WO2004077999A1

WO2004077999A1 - Control device for office chairs and the like

Info

Publication number: WO2004077999A1
Application number: PCT/IT2004/000093
Authority: WO
Inventors: Sergio Moreschi
Original assignee: Cofemo SpA
Current assignee: Cofemo SpA
Priority date: 2003-03-07
Filing date: 2004-02-27
Publication date: 2004-09-16
Anticipated expiration: 2005-09-07
Also published as: EP1601268A1; ITBS20030025A1

Abstract

Control device (1) for office chairs and the like comprising of a command lever (6) associable externally to a mechanism of the chair (2) and mobile between at least two working positions to command selectively the locking and the unlocking of at least one mobile portion (5) of the mechanism (2). The device includes means of pre-selection and anti-shock (7) operatively lodged in the lever of command (6). The means of pre-selection and antishock (7) include at least bi-stable means (8) associated to lever (6) to define two positions of stability in correspondence to the two operative working positions, an element of a mobile command (13) at least partially housed in the lever (6) and an elastic element (14) operatively active between the lever (6) and the element of command (13).

Description

CONTROL DEVICE FOR OFFICE CHAIRS AND THE LIKE

DESCRIPTION

The present invention relates to a control device for office chairs and the like. As it is known, office chairs generally present adjustable parts in height and tilt. These chairs might present the back, and sometimes also the seat, adjustable in tilt in respect to a base unit, for example of a box form, which is connected at the top end of an upright which defines the vertical support of the chair. Particular mechanism are known which can tilt the back only, which are called "at permanent contact" , mechanisms which allow the independent tilt of back and seat , called "asynchronous" type, and mechanisms which allow the simultaneous and proportional tilt of the back and seat, which are called "synchronous" type. Mechanisms are also known with reclining back and seat and solid in between, called "swinging" . In all the above cases elastic elements are provided constrasting the tilting and it is possible selectively to prevent the swing of the parts which can tilt through proper locking devices, which are usually made of multiple slotting positions and by at least a locking element fit to engage selectively into the slotting positions to stop the swing of the tilting portions . Such locking mechanisms are usually provided with a command lever and, inside the base unit of the chair, with means which allow a function of pre-selection and anti-shock on the locking. The pre-selection allows the preloading of a spring and to activate the locking through a command lever also when the locking element is not in a suitable position to mesh into a locking slot, in such a way that the engaging can happen automatically under the pressure of the spring as soon as the tilted portion is rotated in a suitable position to allow the locking. The anti-shock function works in a similar way to command the unlocking even when the forces acting on the chair and therefore on the locking element will not allow the sudden extraction from the relative locking slot. Mechanisms are also known which allow the change of the position of the seat between a limited number of angular positions, for example a horizontal position and two reclined positions of some degrees (typically 4°) and symmetrical in. relation to the horizontal position. The known technique, described briefly above, presents some drawbacks. The known mechanisms in fact present always a structure rather complex and costly^'. Moreover the means for the pre-selection and anti-shock are very cumbersome and require the necessity of proper designing of the entire mechanism of the chair. In fact the mechanisms for the pre-selection and anti-shock are made up of a series of elements which occupy a considerable space and restrict the positioning of other elements of the mechanism. Such problems require the necessity of a very accurate and specific planning for each type of mechanism, with consequent higher costs of designing, realization, assembly and stocking of the mechanisms. It has also to be noted that for mechanisms to change the setting there are not any known mechanisms of preselection or anti-shock.

In this situation the technical task set at the base of the present invention is to invent a control device for office chairs and the like to be in a good enough position to obviate substantially the problems mentioned. For the purpose of the said technical task it is an important aim of the invention to make a control device for office chairs that offers a high degree of freedom in the designing of the locking device and of the mechanism of the chair. Besides it is the aim of the invention to make a control device for office chairs that is efficient and that it is of a simple and fast realization. It is an other aim of the invention to make a control device for office chairs of a universal type, that can be assembled without substantial modifications on all the types of mechanisms for chairs (for example swinging, synchronous, asynchronous, at permanent contact and with variable settings) . It is also the aim of the invention to make a control device which is particularly compact. It is finally the technical aim of the present invention to make a control device for^' office chairs which is of a contained cost and that allows to reduce considerably the designing production, assembly, stocking and transport costs, of the chairs mechanisms. The specific technical task and aims are substantially obtained by a control device for office chairs which is characterized by the fact to include one or more technical solutions which are claimed below. In the following there is, only as an indicative and not as a limitative example, the description of a preferred but not exclusive form of execution of a control device according to the invention, illustrated on the enclosed drawings, in which: fig. 1 shows an exploded prospective view of a control device according to the present invention applied to a part of a mechanism for chairs; fig. 2 is a second exploded prospective view of the device of figure 1; fig. 3 is a top view of the device of figure 1; fig. 4 is a section of the control device accord- ing to line IV-IV of figure 3; fig. 5a, 5b and 5c show a section of the device, according to line V-V of figure 3, in three working positions; fig. 6a, 6b and 6c show a lateral view of a part of the device in three working positions corresponding respectively to figures 5a, 5b and 5c ; fig. 7 shows on a lateral view a mobile portion of the device.

With reference to the said figures, a control device for office chairs and the like according to the invention is globally shown with reference number 1. The control device 1 is attached to a mechanism 2 for an office chair (shown only partially in the figure because the remaining elements are of a known type) , which essentially includes a basic unit fit to engage, through a connecting element, to the top end of an upright which defines the vertical support of the chair. On the base unit at least a turning portion of the chair is generally hinged in a known way, for example an support element for the back. Mechanism 2 includes also an support element of the seat of the chair, assembled above the base unit. Means of elastic support are usually also foreseen, such as a spring, placed between each turning portion in an independent way and the base unit, and therefore at least between the support element and the base unit .

The mechanism portion 2 shown on the figures is relative in particular to means 3 to change the setting of the support element of a chair, which are operatively activated by the control device 1. Such means 3 in order to change the setting of the seat have at least a fixed portion 4 and at least a mobile portion 5 associated in a revolving way to the fixed portion 4. One of such portions 4, 5 is attached to the base unit, while on the other the seat or the support element of the seat can be assembled. Advantageously the mechanism 2 contains two fixed portions 4, 4' and two mobile portions 5, 5' placed symmetrically in respect to the seat and working in conjunction with the control device 1. The control device 1 contains a lever of command 6 which is associated externally to the chair mechanism 2 and it is mobile at least between two working positions to command selectively the locking and the unlocking of at least one mobile portion 5 of the mechanism 2. Preferably the lever 6 is associated in a revolving way to the mechanism 2, and the two working positions are displaced at an angle, for example at 90° . In line with the present invention the device 1 also includes means of pre-selection and anti-shock 7 operatively placed in the command lever 6. Such means of pre-selection and anti-shock 7 are preferably placed in a coaxial way to the control device 1. The means of pre-selection and anti-shock 7 comprise at least bi-stable means 8 associated to the lever 6 to define two positions of stability of lever 6 corresponding to the two working positions.

The bi-stable means 8 include a seat of command 9 "having two working positions 9a connected by a transferring run 9b. The seat of command 9 is operatively as- sociable to mechanism 2 and is preferably achieved on a buckle 10 fixable to a corresponding opening 11 of the mechanism 2. Such seat of command 9 could alternatively be obtained directly on mechanism 2. The bistable means 8 include also a bi-stable element 12 associated to lever 6 and mobile in the seat of command 9 to define the two positions of stability for the lever 6 in correspondence with the two working portions 9a. In practice the working portions 9a of the seat of command 9 are sized in such a way to house the bi-stable element 12, while the transferring run 9b is slightly narrower of the bi-stable element 12 in order to present a predetermined resistance during the rotation of lever 6 and to prevent the passage of the same bi-stable element 12 if not under the manual action of the user. In the form of the illustrated realization the seat of command 9 is associated to the mobile and turning portion 5 (see figure 7) . The means of preselection and anti-shock 7 include besides an element of mobile command 13 at least partially placed in the lever 6 and an elastic element 14 operatively active between the lever 6 and the element of command 13. The element of command 13 includes a sleeve 15 mounted in a revolving way on lever 6 and fixed to a command shaft 16 extending from the lever 6 to command the locking and unlocking of mobile portion 5. The sleeve 15 and the shaft of command 16 are fixed through a transversal pin 17. The transversal pin 17 is inserted in a seat 15b of the sleeve 15 and in a corresponding seat 16b of the shaft 16 through an opening 6c in the lever 6. The command shaft 16 has a working portion 16a having a smaller section along a first perpendicular axle to the longitudinal development of the command element 13 and a bigger section along a second perpendicular axle both to the longitudinal development of the command element 13 than to the first axle. The command shaft 16 is associated in a revolving way to the mobile portion 5 and to the fixed portion 4, in correspondence to which there is a shaped seating 18 having for example three slots 18a with a bigger diameter of the bigger section of the command shaft 16, connected by parts having an inferior width to the bigger section of the command shaft 16. The slots 18a and the shaft 16 could for example have a diameter of approximately 10 mm, while the parts with an inferior width could be of approximately 6 mm. In essence when the shaft 16 is turned in such a way to present the bigger section, the seat cannot vary its tilt^", while when the shaft 16 is turned, preferably of 90°, the same shaft 16 can shift from one slot 18a to an other and the seat can change the setting. The sleeve 15 has a seating-lock 15a for the elastic element 14, for example a coil spring 14, which is provided with a first extremity 14a cooperating with a portion of support of the lever 6 and of a second extremity 14a cooperating with a portion of support of sleeve 15. The spring 14 is therefore put in action by the rotation of lever 6 and in consequence is inclined to rotate the sleeve 15 to compensate such displacement. Advantageously the lever 6 might include a lengthened body 6a hollow inside and a knob of command 6b interchangeable and fixable to the lengthened body 6a to rotate jointly to it, for example through a hexagonal coupling. Preferably, as illustrated, the mobile portions 5, 5' and fixed 4, 4' are realized in a symmetric way, to allow the assembly of the command mechanism 1 indifferently on both sides of the seat. It has to be noted that the control device 1 illustrated above has been associated to means 3 to change the setting of the seat purely as an example, inasmuch as the control device 1 illustrated becomes substantially universal, and it is therefore advantageously applicable in a similar manner to all the types of known mechanisms. The device is therefore applicable to mechanisms at "permanent contact" , in which the support element of the seat is joined to the base unit and the only part that can be tilted is the back, to mechanisms of "synchronous" type, in which the support element of the seat is associated in a revolving way to the base unit and to the support element of the back to swing proportionally to the swinging of the elements of support of the back, to mechanisms of "swinging" type, in which the support element of the seat is fixed to the support element of the back to swing jointly to the same and also to mechanisms of "asynchronous" type, in which the support element of the seat is associated in a revolving way to the base unit, to swing in an independent way. In such cases the device might also include a flexible element (not shown on the figures) operatively connected to the means of preselection and anti-shock 7, and in particular, to the element of command 13 or to the shaft of command 16. Such a flexible element is suitable to extend itself inside the mechanism 2 to command selectively the locking and the unlocking of the mobile portion 5, which can be in particular the support element of a back or the support element of a seat of the chair. The functioning of a control device, described above in a prevalently structural sense, is the following. In the figures 5a, 5b, 5c and 6a, 6b, 6c are illustrated in a schematic way three working phases of the control device 1, with the shifting from the position of the seat with the setting in a horizontal position (figures 5a and 6a) to a position of unlocking of the seat to shift to a different setting (figures 5c and 6c) . When the seat is in a locking position (figures 5a and 6a) , the spring 14 is relaxed and the shaft 16 is in position to lock in regard to a respective slot 18a. To change the setting, the user turns the lever 6 of 90°, bringing the device in the illustrated position in the figures 5b and 6b, in which the shaft 16 is not rotated because the user's weight on the seat does not allow the rotation, but the bi-stable element 12 has passed in the opposite working position and the spring 14 has been loaded. The spring 14 is not able to rotate the lever 6 backwards because the length of the transfer run 9b of the seat of command 9 presents a bigger resistance than the thrust of the lever 6. When the user lightens the weight on the seat below a certain value, the preloaded spring 14 turns the shaft 16 of 90°, in a position (illustrated in the figures 5c and 6c) in which the shaft 16 itself can pass in a different slot 18a changing the setting of the seat. The phases described above are relating to the shock resisting function of the device 1. When one wishes to lock the mechanism 2 the function of pre-selection works in a similar manner in every way. In this case the lever 6 is rotated in the opposite direction, suitably loading the spring 14 in the case where the shaft 16 is not located exactly in line with one of the three slots 18a. When the seat is brought into one of the three working positions, the shaft 16 can rotate under the thrust of the spring 14 and lock the mechanism 2. The invention achieves important advantages . In fact, a control device in accordance with the present invention offers complete freedom in the designing of the locking device of the mechanism of the chair. Besides a control device according to the invention is particularly compact, efficient and of simple and fast realization. Besides it has to be noted that a control device according to the invention is substantially universal in as much as it can be mounted without substantial modifications on all the types of mechanisms for chairs, permitting functions of pre-selection and anti-shock also on a mechanism to alter the setting of the seat. Lastly it has to be underlined that the control device results in contained cost and reduces remarkably the designing costs, production, assembly, stocking and transport of the mechanisms of the chairs. Naturally several modifications and variations could be made to the device according to the present invention without digressing from the inventive concept which characterized it. All the items are replaceable with other technically equivalent elements and in practice all the materials used, and also the dimensions, could be of any type according to the need.

Claims

1. Control device (1) for office chairs and the like comprising of a lever of command (6) associable externally to a mechanism (2) of the said chair and mobile at least between two working positions to command selectively the locking and the unlocking of at least a mobile portion (5) of said mechanism (2) , characterized in that includes also means of pre-selection and anti-shock (7) operatively lodged in the said lever of command (6) .

2. Device according to claim 1 characterized in that said means of pre-selection and anti-shock (7) comprise at least bi-stable means (8) associated to said lever (6) to define two positions of stability of said lever (6) in correspondence of said two working positions, an element of mobile command (13) at least partially lodged in said lever (6) and an elastic element (14) operatively active between said lever (6) and said element of command (13) .

3. Device according to claim 2, characterized in that said bi-stable means (8) comprise a seat of command (9) having at least two working positions (9a) connected by a transfer run (9b) and operatively associable to the said mechanism (2) , and a bi-stable element (12) associated to the said lever (6) and mobile in said seat of command (9) to define the said two positions of stability of said lever (6) corresponding to the said two working portions (9a) .

4. Device according to claim 3, characterized by the fact that said seat of command (9) is realized on a bushing (10) fixable to said mechanism (2) .

5. Device according to any one of the previous claims characterized in that said lever (6) is associated in a revolving way to said mechanism (2) .

6. Device according to any of the claims from 2 to 5, characterized in that the said element of command (13) comprise a sleeve (15) mounted in a revolving way on the said lever (6) and fixed to a shaft of command

(16) extending from said lever (6) to command the locking and the unlocking of the said mobile portion

(5) .

7. Device according to claim (6), characterized in that the said sleeve (15) is provided with a housing seat (15a) for the said elastic element (14) , which is provided with a first extremity (14a) operatively active on said lever (6) and of a second extremity (14b) operatively active on the said sleeve (15) to rotate said sleeve (15) in consequence to the rotation of said lever (6) .

8. Device according to any one of the previous claims, characterized in that said lever (6) includes a lengthened body (6a) and a control knob (6b) interchangeable and fixable to said lengthened body (6a) .

9. Device according to any one of the previous claims, characterized in that includes as well a flexible element operatively connected to said means of pre-selection and anti-shock (7) and capable to extend itself in said mechanism (2) to command selectively the locking and the unlocking of such mobile portion (5) .

10. Mechanism for office chairs and the like which includes a base unit, an support element of the back of the seat assembled on the base unit and an support element of the seat of the chair assembled above the base unit, characterized in that a control device (1) is included in accordance with any one of the previous claims .

11. Mechanism according to claim 10 characterized in that it includes means (3) to change the setting of the seat, operatively activated by the said control device (1) .

12. Mechanism according to claim 11 characterized in that said means (3) in order to change the setting include at least a fixed portion (4) and at least a mobile portion (5) engaged in a revolving way to said fixed portion (4) , the said housing of command (9) and the said element of command (13) being respectively associated to the said mobile portion (5) and to the said fixed portion (4) or vice versa.

13. Mechanism according to claim 12 characterized in that the said element of command (13) is revolving and is provided with a part of the work (16a) having a smaller section along a first axle perpendicular to the longitudinal development of the element of command (13) and a bigger section along a second axle perpendicular to the longitudinal development of the element of command (13), the said element of command (13) being operatively associated to the said mobile portion (5) or fixed (4) corresponding to a shaped housing (18) having at least two slots (18a) with a bigger diameter of the said bigger section, connected by a piece having inferior width to the said bigger section.

14. Mechanism according to claims 12 or 13 characterized in that it includes two of the said fixed portions (4, 4') and two of the said mobile portions (5, 5') placed symmetrically in relation to the said seat and cooperating with the said control device (1) .

15. Mechanism according to claim 10 characterized in that said control device (1) is operatively active to command the locking and the unlocking of the rotation of the said support element of a seat-back.

16. Mechanism according to claim 10 characterized in that said control device (1) is operatively active to command the locking and the unlocking of the rotation of the support element of a seat of a chair.

17. Chair characterized in that it includes a control device (1) in accordance with any one of the claims from 1 to 9.

18. Chairs characterized in that includes a mechanism (2) in accordance with any one of the claims from 10 to 16.