Abstract
The invention relates to a synchronizing mechanism for a chair comprising a base part which defines a rotational axis, a backrest support for supporting a backrest and a seat support for supporting a seat. The backrest support is pivotably supported on the base part about a first pivot, and the seat support is pivotably supported on the backrest support about a second pivot. The first pivot of the backrest support is fixed relative to the base part and the second pivot of the seat support is movable relative to the base part. In a basic position, the second pivot is in a lower basic position and the seat support rests against a support structure. In an upper end position, the movable second pivot is moved substantially vertically into an upper end position and the seat support is arranged at a distance to the support structure.
Claims
1. A synchronizing mechanism for a chair, in particular an office chair, comprising a base part defining an axis of rotation, a backrest support for holding a backrest and a seat support for holding a seat, wherein the backrest support is mounted on the base part so as to be pivotable about a first pivot, wherein the seat support is mounted on the backrest support so as to be pivotable about a second pivot, wherein the first pivot of the backrest support is fixed relative to the base part and the second pivot of the seat support is movable relative to the base part, wherein in a basic position, the second pivot is in a lower basic position and the seat support abuts on a support structure, and wherein in an upper end position, the movable second pivot is moved essentially vertically into an upper end position and the seat support is spaced apart from the support structure.
2. The synchronizing mechanism according to claim 1, wherein the second pivot is fixed relative to the backrest support and is movable essentially vertically upwards with the backrest support.
3. The synchronizing mechanism according to claim 1, wherein in a first intermediate position the second pivot is moved from the lower basic position essentially vertically upwards into a first intermediate position and the seat support is arranged so as to tilt relative to the support structure.
4. The synchronizing mechanism according to claim 1, wherein in the end position the seat support is maximally pivotable relative to the backrest support about the second pivot.
5. The synchronizing mechanism according to claim 1, wherein the base part is arranged as a rigid component.
6. The synchronizing mechanism according to claim 1, wherein, when viewed from a side, the first pivot is arranged in a seat direction behind the axis of rotation and the second pivot is arranged in the seat direction in front of the axis of rotation of the base part.
7. The synchronizing mechanism according to claim 1, wherein the support structure is arranged in front of the axis of rotation of the base part in the seating direction, when viewed from the side.
8. The synchronizing mechanism according to claim 7, wherein the second pivot is arranged between the support structure and the fixed first pivot, when viewed from the side.
9. The synchronizing mechanism according to claim 1, wherein in the basic position a support point of the seat support on the support structure is located in the vertical direction above the first pivot.
10. The synchronizing mechanism according to claim 1, wherein the seat support is designed as a U-shaped profile which, downwardly open, is arranged on the underside of the seat plate.
11. The synchronizing mechanism according to claim 1, wherein the support structure comprises a sliding block which is preferably mounted so as to be rotatable about a third pivot between two tab-like projections of the base part.
12. The synchronizing mechanism according to claim 11, wherein in the basic position and in the first intermediate position the seat support rests with the inner surface of its upper side on the sliding block.
13. The synchronizing mechanism according to claim 1, wherein the backrest support has a slotted guide for the seat support.
14. The synchronizing mechanism according to claim 13, wherein, when viewed from the side, the slotted guide for the seat support comprises a guide slot which is convexly curved upwards and which runs at least partially over an upper edge of the base part.
15. The synchronizing mechanism according to claim 1, wherein the seat support is configured to execute a lateral forward movement from the basic position to the first intermediate position and from the basic position to the end position.
16. The synchronizing mechanism according to claim 1, wherein in a second intermediate position the second pivot is moved from the lower basic position essentially vertically upwards into a second intermediate position in which the seat support is raised so far that it is out of contact with the support structure, so that the seat support with the seat plate can be tilted without guidance about the second pivot.
17. The synchronizing mechanism according to claim 15, wherein in the second intermediate position the seat support has not yet reached its maximum pivotability.
18. The synchronizing mechanism according to claim 1, wherein in a second intermediate position the second pivot is moved from the lower basic position essentially vertically upwards into a second intermediate position in which guide pins operatively connected to the seat support via a slotted guide are raised so far that they are out of contact with the base part, but the seat support has not yet reached its maximum pivotability.
19. The synchronizing mechanism according to claim 1, wherein the fixed first pivot and/or the movable second pivot is/are realized by means of a deformable structure.
20. A chair, in particular an office chair, with a synchronizing mechanism according to claim 1.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] Further advantageous embodiments of the invention emerge from the following description of exemplary embodiments of the invention with the aid of the schematic drawing. In particular, the mechanism according to the invention and the chair according to the invention are described in more detail below with reference to the accompanying drawings on the basis of exemplary embodiments. In the drawings:
[0045] FIG. 1: shows a perspective view of a first embodiment of a synchronizing mechanism according to the invention;
[0046] FIG. 2: shows a side sectional view of the first embodiment of the synchronizing mechanism according to the invention in the basic position with horizontal seat support;
[0047] FIG. 3: shows a side sectional view of the first embodiment of the synchronizing mechanism according to the invention in the first intermediate position with the seat support tilted forwards;
[0048] FIG. 4: shows a side sectional view of the first embodiment of the synchronizing mechanism according to the invention in a second intermediate position with a raised and essentially horizontal seat support;
[0049] FIG. 5: shows a side sectional view of the first embodiment of the synchronizing mechanism according to the invention in an end position with the seat support in the highest position;
[0050] FIG. 6: shows a side sectional view of the first embodiment of the synchronizing mechanism according to the invention in the end position with the seat support tilted backwards;
[0051] FIG. 7: shows a side sectional view of a second embodiment of the synchronizing mechanism according to the invention in the basic position with the seat support slightly inclined backwards;
[0052] FIG. 8: shows a side sectional view of the second embodiment of the synchronizing mechanism according to the invention in the first intermediate position with the seat support tilted forwards;
[0053] FIG. 9: shows a side sectional view of the second embodiment of the synchronizing mechanism according to the invention in the second intermediate position with raised seat support;
[0054] FIG. 10: shows a side sectional view of the second embodiment of the synchronizing mechanism according to the invention in the end position with the seat support in the highest position; and
[0055] FIG. 11: shows a side sectional view of the second embodiment of the synchronizing mechanism according to the invention in the end position with the seat support tilted backwards.
EMBODIMENT(S) OF THE INVENTION
[0056] Certain expressions are used in the following description for practical reasons and are not to be understood as limiting. The words right, left, bottom and top denote directions in the drawing to which reference is made. The terms inward, outward, below, above, left, right or similar are used to describe the arrangement of designated parts relative to one another, the movement of designated parts relative to one another and the directions toward or away from the geometric center of the invention and designated parts thereof as shown in the drawings. This spatial relative information also comprises different positions and orientations from those shown in the drawings. For example, if a part shown in the drawings is reversed, elements or features that are described as below are then above. The terminology comprises the words expressly mentioned above, their derivations and words with similar meanings.
[0057] In order to avoid repetitions in the drawings and the associated description of the different aspects and embodiments, certain features are to be understood as common for different aspects and embodiments. The omission of an aspect in the description or a drawing does not suggest that this aspect is missing in the associated embodiment. Rather, such omissions are made for the sake of clarity and to avoid repetition. In this context, the following stipulation applies to the entire further description: If reference numerals are contained in a figure for the purpose of graphic unambiguity but are not mentioned in the directly associated descriptive text, reference is made to their explanation in preceding figure descriptions. If reference signs are also mentioned in the text of the description relating directly to a figure that are not included in the corresponding figure, reference is made to the preceding and following figures. Similar reference signs in two or more drawings represent similar or identical elements.
[0058] In FIG. 1 a perspective view of a first embodiment of the synchronizing mechanism 1 according to the invention for a chair, in particular an office chair, is illustrated. The synchronizing mechanism 1 comprises a base part 5 with a receptacle 11 for a column of a chair as well as two side parts 5a and 5b. At the rear end of the side parts 5a and 5b, an articulated connection is provided with the side parts 2a and 2b of a backrest support 2, which serves to hold a backrest, wherein the articulated connection comprises the fixed first pivot D1. In the front area of the two side parts 2a and 2b of the backrest support 2, a U-profile-shaped seat support 3 is articulated with its two side parts 3a and 3b, wherein this articulated connection includes the movable second pivot D2. The second pivot D2 is thus fixed relative to the backrest support 2 and can be moved essentially vertically upwards with the backrest support 2. The U-profile-shaped seat support 3 is arranged essentially centrally on the underside of a seat plate 4. With the inner surface of its upper side 7, the U-profile-shaped seat support 3 rests on a sliding block 6, which is rotatably mounted between two tab-like projections 5c and 5d of the base part 5 and which serves as a seat stabilizer and as a seat support pivot, i.e. for tilting the seat support 3 with the seat plate 4 forwards in the seat direction. In the synchronizing mechanism 1 according to the invention, the side parts 3a and 3b of the seat support 3 are arranged on the outside and the two side parts 5a and 5b of the base part 5 are arranged on the inside and the two side parts 2a and 2b of the backrest support 2 are arranged in between. The individual movement sequences of the synchronizing mechanism 1 according to the invention are described in detail below.
[0059] FIG. 2 shows a side sectional view of the first embodiment of the synchronizing
[0060] mechanism 1 according to the invention in the basic position with horizontal seat support 3 and correspondingly horizontal seat plate 4. The basic position comprises the basic state of a corresponding chair in which the movable second pivot D2 is in its lowest position, i.e. its lower basic position, and the seat support 3 with the seat plate 4 is in a non-tilted, i.e. in this case horizontal, state. The fixed first pivot D1 and the movable second pivot D2 are located approximately at the same height but at different ends of the axis of rotation X, with the fixed first pivot D1 on the rear end being routinely slightly further away from the axis of rotation X than the movable second pivot D2 on the front end. The U-profile-shaped seat support 3 rests with its inner surface 7a on the sliding block 6, with the sliding block 6 being arranged between the two tab-like projections 5c and 5d of the base part 5 so as to be rotatable about the third pivot D3. This support area of the seat support 3 on the sliding block 6 comprises the support point P of the support structure A, which is formed here by the tab-like projections 5c and 5 as well as by the sliding block 6. The user must overcome the support structure A if he wants to get from the basic position of the synchronizing mechanism to a first intermediate position, which is explained below. The support point P (and also the third pivot D3) is routinely located, seen in the vertical direction along the axis of rotation X, above the movable second pivot D2 as well as above the fixed first pivot D1 and in the horizontal direction further away from the axis of rotation X than the movable second pivot D2 as well as further away from the central axis X than the fixed first pivot (on the rear end) in order to ensure optimal functionality of the mechanism. In this position with the backrest support 2 not deflected, a backward tilting of the seat support 3 with the seat plate 4 is prevented by the lower transverse connection 13 of the seat support 3, which here rests on the front lower edge 14 of the backrest support 2 or its side parts.
[0061] FIG. 3 now shows a side sectional view of the first embodiment of the synchronizing mechanism 1 according to the invention in a first intermediate position with the seat support 3 tilted forwards and the seat plate 4 tilted forwards. For this movement, a shift of the user's weight on the seat plate 4 is routinely required in order to overcome the support structure A, i.e. to perform a rotation of the seat support 3 about the fixed third pivot D3. During this movement or due to the shift in weight, the movable second pivot D2 is pivoted together with the backrest support 2 essentially vertically upwards, which also leads to a slight backward inclination of the backrest support 2 (and possibly of a corresponding backrest). The forward inclination or forward tipping of the seat support 3 with the seat plate 4 is limited by the front bevel 12 of the backrest support 2.
[0062] In FIG. 4 a side sectional view of the first embodiment of the synchronizing mechanism 1 according to the invention in a second intermediate position with a raised and essentially horizontal seat support 3 is illustrated. For this second intermediate position, the user must lean back from the basic position, in which case the backrest support 2 or its front part will be pivoted upwards about the fixed first pivot D1 so far that the movable second pivot D2 moves accordingly further upwards into a second intermediate position. The inner surface 7a of the U-profile-shaped seat support 3 moves correspondingly upwards away from the support structure. Here, the backrest support 2 is with its front lower edge 14 out of contact with the lower transverse connection 13 of the seat support 3, but is not yet in contact with the inner surface 7a of the seat support 3 with its beveled front end 12. The second intermediate position represents a quasi-flexible transition position of the synchronizing mechanism 1 on its way to the end position (highest position of the second pivot D2) according to the following FIG. 5, and possibly back to the basic position according to FIG. 2.
[0063] In the second intermediate position according to FIG. 4, the angle of the seat support 3 and the seat plate 4 can be controlled without any guide, i.e. without supporting guide rods or other guide elements, solely and directly by the lower legs of the user and not necessarily by the mechanism. Here, due to its albeit limited pivotability, the seat plate 4 adapts ideally to the user, thereby generating a specially optimized seating comfort.
[0064] FIG. 5 shows a side sectional view of the first embodiment of the synchronizing mechanism 1 according to the invention in the end position, in which the seat support 3 with the movable second pivot D2 is in the highest position or the upper end position of the movable second pivot D2. Here, the second pivot is located approximately above the upper edge 10 of the base part 5 or above its side parts. As the user leans back further, the beveled front end 12 of the backrest support 2 will have been pivoted even further upwards about the fixed first pivot D1 compared to the second intermediate position according to FIG. 4, with the beveled end 12 of the backrest support 2 or of its side parts coming into contact with the inner surface 7a of the U-profile-shaped seat support 3 and abutting it. The backrest support 2 is now with its beveled front end 12 in surface contact with the inner surface 7a of the seat support 3, so that the seat support 3 with the seat plate 4 is supported by the beveled front end 12 of the backrest support 12 in an essentially horizontal orientation. In this upper end position of the movable second pivot D2, the seat support 3 can now be rotated about the latter, with the contact with the beveled front end 12 (first limiting means) of the backrest support 2 preventing the seat support 3 with the seat plate 4 from tipping forwards out of the horizontal when leaning back into the end position of the backrest support 2 shown here, which could potentially lead to the user slipping in an undesirable manner on the chair.
[0065] On the other hand, however, the user can cause the seat support 3 with the seat plate 4 to tilt backwards from the end position of the synchronizing mechanism 1 according to FIG. 5 by shifting his weight backwards on the seat plate 4, although, as shown in FIG. 6, the backrest support 2 and the movable second pivot D2 no longer change their position. This backward tilting is limited by the front lower edge 14 (second limiting means) of the backrest support 2 or by its side parts against which the seat support 3 comes to rest with its lower transverse connection 13. In other words, in the end position, a maximum pivotability or a maximum rotatability of the seat support about the pivot D2 is provided, namely between the beveled front end 12 of the backrest support 2 as the first limiting means, which limits a tilting of the seat support 3 from the horizontal forwards, and the lower front edge 14 of the backrest support 2 as the second limiting means, which limits a tilting of the seat support backwards (i.e. in that the lower transverse connection 13 of the seat support 3 comes to abutment here). In the final position with the seat support 3 tilted backwards, the seat plate 4 is essentially parallel to the backrest support 2. In the backwards tilted end position, the seat plate 4 assumes a maximum tilt angle perpendicular to the axis of rotation X, as illustrated in FIG. 6.
[0066] In FIG. 7 a side sectional view of the second embodiment of the synchronizing mechanism 1 according to the invention in the basic position is now shown. In the second embodiment of the synchronizing mechanism according to the invention, the side parts of the seat support 3 are also arranged on the outside and the two side parts of the base part 5 are arranged on the inside. The two side parts of the backrest support 2 are arranged in between. In this second embodiment, however, the side parts of the backrest support 2 have a slotted guide 8 which has a guide slot 9 which is convexly curved upwards and in which guide pins 11a, 11b, which movably connect the seat support 3 to the backrest support 2, are guided. The guide slot 8 itself has a corresponding upwardly convex curvature like the guide slot 9. The seat support 3 rests with the inner surface 7a on the upper side of the slotted guide 8 (support point P of the support structure A, which is formed here by the slotted guide 8). At the rear end of the side parts of the base part 5, an articulated connection with the side parts of the backrest support 2 is again provided, which comprises the fixed first pivot D1. The movable second pivot D2 is designed here as a notional pivot, which lies outside the synchronizing mechanism 1, namely as the pivot of the seat support 3, which moves with the backrest support 2 from the basic position essentially vertically upwards, i.e. here also slightly laterally forwards (due to the mobility of the seat support or its guide pins 11a, 11b in the guide slot 9), which results in an upwardly curved movement path of the movable second pivot D2. The individual movement sequences of the second embodiment of the synchronizing mechanism according to the invention are described in detail below.
[0067] In the basic position of this embodiment, the seat support 3 and the seat plate 4 are slightly inclined backwards relative to the axis of rotation X. However, the basic position also includes the basic state of a corresponding chair in which the movable second pivot D2 is in its lowest position, i.e. its lower basic position, and the seat support 3 with the seat plate 4 is in a non-tilted state, i.e. here slightly tilted backwards. The rear guide pin 11b of the seat support 3 abuts the rear end of the guide slot 9, which initially prevents a further or stronger backward tilt, and the front guide pin 11a abuts the stopping point H in the region of the front end of the base part 5. At the stopping point H, in the basic position, the curvature of the guide slot 9 together with the upper edge 10 of the base part 5 basically prevents a forward/tilting movement of the seat support 3 and the seat plate 4. Here too, a shift in the user's weight on the seat plate 4 is necessary in order to overcome the support structure A (and the stopping H) if the user wants to move from the basic position of the synchronizing mechanism 1 to a first intermediate position, which is explained below. The movable second pivot D2 is located below the fixed first pivot D1. The two pivots D1 and D2 are located at different ends of the axis of rotation X, with the fixed first pivot D1 on the rear end routinely being somewhat closer to the axis of rotation X than the movable second pivot D2 on the front end.
[0068] FIG. 8 now shows a side sectional view of the second embodiment of the synchronizing mechanism 1 according to the invention in the first intermediate position with the seat support 3 tilted forwards, wherein the seat support and the seat plate 4 move from the slightly backwards inclined position to an essentially horizontal orientation when tilted. As mentioned, this forward/tilting movement requires the user to shift his weight on the seat plate 4 in order to overcome the support point P (and the stopping point H). During this weight shift, the movable second pivot D2 is pivoted together with the backrest support 2 essentially vertically upwards, which correspondingly also leads to a slight backward inclination of the backrest support 2 and to a gradual lifting of the curved guide slot 9 relative to the base part 5. In this way, the front guide pin 11a can move approximately to the front edge 15 of the base part 5 but not beyond that, because further movement is blocked by the curvature of the guide slot 9 in interaction with the base part 5. This blocking at the stopping point H can be removed by a further raising of the seat support 3.
[0069] In FIG. 9 a side sectional view of the second embodiment of the synchronizing mechanism 1 according to the invention in a second intermediate position with a raised and essentially horizontal or slightly backwards inclined seat support 3 is illustrated. For this second intermediate position, the user must lean back from the basic position, in which case the backrest support 2 or its front part is pivoted upwards about the fixed first pivot D1 so far that the movable second pivot D2 moves further upwards into a second intermediate position. In the process, the guide slot 9 with the guide pins 11a and 11b is lifted upwards away from the base part 5 together with the seat support 3 and the seat plate 4 and at the same time the guide pins 11a and 11b of the seat support 3 move laterally a little way forwards in the guide slot 9 of the slotted guide 8, whereby, however, the front guide pin 11a does not yet come to abut the front end 9a of the guide slot 9. The second intermediate position represents a flexible transition position of the synchronizing mechanism 1 on the way to the end position according to the following FIG. 10 (and possibly back to the basic position according to FIG. 7).
[0070] In the second intermediate position according to FIG. 9, the angle of the seat support 3 and the seat plate 4 can be controlled by the user's lower legs and not necessarily by the mechanism, in contrast to conventional synchronizing mechanisms. Here, the seat plate 4 adapts to the user through its albeit limited pivotability, thereby generating a special seating comfort.
[0071] FIG. 10 shows a side sectional view of the second embodiment of the synchronizing mechanism 1 according to the invention in the end position, in which the seat support 3 with the movable second pivot D2 is in the highest position or its upper end position, in which the movable second pivot D2 is located slightly below the front edge 15 of the base part 5 or of its side parts. By leaning back further with a corresponding shift of the user's weight, the front part of the backrest support 2 with the slotted guide 8 has been raised further upwards and tilted backwards compared to the second intermediate position according to FIG. 9. At the same time, the seat support 3 with the seat plate 4 together with the guide pins 11a and 11b has moved laterally forwards, i.e. until the front guide pin 11a abuts the front end 9a of the guide slot 9. The seat support 3 and the seat plate 4 have retained their slight backward inclination in which they are supported here. In this upper end position of the movable second pivot D2, the seat support 3 can now be freely rotated about it or moved in the guide slot, wherein, however, by the front guide pin 11a abutting the front end 9a (first limiting means) of the guide slot 9, when leaning back into the end position of the back rest 2 shown here, the seat support 3 with the seat plate 4 is prevented from simultaneously tipping further forwards from the horizontal, which could possibly lead to the user slipping off the chair.
[0072] In this respect, the user can still cause the seat support 3 with the seat plate 4 to tilt backwards from the end position of the synchronizing mechanism 1 according to FIG. 10 by shifting his weight backwards on the seat plate, wherein, however, as shown in FIG. 11, the backrest support and the movable second pivot D2 no longer change their position. This backwards tilting is correspondingly limited by the rear end 9b (second limiting means) of the guide slot 9, against which the seat support 3 with the rear guide pin 11b comes to abutment. In other words, in the end position, there is a maximum pivotability or a maximum rotatability or mobility of the seat support 3 around the pivot D2 between the front end 9a of the guide slot 9 as the first limiting means, which limits tilting forward of the seat support 3 from the slight backwards inclination, and the rear end 9b of the guide slot 9 as the second limiting means, which limits tilting backward of the seat support 3 (i.e. by the rear guide pin 11b of the seat support 3 coming to abutment here). In the backwards tilted end position, the seat plate 4 is essentially parallel to the backrest support 2. In the backwards tilted end position, the seat plate 4 assumes a maximum tilt angle perpendicular to the axis of rotation X (or a maximum inclination), as illustrated in FIG. 11.
[0073] From the above explanations it is clear that by means of the synchronizing mechanism according to the invention, not only according to the first but also according to the second embodiment, the user can carry out a practically fluid adjustment of a corresponding chair solely on the basis of his body posture and/or his muscle strength without the need for further support or return elements. Nevertheless, the use of such elements in connection with the synchronizing mechanism according to the invention is fundamentally possible.
List of Reference Signs
[0074] 1 synchronizing mechanism [0075] 2 backrest support [0076] 2a, b side parts [0077] 3 seat support [0078] 3a, b side parts [0079] 4 seat plate [0080] 5 base part [0081] 5a, b side parts [0082] 5c, d tab-like projections [0083] 6 sliding block [0084] 7 upper side of seat support [0085] 7a inner surface of upper side of seat support [0086] 8 slotted guide [0087] 9 guide slot [0088] 9a front end guide slot [0089] 9b rear end guide slot [0090] 10 upper edge of base part [0091] 11a, b guide elements of seat support [0092] 11 receptacle for column [0093] 12 beveled front end of backrest support [0094] 13 lower transverse connection of seat support [0095] 14 front lower edge of backrest support [0096] 15 front edge of base part [0097] A, A support structure [0098] P, P support point [0099] D1 fixed first pivot [0100] D2, D2 movable second pivot [0101] D3 third pivot (sliding block) [0102] H stopping point [0103] X axis of rotation [0104] max. tilt angle
