WO2002029172A1

WO2002029172A1 - Coupling device and building element with this coupling device and method for manufacturing this coupling device

Info

Publication number: WO2002029172A1
Application number: PCT/SE2001/002112
Authority: WO
Inventors: Per-Henrik Olsson; Mats Sahlin
Original assignee: Olsson Per Henrik; Mats Sahlin
Priority date: 2000-10-02
Filing date: 2001-10-01
Publication date: 2002-04-11
Also published as: AU2001292488A1; SE517418C2; SE0003527D0; SE0003527L

Abstract

A device for coupling a first and a second building element, comprising a coupling element (1) which is attached to each building element. The coupling element (1) has at least one recess (5). The device also comprises a locking means (2) which is engageable with the recess (5) in each coupling element (1) in order to lock them together. The coupling element (1) of the first and the second building element comprises a plate (1), the recess of which has the shape of a through groove (5). In the coupling position, the plane of the plate (1) of the first building element is essentially parallel to the plane of the plate (1) of the second building element. In addition, the plates (1) of the respective building elements are positioned in such a manner that the groove (5) of the plate (1) of the first element is parallel to the groove (5) of the plate (1) of the second element and overlap in such a manner that the locking means (2) is insertable into the overlapping grooves (5) and engagable with the respective plates (1).

Description

Coupling device and building element with this coupling device and method for manufacturing this coupling device

Field of the Invention

The present invention relates to a device for coupling a first and a second building element, comprising a plate-shaped coupling element which is attached to each building element and has at least one groove-shaped recess, and a locking means which is engageable with the recess in each coupling element in order to lock them together, in the coupling position the plane of the coupling element of the first building element being essen- tially parallel to the plane of the coupling element of the second building element and the coupling elements of the respective building elements being positioned in such a manner that the recess of the coupling element of the first building element is parallel to the recess of the coupling element of the second building element and overlapping in such a manner that the locking means is in- sertable -into the overlapping recesses and engageable with the respective coupling elements.

The invention also relates to a building element and a method as claimed in claims 9 and 10, respectively.

Background Art

In many building constructions, wooden beams and wooden pillars are used as supporting framework. The tra- ditional way of connecting these. in the joints of the construction has been to make pins and recesses. Nowadays, the most common method is to use different types of metal fittings which are fastened by nailing, screwing or pressing to each of the beams which are to be connected. Many coupling devices have the disadvantage that a recess must be made in at least one building element, which is time-consuming and requires a certain amount of precision work. In addition, a milling machine is required, which is a disadvantage since the recess thus in most cases cannot be made on the building site, but has to be made in advance in a factory. Moreover, many coupling devices have the disadvantage of being visible in the final construction, which often is not desirable. Many types of coupling devices also have the disadvantage of not absorbing all sorts of forces, such as compressive force, tractive force and shearing force and torques in all directions.

Other prior-art coupling devices have, for example, the disadvantages of taking up a great deal of space and thus "steeling" volume. This is a disadvantage especially in buildings where the costs per square meter are high, for example in large cities. Some devices also allow beams to be connected only end to end, which limits the range of application. Besides, many fittings are relatively complicated constructions and thus also expensive to manufacture. In addition, large, heavy fittings are comparatively expensive to transport and handle.

Nail plates, i.e. plates with nails evenly distrib- uted over one side of the plate, have per se a relatively low weight and are easy to manufacture but the problem that they show in the final construction remains. Furthermore, nail plates are not approved for use in building constructions which are earthquakeproof . Moreover, it is difficult to connect the beams by means of nail plates on the actual building site since usually a device which presses the plate into the wood is required. Nail plates are therefore most frequent in houses that are made in a factory and, subsequently, are mounted on the site. SE 152 032, SE 331 261 and DE 2 013 953 disclose coupling devices for joining of concrete piles of the type which is used for soil consolidation in connection with foundations. In such joining of piles no aesthetic aspects have to be taken into consideration regarding the appearance of the joints or the condition that they should be as non-conspicuous as possible in the final construction since the piles will be hidden in the ground beneath the basic construction. Consequently, the coupling devices in all the above-mentioned patent specifications are made of relatively thick coupling elements. A coupling element according to any of the above-mentioned patent specifications is intended to be mounted on either end of the pile sections which are to be joined. On the sides of the coupling elements which are facing away from the piles, shallow grooves are made from the lateral edges towards the centre. The grooves are wedge-shaped in cross-section in such a manner that they are narrower at the surface of the coupling element than at the bottom of the respective grooves. When the piles are being joined, the coupling elements are moved together surface to surface so that the grooves in the respective coupling ele- ments overlap and, subsequently, a locking means in the form of a wedge which in cross-section is dovetail-shaped is inserted into each of the overlapping grooves and, thus, connects the pile sections to one another.

In SE 152 032, which constitutes the point of depar- ture for the preamble of claim 1 in the present application, the coupling element essentially has the shape of a plate. In this plate, key grooves are made by milling or the like from one side, whereas the other side is essentially smooth apart from a few shallow holes which serve to facilitate fastening of the plate by welding to the main reinforcement of the pile or special anchoring rods in order to be subsequently fastened by casting into the concrete in connection with the manufacturing of the pile. The costs of production of such a coupling element become relatively large due to the fact that the grooves have to be made by relatively expensive machining of the plate by milling, or alternatively casting. Since there must be no through holes in the plate in order to prevent concrete from penetrating in connection with the manufac- turing of the pile, the plate also has to be made relatively thick, which, on the one hand, makes it visible in the finished construction and, on the other, causes the material contents of each plate to become relatively large and, consequently, also the cost increases. The range of application of such a coupling element is further highly limited since it cannot easily be applied to a building element and, above all, this cannot be made on the site where a building is to be erected.

The coupling devices according to the other two patent specifications mentioned, SE 331 261 and DE 2 013 953, apart from the above-mentioned disadvan- tages also have the disadvantage of not being essentially plate-shaped, but exhibiting such a complicated shape that they must be manufactured by casting.

Summary of the Invention The object of the present invention is to eliminate the above-mentioned problems and disadvantages of prior- art technique and provide a coupling device for building elements, which without deviating from the strength requirements is relatively invisible in the final construc- tion. In addition, an object of the invention is to provide a device which is not bulky and, thus, takes up volume in the finished building. It is also an object to provide a coupling device which gives a flexible building system, i.e. which allows a building element to be con- nected with other building elements also in other ways than end to end. Another object of the invention is that it should be possible to easily apply the coupling device to the building elements on the actual building site without considerable machining. Yet another object of the invention is to provide a coupling device which is inexpensive to manufacture and transport . At least these ob- jects are achieved by means of a coupling device as claimed in claim 1.

According to an alternative embodiment, one object is that it should be possible to connect building elements without bevelling of the ends, when the building elements form angles to one another other than 90°. The invention is thus based on the understanding that a discreet, flexible, torsionally rigid and non- bulky coupling device for building elements is provided by forming each coupling element, such as a plate, the recesses of which have the form of through grooves in which locking means are insertable. By forming several grooves in different directions, yet another advantage of the invention is achieved, which means that the coupling can absorb shearing force and torques in all directions and it is possible by means of a device according to the invention to fulfill the requirements for earthquake- proofness. In the coupling position the plane of the plate of the first building element is essentially parallel to the plane of the plate of the second building ele- ment, i.e. they are positioned so that the sides of the plates which are facing away from the respective building elements are facing one another surface to surface. Furthermore, in the coupling position the plates of the respective building elements are positioned in such a man- ner that a groove of the plate of the first element is parallel to and overlaps a groove of the plate of the second element . The grooves of the plates are thus in the coupling position located straight in front of one another with the plates centred relative to one another, so that a locking means is insertable in both grooves at the same time in order to connect the plates and, thus, the building elements. A great advantage of a plate according to the invention is that it can be attached not only to the ends of the building element, but also, anywhere along the length of a building element, which allows many coupling combinations of building elements.

The appended claims should be extensively interpreted in such a manner that the invention can also comprise a coupling element which allows angular coupling of building elements. This embodiment of the invention comprises an angle element which in cross-section has the shape of a triangle or a piece of cake and to which two plates of the type previously described are attached at a desired angle. The angle element having the shape of a triangle or a piece of cake is intended to be located in such a manner that one side having a plate faces a first building element which, in its turn, has a corresponding plate and the other side having a plate facing a second building element which also has a plate, i.e. altogether four plates in each joint. The locking means is thus engageable with the plates, on the one hand, in the connec- tion between the plates of the angle element and the plates of the first building element and, on the other, between the plates of the angle element and the plates of the second building element in order to lock the building elements together. This embodiment of the invention can be manufactured to have many different angles depending on the range of application. As regards for example house construction, it is preferred to manufacture coupling elements which allow coupling at the angles 30°, 45° and 60°. The great advantage of a coupling element which al- lows angular coupling is that bevelling of building elements which are to be coupled is not necessary.

In a preferred embodiment of the invention, the groove in each plate is wedge-shaped in cross-section, i.e. the cross-section has the shape of a truncated V or a truncated point. However, it is not necessary that the grooves should be wedge-shaped. Of course, they might also have other shapes, for example, lateral surfaces which are straight and perpendicular to the plane of the plate, and a locking effect between the plates could then instead be provided by a locking means having an I-shaped cross-section. However, milling of the building element for the flanges of the I cross-section would be necessary in that case, which is a disadvantage as mentioned above. In addition, the groove in the preferred embodiment has a greater width towards that side of the plate which, when the plate is attached to the building element, faces the building element. The cross-section of the locking means is in a preferred embodiment narrower at the middle than at the ends, i.e. has a waist, as an hourglass shape or a bow shape or as opposed dovetail-shaped wedges having the narrow ends connected to one another. The pre- ferred embodiment having a truncated V shape of the cross-section of the groove and the form of two interconnected opposed dovetail -shaped wedges of the cross- section of the locking means has the advantage of locking of the plates possibly being performed without flanges or other locking devices being required in the plate or the locking means.

In a preferred embodiment, the grooves are formed in the plates by through grooves first being punched in the respective plates. This results in through grooves having essentially straight lateral edges. By forming the punching tool in a suitable manner, the same punching tool can subsequently be used to forge or upset the lateral edges of the grooves from one side of the plate so that the desirable groove shape with inclined or wedge-shaped edges is obtained. Thus, the manufacturing process is simplified and the costs can be limited further.

In addition, in a preferred embodiment the locking means has an internally threaded through hole in the longitudinal direction in order to facilitate the insertion and possibly removal of the locking means with the aid of a suitably formed tool. In one embodiment, the locking means also has fluted surfaces on the upper side and underside. The flutes engage with the end surfaces of the building element and thus counteract that the locking means entirely or partly falls out of the groove, for example, when the locking means is vertically positioned in a groove .

In order to further counteract that the locking means intentionally slides out of the groove, this is preferably slightly tapering in the longitudinal direction, i.e. the width of the groove at the lateral edge of the plate is slightly greater than its width at its inner end. The tapering is less than 4° at each edge of the groove, preferably less than 3°, and most preferably less than 2°. Thus, the width of the groove at the lateral edge of the plate can be so large that the insertion of the locking means will be smooth and easy at the same time as a wedge effect is obtained, which keeps the locking means in position when it is driven or pressed towards the centre of the plate. On the other hand, in the preferred embodiment the locking means has the same thickness over its entire length seen in a plan view as well as a side view.

In a preferred embodiment, the plates are further arranged surface to surface in the coupling position in order to obtain a strong and durable joint. However, de- pending on the strength requirements, there may be a certain space between the plates. In that case, the waist of the locking means could have a longitudinal extent corresponding to the space between the plates. The locking means may, for example, also have the shape of a yoke or a U having two parallel locking parts which are interconnected by means of a straight or bent spacer attached to one end of each locking part .

Besides, in a preferred embodiment the plate has four grooves, each of which extends towards the centre of the plate from one side each of the preferably square or rectangular plate. This is an advantage since absorbed forces are evenly distributed over the cross-section of the plate. However, depending on the strength requirements, the number and location of the grooves can be com- bined in many different ways. For example, the plate could have only one groove which extends across essentially the whole plate. Another variant is to arrange altogether four grooves in such a manner that two parallel grooves extend inwards to the centre of the plate from two of the sides of the plate. In order to connect rectangular beams and pillars to one another, it may be advantageous if the plate is rectangular. In that case, for example two grooves could be arranged on each long side of the plate, whereas one groove is arranged on each short side.

Preferably, the plate is attached to a building ele- ment by a screw joint, a so-called dowel pin, which is common within the furniture industry. The dowel pin comprises a pin having two threaded through holes, one in the longitudinal direction and one in the transverse direction. A screw which is passed through a hole made in the plate and further inserted into a bore in the build- . ing element engages in the transversely threaded hole in the pin which is inserted perpendicular to the bore in the building element. However, it could be possible to fasten the plate in another manner, for example, by means of ordinary screws only. In a preferred embodiment, the plate has a recess in the form of a hole in its centre. The hole is intended to facilitate centering of the plate, on the one hand, when it is to be attached to the building element and, on the other, when it is to be po- sitioned in the coupling position relative to another plate .

In a preferred embodiment, the thickness of the locking means is smaller than or equals the thickness of two plates which are brought together. Thus, the locking means can easily be inserted into a groove in the respective plates, without recesses being made in the building element .

A great advantage of a coupling device according to the invention is that the separate coupling elements or plates can be made very thin. Consequently, they become almost invisible in the finished construction. Usually, the thickness is only about 5 mm, which means that the total thickness of the coupling device becomes about 10 mm. However, the thickness is determined with regard to the strength requirements concerning the forces to which the plates will be exposed and can thus be varied depending on the range of application. Usually, the

FIG. 3 is an exploded view which illustrates coupling of two building elements end to end by means of two coupling elements according to a preferred embodiment of the invention, FIG. 4 is a top plan view of two building elements which have been connected end to end by means of two coupling elements according to the present invention, FIG. 5 is a top plan view of a joint where a vertical building element is to be connected with four horizontal building elements, FIG. 6 is a top plan view of a joint where a horizontal building element is to be connected at an angle of 90° with another horizontal building element, and

FIG. 7 is a top plan view of a joint where a horizontal building element is to be connected at an angle of 45° with another horizontal building element .

Description of Preferred Embodiments

Reference is first made to Fig. 1 which shows a coupling element and a locking means in the form of a plate 1 and a key 2, respectively. The plate has four sides 3 of the same length and four holes 4 through which screws are intended to be inserted in order to attach the plate 1 to a building element. In addition, the plate 1 according to a preferred embodiment has four wedge-shaped grooves 5. The grooves 5 are arranged in such a manner that the plate 1 has a groove 5 which extends towards the centre of the plate from each side 3. The figure also shows the key 2, on the one hand, inserted into one of the grooves 5 and, on the other, removed. Each groove 5 is wedge-shaped, having a greater width on the side of the plate 1 which faces the building element than on the side which faces the second plate. A hole 6 is arranged in the centre of the plate 1 in order to facilitate cen- trering of the plate 1.

Fig. 2 shows the plate 1 from the side, illustrating that the key groove 5 has a smaller width on the upper side than on the underside of the plate 1. The screw holes 4 are shown by dashed lines.

Fig. 3 shows two beams or pillars which are to be connected end to end by means of two plates 1 according to the invention. The beams have in their ends drilled holes 9, into which screws 10 are intended to be inserted in order to attach the plates 1. On each beam, a plate 1 is positioned in such a manner that the screw holes 4 of the plate 1 are aligned with the bores 9 of the beam. The beam also has a bore 11 on each side 12, in which bore 11 a dowel pin 8 is insertable. The screws 10 are passed through the screw holes 4 of the plate, down through the bores 9 and engage in a transverse threaded hole 13 of the dowel pin 8. Subsequently, the plates 1 can be brought together in the coupling position, keys 2 being inserted into the grooves 5 of the plates 1 and locking the plates 1 together. In order to facilitate insertion and possibly removal of the key 2 , it has an internal threaded hole 7 which extends in the longitudinal direction and in which a tool can engage. The dowel pin 8 also has an internally threaded through hole 14 which extends in the longitudinal direction of the dowel pin 8 and which is intended to facilitate attachment of a plate 1 to the side 12 of the beam, if desirable. The screw hole 4 of a plate 1 which is to be attached to the side 12 of the beam is thus aligned with the threaded hole 14 of the dowel pin 8, a screw being inserted into and screwed into the threaded hole 14.

Fig. 4 shows the principle of coupling of two plates 1 attached to one beam end each and brought together in a coupling position. A key 2 is inserted into the grooves 5 of the plates 1. Due to the fact that the grooves 5 of each plate 1 (see Fig. 2) is wedge-shaped and that the t DO μ>

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Claims

1. A device for coupling a first and a second build- ing element, comprising a plate- shaped coupling element

(1) which is attached to each building element and has at least one groove-shaped recess (5) , and a locking means

(2) which is engageable with the recess (5) in each coupling element (1) in order to lock them together, in the coupling position the plane of the coupling element (1) of the first building element being essentially parallel to the plane of the coupling element (1) of the second building element and the coupling elements (1) of the respective building elements being positioned in such a manner that the recess (5) of the coupling element (1) of the first building element is parallel to the recess (5) of the coupling element (1) of the second building element (1) and overlapping in such a manner that the locking means (2) is insertable into the overlapping recesses (5) and engageable with the respective coupling elements (1) , c h a r a c t e r i s e d in that the recesses (5) are through recesses in the respective coupling elements

(1) •

2. A device as claimed in claim 1, wherein the re- cess (5) is in the shape of a truncated wedge in cross- section.

3. A device as claimed in claim 2, wherein the broadest part of the recess (5) on the coupling element

(1) in a mounted state faces the building element.

4. A device as claimed in any one of the preceding claims, wherein the cross-section of the locking means

(2) is thinner in the middle than at the ends.

5. A device as claimed in any one of the preceding claims, wherein the cross-section of the locking means (2) has the form of two dovetail -shaped wedges connected to one another at their narrow ends .

6. A device as claimed in any one of the preceding claims, wherein the coupling element (1) of the first building element and the coupling element (1) of the second building element in a coupling position are arranged surface to surface.

7. A device as claimed in any one of the preceding claims, wherein the coupling element (1) has four recesses (5) which extend from one side each of the coupling element (1) towards its (1) centre.

8. A device as claimed in any one of the preceding claims, wherein the thickness of the locking means (2) is smaller than or equals the thickness of the two coupling elements (1) which are brought together.

9. A building element comprising a device as claimed in any one of the preceding claims.

10. A method for manufacturing a coupling element constituting part of a coupling device as claimed in any one of the preceding claims, comprising the steps of punching at least one through groove in a plate, the through groove having straight edges which are perpendicular to the main surfaces of the plate, from at least one of the lateral edges of the plate, and by means of a tool upsetting or forging the edges of the groove from one of the main surfaces of the plate in order to form grooves having edges which are inclined or wedge-shaped in cross-section.