IMPROVED FASTENING ELEMENT FOR SECURING STRUCTURES IN TREES

Description

Technical Field

[0001] This presentation concerns a fastening element for equipment and structures intended to be fixed to trees. Previous technique

[0002] The fixing or anchoring of structures in trees responds to specific constraints and problems, both in terms of safety and structural stability, but also in terms of respecting the trees in which the fixing or anchoring elements are installed.

[0003] Therefore, fasteners or anchors intended for installation in trees to support structures or connecting elements must be designed not only to avoid damaging the tree but also to allow for its growth, while meeting strict safety requirements. US5755542 provides an example of a fastener in a metal support for a fire-resistant structure.

[0004] US patent 4636125 A describes a mounting device for attaching to a shaft or the like an element having a threaded machine mounting rod, said device comprising an elongated body having, at one end, an externally threaded wood screw and, at its other end, a blind hole, machine threads inside said blind hole, and a gripping means attached to said body to facilitate the attachment of said body to a shaft or the like, said body having two parts, a first part comprising said wood screw and a threaded end, the other part being an adapter screwed onto said threaded end and comprising said machine threads, a through hole in each of said parts, said gripping means comprising a pin passing through said through holes in the parts to hold the parts assembled while serving as a handle.

[0005] The present invention thus aims to address at least partially these problems. Description of the invention

[0006] The present invention thus relates to a fastening element adapted to be partially inserted into a tree, comprising a body extending along a longitudinal direction defined by a longitudinal axis, said body comprising successively, from a proximal end to a distal end along the longitudinal direction: a threaded portion, adapted to be inserted into a tree trunk, a collar and a nut, the fastening element comprising a thread extending from the distal end into an internal volume of the nut and into an internal volume of the collar, the fastening element being formed in one piece.

[0007] In the fastening element according to the invention: the threaded portion has a maximum diameter D1 with respect to the longitudinal axis, the collar has a cross-section with a diameter between D32 and D34 along the longitudinal axis, such that D32≤D34, and D32 > 1.3 D1, the nut has a section along a plane perpendicular to the longitudinal axis inscribed in a regular polygon, said regular polygon being inscribed in a circle of diameter D4, such that D4 < D34, and D4 > D1.

[0008] The collar has a cylindrical shape of revolution, such that D32 = D34.

[0009] Alternatively, the collar has a conical shape of revolution, such that D32 < D34, the collar having a section increasing from a proximal end of diameter D32 to a distal end of diameter D34.

[0010] According to one example, the threaded portion comprises a thread consisting of a plurality of threads separated by a groove, the thread having a pitch between 7 and 11 mm, said threads having a triangular shape with a vertex defining an angle between 35 and 45°, the groove between two successive threads extending over a distance greater than or equal to 3mm, each groove between two successive threads having two inclined faces defining an angle between 165° and 175°.

[0011] According to a particular embodiment, the thread having a pitch of 9 mm, said threads having a triangular shape with a vertex defining an angle equal to 40°, the groove between two successive threads extending over a distance between 5 and 6 mm, each groove between two successive threads having two inclined faces defining an angle equal to 170°.

[0012] This presentation also concerns a set including: a fastening element as defined above, a connecting element, having a body extending along a longitudinal direction defined by a longitudinal axis, said body comprising successively, from a proximal end to a distal end along the longitudinal direction * a threaded portion adapted to be engaged in the tapping of the fastening element, * a collar, * a functional portion, said connecting element being formed in one piece, a ring, adapted to partially enclose the threaded portion of the fastening element.

[0013] This presentation also concerns a set including: a fastening element according to one of the preceding claims, a first ring, adapted to enclose the nut of the fastening element, an extension, having a body extending along a longitudinal direction defined by a longitudinal axis, said body comprising successively, from a proximal end to a distal end along the longitudinal direction: a threaded portion, a collar and a nut, in which the threaded portion of the extension is adapted to be engaged in the tapping of the fastener, the collar of the fastener, the collar of the extension and the first ring have the same external section.

[0014] In one example, the extension has a thread extending from the distal end into an internal volume of the nut and into an internal volume of the collar.

[0015] This presentation also concerns such a set, including further a connecting element, having a body extending along a longitudinal direction defined by a longitudinal axis, said body comprising successively, from a proximal end to a distal end along the longitudinal direction * a threaded portion adapted to be engaged in the tapping of the extension, * a collar, * a functional portion, said connecting element being formed in one piece, a second ring, adapted to partially enclose the threaded portion of the fixing element. Brief description of the drawings

[0016] The invention and its advantages will be better understood upon reading the detailed description below of various embodiments of the invention given by way of non-limiting examples. [ Fig. 1 ] There figure 1 presents a fastening element according to one aspect of the invention. Fig. 2 ] There figure 2 represents a fastening element associated with a connecting element. Fig. 3 ] There figure 3 represents a fastening element associated with a connecting element. Fig. 4 ] There figure 4 is a partial cross-sectional view of a fastener associated with an extension. Fig. 5 ] There figure 5 represents a ring for a fastening element according to one aspect of the invention. Fig. 6 ] There figure 6 is a partial cross-sectional view representing the combination of a fastener, a ring, and an extension in exploded view. Fig. 7 ] There figure 7 is a partial cross-sectional view that represents the combination of a fastener, a ring, and an extension. Fig. 8 ] There figure 8 presents an example of a thread for the fastener. Fig. 9 ] There figure 9 presents a variant of the figure 1 .

[0017] Across all figures, common elements are identified by identical numerical references. Description of the implementation methods

[0018] We now describe a fastening element and its associated elements with reference to figures 1 à 8 .

[0019] The figures show a fixing element 100 which comprises a body 10 extending along a longitudinal direction defined by a longitudinal axis XX. In the following description, elements extending axially will be understood as elements extending along the longitudinal axis XX, and elements extending radially will be understood as elements extending radially with respect to the longitudinal axis XX.

[0020] A proximal end 102 and a distal end 104 are arbitrarily defined for the body 110 along the longitudinal axis XX; these designations are purely arbitrary. The proximal and distal ends of the various elements will subsequently be defined with respect to these two ends of the body 110.

[0021] The fastening element 100 comprises successively, from its proximal end 102 to its distal end 104, a first threaded portion 120, a collar 130 and a nut 140. The fastening element 100 is formed in one piece, for example in one piece made from material by molding and machining.

[0022] Optionally, the fastener 100 includes a transition portion 105 interposed between the first threaded portion 120 and the collar 130. The transition portion 105 typically forms a rounded edge with a radius between 1 and 4 mm, typically between 1 and 3 mm, or equal to 2 mm. Such a transition portion 105 improves the mechanical strength of the fastener 100 by preventing the formation of crack initiation points between these two regions having different diameters.

[0023] The first threaded portion 120 includes a thread adapted to allow its insertion into a wood-like material, typically into a tree trunk.

[0024] The first threaded portion 20 typically has a length along the axial direction of between 70 mm and 160 mm, for example between 80 mm and 130 mm, or more precisely between 85 and 100 mm, or even equal to 90 mm.

[0025] There figure 8 presents an example of a thread that can be used to make the first threaded portion 120.

[0026] The first 120 thread as proposed typically has a maximum diameter D1 between 25 and 35 mm, typically equal to 29 mm and a minimum diameter between 15 and 25 mm, typically equal to 20 mm.

[0027] The 125 threads have a triangular cross-section with a truncated vertex 126. Unlike conventional threads, the 125 threads here have a triangular cross-section where the angle A1 at the vertex 126 is between 35° and 45°, typically equal to 40°.

[0028] The apex 126 of the teeth is thus truncated, and defines a flat surface having for example a length of the order of 0.2 to 0.7 mm or equal to 0.5 mm along the longitudinal axis XX.

[0029] The thread as proposed typically has a pitch between 7 and 11 mm, for example equal to 9 mm.

[0030] The successive threads 125 are separated by grooves 127 which have two inclined faces so as to define an angle A2 between 165 and 175°, typically equal to 170°. The creation of grooves instead of flat sections between the different threads improves chip evacuation.

[0031] The thread as proposed offers improved penetration and holding power in wood, particularly in a tree.

[0032] The collar 130 has a cylindrical shape, typically a cylindrical shape of revolution with diameter D3 around the longitudinal axis XX. The diameter D3 of the collar 130 is strictly greater than D1, for example, D3 > 1.3 D1, or D3 > 1.5 D1. The diameter D3 is typically between 30 mm and 80 mm, or between 30 mm and 70 mm, or more precisely between 30 mm and 60 mm, or for example, equal to 40 mm.

[0033] Alternatively, the collar 130 can have a conical or frustoconical shape. For example, the collar 130 can have a frustoconical shape, with a cross-section increasing from diameter D32 to diameter D34 from its proximal end 102 to its distal end 104. In such an embodiment, the diameter D34 is strictly greater than D1, for example, D34 > 1.3 D1, or D34 > 1.5 D1. The diameter D34 is typically between 30 mm and 80 mm, or between 30 mm and 70 mm, or more precisely between 30 mm and 60 mm, or for example, 40 mm. The diameter D32 is strictly less than D34, and is such that D32 > D1. The diameter D32 is typically between 30 and 40 mm. This shape improves shear strength and reduces the stresses applied in the shaft. figure 9 represents such a mode of implementation.

[0034] The collar 130 typically has a length Lc along the axial direction, typically between 25 mm and 70 mm, or for example between 25 mm and 50 mm, or between 30 mm and 40 mm, or for example equal to 35 mm.

[0035] The nut 140 typically has a cross-section along a plane perpendicular to the longitudinal axis XX defining a regular polygon, for example a regular hexagon, which may, for example, have truncated or rounded edges, said regular polygon being typically inscribed in a circle of diameter D4 strictly less than D3, for example such that D3 > 1.1 D4, or D3 > 1.2 D4. The diameter D4 is typically between 20 and 60 mm, for example between 25 and 50 mm, or between 30 and 40 mm, or for example equal to 34 mm.

[0036] Nut 140 typically has a length L40 along the axial direction of between 10 mm and 30 mm, or between 10 mm and 20 mm, or for example equal to 15 mm.

[0037] The fastening element 100 also includes an internal thread 150, extending from the distal end 104 into an internal volume of the nut 140 and into an internal volume of the collar 130.

[0038] The 150 tapped hole typically extends over a length (or depth) L50 along the axial direction, between 30 and 60 mm, or between 30 and 50 mm, for example, equal to 40 mm. The 150 tapped hole is typically of type M20-6H, or more generally of any type suitable for screwing in an additional component, as will be described later.

[0039] We now describe the functions and use of the fixing element 100 as presented.

[0040] The fixing element 100 is suitable for insertion, for example, into a tree, for example for the support of a structure or equipment.

[0041] The first threaded portion 120 is inserted into a shaft by screwing, in particular by means of a tool engaging the nut 140.

[0042] The fixing element 100 is thus inserted into the shaft until the collar 130 is at least partially inserted into the shaft.

[0043] To facilitate insertion, a pre-drilling is typically carried out beforehand in the trunk of the tree, using a drill bit with two distinct sections; a first section having a diameter strictly less than D1 and forming a pre-drilling for the first threaded portion 120, and a second section having a diameter equal to D3, to form a housing receiving the collar 130.

[0044] Thus, nut 140 and, where applicable, a portion of collar 30 remain outside the tree trunk. Keeping a portion of collar 130 outside the tree trunk allows for tree growth, and therefore an increase in its diameter, which gradually covers the rest of collar 130, while keeping nut 140 accessible to allow for the possible removal of the fastener 100.

[0045] The fixing element 100 as shown can be associated with various other elements.

[0046] We represent on the figures 2 et 3 the association of the fixing element 100 with a connecting element 200.

[0047] The connecting element 200, as shown, has a body extending along a longitudinal direction defined by a longitudinal axis (XX). A proximal end 202 and a distal end 204 are arbitrarily defined for descriptive purposes.

[0048] The connecting element 200 has successively, from its proximal end 202 to its distal end 204 along the longitudinal direction XX: a threaded portion adapted 220 to be engaged in the tapped hole 150 of the fixing element 100, a collar 230, and a ring 240. The connecting element 200 is typically formed in one piece, for example in one piece made from material by molding and machining.

[0049] The threaded portion 220 typically includes a complementary thread to the tapped 150.

[0050] The collar 230 has a cylindrical shape, typically a cylindrical shape of revolution, typically with the same diameter as the collar 130 of the fixing element 100.

[0051] Optionally, the connecting element 200 includes a transition portion 205 interposed between the first threaded portion 220 and the collar 230. The transition portion 205 typically forms a rounded shape with a radius between 1 and 4 mm, typically between 1 and 3 mm, or equal to 2 mm. Such a transition portion 105 improves the mechanical strength of the fastener 10 by preventing the formation of crack initiation points between these two regions having different diameters.

[0052] Ring 240 is illustrated as an example. More generally, it is a functional portion 240 of the connecting element 200, notably to allow the fixing of structures or the passage of ropes.

[0053] The connecting element 200 is typically screwed into the fixing element 100 once the latter is inserted into a support such as a shaft. The connecting element 200 can be replaced if necessary, while keeping the fixing element 100 anchored in the support, thus preserving the support.

[0054] There figure 3 This illustrates an example of a connecting element 200 associated with a fastening element 100. In this example, a cover 270 has been positioned around the threaded portion 220 of the connecting element 200, thus concealing the part of the threaded portion 220 that remains outside the fastening element 100 in cases where the threaded portion 220 is longer than the length L50 or the tapping depth 150. Such a cover 270 thus protects the threaded portion 220. The cover 270 is typically a cylindrical sleeve of revolution, having an internal diameter greater than or equal to the external diameter of the threaded portion 220 of the connecting element 220, and having an external diameter typically less than or equal to the external diameter of the collar 230 of the connecting element 200.

[0055] In one embodiment, the cover 270, the collar 230 of the connecting element 200, and the collar 130 of the fastening element 100 have the same external cross-section, thus defining a continuous and uniform or substantially uniform surface, except for chamfers and rounded edges. The cover 270 typically has an internal diameter adapted to fit around the nut 140 of the fastening element 100 in a manner similar to the ring 400 described below.

[0056] THE figures 4, 5 , 6 And 7 present two other elements that can be associated with the fixing element 100.

[0057] The items as shown include a 300 extension cord shown on the figure 4 , and a ring depicted on the figure 5 . THE figures 6 And 7 represent the association with the fixing element 100.

[0058] The 300 extension cord as shown in isolation on the figure 4 is an element adapted to be inserted into the fixing element 100 in order in particular to take into account the growth of the tree into which the fixing element 100 is inserted.

[0059] The extension 300, as shown, has a body extending along a longitudinal direction defined by a longitudinal axis (XX). For descriptive purposes, a proximal end 302 and a distal end 304 are arbitrarily defined.

[0060] The extension 300 has successively, from the proximal end 302 to the distal end 304 in the longitudinal direction: a threaded portion 320, a collar 330 and a nut 340. An internal tapped hole 350 extends from the distal end 304 into an internal volume of the nut 340 and into an internal volume of the collar 330. The extension 300 is typically formed in one piece, for example in one piece produced from material by molding and machining.

[0061] The threaded portion 320 is adapted to be engaged in the tapping 150, or in the tapping 350 of an extension 300 when several extensions 300 are used successively as will be seen later.

[0062] The collar 330 has a cylindrical shape, typically a cylindrical shape of revolution, typically with the same diameter D3 as the collar 130 of the fastener 100. Thus, the collar 330 has a cylindrical shape, typically a cylindrical shape of revolution, with diameter D3 around the longitudinal axis XX. The collar 130 has a diameter D3 that is strictly greater than D1, for example, D3 > 1.3 D1, or D3 > 1.5 D1. The diameter D3 is typically between 30 mm and 80 mm, or between 30 mm and 70 mm, or more precisely between 30 mm and 60 mm, or for example, equal to 40 mm. The 330 collar typically has a length Lc along the axial direction, typically between 25 mm and 70 mm, or for example between 25 mm and 50 mm, or between 30 mm and 40 mm, or for example equal to 35 mm.

[0063] Nut 340 typically has the same geometry as nut 140 of fastener 100. Thus, nut 340 typically has a cross-section along a plane perpendicular to the longitudinal axis XX, defining a regular polygon, for example, a regular hexagon, which may, for example, have truncated or rounded edges. This regular polygon is typically inscribed in a circle with a diameter D4 strictly less than D3, for example, D3 > 1.1 D4, or D3 > 1.2 D4. The diameter D4 is typically between 20 and 60 mm, for example, between 25 and 50 mm, or between 30 and 40 mm, or for example, equal to 34 mm. Nut 340 typically has a length L40 along the axial direction of between 10 mm and 30 mm, or between 10 mm and 20 mm, or for example, equal to 15 mm. Nut 340 allows the extension 300 to be screwed on typically by means of a tool engaging nut 340, such as a wrench.

[0064] The 350 tapped hole typically has the same geometry as the 150 tapped hole of the 100 connecting element. Thus, the 350 tapped hole typically extends over a length (or depth) L50 along the axial direction, between 30 and 60 mm, or between 30 and 50 mm, for example, 40 mm. The 350 tapped hole is typically of type M20-6H, or more generally of any type suitable for screwing in a complementary element, as will be described later.

[0065] Optionally, the extension 300 includes a transition portion 305 interposed between the threaded portion 320 and the collar 330. The transition portion 305 typically forms a rounded shape with a radius between 1 and 4 mm, typically between 1 and 3 mm, or equal to 2 mm. Such a transition portion 305 improves the mechanical strength of the extension 300 by preventing the formation of fracture initiation points between these two regions with distinct diameters. Alternatively, the transition portion may have a cone or truncated cone shape, with a cross-section increasing from its proximal end to its distal end, its distal end typically having a cross-section smaller than that of the proximal end of the collar 130. figure 9 represents such a mode of implementation.

[0066] The 400 ring as shown in isolation on the figure 5 presents an annular sleeve shape, having an internal diameter D4i equal to or substantially greater than the diameter D4, and an external diameter D4e equal to or substantially equal to the diameter D3. The ring is typically formed in one piece, for example in one piece obtained from material by molding and machining.

[0067] The ring 400 typically has a length L400 greater than or equal to the length L40 of the nut 140 of the fastener 100 or of the nut 340 of the extension 300.

[0068] THE figures 6 And 7The diagrams show the assembly of the ring 400 and the extension 300 on a fastener 100, typically assuming that the fastener 100 has been inserted into a support such as a shaft. The ring 400 is then positioned to encircle the nut 140 of the fastener 100. The internal diameter of the ring 400 is typically sized to allow the ring 400 to fit around the nut 140, thus centering the ring 400 around the longitudinal axis XX. Next, the extension 300 is screwed into the fixing element 100, or more precisely, the threaded portion 320 of the extension 300 is screwed into the thread 150 of the fixing element 100, typically until the extension 300 clamps the ring 400 between the collar 130 of the fixing element 100 and the collar 330 of the extension 300.

[0069] Since the ring 400, the collar 130 of the fixing element 100 and the collar 330 of the extension 300 have the same external section, a continuous and substantially smooth external surface is obtained, except for the rounded edges.

[0070] The combination of ring 400 and extension 300 on the fixing element 100 allows the device to adapt as the tree grows. Indeed, as the tree into which the fixing element 100 is inserted grows, the external diameter of the trunk increases, and the trunk gradually encircles the fixing element 100, which could eventually render the fixing element 100 unusable or necessitate its replacement.

[0071] The proposed system allows for the insertion of a 300 extension into the 100 fixing element, while the 400 ring prevents the formation of grooves or cavities that could disrupt the tree's growth. Several 300 extensions and 400 rings can be assembled successively to obtain the desired length. A 200 connecting element, as shown in the diagram, can then be inserted. figures 2 et 3 , typically with or without cover 270, or any other element comprising a thread suitable to cooperate with the tapping 350 of an extension 300 and having a functional portion 240.

[0072] The various elements as proposed thus offer a modular, robust fixing and anchoring system that respects the trees into which the 100 fixing elements are inserted, taking into account their growth.

[0073] The proposed system avoids the need to replace the fixing elements 100 due to tree growth. Replacing the fixing element is clearly more damaging to the tree than adding an extension as proposed. Furthermore, the use of a ring 400 as proposed promotes growth by preventing the formation of roughness and irregularities that could disrupt the tree's development and potentially weaken it. In addition, by ensuring a virtually continuous external surface, the fixing element 100 can still be removed without damaging the tree. This would not be possible without the ring 400, as the tree would then form a shoulder around the collar 130 of the fixing element 100, requiring partial destruction to remove the fixing element 100.

[0074] Although the present invention has been described with reference to specific embodiments, it is evident that modifications and changes can be made to these examples without departing from the general scope of the invention as defined by the claims. In particular, individual features of the various embodiments illustrated / mentioned can be combined in additional embodiments. Therefore, the description and drawings should be considered in an illustrative rather than restrictive sense.

[0075] It is also evident that all the characteristics described with reference to a process are transposable, alone or in combination, to a device, and conversely, all the characteristics described with reference to a device are transposable, alone or in combination, to a process.

Claims

1. A fastening element (100) able to be partially inserted into a shaft, comprising a body extending according to a longitudinal direction defined by a longitudinal axis (X-X), said body comprising successively, from a proximal end (102) toward a distal end (104) according to the longitudinal direction: - a threaded portion (120), able to be inserted into a tree trunk, - a collar (130), and - a nut (140), the fastening element (100) comprising a tapped bore extending from the distal end (104) into an internal volume of the nut (140) and into an internal volume of the collar (130), the fastening element (100) being formed in a single piece, - the threaded portion (120) presenting a maximum diameter D1 relative to the longitudinal axis, - the collar (130) presenting a section of diameter between D32 and D34 according to the longitudinal axis, such that D32 ≤ D34, and D32 > 1.3 D1, the nut (140) presenting a section according to a plane perpendicular to the longitudinal axis (X-X) inscribed in a regular polygon, said regular polygon being inscribed in a circle of diameter D4, such that D4 < D34, and D4 > D1, wherein the collar (130) presents - a cylindrical shape of revolution, such that D32 = D34, or - a conical shape of revolution, such that D32 < D34, the collar presenting a section increasing from a proximal end of diameter D32 toward a distal end of diameter D34.

2. The fastening element (100) according to claim 1, wherein the threaded portion (120) comprises a thread comprising a plurality of threads (125) separated by a groove (127), the thread presenting a pitch between 7 and 11 mm, said threads (125) presenting a triangular shape with an apex (126) defining an angle (A1) between 35 and 45°, the groove (127) between two successive threads (125) extending according to a distance greater than or equal to 3 mm, each groove (127) between two successive threads (125) presenting two inclined flanks defining an angle (A2) between 165° and 175°.

3. The fastening element (100) according to claim 2, wherein, the thread presenting a pitch of 9 mm, said threads (125) presenting a triangular shape with an apex (126) defining an angle (A1) equal to 40°, the groove (127) between two successive threads (125) extends according to a distance between 5 and 6 mm, each groove (127) between two successive threads (125) presenting two inclined flanks defining an angle (A2) equal to 170°.

4. Assembly comprising: - a fastening element (100) according to one of claims 1 to 3, - a connecting element (200), presenting a body extending according to a longitudinal direction defined by a longitudinal axis (X-X), said body comprising successively, from a proximal end (202) toward a distal end (204) according to the longitudinal direction: * a threaded portion (220) able to be engaged in the tapped bore (150) of the fastening element (100), * a collar (230), * a functional portion (240), said connecting element (200) being formed in a single piece, - a ring (400), able to partially surround the threaded portion (120) of the fastening element (100).

5. Assembly comprising: - a fastening element (100) according to one of claims 1 to 3, - a first ring (400), able to surround the nut (140) of the fastening element (100), - an extension (300), presenting a body extending according to a longitudinal direction defined by a longitudinal axis (X-X), said body comprising successively, from a proximal end (302) toward a distal end (304) according to the longitudinal direction: a threaded portion (320), a collar (330), and a nut (340), - wherein the threaded portion (320) of the extension (300) is able to be engaged in the tapped bore (150) of the fastening element (100), the collar (130) of the fastening element (100), the collar (330) of the extension (300), and the first ring (400) presenting a same external section.

6. Assembly according to claim 5, wherein the extension (300) presents a tapped bore (350) extending from the distal end (304) into an internal volume of the nut (340) and into an internal volume of the collar (330).

7. Assembly according to one of claims 5 or 6, comprising - a connecting element (200), presenting a body extending according to a longitudinal direction defined by a longitudinal axis (X-X), said body comprising successively, from a proximal end (202) toward a distal end (204) according to the longitudinal direction: * a threaded portion (220) able to be engaged in the tapped bore (350) of the extension (300), * a collar (230), * a functional portion (240), said connecting element (200) being formed in a single piece, - a second ring (400), able to partially surround the threaded portion (120) of the fastening element (100).