Swing mechanism for chairs or armchairs

Abstract

A rocking mechanism (6) for a chair or armchair comprises a functional body (40) having at least one flexible unit portion which can be elastically deformed in a curved manner for rocking of the seat and the backrest.

Description

[0001] The invention belongs to the field of rocking mechanisms for the seat of a chair or armchair, for example an office chair or armchair.

[0002] The field of chairs and armchairs (especially office chairs or armchairs) is demanding in terms of comfort in use, so that modern solutions offer a variety of adjustments (e.g. seat height, backrest and seat inclination, etc.) so that the user can better adjust his / her position.

[0003] Some solutions also include a swivel backrest so that it moves backwards when the user leans his back against it, or a swivel seat so that it adapts to the position of the user, for example sitting very far forwards or very far backwards.

[0004] The possibility of swinging the backrest and the seat is given by a swing mechanism which is supported at a predetermined height by a rod and which in turn carries the seat and the backrest of the chair.

[0005] Some solutions of oscillating mechanisms are described in documents WO-A1-2010 / 097818, WO-A1-2011 / 104735, WO-A1-2015 / 145216, IT201800003431 of the present applicant.

[0006] In such a sector, competition is very fierce and companies make considerable efforts to research and develop new solutions, both aiming to improve the comfort of the final product and to increase its profitability by reducing its production costs.

[0007] In particular, considering the structural and functional complexity of oscillating mechanisms, considerable efforts have been made to simplify such mechanisms.

[0008] The object of the present invention is to provide a rocking mechanism for a chair or armchair that meets the comfort requirements of the state of the art and overcomes the drawbacks mentioned above with regard to the structural complexity of existing solutions.

[0009] This object is achieved by a pivot mechanism according to claim 1. The dependent claims describe further advantageous embodiments.

[0010] The characteristics and advantages of the oscillating mechanism according to the invention will become clear from the following description given by way of non-limiting example with the aid of the accompanying drawings, in which:

[0011] - Figure 1 A chair provided with a swing mechanism according to an embodiment of the present invention is shown;

[0012] - Figure 2 Shown Figure 1The swing mechanism in the

[0013] - Figure 3 Depicts Figure 2 An oscillating mechanism in which the parts are separated;

[0014] - Figure 4 shows the functional body of the swing mechanism according to an embodiment of the present invention;

[0015] - Figure 5 The oscillating mechanism is shown in an initial or rest configuration; and

[0016] - Figure 6 Depicts the swing mechanism in its final configuration.

[0017] With reference to the figures of the drawings, reference numeral 1 generally indicates a chair or armchair comprising a seat 2 , a backrest 4 , a rocking mechanism 6 and a lever 8 .

[0018] A rod 8 (eg, consisting of a gas piston) supports the swing mechanism 6 at a predetermined height relative to the ground plane and is adjustable according to the user's needs.

[0019] The rocking mechanism 6 comprises a seat coupling 10 which can be mechanically connected to the seat 2 of the chair by means of screws, for example.

[0020] The seat coupling 10 extends between a rear portion 12 , at which it has a rear seat coupling axis 14 , and a front portion 16 , at which it has a front seat coupling axis 18 .

[0021] The rocking mechanism 6 further comprises a backrest coupling 20 which can be mechanically connected to the backrest 4 of the chair by means of screws, for example.

[0022] For example, said backrest coupling 20 , which is for example L-shaped, comprises a rear connection portion 22 intended to be connected to the backrest 6 and comprises a front connection portion 24 .

[0023] The front connecting part has an upper backrest connection axis 26 and a lower backrest connection axis 28 .

[0024] The seat connection 10 is articulated to the backrest connection 20 by joining the rear seat connection axis 14 with the upper backrest connection axis 26 by means of, for example, a first pin 30 , which forms a rear articulation axis 30 ′.

[0025] The oscillating mechanism 6 also comprises a functional body 40 made in a single piece, for example by moulding of plastic material.

[0026] For example, the functional body 40 is made of polyamide.

[0027] The functional body 40 extends from a rear part 42, where it has a rear body axis 44, to a front part 46, where it has a front body axis 48, which is obtained, for example, by means of multiple hinge elements 50, 52 separated along the front body axis 48.

[0028] The functional body 40 is articulated to the backrest link 20 by joining the lower coupling axis 28 with the rear body axis 44 by means of, for example, a second pin 54 , which forms a lower articulation axis 54 ′.

[0029] The functional body 40 is articulated to the seat coupling 10 by joining the front body axis 48 with the front seat coupling axis 18 by means of, for example, a third pin 56 , which forms a front articulation axis 56 ′.

[0030] The functional body 40 is configured to be elastically deformable by bending between the rear body axis 44 and the front body axis 48 (ie, between the lower hinge axis 54 ′ and the front hinge axis 56 ′).

[0031] According to a preferred embodiment, the functional body 40 has differentiated flexible areas between the rear body axis 44 and the front body axis 48 , specifically a low flexibility area 60 and a high flexibility area 62 , wherein the low flexibility area is close to the rear body axis 44 and the high flexibility area is close to the front body axis 48 .

[0032] For example, the functional body 40 includes a plurality of ribs 64 in the low-flexibility region 60 , which structurally reinforce the bending rigidity of the low-flexibility region 60 .

[0033] Due to the deformability of the functional body 40, the swing mechanism 6 is suitable for moving from an initial or static configuration ( Figure 4 )Switch to the final configuration ( Figure 6 ), in the initial or static configuration, the front articulation axis 56 ′ and the rear articulation axis 30 ′ are located on a first imaginary plane 70 , and in the final configuration, the front articulation axis 56 ′ and the rear articulation axis 30 ′ are located on a second imaginary plane 72 .

[0034] The second imaginary plane 72 is inclined relative to the first imaginary plane 70 at an angle α corresponding to the maximum inclination of the seat.

[0035] According to an embodiment, the mutual distances between the front articulation axis 56 ′, the rear articulation axis 30 ′ and the lower articulation axis 54 ′ are configured such that the rear articulation axis 30 ′ is located at a predetermined height H above the first imaginary plane 70 in the final configuration.

[0036] In other words, such a feature ensures that the oscillating mechanism is of the "deadweight" type.

[0037] According to an embodiment of the present invention, the swing mechanism 10 further includes an adjustment device adapted to manually adjust the flexibility of the functional body 40 .

[0038] For example, the adjustment device comprises a bracket 80 which cooperates with the functional body 40 in order to structurally stiffen the functional body and which can be manually positioned between the rear portion 42 and the front portion 46. For example, the bracket 80 cooperates with the functional body 40 by sliding on an upper surface 82 of the functional body.

[0039] When the bracket 80 is near the rear portion 42 , the section of the functional body 40 spanning from the bracket 80 to the front body axis 48 is not stiffened and therefore has high flexibility; as the bracket 80 is positioned closer to the front body axis 48 , the high flexibility area decreases.

[0040] Preferably, said adjustment means comprise an adjustment knob 84 that slides along a lower surface 87 of the functional body 40 , this adjustment knob being connected to the support 80 by means of slots 86 , 88 obtained through the thickness of the functional body 40 .

[0041] According to a variant of the invention, the functional body comprises a single flexible portion, ie is made of a single piece of flexible, deformable material, typically plastic material, which allows the oscillation of the seat and backrest due to the elastic deformability of the material.

[0042] According to a further variant of the invention, these differentiated flexible areas have different stiffnesses because they are made of different materials with different elastic characteristics.

[0043] Innovatively, the rocking mechanism according to the invention meets the needs of the art since it allows the seat and the backrest of a chair or armchair to be tilted, while at the same time overcoming some of the above-mentioned drawbacks since it is particularly simple in construction.

[0044] In fact, the deformable functional body can be integrated in a single piece, which is easily achieved by means of a moulded plastic material, a steel or aluminium box and the usual functions of a steel spring of prior art solutions.

[0045] Furthermore, advantageously, the user can easily adjust the stiffness of the swing mechanism according to his / her own comfort needs.

[0046] It is clear that a person skilled in the art may make modifications to the oscillating mechanism described above in order to meet the needs as the case may be, all of which are included in the scope of protection defined by the appended claims.

Claims

1. A swing mechanism (6) for a seat and backrest of a chair or armchair, the swing mechanism comprising a seat coupling (10) mechanically connectable to the seat (2), a backrest coupling (20) mechanically connectable to the backrest (4), and a functional body (40), wherein: The seat connection member (10) and the backrest connection member (20) are hinged to each other along a rear hinge axis (30'), the backrest connection member (20) and the functional body (40) are hinged to each other along a lower hinge axis (54'), and the functional body (40) and the seat connection member (10) are hinged to each other along a front hinge axis (56'), wherein the functional body (40) is made of a single piece of plastic material by molding and consists of a flexible unit portion that can be elastically deformed in a curved manner between the front hinge axis (56') and the lower hinge axis (54') for the swinging of the seat and the backrest, wherein the functional body (40) extends from a rear portion (42) to a front portion (46), has a rear body axis (44) at the rear portion (42), and has a front body axis (48) at the front portion (46); wherein the seat coupling (10) extends between a rear portion (12) and a front portion (16), having a rear seat coupling axis (14) at the rear portion (12) and a front seat coupling axis (18) at the front portion (16); wherein the backrest connecting member (20) comprises a rear connecting portion (22) for connecting to the backrest (4), and comprises a front connecting portion (24) having an upper backrest connecting axis (26) and a lower backrest connecting axis (28); wherein the seat coupling (10) is articulated to the backrest coupling (20) by engaging the rear seat coupling axis (14) with the upper backrest coupling axis (26) by means of a first pin (30), the first pin (30) forming a rear articulation axis (30'); wherein the functional body (40) is articulated to the backrest coupling (20) by joining the lower backrest coupling axis (28) with the rear body axis (44) by means of a second pin (54), the second pin (54) forming a lower articulation axis (54'); Therein, the functional body (40) is articulated to the seat coupling (10) by joining the front body axis (48) with the front seat coupling axis (18) by means of a third pin (56), the third pin (56) forming a front articulation axis (56').

2. The swing mechanism according to claim 1, wherein: The functional body (40) has differentiated flexible areas (62, 64) between the lower articulation axis (54') and the front articulation axis (56'), the flexible areas being configured to have different stiffnesses.

3. The swing mechanism according to claim 2, wherein: The functional body (40) has a low-flexibility region (60) and a high-flexibility region (62), wherein the low-flexibility region is close to the lower hinge axis (54') and the high-flexibility region is close to the front hinge axis (56').

4. The swing mechanism according to claim 3, wherein: The low-flexibility region (60) has at least one rib (64) for increasing rigidity.

5. The swing mechanism according to claim 1, wherein: - in an initial or rest configuration, the front articulation axis (56') and the rear articulation axis (30') lie on a first imaginary plane (70); - in the final configuration, the front articulation axis (56') and the rear articulation axis (30') lie on a second imaginary plane (72); - the second imaginary plane (72) is inclined relative to the first imaginary plane (70) at an angle (α) corresponding to the maximum inclination of the seat.

6. The swing mechanism according to claim 5, wherein: The mutual distances between the front articulation axis (56'), the rear articulation axis (30') and the lower articulation axis (54') are configured so that the rear articulation axis (30') is located at a predetermined height (H) above the first imaginary plane (70) in the final configuration.

7. The oscillating mechanism according to any one of the preceding claims, comprising an adjusting device adapted to manually adjust the flexibility of the functional body (40).

8. The swing mechanism according to claim 7, wherein: The adjustment device comprises a bracket (80) which engages with the functional body (40) to stiffen the functional body when bent and which can be manually positioned between the front articulation axis (56') and the lower articulation axis (54').

9. The swing mechanism according to claim 8, wherein: The adjusting device comprises an adjusting button (84) which slides along a lower surface (87) of the functional body (40), and the adjusting button is connected to the bracket (80) which slides along an upper surface (82) of the functional body (40).

10. The swing mechanism according to claim 9, wherein: The adjustment knob (84) is connected to the support (80) by means of slots (86, 88) obtained through the thickness of the functional body (40).

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