EP0109542B1 - Wall clock or free standing clock - Google Patents

Abstract

1. A wall clock or standing clock having a clock movement arranged at the one side of a solid slice of a tree cut approximately perpendicular to the longitudinal axis of a tree trunk (10) and held by the tree slice, and a display device arranged on the other side, in particular hands (20, 21) which run directly on the cut surface forming the front side (13) of the clock, characterized in that the tree slice (12) is cut from a tree trunk of any desired tree ; and in that all the surfaces of the tree slice are sealed by a water impermeable paint, preferably by a twocomponent paint.

Description

The present invention relates to a wall or grandfather clock with a solid tree disc arranged on one side of a tree trunk cut approximately perpendicular to the longitudinal axis of a tree trunk and held by it, and a display device, in particular pointers, arranged on the other side, which point directly at the front the cutting surface forming the clock.

Conventional watch cases made of solid wood consist of several individual parts that have to be manufactured and assembled in sections. Otherwise, the outward-facing surfaces are usually finely ground and polished; accordingly, such housings are expensive to manufacture, but they are not particularly robust.

A wall clock of the type mentioned is known from DE-U 1 942081. However, it has been found that most conventional types of wood develop a pronounced crack, which is so strong that the tree grates are no longer suitable for the intended purpose. The aim of the present invention is to provide an economically producible, particularly flat, but possibly large-diameter watch of the type mentioned at the outset, which is robust and insensitive to impact and less susceptible to falling apart under rough treatment or due to aging simple structure the risk of annoying cracking should be avoided.

To achieve the above object, it is now provided according to the invention that the tree disk is cut out of a tree trunk of any tree and that all surfaces of the plate are sealed by a water-impermeable lacquer.

This lacquer sealing, which is preferably brought about by pressure impregnation, effectively prevents the board or the wooden disc from drying out and thus also the risk of cracking. In this way, all tree species can be used for the purpose according to the invention.

A continuous impregnation of solid wooden parts for use in a wristwatch case is proposed in FR-A-2103398, but not alone, but in connection with a special pressure treatment that compresses the wood and the wood that has penetrated into it, a substantial one The tensile strength is increased to 2100-3500 kg / cm ² compared to 1324 kg / cm ² for the untreated wood.

The housing of the FR-A 2103398 also consists of a block of wood that was created by cutting in the longitudinal direction of a tree trunk, which is known to minimize the risk of cracking, especially in the case of very small wooden blocks, such as those in FR-A 2103398 Find application. Due to the smaller dimensions of the wooden blocks, the wood is also completely saturated with the resin, so that in the end you are not dealing with pure wood, but with a special composite.

An alternative solution to the stated problem is that the tree disk is cut out of a rootstock, the two cutting surfaces which are essentially parallel to one another and can also run obliquely to the longitudinal axis of the tree trunk. This solution is based on the surprising discovery that, even in the case of wood types in which slices cut from the tree trunk lead to very severe crack formation, slices cut from the rhizome show no such crack formation.

As a further solution, it has also been found that tree slices from a tree trunk of the yew, plum, cherry or rüster tree type do not lead to any crack formation if the tree has died while standing in the rüster tree category.

Under the conditions specified above, only two parallel cuts are used to create wooden disks that are robust and insensitive to impact and cracking. In addition, the risk of the watch slipping is significantly reduced since the rough side surfaces of the wooden disks make it much easier to handle them safely.

The thickness of the wooden disc is preferably between 3 and 12 cm, preferably between 5 and 10 cm and in particular approximately 7 cm. This creates a fairly flat structure, especially for wall clocks, even with a larger diameter.

The clock positions are preferably formed by nails, in particular in each case by a forged nail.

The cut surface that forms the face of the watch is preferably machined by a planer or grinding process and can then be treated with a stain or clear varnish to emphasize the normally circular grain that simplifies reading the time. The natural bark of the tree trunk or the root stokke preferably forms the side walls of the plate, especially for clocks that are not set up or hung outdoors. The bark forms a rough surface that prevents the watch from slipping.

The clocks according to the invention are not only intended for use with clockworks with hands, they can also be equipped with digital displays. For this purpose, the cut surface forming the dial is designed to accommodate a digital display.

Since the clocks according to the invention are particularly suitable for wall clocks, they should accordingly have a device for hanging up. This device is preferably provided through a hole in the cut surface forming the back of the watch.

The wood used can possibly be subjected to a ripening process before cutting, but this is not absolutely necessary, not even for the rhizomes. The wooden disks preferably have essentially closed annual rings, which serves for stability or for reading the time.

Finally, it must be mentioned that so-called bog pines, i.e. Pine trees that have stood in a bog for centuries are particularly suitable for the purpose according to the invention.

• Fig. 1 eine perspektive Darstellung eines Baumstammes,
• Fig. 2 die Vorderseite eines Uhrgehäuses, das aus dem Baumstamm der Fig. 1 geschnitten wird,
• Fig. 3 die Rückseite des Uhrgehäuses nach Fig. 2,
• Fig. 4 eine perspektive Darstellung eines Wurzelstockes, und
• Fig. 5 ein aus dem Wurzelstock der Fig. 4 geschnittenes Uhrgehäuse.

The invention is explained in more detail below with reference to the two exemplary embodiments illustrated in the accompanying drawings. The drawing shows:

• 1 is a perspective view of a tree trunk,
• 2 the front of a watch case, which is cut from the tree trunk of FIG. 1,
• 3 shows the back of the watch case according to FIG. 2,
• Fig. 4 is a perspective view of a rhizome, and
• Fig. 5 a cut from the rhizome of Fig. 4 watch case.

1 shows a section from the trunk 10 of a tree of the genus yew, which has a longitudinal axis 11. The trunk is suitable for being cut into individual slices or pieces 12 without any annoying crack formation. The individual wooden disks 12 are formed by two substantially parallel cuts through the trunk of the tree and perpendicular to the longitudinal axis 11. The individual disks are shown in Fig. 2 as a plate for carrying a clockwork 17, i.e. used as a watch case, one cut surface 13 forming the front and the second cut surface 14 forming the back of the plate. A substantially rectangular recess 15 for receiving a clockwork 17 provided with battery drive 16 is milled into the rear side 14 of the plate. The clockwork 17 is held in the recess by means of screws or pins 18. An axis 19, which can only be seen in FIG. 2, projects through an essentially centrally arranged bore and carries the usual clock and minute hands 20, 21 on the front of the plate. The individual digits are marked by hammered-in forged nails 22. As can be seen from FIG. 2, the dial is formed directly by the cut surface 13, the grain 22 being able to be highlighted by planing, grinding, polishing, staining or by means of clear lacquer, etc. The side walls of the plate preferably have the natural bark 24 of the wooden disc, which facilitates the safe handling of the watch. In the back 14 of the plate, a device for hanging it in the form of a hole or a blind bore 25 is introduced.

Fig. 4 shows the rootstock of any tree, which is preferably the rootstock of a pine, fir or spruce. It has surprisingly been found that no disruptive crack formation is to be feared in the case of wooden disks cut from the rootstock, regardless of the direction of the cutting lines. Fig. 2 shows two different cutting directions that can be easily used to produce suitable plates. 4 shows the two parallel cuts 26, 27 which are inclined to the longitudinal axis 11 of the tree. The rhizome is broken down into wooden disks by further parallel cuts, whereby all resulting wooden disks can be used for watch cases. However, the cutting direction is not limited to this example; in principle, all cutting directions are possible, including parallel cuts perpendicular to the longitudinal axis 11 as shown by the dashed lines 28, 29.

Fig. 5 shows a schematic representation of a wooden disc as it is formed by the two parallel cuts 26, 27 through the rhizome of Fig. 4. This wooden disc is in turn suitable for the production of a clock and must of course be further processed in accordance with FIGS. 2 and 3. A central arrangement of the clockwork is not necessary, the position of the clockwork can be freely selected depending on the wooden disc. The fact that a number of different housings can be cut from a rootstock is very advantageous when using a rootstock. The individual housings therefore have a certain peculiarity. A further possibility with the hollow disk according to FIG. 5 is to insert a feed cable for an electrical clockwork through one of the root branches into the recess provided for the clockwork. This possibility is shown at 30.

If you use a type of wood for the watch case that has a strong tendency to crack, e.g. Pine, the wooden disc can be sealed with a waterproof varnish, whereby a pressure impregnation process is preferred. This prevents the wood from drying out and thus the associated tendency to crack.

According to the invention, the pressure impregnation takes place as explained below in a chamber which consists of two essentially identical parts, which can be two hemispheres or two cylinders closed on one side, which can be attached to one another in a mirror-image and sealed manner. First, the lower part of the chamber is filled with about a quarter of its volume with a two-component clear lacquer, while the wooden disc to be treated is held in the upper part of the chamber, the disc not being immersed in the lacquer. The chamber is then evacuated using a vacuum pump. The vacuum is then maintained for about 2 to 5 minutes. The disc is then immersed in the paint bath, which is indicated by the top Chamber part is possible without having to separate it from the lower chamber part. Compressed air is then introduced into the chamber, the paint penetrating into the wooden disc and sealing it in the required manner. After about 5 minutes after introducing the compressed air, the wooden disc can be removed from the chamber and put down to dry or harden.

Claims (8)

1. A wall clock or standing clock having a clock movement arranged at the one side of a solid slice of a tree cut approximately perpendicular to the longitudinal axis of a tree trunk (10) and held by the tree slice, and a display device arranged on the other side, in particular hands (20, 21) which run directly on the cut surface forming the front side (13) of the clock, characterized in that the tree slice (12) is cut from a tree trunk of any desired tree; and in that all the surfaces of the tree slice are sealed by a water impermeable paint, preferably by a twocomponent paint.

2. A wall clock or standing clock in accordance with claim 1, characterized in that the paint sealing is effected by pressure impregnation.

3. A wall clock or standing clock having a clock movement arranged at the one side of a solid slice of a tree cut approximately perpendicular to the longitudinal axis of a tree trunk (10) and held by the tree slice, and a display device arranged on the other side, in particular hands (20, 21) which run directly on the cut surface forming the front side (13) of the dock, characterized in that the tree slice is cut from a rootstock, with the two substantially parallel cut surfaces also being permitted to extend obliquely to the longitudinal axis (11) of the tree trunk.

4. A wall clock or standing clock having a clock movement arranged at the one side of a solid slice of a tree cut approximately perpendicular to the longitudinal axis of a tree trunk (10) and held by the tree slice, and a display device arranged on the other side, in particular hands (20, 21) which run directly on the cut surface forming the front side (13) of the clock, characterized in that the tree slice (12) is cut from the trunk of a tree of the species yew, damson, cherry or elm, providing that in the case of the tree species elm the tree died whilst standing.

5. A wall clock or standing clock in accordance with one of the preceding claims, characterized in that the thickness of the wood slice (12) lies between 3 cm and 12 cm, preferably between 5 cm and 10cm, and is in particular approximately 7 cm.

6. A wall clock or standing clock in accordance with one of the preceding claims, characterized in that the cut surface (13) forming the dial is machined by a planing and/or sanding process.

7. A wall clock or standing clock in accordance with one of the preceding claims, characterized in that the positions of the numbers are formed by nails (22), in particular in each case by a forged nail; and in that the side walls of the clock have the natural bark.

8. A wall clock or standing clock in accordance with one of the preceding claims, characterized in that the tree trunk or rootstock has been subjected to a seasoning process prior to the cutting.

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