US3869663A
Expired / Lapsed
US
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Method and apparatus for checking metallic objects by monitoring its effect on one cycle of an alternating field
Assignee: Berliner Mashinenbau AG
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Filing: 1972-06-12
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Granted: 1975-03-04
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Expires: 1992-06-12
Abstract
Abstract A method and apparatus of checking metallic objects to determine whether they conform to a desired standard by passing the object between the primary and secondary coils of a transformer so that the amplitude of the A.C. voltage output from the secondary is varied. Then the half-wave amplitude of this output is compared with the amplitude of a reference A.C. voltage, which is also used to energize the primary coil, to determine whether the halfwave amplitude of the output lies within a predetermined range correlated to the desired standard. To make allowance for the fact that the output is above the lower limit for longer than it will be above the upper limit if this latter is exceeded, the comparison is by first and second comparators relating to the lower and upper limit respectively, the first comparator giving an output pulse when the upper limit is exceeded. The output pulse for the first comparator is divided into two paths one to a negator giving an output pulse assigned the binary value 1 to an input of a NAND-gate, the other path leading to a first flip-flop which when triggered by the output pulse from the first comparator gives an output pulse also assigned binary value 1 to another input of the NAND-gate. The output from the second comparator is fed to a second flip-flop which if triggered by a pulse for the second comparator gives an output pulse of binary value 0 to a third input of the NAND-gate, otherwise the absence of a pulse from the second flip-flop has a binary value 1. Only when all the three inputs to the NAND-gate are each of value 1 will output for the gate change for binary value 1 to 0 to indicate that the object satisfies the desired standard. The flip-flops are reset automatically, to permit evaluation of each output pulse from the comparator.
Inventors
- 👤 Klaus Tschierse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:05
CPC Classifications
G; G07; G07D; G07D5/00; G07D5/08; G07D5/02
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
132 words
A system for checking metallic objects, such as coins or the like comprising means for generating a periodically alternating field through which the object is moved, detector means for measuring the change in the field at a measuring point caused by the presence of the object and providing an output signal having an alternating waveform, and evaluation circuiT means connected to said detector means for comparing the positive or negative amplitude of the alternating signal within one period of the signal spread over its peak value, with a defined range of tolerance formed by two different reference voltages such that a ''''good-indication'''' of the object occurs, only if the amplitude lies between the two reference voltages, and resetting means for resetting said evaluation circuit means for each period of the signal evaluated.
Claim 2
Independent Claim
132 words
A system for checking metallic objects, such as coins or the like comprising means for generating a periodically alternating field through which the object is moved, detector means for measuring the change in the field at a measuring point caused by the presence of the object and providing an output signal having an alternating waveform, and evaluation circuiT means connected to said detector means for comparing the positive or negative amplitude of the alternating signal within one period of the signal spread over its peak value, with a defined range of tolerance formed by two different reference voltages such that a ''''good-indication'''' of the object occurs, only if the amplitude lies between the two reference voltages, and resetting means for resetting said evaluation circuit means for each period of the signal evaluated.
Claim 3
Dependent Claim
96 words
A system according to claim 1, wherein said means for generating the alternating field includes a plurality of inductively connected coils generating the field through which said object is moved, said detector means providing the output signal in the form of a measuring voltage having voltage amplitudes, said evaluation circuit means including logic circuit means for comparing the voltage amplitudes of the measuring voltage with the two different reference voltages and a digital electronic switching means for evaluating the result of said comparison, the frequency of the reference voltages being identical to that of the field.
Claim 4
Dependent Claim
31 words
A system according to claim 2 in which the reference voltages are generated by a measuring frequency generator to which a primary coil of said plurality of coils is also connected.
Claim 5
Dependent Claim
42 words
A system according to claim 3 wherein said evaluation circuit means includes first and second comparators each having a corresponding input connected to a secondary coil of said plurality of coils and another input to which a respective reference voltage is connected.
Claim 6
Dependent Claim
41 words
A system according to claim 4 in which the outputs of said first and second comparators are in the form of pulses and are connected to respective bistable flip-flop units and a NAND-gate connected to the outputs of said flip-flop units.
Claim 7
Dependent Claim
79 words
A system according to claim 5 wherein said resetting means reset the flip-flop units to the initial condition for each period of the measuring frequency to be evaluated, said resetting means including a common RC circuit connected to the flip-flop units for resetting the units in accordance with a predetermined edge of the pulses emitted by one of said first and second comparators, said one comparator being associated with a lower reference voltage of the two different reference voltages.
Claim 8
Dependent Claim
74 words
A system according to claim 10 wherein the outputs of the first and second comparators are connected to a Nand gate providing an output to a bistable flip-flop unit said resetting means includes trigger pulse means responsive to the zero crossing of the measuring voltage for providing a trigger pulse to the bistable flip-flop unit for comparison with the output of said NAND-gate at the time of the peak value of the measuring frequency.
Claim 9
Dependent Claim
22 words
A system according to claim 7 in which said trigger pulse means supplies to the bistable flip-flop unit, having a rectangular waveform.
Claim 10
Independent Claim
131 words
A method for checking metallic objects, such as coins or the like, comprising moving the object through a periodically alternating field, detecting a change in the field at a measuring point caused by the presence of the object, supplying a signal having an alternating waveform representing the change in the field to an evaluation circuit, determining by the evaluation circuit whether the amplitude of one polarity of the alternating signal within one period of the signal spread over its peak value is within a defined range of tolerance formed by two different reference voltages such that a ''''good-indication'''' of the object occurs only if the the amplitude lies between the two reference voltages, and resetting the evaluation circuit for each period of the signal in which a determination is carried out.
Claim 11
Independent Claim
131 words
A method for checking metallic objects, such as coins or the like, comprising moving the object through a periodically alternating field, detecting a change in the field at a measuring point caused by the presence of the object, supplying a signal having an alternating waveform representing the change in the field to an evaluation circuit, determining by the evaluation circuit whether the amplitude of one polarity of the alternating signal within one period of the signal spread over its peak value is within a defined range of tolerance formed by two different reference voltages such that a ''''good-indication'''' of the object occurs only if the the amplitude lies between the two reference voltages, and resetting the evaluation circuit for each period of the signal in which a determination is carried out.
Claim 12
Independent Claim
137 words
A method for checking metallic objects, such as coins or the like, comprising moving the object through a periodically alternating field, detecting a change in the field at a measuring point caused by the presence of the object, supplying a signal having an alternatIng waveform representing the change in the field to an evaluation circuit, determining by the evaluation circuit whether the amplitude of one polarity of the alternating signal within one period of the signal spread over its peak value is within a defined range of tolerance formed by a reference voltage and a time value, such that a ''''good-indication'''' of the object occurs only if the amplitude exceeds the reference voltage and lies within the time value, and resetting the evaluating circuit for each period of the signal in which a determination is carried out.
Claim 13
Independent Claim
137 words
A method for checking metallic objects, such as coins or the like, comprising moving the object through a periodically alternating field, detecting a change in the field at a measuring point caused by the presence of the object, supplying a signal having an alternatIng waveform representing the change in the field to an evaluation circuit, determining by the evaluation circuit whether the amplitude of one polarity of the alternating signal within one period of the signal spread over its peak value is within a defined range of tolerance formed by a reference voltage and a time value, such that a ''''good-indication'''' of the object occurs only if the amplitude exceeds the reference voltage and lies within the time value, and resetting the evaluating circuit for each period of the signal in which a determination is carried out.
Claim 14
Independent Claim
145 words
A system for checking metallic objects, such as coins or the like, comprising means for generating a periodically alternating field through which the object is moved, detector means for measuring the change in the field at a measuring point caused by the presence of the object and providing an output signal having an alternating waveform, an evaluation circuit means connected to said detector means for comparing the positive or negative amplitude of the alternating signal within one period of the signal spread over its peak value, with a defined range of tolerance formed by one reference voltage and a time value supplied to said evaluation circuit means such that a ''''good-indication'''' of the object occurs only if the amplitude exceeds the reference voltage and lies within the time value, and resetting means for resetting said evaluation circuit means for each period of the signal evaluated.
Claim 15
Independent Claim
145 words
A system for checking metallic objects, such as coins or the like, comprising means for generating a periodically alternating field through which the object is moved, detector means for measuring the change in the field at a measuring point caused by the presence of the object and providing an output signal having an alternating waveform, an evaluation circuit means connected to said detector means for comparing the positive or negative amplitude of the alternating signal within one period of the signal spread over its peak value, with a defined range of tolerance formed by one reference voltage and a time value supplied to said evaluation circuit means such that a ''''good-indication'''' of the object occurs only if the amplitude exceeds the reference voltage and lies within the time value, and resetting means for resetting said evaluation circuit means for each period of the signal evaluated.
Claim 16
Dependent Claim
86 words
A method according to claim 18, further including forming the alternating field by inductively connected coils and moving the object therethrough, detecting the change in the coupling field in the form of induced voltage amplitudes of a measuring voltage, comparing the amplitudes of the measuring voltage with the two different reference voltages defining the range of tolerance and evaluating the results of the comparison by means of a digital electronic switching system, the frequency of the reference voltage being identical to that of the coupling field.
Claim 17
Dependent Claim
30 words
A method according to claim 12, further including generating the reference voltages with a measuring frequency generator to which a primary coil of the alternating field coils is also connected.
Claim 18
Dependent Claim
182 words
A method according to claim 9 in which the amplitude of the alternating signal is compared with the two reference voltages defining a range of tolerance so that the ''''good-indication'''' corresponds to a peak value lying between the two difference reference voltages, and further including the steps of forming the alternating field by a coupling field of inductively connected coils and moving the object therethrough, inducing a measuring voltage having voltage amplitudes in one of the coils, comparing the voltage amplitude with the two different reference voltages and evaluating the results of the comparison by means of a digital electronic switching system, the frequency of the reference voltages being identical to that of the coupling field, and supplying the reference voltages defining the upper and lower limit of the range of tolerance and the measuring voltage produced in a secondary coil of the said inductively connected coils to an identification emitter consisting of two comparators, the ''''good-identification'''' occurring through the occurrence of pulses at the output side at only one comparator, and in particular the comparator associated with the lower reference voltage.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-03 | 1978-09-02 | 1979-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-03 | 1982-09-02 | 1983-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-03 | 1986-09-02 | 1987-03-04 | $7700.00 | Window Closed / Lapsed |