WO1997032140A2

WO1997032140A2 - Connection element for wooden building elements

Info

Publication number: WO1997032140A2
Application number: PCT/AT1997/000038
Authority: WO
Inventors: Friedrich Stich; Brunhard Ziegelwagner
Original assignee: Friedrich Stich; Brunhard Ziegelwagner
Priority date: 1996-02-28
Filing date: 1997-02-26
Publication date: 1997-09-04
Also published as: DE29780209U1; WO1997032140A3; AU2086097A

Abstract

The invention relates to the use of a building element known in furniture manufacturing, i.e. a clamping-eccentric screw connection (6, 7), for connecting wooden building elements (1, 2, 3) in joinery and in post and beam construction for pergolas, winter gardens, roof framing and the like. Embodiments of the invention relate to a special threaded shape for the bolt (7), an elongate clamping eccentric (6) and a double-headed pin instead of the bolt (7). There is also an embodiment for three-dimensional joints and a permanent elastic connection.

Description

Connecting element for wooden components

The invention relates to a connecting element for wooden components. In particular, it relates to the use of a component known from furniture production, namely a clamping eccentric screw connection.

According to the prior art, such clamping eccentric screw connections consist of: a) a screw which, with a predetermined projection m, is to be connected to one of the two

Wooden parts are screwed, b) from a receptacle opening provided in the other component for the screw and its head, and c) from an essentially hollow-cylindrical clamping eccentric, rotatably arranged in the area of the screw head in the receptacle opening, when the head is turned the screw is gripped and the screw is subjected to tension, whereby the two components are pressed against each other. Such clamping eccentric screw connections have been known for a long time for the production of shops and also of furniture from the carpentry. Their advantages lie in the simple connectivity and releasability of the parts assembled in this way and in the simple and precise application, since only the screw has to be set exactly and the hole for the receiving opening of the clamping eccentric has to be drilled exactly, but with milling or other com ¬ complicated and time-consuming work can be dispensed with. In furniture construction, wooden dowels or "little fish" are additionally used as adjustment aids and for the transmission of transverse forces in the case of qualitatively higher versions.

A use in construction joinery, in which essentially posts with an approximately square cross section have to be connected to one another, was never considered, probably because this was opposed by the belief that in the case of the forces to be transmitted, both the individual parts of the clamping eccentric screw connection and the weakening of the cross sections of the components through the bores for the receiving opening for the clamping eccentric and the surface pressure occurring in the area of the clamping eccentric would be too great.

Surprisingly, it has now been shown that these fears are unfounded and that eccentric screw connections, similar to those known from the manufacture of furniture, can also be used in joinery, especially when various adaptations have been made to the connecting elements used become.

The first adaptation concerns the diameter / height ratio of the clamping eccentric. In furniture joinery, boards are practically exclusively connected to one another, as a result of which a large area is available with a small thickness of the parts to be connected. Accordingly, all known clamping eccentrics are designed with a relatively large diameter and a comparatively small height (length in the axial direction). For the use according to the invention, clamping eccentrics have now proven to be particularly suitable, in which the axial length is greater than the diameter.

The second adaptation relates to the thread of the clamping screw, which is usually screwed in essentially along the grain of the wood when used in construction joinery, while in furniture joinery almost exclusively particle boards are to be connected to one another, so that from the start only screws with chipboard threads were used. The thread according to the invention, preferred is asymmetric and has, for Schrau ^¬ benkopf out (loaded in the extension direction) almost nor¬ times running on the screw shaft thread flank, while the directed towards the screw tip flank of the thread has an inclination of about 45 °. Such a thread formation occurs when screwing in the Screw for compression and compression of the material and for an excellent resistance of the screw to pulling out.

A further adaptation, which is unknown from use in furniture and cannot be used there, relates to the replacement of the thread of the tensioning screw by a constriction and the formation of a further head, this second head being held by an essentially cylindrical sleeve. Embodiments of the invention relate to the possibility of creating a firm connection in the case of corner joints of three bars which are normal to one another.

The invention is illustrated in the accompanying drawing with the aid of examples, in which FIG. 1 shows a connection of three wooden components according to the invention, FIG. 2 shows an oblique connection according to the invention of two wooden components, FIG. 3 shows a clamping eccentric, partly in axial section 4 shows a clamping eccentric in an axial plan view according to arrow IV in FIG. 3, FIG. 5 shows a preferred embodiment of a screw according to the invention, FIG. 6 shows part of a screw according to the invention for a wood connection according to FIG. 1, FIG. 7 a bolt according to the invention including the associated one

Support cylinder, FIG. 8 shows a connection of three normally standing posts, FIG. 9 shows a support shell according to the invention, FIG. 10 shows an eyebolt according to the invention, FIG. 11 shows a variant of a clamping eccentric according to the invention and FIG. 12 shows a variant of a represents bolts according to the invention for the connections according to FIGS. 1 and 8. 1 and 2 show two wood connections which are particularly unpopular in carpentry and which can hardly be made optically satisfactory. 1 shows a connection of three wooden parts 1, 2 and 3, of which parts 1 and 3 are aligned, and part 2 is sandwiched by these two parts and with its longitudinal axis at right angles to the common longitudinal axis of parts 1 and 3 runs. Such connections and joints, as they occur repeatedly in Pergoli, in roof trusses, in winter gardens and in other stand structures, have so far only been able to be created using various metal brackets or connecting plates, such constructions being less attractive.

The classic connection method by means of tenons and recesses is extremely labor-intensive and, moreover, requires precise work that only trained specialists can do.

According to the invention, all of these problems are avoided by drilling blind holes 4 in the mutually aligned components 1 and 3 for receiving clamping eccentrics 6 and creating a through-hole 5 in the components 2 clamped between them, which in the finished wood connection m is the connecting plane of the axes the blind holes 4 is located. Then, clamping eccentrics 6, such as the one shown in FIG. 3, are inserted into the blind holes 4, and a screw, as shown in FIG. 6, with its counterpart, which has an external thread at the tip, which fits into the internal thread 18 of the 6 screw can be screwed in, inserted into the through hole 5 and screwed together. Then the wood connection can be fixed by turning the clamping eccentric 6 in the blind holes 4

Usual adjustment aids or devices for transmitting transverse forces, such as wood, dowels or fish can of course be used.

Fischchen are wooden plates in the shape of a fish that are in grooves of a wooden surface delimited in the form of a circular arc are inserted and the part thereof projecting over this surface is fitted into an analog groove of the opposite wooden surface which is delimited in the form of an arc of a circle. Their use is known in timber construction and therefore needs no further discussion here.

FIG. 2 shows another construction situation that is difficult to solve in an optically satisfactory manner in carpentry: it is a bevelled corner in which two wooden components 1, 3 which are at 90 ° to one another are not mitred or butt, but with the interposition of a wooden component 2 inclined at 45 ° to be connected to each other.

Even in such a situation, as in the case described above, the use of tabs or connecting plates has always been necessary, which does not leave a satisfactory impression optically.

According to the invention, a clamping eccentric screw connection is used for each of the two joints in this situation (as also in the case of normal 90 ° joints), the screw axis being normal to the joint plane. The screw 7 used in this application is shown in FIG. 5, this illustration representing a preferred embodiment of the screw. The screw 7 has a thread 9, a shaft 10 and a stepped head 11. The thread 9 is asymmetrical, its head-side flanks 12 enclosing an angle of approximately 90 ° with the screw axis, while the tip-side flanks 13 enclose an angle of approximately 45 ° with the screw axis. This thread provides excellent pull-out resistance for screw 7.

The screw shaft 10 adjoins the thread 9, which is thicker than the threaded shaft, preferably corresponds to the "blank" and its thread side

Shoulder 14 as a mark for the screw-in depth of the Screw serves. The transition between thread and shaft is preferably designed without forming a collar, such as collar 15 in FIG. 6.

The advantage of the collarless design lies not only in the material saving and the simplified processing of the screw, but also in the fact that the screw does not have to be pre-tensioned in the wood due to the fact that the collar rests on the wood surface, but that it may also be necessary a little too tight tightening of the screw the shoulder 14 presses itself a little into the wood without causing significant tensile forces on the thread, so that the pull-out safety is not impaired.

Between the shaft 10 and the head 11 of the screw there is a constriction 16 which interacts with the clamping eccentric 6. With this constriction, the head 11 of the screw is gripped behind by the clamping eccentric and thus secures the connection of the two components in which the screw 7 or the clamping eccentric 6 are arranged.

6 shows a screw 7 'as used in the application according to FIG. 1. The screw 7 'has, after the head 11 and the constriction 16, a shaft 10 and does not differ in this area from the screw 7. However, there is a collar 15 next to the shaft 10, which serves as an insertion mark for the screw 7 'and the tip-side end face of which rests on the surface of the component in which the screw is inserted.

Instead of a thread 9 there follows a shaft 9 'which, in the exemplary embodiment shown, has a smaller outer diameter than the shaft 10, but this need not be the case. Starting from its end remote from the head, the shaft 9 'has a pocket bore 17 lying coaxially to the screw, which is provided with an internal thread 18 over at least part of its length. The screw 7 'is used together with a screw, not shown, which is similar to the screw 7'. is built, but in the area of its tip has an external thread corresponding to the internal thread 18, so that the installation situation shown in FIG. 1 can be achieved. If the component 2 to be traversed has larger dimensions, the use of two screws 7 is advantageous, but it is also conceivable in this case to use two screws 7 'with an intermediate piece of threaded rod with a thread matching the thread 18. FIG. 3 shows a clamping eccentric 6 used according to the invention, partly in axial section, in FIG. 4 in a top view in the direction of arrow IV in FIG. 3.

Such clamping eccentrics are, as already mentioned at the beginning, known per se and therefore require only a brief explanation at this point: the clamping eccentric is essentially cylindrical in shape and can be rotated by means of a coaxially arranged hexagon attachment 19. It is of course possible to provide other organs instead of a hexagon, for example a square or two bores provided eccentrically to the axis of the clamping eccentric 6 and arranged axially in the end wall, into which a suitable key can engage.

On the side of the clamping eccentric 6 facing away from the hexagon, a either spiral or eccentrically circular recess 20 is provided. Approximately in the middle of the axial extension of the clamping eccentric 6, an opening is provided in at least half the circumference in a plane normal to the clamping eccentric axis 21, which extends from the outer circumferential surface of the clamping eccentric to the recess and thus forms a circumferential groove 22. At one end of this circumferential groove 22 there is an axial groove 23 which extends as far as the end face of the clamping eccentric, which lies opposite in the hexagon 19. The width of the two grooves 22, 23 is selected so that the screws 7 and 7 'with their constriction 16, but not with their head 11 can get through the groove and can move with play in it.

The axial groove 23 lies with respect to the recess 20 so that the eccentric ring 24 remaining between the recess 20 and the jacket of the tensioning eccentric has its smallest wall thickness at this point. It is thus possible to insert the screw 7, 7 ', which is firmly screwed or held in its component, with its constriction 16 into the axial groove 23 until it reaches the region of the circumferential groove 22 and then by turning the clamping eccentric 6 accordingly to gradually bring the screw into areas of the eccentric ring 24, in which it has an ever increasing wall thickness, so that it finally engages behind the head 11 and the screw 7, 7 'is subjected to tension.

Preferably, the outer surface of the recess 20 is not continuously smooth, but, as can be seen in FIG. 4, is designed to be corrugated in order to carry out the tightening of the screw 7, 7 'almost step by step, thereby preventing the connection from being loosened by twisting the clamping eccentric 6, since in the worst case, the screw with its head 11 remains on the next “step” without being able to exert sufficient force in the circumferential direction that would be sufficient for further rotation of the clamping eccentric 6. As can be seen from FIG. 3, the axial length H of the clamping eccentric 6 is greater than its outer diameter D, which is advantageous for use in timber construction and in carpentry.

FIG. 7 shows an advantageous replacement for a tensioning screw. This replacement consists of a ^bolt 25 with constrictions 26 near its ends. Through these constrictions the bolt ends are formed as heads out ^¬ even if the diameter of the bolt ent speaks. As described above, at least one of the two heads interacts with a clamping eccentric, but the second head can also be used with a holding plate, e.g. one simple cylindrical sleeve 27 cooperate with a longitudinal slot 28 leading to about m their center.

In this case, a half cylinder with a slot can even be used instead of the sleeve, which can be produced by stamping and bending much cheaper than a cylindrical sleeve.

In a further embodiment, a plurality of notches 26 can be provided on the shaft at least near one of its ends, so that when cut in one of the notches, a double-headed bolt of the required length is produced. This simplifies the manufacture and storage and the announcement of the bolt is easier on construction than the provision of different bolt lengths.

8 shows a connection according to the invention of three mutually normal posts 29, 30 and 31, as they meet for example at the upper corners of a rectangular wooden stand construction. The horizontal bars 29, 30 have pocket holes on their underside for receiving a clamping eccentric 31 and a semi-cylindrical support shell 33.

Between these two elements, a bolt 25 is kept tensioned in the manner described above. The two beams 29, 30 are mitred and the butt of the stator 31 is butted on the cut ¬ running blind hole 35, in which em eye bolt 36 (Fig. 10) is inserted.

This eye bolt has at one end an eye 37 with which it encompasses the bolt 25, at its other end it is designed like the bolts described above and is held in tension by a clamping eccentric 32

9 shows a support shell 33 according to the invention in detail. It essentially consists of a semi-cylindrical surface 34 and an axial groove 42 similar to the axial groove 23 (FIG. 4). If the outer diameter of the support shell 33 is selected to be larger than the diameter of its receptacle 43 and it extends over less than half the circumference in order to fit the receptacle, it can be elastically deformed by the tension exerted by the clamping eccentric 32 and thus keep the connection non-positive and therefore free of play despite the wood shrinking.

This can also be achieved if the support shell 33 and / or the clamping eccentric 32 are not inserted directly into the corresponding recesses, but at least on the side facing one another by means of a plastic or rubber insert or the like. an elastically deformable layer is created which serves the same purpose.

10, partly already described above, shows an eye bolt 36. It has an eye 37 at one end through which, as can be seen from FIG. 8, a bolt 25 can be inserted, the axis of which then normal to the axis of the Eye bolt runs.

11 shows a clamping eccentric 37 according to the invention, preferably used. This essentially consists of a hollow cylinder with only one closed end face 38, the axis of the inner lateral surface being offset with respect to the axis of the outer lateral surface. At the thinnest point of the jacket 39, starting from the open edge 40, an axially parallel opening - axial groove 23 - is provided, which passes at a distance from the open edge 40 into a circumferential opening, the peripheral groove 22. The circumferential groove 22 preferably extends over approximately half the circumference of the clamping eccentric 32.

In the case of the clamping eccentric 32, the inner lateral surface is essentially smooth, the outer lateral surface, as can be seen in the detailed illustration in FIG. 11, has a roughening, preferably a fine toothing 41 with tooth tips running parallel to the axis. This toothing 41 prevents unintentional loosening of the clamping eccentric, for example. at vibrating load, by twisting the same and is more efficient and more economical to manufacture, for example by rolling, than the internal toothing according to FIG. 4. FIG. 12 shows a bolt 25 similar to that of FIG. 7, with a shaft 10 and constrictions 16 close two shaft ends, through which each head 11 forms an em head 11. The diameter of the bolt 25 is chosen so that it can be pushed quickly or with little play through the eye 37 of the eye bolt 36 (FIG. 10) to create the connection according to FIG. 8.

Steel, but also high-strength plastic (Kevlar, etc.) can be used as the material for the clamping eccentric 6, the screws 7, 7 ', the bolts 25 and the support cylinder 27 or support shells 33. The dimensioning depends on the intended use and can easily be determined by a person skilled in the art knowing the invention.

Claims

Claims:

1. Use of a component known from furniture production, namely a clamping eccentric screw connection, for connecting wooden components in the joinery, in stand construction, for pergolas, winter gardens, roof trusses and the like.

2. clamping eccentric screw connection for use according to claim 1, characterized in that the clamping eccentric (6) has an axial extent (H) which is at least as large as its diameter (D).

3. eccentric screw connection for use according to claim 1, characterized in that the screw (7) has a thread (9), the head-side flanks (12) include an angle of approximately 90 ° with the screw axis and the tip-side Flanks (13) form an angle of approximately 45 ° with the screw axis.

4. Clamping eccentric screw connection for use according to claim 1, particularly in the connection of three sandwich-like components (1, 2, 3) characterized in that the screw (7 ') has an internal thread (18) at its tip area. is provided, which can be screwed with an external thread of a counter screw, and that in each of the outer components (1, 3) a clamping eccentric (6) or a supporting cylinder (27) or a supporting shell (32) is arranged, the or the interacts with the head of one of the two screws, and that the screw (7 ') is screwed with its counter screw in the central component (2)

5. clamping eccentric bolt connection for connecting Bau¬ parts of wood m the joinery, in stand construction, in pergolas, conservatories, roof trusses and the like., Characterized in that a) the connection from a bolt (25) and two Eccentric (6) or b) consists of a bolt (25 and a clamping eccentric (6) and a support cylinder (27) or a support shell (32), and that c) the bolt has at least one constriction (26) near its ends, which on form the bolt ends heads (11).

6. Bolt (25) for use in a Spannexzenter-Bol¬ zen-Verbmdung according to claim 5, characterized in that it has at least in the region of one of its ends several, axially spaced constrictions (26).

7. support shell (33) for use in a Spannexzen¬ ter screw connection according to one of claims 2, 3 or 4 or in a clamping eccentric bolt connection according to claim 5, characterized in that it consists of a substantially semi-cylindrical shell (34), with an axially extending cut, the axial groove (42), which extends from the edge substantially over half the axial length of the support shell and has a width (B) that is smaller than the diameter of the bolt (25) or the screw (7, 7 ') but larger than the diameter of the constriction (16, 26).

8. support cylinder (27) for use in a Spannexzen¬ ter-bolt connection according to claim 5, characterized in that it consists of a cylinder with an axially ver¬ incision, the axial groove (28), which from the edge extends substantially over half the axial length of the cylinder and has a width (B) which is smaller than the diameter of the bolt (25) but larger than the diameter of the constriction (26).

9. eye bolt (36) for use in a Spannexzen¬ ter bolt connection according to claim 5, characterized gekenn¬ characterized in that it has a head (11) at one end and at the other end em normal to its longitudinal axis eye (37) has, the diameter of which allows a bolt (25) or a screw (7) to be pushed through.

10. clamping eccentric screw connection according to claim 2, 3 or 4, or clamping eccentric bolt connection according to claim 5, characterized in that at least in the region of the respective axial groove (28) between the wall of the receptacle (43) and the clamping eccentric (6, 32) and / or the support cylinder (27) or the support shell (33) a permanently elastic material, for example a plate made of rubber or plastic, is inserted, which is subjected to the tensile load of the bolt (25) or the screw ( 7, 7 ') is elastically deformed.

11. Support shell according to claim 7, characterized in that the diameter of its outer lateral surface is larger than the diameter of the associated receptacle (43) so that it is elastically deformed by the tensile load of the bolt (25) or the screw (7, 7 ') .