EP0033352A1 - Writing board, in particular large wallboard - Google Patents

Writing board, in particular large wallboard Download PDF

Info

Publication number
EP0033352A1
EP0033352A1 EP80100505A EP80100505A EP0033352A1 EP 0033352 A1 EP0033352 A1 EP 0033352A1 EP 80100505 A EP80100505 A EP 80100505A EP 80100505 A EP80100505 A EP 80100505A EP 0033352 A1 EP0033352 A1 EP 0033352A1
Authority
EP
European Patent Office
Prior art keywords
sheet
glass plate
glass
writing board
writing
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
EP80100505A
Other languages
German (de)
French (fr)
Other versions
EP0033352B1 (en
Inventor
Karl-Hermann Weyel
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.)
Weyel KG
Original Assignee
Weyel KG
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 Weyel KG filed Critical Weyel KG
Priority to DE8080100505T priority Critical patent/DE3068483D1/en
Priority to AT80100505T priority patent/ATE8359T1/en
Priority to EP80100505A priority patent/EP0033352B1/en
Publication of EP0033352A1 publication Critical patent/EP0033352A1/en
Application granted granted Critical
Publication of EP0033352B1 publication Critical patent/EP0033352B1/en
Expired legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B43—WRITING OR DRAWING IMPLEMENTS; BUREAU ACCESSORIES
    • B43L—ARTICLES FOR WRITING OR DRAWING UPON; WRITING OR DRAWING AIDS; ACCESSORIES FOR WRITING OR DRAWING
    • B43L1/00—Repeatedly-usable boards or tablets for writing or drawing
    • B43L1/04—Blackboards
    • B43L1/06—Blackboards rigid

Definitions

  • the invention relates to a writing board, in particular to a large-scale wall board, with a transparent glass plate, one side of which serves as a writing surface and is roughened, and with a support on which the glass plate rests.
  • a main advantage is that even after a long period of use of the board, the writing surface is still rough and therefore easy to write on, since glass is very hard and therefore bumps that result in the desired roughness are not removed.
  • Another advantage is that the writing on glass panels has a plastic effect, since the glass plate is translucent and therefore the writing on the back of the glass plate, on which a non-translucent, e.g. layer consisting of a varnish on the back and possibly the ruling is casting a shadow. Glass plates also have a high resistance to chemical influences. The writing surface of glass boards can be made very evenly without difficulty.
  • the glass plates of known sheets have a relatively large thickness of, for example, 4 to 5 mm in order to obtain adequate security against breakage. This results in a relatively large weight of known boards. Nevertheless, the security against breakage still leaves something to be desired. Sheets cannot be held on glass panels by means of magnets, as is often desirable for teaching purposes.
  • Blackboards are also known whose writing surface consists of an enamelled steel sheet. Such boards can not break, because in the event of impact, the enamel can flake off and are good for interacting with holding magnets, but all the advantages that a board with a writing surface made of glass lack, because enamel is less hard than glass, a shadow cast of the writing is not chemical resistance is lower than that of glass and the enamel surface cannot be produced as evenly as a roughened glass surface.
  • the invention has for its object to form a board of the type mentioned in such a way that the advantages of boards with a glass pane are combined with the advantages of boards whose writing surface consists of an enamelled steel sheet.
  • the carrier is a sheet, preferably a steel sheet, and in that an elastic intermediate layer connected to both the sheet and the glass sheet is arranged between the glass sheet and the sheet.
  • a panel designed in this way has a much greater break resistance than a glass panel of a known type. If the glass plate is nevertheless destroyed, the risk of an accident is extremely low, since the plate acts like laminated safety glass, i.e. the glass sheet will usually only get cracks that remain connected to the elastic intermediate layer, so that no dangerous splinters detach from the sheet. Since the font can cast a shadow in the Tael tablet according to the invention, the plasticity of the font is preserved, as in the case of known glass panels. The uniformity of the surface can also be achieved as with known glass panels. The other advantageous properties of a glass sheet (chemically resistant surface, long retention of the roughening) are also present. When using steel sheet for the carrier, the advantage is gained over known boards that magnets can be attached to the writing surface, since the distance of the writing surface from the steel sheet is relatively small and therefore sufficiently large magnetic forces are still present.
  • sheet and glass have different coefficients of thermal expansion, thanks to the elastic intermediate layer, the glass does not separate from the sheet, since different thermal expansions are absorbed by the elastic intermediate layer through its elastic deformation, without this layer being destroyed or detached from the sheet or the glass plate .
  • the sheet usually a steel sheet, has a greater coefficient of thermal expansion than glass. Since temperature influences act on the front of the panel in particular, the disadvantage of the different coefficients of thermal expansion is alleviated, i.e. the temperature fluctuations on the sheet are generally slower than the temperature fluctuations on the glass plate.
  • the sheet can serve as the only support. But you can also provide a further support on which the sheet rests (claim 10). An additional support will be provided especially if the board is movable and / or free-standing. If the board is fixed to a wall, however, comes the use without additional carrier into consideration. If the panel according to the embodiment of claim 2 has a glass plate on both sides of the sheet, an additional support is naturally not used. In this case, the board consists of five layers, namely two glass plates, two elastic intermediate layers and a sheet. This layer structure already achieves a high level of dimensional stability of the board.
  • the coating of the metal sheet according to claim 3 is particularly advantageous.
  • a high degree of security against detachment of the coating is achieved, since paint, in particular baked paint, adheres very well to a steel sheet and does not detach even under the influence of moisture.
  • An equally good connection of a lacquer layer with glass cannot be achieved.
  • the lacquer layer can also have the ruling, which will also usually be the case if the sheet is lacquered.
  • the elastic intermediate layer must be transparent if the lacquer is to be visible from the writing surface. However, it is possible that the elastic intermediate layer is itself colored and thus forms the background against which the writing stands out.
  • Silicone is particularly well suited as an elastic intermediate layer (claim 5).
  • Other materials, in particular plastics, are also suitable, which can be bonded sufficiently firmly to glass and the sheet metal or the coating of the sheet and have a sufficiently high elasticity over a sufficiently large temperature range.
  • the same material can be used for the glass plate as for known glass panels, namely a silicate glass (claim 6).
  • the thicknesses of the layers can be in the ranges specified in claims 7 to 9.
  • the thicknesses also depend on the size of the sheet, generally the thicker the sheet the larger the dimensions of the sheet. Is essential Lich 1, that the glass plate is much thinner than in prior art glass sheets. This has the advantage of relatively low weight and material savings. The usage Thinner glass plates are possible because the break resistance is no longer essentially achieved by a large thickness of the glass plate, but by the connection with a sheet.
  • the board can have relatively large dimensions, namely the usual dimensions of a wall board, the height h being 1500 mm and the width b being 2100 mm.
  • the layer structure of the table is shown in Fig. 2.
  • the board has a support 1 made of sheet steel, a lacquer layer 2, a transparent elastic intermediate layer 3 and a glass plate 4.
  • the sheet 1 can have a thickness s 1 of 0.3 to 0.6 mm, the elastic intermediate layer a thickness s 3 of 0, 5 mm and the glass plate 4 have a thickness s 4 of 1.5 to 3.2 mm.
  • the paint layer 2 is comparatively very thin. Its thickness s 2 can be, for example, 0.03 mm.
  • the glass plate 4 is roughened on its free side 4a as is usual with glass writing boards, e.g. by sandblasting, whereby a roughness depth of 17 ⁇ (0.017 millimeters) is produced.
  • the rear side 4b can also be roughened in order to obtain a good connection with the elastic intermediate layer 3, which is preferably made of silicone.
  • the lacquer layer 2 preferably a stove enamel, can have the usual green blackboard color.
  • the lacquer layer can also contain a ruling 5 which is visible from the front of the board (see FIG. 1).
  • the varnish layer can be produced in such a way that first a basic color is applied, for example by spraying, and that after drying of the base layer with a different color, preferably white-colored, an L is applied ineatur and that subsequently thereto heated in a drying oven of the paint.
  • the sheet is preferably protected against rust overall. This can be done, for example, by painting the entire metal sheet or by applying another anti-rust coating, e.g. a galvanizing.
  • the silicone layer 3 is applied in the liquid state in order to obtain a good connection with the adjacent layers. It may be expedient to use a vacuum in order to avoid air bubbles or other gas bubbles in the layer 3.
  • the writing surface 4a for example, writing applied with chalk casts a shadow on the lacquer layer 2, so that the writing is as plastic as in known glass boards.
  • a thickness of the glass plate of, for example, 3 mm and a thickness of the layer 3 of, for example, 0.5 mm, this distance is 3.5 mm.
  • the glass plate 4 is thinner than in known glass plates. For the plasticity of the writing, however, it is not only the thickness of the glass plate that is decisive, but also the sum of the thicknesses of layers 3 and 4.
  • the coefficient of thermal expansion of the plate 1 is greater than the coefficient of thermal expansion of the glass plate 4. Nevertheless, the glass plate 4 and the plate 1 do not detach from the layer 3, since different thermal expansions only lead to an elastic deformation of the layer 3. Fluctuations in temperature, for example due to solar radiation, generally act on the panel from the front 4a, which is favorable for the overall deformation, since relative displacements between the sheet 1 and the glass plate 4 are less pronounced than with the preferred effect of temperature fluctuations the sheet 1. However, the intermediate layer 3 is still able to absorb different thermal expansions even in the event of such temperature fluctuations.
  • a tablet can also be used without an additional support, e.g. as a blackboard fixed to a wall.
  • the layer structure is the same on both sides and corresponds to the layer structure according to FIG. 2.
  • the board has two writing surfaces 4a and 4'a.
  • one side of the board has a non-lined writing surface and the other side has a lined writing surface.
  • paint layer 2 in one color and paint layer 2 'with a ruling.
  • the board can be surrounded by a frame.
  • a frame is definitely advantageous, even for a table according to FIG. 2, in order to protect the edges of the glass plates 4, 4 'and to avoid sharp edges.

Landscapes

  • Drawing Aids And Blackboards (AREA)
  • Rod-Shaped Construction Members (AREA)
  • Laminated Bodies (AREA)
  • Panels For Use In Building Construction (AREA)
  • Surface Treatment Of Glass (AREA)

Abstract

1. Writing boards, in particular large-surface blackboards, having a transparent glass plate (4 ; 4, 4'), one side (4a ; 4a, 4'a) of which is used as the writing surface and is roughened, and having a support made of sheet metal (1), preferably of sheet steel, to which the glass plate is secured by adhesion, characterized in that a coloured lacquer layer (2 ; 2, 2') is connected to the sheet metal (1), and in that an adhesive transparent resilient intermediate layer (3 ; 3, 3') is arranged between this lacquer layer (2 ; 2, 2') and the glass plate (4 ; 4, 4').

Description

Die Erfindung bezieht sich auf eine Schreibtafel, insbesondere auf eine großflächige Wandtafel, mit einer transparenten Glasplatte, deren eine Seite als Schreibfläche dient und aufgerauht ist und mit einem Träger, auf dem die Glasplatte aufliegt.The invention relates to a writing board, in particular to a large-scale wall board, with a transparent glass plate, one side of which serves as a writing surface and is roughened, and with a support on which the glass plate rests.

Schreibtafeln dieser Art haben sich in den letzten Jahrzehnten wegen ihrer großen Gebrauchsvorteile gegenüber Holztafeln durchgesetzt. Ein Hauptvorteil besteht darin, daß die Schreibfläche auch nach langer Gebrauchsdauer der Tafel noch rauh und damit gut beschreibbar ist, da Glas eine große Härte hat und deshalb Unebenheiten, die die erwünschte Rauhigkeit ergeben, nicht abgetragen werden. Ein weiterer Vorteil besteht darin, daß die Schrift auf Glastafeln plastisch wirkt, da die Glasplatte durchscheinend ist und deshalb die Schrift auf die Rückseite der Glasplatte, an der sich eine nicht durchscheinende, z.B. aus einer Lackierung der Rückseite bestehende Schicht und gegebenenfalls die Lineatur befindet, einen Schatten wirft. Glasplatten haben auch eine hohe Widerstandsfähigkeit gegen chemische Einflüsse. Die Schreibfläche von Glastafeln läßt sich ohne Schwierigkeiten'sehr gleichmäßig herstellen.Writing boards of this type have prevailed over the past few decades because of their great use advantages over wooden boards. A main advantage is that even after a long period of use of the board, the writing surface is still rough and therefore easy to write on, since glass is very hard and therefore bumps that result in the desired roughness are not removed. Another advantage is that the writing on glass panels has a plastic effect, since the glass plate is translucent and therefore the writing on the back of the glass plate, on which a non-translucent, e.g. layer consisting of a varnish on the back and possibly the ruling is casting a shadow. Glass plates also have a high resistance to chemical influences. The writing surface of glass boards can be made very evenly without difficulty.

Bei bekannten Tafeln mit Glasplatten sind diese auf einem Träger aufgebracht, dessen Dicke ein Vielfaches der Dicke der Glasplatte ist. Ein Träger ist erforderlich, da bei einer Glasplatte ohne Träger die Bruchgefahr untragbar groß ist. Die Träger sind bei bekannten Tafeln z.B. sogenannte Sperrplatten aus Holz.In known panels with glass plates, these are applied to a carrier, the thickness of which is a multiple of the thickness of the glass plate. A carrier is required because the risk of breakage is unbearably high with a glass plate without a carrier. The supports in known boards are e.g. so-called wooden locking plates.

Die Glasplatten bekannter Tafeln haben eine relativ große Dicke von z.B.4 bis 5 mm, um eine ausreichende Sicherheit gegen Bruch zu erhalten. Daraus ergibt sich ein verhältnismäßig großes Gewicht bekannter Tafeln. Trotzdem läßt die Bruchsicherheit noch zu wünschen übrig. An Glastafeln können auch nicht Blätter mittels Haftmagneten gehalten werden, wie dies für Unterrichtszwecke häufig erwünscht ist.The glass plates of known sheets have a relatively large thickness of, for example, 4 to 5 mm in order to obtain adequate security against breakage. This results in a relatively large weight of known boards. Nevertheless, the security against breakage still leaves something to be desired. Sheets cannot be held on glass panels by means of magnets, as is often desirable for teaching purposes.

Bekannt sind auch Tafeln, deren Schreibfläche aus einem emaillierten Stahlblech besteht. Solche Tafeln können zwar nicht zerbrechen, da bei Stößen allenfalls Email abplatzen kann und sind gut zum Zusammenwirken mit Haftmagneten geeignet, jedoch fehlen alle Vorteile, die eine Tafel mit Schreibfläche aus Glas aufweist, da Email weniger hart ist als Glas, ein Schattenwurf der Schrift nicht stattfindet, die chemische Widerstandsfähigkeit geringer ist als bei Glas und die Emailfläche nicht so gleichmäßig hergestellt werden kann wie eine aufgerauhte Glasfläche.Blackboards are also known whose writing surface consists of an enamelled steel sheet. Such boards can not break, because in the event of impact, the enamel can flake off and are good for interacting with holding magnets, but all the advantages that a board with a writing surface made of glass lack, because enamel is less hard than glass, a shadow cast of the writing is not chemical resistance is lower than that of glass and the enamel surface cannot be produced as evenly as a roughened glass surface.

Der Erfindung liegt die Aufgabe zugrunde, eine Tafel der eingangs genannten Art so auszubilden, daß die Vorteile von Tafeln mit Glasscheibe verbunden werden mit den Vorteilen von Tafeln, deren Schreibfläche aus einem emaillierten Stahlblech besteht.The invention has for its object to form a board of the type mentioned in such a way that the advantages of boards with a glass pane are combined with the advantages of boards whose writing surface consists of an enamelled steel sheet.

Diese Aufgabe wird nach der Erfindung dadurch gelöst, daß der Träger ein Blech, vorzugsweise ein Stahlblech, ist und daß zwischen der Glasplatte und dem Blech eine sowohl mit dem Blech als auch mit der Glasplatte verbundene elastische Zwischenschicht angeordnet ist.This object is achieved according to the invention in that the carrier is a sheet, preferably a steel sheet, and in that an elastic intermediate layer connected to both the sheet and the glass sheet is arranged between the glass sheet and the sheet.

Eine so ausgebildete Tafel hat eine wesentlich größere Bruchsicherheit als eine Glastafel bekannter Bauart. Sollte die Glasplatte dennoch zerstört werden, so ist die Unfallgefahr außerordentlich gering, da die Tafel wie Verbund-Sicherheitsglas wirkt, d.h. die Glastafel wird in der Regel nur Risse bekommen, die weiterhin mit der elastischen Zwischenschicht verbunden bleiben, so daß sich keine gefährlichen Splitter von der Tafel lösen. Da auch bei der erfindungsgemäßen Tael Tafel die Schrift einen Schatten werfen kann, wird die Plastizität der Schrift ebenso wie bei bekannten Glastafeln erhalten. Auch die Gleichmäßigkeit der Oberfläche ist wie bei bekannten Glastafeln erreichbar. Auch die weiteren vorteilhaften Eigenschaften einer Glastafel (chemisch resistente Oberfläche, lange Erhaltung der Aufrauhung) sind vorhanden. Bei Verwendung von Stahlblech für den Träger wird gegenüber bekannten Tafeln der Vorteil gewonnen, daß Magnete an die Schreibfläche angesetzt werden können, da der Abstand der Schreibfläche von dem Stahlblech relativ gering ist und deshalb noch genügend große Magnetkräfte vorhanden sind.A panel designed in this way has a much greater break resistance than a glass panel of a known type. If the glass plate is nevertheless destroyed, the risk of an accident is extremely low, since the plate acts like laminated safety glass, i.e. the glass sheet will usually only get cracks that remain connected to the elastic intermediate layer, so that no dangerous splinters detach from the sheet. Since the font can cast a shadow in the Tael tablet according to the invention, the plasticity of the font is preserved, as in the case of known glass panels. The uniformity of the surface can also be achieved as with known glass panels. The other advantageous properties of a glass sheet (chemically resistant surface, long retention of the roughening) are also present. When using steel sheet for the carrier, the advantage is gained over known boards that magnets can be attached to the writing surface, since the distance of the writing surface from the steel sheet is relatively small and therefore sufficiently large magnetic forces are still present.

Obwohl Blech und Glas verschiedene Wärmedehnungskoeffizienten aufweisen, löst sich das Glas dank der elastischen Zwischenschicht nicht von dem Blech, da unterschiedliche Wärmedehnungen von der elastischen Zwischenschicht durch deren elastische Verformung aufgefangen werden, ohne daß diese Schicht zerstört wird oder sich von dem Blech oder der Glasplatte löst. Das Blech, in der Regel ein Stahlblech, hat einen größeren Wärmeausdehnungskoeffizienten als Glas. Da Temperatureinflüsse vor allem von der Vorderseite der Tafel her auf diese einwirken, wird der Nachteil der verschiedenen Wärmedehnungskoeffizienten gemildert, d.h. die Temperaturschwankungen am Blech sind im allgemeinen langsamer als die Temperaturschwankungen an der Glasplatte.Although sheet and glass have different coefficients of thermal expansion, thanks to the elastic intermediate layer, the glass does not separate from the sheet, since different thermal expansions are absorbed by the elastic intermediate layer through its elastic deformation, without this layer being destroyed or detached from the sheet or the glass plate . The sheet, usually a steel sheet, has a greater coefficient of thermal expansion than glass. Since temperature influences act on the front of the panel in particular, the disadvantage of the different coefficients of thermal expansion is alleviated, i.e. the temperature fluctuations on the sheet are generally slower than the temperature fluctuations on the glass plate.

Das Blech kann als einziger Träger dienen. Man kann aber auch einen weiteren Träger vorsehen, auf dem das Blech aufliegt (Anspruch 10). Einen zusätzlichen Träger wird man vor allem dann vorsehen, wenn die Tafel beweglich und/oder freistehend ist. Bei fester Aufhängung der Tafel an einer Wand jedoch kommt die Verwendung ohne zusätzlichen Träger in Betracht. Wenn die Tafel gemäß der Ausführungsform nach Anspruch 2 zu beiden Seiten des Bleches eine Glasplatte aufweist, wird ein zusätzlicher Träger naturgemäß nicht verwendet. Die Tafel besteht in diesem Fall aus fünf Schichten, nämlich aus zwei Glasplatten, zwei elastischen Zwischenschichten und einem Blech. Bei diesem Schichtaufbau wird bereits eine hohe Formsteifigkeit der Tafel erzielt.The sheet can serve as the only support. But you can also provide a further support on which the sheet rests (claim 10). An additional support will be provided especially if the board is movable and / or free-standing. If the board is fixed to a wall, however, comes the use without additional carrier into consideration. If the panel according to the embodiment of claim 2 has a glass plate on both sides of the sheet, an additional support is naturally not used. In this case, the board consists of five layers, namely two glass plates, two elastic intermediate layers and a sheet. This layer structure already achieves a high level of dimensional stability of the board.

Besonders vorteilhaft ist die Lackierung des Bleches gemäß Anspruch 3. Bei dieser Ausführungsform wird eine große Sicherheit gegen ein Ablösen der Lackierung erreicht, da Lack, insbesondere eingebrannter Lack, auf einem Stahlblech sehr gut haftet und sich auch bei Einfluß von Feuchtigkeit nicht ablöst. Eine ebenso gute Verbindung einer Lackschicht mit Glas ist nicht erreichbar. Die Lackschicht kann gemäß Anspruch 4 auch die Lineatur aufweisen, was auch üblicherweise der-Fall sein wird, wenn das Blech lackiert wird. Die elastische Zwischenschicht muß dann transparent sein, wenn die Lackierung von der Schreibfläche her sichtbar sein soll. Es ist jedoch möglich, daß die elastische Zwischenschicht ihrerseits eingefärbt ist und so den Hintergrund bildet, vor dem sich die Schrift abhebt.The coating of the metal sheet according to claim 3 is particularly advantageous. In this embodiment, a high degree of security against detachment of the coating is achieved, since paint, in particular baked paint, adheres very well to a steel sheet and does not detach even under the influence of moisture. An equally good connection of a lacquer layer with glass cannot be achieved. According to claim 4, the lacquer layer can also have the ruling, which will also usually be the case if the sheet is lacquered. The elastic intermediate layer must be transparent if the lacquer is to be visible from the writing surface. However, it is possible that the elastic intermediate layer is itself colored and thus forms the background against which the writing stands out.

Besonders gut als elastische Zwischenschicht ist Silikon geeignet (Anspruch 5). Es kommen auch sonstige Materialien, insbesondere Kunststoffe, in Betracht, die sich genügend fest mit Glas und dem Blech bzw. der Lackierung des Bleches, verbinden lassen und eine genügend große Elastizität über einen : genügend großen Temperaturbereich haben. Für die Glasplatte kann das gleiche Material verwendet werden wie für bekannte Glastafeln, nämlich ein Silikatglas (Anspruch 6).Silicone is particularly well suited as an elastic intermediate layer (claim 5). Other materials, in particular plastics, are also suitable, which can be bonded sufficiently firmly to glass and the sheet metal or the coating of the sheet and have a sufficiently high elasticity over a sufficiently large temperature range. The same material can be used for the glass plate as for known glass panels, namely a silicate glass (claim 6).

Die Dicken der Schichten können in den in den Ansprüchen 7 bis 9 angegebenen Bereichen liegen. Die Dicken hängen auch von der Größe der Tafel ab, wobei im allgemeinen die Schichtdicken umso größer sind, je größer die Abmessungen der Tafel sind. Wesent- 1 lich ist, daß die Glasplatte wesentlich dünner ist als bei bekannten Glastafeln. Dies bringt den Vorteil eines relativ geringen Gewichtes und eine Materialersparnis mit sich. Die Verwendung dünner Glasplatten ist möglich, da die Bruchsicherheit nicht mehr im wesentlichen durch eine große Dicke der Glasplatte erreicht wird, sondern durch die Verbindung mit einem Blech.The thicknesses of the layers can be in the ranges specified in claims 7 to 9. The thicknesses also depend on the size of the sheet, generally the thicker the sheet the larger the dimensions of the sheet. Is essential Lich 1, that the glass plate is much thinner than in prior art glass sheets. This has the advantage of relatively low weight and material savings. The usage Thinner glass plates are possible because the break resistance is no longer essentially achieved by a large thickness of the glass plate, but by the connection with a sheet.

In der Zeichnung sind zwei Ausführungsbeispiele der Erfindung dargestellt. Es zeigen:

  • Fig. 1 eine Ansicht einer Tafel,
  • Fig. 2 einen vergrößerten Schnitt nach Linie II-II in Fig. 1 und
  • Fig. 3 einen entsprechenden Querschnitt bei einer Tafel, die beidseitig eine Glasplatte aufweist.
Two exemplary embodiments of the invention are shown in the drawing. Show it:
  • 1 is a view of a board,
  • Fig. 2 is an enlarged section along line II-II in Fig. 1 and
  • Fig. 3 shows a corresponding cross section in a table that has a glass plate on both sides.

Die Tafel kann verhältnismäßig große Abmessungen aufweisen, nämlich übliche Abmessungen einer Wandtafel, wobei die Höhe h z.B.1500 mm und die Breite b z.B. 2100 mm betragen kann. Der Schichtaufbau der Tafel ist in Fig. 2 dargestellt. Die Tafel hat einen Träger 1 aus Stahlblech, eine Lackschicht 2, eine transparente elastische Zwischenschicht 3 und eine Glasplatte 4. Das Blech 1 kann eine Dicke s1 von 0,3 bis 0,6 mm die elastische Zwischenschicht eine Dicke s3 von 0,5 mm und die Glasplatte 4 eine Dicke s4 von 1,5 bis 3,2 mm aufweisen. Die.Lackschicht 2 ist vergleichsweise sehr dünn. Ihre Dicke s2 kann z.B. 0,03 mm betragen.The board can have relatively large dimensions, namely the usual dimensions of a wall board, the height h being 1500 mm and the width b being 2100 mm. The layer structure of the table is shown in Fig. 2. The board has a support 1 made of sheet steel, a lacquer layer 2, a transparent elastic intermediate layer 3 and a glass plate 4. The sheet 1 can have a thickness s 1 of 0.3 to 0.6 mm, the elastic intermediate layer a thickness s 3 of 0, 5 mm and the glass plate 4 have a thickness s 4 of 1.5 to 3.2 mm. The paint layer 2 is comparatively very thin. Its thickness s 2 can be, for example, 0.03 mm.

Die Glasplatte 4 ist an ihrer freien Seite 4a so aufgerauht, wie dies bei Schreibtafeln aus Glas üblich ist, z.B. durch Sandstrahlen, wobei eine Rauhtiefe von 17µ (0,017 Millimeter) hergestellt wird.'Die Rückseite 4b kann ebenfalls aufgerauht sein, um eine gute Verbindung mit der elastischen Zwischenschicht 3 zu erhalten, die vorzugsweise aus Silikon besteht.The glass plate 4 is roughened on its free side 4a as is usual with glass writing boards, e.g. by sandblasting, whereby a roughness depth of 17µ (0.017 millimeters) is produced. The rear side 4b can also be roughened in order to obtain a good connection with the elastic intermediate layer 3, which is preferably made of silicone.

Die Schicht 3 ist, ebenso wie die Glasplatte 4, transparent, so daß die Lackschicht 2 von der Vorderseite der Tafel her sichtbar ist. Die Lackschicht 2, vorzugsweise eine Einbrennlackierung, kann die übliche grüne Tafelfarbehaben. Die Lackschicht kann auch eine Lineatur 5 enthalten, die von der Vorderseite der Tafel her sichtbar ist (siehe Fig. 1). Die Lackschicht kann derart hergestellt werden, daß zunächst eine Grundfarbe aufgetragen wird, z.B. durch Spritzen, und daß nach Trocknen der Grundschicht mit anderer Farbe, vorzugsweise mit weißer Farbe, eine Lineatur aufgetragen wird und daß anschließend daran in einem Trockenofen der Lack gebrannt wird.The layer 3, like the glass plate 4, is transparent, so that the lacquer layer 2 is visible from the front of the board. The lacquer layer 2, preferably a stove enamel, can have the usual green blackboard color. The lacquer layer can also contain a ruling 5 which is visible from the front of the board (see FIG. 1). The varnish layer can be produced in such a way that first a basic color is applied, for example by spraying, and that after drying of the base layer with a different color, preferably white-colored, an L is applied ineatur and that subsequently thereto heated in a drying oven of the paint.

Das Blech ist vorzugsweise insgesamt rostgeschützt. Dies kann beispielsweise dadurch geschehen, daß das gesamte Blech lackiert wird oder daß ein sonstiger Rostschutzüberzug angebracht wird, z.B. eine Verzinkung.The sheet is preferably protected against rust overall. This can be done, for example, by painting the entire metal sheet or by applying another anti-rust coating, e.g. a galvanizing.

Die Silikonschicht 3 wird in flüssigem Zustand aufgebracht, um eine gute Verbindung mit den angrenzenden Schichten zu erhalten. Dabei kann es zweckmäßig sein, Vakuum anzuwenden, um Luftblasen oder sonstige Gasblasen in der Schicht 3 zu vermeiden.The silicone layer 3 is applied in the liquid state in order to obtain a good connection with the adjacent layers. It may be expedient to use a vacuum in order to avoid air bubbles or other gas bubbles in the layer 3.

Auf die Schreibfläche 4a z.B. mit Kreide aufgetragene Schrift wirft auf die Lackschicht 2 einen Schatten, so daß eine Plastizität der Schrift wie bei bekannten Glastafeln besteht. Der Grund, von dem sich die Schrift optisch abhebt, liegt gegenüber der Schreibfläche 4a um das Maß s4 + s3 zurück. Bei einer Dicke der Glasplatte von.z.B. 3 mm und einer Dicke der Schicht 3 von z.B. 0,5 mm beträgt also dieser Abstand 3,5 mm. Die Glasplatte 4-ist dünner als bei bekannten Glastafeln. Für die Plastizität der Schrift ist jedoch, wie gesagt, nicht nur die Dicke der Glasplatte allein maßgebend, sondern die Summe der Dicken der Schichten 3 und 4.On the writing surface 4a, for example, writing applied with chalk casts a shadow on the lacquer layer 2, so that the writing is as plastic as in known glass boards. The reason from which the writing stands out visually lies behind the writing surface 4a by the dimension s 4 + s 3 . With a thickness of the glass plate of, for example, 3 mm and a thickness of the layer 3 of, for example, 0.5 mm, this distance is 3.5 mm. The glass plate 4 is thinner than in known glass plates. For the plasticity of the writing, however, it is not only the thickness of the glass plate that is decisive, but also the sum of the thicknesses of layers 3 and 4.

Wie schon in der Beschreibungseinleitung erwähnt, ist der Wärmeausdehnungskoeffizient des Bleches 1 größer als der Wärmeausdehnungskoeffizient der Glasplatte 4. Dennoch findet ein Ablösen der Glasplatte 4 und des Bleches 1 von der Schicht 3 nicht statt, da verschiedene Wärmedehnungen lediglich zu einer elastischen Verformung der Schicht 3 führen. Temperaturschwankungen, z.B. bedingt durch Sonnenbestrahlung, wirken in der Regel zunächst von der Vorderseite 4a her auf die Tafel ein, was für die Gesamtverformung günstig ist, da Relativverschiebungen zwischen dem Blech 1 und der Glasplatte 4 weniger stark sind, als bei bevorzugter Einwirkung von Temperaturschwankungen auf das Blech 1. Jedoch ist die Zwischenschicht 3 auch bei derartiger Einwirkung von Temperaturschwankungen noch in der Lage, unterschiedliche Wärmedehnungen aufzufangen.As already mentioned in the introduction to the description, the coefficient of thermal expansion of the plate 1 is greater than the coefficient of thermal expansion of the glass plate 4. Nevertheless, the glass plate 4 and the plate 1 do not detach from the layer 3, since different thermal expansions only lead to an elastic deformation of the layer 3. Fluctuations in temperature, for example due to solar radiation, generally act on the panel from the front 4a, which is favorable for the overall deformation, since relative displacements between the sheet 1 and the glass plate 4 are less pronounced than with the preferred effect of temperature fluctuations the sheet 1. However, the intermediate layer 3 is still able to absorb different thermal expansions even in the event of such temperature fluctuations.

Eine Tafel gemäß Fig. 2 kann mit einem zusätzlichen Träger versehen werden, auf dem das Blech 1 aufliegt. Man kann jedoch eine Tafel auch ohne zusätzlichen Träger verwenden, z.B. als fest an einer Wand aufgehängte Tafel.2 can be provided with an additional support on which the sheet 1 rests. However, a tablet can also be used without an additional support, e.g. as a blackboard fixed to a wall.

Die Tafel nach Fig. 3 unterscheidet sich von der Tafel nach Fig. 2 dadurch, daß zu beiden Seiten des Bleches 1 Glasplatten 4 angeordnet sind. Der Schichtaufbau ist auf beiden Seiten gleich und entspricht dem Schichtaufbau nach Fig. 2. Zur Unterscheidung der Schichten sind die in Fig. 3 links auf das Blech 1 aufgebauten Schichten mit 2', 3' und 4' bezeichnet. Die Tafel hat zwei Schreibflächen 4a und 4'a. Hierbei kann z.B. eine Seite der Tafel eine nichtlinierte Schreibfläche haben und die andere Seite eine linierte Schreibfläche. In diesem Fall ist z.B. die Lackschicht 2 einfarbig und die Lackschicht 2' mit einer Lineatur versehen.3 differs from the table of FIG. 2 in that 1 glass plates 4 are arranged on both sides of the plate. The layer structure is the same on both sides and corresponds to the layer structure according to FIG. 2. To differentiate the layers, the layers built up on the sheet 1 on the left in FIG. 3 are denoted by 2 ', 3' and 4 '. The board has two writing surfaces 4a and 4'a. Here, e.g. one side of the board has a non-lined writing surface and the other side has a lined writing surface. In this case e.g. paint layer 2 in one color and paint layer 2 'with a ruling.

Die Tafel nach Fig. 3 muß ohne zusätzlichen Träger verwendet werden, weil ja beide Seiten 4a und 4'a zugänglich sein müssen. Die Tafel kann jedoch von einem Rahmen umgeben werden. Ein Rahmen ist auf jeden Fall vorteilhaft, auch für eine Tafel nach Fig. 2, um die Ränder der Glasplatten 4, 4' zu schützen und um scharfe Kanten zu vermeiden.3 must be used without an additional support, because both sides 4a and 4'a must be accessible. However, the board can be surrounded by a frame. A frame is definitely advantageous, even for a table according to FIG. 2, in order to protect the edges of the glass plates 4, 4 'and to avoid sharp edges.

Claims (10)

1. Schreibtafel, insbesondere großflächige Wandtafel, mit einer transparenten Glasplatte, deren eine Seite als Schreibfläche dient und aufgerauht ist und mit einem Träger, auf dem die Glasplatte aufliegt, dadurch gekennzeichnet, daß der Träger ein Blech (1), vorzugsweise ein Stahlblech ist, und daß zwischen der Glasplatte (4; 4, 4') und dem Blech (1) eine sowohl mit dem Blech (1) als auch mit der Glasplatte (4; 4, 4') verbundene elastische Zwischenschicht (3; 3, 3') angeordnet ist.1. writing board, in particular a large wall board, with a transparent glass plate, one side of which serves as a writing surface and is roughened, and with a support on which the glass plate rests, characterized in that the support is a sheet (1), preferably a steel sheet, and that between the glass plate (4; 4, 4 ') and the sheet metal (1) an elastic intermediate layer (3; 3, 3') connected both to the sheet metal (1) and to the glass plate (4; 4, 4 ') ) is arranged. 2. Schreibtafel nach Anspruch 1, dadurch gekennzeichnet, daß auf beiden Seiten des Bleches (1) eine mittels einer elastischen Zwischenschicht (3, 3') mit dem Blech (1) verbundene Glasplatte (4, 4') angeordnet ist (Fig. 3).2. Writing board according to claim 1, characterized in that on both sides of the sheet (1) by means of an elastic intermediate layer (3, 3 ') with the sheet (1) connected glass plate (4, 4') is arranged (Fig. 3rd ). 3. Schreibtafel nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß zwischen dem Blech (1) und der elastischen Zwischenschicht (3; 3, 3') eine mit dem Blech (1) verbundene eingefärbte Lackschicht (2; 2, 2'), vorzugsweise eine Einbrennlackierung, angeordnet ist, und daß die Zwischenschicht (3; 3, 3') transparent ist.3. Writing board according to one of the preceding claims, characterized in that between the sheet (1) and the elastic intermediate layer (3; 3, 3 ') a colored paint layer (2; 2, 2') connected to the sheet (1), preferably a stove enamelling is arranged, and that the intermediate layer (3; 3, 3 ') is transparent. 4: Schreibtafel nach Anspruch 3, dadurch gekennzeichnet, daß die Lackschicht (2; 2') mit Markierungen versehen ist, insbesondere mit einer Lineatur (5).4: Writing board according to claim 3, characterized in that the lacquer layer (2; 2 ') is provided with markings, in particular with a ruling (5). 5. Schreibtafel nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß die elastische Zwischenschicht (3; 3, 3') aus Silikon besteht.5. Writing board according to one of the preceding claims, characterized in that the elastic intermediate layer (3; 3, 3 ') consists of silicone. 6. Schreibtafel nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß die Glasplatte (4; 4, 4') aus Silikatglas besteht.6. Writing board according to one of the preceding claims, characterized in that the glass plate (4; 4, 4 ') consists of silicate glass. 7. Schreibtafel nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß das Blech (1) eine Dicke von 0,3 bis 0,6 mm aufweist.7. Writing board according to one of the preceding claims, characterized in that the sheet (1) has a thickness of 0.3 to 0.6 mm. 8. Schreibtafel nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß die Zwischenschicht (3; 3, 3') eine Dicke von ca. 0,5 mm aufweist.8. Writing board according to one of the preceding claims, characterized in that the intermediate layer (3; 3, 3 ') has a thickness of approximately 0.5 mm. 9. Schreibtafel nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß die Glasplatte (4; 4, 4') eine Dicke von 1,5 bis 3,2 mm aufweist.9. Writing board according to one of the preceding claims, characterized in that the glass plate (4; 4, 4 ') has a thickness of 1.5 to 3.2 mm. 10. Schreibtafel nach Anspruch 1 oder einem der Ansprüche 3 bis 9, dadurch gekennzeichnet, daß ein weiterer Träger vorgesehen ist, auf dem das Blech aufliegt.10. Writing board according to claim 1 or one of claims 3 to 9, characterized in that a further carrier is provided on which the sheet rests.
EP80100505A 1980-02-01 1980-02-01 Writing board, in particular large wallboard Expired EP0033352B1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
DE8080100505T DE3068483D1 (en) 1980-02-01 1980-02-01 Writing board, in particular large wallboard
AT80100505T ATE8359T1 (en) 1980-02-01 1980-02-01 WRITING BOARD, ESPECIALLY LARGE WALL BOARD.
EP80100505A EP0033352B1 (en) 1980-02-01 1980-02-01 Writing board, in particular large wallboard

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP80100505A EP0033352B1 (en) 1980-02-01 1980-02-01 Writing board, in particular large wallboard

Publications (2)

Publication Number Publication Date
EP0033352A1 true EP0033352A1 (en) 1981-08-12
EP0033352B1 EP0033352B1 (en) 1984-07-11

Family

ID=8186588

Family Applications (1)

Application Number Title Priority Date Filing Date
EP80100505A Expired EP0033352B1 (en) 1980-02-01 1980-02-01 Writing board, in particular large wallboard

Country Status (3)

Country Link
EP (1) EP0033352B1 (en)
AT (1) ATE8359T1 (en)
DE (1) DE3068483D1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5116979A (en) * 1989-09-12 1992-05-26 Mitsui Toatsu Chemicals, Incorporated Dihydrocaffeic acid derivatives and pharmaceutical preparations containing same
WO2000030867A1 (en) * 1998-11-19 2000-06-02 Guardian Llodio, S.A. Process for fabricating a writing board, and writing board obtained with such process
CH699483A1 (en) * 2008-09-01 2010-03-15 Troesch Glas Ag Re-writable ferromagnetic device e.g. writing board marking device, for presentation and teaching purpose in e.g. school, has front glass plate whose thickness is made to be small such that attractive force stays at active surface
CN105159024A (en) * 2014-06-03 2015-12-16 波利视觉股份有限公司 Projection and communication board and method for manufacturing it

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE78125C (en) * J. KÖSTNER, J. klein 11. J. HASTREITER, Furth i. Walde, Bayern Writing board
FR371344A (en) * 1906-11-12 1907-03-05 Wojislav Stevanovitsch Artificial slate for writing or drawing
DE356889C (en) * 1921-03-30 1922-08-04 Jacob Kranz Process for the production of an unbreakable writing board
US2303120A (en) * 1940-06-25 1942-11-24 Adelaide M Greaves Walker Glass chalkboard
FR987539A (en) * 1949-04-02 1951-08-14 Mullca Advanced writing board
FR59717E (en) * 1949-10-08 1954-07-16 Mullca Advanced writing board
DE1916397A1 (en) * 1969-03-31 1971-01-07 Schulwandtafelfabrik Walter We school board

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE78125C (en) * J. KÖSTNER, J. klein 11. J. HASTREITER, Furth i. Walde, Bayern Writing board
FR371344A (en) * 1906-11-12 1907-03-05 Wojislav Stevanovitsch Artificial slate for writing or drawing
DE356889C (en) * 1921-03-30 1922-08-04 Jacob Kranz Process for the production of an unbreakable writing board
US2303120A (en) * 1940-06-25 1942-11-24 Adelaide M Greaves Walker Glass chalkboard
FR987539A (en) * 1949-04-02 1951-08-14 Mullca Advanced writing board
FR59717E (en) * 1949-10-08 1954-07-16 Mullca Advanced writing board
DE1916397A1 (en) * 1969-03-31 1971-01-07 Schulwandtafelfabrik Walter We school board

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5116979A (en) * 1989-09-12 1992-05-26 Mitsui Toatsu Chemicals, Incorporated Dihydrocaffeic acid derivatives and pharmaceutical preparations containing same
WO2000030867A1 (en) * 1998-11-19 2000-06-02 Guardian Llodio, S.A. Process for fabricating a writing board, and writing board obtained with such process
CH699483A1 (en) * 2008-09-01 2010-03-15 Troesch Glas Ag Re-writable ferromagnetic device e.g. writing board marking device, for presentation and teaching purpose in e.g. school, has front glass plate whose thickness is made to be small such that attractive force stays at active surface
CN105159024A (en) * 2014-06-03 2015-12-16 波利视觉股份有限公司 Projection and communication board and method for manufacturing it

Also Published As

Publication number Publication date
DE3068483D1 (en) 1984-08-16
ATE8359T1 (en) 1984-07-15
EP0033352B1 (en) 1984-07-11

Similar Documents

Publication Publication Date Title
EP0033352B1 (en) Writing board, in particular large wallboard
DE1291661B (en) Process for the production of a laminated body panel with a fine wood imitation surface
EP0545390A1 (en) Board with postforming edge
DE1247251B (en) Draw sheet for drawn parts
CH636153A5 (en) MULTI-LAYER COMPOSITE PANEL.
EP0109565A2 (en) Board for teaching purposes
DE7809167U1 (en) FURNITURE, IN PARTICULAR KITCHEN FURNITURE, WITH PANELING
DE19742825B4 (en) Method for applying a ruling and panel with a ruling
DE676596C (en) Coasters for furniture and stove feet
DE60104239T2 (en) Method for producing a metal imitation cover sheet for household electrical appliances
DE730749C (en) Wood fiber board
DE1772236U (en) HOLLOW GLASS PLATE.
DE3325726A1 (en) Method of producing a picture or lettering plate
DE8002541U1 (en) WRITING BOARD, PARTICULARLY LARGE-SCALE WALLBOARD
DE3922583A1 (en) FACADE ELEMENT FROM A GLASS PANEL AND A METAL PLATE
DE2712758A1 (en) Decorative panel for doors or table-tops - is made from metal foil cut into squares and coated with paint or lacquer
DE2704475A1 (en) Weatherproof decorative wall panel - has copper skin with peripheral skirt filled with foamed polyurethane mixed with metallic shavings powder or beads
DE102020122315A1 (en) Enamel product and method for producing an enamel product
DE102019128867A1 (en) Composite material comprising glass provided with a metal layer
DE2008415A1 (en) Composite crystal glass with shattered central layer
DE3021070A1 (en) ONE-PIECE GLAZING ELEMENTS WITH SEVERAL ORGANIC GLASS WINDOW DISC UNITS AND METHOD FOR THEIR PRODUCTION
DE2614190B1 (en) Process for the production of wallpaper, tiles or wall panels with a rough surface structure
DE19859547A1 (en) Composite panel and process for its manufacture
DE7426666U (en) Cladding panel with metal coating
DE102018118964A1 (en) Process for producing at least one partial ceramic print on a float glass substrate provided with a prestressable functional coating

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): AT BE CH DE FR GB IT LU NL SE

17P Request for examination filed

Effective date: 19820203

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: WEYEL KG

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

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

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

Ref country code: SE

Effective date: 19840711

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 19840711

Ref country code: FR

Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY

Effective date: 19840711

Ref country code: BE

Effective date: 19840711

REF Corresponds to:

Ref document number: 8359

Country of ref document: AT

Date of ref document: 19840715

Kind code of ref document: T

REF Corresponds to:

Ref document number: 3068483

Country of ref document: DE

Date of ref document: 19840816

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

Ref country code: AT

Effective date: 19850201

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: 19850228

Ref country code: CH

Effective date: 19850228

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
EN Fr: translation not filed
GBPC Gb: european patent ceased through non-payment of renewal fee
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: GB

Effective date: 19881118

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

Ref country code: NL

Payment date: 19890228

Year of fee payment: 10

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

Ref country code: DE

Payment date: 19890309

Year of fee payment: 10

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

Ref country code: NL

Effective date: 19900901

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19901101