CONNECTOR FOR TWO COMPONENTS

A connector for two components comprises two fittings each with a mounting side, an abutment side opposite the mounting side, and an end face connecting the mounting and abutment sides. At the end faces the fittings may be hooked into one another. The fittings are made of wood or of wood-plastic composite and have one or more generally cylindrical blind holes on their abutment side. The connector comprises, for each blind hole, a molding for removable insertion into the blind hole. The molding has a base surface, a top surface parallel thereto, a substantially generally cylindrical lateral surface connecting these two, and a slanted bore for a mounting screw. The bore penetrates the molding at an acute angle to the base and top surfaces.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to European Patent Application No. 22 184 024.2 filed Jul. 11, 2022 the disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a connector for two components, in particular wooden components. The connector comprises two fittings, each of which has a mounting side for mounting on one of the components and an abutment side opposite the mounting side for contact against the other of the components, wherein the two fittings may be hooked into one another at an end face connecting the mounting and abutment sides, for which purpose the end face has, over its entire length running along the abutment side, a shoulder which is flush with the abutment side and the width of which in the direction orthogonal to the abutment side corresponds substantially to half the width of the end face.

BACKGROUND

Connectors of this type are particularly suitable for establishing heavy-duty connections in timber engineering, for example for connecting main, secondary or transverse beams, cross members, girders, columns, posts, walls or the like. The fittings are made of metal, for example high-strength aluminium or steel, and the components to be connected are made of wood, in particular glued laminated timber (glulam), laminated beams, etc. At least one of the components may alternatively be made of, for example, concrete, stone, masonry or even metal. For example, EP 3 985 189 A1 describes a connector with a comparable shoulder at its end face.

The fittings of such connectors are usually high-strength but hardly elastic, and therefore they tend to break under strong load impacts, for example during an earthquake or a sudden load peak, and frequent alternating loads, even of lesser magnitude, may lead to fatigue fractures. Due to the often multiple bolting of the fittings to their respective components, this does not lead to immediate failure of the connector in every case, but it does weaken the connection decisively, which often goes unnoticed until complete failure later on.

BRIEF SUMMARY

The invention aims to create a connector for a particularly durable connection of components even under high alternating and peak loads on the components.

This objective is achieved with a connector for two components, comprisingtwo fittings, each of which has a mounting side for mounting on one of the components and an abutment side opposite the mounting side for contact against the other of the components,wherein the two fittings may be hooked into one another at an end face connecting the mounting and abutment sides, for which purpose the end face has, over its entire length running along the abutment side, a shoulder which is flush with the abutment side and the width of which shoulder in the orthogonal direction to the abutment side corresponds substantially to half the width of the end face,wherein the fittings are made of wood, optionally of plywood, or of wood-plastic composite,wherein each fitting has one or more generally cylindrical blind holes on its abutment side,wherein the connector further comprises, for each blind hole, a molding for removable insertion into the blind hole,the molding having a base surface, a top surface parallel thereto, a substantially generally cylindrical lateral surface connecting the base and top surfaces, and a slanted bore for a mounting screw,wherein said slanted bore penetrates the molding at an acute angle to the base and top surfaces.

When hooking into each other, the aforementioned end faces of the fittings are placed one on top of the other, wherein the aforementioned shoulders engage behind each other, which leads to a secure connection of the components. In this context, wood or wood-plastic composite is also elastic despite its respective strength, wherein plywood achieves particularly high strength values, so that, on the one hand, fatigue phenomena and fractures are much less likely and, on the other hand, large load impacts are damped, which significantly reduces the risk of fracture and extends the service life of the connector and the connection. Wood-plastic composites (“WPC”) are made of wood—mostly wood flour—and plastics as well as additives, including flame retardants, and may be processed similarly to plastics.

Even if metal fittings generally have a higher strength, it should be noted that, for fire protection reasons, metal fittings usually have to be encased in a fireproof manner. When joining wooden components, the encasement is usually achieved by countersinking the fittings and thus protecting them from heat and fire from the surrounding wood of the wooden components. On the one hand, the countersinking makes assembly more difficult; on the other hand, the encasement reduces the possible size of the fittings: the fittings must be smaller, by the thickness of the encasement, than the abutment faces of the components against each other. By contrast, the wooden or WPC fittings may use the entire abutment faces and are therefore larger than metal fittings for the same components, which benefits the strength.

The moldings could also be made of wood or WPC or of conventional plastic, for example a fibre-reinforced plastic. In one embodiment, each molding is made of metal, optionally steel. This embodiment takes advantage of the strength of metal, in particular steel. The strong moldings made of metal lead to a particularly good transmission of force between the mounting screws and the fitting. Since each molding is individually inserted into a blind hole of the (elastic) fitting in the assembly position, the risk of breakage is extremely low, even under very high loads or due to fatigue.

In order to achieve good fire resistance of the connector, it is advantageous if each of the blind holes of each fitting has a minimum distance of 2 cm, optionally between 4 and 6.5 cm, from the periphery of the abutment side of the fitting. By choosing the minimum distance, any fire protection requirements may be easily met.

The fittings may be used with moldings that differ in the size of the acute angle as required, for example to achieve adaptation to different grain directions of wooden components. On the other hand, in order to prepare for rapid assembly on site, it is convenient if, from each of the blind holes of each fitting, there is a bore inclined in the direction of the said end face of the fitting and penetrating the mounting side, which bore is arranged and oriented in such a way that, when a molding is inserted, its slanted bore may be brought into alignment with the bore. This also facilitates the correct screwing in of the mounting screws.

Depending on the material and load of the components, for example the woodgrain direction of wooden components, the aforementioned acute angle is optionally between 15° and 60°, further optionally between 25° and 50°. This leads to a reliable, firm connection of the components.

In order to evenly transfer forces from one component to the other, it is advantageous if each fitting has at least two blind holes, wherein the blind holes are arranged mirror-symmetrically to an axis of the abutment side that is orthogonal to and bisects the aforementioned end face. In a higher number, the mounting screws not only introduce the forces more evenly into the respective component, but in the case of a wooden component, they also strengthen the wood in the region of the fittings.

It is also advantageous if each fitting has a central end-face bore on said end face, orthogonal to the end face, into which hole a pin or screw may be inserted. The fittings are thus secured against slipping along the shoulder, i.e. parallel to both the end face and the abutment side. If the pin (or the screw) is inserted into the end-face bore of a fitting before the fittings are hooked into each other, it additionally has a centring effect when the fittings are hooked into each other. Alternatively, in an advantageous embodiment, the pin or the screw may be inserted only after the hooking operation, for which purpose at least one of the fittings is completely penetrated by said end-face bore.

It is particularly favourable if, as the height of the shoulder at the end face of each fitting increases, its width decreases and at half the height corresponds to half the width of the end face. The contact faces of the shoulders that come into contact with each other when the two fittings are hooked into each other are thus slanted, i.e. in such a way that the components are pulled together when they are hooked in. This simplifies the hooking and guarantees a secure fit of the components together.

To protect the fittings from sharp-edged loads, the slanted bore of each molding optionally penetrates its base surface without touching the edge between the base surface and the lateral surface. This edge thus runs around the base surface of the molding without any angular or sharp-edged interruptions and thus lies gently in the blind hole even under high tensile loads caused by the mounting screw for the fitting.

It is advantageous if the moldings are flush with the abutment side after insertion into the blind holes, for which purpose the blind holes have a depth that corresponds to the thickness of the moldings from their base to their top surfaces. On the one hand, this allows the abutment side to be in contact over its entire surface with the other component after assembly, which stabilises the connection. On the other hand, no installation space remains unused or the strength of the fittings is not reduced by excessively deep blind holes.

In an advantageous embodiment, each molding may be received in the blind hole with a form fit, and the blind hole has a recess for screwing in the mounting screw in a region facing away from said end face. The blind hole is thus adapted to the generally cylindrical shape of the molding and the molding lies with its base and—largely—its lateral surfaces against the blind hole, resulting in good introduction of force from the mounting screw via the molding into the blind hole and the fitting. Nevertheless, the mounting screw may be screwed in unhindered.

It is also advantageous if the base surface of each fitting is round. A complementary blind hole in the fitting is particularly easy to produce by milling or drilling. Furthermore, the force introduction of a round molding into the fitting is particularly uniform, since local force peaks, which would occur at the corners of an angled molding, for example, are avoided.

In an optional embodiment, each fitting is penetrated by at least one straight bore for a tension screw, said hole being orthogonal to the mounting side and adjacent to said end face. During the assembly of a fitting on the component, such straight tension screws are screwed in before the slanted mounting screws, which makes the slanted screwing without displacement of the fitting on the component much easier and ensures the correct fit. Furthermore, the tension screw, which is loaded purely by tension, counteracts a lifting of the fitting from the component in the event of a tensile load between the two components.

In order to further increase the strength of the connection, it is favourable if the connector also has at least two further bores for one further screw each, said bores flanking the slanted bore of each molding and penetrating the molding approximately orthogonally to the base and top surfaces. These further screws help to strengthen the components, in particular wooden components, in the region of the fittings.

DETAILED DESCRIPTION

FIGS.1aand1bshow a connector1for two components2,3. One component2is, for example, a column, a wall or the like, here: a column. The other component3is, for example, a main, secondary or transverse beam, a cross member, a girder or the like, here: a beam. The components to be connected are for example made of wood, in particular glued laminated timber (glulam), laminated beams, etc. At least one of the components is optionally made of another material, for example concrete, stone, masonry or even metal.

The connector1comprises two fittings4,5made of wood, optionally plywood, or wood-plastic composite. Wood-plastic composites (“WPC”), which are also known as “wood (fibre) polymer composites”, are made of wood—usually wood flour—and plastics as well as additives (here: in particular flame retardants) and may be processed similarly to plastics. It is understood that optionally, for example, one of the two fittings4,5could also be made of wood and the other of WPC.

Each fitting4,5has, for example, the shape of a—optionally rectangular—plate with a mounting side6(FIG.2b; not visible inFIGS.1aand1b), an abutment side7opposite the mounting side6, and an end face8connecting the mounting and abutment sides6,7; in the case of the rectangular shape, the fittings4,5also have two lateral sides9and a further end face8*, which is opposite the aforementioned end face8and which is not of further interest here, which each connect the mounting and abutment sides6,7. The fittings4,5are mounted with their mounting sides6on one each of the components2,3, i.e. in the example ofFIG.1athe left fitting4with its mounting side6on the left component2and the right fitting5with its mounting side6on the right component3.

The two fittings4,5may be hooked into each other at the aforementioned end face8, which inFIG.1ais at the top on the left fitting4and at the bottom on the right fitting5. In the hooked position (FIG.1B), the abutment sides7of each fitting4,5rest against the other of the components3,2, i.e. against the component3,2on which the fitting4,5is not mounted.

InFIGS.2aand2bonly one of the components4,5(here: component4) is shown, since the two fittings4,5in the present example are of identical construction. According toFIGS.1a,1b,2aand2b, the end face8of each of the fittings4,5has a shoulder10of height H, which is flush with the abutment side7, over the entire length L of the shoulder, running along the abutment side7—which at the same time corresponds to the width of the abutment side7; as a result, the abutment side7at the end face8projects beyond the mounting side6by the height H of the shoulder10, as it were. The width B of the shoulder10, i.e. its extent in the orthogonal direction RN to the abutment side7, corresponds substantially to half the width w of the end face8, i.e. half its extent W in the same direction. Said end face8thus has a higher half (by the height H) adjacent to the abutment side7and a lower half adjacent to the mounting side6. As a result, when one fitting4(with its end face facing upwards) is mounted on one component2and the other fitting5(with its end face facing downwards) is mounted on the other component3, an undercut is created behind each of the shoulders10, in which undercuts the shoulders10engage with each other when they are hooked into each other and thus connect the components to each other.

The fact that the width B of the shoulder10corresponds “substantially” to half the width w of the end face8means here that as the height of the shoulder10increases, its width optionally decreases and corresponds here to half the width w of the end face8at half height h. In this case, the mutual contact face10′ of the shoulders10of the two fittings4,5is thus slanted, so that the fittings4,5, when they are hooked into each other, are aligned with each other and the components2,3are drawn together.

For mounting on the respective component2,3, each fitting4,5has one or more generally cylindrical blind holes11on its abutment side7. In the examples shown, the fittings4,5have at least two blind holes11. In this case, the blind holes are arranged in mirror symmetry with respect to an axis A of the abutment side7, said axis being orthogonal to said end face8and bisecting it, i.e. starting at half of the length L of the end face8. In the case of the rectangular fittings4,5shown, said axis A is thus perpendicular to the end face8and runs centrally over the abutment side7. If in this variant at least one of the fittings4,5has an odd number of blind holes11, at least one of the blind holes11is arranged on the axis A.

For fire safety reasons, each of the blind holes11of each fitting4,5is optionally spaced from the periphery of its abutment side7, if required; it has a minimum spacing5of at least 2 cm depending on the fire safety requirement, and between 4 and 6.5 cm for higher fire safety. The minimum distance5of a blind hole11is the distance which the blind hole11has from the nearest portion of the periphery of the abutment side7.

FIG.3shows an example of a molding12. The connector1comprises such a molding12for each blind hole11, and said molding may be removably inserted into the blind hole11. The moldings12are usually made of a material different from that of the fittings4,5, in particular are made of a—optionally fibre-reinforced—plastic or of metal, optionally of steel or aluminium. Even if moldings12could be made of wood in individual cases, they are always separate from the fittings4,5.

Each molding12has a base surface13, a top surface14parallel thereto, and a lateral surface15, which connects the base and top surfaces13,14and is substantially generally cylindrical; the moldings are “substantially” generally cylindrical because each molding12has a slanted bore16for a mounting screw17(FIG.4), said bore penetrating the molding12at an acute angle α to its base and top surfaces13,14, which is why the top and lateral surfaces14,15have an optional chamfer18transverse to the slanted bore16for better abutment of a head of the mounting screw17.

The acute angle α is between 15 and 60 degrees, depending on the requirements and material of the components2,3; in most cases it is between 25 and 50 degrees, in the case of the molding12ofFIG.3it is about 45° (FIG.4).

In order for the abutment sides7of the fittings4,5to lie flat against the other component2,3in the mutually hooked position, the blind holes11optionally have a depth which is equal to or greater than the thickness D of the moldings12from their respective base surfaces to their top surfaces13,14.

In the example ofFIG.3, the slanted bore16penetrates the base surface13of the molding12without touching or penetrating the edge19between the base surface13and the lateral surface15. The edge19thus runs around the base surface13without interruption.

Furthermore, the molding12shown inFIG.3has a round base surface13; other shapes, for example oval, kidney-shaped or polygonal, are alternatively possible. Optionally, the blind holes11are adapted not only to the thicknesses D but also to the shapes of the moldings12, in particular the shapes of their base surfaces13, so that each molding12is received with a form fit in the blind hole11. In this case, the blind hole11may have a recess20on a region facing away from the end face8of its fitting4,5for easier screwing in of the mounting screw17. In the example ofFIG.2a, each blind hole11is produced by two overlapping blind bores, so that it has an approximately 8-shaped cross-section, in the part of which facing the end face8(here: upper part) the molding12with its round base surface13according toFIG.3may be inserted and in the other part of which (here: lower part) the recess20remains.

According to the example ofFIGS.2band4, the fittings4,5(here: the fitting4) have bores21which, starting from the blind hole11, are inclined in the direction of the end face8and penetrate the mounting side6. These inclined bores21are arranged and aligned in the blind holes11in such a way that, when each molding12is inserted, its slanted bore16may be brought into alignment with the inclined bore21, i.e. the slanted bore16and the inclined bore21run at the same acute angle α, so that the mounting screw17may be turned in a straight line and unhindered through the molding12and the inclined bore21into the component2,3.

Optionally, each fitting4,5also has at least one straight bore22—in the example ofFIGS.2band4: two—orthogonal to the mounting side6, for a tension screw23in each case, said bores being adjacent, i.e. close, to the end face8of the fitting4,5and penetrating the fitting4,5. The tension screws23are used to fix the fitting4,5to the respective component2,3, for example, before the mounting screws17are screwed in.

Alternatively or additionally, the fitting4,5may be glued on its mounting side6to the respective component.

According to the example shown inFIG.4, each fitting4,5may have an end-face bore24on its end face8, which bore is placed in the fitting4,5in the centre of the end face8orthogonally thereto. The end-face bore24may in particular be a blind bore. A pin25, for example, may be inserted into the optional end-face bore24so that the two fittings4,5are centred when hooked into each other and are then locked by the pin25in the longitudinal direction of the end face8.

An alternative is shown inFIG.5, in which the pin25of the example inFIG.4is replaced by a screw (not visible inFIG.5because it is countersunk) that is screwed into the end-face bore24. The end-face bore24completely penetrates the upper fitting5inFIG.5from top to bottom. Instead of the screw, a pin25could also be inserted into the end-face bore24in this example.

It should be noted that, for the aforementioned locking and also for protection against unwanted lifting of one fitting4,5from the other and for further strengthening of the connection of the components2,3, the abutment sides7of the fittings4,5may optionally be glued to the other component3,2.

FIGS.6and7show a further embodiment of the connector1, in which each molding12is penetrated by at least two (here: exactly two) further bores26, which are each for a further screw27and which flank the slanted bore16and penetrate the molding12approximately orthogonally to the base and top surfaces13,14.FIG.7shows the mutually hooked position of the two fittings4,5—for better visibility without the components2,3. The acute angle α in this case is about 30°.

The invention is not limited to the exemplary embodiments presented, but includes those variants, modifications and combinations thereof which fall within the scope of the appended claims.