EP0083045B1 - Magnetic system with annular air-gap, in particular for woofers - Google Patents

Magnetic system with annular air-gap, in particular for woofers Download PDF

Info

Publication number
EP0083045B1
EP0083045B1 EP82111770A EP82111770A EP0083045B1 EP 0083045 B1 EP0083045 B1 EP 0083045B1 EP 82111770 A EP82111770 A EP 82111770A EP 82111770 A EP82111770 A EP 82111770A EP 0083045 B1 EP0083045 B1 EP 0083045B1
Authority
EP
European Patent Office
Prior art keywords
air gap
pole plate
working air
annular
gap
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.)
Expired
Application number
EP82111770A
Other languages
German (de)
French (fr)
Other versions
EP0083045A3 (en
EP0083045A2 (en
Inventor
Eckehard Kort
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.)
Individual
Original Assignee
Individual
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
Priority claimed from DE19813151530 external-priority patent/DE3151530A1/en
Application filed by Individual filed Critical Individual
Publication of EP0083045A2 publication Critical patent/EP0083045A2/en
Publication of EP0083045A3 publication Critical patent/EP0083045A3/en
Application granted granted Critical
Publication of EP0083045B1 publication Critical patent/EP0083045B1/en
Expired legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R9/00—Transducers of moving-coil, moving-strip, or moving-wire type
    • H04R9/02—Details
    • H04R9/025—Magnetic circuit
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2209/00—Details of transducers of the moving-coil, moving-strip, or moving-wire type covered by H04R9/00 but not provided for in any of its subgroups
    • H04R2209/022—Aspects regarding the stray flux internal or external to the magnetic circuit, e.g. shielding, shape of magnetic circuit, flux compensation coils

Definitions

  • the invention relates to an annular gap magnet system according to the preamble of claim 1.
  • the invention further relates to an electromagnetic drive and a woofer with an annular gap magnet system of the generic type.
  • the cylindrical part of the pole core delimiting the working air gap is longer than the magnet height, so that it. extends into an opening of the lower pole plate, the diameter of which is at least equal to the outer diameter of the working air gap.
  • the pole core is connected to the lower pole plate via a soft iron part, which ensures that there is at least a cross section available for the magnetic flux below the opening which corresponds to that of the lower pole plate. A magnetic leakage flux that occurs in the area of the opening is therefore very low.
  • the invention has for its object to provide an annular gap magnet system of the generic type so that even with an overdrive, the voice coil on the lower one, even with overdriving, the voice coil and the element driven by the voice coil, which is the speaker membrane in a loudspeaker Pole plate is avoided with certainty.
  • a low-frequency speaker with an annular gap magnet system 1 a conical membrane 2 and a membrane basket 2a is shown schematically.
  • a cylindrical body 4b, on which a voice coil 4a is arranged, is firmly connected to the membrane.
  • a centering membrane 2b is arranged between the lower end of the membrane 2 and the membrane basket 2a.
  • the speaker basket 2a is firmly connected to the magnet system in the usual way.
  • the annular gap magnet system 1 has a cylindrical pole core 5 on soft iron and an annular permanent magnet 6 with a thickness D, which is arranged concentrically to the pole core 5 between an annular upper pole plate 7 with a thickness d 2 and a lower pole plate 8.
  • a working air gap 3 is formed between the pole core 5 and the inner circumference of the upper pole plate 7, which is concentric with the pole core and into which the voice coil 4a is immersed.
  • pole core 5 and the lower pole plate 8 are shown in one piece. Normally, the pole core 5 and the pole plate 8 are two separate bodies, for example by screws or Rivets are firmly connected. This is symbolized in FIG. 1 by the dashed line 5a.
  • the voice coil 4a is designed in such a way that it moves in the working air gap 3 of the magnet system with a corresponding stroke, for example the large stroke which is typical for a woofer.
  • the open end 9a of the brake air gap 9 is in all embodiments at a distance d 1 from the underside of the upper pole plate 7, which corresponds at least to the thickness d 2 of the upper pole plate 7, but is preferably greater.
  • the magnetic flux, as it results from the brake air gap 9 and the magnetic resistor 10e, is indicated in dashed lines.
  • the magnetic flux through the lower pole plate 8 to the pole core 5 runs due to the magnetic resistance 10e to a substantial extent 10a through the brake air gap 9 and the magnetic leakage flux 10d over the open end 9a of the brake air gap 9 runs from the edge and the top of the pole plate 8 to Pole core 5.
  • the magnetic flux 10a through the brake air gap and the leakage flux 10d form the brake magnetic flux and, in sum, are at least equal to the inner leakage flux 10c between the pole core 5 and the upper pole plate 7, which passes below the working air gap 3. wise they are bigger.
  • the voice coil 4a plunges inward into the magnet system, it finally emerges completely from the field of the working air gap 3 when appropriately excited. It is driven further by the magnetic field of the stray flux 10c.
  • the sum of the brake magnetic fluxes 10a and 10d acts in opposition to this drive by the leakage flux 10c. As a result, the voice coil 4a is actively braked, thus preventing it from striking the lower pole plate.
  • annular gap magnet system only the annular gap magnet system is shown, the same reference numerals being used for the same or equivalent parts, as in FIG. 1. In the following, only the features are described in relation to which the magnet systems differ the embodiment of Fig. 1 differ.
  • the lower pole plate 8 has a shoulder 8a on its underside to the left of the center line radially outward of the brake air gap 9 in order to save material or to reduce weight.
  • An embodiment is shown to the right of the center line, in which the lower pole plate is composed of a ring 8b and a plate c.
  • the pole core 5 is fixed in the center on the plate 8c, the thickness of which determines the magnetic resistance.
  • a soft iron ring 12 is arranged on the upper side of the lower pole plate 8, the outer surface of which softly contacts the inner surface 6a of the permanent magnet ring 6, while its inner surface limits the brake air gap over part of its depth.
  • a soft iron ring 12a is provided, which, however, has such a height here that it limits the outside of the brake air gap over the entire depth d 3 with its inner surface.
  • the soft iron ring 12a is embedded in a corresponding recess 13 in the lower pole plate 8.
  • the described soft iron ring enables easy adjustment of the loudspeaker to certain desired sound qualities. It also leads to an economical production of the annular gap magnet system. By inserting soft iron rings of different heights, the depth of the brake air gap and its distance from the upper pole plate can be varied.
  • the ring-shaped permanent magnet 6 is composed of two partial magnetic rings 6b and 6c, each with a thickness D 1 or D 2 , which overall corresponds approximately to the thickness D of the permanent magnet 6 according to FIG. 1.
  • the upper partial magnet 6b has an inner diameter which corresponds to the inner diameter of the magnet 6 according to FIG. 1.
  • the lower partial magnet 6c has an inner diameter which corresponds to the outer diameter of the brake air gap 9. It therefore forms with its inner surface 6d the outer surface of the brake air gap 9, which extends with an annular recess 9b into the lower pole plate 8, through which the cross-section reduction is determined, which in turn determines the magnetic resistance.
  • the thickness d 1 of the magnet 6b is selected so that the condition is again met that the distance of the open end 9a of the brake air gap 9 from the underside of the upper pole plate 7 corresponds at least to the height of the working air gap and thus the thickness d 2 of the upper pole plate .
  • the advantage of this embodiment is that, given a predetermined height of the brake air gap, the thickness of the lower pole plate can be kept smaller than in the embodiment according to FIG. 1 or 2. This makes the weight of the magnet system is reduced.
  • the magnetic flux density B was measured by means of a Hall probe over the total height d 1 + d 2 + d 3 , the measurement being limited to a total depth of 30 mm, since no usable measurement results could be obtained in the area of the bottom of the brake air gap.
  • the measurement results are shown in the diagram in FIG. 5.
  • the magnetic flux is directed away from the pole core above the abscissa and towards the pole core below the abscissa.
  • the magnetic flux density is essentially constant over the thickness d 2 of the upper pole plate 7, ie over the height of the working air gap 3.
  • the density of the magnetic flux which results from the stray field 10c, drops quite steeply.
  • the magnetic flux density then becomes at point Y, ie at a distance of 9 mm from the lower edge of the upper pole plate 7 to O. From point Y on, the stray field 10d becomes effective.
  • the flux density rises again in the opposite direction of the magnetic flux and reaches its maximum approximately in the area of the open end 9a of the brake air gap 9, the size of which depends on the size of the magnetic resistance in the lower pole plate.
  • the flux density then remains essentially constant over the depth of the brake air gap in the measured area.
  • the flux density is plotted in the diagram in Teslar (T).
  • the voice coil does not open even when the loudspeaker is overdriven to the maximum. Rather, the inward movement of the voice coil is braked by the magnetic opposing field generated above the brake air gap and in the brake air gap and thus limited.
  • Annular gap magnet systems of the type described can be used not only in loudspeakers, but generally for electromagnetic drives in which a relatively large undamped stroke is required.
  • a writing element can be connected to the voice coil.

Description

Die Erfindung betrifft ein Ringspalt- magnetsystem, nach dem Oberbegriff des Patentanspruches 1.The invention relates to an annular gap magnet system according to the preamble of claim 1.

Die Erfindung bezieht sich weiter auf einen elektromagnetischen Antrieb und einen Tiefton-Lautsprecher mit einem Ringspaltmagnetsystem der gattungsgemäßen Art.The invention further relates to an electromagnetic drive and a woofer with an annular gap magnet system of the generic type.

Bei Tiefton-Lautsprechern wird eine möglichst geringe Dämpfung angestrebt, die durch eine extrem weiche Aufhängung der Membran erreichbar ist. Diese führt aber dazu, daß die Schwingspule nach Verlassen des Hauptmagnetfeldes im Arbeitsluftspalt des Magnetsystems durch das unterhalb des Arbeits- luftspaltes wirksame innere Streufeld weiter nach innen angetrieben wird und insbesondere bei einer Übersteuerung des Lautsprechers dann auf die Polplatte aufschlägt. Um ein solchen Aufschlages der Schwingspule an der unteren Polplatte zu verhindern, mußte man bisher einen Kompromiß eingehen, indem man die Membran und die Schwingspule härter aufhängt, als dies im Interesse der Klangqualität des Lautsprechers wünschenswert ist. Entsprechendes gilt für elektromagnetische Antriebe, für die ein relativ großer ungedämpfter Hub verlangt wird.With low-frequency speakers, the lowest possible attenuation is achieved, which can be achieved by an extremely soft suspension of the membrane. However, this causes the voice coil after leaving the main magnetic field in the working air gap of the magnet system is driven by the below the Arbe i ts air gap effective internal stray field further inward and then strikes the pole flange in particular in an overdrive the speaker. In order to prevent the voice coil from striking the lower pole plate in this way, a compromise had to be made up to now by hanging the membrane and the voice coil harder than is desirable in the interest of the sound quality of the loudspeaker. The same applies to electromagnetic drives, for which a relatively large undamped stroke is required.

Bei einem aus der DE-A-1 614164 bekannten Ringspaltmagnetsystem werden für den Magnetring Werkstoffe von hoher Koerzitivfeldstärke verwendet. Hieraus ergibt sich eine verhältnismäßig geringe Höhe der Magnetringe, die ihrerseits zu einer unerwünschten Begrenzung der Amplitude der Spulenbewegung führt. Um für die Spule eine hinreichende Bewegungsamplitude zu erreichen, ist hier der zylindrische, den Arbeitsluftspalt begrenzende Teil des Polkerns länger als die Magnethöhe ausgebildet, so daß er. sich in eine Öffnung der unteren Polplatte erstreckt, deren Durchmesser mindestens gleich dem äußeren Durchmesser des Arbeitsluftspaltes ist. Der Polkern ist dabei mit der unteren Polplatte über -ein Weicheisenteil verbunden, durch das sichergestellt ist, daß für den Magnetfluß unterhalb der Öffnung wenigstens ein Querschnitt zur Verfügung steht, der dem der unteren Polplatte entspricht. Ein magnetischer Streufluß der im Bereich der Öffnung auftritt, ist damit sehr gering.In an annular gap magnet system known from DE-A-1 614164, materials of high coercive field strength are used for the magnetic ring. This results in a relatively small height of the magnetic rings, which in turn leads to an undesired limitation of the amplitude of the coil movement. In order to achieve a sufficient movement amplitude for the coil, the cylindrical part of the pole core delimiting the working air gap is longer than the magnet height, so that it. extends into an opening of the lower pole plate, the diameter of which is at least equal to the outer diameter of the working air gap. The pole core is connected to the lower pole plate via a soft iron part, which ensures that there is at least a cross section available for the magnetic flux below the opening which corresponds to that of the lower pole plate. A magnetic leakage flux that occurs in the area of the opening is therefore very low.

Der Erfindung liegt die Aufgabe zugrunde, ein Ringspaltmagnetsystem der gattungsgemäßen Art so auszubilden, daß auch bei extrem weicher Aufhängung der Schwingspule und des von der Schwingspule angetriebenen Elementes, das bei einem Lautsprecher die Lautsprechermembran ist, auch bei einer Übersteuerung ein Aufschlagen der Schwingspule auf der unteren Polplatte mit Sicherheit vermieden wird.The invention has for its object to provide an annular gap magnet system of the generic type so that even with an overdrive, the voice coil on the lower one, even with overdriving, the voice coil and the element driven by the voice coil, which is the speaker membrane in a loudspeaker Pole plate is avoided with certainty.

Diese Aufgabe wird gemäß der Erfindung gelöst, durch die im Kennzeichen des Patentanspruches 1 herausgestellten Merkmale.This object is achieved according to the invention by the features highlighted in the characterizing part of patent claim 1.

Durch den Magnetfluß durch den Bremsluftspalt und den Streufluß oberhalb des Bremsluftspaltes, die beide umgekehrt zum Magnetfluß des inneren Streufeldes unterhalb des Arbeitsluftspaltes gerichtet sind, wird eine leicht in ihrer Größe festlegbare magnetische Gegenkraft erzeugt, die auch bei Übersteuerung ein Aufschlagen der Schwingspule auf der unteren Polplatte verhindert.Due to the magnetic flux through the brake air gap and the stray flux above the brake air gap, both of which are reversed to the magnetic flux of the inner stray field below the working air gap, an easily definable magnetic counterforce is generated, which, even when overdriven, strikes the voice coil on the lower pole plate prevented.

Zweckmäßige Ausgestaltungen der Erfindung sind Gegenstand der abhängigen Ansprüche 2 bis 4.Expedient embodiments of the invention are the subject of dependent claims 2 to 4.

Die unabhängigen Ansprüche 5 und 6 sind auf erfindungsgemäß ausgebildete Tiefton-Lautsprecher und elektromagnetische Antriebe gerichtet.Independent claims 5 and 6 are directed to low-frequency loudspeakers and electromagnetic drives designed in accordance with the invention.

Einzelheiten und Vorteile der Erfindung ergeben sich aus der folgenden Beschreibung von in der Zeichnung schematisch dargestellten bevorzugten Ausführungsbeispielen.Details and advantages of the invention emerge from the following description of preferred exemplary embodiments schematically illustrated in the drawing.

Es zeigen in axialen Querschnitten

  • Figur 1 eine erste Ausführungsform eines Lautsprechers mit einem Ringspaltsystem mit Bremsluftspalt,
  • Figur 2 eine gegenüber Fig. 1 in materialsparender Weise abgewandelte Ausführungsform,
  • Figuren 3a und 3b jeweils Teildarstellungen von zwei weiteren Ausführungsformen mit Weicheisenringen zur äußeren Begrenzung des Bremsluftspaltes,
  • Figur 4 eine weitere Ausführungsform, bei der der Bremsluftspalt über einen Teil seiner axialen Länge durch den ringförmigen Dauermagneten begrenzt ist.
  • Figur 5 zeigt in einem Diagramm den magnetischen Feldstärkeverlauf über die Höhe eines Ringspaltmagnetsystems gemäß der Erfindung.
They show in axial cross sections
  • FIG. 1 shows a first embodiment of a loudspeaker with an annular gap system with a brake air gap,
  • FIG. 2 shows an embodiment modified in comparison with FIG. 1 in a material-saving manner,
  • FIGS. 3a and 3b are partial representations of two further embodiments with soft iron rings for the outer limitation of the brake air gap,
  • Figure 4 shows a further embodiment in which the brake air gap is limited over part of its axial length by the annular permanent magnet.
  • FIG. 5 shows in a diagram the magnetic field strength curve over the height of an annular gap magnet system according to the invention.

In Fig. 1 ist schematisch ein Tiefton-Lautsprecher mit einem Ringspalt-Magnetsystem 1, einer konischen Membran 2 und einem Membrankorb 2a dargestellt. Mit der Membran ist ein zylindrischer Körper 4b fest verbunden, auf dem eine Schwingspule 4a angeordnet ist. Zwischen dem unteren Ende der Membran 2 und dem Membrankorb 2a ist eine Zentriermembran 2b angeordnet. Der Lautsprecherkorb 2a ist in üblicher Weise mit dem Magnetsystem fest verbunden.In Fig. 1, a low-frequency speaker with an annular gap magnet system 1, a conical membrane 2 and a membrane basket 2a is shown schematically. A cylindrical body 4b, on which a voice coil 4a is arranged, is firmly connected to the membrane. A centering membrane 2b is arranged between the lower end of the membrane 2 and the membrane basket 2a. The speaker basket 2a is firmly connected to the magnet system in the usual way.

Das Ringspaltmagnetsystem 1 weist einen zylindrischen Polkern 5 auf Weicheisen und einen ringförmigen Dauermagneten 6 mit einer Dicke D auf, der konzentrisch zum Polkern 5 zwischen einer ringförmigen oberen Polplatte 7 mit einer Dicke d2 und einer unteren Polplatte 8 fest angeordnet ist. Zwischen dem Polkern 5 und dem inneren Umfang der konzentrisch zum Polkern liegenden oberen Polplatte 7 ist ein Arbeitsluftspalt 3 ausgebildet, in den die Schwingspule 4a eintaucht.The annular gap magnet system 1 has a cylindrical pole core 5 on soft iron and an annular permanent magnet 6 with a thickness D, which is arranged concentrically to the pole core 5 between an annular upper pole plate 7 with a thickness d 2 and a lower pole plate 8. A working air gap 3 is formed between the pole core 5 and the inner circumference of the upper pole plate 7, which is concentric with the pole core and into which the voice coil 4a is immersed.

In Fig. 1 sind, wie in den weiteren Figuren, der Polkern 5 und die untere Polplatte 8 einstückig ausgebildet dargestellt. Normalerweise sind der Polkern 5 und die Polplatte 8 zwei getrennte Körper, die beispielsweise durch Schrauben oder Nieten fest miteinander verbunden sind. Dies ist in Fig. 1 durch die gestrichelte Linie 5a symbolisiert.1, as in the other figures, the pole core 5 and the lower pole plate 8 are shown in one piece. Normally, the pole core 5 and the pole plate 8 are two separate bodies, for example by screws or Rivets are firmly connected. This is symbolized in FIG. 1 by the dashed line 5a.

Die Schwingspule 4a ist so ausgebildet, daß sie sich im Arbeitsluftspalt 3 des Magnetsystems mit einem entsprechenden Hub, beispielsweise dem für einen Tiefton-Lautsprecher (Woofer) typischen großen Hub bewegt.The voice coil 4a is designed in such a way that it moves in the working air gap 3 of the magnet system with a corresponding stroke, for example the large stroke which is typical for a woofer.

In/an der unteren Polplatte 8 ist ein den Polkern 5 in axialer Verlängerung des Arbeitsluftspaltes 3 umgebender zylinderringförmiger Bremsluftspalt 9 mit einer Tiefe d3 vorgesehen, in den die Schwingspule mit ihrem unteren Ende eintauchen kann.In / on the lower pole plate 8 there is a cylindrical ring-shaped brake air gap 9 surrounding the pole core 5 in the axial extension of the working air gap 3 and having a depth d 3 , into which the voice coil can dip with its lower end.

Das offene Ende 9a des Bremsluftspaltes 9 liegt bei allen Ausführungsbeispielen in einem Abstand d1 von der Unterseite der oberen Polplatte 7, der wenigstens der Dicke d2 der oberen Polplatte 7 entspricht, vorzugsweise aber größer ist.The open end 9a of the brake air gap 9 is in all embodiments at a distance d 1 from the underside of the upper pole plate 7, which corresponds at least to the thickness d 2 of the upper pole plate 7, but is preferably greater.

Durch den Bremsluftspalt 9, der sich in die untere Polplatte 8 erstreckt, wird an dessen unterem Ende eine Querschnittsminderung der unteren Polplatte herbeigeführt, die sich als magnetischer Widerstand 10e auswirkt.Through the brake air gap 9, which extends into the lower pole plate 8, a cross-sectional reduction of the lower pole plate is brought about at its lower end, which acts as a magnetic resistor 10e.

In Fig. 1 ist der Magnetfluß, wie er sich durch den Bremsluftspalt 9 und den magnetischen Widerstand 10e ergibt, in gestrichelten Linien angedeutet. Der Magnetfluß durch die untere Polplatte 8 zum Polkern 5 hin verläuft aufgrund des magnetischen Widerstandes 10e zu einem wesentlichen Teil 10a durch den Bremsluftspalt 9 und der magnetische Streufluß 10d über dem offenen Ende 9a des Bremsluftspaltes 9 verläuft von der Kante und der Oberseite der Polplatte 8 zum Polkern 5. Der Magnetfluß 10a durch den Bremsluftspalt und der Streufluß 10d bilden den Bremsmagnetfluß und sind in ihrer Summe wenigstens gleich dem inneren Streufluß 10c zwischen dem Polkern 5 und der oberen Polplatte 7, der unterhalb des Arbeitsluftspaltes 3 übertritt, vorzugs-. weise sind sie größer. Taucht die Schwingspule 4a nach innen in das Magnetsystem ein, so tritt sie bei entsprechender Erregung schließlich ganz aus dem Feld des Arbeitsluftspaltes 3 heraus. Durch das Magnetfeld des Streuflusses 10c wird sie dabei weiter angetrieben. Diesem Antrieb durch den Streufluß 10c entgegengesetzt wirkt die Summe der Bremsmagnetflüsse 10a und 10d. Dadurch wird die Schwingspule 4a aktiv gebremst und so ein Aufschlagen auf die untere Polplatte verhindert.In Fig. 1, the magnetic flux, as it results from the brake air gap 9 and the magnetic resistor 10e, is indicated in dashed lines. The magnetic flux through the lower pole plate 8 to the pole core 5 runs due to the magnetic resistance 10e to a substantial extent 10a through the brake air gap 9 and the magnetic leakage flux 10d over the open end 9a of the brake air gap 9 runs from the edge and the top of the pole plate 8 to Pole core 5. The magnetic flux 10a through the brake air gap and the leakage flux 10d form the brake magnetic flux and, in sum, are at least equal to the inner leakage flux 10c between the pole core 5 and the upper pole plate 7, which passes below the working air gap 3. wise they are bigger. If the voice coil 4a plunges inward into the magnet system, it finally emerges completely from the field of the working air gap 3 when appropriately excited. It is driven further by the magnetic field of the stray flux 10c. The sum of the brake magnetic fluxes 10a and 10d acts in opposition to this drive by the leakage flux 10c. As a result, the voice coil 4a is actively braked, thus preventing it from striking the lower pole plate.

In den weiteren Ausführungsformen ist jeweils nur das Ringspalt-Magnetsystem dargestellt, wobei für gleiche oder gleichwirkende Teile jeweils die gleichen Bezugszeichen verwendet sind, wie in Fig. 1. Im nachstehenden werden daher auch jeweils nur die Merkmale beschrieben, hinsichtlich deren die Magnetsysteme sich jeweils von der Ausführungsform nach Fig. 1 unterscheiden.In the further embodiments, only the annular gap magnet system is shown, the same reference numerals being used for the same or equivalent parts, as in FIG. 1. In the following, only the features are described in relation to which the magnet systems differ the embodiment of Fig. 1 differ.

Nach Fig. 2 weist die untere Polplatte 8 links der Mittellinie radial auswärts des Bremsluftspaltes 9 zur Materialersparnis bzw. zur Gewichtsminderung an ihrer Unterseite einen Absatz 8a auf. Rechts der Mittellinie ist eine Ausführungsform dargestellt, bei der die untere Polplatte aus einem Ring 8b und einer Platte c zusammengesetzt ist. Auf der Platte 8c, deren Dicke den magnetischen Widerstand bestimmt, ist mittig der Polkern 5 befestigt.According to FIG. 2, the lower pole plate 8 has a shoulder 8a on its underside to the left of the center line radially outward of the brake air gap 9 in order to save material or to reduce weight. An embodiment is shown to the right of the center line, in which the lower pole plate is composed of a ring 8b and a plate c. The pole core 5 is fixed in the center on the plate 8c, the thickness of which determines the magnetic resistance.

Während bei der Ausführungsform nach Fig. 1 und 2 der Bremsluftspalt 9 mit seiner gesamten Tiefe d3 in der unteren Polplatte 8 liegt, ist bei der Ausführungsform nach Fig. 3a in der unteren Polplatte nur ein Teil der Tiefe d3 des Bremsluftspaltes ausgebildet, und zwar das untere Ende. Auf der Oberseite der unteren Polplatte 8 ist ein Weicheisenring 12 angeordnet, der mit seiner äußeren Oberfläche magnetisch leitend an der inneren Oberfläche 6a des Dauermagnetringes 6 anliegt, während er mit seiner inneren Oberfläche den Bremsluftspalt über einen Teil seiner Tiefe begrenzt.1 and 2 of the brake air gap 9 lies with its entire depth d 3 in the lower pole plate 8, in the embodiment according to FIG. 3a only a part of the depth d 3 of the brake air gap is formed in the lower pole plate, and the lower end though. A soft iron ring 12 is arranged on the upper side of the lower pole plate 8, the outer surface of which softly contacts the inner surface 6a of the permanent magnet ring 6, while its inner surface limits the brake air gap over part of its depth.

In ähnlicher Weise ist bei der Ausführungsform nach Fig. 3b ein Weicheisenring 12a vorgesehen, der hier jedoch eine solche Höhe hat, daß er mit seiner inneren Oberfläche den Bremsluftspalt außen über die gesamte Tiefe d3 begrenzt. Der Weicheisenring 12a ist hierbei in eine entsprechende Ausnehmung 13 in der unteren Polplatte 8 eingelassen.Similarly, in the embodiment according to FIG. 3b, a soft iron ring 12a is provided, which, however, has such a height here that it limits the outside of the brake air gap over the entire depth d 3 with its inner surface. The soft iron ring 12a is embedded in a corresponding recess 13 in the lower pole plate 8.

Der beschriebene Weicheisenring ermöglicht eine einfache Abstimmung des Lautsprechers auf bestimmte gewünschte Klangqualitäten. Er führt auch zu einer wirtschaftlichen Herstellung des Ringspaltmagnetsystems. Durch Einsetzen unterschiedlich hoher Weicheisenringe können die Tiefe des Bremsluftspaltes und dessen Abstand von der oberen Polplatte variiert werden.The described soft iron ring enables easy adjustment of the loudspeaker to certain desired sound qualities. It also leads to an economical production of the annular gap magnet system. By inserting soft iron rings of different heights, the depth of the brake air gap and its distance from the upper pole plate can be varied.

Bei der Ausführungsform nach Fig. 4 ist der ringförmige Dauermagnet 6 aus zwei Teilmagnetringen 6b und 6c mit jeweils einer Dicke D1 bzw. D2 zusammengesetzt, die insgesamt etwa der Dicke D des Dauermagneten 6 nach Fig. 1 entspricht. Der obere Teilmagnet 6b hat einen Innendurchmesser, der dem Innendurchmesser des Magneten 6 nach Fig. 1 entspricht. Der untere Teilmagnet 6c hat einen inneren Durchmesser, der dem äußeren Durchmesser des Bremsluftspaltes 9 entspricht. Er bildet daher mit seiner inneren Oberfläche 6d die Außenfläche des Bremsluftspaltes 9, der sich mit einer ringförmigen Vertiefung 9b in die untere Polplatte 8 erstreckt, durch die die Querschnittreduktion bestimmt ist, die ihrerseits den magnetischen Widerstand bestimmt. Die Dicke d1 des Magneten 6b ist so gewählt, daß wiederum die Bedingung erfüllt ist, daß der Abstand des offenen Endes 9a des Bremsluftspaltes 9 von der Unterseite der oberen Polplatte 7 wenigstens der Höhe des Arbeitsluftspaltes und damit der Dicke d2 der oberen Polplatte entspricht.In the embodiment according to FIG. 4, the ring-shaped permanent magnet 6 is composed of two partial magnetic rings 6b and 6c, each with a thickness D 1 or D 2 , which overall corresponds approximately to the thickness D of the permanent magnet 6 according to FIG. 1. The upper partial magnet 6b has an inner diameter which corresponds to the inner diameter of the magnet 6 according to FIG. 1. The lower partial magnet 6c has an inner diameter which corresponds to the outer diameter of the brake air gap 9. It therefore forms with its inner surface 6d the outer surface of the brake air gap 9, which extends with an annular recess 9b into the lower pole plate 8, through which the cross-section reduction is determined, which in turn determines the magnetic resistance. The thickness d 1 of the magnet 6b is selected so that the condition is again met that the distance of the open end 9a of the brake air gap 9 from the underside of the upper pole plate 7 corresponds at least to the height of the working air gap and thus the thickness d 2 of the upper pole plate .

Der Vorteil dieser Ausführungsform liegt ebenso wie der der Ausführungsformen nach den Fig. 3a und 3b darin, daß bei einer vorgegebenen Höhe des Bremsluftspaltes die Dicke der unteren Polplatte geringer gehalten werden kann als bei der Ausführungsform nach Fig. 1 oder 2. Dadurch wird das Gewicht des Magnetsystems verringert.The advantage of this embodiment, like that of the embodiments according to FIGS. 3a and 3b, is that, given a predetermined height of the brake air gap, the thickness of the lower pole plate can be kept smaller than in the embodiment according to FIG. 1 or 2. This makes the weight of the magnet system is reduced.

In Fig. 4 ist links vom Polkern der magnetische Streufluß dargestellt, der bei dieser Ausführungsform mit seinem zum Polkern hin gerichteten unteren Bereich 10d im wesentlichen radial durch den Bremsluftspalt 9 fließt.In Fig. 4 to the left of the pole core, the magnetic leakage flux is shown, which in this embodiment form with its lower region 10d directed towards the pole core flows essentially radially through the brake air gap 9.

Bei einem Ringspalt-Magnetsystems entsprechend der Ausführungsform nach Fig. 3b mit folgenden Abmessungen :

Figure imgb0001
Figure imgb0002
Figure imgb0003
wurde mittels einer Hallsonde die magnetische Flußdichte B über die Gesamthöhe d1 + d2 + d3 gemessen, wobei die Messung auf eine Gesamttiefe von 30 mm begrenzt wurde, da im Bereich des Bodens des Bremsluftspaltes keine brauchbaren Messergebnisse mehr erhalten werden konnten. Die Meßergebnisse sind im Diagramm nach Fig. 5 dargestellt.In the case of an annular gap magnet system according to the embodiment according to FIG. 3b with the following dimensions:
Figure imgb0001
Figure imgb0002
Figure imgb0003
 the magnetic flux density B was measured by means of a Hall probe over the total height d 1 + d 2 + d 3 , the measurement being limited to a total depth of 30 mm, since no usable measurement results could be obtained in the area of the bottom of the brake air gap. The measurement results are shown in the diagram in FIG. 5.

Der magnetische Fluß ist oberhalb der Abszisse vom Polkern weg und unterhalb der Abszisse zum Polkern hin gerichtet. Wie aus dem Diagramm ersichtlich, ist die magnetische Flußdichte über die Dicke d2 der oberen Polplatte 7, d. h. über die Höhe des Arbeitsluftspaltes 3 im wesentlichen konstant. Über die Höhe d1, d. h. zwischen der Unterseite der oberen Polplatte 7 und dem offenen Ende 9a des Bremsluftspaltes 9, fällt die Dichte des Magnetflusses, der aus dem Streufeld 10c resultiert, ziemlich steil ab. Die magnetische Flußdichte wird dann im Punkt Y, d. h. in einem Abstand von 9 mm von der Unterkante der oberen Polplatte 7 zu O. Vom Punkt Y an wird das Streufeld 10d wirksam. Die Flußdichte steigt hier bei entgegengesetzt gerichtetem Magnetfluß wieder an und erreicht etwa im Bereich des offenen Endes 9a des Bremsluftspaltes 9 sein Maximum, dessen Größe von der Größe des magnetischen Widerstandes in der unteren Polplatte abhängig ist. Die Flußdichte bleibt dann über die Tiefe des Bremsluftspaltes im gemessenen Bereich im wesentlichen konstant. Die Flußdichte ist im Diagramm in Teslar (T) aufgetragen.The magnetic flux is directed away from the pole core above the abscissa and towards the pole core below the abscissa. As can be seen from the diagram, the magnetic flux density is essentially constant over the thickness d 2 of the upper pole plate 7, ie over the height of the working air gap 3. Over the height d 1 , ie between the underside of the upper pole plate 7 and the open end 9a of the brake air gap 9, the density of the magnetic flux, which results from the stray field 10c, drops quite steeply. The magnetic flux density then becomes at point Y, ie at a distance of 9 mm from the lower edge of the upper pole plate 7 to O. From point Y on, the stray field 10d becomes effective. The flux density rises again in the opposite direction of the magnetic flux and reaches its maximum approximately in the area of the open end 9a of the brake air gap 9, the size of which depends on the size of the magnetic resistance in the lower pole plate. The flux density then remains essentially constant over the depth of the brake air gap in the measured area. The flux density is plotted in the diagram in Teslar (T).

Als Vergleichsmessung wurde eine Messung der magnetischen Flußdichte bei einem Ringspalt-Magnetsystem üblicher Art, d. h. ohne Bremsluftspalt, durchgeführt. Die Flußdichte im Arbeitsluftspalt ist die gleiche wie bei dem Magnetsystem mit Bremsluftspalt. Unterhalb des Arbeitsluftspaltes wurde eine Flußdichte entsprechend der gestrichelt im Diagramm eingetragenen Kurve gemessen. Diese Kurve fällt weniger steil ab und bleibt praktisch über den gesamten Bereich oberhalb der Abszisse. Die Flußdichte beträgt kurz vor auf der Oberseite der unteren Polplatte, d. h. am Punkt X, noch etwa 0,3 T. Es wird also bei einem üblichen Magnetsystem kein die Einwärtsbewegung der Schwingspule begrenzendes magnetisches Gegenfeld aufgebaut. Es wirkt vielmehr bis auf die Oberseite der unteren Polplatte 8 ein Magnetfeld, das in Richtung der Einwärtsbewegung der Schwingspule wirkt und bei Übersteuerung des Lautsprechers Ursache für das Aufschlagen der Schwingspule auf die untere Polplatte ist.As a comparison measurement, a measurement of the magnetic flux density in an annular gap magnet system of a conventional type, i.e. H. without brake air gap. The flux density in the working air gap is the same as in the magnet system with a brake air gap. A flux density was measured below the working air gap in accordance with the curve shown in dashed lines in the diagram. This curve falls off less steeply and remains practically over the entire range above the abscissa. The flux density is just before on the top of the lower pole plate, i.e. H. at point X, still about 0.3 T. Thus, in a conventional magnet system, no opposing magnetic field limiting the inward movement of the voice coil is built up. Rather, a magnetic field acts on the upper side of the lower pole plate 8, which acts in the direction of the inward movement of the voice coil and, when the loudspeaker is overdriven, is the cause of the voice coil striking the lower pole plate.

Bei dem Ringspalt-Magnetsystem mit dem beschriebenen Bremsluftspalt kommt es dagegen auch bei maximaler Übersteuerung des Lautsprechers nicht zu einem Aufschlagen der Schwingspule. Die Einwärtsbewegung der Schwingspule wird vielmehr durch das oberhalb des Bremsluftspaltes und im Bremsluftspalt erzeugte magnetische Gegenfeld abgebremst und damit begrenzt.In the case of the annular gap magnet system with the brake air gap described, however, the voice coil does not open even when the loudspeaker is overdriven to the maximum. Rather, the inward movement of the voice coil is braked by the magnetic opposing field generated above the brake air gap and in the brake air gap and thus limited.

Ringspalt-Magnetsysteme der beschriebenen Art können nicht nur bei Lautsprechern Verwendung finden, sondern allgemein für elektromagnetische Antriebe, bei denen ein relativ großer ungedämpfter Hub verlangt wird. Beispielsweise kann mit der Schwingspule ein Schreibelement verbunden sein.Annular gap magnet systems of the type described can be used not only in loudspeakers, but generally for electromagnetic drives in which a relatively large undamped stroke is required. For example, a writing element can be connected to the voice coil.

Claims (6)

1. An annular gap magnet system, particularly for low frequency loudspeakers, comprising a moving coil (4a) movable in a working air gap (3) with a large stroke, a cylindrical pole core (5) of soft iron and an annular permanent magnet (6) arranged at a distance from the pole core between an upper pole plate (7) which limits the working air gap and a lower pole plate (8), and where in/at the lower pole plate (8) an annular opening (9) is provided surrounding the pole core (5) in its lower part as an axial extension of the working air gap (3), characterised in that the opening is formed as a magnetic braking air gap (9), starting to extend at a distance (d1) to the upper pole plate (7) being at least equal to the thickness (d2) of the upper pole plate (7), and under which the magnetically conductive cross- section of the lower pole plate has been reduced so far (magnetical resistance 10e) that the magnetic flux (10a) through the braking air gap (9) and the stray flux (10d) above the braking air gap (9) both of which are directed oppositely to the magnetic flux (10b) in the working air gap (3) and also oppositely to the stray flux (10c) below the working air gap (3), are in sum at least equal to or greater than the internal stray flux (10c) below the working air gap (3).
2. An annular gap magnet system according to Claim 1, characterised in that in/at the lower pole plate (8) is provided a soft iron ring (12) which limits the braking air gap (9) externally at least over part of its axial length (d3), said soft iron ring extending axially over a part of the height (D) of the permanent magnet (6), which part is less than the difference of the height (D) of the permanent magnet and the thickness (d2) of the upper pole plate and is contacting externally the internal circumference of said permanent magnet with magnetic conductivity.
3. An annular gap magnet system according to Claim 1, characterised in that the braking air gap (9) is limited externally over part of its axial length (d3), which is smaller than the diffence of the height (D) of the permanent magnet and the thickness (d2) of the upper pole plate, by the internal circumference (6d) of the permanent magnet (6).
4. An annular gap magnet system according to Claim 3, characterised in that the annular permanent magnet (6) is constructed from two annular magnets (6b, 6c) in series, of which the permanent magnet (6) which is situated facing away from the working air gap (3) limits the braking air gap (9) externally with its internal circumference (6d).
5. A low frequency loudspeaker having an annular gap magnet system comprising a moving coil (4a) which is movable with a large stroke in the working air gap (3), a cylindrical pole core (5) of soft iron and an annular permanent magnet (6) arranged at a distance from the pole core between an upper pole plate (7) which limits the working air gap and a lower pole plate (8), and where in/at the lower pole plate (8) an annular opening (9) is provided surrounding the pole core (5) in its lower part as an axial extension of the working air gap (9), characterised in that the opening is formed as a magnetic braking air gap (9), starting to extend at a distance (d1) to the upper pole plate (7) being at least equal to the thickness (d2) of the upper pole plate (7), and under which the magnetically conductive cross- section of the lower pole plate has been reduced so far (magnetical resistance 10e) that the magnetic flux (10a) through the braking air gap (9) and the stray flux (10d) above the braking air gap (9), both of which are directed oppositely to the magnetic flux (10b) in the working air gap (3) and also oppositely to the stray flux (10c) below the working air gap (3), are in sum at least equal to or greater than the internal stray flux (10c) below the working air gap (3).
6. An electromagnetic drive having an annular gap magnet system, comprising a moving coil (4a) which is movable with a large stroke in the working air gap (3), a cylindrical pole core (5) of soft iron and an annular permanent magnet (6) arranged at a distance from the pole core between an upper pole plate (7) which limits the working air gap and a lower pole plate (8), and where in/at the lower pole plate (8) an annular opening (9) is provided surrounding the pole core (5) in its lower part as an axial extension of the working air gap (9), characterised in that the opening is formed as a magnetic braking air gap (9), starting to extend at a distance (d1) to the upper pole plate (7) being at least equal to the thickness (d2) of the upper pole plate (7), and. under which the magnetically conductive cross- section of the lower pole plate has been reduced so far (magnetical resistance 10e) that the magnetic flux (10a) through the braking air gap (9) and, the stray flux (10d) above the braking air gap (9) both of which are directed oppositely to the magnetic flux (10b) in the working air gap (3) and also oppositely to the stray flux (10c) below the working air gap (3), are in sum at least equal to or greater than the internal stray flux (10c) below the working air gap (3).
EP82111770A 1981-12-24 1982-12-18 Magnetic system with annular air-gap, in particular for woofers Expired EP0083045B1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DE19813151530 DE3151530A1 (en) 1981-12-24 1981-12-24 Annular-gap magnet system, particularly for low-frequency loudspeakers
DE3151530 1981-12-24
DE8226166U 1982-09-17
DE8226166 1982-09-17

Publications (3)

Publication Number Publication Date
EP0083045A2 EP0083045A2 (en) 1983-07-06
EP0083045A3 EP0083045A3 (en) 1983-09-28
EP0083045B1 true EP0083045B1 (en) 1985-11-21

Family

ID=25798319

Family Applications (1)

Application Number Title Priority Date Filing Date
EP82111770A Expired EP0083045B1 (en) 1981-12-24 1982-12-18 Magnetic system with annular air-gap, in particular for woofers

Country Status (3)

Country Link
US (1) US4628154A (en)
EP (1) EP0083045B1 (en)
DE (1) DE3267630D1 (en)

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5070530A (en) * 1987-04-01 1991-12-03 Grodinsky Robert M Electroacoustic transducers with increased magnetic stability for distortion reduction
US5142260A (en) * 1991-03-08 1992-08-25 Harman International Industries, Incorporated Transducer motor assembly
US5321762A (en) * 1991-08-05 1994-06-14 Aura Systems, Inc. Voice coil actuator
AU672953B2 (en) * 1991-08-05 1996-10-24 Speaker Acquisition Sub Voice coil actuator
US5390257A (en) * 1992-06-05 1995-02-14 Oslac; Michael J. Light-weight speaker system
US5883967A (en) * 1997-04-15 1999-03-16 Harman International Industries, Incorporated Slotted diaphragm loudspeaker
US6963652B1 (en) 2003-04-18 2005-11-08 James M Colombo Low frequency generator
US20080247582A1 (en) 2004-09-09 2008-10-09 Guenther Godehard A Loudspeaker and Systems
US8189840B2 (en) 2007-05-23 2012-05-29 Soundmatters International, Inc. Loudspeaker and electronic devices incorporating same
CN102378083A (en) * 2010-08-12 2012-03-14 郭建文 Dynamic damping middle/low-sound loudspeaker
WO2013016375A1 (en) * 2011-07-25 2013-01-31 Dr. G Licensing, Llc Ultra-low profile loudspeakers
DK180111B1 (en) * 2018-10-04 2020-05-06 Upper Level Aps A magnet system for an electromechanical transducer

Family Cites Families (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE574429C (en) * 1929-06-25 1933-04-18 Heinrich Eberhard Installation on electrodynamic loudspeakers
GB858250A (en) * 1958-07-01 1961-01-11 Darwins Ltd Improvements in or relating to permanent magnet assemblies
NL257376A (en) * 1959-10-29
DE1614164B2 (en) * 1967-06-01 1977-05-26 Magnetfabrik Bonn Gmbh Vorm. Gewerkschaft Windhorst, 5300 Bonn-Bad Godesberg RING GAP MAGNET SYSTEM
DE2024258A1 (en) * 1970-05-19 1971-12-02 Neckarelz Mikrofonbau Magnet system for electroacoustic transducers
US3660618A (en) * 1970-10-01 1972-05-02 Stanley F White Magnetic assembly for loudspeaker
GB1321581A (en) * 1971-01-04 1973-06-27 Rola Celestion Ltd Magnet assemblies for moving coil electroacoustic transducers
JPS542647Y2 (en) * 1971-03-10 1979-02-05
US3803522A (en) * 1973-05-11 1974-04-09 Arnold Eng Co Air gap extending the width of a permanent magnet assembly
DE2511226A1 (en) * 1975-03-14 1976-09-23 Licentia Gmbh ELECTRODYNAMIC SPEAKER
JPS5244627A (en) * 1975-10-04 1977-04-07 Sony Corp Magnet core type speaker
SU587645A1 (en) * 1976-07-21 1978-01-05 Предприятие П/Я А-3150 Electrodynamic loudspeaker magnetic circuit
JPS5376824A (en) * 1976-12-20 1978-07-07 Hitachi Ltd Speaker
DK143879C (en) * 1977-03-01 1982-04-05 Seas Fabrikker As ELECTRODYNAMIC SPEAKER WITH SHORT CIRCUIT
JPS5546645A (en) * 1978-09-29 1980-04-01 Sony Corp Head phone
JPS6038077B2 (en) * 1980-04-16 1985-08-29 松下電器産業株式会社 speaker

Also Published As

Publication number Publication date
DE3267630D1 (en) 1986-01-02
EP0083045A3 (en) 1983-09-28
US4628154A (en) 1986-12-09
EP0083045A2 (en) 1983-07-06

Similar Documents

Publication Publication Date Title
EP0083045B1 (en) Magnetic system with annular air-gap, in particular for woofers
DE3544809C2 (en)
DE1176768B (en) Annular gap magnet system with low scatter, especially for loudspeakers, microphones, etc. like
DE2953568A1 (en) TUBULAR, AXIAL ACTUABLE SOLENOID
WO2009100820A2 (en) Actuating magnet
DE3237262C1 (en) Loudspeaker with membrane counter coupling
DE102014201790A1 (en) Method of manufacturing a sensor
DE10027095B4 (en) Torque detector arrangement
DE2362001C2 (en) Dynamic loudspeaker with voice coil
CH645463A5 (en) SCALE WITH ELECTROMAGNETIC POWER COMPENSATION.
DE2302385A1 (en) PERMANENT MAGNET ARRANGEMENT FOR A SPEAKER
DE2259320C3 (en) Direct current excited electromagnetic system for an electromagnetically releasable brake
EP0069865A2 (en) Electrodynamic movable head
DE4210740C2 (en) Electromagnet with a lifting anchor
DE102013203586A1 (en) Sensor for detecting a position of a transmitter magnet
EP3454349A1 (en) Method for producing a magnetic anchor tappet bond and magnetic anchor tappet bond for a linear actuator,
DE4125088C1 (en)
DE3127164A1 (en) Differential transformers
DE102016112371A1 (en) linear solenoid
DE3437253A1 (en) Electromagnetic measurement probe
DE3211163A1 (en) ELECTROMAGNETIC FORCE COMPENSATING SCALE
DE102006002875B4 (en) Transducer magnet system
AT381204B (en) Magnetic system for electrodynamic transducers in particular microphones and headphones
DE1614164C3 (en) Annular gap magnet system
DE3007115A1 (en) Loudspeaker using single magnet for three diaphragms - has circular pole shoes providing air gaps for concentrically moving coils

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

AK Designated contracting states

Designated state(s): DE FR GB IT

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Designated state(s): DE FR GB IT

17P Request for examination filed

Effective date: 19840323

ITF It: translation for a ep patent filed

Owner name: BARZANO' E ZANARDO MILANO S.P.A.

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): DE FR GB IT

REF Corresponds to:

Ref document number: 3267630

Country of ref document: DE

Date of ref document: 19860102

ET Fr: translation filed
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

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

Ref country code: GB

Payment date: 19981202

Year of fee payment: 17

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

Ref country code: FR

Payment date: 19981216

Year of fee payment: 17

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

Ref country code: DE

Payment date: 19990206

Year of fee payment: 17

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

Ref country code: GB

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

Effective date: 19991218

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19991218

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

Ref country code: FR

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

Effective date: 20000831

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

Ref country code: DE

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

Effective date: 20001003

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST