Tilting mechanism for chair

Abstract

A reclining mechanism for a chair includes a base (10), a backrest support (12) configured to support a chair back (104), a seat support (11) configured to support a seat (103), a first link element (30), a second link element (20), a spring element (40), and a forward-leaning sitting position adjustment element (50). A first end (31) of the first link element (30) is pivotally coupled to the base (10). A first end (21) of the second link element (20) is pivotally coupled to the backrest support (12) and a second end (22) of the second link element (20) is coupled to a second end (32) of the first link element (30). A first end (41) of the spring element (40) is mounted at the base (10) and a second end (42) of the spring element (40) pushes against the first link element (30) at an adjustable position between the first end (31) and the second end (32) of the first link element (30). The forerake seating position adjustment element (50) is movable between a first position and a second position. When the forward leaning sitting posture adjustment element (50) is in the first position, the spacer (51, 52) of the forward leaning sitting posture adjustment element (50) is arranged between the stop surface (24) of the second end (22) of the second link element (20) and the stop surface (17) of the base (10) so as to maintain a predetermined minimum distance (18) between the stop surface (24) of the second end (22) of the second link element (20) and the stop surface (17) of the base (10). When the forward leaning sitting posture adjustment element (50) is in the second position, the spacer (51, 52) of the forward leaning sitting posture adjustment element (50) is not arranged between the stop surface (24) of the second end (22) of the second link element (20) and the stop surface (17) of the base (10), allowing the stop surface (24) of the second end (22) of the second link element (20) to contact the stop surface (17) of the base (10).

Description

Technical Field

[0001] The present invention relates to a tilt mechanism for a chair. In particular, the present invention relates to a tilt mechanism for a chair having a seat and a backrest, wherein the tilt mechanism allows the seat to be displaced and the backrest to be tilted in a coordinated manner. The present invention also relates to a chair comprising a tilt mechanism. Background Art

[0002] For chairs, especially office chairs, common adjustments include seat height adjustment, seat and back tilt adjustment, and seat relative to back arrangement. These chair adjustments allow users to change their sitting position in the chair as needed, so as to minimize fatigue during long periods of sitting.

[0003] The chair may be constructed to implement features that allow the back and seat to move simultaneously during a tilt or recline motion of the back. The seat may also tilt during this motion, or may be otherwise displaced relative to the chair base or back. The combined motion of the back and seat may simplify adjustment of the chair.

[0004] For example, when a user leans back on the chair back and tilts the chair back and seat backward, the spring mechanism can be tensioned to push the chair back and seat forward in the initial position. The force with which the spring mechanism pushes the chair back and seat in the forward direction can be adjustable, for example to take into account the weight of the user. Adjusting this force can be burdensome, especially when the mechanism for adjusting this force changes the bias of the spring mechanism, which may be very high. For example, a screw-based rotation mechanism can be used, which causes one end of the spring of the spring mechanism to move in the longitudinal direction of the spring, that is, in the direction of the spring force. Due to the large spring force, several turns may be required to complete the entire adjustment range, for example, 20 turns or more may be required, and the rotation still requires a large torque.

[0005] Furthermore, it has been found that tilting the seat in a forward direction, i.e. in a position where the rear of the seat is higher relative to the ground than the front of the seat, is advantageous for reducing fatigue during prolonged sitting. However, in any case a simple and reliable way of resetting the seat to the initial horizontal position may be desired.

[0006] Finally, a compact, reliable and cost-effective mechanism design that provides the above-mentioned features may be desired. Summary of the invention

[0007] There is a need in the art for a chair tilt mechanism and a chair that can meet some of the above requirements. In particular, there is a need in the art for a chair tilt mechanism that has a simple and reliable structure and is easily adaptable to different chair requirements.

[0008] According to the invention, these needs are met by a tilt mechanism for a chair and a corresponding chair as defined in the independent claims. Embodiments are defined in the dependent claims.

[0009] According to one embodiment, a tilt mechanism for a chair is provided. The tilt mechanism is configured to affect the coordinated movement of a seat and a backrest. The tilt mechanism includes a base, a backrest support, a seat support, a first link element, a second link element, a spring element, and a forward tilt posture adjustment element. The base can be regarded as a frame for supporting the remaining components. The base can be connected to a chair base assembly, which includes a base column and a plurality of support legs for placing the chair on the ground. The backrest support is configured to support the backrest and is pivotally connected to the base. The seat support is configured to support the seat and is pivotally connected to the backrest support. The pivot axis of the backrest support connected to the base can be different from the pivot axis connecting the seat support and the backrest support. Therefore, the seat can be tilted relative to the backrest in a coordinated manner. The first link element, the second link element, and the spring element constitute a mechanism for providing an adjustable restoring force, which acts on the backrest support and thus indirectly acts on the seat support. To this end, the first end of the first link element is connected to the base in a pivotable manner, and the first end of the second link element is connected to the backrest support in a pivotable manner. The second end of the second link element is connected to the second end of the first link element. The first end of the spring element is mounted at the base, and the second end of the spring element is mounted at the first link element, so that the spring element pushes against the first link element at an adjustable position between the first end and the second end of the first link element. Therefore, when the backrest support is tilted, the second link element can pivot the first link element, which pushes against the spring element. Since the contact position between the spring element and the first link element is adjustable, the length of the lever arm acting on the spring element is adjustable, thereby changing the restoring force. In order to reposition the second end of the spring element along the first link element between the first end and the second end of the first link element, a relatively small force is required, so that the adjustment of the restoring force can be performed with a small force, that is, the adjustment of the restoring force can be performed easily and quickly by the user.

[0010] In addition, the tilt mechanism comprises a forward tilting posture adjustment element, which is movable between a first position and a second position. When the forward tilting posture adjustment element is in the first position, a spacer of the forward tilting posture adjustment element is arranged between a stop surface of the second end of the second link element and a stop surface of the base, thereby maintaining a predetermined minimum distance between the stop surface of the second end of the second link element and the stop surface of the base. When the forward tilting posture adjustment element is in the second position, the spacer of the forward tilting posture adjustment element is not arranged between the stop surface of the second end of the second link element and the stop surface of the base, thereby allowing the stop surface of the second end of the second link element to move into contact with the stop surface of the base. By changing the stop position of the second link element relative to the base, the forward tilting of the seat support can be easily and quickly achieved or prohibited. Changing the sitting position between the basic horizontal arrangement of the seat and the forward tilting arrangement of the seat is ergonomically advantageous. Since this forward tilting function uses the second link element, the additional investment in terms of cost and space requirements may be low. Furthermore, since the second linkage element is pretensioned by the spring element via the first linkage element, a restoring force is provided in both positions, ie the forwardly inclined position and the non-forwardly inclined position, ie the initial horizontal position.

[0011] According to various examples, the tilt mechanism can be constructed as follows. When the backrest support moves from the first position to the second position, the seat support also tilts to a rearwardly tilted position. This coordinated movement can be provided by the connection between the seat support and the backrest support. The first link element and the second link element cause the spring element to be compressed when moving from the first position to the second position. Therefore, a restoring force is generated that pushes the backrest support to the first position. In the first position of the backrest support, the chair back is in a substantially upright position, and in the second position of the backrest support, the chair back is in a rearwardly tilted position.

[0012] The position at which the second end of the spring element pushes against the first link element is adjustable. For example, adjusting this position can change the effective length of the first link element acting on the spring element when the backrest support moves between the first position and the second position. As a result, the restoring force that forces the backrest support to be in the first position can be varied. Thus, the restoring force can be adjusted without changing the preload of the spring element. Changing the preload of the spring element usually requires the user to apply a large amount of force or work. This can be avoided by repositioning only the second end of the spring element relative to the first link element.

[0013] In another example, the reclining mechanism can be configured such that in the substantially upright position of the chair back, the length of the spring element depends on the adjustable position of the second end of the spring element against the first link element. For example, when the second end of the spring element is closer to the second end of the first link element, the length of the spring element can be longer than the length of the spring element when the second end of the spring element is closer to the first end of the first link element. Therefore, adjustment in one direction (e.g., from the first end to the second end of the first link element) may require less force or torque to be applied by the user than adjustment in the opposite direction (e.g., from the second end to the first end of the first link element). Feedback can be provided to the user as to whether the restoring force is increased or decreased. However, when the effective length of the first link element changes, the preload of the spring element changes only slightly, so the force or torque required for adjustment can be moderate compared to changing only the preload of the spring element.

[0014] For example, a portion of the base, a portion of the first link element and the spring element can be arranged in a triangle. The vertices of the triangle can be defined by the first pivot axis, the mounting point and the push-on point. At the first pivot axis, the first end of the first link element is pivotally connected to the base, at the mounting point, the first end of the spring element is mounted at the base, and at the push-on point, the second end of the spring element pushes against the first link element. The geometry of the triangle depends on the adjustable position. The tension adjustment thus changes the geometry and the preload on the spring.

[0015] According to one embodiment, in order to adjust the connection position between the spring element and the first link element, the tilt mechanism may include a threaded bolt engaged with a nut. The nut is fixed to the second end of the spring element. The threaded bolt can be installed at the first link element. When the threaded bolt is rotated, the position between the first end and the second end of the first link element is adjusted, at which position the second end of the spring element pushes against the first link element. For example, the threaded bolt can be driven by a user handle via a bevel gear device. The threaded bolt and the bevel gear device can be configured so that by turning the user handle a few times, for example 4 to 6 times, the nut moves from the first end of the first link element to the second end, or from the second end of the first link element to the first end. The restoring force of the chair back can be adjusted quickly and accurately with almost no effort.

[0016] In addition, the tilt mechanism may include a ratchet, which is coupled to the threaded bolt so that the ratchet rotates with the threaded bolt. The ratchet is provided with a plurality of ratchet tooth structures. The tilt mechanism may include at least one pawl member that cooperates with the ratchet tooth structure. The pawl member engages with the ratchet. The pawl member may be attached to the first link element. The pawl member may elastically engage the ratchet tooth structure of the ratchet so that the ratchet remains in the pawl member step without hindering the rotation of the ratchet. The ratchet combined with the pawl member can provide feedback to the user while adjusting the restoring force, and can also help avoid accidental adjustment caused by the restoring force of the spring element. A plurality of pawl members may be provided, for example, two pawl members arranged in relative positions relative to the circumference of the ratchet. Two or more pawl members arranged at equally spaced positions around the circumference of the ratchet can help align, hold and center the ratchet.

[0017] According to various embodiments, the tilt mechanism can be configured such that when the forward tilt posture adjustment element is in the first position and the stop surface of the second end of the second link element contacts the spacer of the forward tilt posture adjustment element, the back support and the seat support are arranged in a first layout. When the forward tilt posture adjustment element is in the second position and the stop surface of the second end of the second link element contacts the stop surface of the base, the back support and the seat support are arranged in a second layout. In the second layout, the seat support is tilted in a forward direction relative to the second layout. In the first layout, the seat support is arranged to be basically in a non-tilted arrangement, for example, a basically horizontal position. In the second layout, the seat support is arranged to be in a forward tilted arrangement, for example, tilted at least 3 degrees or 4 degrees in the forward direction relative to the first layout. Tilting the seat support forward means that the front of the seat support is lower than the rear of the seat support. Since only the stop position of the second link element is changed when the forward tilt function is activated or deactivated, the adjustment of the restoring force of the back support is basically not affected.

[0018] For example, in the first position of the forward tilting sitting adjustment element, the spring element can push the stop surface of the second end of the second link element through the first link element to contact the spacer of the forward tilting sitting adjustment element. At this time, the forward tilting sitting function is disabled. In the second position of the forward tilting sitting adjustment element, the spring element can push the stop surface of the second end of the second link element through the first link element to contact the stop surface of the base. At this time, the forward tilting sitting function is enabled. In both cases, when the forward tilting sitting function is enabled or disabled, when the chair and the tilting mechanism are unloaded, the seat support is in a defined position, that is, a forward tilting position or a substantially horizontal position without being tilted forward. However, although the spring element places the seat support in a defined position, the adjustment of the restoring force of the backrest support is not affected and can therefore be adjusted independently of the activation or deactivation of the forward tilting sitting function.

[0019] According to another aspect of the present invention, a chair is provided. The chair comprises a chair base assembly, a seat, a chair back and a tilt mechanism as described above. The base of the tilt mechanism is attached to the chair base assembly, the seat is attached to the seat support of the tilt mechanism, and the chair back is attached to the backrest support of the tilt mechanism.

[0020] The tilt mechanism and the chair according to the embodiment can be used in various applications that require the coordinated tilting movement of the chair back and the chair seat. For example, the tilt mechanism of the chair can be used in an office chair. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Embodiments of the present invention will be described with reference to the accompanying drawings.

[0022] Figure 1 is a schematic isometric view of a chair with a tilt mechanism according to one embodiment.

[0023] Figure 2 yes Figure 1 Schematic side view of a chair in a non-reclined position.

[0024] Figure 3 yes Figure 1 Schematic side view of a chair in a reclined position.

[0025] Figure 4 yes Figure 1 Schematic side view of a chair in a forward tilted position.

[0026] Figure 5 is a schematic isometric view of the top side of a tilt mechanism according to one embodiment.

[0027] Figure 6 yes Figure 5 Schematic isometric view of the underside of the tilt mechanism.

[0028] Figure 7 yes Figure 5 Schematic isometric cutaway view of the tilt mechanism.

[0029] Figure 8 yes Figure 5 Schematic cross-sectional side view of the tilt mechanism in a non-tilted position.

[0030] Fig. 9 yes Figure 5 Schematic cross-sectional side view of the tilt mechanism in a rearward tilt position.

[0031] Fig.10 yes Figure 5 Schematic cross-sectional side view of the tilt mechanism in a forward tilt position.

[0032] Fig.11 yes Figure 5 Schematic partial side cross-sectional view of a tilting mechanism of , wherein the tensioning mechanism is in a first setting.

[0033] Fig.12 yes Figure 5 Schematic partial side cross-sectional view of a tilting mechanism with the tensioning mechanism in a second setting.

[0034] Fig.13 yes Figure 5 Schematic isometric cutaway view of the tilt mechanism showing details of the ratchet mechanism of the tensioning mechanism.

[0035] Fig.14 yes Figure 5 Schematic side view of the tilting mechanism in a non-tilted position.

[0036] Fig.15 yes Figure 5 Schematic cross-sectional side view of the tilt mechanism in a forward tilt position.

[0037] Fig.16 yes Figure 5 Schematic isometric view of the front side of the reclining mechanism in a non-reclining position, wherein the forward sitting posture adjustment element is in a first position.

[0038] Fig.17 yes Figure 5 Schematic isometric view of the front side of the tilt mechanism in a forward tilt position, wherein the forward tilt sitting adjustment element is in the second position.

[0039] Fig.18 yes Figure 5 Schematic cross-sectional side view of a reclining mechanism in a non-reclining position, wherein the forward sitting posture adjustment element is in a first position.

[0040] Fig.19 yes Figure 5 Schematic cross-sectional side view of a tilt mechanism in a forward tilt position, wherein the forward tilt posture adjustment element is in a second position.

[0041] Fig. 20 yes Figure 5 Schematic partial isometric sectional view of a reclining mechanism in a non-reclining position, wherein the forward sitting posture adjustment element is in a first position.

[0042] Fig.21 yes Figure 5 A schematic partial isometric sectional view of a tilt mechanism in a forward tilt position, wherein the forward tilt posture adjustment element is in a second position. DETAILED DESCRIPTION

[0043] Exemplary embodiments of the present invention will be described with reference to the accompanying drawings. Although some embodiments will be described in a specific application field, such as an application scenario in an office chair, the embodiments are not limited to the application field. Unless otherwise specifically stated, the features of the various embodiments may be combined with each other. The same reference numerals in the various drawings represent similar or identical components.

[0044] Figures 1 to 4 A chair 101 including a tilt mechanism 100 is shown according to one embodiment. The chair 101 is shown as an office chair having a chair base assembly 102 and an upper structure. The upper structure includes a seat 103, a backrest 104, and components interconnecting the seat 103 with the backrest 104. These components, including the tilt mechanism 100 for achieving coordinated movement of the backrest 104 and the seat 103, will be described in more detail below. The base assembly 102 includes a base column 107, a plurality of support legs 105 extending radially from the base column 107, and a corresponding number of casters 106 supported on the outer ends of the support legs 105. In addition, a cylinder or any other lifting mechanism 108 can be supported by the base column 107 to enable a user to adjust the height of the seat 103, thereby adjusting the height of the chair upper structure.

[0045] It should be understood that the terms "front", "rear", "left", "right", "top" and "bottom" as used herein each have a specific meaning, which is defined relative to a flat support surface below the chair, such as the ground on which the chair is placed, and the situation where a user sits on the chair in a conventional sitting posture. For example, the term "front" refers to the side of the seat where the user's knees are located and the legs are suspended, while the term "rear" refers to the side of the seat where the user's back and the back of the chair are located. The term "left" refers to the left-hand side of the seat from the perspective of a user sitting on the chair, and the term "right" refers to the right-hand side of the seat from the perspective of a user sitting on the chair. The term "bottom" refers to the side facing the flat support surface below the chair, while the term "top" refers to the side facing away from the flat support surface below the chair. It can be assumed that the front-to-back, left-to-right, and up-down directions derived therefrom represent axes of a three-dimensional Cartesian coordinate system, usually referred to as the X-axis, the Y-axis, and the Z-axis, respectively, which are orthogonal to each other. The front-to-back and left-to-right directions can extend in the plane of the flat support surface, and the up-down direction can extend in a direction perpendicular to the flat support surface.

[0046] It should be understood that the terms "forward", "rearward" and "laterally" as used herein also each have a specific meaning defined relative to a flat support surface beneath the chair and relative to a user of the chair. For example, the term "forward" refers to a direction moving away from the seat back and in front of a user of the chair along an axis extending parallel to such flat support surface, while the term "rearward" refers to a direction opposite to the forward direction. The term "laterally" refers to a generally horizontal direction perpendicular to the forward and rearward directions and extending parallel to the above-mentioned flat support surface. For example, the terms "left" and "right" are lateral directions as viewed from a user sitting on the chair.

[0047] Tilting or tilting in a forward direction, such as tilting the seat so that the front side of the seat moves downward and / or the back side of the seat moves upward, can be considered as a rotation about a rotation axis extending in the left-right direction. Tilting or tilting in a rearward direction can be considered as a movement opposite to the tilting or tilting in the forward direction. For example, tilting the backrest in a rearward direction may mean that the upper part of the backrest moves backward relative to the lower part of the backrest.

[0048] Furthermore, it should be understood that the seat, especially when tilted, does not extend precisely only in the front-to-back and left-to-right directions. However, it will be apparent to those skilled in the art that in this tilted state, the seat also substantially extends in the front-to-back and left-to-right directions. Likewise, it should be understood that the chair back does not extend precisely only in the left-to-right and up-down directions, especially when tilted or reclined, but extends substantially in these directions.

[0049] The chair 101 includes a tilt mechanism 100 , which is generally operated to move the seat 103 and the seat back 104 in coordination when the seat back 104 is tilted. Figure 2 The chair 101 is shown in a non-inclined initial position, in which the seat 103 is oriented substantially horizontally, particularly in the front-rear direction. For example, the chair 101 may be automatically in this position when the chair is unloaded, i.e. when no user is sitting on the chair. Figure 3 The rearward tilted position of the chair 101 is shown. For example, the chair may be in this position when a user sits on the chair and leans back, causing the backrest 104 to tilt backward. Due to the action of the tilting mechanism 100, there is a coordinated movement between the backrest 104 and the seat 103. As a result, the seat surface of the seat 103 also tilts backward, i.e., the rear side of the seat surface is lower than the front side. The spring mechanism, which will be described in detail below, is tensioned by the tilting action so that when the user stops pushing the backrest 104 backward, the chair 101 can automatically return to the original position. Figure 2 Initial position shown. Figure 2 The initial position and Figure 3In addition, a locking mechanism may be provided that enables locking at any position between the initial position and the rearward tilted position, thereby maintaining the chair 101 in the corresponding intermediate position even when the user no longer applies a load to the chair back 104. However, when the locking mechanism is unlocked, the chair 101 can be in the initial position again.

[0050] The tilt mechanism 100 also includes another device, which will be referred to as a forward tilt sitting device (FSD) hereinafter. The FSD allows the chair 101 to be adjusted to another initial position, namely a forward tilted position. Figure 4 In this forward tilted position, the seat surface of the seat 103 is tilted forward, that is, the front of the seat surface is lower than the rear of the seat surface. Due to the coordinated movement between the seat back 104 and the seat 103, Figure 2 Compared to the initial position shown, the seat back 104 is in a steeper position. Figure 4 As shown, the backrest 104 is nearly vertical. The chair 101 is selectively positioned by adjusting the FSD, such as by a control element or handle. Figure 2 non-tilted position shown or Figure 4 The forward tilted position shown serves as an initial position, and the chair automatically assumes this initial position when the user no longer pushes the chair back 104 backward.

[0051] like Figures 2 to 4 As particularly shown, the tilt mechanism 100 includes a base 10. In the installed state of the tilt mechanism 100, the tilt mechanism 100 is assembled to the chair 101, and the base 10 is connected to the base column 107 by the lifting mechanism 108. The tilt mechanism 100 includes a seat support 11, which is connected to the seat 103 and supports the seat 103 at the lower side of the seat 103 in the installed state of the tilt mechanism 100. The seat support 11 is connected to the base 10. The seat support 11 can be mounted to the base 10 so that it can be displaced in the front-to-back direction relative to the base 10 and / or pivotally mounted around a transverse axis. The seat 103 can be fixedly connected to the seat support 11, so that the translation or rotation movement of the seat support 11 causes the seat 103 to move in a translation or rotation manner together with the seat support 11. The tilt mechanism 100 includes a backrest support 12, which is connected to the chair back 104 in the installed state of the tilt mechanism 100. The seat back 104 can be attached to the back support 12 using a suitable connection member 109, such as a rod or bridge that is fixed to the back support 12. The connection member 109 can be directly and securely attached to the back support 12.

[0052] The tilt mechanism 100 is configured such that the back support 12 is pivotably coupled to the base 10, thereby allowing the back support 12 to pivot relative to the base 10. For example, Figure 5 , Figure 6 and Figure 8 As can be seen in the figure, the back support 12 can be connected to the base 10 via a pivot 14. The seat support 11 is connected to the back support 12 in a pivotable manner. Figure 6 As shown, the seat support 11 may be coupled to the base 10 via a slidable pivot 15 .

[0053] For example, Figure 7 and Figure 8 As shown, a first link element 30 and a second link element 20 are provided for tensioning the spring element 40. Furthermore, the second link element 20 defines a stop for an initial position of the chair 101, which will be described below in conjunction with the FSD.

[0054] First end 31 of first linkage element 30 is pivotally coupled to base 10, for example, via pivot 33. First end 21 of second linkage element is pivotally coupled to back support 12, for example, via pivot 23. Second linkage element 20 may have a U-shape, with the legs extending in the front-to-back direction and the base extending in the lateral direction. Figure 7 In FIG. 2 , only one leg of the U-shape is visible, and the base of the U-shape forms second end 22 of second linkage member 20. Second end 22 of second linkage member 20 is coupled to second end 32 of first linkage member 30. Figure 7 and Figure 8 As shown, second end 22 of second linkage member 20 may be coupled to second end 32 of first linkage member 30 via curved contact and sliding surface 36. When back support 12 is tilted in the rearward direction relative to base 10, second linkage member 20 is substantially moved in the rearward direction relative to base 10, and first end 22 of second linkage member 20 pushes second end 32 of first linkage member 30, causing first linkage member 30 to rotate about pivot 33. For example, as Figure 7 As shown, second linkage member 20 may extend substantially in the front-to-rear direction from first end 21 to second end 22, while first linkage member 30 may extend substantially in the top-to-bottom direction from first end 31 to second end 32. In other words, the angled arrangement of first linkage member 30 relative to second linkage member 20 allows translational motion of second linkage member 20 to be converted into rotational motion of first linkage member 30.

[0055] The tilt mechanism includes a tensioning mechanism including a spring element 40. The spring element 40 may include, for example, one or more coil springs. A first end 41 of the spring element 40 is mounted on the base 10, and a second end 42 of the spring element 40 pushes against the first link element 30 at an adjustable position between the first end 31 and the second end 32 of the first link element 30. The mechanism for adjusting the position of the spring element 40 pushing against the first link element 30 will be combined with Figures 8 to 13 Describe in more detail.

[0056] As described above, the tilt mechanism includes a FSD. Figures 14 to 21 Described in more detail, the FSD includes a forward tilt sitting posture adjustment element 50, which can be Fig.16 The first position shown is Fig.17 The forward sitting posture adjustment element 50 is movable between the second position shown. The forward sitting posture adjustment element 50 includes one or more spacers. In the example shown, the forward sitting posture adjustment element 50 includes two spacers 51 and 52. When the forward sitting posture adjustment element 50 is in the first position, the spacers 51 and 52 are arranged between the stop surface 24 of the second end 22 of the second link element 20 and the stop surface 17 of the base 10, thereby maintaining a predetermined minimum distance between the stop surface 24 of the second end 22 of the second link element 20 and the stop surface 17 of the base 10. When the forward sitting posture adjustment element 50 is in the second position, the spacers 51, 52 of the forward sitting posture adjustment element 50 are not arranged between the stop surface 24 of the second end 22 of the second link element 20 and the stop surface 17 of the base 10, thereby allowing the stop surface 24 to contact the stop surface 17.

[0057] Thus, when the chair 101 is in an unloaded state, i.e., when no one is sitting on the chair, for example, the spring element 40 pushes the backrest 104 in an upright position via the first link element 30, the second link element 20 and the backrest support 12. Due to the connection between the seat 103 and the backrest 104, the seat 103 is pushed in a substantially horizontal or "middle" initial position. However, depending on the position of the forward sitting position adjustment element 50, the front stop position of the second link element 20 and therefore the position of the seat 103 may change. In the first position of the forward sitting position adjustment element 50, the seat 103 may actually be in a substantially horizontal position, while in the second position of the forward sitting position adjustment element 50, the seat 103 may be slightly tilted in the forward direction relative to the substantially horizontal position when the forward sitting position adjustment element 50 is in the first position, for example by a few degrees, such as 3° or 4° or 5°. When, for example, the user sits on the chair 101 and tilts the chair back 104 backward, the spring element 40 is compressed (tensioned) by the movement of the first link element 30 and the second link element 20. Since the position at which the spring element 40 pushes against the first link element 30 is adjustable, the effective length of the lever arm provided by the first link element 30 can be varied, so that the restoring force applied by the spring element 40 can be adjusted to meet the needs of the user.

[0058] In detail, Figures 8 to 10 Schematic cross-sectional side views ( Figure 8 ), a schematic cross-sectional side view of the tilt mechanism 100 in a rearward tilted position ( Fig. 9 ) and a schematic cross-sectional side view of the tilt mechanism 100 in an initial forward tilt position ( Fig.10 When a user sits on the chair 101 and leans back on the chair back 104, the back support 12 pivots about the pivot 14 in the rearward direction ( Figure 8 and Fig. 9 The seat support 11 is connected to the back support 12 by a pivot 16. When the back support 12 pivots in the rearward direction, the pivot 16 moves rearward and downward, which causes the seat support 11 to tilt in the rearward direction. The slidable pivot 15 (see Figure 6 ) enables the seat support 11 to perform such tilting and sliding movements.

[0059] The tension mechanism of the tilt mechanism 100 functions as follows. When, for example, the user leans back on the seat back 104 to pivot the back support 12 in the rearward direction, the second link element 20 is connected to the seat back 104 by the pivot shaft 23 (see FIG. Figure 7) and is pulled in the rearward direction. The second end 22 of the second link member 20 pushes against the second end 32 of the first link member 30, thereby causing the first link member 30 to pivot about the pivot 33 in the rearward direction. Therefore, the spring member 40 is compressed and pushes the seat back 104 in the forward direction, see Fig. 9 The seat 103 and the seat back 104 move together in a coordinated manner.

[0060] When the user releases the backrest 104, the backrest 104 moves forward and the seat 103 returns to the horizontal position. Figure 8 Depending on the position of the forward sitting posture adjustment element 50, the spacers 51, 52 are either located between the stop surface 24 of the second end 22 of the second link element 20 and the stop surface 17 of the base 10, or are not located between the stop surface 24 of the second end 22 of the second link element 20 and the stop surface 17 of the base 10. Figure 8 In the embodiment, there are spacers 51, 52, and the spacers 51, 52 maintain the distance 18 between the stop surface 24 and the stop surface 17, so that the seat support 11 is in a substantially horizontal position. Fig.10 In the embodiment, the spacers 51, 52 are absent and the stop surface 24 is in contact with the stop surface 17, so that the seat support 11 is in a forwardly tilted position. It should be noted that the spring element 40 is preloaded so that even in Fig.10 In the forward tilted position shown, there is also a force pressing the stop surface 24 against the stop surface 17 .

[0061] Reference Fig.11 and Fig.12 The coupling of the spring element 40 to the first linkage element 30 is described in more detail. A threaded bolt 34 extending from the first end 31 to the second end 32 is arranged along the length of the first linkage element 30. The threaded bolt 34 can be rotatably coupled to the first linkage element 30. A nut 35 is mounted at the second end 42 of the spring element 40 and engages with the threaded bolt 34. When the threaded bolt 34 is rotated, the position of the nut 35 can be changed between the first end 31 and the second end 32 of the first linkage element 30. As an example, Fig.11 As shown, the nut 35 can be positioned near the first end 31. As another example, Fig.12As shown, the nut 35 can be positioned near the second end 32. Generally, the nut 35 can be located at any position between the first end 31 and the second end 32. By changing the position of the nut 35 along the first link member 30, the position of the second end 42 of the spring member 40 against the first link member 30 is adjusted. In this arrangement, the first link member 30 can be considered to compress the lever arm of the spring member 40 when rotating about the pivot 33. By adjusting the position of the second end 42 of the spring member 40 against the first link member 30, the effective length of the lever arm of the first link member 30 is adjusted. Therefore, the restoring force that pushes the seat back 104 in the forward direction is changed. For example, when the nut 35 is closer to the first end 31 of the first link member 30, the restoring force is smaller than when the nut 35 is closer to the second end 32 of the first link member 30 because when the seat back 104 moves from the non-recline position to the rearwardly reclined position, the spring is compressed more when the nut 35 is closer to the second end 32 of the first link member 30.

[0062] For example, combined with Figure 8 from Fig.11 and Fig.12 As can be seen in the figure, a "triangle" is formed by the spring element 40, a portion of the base 10 and the effective length of the first link element 30. The vertices of the triangle are defined by the pivot 33, the mounting point and the push-on point. At the pivot 33, the first end 31 of the first link element 30 is pivotally connected to the base 10. At the mounting point, the first end 41 of the spring element 40 is mounted on the base 10. At the push-on point, the second end 42 of the spring element 40 pushes against the first link element 30. The geometry of the triangle depends on the adjustable position at which the second end 42 of the spring element 40 pushes against the first link element 30. When the position of the chair back 104 and the seat 103 changes between the rearwardly tilted position, the non-tilted position and the forwardly tilted position, the change in the geometry of the triangle changes the characteristics of the restoring force.

[0063] It should be noted that when adjusting the position of the nut 35, the length of the spring element 40 does not change significantly, so that no great force is required to adjust the position of the nut 35. This enables easy and quick adjustment of the restoring force.

[0064] For example, Figure 6As shown, the threaded bolt 34 can be driven by a bevel gear 60. A first bevel gear 61 is coupled to a handle 63 and meshes with a second bevel gear 62, which is coupled to the threaded bolt 34 near the first end 31 of the first connecting rod element 30. When the user turns the handle 63, the threaded bolt 34 is driven. The bevel gear 60 causes the longitudinal axis of the threaded bolt 34 to tilt while maintaining the meshing between the first bevel gear 61 and the second bevel gear 62. Since no great force is required to move the nut 35, the transmission ratio of the bevel gear 60 and the transmission ratio of the threaded bolt 34 connected to the nut 35 can be selected so that the entire adjustment range, i.e., the nut 35 is moved between the first end 31 and the second end 32 of the first connecting rod element 30, can be achieved by turning the handle 63 a few times, for example four to six times.

[0065] like Fig.13 As shown, a pawl mechanism may be provided, including, for example, a ratchet 70 coupled to the threaded bolt 34 near the second end 32 of the first link element 30. The ratchet 70 rotates together with the threaded bolt 34. The ratchet 70 has a plurality of ratchet tooth structures, such as alternating protrusions and depressions. The pawl mechanism includes two pawl members 71, 72 disposed at relative positions relative to the circumference of the ratchet 70. The pawl members 71, 72 match the ratchet tooth structure of the ratchet 70 and mesh with the ratchet 70. The pawl members 71, 72 are elastically displaceable in the radial direction of the ratchet 70. The pawl mechanism may provide feedback to a user turning the handle 63 and may prevent the nut 35 from being accidentally adjusted.

[0066] As described above, the forward sitting device (FSD) is used to set the starting position of the chair 101 to a position such as Figure 2 The basic horizontal position shown or Figure 4 In the following, the FSD is considered to be in an "inactive" state when the forward tilt posture adjustment element 50 is in a first position, wherein the spacer 51 is arranged between the stop surface 24 of the second end 22 of the second linkage element 20 and the stop surface 17 of the base 10, thereby maintaining a predetermined minimum distance 18 between the stop surface 24 and the stop surface 17, see Figure 8 In this inactive state, in the initial position of the chair 101, the back support 104 and the seat support 103 are arranged as follows. Figure 2 The FSD is considered to be in an "active" state when the forward tilt position adjustable element 50 is in a second position, wherein the spacer 51 does not maintain the distance 18 between the stop surface 24 and the stop surface 17, so that the stop surface 24 can push against the stop surface 17, see Fig.10 In this active state, in the initial position of the chair 101, the back support 104 and the seat support 103 are arranged as follows Figure 4 The second layout is shown.

[0067] Fig.14 The tilt mechanism 100 is shown in an initial position with the FSD in an inactive state. In the inactive state, the upper surface of the seat support 11 may be oriented substantially horizontally. Fig.15 The tilt mechanism 100 is shown in an initial position in the active state of the FSD. It can be seen that in the active state of the FSD, the seat support 11 is tilted in the forward direction compared to its arrangement in the inactive state of the FSD. Similarly, in the active state of the FSD, the back support 12 is also tilted in the forward direction compared to its arrangement in the inactive state of the FSD. Therefore, in the active state of the FSD, the seat 103 is tilted in the forward direction by several degrees relative to its arrangement in the inactive state of the FSD. For example, the seat 103 may be tilted in the forward direction by approximately 3°, 4°, or 5°.

[0068] Fig.16 and Fig.17 5 shows further details of the FSD. The FSD includes a forward tilt posture adjustment element 50. The forward tilt posture adjustment element 50 can be actuated by a user via a handle 53. The forward tilt posture adjustment element 50 can be moved laterally in the left-right direction. Fig.16 In the embodiment, the forward sitting posture adjustment element 50 moves to the right (as seen from the perspective of the user sitting on the chair 101, i.e., Fig.16 to the left), and Fig.17 In the embodiment, the forward sitting posture adjustment element 50 moves to the left (as seen from the perspective of the user sitting on the chair 101, i.e., Fig.17 Two spacers 51 and 52 are provided at the forward tilting sitting posture adjustment element 50, and the two spacers 51 and 52 move together with the forward tilting sitting posture adjustment element 50 in the lateral left-right direction.

[0069] In the right position ( Fig.16 , FSD is in an inactive state), the spacers 51 and 52 are arranged between the stop surface 24 of the second end 22 of the second link element 20 and the stop surface 17 of the base 10 (at Fig.16 In this right position, the spacers 51 and 52 prevent the stop surface 24 from contacting and abutting the base 10 at the stop surface 17.

[0070] At the second end 22 of the second linkage element 20, two recesses 25, 26 are provided in the stop surface 24. In the left position ( Fig.17, FSD is in the active state), the spacers 51 and 52 are arranged opposite to the recesses 25, 26. In detail, the spacer 51 is arranged opposite to the recess 25, and the spacer 52 is arranged opposite to the recess 26. The dimensions of the recesses 25, 26 are designed so that the spacers 51, 52 can be fully inserted into the corresponding recesses without protruding from the stop surface 24. Therefore, in this left position, the spacers 51 and 52 do not prevent the stop surface 24 of the second link element 20 from contacting and abutting the base 10 at the stop surface 17. Therefore, in the left position of the forward tilt sitting posture adjustment element 50, the second link element 20 can be moved further forward than in the right position.

[0071] Fig.18 and Fig.19 Details of the FSD are shown in cross-section. Fig.18 , the FSD is in an inactive state. The spacers 51, 52 are not arranged opposite to the corresponding recesses 25, 26, so that the stop surface 24 at the second end 22 of the second linkage member 20 contacts the spacers 51, 52 on one side, and the opposite other side of the spacers 51, 52 contacts the stop surface 17 of the base 10. The spacers 51, 52 maintain the distance between the stop surface 24 and the stop surface 17 and prevent the seat support 11 from tilting forward. Fig.19 The FSD is in an active state. The spacers 51, 52 are arranged opposite to the corresponding recesses 25, 26 so that the spacers 51, 52 do not block the space between the stop surface 24 and the stop surface 17. The stop surface 24 can directly contact the stop surface 17. Therefore, the seat support 11 can be tilted forward.

[0072] Fig. 20 and Fig.21 It further shows that the FSD is in an inactive state ( Fig. 20 ) and active status ( Fig.21 ) Operation details of the spacers 51, 52. In the inactive state ( Fig. 20 ), the spacers 51, 52 are opposed to the stop surface 24, so that the stop surface 24 cannot move in the forward direction to contact the stop surface 17 of the base 10. In the active state ( Fig.21 ), the spacers 51, 52 are arranged opposite to the recesses 25, 26 and can be fully inserted into the recesses 25, 26 so that the stop surface 24 contacts the stop surface 17 of the base 10.

[0073] Although the above exemplary embodiments are described in the context of an office chair, the tilt mechanism 100 and chair 101 according to embodiments of the present invention are not limited to this specific application. Instead, embodiments of the present invention can be used to achieve coordinated movement between the backrest and seat of various chairs, such as living room chairs and vehicle seats.

Claims

1. A tilt mechanism for a chair, the tilt mechanism being configured to affect the coordinated movement of a seat (103) and a chair back (104), the tilt mechanism (100) comprising: Base (10); a back support (12) configured to support the chair back (104) and pivotably coupled to the base (10); a seat support (11) configured to support the seat (103) and to be pivotably connected to the backrest support (12); a first link element (30), wherein a first end (31) of the first link element (30) is pivotably coupled to the base (10); a second link element (20), wherein a first end (21) of the second link element (20) is pivotably coupled to the backrest support (12), and a second end (22) of the second link element (20) is coupled to a second end (32) of the first link element (30); a spring element (40), wherein a first end (41) of the spring element (40) is mounted at the base (10), and a second end (42) of the spring element (40) pushes against the first link element (30) at an adjustable position between the first end (31) and the second end (32) of the first link element (30); and A forward leaning sitting posture adjustment element (50), wherein the forward leaning sitting posture adjustment element (50) is movable between a first position and a second position, wherein, when the forward leaning sitting posture adjustment element (50) is in the first position, the spacers (51, 52) of the forward leaning sitting posture adjustment element (50) are arranged between the stop surface (24) of the second end (22) of the second link element (20) and the stop surface (17) of the base (10), thereby maintaining a predetermined minimum distance (18) between the stop surface (24) of the second end (22) of the second link element (20) and the stop surface (17) of the base (10); and Wherein, when the forward leaning sitting posture adjustment element (50) is in the second position, the spacer (51, 52) of the forward leaning sitting posture adjustment element (50) is not arranged between the stop surface (24) of the second end (22) of the second connecting rod element (20) and the stop surface (17) of the base (10), thereby allowing the stop surface (24) of the second end (22) of the second connecting rod element (20) to contact the stop surface (17) of the base (10).

2. The tilt mechanism according to claim 1, wherein: When the backrest support (12) moves from the first position to the second position, the seat support (11) tilts in the rearward direction and the spring element (40) is compressed, thereby providing a restoring force that urges the backrest support (12) to be in the first position, wherein in the first position of the backrest support (12), the chair back (104) is in a substantially upright position, and in the second position of the backrest support (12), the chair back (104) is in a rearward tilted position.

3. The tilt mechanism according to claim 2, wherein: By adjusting the position at which the second end (42) of the spring element (40) pushes against the first link element (30), it is possible to change the effective length of the first link element (30) that acts when the back support (12) moves between the first position and the second position of the back support (12), thereby changing the restoring force that causes the back support (12) to be in the first position.

4. The tilting mechanism according to claim 2 or claim 3, wherein: In the substantially upright position of the seat back (104), the length of the spring element (40) depends on the adjustable position at which the second end (42) of the spring element (40) pushes against the first linkage element (30).

5. A tilt mechanism according to any one of the preceding claims, wherein: The tilt mechanism (100) comprises a threaded bolt (34) engaged with a nut (35), wherein the nut (35) is fixed to the second end (42) of the spring element (40), wherein when the threaded bolt (35) is rotated, the position between the first end (31) and the second end (32) of the first link element (30) is adjusted, at which position the second end (42) of the spring element (40) pushes against the first link element (30).

6. The tilt mechanism according to claim 5, wherein: The tilting mechanism (100) comprises: a ratchet (70) coupled to the threaded bolt (34) to rotate together with the threaded bolt (34), the ratchet (70) being provided with a plurality of ratchet tooth structures; and At least one pawl member (71, 72) is attached to the first link element (30), wherein each of the at least one pawl member (71, 72) matches the ratchet tooth structure of the ratchet wheel (70) and engages with the ratchet wheel (70).

7. The tilt mechanism according to claim 6, wherein: The at least one pawl member (71, 72) includes two pawl members (71, 72) which are arranged at opposite positions relative to the circumference of the ratchet wheel (70).

8. A tilt mechanism according to any one of the preceding claims, wherein: When the forward tilting posture adjustment element (50) is in the first position and the stop surface (24) of the second end (22) of the second link element (20) is in contact with the spacers (51, 52) of the forward tilting posture adjustment element (50), the backrest support (12) and the seat support (11) are arranged in a first layout, wherein, when the forward-leaning sitting posture adjustment element (50) is in the second position and the stop surface (24) of the second end (22) of the second connecting rod element (20) contacts the stop surface (17) of the base (10), the backrest support (12) and the seat support (11) are arranged in a second layout, Wherein, in the second layout, the seat support (11) is inclined in a forward direction relative to the second layout.

9. The tilt mechanism according to claim 8, wherein: In said first arrangement, said seat support (11) is arranged in a substantially non-inclined position, and Wherein, in the second arrangement, the seat support (11) is arranged in a forwardly inclined position.

10. The tilt mechanism according to claim 9, wherein: The seat support (11) is inclined at least 3 degrees in the forward direction in the second arrangement relative to the first arrangement.

11. A tilt mechanism according to any one of the preceding claims, wherein: In the first position of the forward-tilting posture adjustment element (50), the spring element (40) pushes the stop surface (24) of the second end (22) of the second link element (20) into contact with the spacers (51, 52) of the forward-tilting posture adjustment element (50), and In the second position of the forward-leaning posture adjustment element (50), the spring element (40) pushes the stop surface (24) of the second end (22) of the second link element (20) into contact with the stop surface (17) of the base (10).

12. A tilt mechanism according to any one of the preceding claims, wherein: The vertices of a triangle are defined by the first pivot axis (33), the mounting point, and the abutment point, wherein: The first end (31) of the first linkage element (30) is pivotably coupled to the base (10) at the first pivot axis (33); At the mounting point, the first end (41) of the spring element (40) is mounted at the base (10); and At the abutment point, the second end (42) of the spring element (40) abuts against the first link element (30). The triangular geometry is dependent upon the adjustable position of the second end (42) of the spring element (40) against the first link element (30).

13. A chair, comprising: Chair base assembly (102); Chair seat (103); Chair back (104); and According to the tilt mechanism (100) of any one of the preceding claims, the base (10) of the tilt mechanism (100) is attached to the chair base assembly (102), the seat (103) is attached to the seat support (11) of the tilt mechanism (100), and the chair back (104) is attached to the backrest support (12) of the tilt mechanism (100).

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