ACTUATING DEVICE FOR CONTROL OF ADJUSTMENT MECHANISMS OF CHAIRS, ARM-CHAIRS OR THE LIKE

Description

Field of the invention

[0001] This invention finds application in the field of adjustment mechanisms for task chairs, arm-chairs or the like, and particularly relates to an actuator or actuating device for control of adjustment mechanisms in chairs, arm-chairs or the like.

[0002] The invention further relates to an adjustment assembly and a seating structure for human body support comprising such actuator.

Background Art

[0003] The so-called "task" chairs or arm-chairs are known to have one or more mechanisms for position adjustment of certain parts thereof, e.g. for adjustment of height, seat inclination, backrest tension, and so on.

[0004] Such adjustment mechanisms are controlled by devices typically levers or buttons, which are generally situated below the seat, to be easily operated by a seated user.

[0005] One drawback of the above solutions is that such prior art control levers are not always easily operable by users, and force them to assume unnatural or dangerous positions. Furthermore, these prior art control levers often have long arms extending in the space below the seat, which involve an increase of costs and weight of the chairs on which they are mounted.

[0006] From DE 36 11 512, GB-A-2294872 and US 5 217 278, on which is based the preamble of the attached claim 1, is known an actuating device for part position adjustment mechanisms in chairs, arm-chairs or the like which comprises at least one shaft defining a longitudinal axis, which shaft has one inner end portion for connection to an adjustment mechanism and is integrally mounted to at least one control knob to be turned by a user about the longitudinal axis thereby actuating the adjustment mechanism. The device further comprises means for controlling the knob, which are adapted to selectively lock the knob in a first rest position proximal to said inner end portion of the shaft and to slideably move the knob from the first proximal rest position to a second operating position, distal to the inner end portion, so as to pull the knob out and allow fast and easy grasp thereof by a user.

Summary of the Invention

[0007] The object of this invention is to overcome the above drawbacks, by providing an actuator or actuating device for part position adjustment mechanisms in chairs, arm-chairs or the like, that is highly efficient and relatively cost-effective.

[0008] A particular object is to provide an actuator device that is simple and convenient to use.

[0009] A further object is to provide an actuator device that minimizes structural dimensions.

[0010] Another object of the invention is to provide a position adjustment assembly for chairs, arm chairs, or the like, that allows practical-and easy adjustment.

[0011] Yet another object of the invention is to provide a seating structure for human body support, such as a chair, an arm-chair or the like, that comprises an easily and comfortably operable adjustment device.

[0012] These and other objects, which will be more apparent hereafter, are fulfilled by an actuating device which, in accordance with the characterizing portion of claim 1, the control means are of the snap-lock type.

[0013] Thanks to this particular configuration, the knob may be pulled out, for fast and easy grasp thereof by a user. Thus, the actuating device of the invention allows to simply and easily adjust the position of parts of chairs, arm-chairs or the like, and to further minimize structural dimensions.

[0014] The term "position proximal to an end", as used herein, is intended as the position of an object proximate the relevant end.

[0015] The term "position distal to an end" as used herein is intended as the position of an object proximate the end opposite to the relevant end.

[0016] Advantageous embodiments of the invention are defined in accordance with the dependent claims.

[0017] According to a further aspect of the invention, there is provided a position adjustment assembly for parts of chairs, arm-chairs or the like according to claim 15.

[0018] According to another aspect of the invention, there is provided a seating structure for human body support, such as a chair, an arm-chair or the like- according to claim 16.

Brief Description of the Drawings

[0019] Further features and advantages of the invention will be more apparent from the detailed description of a preferred, non-exclusive embodiment of an actuator device according to the invention, which is described as a non-limiting example with reference to the annexed drawings, in which:

FIG. 1 is an axonometric view of an actuator device according to the invention in the first rest position;

FIG. 2 is an axonometric view of the device according to the invention in the second operating position;

FIG. 3 is a partly exploded axonometric view of the actuating device according to the invention;

FIG. 4 is an exploded axonometric view of the control means 10 in the device according to the invention;

FIG. 5 is a partly broken-away axonometric view of certain details of FIG. 4;

FIG. 6 is a partly broken-away side view of the actuating device according to the invention in a first operating position;

FIG. 7 is a plan view of the actuating device according to the invention in the position of FIG. 6;

FIG. 8 is a partly broken-away side view of the actuator device according to the invention in a second operating position;

FIG. 9 is a plan view of the actuating device according to the invention in the position of FIG. 8;

FIG. 10 is a partly broken-away side view of the actuating device according to the invention in a third operating position;

FIG. 11 is a plan view of the actuating device according to the invention in the position of FIG. 10;

FIG. 12 is an exploded axonometric view of the connection between the control knob and the shaft of the actuating device according to the invention;

FIG. 13 is a partly broken-away view of a seat of a seating structure which incorporates an adjustment assembly comprising the device of the invention.

Detailed description of a preferred embodiment

[0020] Referring to the above figures, the actuator or actuating device of the invention, generally designated by numeral 1, may be associated to mechanisms for adjustment of parts of seats, such as chairs, arm-chairs or the like, to form a so-called "adjustment assembly", which is part of the seat. For example, the device may be associated to a chair backrest inclination adjustment mechanism, or to a seat height adjustment mechanism.

[0021] Nevertheless, it will be understood that the actuator device of the invention may be associated to any adjustment mechanism for any part of a chair, arm-chair or the like, without departure from the scope as set forth in the annexed claims.

[0022] The device 1, as shown in FIGS.1 and 2, generally comprises a shaft 2, which defines a longitudinal axis X, and a control knob 3 which is integrally mounted thereto to turn about the axis X, in the direction indicated by arrow F1 in FIG. 2, so that a rotation of the knob 3 in one direction causes a rotation of the shaft 2 in the same direction.

[0023] In a preferred, non limiting embodiment of the invention, as shown in FIG. 12, the knob 3 may be formed integrally with the shaft 2 by contact fit of a portion 4 of an inner surface 5 thereof, here having a hexagonal plan shape, which is defined by a channel 6 formed therein, with a correspondingly shaped portion 7 of the outer surface 8 of the shaft 2.

[0024] Shaft 2 has an inner end portion 9 for connection to the seat adjustment mechanism in which the device 1 is inserted, not shown due to its being known. The connection may be mechanically operated, e.g. by means of a lever or gear arrangement.

[0025] According to the invention, the device 1 comprises means, generally designated by numeral 10, for axial control of knob 3, which are adapted to lock the latter in a first rest position, as shown in FIG. 1, proximal to the inner portion 9 of the shaft 2 and to slideably move the knob 3, along the axis X, from the first proximal rest position to a second operating position, as shown in FIG. 2, which is distal to said end portion 9.

[0026] The operation of the device 1 is better shown in FIG. 13, in which the device is associated to an adjustment assembly 11 and incorporated in a seat 12. Thanks to the axial control means 10, the knob 3 may be extended from the first rest position, indicated by dash lines in the figure, in which the knob 3 is substantially embedded in the seat 12, to the distal operating position, in which it is pulled out of the seat 12, thereby allowing fast and easy grasp thereof by a user.

[0027] This may occur by simply operating the control means 10, i.e. unlocking the knob 3 and slideably moving it outwards, in the direction of arrow F2.

[0028] In a preferred non-limiting embodiment of the invention, the control means 10 may of the snap-lock type, as shown in detail in Figures 3 to 5.

[0029] Advantageously, they may include a plurality of first tooth-shaped portions 13, which are integral with the knob 3 and adapted to slideably interact with corresponding second substantially correspondingly tooth-shaped portions 14 of an annular ring 15 integral with the shaft 2. Such ring 15 operatively abuts against a support structure 16 for the shaft 2, e.g. a body made of a polymer or metal material.

[0030] As particularly shown in FIG. 5, the first tooth-shaped portions may have a first inclined end wall 17, which faces a second inclined end wall 18, for mutually sliding motion, thereby facilitating rotation of the annular ring 15 about the axis X upon interaction with the knob, as better described hereafter and shown n FIGS. 6 to 11.

[0031] Conveniently, the snap-lock control means 10 may comprise a cylindrical element 19, slideably interposed between the knob 3 and the annular ring 15, which has a plurality of outward projections 20 for guiding the sliding motion of the first tooth-shaped portions 13 along the axis X.

[0032] To assist disengagement of the first tooth-shaped portions 13 from the second tooth-shaped portions 14, the snap-lock means 10 may further have a first elastic member 21, e.g. a helical spring, between the knob 3 and the cylindrical element 19.

[0033] To facilitate the sliding motion of the second tooth-shaped portions 14 relative to the first tooth-shaped portions 13, the projections 20 of the cylindrical element 21 may have the end wall 22 inclined at the same angle as the walls 17 of the first tooth-shaped portions 13.

[0034] Furthermore, the snap-lock control means 10 may advantageously comprise a second elastic member 23, e.g. a second helical spring, between the second tooth-shaped portions 14 and the support structure 16 to promote elastic release along the axis X.

[0035] In a preferred non-limiting embodiment of the invention, the knob 3 may have an elongate hand grip 24 and a widened end extension 25. The latter has a bottom wall defined by the tooth-shaped portions 13 and a cylindrical side wall 26 for sliding engagement with the annular ring 15 to stop the sliding motion of the knob 3 when the latter turns about the axis X.

[0036] Suitably, the cylindrical extension 25 may have a maximum inner diameter D1 greater than the maximum outer diameter D2 of the annular ring 15, to allow mutual sliding engagement.

[0037] Advantageously, the control means 10 may comprise a plurality of male elements 27, for instance a plurality of radial inward projections 28 formed around the cylindrical side wall 26 of the extension 25, for engagement in corresponding female elements 29, for instance a plurality of recesses 30 formed around the peripheral wall 31 of the annular ring 15.

[0038] In order to ensure that the knob is firmly locked in the first rest position, the snap-lock control means 10 may further include a plurality of abutment members 32 which project radially outwards from the outer peripheral wall 31 of the annular ring 15.

[0039] The operation of the control means 10 is better shown in FIGS. 6 to 11.

[0040] For the knob 3 to be locked in the rest position or pulled out, the first tooth-shaped portions 13 shall interact with the second tooth-shaped portions 14, to cause partial rotation of the ring 15. Thus, the abutment members 32 will move from a first position in which the knob 3 is axially locked, as shown in FIG. 11, with the members 32 abutting against the projections 28 of the extension 25, to a second position in which the knob is axially unlocked, as shown in FIG. 7, with the members 32 being released from the projections 28 of the extension 25 and being aligned with the recesses 30, thereby allowing the knob to freely slide along the axis X to reach the second operating position.

[0041] In FIG. 6, the knob 3 is axially displaced along the axis X to bring the tooth-shaped portions 13 of the extension 25 to interaction with the tooth-shaped portions 14 of the ring 15 by lifting it in the direction of arrow F3. The projections 20 guide the sliding motion of the tooth-shaped portions 13, allowing interaction between the walls 17 and 18, and lifting the ring 15 in the direction of arrow F4. The spring 21 is thus loaded, as well as the spring 23 abutting against the ring 15.

[0042] FIG. 7 shows the male projections 28 of the extension 25 in the female recesses 30 of the ring 15.

[0043] In FIG. 8, the tooth-shaped portions 13 of the extension 25 have reached an axial position in which the walls 18 of the tooth-shaped portions 14 of the ring 15 start to slide onto the walls 22 of the projections 20 in the direction of arrow F5. Thus, the ring 15 will rotate in the direction of arrow F6, whereas the springs 21 and 23 will be at their maximum load conditions.

[0044] Due to the rotation of the ring 15, as shown in FIG. 9, the female recesses 30 will rotate relative to the male projections 28, thereby causing the members 32 to abut against the male projections 28.

[0045] FIG. 10 shows that, thanks to the spring 21, the tooth-shaped portions 13 are axially released from the tooth-shaped portions 14, in the direction of arrow F7, to move back to their start position.

[0046] FIG. 11 shows the members 32 of the ring abutting against the projections 28 of the extension 25 of the knob 3. Therefore, the knob is locked in its rest position until the next axial displacement thereof and the next interaction between the tooth-shaped portions 13 and the tooth-shaped portions 14, allowing it to be unlocked and pulled out.

[0047] The above disclosure clearly shows that the invention fulfills the intended objects and particularly meets the requirement of providing an actuating device of simple and comfortable use.

[0048] Thanks to the control means 10 for selectively locking the knob 3 in the first proximal rest position and for slideably moving it into the second distal operating position, the knob 3 may be pulled out for fast and easy grasp thereof by a user.

[0049] The actuating device of this invention is susceptible of a number of changes and variants, within the inventive concept disclosed in the appended claims. All the details thereof may be replaced by other technically equivalent- parts, and the materials may vary depending on different needs, without departure from the scope of the invention according to the appended claims.

[0050] While the actuator has been described with particular reference to the accompanying figures, the numerals referred to in the disclosure and claims are only used for the sake of a better intelligibility of the invention and shall not be intended to limit the claimed scope in any manner.

Claims

1. An actuating device for use in combination with at least one mechanism for position adjustment of parts of chairs, arm-chairs or the like, comprising at least one shaft (2), defining a longitudinal axis (X), said shaft (2) having one inner end portion (9) for connection to the adjustment mechanism and being integrally mounted to at least one control knob (3), to be turned by a user about said axis (X) thereby actuating the adjustment mechanism, and further comprising means (10) for controlling said knob (3), which are adapted to selectively lock said knob (3) in a first rest position proximal to said inner end portion (9) of said shaft (2) and to slideably move said knob (3) from said first proximal rest position to a second operating position, distal to said inner end portion (9), so as to pull said knob (3) out and allow fast and easy grasp thereof by a user, characterized in that said control means (10) are of the snap-lock type.

2. Device as claimed in claim 1, characterized in that said snap-lock control means (10) comprise a plurality of first tooth-shaped portions (13) formed integrally with said knob (3), which are adapted to slideably interact with respective second substantially correspondingly tooth-shaped portions (14) of an annular ring (15) which is able to slide on said shaft (2) and operatively abuts against a support element (16).

3. Device as claimed in claim 2, characterized in that said first tooth-shaped portions (13) have a first inclined end wall (17) facing a second correspondingly inclined end wall (18), to allow mutual sliding motion and assist rotation of said annular ring (15) about said axis (X) upon interaction with said knob (3).

4. Device as claimed in claim 3, characterized in that said snap-lock control means (10) further comprise a cylindrical element (19), slideably interposed between said knob (3) and said annular ring (15), which has a plurality of outward projections (20) for guiding the sliding motion of said first tooth-shaped portions (13) along said axis (X).

5. Device as claimed in claim 4, characterized in that said snap-lock control means (10) further comprise a first elastic member (21) between said knob (3) and said cylindrical element (19), to assist elastic release of said first tooth-shaped portions (13) from said second tooth-shaped portions (14).

6. Device as claimed in claim 5, characterized in that said projections (20) of said cylindrical element (19) have an end wall (21) proximal to said annular ring (15) whose inclination corresponds to the inclination of the end walls (17) of said first tooth-shaped portions (13) to facilitate the sliding motion of said second tooth-shaped portions (14) relative thereto.

7. Device as claimed in claim 6, characterized in that said snap-lock control means (10) further comprise a second elastic member (23) between said second tooth-shaped portions (14) and said support structure (16) to assist elastic release thereof along said axis (X).

8. Device as claimed in claim 7. characterized in that said knob (3) has a widened end extension (25) with a bottom wall defined by said first tooth-shaped portions (13) and a cylindrical side wall (26) for sliding engagement with said annular ring (15) to selectively stop the sliding motion of the knob (3) when the latter turns about said axis (X).

9. Device as claimed in claim 8, characterized in that said cylindrical extension (25) has an outside diameter (D₂₎ that is smaller than the inside diameter (D₁₎ of said tubular element (15).

10. Device as claimed in claim 9, characterized in that said control means (10) have a plurality of male elements (27) formed on one of said widened extension (25) and annular ring (15), and a plurality of corresponding female elements (29) formed on the other of said widened extension (25) and annular ring (15).

11. Device as claimed in claim 10, characterized in that said male elements (27) have radial inward projections (28) formed around said side wall (26) of said extension (25), said female elements (29) having corresponding recesses (30), formed around the outer peripheral wall (31) of said annular ring (15).

12. Device as claimed in claim 10, characterized in that said snap-lock control means further comprise a plurality of abutment members (32) which project radially outwards from said outer peripheral wall (31) of said annular ring (15) for interaction by abutment against said projections (28) of said side wall (26) of said extension (25) to lock the axial sliding motion of said knob (3).

13. A device as claimed in claim 1, characterized in that said control shaft has at least one outer surface portion with a predetermined plan shape, operatively in contact with at least one correspondingly shaped portion of an inner surface of said knob to lock the rotation of said knob relative to said shaft and allow integral displacement thereof about said axis.

14. An adjustment assembly comprising-at least one part position adjustment mechanism for chairs, arm-chairs or the like, characterized in that it comprises an actuating device as claimed in any one of the preceding claims.

15. A seating structure for human body support, such as a chair, an arm-chair or the like, characterized in that it comprises an actuating device as claimed in any one of the preceding claims.

Ansprüche

1. Betätigungsvorrichtung zur Verwendung in Kombination mit mindestens einem Verstellmechanismus von Teilen von Stühlen, Sesseln oder ähnlichem mit:

- mindestens einer Welle (2), die eine longitudinale Achse (X) bestimmt, wobei die Welle (2) einen inneren Endabschnitt (9) aufweist zur Verbindung mit dem Verstellmechanismus und einteilig montiert ist an mindestens einem Steuerelement (3), das von einem Nutzer um die Achse (X) zu drehen ist zur Betätigung des Verstellmechanismus und zudem Einrichtungen (10) vorgesehen sind zur Steuerung des Elements (3), die so ausgebildet sind, dass das Element (3) wahlweise verriegelt ist in einer ersten Ruhestellung nahe dem inneren Endabschnitt (9) der Welle (2) und das Element (3) gleitend zu bewegen von der ersten nahen Ruhestellung in eine zweite Betriebsstellung, die beabstandet ist von dem inneren Endabschnitt (9), um so das Element (3) heraus zu ziehen und so einem Nutzer dessen schnelles und leichtes Ergreifen zu ermöglichen, dadurch
gekennzeichnet, dass die Steuereinrichtungen (10) als Schnappverriegelung ausgebildet sind.

2. Vorrichtung gemäß Anspruch 1, dadurch gekennzeichnet, dass die Schnappverriegelungs-Steuereinrichtungen (10) eine Vielzahl von ersten, zahnförmigen Abschnitten (13) aufweisen, die integral in dem Element (3) gebildet sind und ausgebildet sind gleitend zusammen zu wirken mit jeweils zweiten, entsprechend zahnförmigen Abschnitten (14) eines ringförmigen Rings (15), der auf der Welle (2) gleiten kann und sich im Betrieb gegen ein Tragelement (16) abstützen kann.

3. Vorrichtung gemäß Anspruch 2, dadurch gekennzeichnet, dass die ersten, zahnförmigen Abschnitte (13) eine erste geneigte Abschlusswand (17) aufweisen gegenüber einer zweiten entsprechend geneigten Abschlusswand (18), um gegenseitige Gleitbewegung zu ermöglichen und Drehung des ringförmigen Rings (15) um die Achse (X) zu unterstützen nach Zusammenwirken mit dem Element (3).

4. Vorrichtung gemäß Anspruch 3, dadurch gekennzeichnet, dass die Schnappverriegelungs-Steuereinrichtungen (10) zudem ein zylindrisches Element (19) aufweisen, das gleitend angeordnet ist zwischen dem Element (3) und dem ringförmigen Ring (15), das eine Vielzahl von nach außen gerichteten Vorsprüngen (20) aufweist zur Führung der gleitenden Bewegung der ersten, zahnförmigen Abschnitte (13) entlang der Achse (X).

5. Vorrichtung gemäß Anspruch 4, dadurch gekennzeichnet, dass die Schnappverriegelungs-Steuereinrichtungen (10) zudem ein erstes elastisches Element (21) aufweisen zwischen dem Element (3) und dem zylindrischen Element (19) um die elastische Freigabe der ersten, zahnförmigen Abschnitte (13) von den zweiten, zahnförmigen Abschnitten (14) zu unterstützen.

6. Vorrichtung gemäß Anspruch 5, dadurch gekennzeichnet, dass die Vorsprünge (20) des zylindrischen Elements (19) eine Abschlusswand (21) aufweisen nahe dem ringförmigen Ring (15), dessen Neigung der Neigung der Abschlusswände (17) der ersten, zahnförmigen Abschnitte (13) entspricht um die dazu relative Gleitbewegung der zweiten, zahnförmigen Abschnitte (14) zu erleichtern.

7. Vorrichtung gemäß Anspruch 6, dadurch gekennzeichnet, dass die Schnappverriegelungs-Steuereinrichtungen (10) zudem ein zweites elastisches Element (23) zwischen den zweiten, zahnförmigen Abschnitten (14) und der Tragstruktur (16) aufweisen, um deren elastische Freigabe entlang der Achse (X) zu unterstützen.

8. Vorrichtung gemäß Anspruch 7, dadurch gekennzeichnet, dass das Element (3) eine erweiterte Endverlängerung (25) umfasst mit einer Bodenwand, die gebildet ist aus den ersten, zahnförmigen Abschnitten (13) und einer zylindrischen Seitenwand (26) zum gleitenden Eingriff mit dem ringförmigen Ring (15), um wahlweise die gleitende Bewegung des Elements (3) zu stoppen, wenn das Letztere sich um die Achse (X) dreht.

9. Vorrichtung gemäß Anspruch 8, dadurch gekennzeichnet, dass die zylindrische Verlängerung (25) einen Außendurchmesser (D₂) aufweist, der kleiner ist als der Außendurchmesser (D₁) des rohrförmigen Elements (15).

10. Vorrichtung gemäß Anspruch 9, dadurch gekennzeichnet, dass die Steuereinrichtungen (10) eine Vielzahl männlicher Elemente (27) aufweisen, die auf einer der erweiterten Verlängerungen (25) und dem ringförmigen Ring (15) und eine Vielzahl weiblicher Elemente (29), die auf dem Anderen der erweiterten Verlängerungen (25) und dem ringförmige Ring (15) gebildet sind.

11. Vorrichtung gemäß Anspruch 10, dadurch gekennzeichnet, dass die männlichen Elemente (27) radial nach innen gerichtete Vorsprünge (28) aufweisen, die um die Seitenwand (26) der Verlängerung (25) gebildet sind und die weiblichen Elemente (29) entsprechende Vertiefungen (30) aufweisen, die um die äußere Umfangswand (31) des ringförmigen Rings (15) gebildet sind.

12. Vorrichtung gemäß Anspruch 10, dadurch gekennzeichnet, dass die Schnappverriegelungs-Steuereinrichtungen (10) zudem eine Vielzahl von Anschlagelementen (32) aufweisen, die sich radial nach außen erstrecken von der äußeren Umfangswand (31) des ringförmigen Rings (15) zum Zusammenwirken mittels Anlage gegen die Vorsprünge (28) der Seitenwand (26) der Verlängerung (25), um die axiale Gleitbewegung des Elements (3) zu verriegeln.

13. Vorrichtung gemäß Anspruch 1, dadurch gekennzeichnet, dass die Steuerwelle mindestens einen äußeren Oberflächenbereich aufweist mit einer vorbestimmten, ebenen Form, die im Betrieb mindestens mit einer entsprechend geformten Abschnitt einer inneren Oberfläche des Elements, um die Drehung des Elements um die Achse zu verriegeln und dessen gesamte Verschiebung um die Achse zu ermöglichen.

14. Einstellvorrichtung mit mindestens einem Verstellmechanismus eines Teils von Stühlen, Sesseln oder ähnlichem, dadurch gekennzeichnet, dass es eine Betätigungsvorrichtung aufweist, wie in einem der vorhergehenden Ansprüche beansprucht.

15. Sitzstruktur zur Aufnahme menschlicher Körper wie z. B. Stuhl, Sessel oder ähnliches, dadurch gekennzeichnet, dass sie eine Betätigungsvorrichtung aufweist, wie in einem der vorhergehenden Ansprüche beansprucht.

Revendications

1. Dispositif d'actionnement destiné à être utilisé en combinaison avec au moins un mécanisme pour le réglage de la position de parties de chaises, fauteuils et analogues, comprenant au moins un arbre (2) qui définit un axe longitudinal (X), ledit arbre (2) ayant une partie d'extrémité intérieure (9) prévue pour la liaison avec le mécanisme de réglage et étant monté en une seule pièce sur au moins un bouton de commande (3) destiné à être tourné autour dudit axe (X) par l'utilisateur en actionnant ainsi le mécanisme de réglage, et comprenant en outre des moyens (10) servant à commander ledit bouton (3) qui sont adaptés pour verrouiller sélectivement ledit bouton (3) dans une première position de repos proximale relativement rapport à ladite partie d'extrémité intérieure (9) dudit arbre (2) et pour faire coulisser ledit bouton (3) depuis ladite première position de repos proximale jusqu'à une seconde position de travail, distale relativement à ladite partie d'extrémité intérieure (9), de manière à tirer ledit bouton (3) vers l'extérieur et à permettre à un utilisateur de le saisir rapidement et facilement, caractérisé en ce que lesdits moyens de commande sont du type verrou d'accrochage

2. Dispositif selon la revendication 1, caractérisé en ce que lesdits moyens de commande à verrou d'accrochage (10) comprennent une pluralité de premières parties en forme de dent (13) formées en une seule pièce avec ledit bouton (3), qui sont adaptées pour interagir par coulissement avec des deuxièmes parties respectives en forme de dent (14) sensiblement correspondantes d'une bague annulaire (15) qui peut coulisser sur ledit arbre (2) et qui bute en fonctionnement contre un élément de support (16).

3. Dispositif selon la revendication 2, caractérisé en ce que lesdites premières parties en forme de dent (13) ont une première paroi d'extrémité inclinée (17) qui fait face à une deuxième paroi d'extrémité (18) inclinée de façon correspondante, pour permettre un mouvement de coulissement mutuel et assister la rotation de ladite bague annulaire (15) autour dudit axe (X) à la suite de l'interaction avec ledit bouton (3).

4. Dispositif selon la revendication 3, caractérisé en ce que lesdits moyens de commande à verrou d'accrochage (10) comprennent en outre un élément cylindrique (19) interposé avec possibilité de coulissement entre ledit bouton (3) et ladite bague annulaires (15), qui possède une pluralité de saillies extérieures (20) servant à guider le mouvement de coulissement desdites premières parties en forme de dent (13) le long dudit axe (X).

5. Dispositif selon la revendication 4, caractérisé en ce que lesdits moyens de commande à verrou d'accrochage (10) comprennent en outre un premier organe élastique (21) entre ledit bouton (3) et ledit élément cylindrique (19) pour assister la désolidarisation élastique desdites premières parties en forme de dent (13) par rapport auxdites secondes parties en forme de dent (14).

6. Dispositif selon la revendication 5, caractérisé en ce que lesdites saillies (20) dudit élément cylindrique (19) ont une paroi d'extrémité (21) proximale par rapport à ladite bague annulaire (15), dont l'inclinaison correspond à l'inclinaison des parois d'extrémité (17) desdites premières parties en forme de dent (13) pour faciliter le mouvement de coulissement desdites secondes parties en forme de dent (14) par rapport à elles.

7. Dispositif selon la revendication 6, caractérisé en ce que lesdits moyens de commande à verrou d'accrochage (10) comprennent en outre un second organe élastique (23) entre lesdites secondes parties en forme de dent (14) et ladite structure de support (16) pour assister leur désolidarisation élastique le long dudit axe (X).

8. Dispositif selon la revendication 7, caractérisé en ce que ledit bouton (3) possède un prolongement d'extrémité agrandi (25) muni d'une paroi de fond définie par lesdites premières parties en forme de dent (13) et une paroi latérale cylindrique (26) destinée à coopérer par coulissement avec ladite bague annulaire (15) pour arrêter sélectivement le mouvement de coulissement du bouton (3) lorsque ce dernier tourne autour dudit axe (X).

9. Dispositif selon la revendication 8, caractérisé en ce que ledit prolongement cylindrique (25) possède un diamètre extérieur (D2) qui est plus petit que le diamètre intérieur (D1) dudit élément tubulaire (15).

10. Dispositif selon la revendication 9, caractérisé en ce que lesdits moyens de commande (10) possèdent une pluralité d'éléments mâles (27) formés sur l'un dudit prolongement agrandi (25) et de la bague annulaire (15), et une pluralité d'éléments femelles correspondants (29) formés sur l'autre dudit prolongement agrandi (25) et de la bague annulaire (15).

11. Dispositif selon la revendication 10, caractérisé en ce que lesdits éléments mâles (27) ont des saillies intérieures radiales (28) formées sur le tour de ladite paroi latérale (26) dudit prolongement (25), lesdits éléments femelles (29) ayant des creux correspondants (30) formés sur le tour de la paroi périphérique extérieure (31) de ladite bague annulaire (15).

12. Dispositif selon la revendication 10, caractérisé en ce que lesdits moyens de commande a verrou d'accrochage comprennent en outre une pluralité d'éléments de butée (32) qui font saillie radialement vers l'extérieur à partir de ladite paroi périphérique ultérieure (31) de ladite bague annulaires (15) pour interagir par mise en butée contre lesdites saillies (28) de ladite paroi latérale (26) dudit prolongement (25) afin de verrouiller le mouvement de coulissement axial dudit bouton (3).

13. Dispositif selon la revendication 1, caractérisé en ce que ledit arbre de commande possède au moins une partie de surface extérieure présentant une forme en plan prédéterminée, qui est en fonctionnement en contact avec au moins une partie de forme correspondante d'une surface intérieure dudit bouton pour verrouiller la rotation dudit bouton par rapport audit arbre et permettre son déplacement conjoint autour dudit axe.

14. Ensemble de réglage comprenant au moins un mécanisme de réglage de la position d'une pièce pour chaises, fauteuils ou équivalents, caractérisé en ce qu'il comprend un dispositif d'actionnement selon une quelconque des revendications précédentes.

15. Structure d'assise destinée à supporter un corps humain, tel qu'une chaise, un fauteuil ou analogue, caractérisée en ce qu'elle comprend un dispositif d'actionnement selon une quelconque des revendications précédentes.

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