The present invention relates to a dynamic seating device with a seat plate, which is tiltably and rotatably mounted by means of a bearing head on an under-frame with a height-adjustable column or on a bearing surface.
“Sitting as stress” is the title of a book by the SVSS author team (Verlag pmsi Holdings Deutschland GmbH, 1993, recommended by the Federal Association of German Back Schools). It explains in 200 pages that correct sitting is not a rigid posture, but requires constant mobility. Since these unrestricted movements are not attainable when sitting on normal seats, various changes of sitting postures, which humans must consciously take up in alternation, are suggested in this book. It is illustrated how difficult it is in everyday life and at the workplace to move sitting in a body-conformal way. Some of the recommended sitting postures however do not permit desk work or other activities such as piano playing among other things to be performed. To some extent work-preventing postures are suggested, which although able to produce physical sensitisation processes, are unfit for work and everyday tasks over longer periods. These shortcomings in sitting and movement however can be prevented by a suitable seating device.
A stool, which through cylindrical segments placed one above the other allow movement of the seat face over two horizontal axes offset by 90°, is known as a seating device, which should improve sitting from a health point of view, from German Patent DE 201 10 832 U1. As a result of the distance between the two axes there is a difference between pitch- and lateral tilting movement. Overall, both fulcrums of the coccyx are spaced too far apart to allow physiological optimum and homogeneous transmission of movement to take place.
A further mobile seating device is described in German Patent DE 295 16 794 U1, whose main feature however is a flexible seat with a resetting force and therefore does not meet the demands made here.
In addition fromFrench Patent FR 27 94 349 A1 it is known how to mount a seat plate on a hemispherical bearing head so that it can tilt and rotate, wherein the hemispherical bearing head is mounted in a spherical recess on the lower side of the seat plate.
It is common to the dynamic seating devices described above that the user, with the structure of the known seating device selected in each case, is forced into unnatural and over longer duration unpleasant movements. For work and everyday tasks these seating devices are therefore only suitable to a limited extent.
On the basis of the state of the art described above the object of the present invention is to create a seating device of the kind initially specified, which automatically allows natural movements of the user at the same time with free mobility.
The object stated above is achieved in accordance with a first teaching of the present invention by the fact that the seat plate comprises a recess arranged in its centre, becoming larger from its top side towards its lower side, that a base plate with a dome-shaped protuberance is secured in the centre of the seat plate on its top side, that the base plate rests on the bearing head of a support pin, wherein the bearing head is shaped hemispherically and that the support pin is rigidly connected to the column or to a plate forming the bearing surface and protrudes through the recess through the seat plate, so that the seat plate can tilt in all directions and rotate without hindrance.
Furthermore, the object stated is achieved in accordance with a second teaching of the present invention by the fact that a conical bush, which is secured to the lower side of the seat plate, protrudes through a central hole in the seat plate, that the bush rests on the bearing head of a support pin, wherein the bearing head is shaped spherically, and that the support pin is rigidly connected to the column or to a plate forming the bearing surface, so that the seat plate can tilt in all directions and rotate without hindrance.
Finally, the object stated is achieved in accordance with a third teaching of the present invention by the fact that the seat plate comprises a recess arranged in its centre, becoming larger from its top side towards its lower side, that a conical metal cap, reduced in diameter from bottom to top, is passed from below through the recess in the seat plate and secured, and that the metal cap rests on the bearing head of a support pin and forms the bush, wherein the bearing head is shaped hemispherically so that a common rotating and swivelling point arises above the seat plate.
The present invention therefore consists of a dynamic seating device, in which to achieve natural movements of the user at the same time with free mobility, according to the invention it is proposed that the seat plate has a central recess running conically from top to bottom with a bush inserted from below, which rests on the spherical or hemispherical bearing head of a support pin, so that a common rotating and swivelling point arises above the seat plate, not under it.
This invention concerns a seating device, which prevents posture injuries particularly within the extended spinal column region, by permitting free mobility and simultaneously physiologically centred sitting through a common rotating and swivelling point above the seat plate. In addition, body regions which have already become stiff can be rehabilitated thereby. This seating device can be employed both for daily use and for therapeutic purposes.
The seating device can offer possibilities to again achieve a natural upright posture, which can no longer be taken up due to reduced work and everyday tasks, and to avoid damage to the body—particularly to the spinal column. The seating device should create possibilities for the individual to recover an already lost sensitivity for dealing naturally with his/her own body as well as offering movement possibilities, which allow total freedom for constant movement when sitting. Although humans sit, they must be in continuous movement and in constant play with the equilibrium if the natural oscillations of the body are to be continually allowed and tensions are not to build up in any way. Rigid sitting should be avoided, so that constant play with the equilibrium can take place and many natural bodily functions are not lost and are regained, respectively.
In order to achieve this, a seat face must allow free tilting movements to all sides without disturbing resetting forces of the seat and the common rotating and swivelling point of the seat plate must lie directly above so that a natural extension of the spinal column beyond the coccyx is provided and thus constant transmission of movement can take place within the entire body.
Further arrangements of the invention are indicated in the dependent claims and are elucidated in detail below in connection with the explanation given with reference to a drawing of several exemplary embodiments. In the drawing there are shown in each case schematically, in cross section:
FIG. 1 a first exemplary embodiment of a seating device according to the invention with a height-adjustable column;
FIG. 2 a second exemplary embodiment of a seating device according to the invention for placing on any sub-base;
FIG. 3 a third exemplary embodiment of a seating device according to the invention with a height-adjustable column;
FIG. 4 a fourth exemplary embodiment of a seating device according to the invention for placing on any sub-base;
FIG. 5 a fifth exemplary embodiment of a seating device according to the invention with a height-adjustable column; and
FIG. 6 in sectional view a mounting in the case of a sixth exemplary embodiment of a seating device according to the invention.
In accordance withFIG. 1 a seat plate1, preferably made from wood, is rigidly connected byseveral bolt connections4 to abase plate7, which through a dome shaped protuberance forms the upper shell of a slide bearing. A thin foam-material sheet2 glued with the seat plate1 covers thisbase plate7 and ensures a soft, anti-slip seat face. The centre of the seat plate is provided with arecess8, so that the dome of thebase plate7 can rest on a hemisphericalplastic part5 pressed in asupport pin6 and the conjoined seat plate1 could tilt at least +/−20° in all directions. In order to keep the friction in this bearing to a minimum and nevertheless achieve the necessary stability, steel was selected as the material together with its diameter of 14 mm for thesupport pin6. Thesupport pin6 is rigidly connected to a height-adjustable column14 by adhesive, adowel pin15 or a screw. Thecolumn14 is vertically adjustable and can be fixed in an under-frame consisting of aplate16 and at least threefeet17. For example, thecolumn14 can be constructed as a spindle and engage in a screw thread of theplate16 in the manner of a piano stool, so that vertical adjustment can take place by rotating theplate13. Seat plate1 and around plate13 rigidly connected to thecolumn14 form the stop for limiting the tilting movement. Theplate13 at the same time prevents thecolumn14 from being torn out, if this should be made of wood. In order to prevent the seat plate1 from lifting off when being transported, aspring washer11 is pushed onto thesupport pin6, and awasher12 mounted betweenspring washer11 andplate3 is dimensioned so that it does not obstruct the tilting movement of the seat plate1 and also does not pass through the central hole of theplate3, which is rigidly connected to the lower side of the seat plate1.
InFIG. 2 an embodiment without vertical adjustment is illustrated. Here the under-frame is replaced by aplate10, so that the seating device can be placed on any sub-bases suitable for seating.
A seat plate1, preferably made from wood, in accordance withFIG. 3 is provided with a central conical hole, through which theconical bush19 protrudes and is rigidly connected to the lower side of the seat plate1 byfastening elements4. As the lower part of the slide bearing thesupport pin6 is connected at its tip to a spherical bearinghead5. Acap20 made from self-lubricating plastic lies between them. As a result of this construction the bearing point is able to lie above the seat plate1 and the latter can tilt approximately ±20° in all directions. To prevent the seat plate1 lifting off from the support pin6 aconical bracket21, through which thebearing head5 on its top side does not pass, is secured together with theconical bush19 on the lower side of the seat plate1. A foam-material sheet2 glued to the seat plate1 covers theconical bush19 and ensures a soft, anti-slip seat face. Thesupport pin6 is rigidly connected to a height-adjustable column14 by adhesive, adowel pin15 or ascrew thread22. Thecolumn14 is vertically adjustable and can be locked in an under-frame consisting of aplate16 and at least threefeet17. For example, thecolumn14 can be constructed as a spindle and engage in a screw thread of theplate16 in the manner of a piano stool, so that vertical adjustment can take place by rotating theplate13. Seat plate1 and around plate13 rigidly connected to thecolumn14 form the stop for limiting the tilting movement. Theplate13 at the same time prevents thecolumn14 from being torn out, if this should be made of wood.
InFIG. 4 an embodiment without vertical adjustment is illustrated. Here the under-frame is replaced by aplate10, so that the seating device can be placed on any sub-bases suitable for seating.
In accordance withFIG. 5 aconical bush19 provided with anedge24 at the bottom is secured from below to the seat plate1 through arecess8 in the seat plate1, which preferably consists of wood. A foam-material sheet2 glued to the seat plate1 covers the seat plate1 and thebush19 and ensures a soft, anti-slip seat face. Thesupport pin6 is rigidly connected to a height-adjustable column14 by adhesive, a dowel pin or ascrew thread22 and forms the lower part of the bearing, so that the seat plate1 mounted with thebush19 can tilt in all directions as far as the angle of the cone of thebush19 permits and allows it rotate without hindrance. In order to keep the friction in this bearing to a minimum and nevertheless achieve the necessary stability, metal was selected as the material for thesupport pin6 and itshead5 consists of a hemispherical plastic part, which is held in position by alocking pin23. Thecolumn14 is vertically adjustable and can be fixed in an under-frame consisting of aplate16 and at least threefeet17. For example, thecolumn14 can be constructed as a spindle and engage in a screw thread of theplate16 in the way of a piano stool, so that the vertical adjustment can take place by rotating theplate13, which is rigidly connected to thecolumn14. Seat plate1 and theround plate13 form the stop for limiting the tilting movement. Theplate13 at the same time prevents thecolumn14 from being torn out, if this should be made of wood. In order to prevent the seat plate1 from lifting off, thebush19 is pressed circularly at itsconstriction25, after being placed on thesupport pin6.
A further arrangement for preventing the seat plate1 from lifting off is illustrated inFIG. 6. Ahollow cone26, which consists of two parts and extends to the bearinghead5, is inserted into thebush19 after being placed on thesupport pin6 and is held with acircular metal plate27, which is secured together with thebush19 to the lower side of the seat plate1. Thehollow cone26 can also consist of only one part if the diameter of the shank of thesupport pin6 is less than its bearing head.
REFERENCE NUMERAL LIST- 1 seat plate
- 2 flexible material or upholstery
- 3 plate
- 4 fastening element
- 5 bearing head
- 6 support pin
- 7 base plate
- 8 recess
- 9 fastening element
- 10 plate
- 11 pressed-on spring washer
- 12 washer mounted on the support pin
- 13 plate
- 14 column
- 15 dowel pin
- 16 plate
- 17 feet
- 18 recess
- 19 bush
- 20 cap
- 21 conical bracket
- 22 screw thread
- 23 pin
- 24 edge of the bush
- 25 constriction
- 26 hollow cone
- 27 circular metal plate