U.S. patent number 3,899,207 [Application Number 05/429,626] was granted by the patent office on 1975-08-12 for chairs.
This patent grant is currently assigned to VS-Schulmoebel Verwaltungs-GmbH. Invention is credited to Falk Mueller.
United States Patent |
3,899,207 |
Mueller |
August 12, 1975 |
**Please see images for:
( Certificate of Correction ) ** |
Chairs
Abstract
A stackable chair has a frame which comprises a U-shaped base,
open to the front and two lateral supports welded or otherwise
secured to the limbs of the base and upstanding therefrom. A seat
is attached to a U-shaped seat supporting frame, open to the rear,
which is welded or otherwise secured to the supports. A back rest
is attached to the upper ends of the supports. The seat and/or the
back rest may comprise a blow moulded hollow body.
Inventors: |
Mueller; Falk
(Tauberbischofsheim, DT) |
Assignee: |
VS-Schulmoebel Verwaltungs-GmbH
(DT)
|
Family
ID: |
6634577 |
Appl.
No.: |
05/429,626 |
Filed: |
December 28, 1973 |
Foreign Application Priority Data
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Dec 20, 1972 [DT] |
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465033[U] |
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Current U.S.
Class: |
297/239; D6/371;
D6/380; D6/372; 297/446.1; 297/451.3 |
Current CPC
Class: |
A47C
5/043 (20130101); A47C 5/04 (20130101); A47C
3/04 (20130101) |
Current International
Class: |
A47C
3/04 (20060101); A47C 5/04 (20060101); A47C
5/00 (20060101); A47C 3/00 (20060101); A47C
003/04 () |
Field of
Search: |
;297/239,452,442,445,331,336,446,448 ;108/91 ;248/188.9 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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342,710 |
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Jan 1960 |
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CH |
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524,397 |
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Aug 1940 |
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GB |
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602,218 |
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May 1948 |
|
GB |
|
Primary Examiner: Zugel; Francis K.
Attorney, Agent or Firm: Brumbaugh, Graves, Donohue &
Raymond
Claims
I claim:
1. A stackable chair comprising:
a. a continuous U-shaped metal base having a pair of substantially
parallel runners, said U-shaped base being open toward the front of
the chair;
b. a pair of lateral supports attached to the outer sides of the
central portions of said runners and sloping upwardly towards the
rear of the chair;
c. a U-shaped metal seat support attached to said lateral supports,
said seat support being open toward the rear of the chair;
d. a seat attached to and peripherally surrounded by said seat
support; and
e. a back rest attached to said lateral supports above said seat
support.
2. A chair according to claim 1, in which said means attaching said
supports to said base and to said seat supporting frame comprises
welding.
3. A chair according to claim 1 in which said base and said
supports comprise metal tubing.
4. A chair according to claim 3 further comprising closure members
closing the front ends of the runners formed by said limbs of the
base, each of said closure members being provided with a lower
supporting face.
5. A chair according to claim 3 in which said frame is made
essentially from flat oval tubing.
6. A chair according to claim 1 in which said seat supporting frame
passes around the outer edge of said seat and projects a little
beyond such outer edge.
7. A chair according to claim 1 in which said seat supporting frame
comprises metal tubing.
8. A chair according to claim 1, in which said seat supporting
frame comprises a bent metal profiled bar whose underside is
provided with means for accommodating a protective profiled strip
of resilient material, and in which a strip of resilient profiled
material is received in the last mentioned means.
9. A chair according to claim 8, in which the last mentioned means
comprises an undercut profile on the underside of said seat
supporting frame.
10. A chair according to claim 1, in which said seat comprises a
hollow body of plastics material.
11. A chair according to claim 10 in which said seat, in its outer
edge region, has a moulded recess which is shaped to partially
accommodate said seat support frame.
12. A chair according to claim 10 in which said hollow body of
plastics material has a lower wall forming the underside of the
seat, said lower wall having a strengthening profile.
13. A chair according to claim 10, in which said hollow body of
plastics material has a lower wall forming the underside of the
seat, said lower wall having moulded therein receiving means for
supporting pads and in which protective supporting pads are
received in said receiving means.
14. A chair according to claim 1, in which said back rest is
inserted between the upper ends of said supports and has a
thickness no greater than the dimensions of said supports in the
longitudinal direction of the chair.
15. A chair according to claim 1, in which said back rest comprises
a hollow body of plastics material.
16. A chair according to claim 15, in which said hollow body of
plastics material has a rear wall forming the rear of the back
rest, said rear wall having therein a handle-like recess which does
not pierce said rear wall.
17. A chair according to claim 15 in which said hollow body forming
said back rest comprises a substantially closed blow-moulded
body.
18. A chair according to claim 10 in which said hollow body forming
said seat comprises a substantially closed blow-moulded body.
19. A chair according to claim 1 in which said seat supporting
frame is so shaped that said seat can be pushed therein position
from the rear.
20. A chair according to claim 10 in which said seat supporting
frame is so shaped that said seat can be pushed into seat
supporting frame from the rear.
21. A chair according to claim 20 further comprising projection
means in the region between the seat and the seat supporting frame
for latching said seat in said seat supporting frame.
22. A chair according to claim 21 in which said projection means is
formed integrally on said seat and said seat supporting frame has
aperture means therein receiving said projecting means.
23. A chair according to claim 1 in which said seat lies on top of
said seat supporting frame and in which fastening means extends
through said seat to said seat supporting frame to secure the
former to the latter.
Description
The invention relates to stackable chairs.
One previously proposed stackable chair has a base formed by two
side runners which are joined together in the form of an H.
Upstanding lateral supports for the seat and the backrest are
outwardly secured to the runners. Thus the connections between the
supports and the runners are liable to bend when the chair is
tilted on edge. The central part of the H also reduces leg
movement. The supports and the central part connecting them
comprise separate parts so that a very large number of points of
welding is required, or very sharp bending is needed and this
precludes the use of tubing or hollow profiles for the
manufacturing material.
Another previously proposed stackable chair has a U-shaped base
lying on the floor and comprise a single U-shaped piece of steel
tubing which is closed at the rear and from the front ends of which
two lateral supports are bent upwardly to the two front corners of
the seat, pass beneath the seat and in turn are bent upwardly in
the rear region to form a support for the back rest.
An advantage of this chair in fact is that its frame can be bent
substantially from one piece of tubing without much welding, but it
needs a relatively large quantity of material because, on the one
hand, the length of its tubing is relatively long and, on the other
hand, the tubing must have a very large cross-section or a high
quality. The weight of the person using the chair is in fact
largely concentrated to the rear portion of the chair, i.e. in
precisely that portion where there is no support, and consequently
the whole chair is compressed like a spring.
A feature of the invention is, therefore, to produce a a stackable
chair on runners which keeps its shape whilst not requiring much
material and can be produced simply.
According to the invention, a stackable chair comprises a metal
frame having a continuous U-shaped base and two lateral supports
which slope backwards and are outwardly attached to the central
regions of the two substantially parallel runners formed by the
limbs of the U-shaped continuous base which is open at the front
and is closed at the rear by a crosspiece, a seat having a U-shaped
seat supporting frame attached to the supports, said seat
supporting frame being closed at the front and extending round the
peripheral region of the seat, and a back rest attached to the
upper ends of the supports.
It should be recognised that such a chair needs only four parts for
its frame, i.e. the two substantially straight or slightly curved
lateral supports and two U-shaped frames. The two U-shaped frames
which are preferably welded between the supports create a very
sturdy, self-supporting frame to be produced which is very
resistant to twisting or buckling especially because of the frame
arrangement which is closed at the front at the seat and is closed
at the rear at the base. The chair can be readily stacked and saves
a great deal of space. Compared with the previous proposal wherein
the supports were produced integrally with the base and, by
bending, were converted into a section running forwards parallel to
the limbs, considerably less and more simple bending is necessary
and consequently harder materials may be used.
In one preferred embodiment of the invention the front ends of the
limbs of the base are closed by closure members having a lower
supporting face. The frame is made preferably from substantially
flat oval tubing. What is also meant hereby is a tubing whose
cross-sectional form consists of two semi-circular arcs and
straight lines connecting these arcs. The flat oval tubing has the
advantage of being very resistent to bending in the main bending
direction which corresponds to the alignment of the flat oval
tubing, i.e. in the longitudinal direction of the chair in the case
of the supports and in the vertical direction in the case of the
base.
In the preferred embodiment of the invention, the two supports in
the region of the seat are joined together by means of a seat
supporting frame to which the seat is attached and which passes
below the seat. This seat supporting frame is preferably welded to
the supports and thus serves to achieve a very sturdy chair. It
also enables the seat to be made from a less rigid, i.e. not
necessarily self-supporting material.
The seat supporting frame may preferably pass round the outer edge
of the seat and project a little beyond this outer edge. Besides
giving the chair a very good appearance, this frame also protects
the material of the seat which is generally made of a softer and
less robust material. However, the person using the chair does not
normally feel the edge of the seat supporting frame, which only
projects a few millimeters, whilst he is sitting.
The seat supporting frame may be made of a metal profile whose
underside is constructed so as to accommodate a protective profiled
strip made of a resilient adherent material. The structure of the
seat supporting frame will preferably be a closed or open square
structure. The underside of the seat supporting frame may have an
undercut structure which is highly suitable for inserting and
holding the protective profiled strip.
The seat and/or the back rest may be made from a hollow body of
plastics material. This can be made relatively easily as a
substantially closed body by a blow moulding process. It is very
sturdy and the parts which are in contact with the occupant's body
have a relatively small mass so that it does not feed cold. A
substantial advantage lies in the fact that the underside of the
chair is also closed.
Such a seat may have a recess formed in the region of its outer
edge, this recess being so constructed that it at least partially
accommodates the seat supporting frame. It is also possible to give
the wall forming the underside of the hollow seat a reinforcing
structure which, if need be, provides direct support for a load
applied to the top of the seat.
The same advantages are produced when the back rest is constructed
as a hollow body made of plastics material. It is important for the
back wall of the back rest to also be closed, thus giving a very
good appearance without the chair becoming heavy thereby. The back
rest can advantageously be inserted between the upper ends of the
supports, but may also overlap these supports.
A handle-type recess, which does not go through the rear wall of
the hollow back rest, may be formed in this wall. This handle-type
recess which is important for carrying the chair does not therefore
need to be obtained at the expense of an inconvenient cut in the
back rest.
The invention is further described, by way of example, with
reference to the accompanying drawings, in which:
FIG. 1 is a perspective view of a chair according to the
invention
FIG. 2 is a fragmented section along line II--II in FIG. 1 to a
much larger scale.
FIG. 3 is a likewise fragmented section along the line III--III in
FIG. 1, also on a larger scale,
FIG. 4 is a side view of chairs which have been stacked one on top
of the other according to a modified embodiment of the
invention.
FIG. 5 is a side view of a chair with the underside of the seat
suspended on a table,
FIG. 6 is a front view of the chair of FIGS. 4 and 5, and
FIG. 7 is a sectional detail of a front or side edge of the seat of
the chair of FIGS. 4 to 6.
The chair 11 shown in FIGS. 1 to 3 has a frame 12 made of steel
tubing, i.e. from flat oval-sectioned tubing. The cross-section of
this tubing comprises two semicircular arcs and straight lines
connnecting these arcs. The frame 12 has a U-shaped base 13
comprising two lateral runners 14, which extend substantially in
the longitudinal direction (forwards and backwards) of the chair,
and a rear crosspiece 15 which joins the two runners 14 together.
The U-shaped base 13 thus formed is curved integrally with
relatively large rounded portions at the corners and is open at the
front. The front ends are closed by closure members 16 of plastics
material which are slipped over the free ends of the runners 14.
They also have on their underside a supporting face 17 which serves
as a foot to protect the floor from being damaged. Large supporting
members 18 are situated in the region of the rear corners. In
particular, both these supporting members serve to protect carpeted
floors.
The frame 12 also has two lateral upright supports 19 whose lower
ends are outwardly joined to the central region (a little in front
of the middle) of the runners 14. The joints are thereby subjected
to a relatively small leverage. The joints are made by welds 20.
The substantially straight, but in the embodiment shown in FIG. 1
slightly forwardly curved supports 19 are welded on to the base
frame so that they slope upwardly rearwards. During attachment it
should be ensured that the supports 19 are attached to the runners
14 from the outside in such a way that the base of a chair which is
stacked on top can pass between the supports as shown in FIG. 4. If
need be, it may therefore be advisable to provide a small
intermediate layer between the support 19 and base runner 14 before
welding or to weld the support and the base runner together so that
there is a gap therebetween. This object can also be achieved,
however, by reducing the space between the runners 14 rearwardly of
the base 13.
At seat level the supports 19 are joined together by means of a
U-shaped seat supporting frame 21 which is closed at the front and
open at the rear. This seat supporting frame extends round the
outside of a seat 22 and projects a little outwardly of the seat
22. The seat supporting frame 21 is inserted between the supports
19 and connected to these supports by welds 23. It is also
important here for the seat of a chair to be able to slide between
the supports of an identical chair during stacking.
As can be seen from FIG. 2 the seat supporting frame 21 is made of
rectangular section steel tubing which is bent into its
U-shape.
The seat 22 is a hollow member made of plastics material which is
substantially closed on all sides and is manufactured by a blow
moulding process. It has an upper side 24 serving as a seat face
and an underside 25 provided with channel like indentations 26
which form a structure to reinforce the underside of the seat. As
can be seen, there is only a relatively small gap between the upper
side 24 and the base of the indentation 26 and this gap can be
closed upon deflection of the seat upper side 24 so that the
underside then carries part of the weight of the person using the
chair. The seat can be very well adapted to this seat form during
manufacture. In the region which is enclosed by the seat supporting
frame 21, the periphery of the seat has a recess 27 which is
partially adapted to the outer structural form of the seat
supporting frame 21 which is rectangular in the present embodiment.
A continuous projection 28 on the seat 22 engages beneath the lower
face of the seat supporting frame 21 so that the seat can be
slipped from the rear into the seat supporting frame and be guided
therein. A sloping stop projection (not shown) may be moulded on a
surface of the seat 22 which is in contact with the seat supporting
frame 21, this stop projection engaging with a hole in the seat
supporting frame and securing the seat in position.
In the peripheral region of the underside 25 of the seat, recesses
29 are formed in which resilient supporting pads 30 can be
inserted. These recesses may alternatively be moulded in so that
they extend round the underside of the seat and can receive
profiled padding. These supporting pads 30 serve to protect the
seat face during stacking (cf. FIG. 4) and to protect a table face
when the chair is possibly and advantageously suspended on the
table whilst the floor is being cleaned, or during a similar
process, (of. FIG. 5). On advantage of the chair according to the
invention is that this type of chair suspension is possible.
A back rest 31 is also made of a hollow body of plastics material
which is manufactured by a blow moulding process. This body is also
substantially closed on all sides. FIG. 3 is a central
cross-section through the back rest 31. It is inserted internally
between the supports 19. The back rest 31 is secured by means of
screws 33. The hollow body may alternatively be of such a shape
that it overlaps the upper ends of the supports 19. In the present
embodiment, the upper ends of the supports 19 are closed by end
pieces 34. The back rest 31 is not thicker than the dimensions of
the supports 19 in this direction, i.e. the longitudinal direction
of the chair. It is thereby ensured that the chairs are parallel to
each other during stacking and are not pushed forwards like a fan
as a result of a thickened or screwedon back rest.
In the rear wall 35 remote from the person using the chair, a
handle-like recess 36 is provided, but this does not impair the
closed form of the hollow space and the back support face.
FIG. 4 shows principally the advantageous manner of stacking chairs
according to the invention. Because the supports 19 are externally
located and there is room for the bases 13 and the seats between
the supports 19, the chairs can be stacked very compactly and very
sturdily. Because of the substantial parallelism between the upper
and lower faces of the seat, a straight stack is formed which does
not tilt forwards, as would be the case with sloping undersides for
the seats.
The embodiment shown in FIGS. 4 to 7 differs from that shown in
FIGS. 1 to 3 in that the supports 19 are completely rectilinear and
in that seats 22' made of shaped plywood are used instead of seats
made of hollow pieces of plastics material as illustrated
particularly in FIGS. 2 and 3. The seat supporting frame 21', which
is used thereby, is shown in detail in FIG. 7. It consists of an
open steel structure forming an angle with an upper limb and a
front limb to which a U-shaped structure 40, which is open towards
the bottom but which is slightly undercut, is connected on the
underside. A resilient profiled strip 30' of plastics material
which serves as a supporting pad is inserted in this U-shaped
structure. The seat 22' is made of pre-formed plywood and is
connected to the seat supporting frame 21' by means of screws or
rivets 37. This seat supporting frame may have the most varied
shapes and in particular a closed structure can also be used or a
C-shaped structure wherein the structure 30' is inserted in its
lower opening.
The seat supporting frame may also have the form of an angular
frame which is open towards the top and into which an upholstered
seat may be inserted or pushed in from the rear. The cushion can be
prevented from falling out by screws, but the entire seat load is
transferred directly from the seat to the lower horizontal members
of the angular frame. The angular frame may become flatter towards
the front from its mounting point to the supports so that there is
also an adequate amount of upholstery in the edge region and a
person does not sit on the high edge of the angular frame when the
upholstery is compressed.
The U-shaped seat supporting frame and the U-shaped base should, in
the region of their curves have smaller dimensions between the
limbs (in the case of the seat supporting frame) and between the
runners (in the case of the base) than at the ends remote from
their curves. These ends then slightly diverge in the direction of
their free ends in the case of the base or in the direction of
their welded ends in the case of the seat supporting frame. This
makes stacking easier and also enables, if necessary, the supports
to be formed so that they slightly converge towards the top, this
possibly being desirable from the point of view of appearance and
statics.
* * * * *