The present invention relates to an exercise or "active" chair for exercising and developing several muscle groups at the same time. The chair is a recreating device as well, which may be used both in homes and offices as well as in fitness rooms or communal places.

Lately, a great number of different exercising, strengthening or fat reducing devices appeared on the market, due to the fashionable fitness tendency. EP 215 0321 A1 discloses an exercising device for domestic or outdoor use, which is relatively cheap and requires small room.

There are other devices for developing balancing ability and improving training several muscle groups. The device according to DE 10 2005 047 803 A1 consists of a plate and a hemispherical base, wherein the user is standing on the plate and trying to keep the balance.

These devices, as almost all the devices of the art, are single purpose de- vices, they can only be used for exercising or fat reducing, are of rather poor aesthetic appearance and need room for storing when out of use. Moreover, the use of these devices means work only and not amusement.

Improvements of the device shown in DE 10 2005 047 803 A1 are the exercise assisting apparatuses published in SI 211 14 A2 and WO 03/024538 A1. With these constructions the user is not standing, but is trying to keep balance sitting on a seat supported by a hemispherical base. This device could already be used for everyday work besides or during exercising, but it is rather easeless and, moreover, the deflection of the seat is rather wide, and therefor the chair needs a bright space for accommodation. A further disadvantage is that the foot of the user is resting on a foot stand and does not play important role in keeping the balance. Muscles of the upper body and of the arm are not strengthened during the use either.

Object of WO 2006/126705 A1 is an exercise apparatus or chair, which enables contracting the muscle of a user by regulating a burden due to own weight of the user acting on legs of the user under a state that buttocks of the user is on the seat. This apparatus is preferably used for raising glucose metabolism by uptake of glucose to muscle due to the contraction of muscle and, accordingly, for recovering from diseases such as diabetes. There is a burden regulator between the seat and a support base, which comprises one or more rollers driven by motors.

The apparatus according to the WO 2006/126705 A1 is a "passive" chair, as the user does not really makes exercises. When sitting in the chair muscles of the foot are strengthened only, due to the burden regulation, but there is no active motion of the upper body of the user.

Therefor, the purpose of the present invention is to provide an exercise device, which functions as an active chair and enables not only an efficient exercising and fat removing, but may be used as a furniture of any home or communal room as well and enables the use as office chair which strengthens among others muscles of the backbone. Further to that, the device may be used as plaything, even as means for competition.

Accordingly, the present invention is an exercise chair comprising a foot, a seat and an upper body support member, wherein a ball and socket joint is ar- ranged between the foot and the chair seat, and which may be provided with foot rests connected to the seat and the upper body support member may be formed as a handhold.

The ball and socket joint comprises a ball head on a support rod arranged between the foot and the seat and a socket provided with a spherical hole and fixed to the bottom of the seat. Alternatively, the ball head is fixed to the bottom of the seat and the socket is fixed on the support rod. It is preferably provided with means for limiting swivelling motion, which may be the socket itself provided with a conical part adjoining the spherical hole and co-operates with a stop bush intruding into said conical part.

According to a preferred embodiment, the handhold is a horizontally curved rod, which may be held firmly, similar to a bike handle-bar.

Preferably the height of the upper body support member and/or the seat is adjustable, for enabling easy exercising of any user.

The exercise chair is preferably provided with an electronic display showing the parameters of the exercise.

Another object of the invention is a swivelling unit for converting a conventional chair to an exercise chair described above. The unit comprises a lower plate to be fixed on the support rod of the conventional chair and an upper plate to be fixed to the bottom of the seat of the conventional chair, wherein there is a ball and socket joint between the lower plate and the upper plate. The unit is preferably provided with a latch for locking the ball and socket joint.

The exercise chair can be used both in homes and offices or communal rooms. Already a short exercise generates intensive stress in the muscles of the abdominal, buttock, femoral and waist, which goes with strengthening and fat reducing effect. Besides exercising, the device may be used for playing games as well, e.g. domesticated "rodeo" game. Furthermore, it is possible to organise competition, if the device is provided with an electronic unit, showing on the display the duration of keeping the body of the user in balance.

When the device is out of use or if the user does not want to exercise, the swivelling path of the seat may be restricted or locked with appropriate locking element. Accordingly, the active chair can be used as normal chair (office chair, bar stool etc) as well.

Further details of the invention will be explained by preferred embodiments, with reference to the accompanying drawing, wherein:

Fig. 1 is a schematic drawing of an embodiment of the exercise chair according to the invention,

Fig. 2 is the side view of a part of Fig. 1 ,

Fig. 3 is the side view of a part of Fig. 1 , according to another variant of the exercising chair, and

Fig. 4. is a schematic drawing of an embodiment of the swivelling unit according to the invention.

The exercise chair shown in the Figures comprises a seat 1 and a foot 2. Seat 1 may be a simple padded plate, or may be designed as a bike seat or a saddle.

Foot 2 should provide an appropriate support for the seat, therefor it is preferably designed as a rigid, scaffold like structure. In some cases it may be a beam embedded in the floor or the ground.

Foot 2 is holding - as usual - a support rod 3 provided with the seat 2, and is preferably of adjustable height. Means for adjusting the height are known in many variants in the art, details thereof are therefor not indicated in the drawing.

At the top of the support rod 3, there is a ball head 4, which holds a socket 5 fixed to the seat (e.g. with a plate and appropriate screws). Ball head 4 and socket 5 co-operate with each other as a ball and socket joint. Accordingly, seat 1 is not fixed in horizontal position, but can swivel in any direction, depending on the position and movement of the user. The tilting movement can be limited by some lock, e.g. a stop bush 6, as shown in Fig. 1. The upper end of the stop bush 6 may be pushed into the socket 5 and, in this way, the amplitude of the tilting depends on the position of the stop bush 6. The position i.e. the height of the stop bush may be adjusted by pin 7, which can be inserted into bores made in different heights on the support rod 3. If the top of the stop bush is in contact with the inner surface of socket 5, the seat is locked and may be used as a conventional chair.

The body support member 8 of the chair is mounted to the seat , as usual.

According to a preferred embodiment, it consists of a handhold 10 fixed on or made as one piece with a carrier 9. Carrier 9 may be a tube or a flat rod, handhold 10 is preferably a horizontally curved tube, which can be gripped easily like a bike handle-bar. It is also advantageous if the handhold, or at least a part of it, is covered with some soft material, like rubber foam, to ensure comfortable use. For domestic or office use, the chair may be designed with conventional body support 8 and arm rests 1 1 , as shown in Fig. 3.

When exercising, the user takes a seat opposite to the body support 8. The chair is tilting immediately. Therefor, the user bends to the other direction as a re- flex action and tries to hold the balance, which is, however, impossible and in this way tilting and bending is continuing all the time. In the meantime, different muscles of the user are strained and relaxed continuously, until he gets tired or gives up, after a shorter or longer time. It is surprising how weariful this type of exercising is, and how strong fatigue-fever is the result thereof, which means that the exercise is effective.

The exercise chair may be used for entertainment as well. Rodeo competitions may be organised, and the duration of remaining in seat or keeping the balance can be measured for the competitors. For this purpose (and for others too), the chair may be provided with a display 12 of an electronic unit on an appropriate part of the device, e.g. on the body support 8. Electronic bobbing drill or shooting may also be carried out during exercising.

After exercising, the seat can be locked and the chair can be used as a conventional chair (or barstool). A further possibility is to apply a relatively big ball head in the ball and socket joint, which makes the tilting softer and thus the user need not to concentrate intensively to keep balance and can read, work or relax during use. For this purpose, the chair may be designed conventionally, as shown in Fig. 3. This variant can replace e.g. the known rubber ball chair, as it provides the same effect, but looks more aesthetical. Embodiments in Fig. 1 and 3 can be converted easily to each other, by changing the body supports 8.

According to a preferred embodiment, seat 1 is provided with foot rests Ci13, preferably with stirrups (e.g. when playing rodeo). This construction is very good for exercising femoral muscles and makes the use of the device more convenient with- out reducing effectiveness.

The embodiments described above are only illustrating the invention without limiting the scope claimed in the attached claims. Both the seat and the body support may be designed in many other ways and made of different materials. Various changes and modifications of the construction and adjustment of the ball and socket joint or the support will be apparent to those skilled in the art.

In Fig. 4, a ball and socket unit may be seen, which can be used in exercise chairs. It enables converting a conventional chair to an active/exercise chair to be used as outlined above. In this swivelling unit, the ball and socket joint 4 is arranged between a lower plate 14 and an upper plate 15. The lower plate may be mounted to the support rod 3 of a chair, and the upper plate may be mounted to the seat 1 of the chair. There is a supporting block 16 between the two plates, for receiving the ball head 4. Tilting of the ball head is limited by the spherical inner surface of the supporting block 16, as sown in Fig. 4. The swivelling unit is preferably also provided with means for locking the ball and socket joint, when out of use and the chair is used as a conventional chair.

In possession of the swivelling unit according to the invention, any domestic or office chair can be converted to an active chair. Upon releasing the connection between the support rod mounted to the foot of the chair and the seat, the lower plate of the swivelling unit can be fixed on the support rod and the upper plate can be screwed to the bottom of the seat. Then, the chair can be used as an active or exercise chair according to the invention.