EP1711288B2 - Joining apparatus - Google Patents

Description

The invention relates to a joining device according to the preamble of claim 1 or the preamble of claim 2 with a punch tool and a counter tool and a holder having an opening for receiving the punch tool or the counter tool. Both tools are arranged coaxially aligned with each other at different ends of a C-bracket.

Such joining devices are known and are used in particular for producing connections, for example rivet and punched rivet connections. The known joining devices have a stamp provided with a drive and as a counter tool on a matching die, which are arranged coaxially to each other, wherein the coaxiality of the punch and die high demands are made, since this the strength and appearance of the compound produced to a large extent is dependent. The coaxiality must be ensured here in the long term and during movement of the joining device, since these devices produce a high number of connections per unit time with the aid of robots. The so-called C-frame or C-bracket serves as a holder and an abutment in the movement of the tools, the C-bracket on the one hand have a low mass and on the other to absorb the forces occurring in the connection processes.

Similar problems also occur in presses, embossing machines and stamping, i. wherever two co-acting tools (punch and die or anvil) must be aligned coaxially with each other.

Out US 4,756,072 is a joining device specified in the preamble of claim 1 type, in which the holder for the counter-tool is releasably clamped by means of a dovetail-shaped guide formed at its attachment end to the correspondingly shaped end of a C-bracket.

At one off US 3 127 044 A known joining device forms a solid body, the holder for a counter-tool in the form of a tongue with a socket for receiving a rivet. The holder is integrally connected to a back plate, with which the holder is attached to an end face of a C-bracket.

In the publication DE 197 43 277 A1 a joining device of the type mentioned is described in which two eccentric bushes are arranged in a receiving bore in the upper web of a C-bracket for holding a Nietsetzwerkzeuges. The eccentric bushes have the same eccentricity and are rotated against each other to adjust the coaxiality or to compensate for misalignment with a hook wrench. The rotational position can be locked by means of a screw which can be inserted into cutouts on the circumference of the eccentric bushing.

From the article " Punch rivets is promising in the sheet metal processing "from the magazine" bands, sheets, tubes "5/91, page 94 ff ., A punch riveting system is known in which the stamping tool is screwed to the upper end of a C-bracket.

The invention has for its object to provide a joining device, the coaxial adjustment of stamping tool and counter tool is easy and inexpensive to reach. It must be ensured that the coaxiality is given over time and during movement of the joining device.

The object is achieved by the joining device with the features of claim 1.

In addition to the task corresponding advantages of the invention to achieve a cost-effective, simple and way permanent coaxiality of punching tool and counter tool, it is also possible by the joining device according to the invention, different tool spacings and the use of different tools of different materials and the use of tool holders to realize with a different diameter of the receiving bore with a C-bracket. In addition, the tools can be retrofitted for wear or a further development easier, faster and cheaper or adapted to new tasks. This is particularly advantageous because C-clamps are very expensive. Due to the high rigidity requirements, they are usually manufactured in one piece with the holder. Due to the separate production of two or more items, the production of the entire C-bracket can be made cheaper and the production time for the C-bracket is shortened.

The objects described in the dependent claims represent advantageous developments of the subject matter of claim 1. It is particularly advantageous to form the intermediate wedge-shaped, since so the axial position of the punch or counter tool can be selectively influenced in one direction. It is also advantageous to provide a plurality of contact surfaces which are perpendicular to each other or formed by the inner surfaces of a U-shaped element, so that the tool is designed to be more stable during movements. A very advantageous versatility versatility of the holder with respect to the distance to the counter tool is made possible when the holder and the associated end of the C-bracket are formed such that the holder is rotatable by 180 °. Further advantages of the preferred embodiments can be found in the following description.

Figur 1

Teile einer erfindungsgemäßen Fügeeinrichtung in einer Ansicht von der Seite,

Figur 2

den C-Bügel, Halter und Gegenwerkzeug einer Fügeeinrichtung in Explosionsdarstellung,

Figur 3

C-Bügel, Halter und Gegenwerkzeug in einer perspektivischen Ansicht von schräg vorn,

Figur 4

verschiedene Anordnungen von Halter und Gegenwerkzeug am C-Bügel einer Fügeeinrichtung in Seitenansichten,

Figur 5

eine weitere Ausführungsform für Halter und zugehöriges Ende des C-Bügels einer erfindungsgemäßen Fügeeinrichtung in einer perspektivischen Explosionsansicht (a) und einer Ansicht von der Seite (b) sowie ein Ausführungsbeispiel einer Passfeder in einer perspektivischen Ansicht von der Seite (c),

Figur 6

eine weitere Ausführungsform für Halter und zugehöriges Ende des C-Bügels einer Fügeeinrichtung in einer Ansicht von unten (a), einer Ansicht von der Seite (b), einer Ansicht von vorn (c) und einer perspektivischen Ansicht von der Seite (d),

Figur 7

eine weitere Ausführungsform für Halter und zugehöriges Ende des C-Bügels einer Fügeeinrichtung in einer Ansicht von unten (a), einer Ansicht von der Seite (b) und einer perspektivischen Ansicht von der Seite (c),

Figur 8

eine weitere Ausführungsform für Halter und zugehöriges Ende des C-Bügels einer Fügeeinrichtung in einer Ansicht von unten (a), einer Ansicht von der Seite (b) und einer perspektivischen Ansicht von der Seite (c),

Figur 9

eine weitere Ausführungsform für Halter und zugehöriges Ende des C-Bügels einer Fügeeinrichtung in einer Ansicht von unten (a), einer Ansicht von der Seite (b) und einer perspektivischen Ansicht von der Seite (c) und

Figur 10

eine weitere Ausführungsform für Halter und zugehöriges Ende des C-Bügels einer erfindungsgemäßen Fügeeinrichtung in einer Ansicht von der Seite (a), einer Ansicht von oben (b) und einer perspektivischen Ansicht von der Seite (c).

The invention will be explained in more detail by means of embodiments which are illustrated in the drawing. Show it

FIG. 1

Parts of a joining device according to the invention in a view from the side,

FIG. 2

the C-bracket, holder and counter tool of a joining device in exploded view,

FIG. 3

C-bracket, holder and counter tool in a perspective view obliquely from the front,

FIG. 4

various arrangements of holder and counter-tool on the C-bracket of a joining device in side views,

FIG. 5

a further embodiment of the holder and associated end of the C-bracket of a joining device according to the invention in an exploded perspective view (a) and a view from the side (b) and an embodiment of a key in a perspective view from the side (c),

FIG. 6

a further embodiment for holder and associated end of the C-bracket of a joining device in a view from below (a), a view from the side (b), a front view (c) and a perspective view from the side (d),

FIG. 7

a further embodiment for holder and associated end of the C-bracket of a joining device in a view from below (a), a view from the side (b) and a perspective view from the side (c),

FIG. 8

a further embodiment for holder and associated end of the C-bracket of a joining device in a view from below (a), a view from the side (b) and a perspective view from the side (c),

FIG. 9

a further embodiment of the holder and associated end of the C-bracket of a joining device in a view from below (a), a view from the side (b) and a perspective view from the side (c) and

FIG. 10

a further embodiment of the holder and associated end of the C-bracket of a joining device according to the invention in a view from the side (a), a view from above (b) and a perspective view from the side (c).

In FIG. 1 are parts of a joining device, in this case a Stanznieteinrichtung shown. On the C-bracket 1, a holder 4 is arranged on one, in this case the upper end 2 of the C-bracket 1, in the continuous, preferably cylindrical opening or bore 5, a punch tool 8, in this case a punch riveting tool, is arranged. Here is in FIG. 1 not shown that the punch tool 8 at its end remote from the C-bracket 1 still has a number of means for moving the punch tool 8 and the power supply. At the end of the punch tool 8, which faces the other, in this case the lower end 9 of the C-bracket 1, there is a feed device 11, which provides the small parts required for the connection, in this case punch rivets. The extreme end of the punch tool, which faces the lower end 9 of the C-bracket 1, has a punch 13. At the other, lower end 9 of the C-bracket 1, a Matrizenträger 15 with a die or anvil 25 is arranged. To make a connection, for example, a punch rivet arranged on the punch 13 is pressed into two dies arranged between punch 13 and die 25 by movement of the punch 13 in the direction of the die 25 along the axis 16, so that the ends of the punch rivet cut into the sheets and together makes a connection of these sheets with a corresponding deformation of the sheets. Due to the interaction between the punch 13 and die 25 required for this and similar processes, they must be aligned exactly coaxially, the coaxiality being influenced by the attachment of the holder 4 at the upper end 2 of the C-bracket 1.

In a further embodiment, the feeding device 11 can also be guided through a hole in the holder 4 (not shown). Such a bore extends substantially parallel to the holder opening 5 and may be arranged, for example, behind the holder opening 5 in the direction of the front end 2 of the C-bracket 1. The bore for the feeding device may have, for example, a round or a rectangular cross section.

FIG. 2 shows the C-bracket 1, the holder 4, the Matrizenträger 15 with die 25 and all the other other parts again in a perspective exploded view. At the upper end 2 of the C-bracket 1, the planar contact surface 6 of the holder 4 is arranged opposite the front, flat end face 3 of the C-bracket. The end face 3 and the contact surface 7 extend parallel to the middle part of the C-bracket 1 or parallel to the axis of the holder opening 5. The holder 4 is provided with a U-shaped recess which through the contact surface 6 and perpendicular to this contact surfaces 7 are formed. The contact surfaces 7 are arranged opposite the upper and lower end faces 33 of the C-bracket 1. The contact surfaces 7 and end faces 33 in this case run approximately perpendicular to the middle section of the C-bracket 1 or perpendicular to the axis of the holder opening 5.

The following are all at the front end of the upper end 2 of the C-bracket 1 the contact surfaces of the holder opposite surfaces of the C-bracket referred to as end surfaces.

The holder 4 consists of a plate-shaped portion 10 and a receiving body 12 which on the plate-shaped portion 10 on the

Abutment surface 6 opposite side is arranged. The longest extent of the plate-shaped portion 10 extends parallel to the axis through the holder opening 5. On the receiving body 12 opposite side of the plate-shaped portion 10, the holder 4, the U-shaped recess for the contact surfaces 6 and 7. The holder opening 5 is arranged in the receiving body 12. The receiving body is arranged eccentrically on the plate-shaped portion, so that in this embodiment, the above, on the die 25 opposite side of the receiving body 12 of the longer part 41 of the plate-shaped portion 10 and below the receiving body of the shorter portion 40 of the plate-shaped portion 10 is located.

For better illustration of directional descriptions is sideways in FIG. 2 a Cartesian coordinate system 100 is arranged, which shows the three mutually perpendicular spatial directions x, y and z. These directions should also be retained for the following figures.

In order to align the holder opening 5 and thus also the punch coaxial with the die 25, an intermediate layer 17 is inserted between the contact surface 6 and the end face 3, which is formed here as an example wedge-shaped. By the intermediate layer 17, the lower end of the axis of the punch 13 is tilted a little in the x direction, since the wedge is thickened in the direction of the upper end 10 of the C-bracket 1. After inserting the appropriate intermediate layer 17, the holder 4 and the intermediate layer 17 are releasably secured by means of screws 19 and washers 20 on the end face 3. For this purpose, the holder 4 in the plate-shaped portion 10 corresponding stepped holes 18, the intermediate layer 17 through holes and the C-bracket in the end face 3 threaded holes. Here, the stepped holes 18 and the U-shaped recess for the contact surfaces 6 and 7 are arranged rotationally symmetrical, that the holder 4 even after a rotation through 180 ° about the x-axis, which is perpendicular to the plate-shaped portion 10 at the upper end 2 of the C-bracket 1 can be attached.

The intermediate layer 17 may be formed to adjust the holder 4 as a wedge or triangular prism whose thickening in the in FIG. 2 illustrated embodiment in the direction of the other end 9 of the C-bracket has. In a further embodiment, the intermediate layer 17 may also be formed as a parallelepiped plate, so that the axis of the bore 5 and thus the direction of movement of the punch 13 is moved only in the direction away from the C-bracket 1, ie in the direction of the x-axis. In general, the intermediate layer 17 is formed very thin with two parallel, flat surfaces, so that the existing holes for mounting the holder 4 on the C-bracket 1 can be used. The first flat surface is arranged adjacent to the end face 3 of the C-bracket 1 and the second flat surface faces the contact surface 6 of the holder 4. The two flat surfaces can be arranged parallel to one another (cuboid intermediate layer) or enclose any angle in any desired spatial direction, the angle being at most a few degrees. In one embodiment, both planes preferably have a thickness of a few tenths of a millimeter to a few millimeters, in particular from 2 mm to 4 mm, at the location of their greatest thickness. The intermediate layer 17 can be arranged both on the contact surface 6 of the holder 4, which runs parallel to the axis of the bore / opening 5. By using different intermediate layers on the contact surface 6, the orientation of the axis of the holder bore 5 and thus the direction of movement of the punch tool can be selectively influenced such that a displacement of the axis of the holder bore 5 in the direction of the x-axis and / or the y-axis and / or the z-axis and / or a tilting of the axis of the holder bore to the x-axis and / or the y-axis takes place.

At the lower end 9 of the C-bracket 1, the Matrizenträger 15 is attached. On the Matrizenträger 15, the die 25 is arranged. It is also conceivable that, in particular during a movement of the die carrier, instead of the punch 13, the die carrier 15 has a holder analogous to the holder 4 of the punch 13, which can be adjusted analogously to this.

In FIG. 3 is the C-bracket 1 with holder 4 and 15 Matrizenträger of FIG. 2 again shown in a perspective view obliquely from the front.

In Figure 4a to Figure 4c are different embodiments for the arrangement of the holder 4 after FIG. 2 and 3 and for the Matrizenträger 15 shown.

In FIG. 4a the die carrier 15 has a height h1, so that in this arrangement between the upper end of the Matrizenträgers 15 and the lower end of the receiving body 12 in the direction of the z-axis, a length I1 is given, in which the stamping tool can act. The bore 5 has the diameter d in this embodiment. To solve different connection tasks, the holder 4, which is designed to be detachable and replaceable, can now be combined with different diameters d of the bore 5, with different holder design and different holder materials and with different heights of the counter tool.

In FIG. 4b For example, it is shown to provide the die carrier 15 with a height h2 greater than h1. Furthermore, the holder 4 was compared to the embodiment in FIG. 4a rotated by 180 ° about the x-axis, which is perpendicular to the plate-shaped portion, so that the shorter portion 40 of the plate-shaped portion 10 now above the receiving body 12 is arranged. The longer part 41 of the plate-shaped portion 10 is accordingly arranged on the side of the receiving body 12, which lies opposite the lower end 9 of the C-bracket 1. Accordingly, a length 12 is formed in the direction of the z-axis between the lower end of the receiving body 12 and the upper end of the die carrier 15, the die carrier 15 having a height h 2 above the lower end of the C-bow 1.

This in Figure 4c illustrated embodiment corresponds to the embodiment according to FIG. 4b , wherein the height h3 of the die carrier 15 above the lower end 9 of the C-bracket 1 is smaller than the height h2 and greater than the height h1. Between the lower end of the receiving body 12 and the upper end of the Matrizenträgers 15 thus a length I3 is formed in the direction of the z-axis.

In FIG. 5a is arranged in an embodiment of the invention at the end 2 of the C-bracket of the holder 4, between the contact surface 6 and the end face 3 of the upper end 2 of the C-bracket, the intermediate layer 22 is inserted. The holder 4 has analogous to the holder 4 in Figures 2 . 3 and 4 U-shaped contact surfaces 6, 7 on. The arranged perpendicular to the axis of the bore 5 contact surfaces 7 are in the mounted state on the upper and lower end surfaces 33, which are offset by means of a step of the remaining areas of the one end 2 of the C-bracket. In order to prevent slippage of the intermediate layer 22 with respect to the holder 4, the intermediate layer 22 and (not shown), the contact surfaces 6 of the holder 4 and the front end face 3 of the end 2 each have a recess 21 or a slot into which a Key 23 is inserted. Here are the recesses 21 in the intermediate layer 22, in the contact surface 6 and in the end face 3 of the holder 4 above the other. The holder 4 and the intermediate layer 22 are analogous to the embodiment according to Figures 2 . 3 and 4 releasably secured by screws 19 at the upper end 2 of the C-bracket. In the FIG. 5a Pictured key 23 has a rectangular cross-section.

In FIG. 5c is a further embodiment of a key 23 'shown, which is provided with steps which are arranged along the longitudinal direction of the key. As a result, the compensation of an offset between the recesses 21 in the front end face 3 and in the contact surface 6 and possibly the intermediate layer 22 in the y direction is possible.

In FIG. 5b It can be seen that the contact surfaces 7 are arranged to support the reaction force on the separated with a step from the remaining part of the end 2 of the C-bracket end surfaces 33.

FIG. 6 shows an embodiment with a holder 24 and the one end 2 of the C-bracket. The holder 24, which is arranged on the end face 3 of the upper end 2 of the C-bracket, has the shape of a cylinder with a stalk-like extension. In the cylinder, the through hole 5 is arranged for receiving the punch tool. At the end of the extension, the holder 24 has a contact surface 6 which runs parallel to the axis of the bore 5. Analogous to the embodiments according to FIGS. 2 to 5 can be arranged between the contact surface 6 and end face 3 an intermediate layer (not shown here).

The stepped bores 18 for receiving the fastening elements (screws 19) are located on the stalk-like, the contact surface 6 forming region of the cylindrical holder part. In FIG. 6b the region of an upper stepped bore 18 and the region of the associated threaded bore arranged in the end face are shown cut out. The screw 19 is sunk in the stepped bore 18 and engages with its thread in the thread of the threaded hole in the end face 3. To arrange the screw 19 in the stepped bore 18 are in the stepped bore 18 opposite side of the cylindrical portion of the holder 24 holes 18 'are provided, which serve to pass through the screws 19 in the direction of the stepped bore 18.

Based on Figure 7a to Figure 7c another embodiment is explained, of which one end 2 of the C-bracket and the holder 34 is shown. The cylindrical part of the holder with bore 5 has an extension, which has a contact surface 6 parallel to the axis of the bore 5 and a perpendicular thereto bearing surface 7. Accordingly, the end faces 3 and 33 of the upper end 2 of the C-bracket 1 are formed perpendicular to each other. In this embodiment, the holes 18 for receiving the fasteners are on the contact surface 7 opposite side of the holder extension. This is in Figure 7a clearly visible. Not shown in the drawing, the thin intermediate layers between the contact surface 6 and end face 3 and / or contact surface 7 and end face 33 for adjusting the holder 34 in the direction of the x-axis and / or the y-axis and / or the z-axis are arranged.

In FIG. 8 another embodiment is shown. In this case, the holder 44 is provided with U-shaped arranged contact surfaces 47 and 6, all of which are parallel to the axis of the bore 5, wherein the parallel bearing surfaces 47 and the abutment surface 6 are perpendicular to each other. The holder 44 comprises the front end 2 of the C-bracket with the corresponding lateral end faces 43 and is located with the perpendicular to this end face 3 on the contact surface 6 at. The holes 18 for the releasable attachment of the holder 44 at the end 2 of the C-bracket are arranged in the abutment surfaces 47 forming legs of the holder 44 and the intermediate end 2.

FIG. 9 shows a further embodiment, with a lateral contact surface 47 and two perpendicular thereto arranged abutment surfaces 6 on the holder 54 and corresponding end faces 3 at one end 2 of the C-bracket. The two contact surfaces 6 and the corresponding end faces 3 are offset in the x direction and are separated from one another by a lateral contact surface 47 or a lateral end face 43. Compared to FIG. 8 is the lateral abutment surface 47 and accordingly the lateral end face 43 provided only once. Also in this case, the attachment of the holder 54 takes place at the upper end 2 of the C-bracket 1 by means of holes 18. The holes are arranged in the extension or leg of the holder 54, which forms the contact surface 47.

In the light of FIGS. 8 and 9 illustrated embodiments, thin intermediate layers (not shown) between contact surface 47 and lateral end face 43 and / or abutment surface 6 and end face 3 are arranged, which allow an adjustment of the holder 44 or 54 for adjusting the coaxiality. To relieve the screw connection of the embodiments according to FIG. 8 or 9 may be provided a tongue and groove connection.

Another embodiment of the invention is the FIG. 10 refer to. The figures show the one end 2 of the C-bracket and the holder 64, which is arranged on the flat end face 3 of the C-bracket. The end face 3 of the C-bracket extends parallel to the axis of movement of the punch or the holder bore 5. The holder 64 is prism-shaped with an octagonal base. The holder 64 has a through hole 5, which serves to receive the punch tool. The bore 5 is formed so that it is not concentric with the axis of the octagonal prism and / or does not coincide with this axis. In a further embodiment, the prism is not circularly symmetrical, so that no axis can be defined for the prism. The deviations, ie the angle between the prism axis and the bore axis or the deviations from the circular symmetry are very small. In this way, the bore to at least two different, preferably all flat contact surfaces 6, which are also side surfaces of the holder 64, a different distance and / or a different inclination. All abutment surfaces 6 form the mantle of the prism. The holder 64 can with each of the contact surfaces 6 on the end face 3 according to the required inclination of the bore axis and / or respectively the required distance of the bore axis of the end face 3 in the direction of the x-axis and / or the y-axis and / or Z axis are arranged so that a particularly simple adjustment of the holder and thus the punch tool or the counter tool is possible.

In a preferred embodiment, the end 2 of the C-bracket at the front end to a plate-shaped portion 62 which is formed substantially cuboid and the holder 64 facing, planar side of the end face 3 for mounting the holder forms. This end face 3 is at the same time the largest surface of the cuboid and serves for better attachment of the holder 64 on the end face third

The holes 18 for the releasable attachment of the holder 64 are present on each contact surface 6, wherein in a preferred embodiment, analogous to the embodiment according to FIG. 6 On the opposite side of the prism through openings may be present, through which the screws are stuck when attaching the holder 64 to the end face 3 therethrough. In this case, the bores 18 are provided symmetrically such that when the prism is rotated by 180 ° about the x-axis, which is perpendicular to the axis of the bore 5, the prism can also be fastened to the end face 3.

As an alternative to the flat side surfaces of the holder 64, in a further embodiment (not shown) the side surfaces may have notches and correspondingly the end surface 3 lugs, wherein when mounting the holder at the end of the C-bracket, the nose of the end face into the notch of a side surface intervenes.

In a further embodiment, the prism of the holder 64 may also have other base surfaces, for example a triangle, square or hexagon.

Another embodiment of the invention may be that one of the holders described above simultaneously forms the housing of the stamping tool.

Claims (11)

1. Joining apparatus having a ram tool (8) and a countertool (25) and a holder (4, 24, 34, 44, 54) having an opening (5) to accommodate the ram tool or the countertool, the two tools being oriented coaxial with each other at different ends (2, 9) of a C-bracket (1), wherein the holder comprises at least one plane contact surface (6, 7, 47) arranged on the outside surface of the holder, which contact surface can be in contact with at least one plane end face (3, 33, 43) of the corresponding end of the C-bracket and the holder is detachably fastened to said end face, characterized in that at least one interlay (17, 22) is arranged between the contact surface and the end face, determining the inclination and/or the distance of the contact surface from the end face, wherein the end face and the contact surface and the interlay each comprise a recess (21) intended to accommodate a fitting key (23), where in case of use of a non-stepped fitting key, the recesses are aligned with each other in installed condition and in case of use of a stepped fitting key, the recesses of the end face and of the contact surface are offset from each other.
2. Joining apparatus having a ram tool (8) and a countertool (25) and a holder (64) having an opening (5) to accommodate the ram tool or the countertool, the two tools being oriented coaxial with each other at different ends (2, 9) of a C-bracket (1), characterized in that one or more contact surfaces (6) arranged on the outer surface of the holder are in contact with a plane end face (3) of the corresponding end of the C-bracket and detachably fastened to said end face, the axis of the opening having different distances and/or inclinations with respect to each contact surface.
3. Joining apparatus according to claim 1, characterized in that the interlay comprises two plane surfaces, one neighboring upon the contact and the other upon the end face.
4. Joining apparatus according to claim 3, characterized in that the interlay is configured wedge-shaped.
5. Joining apparatus according to any of claims 1, 3 and 4, characterized in that the holder comprises two contact surfaces arranged at right angles to each other.
6. Joining apparatus according to any of claims 1, 3 and 4, characterized in that the contact surfaces of the holder are formed by the inner surfaces (6, 7) of a U-shaped element.
7. Joining apparatus according to any of claims 1 and 3 to 6, characterized in that the contact surface and the bores (18) for attachment of the holder to the C-bracket are arranged symmetrically in the holder and the receiving body (12) with the opening (5) eccentrically, so that according to the rotation of the holder, two length adjustments with respect to the distance of the lower end of the receiving body from the upper end of the countertool are realizable.
8. Joining apparatus according to claim 2, characterized in that the contact surfaces more or less form an envelope of a prism having a triangular or polygonal base.
9. Joining apparatus according to any of claims 1 to 8, characterized in that the opening (5) is a through opening of cylindrical configuration.
10. Joining apparatus according to any of claims 1 to 9, characterized in that the holder is detachably fastened by means of screws (19) to the at least one end face of the corresponding end of the C-bracket.
11. Joining apparatus according to any of claims 1 to 10, characterized in that the holder and the corresponding end of the C-bracket are of such configuration that the axis of the opening is rotatable through 180°, the course of the axis after the rotation corresponding essentially to the course of the axis before the rotation.

Images