EP0031049A2 - Transducteur acoustique - Google Patents

Transducteur acoustique Download PDF

Info

Publication number
EP0031049A2
EP0031049A2 EP80107438A EP80107438A EP0031049A2 EP 0031049 A2 EP0031049 A2 EP 0031049A2 EP 80107438 A EP80107438 A EP 80107438A EP 80107438 A EP80107438 A EP 80107438A EP 0031049 A2 EP0031049 A2 EP 0031049A2
Authority
EP
European Patent Office
Prior art keywords
following features
sintered metal
grain size
acoustic transducer
damping
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP80107438A
Other languages
German (de)
English (en)
Other versions
EP0031049A3 (en
EP0031049B1 (fr
Inventor
Christian Göhlert
Peter Kanngiesser
Hansjakob Weiss
Werner Wilke
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Interatom T GmbH
Original Assignee
Interatom Internationale Atomreaktorbau GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Interatom Internationale Atomreaktorbau GmbH filed Critical Interatom Internationale Atomreaktorbau GmbH
Priority to AT80107438T priority Critical patent/ATE7429T1/de
Publication of EP0031049A2 publication Critical patent/EP0031049A2/fr
Publication of EP0031049A3 publication Critical patent/EP0031049A3/de
Application granted granted Critical
Publication of EP0031049B1 publication Critical patent/EP0031049B1/fr
Expired legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/02—Mechanical acoustic impedances; Impedance matching, e.g. by horns; Acoustic resonators

Definitions

  • the present invention relates to an acoustic transducer for transmitting and receiving sound, in particular ultrasound signals, consisting of a piezoelectric element, a lead section and a damping body.
  • this acoustic transducer can be made entirely of metal and is therefore particularly suitable at high temperatures and / or with radioactive radiation. With these converters in opaque media such. B. liquid sodium, metallic materials tested or surfaces are scanned contactless.
  • the so-called lead section protects the piezo-electric element from wear and tear or from contact with an aggressive medium and can change the direction of the sound if it is of the appropriate shape.
  • plastic wedges are used as the lead sections, which have a wave resistance suitable for this purpose.
  • the wave resistance of two adjacent media or bodies determines the reflection at the interface of these media and is in each case the product of the density and speed of sound of a medium.
  • a lead section should have a wave resistance that lies between that of the two adjacent media.
  • a leading section should have a characteristic impedance that is the geometric mean between the characteristic resistances of the two adjacent media represents.
  • German Offenlegungsschrift 26 14 376 describes an ultrasonic transducer for high temperatures, for example for a nuclear reactor cooled with liquid metal.
  • the coupling wedge proposed there consists of a multiplicity of thin metal plates which are held together under pressure and which have an optically smooth surface towards the piezoelectric element.
  • a wedge made of numerous thin sheets of metal can only be produced with considerable effort and must be constantly pressed together with considerable pressure so that the liquid metal does not creep through the gaps and attack the piezoelectric element.
  • such a wedge constructed from numerous thin sheets has the disadvantage that the transmission of the sound depends on the direction of these sheets.
  • a damping body which can consist of a loose wire mesh or a mixture of rubber and tungsten powder. But rubber is neither temperature nor radiation resistant and the wire mesh is not mechanically strong.
  • the object of the present invention is an acoustic transducer which avoids the disadvantages mentioned and is suitable for high temperatures and / or raioactive radiation exposure and in aggressive media.
  • the pore dimensions are chosen to be smaller than the ultrasonic wavelengths, the sound attenuation caused by scattering becomes small compared to the material-related sound attenuation.
  • the pore volume can be adjusted practically by the grain size of the metal powder.
  • porous metallic bodies proposed in the second claim can be produced in different ways. Most useful z. B. porous body made of so-called sintered metal, as stated in the third claim. This sintered metal made of corrosion-resistant, heat-resistant material is produced under high pressure and high temperature from metal powder of small grain size. A homogeneous sintered metal according to the third claim conducts the sound equally well in all directions and is therefore suitable for acoustic lenses or wedges in which the sound waves are to propagate in different directions. Acoustic lenses are bodies in the form of lenses, which actually concentrate or disperse the sound in a manner similar to that of optical lenses.
  • Alloys of iron, chrome and aluminum can be manufactured with a high specific damping capacity, which makes them suitable for use as damping material in acoustic transducers.
  • a lead section made of such material does not need to be sealed and also meets the requirements for temperature behavior, radiation resistance and mechanical strength.
  • the transducer proposed in the fifth claim avoids disturbing reflections within the lead section on the surfaces not used to pass the sound.
  • the sintered metal body has essentially a small grain size, so that the sound is transmitted from one surface to the other with little attenuation.
  • the sintered metal has a larger grain size and a correspondingly larger pore volume, so that the sound in this area is weakened more by higher absorption.
  • the transducer proposed in claim six can be largely adapted to the adjacent materials or media on both sides.
  • a larger wave size of approx. 50-100 ⁇ m allows a low wave resistance and on the side of the piezoelectric element a small size of approx. 20 ⁇ m is possible Set higher wave resistance.
  • the reflections occurring at a boundary layer between two media are largely reduced and the performance of the converter is increased.
  • the transducer proposed in the seventh claim is to be mechanically damped in order to achieve the shortest possible transmission pulses, so that the piezoelectric element can emit or record as little loss as possible not only on the side facing the object to be examined, ie without reflections, sound waves, but also on it damped back can absorb sound waves as far as possible and without reflections.
  • damping body made of such a material would, however, have to have considerable dimensions in the direction of sound in order to achieve sufficient damping.
  • the greatest attenuation with the least reflection is achieved in an attenuator in which the grain size of the sintered metal increases continuously in the direction from the piezoelectric element to the rear of the damping body. In practice, however, it appears sufficient to arrange two or three different grain sizes in one damping body.
  • the largest grain size for damping bodies should be 0.3 mm 300 ⁇ m.
  • porous metallic bodies proposed in the eighth, ninth and tenth claims are suitable for contact with such aggressive substances which are able to attack the piezoelectric element. It has been found that such a superficial sealing of a sintered metal body does not interfere with the desired acoustic properties.
  • a galvanic coating or the application of solder to the surface has proven to be unsuitable because in the one case the galvanic liquid in the other case residual solder remains in the fine pores of the sintered metal and causes corrosion there.
  • a stainless steel sintered metal can be sealed by grinding with a diamond tool. The numerous small protrusions of the sintered metal are pressed into the adjacent depressions and cavities and seal them. Also by boriding, i.e. H. Coating with a boron-containing material and subsequent long annealing at approx. 900 ° C can be used to treat and seal machined steel surfaces with iron boride that occurs during structural transformation.
  • a body according to the eleventh claim with metallic foils as a seal has a better wave resistance adjustment when adhering to certain foil thicknesses (approximately 1/4 of the wavelength), since the foil has an effect comparable to an optical interference filter.
  • metallic foils As a seal, aluminum, magnesium, stainless steel, etc. are considered as materials.
  • Application by diffusion welding also avoids disadvantages that occur during soldering.
  • the foils can be coated or coated with a noble metal, for example gold.
  • the lead section 1 made of sintered metal or a metal with high specific damping consists of two separate wedge halves 1 a and 1 b.
  • the angle ⁇ of the lead section is like this for material testing chosen that, depending on the speed of sound in the leading section of the wedge and in the material to be tested, the angle of incidence in the material has a fixed value which is between 45 ° and 70 °.
  • Executed lead sections have wedge angles between 24 ° and 35 ° for longitudinal waves.
  • the surfaces set up to accommodate the piezoelectric transducers 2 are lapped optically smooth to less than 1 micron ripple.
  • the pressure device 3 made of stainless steel contains an adjustable pressure piece 4 for receiving disc springs 5 made of temperature-resistant material.
  • the contact pressure is 40 - 60 kp / cm '.
  • the pressing device 3 is fastened on the lead section 1 by a screw 6 and a bolt 7.
  • the pressure force of the disc springs 5 is transmitted to a metallic damping body 8 with high specific damping. Due to the mechanically stable damping body 8, the compressive force is transmitted uniformly to the piezoelectric element 2.
  • the contact surface of the damping body 8 is also machined by lapping to an accuracy of less than 1 micron.
  • Foils made of gold or other ductile and temperature-resistant materials can be used to couple the piezoelectric element 2.
  • the electrical contact is made via a signal conductor 9 connected to the metallic damping body 8 and via the lead section 1 to the ground connection.
  • the two parts of the lead section 1 are fitted in a frame 10 made of stainless steel.
  • the housing 11 is attached to the frame 10 and designed so that it can accommodate the coil 12 for the electrical balance for each piezo-electric element 2 and the connection sockets 13 for the measuring cable.
  • FIG. 2 shows a cross section through the transducer according to the invention from FIG. 1.
  • the inclination of the two half wedge halves 1 a and 1 b can be seen in order to be able to focus the piezoelectric elements 2 for material testing.
  • the pressing device 3 for the defined application of the contact pressure contains a fine thread for receiving an adjusting screw 15.
  • the adjusting screw 15 has a conical bearing surface for the pressure piece 4, which applies the pressure force to the damping body 8 via the plate springs 5 and the disk 16 consisting of insulating material .
  • the pin 17 is also made of insulating material and is used to keep the damping body 2 in position during assembly.
  • the defined contact pressure is applied to the pressure piece 4 from the outside. Then the set screw 15 is tightened tight. Since the pressure device 3 has no inherent elasticity due to a suitable shape, the force of the plate springs 5 can be supported on it. There is a gap between the two front wedge halves 1 a and 1 b, which prevents the sound waves from passing through
  • the transducer consists of a housing 18, one side of which is designed as a sound membrane 19.
  • the element 2 is applied to the inside of the sound membrane 19.
  • the damping body 20 which consists of sintered metal or a metal with high specific damping, is connected to the rear side of the element 2.
  • the connection technology is adapted to the respective operating temperatures.
  • the plate springs 5 prevent the damping body 20 from being detached from the element 2 in the event of unfavorable vibrations.
  • the damping Body 20 also serves as an electrical connector and is conductively connected to a temperature-resistant coaxial line 21.
  • a galvanic separation between the damping body 20 and the housing 18 is achieved via the ceramic insulating parts 22 and 23.
  • the housing 18 is sealed with the cover 24, which also serves as a counter bearing for the plate springs 5, which are centered by the bolt 25.
  • FIG. 4 shows a schematic illustration of a wedge as a leading section of an ultrasonic transducer according to claim 5.
  • the piezoelectric element 2 is applied to the top of the wedge.
  • the wave fronts emanating from element 2 spread out as straight waves in a wedge.
  • the surface A When the surface A is coupled to a body 26 to be tested, only part of the sound energy reaches this body, the other part of the sound energy is reflected at the interface in the direction of the surface B, the angle of reflection being equal to the angle of incidence of the sound waves.
  • a metal powder of larger grain size e.g. B. grain size 200-300 microns arranged, which causes increased sound absorption.
  • the other areas of the wedge contain a homogeneous material with metal powder of z. B. 100 - 200 micron grain size with constant and low sound attenuation.
  • the transition surface between different grain sizes can be created at a defined angle to surface B.
  • the transition from coarse-grained to fine-grained material through a mixing process during production is fluid, so that there is no sharply defined interface with disruptive reflection behavior.
  • the lead section 27 is formed in the area of the piezoelectric element 2 with a homogeneous layer C of smaller grain size, the area D consists of material of coarser grain size and the area E is in turn characterized by a layer of even larger grain size.
  • Figure 6 shows a damping body 28 made of sintered metal of different grain size according to claim 7.
  • the grain size is selected so that a sound wave resistance is achieved which is matched to that of the piezo material as possible.
  • the grain size of the sintered metal is chosen so large that a sufficiently high damping occurs and rear wall echoes from the surface H are practically no longer reflected to the piezoelectric element 2.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
  • Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
  • Transducers For Ultrasonic Waves (AREA)
  • Electrophonic Musical Instruments (AREA)
  • Surgical Instruments (AREA)
  • Ultra Sonic Daignosis Equipment (AREA)
  • Piezo-Electric Transducers For Audible Bands (AREA)
EP80107438A 1979-12-19 1980-11-27 Transducteur acoustique Expired EP0031049B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT80107438T ATE7429T1 (de) 1979-12-19 1980-11-27 Akustischer wandler.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE2951075A DE2951075C2 (de) 1979-12-19 1979-12-19 Akustischer Wandler mit piezoelektrischem Element
DE2951075 1979-12-19

Publications (3)

Publication Number Publication Date
EP0031049A2 true EP0031049A2 (fr) 1981-07-01
EP0031049A3 EP0031049A3 (en) 1981-07-15
EP0031049B1 EP0031049B1 (fr) 1984-05-09

Family

ID=6088896

Family Applications (1)

Application Number Title Priority Date Filing Date
EP80107438A Expired EP0031049B1 (fr) 1979-12-19 1980-11-27 Transducteur acoustique

Country Status (5)

Country Link
US (1) US4430593A (fr)
EP (1) EP0031049B1 (fr)
JP (2) JPS5698651A (fr)
AT (1) ATE7429T1 (fr)
DE (2) DE2951075C2 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0095619A3 (fr) * 1982-05-24 1984-07-04 INTERATOM Gesellschaft mit beschränkter Haftung Milieu pour accouplage acoustique à températures élevées et procédé de l'application
EP0361757A3 (fr) * 1988-09-29 1991-09-25 British Gas plc Dispositif d'adaptation
EP0590176A1 (fr) * 1992-09-28 1994-04-06 Siemens Aktiengesellschaft Transducteur ultrasonore muni d'une couche d'adaptation acoustique
EP2034471A3 (fr) * 2007-09-10 2014-06-18 Krohne AG Sonde à ultrasons

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4556813A (en) * 1983-10-17 1985-12-03 Joseph Baumoel Cast metal sonic transducer housing
JPS6199860A (ja) * 1984-10-19 1986-05-17 Tokyo Keiki Co Ltd 超音波探触子
US4728844A (en) * 1985-03-23 1988-03-01 Cogent Limited Piezoelectric transducer and components therefor
SE455538B (sv) * 1985-12-06 1988-07-18 Tekniska Roentgencentralen Ab Ultraljudssond for provning av ett slitsat eller halforsett materialstycke
JP3926448B2 (ja) * 1997-12-01 2007-06-06 株式会社日立メディコ 超音波探触子及びこれを用いた超音波診断装置
AUPQ615000A0 (en) * 2000-03-09 2000-03-30 Tele-Ip Limited Acoustic sounding
US6788620B2 (en) * 2002-05-15 2004-09-07 Matsushita Electric Industrial Co Ltd Acoustic matching member, ultrasound transducer, ultrasonic flowmeter and method for manufacturing the same
DE102006012114A1 (de) * 2006-03-14 2007-09-20 Endress + Hauser Flowtec Ag Vorrichtung zur Bestimmung und/oder Überwachung des Volumen- oder des Massedurchflusses eines Mediums in einer Rohrleitung
US20080195003A1 (en) * 2007-02-08 2008-08-14 Sliwa John W High intensity focused ultrasound transducer with acoustic lens
US9078063B2 (en) 2012-08-10 2015-07-07 Knowles Electronics, Llc Microphone assembly with barrier to prevent contaminant infiltration
EP2979644B1 (fr) * 2013-03-29 2017-09-13 Fujifilm Corporation Sonde ultrasonore pour aiguille de ponction et dispositif de diagnostic par ultrasons l'utilisant
FR3016045B1 (fr) * 2014-01-02 2017-09-29 Aircelle Sa Dispositif et ensemble pour le controle non-destructif d’une piece composite, et procede de controle non-destructif d’une piece composite par ultrasons en transmission
GB2573305A (en) 2018-05-01 2019-11-06 Tribosonics Ltd An ultrasonic transducer

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1648361U (de) 1952-10-29 1952-12-24 Hans-Georg Hannak Nebenfelge fuer pneumatische fahrzeugreifen.
BE533571A (fr) * 1954-10-27
US3325781A (en) * 1966-07-07 1967-06-13 Branson Instr Dual transducer probe for ultrasonic testing
BE757591A (fr) 1969-11-25 1971-03-16 Thomson Csf Perfectionnements aux domes de systemes sonars et procede de leur fabrication
FR2097451A5 (fr) * 1970-07-07 1972-03-03 Commissariat Energie Atomique
US3663842A (en) * 1970-09-14 1972-05-16 North American Rockwell Elastomeric graded acoustic impedance coupling device
US3783967A (en) 1972-02-24 1974-01-08 Us Health Focusing protective enclosure for ultrasonic transducer
US3989965A (en) * 1973-07-27 1976-11-02 Westinghouse Electric Corporation Acoustic transducer with damping means
US3973152A (en) * 1975-04-03 1976-08-03 The United States Of America As Represented By The United States Energy Research And Development Administration Ultrasonic transducer with laminated coupling wedge
JPS51140782A (en) * 1975-05-30 1976-12-03 Yokogawa Hewlett Packard Ltd Wide band ultrasonic senser and manufacturing method
FR2417776A1 (fr) 1978-02-16 1979-09-14 Onera (Off Nat Aerospatiale) Sonde a ultrasons pour la mesure dans les liquides a temperature et a pression elevees
JPS54155087A (en) * 1978-05-26 1979-12-06 Nippon Steel Corp Metallic wedge for ultrasonic-wave high temperature skew angle flaw detection
US4313070A (en) 1980-05-09 1982-01-26 The United States Of America As Represented By The United States Department Of Energy Single crystal metal wedges for surface acoustic wave propagation

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0095619A3 (fr) * 1982-05-24 1984-07-04 INTERATOM Gesellschaft mit beschränkter Haftung Milieu pour accouplage acoustique à températures élevées et procédé de l'application
EP0361757A3 (fr) * 1988-09-29 1991-09-25 British Gas plc Dispositif d'adaptation
GB2225426B (en) * 1988-09-29 1993-05-26 Michael John Gill A transducer
EP0590176A1 (fr) * 1992-09-28 1994-04-06 Siemens Aktiengesellschaft Transducteur ultrasonore muni d'une couche d'adaptation acoustique
US5418759A (en) * 1992-09-28 1995-05-23 Siemens Aktiengesellschaft Ultrasound transducer arrangement having an acoustic matching layer
EP2034471A3 (fr) * 2007-09-10 2014-06-18 Krohne AG Sonde à ultrasons

Also Published As

Publication number Publication date
JPS5698651A (en) 1981-08-08
US4430593A (en) 1984-02-07
DE3067783D1 (en) 1984-06-14
DE2951075A1 (de) 1981-07-02
JPH0167562U (fr) 1989-05-01
DE2951075C2 (de) 1982-04-15
ATE7429T1 (de) 1984-05-15
EP0031049A3 (en) 1981-07-15
EP0031049B1 (fr) 1984-05-09

Similar Documents

Publication Publication Date Title
EP0031049B1 (fr) Transducteur acoustique
DE3225586C2 (de) Ultraschall-Mikroskop
DE2245322C3 (de) Verfahren zur zerstörungsfreien Messung der Schichtdicke einer durch eine oberflächliche Werkstoffstrukturveränderung betroffenen Schicht eines Körpers
DE3149933A1 (de) Schallimpuls-echogeraet
DE3437488A1 (de) Schallsender
AT392357B (de) Tastkopf fuer die ultraschall-pruefung
DE3732410A1 (de) Ultraschallwandler mit astigmatischer sende-/empfangscharakteristik
DE3924919C2 (fr)
DE3301023A1 (de) Kollimation von einem ultraschallwandler
EP0590176B1 (fr) Transducteur ultrasonore muni d'une couche d'adaptation acoustique
EP0229981B1 (fr) Procédé pour contrôler les caractéristiques du foyer d'un champ ultrasonique et dispositif de sa mise en oeuvre
DE3137973A1 (de) Einrichtung zum zerstoerungsfreien pruefen von werkstoffen mit hilfe von akustischen oberflaechenwellen
EP0045412A2 (fr) Installation pour le contrôle de matériaux
DE3500640C2 (de) Akustisches Abtastmikroskop
DE3149732C2 (fr)
DE3013482A1 (de) Ultraschallkopf mit elektroakustischem wandler fuer ultraschall-durchflussmessungen nach dem doppler-prinzip
EP1462204B1 (fr) Porte-électrodes pour machine de soudage par résistance avec capteur à ultrasons intégré
EP0033463B1 (fr) Multisonde ultrasonore
DE19937479A1 (de) Ultraschall-Sensoranordnung
DE8717503U1 (de) Stoßwellenquelle mit zentralem Ortungssystem
EP0459431A2 (fr) Tête de mesure à ultrasons pour milieux chauds
DE3147900A1 (de) "ultraschall-winkelpruefkopf"
EP1829620A2 (fr) Procédé de fabrication d'une tête de vérification par ultrasons avec un agencement de convertisseur à ultrasons doté d'une bouteille de réception et d'émission incurvée
EP0418663A1 (fr) Hydrophone à membrane piezoélectrique
DE4207031C2 (de) Vorrichtung zur Strömungsmessung abrasiver Teilchen in Fluiden in einer Leitung

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Designated state(s): AT BE CH DE FR GB IT LU NL SE

AK Designated contracting states

Designated state(s): AT BE CH DE FR GB IT LU NL SE

17P Request for examination filed

Effective date: 19810914

ITF It: translation for a ep patent filed
GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): AT BE CH DE FR GB IT LI LU NL SE

REF Corresponds to:

Ref document number: 7429

Country of ref document: AT

Date of ref document: 19840515

Kind code of ref document: T

REF Corresponds to:

Ref document number: 3067783

Country of ref document: DE

Date of ref document: 19840614

ET Fr: translation filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19841120

Year of fee payment: 5

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19841130

BECN Be: change of holder's name

Effective date: 19840509

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 19841231

Year of fee payment: 5

Ref country code: BE

Payment date: 19841231

Year of fee payment: 5

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

RAP2 Party data changed (patent owner data changed or rights of a patent transferred)

Owner name: INTERATOM GESELLSCHAFT MIT BESCHRAENKTER HAFTUNG

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: AT

Payment date: 19851030

Year of fee payment: 6

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19851130

Year of fee payment: 6

NLT2 Nl: modifications (of names), taken from the european patent patent bulletin

Owner name: INTERATOM GESELLSCHAFT MIT BESCHRAENKTER HAFTUNG T

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Effective date: 19861127

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19861128

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Effective date: 19861130

BERE Be: lapsed

Owner name: INTERATOM G.M.B.H.

Effective date: 19861130

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Effective date: 19870601

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19890126

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 19890222

Year of fee payment: 9

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19891127

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Effective date: 19891130

Ref country code: CH

Effective date: 19891130

GBPC Gb: european patent ceased through non-payment of renewal fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19900731

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19900801

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

EUG Se: european patent has lapsed

Ref document number: 80107438.6

Effective date: 19870901