CHAIR FOR THE SITTING OF A USER AND METHOD OF MOUNTING SAID CHAIR

Abstract

Chair comprising a support structure provided with a first housing seat having a first non-circular opening, and with a support element, which is mechanically connected to the support structure and is provided with a second housing seat, which is aligned and communicating with the first housing seat. The chair also comprises a removable connection system having a locking pin provided with a non-circular head, which engages the first housing seat and the second housing seat and is rotatable between a release position, in which it releases the support element from the support structure, and a constraint position, in which the support element is constrained to the support structure. The locking pin comprises an elastic retention element which is elastically engaged in a first retention recess of the first housing seat when the locking pin is in the constraint position, in order to retain the locking pin therein.

Claims

1. A chair for the sitting of a user, said chair comprising: a support structure (2), which comprises a support base (21), which is intended to be placed in abutment against a ground, and a seat (210), which is mounted above said support base (21) and is intended to support a user in seated position; wherein said support structure (2) is provided with at least one first housing seat (20) provided with a first opening (200); at least one support element (3), which is mechanically connected to said support structure (2) and is selected from among a back (31) and a pair of arms (32), in order to respectively support a back or an arm of the user; wherein said at least one support element (3) is provided with a second housing seat (30), which is aligned and communicating with the at least one first housing seat (20) of said support structure (2), when said at least one support element (3) is mounted on said support structure (2); a removable connection system (4), which is placed as a mechanical connection between said support structure (2) and said at least one support element (3) and comprises a locking pin (41) provided with a non-circular head (410); wherein said locking pin (41) engages said at least one first housing seat (20) and said second housing seat (30) and is rotatable in a constraint sense, around a rotation axis (R), between at least one release position (B), in which said locking pin (41) releases said at least one support element (3) from said support structure (2), and a constraint position (C), in which said at least one support element (3) is constrained to said support structure (2); wherein said locking pin (41) comprises an elastic retention element (411), and wherein said support structure (2) defines, in said at least one first housing seat (20), a first retention recess (21), in which said retention element (411) is elastically engaged when said locking pin (41) is in said constraint position (C), in order to retain said locking pin (41) in position, by impeding said locking pin (41) from rotating around said rotation axis (R).

2. The chair of claim 1, wherein said support structure (2) defines, in said at least one first housing seat (20), a second retention recess (21), which is engageable by said elastic retention element (411) when said locking pin (41) is in said at least one release position (B).

3. The chair of claim 2, wherein said first retention recess (21) and said second retention recess (21) are made on opposite sides of said at least one first housing seat (20) and are substantially spaced by an angle equal to 180.

4. The chair of claim 1, wherein said locking pin (41) comprises a main body (413), substantially cylindrical, which is provided with a lateral surface; wherein said elastic retention element (411) is extended radially projecting from the lateral surface of said main body (413); wherein said support structure (2) is provided with an internal surface, which is directed towards said at least one first retention seat (20) and laterally delimits said at least one first retention seat (20); and wherein said first retention access (21) and said second retention recess (21) are made in a depression from the internal surface of said support structure (2) along a radial extension direction.

5. The chair of claim 4, wherein said elastic retention element (411) has a U shape, wherein said elastic retention element (411) is provided with: a convex portion (411) that projects radially from the lateral surface of said main body (413) and is configured to be engaged in said first retention recess (21) and second retention recess (21), and two connection arms (411) which connect the convex portion (411) to said main body (413), are configured for being bent during rotation of said locking pin (41) around said rotation axis (R), and allow elastic deformation of said elastic retention element (411).

6. The chair of claim 1, wherein said support structure (2) is provided with at least one first stop shoulder (22), which is placed in at least one said first housing seat (20), and said locking pin (41) comprises at least one first stop element (412), which is susceptible of abutting against the at least one first stop shoulder (22) in order to prevent said locking pin (41) from rotating in a release sense, which is opposite said constraint sense.

7. The chair of claim 6, wherein said locking pin (41) comprises main body (413), substantially cylindrical, which is provided with a lateral surface; wherein said first stop element (412) comprises an elastic tab, which is extended projecting from the lateral surface of said main body (413) up to a free end (412); wherein said elastic tab is configured for being bent between: am extended position, in which the free end (412) of said elastic tab is placed spaced from the lateral surface of said main body (413) and said elastic tab is susceptible of abutting against said first stop shoulder (22) in order to prevent said locking pin (41) from rotating in said release direction; and a bent position, in which the free end of said elastic tab is placed approached to the lateral surface of said main body (413) in order to allow free rotation of said locking pin (41) in said constraint sense.

8. The chair of claim 1, wherein said support structure (2) is provided with at least one second stop shoulder (23), which is placed in said at least one first housing seat (20), and wherein said locking pin (41) comprises at least one second stop element (414), which is susceptible of abutting against the at least one second stop shoulder (23) in order to prevent said locking pin (41) from rotating in said constraint sense, when said locking pin (41) is in said constraint position (C).

9. The chair of claim 1, wherein: said locking pin (41) has a substantially L shape, wherein said non-circular head (410) is extended substantially orthogonal to said rotation axis (R) and is provided with a first abutment wall (418), which is directed towards the at least one first opening (200) of said at least one first housing seat (20); said at least one support element (3) being provided with a second abutment wall (33), substantially planar, which is placed in said second housing seat (30) and against which the first abutment wall (418) of said non-circular head (410) is susceptible of abutting, in order to constrain said locking pin (41) in said second housing seat (30); wherein the first abutment wall (418) of said non-circular head (410) has: at least one first section (418), which is tilted with respect to the second abutment wall (33) of said at least one support element (3) by a first angle (), and a second section (418), which is tilted with respect to the second abutment wall (33) of said at least one support element (3) by a second angle (), which is greater than said first angle (); wherein, when said locking pin (410) is in rotation in said constraint sense, said second section (418) is susceptible of intercepting the second abutment wall (33) of said at least one support element (3), previously with respect to said at least one first section (418).

10. A method of mounting the chair of claim 1, wherein the method comprises: a step of arranging said support structure (2) provided with said at least one first housing seat (20) provided with said non-circular first opening (200); a step of arranging said at least one support element (3), selected from among a back (31) and a pair of arms (32) and provided with said second housing seat (30); a step of inserting said locking pin (41) in the at least one first opening (200) of the at least one first housing seat (20) of said support structure (2); a locking step, in which said locking pin (41) is rotated around said rotation axis (R) in said constraint sense, up to said at least one release position (B), in order to retain said locking pin (41) in said at least one first housing seat (20) and mounted in said support structure (2); a step of connecting said at least one support element (3) to said support structure (2), with said second housing seat (30) aligned and communicating with said at least one first housing scat (20); a fixing step, in which said locking pin (41) is rotated around said rotation axis (R) in said constraint sense, up to said constraint position (C), in order to constrain said support structure (2) and said at least one support clement (3).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The technical characteristics of the invention, according to the aforesaid objects, and the advantages thereof, will be more evident in the following detailed description, made with reference to the enclosed drawings, which represent a merely exemplifying and non-limiting embodiment of the invention, in which:

[0027] FIG. 1 shows a perspective view of the chair for the sitting of a user, object of the present invention;

[0028] FIG. 2 shows a perspective view of a detail of the chair of FIG. 1, relative to a locking pin in accordance with a first embodiment;

[0029] FIG. 3 shows a further perspective view of the locking pin of FIG. 2;

[0030] FIG. 4 shows a perspective view of a detail of the chair of FIG. 1, relative to a locking pin in accordance with a second embodiment;

[0031] FIG. 5 shows a further perspective view of the locking pin of FIG. 4;

[0032] FIG. 6 shows a sectional view of a detail of the chair of FIG. 1, with the locking pin of FIG. 2 in an insertion position;

[0033] FIG. 7 shows a sectional view of a detail of the chair of FIG. 1, with the locking pin of FIG. 2 in a release position;

[0034] FIG. 8 shows a top view of the chair of FIG. 1, with the locking pin in an insertion position, and with several parts removed in order to better illustrate other parts;

[0035] FIG. 9 shows a top view of the chair of FIG. 1, with the locking pin in a release position, and with several parts removed in order to better illustrate other parts;

[0036] FIG. 10 shows a sectional view of the detail of FIG. 8, with the locking pin in an insertion position, and with several parts removed in order to better illustrate other parts;

[0037] FIG. 11 shows a sectional view of the detail of FIG. 9, with the locking pin in a release position, and with several parts removed in order to better illustrate other parts;

[0038] FIG. 12 shows a further view of the detail of FIG. 11, made from a different section;

[0039] FIG. 13 shows a sectional view of a detail of the chair of FIG. 1, with the locking pin in a constraint position;

[0040] FIG. 14 shows a sectional view of the detail of FIG. 13, with the locking pin in a constraint position, and with several parts removed in order to better illustrate other parts;

[0041] FIG. 15 shows a further view of the detail of FIG. 14, made from a different section;

[0042] FIG. 16 shows a further view of the detail of FIG. 13, made from a different section;

[0043] FIG. 17 shows a rear view of the locking pin of FIG. 2;

[0044] FIGS. 18, 19 and 20 show a sectional view of the chair of FIG. 1, with the locking pin respectively in a release position, insertion position and constraint position.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

[0045] With reference to the enclosed drawings, reference number 1 overall indicates chair for the sitting of a user, object of the present invention.

[0046] Advantageously, the present chair 1 is adapted to be placed as a furnishing element in both public and private settings, both work and home environments.

[0047] More in detail, the chair 1, object of the present invention, is intended to be advantageously used for the sitting of a user, for example for the sitting of a worker in an office or for the sitting of a user in a private and/or home setting.

[0048] In particular, the chair 1, object of the present invention, is advantageously of reclinable type, so as to allow a user to vary his/her own sitting position between a first position, e.g. an operative position in which the back is placed substantially at right angle with respect to the legs, and multiple reclined positions, substantially rest positions, in which the back is tilted with respect to the legs and the user takes on a more laid back position with respect to the aforesaid operative position.

[0049] The chair 1 for the sitting of a user according to the invention comprises a support structure 2, provided with a support base 21, which is intended to be placed in abutment against the ground (e.g. a floor).

[0050] Advantageously, the support base 21 of the chair 1 comprises multiple support legs which are preferably provided with wheels in order to allow the movement of the chair on the floor during its use.

[0051] Of course, it is also possible to provide for a support base 21 of base type, without support legs, or even provide for a support base 21 in which the legs lack wheels, so as to allow greater stability of the chair 1 in position during the use thereof.

[0052] Preferably, the support base 21 of the chair 1 is made of resistant material, in particular of metal material, such as for example steel or aluminum, or alternatively of a plastic material.

[0053] The chair 1 also comprises a seat 210, mounted above the support base 21 and intended to support a user in seated position. Without departing from the protective scope of the present invention, the seat 210 can be fixed with respect to the support base 21 or, alternatively, rotatable and preferably adjustable, e.g. height-wise, with respect to the same support base 21.

[0054] In particular, the seat 210 defines a seat plane, substantially horizontal, and it can be formed by a rigid element (in a single body) or by a perimeter frame to which a support element (e.g. a mesh) is fixed in order to allow a certain flexibility (and ergonomics) of the seat. Alternatively, it is also possible that the seat 210 comprises a padding layer, placed on top of the rigid element, which is subsequently covered by a cover (made of leather, imitation leather or fabric) which encloses the rigid element and the padding layer.

[0055] In accordance with the invention, the support structure 2 is provided with at least one first housing seat 20, which is provided with a first opening 200, preferably non-circular.

[0056] More in detail, as is better explained hereinbelow, such first housing seat 20 can be made on the support base 21 or on the seat 210, depending on the desired configuration and design of the chair 1.

[0057] More in detail, the first opening 200 is accessible externally, and is preferably placed in a position in which it can simultaneously be hidden from view but easily accessible by the user, preferably at one face of the support structure 2 that is directed towards the floor during the normal use of the chair 1.

[0058] Advantageously, the first housing seat 20 is a through seat, which is extended between the first opening 200 and an outlet opening 201, which preferably also has a non-circular shape.

[0059] The chair 1 also comprises at least one support element 3, which is mechanically connected to the support structure 2 and is selected from among a back 31 and a pair of arms 32, in order to respectively support the back or the arm of the user, in which the support element 3 is provided with a second housing seat 30, which is aligned and communicating with the first housing seat 20 of the support structure 2, when the support element 3 is mounted on the support structure 2.

[0060] The support element 3 can be connected, depending on the needs and on the configuration of the chair 1, to the support base 21 or to the seat 210, without departing from the protective scope of the present invention.

[0061] Advantageously, in a non-limiting manner, in the event in which the support element 3 is a back 31, this is preferably connected to the support base 21, while the pair of arms 32 is preferably connected to the seat 210.

[0062] More in detail, the second housing seat 30 is provided with a second opening 300, preferably also with non-circular shape, which is aligned (and preferably coinciding) with the outlet opening 201 of the first housing seat 20.

[0063] Preferably, the second housing seat 30 is not through, and is only open at the second opening 300, otherwise being blind in order to prevent the access also from an opposite side with respect to the second opening 300.

[0064] In other words, when the support element 3 is mounted on the support structure 2, the first housing seat 20 and the second housing seat 30 are aligned with each other and define a single housing seat which is accessible, preferably exclusively, from the first opening 200.

[0065] The chair 1 also comprises a removable connection system 4, which is placed as a mechanical connection between the support structure 2 and the support element 3.

[0066] More in detail, with the expression removable connection system 4 a system is intended which allows a facilitated mounting and disassembly of the chair 1 and of the relative components, also by a user, even during the lifetime of the chair and not simply following the production process of the chair 1 itself. In other words, as is clearer below, it is not only intended a system that if removed allows the separation of the components of the chair 1, but also means that it facilitates such separation.

[0067] The removable connection system 4 comprises a locking pin 41, which is provided with a non-circular head 410 and which engages the first housing seat 20 and the second housing seat 30. In particular, the locking pin 41 engages, at least with its own head 410, the first housing seat 20 and the second housing seat 30.

[0068] More in detail, the head 410 is provided with a form which has a radial asymmetry, and is preferably provided with an elongated form, substantially rectangular, such to determine a plurality of distinct positions during its rotation around the rotation axis R, as is better explained hereinbelow. In particular, the head 410 is extended along a direction substantially orthogonal to the rotation axis R.

[0069] Advantageously, the first opening 200 of the first engagement seat 20 is counter-shaped with respect to the head 410, and still more preferably also the outlet opening 201 and the second opening 300 are counter-shaped with respect to the head 410. In this manner, the locking pin 41 can be inserted with its own head 410 in an unambiguous manner, with the head 410 positioned in a specific insertion position A.

[0070] In accordance with a first embodiment of the locking pin 41, illustrated in FIGS. 2 and 3, the head 410 of the pin 41 is provided with a tooth 419, which projects above the pin 41, which is intended to abut against a shoulder made in the second housing seat 30, in particular in the second housing seat 30 of the pair of arms 32, in order to maintain the arm in position, preventing the removal thereof.

[0071] Otherwise, in accordance with a second embodiment of the locking pin 41, illustrated in FIGS. 4 and 5, the head 410 is flat, and therefore preferably has an upper surface that is substantially planar.

[0072] The locking pin 41 is rotatable in a constraint sense, around a rotation axis R, between a release position B, in which the locking pin 41 releases the support element 3 from the support structure 2, and a constraint position C, in which the locking pin 41 constrains the support element 3 to the support structure 2.

[0073] In accordance with the idea underlying the present invention, the locking pin 41 of the removable connection system 4 comprises an elastic retention element 411, and the support structure 2 defines, in the first housing seat 20, at least one first retention recess 21, in which the retention element 411 is elastically engaged with the locking pin 41 in release position B, in order to retain the locking pin 41 in position, by impeding the rotation thereof around the rotation axis R.

[0074] More in detail, the first retention recess 21 is positioned such that the elastic retention element 411 is engaged in the latter when the locking pin 41 is situated in the release position B.

[0075] Advantageously, the elastic retention element 411 is configured in order to be elastically deformed along a direction substantially orthogonal to the rotation axis R during the rotation of the locking pin 41 around the rotation axis R, and return into a rest position when it reaches the first retention recess 21.

[0076] In this manner, it is possible to easily and quickly mount the support element 3 on the support structure 2, by means of a simple rotation of the locking pin 41, while simultaneously ensuring the safe and stable positioning of the locking pin 41 in the constraint position, reducing the risk of undesired movements of the latter which could determine the release of the support element 3 from the support structure 2.

[0077] Advantageously, the support structure 2 defines, in the first housing seat 20, also a second retention recess 21, which is engageable by the elastic retention element 411, with the locking pin 41 in the constraint position C, in order to retain the locking pin 41 in the aforesaid constraint position C.

[0078] Advantageously, the first retention recess 21 and the second retention recess 21 are made on opposite sides of the first housing seat 20, substantially spaced by an angle equal to 180. In other words, the locking pin 41 is advantageously rotated 180 in order to pass from the release position B to the constraint position C, and vice versa, so as to prevent a small rotation of the locking pin 41 from determining the release of the support element 3 from the support structure 2.

[0079] Advantageously, the locking pin 41 comprises a main body 413, substantially cylindrical, which is provided with a lateral surface.

[0080] Preferably, the main body 413 is substantially housed entirely within the first housing seat 20 of the support structure 2.

[0081] Advantageously, the locking pin 41 comprises a grip portion 415, preferably placed outside the first housing seat 20 of the support structure 2, and which is advantageously provided with an enlarged form.

[0082] Advantageously, the grip portion 415 is placed to close the first opening 200 of the first housing seat 20 and defines a surface that is substantially continuous with the support structure 2, in order to reduce the aesthetic impact of the locking pin 41.

[0083] Advantageously, the entire locking pin 41 is extended along a main extension direction X between the grip portion 415 and the head 410, with the main body 413 that connects together the grip portion 415 and the head 410, as is visible in FIGS. 2-5.

[0084] Preferably, the main body 413 is extended along the aforesaid main extension direction X, substantially parallel to the rotation axis R, between a lower end, connected to the grip portion 415, and an opposite upper end, connected to the head 410.

[0085] More in detail, the head 410 is extended projecting from the main body 413, along a direction substantially orthogonal to the main extension direction X.

[0086] In other words, the locking pin 41 has a substantially L shape.

[0087] Advantageously, the elastic retention element 411 is extended radially projecting from the lateral surface of the main body 413. Preferably, the elastic retention element 411 is extended along a direction Y that is substantially orthogonal to the main extension direction X of the main body 413.

[0088] More in detail, the elastic retention element 411 is susceptible of being elastically deformed along the direction Y, in particular being compressed during the rotation of the locking pin 41 around the rotation axis R, and on the contrary returning to a rest position, substantially not compressed, when the locking pin 41 reaches one of the retention recesses 21, 21.

[0089] Advantageously, the support structure 2 is provided with an internal surface 203, which is directed towards the interior of the first retention seat 20 and laterally delimits the first retention seat 20, and the retention recesses 21, 21 are made in a depression from the internal surface 203 of the support structure 2, along a radial extension direction. More in detail, the retention recesses 21, 21 are extended in a depression along a direction parallel to the direction Y and substantially orthogonal to the rotation axis R. Preferably, the retention recesses 21, 21 have cavity form.

[0090] Advantageously, the elastic retention element 411 has a U shape, and is provided with a convex portion 411 that projects radially from the lateral surface of the main body 413 and is configured in order to be engaged in the retention recesses 21, 21.

[0091] Advantageously, the elastic retention element 411 comprises two connection arms 411, which connect the convex portion 411 to the main body 413, which are configured for being bent during the rotation of the locking pin 41 around the rotation axis R and allow the elastic deformation of the elastic retention element 411.

[0092] Advantageously, the two connection arms 411 of the elastic retention element 411 are provided with respective bent portions, which preferably have a U shape, so as to improve the elasticity of the retention element 411.

[0093] More in detail, the bent portions of the connection arms 411 of the elastic retention element 411 are susceptible of being compressed and/or enlarged during the rotation of the locking pin 41 around the rotation axis R. In particular, during the rotation of the locking pin 41, the convex portion 411 of the elastic retention element 411 will tend to slide against the internal surface 203 of the first housing seat 20, determining an elastic deformation of the arms 411 and a consequent compression of a bent portion of a first connection arm 411 (placed downstream in the rotation sense) and the enlarging of the bent portion of a second connection arm 411 (placed upstream in the rotation sense).

[0094] Advantageously, the elastic retention element 411 is connected to the main body 413 by means of only the connection arms 411, and preferably lacks any connection at the convex portion 411. In other words, the convex portion 411 of the elastic retention element 411 is released from other elements, as well as from the connection arms 411.

[0095] Advantageously, the main body 413 comprises an enlarged cylindrical base portion 416, which has an external diameter substantially coinciding with the internal diameter of the first housing seat 20, so as to determine a housing and a guided rotation, substantially to size, within the first housing seat 20.

[0096] Advantageously, the cylindrical base portion 416 is extended upwards from the grip portion 415.

[0097] Advantageously, the aforesaid cylindrical base portion 416 has at least one channel which interrupts the continuity thereof, which is delimited by two lateral walls 417, and preferably the elastic retention element 411 is interposed between the lateral walls 417 of the cylindrical base portion 416, with the connection arms 411 which project from the lateral walls 417 themselves, as is visible in FIGS. 2-5.

[0098] Preferably, the convex portion 411 of the elastic retention element 411 has a radial bulk that substantially coincides with the external diameter of the cylindrical base portion 416. Advantageously, the elastic retention element 411 is placed raised from the grip portion 415. Advantageously, the support structure 2 is provided with at least one first stop shoulder 22, which is placed in the first housing seat 20, and the locking pin 41 comprises at least one first stop element 412, which is susceptible of abutting against the first stop shoulder 22 of the first housing seat 20 in order to prevent the rotation of the locking pin 41 in a release sense, opposite the constraint sense.

[0099] Advantageously, the first stop element 412 is an elastic element, which is configured for being elastically deformed at least along a radial direction, substantially orthogonal to the rotation axis R.

[0100] Advantageously, as described above, the locking pin 41 comprises a main body 413, which is provided with a lateral surface, and the first stop element 412 is extended preferably projecting from the lateral surface of the main body 413.

[0101] More in detail, the first stop element 412 comprises an elastic tab, which is extended projecting from the lateral surface of the main body 413 up to a free end 412 thereof. Preferably, the elastic tab is extended with a substantially L shape.

[0102] In particular, the elastic tab is configured for being bent from an extended position, in which the free end 412 of the elastic tab is placed spaced from the lateral surface of the main body 413 and the elastic tab is susceptible of abutting against the first stop shoulder 22 in order to prevent the rotation of the locking pin 41 in the release sense.

[0103] Advantageously, the elastic tab is configured for being bent up to a bent position, in which the free end 412 of the elastic tab is placed approached to the lateral surface of the main body 413 in order to allow the free rotation of the locking pin 41 in the constraint sense.

[0104] Advantageously, the support structure 2 is provided with at least one second stop shoulder 23, which is placed in the first housing seat 20, and the locking pin 41 comprises at least one second stop element 414, which is susceptible of abutting against the second stop shoulder 23 of the first housing seat 20 in order to prevent the rotation of the locking pin 41 in the release sense, when the locking pin 41 is in constraint position C.

[0105] Preferably, the second stop element 414 has tooth form, with substantially parallelepiped shape. Advantageously, the second stop element 414 is extended projecting from the lateral surface of the main body 413, preferably from an opposite side with respect to the first stop element 412, as is visible in FIG. 15.

[0106] Advantageously, the head 410 of the locking pin 41 is provided with a first abutment wall 418, which is directed towards the first opening 200 of the first housing seat 20.

[0107] More in detail, the head 410 has a parallelepiped form, substantially with rectangular base, and is provided with a lower face, directed towards the grip portion 415 of the locking pin 41, and an opposite upper face.

[0108] In particular, when the locking pin 41 is housed in the first housing seat 20, the lower face of the head 410 is directed towards the first opening 200.

[0109] Advantageously, the first abutment wall 418 of the head 410 is made on the lower face.

[0110] Advantageously, the support element 3 is provided with a second abutment wall 33, substantially planar, which is placed in the second housing seat 30 and against which the first abutment wall 418 of the head 410 is susceptible of abutting, in order to constrain the locking pin 41 in the second housing seat 30.

[0111] More in detail, the second abutment wall 33 of the support element 3 is directed in a sense opposite the first abutment wall 418.

[0112] Advantageously, the support element 3 is provided with a protuberance, which is extended projecting from an internal surface of the support element 3, towards the interior of the second housing seat 30, and which defines the aforesaid second abutment wall 33.

[0113] Advantageously, the first abutment wall 418 of the head 410 has at least one first section 418, tilted with respect to the second abutment wall 33 of the support element 3 by a first angle , and a second section 418, which is tilted with respect to the second abutment wall 33 of the support element 3 by a second angle , greater than the first angle .

[0114] Advantageously, with the locking pin 410 in rotation in the constraint sense, the second section 418 is susceptible of intercepting the first abutment surface 33 of the support element 3, previously with respect to the first section 418.

[0115] More in detail, the second section 418 of the first abutment wall 418 defines an introduction or slide section, which allows easily rotating the locking pin 410 in the constraint sense when the latter is positioned in the second housing seat 30, when the head 410 is at the second abutment wall 33 of the support element 3. In addition, the tilt of the first section 418 of the first abutment wall 418 determines a forced sliding of the first abutment wall 418 against the second abutment wall 33 of the support element 3 during the rotation of the locking pin 41, and such forced sliding determines a force oriented substantially orthogonal with respect to the two abutment walls 33, 418.

[0116] The aforesaid force determines a movement of the locking pin 41 within the first and the second housing seat 20, 30, parallel to the rotation axis R, which is possible due to the normal clearances that are present between the components, and which therefore increases the necessary force for rotating the locking pin 41 in the release sense, opposite the constraint sense.

[0117] In operation, the locking pin 41 is inserted in the first housing seat 20, by making it translate along an insertion direction X substantially parallel to the rotation axis R and to the main extension direction X, in particular by passing the head 410 through the first opening 200. Subsequently, the pin 41 is rotated around the rotation axis R up to the aforesaid release position B.

[0118] In such release position B, as described above, the support element 3 is released from the support structure 2 and separable from the latter, while the locking pin 41 is advantageously constrained to the support structure 2 along the insertion direction X.

[0119] In other words, when the locking pin 41 is placed in the release position B, it cannot be removed by translating it along the insertion direction X.

[0120] This allows the producer to pre-assemble the locking pin 41 with the support structure 2 and send the support structure 2 thus pre-assembled, reducing the risk of loss of the components (in particular the locking pin 41) and reducing the number of the necessary operations that the retailer or final client must carry out in order to assemble the chair 1.

[0121] For such purpose, the support structure 2 is advantageously provided with a retention wall 24, which is configured for interfering with the locking pin 41 (in particular with its head 410) in the release position B, in order to prevent the translation of the locking pin 41 along the insertion direction X.

[0122] More in detail, the retention wall 24 of the support structure 2 is placed substantially parallel to the first abutment wall 418 of the head 410, and is intended to abuttingly receive such first abutment wall 418, constraining the head 410, and thus the locking pin 41, along the insertion direction X.

[0123] Advantageously, the retention wall 24 of the support structure 2 is placed in a position diametrically opposite with respect to the locking pin 41, with respect to the second abutment wall 33 of the support element 3.

[0124] In particular, the retention wall 24 of the support structure 2 is placed outside the first housing seat 20, in proximity to the outlet opening 201. In other words, the locking pin 41 is advantageously inserted in the first housing seat 20 with the head 410 that projects externally from the outlet opening 201, and is subsequently rotated around the rotation axis R in a manner such to place the head 410 in abutment against the retention wall 24 of the support structure 2, as is visible in FIG. 6.

[0125] Also forming the object of the present invention is a method of mounting a chair 1 of the above-described type, regarding which for the sake of description simplicity the same reference numbers will be maintained.

[0126] The method, object of the present invention, comprises a step of arranging the support structure 2, which is provided with at least one first housing seat 20 provided with the first non-circular opening 200, and a step of arranging the support element 3, selected from among a back 31 and a pair of arms 32, which is provided with the second housing seat 30.

[0127] The method also comprises a step of inserting the locking pin 41 in the first opening 200 of the first housing seat 20 of the support structure 2, and a locking step, in which the locking pin 41 is rotated around the rotation axis R in the constraint sense, up to the release position B, in order to retain the locking pin 41 in the first housing seat 20, mounted in the support structure 2.

[0128] As set forth above, the insertion step provides for the insertion of the head 410 of the locking pin 41 along the insertion direction X, until the head 410 does not project outside the outlet opening 201 of the first housing seat 20, while the central body 413 is housed within the latter. The locking step also provides that the locking pin 41 be rotated around the rotation axis R (in particular in the constraint sense) up to the release position B in order to bring the first abutment wall 418 of the head 410 in abutment against the retention wall 24 of the support structure 2, constraining the locking pin 41 within the first housing seat 20, at least along the insertion direction X. In addition, in such release position B, the locking pin 41 is also advantageously impeded in its rotation around the rotation axis R by the elastic engagement between the elastic retention element 411 and the first retention recess 21, in particular with the engagement (preferably shape coupling) between the convex portion 411 of the elastic retention element 411 and the cavity of the first retention recess 21.

[0129] Still more preferably, in such release position B, the locking pin 41 is also prevented in its rotation around the rotation axis R, in the release sense, by the engagement between the second stop element 414 and the second stop shoulder 23 of the first housing seat 20.

[0130] The method also comprises a step of connecting the support element 3 to the support structure 2, with the second housing seat 30 aligned and communicating with the first housing seat 20. More in detail, such connection step provides that the support element 3 be placed with the second housing seat 30 aligned and communicating with the first housing seat 20, so as to be able to allow the engagement of the locking pin 41 (in particular of the head 410) in the second housing seat 30.

[0131] In particular, during the connection step, the back 3 is inserted tilted by an angle such to allow the insertion thereof without interfering with anti-removal elements provided on the support structure 2, which are visible in FIG. 16.

[0132] More in detail, as is seen in FIG. 16, the back 3 has an shaped engagement portion, and the support structure 2 has an insertion cavity that is counter-shaped with respect to the shaped engagement portion of the back 3, so as to prevent the removal of the back 3 once mounted on the support structure 2.

[0133] Advantageously, the support element 3 and the support structure 2 are configured for being connected at least partially to each other already in such connection step, preferably by means of a shape coupling of their components, so as to allow the user to mount the support element 3 on the support structure 2 in a nearly stable manner, before then proceeding with the subsequent fixing step without having to manually maintain the support element 3 in position on the support structure 2. For such purpose, the support element 3 is advantageously provided with an engagement portion that is inserted in a counter-shaped seat of the support structure 2, retaining the support element 3 in position and preventing the fall thereof during mounting.

[0134] The method also comprises a fixing step, in which the locking pin 41 is rotated around the rotation axis R in the constraint sense, up to the constraint position C, in order to constrain the support structure 2 to the support element 3.

[0135] More in detail, the fixing step provides that the locking pin 41 be rotated around the rotation axis R up to the constraint position C in order to bring the first abutment wall 418 of the head 410 in abutment against the second abutment wall 33 of the support element 3, constraining the locking pin 41 within the second housing seat 20 and constraining the support element 3 to the support structure 2.

[0136] In such constraint position C the locking pin 41 is also impeded in its rotation around the rotation axis R, in the release sense, also by the above-described engagement generated by the tilt between the first abutment wall 418 of the head 410 and the second abutment wall 33 of the support element 3.

[0137] In addition, in such constraint position C, the locking pin 41 is also advantageously impeded in its rotation around the rotation axis R (in particular in the release sense) by the elastic engagement between the elastic retention element 411 and the second retention recess 21, in particular with the engagement (preferably shape coupling) between the convex portion of the elastic retention element 411 and the cavity of the second retention recess 21.

[0138] Still more preferably, in such constraint position C, the locking pin 41 is also prevented in its rotation around the rotation axis R, in the constraint sense, by the engagement between the first stop element 412 and the first stop shoulder 22 of the first housing seat 20.

[0139] The invention thus conceived therefore attains the pre-established objects.

[0140] The contents of the Italian patent application number 102024000005005, from which this application claims priority, are incorporated herein by reference.