RUBBING PLATE FOR A WOOD JOINT

Description

[0001] The invention relates to a friction plate for a wood joint and to a wood joint formed with the friction plate.

[0002] It is known to join wooden beams with butt joints using a shear or tension shear connection. For example, one end of a beam is attached to another beam at an angle of 0° to 90° and fastened there with screws or other pin-type fasteners. The screws can be driven at an angle through both or more beams, particularly at a 90° angle from the side opposite one of the beams.

[0003] It is also known to fasten wooden beams to a concrete wall or a metal plate, e.g., a timber connector. For this purpose, screws or pin-shaped fasteners are screwed through the wood and then into the concrete wall or the metal plate.

[0004] A disadvantage of wood joints is always that the loads holding the joints are too low, and higher load-bearing capacities or higher stiffnesses are desired.

[0005] The object of the present invention is therefore to increase the load-bearing capacity and / or the stiffness of wood joints.

[0006] The object is achieved according to the invention by a friction plate having the features of claim 1 and a wood joint created with the friction plate according to the further main claim.

[0007] Document US2,990,058A discloses a friction plate according to the preamble of claim 1.

[0008] At a joint, the first and second connecting elements abut each other, with the friction plate positioned between them. Preferably, the connecting elements rest fully against the friction plate at the joint, so that they make contact with the friction plate as evenly as possible. However, it is also possible for sections of the connecting elements to rest directly against each other. The resulting wood joint between the first connecting element, the friction plate, and the second connecting element is held together by fasteners, in particular wood screws. The fasteners thus press the connecting elements against the friction plate with a specific contact pressure.Due to the roughening of the respective contact surface of the friction plate, the connecting element has a higher static friction against the friction plate than would be the case with a wood joint without a friction plate. The increased static friction between the elements, caused by the friction plate, counteracts any relative displacement of the elements; that is, the initial displacement of the connecting elements relative to each other is made more difficult. A relative displacement of the elements relative to each other therefore only occurs under higher loads compared to a wood joint without a friction plate. The roughening of the contact surfaces of the friction plate can be achieved through projections or recesses, such as milled grooves. The crucial point is that only the roughness of the respective contact surface is increased, thereby increasing the static friction between the connecting elements.This contrasts with metal plates for wood connections, which have projections, e.g., in the form of hooks, that penetrate the wood. The plate according to the invention is specifically designed to avoid this penetration of projections; instead, it aims to increase only the static friction between the elements to be joined, i.e., the two connecting elements and the friction plate.

[0009] Comparing the load-bearing capacities of two identical timber joints (comprising a first connecting element made of wood, a second connecting element, and fastening elements to hold the connecting elements together), where one timber joint is formed with and one timber joint without the friction plate between the connecting elements, the friction plate – with the same contact pressure from the fastening elements – ensures a higher static friction between the elements and thus a higher load-bearing capacity, because the "slipping" of the elements relative to each other only occurs at higher load-bearing capacities.

[0010] The carrier of the friction plate can consist of a metal, e.g. aluminium or steel, in particular stainless steel, or plastic, in particular a glass fiber reinforced plastic, a laminate, nonwoven fabric or multi-layered paper, e.g. single-sided or double-sided sandpaper.

[0011] If the substrate is made of plastic, laminate, non-woven fabric, or multi-layered paper, additional roughening can be introduced into the substrate by embedding small spheres within it. For example, small stones, small spheres of hard plastic, small shards of glass, or similar materials can be embedded in the substrate. It is crucial that these spheres are sufficiently hard so that they are not compressed by the contact pressure, and that they protrude only slightly from the substrate to merely increase the static friction with the connecting element.

[0012] The first connecting element can be, for example, a wooden beam, especially for roof construction, e.g., a girder.

[0013] The second connecting element can be made of wood, in particular a wooden beam, or of steel, e.g. a steel beam, or a section of a building wall, e.g. made of masonry or concrete.

[0014] The friction plate according to the invention is therefore suitable for wood connections between a connecting element made of wood and another connecting element, which can be made of wood, steel, concrete or masonry. Fastening elements, e.g. screws, hold the first and the second connecting elements, between which the friction plate is arranged, together.

[0015] The roughening can be formed on one carrier connection side or both carrier connection sides of the friction plate.

[0016] The friction plate has a first support surface for contact with the first connecting element and a second support surface for contact with the second connecting element. The roughening can be present on both sides or on one side. In the first case, one roughened support surface rests against each connecting element. In the second case, the friction plate has only one roughened support surface that rests against a connecting element. In this variant, the opposite, unroughened support surface is preferably firmly connected to the other connecting element. For example, the friction plate with its smooth support surface can be firmly attached to a connecting element before the wood joint is assembled, e.g., by screwing it in place, thus preventing the friction plate from slipping relative to that connecting element.This variant is particularly preferred in applications where a metal component is permanently connected to a connecting element, e.g., a joist hanger is permanently attached to a connecting element, for example, by being screwed to it. The outer surface of the joist hanger, which is intended to rest against the other connecting element to form the wood connection, has a roughened surface to increase the static friction between the joist hanger and the adjacent connecting element – ​​the joist hanger is already permanently attached to the other connecting element, for example, by being screwed to it.

[0017] The roughening is advantageously formed in at least one section of the respective beam connection side and preferably fills the entire beam connection side. However, for the formation of the wood joint, it is sufficient if the roughening is formed in the section of the beam connection side where the friction plate rests against the respective connection element; preferably, however, at least half of this area is roughened to achieve higher static friction and thus a higher load-bearing capacity.

[0018] In at least one section, the roughening is formed in a first variant by pyramid-shaped or cone-shaped projections, which are preferably arranged in a matrix-like manner.

[0019] In at least one section, the roughening is formed in a second variant by milled grooves in the form of lines.

[0020] The different types of roughening, such as protrusions and milled grooves, can occur separately or in a mixed form. For example, one section of a beam connection face might have only protrusions, while another section might have only milled grooves. However, a section of a beam connection face could also contain both protrusions and milled grooves.

[0021] If the friction plate has pre-punched holes for mounting fasteners, the burr created during the punching process can serve as additional roughening. Alternatively, the roughening, e.g., linear indentations, can be incorporated during the rolling of the sheet metal to manufacture the friction plate. Roughening elements can also be permanently attached to a smooth friction plate substrate. For example, sandpaper can be glued to one side of the substrate to create additional roughening. Similarly, fabrics can be firmly glued to a substrate connection side to create additional roughening.

[0022] The support has a thickness of 0.2 to 12mm, in particular from 0.5 to 4mm.

[0023] The roughening of the respective support connection side, in the form of protrusions or milled lines, has a height or depth of 0.5 to 1.5 mm compared to the surface of the respective support connection side.

[0024] Since the roughened surface only rises slightly from the surface of the respective support connection side, simply applying the roughened surface to the connection element increases the static friction. Therefore, when creating the wood joint, especially when tightening the fasteners, no force is required to press the roughened surface into the wood.

[0025] Advantageously, the friction plate has at least one through-hole to allow a fastening element, in particular a wood screw, to be guided through it when forming the wood joint.

[0026] The friction plate can also be drilled through by a wood screw, especially a self-drilling wood screw, without pre-drilling. To enable the friction plate to be drilled through by a wood screw without pre-drilling, several parameters can be appropriately selected: For example, the material of the friction plate's support can be chosen. Suitable materials include plastics or soft metals such as aluminum. Alternatively or additionally, the support's thickness can be selected to allow for easy drilling, for example, a thickness of less than 3 mm. At least one fastening element is advantageously provided by screws, especially wood screws, and / or dowels, especially self-drilling dowels.

[0027] Further features, details and advantages of the invention will become apparent from the claims and the following description of preferred embodiments, as well as from the drawings. These show: Fig. 1a) a cross-sectional view and b) a top view of a friction plate, Fig. 2a) a top view and b) a side view and c) a cross-sectional view of a shear connection with the friction plate of the Fig. 1 , Fig. 3a) a side view and b) a cross-sectional view and c) a top view with a friction plate as in Fig. 1 , however with a different base area, Fig. 4a) a first side view and b) a second side view and c) a top view of a joist hanger with a friction plate in a further embodiment, Fig. 5a) a first cross-sectional view and b) a side view and c) a top view of a timber joint with the joist hanger of the Fig. 4, Fig. 6a) a cross-sectional view and b) a top view of a friction plate in a further embodiment, and Fig. 7 the friction plate of the Fig. 6 between two connecting elements made of wood to form a wood connection.

[0028] Fig. 1a ) shows a cross-sectional view and Fig. 1b ) a top view of a friction plate 1 in a first embodiment with a support 1T and a roughening 3 in the form of projections 3V. The friction plate 1 has two opposite side surfaces as first and second support connection sides 1ETAS, 1ZTAS for connection with a respective connection element 7, 9 (in Fig. 1 (not shown).

[0029] The friction plate 1 is made of stainless steel and has through holes 1D for the insertion of fastening elements 11 (in Fig. 1(not shown) the through holes were punched into the friction plate 1. The through holes 1D were punched into the friction plate 1 such that each through hole has an annular collar as a projection 3V. The projections 3V form the roughening 3 of the respective carrier connection side 1ETAS, 1ZTAS. The through holes 1D and thus the projections 3V are arranged in a matrix pattern, with the projections 3V protruding alternately from both carrier connection sides 1ETAS, 1ZTAS.

[0030] The carrier 1T of the friction plate 1 has a thickness of 0.8 mm. The projections 3V protrude 0.25 mm from the surface 1O of the respective carrier connection sides 1ETAS, 1ZTAS.

[0031] Fig. 2 shows a wood joint 5 with a first and a second connecting element 7, 9, wherein the friction plate 1 is located between these. Fig. 1is arranged. The first and second connecting elements 7, 9 are each a wooden beam. The two connecting elements 7, 9 lie flat against each other at one of their respective ends. As particularly evident from the Fig. 2b As can be seen in the diagram, the connecting elements have a contact area larger than the friction plate 1. As shown in the diagram, the connecting elements have a contact area larger than the friction plate 1. Figures 2a) and 2c As shown in the figure, the friction plate 1 is attached to the connecting element 7 with a nail 13, and a wood screw 11 is screwed through the other connecting element 9 and through a through hole 1D in the friction plate 1 into the connecting element 7. The wood screw 11 is a self-drilling wood screw and is countersunk flush in the connecting element 9. A thread of the wood screw 11 is completely in the connecting element 7 and an unthreaded shank is completely in the connecting element 9, so that a head of the wood screw 11 presses the connecting element 9 against the connecting element 7. Fig. 2Only one wood screw 11 is shown, which presses the connecting elements 7, 9 together. Further wood screws 11 can be screwed through the connecting elements 7, 9 and the friction plate 1 to hold them together, depending on the application and / or load-bearing capacity.

[0032] Fig. 3 Figure 1 shows a wooden joint 5 between two wooden beams as connecting elements 7, 9, between which a friction plate 1 is arranged. While the connecting elements 7, 9 are in the Fig. 2 Running parallel to each other, the connecting elements 7 and 9 of the Fig. 3 They form an angle of approximately 135° with each other. The friction plate 1 of the Fig. 3 is analogous to the friction plate 1 of the Fig. 1 It is constructed, but instead of a square base, it has a trapezoidal one. As in Fig. 2a As shown, the projections 3V forming through holes 1D are arranged in two rows through which wood screws 11 are screwed, as in particular the Figures 3b) and 3c ) can be seen. How to Fig. 2 As described, the thread of the wood screws 11 is completely in one connecting element 7 and the unthreaded shank of the wood screws is completely in the other connecting element 9, with the friction plate 1 being arranged between them and the wood screws being screwed through through holes 1D.

[0033] Fig. 4 shows a steel beam shoe 15 in three views. Particularly the Figures 4b) and 4c As can be seen from the diagram, there are 15 through holes in one side of the beam shoe arranged in a matrix-like manner, forming projections 3V, as described above. Fig. 4b ) shows four through holes 1D in two opposite sides of the beam shoe 15, which do not form any projections 3V.

[0034] Fig. 5 shows the beam shoe 15 of the Fig. 4, wherein a first connecting element 7 in the form of a wooden beam is inserted into the joist hanger 15 in order to connect it at a 90° angle to a further connecting element 9 in the form of a wooden beam. The connecting element 7 is fastened in the joist hanger 15 by means of wood screws 11 screwed through the through holes 1D on the opposite sides of the joist hanger 15, which do not form any projections 3V, see in particular Fig. 5cThrough the through holes 1D of the joist hanger 15, which form projections 3V, wood screws 11 are screwed into the further connection element 9. The side surface of the joist hanger 15 with projections 3V, which rests against the connection element 9, forms a friction plate 1. The friction plate 1 differs from those described above, among other things, in that, firstly, the roughening 3 is only formed on one beam connection side 1ETAS (and the other beam connection side 1ZTAS has no roughening 3), and secondly, the friction plate 1 is an integral part of another component, in this case forming a part or section of the joist hanger 15.

[0035] Fig. 6Figure 1 shows another embodiment of the friction plate 1. In this case, the friction plate 1 has a plastic carrier 1T. Small stones 17 were cast into the carrier 1T during its casting, so that the stones 17 are enclosed and held by the plastic. The stones 17 are irregularly cast into the carrier 1T, as can be seen in particular from the figure 1. Fig. 6b ) can be seen.

[0036] The plastic from which the carrier 1T is cast is a hard plastic, making the carrier 1T rigid. However, it is also possible to use a soft plastic, allowing the carrier 1T to be rolled up. In this version, the friction plate 1 can be in the form of a roll, from which the required pieces of the desired size can be cut off.

[0037] The support 1T of the friction plate 1 has a thickness of 1.5 mm. The stones have a maximum size of 2.5 mm, so that they protrude no more than 1 mm from a surface 1O of the support.

[0038] Fig. 7 Figure 1 shows a wooden connection 5 between two connecting elements 7, 9 (each a wooden beam), with the friction plate 1 between them. Fig. 6 The wooden beams 7 and 9 were arranged to create the wood joint 5, and the friction plate 1 was positioned between them. Wood screws 11 were then driven through the connecting element 7 and the friction plate 1 into the connecting element 9. Pre-drilling of the connecting elements 7 and 9 or the friction plate 1 is not necessary, as the wood screws 11 are self-drilling. The wood screws can easily penetrate the friction plate 1 because the friction plate 1 is made of plastic and is only thin.

[0039] The friction plate 1 is designed in the embodiments described above such that several fastening elements 11 can be passed through it. However, it is possible to manufacture the friction plate 1 in a circular shape, e.g., with a diameter of less than 15 cm, in particular less than 10 cm, or in a square shape, e.g., with an edge length of less than 15 cm, in particular less than 10 cm. In this embodiment, friction plates 1 can be arranged at selected locations of a wood joint 5, and a fastening element 11 can be passed through each of them to increase the static friction only at these selected locations. One or more such friction plates 1 can be arranged between the two connecting elements 7, 9, optionally with the possibility of additionally adding one or more friction plates 1 of the embodiments described above. Figures 1 to 7 can be used.

[0040] Thus, several identical or several different friction plates 1 can be arranged between the connecting elements 7, 9 to form the wood connection 5. Reference symbol list

[0041] 1 Friction plate 1D Through hole 1T Beam 1ETA First beam connection side 1OO Beam surface 1ZTA Second beam connection side 3 Roughening 3V Projection 5 Wood connection 7 First wooden connection element 9 Second connection element 11 Fastening element 13 Nail 15 Beam shoe 17 Stone

Claims

1. A friction plate (1) for a wood connection (5) between a first connection element (7) made of wood and a second connection element (9), comprising a plate-shaped support (1T) with a first support connection side (1ETAS) for the planar connection to the first connection element (7) and a second support connection side (1ZTAS) for the planar connection to the second connection element (9), and a roughening (3) of at least one section of the first and / or second support connection side (1ETAS, 1ZTAS), characterized in that the roughening (3) is formed in at least one section by pyramid-shaped projections (3V), conical projections (3V) or milled-in portions in linear form; and the support (1T) has a thickness of 0.2 to 12 mm, in particular of 0.5 to 4 mm, and the pyramid-shaped projections (3V), the conical projections (3V) or the milled-in portions in linear form have a height or depth of 0.5 to 1.5 mm with respect to the surface (1O) of the respective support connection side (1ETAS, 1ZTAS).

2. The friction plate according to claim 1, characterized in that the support (1T) consists of a metal, for example aluminum or steel, in particular stainless steel, or plastic, in particular a glass-fiber-reinforced plastic, a laminate, a nonwoven or multi-ply paper, for example one or two-sided abrasive paper.

3. The friction plate according to claim 1 or 2, characterized in that the first connection element (7) is a wooden beam, in particular for roofing, for example a support.

4. The friction plate according to one of the preceding claims, characterized in that the second connection element (9) consists of wood, in particular is a wooden beam, or consists of steel, for example is a steel support, or is a wall section of a building, for example made of masonry or of concrete.

5. The friction plate according to one of the preceding claims, characterized in that the roughening (3) is formed on one support connection side (1ETAS; 1ZTAS) or both support connection sides (1ETAS, 1ZTAS).

6. The friction plate according to one of the preceding claims, characterized in that the roughening (3) is formed in at least one section of the respective support connection side (1ETAS, 1ZTAS), preferably fills the entire support connection side (1ETAS, 1ZTAS), or has a roughening (3) in the section of the support connection side (1ETAS, 1ZTAS), with which it bears against the connection element (7, 9), but preferably at least half of this area.

7. The friction plate according to one of the preceding claims, characterized in that the projections (3V) are arranged in a matrix-like manner.

8. The friction plate according to one of the preceding claims, characterized by at least one through-hole (1D), in order to guide a fastening element (11), in particular a wood screw, through it when forming the wood connection (5).

9. The friction plate according to one of the preceding claims, characterized in that the friction plate (1) can be drilled through without pre-drilling by a wood screw (11), in particular a self-drilling wood screw, for example by a suitable choice of the material of which the support (1T) consists, for example plastic or aluminum.

10. A wood connection between a first connection element (7) made of wood and a second connection element (9), wherein a friction plate (1) according to one of the preceding claims is arranged between the first and the second connection element (7, 9), and at least one fastening element (11) for holding the friction plate (1) and the first and the second connection element (7, 9) against one another.

11. The wood connection according to the preceding claim, characterized in that the at least one fastening element (11) is formed by screws, in particular wood screws, further in particular self-drilling wood screws, and / or drill rod dowels, in particular self-drilling drill rod dowels.