US4164873A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of and device for material checking by ultra sound while employing an electrodynamic sound converter
Assignee: Hoesch Werke AG
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Filing: 1977-09-27
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Granted: 1979-08-21
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Expires: 1997-09-27
Abstract
Abstract A method of and device for ultrasonically checking a workpiece while employing an electrodynamic sound converter including a checking head and a coil adapted to be energized to create a magnetic field, according to which during the checking operation the workpiece in a continuous movement relatively is passed by the testing or checking head of the electrodynamic sound converter. The coil for generating the magnetic field is energized by an alternating current or an intermittent or alternating direct current. Furthermore, the electrodynamic sound converter in conformity with the intensity of the magnetization of the coil is switched on and off in such a way that a sound converter is switched on when the magnetization has reached a predetermined value, and is switched off as soon as the magnetization drops below another predetermined value.
Inventors
- 👤 Wolfgang Bottcher
- 👤 Hermann-Josef Kopineck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:20
CPC Classifications
G; G01; G01N; G01N29/00; G01N29/22; G01N29/26; G01N29/27; G01N29/24; G01N29/2412; G01N2291/00; G01N2291/02; G01N2291/028; G01N2291/02827
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
102 words
A method of ultrasonically checking a moving workpiece utilizing an electrodynamic sound converter which includes an electromagnetic coil means for creating a magnetic field when energized and a high frequency coil for testing the workpiece magnetized by said electromagnetic coil means when energized by a current of varying amplitude, said method comprising: initiating operation of a control device when the amplitude of the current to said electromagnetic coil means reaches a given value to turn on energization of said high frequency coil for testing said workpiece and terminating operation of said high frequency coil when said amplitude falls below a given value.
Claim 2
Independent Claim
102 words
A method of ultrasonically checking a moving workpiece utilizing an electrodynamic sound converter which includes an electromagnetic coil means for creating a magnetic field when energized and a high frequency coil for testing the workpiece magnetized by said electromagnetic coil means when energized by a current of varying amplitude, said method comprising: initiating operation of a control device when the amplitude of the current to said electromagnetic coil means reaches a given value to turn on energization of said high frequency coil for testing said workpiece and terminating operation of said high frequency coil when said amplitude falls below a given value.
Claim 3
Dependent Claim
27 words
A method in combination according to claim 1, which includes the step of energizing said coil means by an alternating current of from 50 to 60 Hz.
Claim 4
Dependent Claim
35 words
A method in combination according to claim 1, which includes the step of reducing the current intensity of said coil means when the edge of a workpiece reaches the proximity of said high frequency coil.
Claim 5
Independent Claim
118 words
An apparatus for ultrasonically checking a moving workpiece comprising: an electrodynamic sound converter having an electromagnetic coil means for creating a magnetic field when energized and a high frequency coil for testing the workpiece magnetized by said electromagnetic coil means when energized by a current of varying magnitude, and a control device connected to said electromagnetic coil means and said high frequency coil, said electromagnetic coil means initiating operation of said control device when the amplitude of the current to said electromagnetic coil means reaches a given value to turn on energization of said high frequency coil for testing said workpiece and to terminate operation of said high frequency coil when said amplitude falls below a given value.
Claim 6
Independent Claim
118 words
An apparatus for ultrasonically checking a moving workpiece comprising: an electrodynamic sound converter having an electromagnetic coil means for creating a magnetic field when energized and a high frequency coil for testing the workpiece magnetized by said electromagnetic coil means when energized by a current of varying magnitude, and a control device connected to said electromagnetic coil means and said high frequency coil, said electromagnetic coil means initiating operation of said control device when the amplitude of the current to said electromagnetic coil means reaches a given value to turn on energization of said high frequency coil for testing said workpiece and to terminate operation of said high frequency coil when said amplitude falls below a given value.
Claim 7
Dependent Claim
72 words
A device in combination according to claim 4, which includes a second coil forming a customary demagnetizing coil and located behind said first coil when viewing the relative movement of the workpiece with regard to said first coil, said second coil being electrically connected to said control device and being adapted to be switched on by said control device in response to a workpiece edge reaching the proximity of said first coil.
Claim 8
Dependent Claim
86 words
A device in combination according to claim 4, which includes at least one third coil arranged opposite and in spaced relationship to said first coil and electrically connected to said control device, said at least one third coil being energizable by alternating current controlled by said control device for generating a counter force acting upon a workpiece passing between said first and third coil and counteracting the magnetic force of attraction exerted by said first coil upon a workpiece passing between said first and third coil.
Claim 9
Dependent Claim
61 words
An apparatus as claimed in claim 4, in which a detector connected to said control device is placed adjacent said workpiece ahead of said sound converter, said detector sensing the end of a workpiece and initiating operation of said control device to reduce the current in said electromagnetic coil means and thereby decrease the magnetization of the end of said workpiece.
References Cited (Backward Citations)
US3583213A
Cited
US3850028A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-08-20 | 1983-02-19 | 1983-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-08-20 | 1987-02-19 | 1987-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-08-20 | 1991-02-19 | 1991-08-21 | $7700.00 | Window Closed / Lapsed |