a first resonant frequency with the fault-responsive component in the intact condition, and operates at a second resonant frequency with the fault-responsive component in the non-intact condition, and said fault-monitoring section has a receiving/responding portion which is responsive to said first and second frequencies in order to generate a reporting signal corresponding to the frequency of the signal received from the fault-sensing component. 6. The system as recited in claim 5, wherein said fault-sensing circuit comprises a coil portion and a capacitance portion, said electrically conductive fault-responsive component has an operative connection with at least said capacitance portion in a manner that in the no-fault condition, the capacitance portion has a first capacitance value, and in the fault condition, the capacitance portion has a second capacitance value in order to provide said first and second frequency outputs. 7. The system as recited in claim 6, wherein said electrically conductive fault-responsive component is in series with at least one capacitor of said capacitance portion. 8. The system as recited in claim 7, wherein said electrically conductive fault-responsive component is in parallel with at least one capacitor of said capacitance portion. 9. The system as recited in claim 1, wherein said mon itoring section comprises a detecting section arranged to transmit an interrogating signal which energizes the fault-sensing unit, and said interrogating signal is arranged to energize the fault-sensing circuit in each of a no-fault operating mode of the fault-sensing circuit or in a fault operating mode of the fault-sensing circuit to cause the no-fault or fault response. 10. The system as recited in claim 1, wherein said interrogating signal comprises first and second signal components matching characteristics of the fault-sensing circuit in a no-fault or fault responding operating mode to generate the no-fault or fault response. 11. The system as recited in claim 1, wherein said detecting section is arranged to transmit the interrogative signal having first and second frequency components to energize the fault-detecting circuit operating in first or second frequency modes to transmit a no-fault response or a fault corresponding to said first and second frequencies, respectively. 12. The system as recited in claim 1, wherein said fault-monitoring section is arranged to transmit said interrogated signal or signals as a wave form having at least first and second frequency components, and said fault-sensing circuit has a resonant frequency portion which operates at a first resonant frequency with the fault-responsive component in the intact condition, and operates at a second resonant frequency with the fault-responsive component in the non-intact condition, said system being characterized so that when one of the fault-sensing units is in proximity to the fault-monitoring section, when the fault-sensing circuit is operating at the first resonant frequency with the fault-responsive component in the intact condition, the resonant circuit portion draws energy from the first frequency component of the monitoring section, and when the fault-sensing circuitry is operating at the second resonant frequency with the fault-responsive component in the non-intact condition, energy is drawn from the second frequency component of the fault-monitoring section; said fault-monitoring section being arranged to generate a reporting signal of the no-fault or fault condition in response to the change in the energy level of either the first or second frequency components of the fault-monitoring section. 13. The system as recited in claim 12, wherein said system further comprises a signal-processing section operatively connected to the fault-monitoring section to receive reporting signals from the fault-monitoring section of first and second frequencies, said signal-processing system being arranged to detect a decrease in amplitude of the reporting signal of either the first or second frequency to ascertain a fault or no-fault condition, said signal-processing section being arranged to transmit a further signal indicating a fault or no-fault condition. 14. The system as recited in claim 13, wherein said signal processing section comprises a rectifier to rectify the reporting signals from the fault-monitoring section and a comparator to compare the rectified signal with a reference signal to provide the signal. 15. The system as recited in claim 14, wherein said signal-processing section comprises a low-pass filter to receive the signal from the rectifier, an amplifier to amplify the signal from the low-pass filter, with an amplified signal from the amplifier being directed to the comparator, and there is a threshold generator that is responsive to the strength of the signals generated by the monitoring section to establish a reference signal corresponding to the strength of the signals from the monitoring section, so that the reference signal has a proportional relationship to the signals generated from the fault-monitoring section. 16. The system as recited in claim 1, wherein said fault-monitoring section comprises a detecting section having first and second detecting subsections which operate at said first and second frequencies, respectively, eac h detecting subsection comprising a driver section which provides a driver signal to a driver coil, a resonant idler section coupled to the coil of said driver, and a pickup coil coupled to the idler section, with said pickup coil providing an output signal. 17. A method of detecting a fault condition in a conveyor belt having a longitudinal axis, a transverse axis, and first and second side portions, system comprising:a) positioning a plurality of fault-sensing units at spaced fault-sensing locations along the longitudinal axis of the belt, with each of said fault-sensing units comprising:i. an electrically conductive fault-responsive component which extends between the side portions of the belt and which has an intact condition in a belt no-fault condition, and a non-intact condition in a belt fault condition;ii. a fault-sensing component comprising a fault-sensing circuit operatively connected to the fault-responsive component and arranged to provide no-fault or fault responses corresponding to the intact and non-intact conditions, respectively;b) moving said belt along a belt traveling path aligned with said longitudinal axis, with the fault-sensing components being positioned to move along a monitoring path;c) positioning a fault-monitoring section at a monitoring location adjacent to the monitoring path;d) transmitting interrogating signals to said fault-sensing units as the units are passing by the monitoring location initiate the fault or no-fault responses from the sensing unit and, in turn, generating a reporting signal corresponding to the response or responses from the sensing unit,whereby, as the belt travels and the fault-sensing units pass by the fault-monitoring section, the fault or no-fault condition of the belt at the location of the fault-sensing units is detected. 18. The method as recited in claim 17, wherein said electrically conductive fault-responsive component provides an electrically conductive path extending between first and second side portions of the belt and connecting to said fault-sensing circuit, said method further causing said fault-sensing circuit to operate in a first operating mode with the conductive path of the fault-responsive component intact to transmit said no-fault response, or causing said fault-sensing circuit to operate in a second operating mode with the conductive path of the fault-responsive component in a non-intact condition to transmit said second fault response. 19. The method as recited in claim 18, wherein said electrically conductive fault-responsive component comprises a conductive loop having two end connecting portions connecting to the fault-sensing circuit to form a bypass connection, and with the fault-responsive component in its non-intact condition, said electrically conductive path is interrupted and the bypass connection becomes nonfunctional, with said bypass connection being in parallel with at least one circuit component of said fault-sensing circuits. 20. The method as recited in claim 17, wherein said fault-sensing circuit comprises, at least in part, a resonant circuit portion, said method comprising operating causing said resonant circuit portion to respond at a first resonant frequency with the fault-responsive component in the intact condition, and at a second resonant frequency with the fault-responsive component in the non-intact condition.