EP1396213A1 - Synchronised mecanism for office chairs - Google Patents

Abstract

The synchronising mechanism is biased by a spring assembly (23) which has at least one coil compression spring (24) mounted parallel to the sliding direction of the seat support (4) and associated with its own abutment arm (25) whose front end is attached to the base support (1) and whose rear end freely extends to form an abutment (27) for the rear support of the compression spring. The at least one compression spring is supported by its front end on an abutment (28) formed on the seat support. To adjust the pretension of the compression spring the associated abutment arm is mounted on the base support longitudinally displaceable in the longitudinal direction of the seat.

Description

The invention relates to a synchronous mechanism for office chairs with the im The preamble of claim 1 features specified, as from the DE 198 10 768 A1 or based on an earlier application by the applicant DE 101 25 994 A1 are known.

Assemblies in the seat substructure are called "synchronous mechanics" of an office chair understood for a coupled, a certain relative movement of the seat and backrest to each other associated kinematics. There is a base support on a chair column placed on which, on the one hand, a pivotable about a transverse axis, articulated to the base support and to the other also pivotable about a transverse axis, articulated with the base support connected backrest supports are stored. On the seat support is the usually office chair with a padded seat assembled. The backrest support, which differs commonly from the actual synchro mechanism extends to the rear, carries on to one the arm of the office chair runs at the top.

Seat support and backrest support are articulated so that a Swiveling movement of the backrest to the rear - as for example caused by the chair user leaning against the backrest can be - a lowering movement of the rear edge of the seat down induced. This correlated seat-backrest movement brings you considerable comfort advantage and is for orthopedic reasons he wishes.

To with a pure swivel coupling of the backrest support Base and seat supports swivel the backrest and seat towards To enable the bottom back, a degree of freedom must be introduced in the mechanics be the back of a shift of the seat support allows simultaneous pivoting around its front end. Therefor disclose the two publications mentioned at the beginning of the stand the technology a rotary-slide joint between the base support and the front End of the seat support. Depending on whether and how strong the slide-swivel movement an increase in the front edge of the seat is desired is the slot-like sliding guide for the seat carrier rather steep, as in DE 198 10 768 A1 or rather flat, as in DE 101 25 994 A1.

Another fundamental issue with synchronous mechanisms is in their spring action against the pivoting to the rear. For this a large number of spring constructions are known from the prior art. The combination is the synchronous mechanism according to DE 198 10 768 A1 a gas and helical compression spring is provided, which turns out to be relative high-rise unit extends under the seat support. The one point of attack this spring arrangement is the front bearing end of the seat support, with the rear end of the spring arrangement is in an abutment supported by the cone seat of the seat carrier.

The spring arrangement provided in the construction according to DE 101 25 994 A1 is based on two leg springs housed in the base support are. One leg of the spring is in an adjustment arrangement in the base support housed, whereas the second leg upwards in the direction Seat carrier protrudes, which is located on a corresponding abutment on this Thigh supports and thus against his backward Swing direction is applied.

Both prior art spring assemblies take a considerable amount Part of the available space in the base support so that its free design is relatively narrow. In particular are using such known synchronous mechanisms the base supports are relatively voluminous for aesthetic reasons Have panels to the spring assembly and the associated Hide adjustment elements as much as possible.

On the problem of the adjustability of the bias of the spring assembly Reference is made to DE 100 08 453 C2, which includes a spring assembly switchable spring units for varying the spring preload and thus reveals counterforce against pivoting. The spring arrangement but here itself is between the base support and a one-piece, combined seat-backrest support arranged as a whole is pivotable to the rear. This is not a synchronous mechanism in itself represents.

The invention has for its object a synchronous mechanism for Improve office chairs so that the spring arrangements are more constructive Simplicity particularly compact and especially in a narrower space To be arranged close under the seat support, so that the area of the base support essentially free while achieving the greatest possible design freedom remains.

• die Federanordnung mindestens eine im wesentlichen parallel zur Schieberichtung des Sitzträgers flach unter diesem angeordnete Schraubendruckfeder aufweist, wobei
• für jede Schraubendruckfeder ein Widerlagerausleger vorgesehen ist, dessen vorderes Ende am Basisträger angelenkt ist und dessen rückwärtiges Ende frei auskragend ein Widerlager für die rückwärtige Abstützung der Schaubendruckfeder bildet, und
• sich die mindestens eine Schraubendruckfeder jeweils mit ihrem vorderen Ende an einem am Sitzträger gebildeten Widerlager abstützt.

This object is achieved by the features specified in the characterizing part of claim 1, according to which

• the spring arrangement has at least one helical compression spring arranged substantially parallel to the sliding direction of the seat support, wherein
• an abutment boom is provided for each helical compression spring, the front end of which is articulated on the base support and the rear end of which cantilever forms an abutment for the rearward support of the screw compression spring, and
• the at least one helical compression spring is supported with its front end on an abutment formed on the seat support.

Due to the specified design, the entire spring arrangement practically only via its front end with the rest of the kinematics Synchronous mechanism connected. Starting from the front end of the abutment boom, at the level of the rotating sliding joint between the seat support and the base support is arranged, the spring arrangement projects practically horizontally backwards along the seat support. Due to the flat design it has a very low overall height. Since also any connecting elements missing that towards the backrest or base support stand below, this area may be different from other construction and design parts of the chair can be taken in any way.

The basic construction of the spring arrangement according to the abutment boom also enables preferred further training in which the adjustment the bias of the spring assembly can be accomplished in a simple manner is. The abutment boom only needs to be in the longitudinal direction of the seat be slidably mounted. A longitudinal shift changes the Position of the abutment for the rear support of the helical compression spring, which are either stronger or weaker under the corresponding Change the bias is compressed. Is preferred the displacement of the abutment boom by means of an adjusting shaft with eccentric cam realized.

According to a further preferred embodiment, is as a spring arrangement a spring package from several helical compression springs is provided, the Total preload due to different gradation of the individual Eccentric cam of the control shaft can be varied in narrow steps. this has on the one hand the advantage that the counterforce in the Synchronous mechanism can be achieved with a wide range of absolute variations is. In contrast to the construction according to the above-mentioned DE 100 08 453 C2 is based on the ability to connect and disconnect individuals Feathers completely dispensed with.

Further preferred embodiments of the invention see the implementation the abutment boom as rods on which the helical compression springs are put on. The helical compression springs can Support on a support bar on the abutment of the seat support, which in a Bearing recess of the abutment is pivotally sliding. The support the helical compression spring towards the seat support is improved, because due to the movement of the seat support plate towards the bottom down an actuation of the synchronous mechanism a certain swivel angle in balance the support of the helical compression spring.

Further preferred embodiments relate to the training the bearing head of the respective abutment boom in the form of a frame, on the one hand for the storage of the abutment boom on the base beam and on the other hand as a contact surface for the eccentric cam of the control shaft is used.

According to further preferred embodiments, at least one is An additional abutment is provided at the rear end, which is adjustable in the longitudinal direction of the seat. This allows the on this abutment boom sitting helical compression spring in its basic preload can be varied so that together with the adjustability of the abutment boom itself at least two different counterforce ranges to adapt the synchronous mechanism to light or heavyweight people are made available. Within this Areas can then be adjusted via the actual adjustment of the abutment boom a fine adjustment can be made.

Finally, in a further variant of the invention, the at least one Abutment boom designed as a control shaft, on the one hand by a Actuator on the base carrier rotatable and on the other hand with your rear end with an adjustable abutment stop is. This is spindle-like due to a shaft rotation in the direction of the spring force the helical compression spring adjustable so that only by the Actuation of the actuator pre-tensioning the helical compression springs is easily adjustable over a wide range.

The actuator is preferably operated by a manually operated actuating shaft formed in the front area of the base support, which over a Deflection gear is coupled to the front end of the actuating shafts. In order to is the adjustment of the spring preload in a convenient manner a rotary knob on the end of the actuating shaft protruding from the side of the chair to accomplish.

A structurally simple mounting of the control shafts results from that this is in a bearing bracket sitting on a reversing gear shaft are rotatably supported with their front end. The reversing gear is for Achieving a compact design as a bevel gear between each an actuating shaft and one driven by the actuating shaft Gear shaft formed.

Fig. 1 und 2

eine Seiten- und Frontansicht einer Synchronmechanik in einer ersten Ausführungsform,

Fig. 3

einen im wesentlichen horizontalen Schnitt durch die Synchronmechanik entlang der Schnittlinie III-III nach Fig. 1,

Fig. 4

ein Vertikalschnitt entlang der Schnittlinie IV-IV nach Fig. 3,

Fig. 5 und 6

Schnitte analog Fig. 3 und 4 mit veränderter Federvorspannung,

Fig. 7 und 8

zentral gelegte Vertikalschnitte durch die Synchronmechanik gemäß der Schnittlinie VII-VII nach Fig. 3 mit unterschiedlichen Stellungen des Zusatz-Widerlagers,

Fig. 9, 10 und 11

Schnitte analog den Fig. 1, 3 und 7 in nach hinten verschwenkter Stellung der Synchronmechanik,

Fig. 12

eine perspektivische, ausschnittsweise Darstellung einer Synchronmechanik in einer zweiten Ausführungsform von schräg hinten, sowie

Fig. 13 und 14

eine Draufsicht bzw. Seitenansicht der Synchronmechanik gemäß Fig. 12.

Further features, details and advantages of the invention result from the following description, in which an embodiment of the subject matter of the invention is explained in more detail with reference to the drawings. Show it:

1 and 2

a side and front view of a synchronous mechanism in a first embodiment,

Fig. 3

an essentially horizontal section through the synchronous mechanism along the section line III-III of FIG. 1,

Fig. 4

3 shows a vertical section along the section line IV-IV according to FIG. 3,

5 and 6

3 and 4 with modified spring preload,

7 and 8

centrally placed vertical sections through the synchronous mechanism according to section line VII-VII according to FIG. 3 with different positions of the additional abutment,

9, 10 and 11

Cuts analogous to FIGS. 1, 3 and 7 in the position of the synchronous mechanism pivoted backwards,

Fig. 12

a perspective, partial representation of a synchronous mechanism in a second embodiment from obliquely behind, and

13 and 14

12 shows a top view or side view of the synchronous mechanism according to FIG. 12.

The basic structure of the synchronous mechanism is described below with reference to FIGS. 1 to 4 explained. A base support 1 is provided as the load-bearing part, that in the area of its rear end with a cone holder 2 to attach the synchronous mechanism to the upper end of a (not shown) chair column is provided. Other basic components of synchronous mechanics are the backrest support 3 and the seat support 4. The backrest support 3 is shortly before the cone receptacle 2 via a transverse axis 5 pivoted on the base support 1. It consists of two at an angle rear side struts 6, 7, which at the rear end in a only schematically indicated backrest base 8 open.

In the front end area of the base support 1, which widens towards the front are two upstanding projecting bearing posts on both sides of the central longitudinal plane M. 9, 10 integrally formed, in which a control shaft 11 with a Knob 12 is rotatably supported at one end.

The essentially plate-shaped seat support 4 has in the area of its at the front end two cheeks 13, 14 projecting downwards, those with an elongated hole that slopes slightly towards the rear in the longitudinal direction SL 15, 16 are provided. The seat support sits with these elongated holes 15, 16 4 on the actuating shaft 11, whereby the engagement of these two components a rotary slide joint 17 is formed between the base and seat supports 1, 4 is, d. H. the seat support 4 can pivot about the adjusting shaft 11 and simultaneously move relative to it in the direction of the elongated holes 15, 16.

In the area of its rear end, the seat support 4 is also with two lateral, downwardly projecting bearing tabs 18, 19 provided together with a corresponding, protruding bearing protrusion 20, 21 on the two side struts 6, 7 of the backrest support 3 form a pivot bearing about a transverse axis 22.

To act on the synchronous mechanism against the synchronous adjustment movement from the basic position shown in FIGS. 1 to 4 a spring arrangement designated as a whole with 23 is provided, which four parallel to each other, on both sides of the central longitudinal plane M in a common helical compression springs 24.1 to 24.4 (hereinafter provided with the common reference number 24, unless a single helical compression spring is a separate discussion needs). For each helical compression spring 24 is in each case an abutment boom 25.1 to 25.4 is provided, the front end pivotable relative to the base support 1 via a bearing head 26.1 to 26.4 is articulated. The rod-shaped shaft of the abutment boom 25 stands cantilevered to the rear and is there with an abutment projection 27 provided. The rear end of the is supported on this Helical compression springs 24.

Its front end sits on a horizontal and transverse to the longitudinal direction SL extending, in cross section semi-circular support bar 28 as Abutments that face with their semi-cylindrical, forward Lateral surface in corresponding inner cylindrical bearing recesses 29 support at the rear end of the cheeks 13, 14 of the seat support 4. In addition, there are 25 more from the support bracket between the abutment arms 4 intermediate posts 30 protruding downwards, which with the Bearing recesses 29 aligned bearing recesses 31 for additional Have counter support of the support bar 28. The pressure force between the abutment projection 27 and the support bar 28 clamped Helical compression springs 24 act on the seat support 4 in the forward direction 1 to 4 basic position shown.

The abutment boom 25 pass through with its rod-shaped shaft Supporting strip 28, moreover, through feedthrough openings 32.

The bearing head 26 at the front end of the abutment boom 25 is as at least frame-shaped or box-shaped part, its parallel lateral frame walls 33 each extending to the longitudinal direction of the seat SL are provided with an elongated hole 34 with which the abutment bracket 25th on the adjusting shaft 11 pivotable and in the longitudinal direction SL relative thereto is slidably mounted. On the adjusting shaft 11 are inside the bearing heads Eccentric cams 35.1 to 35.4 non-rotatably connected to the actuating shaft 11, on their respective forward-facing eccentric flanks 36 supports the front frame wall 37 of the bearing head 26. The contact between frame wall 37 and eccentric flank 36 is by the Compressed force of the helical compression springs 24 secured.

Regarding the basic configuration of the synchronous mechanism, it should be noted that by the spring assembly 23 due to the bias of the helical compression spring 24 the seat support 4 is loaded forward relative to the base support 1 is so that he with the rear ends of his elongated holes 15, 16 on the Actuating shaft 11 rests in the basic position shown in FIGS. 1 to 4. The Backrest support 3 is in its maximum upright position.

If the preload of the helical compression springs 24 is now to be changed, only the adjusting shaft 11 needs to be rotated. Their eccentric cams 35 then move the abutment boom 25 further, for example forward so that the rear abutment projection 27 closer to the support bar 28 is brought up. The helical compression springs 24 are this compresses more and exert greater pressure on the Support bar 28 and thus the seat support 4. As from the drawings is not clear, the eccentric cam 35 different Have degrees of eccentricity and slopes, so that different Helical compression springs 24 differ when actuating the actuating shaft 11 heavily compressed or relieved.

To make another adjustment for the preload of the inner Creating helical compression springs 24.2 and 24.3 is an adjustable additional abutment 38 provided. This is primarily one transversely to the seat longitudinal direction SL vertically arranged, plate-shaped Slider 39, the two bearing openings 40 on the two inner abutment arms 25.2, 25.3 slidably guided in the longitudinal direction SL is. This slide 39 is between the two helical compression springs 24.2, 24.3 and their abutment projection 27.2, 27.3 used. It acts with another eccentric camshaft 41, the eccentric cam 42 is centered in the median longitudinal plane M and the slide 39 of acted on the rear.

The eccentric camshaft 41 is supported by two bearing struts 43.1, 43.2, each extending from the underside of the bearing heads 26.3, 26.3 extend parallel to the lower abutment arms 25.2, 25.3 to the rear. At their free ends, these struts 43 have four upright standing bearing plates 44.1 to 44.4, which are aligned with one another Bearing eyes 45 are provided. The eccentric camshaft 41 sits in these which can be actuated by a lateral rotary knob 46.

Now the bias of the spring assembly 23 to a heavier Person can be adjusted, so the eccentric camshaft via the rotary knob 46 41 operated, and the eccentric cam 42 moves the Slide 39 on the abutment arms 25.2, 25.3 to the front. The Helical compression springs 24.2, 24.3 are under increasing pressure more compressed. The adjustment range achievable by the control shaft 11 the spring force is retained since the actuating shaft is actuated 11, the entire additional abutment 38 is also moved, so that the two compression springs 24.2, 24.3 which are already compressed to a greater extent be compressed even further.

The functioning of the synchronous mechanism can be seen in FIGS. 9 to 11 in connection with FIGS. 1 to 4 explain. So when pushing back the backrest of the backrest support 3 is pivoted backwards, the seat support 4 backwards around the rotating sliding joint 17 pivoted. The support bar 28 moves closer to the end of the Abutment boom 25 out, so that the helical compression springs 24 stronger be compressed and thus build a higher counterforce. The Rotation-slide movement can be carried out until the control shaft 11 at the rear end of the elongated holes 15, 16 on the seat support.

If the backrest is relieved, the seat support 4 is by the helical compression springs 24 swung back upwards again, with the backrest support 3 is also pivoted. This movement is again by striking the adjusting shaft 11 at the front end of the elongated holes 15, 16 limited.

A second embodiment of a synchronous mechanism according to the invention is shown in Figs. 12 to 14. To avoid repetitions in this context it should be noted that the basic elements of Synchronous mechanism, such as base bracket 1, backrest bracket 3 and seat bracket 4 with their mutual coupling via transverse axes 5, 22 and Rotary sliding joint 17 with the embodiment according to FIGS. 1 to 11 to match. In this respect, they are constructive and functional for them matching elements in the embodiment of FIG. 12 to 14 corresponding reference numerals are used and will be used to explain them to the corresponding statements in connection with 1 to 11 referenced.

In the following, only the alternative design and storage of the described the helical compression springs 24 supporting abutment boom 25 become. Accordingly, these abutment booms 25 are in turn basically hinged at its front end to the base support 1, however, in the linkage there is an actuator designated as a whole by 50 for a rotation of the abutment boom acting as the actuating shaft 51 25 integrated. This actuator 50 has a transverse to the direction of extension of the actuating shafts 51 rotatable below it on the base support 1 mounted actuating shaft 52, which to one side of the base support 1 protrudes and is provided with a rotary knob 53. Within the base support 1 is the actuating shaft 52 with a gear 54 of a reduction gear 55 provided, the output-side gear 56 on a also located in the base support 1 intermediate shaft 57. This intermediate wave 57 is completed by coaxial shaft stub 58, on which each bevel gear 59 sit. These form with corresponding bevel gears 60 at the front ends of the Abutment boom 25 forming control shafts 51 each have a bevel gear 61, which in turn with the reduction gear 55 the total so-called deflection gear 49 results. This will turn the Actuating shaft 52 transformed into a rotary movement of the actuating shafts 51.

The adjusting shafts 51 are each with threads at their rear end 62 provided with which spindle nuts 63 are engaged. These spindle nuts 63 are by a common, transverse to the direction of extension the control shaft 51 extending abutment bolt connected to the the helical compression springs 24 are each supported with their rear end. Its front end is - as in the embodiment according to FIG. 1 - on one on the seat support 4 in a semicircular bearing shell (in FIGS. 12 to 14 not recognizable) pivotally supported support bar 28 supported.

It remains to be added that the front of the support strip 28 reaching through Ends of the actuating shafts 51 are rotatably supported in pairs in bearing brackets 65 which in turn have bearing extensions 66 on the intermediate shaft 57 are pivotally mounted. This means that the adjusting shafts 51 are not just about theirs Rotatable longitudinal axis, but also pivotable about the intermediate shaft 57 mounted so that the actuating shafts 51 the slight tilting movement of the seat carrier 4 can perform down to the back with. With this movement the seat support 4 with the support strip 28 against the force of the helical compression springs 24 moved to the rear. This counterforce is through a Adjustment of the rear abutment latch 64 variable.

It should be noted that in FIGS. 12 to 14, components such as two Adjustment shafts 51 on the left half of FIGS. 12 and 14 and those there located parts of the deflection gear 49, the left leg of the Backrest support 3 and the seat support 4 for a better overview the construction have been omitted.

Claims (15)

Comprehensive synchronous mechanism for office chairs a base support (1) which can be placed on a chair column, a backrest support (3) hinged to the base support (1) about a transverse axis (5), a seat support (4) which can be pivoted about a transverse axis (11) in the region of its front end via a rotary / sliding joint (17) and displaceable in the longitudinal direction of the seat (SL) with the base support (1) and in the region of its rear end by one Transverse axis (22) is pivotally coupled to the backrest support (4), and a spring arrangement (23) for acting on the synchronous mechanism against its synchronous adjustment movement of the seat (4) and backrest supports (3), characterized in that the spring arrangement (23) has at least one helical compression spring (24) arranged essentially parallel to the sliding direction of the seat support (4), wherein for each helical compression spring (24) an abutment boom (25) is provided, the front end of which is articulated on the base support (1) and the rear end of which cantilever forms an abutment (27) for the rearward support of the screw compression spring (24), and the at least one helical compression spring (24) is supported with its front end on an abutment (28) formed on the seat support (4). Synchronous mechanism according to claim 1, characterized in that for adjusting the pretensioning of the at least one helical compression spring (24) the associated abutment bracket (25) is mounted on the base support (1) so as to be displaceable in the longitudinal direction of the seat (SL). Synchronous mechanism according to claim 2, characterized in that the abutment bracket (25) with a bearing head (26) is slidably mounted on an actuating shaft (11) forming the transverse axis of the rotary sliding joint (17) on the seat support (4), the actuating shaft (11) each carries an eccentric cam (35) for adjusting the associated abutment boom (25). Synchronous mechanism according to claim 3, characterized in that a spring assembly comprising a plurality of helical compression springs (24) is provided, the total preload of which can be varied in narrow steps by different steps of the individual eccentric cams (35) of the actuating shaft (11). Synchronous mechanism according to one of the preceding claims, characterized in that the abutment arms (25) are designed as rods on which the helical compression springs (24) are placed. Synchronous mechanism according to one of the preceding claims, characterized in that the at least one helical compression spring (24) is supported via a support bar (28) extending transversely to the longitudinal direction of the seat (SL) as an abutment of the seat support (4), which is pivotably mounted in a bearing recess (29) is. Synchronous mechanism at least according to claim 3, characterized in that the bearing head (26) of the respective abutment bracket (25) is designed as a frame, the frame walls (33) of which run parallel to the longitudinal direction of the seat (SL) each have an elongated hole-shaped bearing recess (34) by means of which the Abutment bracket (25) in the longitudinal direction of the seat (SL) on the adjusting shaft (11) is slidably mounted. Synchronous mechanism according to claim 7, characterized in that the front frame wall (37) of the respective bearing head frame (26) is acted upon by the associated eccentric cam (35). Synchronous mechanism according to one of the preceding claims, characterized in that at least one abutment arm (25) is provided at the rear end with an additional abutment (38) adjustable in the longitudinal direction of the seat (SL). Synchronous mechanism according to claim 9, characterized in that the adjustable additional abutment is formed by a slide (39) which is displaceably guided on the abutment bracket (25) and can be actuated by an eccentric camshaft (41). Synchronous mechanism according to claim 10, characterized in that the eccentric camshaft (41) is attached to a bearing strut (43) which extends from the front end of the abutment bracket (25) to the rear. Synchronous mechanism according to claim 1, characterized in that the at least one abutment arm (25) is designed as an actuating shaft (51) which can be driven in rotation by an actuator (50) on the base support (1), on the rear end of which a spindle-like rotation of the shaft in the direction of the spring force of the Helical compression spring (24) adjustable abutment stop (64) is mounted. Synchronous mechanism according to claim 12, characterized in that the actuating drive (50) has an actuating shaft (52) which is arranged transversely to the direction of extension of the actuating shaft (s) (51) in the front region of the base support (1) and which is connected to the front end of the actuating shaft (s) (51) is coupled. Synchronous mechanism according to claim 13, characterized in that at least two adjusting shafts (51) are rotatably mounted with their front ends in a bearing bracket (65) seated on a deflection gear shaft (49). Synchronous mechanism according to claim 12, characterized in that the deflection gear (49) has a bevel gear (61) between the at least one adjusting shaft (51) and a gear shaft (57).

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