Note: Descriptions are shown in the official language in which they were submitted.
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Dynamic seating device
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
colwmn 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 po-
sture, but requires constant mobility. Since these unrestric-
ted movements are not attainable when sitting on normal seats,
various changes of sitting postures, which humans must consci-
ously 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 sensitisa-
tion processes, are unfit for work and everyday tasks over
longer periods. These shortcomings in sitting and movement ho-
wever 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 Pa-
tent DE 201 10 832 U1. As a result of the distance between the
two axes there is a difference between pitch- and lateral til-
ting 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
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seat with a resetting force and therefore does not meet the
demands made here.
In addition from French 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 lon-
ger 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 ob-
ject of the present invention is to create a seating device of
the kind initially specified, which automatically allows natu-
ral 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 lar-
ger from its top side towards its lower side, that a base pla-
te 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 sur-
face 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, whe-
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rein the bearing head is shaped spherically, and that the sup-
port pin is rigidly connected to the column or to a plate for-
ming 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 coni-
cal metal cap, reduced in diameter from bottom to top, is pas-
sed from below through the recess in the seat plate and secu-
red, 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 swivel-
ling 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 run-
ning sonically 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 swivel-
ling point arises above the seat plate, not under it.
This invention concerns a seating device, which prevents po-
sture injuries particularly within the extended spinal column
region, by permitting free mobility and simultaneously physio-
logically centred sitting through a common rotating and swi-
velling 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
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_ already lost sensitivity for dealing naturally with his/her
own body as well as offering movement possibilities, which al-
low 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 ma-
ny 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 de-
pendent claims and are elucidated in detail below in connecti-
on 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 ac-
cording 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 ac-
cording to the invention with a height-adjustable
column;
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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 ac-
cording 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 with Fig. 1 a seat plate 1, preferably made from
wood, is rigidly connected by several bolt connections 4 to a
base plate 7, which through a dome shaped protuberance forms
the upper shell of a slide bearing. A thin foam-material
sheet 2 glued with the seat plate 1 covers this base plate 7
and ensures a soft, anti-slip seat face. The centre of the
seat plate is provided with a recess 8, so that the dome of
the base plate 7 can rest on a hemispherical plastic part 5
pressed in a support pin 6 and the conjoined seat plate 1
could tilt at least +/-20° in all directions. In order to keep
the friction in this bearing to a minimum and nevertheless a-
chieve the necessary stability, steel was selected as the ma-
terial together with its diameter of 14 mm for the support pin
6. The support pin 6 is rigidly connected to a height-
adjustable column 14 by adhesive, a dowel pin 15 or a screw.
The column 14 is vertically adjustable and can be fixed in an
under-frame consisting of a plate 16 and at least three feet
17. For example, the column 14 can be constructed as a spindle
and engage in a screw thread of the plate 16 in the manner of
a piano stool, so that vertical adjustment can take place by
rotating the plate 13. Seat plate 1 and a round plate 13 ri-
gidly connected to the column 14 form the stop for limiting
the tilting movement. The plate 13 at the same time prevents
the column 14 from being torn out, if this should be made of
wood. In order to prevent the seat plate 1 from lifting off
when being transported, a spring washer 11 is pushed onto the
support pin 6, and a washer 12 mounted between spring washer
11 and plate 3 is dimensioned so that it does not obstruct the
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tilting movement of the seat plate 1 and also does not pass
through the central hole of the plate 3, which is rigidly con-
nected to the lower side of the seat plate 1.
In Fig. 2 an embodiment without vertical adjustment is il-
lustrated. Here the under-frame is replaced by a plate 10, so
that the seating device can be placed on any sub-bases sui-
table for seating.
A seat plate 1, preferably made from wood, in accordance with
Fig. 3 is provided with a central conical hole, through which
the conical bush 19 protrudes and is rigidly connected to the
lower side of the seat plate 1 by fastening elements 4. As the
lower part of the slide bearing the support pin 6 is connected
at its tip to a spherical bearing head 5. A cap 20 made from
self-lubricating plastic lies between them. As a result of
this construction the bearing point is able to lie above the
seat plate 1 and the latter can tilt approximately ~20° in all
directions. To prevent the seat plate 1 lifting off from the
support pin 6 a conical bracket 21, through which the bearing
head 5 on its top side does not pass, is secured together with
the conical bush 19 on the lower side of the seat plate 1. A
foam-material sheet 2 glued to the seat plate 1 covers the co-
nical bush 19 and ensures a soft, anti-slip seat face. The
support pin 6 is rigidly connected to a height-adjustable co-
lumn 14 by adhesive, a dowel pin 15 or a screw thread 22. The
column 14 is vertically adjustable and can be locked in an un-
der-frame consisting of a plate 16 and at least three feet 17.
For example, the column 14 can be constructed as a spindle and
engage in a screw thread of the plate 16 in the manner of a
piano stool, so that vertical adjustment can take place by ro-
tating the plate 13. Seat plate 1 and a round plate 13 rigidly
connected to the column 14 form the stop for limiting the til-
ting movement. The plate 13 at the same time prevents the co-
lumn 14 from being torn out, if this should be made of wood.
In Fig. 4 an embodiment without vertical adjustment is il-
lustrated. Here the under-frame is replaced by a plate 10, so
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that the seating device can be placed on any sub-bases sui-
table for seating.
In accordance with Fig. 5 a conical bush 19 provided with an
edge 24 at the bottom is secured from below to the seat plate
1 through a recess 8 in the seat plate 1, which preferably
consists of wood. A foam-material sheet 2 glued to the seat
plate 1 covers the seat plate 1 and the bush 19 and ensures a
soft, anti-slip seat face. The support pin 6 is rigidly con-
nected to a height-adjustable column 14 by adhesive, a dowel
pin or a screw thread 22 and forms the lower part of the bea-
ring, so that the seat plate 1 mounted with the bush 19 can
tilt in all directions as far as the angle of the cone of the
bush 19 permits and allows it rotate without hindrance. In or-
der to keep the friction in this bearing to a minimum and ne-
vertheless achieve the necessary stability, metal was selected
as the material for the support pin 6 and its head 5 consists
of a hemispherical plastic part, which is held in position by
a locking pin 23. The column 14 is vertically adjustable and
can be fixed in an under-frame consisting of a plate 16 and at
least three feet 17. For example, the column 14 can be
constructed as a spindle and engage in a screw thread of the
plate 16 in the way of a piano stool, so that the vertical ad-
justment can take place by rotating the plate 13, which is ri-
gidly connected to the column 14. Seat plate 1 and the round
plate 13 form the stop for limiting the tilting movement. The
plate 13 at the same time prevents the column 14 from being
torn out, if this should be made of wood. In order to prevent
the seat plate 1 from lifting off, the bush 19 is pressed cir-
cularly at its constriction 25, after being placed on the sup-
port pin 6.
A further arrangement for preventing the seat plate 1 from
lifting off is illustrated in Fig. 6. A hollow cone 26, which
consists of two parts and extends to the bearing head 5, is
inserted into the bush 19 after being placed on the support
pin 6 and is held with a circular metal plate 27, which is se-
cured together with the bush 19 to the lower side of the seat
plate 1. The hollow cone 26 can also consist of only one part
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if the diameter of the shank of the support pin 6 is less than
its bearing head.
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Reference numeral list:
1 seat plate
2 flexible material or upholstery
3 plate
4 fastening element
bearing head
6 support pin
7 base plate
8 recess
9 fastening element
plate
11 pressed-on spring washer
12 washer mounted on the support pin
13 plate
14 column
dowel pin
16 plate
17 feet
18 recess
19 bush
cap
21 conical bracket
22 screw thread
23 pin
24 edge of the bush
constriction
26 hollow cone
27 circular metal plate
