Field of the invention

The present invention relates to a cavity plug for insertion into a hole of a building element to thereby at least partly fill the hole.

Background of the invention

During repair and maintenance of buildings, scaffolding allows workers to work high above the ground. Such scaffolding has to be secured by fastening it directly to the building by a number of bolts. During removal of the scaffolding, the fastening bolts will result in a plurality of holes in the outer wall.

Traditionally, these holes are filled with a sealer, e.g. silicone, from a spray gun by scaffold workers while at the same time removing the scaffolding.

In a similar manner, in-door walls are typically repaired by an in-door sealer, e.g. in the form of a putty from a tube, and generally, any kind of holes which are not desired, are filled with a partly liquid or pasty compound. The filling is typically carried out by use of a putty knife, etc.

Working with spray guns or tubes, and shaping of liquid sealers or putty is difficult and the result is often not aesthetically satisfactory. Further, colour variations in the wall may further reduce the aesthetic appearance of the wall after the holes have been filed with a sealer having a uniform colour. Further, the process of working with liquid sealer or putty from a gun or tube is time consuming and may soil the environment with sealer which is spilled. Further, working with a putty knife requires skills to provide a good result.

US 6,156,248 discloses a method and an apparatus for applying putty and filler material to fill a hole in a surface. The method is based on a template and therefore requires the use of tools, which may complicate the filling process further. The disclosure provides no improvement relative to the appearance on a wall with colour variations. Description of the invention

It is an object of embodiments of the invention to provide a cavity plug for filling holes in buildings.

It is a further object of embodiments of the invention to provide a cavity plug which seals a hole and provides a durable and aesthetic solution.

It is a further object of embodiments of the invention to provide an improved method of filling a hole in a building element by use of a cavity plug.

According to a first aspect, the invention provides a cavity plug configured for insertion into a hole of a building element, the cavity plug comprising a body extending in a longitudinal direction from a front end to a rear end, the body having a thickness being transverse to the longitudinal direction, and defining a deformable part allowing at least the rear end to be deformed by hand.

Since the cavity plug has a deformable part, it can be inserted as a piece of material and deformed afterwards. Accordingly, handling is facilitated and use of a putty knife can be avoided. Further, since the hole is filed with a plug, different plugs can be used for different holes, and colour variations in the wall can be accounted for by use of different cavity plugs with different colours.

In the context of the present invention, the term "allowed to be deformed by hand" covers materials with a viscosity which allows the material to be deformed without use of tools, e.g. smeared out over a part of the building surface in which the hole is formed, with a viscosity being sufficient to allow modelling of the cavity plug relative to the hole, and which increases bonding between the cavity plug and the hole.

The deformable part could be the entire plug or a part of the plug. The deformable part may constitute at least 50 percent by volume of the plug.

To facilitate deformation by hand, the body may be made from a material having a viscosity in the range of 1,000,000-500,000,000 centistrokes. E.g. 1-500,000,000 or 20-200,000,000, or 50-150,000,000. These intervals represent particularly advantageous viscosities providing the ability to deform the cavity plug by hand and still maintaining the shape and size of the plug until it is deformed. Further, by viscosities in these intervals, the cavity plug does not mess the surroundings or the hands of the user, i.e. by the mentioned viscosities, the cavity plug may remain coherent with an intended shape and still allow deformation by hand. Consequently, it is achieved that the cavity plug can be deformed to a shape where it is essentially flush with the building element after insertion into the hole. Any superfluous material may be removed by hand by deformation of at least the rear end of the body, and due to the stated viscosity, the removed part of the cavity plug can be handled conveniently and the shape of the plug can be maintained until the intended deformation when the plug is inserted in the hole.

The cavity plug comprises a body extending in a longitudinal direction from a front end to a rear end, where the front end forms the first part to the inserted into the hole and the rear end forms an outer part, i.e. the part of the cavity plug which can be seen on the surface of the wall when the cavity plug is inserted into the hole. The longitudinal direction thereby corresponds to the insertion direction of the cavity plug.

In one embodiment, the rear end and the front end may be substantially identical allowing for optional insertion direction of the cavity plug.

The body has a thickness which is the dimension being transverse to the longitudinal direction. In one embodiment, the thickness of the body may correspond to the diameter of the hole which should be at least partly filled by the cavity plug. It should however be understood, that the cross-sectional shape, in one embodiment, may be substantially circular whereas in another embodiments, it may be of another shape, such a square-shaped, oval, triangular, or any other shape.

The cavity plug may further have a length substantially corresponding to the depth of the hole in which the cavity plug should be inserted. The length of the body in the longitudinal direction may in one embodiment be at least twice the thickness.

Thus, in one embodiment, the thickness of the body may be in the range of 4-20 mm, such as 6-15 mm. The length may be in the range of 20-150 mm, such as 40-120 mm. It should be understood, that the thickness may be non-uniform along the length of the body.

The body may define a deformable part with a plasticity allowing at least the rear end to be deformed by hand. In one embodiment, the cavity plug may be formed in one piece of monolithic material or a material having a uniform material composition, whereby not only the rear end but the cavity plug as a whole may be deformed by hand.

To ensure that the cavity plug is kept in place in the hole, the body may have a surface tackiness, e.g. defined by an adhesion strength being in the range of 0,00001-0,1 MPa such as 0,0001-0,05 MPa, such as about 0,0001 MPa. The mentioned adhesion strength is for a comparable area of 4 square centimetres where the cavity plug forms contact with the hole. This may ensure adherence of the cavity plug to the surface forming the hole. Even though it is considered advantageous for the use of the cavity plug that it may be used directly in any kind of hole without pre-preparation of the hole, the cavity plug may be made with a shape matching a pre-preparation tool which can be used for predefining a specific shape or surface characteristic of the hole or inner surface of the hole.

The tool may e.g. be provided together with the cavity plug, and it may be used in a procedure where the tool is pressed into the hole to pre-shape the hole, and subsequently, the cavity plug is inserted into the hole and deformed by hand to match the shape of the hole and wall.

In one embodiment, the tool provides a surface shape of the inner surface of the hole which ensures mechanical bonding or sintering of the cavity plug into the inner surface of the hole.

In one embodiment, the body may comprise a first part made from a first material and a second part made from a second material.

The first and second material may have different hardness, surface tackiness, and/or different viscosity.

The second material may cover the first material and e.g. form an outer surface of the cavity plug. The second material may e.g. have a larger hardness or viscosity or a lower surface tackiness than the first material and thereby ensure that the body can remain its shape during insertion. Subsequent to the insertion, the first material, which has a lower hardness or viscosity, and/or a larger surface tackiness, may increase the ability of the cavity plug to be deformed by hand and/or the ability of the plug to adhere firmly to the hole. For this purpose, the second material may be configured to rupture or to dissolve or in other way to allow the first material to get into contact with the hole.

It should be understood, that the surface tackiness may depend on temperature and/or humidity.

To facilitate insertion of the cavity plug, the body may form a tapered section in which the thickness tapers down from a large dimension towards the rear end to a smaller dimension towards the front end. As an example, the large dimension may be 12 mm, whereas the smaller dimension may be 6 mm. It should however be understood, that other dimensions may also be applicable, e.g. dependent on the size of the hole. Thus, the small dimension may be in the range of 25-75% of the large dimension.

The tapered section may extend from the front end to the rear end. Alternatively, the tapered section may be located between the front end and the rear end without extending fully to and/or from one of the two ends.

In one embodiment, the thickness may taper linearly from the large dimension to the smaller dimension. In an alternative embodiment, the thickness may stepwise taper from the large to the smaller dimension. The steps may be uniformly or non-uniformly distributed along the length of the body. It should furthermore be understood that a single step may provide the tapering from the large to the smaller dimension.

The tapered section may form an angle of 1-20° to the longitudinal direction.

A cross-sectional shape of the cavity plug perpendicular to the longitudinal direction may in one embodiment be substantially circular. Thus, the cavity plug may be substantially rod shaped if the cavity plug does not comprise a tapered section or substantially cone-shaped if the cavity plug comprises a tapered section.

The deformable part could be plastically deformable thereby introducing a permanent deformation. Alternatively, or additionally, the deformable material may be elastically deformable by hand. Accordingly, the element may be inserted into the hole by elastic compression and subsequently, the cavity plug may provide an outwards pressure against the inner surface of the hole when it elastically seeks back towards its original shape.

The body may be made from a material having a hardness in the range of 15-75 Shore 00. This may be particularly suitable in connection with an elastically deformable cavity plug.

The body may be made from a material having an elastic modulus in the range of 500-15000 MPa, e.g. 700-144 MPa, as this will allow the cavity plug to be compressed during insertion into the hole. Subsequently, the cavity plug may regain its original shape thereby keeping the cavity plug in place in the hole.

To allow the filled holes to be open to diffusion, the body may be made from a material having a diffusion coefficient in the range of 0.4-0.7 g/m ² h.

To facilitate insertion of the cavity plug into a hole, the cavity plug may comprise a guiding tip arranged at the front end. The guiding tip may have a hardness being larger than the deformable part to protect the guiding tip during insertion and thus improve the insertion hereof.

The body may be made from a material which is configured to change hardness upon interaction with the ambient space. Thereby it may be achieved that the cavity plug is retained in the hole, as a hardened cavity plug may be difficult to remove. To protect the cavity plug from hardening before it is inserted into the hole, the cavity plug may further comprise a removable cover separating the material from the ambient space.

The cover may be formed by a water-soluble material. Consequently, it may not be necessary to remove the cover before inserting the cavity plug into the hole, as moisture in the construction may dissolve the cover and thereby remove it.

In one embodiment, the body may comprise a first section and a second section, the first section having a higher plasticity than the second section, and the first section forming the rear end. By providing the rear end of a material with a higher plasticity, it may be possible to remove superfluous material, if any, from the surface of the building if the cavity plug extends from the hole after insertion. The superfluous material may be removed by hand, e.g. by a thumb being moved across the surface above the filled hole.

At least one of the first and second sections may be made from a polymer material or a rubber material, such as a cellular rubber type.

In one embodiment, the front end and the rear end have different colours. By this embodiment, the user may find a best match between the colour of the wall and the colour of the cavity plug by turning one end or the other outwards, and one and the same cavity plug may therefore provide a good colour match on a wall having an uneven colour or a wall having more than one colour.

According to a second aspect, the invention provides a repair kit comprising a plurality of cavity plugs according to the first aspect of the invention, wherein at least two of the cavity plugs are of different colours.

By providing the cavity plugs in the repair kit of different colours it may be possible to choose the cavity plug with the colour which matches the colour of the building part in the best way.

The repair kit may further comprise cavity plugs of different size and/or shape. Further, the repair kit may comprise a holding structure by which the plurality of cavity plugs are held in an upright and parallel orientation, where the longitudinal direction of each cavity plug is parallel to the longitudinal direction of the other cavity plugs, e.g. in an array of cavity plugs or in a matrix of cavity plugs. In that way, the user may easier find the right colour by holding the cavity plugs against the wall and selecting the cavity plug making the best colour match with the wall.

The plugs may particularly be held in a holding structure made from a transparent material, e.g. glass, Polymethacrylate or acrylic glass. The transparent structure may facilitate that the wall which is to be repaired can be seen through the holding structure, and a colour match and selection of a plug based on colour can therefore be carried out without having to remove the cavity plugs from the holding structure.

It should be understood, that a skilled person would readily recognise that any feature described in combination with the first aspect of the invention could also be combined with the second aspect of the invention, and vice versa.

In a third aspect, the invention provides a repair kit comprising cavity plugs as discussed above, and a hole modelling tool which can be pressed into the hole of a wall and thereby modify at least one of the size, shape and surface of the hole such that the hole and the cavity plug match each other in shape and size.

According to a fourth aspect, the invention provides a method of filling a hole in a building element, by use of a cavity plug of the kind described above.

The method may comprise the step of inserting the front end into the hole while leaving the rear end to extend out of the hole, breaking the rear end from the front end to thereby form a section of the cavity plug, the section extending from the front end in the hole to an intermediate end outside the hole, and deforming the intermediate end to thereby terminate the section essentially flush with a surface of the building element.

The steps may take place subsequently, i.e. one step after another, or the steps may be carried out simultaneously.

It should be understood, that a skilled person would readily recognise that any feature described in combination with the first and second aspects of the invention could also be combined with the third aspect of the invention, and vice versa. The cavity plug according to the first aspect of the invention is very suitable for performing the method steps according to the fourth aspect of the invention. The remarks set forth above in relation to the cavity plug are therefore equally applicable in relation to the method.

Brief description of the drawings

Embodiments of the invention will now be further described with reference to the drawings, in which:

Figs. 1A-1C illustrate different embodiments of a cavity plug,

Figs. 2-4 illustrate a sequence of steps for insertion of a cavity plug into a hole,

Fig. 5 illustrates an embodiment of a cavity plug,

Fig. 6 illustrates an alternative embodiment of a cavity plug, and

Fig. 7 illustrates a sequence of steps for insertion of the cavity plug of Fig. 6 into a hole.

Detailed description of the drawinqs

It should be understood that the detailed description and specific examples, while indicating embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

Figs. 1A-1C illustrate different embodiments of a cavity plug 1A, IB, and 1C. The cavity plug 1A-1C is configured for insertion into a hole 2 (see Fig. 2) of a building element 3 (see Fig.

2). The cavity plug 1A-1C comprising a body 4 extending in a longitudinal direction L from a front end 5 to a rear end 6. The body 4 has a thickness T being transverse to the longitudinal direction L. The body 4 defines a deformable part with a plasticity allowing at least the rear end to be deformed by hand 7.

The cavity plug 1A illustrated in Fig. 1A comprises a tapered section from the front end 5 to the rear end 6 and is substantially cone-shaped. The cavity plug IB illustrated in Fig. IB is substantially rod-shaped, and does not comprise a tapered section. The cavity plug 1C illustrated in Fig. 1C is substantially sphere-shaped with a length L and a thickness T being substantially identical.

Figs. 2-4 illustrate a sequence of steps for insertion of a cavity plug 1 into a hole 2 of a building element 3. Fig. 2 illustrates the first step of inserting the front end (not shown) into the hole 2 in the insertion direction illustrated by the arrow I. In step 2 illustrated in Fig. 3, the hole 2 is filled with the cavity plug 1, and a part hereof extends from the hole. This superfluous material 1' is removed by a stroke by a hand 7 as illustrated in Fig. 4 illustrating step 3.

Fig. 5 illustrates an embodiment of a cavity plug 1 comprising a removable cover 8. The cover 8 may protect the cavity plug 1 before it is inserted into the hole 2. The cover 8 may serve as protection from hardening as the cavity plug 1 may harden upon interaction with the ambient space and/or may serve as protection for bonding as the surface tackiness of the cavity plug 1 may cause the cavity plug to bond at the fingers of the user. The tackiness may depend on temperature and/or humidity.

In the illustrated embodiment, the cover 8 may be separated in a front end cover 8B and a rear end cover 8A. As illustrated in the lower part of Fig. 5, the rear end cover 8A may be used as protection, while inserting the cavity plug 1 into the hole 2.

Fig. 6 illustrates an alternative embodiment of a cavity plug ID. The body 4 defines a deformable part with a plasticity allowing at least the rear end 6 to be deformed by hand. To facilitate insertion of the cavity plug ID into the hole 2 (see Fig. 7), the cavity plug ID comprises a guiding tip 9 arranged at the front end 5. The guiding tip 9 has a hardness being larger than the deformable part. It should be understood that the illustrated embodiment of the cavity plug ID is just one example. In another embodiment, the guiding tip may have a different shape, e.g. be a small cap arranged at the front end 5.

The cavity plug ID further comprises a handle 10 attached at the rear end 6. After insertion of the cavity plug ID in the hole 2, the handle 10 can be removed as illustrated in Fig. 7. The handle 10 may, after removal, be used to remove superfluous material, as illustrated in the lower part of Fig. 7.

Fig. 7 illustrates a sequence of steps for insertion of the cavity plug ID illustrated in Fig. 6 into a hole 2 of a building element 3.