WO2008140777A2

WO2008140777A2 - Control device for a seat, particularly for adjustable chairs

Info

Publication number: WO2008140777A2
Application number: PCT/US2008/005988
Authority: WO
Inventors: Massimo Costaglia; Alessandro Slongo
Original assignee: L & P Property Management Company
Priority date: 2007-05-09
Filing date: 2008-05-09
Publication date: 2008-11-20
Also published as: ITMI20070944A1; WO2008140777A3

Abstract

Embodiments of the present invention are directed to a control device for a seat of a chair, which includes a seat support connected to a support base. The support base is substantially U-shaped, with an internal part hollow at a central portion thereof. A coaxial torsion bar is also provided with an actuator lever for raising/lowering the seat of the chair.

Description

CONTROL DEVICE FOR A SEAT, PARTICULARLY FOR ADJUSTABLE CHAIRS

BACKGROUND OF THE INVENTION

The present invention relates to a seat control device, particularly for adjustable chairs.

As is known, conventional chairs with an adjustable seat and/or backrest are becoming increasingly common especially in the work environment. This is because users desire to find the "best" seating position given that such persons frequently spend many hours in the same position in a seat, in front of, for example, a computer monitor.

Therefore, to avoid the onset of back problems, it is desirable for a chair occupant to have available a chair whose seat is adequately adjustable so as to be able to adapt both to his or her stature, as well as to the seating needs which relate to habits of the chair occupant.

The various adjustments of a seat of a conventional chair often require a rather complex and therefore cumbersome mechanism to be located below the seat surface of the chair, a mechanism which in most cases is not esthetically pleasing, and which involves a large number of components, with the resulting risk of malfunctioning.

One task of the present invention is to produce a control device for a chair seat which has reduced dimensions, and is therefore esthetically pleasing and on the other a similarly reduced number of components in order to reduce the complexity of the device. Within the scope of this task, a seat control device for a chair is realized whose compactness constitutes an advantage for the user for whom the adjustment controls are readily available. Another goal is to realize a control device for the seat of a chair, which also makes it possible to adjust the height of the seat. SUMMARY OF THE INVENTION

This task, as well as this and other purposes which will be better explained below, is achieved by a seat control device for a chair, comprising a seat support connected to a support base, characterized in that said support base is essentially U-shaped, with a hollow inner part at the central portion, and by the fact that a coaxial torsion bar is provided with a anctuator lever to raise and lower the chair seat.

BRIEF DESCRIPTION OF THE DRAWING

Additional characteristics and advantages of the invention will be shown in the specification of preferred though not exclusive embodiments of the device according to the present invention, illustrated by way of non-limiting examples in the attached drawings, in which:

Figure 1 illustrates a perspective view of a first embodiment of the device according to the present invention;

Figure 2 illustrates a perspective view of a second embodiment of the device according to the present invention;

Figure 3 illustrate a perspective view of a detail of both the first and the second embodiment of the device according to the invention;

Figure 4 illustrates a detail of the first and second embodiment according to the invention;

Figures 5a and 5b illustrate a perspective view of a normal position and an extended forward position, respectively, for the device of the first and the second embodiment according to the present invention;

Figure 6 illustrates a perspective view of a detail of the first and the second embodiment according to the present invention; Figure 7 illustrates a perspective view of a detail of Figures 5a and 5b;

Figure 8 illustrates a perspective view of another detail of the first and the second embodiment according to the invention;

Figure 9 illustrates from different angle the detail illustrated in Figure 8;

Figure 10 illustrates a side view of the device according to the present invention;

Figure 11 illustrates a perspective view of the device illustrated in Figure 10, with additional details;

Figure 12 illustrates a perspective view of a detail of the second embodiment of the present invention; and

Figure 13 illustrates in another perspective view the second embodiment of

Figure 12.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the Figures, various embodiments of the seat control device according to the present invention are referred to universally by reference number 100 for the first embodiment illustrated in Figure 1 and by reference number 200 for the second embodiment illustrated in Figure 2. In embodiments, the seat control device includes a support base 1 to which is connected a support 2 capable of supporting the seat, not illustrated, and, as relates to the second embodiment 200, a backrest support 3, articulated on the seat support 2 and on the support base 1.

The first embodiment of the control device 100 is adapted for chairs with a monococque or with seat and backrest firmly attached to each other. However as relates to the second embodiment, the device 200 in question provides that the seat back of the chair be articulated between them and during movement of the mechanism assume synchronized reciprocal positions.

The travel of the backrest is in this case greater than that of the seat. To achieve these functionalities, a support 3 of the backrest is provided articulated both on the seat support 2 and on the support base 1.

Support base 1 is advantageously essentially U-shaped, a hollow interior portion, with a group of control levers arranged coaxially to the coaxial torsion bar, as will be described in greater detail below.

With reference in particular to Figure 3, the control device includes a blocking lever 6 which is firmly attached to a drum 7 formed with a series of steps 7a on which a pin 8 acts according to a translational motion dependant on the step shape of the drum 7. In one embodiment the pin transmits the movement by the limiting means 9, advantageously consistent of a block which slides on a special track 10 housed in a seat of the support base 1.

The contrary motion of the limiting means 9 is facilitated by the elastic means 1 1. This condition occurs when the blocking lever 6, and therefore the drum 7, are rotated counterclockwise. The limiting means 9 is formed with a series of steps 9a, each of which corresponds to a precise travel of the seat support 2.

With reference to Figure 4, it may be observed how the seat support 2 is structured, in its internal area (e.g. the part directed toward the limiting means 9) with a protrusion or tooth 12 capable of engaging alternately in one of the corresponding positions on the limiting means 9, for engagement with the steps 9a. Through this arrangement, the adjusting of the seat support with respect to the support base 1, is facilitated.

In embodiments, the control device according to the invention also provides a device capable of achieving a position defined as "operative" in which the seat is in a more forward position to be more suitable for use with a computer monitor. To this end, at a front portion of the support base 1 is a slider 13. The slider 13, which is configured for rotation around the axis of the coaxial torsion bar 18, illustrated for example in Figure 3. The slider 13 therefore rotates around the axis of the coaxial torsion bar 18 following the cylindrical shape of the support base 1 in that area.

The slider 13 contains a wedge-shaped front clamp, 13a, which works on a portion of an actuator element 14. Therefore, by the rotating slider 13 (e.g., by moving along the cylindrical portion of the support base 1) rectilinear movement of the actuator body 14 is specified. This movement sets in motion a block 15 through the thrust of the elastic means 16. The block 15 has a protrusion 15a which makes it possible to alternately block one of two corresponding outlets or cavities 17 provided on the seat support 2, as illustrated in Figure 4. Such outlets 17 determine the end of the forward travel: standard or forward. A spring 16a regulates the return of the block 15 to the initial position. The spring 16 has the function of guaranteeing an automatic movement of the block 15 in the event that the slider 13 is operated but the necessary condition does not exist for coupling the block 15 and the outlets 17.

Figure 6 illustrates in a perspective view the position in which the protrusion 15a of block 15 functions as a travel stop through the outlet 17 of the seat support 2.

Figure 7 shows, on the other hand, that the slider 13 has on one end a flexible tab 19 which intercepts a half ball 20 in the track in which the slider slides, thus guaranteeing the bistability of the slider 13.

In embodiments, the device according to the invention also comprises a tension adjustment system. In particular, a support element 23 of the torsion bar 18 is inserted in the support base 1 through a hexagonal coupling, and therefore the support element 23 is unable to rotate relative to the support base 1. At the opposite ends, the support 23 has a female hexagonal seat in which the coaxial torsion bar 18 is inserted, which is also hexagonal. This means ensures that one end of the coaxial torsion bar 18 cannot rotate. Figure 9 illustrates, at the end opposite the non-rotational end of the coaxial torsion bar 18, a tensioner element 24 which holds an end of the hexagonal bar. However, unlike the support 23, the tensioner element 24 can rotate around the support base 1. An end portion 25, generally shaped like a pawl, is in contact with the seat support 2 such that the connection enables the transmission to the seat support 2 an elastic thrust operated by the coaxial torsion bar 18. The thrust of coaxial torsion bar 18 is determined by the preload which can be adjusted acting on the angle of element 24.

Figure 1 1 illustrates the adjustment system of the preload of the coaxial torsion bar, which provides a rotatable knob 26 transferring motion to a first gear 27, which in turn transfers motion to a second gear 28. The second gear 28 contains a bevel gear pair.

Through the bevel gear pair, a pinion 29, which has a threaded end, is placed in rotation. A wedge element 30 is provided with a seat for a threaded nut on which the threaded end of the pinion 29 engages. The rotation of the pinion 29 therefore determines a rectilinear movement of the wedge 30 which determines the rotation of the tensioner element 25. Such rotation, in turn, creates a twisting of coaxial torsion bar 18 with a resulting increase of the preload.

The combination of the gears 27 and 28 and the tilted surface defined by the wedge 30 result in a significant reduction of the effort necessary on knob 26. Another advantage of the system described above is that the knob 26 is positioned far from a lever 22, in other words, the lever for the gas positioning that permits operating the lever of the gas column not illustrated in the Figures (i.e., for raising and lowering of the seat surface).

Advantageously, as illustrated in Figures 1 and 2, the device according to the invention is also provided with a knob 5 which has the additional function of adjusting the height of the seat. In this case, as illustrated in Figures 12 and 13, a pair of skids 31 is applied to the seat support 2, in particular a repeater runner on the left side comprising a plurality of openings 31 on which a locking element 32 engages or disengages. When the stop 32 is engaged, the fixed seat position is obtained. When the stop 32 is disengaged, there is the possibility of moving the seat to the desired position. The movement of the stop 32 is controlled by knob 5. The knob 5, as illustrated in detail in Figure 13, is firmly attached to a lever 34, which has an arm which operates a torsion spring 35. This torsion spring determines the return of the lever 34. The other arm of lever 34 thrusts the locking element 32, by raising it. A compression spring (not shown) guarantees the return of the stop 32.

It has been observed in practice how the device according to the invention fully performs the task as well as the envisioned aims in that it makes possible having a reduced number of components with similarly reduced dimensions and with a coaxialty of the coaxial torsion bar with group of control levers.

The thus conceived device is subject to many modifications and variants, all of which fall within the scope of the inventive; also all of the details can be replaced by other technically equivalent elements. In practice, the materials used, as well as the dimensions and contingent shapes can be any ones according to needs and the state of the art.

Claims

CLAIMSWhat is claimed is:

1. A control device for the seat of a chair, comprising a seat support connected to a support base, characterized in that said support base is essentially U-shaped, with the hollow internal part at the central portion, and by the fact that a coaxial torsion bar is provided with an actuator lever for the raising/lowering of the seat of the chair.

2. A device according to Claim 1, comprising a lever firmly attached to a drum provided with a series of steps on which a pin acts, said pin having a translational motion and [by] transmitting the movement a travel limiting means capable of sliding in a track housed in a seat of said support base.

3. A device according to Claim 1, characterized in that said lever firmly attached to said drum is coaxial with said torsion bar.

4. A device according to Claim 1, characterized in that it comprises an elastic means capable of permitting the contrary movement of said limiting means, said limiting means having a series of steps capable of being engaged by at least one tooth defined at the internal part of said seat support, when said seat support is connected to said support base.

5. A device according to Claim 1, characterized in that said support base is provided with a slider capable of rotating around the axis of the coaxial torsion bar, a front portion of said slider being a wedge-shaped actuator means engaged with said wedge-shaped portion, said actuator means being capable of moving a block provided with a protrusion capable of engaging alternately in one of at least corresponding two outlets defined on the seat support, said outlets defining end travel positions of said seat.

6. A device according to Claim 1, characterized in that said slider has at one end a flexible tab capable of block a half ball housed in a track inside which moves said slider.

7. A device according to Claim 1, characterized in that it comprises preload means of said coaxial torsion bar, said preload means comprising a knob capable of transferring its rotatory movement to a gear which transfers movement to a second gear, said second gear being provided with a bevel gear pair capable of placing in rotation a pinion having a threaded end capable of engaging with a wedge-shaped element, said wedge-shaped element being moved rectilinearly and determining the rotation of a tensioner element of said coaxial torsion bar.

8. A device according to Claim 1, characterized in that it comprises, provided at said seat support, a part of skids capable of permitting the movement of said seat.

9. A device according to Claim 1 , characterized in that at least one of said skids is provided with a plurality of openings capable of to allow the engagement of at least one locking element provided at said seat support, and on the underside of said skids.

10. A device according to Claim 1, characterized in that said locking element is operated by a knob provided crosswise with respect to said seat support and having an arm on which a torsion spring operates capable of determining the return of said knob, a second arm of said knob being capable of thrusting said locking element by raising it.