Method for securing a wall opening on a construction site

Abstract

The invention relates to a method for securing an opening (1) in a wall (2) on a construction site by means of two supports (4) and a guardrail tube (3), each support (4) comprising: - a fastening means (5) configured to allow partial fixing of the support (4) to the wall (2) in which it is possible to rotate said support (4) relative to the wall (2), and - an opening (7) configured to be traversed by the guardrail tube (3), said method comprising the following steps: - partial fixing of the supports (4) to the wall (2), on either side of said opening (1), - for each support (4), insertion of the guardrail tube (3) into said opening (7), - rotation of said supports (4), until the guardrail tube (3) is in a locked position. The invention also relates to a device for implementing said method. Figure for the abstract: Fig 3

Description

Title of the invention: Method for securing a wall opening on a construction site technical field

[0001] The present invention relates to the field of construction. More particularly, it concerns a method for securing an opening in a wall on a construction site. The invention notably allows for the simple and rapid attachment of a guardrail to an opening. Previous technique

[0002] Construction sites must comply with a number of safety rules to avoid endangering the physical integrity of the various people working on these sites. Openings in exterior walls, in particular, must be secured to prevent falls. To this end, it is common practice to install a guardrail spanning the opening and fixed to the wall on both sides of the opening by means of brackets.

[0003] Such supports are proposed in the prior art, for example in documents CN115434530 A and US20190264497 AL. These solutions are simple and effective, but impractical. Indeed, they require several steps to install or remove the guardrail, which is tedious and time-consuming, especially on construction sites where it is regularly necessary to retract and then reinstall the guardrails.

[0004] The technical problem that the present invention aims to solve is therefore to propose a method of securing a bay in a wall allowing the railing to be mounted and dismounted very quickly and simply from its supports. Description of the invention

[0005] The present invention aims to overcome these drawbacks by proposing a method for securing a wall opening on a construction site using two supports and a guardrail tube, each support comprising: - a means for fixing the support to said wall, configured to allow partial fixing of the support to the wall in which it is possible to rotate said support relative to the wall, around a horizontal axis of rotation perpendicular to said wall, and - an opening whose plane has an angle strictly less than 90° with said axis of rotation, said opening being configured to be traversed by the guardrail tube, and such that when the longitudinal axis of the guardrail tube is perpendicular to the plane of the opening, the guardrail tube is in the unlocked position and can slide freely along said opening, and when the axis of the guardrail tube has a angle less than a value between 45 and 85° with the plane of the opening, the guardrail tube is blocked in the locked position, pinched in the opening.

[0006] Said process comprises the following steps: - partial fixing of the brackets to the wall, on either side of said bay - for each support, insertion of the guardrail tube into said opening, the support being positioned so that the guardrail tube is in the unlocked position, - rotation of said supports around said axis of rotation, until the guardrail tube is in the locked position in the openings of the supports.

[0007] Thanks to these provisions, the wall can be reliably secured by means of a particularly simple and quick process, in which the parts used are simple to manufacture, inexpensive, and reusable.

[0008] During the step of rotating the supports until the guardrail tube is in the locked position, the guardrail tube can be moved downwards, which is an easier embodiment to implement, and safer, for an operator.

[0009] The means of fixing the support to the wall can be configured to allow complete fixing which does not permit any movement of the support relative to the wall, said method may further include the following step, during or after the locking of the guardrail tube in the openings of the supports: - complete fixing of the supports to the wall.

[0010] These provisions make it possible to reduce the risk that the guardrail tube will accidentally move into the unlocked position, and thus enhance the reliability of securing the bay by the method according to the invention.

[0011] The step of rotating said supports around said axis of rotation, until the guardrail tube is in a locked position in the openings of the supports, may include the following sub-steps: - the first part of the rotation, driven by the weight of the guardrail tube and / or a manual push on the guardrail tube downwards, and - second part of the rotation, driven by the complete fixing of the supports to the wall.

[0012] These provisions prevent the complete fixing of the supports from causing the guardrail tube to move into the unlocked position, and strengthen the locking of the guardrail tube by increasing the pinching forces it experiences in the opening.

[0013] For each support, after the first part of the rotation, the line parallel to the wall passing through the axis of rotation of the supports and the center of the opening can have an angle greater than or equal to 15° with the horizontal, which allows the guardrail tube to be sufficiently offset vertically to access a fixing means which is located at the level of the axis of rotation of the support.

[0014] For each support, the means of fixing to the wall can be a screw, and the second part of the rotation is achieved by tightening said screw, which is a simple and robust embodiment of the invention.

[0015] For each support, the opening can have a shape having at least three sides, and when the guardrail tube is in the locked position, the guardrail tube can be in contact with at least three sides of the opening, which reinforces the stability of the guardrail tube in its locked position, and thus makes the securing method according to the invention more reliable.

[0016] For each support, the opening can have a hexagonal shape, comprising four sides of a first length, and two opposite sides, of a second length greater than the first length, which is a simple and effective embodiment of the invention, allowing in particular four points of contact between the support and the guardrail tube in the locked position.

[0017] For each support, the distance between the plane of the opening and the axis of rotation can be greater than or equal to 5 cm, which allows that when the guardrail tube pulls the support downwards by its weight, the guardrail tube is no longer opposite the axis of rotation, and that access to a fixing means located at the level of this axis is facilitated.

[0018] Each support can be made of a metal plate folded in half at an angle between 85 and 95°, preferably 90°, which is a simple and robust embodiment of the invention.

[0019] When the guardrail tube is in the locked position, the line parallel to the wall passing through the axis of rotation of the supports and the center of the guardrail section at the opening can have an angle between 25 and 45° with the horizontal, which allows a certain margin to find the locked position when assembling or disassembling the guardrail tube, and thus to simplify the implementation of the method according to the invention.

[0020] The present invention also relates to a device for securing a bay in a wall on a construction site, for the implementation of a securing method according to the invention, comprising at least one guardrail tube, and two supports per guardrail tube.

[0021] Thanks to these provisions, the wall can be reliably secured by means of a particularly simple and quick process, in which the parts used are simple to manufacture, inexpensive, and reusable. Brief description of the drawings

[0022] The present invention and its advantages will become more apparent from the following description of several embodiments given by way of non-limiting examples, with reference to the accompanying drawings, in which:

[0023] [Fig. 1] [Fig. 1] is a schematic front view of a wall secured by the method according to a preferred embodiment of the invention, [Fig. 2] [Fig. 2] is an enlarged view of the detail inscribed in circle F of [Fig. 1], [Fig. 3] [Fig. 3] is a perspective view of the detail of [Fig. 2], [Fig. 4] [Fig. 4] is a view of the position of a guardrail tube in the opening of a support, according to the embodiment of [Fig. 1], with a step A in which the guardrail tube is in the unlocked position, and a step B in which the guardrail tube is in the locked position, [Fig. 5] [Fig. 5] is a perspective view of the support of Figures 1 to 3. Description of embodiments

[0024] In the illustrated embodiments, identical elements or parts bear the same reference numbers. Furthermore, terms with a relative meaning, such as vertical, horizontal, right, left, front, back, above, below, etc., should be interpreted under normal conditions of use of the invention, and as shown in the figures. Moreover, the geometric positions indicated in the description and the claims, such as "perpendicular," "parallel," and "symmetrical," are not limited to the strict sense defined in geometry, but extend to geometric positions that are close, that is, that allow a certain tolerance within the technical field considered, without affecting the result obtained. This tolerance is notably introduced by the adverb "substantially," without this term necessarily being repeated before each adjective.

[0025] The securing method according to the invention, an example of which is illustrated in figures 1 to 5, makes it possible to secure a bay 1 of a wall 2 on a construction site, by fixing a guardrail tube 3 to the wall 2, by means of two supports 4 arranged on either side of the bay 1.

[0026] Each support 4 is fixed to the wall 2 by means of a fastening means 5. The fastening means 5 allows for a partial fixing of the support 4 to the wall 2, in which rotation of the support 4 relative to the wall 2 is possible, about a horizontal axis of rotation 6 perpendicular to the wall 2. In partial fixing, any other movement of the support 4 relative to the wall 2 is blocked. In particular, in this mode, the supports 4 can together support the weight of the guardrail tube 3 and remain fixed to the wall 2 without falling. The fastening means 5 also preferably allows for a complete fixing of the support 4 to the wall 2, in which any movement of the support 4 relative to the wall 2 is blocked.

[0027] Each support 4 has a through opening 7 defined by a contour formed by the material of the support 4 around the opening 7. Along this contour, the support 4 has a reduced thickness, preferably between 2 and 5 mm, for example 3 mm. Thus, when referring to the plane of the opening 7, this refers to the plane in which the contour is inscribed, the latter being defined in a thickness of material sufficiently thin to be considered, by approximation, as planar.

[0028] The opening 7 is configured to be crossed by the guardrail tube 3. It is therefore at the level of the openings 7 that the guardrail tube 3 is held in the position of securing the bay 1 of the wall 2.

[0029] The plane of the opening 7, that is, the plane defined by the contour mentioned above, has an angle of less than 90° with the axis of rotation 6. This is necessary to allow the guardrail tube to pass through it, which is ideally positioned when mounted parallel to, or nearly parallel to, the wall, i.e., perpendicular to, the axis of rotation 6. The angle between the plane of the opening 7 and the axis of rotation 6 is preferably less than 45°. In a preferred embodiment of the invention, the plane of the opening 7 is parallel to the axis of rotation 6, which allows the opening 7 to have a minimal cross-section for the guardrail tube 3 to pass through it.

[0030] When the axis of the guardrail tube 3 is perpendicular to the plane of the opening 7, in other words, when the opening 7 has a maximum cross-section through which the guardrail tube 3 can pass, the respective geometries of the opening 7 and the guardrail tube 3 allow the guardrail tube 3 to slide freely within the opening 7. It is then said to be in the unlocked position, a position which is used to insert the guardrail tube 3 into the openings 7 of the supports 4, or to remove it from these openings 7, and thus to raise or lower the guardrail tube from its position securing the bay 1. The unlocked position is not limited to an angle of exactly 90° between the axis of the guardrail tube and the plane of the opening 7, otherwise it would be tedious for an operator to find this position when implementing the method according to the invention.For example, one can imagine that it is in the unlocked position when the angle formed by the longitudinal axis of the guardrail tube 3 and the opening 7 is greater than or equal to 75, 80, or even 85°.

[0031] However, when the axis of the guardrail tube 3 presents an angle with the plane of the opening 7 that is less than a blocking threshold value, which is for example between 45 and 85°, preferably between 45 and 65°, the guardrail tube 3 becomes pinched in the opening 7 by the contour of the opening 7. The guardrail tube 3 is then locked in position and can no longer slide inside the opening 7. It is then said to be in the locked position, a position which is used to place the guardrail tube 3 in the position for securing the bay 1.

[0032] For each support 4, the opening 7 can take any shape suitable for the invention, for example, a circular shape. Preferably, the opening 7 has a shape with at least three sides, and these three sides are arranged so that when the guardrail tube 3 is in the locked position, it is in contact with each of these three sides. This feature allows for more reliable retention of the guardrail tube 3 in the locked position than if the opening 7 were, for example, circular. Indeed, if the opening 7 is circular, when the support 4 rotates around the axis of rotation 6, the opening 7 presents the guardrail tube 3 with an elliptical shape. If both the opening 7 and the guardrail tube 3 have circular cross-sections, there are therefore only two points of contact between the guardrail tube 3 and the support 4 in the locked position, which provides less reliable retention than with three points of contact.However, an opening shape 7 can be used allowing two, three, four, five, or more than five points of contact between the guardrail tube 3 and the support 4 when the guardrail tube 3 is in the locked position.

[0033] In an embodiment illustrated in Figures 2 to 5, the opening 7 has a hexagonal shape. This shape is not a hexagon in the strict sense, in that all sides are not the same length. More precisely, four sides, intended to be in contact with the guardrail tube in the locked position, have a first length, and the other two sides, which are opposite sides of the hexagon, have a second length greater than the first. The first length is preferably between 16 and 24 mm, for example 20 mm. The second length is preferably between 20 and 28 mm, for example 24 mm. These lengths are, of course, to be adapted according to the cross-section of the guardrail tube 3. This shape ensures that, in the locked position, the guardrail tube 3 is in contact on four sides, thus providing reliable support.The two longer sides, preferably positioned so as not to contribute to pinching the guardrail tube 3 in the locked position, parallel to the wall 2, ensure that the angle of rotation between the locked and unlocked positions is not too small, in other words, that a certain margin of rotation is possible while remaining in the unlocked position, which allows a user to more easily find the unlocked position when, on the one hand, they wish to insert the guardrail tube 3 into the opening 7 during assembly, and on the other hand, remove the guardrail tube 3 from the opening 7 during disassembly.

[0034] Figure 4 illustrates an example of the position of a guardrail 3, relative to an opening 7, in an unlocked position (step A) and in a locked position (step B), with a view along an axis perpendicular to the plane of the opening 7. In step A, the guardrail tube 3 passes through the opening 7 along an axis substantially perpendicular to the plane of the opening 7; its cross-section therefore appears circular in this plane. The guardrail tube 3 can slide within the opening 7, since it is not not necessarily in contact with the contours of opening 7. In step B, the guardrail tube 3 passes through opening 7 along an axis forming an angle of less than 90°, for example, approximately 65°, with the plane of opening 7. Its cross-section therefore appears elliptical in this plane. The guardrail tube 3 is in contact with the contour of opening 7 at four distinct points; it is pinched and cannot slide within opening 7.

[0035] As illustrated in Figures 2, 3, and 5, the supports 4 are preferably made of a metal plate folded in half, comprising a first part 4a including the means for attaching the support 4 to the wall 2 and intended to be pressed against the wall 2, and a second part 4b, perpendicular to the first part 4b, including the opening 7 and intended to extend from the wall 2 at an angle between 85° and 95°, for example 90°. The first part 4a thus allows the support 4 to be attached to the wall 2, and the length of the first part 4a is determined according to the desired distance between the axis of rotation 6 and the second part 4b.The second part 4b allows for the formation of an opening 7 in a plane preferably perpendicular to the plane of wall 2. The length of the second part 4b is determined according to the desired distance between wall 2 and the opening 7, that is, between wall 2 and the guardrail tube 3 when it is in the locked position. The first part 4a, for example, has a rectangular shape, with a length preferably between 10 and 14 cm, for example 12 cm, and a width preferably between 5 and 7 mm, for example 6 cm. The second part 4b, for example, has a square shape, with a length preferably between 5 and 7 mm, for example 6 cm.

[0036] For each support 4, the means of fixing the support 4 to the wall 2 can be a screw, located at the axis of rotation 6, cooperating with sockets integrated into the wall 2. Other means of fixing are possible within the scope of the present invention, such as chemical sealing or parts integrated into the wall, particularly during the pouring of the wall, such as anchor bolts, or mounting rails.

[0037] As illustrated in Figures 2, 3 and 5, the support 4 can therefore be a simple manufactured part, consisting of a rectangular metal plate, preferably with a thickness between 2 and 5 mm, for example 3 mm, bent to define a first part 4a and a second part 4b, rectangular and preferably perpendicular to each other, the first part 4a having a hole configured to cooperate with a fixing means 5 such as a screw, and the second part 4b having an opening 7. Of course, the support 4 can be made in other shapes without departing from the scope of the present invention.

[0038] The guardrail tube 3 is preferably a metallic tube, preferably with a circular cross-section. Its length can be adapted according to the dimensions of Bay 1 to be secured. Its external section can be between 25 and 45 mm, preferably between 30 and 40 mm, for example 34 mm.

[0039] The process according to the invention comprises the following steps: - Partial fixing of the brackets 4 to the wall 2, on either side of the opening 1. The distance between the two brackets 4 is less than the length of the guardrail tube 3. - For each bracket 4, insertion of the guardrail tube 3 into the opening 7. To achieve this insertion, the bracket 4 is positioned, rotating around its axis of rotation 6, so as to present the guardrail tube 3 with a cross-section large enough for the guardrail tube to slide within the bracket 4, corresponding to the unlocked position described above. For example, in the embodiment illustrated in Figures 1 to 3, the bracket 4, after its partial fixing to the wall 2, is driven by its own weight into a position in which the plane of the opening 7 is horizontal, and is located below the axis of rotation 6.In this example, it is necessary to rotate the support 4 by an angle of approximately 90°, for example between 80 and 100°, so that the plane of the opening 7 is close enough to the vertical to insert the guardrail tube 3. - Rotation of the supports 4 around the axis of rotation 6, until the guardrail tube 3 is locked into the openings 7 of the supports 4. This rotation is performed at an angle that allows the guardrail tube 3 to move from the unlocked to the locked position as described above. This angle is therefore, for example, between 20 and 40°, for example, approximately 25°. During this rotation, the guardrail tube 3 is preferably moved downwards. This direction of movement facilitates the operation, requiring less energy from the operator, and ensures that the locked position of the guardrail tube 3 is maintained by the weight of the guardrail tube 3 on the supports 4, even if the supports 4 are not fully fixed to the wall 2.In some embodiments, the force exerted by the weight of the guardrail tube 3 and / or the downward pressure exerted by the operator on the guardrail tube allows the guardrail tube 3 to be clamped in the opening 7 sufficiently securely to provide a satisfactory level of safety for the resulting bay 1, thus eliminating the need for a complete fixing step. This also allows the use of a fixing means 5 that provides partial fixing but does not allow for complete fixing of the support 4 to the wall 2.

[0040] Preferably, the above process then includes a step of fully fixing the supports 4 on the wall 2, in order to reliably secure the position of the guardrail tube 3. Indeed, in full fixing, the supports 4 can no longer be moved in rotation, and the guardrail tube is therefore blocked in the locked position.

[0041] Advantageously, for each support 4, the distance between the plane of the opening 7 and the axis of rotation 6 is greater than or equal to 5 cm. Indeed, if this distance is too weak, in some embodiments, the guardrail tube 3 passing through the opening 7 is not sufficiently far from the axis of rotation 6, which poses a problem when the means of fixing 5 of the support 4 to the wall 2 is at the level of the axis of rotation 6, for example when this means of fixing 5 is a screw, and it is necessary to reach the head of the screw to carry out the complete fixing of the support 4 to the wall 2.

[0042] When the guardrail tube 3 is in the locked position, the line parallel to the wall 2 passing through the axis of rotation of the supports 4 and the center of the section of the guardrail tube 3 at the level of the opening 7 presents, for example, an angle between 25 and 45° with the horizontal.

[0043] In a preferred embodiment, the means for fixing the brackets 4 to the wall 2 are configured such that, during tightening towards full fixing, this tightening tends to cause the brackets 4 to rotate in the same direction as the rotation that occurs during the step of rotating the brackets 4 until the guardrail tube 3 is in the locked position. For example, in the embodiment illustrated in Figures 2 and 3, this rotation is clockwise, and the fixing means 5 is a screw whose thread is oriented such that the tightening direction of the screw is also clockwise. In this embodiment, the step of rotating the brackets 4 until the guardrail tube 3 is in the locked position can then be foreseen to take place in two stages: - Initially, a first partial rotation of the supports 4 is carried out by pushing the guardrail tube 3 downwards and / or by allowing the weight of the guardrail tube 3 to move it downwards. After this first partial rotation, each support 4 has, for example, been moved so that the line parallel to the wall 2, passing through the axis of rotation 6 and the center of the opening 7, forms an angle with the horizontal greater than or equal to 15°, for example between 20 and 25°. - Secondly, a second partial rotation, completing the first partial rotation of the supports 4, is carried out by fully fixing the supports 4 to the wall 2, for example by tightening the fixing screws of the supports 4 to the wall 2.

[0044] The invention also makes it easy to remove the guardrail tube 3 from its position securing bay 1, by means of the following method: - if necessary, changing the fastening means 5 from a full fastening to a partial fastening, - rotation of the supports 4 around the rotation axes 6, in order to move the guardrail tube 3 into the unlocked position, - translation of the guardrail tube 3 along the openings 7, until the guardrail tube exits the openings 7.

[0045] The invention makes it possible, as illustrated in [Fig. 1], to use two or more guardrail tubes 3 to secure an opening 1, each guardrail tube 3 cooperating with two supports 4 as described above. The method described above is then repeated as many times as there are guardrail tubes 3.

[0046] In order to complete the securing of bay 1, a plinth 8 can be placed at ground level, and fixed by known means, as illustrated in [Fig.1].

[0047] Once the progress of the construction site no longer requires their use, the guardrail tube 3 and the supports 4 can be recovered to secure other bays 1, their use being particularly simple and requiring only two fixings on the wall 2 per guardrail tube 3.

[0048] The present invention is not limited to the embodiments described but extends to any modification and variant obvious to a person skilled in the art, within the limits of the appended claims. Furthermore, the technical features of the various embodiments and variants mentioned above may be combined, in whole or in part.

Claims

Demands

1. A method for securing a bay (1) in a wall (2) on a construction site by means of two supports (4) and a guardrail tube (3), each support (4) comprising: - a means for fixing the support (4) to said wall (2), configured to allow partial fixing of the support (4) to the wall (2) in which it is possible to rotate said support (4) relative to the wall (2), around a horizontal axis of rotation (6) perpendicular to said wall (2), and - an opening (7) whose plane has, with said axis of rotation (6), an angle strictly less than 90°, said opening (7) being configured to be traversed by the guardrail tube (3), and such that when the longitudinal axis of the guardrail tube (3) is perpendicular to the plane of the opening (7), the guardrail tube (3) is in the unlocked position and can slide freely along said opening (7),and when the longitudinal axis of the guardrail tube (3) has an angle of less than 45° to 85° with the plane of the opening (7), the guardrail tube (3) is locked in the locked position, pinched in the opening (7), said method comprising the following steps: - partial fixing of the brackets (4) to the wall (2), on either side of said opening (1), - for each bracket (4), insertion of the guardrail tube (3) into said opening (7), the bracket (4) being positioned so that the guardrail tube (3) is in the unlocked position, - rotation of said brackets (4) about said axis of rotation (6), until the guardrail tube (3) is locked in the openings (7) of the brackets (4).

2. A securing method according to claim 1, wherein during the step of rotating the supports (4) until the guardrail tube (3) is in the locked position, the guardrail tube (3) is moved downwards.

3. A securing method according to claim 1 or 2, wherein the means for fixing the support (4) to the wall (2) is configured to allow complete fixing that does not permit any movement of the support (4) relative to the wall (2), said method further comprising the following step, during or after the installation of locked position of the guardrail tube (3) in the openings (7) of the brackets (4): - complete fixing of the brackets (4) to the wall (2).

4. A securing method according to claims 2 and 3, characterized in that the step of rotating said supports (4) about said axis of rotation (6), until the guardrail tube (3) is in a locked position in the openings (7) of the supports (4), comprises the following substeps: - first part of the rotation, driven by the weight of the guardrail tube (3) and / or a manual push on the guardrail tube (3) downwards, and - second part of the rotation, driven by the complete fixing of the supports (4) on the wall (2).

5. A securing method according to claim 4, wherein for each support (4), after the first part of the rotation, the line parallel to the wall (2) passing through the axis of rotation of the supports (4) and the center of the opening (7) has an angle greater than or equal to 15° with the horizontal.

6. A securing method according to any one of claims 4 or 5, wherein for each support (4), the means of fixing (5) to the wall is a screw, and the second part of the rotation is carried out by tightening said screw.

7. A securing method according to any one of claims 1 to 6, characterized in that for each support (4), the opening (7) has a shape having at least three sides, and when the guardrail tube (3) is in the locked position, the guardrail tube (3) is in contact with at least three sides of the opening (7).

8. A securing method according to claim 7, characterized in that for each support (4), the opening (7) has a hexagonal shape, comprising four sides of a first length, and two opposite sides, of a second length greater than the first length.

9. A securing method according to any one of claims 1 to 8, wherein for each support (4), the distance between the plane of the opening (7) and the axis of rotation (6) is greater than or equal to 5 cm.

10. A securing method according to any one of claims 1 to 9, wherein each support (4) is made of a metal plate folded in half at an angle between 85 and 95°.

11. A securing method according to any one of claims 1 to 10, characterized in that when the guardrail tube (3) is in the locked position, the line parallel to the wall (2) passing through the axis of rotation (6) of the supports (4) and the center of the section of the guardrail (3) at the level of the opening (7) has an angle between 25 and 45° with the horizontal.

12. A device for securing an opening (1) in a wall (2) on a construction site, for implementing a securing method according to any one of claims 1 to 11, comprising at least one guardrail tube (3), and two supports (4) per guardrail tube (3), each support comprising: - a means for fixing the support (4) to said wall (2), configured to allow partial fixing of the support (4) to the wall (2) in which it is possible to rotate said support (4) relative to the wall (2), about a horizontal axis of rotation (6) perpendicular to said wall (2), and - an opening (7) whose plane has, with said axis of rotation (6), an angle strictly less than 90°, said opening (7) being configured to be traversed by the guardrail tube (3), and such that when the longitudinal axis of the guardrail tube (3) is perpendicular to the plane of the opening (7),The guardrail tube (3) is in the unlocked position and can slide freely along said opening (7), and when the longitudinal axis of the guardrail tube (3) has an angle of less than 45° to 85° with the plane of the opening (7), the guardrail tube (3) is blocked in the locked position, pinched in the opening (7), the opening (7) having a shape with at least three sides, and the device is configured so that when the guardrail tube (3) is in the locked position, the guardrail tube (3) is in contact with at least three sides of the opening (7).

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