DE9005859U1 - Furniture, especially exhibition stands, showcases, tables, etc. - Google Patents

Description

Applicant :

Wulf Markus OTTO
Machfcolfweg 59

7000 Stuttgart-80

4623 002

13.3.yO (90/10)

Title : Furniture, especially exhibition stand, showcase, table and the like.

FM's invention relates to a piece of furniture, in particular a trade fair stand, showcase, table and the like, formed by a spatial or flat supporting or lattice structure essentially assembled from tubular elements, in which a plate is arranged in at least one intermediate opening.

It is known to use one-piece sheet metal fittings for hanging or fastening plate elements in tubular frames. One embodiment provides L-shaped stop flanges that are screwed to the tubular elements and by means of which the plate elements are attached to the

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tubular frame, e.g. screwed on. Other sheet metal fittings2 have a middle area adapted to the outer contour of the tubular element, which is attached to the tube by a screw, for example, and at least one support area protruding radially from the tubular element, in which the ?i-Lten element is hung, loosely placed on it or screwed on.

The disadvantage here is that, for example, in the case of exhibition stands that require quick assembly and disassembly, the time required to screw and secure the panels is considerable. A greater disadvantage, however, is that such fastening fittings significantly impair the visual appearance of a showcase or exhibition stand and become unsightly even with minimal wear.

Plate elements are also used as intermediate compartments or cover plates in display cabinets. The plate elements are held in place directly by the tubular frame or by retaining pins embedded in the tubular wall or by support supports welded onto the tubular element. The disadvantage here is that there is no protection against the plates being moved or removed from the tubular frame.

The object of the present invention is to create a piece of furniture of the type mentioned above, in which a secure picking up

of panels between the tubular elements forming a frame is possible without, however, affecting the smooth appearance of the furniture, in particular of the panels and the tubular elements; furthermore, a quick and safe attachment of the panels should be guaranteed.

This object is achieved in that at least one holding element is provided which can be replaced in one of the pipe elements and fixed therein, and in that at least one locking pin which can be moved through a first opening in the pipe wall is accommodated in a displaceably guided manner in the holding element, which can be brought into and out of engagement with a receiving recess in the plate through a second opening in the pipe wall which is aligned with the locking ^pin .

This creates an effective fastening and locking device by means of which the panels can be fixed in place in a space in the tubular support structure surrounded by tubular elements, without having any externally visible elements that would impair the appearance of the tubular furniture frame provided with panel elements. Except for the necessary through holes in the tubular elements for inserting an adjustment key for the locking pin, which can also point into the interior of the furniture and are therefore not visible from the outside, it is possible to have a tubular frame furniture without

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to create visible connecting fittings for the panels. The access holes can also be closed using elastic plugs that match the color of the tubular elements. The tubular frame elements can be fitted with the retaining elements before the exhibition furniture is assembled, so that after the frame has been assembled, the panel elements can be securely attached by simply moving the locking pins.

The holding elements can be used in a variety of ways, e.g. for attaching and securing cover panels, side panels and intermediate panels in a display cabinet. They can also be used as rotary hinge elements for attaching a door panel. For this purpose, a holding element is inserted into two parallel tubular elements, in each of which a suitable locking pin is arranged so that both lie on a rotation axis and engage through the tubular wall directly into the panel or a holder attached to it, whereby the latter is rotatably mounted. The holding element can also be used as a lock. For this, the first opening through the tubular element, which ensures access to the locking pin in the holding element, must be provided on the outside of the tubular frame furniture; the locking pin then serves as a locking bolt that engages in the panel or a lock on the panel.

The retaining element is protected against axial displacement within the

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The pipe is secured in an effective and simple manner in that the cross section can be designed to match the inner cross section of the pipe element and is preferably accommodated in the pipe element with a slight press fit or a tight sliding fit.

If square tubes are used for the furniture, the holding element can have a cuboid or cube-like shape, the side surfaces of which are divided into two by a longitudinal groove, preferably forming symmetrical clamping surfaces. The clamping surfaces facilitate secure accommodation of the holding element inside the tube, whereby sufficient clamping pressure between the often irregular inner wall of the tube and the side surfaces of the holding element is ensured by the fact that the clamping surfaces can have a preferably triangular, only slightly protruding clamping elevation running in the longitudinal direction of the tube with a small cross-sectional area, which can also be shaved off when inserted into the tube element, so that premature jamming or wedging when inserted into the tube element is prevented. To make it easier to insert the holding element, the longitudinal edges of the holding element can be rounded.

For the introduction and during positioning of the holding element in the pipe element, it is advantageous in a further embodiment that the holding element has a recess in at least one end face, in particular a

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The holding element can have an assembly opening running in the longitudinal direction into which, for example, a rod with a spreading device can engage, which can be removed again after positioning has been carried out.

In order to effectively and safely guide the locking pin in the holding element, a further embodiment provides that the holding element can have at least one guide channel which runs perpendicular to the holding element's longitudinal axis and opens into a side surface aligned with the second opening and in which the locking pin is slidably accommodated, in particular completely, with a slight press fit or tight play/sliding fit. This largely excludes the automatic displacement of the locking pin without the intervention of an external locking lock in the guide channel, which ensures that the plate is securely locked in the tubular frame. Easy access for adjusting the locking pin in the guide channel is provided by the fact that the holding element can have an access channel that opens into the guide channel or extends through it, which also opens into a side surface aligned with the first opening and runs perpendicular to the holding element's longitudinal axis.

A design that ensures the displaceability of the locking pin provides in particular that the locking pin can be designed in the form of a rack with a

front part in the form of a pin head that is smooth on the circumference and is arranged closest to the second opening, and with a rear part that has teeth into which an external adjustment key can be brought into engagement to move the locking pin through the first opening. The locking pin can thus easily be brought into a locking position in which the pin head engages in the receiving recess of the plate, preferably abutting on the front side, and into a rest position in which the front side of the pin head is received in the second opening or in the guide channel.

In order to prevent the locking pin from shearing off when the panels are subjected to a heavy weight load, it is advantageous that the locking pin can still be guided at least halfway into the guide channel in the locking position.

The pin head can take up to a third of the length of the locking pin and can be accommodated in the plate’s recess with a tight clearance/sliding fit or a slight press fit, so that the plates can be fitted in the tubular frame without clearance. The teeth of the rear section run transversely to the locking pin’s longitudinal axis and are machined into it, whereby the tooth height can preferably be up to a third of the pin height.

The tenon head prevents damage to the teeth as they do not engage in the recess of the plate.

It is advantageous that the locking pin can preferably have a rectangular cross-section, although the cross-sectional shape of the pin head can be the same or different from the cross-sectional shape of the rear section. If the pin head has a rectangular ^cross -sectional shape and engages in a correspondingly shaped receiving recess in the plate, the holding element can be used as a rotary hinge as already mentioned above. The longitudinal edges of the locking pin can advantageously be slightly broken or rounded in order to eliminate stress peaks in the event of transverse loading.

Twisting of the locking pin in the guide channel is advantageously avoided by the fact that the guide channel can be designed to match the external cross-section of the locking pin, and that the pin head is accommodated with a slight press fit and the rear section with the teeth is accommodated with a tight play/sliding fit or vice versa between two side surfaces of the guide channel. This also ensures that the teeth in the guide channel are clearly aligned.

In order to ensure the fit between the locking pin and the guide channel, it is particularly advantageous that the side fish

or the side flanks of the locking pin one or more parallel to each other in tenon or

Guide channel longitudinal direction, slightly protruding Have a sliding fit elevation with a small cross-sectional area

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In a further advantageous embodiment, it is provided that the access channel preferably has a circular cross-section in the first third of the area of the guide channel closest to the second opening in the tube, runs perpendicular to the thickness and can be offset in height with respect to the longitudinal axis of the old element so that the engagement teeth of the locking pin protrude into the access channel with an engagement dimension. This engagement dimension can be equal to the tooth height of the engagement teeth, which ensures that the locking key can engage in the guide channel. An engagement in the guide channel is thus possible perpendicular to the plate plane, which considerably simplifies the adjustment of the locking pin.

Because the guide channel in the holding element is arranged in relation to a closest parallel side surface and the receiving recess in a longitudinal or transverse side of the plate so that one of the plate surfaces and the adjacent pipe wall outer surface of the pipe element form a smooth, continuous surface, a furniture outer surface without steps can be achieved. The latter is

This is achieved in a simple manner in a further embodiment in that the central axis of the receiving recess can run symmetrically to both plate surfaces in the long or transverse side of the plate, and that the distance between the central axis of the guide channel and the side surface lying parallel to it is equal to the plate thickness reduced by the pipe wall thickness. The receiving recess can be formed by an insert bush in the long or transverse side of the plate, so that the receiving recess is ^not knocked out when the plates, which are usually made of chipboard, are used frequently, and the locking pin head is held in place better.

In a further embodiment, it is provided that the locking pin in the holding element can be moved against the return effect of a return element in particular from the locking position into the rest position and automatically returns to the locking position. This enables a significantly faster assembly and attachment of the panels to the tubular frame, in which the locking pins are briefly pressed back into the guide channel, for example by hand or by the panel itself, so that when the receiving recess is aligned with the guide channel, the locking pin is automatically pushed into it and the panel is secured. A return spring, in particular a compression coil spring, can be provided as the return element, which is located between the rear face of the locking pin or

a recess in this and a rear guide channel base closing off the guide channel or another stop shoulder of the same. The locking pin can thus be pushed back into its rest position releasing the plate at any time against the spring force effect by means of the locking pin.

The application possibilities of the holding element are improved in that the holding element can have two locking pins which are guided in two guide channels running perpendicularly or parallel to one another, can be moved through two access channels which also run perpendicularly or parallel to one another and open into one of the guide channels, via first openings in the pipe wall of the pipe element which are aligned with them, and can be attached into and out of engagement with the corresponding receiving recess of one of two plates which can be attached to the pipe element running perpendicularly or parallel to one another through second openings in the pipe wall which are aligned with the locking pins or guide channels. This means that plates can be attached to a pipe element which serves as a corner support or connecting support without the need for two separate holding elements. If the pipe element does not have a square cross-section, but for example a circular cross-section, it is also conceivable that the guide channels have any angle of alignment to each other, so that any alignment of two

The plates to be attached to the pipe element can be attached to one another.

It is also advantageous that the guide channel center axes can preferably run in the same plane, in particular the longitudinal center plane of the holding element; this makes it possible to provide receiving recesses in the plates with a uniform distance on the longitudinal and transverse sides.

Since the locking pins are moved by engaging the rotating adjustment key, it is advantageous that the access channels can run on different sides of the longitudinal center plane of the holding element, in particular at the same distance from it. This makes it possible to bring the locking pins, which run perpendicular to one another, into the locking position or rest position by rotating the adjustment key in a uniform direction. If the access channels are on the same side of the longitudinal center plane, one locking pin is moved by rotating it in one direction and the other locking pin is moved by rotating the adjustment key in the other direction.

The adjustment key can advantageously be designed in such a way that it can have a front shaft area with a circular cross-section, the diameter of which is equal to that of the access channel and has a front end area with peripherally extending engagement teeth,

which is designed to match the engagement teeth of the locking pin. The teeth of the locking pin and the engagement counter teeth are coordinated in such a way that easy engagement is ensured when the key is turned.

The holding element can also be effectively secured against axial displacement within the pipe by the holding element having at least one clamping member that can be tightened and released through a further opening in the pipe wall of the pipe element or one of the other openings and that can be clamped against the inner wall surface of the pipe. A threaded pin, preferably with a hexagon socket or slot, can be provided as the clamping element, which is received in a threaded hole that can be connected in particular in an aligned extension to the access channel or the guide channel.

A cost-effective and simple design of the retaining element is provided by the fact that it can be made of hard plastic, in particular of an impact-resistant and abrasion-resistant, possibly GRP-reinforced polyamide. The locking pin can also be made of this material. In order to increase the shear strength under transverse load, the locking pin can then have a pin, preferably made of metal, running along the entire length inside. The retaining element, but also the

Locking pins can also be made of metal, preferably a pressure-moldable aluminum alloy or the like.

Further embodiments according to the invention can be found in the subclaims. These and their advantages are explained in more detail using several embodiments described below and the attached drawings. It shows:

Figure 1 is a spatial view of a*" from

Display case assembled from tubular elements with panels housed in the spaces between the tubular frames;

Figure 2 is an isometric view of a

Holding element according to detail II of the tubular frame furniture shown in Figure 1 with two locking pins and tensioning members, which are shown removed from the holding element for clarity, and an adjustment key;

Figure 3a is a view along the arrows &Pgr;&Igr;-&Igr;&Igr;&Igr; according to

a longitudinal section of the holding element shown in Figure 2 in a first embodiment variant;

Figure 3b shows a device designed according to Figure 3a.

Longitudinal section of a second variant of the retaining element;

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Figure 4

a cross-section through a holding element inserted in a tubular element according to Detail IV of the tubular frame furniture shown in Figure 1;

Figure 5

a cross section through a holding element inserted in a tubular element in a second embodiment according to detail V of the tubular frame furniture shown in Figure 1;

Figure 6

a cross-section through a holding element inserted into a tubular element in a third design variant according to detail VI of the tubular frame furniture shown in Figure 1;

Figure 7

a locking pin of the holding element shown in Figure 6, which serves as a rotary hinge element.

Figure 1 shows an exhibition showcase 1, which is in the form of a tubular frame made of square tubular elements 4, put together using a number of connecting fittings 2. In the tubular elements that border an intermediate area 3, different panels are fastened using holding elements 20 according to the invention. Furniture formed in this way is used as an exhibition stand and can therefore be set up and dismantled quickly and easily.

degradable.

In Figure 2, according to a detail II from Figure 1, a shark element 20 is shown isometrically in a dismantled state and disassembled into its individual parts. The shark element 20 consists of a cuboid or cube-shaped plastic body, the outer cross section of which is adapted to the inner cross section of the pipe element 4 and can be inserted into it with a slight press fit. The side surfaces 21 of the base body 20, which have a longitudinal groove 22, come to rest on the inner wall surface 6 of the pipe with their clamping surfaces 23, which are arranged symmetrically to one another in the edge area. The clamping surfaces 23 can, although not shown here, have clamping elevations running in the longitudinal direction of the pipe element, protruding only slightly and having a small cross-sectional area, in order to ensure secure axially immovable support in the event of existing irregularities in the inner wall of the pipe.

In a front side 24 of the holding element 20, a recess arranged around the holding element longitudinal axis 25 is provided as an assembly opening. A rod having a corresponding clamping and spreading device can be inserted into this in order to introduce and position the holding element 20 in the tubular element.

The holding element 20 has two perpendicular

The side surfaces 21 each have a guide channel 32, 32' which protrude into the interior of the holding element 20 perpendicular to the holding element's longitudinal axis 25 and to the respective side surface 21. In the clamping surfaces 23 forming a common edge, there are also provided access channels 30, 30' which run perpendicular to one another and which also run perpendicular to the holding element's longitudinal axis 25 and each extend vertically into one of the guide channels 32, 32'.

In Figure Ja, the arrangement and the course of the access channels 30 and 30' in relation to the associated guide channels 32 and 32' are shown in a longitudinal section. Both guide channels 32, 32' run with their central axes 33, 33' perpendicular to each other in the longitudinal center plane 26 of the holding element 20, i.e. in the middle plane of symmetry in relation to the holding element longitudinal axis 25. The depth of the guide channels 32, 32' is selected so that they do not protrude through each other and form a flat frontal base 40. The two access channels 30, 30' are arranged with their* central axes 31, 31' running parallel to the longitudinal center plane 26 at a distance 36, so that they open into the associated guide channels 32, 32', which have a rectangular cross-section, at an engagement dimension 37 at a height offset. The access channels 30, 30' can be arranged on opposite sides with respect to the longitudinal center plane 26, or, as shown in Figure 3b, on the same side of each other.

In the extension of the access channels 30, 30', a threaded bore 38 is provided which is open towards the opposite clamping surface 23. As can also be seen from Figure 3b, the guide channels 32, 32' can also be provided so as to protrude through one another.

As can be seen in Figure 2, the holding element 20 has two locking pins 10, 10', which are designed in the form of a rack and can be slidably received in the guide channels 32, 32'. The side flanks 15 of the locking pin 10, 10' have a sliding fit elevation 16 running in the longitudinal direction, only slightly protruding and equipped with a small cross-sectional area, by means of which a correct sliding or slight press fit is provided between the locking pins 10, 10' and the guide channels 32, 32' at least over a partial longitudinal area.

The locking pin 10, 10' is inserted into the guide channel 32, 32' with its teeth 11 arranged in the rear section so that the teeth protrude into the access channel 30, 30' and the front section with the smooth-surfaced pin head 12 comes to rest in the side surface opening area. The locking pins 10, 10', made of an abrasion-resistant hard plastic, have a metal pin 14 embedded in a longitudinal bore 13 on the front side to improve the shear strength.

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In another embodiment according to Figure 7, the pin head 12 is designed with a circular cross-section, in contrast to the rectangular cross-section of the rear portion having the toothing 11.

Figure 2 also shows the front end of a pipe element 4, in which first openings 8,8' and second openings 7,7' are provided in two pipe walls 5 running perpendicular to one another, the arrangement of which is such that it corresponds to that of the access channels 30,30 ^{' and} guide channels 32,32' opening into the side surface 21 of the holding element 20 and, when the holding element 20 is inserted, the openings (7,7' and 8,8') are aligned with the corresponding channels (32,32' and 30,30', respectively). The cross-sectional shape of the corresponding channels and openings is preferably the same, but they have slightly larger dimensions in order to compensate for manufacturing tolerances.

In order to ensure secure clamping of the holding element 20 in the pipe element even when it is removed and reinserted several times, two clamping elements 42 in the form of threaded pins with hexagon socket or slot are also provided, which are received in the threaded holes 38 of the holding element 20 and which can be clamped to the pipe inner wall 6 through the second openings 7, 7'.

The locking pins 10, 10' can be inserted through the first openings 8, 8' into the '(anal 32, 32' before or after positioning the holding element 20 in the tubular element 4, depending on whether their length is such that when completely ^received in the access channel 32, 32' their front end protrudes slightly from the clamping surface 23 or is flush with it.

In order to push the locking pin 10, 10' from its rest position, in which it is completely in the holding element 20 or with the front end in the area of the second opening 7, 7', into a locking position in which the pin head 12 protrudes through the second opening 7, 7', a special adjustment key 60 is provided which has a front shaft area 61 in the manner of an Allen key, which has a circumferential engagement counter toothing 62. This is designed to correspond to the toothing 11 of the locking pin 10, 10', so that when the toothings 11, 62 engage and the adjustment key 60 is turned, the locking pin 10 can easily be moved.

Figures 4 to 6 show several possible uses of the holding element.

Figure 4 shows a cross section through a holding element 20 according to detail IV of Figure 1, which serves as a corner connection holding element. In a corner support

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A previously described holding element 20 is inserted into the tubular element 4 serving as the locking element, by means of which two plates 50, 50' running perpendicular to one another can be locked to the tubular element. For this purpose, the plates 50, 50' have a receiving recess 53 on their transverse and longitudinal sides, into which the locking pin 10 with its pin head 12 can be received, preferably with a slight press fit or tight sliding fit. The receiving recess 53 can be formed either by individually provided insert bushes S4 or by a circumferential groove along the transverse and longitudinal sides.

The guide channel 32 in the holding element 20 runs with respect to a parallel side surface 21 closest to it in such a way that when the locking pin 10 engages in the receiving recess 53, the outer plate surface 52 and the flush pipe wall outer surface 6' form a smooth, continuous surface. For this purpose, the center axis of the receiving recess 53 is arranged symmetrically to both plate surfaces 52 in the longitudinal or transverse side of the plate 50 and the distance between the guide channel center axis and the side surface 21 closest parallel to it is equal to the plate thickness reduced by the pipe wall thickness. The engagement channels (30,30 ¹ ) protrude through one another in the manner shown in Fig. 3b.

In Figure 5, a retaining element inserted in the pipe element 4 is

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20 in cross-section, in which a compression coil spring 41 is arranged between the container wall 40 of the guide channels 32, 32' and the locking pins 10, 10' received therein. As a result, the locking pins 10, 10' are held in the locking position through the second pipe wall openings 7, 7', in which they are received with their pin head 12 abutting on the front in the receiving recess 53. The locking pins 10, 10' can be brought into their rest position by means of the adjustment lock 1s 60 against the return spring force effect; only then is it possible to remove the plates 50', ⁵⁰ '''. The cover plate 50' rests on a plate 61 on the pipe element &lgr; welded support 45 with support damping 46 and is fixed by means of the locking pin 10'. The adjustment key 60 can engage the locking pin 10' via the first opening 8' indicated by its axis and the access channel 30' from the interior of the furniture. The other first opening 8 and the access channel 30 running coaxially therewith are, however, provided to be accessible from the outside of the furniture, so that the locking ^pin 10 engages in the door panel 50'' designed as a door and thus forms a locking device for the latter.

In Fig. 6, a holding element 20 designed as a door hinge is shown in cross section according to detail VI of the display case shown in Fig. 1, the locking pin 10 engaging in the door panel 50' ' ' is shown in Fig. 7. The

Pin head 12 has a circular cross-sectional shape to; Rotatability when engaging the cylindrical insert bushing |

i 54 of the door plate 50"'. The rear i

Tenon area with the toothing 11 is in cross section |

rectangular, so that twisting in the also &iacgr;

Rectangular cross-section guide channel 32 is blocked and the teeth 11 remain projecting into the access channel 30 in order to ensure the possibility of adjusting the locking pin 10.

Claims (1)

1. Furniture, in particular exhibition stand, showcase, table and the like, formed by a spatial or flat frame or framework assembled from tubular elements (4) in the sense of a joint, in which a ^slat (50) is arranged in at least one intermediate opening (3), characterized in that at least one holding element (20) which can be inserted into and fixed to one of the tubular elements (4) is provided, and in that furthermore at least one locking pin (10) which can be moved through a first opening (8) in the tubular wall (5) is slidably guided in the holding element (20), which can be brought into and out of engagement with a receiving recess (53) in the plate (50) through a second opening (7) in the tubular wall (5) which is aligned with the locking pin (10). 2. Furniture according to claim 1, characterized in that the holding element (20) is designed to be adapted in cross section to the inner cross section of the tube element (4) and is received in the tube element (4), preferably with a slight press fit or a tight play/sliding fit. 3. Furniture according to claim 1 or 2, characterized in that the holding element (20) has a cuboid or cube-like shape, whose side surfaces (21) are formed by a longitudinal groove (22) divided into two, preferably symmetrical clamping surfaces (23) and has a recess (27) in at least one end face (24), in particular a mounting opening running in the longitudinal direction of the holding element. 4. Furniture according to claim 3, characterized in that the clamping surfaces (23) have a preferably triangular, only slightly protruding clamping elevation - ¹ I small cross-sectional area - running in the longitudinal direction. 5. Furniture according to one of claims ^: ,'s 4. characterized in that the locking pin (10) is designed in the form of a rack, with a front portion in the form of a pin head (12) which is smooth on the circumference and is arranged closest to the second opening (7), and with a rear portion having the toothing (11) into which an external adjustment key (60) can be brought into engagement for moving the locking pin (10) through the first opening (8). 6. Furniture according to claim 5, characterized in that the pin head (12) can be received in the receiving recess (53) of the plate (50) with a tight play/sliding fit or a slight press fit. 7. Furniture according to claim 5 or 6, characterized in that the locking pin (10) preferably has a rectangular cross-section, wherein the pin head cross-sectional shape is preferably equal to the cross-sectional shape of the rear section. %: Furniture according to one of claims 1 to 7, characterized characterized in that the holding element (20) has at least one guide channel (32) which runs perpendicular to the holding element longitudinal axis (25) and opens into a side surface (21) in alignment with the second opening (7) and in ^which the locking pin (10) is displaceably received, in particular completely, with a slight press fit or close play/sliding fit, and in that the holding element (20) has an access channel (30) which opens into the guide channel (32) or projects through it and which also opens into a side surface (21) in alignment with the first opening (8) running perpendicular to the holding element longitudinal axis (25). 9. Furniture according to claim 8, characterized in that the guide channel (32) is designed to match the external cross section of the locking pin (10), and that the pin head (12) is accommodated with a slight press fit and the rear portion with the toothing (11) with a tight clearance/sliding fit or vice versa between two side surfaces (34) of the guide channel (32). 10. Furniture according to claim 9, characterized in that the side surfaces (34) or the side flanks (15) of the locking pin (10) have one or more slightly protruding sliding fit elevations (16) with a small cross-sectional area, running parallel to one another in the longitudinal direction of the pin or guide channel. 11. Furniture according to any one of claims 8 to 10, characterized in that the access channel (30) preferably has a circular cross-section in the first third of the opening (7) of the tube wall (5) the next area of the guide channel 15 (32) running perpendicularly to it and at a height offset with respect to the holding element longitudinal axis (25) such that the engagement teeth (11) of the locking pin (11) protrude into the access channel (30) with an engagement dimension (37). 12. Furniture according to claim 11, characterized in that the engagement dimension (37) is equal to the tooth height of the engagement teeth (11). 13. Furniture according to one of claims 1 to 12, characterized in that the locking pin (1Q) can be brought into a locking position in which the pin head (12) engages in the receiving recess (53) of the plate (50) preferably in abutting manner on the front side and can be brought into a rest position in which the front side of the ZapTen head (12) is in the 7wide opening (7) or in the guide channel (32). 14. Furniture according to claim 13, characterized in that the locking pin (10) is still guided at least halfway in the guide channel (32) in the locking position. 15. Furniture according to one of claims 8 to 14, characterized in that the guide channel (32) in the holding element (20) with respect to a side surface (21) lying closest thereto and running parallel to it and the receiving recess (53) in a longitudinal or transverse side (51) of the plate (50) are arranged in such a way that one of the plate surfaces (52) and the adjacent pipe wall outer surface (6') of the pipe element (4) form a smooth, continuous surface. 16. Furniture according to claim 15, characterized in that the central axis of the receiving recess (53) runs symmetrically to both plate surfaces (52) in the longitudinal and transverse sides (51) of the plate (50), and that the distance between the guide channel central axis (33) and the side surface (21) of the holding element (20) closest to it, parallel to it, is equal to the plate thickness reduced by the tube wall thickness. 17. Furniture according to one of claims 1 to 16, characterized in that the locking pin (10) in the holding element (20) can be moved from the locking position into the rest position against the restoring action of a restoring element (41) and automatically returns to the locking position. 18. Furniture according to claim 17, characterized in that the return element (41) is a return spring, in particular a compression coil spring, and that the return spring is arranged between the rear end face of the locking pin (10) or a recess in this and a rear guide channel base (40) closing off the guide channel (32) or a stop shoulder of the same. 19. Furniture according to one of claims 1 to 18, characterized in that the holding element (20) has two locking pins (10, 10'), which are guided in two guide channels (32,32') running perpendicularly or parallel to each other, which can be moved through two access channels (30,30') which also run perpendicularly or parallel to one another and open into one of the guide channels (32,32') via first openings (8,8') aligned therewith in the pipe wall (5) of the pipe element (4) III· If and through second openings (7,7') in the pipe wall (5) aligned with the mirror pins (10,10') or guide channels (32,32') can be brought into and out of engagement with the corresponding receiving recess (53,53') of one of two plates (50, 50 ', 50" , 50 ' ' ') that can be attached to the pipe element (4) running perpendicularly or parallel to one another. 2ü. Mc bei according to claim 19, characterized in that the guide channel center axes (33, 33') preferably run in the same plane, in particular the longitudinal center plane (26) of the holding element (20). 21. Furniture according to claim 19 and 20, characterized in that the access channels (30, 30') run on the same side or different sides, in particular at the same distance (36) from the longitudinal center plane (26) of the holding element (20). 22. Furniture according to one of claims 1 to 21, characterized in that the holding element (20) has at least one clamping member (42) which can be tightened and released through a further opening in the tube wall (5) of the tube element (4) or one of the other openings (7, 8) and which can be clamped against the tube inner wall surface (6). 23. Furniture according to claim 22, characterized in that the tensioning element (42) is a threaded pin, preferably with »· · · · ■■■■ Internal hexagon or slot and is received in a threaded bore (38) which is connected in particular in an aligned extension to the access channel (30) or the guide channel (32). 24. Planer according to one of claims 1 to 23, characterized in that the holding element (20) consists of hard plastic, in particular an impact-resistant and abrasion-resistant, optionally GRP-reinforced polyamide. 15. Furniture according to one of claims 1 to 24, characterized in that the locking pin (10) consists of an abrasion-resistant, impact-resistant hard plastic, in particular polyamide, optionally reinforced with GRP. 26. Furniture according to claim 25, characterized in that the locking pin (10) has a pin (14) which preferably runs over the entire longitudinal extent inside the locking pin (10) and is preferably made of metal. 27. Furniture according to one of claims 5 to 26, characterized in that the adjustment key (17) has a front shaft region (61) with a circular cross-section, the diameter of which is equal to the diameter of the access channel (30) and a front end region with a circumferentially extending F innrif f saeuenvi^ rzahnuna (18) which corresponds the engagement teeth (11) of the locking pin (10).