SURFACE OF A CHAIR

Technical Field

The invention relates to a chair, in particular an active office chair. The invention furthermore relates to a method for bringing into motion, in a periodically repeating manner, the seat surface of a chair.

Background Art

Evolution has optimized the human spine for dynamic, upright barefoot walking movement on uneven ground.

Over the recent decades, an increasing portion of human population have entered“desk jobs” that involve subjecting the spine to prolonged static, asymmetric loads. In 15-20 years, 8 hours of sedentary work carried out each workday causes two typical spinal conditions: lumbar disc herniation and cervical disc herniation. As a result of asymmetric, static loads, the intervertebral discs become deformed and bulge out. Pressure on the nerves extending beside the spine causes hernia pain, and in extreme cases the intervertebral disc can become tom.

Based on spinal therapeutic practice, as much as 98% of hemia-related problems can be corrected without surgery, i.e. by physiotherapy treatment (for example, the McKenzie method) by an expert therapist. The real-world number of surgery cases is much greater than that, while without a lifestyle change surgery can only offer a temporary solution.

The devices adapted for preventing vertebral disc herniation typically involve two types of solutions.

One of the solutions aims at transforming the asymmetrical static loads into more dynamic loads, i.e. not allowing the patient to hold a motionless, firm sedentary position for a long time. Such solutions include spinal chairs, fitness balls and special seat cushions. The known spinal chair is an office chair comprising a support point, with the support and height adjustment mechanism of the chair comprising, in a manner known per se, an adjustment lever disposed on the column supporting the seat portion. Support of the seat portion is implemented applying ball joints, with a spring being disposed between the support portion and a seat surface. The active seat surface of the spinal chair subjects all vertebrae of the spine of the person seated thereon to a uniform load. The disadvantage of this technical solution is that, once the user has got accustomed to the chair, s/he tends to assume a static seating position, which results in unfavourable loads on the musculature of the spine, and increased wear caused by the reduced amount of synovial fluid.

The other type of known technical solutions aims at changing the direction of static loads such that the loads are exerted in more favourable directions. Such solutions include wedge cushions and kneeling chairs (for example the cushions known by the trade names Dynair and Alvital). Their disadvantage is that, although they allow the easy movement of the spine during their use, they not provide for actively moving the spine.

Disclosure of Invention

The objective of the invention is to eliminate the disadvantages of known technical solutions and provide an alternative solution that comprises improvements over the state of the art.

The objective is realized based on the recognition that, if a seat surface of a chair or other seating appliance is brought into motion applying external power, then the occupant of the chair or other seating appliance will perform involuntary corrective movements, thereby ensuring that his/her spine is actively moved.

The objective of the invention is to provide a novel chair, in particular an active office chair, and a method for bringing into motion the seat surface of a chair that provide the active, involuntary movement of the user’s spine, and also provides for the adjustment of the office chair utilizing common moving means. Following an appropriately configured program, it induces a dynamic movement of the spine without overloading it, or, when the seat surface is not in motion, it is kept in a position that is optimized with respect to the physiological characteristics of the user.

The inventive objective is realized by providing a chair, in particular an active office chair that comprises a base portion, a seat surface with a backrest, and a support member adapted for connecting the seat surface to the base portion, wherein the support member situated between the base portion and the seat surface is formed of an adjustment and fixing means that is adapted for adjusting the height of the seat surface and is connected to a mounting plate disposed under the seat surface, and means that are disposed symmetrically beside the adjustment and fixing means and are adapted for moving the seat surface, wherein the means adapted for moving the seat surface and the height adjustment and fixing means are connected to the mounting plate carrying the seat surface of the chair by articulated members, with the moving members adapted for moving the seat surface being connected to the base portion through resilient connecting members, the chair further comprising a connecting member adapted for connecting the height adjustment and fixing means to the articulated members, a power supply adapted for supplying power to the means disposed in the base portion, and a control unit adapted for operating said means.

In a preferred embodiment of the chair according to the invention, the means adapted for adjusting the height of the seat surface is an electric telescopic actuator known per se.

In a preferred embodiment of the chair according to the invention, the means adapted for bringing into motion the seat surface are linear actuators known per se.

In another preferred embodiment of the chair according to the invention, the articulated members connecting the means adapted for moving the seat surface and the height adjustment and fixing means to the mounting plate by way of connecting members are universal joints. In another preferred embodiment of the chair according to the invention, the resilient connecting members adapted for connecting the means adapted for bringing into motion the seat surface and the base portion are rubber springs.

A still further preferred embodiment of the chair according to the invention comprises a power supply with a power connector disposed in the base portion.

In an expedient embodiment of the chair according to the invention, the power supply is a battery disposed at the base portion.

In another expedient embodiment of the chair according to the invention, the control unit is a specialized hardware unit that can be controlled via a wired or wireless communications link utilizing a mobile phone and/or computer application, the control unit being implemented applying a pre-programmed printed circuit board.

In a further expedient embodiment of the chair according to the invention, the seat surface is implemented as a rigid plate that is optionally made integral with the backrest, the seat surface being implemented as a shaped seat surface.

In a preferred embodiment of the chair according to the invention, the seat surface is a shaped seat surface formed according to the bodily dimensions of the user, where the seat surface comprises padding.

The objective of the invention is further realized by providing a method for bringing into motion, in a periodically repeating manner, the seat surface of a chair, in particular an active office chair, the office chair comprising a base portion, a seat surface with a backrest, and a support member adapted for connecting the seat surface to the base portion, wherein, in the case of the chair applied in the course of the method, the support member situated between the base portion and the seat surface is formed of an adjustment and fixing means that is adapted for adjusting the height of the seat surface and is connected to a mounting plate disposed under the seat surface, and means that are disposed symmetrically beside the adjustment and fixing means and are adapted for moving the seat surface, wherein the means adapted for moving the seat surface and the height adjustment and fixing means are connected to the mounting plate carrying the seat surface of the chair by articulated members, with the moving members adapted for moving the seat surface being connected to the base portion through resilient connecting members, the chair further comprising a connecting member adapted for connecting the height adjustment and fixing means to the articulated members, a power supply adapted for supplying power to the means disposed in the base portion, and a control unit adapted for operating said means, the method comprising the step of bringing the seat surface into motion in a periodically repeating manner by means of a control program, stored in the control unit, that is configured according to the needs of the occupant seated on the seat surface.

In a preferred embodiment of the method according to the invention, the loading of the seat surface is monitored applying the control unit of the chair, and the starting of the control program is triggered on the basis of the load data. Brief description of Drawings

The chair, preferably active office chair according to the invention is explained in detail referring to the accompanying drawings, where

Fig. l .a shows a perspective front view of the chair according to the invention,

Fig. l.b shows a perspective side view of the chair according to the invention,

Fig. 2 schematically illustrates the motion of the chair according to the invention, and

Fig. 3 shows the side view of the seat surface and the moving members of the chair according to the invention.

Best Mode of carrying out the Invention

Fig. l .a and Fig. l.b show a perspective front view and a perspective side view, respectively, of the supporting-moving portion of the chair 1 , preferably active office chair according to the invention, also showing support and moving means.

The chair 1 according to the invention essentially consists of a base portion 2 lying on the ground; a seat surface 3 fitted with a backrest 4; means 8 that is fixedly attached to the base portion 2 and is adapted for adjusting the height and fixing the position of the chair 1 ; means 6 and 7 that are situated beside the means 8, are attached to the base portion 2 by means of a resilient connecting member 13 (rubber spring), and are adapted for moving the seat surface 3; and a mounting plate 5 that is disposed under the seat surface 3 and is connected to the means 6, 7, and 8.

Of the means 6, 7 and 8 forming the support frame of the seat surface 3 of the chair 1 , preferably active office chair according to the invention, the means 8 is adapted for adjusting the height of the seat surface 3, retaining the seat surface 3 in a fixed position, and providing a fixed point of attachment thereto.

However, in addition to adjusting the height of the seat surface 3 and fixing it at a given height, in the case of the chair 1 according to the invention the seat surface 3 can also be tilted according to the user’s needs. In the following, the tilting of the seat surface 3 will be described referring to the schematic drawing of Fig. 2.

The position of point A of Fig. 2, about which point a tilting motion of the seat surface 3 is achieved, is defined by the height adjustment and fixing means 8 adapted for adjusting the height of the seat surface 3. The tilting motion is achieved by the means 6 and 7, which means 6, 7 are disposed symmetrically with respect to the means 8, and are connected to the seat surface 3 at points B and C and to the base portion 2 in points D and E.

Rotations about axes extending in any direction are allowed by the points A, B and C (except rotation about the axes of the universal joints 9, 10), so a linear movement of the moving means 6 and 7 results in a rotating and tilting motion about the fixed point A at points B and C. For achieving the above mentioned motion, it is also required to allow that the means 6 and 7 can be tilted at a low angle (typically under 1 °) with respect to the base portion 2 in any direction, because otherwise the moving mechanism can become stuck. This is provided by resilient connecting members 13, preferably rubber springs, disposed at points D and E. The same resilient connecting member 13 also fulfils the condition, necessary for appropriate operation, that the means 6 and 7 are not able to rotate about their own respective longitudinal axes. An additional function of the resilient connecting members 13 disposed at points D and E is to compensate for potential manufacturing inaccuracies of shape and dimensions.

For example, in case the height adjustment means 8 and one of the moving means are fixed in a given state at points A and B, with the other moving means undergoing upward and downward motion along a straight line, the seat surface 3 will undergo a reciprocating tilting motion about the axis defined by the points A and B. Thus, by applying control of the moving means 6 and 7 and by retaining it at a given height by the means 8, the seat surface 3 can be adjusted to an arbitrary angular position in a given range of motion.

The relationship between the seat surface 3 and the means can be observed in Fig. 3 that shows the components of the chair 1 according to the invention in side view.

As it was set forth above in relation to Fig. 2, the means 6, 7 and 8 are connected to the seat surface 3 at three points, which, in a ball joint-like manner, allows rotation about two axes.

Rotation about two axes - AB and AC, see Fig. 2 - between the seat surface 3 and the moving means are enabled by the two universal joints 9 that are connected to the mounting plate 5 carrying the seat surface 3. The universal joints 9 are connected to the means 6 and 7 by means of two connecting members 11.

The height adjustment and fixing means 8 is implemented as an electric telescopic actuator known per se, wherein an upper portion is displaced with respect to a lower portion that is affixed to the base portion 2 of the chair 1. The height adjustment and fixing means 8 and a universal joint 10 are connected to the mounting plate 5 disposed under the seat surface 3 by a connecting member 12.

The moving means 6 and 7 are each implemented as a linear actuator known per se, wherein an upper portion is displaced with respect to a lower portion that is affixed to the base portion 2 of the chair 1.

The moving means 6, 7 and a universal joint 9 are connected to the mounting plate 5 disposed under the seat surface 3 by a connecting member 11 , and to the base portion 2 by a respective resilient connecting member 13, preferably a rubber spring.

Electric power is supplied to the motors driving the means 6, 7 and 8 by a power supply comprising a power connector that is built into the base portion 2, or a battery built into the base portion 2.

A control unit is included for adjusting and controlling the motion of the seat surface 3 of the chair 1 according to the user’s needs; electric power to the control unit is also supplied by a power supply or battery built into the base portion 2.

The exact path of the positive movement of the seat surface 3 is generated by the control unit by adjusting the position of the means 6 and 7 according to a suitable program.

The control unit can be operated via a wireless link preferably by a mobile phone application.

Depending on the preset conditions, the control unit provides for the continuous or intermittent movement of the seat surface 3. Furthermore, thanks to the sensors built into the control unit, the control program of the seat surface 3 can be modified according to the detected changes in the user’s state.

The method according to the invention comprises moving the seat surface 3 by means of a control program stored in a control unit, where the components and periodicity of the movement can be customized by the user (within the available limits). This involves changing the parameters of the control program. The parameters of the program can be modified in a user-friendly manner, expediently by compiling preprogrammed movement sections. The length of the period between the start of successive movement sessions is about an hour, preferably for example 60 minutes, with the duration of a session being maximum 10 minutes, preferably 2-5 minutes. The user is alerted to the impending start of a movement session by a short vibratory and/or auditory signal. The control program and its parameters can be configured for example from an electronic device, for example utilizing a mobile phone application.

In an embodiment of the method according to the invention, a chair (preferably an active office chair) described above is applied. It has to be noted, however, that the method can be implemented applying any such chair or other seating appliance that has a freely movable seating surface, a moving mechanism, and a control unit adapted to control the moving mechanisms in a programmable manner.

The load on the seat surface is monitored by the control unit of the chair, preferably by means of sensors, in particular the total time under load of the seat surface 3 of the chair 1 is measured and recorded, based on which value the starting of the control program is scheduled by the control unit.

This can be achieved, for example, by recording the load values while the seat surface 3 of the chair 1 is under load, and calculating the cumulated time of the static load. The stored motion program is started by the control unit only in a loaded state, and only after a continuously loaded period of a given length (for example 30 minutes) has elapsed.

In a preferred embodiment of the method according to the invention, the seat surface 3 of the chair 1 is occupied by a person, which state is detected by one or more sensors disposed on/inside the seat surface 3, and the sensor signal is transferred to the control unit. Based on the received signal, the detected load values are analysed and the load time is accumulated by the control unit, and, based on the resulting cumulated time value, after 30-60 minutes the preprogrammed control program - customized according to the occupant’s needs - that is adapted for moving the moving means 6, 7, 8 is started. According to the user’s needs, a motion sequence with a length of preferably 2-5 minutes is generated from the predetermined motion components by the preconfigured control program. Before starting the control program, a customized vibratory or auditory signal can be issued to the user. After the control program has completed execution, the load of the seat surface 3 of the chair 1 is continued to be monitored utilizing the sensors arranged on and or inside the seat surface 3, and taking into account the cumulated time under load, after another 30-60 minutes the program is executed again by the control unit.

Certain motion components of the control program and the periodicity of starting the control program can be modified within predetermined limits. The modification can be performed utilizing the control unit, or over a wifi or bluetooth connection utilizing other electronic devices, for example a mobile phone.

The advantage of the method is that the periodic, programmed, customized, user-friendly movement of the seat surface contributes to alleviating diseases of civilization caused by sedentary work, and to improving the mood, well-being, and physical condition of the user. Another advantage of the method is that it improves the conditions of sedentary work, but it can also be preferably applied for home activities requiring a prolonged seated position. The advantage of the chair 1 , preferably active office chair according to the invention is that the seat surface is subjected to motion always according to the individual user’s needs, and that the motion plan can be modified by active feedback from the user, or by monitoring the state of the user.

LIST OF REFERENCE NUMERALS

chair

base portion

seat surface

backrest

mounting plate

means

means

means

universal joint

universal joint

connecting member

connecting member

resilient connecting member (rubber spring)