The invention has reference to a plug of deformable material such as wood or plastic, for tightly sealing a cylindrical recess pro¬ vided in wood, in which recess a crushable ampulla with a wood attack combating agent can be accommodated, said ampuila being attachable in a cavity of said plug by means of spring lugs, said plug being provided with a conical drive-in surface, and at least one deformable sealing clamping means being provided on said plug.

Such a plug is generally known. In the known plug, which is usually provided with an edge, the upper side of the plug will generally not be perpendicular to the surface of the wood when the recess is being drilled and will therefore not flush with said surface. As a result extra expenses will have to be incurred for smooth burnishing as a preliminary operation before repainting. The eccentric location of the plug edge brings about a sealing that is not quite so good. In consequence of this, when applying liquid wood preservatives which are applied under pressure, the wood preservative may escape along the plug and come into contact with the paint, which may lead to discoloura¬ tion, yellowing, soaking off or peeling off of the paint. Applica¬ tion to damp wood, in particular, causes the plug to become visible when the wood is drying. The sealing may not suffice when the wood is affected even slightly. If the plug is not hingeably connected to the ampulla, the ampulla may break too soon, before sealing has taken place. The use of plugs with too large a diameter will cause the wood, especially dry wood, to split. When using sawtooth- shaped ribs or clamping means, of which the sloping surface forms an angle larger than 45 with the horizontal, the wood is deformed

and damaged, as a result of which this may serve as a guide-way for the wood preservative liquid and leakage may occur.

It is the object of the invention to remove the above-described objections and to that end the invention is characterized in that the plug, at the end facing away from the drive-in end, contains a separate clamping sealing means for engaging the inner circum¬ ference of the recess, the outer radial dimensions of the sealing means and of the plug being such that complete sealing is acquired and maintained without damaging the wood after the plug has been driven-in into the recess, even in the event of high pressure- build-up in said recess.

In several embodiments of the present device the plug can move as a kind of hinge, by which the plug always flushes with the surface of the wood without drilling, perpendicular to said wood surface, having to take place. TV/o spring, sawtooth-shaped clamping means with different diameters, of which the sloping surface forms an angle smaller than or equal to 45 with the horizontal, are applied, said spring clamping means deforming when they are driven-in into the wood, as a result of which warping of the plug is prevented. When applying a clamping jacket good sealing is obtained before the ampulla is crushed anci its contents are released. The use of a clamping jacket with or with¬ out a cap, and provided with a tapered drive-in surface, serves for a seal between the transition of two recesses with different diameters. An O-ring, which is arranged in a circumferential groove of the plug, is used for sealing in hard types of wood and for wood weakened by attack. By slightly countersinking the plug with ampulla or an impregnated plug, the finishing operation can take place by means of a round wooden disk that can follow the surface of the wood, thus preventing the plugs from becoming visible. The difference between the outer diameter of the plug and the inner diameter of one of the drilled holes is 1 mm at the most. If this difference in diameter should be larger than

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lmm, then cracks will appear in the wood and premature glass- breakage will occur when driving-in takes place. The same type of disk is applied to each type of wood, so that, especially when using transparant paint, which causes the structure of the wood to remain visible, an esthetic finish is the result.- For the cap laminated wood is preferably used. The plug may also be made of laminated wood. The O-ring, mentioned above, is preferably located at the end of the plug facing away from the drive-in end of said plug, because, after the ampulla has been crushed, the seal still has to move when driving-in has taken place, in connection with the proper crushing of the glass ampulla.

By applying the present invention a number of seals, placed one after the other, are obtained in the direction of the surface of the wood, which seals, when applying mutually different materials for plug and clamping jacket with or without a cap, bring about a permanent complete seal and maintain it without the wood around the recess being damaged. Such damage (splits, chip formation in the wall of the recess) would result in leakage of the wood attack combating agent.

It is finally remarked that the applied synthetic material may be . reinforced with glass in order to avoid stripping-up of the outer wall of the clamping jacket. At the open end of the drilled hole the inner wall of the drilled hole may be provided with a layer of primer or the like before the plug is driven-in, through which a gas tight high pressure seal is obtained, in particular. Further¬ more, the outer diameter of the wooden plug should be equal to the outer diameter of the drive-in end of a cap which, at that end, has an outer diameter which is smaller than that of the opposite end of the cap.

The invention will be elucidated further with the aid of the drawing.

Figures 1 through 9 each show half an axial section and a semi-view of the various embodiments according to the invention.

Figure 10 shows half an axial section and a semi-view of a plug that is provided with lugs for attaching an ampulla in the cavity of the plug.

Figure 11 shows a cross section of the plug of figure 10, viewed along the arrows XI - XI.

The plug 1 according to figure 1 contains a plurality of sawtooth- shaped clamping means 2 having various radial dimensions, a gui¬ ding edge 3 being provided at one side of said clamping means and an O-ring 5 being provided in a circumferential groove 5 at the other side. At the end facing away from the drive-in end the plug is provided with a central pin 6 which has a bevelled edge 7 at its end. The pin 6 fits in a cavity 8 of a cylindrical wooden disk 9 which, on account of its bevel, can pivot around the pin 6 so that, when the drilled recess 10 in the wood is not perpendicu¬ lar to the surface of the wood, the disk is able to adjust it¬ self to a slight degree so that it flushes with the surface of the wood. The plug is furthermore provided with a cavity 11 for accommodating and attaching an ampulla by means of spring lugs 13 (vide figure 11) .

In figure 2 the recess 10 has a broadened portion 12 in which the girder of the T-shaped axial section of the plug 1 is accommodated. A cylindrical disk 14 makes provision for the end sealing of the the recess and is also accommodated in the broadened portion. The plug may be made of wood or synthetic material. The cylindrical disk is preferably made of structure wood.

Figure 3 shows a plug which is made of wood and which contains a circumferential groove 5 for accommodating an O-ring 4. The

sealing means 15, embodied in the wooden disk, form the end sealing of which structure, colour and the like are adapted to that of the surface of the wood.

In figure 4 the plug 1 also has a T-shaped axial section. In the broadened portion 12 a clamping jacket 16 is provided which has a tapered inner wall portion 17 at the inner circumference of its drive-in end in order to form a space that is filled with wood when the clamping jacket is driven-in, after which the plug 1 is driven-in. The clamping jacket engages an O-ring accommodated in a circumferential groove 5.

Figure 5 shows a plug that is provided with a cap 18 and a clamping jacket 19 forming part of said cap, on which clamping jacket a plurality of sawtooth-shaped clamping means 2 are pro¬ vided. The clamping jacket 19 is provided with a tapered drive- in end 20 and is located in the broadened portion 12 of the recess 10. The plug has a bevel at the end for accommodating the cap, so that the cap can hinge with respect to the plug.

In the plug 1 of figure 6 a sawtooth-shaped clamping means 2 is provided on the clamping jacket 21 of the cap 18, aswell as an adja bevelled cylindrical collar 22. The clamping jacket 21 is pro- * vided with a drive-in end 23. On the drive-in end of the plug a circumferential groove 24 is provided in which an O-ring is loca¬ ted. At the accommodating end of the cap the plug contains a bevel for hingeably accommodating the cap 18.

At the drive-in end the plug 1 of figure 7 contains a plurality of sawtooth-shaped clamping means 2, limited by guiding surfaces 32 and 33. The plug, at its accommodating end for the hingeable cap 18, has a bevel.

The plug 1 according to figure 8 has a T-shaped axial section,

the clamping jacket 26 being accommodated in a broadened portion Ξ7 of the recess 10. The inner side of the clamping jacket en¬ gages an O-ring 28 provided in a circumferential groove of the plug.

The plug 1 illustrated in figure 9 has a substantially rectangu¬ lar axial section, the clamping jacket 30 being accommodated in the broadened portion 29 of the recess 10, the inner side of said clamping jacket engaging an O-ring 31 provided in a circumferentia groove of the plug, both the clamping jacket and the plug exten¬ ding until below the surface of the wood. The space above the plug is filled with a sealing material until the surface of the wood.

It would be preferable to provide resilient (13, figure 11) lugs in the embodiment described above, said lugs extending from the inner wall of the cavity for attachment of the ampulla (not shown) into said cavity and in its longitudinal direction (vide figures 10 and 11) .

The sloping surfaces on the sawtooth-shaped βlamping means form an angle, which is smaller than or equal to 45 , with the horizontal

The taper of the drive-in end of a clamping means, for instance as shown in figure 5, no. 20, lies between 90 - 96 with respect to a surface perpendicular to the central axis of the plug. As synthetic material for the clamping jacket and the cap PVC or ABS is used. These materials are well-suited for repainting and they swell when they come into contact with organic and inorganic liquids.