Patent Description:
In construction work there often arises a need to fasten relatively soft covering layers to relatively hard structures. Fastening insulation boards to a concrete wall is an example of such need. Usually fasteners based on various screws or nails are used, the screws and nails being screwed or hammered into the receiving structure either directly or via a wall plug. The fasteners usually comprise a relatively large end flange for maximizing the area contacting the relatively soft covering layer.

However, the receiving structures and covering layers are not always completely flat. Therefore a sufficiently deep hole must often be bored into the receiving structure for allowing height adjustment of the screw, which requires additional work. However, adjustable fasteners are known in prior art. One such fastener is described in publication <CIT>. The known adjustable fasteners often require using a fairly large sleeve and adjustment shims. This increases the challenges on logistics, when products are stored and transported before and after selling.

<CIT> discloses a fastener for fastening insulation panels to roofs. The fastener has a screw extending through a flanged sleeve, the depth of which is adjusted through rotation by a separate tool, such as a hex key, after fastening the screw to the roof.

Because of this it would be advantageous to provide a fastener with reliable grip on the receiving structure and that is relatively freely adjustable, or at least a useful alternative to known fasteners. It would be especially advantageous to provide an adjustable fastener with efficient use of space as far as logistics is concerned.

The present invention provides a fastening kit with a fastener, according to claim <NUM>, the kit comprising also a tool comprising a shaft and a bit. The fastener comprises a sleeve and a screw for fastening a covering layer to a receiving structure. A channel having a first section, which has a non-circular, i.e. non-rotationally symmetrical, cross-section, and a second section extends through the elongated body of the sleeve. The body which extends between a tip and an end flange, wherein the diameter of the end flange is larger than the diameter of the body. The screw comprises a threaded shank that can be arranged into the first and second section of the channel, and a head arranged at the end of the shank and that can be slidably arranged into the first section of the channel. There is a thread fit between the shank of the screw and the second portion of the sleeve. The shaft of the tool comprises a non-circular, i.e. non-rotationally symmetrical cross-section shape, corresponding with the corresponding cross-section form of the first section of the channel of the sleeve, whereby the shaft can be arranged into the first section of the channel slidably in axial direction and form-lockingly in rotational direction. The bit of the tool is arranged to at the end of the shaft to connect with the head of the screw for rotating the screw into the receiving structure. The relative position of the sleeve and the screw is axially adjustable by rotating the sleeve in relation to the screw by means of the shaft of the tool, when the bit of the tool is not in contact with the head of the screw.

The invention also relates to a method of fastening the covering layer to a receiving structure, according to claim <NUM>. In the method, the covering layer is placed onto the receiving structure and the said fastening kit is utilized by connecting the bit of the torque tool to the head of the screw and rotating the screw through the covering layer into the receiving structure. The end flange or washer of the sleeve is adjusted to contact the covering layer by pulling the bit of the torque tool off from the head of the screw and by rotating the sleeve in relation to the screw by means the shaft of the torque tool.

The invention is characterized by the independent claims.

The numerous embodiments of the novel solutions can comprise one or more features from the following list:.

Considerable advantages are achieved by means of the invention. The novel fastener construction enables adjustment of the fastener so that the covering layer to be installed is positioned tightly against the receiving structure. This is made possible by the adjustment of the axial position between the sleeve and the screw.

On the other hand, the construction allows using a separate cover plate. In the case of a separate cover plate the size of the area contacting the covering layer can on one hand be maximized, and on the other hand the size of a disassembled fastener in a package can be minimized, which reduces the pressure on logistics. Compared with conventional fasteners having a large end flange their packability on a pallet is much better than that of prior art. On the other hand, the construction allows efficient modularity by making it possible to provide a large range of fasteners designed for covering layers of different sizes by varying the length of the sleeve, whereby the screw and the possible separate cover plate can be standardized. This further improves the storage and transport efficiency of the fastener, as contractors are required e.g. to keep only one size of screws and washers in their inventory in addition to different sizes of sleeves. The advantage is especially obvious in situations where the contractor maintains their inventory in e.g. a drawer storage installed in the load compartment of a van, as these are usually quite small.

In the following, some embodiments of the invention are disclosed in more detail by means of reference to the appended drawings, in which:.

In this context the terms "circular in cross-section" and "rotationally symmetrical in cross-section" are synonymous with each other.

<FIG> show a first fastening kit according to the first embodiment for fastening the covering layer <NUM> to the receiving structure <NUM>. The covering layer <NUM> can be, for example, an insulation or acoustic board fastened to the wall. The insulation board can be e.g. a sheet pressed into a board from mineral or glass wool or styrofoam polyurethane. Usually the insulation boards to be fastened are <NUM> or less in thickness, such as <NUM>. More generally the fastening kit is designed to fasten slab-like or layered slab-like pieces to vertical surfaces. In the embodiment of <FIG> the fastening kit comprises a fastener <NUM> and a torque tool <NUM>. The fastener <NUM> comprises a sleeve <NUM> and a screw <NUM>. <FIG> show a first fastening kit according to the second embodiment for fastening the covering layer <NUM> to the receiving structure <NUM>. In this embodiment the fastener <NUM> also comprises a washer <NUM>.

<FIG> and <FIG> show the fastener <NUM> according to the first embodiment and <FIG> shows the two phases of installing the fastener <NUM>. In the first embodiment the fastener <NUM> comprises two main components, the sleeve <NUM> and the screw <NUM>, designed to cooperate with the sleeve <NUM>. As can be seen, the shank <NUM> of the screw <NUM> provided with an external thread extends between the tip <NUM> and the head <NUM>. The length of the shank <NUM> can be in the range of <NUM> to <NUM>, e.g. <NUM>, in measurement. The tip <NUM> arranged to the first end of the screw <NUM> can be sharp and cutting, as shown, whereby it is suitable for being screwed into, for example, a wooden wall, vertical stud, or a wall plug. Alternatively, the screw <NUM> can be a machine screw with a blunt tip. Preferably the thread portion continues along the whole length of the shank <NUM> from the head <NUM> to the tip <NUM>. The end of the head <NUM> arranged at one end of the screw <NUM> is provided with a slot <NUM> connecting with the tool, the slot being a Torx slot in the example of <FIG>. Other tool slots, such as Phillips, Allen and the like are also possible.

The sleeve <NUM> can be made of injection moulded or 3D-printed polymer, for example, or other suitable formable material, such as metal or composite. The sleeve <NUM> comprises an elongated body <NUM> extending between the tip <NUM> and the end flange <NUM>. The outer diameter of the tip <NUM> arranged at the first end of the body <NUM> is narrower than the rest of the body <NUM> for making it easier to install the sleeve <NUM> through the insulation layer. In the example of <FIG> the end of the tip <NUM> is chamfered for providing a narrower outer diameter, but a tip <NUM> rounded or throughout narrower than the rest of the body <NUM> could be used. On the other hand, the end flange <NUM> arranged at the other end of the body <NUM> has a radially extending shape, with a larger outer diameter than the body <NUM> to prevent the sleeve <NUM> from penetrating the insulation layer.

A channel <NUM> runs through the body <NUM>, the channel having a wide first section 13a and a narrow second section 13b. The first section 13a of the channel <NUM> can also be called the wide section and the second section 13b can be called the narrower section. In more detail, the inner diameter d13a of the first section 13a is larger than the diameter d13b of the second diameter. In other words, the dimensions d13a and d13b are the inner diameters of the sleeve <NUM>. The purpose of the first section 13a is to allow axial movement of the screw <NUM> inside the channel <NUM>, whereas the purpose of the second section 13b is to allow the movement of the shank <NUM> of the screw <NUM> but to prevent the movement of the head <NUM> of the screw <NUM> through the tip <NUM> of the sleeve <NUM>. In this context the term axial dimension refers to the dimension in which the channel <NUM> of the sleeve <NUM> extends, i.e. its longitudinal axis. Thus the axial movement of the screw <NUM> takes place in the direction of the longitudinal axis of the body <NUM> of the sleeve <NUM>. Thus the narrow section 13b of the channel <NUM> is in the area of the tip <NUM> and the wide section 13a in other areas of the body <NUM>, especially in the area of the end flange <NUM>. The diameter d13a of the wide section transforms preferably abruptly into the diameter d13b of the narrow section for forming a shoulder into the channel <NUM>, the shoulder functioning as the bottom for the head <NUM> of the screw <NUM>. In the example of <FIG> the shoulder is straight.

The cross-sectional shape of the channel <NUM> varies along the longitudinal axis. The first section 13a of the channel <NUM> is non-rotationally symmetrical, i.e. non-circular, in cross-section. In this context, the cross-section is seen as a cross-section in relation to the axial dimension. For example, the cross-section of the channel can be hexagonal, which is a common form used in torque tools. Alternative cross-section forms include e.g. other polygons and oval. According to the embodiment shown in the figures the second section 13b of the channel <NUM> is circular for facilitating the penetration of the shank <NUM> of the screw <NUM>. Preferably there is a screw fit between the second section 13b and the shank <NUM> of the screw <NUM>. The screw fit can be arranged so that as the screw <NUM> penetrates the second portion 13b, it cuts a thread into the second section 13b of the channel <NUM> of the sleeve <NUM>. The cutting of the thread can be carried out during assembly by means of, for example, an industrial robot. Alternatively, a female thread can be prefabricated into the second portion 13b. The second portion 13b can alternatively be provided with a thread adapter having a female thread (not shown in the figures) receiving the male thread of the shank <NUM> of the screw <NUM>. The described thread adapter can be produced as a mould insert, whereby it can be made of a material different from that of the body <NUM>.

The head <NUM> of the screw <NUM> is remarkably narrow. The head <NUM> has a diameter that is preferably only marginally larger than the diameter of the shank <NUM>. The diameter of the head <NUM> can also be as big as the diameter of the shank <NUM>. The diameter of the shank <NUM> is taken from the tip of the thread, i.e. it represents the largest diameter of the thread section. The screw <NUM> is dimensioned so in relation to the sleeve <NUM> that the screw <NUM> can be driven through the sleeve <NUM>. In other words, the diameters of the shank <NUM> and the head <NUM> of the screw <NUM> are smaller than the diameter D13b of the wide portion 13b of the channel <NUM> of the sleeve <NUM>, which allows axial movement of the screw <NUM> in the channel <NUM>. On the other hand, the screw <NUM> and the sleeve <NUM> are dimensioned so that the screw <NUM> is not allowed to escape from the tip <NUM> of the sleeve <NUM>. In other words, the diameter of the shank <NUM> of the screw <NUM> is dimensioned so as to be a thread fit in relation to the narrow section 13b of the channel <NUM> of the sleeve <NUM>.

In this context rotation refers to a rotation movement around an axis, wherein a rotation of over <NUM> degrees is allowed.

The fastener according to <FIG> and <FIG> can be installed as shown in <FIG> shows a torque tool <NUM> for rotating the screw <NUM> to into the receiving structure <NUM>. In this context, the term "tool" can also be used to indicate a torque tool. In the example shown in the FIGURE the tool <NUM> is a manual screwdriver, but power tools can also be used. The shaft <NUM> of the tool <NUM> is elongated and dimensioned to pass through even a thick covering layer <NUM>. For example, fastening a covering layer <NUM> with a thickness of <NUM> into the receiving structure <NUM> requires a tool <NUM> with a shaft <NUM> of at least <NUM> in length. The diameter of the shaft <NUM> and bit <NUM> of the tool <NUM> is selected so that the screwdriver <NUM> can slide in the channel <NUM> of the sleeve <NUM>. The cross-sectional shape of the shaft <NUM> corresponds with the cross-sectional shape of the first section 13a of the channel <NUM>. In other words, it is non-circular, such as hexagonal. The purpose of the shapes of the shaft <NUM> and the channel <NUM> is to provide a co-functionality, wherein the first section 13a and the shaft <NUM> are mutually axially slidable and form-fitting in rotational direction.

One end of the shaft <NUM> includes a bit <NUM> arranged to connect with a slot in the head <NUM> of the screw <NUM>. In the shown example the bit <NUM> is a Torx head. A drive is provided at the opposite end of the shank for connecting the tool <NUM> to a driver or a handle for manual rotation (not shown in the drawings). The shaft <NUM> is a non-rotationally symmetrical, non-circular, such as hexagonal, star-like or other male shape that can connect with the corresponding female non-rotationally symmetrical shape in the first section 13a of the channel <NUM>. Thus the screwdriver <NUM> can be used for rotating the screw <NUM> by connecting with the slot <NUM> in the head <NUM> thereof, and the sleeve <NUM> can, on the other hand, be rotated by connecting to the internal mating surface of the first section 13a, which will be described in more detail hereinafter.

The fastener <NUM> is simple to use. In the beginning the covering layer <NUM> is positioned over the receiving structure <NUM> and a pilot hole <NUM> is produced into the receiving structure <NUM> by means of a drilling tool (not shown in the drawings). The pilot hole can be, for example, <NUM> thick and <NUM> long. The drilling tool is selected according to the thickness of the covering layer <NUM> so that a drilling tool with a length of at least <NUM> is selected for installing a covering layer <NUM> with a thickness of e.g. <NUM>. During the drilling operation the drill bit penetrates the outer surface <NUM> of the shell cover <NUM> and the covering layer and works a pilot hole <NUM> into the concrete, the depth of the hole being limited by a shoulder at the end of the drill bit. When the pilot hole <NUM> is ready, the fastener <NUM> is positioned into the shell cover <NUM> pushing it in through the pilot hole. Thereby the fastener <NUM> can be preassembled so that the screw <NUM> is already in the sleeve <NUM>.

When the sleeve <NUM> is pushed in, the screw <NUM> is screwed into the pilot hole <NUM> by means of a screwdriver <NUM> that can be rotated manually or by means of a power drill or a mains- or battery-operated power screwdriver (<FIG>, right fastener, rotation arrow). When the screw <NUM> is being rotated by means of the tool <NUM>, the sleeve <NUM> rotates as well, because there is a sliding form fit between the shaft <NUM> of the tool <NUM> and the first portion 13a of the channel <NUM> of the sleeve <NUM>. As the pilot hole <NUM> has been drilled to the specified dimension, the installer will feel through the driver when the screw <NUM> hits the bottom of the pilot hole <NUM>. Thus the screw <NUM> is deep enough in the receiving structure for providing a sufficient attachment. When the above-described shell cover <NUM> is installed in concrete, the screw <NUM> can be, for example, <NUM>,<NUM> x <NUM> concrete screw with T-<NUM> cross slot.

When the screw <NUM> has been rotated to the pilot hole <NUM>, the installer will check whether the fastener <NUM> is at the bottom, i.e. whether the end flange <NUM> of the sleeve <NUM> is in contact with the outer surface <NUM> of the shell cover <NUM>. If not (right-hand fastener in <FIG>), the fastener <NUM> must be adjusted to close the gap between the end flange <NUM> and the outer surface <NUM> of the shell cover <NUM>. The adjustment is started by lifting the tool <NUM> in the axial direction indicated by the upwards pointing arrow for detaching the bit <NUM> of the tool <NUM> from the head <NUM> of the screw <NUM>, whereby the rotation movement of the tool <NUM> is transmitted to the sleeve <NUM> only (<FIG>, right fastener, arrow upwards). When the sleeve <NUM> is rotated about its longitudinal axis, the thread fit between the second portion 13b of the channel <NUM> of the sleeve <NUM> and the shank <NUM> of the screw <NUM> transports the sleeve <NUM> towards the receiving structure <NUM> while the screw <NUM> stays in place (<FIG>, left fastener, rotation arrow). The screw <NUM> does not move, because the friction between the screw <NUM> and the receiving structure <NUM>, such as concrete, is larger than the friction between the screw <NUM> and the sleeve <NUM>. The sleeve is rotated in relation to the screw <NUM> until the sleeve <NUM> has moved so far in axial direction towards the receiving structure <NUM> that the end flange <NUM> of the sleeve <NUM> contacts the outer surface <NUM> of the shell cover <NUM>.

If a screw provided with a drill tip is fastened to, for example, a wood wall or vertical studs, it is not necessary to produce the pilot hole. The screw can be rotated straight to its place into the receiving structure. In this case it depends on the material of the shell cover whether it is necessary or optional to produce a pilot hole into the shell cover prior to installing the fastener.

<FIG> show an alternative different from the embodiments of <FIG> for arranging the fastener <NUM>. In the embodiment of <FIG> the sleeve <NUM> is otherwise similar to the embodiment in <FIG>, with the difference that in the embodiment of <FIG> the end flange <NUM> is relatively narrow. In the alternative embodiment shown in <FIG> the fastener <NUM> comprises a washer <NUM>, separate from the body <NUM>, located between the end flange <NUM> and the covering layer <NUM> when installed. Preferably the washer <NUM> is a piece made of a flexible material, such as plastic, especially polypropene, the purpose of which is to maximize the area by which the fastener <NUM> is pressed against the covering layer <NUM>. More specifically, the outer ring <NUM> of the washer <NUM> is supported by the covering layer <NUM> on an area larger than the area by which the end flange <NUM> of the sleeve <NUM> is supported by the inner ring <NUM> of the washer <NUM>. The area covered by the washer <NUM> is preferably at least <NUM>% larger than the area covered by the end flange.

The washer <NUM> can be produced, for example, by means of injection moulding or other additive manufacturing method. The washer <NUM> can be generally flat and circular in shape as shown in <FIG>. The washer <NUM> comprises an outer ring <NUM> that can be circular in shape or of almost any form in shape, such as an oval or a polygon. In the middle of the washer is an opening <NUM> limited by the inner edge of the inner ring <NUM>. The purpose of the opening <NUM> is to accept the body <NUM> of the sleeve <NUM>, whereby its shape and size are arranged to correspond with the shape and size of the body <NUM> of the sleeve <NUM>. Preferably the inner ring <NUM> is concentric with the outer ring <NUM> so that the washer <NUM> exerts an even pressure against the covering layer <NUM>. Preferably the inner ring <NUM> comprises an indentation around the opening <NUM>. The indentation is arranged to receive the end flange <NUM> of the sleeve <NUM>. In the embodiments shown in <FIG> the inner and outer ring <NUM>, <NUM> are arranged to be circular with an empty gap between them. The inner and outer ring <NUM>, <NUM> are connected by means of an isthmus part <NUM> comprising a number of parts, e.g. five, extending radially between the inner and outer ring <NUM>, <NUM>. Even though in this illustrative example the isthmus part <NUM> forms openings between the inner and outer ring <NUM>, <NUM>, it would also be possible to provide a closed isthmus part <NUM> or an isthmus part of a different shape, such as an isthmus part <NUM> having spiral or curved connecting parts (not shown in the drawings). The isthmus part can also comprise a smaller or larger number of parts connecting the inner and outer ring <NUM>, <NUM>.

<FIG> also show that the washer <NUM> is not completely planar. The outer ring <NUM> of the washer <NUM> is offset from the inner ring <NUM> in axial direction, i.e. in the direction in which the washer <NUM> is arranged to receive the sleeve <NUM>. When installed, the outer ring <NUM> is positioned to face the covering layer <NUM> so that the inner ring <NUM> is not in contact with the covering layer <NUM>. When the sleeve <NUM> is tightened to its place, the washer <NUM> can be compressed to a degree or fully, whereby the inner ring <NUM> is closer to the surface <NUM> of the covering layer <NUM> or in contact with it.

The installation of the fastener <NUM> according to the embodiment shown in <FIG> is similar to the installation of the fastener <NUM> according to the embodiment shown in <FIG> as far as fastening the screw <NUM> to the receiving structure <NUM> and adjusting the sleeve <NUM> to the correct distance from the receiving structure <NUM> is concerned. In addition, in the installation method of the fastener <NUM> shown in <FIG> the washer <NUM> is initially positioned to its place by pushing the sleeve <NUM> through the opening <NUM> with the tip <NUM> first. Thus, also the screw <NUM> pre-installed into the sleeve <NUM> is pushed through the opening <NUM> of the washer <NUM>. When the screw <NUM> is rotated to be in contact with the receiving structure <NUM>, the sleeve <NUM> is adjusted as described above, until the outer ring <NUM> of the washer <NUM> is in contact with the surface <NUM> of the covering layer <NUM>. If the sleeve <NUM> is tightened further, the shape of the washer <NUM> is elastically transformed, whereby the inner ring <NUM> is pressed towards the surface <NUM> of the covering layer <NUM> or contacts it.

<FIG> show an alternative washer <NUM>. Similar to the washer shown in <FIG>, the washer <NUM> comprises concentric outer and inner rings <NUM>, <NUM>, an isthmus part <NUM> connecting these as well as an opening <NUM> arranged into the inner ring <NUM> for receiving the body <NUM> of the sleeve <NUM>. The difference to the washer shown in <FIG> is the design of the isthmus part <NUM>, whereby the arms of the isthmus part are connected to the outer and inner rings <NUM>, <NUM> by means of rounded forms, whereby the arms of the isthmus part are relatively narrow at the middle section. Thus the openings of the isthmus part are rounded triangles in shape.

<FIG> shows a cross-sectional view of a range of fasteners provided with sleeves of different sizes without the washer. The channel <NUM> of the sleeve <NUM> according to the embodiment of <FIG> comprises an optional section 13c. The third section is arranged at the area of the end flange <NUM>. Thus the first section 13a is arranged between the second section 13b arranged within the area of the tip <NUM> and the third section 13c, when the channel is seen in the axial direction of the body <NUM>. The third section 13c is rotationally symmetrical in cross-section, i.e. circular, which is advantageous for the production. If the sleeve <NUM> is produced by means of moulding, such as by injection moulding, the split level can be arranged within the level of the end flange <NUM>,whereby the core (not shown in the drawings) forming the channel <NUM> can be brought through the split level as a stud-like piece, which is advantageous for the manufacturing of the mould.

<FIG> shows a fastener according to an embodiment provided with an optional third section 13c in five different sizes A to E from the smallest to the largest. The washer is omitted in <FIG> to emphasize the size difference. As has been stated above, the present fastener construction makes it possible to provide a modular selection of fastener components, of which the size of the screw <NUM> and the washer <NUM> can be standardized, whereby the fastener <NUM> can be arranged to be suitable for fastening covering layers of different thicknesses by changing the size of the sleeve <NUM>. The range of sleeves of different sizes in <FIG> shows the said conversion.

<FIG> shows five sleeves A to E of different lengths, dimensioned to cooperate with a screw <NUM> having a shank length of <NUM> to <NUM>. The outer diameter of the washer (not shown in <FIG>) can be, for example, <NUM>, the inner diameter of the opening <NUM> can be <NUM> and the inner diameter of the receiving indentation of the end flange <NUM> can be <NUM>. Thereby the outer diameter of the end flange <NUM> and body <NUM> of the sleeve <NUM> can be standardized to be e.g. <NUM> and <NUM>, correspondingly. The dimension of the washer in axial direction can be, for example, <NUM>. The inner diameter of the third section 13c of the channel <NUM> can be, for example <NUM>, whereby the outer diameter of the head <NUM> of the screw <NUM> can be <NUM>, whereby it can receive a size T25 tool bit. The first and second section 13a, 13b of the channel <NUM> can also be standardized in size. The length of the first section 13a can be, for example, <NUM> and the length of the second section 13b can be <NUM>. Thereby the tool can also be standardized. These dimensions are concrete examples of standard dimensions of the fastener.

By varying the third section 13c of the channel, fasteners suitable for different sizes of insulation layers can be produced. Table <NUM> shows examples of dimensions for the length of the body <NUM> and the third section 13c of the channel <NUM>, measured from the lower surface of the end flange, as well as the suitability of the said fastener for a covering layer of certain thickness.

Regardless of whether the sleeve comprises a third section 13c of the channel <NUM> of the sleeve <NUM> or not, the length of the sleeve <NUM> can be varied by converting the length of the first section 13a, second section 13b or both sections of the channel <NUM> or the length of one or two sleeves in a channel comprising more than two sections.

In the above-described embodiments the mutual fastening of the sleeve <NUM> and the washer <NUM> of the fastener <NUM> is based on the tension strength created by the end flange <NUM> of the sleeve <NUM> and the corresponding indentation of the shell board <NUM>. The mutual fastening of the sleeve and end flange can also be varied. According to an alternative embodiment (not shown in the drawings) the sleeve can be fastened to the washer with thread fit. The thread fit can be provided by arranging an external thread to the end of the body, whereby the end flange at the place of the thread is optional. Correspondingly, the opening of the washer can be provided with an internal thread, cooperating with the external thread of the sleeve.

Alternatively, the sleeve can comprise grooves arranged on the external surface for receiving lock rings or cotter pins (not shown in the pictures), whereby the end flange of the body can also be optional.

Claim 1:
A fastening kit for fastening a covering layer (<NUM>) to a receiving structure (<NUM>), the fastening kit comprising a fastener (<NUM>), which comprises:
- a sleeve (<NUM>), comprising:
o an elongated body (<NUM>), which extends between a tip (<NUM>) and an end flange (<NUM>), wherein the diameter (D14) of the end flange (<NUM>) is larger than the diameter (D11) of the body (<NUM>), and
o a channel (<NUM>), which extends through the body (<NUM>) and comprises:
• a first section (13a), which has a non-circular cross-section, and
• a second section (13b), and
- a screw (<NUM>), comprising:
o a threaded shank (<NUM>), which can be arranged into the first and second section (13a, 13b) of the channel (<NUM>), and
o a head (<NUM>), which is provided at an end of the shank (<NUM>) and which can be slidably fitted to the first section (13a) of the channel (<NUM>),
whereby:
- a thread fit between the shank (<NUM>) of the screw (<NUM>) and the second section (13b) of the sleeve (<NUM>), and
- a tool (<NUM>), which comprises:
o a shaft (<NUM>), which comprises a non-circular cross-section corresponding with the cross-section form of the first section (13b) of the channel (<NUM>) of the sleeve (<NUM>), whereby the shaft (<NUM>) can be arranged into the first section of the channel (<NUM>) slidably in axial direction and form-lockingly in rotational direction, and
o a bit (<NUM>), which is provided to an end of the shaft (<NUM>) to connect with the head (<NUM>) of the screw (<NUM>) for driving the screw (<NUM>) into the receiving structure (<NUM>),
whereby the relative axial position of the sleeve (<NUM>) and the screw (<NUM>) is adjustable by rotating the sleeve (<NUM>) in relation to the screw (<NUM>) by means of the shaft (<NUM>) of the tool (<NUM>), when the bit (<NUM>) of the tool (<NUM>) is detached from the head (<NUM>) of the screw (<NUM>).