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US4593567A Expired / Lapsed US ⏱️ 0.0 years remaining

Electromagnet transducer

Assignee: VDEh-Betriebsforschungsinstitut
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Filing: 1984-08-29
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Granted: 1986-06-10
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Expires: 2004-08-29
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Abstract

Abstract There is disclosed an electromagnetic transducer for the transmission and ception of ultrasonic waves in the touchless testing of metal workpieces, particularly made of steel, in the shape of sheet and strip material. The transducer is arranged for continuous testing, particularly as applied to continuously advancing material, by wavelength spectroscopy and particularly modal spectroscopy of received ultrasonic waves. To this end, the transducer comprises a pair of transducer segments each of which has a set of mutually parallel conductor tracks formed on a substantially planar printed circuit board in which the frequencies and wavelengths for each segment can be preset in a matrix logic circuit having a short time sequence. The conductor tracks comprise windings arranged to be connected for operation through a set of switching elements in such a manner as to produce in various switching states of the switching elements a plurality of wavelengths for each frequency. The wavelengths being proportionally related to each other by small integral numbers.

Inventors

  • 👤 Fritz Isselstein
  • 👤 Ernst Luhn
  • 👤 Gunther Coen
  • 👤 Dietmar Oberhoff
  • 👤 Roland Keck

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 06:36
CPC Classifications
G; G01; G01N; G01N29/00; G01N29/22; G01N29/24; G01N29/2412; G01N2291/00; G01N2291/04; G01N2291/042; G01N2291/0421; G01N2291/0422

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 106 words
An electromagnetic transducer for the transmission and reception of ultrasonic waves in the touchless testing of flat strip and sheet metal by wavelength spectroscopy, comprising: at least one transducer segment having a plurality of mutually parallel conductor tracks formed on a substantially plane printed circuit board in which the frequencies and wavelengths for each segment are preset in a matrix logic circuit having a short time sequence and in which said conductor tracks include windings operably connected through a set of switching elements to produce in various switching states of said elements a plurality of wavelengths being proportionally related to one another by small integral numbers.
Claim 2
Dependent Claim 106 words
An electromagnetic transducer for the transmission and reception of ultrasonic waves in the touchless testing of flat strip and sheet metal by wavelength spectroscopy, comprising: at least one transducer segment having a plurality of mutually parallel conductor tracks formed on a substantially plane printed circuit board in which the frequencies and wavelengths for each segment are preset in a matrix logic circuit having a short time sequence and in which said conductor tracks include windings operably connected through a set of switching elements to produce in various switching states of said elements a plurality of wavelengths being proportionally related to one another by small integral numbers.
Claim 3
Dependent Claim 31 words
An electromagnetic transducer according to claim 1, in which each one of said conductor tracks is a multiwinding track and in which said conductor tracks are relatively spaced at equi-distant intervals.
Claim 4
Dependent Claim 31 words
An electromagnetic transducer according to claim 1 in which said conductor tracks are constructed for optional variation of their polarity arrangement to function either as a coil or as a meander.
Claim 5
Dependent Claim 36 words
An electromagnetic transducer according to claim 1 in which said conductor tracks are provided with junctions spaced so as to allow the frequency response curve of said transducer to be smoothed in the operative frequency range.
Claim 6
Dependent Claim 39 words
An electromagnetic transducer according to claim 1 in which two laterally spaced overlapping segments are provided of identical configuration and in which a delay circuit is provided so that said overlapping segments can be operated with a phase difference.
Claim 7
Dependent Claim 46 words
An electromagnetic transducer according to claim 1 which is connected via its earth terminal to electrically conducting rollers formed from synthetic material and which are arranged to maintain conductive rolling contact with the workpiece under test for keeping the workpiece in spaced relationship with the transducer.
Claim 8
Dependent Claim 97 words
An electromagnetic transducer according to claim 1 in which the received signal is subjected to interference suppression by means of a digital signals detector circuit in which the received signal is applied to a first shift register together with clock pulses from a pulse generator and a comparator and to a backward counter, a second shift register being provided in series with said first shift register and both shift register outputs being fed into the comparator which is followed by said backward counter, the carry-out output of which is activated when a pre-set pulse number is exceeded.
Claim 9
Dependent Claim 27 words
An electromagnetic transducer according to claim 1 in which said conductor tracks are photolithographically structured metal lines applied by vapour-deposition on an electrically and magnetically non-conductive substrate.
Claim 10
Dependent Claim 15 words
An electromagnetic transducer according to claim 8, in which said metal lines consist of aluminum.
Claim 11
Dependent Claim 20 words
An electromagnetic transducer according to claim 8 in which said metal tracks are vapour-deposited on a thin film coated foil.
Claim 12
Dependent Claim 19 words
An electromagnetic transducer according to claim 8 in that the substrate consists of silicon-monocrystal platelets carrying an oxidation layer.
Claim 13
Dependent Claim 37 words
An electromagnetic transducer according to claim 8 in which the substrate is provided on one side thereof with said conductor tracks on the other side with said conductors which cross said conductor tracks or their winding parts.

References Cited (Backward Citations)

US3850028A Cited
SU868561A1 Cited
SU794491A1 Cited
US4434663A Cited
US4522071A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-06-09 1989-12-09 1990-06-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-06-09 1993-12-09 1994-06-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-06-09 1997-12-09 1998-06-10 $7700.00 Window Closed / Lapsed

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