HK1058138B - Ergonomic office chair with an extending foot - Google Patents

Description

Human body effect office chair with telescopic support legs

Background

Technical Field

The invention belongs to the field of furniture. More particularly, the present invention pertains to the field of chairs with telescoping legs or other attachments.

Description of the Related Art

For ergonomics of sitting for a long time, it is necessary to change the posture of the body frequently. The rubber ball seat and the spring chair need to be constantly readjusted in balance, so that the body cannot get any rest. Some inventions relating to chairs connect the backward tilting of the back to the forward movement of the seat. In these known inventions, the movement of the seat is usually achieved by a complex linkage, but this system allows a small amount of translation of the seat.

This (synchronised) idea has long been known especially for non-swivel chairs, although it has emerged in some inventions for other reasons, for example from the swedish patent CH 269755. In this patent, the back rest and support surface are lowered to a substantially horizontal position by the long forward movement of the seat, so that the seat and back rest, together with the top-mounted support surface, connected by a swivel joint, can even become a horizontal table.

But the reason for designing such a synchronized chair is usually to obtain a comfortable sitting position. An example of a technique for allowing the seat to be moved forward is disclosed in the swivel chair of european patent EP0460717a2, but for this movement, a bolt arrangement is claimed. The chair back is connected to the chair seat through a rotary joint, the chair back can be inclined backwards through the armrests, and the armrests movably arranged on the rotary joints are used as main supporting rods of the chair back. An extension spring is installed under the seat to resist the weight of the seated person on the backrest. Thus, the angle of the seat may also vary somewhat.

Another example of a movable seat is disclosed in german patent DE3315237a 1. However, in this patent, the back rest is not supported by the armrests, but is mounted directly on the base of the chair, as is the seat; when the backrest is tilted, the seat is slid forward.

However, in these known swivel chairs, the translation of the seat needs to be controlled very slowly. If the forward movement is rapid, the chair and the seated person are at risk of tipping over forward. The inventors have therefore not made a design that actually achieves the objects stated in the introduction. Alternatively, a larger area is reserved on the floor to support the legs of the chair, but this is not usually used. It is also not feasible to bolt office chairs to the floor. In this case, the magnetic transformational binding system is the best option, but the intended purpose is still not achieved because a 30-50cm translation is required to compensate for approximately 30-40 degrees of tilt of the chair back. The addition of rubber ball devices is also a matter of convenience, as they do not solve the distance problem and the seated person risks falling while constantly adjusting his balance. They are not back-rest reliable when different seating postures are provided.

The aim of the invention is to design a chair whose seat can be translated without effort and without noise. At the same time, the advantages and the size of a common office swivel chair can be kept as much as possible, at least for a common sitting position.

To achieve this, a variety of methods may be employed. The base of a (office) swivel chair usually consists of five legs and a typical pneumatic spring mechanism for vertical height adjustment. A known way of accomplishing the technical task related to the seat and backrest is to use a lever mechanism, incorporating a (very) small amount of slippage, thereby avoiding an excessive forward shift of the center of gravity.

Summary of The Invention

The recognized advantages of changing the sitting position in a chair are achieved by a novel combination of several parts, some of which are known but which are logically connected so that their movement is interdependent with each other. The position of the protruding hand remains almost unchanged relative to the desk when the seat is moved back and forth on the chair and the backrest is tilted. The general function of the swivel chair can be possessed as long as the backrest is not steeply inclined. When the connection is fully opened, the backrest can be tilted without the seat being moved, and used as a conventional chair.

The invention relates to a telescopic leg connected and the possibility of rotation by synchronizing the inclination of the back with the translation of the seat. The attachment system is mounted on a swivel chair. With such (office) chairs, it is possible to synchronize the tilting of the backrest with the forward movement of the seat, so that the distance between the two hands of the seated person with respect to the office equipment on the table remains almost constant at all times.

Brief description of the drawings

Figure 1 illustrates a schematic side view of a chair according to the invention.

Figure 2 illustrates a schematic side view of the chair of the present invention as one embodiment having a short bar at the top end of the backrest.

Figure 3 illustrates a schematic side view of the chair of the invention as an embodiment having a short strut at the top end of the backrest, a vertical extension of the base, and telescoping movable legs.

Figure 4 illustrates a side view of the chair of the present invention with the back rest having a telescoping support.

Figure 5 illustrates a schematic side view of the chair of the present invention having a hinged or pivoting movable leg and a weight to return the seat.

Figure 6 illustrates a schematic front view of the chair of the present invention.

Figure 7 illustrates a schematic side view of a chair of the present invention as one embodiment having a back panel.

Figure 8 illustrates a schematic side view of the chair of the present invention, similar to figure 2.

Figure 9 illustrates a schematic side view of the chair of the present invention, similar to figure 1.

Figure 10 illustrates a schematic side view of the chair of the present invention as an embodiment having a back panel and a spring to move the seat.

Figure 11 illustrates a schematic side view of the chair of the present invention with a cable connection between the swivel joint of the seat and the movable leg.

Detailed description of the invention

This entirely new design method is most important to allow a sufficient amount of slippage that can be achieved with a small amount of lever movement to achieve the desired seat angle. Thus, the center of gravity can be moved significantly forward, but this will result in the possibility of the chair tipping forward unless resisted by additional members. The possibility of using a larger support surface on the floor is not considered because potential users will not purchase such chairs.

The risk of tipping over can be avoided by a weight which is movably or non-movably mounted on the chair, for example a large half-moon shaped weight which is suspended below the back of the lower hinge joint of the back rest bar or below the base, between all or some of the leg parts. This solution is also less likely to be popular because it would increase manufacturing and shipping costs and the chair itself would look strange. The removability of the seat with the weight implies a considerable pulling force, contrary to the case with the return spring. (FIG. 5)

The solution envisaged can also be achieved by sliding or spreading forward one or more telescopic legs 7. An additional foot 7 is placed between the feet/legs of the sitting person before the seat 1 is moved. The folding legs 7, 8, 9 (all figures except fig. 3) have the advantage of being a mechanical system with little failure in terms of operability and durability; but on the other hand it is practically unattractive if the chair is not in use. The downward unfolding motion may be vertical or even inclined, which enables a somewhat longer extension of the underside of the chair. The folding legs are provided on their sides with footrests enabling the legs to be extended by the occupant's feet, and with a lever for retracting the extended legs when not in use. The elongated legs may be secured by a locking structure or may be compressed by a coupler.

Telescopic legs (fig. 3) may also be used, especially for electric chairs. This has two possibilities: the existing foot can be changed to a telescopic foot so that the telescopic foot is always located in the foot area of the seated person. Or the telescopic legs 7, 8, 34 and 35 extend obliquely directly from under the seat to the floor as an elongated leg, which will be referred to below by the same name; this telescopic leg rests on the floor in front of the chair, as the 6 th leg, at a distance of about 20-35cm from the chair, and must be extended and fixed before the chair is adjusted from the normal position to the position in which the backrest is steeply inclined.

The movement of the telescopic legs can be operated and locked with feet or handles or hand crankshafts. For luxury chairs, this movement can also be achieved electrically, pneumatically or hydraulically, as can sleeves that move the seat. The telescopic legs 7 extend forwards from the lower part of the chair to reach the floor when extending; thus, its extended position is obliquely located between the legs or feet of the seated person, which is clearly less than ideal. An interlocking or connecting device ensures that only the inclination of the backrest and the position of the seat are changed, while the chair is prevented from rotating, when the telescopic legs are supported on the floor. But it appears easier for the user to accept only one telescoping foot below the foot area.

With respect to the problem of the tilting of the movable seat, there can be 3 different solutions, of which solution C appears to be the best:

A) the chair back (and likewise the seat) can be fixed in any inclined position. This requires a large support surface on the floor, in which case the occupant can tilt his/her body forward, thereby moving the center of gravity forward. The telescopic legs must rest on the floor approximately 35cm in front of the chair. The folding legs provide a simple solution if the chair is not powered.

The following solutions B and C require a smaller support surface, i.e. shorter telescopic legs. In this case the telescopic legs have to rest on the floor approximately 20cm in front of the chair.

B) The back is not locked but has an extension spring that applies a forward force. The disadvantage of this solution is that the spring force (adapted to the weight of each individual seat) must be precisely controlled. The seated person must resist this potential movement at all times without having to actually take a back rest, only with the spring force against the back.

C) The backrest is not fixed in terms of forward movement, that is, as soon as the seated person leans forward, the backrest starts to move forward, but the elasticity of the spring used by the backrest is so small that the seat on which the seated person sits can be moved exactly; but the backrest is fixed by an additional rod when the backrest leans backwards. Thus, the occupant can comfortably lean backward, and if the occupant leans forward and the center of gravity is moved, the seat immediately moves backward, thereby reducing the risk of the entire chair tipping forward. Thus, if the occupant wants to recline the backrest a little more, he/she must operate a lever or the like to open the securing mechanism. The flywheel with the manual clutch can realize the unidirectional free motion. A ratchet mechanism may also be used, but continuous adjustment is not possible and is noisy. The joystick may also employ a foot-operated mechanism. It may also be incorporated into the chair back, operated by head or specific back pressure or arm pressure.

The connection between the telescopic legs on the base of the chair and the rotation of the chair and the tilting movement of the backrest must also be considered; the telescopic legs can be used in all directions, but in the present invention only in front of the chair. When the additional telescopic legs are deployed in the front direction, the rotation of the chair is hindered, allowing only a substantial forward movement of the seat and a substantial tilting of the backrest.

This connection can be made both by pivoting and sliding with two tension cables with locking pins, or one from the telescopic leg 7 to the under-chair tension cable 111, possibly with a folding lever mechanism 74 for other purposes, since the height adjustment of the chair base also needs to be considered. In chairs with electric motors, this connection can be realized by simple control logic. The telescopic legs can also be rotatably mounted (fig. 11)110 on the top frame/seat through internally and externally threaded pipe joints; for this case, it is not necessary to fix the base before opening the legs downward/outward. But this solution would be difficult to design due to the height adjustment required.

A lever mechanism can also be used with a common universal joint at the tension cable. But no matter what system is used, height adjustment of the chair is necessary.

As shown in fig. 7 and 10, the chair back itself can be composed of two parts: the backrest 2 itself can be provided with a further cushion part 71 or "backrest panel" on the occupant side, which can be moved slightly parallel to the backrest by means of slide bearings 73 or small struts 72; the chair back 2 itself is supported by a small force spring. The design of the back panel 71 can be used for all chairs below. The purpose is to compensate for pressure displacements acting on the body of the seated person when tilting.

The seat 1 should be easily movable. This can be achieved by mounting it in one or two panel sleeves with double tubes/pullable members 15 which enable a large amount of translation of the seat, while the backrest 2 is fixed to the rear end of the seat 1 by one or more swivel joints 10. A long spring 100 is provided in the sleeve 15 to pull the seat 1 back to the normal position. Alternatively, the seat may be returned by one or more springs mounted in one of the swivel joints 10 or 11. For this purpose, a weight 51 may also be attached to the tension cable 50 in order to pull the seat 1 backwards.

With regard to the connection between the seat 1, the backrest 2 (possibly also with a backrest panel 71) and any backrest bar and the bases 3, 5, four different mechanical systems are conceivable. Their common factor is that the seat 1 is connected to the bottom of the backrest 2 by means of a swivel joint 10 in order to move/adjust the seat. Naturally, in order to make the chair operate like a normal chair, said swivel joint 10 may also be accompanied by a clutch; in other words, the backrest can be tilted without the seat moving forward. a) The difference between d) is that the apex orientation of the back rest (panel) is different. The adjustability of the length and slope of the bar/sleeve will be described below to provide the occupant with a variety of adjustment options.

In the embodiment shown in fig. 1-9, an additional lever mechanism, the "back lever", is mounted on top of the back rest (panel) by means of a swivel joint 11 and extends down to the base 14 of the chair, in this case the part above the vertical pneumatic spring 3, and is fixed by means of a swivel joint 13. So that the seat 1 can be moved forward and backward through the sleeve 15.

The system thus consists of three system parts, a horizontal seat plane 1, a backrest 2 (and a panel 71) located above the sleeve 15, which can also comprise a couple of bars, and a couple of vertical swivel bars or planes and a back bar 12 supporting the backrest; in practice, of course, several close joints may be used with the three swivel joints. The motion of the entire structure is similar to the motion of a piston rod in an engine, except that the piston rod makes a full circular motion, whereas the structure of the present invention makes less than a half circular motion.

The backrest bar is made adjustable according to the different needs of the sitting person, for example by means of adjustable connecting joints on the backrest panel.

To prevent injury, the mechanism behind the chair is enclosed in a bellows for safety reasons. This also makes the chair look more harmonious. For the same reason, it is preferable to use one bar as the back lever.

For noise reasons, the double tube sleeve 15 can be mounted using plastic ball bearings. Simple sliding bearings can also be used, but with wear problems. The movement of the seat 1 can be controlled by one hand.

In the embodiment shown in figures 2 and 8, a small strut 21 is provided at the top of each side of the backrest 2, connected by a swivel joint 20 and connected by a swivel joint 22 to a member 23 extending vertically from the base of the chair, which requires a tall chair.

In the embodiment shown in fig. 3, there is a small strut 36 at the bottom of each side of the backrest 2, connected by a swivel joint 11 and by a swivel joint 32 to a member 33 extending vertically from the chair base.

In the embodiment shown in figure 4 there are short (double tube) telescopic elements 41, 42 at the top or middle of each side of the backrest 2, which move obliquely upwards at the backrest and are connected to a member 40 extending vertically from the base. The inclination of the sleeve may also be made adjustable.

One advantage of the present invention is that the occupant can change the sitting position by adjusting the backrest 2 from the upright position to the reclined position and the risk of falling over is reduced. And the chair is capable of supporting a body. When the seat 1 is moved back and forth by changing the inclination of the backrest 2, the position of the outstretched hand is slightly changed with respect to the desk.

Powered chairs may be more attractive and convenient to use. The different components may be controlled separately depending on the number of engines installed. But this complicates the chair and leads to a reduced reliability. There is also the disadvantage that the chair requires cable connections or batteries. On the other hand, it has the advantage that the seated person can adjust the parameters very slowly and continuously within the nominal range. Naturally, all these systems can also be equipped with some habitual adjustments, such as rocking, tilting, back-rest adjustment, etc.

Basically, no armrests are provided, since the patented movable armrests in the inventor's USP6267336 can be suitably combined with the chair of the present invention to move them by an amount of 1m, so that a predetermined movement amount of 35cm can be easily achieved in the chair of the present invention.

If these movable armrests are not used, it is preferable to mount the armrests on the seat so that their positions relative to the seated occupant are substantially unchanged. With small struts, they can be adjusted with assistance by the occupant's movement.

For a standard chair, it is also possible to provide a slightly shorter support at the armrest 74 (fig. 7) position, which can facilitate rearward tilting by adding a support point; this can be done by renewing the handrail if necessary.

Accordingly, it is to be understood that the embodiments of the invention as described herein are merely illustrative of the application of the principles of the invention. The detailed description of the embodiments is given by way of reference only and does not limit the scope of the claims, which themselves define essential features relating to the invention.

Claims (19)

1. A chair, comprising:

a) a base;

b) at least one telescoping leg mounted to the chair and movable from an extended position to a non-extended position on the floor;

c) a seat supported on the base, the seat having a front end and a rear end and being horizontally movable forward and rearward;

d) a reclining backrest located at the rear end of the seat, the movement of the seat being linked to the tilting of the backrest, whereby increasing the inclination of the backrest causes the seat to move forward;

the movement of the seat and the tilting of the backrest are linked to the telescopic legs in such a way that the tilting of the backrest and the movement of the seat are hindered when the telescopic legs are in said non-extended position.

2. The chair of claim 1 wherein the seat is supported on the base by a swivel bearing, the swivel bearing being connected to the telescoping leg such that when the telescoping leg is moved to the extended position, the swivel bearing is locked, preventing rotation of the chair.

3. The chair of claim 2 wherein the horizontal movement of the swivel bearing, telescoping legs, and seat is coupled by a mechanism selected from the group consisting of a tension cable, a linkage, a combination of a linkage and a tension cable, and an electric, pneumatic, or hydraulic device in combination with a locking pin or locking clutch.

4. The chair of claim 1 wherein the seat is moved horizontally by sliding or moving on a telescoping rail or double tube sleeve.

5. The chair of claim 1 wherein the backrest includes a backrest for supporting the occupant and a backrest panel connected to the seat and mounted adjacent the backrest, the backrest panel being movable relative to the backrest.

6. A chair as claimed in claim 5, wherein the back panel is movably mounted to the back by means of a slide or small rocker between the back and the back panel, and the back panel is drawn upwardly by means of a spring.

7. The chair of claim 1 further comprising a strut connecting the backrest to the base, the strut being connected to the top end of the backrest by a swivel joint and to the base by another swivel joint.

8. The chair of claim 1, further comprising a small strut for connecting the movement of the seat and the back; the small strut is connected to the top or middle of each side of the backrest by a swivel joint, and the other end is connected to a member extending vertically from the base of the chair by a swivel joint.

9. The chair of claim 1 wherein the movement of the seat and the backrest are linked by a mechanical system, wherein the backrest has sleeves at the top or middle of each side thereof, which sleeves are extended obliquely upward and linked to members extending vertically from the chair base.

10. The chair of claim 1 further comprising a biasing member for returning the seat.

11. The chair of claim 10 wherein the biasing member is a spring connected between the seat and the back.

12. The chair of claim 10 wherein the biasing member is a resilient member disposed within or parallel to the sleeve.

13. The chair of claim 1 further comprising a weight located behind the seat for imparting a return motion to the seat.

14. The chair of claim 1 wherein the telescoping legs are moved between the extended and non-extended positions by a telescoping mechanism.

15. The chair of claim 1 wherein the telescoping legs are moved between the extended and non-extended positions by folding arms.

16. The chair of claim 1 wherein the telescoping legs are mounted to the base.

17. The chair of claim 1 wherein the telescoping legs are mounted on a seat.

18. The chair of claim 1, wherein the forward movement of the seat and the tilt of the backrest are achieved within a predetermined range when the telescoping legs are in the non-extended position.

19. A chair, comprising:

a) a base;

b) a seat supported on the base, the seat having a front end and a rear end;

c) means for moving the seat horizontally back and forth;

d) a reclining backrest located at the rear end of the seat;

e) means for connecting the backrest to the seat such that increasing the inclination of the backrest is linked to forward movement of the seat and erecting the backrest is linked to rearward movement of the seat;

f) at least one telescoping leg assembly mounted to the chair for preventing the chair from tilting and movable between a non-extended position and an extended position on the floor;

g) means for preventing forward movement of the seat and downward movement of the backrest are associated with the means for moving the seat, the means for tilting the backrest and the means for preventing the chair from tilting, thereby locking the means for moving the seat forward and the means for allowing the backrest to lie down before the means for preventing the chair from tilting has not been moved to the extended position.