U.S. patent number 3,874,727 [Application Number 05/340,824] was granted by the patent office on 1975-04-01 for chair.
This patent grant is currently assigned to Rudolph Baresel-Bofinger. Invention is credited to Klaus Mehnert, Guenter Valenta.
United States Patent |
3,874,727 |
Mehnert , et al. |
April 1, 1975 |
Chair
Abstract
An adjustable arm chair has a chair body including a stiff
tub-shaped back rest portion, a stiff tub-shaped leg portion, and a
flexible substantially flat seat portion connecting the back rest
portion and the leg portion; and a support construction for the
chair body for continuous adjustment of the back rest portion, the
seat portion and the leg portion relative to one another and to the
support construction, so that the chair can be tilted forwardly and
rearwardly in a continuous stepless manner into any desirable rest
or upright positions, when the user shifts his body weight in the
chair, without requiring the provision of separate adjustment means
of any kind.
Inventors: |
Mehnert; Klaus (Stuttgart,
DT), Valenta; Guenter (Stuttgart, DT) |
Assignee: |
Rudolph Baresel-Bofinger
(Ilsfeld, DT)
|
Family
ID: |
5844567 |
Appl.
No.: |
05/340,824 |
Filed: |
March 13, 1973 |
Foreign Application Priority Data
|
|
|
|
|
May 10, 1972 [DT] |
|
|
2222840 |
|
Current U.S.
Class: |
297/320;
297/452.14 |
Current CPC
Class: |
A47C
1/033 (20130101); A47C 3/12 (20130101) |
Current International
Class: |
A47C
1/031 (20060101); A47C 1/033 (20060101); A47c
001/033 () |
Field of
Search: |
;297/320,321,323,457,460,445,29,59,287,286,420,419 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Zugel; Francis K.
Attorney, Agent or Firm: Striker; Michael S.
Claims
What is claimed as new and desired to be protected by Letters
Patent is set forth in the appended claims:
1. A chair, especially an armchair, comprising a chair body
including a rigid backrest portion, a rigid leg portion, and a
flexible seat portion connecting said backrest portion and said leg
portion so that said backrest portion and said leg portion are
pivotable forward and backward about and with reference to said
seat portion; and support means including rearward legs and
supporting said chair body for continuous adjustment of the
position of said portions relative to one another and to said
support means, at the will of a user, said support means comprising
connecting means between said chair body and said support means, in
one area between said seat portion and said leg portion and in
another area in that region of said back rest portion which is
adjacent said seat portion, said connecting means in said other
area comprising a strap extending in a direction substantially
normal to a line intermediate said back rest and leg portion, two
laterally disposed studs on said strap extending in a direction
substantially normal to said line, and two arm rests, said arm
rests connecting said rearward legs and said studs,
respectively.
2. A chair as defined in claim 1, wherein said rearward legs are
provided with hand supports, to which said arm rests are
connected.
3. A chair as defined in claim 1, wherein said arm rests consist of
flexible, endless, loop-shaped bands, made of a material selected
from the group composed of leather, artificial leather, and textile
fabrics.
4. A chair as defined in claim 3, wherein said bands are suspended
from said studs of said strap and said hand supports of said
rearward legs, respectively.
Description
BACKGROUND OF THE INVENTION
The present invention relates generally to a chair, and more
particularly to an upholstered arm chair having a chair body and
support means.
It is already known in the art to provide arm chairs or the like,
which can be tilted from a more or less upright position to a more
or less inclined rest position and back again to an upright
position by means of an adjustment system consisting of levers,
bars, rod and/or the like. The construction of such an adjustment
system naturally is difficult and expensive. In addition, such an
adjustment system usually makes the chair bulky and clumsy.
SUMMARY OF THE INVENTION
It is, accordingly, an object of the present invention to provide
an improved adjustable or tiltable chair, such as an upholstered
arm chair or the like, which does not have the foregoing
disadvantages.
More particularly it is an object of the present invention to
provide a chair which can be tilted from a substantially upright
position to a substantially inclined rest position in a continuous
manner, without any steps and without any special separate
adjusting means.
Still a further object of the present invention is to provide a
chair which can be tilted from a substantial upright position to
any inclined rest position in a continuous manner and raised again
to said upright position, when the user shifts the weight of his
body in the chair, backwardly and forwardly, respectively.
In pursuance of the foregoing objects, and others which will become
apparent hereafter, a novel adjustable chair has been developed
which, briefly stated, comprises a chair body including a back rest
portion, a leg portion and a seat portion connecting the back rest
portion and the leg portion, and support means to support the chair
body for continuous adjustment of the back rest, seat and leg
portions relative to one another and relative to the support means.
The back rest portion and the leg portion can be made nonyielding
and stiff while the seat portion is made flexible according to one
currently preferred embodiment of the present invention.
The design of the novel chair, its chair body and its support means
allows the user to adjust the chair from a substantially upright
position to a more or less inclined rest position in a continuous
stepless manner and vice versa, without any separate adjustment
means and without any levers, rods or bar or the like. He only
shifts or displaces his body weight forwardly or backwardly, e.g.
by bending or stretching his legs or bending the upper portion of
his body forward. He thus is able to select any stable intermediate
position between the substantially upright and an extreme inclined
rest position.
The back rest portion and the leg portion are preferably
substantially tub- or trough-shaped, whereas the transverse
cross-section of the seat portion is substantially flat. However,
the shape of the seat portion in a direction intermediate the back
rest portion and the leg portion preferably is part circular at
least when the chair is not used. The length of the part-circular
outline in this direction preferably is between approximately 12
and 18 cm.
The chair body is preferably supported by the support means in one
area between the seat portion and the leg portion and in another
area in that region of the back rest portion which is adjacent the
seat portion. The chair body and the support means are preferably
connected in the first-mentioned area by means of two brackets
fastened to said area under the chair body, rotatable on a
transversely extending shaft held by two forwardly disposed legs of
the support means; and in the second area by means of a strap
extending transversely under the chair body and normal to a line
intermediate the back rest portion and the leg portion, and two arm
rests, suspended from two studs, which are transversely spaced
parts of the strap, and from two hand supports, which are integral
parts of two rearwardly placed legs of the support means.
The arm rests are preferably made of a flexible material, leather,
artificial leather, a textile fabric or the like. They preferably
consist of endless, loop-shaped bands, suspended from the studs of
the strap and from studs on the hand supports, respectively.
The brackets of the forwardly disposed connecting means may each
consist of two angularly spaced bars and spacing means, such as a
screw, extending through two bars, so that the frictional forces
between the brackets and the shaft hold by the two forwardly
disposed legs of the support means can be adjusted.
The contact points between the chair body and the two brackets,
rotatable on the shaft, preferably are located rearwardly of a
vertical plane which includes the axis of the shaft, so that the
two brackets can pivot rearwardly about the shaft, when the chair
is used and the user shifts his body weight forwardly.
The shaft holding the brackets may be secured on the two forwardly
disposed legs of the support means by means of adapter bushes, and
the brackets may be held in place by spacer sleeves on the
shaft.
The chair body can be made of an ABS-polymerization product of the
like. The thickness of the body chair can amount to between
approximately 2.5 and 5 mm.
The novel features which are considered as characteristic for the
invention are set forth in particular in the appended claims. The
invention itself, however, both as to its construction and its
method of operation, together with additional objects and
advantages thereof, will be best understood from the following
description of specific embodiments when read in connection with
the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a side-elevational view of a chair according to the
present invention;
FIG. 2 is a part-sectional exploded view of a detail of the chair
in FIG. 1;
FIG. 3 is a cross-section of a detail of the chair in FIG. 1;
FIG. 4 is a cross-section of a further detail, taken on the line
IV--IV of FIG. 1;
FIG. 5 is a fragmentary top view of a portion of the chair in FIG.
1;
FIG. 6 is a cross-section taken on line VI--VI of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The embodiments in the drawing will now be discussed. It will be
seen that the adjustable arm chair 10 (FIG. 1) comprises a support
means 12 which is made of metal, such as extruded aluminum, or of
other suitable materials, such as synthetic plastic materials or
wood. The support means 12 can comprise a base 22, two forwardly
disposed but rearwardly inclined legs 16 and two rearwardly
disposed but forwardly inclined legs 18. Legs 18 are, as is evident
from the drawing, longer than legs 16 and are provided with
horizontally and forwardly disposed hand supports 20 which are
integral parts of legs 18. The forward ends of hand supports 20 are
shaped as two rings 24 (see especially FIG. 4), through which studs
26 are inserted. Arm rests 28 and 34 (FIGS. 1 and 5) run around
studs 26 and between the two rings 24 respectively. The arm rests
28 and 34 preferably are flexibly, endless, loop-shaped bands, made
of leather, artificial leather, a plastic material, a textile
fabric, or the like. The free end of each leg 16 of support means
12 is shaped as a ring 42 with bore 44, in which bores 44 legs 16
hold end portions 46 of a tube-shaped shaft 48 (FIG. 2).
The chair of the present invention comprises, in addition to the
support means, the chair body and the upholstering, two foot
portions 22, two forward legs 16, two rear legs 18 and two hand
supports 20, which elements are laterally disposed in relation to
each other, respectively, along lines and planes normal to the
drawing plane of FIG. 1. The chair body 14 is disposed between and
supported by these element pairs, which will be discussed in more
detail in the following.
Shaft 48 (FIG. 3) connects the end portions of the two legs 16. End
portions 46 (FIG. 2) of shaft 48 are inserted in bores 44 of rings
42 and held by the legs 16 (FIG. 1). End portions 46 can for
example be provided with two axially extending slits 50 (FIG. 2),
so that end portions 46 can be expanded outwardly and pressed
against the inner walls of bore 44. Adapter bushes 52 for each end
portion 46 of shaft 48 are provided for this purpose. Adapter
bushes 52 can for example have four axially extending
equi-angularly arranged slits 54. Adapter bushes 52 also have an
inner bore with an inner thread 58 and a conical enlargement 59.
When supporting means 12 and the connecting means between
supporting means 12 and chair body 14 are assembled, adapter bushes
52 are inserted in the end portions of shaft 48, and two screws 56
having conical heads are screwed into the threads 58 of adapter
bushes 52, whereby portions 51 of the adapter bushes 52 are pressed
outwardly and radially against the inner walls of end portions 46
of shaft 48, so that portions 55 of end portions 46 are pressed
outwardly and substantially radially against the inner walls of
bore 44, and so that shaft 48 is firmly held in the rings 42 of
legs 16.
Chair body 14 can be made of an ABS-polymerization product, e.g. by
a vacuum process within the skill of those conversant with the art.
Other synthetic plastic materials, e.g. polyamides, can also be
used for the production of the chair body, and other manufacturing
or production processes, e.g. extrusion processes, can be resorted
to. Suitable upholstering can be provided, fastened if so desired,
to the chair body 14, as is indicated by a dotted line in FIG. 1.
It extends along substantially the whole length of chair body 14. A
support for the back of the neck can also be provided, which can be
fastened to or suspended from the chair body itself, or to or from
the upholstery.
Chair body 14 consists of one substantially nonyielding and stiff
back rest portion 80, one substantially nonyielding and stiff leg
portion 82, and one flexible, elastic seat portion 84. The three
portions form the integral chair body 14. Seat portion 84 is the
connecting link between back rest portion 80 and leg portion 82.
Back rest portion 80 and leg portion 82 have, as is illustrated in
FIG. 6, schematically and in cross-section, substantially the shape
of a tub or a trough with an arcuately shaped main part 81,
laterally disposed ribs 83, and edge portions 85, which latter
extend in a plane which is substantially normal to the plane of
lateral ribs 83. The nonyielding and stiffness properties of back
rest portion 80 and leg portion 82 are obtained mainly as a
consequence of the arcuate or tub-shape of main part 81 of these
portions 80 and 82. However, lateral ribs 83 contribute of course
also to these properties. The upholstery can also contribute
substantially to such properties of the chair body.
Seat portion 84 is shaped substantially as a part of a cylinder. A
cross-section of seat portion 84 in a plane normal to the drawing
plane of FIG. 1 will show that seat portion 84 is substantially
flat along a line normal to a line intermediate the back rest
portion 80 and leg portion 82. The stiff back rest portion 80 and
the stiff leg portion 82 change into the flexible seat portion 84
in the areas 86 and 88 respectively, and seat portion 84 thus
constitutes an elastic or flexible joint or link between the back
rest and the leg portions. A slight arching of seat portion 84 in
transverse direction is admissible in order to better hold the
upholstery. The flexibility and elasticity is not substantially
impaired by such a measure.
Chair body 14 is held by support means 12 in two areas. Strap 36 is
arranged in the lower third region of back rest portion 80 (FIG.
5). It is extended along a substantially horizontal line normal to
a line intermediate back rest portion 80 and leg portion 82 and
encircles tub-shaped part 81 of back rest portion 80. Strap 36 can,
as is illustrated in FIG. 5, be provided with projections 38 facing
and fastened to part 81 on the outer wall of back rest portion 80,
for instance with screws. Strap 36 is also provided with studs 30
on each of its lateral portions, as is depicted in FIG. 5. Studs 30
can be integral parts of strap 36 and be extended along a line
normal to a line intermediate the back rest portion 80 and the leg
portion 82.
The flexible arm rests 28 and 34, described above, which consist of
endless loop-shaped bands, the forward end portions of which run
around studs 26 and are held by these studs, also run around and
held by studs 30 of strap 36 (the rearward end portions of the
bands). Thus, arm rests 28 and 34 are holding the strap 36. Studs
30 are suspended or inserted in the rearwardly extended loops of
arm rests 28 and 34 for this purpose. To prevent the loops from
sliding off studs 30, the latter can be provided with heads having
a larger diameter than the diameter of the rest of the stud body
and being placed on the front end portions of the studs. Other
means, e.g. suitable stops, can of course be used for this
purpose.
The second support area for chair body 14 is located in the region
between seat portion 84 and leg portion 82. Body portion 70 of
chair body 14 (FIG. 3) is provided with a downwardly directed
tub-shaped cavity 72 in this area. Shaft 48 holds two laterally
disposed brackets 60, which preferably can be made of an elastic
synthetic material, although other materials such as metals and
wood can be used.
FIG. 3 is a cross-section of one of brackets 60 showing a bore 68
extending in the same direction as the direction of shaft 48. Bore
68 surrounds shaft 48. Bracket 60 consists of two bars 62 and 64,
angularly separated from each other by a slit 65. A bore 66 extends
in a direction normal to the direction of bore 68 and through the
two bars 62 and 64. The two brackets 60 are, as illustrated in
FIGS. 1 and 3, fastened by screws to chair body 14 or rather to the
downwardly directed tub-shaped cavity 72 of chair body 14.
Triangular blocks 74 are used to fasten brackets 60 to the inner
wall of cavity 72. Blocks 74 can preferably be made of the same
material as brackets 60 and have a width which is the same as the
width of brackets 60, e.g. between approximately 4 and 6 cm. This
is of course not a necessary dimensional limitation; brackets 60
and blocks 74 can have any desired width in lateral direction.
FIG. 3 shows how block 74 is fastened to legs 62 and 64 of bracket
60 by means of screws 76 and 78 through the body of cavity 72. The
profile of block 74 preferably is the same as the profile of cavity
72 to conform to the latter so that as large as possible bearing
area between block 74 and the body of cavity 72 can be
obtained.
FIG. 1 shows that the center line of brackets 60 is tilted
rearwardly and counterclockwise at an angle .alpha. relative to a
vertical line through the axis of shaft 48. This angle varies as
the position of the chair body varies. The arrangement is however
so balanced that the center line of brackets 60 is always tilted
rearwardly, never forwardly, for all possible positions of the
chair body. Angle .alpha. can for instance be 30.degree. when the
chair is not used.
The mode of operation of the novel chair is as follows: If a person
positions himself in the chair in a normal sitting position, leg
portion 82 of the chair body will extend forwardly in a substantial
horizontal direction, whereas back rest portion 80 will be inclined
rearwardly, but only to a small degree (FIG. 1) and support the
back of the user. The arms of the user are supported by flexible
arm rests 28 and 34. The steeper the sitting position is, the
larger is the angle .alpha..
If the user now leans rearwardly and/or more or less straightens
out his legs at the same time, the back rest portion 80 will tilt
in a rearward direction, and the brackets will turn in a clockwise
manner. The angle .alpha. between the center line of brackets 60
and the vertical line through the axis of shaft 48 will grow
smaller. Leg portion 82 will be tilted more or less downwardly from
its previous substantially horizontal position. Seat portion 84
which has a part-circular outline in the upright position will be
flatter when the chair body is thus tilted rearwardly and
counterclockwise. Studs 30 of strap 36 which supports back rest
portion 80 follow, when back rest portion 80 is tilted rearwardly
and downwardly, a circular line around a point 90, which is the
point of intersection between legs 18 and hand supports 20,
respectively. Arm rests 28 and 34 remain stretched but are now
stretched downwardly from point 90.
When the user raises his body forwardly and/or bends his legs, back
rest portion 80 returns to a more or less upright or steep
position, whereas leg portion 82 returns to a more or less
horizontal position from its downwardly inclined position. When the
user raises his body from a tilted rest position to an upright
sitting position, brackets 60 rotate rearwardly and downwardly
around shaft 48, namely counterclockwise, in FIG. 1.
All positions of the chair body 14, between an extreme upright
position and an extreme rest position are stable. The tub-shaped
design of back rest portion 80 and leg portion 82 give these
portions the necessary stiffness and nonyielding characteristics,
whereas seat portion 84 functions as a flexible joint or link
between the two stiff and nonyielding portions 80 and 82 due to its
substantially flat cross-section in a plane normal to a line
intermediate back rest portion 80 and leg portion 82.
The various possible upright, rest and lying positions can be
reached by a simple shifting or displacement of the body weight of
the user, e.g. by thraightening out, pulling up or bending his legs
and/or by more or less strong bending or inclination of the upper
portion of his body.
The following dimensions for the various elements of the support
means of the chair of the present invention have proven to be
suitable for a well-balanced arrangement, although they are to be
considered as being exemplary only. The center of shaft 48 has been
taken as a reference point.
The point of intersection between leg 18 and hand support 20,
namely point 90, around which arm rests 28 and 34 can rotate,
located for instance between approximately 30 and 35 cm over the
reference point and between approximately 5 and 8 cm behind the
reference point. The center point of stands 30 of strap 36 is
located, when the chair is not used, between approximately 23 and
28 cm over the reference point, whereas the length of arm rests 28
and 34 between point 90 and the center point of studs 30 is between
approximately 30 and 33 cm. The length of the flexible seat portion
84 along its outer curvature, is between approximately 12 and 18
cm, preferably 15 cm, when the chair is used, whereas it is between
12 and 15 cm, when the chair is not used.
The larger the angle between the bars 62 and 64 of brackets 60 is,
the more braking action between the chair body and the shaft of the
support means can be achieved. Thus, the ease or difficulty with
which the chair body can be tilted or lifted into various positions
can be readily adjusted by increasing or decreasing the angle
between bars 62 and 64 of brackets 60 by means of screws in bores
66.
The chair of the present invention can be tilted or lifted in a
continuous stepless manner into any of the rest or upright
positions if the user shifts or displaces his body weight in
various ways and no separate adjustment means of any sort are
required.
While the invention has been illustrated and described as embodied
in an adjustable arm chair with upholstering, it is not intended to
be limited to the details shown, since various modifications and
structural changes may be made without departing in any way from
the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the
gist of the present invention that others can by applying current
knowledge readily adapt it for various applications without
omitting features that from the standpoint of prior art fairly
constitute essential characteristics of the generic or specific
aspects of this invention and, therefore, such adaptations should
and are intended to be comprehended within the meaning and range of
equivalence of the following claims.
* * * * *