WO2018158149A1

WO2018158149A1 - A fixing clamp for fixing adjacent boards

Info

Publication number: WO2018158149A1
Application number: PCT/EP2018/054512
Authority: WO
Inventors: Urmas Ild
Original assignee: Bole Oü; Silvernet Group Oü
Priority date: 2017-03-01
Filing date: 2018-02-23
Publication date: 2018-09-07
Also published as: EE01433U1

Abstract

Present invention relates to a fixing clamp for fixing adjacent boards, said clamp comprising an L-shaped main part with a footing, in use said main part is intended to be placed between the adjacent boards between opposite edges and where at the end of the L-shaped main part said footing is comprising at least one fixing hole, and which is intended to be fixed to a substructure. At the distal end of the L-shaped main part in relation to said footing said main part comprises three fixing tongues at angles in relation to the main part, which are intended to engage grooves in the opposite edges of the adjacent boards.

Description

A FIXING CLAMP FOR FIXING ADJACENT BOARDS

Technical Field

The present invention belongs to the field of construction and relates to a fixing clamp for fixing adjacent boards to a substructure.

In the context of the present invention, in particular floor boards, including the terrace boards are meant. However, the present invention is not limited to the fixing of floor boards only – the fixing clamps according to the present invention are also usable for fixing other boards, such as wall boards, scaffold boards, finishing boards or weatherboards. The fixing clamps according to the invention are also usable for fixing plates, boards and panels. In the following description of the invention and in the accompanying drawings, the fixing of the boards is described and shown in the position of the fixing clamp, which corresponds to the position of the fixing clamp on a horizontal substructure (e.g., on the floor).

For the person skilled in the art this understandably means that when using the same fixing clamp, for example, for fixing the wall boards, the same fixing clamp should be seen in the context of the location of the fixing clamps and the wall boards on the vertical substructure, and thus, in describing the embodiments, such expressions as under, above, beside, on the left, on the right are used in the description of the invention to describe the fixing clamp in the context of a horizontal substructure.

The groove in the side edge of the board to be fixed marks in the context of the present invention a discrete sunken groove separately for each fixing clamp, as well as a continuous sunken groove slot running along the side edge of the board. The cut or chamfer in the lower part (lower side edge) of the board to be fixed marks in the context of the present invention a discrete cut or chamfer in the place of each fixing clamp or in the lower part of the board edge along the continuous sunken cut or chamfer running along the side edge and the lower side of the board.

Background Art

From the U.S. Patent Application US2007/0234670A1 (published on 11 October 2007) a fixing clamp is known that comprises a footing at the lower end of the L-shaped main part, and at the other end of the main part two fixing tongues one of which is bent to one side of the main part and the other is bent to the other side of the main part. A hole is made for the fastening screw in this fixing clamp in the curved connecting section between the footing and the main part. The hole is located at one edge of the footing. In this embodiment, the fastening screw is screwed into the substructure, askew in relation to the substructure. The position of the fixing tongues with respect to the fixing hole in the footing is asymmetrical – the fastening screw is in alignment with one fixing tongue. During fastening, this results in a situation where the arms of force of the fixing tongues at the different sides of the main part are different in use of the fixing clamp in relation to the fastening screw, and the fixing clamp can easily twist in relation to the fastening screw.

From the U.S. Patent Application US2007/0234670A1 (published on 19/08/2010) a fixing clamp is known that comprises three footings and three fixing tongues. The fixing clamp is fastened to the substructure with a screw. The fixing tongues are located so that the two outermost fixing tongues are intended to engage one slot at the edge of the adjacent board, and the middle tongue between these outermost fixing tongues is intended to engage the other slot at the side of the adjacent board at the other edge of the fixing clamp. The footings are also located symmetrically – in use one middle footing is placed under the edge of one of the adjacent boards, and the two outermost footings are placed under the edge of the adjacent board at the other side of the fixing clamp. The screw is screwed through the middle footing.

Although this fixing clamp fixes the adjacent boards in the direction of their thickness to the substructure, the both boards may shift in relation to the fixing clamps when the load or the moisture content of the boards changes or the temperature fluctuates, since the position of neither of the adjacent boards is prevented from shifting in relation to the fixing clamp in the direction of the length or width of the board.

The closest known solution to the present invention is known from the U.S. Patent Application US2003/0121226A1 (published on 03/06/2003), which describes a floor installation system and method. This patent application describes a fixing clamp for fixing boards, the said clamp comprising a L-shaped main part, in use the said main part is intended to be placed between the opposite edges of the two adjacent boards, and where at the end of the L-shaped main part a footing with at least one fixing hole is intended for fixing the fixing clamp to a substructure. The L-shaped main part of the fixing clamp comprises, at the other end of the main part at an angle in relation to the main part, three fixing tongues intended to engage the corresponding grooves at the opposite edges of the adjacent boards.

The main disadvantage of this fixing clamp is that neither of the adjacent boards can be fixed in an immovable position in relation to the fixing clamp. The fixing tongues in this clamp fix the boards only to the substructure in the direction of the board thickness, but the both adjacent boards can shift in relation to the fixing clamp in the direction of the board's length and width.

Aim of Invention

The object of the invention is to eliminate the disadvantages of the fixing clamps, known in the background art. The object of the invention is also to propose a fixing clamp that, by way of at least one edge of the board to be fastened, fixes the position of the board to the substructure both in the direction of the length and the width of the board. It is also the object of the invention to propose a fixing clamp that allows the shifting of the other edge of the board to be fastened in relation to the fixing clamp due to the thermal expansion of the board and/or change of its moisture content.

The object of the invention is to propose a fixing clamp that in use, in case of maximum expansion of the boards, the shifting between the two adjacent boards is restrained only by the thickness of the material of the fixing clamp itself (the thickness of the main part of the fixing clamp).

The object of the present invention is to propose a fixing clamp that preferably fulfils the following requirements:

The fixing clamp must be weathertight and durable over time.
By increasing and decreasing the measurements of the fixing clamp it must be usable with wooden material of different dimensions.
The fixing clamp must be able to withstand the expansion, twisting and the lifting force of the wood without structural damage to the fixing clamp and the boards to be fastened.
The fixing clamp must remain as discrete as possible in use, i.e. as difficult to notice as possible, or hidden.
The fixing clamp must tighten the boards and hold them against the substructure (base frame).
The fixing clamp must preferably be fixed to the substructure with a fastening screw that is driven to the substructure directly down from the top (i.e., the screw is at an angle of 90 degrees to the substructure) that allows, if necessary, the fastening screw to be unscrewed from between the two boards, or, if necessary, retightened. The possible later unscrewing of the fixing clamps may be necessary for the replacement, for example, of the damaged boards.
By driving the fastening screw straight down, it works best in terms of strength, equally in relation to the both boards and also taking into account the strength of the fixing screw itself, compared, for example, to the fastening alternatives when the fastening screw is driven at an angle.
Driving the fastening screw straight down will make the use an aluminium structure easier (i.e. an aluminium substructure) because driving a fastening screw at an angle to the aluminium structure is more troublesome.
Driving a fastening grew at an angle to the substructure (such as a framework) and also the screwing of the lower part through the groove/slot at the edge of the board must be avoided, because such fixing method damages the board from its fixing point and thus weakens the board structurally.
An askew fastening screw does not work as a fastener for the two adjacent boards with equal firmness. Working of the fastening screw in bending position must be avoided as they are not designed for this purpose as a rule. The damaged place of the board is also apt to the moisture damages and also to the mould, rot, etc., and again in a structurally important place, thus shortening the life of the wood and reducing the strength of the fastening.
Depending on the expansion and shrinkage of wood due to changes in humidity and temperature, the fixing clamp must allow the wood to move freely in the direction of expansion and shrinkage to the maximum extent, that is, across the grain. Along the grain, the expansion and shrinkage of wood are marginal, as compared to moving across the grain. The climatic conditions vary widely in different parts of the world, so the fixing clamp must work in all climatic conditions in the same way and predictably.
The fixing clamp must hold fast the boards at one edge of each board to prevent their longitudinal and transverse movement in relation to the fixing point of the fixing clamp. At the other end of each board, the same fixing clamp must allow free movement of the wood due to its expansion. This ensures the stability of the positions of installed and adjacent boards during the temperature and humidity changes due to the expansion and contraction of the boards.
The shape of the fixing clamp must also be such that it cannot be easily installed once in one position, once in another position, and it should be as difficult as possible for the installer to install the fixing clamp in the wrong position or wrongly, since the installation of the fixing clamp in the wrong position does not allow the board to be fastened.

Disclosure of Invention

Taking into account the disadvantages of the background art and the objectives of the invention as listed above, the present invention proposes a fixing clamp for fixing boards, the said clamp comprising a L-shaped main part, in use the said main part is intended to be placed between the opposite edges of the two adjacent boards, and where at the end of the L-shaped main part a footing with at least one fixing hole is intended for fastening the fixing clamp to a substructure.

The L-shaped main part with the footing comprises, at the distal end of the footing at an angle in relation to the main part, three fixing tongues, which are intended to engage the corresponding grooves in the opposite edges of the adjacent boards.

The two outermost fixing tongues are bent at an angle in relation to the main part to one side of the main part and are intended to engage a groove at the edge of one adjacent board.

The middle fixing tongue between the two outermost fixing tongues is bent in the opposite direction in relation to the outermost fixing tongues, at an angle towards the other side of the main part and is intended to engage the groove at the other edge of the adjacent board.

All the ends of the fixing tongues have been bent away from the footing.

At least one fixing tongue bent towards one side of the main part comprises at least one tooth protruding towards the footing.

In the most preferred embodiment of the invention, the fixing clamp is made of sheet material and of one piece, in which the footing of the L-shaped main part is bent essentially transversely to the main part of the fixing clamp and the footing comprises at least one hole for the fastening device in the central part.

At the end of the L-shaped main part of the fixing clamp, at the distal end of the footing, a single middle fixing tongue with at least two teeth has been bent in relation to the footing away from the other side of the main part, and one toothless outermost fixing tongue has been bent to the both sides of the central toothed fixing tongue to the same side with the main part in relation to the footing.

Preferably, the teeth are stamped at the sides of the fixing tongues. But the teeth can also be positioned in some other place on the width of the tongue. For example, a tooth or teeth may be stamped within the width of the fixing tongue, i.e. the tooth or teeth may be stamped between the side edges on the width of the fixing tongue.

Preferably, the middle fixing tongue comprises two teeth formed at the opposite edges of the middle fixing tongue.

Preferably, the end of the middle fixing tongue is bent away from the footing beside the teeth in the middle fixing tongue. The end of the fixing tongue is bent away from the teeth, i.e. when the fixing clamp is seen in use the end is bent away from the substructure.

The ends of the outermost fixing tongues of the fixing clamp are formed as curved sections so that the convexity of these curved sections is at the footing side of the fixing tongue, i.e. in use the convexity is at the side of the substructure.

Preferably, the width of the outermost fixing tongue of the fixing clamp is from 50 to 80 per cent, preferably 65 to 70 per cent of the width of the middle fixing tongue.

In a most preferred embodiment, the width of the outermost fixing tongue of the fixing clamp is approximately 2/3 of the width of the middle fixing tongue.

Preferably, the distance of the centre of the teeth on the fixing tongue of the fixing clamp from the end of the said fixing tongue is from 30 to 65 per cent of the length of the fixing tongue, most preferably from 45 to 55 per cent of the length of the fixing tongue.

Preferably, the fixing clamp is made of one piece of the blank of planar sheet material where the footing of the main part of the fixing clamp is connected with the rest of the main part with curved bent section, and where the outermost fixing tongues are separated from the middle fixing tongue, located between them, by lines of intersection, which has left material at the opposite edges of the middle fixing tongue to form teeth. Each outermost fixing tongue is connected to the main part through the second curved bent section where the second bent section is followed by a flat part in the fixing tongue, connected by means of the third curved bent section to the end part of the outermost curved fixing tongue. The middle fixing tongue is connected to the main part with the fourth bent section followed by a flat part, followed by the fifth bending part, followed by a toothed part of the middle fixing tongue, and the end part of the middle fixing tongue is connected to the toothed section with the sixth bent section.

In the most preferred embodiment, the bent section connecting the footing part of the main part of the fixing clamp to the rest of the main part, comprises a cut-out beside the fixing hole in the footing part. This allows to make the hole to be made in the footing for the fastening device such as a fastening screw as close as possible to the main part, i.e. when fastening the fixing clamp to the substructure, for example, the main part of the screw head is located as close to the angle (L-part’s angle) of the footing as possible.

In use the middle tongue is placed in the groove (or slot) at the edge of the board to be fastened so that the end of the toothed middle fixing tongue rests against the upper wall of the groove and the teeth against the lower wall of the groove. The fixing clamp is then pressed against the substructure, and the fixing clamp is fixed by turning the fastening screw crosswise to the substructure through the hole in the footing.

By pressing on the footing part of the fixing clamp, the end of the middle fixing tongue which is supported against the upper wall of the groove, acts as a point of support around which the footing part is rotated against the substructure by pressing the toothed fixing tongue together with the rest of the fixing clamp so that the teeth in the fixing tongue are pushed into the lower wall of the groove and the main section of the fixing clamp is pressed against the edge part of the board being fastened. This way the board being fastened is fixed from one edge against shifting in the direction of the width and the length of the board.

As the outermost fixing tongues of the fixing clamp are curved and without teeth, they can be pushed into the groove/slot at the edge of the adjacent board in such a way that the outermost tongues are supported on the lower wall of the groove (or slot) at the edge of the adjacent board, fixing the board in the direction of thickness, but allowing the board to shift in the direction of the length and the width of the board. The subsequent fixing clamps are fastened in turn in the groove/slot at the opposite edge of this board in such a way that there is a toothed fixing tongue in that groove, which in turn fixes the board also in the direction of the length and the width of the board.

To this fixing clamp, the next adjacent board to be fastened is fixed again, using toothless fixing tongues, etc. Preferably, the edge of the board being fastened with toothed fixing tongues rests against the main part of the fixing clamp. Preferably, in the lower part of the board to be fastened there is a cut or a chamfer that in use accommodates the footing of the fixing clamp with a screw head.

Brief Description of Drawings

The method according to the present invention and the embodiment thereof is hereinafter described with references to the accompanying schematic drawings, wherein:
Figure 1 depicts the fixing clamp according to the present invention in the axonometric view from the side of the fixing tongues;
Figure 2 depicts the fixing clamp according to Figure 1 in the axonometric view from the side of the footing;
Figure 3 depicts the fixing clamp according to Figure 1 in side view;
Figure 4 depicts the fixing clamp according to Figure 1 in rear view from the side of the middle fixing tongue;
Figure 5 depicts the fixing clamp according to Figure 1 in top view;
Figure 6 depicts the workpiece made of sheet material of the fixing clamp according to Figure 1 in top view before the footing and the fixing tongue have been bent out;
Figure 7 depicts installation of the clamp according to Figure 1 into the groove (slot) at the edge of the board being fastened (without fastening screw);
Figure 8 depicts installation of the clamp according to Figure 7 into the groove (slot) at the edge of the board being fastened where the clamp is pressed with the footing against the substructure (without fastening screw);
Figure 9 depicts in addition to the board fastened with the fixing clamp according to Figure 8 an adjacent board (e.g. terrace board);
Figure 10 depicts the fixing clamps installed according to Figure 9 together with the boards being fastened in end view;
Figures 11 to 14 depict in enlarged fragmentary view the fastening of two adjacent boards with the fixing clamp according to the present invention, wherein:
Figure 11 depicts the installation of the fixing clamp into the groove (slot) at the edge of the board (without fastening screw);
Figure 12 depicts the fixing clamp fastened to the substructure with a fastening screw where the teeth of the middle fixing tongue are pressed into the groove and the footing with the fastening screw is pressed against the substructure;
Figure 13 depicts the installation of the adjacent board into the groove (e.g. groove) at its corresponding edge by placing the outermost fixing tongues of the fixing clamp, and;
Figure 14 depicts the position of two adjacent boards where the second added board has expanded with its edge against the main part of the fixing clamp.

Best Mode for Carrying Out the Invention

The present invention and the embodiment thereof is hereinafter described with references to the accompanying schematic drawings. The accompanying drawings show the fastening of floor boards; so the positions of the fixing clamp in the following detailed description correspond to the position of the fixing clamp on an horizontal substructure.

Figure 1 and Figure 2 in particular depict a fixing clamp 1, comprising generally a L-shaped main part 2, in the lower part of which there is a footing 4 with a fixing hole 3.

The L-shaped main part 2 comprises three fixing

tongues

5, 6 and 6’ at the other end of the main part 2, at an angle to the main part 2.

The middle fixing tongue 5 between the two outermost fixing tongues 6 and 6' is bent in the opposite direction in relation to the outermost fixing tongues 6 and 6', at an angle to the main part 2, to the other side of the main part. In other words, the middle fixing tongue 5 is bent to the other side of the main part 2 in relation to the footing 4.

The ends 7, 7 'and 8 of the fixing tongues are bent away from the fixing tongue 4, in other words, the

ends

7, 7' and 8 are bent upwards at an angle.

There are two teeth 9 at the edges of the middle fixing tongue 5. They are intended to engage (i.e. sunk) with the wall of the slot or groove at the edge of the board.

The fixing clamp 1 depicted in the drawings is made of one workpiece of planar sheet material, preferably steel, stainless steel or aluminium, see Figure 6. The thickness of the sheet material is from 0.5 to 2 mm, preferably 1.5 mm.

Alternatively, the fixing clamp may also be made of plastic or composite plastic using a die-casting technology instead of metal stamping and bending.

The footing 2 of the fixing clamp 1 is connected to the main part 2 of the fixing clamp at the right angle by means of a curved bent section 10, see Figures 3 and 6. In Figure 6 the bending points of the bent sections are correspondingly marked by dashed lines.

The outermost fixing tongues 6, 6' are separated from the middle tongue 5 placed between them along the lines of intersection 11, 11', which leaves material at the opposite edges of the middle fixing tongue 5 for forming teeth 9.

Each outermost fixing tongue 6, 6’ is connected to the main part 2 through the second curved bent section 12, where the second bent section 12 is followed by a flat part 13 in the fixing tongue, connected by means of the third curved bent section 14 to the end part 7 of the outermost curved fixing tongue.

The middle fixing tongue 5 is connected to the main part 2 with the fourth bent section 15, followed by a flat part 16, followed by the fifth bent section 17, followed by a section 18 with teeth 9 of the middle fixing tongue, and the end part 8 of the middle fixing tongue 5 is connected to the toothed section 18 with the sixth bent section 19.

There is a fixing hole 3 in the footing 4 whereby the wall part of the fixing hole 3 is separated from the main part 2 by a cut-out 20. This cut-out 20 allows bending the footing 4 in relation to the main part 12 relatively closely to the fixing hole 3.

As is apparent from Figure 3 in particular, the toothed 9 end 8 of the fixing tongue 5 is bent upward in relation to the footing 4. The ends 7, 7’ of the outermost fixing tongues 6, 6’ have been formed as curved sections. The purpose of these curved sections is to allow the sliding of the fixing tongues 6, 6' of the clamp into the groove 24 at the edge 23 of the board 21.

In use the middle tongue 5 is placed in the groove 25 (or slot) at the edge 24 of the board 21 to be fastened so that the end 8 of the toothed middle fixing tongue 5 rests against the upper wall of the groove 25 and the teeth 9 against the lower wall of the groove 25. Then, the fixing clamp 1 will be screwed, for example, with a fastening screw 26 (see Figures 9, 10, 12) against the substructure 27.

By pressing the footing 4 against the substructure 27, the end 8 of the middle fixing tongue 5 which is supported against the upper wall of the groove 25 acts as a point of support around which the toothed 9 fixing clamp 5 together with the rest of the fixing clamp 1, while pressing the footing 4 further downwards, is rotated so that the teeth 9 in the fixing tongue 5 are pressed into the lower wall of the groove, and the main part 2 of the fixing clamp 1 into the edge 24 of the board 21 being fastened. This way the board 21 being fastened is fixed from one edge 24 against shifting in the direction of the width and the length of the board. As the fastening screw 26 is turned into the substructure 27 perpendicularly to the substructure, the fastening screw works in the most optimal way in terms of its strength.

As the outermost fixing tongues 6, 6’ of the fixing clamp 1 are curved at the ends and without teeth, an adjacent board 21 can be pushed beneath them so that the outermost fixing tongues 6, 6’ are supported on the lower wall of the groove 23 (or slot) at the edge 22 of the adjacent board 21, fixing the board 21 in the direction of thickness, but allowing the board to shift in the direction of the length and width of the board. In the groove 25 at the opposite end 24 of the board 21, the subsequent fixing clamps 1 are fixed in turn in such a way that, in this groove 25, a fixing tongue 5 with teeth 9 is located, which in turn fixes the board 21 in the direction of the length and the width, see Figure 10.

To this fixing clamp 1, the next adjacent board 21 to be fastened is fixed again, using toothless fixing tongues 6, 6’, etc. Preferably, the edge 23 of the board 21 being fastened with fixing tongues 5 with teeth 9 is supported against the main part 2 of the fixing clamp 1. In the lower part of the

edge

22, 24 of the board 21 being fastened, there is a cut or a chamfer 28, which in use accommodates the footing 2 of the fixing clamp 1 together with the head of the screw 26.

Figures 11 to 14 depict the fastening of boards (e.g., terrace boards) by means of fixing clamps 1. In the first stage shown in Figure 11 (enlarged image shown also in Figure 7), the fixing clamp 1 is placed with the fixing tongue 5 with teeth 9 into the groove 24 at the edge 24 of the board 21, and the footing 4 is pushed towards the substructure 27, and the driving in of the fastening screw 26 (not shown) is started through the hole 3 in the footing 4.

In the next stage shown in Figure 12 (enlarged in Figure 8), the footing 4 of the fixing clamp 1 is tightened with the fastening screw 26 against the substructure 27. While driving the fastening screw 26, the fixing tongue 5 in the groove 25 turns around the end 8 and presses the teeth 9 into the lower wall of the groove 25.

In the next stage shown in Figure 13 (enlarged in Figure 9), the adjacent board 21 is pushed from the side of the toothless fixing tongues 6, 6’ into engagement with the fixing clamp 1, in other words, the fixing tongues 6, 6' are pushed into the groove 23 at the edge 22 of the board 21 by pressing the board towards the fixing clamp (to the left in Figure 13).

In Figure 14, the board 21, which has been pressed from the right to the connection with the fixing clamp 1 is pressed with its edge 22 against the main part 2 of the fixing clamp. The drawing shows a situation in which, for example, due to temperature and/or humidity, the board has swollen and pushed itself fully against the main part 2 of the fixing clamp 1. The drawing also shows that the footing 4 and the head of the fixing screw 26 are located in the chamfer 28 at the lower edge of the board 21.

It is obvious for the person skilled in the art that present invention is not limited to the embodiments described above and depicted in the drawings but also other embodiments are possible within the scope of the accompanying claims, not described or depicted herein.

Claims

A fixing clamp (1) for fixing adjacent boards to the substructure, comprising a L-shaped main part (2) with a footing (4), where the main part (2) is in use intended to be placed between the opposite edges (22, 24) of two adjacent boards (21), where the footing (4) with at least one fixing hole (3) at the end of the L-shaped main part (2) is intended to be fastened with the fixing clamp (1) to the substructure (27), characterized in that, the L-shaped main part (2) with the footing (4) comprises at the distal end of the footing (4) at an angle in relation to the main part (2) three fixing tongues (5, 6, 6’) that are intended to engage with the corresponding grooves (23, 25) in the opposite edges (22, 24) of adjacent boards (21), where two next fixing tongues (6, 6’) have been bent at an angle in relation to the main part (2) towards one side of the main part (29) and is intended to be engaged with a groove (23) at the edge (22) of one adjacent board (21), and the middle fixing tongue (5) between two outermost fixing tongues is bent in the opposite direction in relation to the outermost fixing tongues (6, 6’), at an angle in relation to the main part (2) towards the other side of the main part (2), and is intended to be engaged with the groove (25) at the edge (24) of the other adjacent board (21), where the ends (7, 7’, 8) of the fixing tongues (5, 6, 6’) have been bent away from the footing (4), where at least one fixing tongue (5) bent to the one side of the main part (2) comprises at least one tooth (9) protruding towards the footing (4).
The fixing clamp (1) according to claim 1, characterized in that, the fixing clamp (1) is made of sheet material and of one piece, where the footing (4) of the main part (2) is bent mainly transversely to the main part (2) of the fixing clamp (1) and the footing (4) comprises in the middle part at least one hole (3) for a fastening device, and where the L-shaped main part comprises at the distal end of the footing (4) one middle fixing tongue (5) with at least two teeth (9) bent to the other side of the main part (2) in relation to the footing (4) of the main part, and one toothless outermost fixing tongue (6, 6’) is bent to the both sides of the middle fixing tongue (5) with teeth (9).
The fixing clamp (1) according to claim 2, characterized in that, the end (8) of the middle fixing tongue (5) is bent away from the footing (4) beside the teeth (9) in the middle fixing tongue (5).
The fixing clamp according to any preceding claim, characterized in that, the ends (7, 7’) of the outermost fixing tongues (6, 6’) are formed as curved sections.
The fixing clamp according to any preceding claim, characterized in that, the middle fixing tongue (5) comprises two teeth (9) formed at the opposite edges of the middle fixing tongue (5).
The fixing clamp according to any preceding claims 1 to 4, characterized in that, the middle fixing tongue (5) comprises at least one tooth (9), formed on the width of the fixing tongue (5) between its side edges.
The fixing clamp according to any preceding claim, characterized in that, the width of the outermost fixing tongue (6, 6’) is from 50 to 80 per cent, preferably from 65 to 70 per cent of the width of the middle fixing tongue (5).
The fixing clamp according to any preceding claims 1 to 6, characterized in that, the width of the outermost fixing tongue (6, 6’) is 2/3 of the width of the middle fixing tongue (5).
The fixing clamp according to any preceding claim, characterized in that, the distance of the teeth (9) centre from the end of the fixing tongue (5) is from 30 to 60 per cent, preferably from 45 to 55 per cent from the length of the corresponding fixing tongue (5).
The fixing clamp according to any preceding claim, characterized in that, the fixing clamp (1) is made of one piece from a planar sheet material workpiece where the footing (4) of the main part (2) of the fixing clamp (1) is connected to the main part (2) by means of a curved bent section(10), where outermost fixing tongues (6, 6') are separated from the middle tongue, placed between them along the lines of intersection, which leaves material at the opposite edges of the middle fixing tongue (5) for forming teeth (9), where each outermost fixing tongue (6, 6’) is connected to the main part (2) through the second curved bent section (12), where the second bent section (12) is followed by a flat part (13) in the fixing tongue (6, 6’), followed by the curved end section (7, 7’) of the outermost fixing tongue (6, 6’) through the third curved bent section(14), the middle fixing tongue (5) is connected to the main part (2) with the fourth bent section (15), followed by a flat part (16), followed by the fifth bent section(17), followed by the part (18) with teeth (9) of the middle fixing tongue (5), and the end part (8) of the middle fixing tongue (5) is connected to the toothed part (18) with the sixth bent section(19).
The fixing clamp according to claim 10, characterized in that, the bent section (10) connecting the footing part (4) of the main part (2) to the rest of the main part (2) comprises a cut-out (20) beside the fixing hole (3) in the footing part (4).