WO2020224849A1

WO2020224849A1 - Adjustment device for a chair with rocking mechanism

Info

Publication number: WO2020224849A1
Application number: PCT/EP2020/057981
Authority: WO
Inventors: Stefano Serena; Marco DALL'ACQUA; Simone DE ROSSI
Original assignee: Brado S.P.A.
Priority date: 2019-05-09
Filing date: 2020-03-23
Publication date: 2020-11-12
Also published as: EP3965618A1; ES2978891T3; PL3965618T3; EP3965618B1; IT201900006667A1

Abstract

An adjustment device (1) for a chair, which comprises a rocking mechanism composed of a first plate (2), which is fixed to a central gas- operated post (7) for the height adjustment of a seat and to which a second plate (10) is articulated, about a first axis (9) that is transverse thereto and so that it can rock, the second plate being fixed to a seat and interacting with means (8a, 8b) which are adapted to contrast the rocking of a backrest, a lever (13) being articulated laterally to the first plate (2), at an axis that is different from the first axis (9). The device is provided with first means for elastic interconnection between the lever (13) and a first head (32) which is adapted to block/release the rocking between the first plate and the second plate (2, 10), and second means for temporarily locking the rotation of the lever (13) in two distinct positions. The second means preload the first means in order to block/release the rocking in the presence of a load applied to the seat.

Description

ADJUSTMENT DEVICE FOR A CHAIR WITH ROCKING MECHANISM

The present invention relates to an adjustment device for a chair that has a rocking mechanism.

Nowadays it is known to provide chairs that are fitted with a mechanism the function of which is to enable for example the height adjustment of a seat and the adjustment of the rocking, or the locking in place, of a backrest.

An example of the mentioned prior art is disclosed in US 6,120,096, where the activation of the mechanisms which interact with the seat and with the backrest are activated by way of using a first lever, the rotation of which leads to the packing or otherwise of special slats, and also a second lever, the lifting of which leads to its terminal end interacting with a gas-filled piston present on a central gas-operated post.

Such rocking mechanisms are structurally complex and require a certain force of the user in order to activate the packing of the slats, which may also be subject to possible seizing.

EP 2554075B1 is also known, which relates to a chair with a rocking mechanism,

- wherein the rocking mechanism has a fixed base support with a conical receptacle, said fixed base support being placeable by means of the conical receptacle on a chair pillar of the chair,

- wherein the base support is connected pivotably to a mechanism upper part which forms a housing at least partially enclosing the base support,

- wherein the pivot axis of the mechanism upper part, which pivot axis runs transversely with respect to the chair longitudinal direction, is arranged next to the conical receptacle, as seen in the chair longitudinal direction,

- wherein at least one spring element interacting on the one hand with the mechanism upper part and on the other hand with the base support is provided in order to return the mechanism upper part from a pivoted position into a starting position, and - wherein the rocking mechanism is fastened by means of the mechanism upper part to a seat, a seat support or a frame of the chair, or the rocking mechanism is integrated into the seat, the seat support or the frame of the chair, in such a manner that the mechanism upper part is formed by part of the seat, of the seat support or of the chair frame,

wherein a valve pin for triggering a pneumatic spring placed in the interior of the chair pillar is located in the region of the conical receptacle, and, in order to trigger the pneumatic spring, a pivot lever interacting with at least part of the rocking mechanism is provided for actuating the valve pin, and wherein the pivot lever is placed in such a manner that the axis of rotation of the pivot lever coincides with the pivot axis of the mechanism upper part.

This solution is also structurally complex, and a compaction has been found of the positioning of the components, which compromises the achievement of an optimal rocking.

Furthermore, in the known art it has been found that, in conventional devices, sticking and breakages of the internal mechanisms are possible if, with a load applied on the seat, the user tries to activate or block the rocking function again using the lever.

The aim of the present invention is to solve the above mentioned technical problems, eliminating the drawbacks in the cited known art, by providing an adjustment device for a chair that makes it possible to achieve at the same time, rapidly, simply and optimally, both the activation and prevention of rocking for a chair, and also the activation of the raising of said chair.

Within this aim, an object of the invention is to provide an adjustment device for a chair that, in addition to the foregoing characteristics, also makes it possible to preserve the structural integrity of the various components even upon the accidental activation/deactivation, using a lever, of the rocking by the user. Another object of the invention is to provide an adjustment device that can be activated in order to activate the rocking, block the rocking, and adjust the height of the chair all using a single lever.

Another object of the invention is to provide an adjustment device that, in addition to the foregoing characteristics, also enables the user to automatically determine the condition of activation/deactivation of the rocking after the actuation of the lever even in the presence of a load applied to the chair while at the same time preserving the internal components from accidental breakage.

Another object of the invention is to provide an adjustment device that is structurally simple and free from sticking.

Another object of the invention is to provide an adjustment device that is of low cost and which can be made with the usual conventional systems.

This aim and these and other objects which will become better apparent hereinafter are achieved by an adjustment device for a chair, which comprises a rocking mechanism composed of a first plate, which is fixed to a central gas-operated post for a height adjustment of a seat and to which a second plate is articulated, about a first axis that is transverse thereto and so that it can rock, said second plate being fixed to a seat and interacting with means which are adapted to contrast a rocking of a backrest, a lever being articulated laterally to said first plate, at an axis that is different from said first axis, characterized in that it is provided with first means for elastic interconnection between said lever and a first head which is adapted to block/release a rocking between said first plate and said second plate,

and second means for temporarily locking a rotation of said lever in two distinct positions,

said second means preloading said first means in order to block/release said rocking in the presence of a load applied to said seat.

Further characteristics and advantages of the invention will become better apparent from the detailed description of a particular, but not exclusive, embodiment thereof which is illustrated by way of non-limiting example in the accompanying drawings wherein:

Figure 1 is a perspective view from below of the device applied to a central gas-operated post;

Figure 2 shows the device without the plate associated with a seat;

Figure 3 is a different view of the device in the previous figure, shown in the rocking-enabled condition;

Figure 4 is a side view of the device of the previous figure, in the free position;

Figure 5 is a view from above of the device of Figure 3 in the free position;

Figure 6 is a cross-sectional view of the device taken along the line VI- VI of Figure 5;

Figure 7 shows the device of the previous figure when rocking;

Figure 8 is a cross-sectional view of the device taken along the line

VIII- VIII in Figure 5;

Figure 9 is a view from above of the device in the blocked position;

Figure 10 shows the device of the previous figure in the free position with some components transparent;

Figure 11 is a view from above of the device in the position in which rocking is permitted;

Figure 12 is a cross-sectional view of the device taken along the line XII-XII of Figure 11 ;

Figure 13 is a cross-sectional view of the device taken along the line XIII-XIII of Figure 11;

Figure 14 is a side view of the lever in the position for activating the gas-operated post;

Figure 15 is a perspective side view from above of the device in the position for actuating the gas-operated post; Figure 16 is a cross-sectional view of the device taken along a horizontal plane passing through the second spring;

Figure 17 is a cross-sectional view of the device taken along a horizontal plane passing through the piston;

Figure 18 shows the device in the blocking condition;

Figure 19 is a cross-sectional view of the device taken along the line XIX-XIX of Figure 18.

In the embodiments illustrated below, individual characteristics shown in relation to specific examples may in reality be interchanged with other, different characteristics, existing in other embodiments.

With reference to the figures, the reference numeral 1 generally designates an adjustment device for a chair (not shown) which comprises a rocking mechanism composed of a first plate 2, which has a substantially C- shaped box-like shape so as to define a base 3 and two first lateral wings 4a, 4b; in the inner part of the base 3 there is a protruding bushing 5 at which the end of the stem 6 of a central gas-operated post 7, mounted on a footing and used for the height adjustment of a seat (not shown), is associated.

A second plate 10, which can be fixed to a seat (not shown), is articulated to the first plate 2 so that it can rock, by virtue of a first pivot 8a and a screw 8b which lie on a first axis 9 which is transverse and eccentric with respect to the first plate 2.

The plate 10 is preferably made of plastic material, in this way it being possible to modify its shape and color for customization.

The first plate 2 interacts with means adapted to contrast the rocking of the seat, such means being constituted by a pair of first springs 11a, l ib which protrude inside the base 3 and are interposed between the latter and the second plate 10.

Preferably at the lateral wing 4a there is an opening 12 at which a lever 13 can be positioned.

An element for protecting the fingers of the user, such as a bushing made of elastically deformable plastic material 150, can advantageously be inserted into such opening 12, coaxially to the lever 13.

The lever 13 is also preferably made of plastic material, in this way it being possible to modify its shape and color for customization.

The opening 12 has dimensions that are such as to allow the lever 13 to perform movements both on a first plane 100, which is perpendicular to the base 3 of the plate 2, and on a second plane 200, which is substantially parallel to the plane of the base 3.

The lever 13 has a first portion 14, which is external to the plate 2, and a second portion 15, which is internal to the plate.

The lever 13 when inactive lies on a different axis with respect to the first axis 9.

The second portion 15 has, adjacent to the opening 12, a cylindrical insert 16 which acts as a seat for a second pivot 17 for pivoting the lever 13 to the first plate 2; the second pivot 17 has a first stem 18 which can be positioned in a fixed manner at an adapted first seat 19a which is provided inside the base 3 of the first plate 2, and so that it can rock within a second seat 19b which is shaped substantially like an opposing double truncated cone.

A movement of the lever 13 on the first plane 100, which is perpendicular to the first plate 2, corresponds to a rocking of the second portion 15 of the lever 13 with respect to the second pivot 17 for pivoting.

The second portion 15 has a radial tab 20, facing in the direction of the lateral wing 4b, which is such as to be positioned above the central gas- operated post 7 so as to be able to activate it upon a movement that can be imparted to the first portion 14 of the lever 13 on the first plane 100 substantially at right angles to the base 3 and in the opposite direction with respect to the base 3.

This movement makes it possible to perform the height adjustment of the seat. The vertical movement of the lever 13 with respect to the first plate 2 is freely allowed.

The device 1 comprises means adapted to prevent the rocking of the second plate 10 with respect to the first plate 2, the means being constituted by a mechanism 23 which is arranged slideably and inside the first plate 2 in a direction radial to the gas-operated post 7 and being directed toward the first springs 11a, l ib.

The mechanism 23, which is substantially T-shaped in plan view, is accommodated in an adapted first cavity 28 which is provided in the zone of the first plate 2 where the first springs 11a, 1 lb are also arranged.

The mechanism 23 comprises a second stem 29, rectangular in plan view, which is arranged in the interspace between the first springs 11a, l ib.

The second stem 29, which slides between the pair of first springs 11a, 1 lb, is connected to a first head 32, which is rectangular in plan view and the second wings 33a, 33b of which protrude laterally and transversely to the second stem 29.

The mechanism 23 can assume two different positions: a first, retracted position which is retracted in the direction of the gas-operated post 7, shown in Figure 6, in which an empty space 38 is formed between the second wings 33a, 33b of the first head 32 and the end wall 39 of the first cavity 28, which constitutes a temporary seat for a tooth 40 which protrudes internally and downward with respect to the second plate 10.

In this condition therefore the second plate 10 is able to rock with respect to the first plate 2.

The mechanism 23 can also assume a second, advanced position which is advanced in the direction of the end wall 39, shown in Figure 12.

A guide for the sliding of the second stem 29 and the first head 32 is provided by the presence of a longitudinal ridge 41 which protrudes from the bottom of the first cavity 28 and is accommodated inside a complementarily- shaped third seat 42 which is provided below the second stem 29 and optionally also below the first head 32.

In this condition therefore the first head 32 of the mechanism 23 occupies the empty space 38 between its terminal end and the end wall 39 of the first cavity 28 and acts as an abutment for the overlying tooth 40 which protrudes internally and downward with respect to the second plate 10.

Thus the second plate 10 is prevented from rocking with respect to the first plate 2.

The device comprises first means for elastic interconnection between the lever 13 and the first head 32, such first means being constituted by a second spring 60, which is a leaf spring with a first end 61a shaped like an eyelet which is associated, so as to rotate integrally therewith, inside an approximately complementarily-shaped third seat 62a which is provided in an annular fashion and inside the second portion 15 of the lever 13 concentrically to the second pivot 17.

The second spring 60 has a second, free end 61b, which is directed toward the second stem 29 and which acts slideably inside an adapted fourth seat 63 which is provided proximate to the terminal end 64 of the second stem 29.

Upon a counterclockwise rotation of the lever 13, such lever acts on the second spring 60 which transmits a force to the second stem 29 which forces the movement of the mechanism 23, and therefore of the first head 32, in the direction of the end wall 39 of the first cavity 28 until the tooth 40 which protrudes inside and below the second plate 10 abuts against the first head 32, thus preventing the second plate 10 from rocking with respect to the first plate 2.

Instead, upon a clockwise rotation of the lever 13, a force is imparted by way of the second spring 60 to the second stem 29, which entails the movement of the mechanism 23, and therefore of the first head 32, in the opposite direction with respect to the end wall 39 so as disengage the tooth 40 from the first head 32, thus allowing the rocking. The device further comprises second means for temporarily locking the rotation of the lever 13 in two distinct positions, which are the positions indicated previously in order to allow or prevent the rocking of the second plate 10 with respect to the first plate 2.

Such second means are constituted by an elastically deformable slider which is constituted, in the specific embodiment, by a piston 65, which advantageously has a second head 66, approximately hemispherical, which can slide axially, in contrast with a third spring 67, helical, within an adapted fifth seat 68 which is provided axially with respect to a projection 69 which protrudes radially from the second portion 15 of the lever 13 in the opposite direction with respect to the end wall 39 and on a plane that is preferably substantially lower than the plane of arrangement of the cylindrical insert 16.

The second head 66 can act, stably but temporarily, in two distinct and adjacent positions which correspond to a sixth seat 70 and to a seventh seat 71 , which are substantially shaped complementarily thereto and are provided at an adjacent wall 72 which is present inside the first plate 2.

The second spring and the third spring 60, 67 are actuated by the same lever 13 and they are dimensioned so that the third spring 67 keeps the piston 65 firmly positioned despite the loading of the second spring 60.

Advantageously the third spring 67 has an elastic constant that exceeds that of the second spring 60 so that the piston 65 firmly locks the lever 13 in position when it acts either in the sixth seat 70 or in the seventh seat 71.

Thus it is possible to automatically determine the condition of activation/deactivation of the rocking after the actuation of the lever by the user, despite the presence of a load applied to the chair.

In fact once the user is seated and the device is, for example, in the condition of deactivation of the rocking shown in Figure 18 in which the lever 13 is rotated so as to position the piston 65 in the sixth seat 70, the user can activate the second means, by rotating the lever 13 clockwise until the second head 66 of the piston 65 is positioned within the seventh seat 71 ; in the meantime, the weight of the user keeps the first head 32 of the mechanism 23 in position so as to block the rocking.

When the user imparts a clockwise rotation to the lever 13, shown in Figure 9, the weight of the user keeps the first head 32 of the mechanism 23 still in position so as to block the rocking, and at the same time the second means have preloaded the second spring 60.

Only when the user, by rocking, arrives in the condition of discharging the weight on the first head 32 of the mechanism 23, will the second spring 60, which is preloaded, automatically impart the movement to the first head 32 of the mechanism 23 until it allows the rocking, as shown in Figure 5.

The opposite case is shown, in sequence, in Figures 5, 11 and 18 where one passes from a condition of free rocking (Figure 5) to a condition in which the lever 13 is rotated anticlockwise with the weight of the user keeping the first head 32 of the mechanism 23 still in position so as to allow the rocking but the second spring 60 is preloaded (Figure 11), to the condition in which, when the user, by rocking, arrives in the condition of discharging the weight on the first head 32 of the mechanism 23, the preloaded second spring 60 automatically imparts the movement to the first head 32 of the mechanism 23 until the rocking is blocked (Figure 18).

Thus it has been found that the invention fully achieves the intended aim and objects, an adjustment device for a chair that has a rocking mechanism having been obtained that makes it possible to achieve at the same time, rapidly, simply and optimally, both the activation and prevention of rocking for a chair, and also the activation of the raising of that chair, the device making it possible at the same time to achieve the activation and the blocking of the rocking by way of a single lever that makes it possible to preset both the activation and the blocking of the rocking with a load applied, while at the same time preserving the internal components from accidental breakage.

Naturally the materials used as well as the dimensions of the individual components of the invention may be more relevant according to specific requirements.

The characteristics indicated above as advantageous, convenient or the like, may also be missing or be substituted by equivalent characteristics.

The disclosures in Italian Patent Application No. 102019000006667 from which this application claims priority are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. An adjustment device (1) for a chair, which comprises a rocking mechanism composed of a first plate (2), which is fixed to a central gas- operated post (7) for a height adjustment of a seat and to which a second plate (10) is articulated, about a first axis (9) that is transverse thereto and so that it can rock, said second plate being fixed to a seat and interacting with means (8a, 8b) which are adapted to contrast a rocking of a backrest, a lever (13) being articulated laterally to said first plate (2), at an axis that is different from said first axis (9), characterized in that it is provided with first means for elastic interconnection between said lever (13) and a first head (32) which is adapted to block/release a rocking between said first plate and said second plate (2, 10), and second means for temporarily locking a rotation of said lever (13) in two distinct positions, said second means preloading said first means in order to block/release said rocking in the presence of a load applied to said seat.

2. The device according to claim 1 , wherein a pair of first springs (11a, 1 lb) is associated with said first plate (2), which has a substantially C-shaped box-like shape so as to define a base (3) and two first lateral wings (4a, 4b), said pair of first springs being adapted to contrast the rocking of said seat, at one of said lateral wings (4a, 4b) there being an opening (12) at which said lever (13) can be positioned, said opening (12) having dimensions that are such as to allow said lever (13) to perform movements both on a first plane (100), which is perpendicular to said base (3) of said plate (2), and on a second plane (200), which is substantially parallel to the plane of the base (3), said lever (13) having a first portion (14) which is external to said plate (2) and a second portion (15) which is internal to said plate, characterized in that said second portion (15) has, adjacent to said opening (12), a cylindrical insert (16) which accommodates a second pivot (17) for pivoting said lever (13) to said first plate (2), said second pivot (17) having a first stem (18) which can be arranged in a fixed manner at an adapted and complementarily- shaped first seat (19a) which is provided at the inside of said base (3) of said first plate (2) and so that it can rock within a second seat (19b) which is shaped substantially like an opposing double truncated cone, a movement of said lever (13) along said first plane (100) that is perpendicular to said first plate (2) corresponding to a rocking of said second portion (15) of said lever (13) with respect to said second pivot (17) for pivoting.

3. The device according to one or more of the preceding claims, characterized in that said second portion (15) has a radial tab (20), directed toward said lateral wing (4b), which is such as to be arranged above said central gas-operated post (7).

4. The device according to one or more of the preceding claims, characterized in that said means adapted to prevent the rocking of said second plate (10) with respect to said first plate (2) are constituted by a mechanism (23) which is arranged slideably and inside said first plate (2) in a direction radial to said gas-operated post (7) and is directed toward said first springs (11a, l ib), said mechanism (23), which is substantially T-shaped in plan view, being accommodated in an adapted first cavity (28) which is provided in the zone of said first plate (2) where said first springs (11a, l ib) are also arranged, said mechanism (23) comprising a second stem (29), rectangular in plan view, which is arranged in the interspace between said first springs (11a, l ib), said second stem (29), which slides between said pair of first springs (11a, l ib), being connected to a first head (32), which is rectangular in plan view and the second wings (33 a, 33b) of which protrude laterally and transversely to said second stem (29).

5. The device according to one or more of the preceding claims, characterized in that said mechanism (23) assumes a first, retracted position which is retracted in the direction of said gas-operated post (7), in which an empty space (38) is formed between said second wings (33a, 33b) of said first head (32) and the end wall (39) of said first cavity (28) and constitutes a temporary seat for a tooth (40) that protrudes inside and below said second plate (10), in this condition said second plate (10) rocking with respect to said first plate (2).

6. The device according to one or more of the preceding claims, characterized in that said mechanism (23) assumes a second, advanced position which is approximately adjacent to said end wall (39), in this condition said first head (32) occupying said empty space (38) between its terminal end and said end wall (39) of said first cavity (28) and said overlying tooth (40) abutting against it and protruding inside and below said second plate (10) so as to prevent said second plate (10) from rocking with respect to said first plate (2).

7. The device according to one or more of the preceding claims, characterized in that said first means for elastic interconnection between said lever (13) and said first head (32) are constituted by a second spring (60), which is a leaf spring with a first end (61a) shaped like an eyelet which is associated, so as to rotate integrally therewith, inside an approximately complementarily-shaped third seat (62a) which is provided in an annular fashion and inside said second portion (15) of said lever (13) concentrically to said second pivot (17), said second spring (60) having a second, free end (61b), which is directed toward said second stem (29) and which acts slideably inside a fourth seat (63) which is provided proximate to the terminal end (64) of said second stem (29).

8. The device according to one or more of the preceding claims, characterized in that, upon a counterclockwise rotation of said lever (13), said lever acts on said second spring (60), which acts on said second stem (29), which in turn forces the movement of said mechanism (23) and of said first head (32) in the direction of said end wall (39) of said first cavity (28) until said tooth (40) which protrudes inside and below said second plate (10) abuts against said first head (32), thus preventing said second plate (10) from rocking with respect to said first plate (2).

9. The device according to one or more of the preceding claims, characterized in that upon a clockwise rotation of said lever (13), by means of said second spring (60), a force is imparted to said second stem (29) which entails the movement of said mechanism (23) of said first head (32) in the opposite direction with respect to said end wall (39) so as to disengage said tooth (40) from said first head (32), allowing the rocking thereof.

10. The device according to one or more of the preceding claims, characterized in that said second means for temporarily locking the rotation of said lever (13) in two distinct positions in order to allow or prevent the rocking of said second plate (10) with respect to said first plate (2) are constituted by an elastically deformable slider which is constituted by a piston (65), which has a second head (66), substantially hemispherical, which can slide axially, in contrast with a third spring (67), helical, within a fifth seat (68) which is provided axially with respect to a projection (69) which protrudes radially from said second portion (15) of said lever (13) in the opposite direction with respect to said end wall (39) and on a plane that is substantially lower than the plane of arrangement of said cylindrical insert (16), said second head (66) being able to act, stably but temporarily, in two distinct and adjacent positions which correspond to a sixth seat (70) and to a seventh seat (71), which are substantially shaped complementarily thereto and are provided at an adjacent wall (72) which is present inside said first plate (2)·

11. The device according to one or more of the preceding claims, characterized in that said second spring and said third spring (60, 67), which are both actuated by said lever (13), are dimensioned so that said third spring (67) keeps said piston (65) firmly positioned despite the loading of said second spring (60), thus making it possible to automatically determine the condition of activation/deactivation of the rocking after the actuation of said lever (13) by the user, despite the presence of a load applied to said chair.

12. The device according to one or more of the preceding claims, characterized in that said third spring (67) has an elastic constant that is greater than that of said second spring (60) so that said piston (65) firmly locks said lever (13) in position when it acts either in said sixth seat (70) or in said seventh seat (71), thus making it possible to automatically determine the condition of activation/deactivation of the rocking after the actuation of said lever (13) by the user, despite the presence of a load applied to said chair.

13. The device according to one or more of the preceding claims, characterized in that an element for protecting the fingers of the user, such as a bushing made of elastically deformable plastic material (150), is inserted in said opening (12) coaxially to said lever (13).