EP0566045B1 - Adjustable column, particularly for chairs - Google Patents

Description

The invention relates to a column unit, in particular a chair column unit, comprising a base tube with a base tube axis, a first base tube end, a second base tube end and guide means inserted into the base tube in the region of the second base tube end, further comprising a positioning device with a device axis which essentially coincides with the base tube axis , with a first sub-group unit and a second sub-group unit, these sub-group units being axially movable with respect to one another and being mutually lockable in a plurality of axial relative positions, the first sub-group unit being supported essentially axially immovably with respect to the base pipe on a support means connected to the base tube and possibly opposite this support means is rotatable, with the second sub-group unit extending beyond the second base tube end and between an innermost position and an outer one Most position is adjustable relative to the second base tube end, further comprising an outer portion of the second subgroup unit, which extends beyond the second base tube end and beyond the guide means and is designed for connection to a column-borne object, and wherein the second subgroup unit is in axially sliding engagement with the management means.

Such a column unit is known for example from DE-PS 19 31 012 and from US-PS 4,848,524. In the known embodiments, which have proven to be excellent in practice, the guide means are axially fixed relative to the second, ie the upper end of the base tube. The problem can arise that the upper, ie the second subgroup unit no longer has a sufficient guide length on the guide means when the second subgroup unit is in its outermost position. This problem cannot be solved simply by changing the length of the base tube with the positioning device unchanged is extended, because such an extension of the base tube could possibly lead to a limitation of the stroke of the positioning device, so that the shortest possible position of the column unit due to the design of the positioning device could no longer be achieved.

• a) Die Führungsmittel sind längs des Basisrohrs axial verschiebbar geführt;
• b) die Führungsmittel sind von der zweiten Teilgruppeneinheit bei deren Auswärtsbewegung zwischen deren innerster Stellung und deren äußerster Stellung auf einem Teilweg mitnehmbar;
• c) die Auswärtsbewegung der Führungsmittel gegenüber dem zweiten Basisrohrende ist durch zusammenwirkende, an den Führungsmitteln und an dem Basisrohr angebrachte auszugbegrenzende Anschlagmittel begrenzt.

The invention is therefore based on the object of designing a column unit of the type mentioned at the outset in such a way that, with almost complete utilization of the base tube length, in order to enable a stroke of the positioning device approximately corresponding to the base tube length, this positioning device by means of the second subgroup unit also in the outermost position of the second subgroup unit still has a sufficient lead length within the lead. To solve this task, the combination of the following features is proposed:

• a) The guide means are guided axially displaceably along the base tube;
• b) the guide means can be taken along on a partial path by the second sub-group unit when it moves outward between its innermost position and its outermost position;
• c) the outward movement of the guide means relative to the second base tube end is limited by interacting stop means attached to the guide means and to the base tube and to be limited.

Characterized in that the guide means are axially displaceable with respect to the base tube and that the guide means on the second subgroup unit during its outward movement between its innermost and outermost position are taken along a partial route, the guide length of the second subgroup unit inevitably adapts to the length setting of the positioning device.

However, if the guide means are "axially floating" attached to the second base tube end, there could be a risk that the guide means disengage from the base tube when the positioning device is fully or partially extended towards the outermost position. This could happen in particular if the guide means are received in the base tube essentially without friction and if, in such an embodiment, the column unit is turned upside down so that its originally upper end on the object side is at the bottom. The case of a loss of guidance of the guide means on the base tube could also occur, for example, when the guide means are gripped during cleaning by a wiping movement along the base tube and are taken along in the pull-out direction. In order to prevent this possibility, the outward movement of the guide means relative to the second base tube end is limited by interacting stop means which are attached to the guide means and to the base tube and are to be limited.

It is recommended that the stop means to be limited are arranged in such a way that they define an axially outer limit position of the guide means, in which the second subgroup unit, when in the outermost position relative to the second base tube end, is optimally supported on the base tube; This means, for example, the following: If the second sub-group unit is in its outermost position, it should be guided in the base tube for approximately half its length, and on the other hand the other half of its length should be protrude beyond the second base pipe end and lead the second sub-group unit. In this way it is possible to extend the second subgroup unit without losing sufficient guidance so that the end of the second subgroup unit facing the first base tube end is in the region of the second base tube end or even outside the second base tube end.

There is occasionally a need to replace the gas spring in a column unit, in particular a chair column unit. For this purpose, the first subgroup unit is operationally easily detachably connected to the associated support means. This means that the positioning device can be easily removed from the column. In connection with the removal of the positioning device from the base tube, the requirement to remove the guide means from the base tube, for example also to replace worn guide means or in order to adapt, now also arises occasionally, in particular when there are entraining attachment means on the positioning device and the guide means to use a different guide means for a changed dimensioning of the positioning device. In order not to complicate the possibility of replacing the guide means in that the stop means to be limited are available, it is further proposed according to claim 29 that the pull-out limiting effect of the stop means to be limited can be overcome.

There are various possibilities here: It can be provided that the pull-out limiting effect of the sling means to be limited can be switched off by applying a predetermined minimum pull-out force to the guide means.

This basic possibility can be carried out, for example, in such a way that the stop means to be limited have a pull-out limit stop and a Guide-side pull-out limit stop, the guide-side pull-out limit stop being formed by a pull-out limit ring attached to an end region of the guide means lying inside the base tube, which can be stripped from the guide means when the predetermined minimum pull-out force or a greater pull-out force is applied to the guide means by interaction with the base tube-side pull-out limit stop. It is possible for the extension limiting ring to be elastically expandable and to be received in an annular recess on an outer circumferential surface of the guide means. Furthermore, it is possible for the pull-out limit stop on the base tube side to be formed by an end directed toward the first base tube end of a centering tube inserted axially immovably into the second base tube end.

A further preferred possibility is that the stop means to be limited are fundamentally unsolvable simply by applying an axial pull-out force to the guide means, but are ineffectively feasible by at least one release measure different from the application of a pull-out force. This option has the advantage over the first-discussed option that the pull-out limiting effect of the sling gear that is limited can also absorb very large pull-out forces that are applied to the guide means without the intention of removing it, and that, on the other hand, the guide means can be released with little effort if the intention is to remove it can. A wide variety of options are now subordinate to this design principle.

For example, it is possible for the stop means to be limited to have an essentially axially extending slot in the base tube and a slot which engages in the slot. include slot engagement member connected to the guide means for common axial movement, which cooperates with a slot end to limit the outward movement of the guide means and can be disengaged from the slot. It is conceivable that the slot engaging member can be detached from the guide means, or that the slot engaging member can be elastically displaced with respect to the guide means as it emerges from the slot.

Another possibility is that the guide means can be rotated relative to the base tube and that the stop means to be limited can be released by turning the guide means into a specific angular position range relative to the base tube or can be brought into a release standby position.

This possibility can be realized, for example, in such a way that the stop means to be limited have a ring-shaped stop edge attached below the base tube and essentially axially directed towards the first end of the base tube and a counter stop which is attached to the guide means and can be adjusted substantially radially inward against elastic restoring force from an active position into a release position comprise, which is brought into a release position by cam means when rotating the guide means in the direction of the predetermined angular position range.

Another possible implementation is that the stop means to be limited have an annular stop which is attached within the base tube and is directed essentially axially towards the first end of the base tube and a counter stop which is attached to the guide means and can be adjusted substantially radially inward against elastic restoring force from an operative position into a release position comprise, which comes into the ready-to-release position when the guide means is rotated into the predetermined angular position range and can be disengaged into its release position by a cam action in the case of a subsequent axial pull-out movement of the guide means from the base tube - if necessary only after a further twist of the guide means relative to the base tube following a partial pull-out movement. This latter implementation possibility can be further developed in such a way that the stop edge has a recess and that, adjacent to this recess, cam means are provided on the base tube for interacting with the counter stop, which transfer after the counter stop has been introduced into the recess with subsequent relative movement of the guide means relative to the base tube the counter-stop in the release position. The cam means can either be arranged such that the counter-stop, if it is located within the recess, can be moved into the release position by axially pulling out the guide means, or they can be arranged such that the counter-stop, if it is located within the recess, can be brought into the release position by rotating the guide means relative to the base tube. The combined use of the two cam arrangement options is also conceivable.

In order to be able to provide a stop edge in a simple manner without complicated machining of the base tube, it can be provided that the stop edge and the cam means are formed on a centering tube inserted into the base tube in the region of the second base tube end. The centering tube, like the guide means, can be designed as a molded part, in particular a plastic molded part, which is easily manufactured by injection molding.

A particularly inexpensive way to provide the counterstop is that the counterstop of a section, for. B. end portion, a wire bracket is formed, which is inserted on an outer circumferential surface of the guide means in an annular receiving trough, this section in the region of a notch cutting the annular trough of the guide means against elastic force is displaceable radially inwards into the release position. It is possible that the section of the wire bracket on the guide means fixed and rotatable by rotating the guide means relative to the base tube in the angular range of a recess of the stop edge and that adjacent to this recess on the base tube cam means are provided, which after insertion of the section Transfer the section into the release position into the recess by subsequent relative movement of the guide means relative to the base tube. The non-rotatable fixing of the wire bracket can be achieved in the simplest manner in that this wire bracket is formed at its other end remote from the end section into a hook which engages in the notch in a rotationally inhibiting manner.

The cam means can in particular be arranged in such a way that the section of the wire bow can be moved into the release position after insertion into the recess by rotating the guide means relative to the base tube. There is then the following handling option for the removal of the guide means: The guide means are rotated with the counter-stop attached to them, while this stop lies against the stop edge. As soon as the counter-stop reaches the angular region of the recess, the operator feels the coincidence of the counter-stop, ie the wire bracket end, with the recess in any case when he exerts a slight force on the guide means in the pull-out direction during the rotational movement exercises. As soon as he sensed this coincidence, he knows that he can now pull out on the guide means. The counter stop, that is to say the section of the wire bracket, then reaches the region of the recess. Depending on the cam design of the edge delimiting the recess, the counterstop can now be brought into the release position by applying either a tensile force or a torque to the guide means. By designing the spring properties of the counterstop and by designing the cam means, the counterstop can be moved into the release position in the singular angular range with a relatively small force, the dimensioning of the pull-out force or the torque to be applied being adjusted such that even in this singular angular range there is still one some resistance counteracts the loosening of the counter-stop, but on the other hand it can be loosened by hand without special tools. This provides sufficient security against unintentional pulling out of the guide means in practice, because on the one hand it is very unlikely that the guide means will even reach the singular angular range, since this is very small compared to the total circumference of the stop edge. On the other hand, a certain force or a certain moment must also be exerted in this singular angular range in order to bring the counter-stop into the release position.

In order to ensure a highly effective pull-out limitation with a wire bracket in the rotating range outside the singular angular range, even with relatively weak spring wire brackets, it is recommended that the section of the wire bracket when adjusted to an angular range outside the recess in a radial space between the stop edge and an inner circumferential surface of the Interlocking base tube engages. The hooking can easily be caused by a 180 ° bend of the spring wire, which is difficult to undo. The radial space can be formed by a spacer means between a centering tube inserted into the second base tube end and an inner peripheral surface of the base tube.

The guide means can be entrained in at least one axial direction of movement by frictional engagement with the second sub-group unit. Alternatively, it is possible that the guide means can be carried along by the second sub-group unit with movement play in at least one axial direction of movement by means of entraining stop means. A preferred embodiment consists in that the guide means are taken out of the base tube at least in the direction of movement by means of moving stop means with play so that they always reach their extending guide position in good time when the positioning device is extended. A later inward movement can in turn take place by means of entraining slings. For this purpose, on the one hand, the outer end of the guide means and, on the other hand, an annular collar on the second subgroup unit are available, in the simplest case this annular collar can be formed by the lower end of the object carried by the column, for example a seat fastening hub. The result of this is that the guide means can be moved in the axial direction between two driving stops present on the second subgroup unit. Then there is a particular need for the guide means to be detachable from the base tube in order to be able to bring the positioning device out of the base tube at all, together with the guide means. Once the positioning device has been removed, the guide means can then be easily removed from the positioning device in the following, because then the guide means outward-moving stop is accessible and can be released from the second sub-group unit. A particularly favorable design for a stop means which takes the guide means outwards consists in that a spring steel claw ring is fastened to an end section of the second sub-assembly unit facing the first base tube end, which spring ring on an entrainment surface when the second sub-assembly unit moves axially outward relative to the base tube Guide means comes to the plant. Such a claw ring is normally not removable from the second sub-group unit by axial force, but on the other hand, as soon as it is accessible, it can easily be removed using a release tool. The claw ring can engage with the free ends of its claws, for example, on a cylindrical outer peripheral surface of one end of the second subgroup unit. The ring part carrying the claws is then located radially on the outside, in such a way that it comes into abutment with a shoulder surface between a radially inner guide surface of the guide means and a larger-diameter recess, this recess providing the claw ring with a free path over a partial length of the guide means.

The use of the claw ring is not tied to the presence of lifting accessories to be limited, but can also be used if there are no lifting devices to limit the stroke.

Furthermore, the use of the stop means to be limited is not tied to the fact that the first sub-group unit is supported essentially axially immovably with respect to the base tube. Rather, such slinging means to be limited are also to be used with advantage if the first subgroup unit is supported on a height-adjustable platform, the height of which is determined by a block and tackle. which is controlled by the relative movement of the two subgroup units.

Fig. 1

eine erste Bauform einer erfindungsgemäßen Säuleneinheit;

Fig. 2

eine zweite Bauform einer erfindungsgemäßen Säuleneinheit;

Fig. 3

eine dritte Ausführungsform einer erfindungsgemäßen Säuleneinheit;

Fig. 4

eine vierte Ausführungsform einer erfindungsgemäßen Säuleneinheit;

Fig. 5

eine Teilansicht einer Abwandlung zu der Ausführungsform nach Fig. 4;

Fig. 6, 7 und 8

eine abgewandelte Ausführungsform des Drahtbügels gemäß Fig. 5.

The accompanying figures explain the invention using exemplary embodiments. They represent:

Fig. 1

a first design of a column unit according to the invention;

Fig. 2

a second design of a column unit according to the invention;

Fig. 3

a third embodiment of a column unit according to the invention;

Fig. 4

a fourth embodiment of a column unit according to the invention;

Fig. 5

a partial view of a modification to the embodiment of FIG. 4;

6, 7 and 8

a modified embodiment of the wire bracket according to FIG. 5.

In Fig. 1, a base tube is designated 10. This base tube has a first or lower end 10a and a second or upper end 10b. On the jacket of the base tube 10, a conical section 10c is provided, which for inserting the base tube into a carrier, for. B. a chair cross (not shown) is determined. A centering tube 12 is inserted into the upper end 10b. This centering tube 12 is centered by an annular flange 12a in the base tube 10 and supported by a radial flange 12b on the upper end 10b of the base tube. The centering tube 12 also has an inner jacket 12c, which is supported radially by radial ribs 12d on the inner circumferential surface of the base tube 10. The centering tube 12 is axial on the base tube 10 by at least one notch pin 12e and secured in the circumferential direction.

A guide sleeve 14 is inserted into the centering tube 12. At its upper end, this guide sleeve has a radially outwardly projecting collar 14a, which is designed to engage with the upper end 12f of the centering tube. At its lower end, an annular recess 14b is inserted into the guide sleeve, which receives an elastically expandable pull-out limiting ring 16. This pull-out limiting ring 16 faces a lower end edge 12g of the centering tube 12 in the axial direction. It can be seen that the guide sleeve is axially displaceable relative to the centering tube 12 in a limited way. A lower or a basic position of the guide sleeve 14 is determined in that the collar 14a rests on the upper end 12f of the centering tube 12. An upper or outer end position of the guide sleeve 14 is determined in that the pull-out limiting ring 16 bears against the lower edge 12g of the centering tube 12.

A gas spring 18 is provided. This gas spring 18 comprises a piston rod 18a as a first or lower sub-group unit. It further comprises a cylinder 18b as an upper or second sub-group unit. The piston rod 18a is inserted through a guide and sealing unit 18c into the cavity 18d of the cylinder 18b and carries a piston assembly 18e inside the cylinder, which divides the cavity 18d into two working chambers 18d1 and 18d2. The two working chambers 18d1 and 18d2 are connected to one another by an annular channel 18f. This connection can be shut off by a valve body 18g which is tensioned in the closed position by the gas pressure prevailing within the cavity 18d and is sealingly and displaceably guided by a shaft 18h. By pressing down The shaft 18h and thus the valve body 18g can be used to establish the connection between the two working chambers 18d1 and 18d2. The lower end of the piston rod 18a is supported by a thrust ball bearing 18i on a support wall 20 which is fixedly connected to the base tube 10. A lower end extension 18k of the piston rod 18a is guided through a hole 20a of the support wall 20 and axially fixed by a split pin 18l. The end extension 18k has slight radial play in the hole 20a.

The cylinder 18b is guided with an outer peripheral surface 18m on an inner peripheral surface 14e of the guide sleeve 14. On the other hand, the guide sleeve 14 is guided with an outer circumferential surface 14f on an inner circumferential surface 12i of the centering tube 12.

The cylinder 18b is designed as a cone 18n at its upper end region. A hub body 22 of a seat carrier is attached to this cone 18n with a corresponding hollow cone. A release lever 24 is mounted in the hub body 22 so as to be pivotable about a pivot axis 24a in the plane of the drawing. This release lever 24 penetrates the conical section 18n of the cylinder 18b and acts with a socket 24b on the valve stem 18h.

In Fig. 1, the gas spring is in its outermost position, i.e. H. the piston rod 18a is in its outermost position relative to the cylinder 18b. This outermost position is defined by an elastic stop ring 18o.

After opening the valve body 18g, the cylinder 18b can be pushed downward against gas pressure until the piston unit 18e reaches the area of the valve body 18g and, if necessary, fixes an innermost position there by means of an insertion limiting stop (not shown).

At the lower end of the cylinder 18b in the region of the guiding and sealing unit 18c there is a claw ring 26 which is clawed with its claws 26a on an outer peripheral surface 18p of the cylinder 18b. An annular disk 26b carrying the claws 26a is in abutment engagement with an annular shoulder 14g which is formed at the transition between the inner peripheral surface 14e of the guide sleeve and the inner peripheral surface 14h of an annular recess 14i of the guide sleeve 14. It can be seen that the cylinder 18b has brought the guide sleeve 14 into the position shown in the transition to its outermost position shown in FIG. 1 via the claw ring 26. In this position, the lower end of the cylinder 18b is at approximately the height of the upper end 10b of the base tube 10. Nevertheless, sufficient guidance and centering of the cylinder 18b is ensured because, on the one hand, the cylinder 18b rests on the peripheral surface 14e of the guide sleeve 14 and also the lower part of the guide sleeve 14 bears with its outer peripheral surface 14f of the inner peripheral surface 12i of the centering tube 12.

After the valve body 18g has been opened again, the cylinder can be pressed down against the effect of the gas pressure on the cross section of the piston rod, gas passing between the two working chambers 18d1 and 18d2. With such a downward movement of the cylinder 18b, the guide sleeve 14, which is guided in the centering tube 12 loosely and practically without friction, falls downward under the action of gravity, while remaining in contact with the claw ring 26. As soon as the collar 14a of the guide sleeve 14 abuts against the upper end 12f of the centering tube 12, the guide sleeve 14 stops and the cylinder 18b can be pushed further down until the lower end surface 22a of the hub body 22 against the upper end surface 14k the guide sleeve 14 abuts. The lowest position of the cylinder 18b corresponding to the innermost position of the piston rod 18a relative to the cylinder 18b is thus reached. It is also conceivable that the guide sleeve 14 is guided in the centering tube 12 with a friction which counteracts a sagging of the guide sleeve 14 under the action of gravity, so that the guide sleeve 14 initially moves in the direction shown in FIG. 1 remains in the position shown and is only taken down when the lower end surface 22a abuts the upper end surface 14k of the guide sleeve 14 and then takes it downward. The position of the cylinder 18b relative to the piston rod 18a can be blocked in any intermediate position by closing the valve body 18g.

It can be seen that even in the uppermost position of the cylinder 18b shown in FIG. 1, the guide sleeve 14 cannot be pulled up substantially from its outermost position shown in FIG. 1: this is opposed by the pull-out limiting ring 16, which against the lower edge 12g of the Centering tube 12 comes to a stop. This ensures that the guide sleeve 14 in any case in the critical uppermost position of the cylinder 18b cannot leave its position of optimal guidance and centering for the cylinder 18b shown in FIG. 1.

To remove the gas spring 18 from the base tube 10, the split pin 18l is released. However, the gas spring cannot then be pulled out of the base tube 10 because it abuts the shoulder surface 14g of the guide sleeve 14 with the claw ring 26 and, on the other hand, the guide sleeve with the pull-out limiting ring 16 abuts against the lower edge 12g of the centering tube 12. The elasticity of the extension limiting ring 16 and the depth of the annular recess 14b are coordinated with one another in such a way that that the pull-out limiting ring 16 can be stripped from the lower end of the guide sleeve 14 with a predetermined minimum pull-out force. This minimum pull-out force is dimensioned such that the pull-out limiting ring 16 is stripped from the guide sleeve 14 before the claw ring 26 detaches itself from the cylinder 18b. As soon as the pull-out limiting ring 16 is stripped from the guide sleeve 14, the cylinder 18b with the guide sleeve 14 can be pulled out of the base tube 10. The claw ring 26 can then be detached from the lower end 18p of the cylinder 18b by means of a screwdriver or the like. A reinstallation of a gas spring or a guide sleeve is only possible in this embodiment in such a way that the centering tube 12 is also loosened and reinstalled. One could, however, think of storing the pull-out limiting ring 16 in the annular recess 14b and providing a guide cone at the upper end of the inner casing 12c in such a way that the pull-out limiting ring 16 can be pushed in again with radial compression until it drops below the lower edge 12g of the centering tube 12 returns to an effective stop position.

In the embodiment according to FIG. 2, analog parts are provided with the same reference numerals as in the embodiment according to FIG. 1, increased by the number 100.

Different from the embodiment according to FIG. 1 are only the means which prevent the excessive pulling out of the guide sleeve 114 from the base tube 110. A pull-out limiting pin 116 can be seen in FIG. 2, which engages in an elongated hole 110e under the action of a leaf spring 116a supported on the guide sleeve 114. The pull-out limit pin 116 cooperates with the upper end 110f of the elongated hole 110e and prevents it unintentionally pulling the guide sleeve 114 out of the base tube 110. If it proves necessary in the course of removal work, the pull-out limiting pin 116 can be displaced radially inwards with respect to the guide sleeve 114 carrying it by means of a screwdriver or the like, whereupon the guide sleeve 114 out of the base tube 110 can be deducted.

Otherwise, the embodiment of FIG. 2 corresponds in structure and mode of operation to that of FIG. 1.

In the embodiment according to FIG. 3, analog parts are again provided with the same reference numerals as in the embodiment according to FIG. 1, each increased by the number 200. In this embodiment, the pull-out limiting pin 216 already known from FIG. 2 can be seen, which is characterized by the Leaf spring 216a is biased into an active position. This pull-out limiting pin can be rotated by rotating the guide sleeve 214 into the narrow angular range of a downward extension 212 m. This extension 212m is provided with cam surfaces 212n at its edges, so that when the extension limiting pin 216 is rotated from its position in FIG. 3 in radial alignment with the extension 212m, the extension limiting pin 216 is pushed radially inward into a release position, so that the Guide sleeve 214 can then be easily pulled out in the axial direction.
A pull-out is therefore only possible in a limited angular range of the rotational path of the guide sleeve 214, which occurs in extremely rare cases for statistical reasons alone. Furthermore, the release position cannot be reached accidentally because a certain torque has to be overcome when the pull-out limiting pin 216 slides onto one of the two cam surfaces 212n. That torque is adjusted by adjusting the spring force of the leaf spring 216a and the inclination of the cam surfaces 212n so that on the one hand an unintentional adjustment of the pull-out limiting pin 216 in radial alignment with the extension 212m is not to be expected, but on the other hand in preparation for an intended solution of the guide sleeve 214 by a relatively small one , torque to be applied by hand allows the extension limiting pin 216 to slide onto the extension 212 m.

In the embodiment according to FIG. 4, analog parts are provided with the same reference numerals as in the embodiment according to FIG. 1, each increased by the number 300.

The embodiment according to FIG. 4 differs from that according to FIG. 3 only in that instead of the extension 212m of the centering tube 212 on the centering tube 312, a recess 312m is made in the lower edge 312g thereof, which is framed by cam surfaces 312n and 312o. A solution is possible here that the pull-out limiting pin 316 is first rotated along the lower edge 312g into the region of the recess 312m and that the pull-out limiting pin 316 is then pulled axially over the cam surface 312o or by rotating the guide sleeve 314 relative to the centering tube 312 via one of the Cam surfaces 312n rotated away and pressed back into the release position.

In the embodiment according to FIG. 5, analog parts are provided with the same reference numerals as in the embodiment according to FIG. 1, each increased by the number 400.

The embodiment according to FIG. 5 differs from that according to FIG. 4 in another embodiment of the counter-stop: in place of the pull-out limiting pin 316, an end section 416c of a wire bracket 416b has taken place. This wire bracket 416b is inserted into an annular recess 414m on the outer peripheral surface 414f of the guide sleeve 414. In the circumferential direction, the wire bracket 416b is secured in that a tail 416d of the wire bracket 416b engages in a notch 414n. In the radial direction, the wire bracket 416b is due to the contact with the inner peripheral surface 412i of the centering tube 412 secured. The notch 414n cuts the annular recess 414m, so that in the region of this notch the end section 416c of the wire bracket 416b is exposed radially inwards and can be resiliently bent radially inwards.

The end section 416c is provided with an end hook 416i which can grip around the lower edge 412g of the centering tube 412 and can engage in the spaces 430 between the base tube 410 and the inner jacket 412c of the centering tube 412 as the guide sleeve 414 upwards, i.e. H. is pulled outward and the end portion of the wire bracket reaches the area of the lower edge 412g of the centering tube 412. Only when the guide sleeve 414 is set at an angle to the centering tube 412 such that the end section 416c coincides with the angular range of the recess 412m, does the end section 416c enter the recess 412m when the guide sleeve 414 is displaced upward. If this has happened, the guide sleeve 414 can then be rotated relative to the centering tube 412 and the end section 416c or its end hook 416i can come into engagement with one of the cam surfaces 412n, so that the end section 416c is then pressed radially inward in the region of the notch 414n can by pulling the end hook 416i over one of the cam surfaces 412n. The guide sleeve 414 can then be pulled upward unhindered. If the end hook 416i was designed differently, it could also be possible for this end hook to interact with the cam surface 412o, so that the end hook could be moved radially inward into its release position by purely axial withdrawal.

In the embodiment described here, the guide sleeve 414 is unintentionally released from the centering tube 412 is particularly unlikely if the spacing ribs 412d continue to the lower edge 412g, because then the recess 412m must first be determined by gradually turning the guide sleeve 414 and each attempt to pull it out following the turning. In order to make accidental disassembly of the guide sleeve 414 even more unlikely, the cam surfaces 412n in the recess 412m could be modified such that only a single effective cam surface 412n1 is formed, but the other cam surface 412n2 is omitted. The release position can only be reached when the end section 416c is pushed onto the effective cam surface 412n1, that is to say when the guide sleeve 414 rotates in a certain direction.

The end hook 416i of the wire bracket 416b can be bent such that after reaching the release position when the guide sleeve 414 is pulled out of the centering tube 412 or during installation and thus when the guide bushing 414 is inserted into the centering tube 412, it does not cause any damage or clamping effects in the centering tube 412.

The embodiment shown in Fig. 5 is characterized by a particularly inexpensive manufacture and a special pull-out security.

6, 7 and 8, a further embodiment of the wire bracket is shown. 6 shows a plan view of the wire bracket, FIG. 7 shows a side view in the direction of arrow VII of FIG. 6 and FIG. 8 shows a side view in the direction of arrow VIII of FIG. 7. The wire bracket is designated 516b overall. This wire bracket has a slot 516f on, so that it can easily be inserted by expansion into the annular recess corresponding to 414m of FIG. 5. A section 516g designed as a hook is arranged diametrically opposite the slot. As can be seen from FIG. 6, this hook jumps radially inwards at 516h into the circumference of the wire bracket 516b.

The wire bracket 516b is inserted into the guide sleeve 414f according to FIG. 5 such that the hook-like section 516g projects downward. The protrusion 516h comes to lie in the notch 414n, so that the wire bracket 516b is fixed non-rotatably in the annular recess 414m.

If the guide sleeve 414 is set relative to the centering tube 412 such that the hook 516g is located outside the recess 412m, the hook 516g hooks with its radially outer end 516k with the stop edge 412g of the centering tube 412 and can reach into the intermediate space 430. If the hook 516g is located in the area of the recess 412m, then by rotating the guide sleeve 414 and thus the hook 516g, the latter can be pressed radially inward into the notch 414n of the guide sleeve 414 by one of the cam surfaces 412n1 and 412n2, preferably only by one. so that the guide sleeve 414 with the wire bracket 516b can subsequently be pulled out of the centering tube 412.

Claims (29)

1. Column unit, in particular chair column unit, encompassing a base tube (10) with a base-tube axis (AA), a first base-tube end (10a), a second base-tube end (10b), and guides (14) inserted in base-tube (10) in the region of the second base-tube end (10b);
   furthermore encompassing a positioning device (18) with a device axis which substantially coincides with base-tube axis (AA), with a first component-group unit (18a) and a second component-group unit (18b), wherein these component-group units (18a, 18b) are movable axially to each other and are lockable in a plurality of axial relative positions against each other;
   wherein furthermore the first component-group unit (18a) is supported on a support (20) connected to base tube (10) in a manner such as to be substantially immovable axially with respect to base tube (10) and which is, if applicable, rotatable with respect to said support (20);
   wherein furthermore the second component-group unit (18b) extends beyond the second base-tube end (10b) and is adjustable between an innermost position and an outermost position with respect to the second base-tube end (10b);
   wherein furthermore an outer section (18n) of the second component-group unit (18b) -- which extends over the second base-tube end (10b) and beyond the guides (14) -- is shaped to connect with a column-borne object (22);
   and wherein the second component-group unit (18b) is in axially sliding engagement with the guides (14),
   characterized by the combination of the following distinguishing features:

   (a) the guides (14) are guided along base tube (10) in an axially shiftable manner;

   (b) when the second component-group unit moves outwards between its innermost position and its outermost position, the guides (14) are capable of being driven on a partial path;

   (c) the outward movement of the guides (14) with respect to the second base-tube end (10b) is restricted by pullout-restricting stops (16, 12g) acting jointly, said stops being attached to guides (14) and to the base tube (10).
2. Column unit according to Claim 1,
   characterized in that the pullout-restricting stops (16, 12g) are arranged in a manner such that they define an axially outermost limit position of guides (14) in which position the second component-group unit (18b), when located in the outermost position with respect to the second base-tube end (10b), is supported in an optimum manner on base tube (10).
3. Column unit according to one of the Claims 1 and 2, characterized in that the pullout-restricting effect of pullout-restricting stops (16, 12g) is capable of being overcome.
4. Column unit according to Claim 3, characterized in that the pullout-restricting effect of pullout-restricting stops (16, 12g) is capable of being cancelled by the application of a predetermined minimum pullout force to the guides (14);
5. Column unit according to Claim 4, characterized in that the pullout-restricting stops (16, 12g) encompass a pullout-restriction stop (12g) on the base-tube side and a pullout-restriction stop (16) on the guides side, wherein the pullout-restriction stop on the guides side (16) is made up of a pullout-restriction ring (16) attached to an end region (14b) of guides (14) which lies within base tube (10), said pullout-restriction ring (16) being capable of being stripped off the guides (14) via joint action with the pullout-restriction stop (12g) on the base-tube side, when a predetermined minimum pullout-force, or a greater pullout force, are applied to guides (14).
6. Column unit according to Claim 5, characterized in that the pullout-restriction ring (16) is elastically expandable and is accommodated in an annular trough (14b) on an external-perimeter surface (14f) of guides (14).
7. Column unit according to one of the Claims 5 and 6, characterized in that the pullout-restriction stop on the base-tube side (12g) is made up of the end (12g), oriented toward the first base-tube end (10a), of a centering tube (12) that is inserted in an axially immovable manner into the second base-tube end (10b) the first base-tube end (10a).
8. Column unit according to Claim 3, characterized in that the pullout-restricting stops (116, 110f) are basically non-releasable by the mere application of an axial pullout-force upon guides 114, but are capable of being rendered inoperative by at least one release step different from the application of a pullout force.
9. Column unit according to Claim 8, characterized in that the pullout-restricting stops (116, 110f) encompass a slit [sic] (110e) in the base tube (110), said slit running in a substantially axial direction, and a slit-engagement member (116) which engages into the slit (110e) and is linked with the guides (114) for joint axial movement, which slit-engagement member acts jointly with a slit end (110f) to restrict the outward movement of the guides (114) and [which slit-engagement member] is capable of being disengaged from the slit (110e).
10. Column unit according to Claim 9, characterized in that the slit-engagement member is releasable from the guides.
11. Column unit according to Claim 9, characterized in that slit-engagement member (116) is elastically displaceable with respect to guides (114), in conjunction with exit from the slit (110e).
12. Column unit according to Claim 8, characterized in that the guides (214) are twistable with respect to the base tube (210) and the pullout-restricting stops (216, 212g) are releasable, or capable of being placed in a release-ready position, by twisting the guides (214) into a specific angulation range (212m) in relation to the base tube (210).
13. Column unit according to Claim 12, characterized in that the pullout-restricting stops (216, 212g) encompass an annular stop-edge (212g), attached within the base tube (210) and substantially oriented axially to the first base-tube end (210a); and a counter-stop (216), attached to the guides (214) and capable of being adjusted in a substantially radially-inward direction from an operating position into a release position, against elastic restoring force (216a), said counter-stop being brought into a release position by camming (212n) when the guides (214) are twisted in the direction of the predetermined angulation range (212m).
14. Column unit according to Claim 12, characterized in that the pullout-restricting stops (316, 312g) encompass an annular stop-edge (312g), attached within the base-tube (310) and oriented in a substantially axial direction toward the first base-tube end (310a), and a counter-stop (316), attached to the the guides (314) adjustable against elastic force (316a) in a substantially radial inward direction, from an operating position into a release position; said counter-stop reaching the release-ready position when the guides (314) are twisted into the predetermined angulation range (312m), and being disengageable into its release position, after a subsequent axial pullout motion of the guides (314) from the base tube (310) -- or, if applicable, only after a partial pullout motion followed by a renewed twisting of the guides (314) with respect to the base tube (310).
15. Column unit according to Claim 14, characterized in that the stop-edge (312g) features a recess (312m), and in that camming (312n, 312o) is provided adjacent to said recess (312m) on the base tube, for the purpose of acting jointly with the counter-stop (316), said camming causing a transfer of the counter-stop (316) into the release position, after the counter-stop (316) has been introduced into the recess (312m) and after a subsequent relative motion of the the guides relative to the base tube (310).
16. Column unit according to Claim 15, characterized in that the camming (312o) is arranged in a manner such that the counter-stop (316) which is located within the recess (312m) is transferable into release position by means of axial pullout of the guides (314).
17. Column unit according to Claim 15 or 16, characterized in that the camming (312n) is arranged in a manner such that the counter-stop (316), when located within the recess (312m), is transferable into release position by twisting the guides (314) with respect to the base tube (310), preferably by means of cams in one direction only.
18. Column unit according to one of the Claims 13 - 17, characterized in that the stop-edge (312g) and the camming (312n, 312o) are formed on a centering tube (312) introduced into the base tube (310) in the region of the second base-tube end (310b).
19. Column unit according to one of the Claims 13 - 18, characterized in that the counter-stop (416i) is formed by a section (416i) -- say an end section -- of a wire strap (416b), said wire strap being inserted into an annular receiving trough (414m) on an external-perimeter surface (414f) of the guides (414), so that, when said section (416i) is in the region of a notch (414n) of the guides (414) which [notch] cuts into the annular trough (414m), it is displaceable radially inward into the release position, against elastic force (416c).
20. Column unit according to Claim 19, characterized in that the section (414i) of the wire strap (416b) is fixed to the guides (414) in an non-twistable manner, being twistable into the angular range of a recess (412m) of the stop edge (412g) by twisting the guides (414) with respect to the base tube (410); and in that camming (412n, 412o) is provided on the base tube (410), adjacent to said recess (412m); which camming, after section (417i) has been intro- duced into the recess (412m), transfers the section (416i) into the release position by means of a subsequent relative motion of the guides (414) with respect to the base tube (410).
21. Column unit according to Claim 20, characterized in that the camming (412n, 412o) is arranged in a manner such that the section (416i) of the wire strap (416b) is transferable into the release position, after introduction into the recess (412m) by means of rotation of the guides (414) relative to the base tube (410), preferably by means of cams in one direction only.
22. Column unit according to one of Claims 20 and 21, characterized in that the section (416i) of the wire strap (416b), when placed in an angular region outside the recess (412m), engages in a hook-like manner into a radial gap (430) between the stop-edge (412g) and an internal-perimeter surface of the base tube (410).
23. Column unit according to Claim 22, characterized in that the radial gap (430), between a centering tube (412) introduced into the second base-tube end (410b) and an internal-perimeter surface of the base tube (410), is formed by spacers (412d).
24. Column unit according to one of the Claims 1 - 23, characterized in that the guides (14) are capable of being driven in at least one axial direction of motion by means of frictional engagement with the second component-group unit (18b).
25. Column unit according to one of the Claims 1 - 24, characterized in that the guides (14) are capable of being driven in at least one axial direction of motion by the second component-group unit (18b), with clearance for movement, by means of driver- or pusher-stops (26, 14g).
26. Column unit according to Claim 25, characterized in that spring-steel claw-ring (26) is attached to an end section (18p) of the second component-group unit (18b), said end section facing the first base-tube end, which claw ring, upon an axially outward movement of the second component-group unit (18b) with respect to the base tube (10), comes to lie against a drive surface (14g) of the guides (14)
27. Column unit according to Claim 26 characterized in that the drive surface (14g) is formed by a shoulder surface (14g) between a radially internal guide surface (14e) of the guides (14) and a larger-diameter (14i) recess of the guides (14).
28. Column unit, in particular chair column unit, encompassing a base tube (10) with a base-tube axis (AA), a first base-tube end (10a), a second base-tube end (10b), and guides (14) inserted in the base tube (10) in the region of the second base-tube end, furthermore encompassing a positioning device (18) with a device axis that substantially coincides with the base-tube axis (AA), with a first component-group unit (18a), and a second component-group unit (18b), with these component-group units (18a, 18b) being movable axially to each other and being lockable in a plurality of axial relative positions against each other, with furthermore the first component-group unit (18a) being supported on a support (20) attached to the base tube (10), in a manner substantially immovable axially with respect to the base tube (10), and, if applicable, being rotatable with respect said support (20),with furthermore the second component-group unit (18b) extending beyond the second base-tube end (10b) and being adjustable between an innermost position and an outermost position with respect to the second base-tube end (10b); with furthermore an outer section (18n) of the second component-group unit (18b), said [section] extending over the second base-tube end (10b) and beyond the guides (14), being shaped to connect with a column-borne object (22); and with the second component-group unit (18b) being in axially sliding engagement with the guides (14),
    characterized by the combination of the following distinguishing features:

    (a) the guides (14) are guided along the base tube (10) in an axially shiftable manner;

    (b) the guides (14) are capable of being driven on a partial path by the second component-group unit (18b) when it moves outwards between its innermost position and its outermost position;

    (c) a spring-steel claw ring (26) is attached to an end section (18p) of the second component-group unit (18b), which end section faces the first base-tube end (10a), said claw ring coming to lie against a drive surface (14g) of the guides (14) when the second component-group unit (18b) moves axially outwards with respect to the base tube (10).
29. Column unit, in particular chair column unit, encompassing a base tube (10) with a base-tube axis (AA), a first base-tube end (10a), a second base-tube end (10b) and guides (14) inserted into the base tube (10) in the region of the second base-tube end (10b);
    further encompassing a positioning device (18) with a device axis which substantially coincides with the base-tube axis (AA), with a first component-group unit (18a) and a second component-group unit (18b), with these component-group units (18a, 18b) being movable axially to each other and being lockable in a plurality of axial relative positions, against each other,
    with furthermore the first component-group unit (18a) being supported on a support (20) connected to the base tube (10) and, if applicable, being rotatable with respect to this support (20),
    with furthermore the second component-group unit (18b) extending beyond the second base-tube end (10b) and being adjustable between an innermost position and an outermost position with respect to the second base-tube end,
    with furthermore an outer section (18n) of the second component-group unit (18b) -- which section extends over the second base-tube end and beyond the guides (14) -- being shaped to connect with a column-borne object (22),
    and with the second component-group unit (18b) being in axially sliding engagement with the guides (14),
    characterized by the following combination of distinguishing features:

    (a) the guides (a) are guided along the base tube (10) in an axially shiftable manner;

    (b) the guides (14) are capable of being driven over a partial path by the second component-group unit (18b) when it moves outwards between its innermost position and its outermost position;

    (c) the outward movement of the guides (14) with respect to the second base-tube end (10b) is restricted by pullout-restricting stops (16, 12g) acting jointly, which are attached to the guides (14) and to the base tube (10);

    (d) the pullout-restriction effect of the pullout-restricting stops (16, 12g) is capable of being overcome.

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