EP1169947A1 - Chair, particularly office chair - Google Patents

Abstract

The office chair has a seat support made up of two sections (12, 13) linked by a central pivot (20). A back rest support (6) is attached to the rear section (13). The relative positions of the back rest and seat (5) can be adjusted using a gas spring (27). The top end of the seat pedestal (3) fits into a recess connected to the front section (12) of the seat support by a second pivot (49) which is parallel to the first. This pivot can be locked by a toothed strip (49a) which cooperates with toothed jaws on the seat support.

Description

The invention relates to a chair, in particular an office chair, according to the preamble of claim 1.

A generic chair is known from EP 0 584 620 A1. This has a front seat support part in which a pivotable relative to this Bearing part is arranged. By pivoting the The inclination of the seat support in relation to the chair column can be adjusted. to Locking this pivoting movement is a plate pack locking device provided, in which plate packs jam each other. The locking is thus carried out along the swivel direction Friction. This has the disadvantage that larger locking devices acting forces, e.g. by heavy users, a complete locking cannot be guaranteed.

Based on this, the object of the invention is a chair the generic type in such a way that the seat together with the backrest regardless of the given inclination adjustment the synchronous mechanism in different inclination positions can be determined as effectively as possible, in particular through the synchronous mechanism given angle of inclination of the seat and backrest within one To be able to change the adjustment range.

This object is achieved by the in the characterizing part of the claim 1 specified features solved. The essence of the invention is to provide a rack locking device. The advantage is there in that the locking along the pivot direction is not through Friction, but is done by positive locking. That way is one particularly effective locking possible.

Further advantageous embodiments of the invention result from the Dependent claims.

Fig. 1

eine perspektivische Darstellung eines Bürostuhls gemäß der Erfindung,

Fig. 2

eine Seitenansicht der Sitzteil-Unterkonstruktion,

Fig. 3

einen Querschnitt der Unterkonstruktion entlang der Schnittlinie III-III nach Fig. 2 in der Arretierposition,

Fig. 4

eine Ansicht gemäß Fig. 3 in Freischwenkposition,

Fig. 5

eine Ausschnittvergrößerung der Ansicht gemäß Fig. 3 und

Fig. 6

eine Ausschnittvergrößerung der Ansicht gemäß Fig. 4.

Additional features and details of the invention will become apparent from the description of an embodiment with reference to the drawings. Show it:

Fig. 1

a perspective view of an office chair according to the invention,

Fig. 2

a side view of the seat part substructure,

Fig. 3

3 shows a cross section of the substructure along the section line III-III according to FIG. 2 in the locking position,

Fig. 4

3 in the free pivoting position,

Fig. 5

an enlarged section of the view of FIG. 3 and

Fig. 6

4 shows an enlarged detail of the view according to FIG. 4.

An office chair shown in Fig. 1 has a base frame 1, which Rollers 2 is supported against the ground. On the base 1 is one height-adjustable chair column 3, covered by a bellows 3a, at the upper end of a seat support 4 is releasably attached, on the again a padded seat 5 is attached. On the seat support 4 is a attached essentially upward extending backrest support 6, at the upper end of a backrest 7 is attached. The height adjustment the chair column 3 is carried out by means of an operating lever 8. To change the inclination of the backrest 7 with backrest support 6 while changing the inclination of the seat 5 is another Operating lever 9 mounted on the seat support 4. The seat support 4 can partially or largely by one attached to the underside of the seat 5 Cover 10 be optically covered. In Fig. 1 it can be seen that the backrest support 6 clad by a bellows 11 for optical reasons is.

The basic structure of the office chair described is generally known. The Height-adjustable chair column 3 is for example from DE-PS 19 31 012 (corresponding to US-PS 3,711,054) or DE-PS 18 12 282 (corresponding U.S. Patent 3,656,593) known. The structure of the seat support 4 including the described pivoting options of backrest 7 and seat 5 for example from EP-PS 0 179 185 (corresponding to ZA-PS 85/6126) known.

As can be seen from FIGS. 2 and 3, the seat support 4 is of split design. He consists of a front seat support part 12 and a rear seat support part 13, which has a substantially U-shaped, downwardly open cross section exhibit. It follows that they each have two side walls 14, 15 or 16, 17, which each have floors 18 facing through the seat 5 or 19 are connected to each other. The two seat support parts 12, 13 are by a pivot axis arranged adjacent to its bottoms 18, 19 20 connected together.

At the front end of the seat support 4 is a seat bracket 21 around a Swivel axis 22 is pivotally attached, the seat bracket 21 through a transverse to the main plane of symmetry of the chair, i.e. across to Drawing level of FIG. 2 extending profile is formed. On this Seat bracket 21, the seat 5 is supported via spacers 23.

The seat 5 is also on the floor 19 of the rear seat support part 13 supported and fastened by means of elastic buffer 26.

At the rear end of the rear seat support part 13, i.e. in the area where the backrest support 6 is fastened to the rear seat support part 13 is a length-adjustable energy accumulator in the form of a length-adjustable gas spring 27 articulated about a pivot axis 28, which is connected to the pivot axes 20 and 22 runs in parallel. This pivot axis 28 is the housing 29 of the Gas spring 27 facing, from the other end of a piston rod 30 is brought out. An actuating pin 31 protrudes from the piston rod 30 out, by means of which a valve in the gas spring for length adjustment can be operated. The piston rod 30 is by means of a Thread connected to an actuator 32 to which the operating lever 9 heard. This actuator is between the side walls 14, 15 of the front seat support part 12 parallel to the pivot axes 20, 22, 28 pivotally mounted. The operating lever 9 is through an elongated hole 33 in the associated side wall 16 of the rear seat support part 13 led out, this elongated hole 33 is curved in such a way that its center coincides with the pivot axis 20. With appropriate Length adjustments of the gas spring 27 are the front and the rear seat support part 12 or 13 against each other about the pivot axis 20 pivoted, which on the one hand changes the inclination of the seat 5 and at the same time the backrest support 6 with the backrest 7 is pivoted. Such devices are called Designated synchronous mechanisms. If the actuating pin 31 not only is briefly inserted into the piston rod 30 of the gas spring 27 in order a change in length of the gas spring 27 and thus a change in To reach the position of the seat 5 and the backrest 7, but if the Operating pin 31 inserted into the piston rod 30 for a longer time then the seat 5 can be rocked together with the backrest 7 become.

The structure of the seat support 4 with the seat 5 is - insofar as it has been described so far became known from EP-PS 0 179 185 (corresponding to ZA-PS 85/6126). Structure and arrangement of the actuator 32 and the gas spring 27 is known from EP-OS 0 179 216.

Around the pivot axis 20 of the front and rear seat support part 12 or 13, a spring abutment 34 is pivotally mounted, the cross section is designed in the manner of an angle lever. One abutment lever 35 extends rearward from the pivot axis 20, i.e. in the direction to the backrest support 6, namely below the bottom 19 of the rear seat support part 13.

In the area of the free end of the abutment lever 35 is an adjusting screw 36 by means of their external thread 37 in an internal thread 38 on the lever 35 arranged. The threads 37, 38 are not self-locking. The set screw 36 is supported with its free end against the bottom 19 of the rear Seat support part 13 from.

The other, approximately perpendicular to the lever 35 from the pivot axis 20 abutment lever 39 running at the bottom lies against a spring element 40 on by a block of elastic material, such as a cellular polyurethane elastomer, available under the name Vulkocell is, is formed. This spring element 40 lies with its other End against a stationary, but pivotable abutment 41, the by a rear wall opposite the lever 39 of the following bearing part 46, which is explained in more detail, is formed. The spring element 40 is attached to a pin-like projection 42 of the lever 39 so that it does not down from the area between the lever 39 and the abutment 41 can fall out.

If - as shown in Fig. 2 - the external thread 37 of the adjusting screw 36 completely screwed through the internal thread 38 of the spring abutment 34 is, then the abutment lever 39 is in his the abutment 41 next position, i.e. the spring element 40 is on strongest biased. The abutment 41 is - which is repeated here - in arranged front seat support part 12.

When the backrest 6 is pivoted backwards when the gas spring 27 is unlocked the front and rear seat support parts 12 and 13 is pivoted towards one another in its area below the pivot axis 20, i.e. the spring element 40 is under progressive damping this back pivoting movement of the backrest 7 compressed more. This counterforce of the spring element 40 thus acts on the pivoting back movement the backrest 7 progressively counter. With a discharge the backrest 7 is swung forward by appropriate Relaxation of the spring element 40 supports, this supporting Force with increasing forward pivoting movement of the backrest 7 decreases.

If the set screw 36 so far from the abutment lever 35 down is unscrewed that its front end 43 is approximately flush with the lever 35 lies, then the spring element 40 comes throughout the possible Swiveling range of the front and rear seat support parts 12, 13 not effective, i.e. it is not between the abutment 41 and the abutment lever 39 with the generation of a corresponding counterforce pressed together.

The spring element 40 comes at intermediate positions of the adjusting screw 36 each with correspondingly different pivot positions from the rear Seat support member 13 relative to the front seat support member 12, i.e. at different Backward inclinations of the backrest 7 and thus also the Seat 5 for engagement. In addition, the block-like spring element 40th in these intermediate positions, first only with an edge 44 with the abutment 41 comes to rest and only with a further swiveling movement steadily increasing comes to full-surface abutment 41. Here too, a certain progression in the spring action is achieved.

So that the spring abutment 34 is inherently rigid, the levers 35, 39 stiffened with one or more intermediate webs 24. So that the adjusting screw 36 not accidentally unscrewed from the internal thread 38 is, its external thread is slotted in the region of the end 43 and set up. To enable the adjusting screw 36 to be actuated easily, it protrudes downwards from the seat support 4 Provide end with a rotary handle 25. The set screw 36 is opposite the gas spring 27 arranged offset. The gas springs 27 are customary in the market and generally known in terms of structure and mode of operation, for example from DE-PS 18 12 282 (corresponding to US-PS 3,656,593).

For additional inclination adjustment of the entire seat 5 with the synchronous mechanism is the front seat support part 12 with the upper, as a bearing cone 45 formed end of the chair column 3 over a whole with 46 designated bearing part articulated. Die-cast aluminum existing bearing part 46 is seated with an inner cone shaped as a receptacle Bearing block 47 on the bearing cone 45 of the chair column 3. The Bearing bracket 47 is fastened in a longitudinally oriented rectangular tube 48, which on its side behind the bearing block 47 a parallel to Pivot axis 20 extending joint axis 49 in the form of a simple one Carries screw with nut. The front seat support part is on this hinge axis 49 12 hinged.

To lock the seat 5 in a certain inclination position front seat support part 12 with one between it and the bearing part 46 effective rack locking device 49a provided in front of the bearing block 47 is arranged. It has two parallel to each other Toothed strips 50, 51, which are formed in one piece with the bearing part 46. The toothed racks 50, 51 are opposite those that run parallel to one another Outer walls 52, 53 of the bearing part 46 set back inwards. The Toothed strips 50, 51 are each perpendicular to the teeth by two Toothed strips 50, 51 extending guide walls 54 limited. On the The pivot axis 22 pointing towards the free end of the bearing part 46 is parallel to the pivot axis 22 extending stop edge 55 is provided with a stop 56 connected to the seat support part 12, which has a plastic coating 57 interacts. Through the stop edge 55 and the stop 56, the pivotability of the seat support part 12 limited with respect to the chair column 3. The locking device 49a also has two toothed rack jaws arranged parallel to one another 58, 59, which are essentially cuboid and on which the cheek bars 50 and 51 side facing a jaw rack 60 or 61. The teeth of toothed racks 60 and 61 are dimensioned such that they with the teeth of the toothed strips 50 or 51 can be engaged, i.e. they run parallel to each other and have the same distance from each other, so that an optimal toothing is possible. The rack bars 58, 59 are in the side leading Guide walls 54 added with a game. The rack bars 58, 59 are held by a clamping bolt 62 and are over this can be acted upon with force in the direction of the toothed strips 50 or 51. The toothed rack jaws 58, 59 have to carry out the clamping bolt 62 holes 63, 64 in the middle. The bearing part 46 has between the Toothed strips 50, 51 are essentially parallel to the clamping bolt 62 Slot 65 on. At the left end of the clamping bolt 62 in FIG. 3 is provided a surrounding application sleeve 66 which for free end of the clamping bolt 62 out through a nut 67 and a washer 68 is set. The loading sleeve 66 is through a Bore 69 slidably guided through the side wall 14. On the the The toothing bar jaw 58 facing side has the loading sleeve 66 an annular groove 70, which in a corresponding recess of the toothed jaw 58 engages. The rack bars 58 and 59 are by a helical compression spring 71 surrounding the clamping bolt 62 towards the outside in Biased towards the side walls 14 and 15 respectively. In the area of the side wall 15 is the clamping bolt 62 by a loading block 72 with a bore 73 receiving the clamping bolt 62. The application block 72 is displaceable through a bore 74 in the side wall 15 guided and points on the toothed rack jaw 59 Side an annular groove 75, which is in a corresponding recess of the toothed jaw 59 is recorded on. The loading sleeve 66 and the block 72 serve as guide elements for the clamping bolt 62.

In the region of the right end of the clamping bolt 62 in FIG Clamping device 76 is provided to engage the toothed rack jaws 58, 59 in To apply force in the direction of the toothed strips 50 or 51. The Tensioning device 76 has one that interacts with the loading block 72 Main clamping body 77, one connected to it Actuating lever 78 and one provided at its free end Handle 79 on. The clamping base 77 has two mutually parallel Sidewalls 80 which have a substantially oval cross-section. The side walls 80 are by an expansion body 81 and a lever receptacle 82 connected to each other, the expansion body 81 and the Lever receptacle 82 is arranged in the region of the two ends of the side walls 80 are. The expansion body 81 has a guide channel 83 through which the clamping bolt 62 is guided. Between the expansion body 81 and the Lever receptacle 82 is arranged at the free end of the clamping bolt 62 and connected to this, the application head 84, the sets the clamping base body 77 in a clamping direction 85. The side wall 15 is with a downwardly open guide profile 86 with a U-shaped Cross-section connected. The guide profile 86 has an upper one Wall 87 and two connected to it, arranged parallel to each other Guide walls 88 on. The top wall 87 faces in the area of its free In the end, a web pulled obliquely upwards from the horizontal 89 on. The side walls 80 and those facing the guide walls 88 Sides of the loading block 72 are between the guide walls 88 guided with respect to the clamping bolt 62 without play.

The loading block 72 faces the clamping base body 77 Side a cam 90 with two these laterally delimiting Flanks 91 and 92. The expansion body 81 faces the loading block 72 facing side a cam 93 with two these laterally bounding flanks 94, 95. On the opposite side points the expansion body 81 has a cam 96 with these limiting flanks 97, 98 on. The guide channel 83 has the shape of two at an angle to one another offset bores, so that pivoting of the expansion body 81 from the locking position shown in Fig. 3 around the clamping bolt 62 into the free pivoting position shown in FIG. 4 is possible. The Guide channel 83 is in the upper area by two angled against each other Channel walls 99, 100 limited. In the lower area the Guide channel 83 through two substantially perpendicular to each other intersecting channel walls 101, 102 limited. The application head 84 has a cam 103 on the side facing the expansion body 81 as well as flanks 104 and 105 laterally delimiting them. The lever mount 82 points on the side facing the application head 84 a projection 106 that the gap between the lever receptacle 82nd and the loading head 84 so far reduced that human extremities, such as. the fingers of children playing, not stuck in them and not pinched when the clamping base 77 is pivoted can be.

In the following the locking of the bearing part 46 relative to the front Seat support part 12 and its subsequent solution with reference 3 and 4 and on the sections in Fig. 5 and 6 respectively. The locking position is shown in FIGS. 3 and 5. The operating lever 78 is in the lower stop position. The spreader 81 is in the maximum spread position, i.e. the loading head 84 and the admission block 72 are as large as possible Scope pushed apart. The cam 96 is in this position on flank 105 and cam 93 on flank 91. In this position the loading block 72 presses the rack jaw 59 with the Toothed strips 61 into the toothed strips 51. The pressurizing sleeve also presses 66 the rack bars 58 with the rack bars 60 in the rack bars 50. A pivoting of the bearing part 46 relative to the seat support part 12 is therefore not possible in this locking position. To solve the Locking the actuating lever 78 up in the in Fig. 4 and in Detail pivoted in Fig. 6 pivoted position. While of pivoting, the cams 93 and 96 move over them cams 90 and 103 lying in the stop, block 72 and the head 84 further apart and the pivoting the Force of the spring 71 counteracts. The point at which the cams 90 and touching 93 and 96 and 103 is a dead center. If the user has pivoted the actuating lever 78 past the dead center, so The lever 78 automatically slips into that shown in FIGS. 4 and 6 Free-pivoting position. In this position, the side walls 80 are against the Bridge 89. The cam 90 bears on the flank 94 and the cam 96 edge 104. In this position the distance A is between the application head 84 and the application block 72 are lower than in FIG the locking position shown in Figs. 3 and 5. As a result, that is on the Rack bars 58 and 59 acting in the direction of the rack bars 50 and 51, respectively Force less than in the locking position, so that the helical compression spring 71 can push the toothed jaws 78 and 79 apart, so that they come out of engagement with the toothed strips 50 and 51. In the Free pivot position can therefore the bearing part 46 relative to the front Seat support part 12 are pivoted. The user of the chair has thus two options for tilt adjustment compared to the Chair column 3. On the one hand, it can be inclined in relation to the chair column 3 in lock the specified positions effectively. A particular advantage of Locking with toothed strips is that along the Direction of pivoting, i.e. essentially perpendicular to Longitudinal extension of the toothed strips 50, 51 when locking Form locking occurs so that even large forces, e.g. by heavy Persons, can be included without it becoming a Tilt adjustment comes without the will of the user. On the other hand the lock can be released. In this case it turns out automatically the optimal one based on the user's seating position Inclination towards the chair column 3. This can prevent it be that the user has a fixed inclination to the Chair column 3 used, which may not be anatomical for him is optimal. The seat 5 thus follows a forward inclination or Backward tilt of the user.

Claims (10)

Chair, especially office chair, with a) a base (1), b) a seat support (4) supported thereon by means of a chair column (3) and having a front and a rear seat support part (12, 13) connected to one another via a pivot axis (20), c) a seat (5) supported on the seat support parts (12, 13), d) a backrest (7) attached to the rear seat support part (13), e) a length-adjustable energy store (27) articulated on the seat support parts (12, 13) at a distance from their pivot axis (20) for mutual adjustment of the backrest (7) and seat (5), f) a receptacle (47) provided on a seat support part (12) for the upper end of the chair column (3), the receptacle (47) on the seat support part (12) via a front and rear seat support part parallel to the pivot axis (20) (12, 13) arranged hinge axis (49) is articulated, and g) a locking device effective between the seat support part (12) and the receptacle (47) for locking or releasing different inclinations of the seat support (4) provided with the receptacle (47) relative to the chair column (3), characterized in that h) the locking device is a toothed rack locking device (49a). Chair according to claim 1, characterized in that the toothed bar locking device (49a) has a tensioning device (76) for locking or releasing the toothed bar locking device (49a). Chair according to claim 2, characterized in that the tensioning device (76) can be pivoted between a first stop position and a second stop position. Chair according to claim 3, characterized in that the tensioning device (76) leads between the first stop position and the second stop position over a dead center. Chair according to one of the preceding claims, characterized in that the toothed bar locking device (49a) has at least one toothed bar (50, 51) connected to the receptacle (47). Chair according to claim 5, characterized in that the toothed bar locking device (49a) has at least one toothed bar jaw (58, 59) connected to the seat support part (12) for interaction with the at least one toothed bar (50, 51). Chair according to claim 6, characterized in that the toothed bar locking device (49a) has two toothed bars (50, 51) and two toothed bar jaws (58, 59) which can be brought into engagement with one another in pairs. Chair according to claim 7, characterized in that the two toothed rack jaws (58, 59) are slidably arranged on a clamping bolt (62). Chair according to claim 8, characterized in that the seat support part has bores (69, 74) in which guide elements (66, 72) are slidably guided to receive the clamping bolt (62). Chair according to one of claims 7 to 9, characterized in that the toothed bar locking device (49a) has a helical compression spring (71) for pressing the toothed bar jaws (58, 59) apart.

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