Sitting device

A sitting device with a seat, the inclination of which may be altered relative to a floor, supporting means along being arranged below and substantially in front of said seat for the knee or calf leg portions of the user, the supporting means being arranged at the front portion of the frame of the device in the form of two cushions spaced apart to provide a free space from the front and in towards the seat, and the seat being fixedly connected to the frame, said frame being provided with substantially curved runners to contact the floor and said supporting means being arranged at the front ends of the runners. The runners may at a middle portion thereof have a bend to define a transition between sections of the runners. The sitting device may have a back rest. Instead of a fixedly connected seat and runners, the seat may be hinged connected to the frame and forwardly tiltable.

The present invention relates to a sitting device with a seat, the 
inclination of which may be changed relative to the support (the floor) 
for the sitting device, with a supporting means being arranged for the 
knee- or calf leg portion of the user below and substantially in front of 
said seat. 
In the industrialized part of the world one assumes a sitting posture too 
extensively, i.e. that one during a large portion of the day has a posture 
providing an angle of approximately 90.degree. between the legs and the 
upper part of the body. The hip joint has difficulty in accepting an angle 
in excess of approximately 50.degree., and the remaining 40.degree. are 
thus bent at the lowermost and soft portion of the spine. Upon forward 
bending for writing or other work, the stress on the spine becomes even 
greater. Such stresses are causing a number of ailments of the back. In 
order to overcome these problems there has now been brought into the 
market office chairs with a tiltable seat which may tilt forwardly and 
thereby increase the angle between the legs and the upper part of the 
body. The disadvantage of these chairs are, inter alia according to the 
research done by the Swedish Furniture Institute, that the user easily may 
slide off the seat and thereby cannot make the said angle as open as 
possible. 
A prior art chair is known from U.S. Pat. No. 3,669,493 which is adapted to 
support a person so that his weight is distributed between his posterior 
and his knee. The chair includes a knee support and a seat support sloping 
generally downward towards the knee support. The sloping seat and the knee 
support cooperate to shift a portion of a persons weight onto the knee 
support so that the weight borne by the person's posterior is reduced, 
thus permitting use of the chair over an extended period of time without 
the person developing a pain in his posterior. An arcuate lateral foot 
rest permits the person to place his feet in a number of positions. 
The inclination of the seat may be changed as well as the inclination of 
the knee support. However the chair is stationary on the floor and is 
difficult to enter, in particular with the embodiments having adjustable 
seat and knee support. 
The present invention has therefore as an object to overcome the 
disadvantages related to chairs of the known types. 
The sitting device according to the preferred embodiment of the present 
invention is characterized in that the said supporting means for the knee 
and/or calf are arranged at the front portion of a frame of the device in 
the form of two cushions spaced apart from each other and from the seat in 
such a manner that there is free space from the front and in towards the 
seat, and that said seat is hinge connected with the said frame and 
forwardly tiltable. According to another preferred embodiment of the 
invention, the said supporting means are arranged at the front portion of 
the frame of the device in the form of two cushions spaced apart from each 
other and from the seat cushion in such a manner that there is free space 
from the front and in towards the seat, and that the seat is fixedly 
connected with the said frame, said frame being provided with 
substantially curved runners to rest against said support, said supporting 
means being arranged at the front ends of said runners. 
According to further features of the sitting device, the said runners have 
at a middle section a bend for causing the sitting device to assume one of 
several possible stable positions in use. The supporting means have such 
position and inclination that the user upon placing his knee or calf-leg 
resting against the supporting means may also place his feet against the 
floor or said runners. The sitting device is also preferably provided with 
a back rest. 
The present invention is now to be described by way of examples with 
reference to the drawings. 
With the present construction the sitting device may be used as a 
conventional chair or stool, or as a chair with a tiltable seat, e.g. a 
rocking chair. When the angle between the leg and the upper portion of the 
body is desired to be so wide that the user can slide down from the seat, 
the knees or the calf portion of each leg are placed against the said 
knee- or calf-portion supporting means. The weight of the body will then 
be distributed between the seat and the knee or calf support so that one 
avoids sitting with tensioned muscles in the legs in order not to slide 
off the seat. The angle between the upper portion of the body and the legs 
becomes in this posture approximately 135.degree., and even with relaxed 
muscles the lumbar region will not project backwards. The rocking 
construction has also the effect that one independently of the upper 
portion of the body being in balance, may rock from the lumbar region and 
downwards and thereby obtain an active sitting method which makes the 
muscles of the hip joint active.

In FIGS. 1-6 there is shown a sitting device 1 having a frame 2, 
substantially curved runners 3 which are unitary with the frame 2, a seat 
4, and knee or calf-leg supporting means 5 in the form of two spaced apart 
cushions. In FIG. 1 the sitting device is shown in a position where the 
upper body and legs of the user form an angle of approximately 90.degree. 
and the legs are between the two cushions. In FIG. 2 the sitting device is 
caused to tilt so that the seat 4, is forwardly inclined and the calf leg 
portion of each of the legs of the user is then resting against the 
supporting means 5. In FIG. 3 as well as in FIGS. 5 and 6 the user is 
shown using the supporting means 5 as a knee support. As will appear from 
FIG. 3 the runners 3 have a bend at 26, thus making a distinct transition 
between the front and rear portions 24 and 25 of the runners. The same is 
also indicated in FIG. 15. 
In FIGS. 7-12 the sitting device is illustrated as a rocking chair 6 where 
the frame 7 has curved runners 8 which are unitarily connected with the 
frame 7. The seat 9 forms an angle with the back rest of the chair 10, 
said angle being wider than 90.degree.. On the front portions of the 
runners there is arranged calf supporting means 11 in the form of two 
spaced apart cushions. As will appear from FIG. 12 these means 11 may also 
be used as a foot support in case the sitting device is used as a 
conventional rocking chair. This is however a marginal effect of the 
present invention. FIG. 8 illustrates in dotted lines how the position of 
the chair is altered upon forwardly inclining the seat relative to the 
floor 12. In FIG. 9 the user sits at a table 13 and the supporting means 
11 serves as shown for supporting the calf leg portion of the user. The 
user has here, in the chosen example, placed his feet on the outside of 
the runners 8. However, the user may, as shown in FIG. 10 arrange his feet 
on the inside of the runners. In FIG. 11 the sitting device is used as a 
conventional rocking chair with the feet of the user on the floor. The 
same is the case in FIG. 12, where, as pointed out the supporting means 11 
serve to support the feet of the user. 
FIGS. 13-18 illustrate an embodiment of the sitting device according to the 
invention, which is similar to the embodiment of FIGS. 1-6. Instead of the 
somewhat solid frame 2 of FIGS. 1-6, there is here chosen a frame made 
from e.g. steel tubes 14. The form of the seat 15 and the supporting means 
16 may of course be varied within the scope of the invention. As pointed 
out in connection with FIG. 3 there is a bend 26 between the sections 24 
and 25 of the runners, thus causing a distinct transition between said 
sections. The same may of course be the case as regards the embodiment 
shown in FIGS. 7-12 as well as in FIG. 19 to be described below. 
FIG. 19 illustrates a modification of the embodiment according to FIG. 7 
where the anchor-like frame is replaced by a frame 17 made from e.g. steel 
tubes. As in FIGS. 7-12, there is also here curved runners 18. The 
technical operation of the sitting device according to FIG. 19 is thus 
substantially identical to that described for the sitting device of FIGS. 
7-12. It appears however from FIG. 19 that the supporting means 19 are 
arranged somewhat higher than in the embodiment of FIGS. 7-12. However, 
one will immediately understand that the supporting means may be arranged 
at any suitable distance from the seat 20. 
FIGS. 20-24 represent a modification of the office chair discussed earlier. 
The principle of the office chair appears substantially from FIGS. 20 and 
21. The seat 21 is tiltable relative to a frame 23 of the chair about a 
hinge 22. In FIGS. 22 and 23 the user has placed his calf leg portion 
against the supporting means 24. In such a sitting posture the user is 
prevented from sliding off the seat. 
There are inter alia two advantages by being able to alternate between the 
shown sitting postures, viz. that one avoids permanent stress on the same 
joints, since it is disadvantageous to sit too long in the same posture, 
and secondly that the different postures cover different functions from 
e.g. normal posture for reading a book to forwardly inclined work on a 
table. With the sitting device according to the invention, as shown in 
FIGS. 7-12 and FIG. 19, one has provided a resting chair which is 
compatible with the requirements to be set to a working chair. If one are 
to carry out something at a table, e.g. to eat, when sitting in a deep arm 
chair, this will prove impossible. This problem is solved by letting the 
comfortable rocking chair of the present invention upon shifting of the 
point of gravity of the human body be changed into an ergonomically 
correct working-chair. 
The partly knee-standing posture provides relieving of stresses and will 
over a length of time prevent certain sufferings in the back. However, the 
sitting device will also be well suitable for users which have so severe 
back pains that they only can stand or lie, but not sit in a traditional 
manner.