U.S. patent application number 12/424940 was filed with the patent office on 2009-10-22 for chair.
This patent application is currently assigned to PRO-CORD Spa. Invention is credited to Alessandro Piretti.
Application Number | 20090261644 12/424940 |
Document ID | / |
Family ID | 39758453 |
Filed Date | 2009-10-22 |
United States Patent
Application |
20090261644 |
Kind Code |
A1 |
Piretti; Alessandro |
October 22, 2009 |
CHAIR
Abstract
A chair comprising two ribbed supporting sectional elements (12)
set at a distance from one another in a transverse direction and
connected to a base (22, 24) by means of a transverse supporting
element (20), wherein each of said ribbed supporting sectional
elements (12) is basically L-shaped, with a seat portion (12a), a
backrest portion (12b), and a rounded radiusing portion (12c)
between the seat portion (12a) and the backrest portion (12b),
wherein extending between said supporting sectional elements (12)
is a material basically in the form of a sheet (42, 62), which
forms a seat (42a, 62a) and a backrest (42b, 62b), and wherein each
of said ribbed supporting sectional elements (12) is provided with
a plurality of through notches (48) set at a distance from one
another in a longitudinal direction, which form respective points
of localized bending, which enable bending of the supporting
sectional element (12) in a vertical plane, said notches (48)
distanced from one another by respective stretches (50)
substantially rigid to bending in said vertical plane.
Inventors: |
Piretti; Alessandro;
(Bologna, IT) |
Correspondence
Address: |
NIXON & VANDERHYE, PC
901 NORTH GLEBE ROAD, 11TH FLOOR
ARLINGTON
VA
22203
US
|
Assignee: |
PRO-CORD Spa
Bologna
IT
|
Family ID: |
39758453 |
Appl. No.: |
12/424940 |
Filed: |
April 16, 2009 |
Current U.S.
Class: |
297/344.12 |
Current CPC
Class: |
A47C 7/282 20130101;
A47C 7/44 20130101; A47C 31/023 20130101; A47C 7/445 20130101 |
Class at
Publication: |
297/344.12 |
International
Class: |
A47C 1/024 20060101
A47C001/024 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 18, 2008 |
EP |
08425266.7 |
Claims
1. A chair comprising: a base, two ribbed supporting sectional
elements set at a distance from one another in a transverse
direction, wherein each of said ribbed supporting sectional
elements is basically L-shaped, with a seat portion, a backrest
portion, and a rounded radiusing portion between the seat portion
and the backrest portion, a supporting element connecting said
ribbed supporting sectional elements to said base, a sheet
extending between said supporting sectional elements forming a seat
and a backrest, wherein, each of said ribbed supporting sectional
elements is provided with a plurality of through notches, which are
set at a distance from one another in a longitudinal direction and
form respective points of localized bending that enable bending of
the supporting sectional element in a vertical plane, said notches
being distanced from one another by respective stretches
substantially rigid to bending in said vertical plane.
2. The chair according to claim 1, wherein each of said notches has
two opposite surfaces that come into contact upon one another to
limit the amplitude of the local bending of the sectional
element.
3. The chair according to claim 1, wherein said notches are formed
in an integral ribbing that extends in a median vertical plane of
the respective supporting sectional element.
4. The chair according to claim 3, wherein said notches are
distributed along said seat portions, said backrest portions and
said radiusing portions of said supporting sectional elements.
5. The chair according to claim 3, wherein said ribbing has a
thickness comprised between 2-20 mm and a height comprised between
10-60 mm.
6. The chair according to claim 2, wherein each of said notches
enables a localized bending of the sectional element with a maximum
amplitude comprised between 1.degree.-22.degree..
7. The chair according to claim 1, wherein said sheet consists of a
fabric or by a mesh with side edges anchored in respective external
grooves of said supporting sectional elements.
8. The chair according to claim 1, wherein said sheet consists of
injected plastic material integral with said supporting sectional
elements.
9. The chair according to claim 1, wherein said supporting
sectional elements are joined together by integral transverse
elements formed integrally with said supporting sectional
elements.
10. The chair according to claim 1, wherein each of said supporting
sectional elements comprises at least one elastic member formed by
a bar of elastic metal material inserted in a seat of the
supporting sectional element.
11. The chair according to claim 2, wherein said supporting
sectional elements with said integral ribbing are made of
injection-moulded plastic material.
12. A chair comprising: a base, two ribbed supporting sectional
elements made of injection-moulded plastic material set at a
distance from one another in a transverse direction, wherein each
of said ribbed supporting sectional elements is basically L-shaped,
with a seat portion, a backrest portion, and a rounded radiusing
portion between the seat portion and the backrest portion, wherein
each of said ribbed supporting sectional elements is provided with
an integral ribbing that extends in a median vertical plane of the
respective supporting sectional element, the integral ribbing
having a plurality of through notches set at a distance from one
another in a longitudinal direction and forming respective points
of localized bending, each of said ribbed supporting sectional
elements having a respective laterally open external groove, a
supporting element connecting said ribbed supporting sectional
elements to said base, a sheet of flexible material having two side
edges anchored in respective external grooves of said supporting
sectional elements, said sheet extending between said supporting
sectional elements and forming a seat and a backrest, and first and
second bar-shaped flexible transverse elements integrally formed
with said supporting sectional elements, said bar-shaped flexible
transverse elements connecting to each other said supporting
sectional elements at a forward end of the respective seat portions
and at an upper end of the respective backrest portions.
13. The chair according to claim 12, wherein said notches are
distributed along said seat portions, said backrest portions and
said radiusing portions of said supporting sectional elements.
14. The chair according to claim 12, wherein each of said
supporting sectional elements comprises at least one elastic member
formed by a bar of elastic metal material inserted in a seat of the
supporting sectional element.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a chair comprising two
ribbed supporting sectional elements set at a distance from one
another in a transverse direction and connected to a base by means
of a transverse supporting element, in which each of said ribbed
supporting sectional elements is basically L-shaped with a seat
portion, a backrest portion, and a rounded radiusing portion
between the seat portion and the backrest portion and in which a
substantially sheet-like material forming a seat and a backrest
extends between said ribbed supporting sectional elements.
DESCRIPTION OF THE RELATED ART
[0002] A chair of the type referred to above is known from the
document No. DE1260721 filed in the name of Hermann Miller Inc. The
chair described in this document was made by the famous designer
Charles Eames in 1958 and became a point of reference of industrial
design.
[0003] The chair designed by Charles Eames envisaged the use of two
basically I-section rigid aluminium supporting sectional elements
fixed together by means of at least two transverse supporting
elements, one of which serves for connection to a column base. A
sheet formed by a fabric or a mesh, is wound on the two lateral
aluminium sectional elements and is anchored laterally in two
external side grooves of the supporting sectional elements.
SUMMARY OF THE INVENTION
[0004] The purpose of the present invention is to provide a chair
that will enable higher characteristics of comfort to be obtained,
maintaining the same stylistic setting of the chair designed by
Eames in 1958.
[0005] According to the present invention, the above purpose is
achieved thanks to the fact that each of the ribbed supporting
sectional elements is provided with a plurality of through notches,
which are set at a distance from one another in a longitudinal
direction and form respective points of localized bending of the
supporting sectional element in a vertical plane, said notches
being set at a distance from one another by respective stretches
that are substantially rigid to bending in said vertical plane.
[0006] By making the supporting sectional elements of plastic
material (typically nylon) and forming the aforesaid notches in a
central stiffening ribbing of the sectional elements, there is the
possibility of introducing a controlled bending in definite
portions of the sectional element. Bending of the sectional element
can be assisted by a small steel bar inserted in a groove of the
sectional element in an area corresponding to the radiusing area
between the seat portion and the backrest portion of each sectional
element.
[0007] The notches have opposite surfaces that enter into contact
with one another in the position of maximum inclination so as to
limit the maximum amount of localized bending in each point of the
sectional element.
DESCRIPTION OF THE DRAWINGS
[0008] The present invention will now be described in detail with
reference to the attached drawings, which are provided purely by
way of non-limiting example and in which:
[0009] FIG. 1 is a perspective view of a first embodiment of a
chair according to the present invention;
[0010] FIG. 2 is an exploded perspective view of the chair of FIG.
1;
[0011] FIG. 2A is a cross section according to the line II-II of
FIG. 2;
[0012] FIG. 3 is a cross section according to the line III-III of
FIG. 1;
[0013] FIG. 3A is an enlarged detail of a part of FIG. 3;
[0014] FIG. 4 is a detail at a larger scale of the part indicated
by the arrow IV in FIG. 2;
[0015] FIG. 5 is a view of the detail of FIG. 4 illustrating the
notches in the position of maximum bending;
[0016] FIG. 6 is a schematic side view illustrating the radiusing
portion of a supporting sectional element in the resting position
and in the position of maximum inclination backwards;
[0017] FIG. 7 is a detail illustrating notches of different
shape;
[0018] FIGS. 8 and 9 are sections according to the lines VIII-VIII
and IX-IX of FIG. 4 illustrating an alternative shape of the
ribbing of the supporting sectional elements;
[0019] FIG. 10 is a perspective view illustrating a second
embodiment of the chair according to the present invention;
[0020] FIG. 11 is a perspective view of the supporting structure of
the chair of FIG. 10;
[0021] FIGS. 12 and 13 are sections according to the lines XII-XII
and XIII-XIII, respectively, of FIG. 10;
[0022] FIG. 12A is an enlarged detail of a part of FIG. 12;
[0023] FIG. 14 is a perspective view of a third embodiment of the
chair according to the present invention;
[0024] FIG. 15 is an exploded perspective view of the chair of FIG.
14;
[0025] FIG. 16 is a cross section according to the line XVI-XVI of
FIG. 14;
[0026] FIGS. 17 and 18 are sections according to the lines
XVII-XVII and XVIII-XVIII of FIG. 15 illustrating an alternative
embodiment of the ribbed sectional elements;
[0027] FIG. 19 is a perspective view of a fourth embodiment of the
chair according to the present invention; and
[0028] FIG. 20 is a perspective view of a further variant of the
seat-backrest assembly of the chair according to the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] With reference to FIGS. 1 and 2, designated by 10 is a chair
according to a first embodiment of the present invention. The chair
10 comprises two ribbed supporting sectional elements 12 that form
the side edges of the chair 10. The two supporting sectional
elements 12 are arranged parallel to one another and are set at a
distance from one another in a transverse direction. The two
supporting sectional elements 12 are preferably identical to one
another and each of them is basically L-shaped, with a seat portion
12a, a backrest portion 12b and an arched radiusing portion 12c,
which extends between the seat portion 12a and the backrest portion
12b.
[0030] Each supporting sectional element 12 is constituted by a
monolithic element made of injection-moulded plastic material, for
example nylon. As may be seen in particular in FIG. 3, each
supporting sectional element 12 has an external groove 14 and an
internal groove 16. The two grooves 14, 16 extend continuously
throughout length of each supporting sectional element 12. Each
supporting sectional element 12 is moreover provided with a ribbing
18 that extends in a vertical plane, made integrally with the
respective supporting sectional element 12. The ribbing 18 extends
throughout the radiusing portion 12c and over a substantial part of
the seat portion 12a and of the backrest portion 12b. The ribbing
18 extends on the bottom side of the seat portion 12a and on the
rear side of the backrest portion 12b.
[0031] With reference to FIGS. 2 and 3, the two supporting
sectional elements 12 are fixed to a transverse supporting element
20 carried by a central column 22 of a base 24 provided with wheels
26. The transverse supporting element 20 has two side portions 28,
fixed to which are the two supporting sectional elements 12. In the
embodiment illustrated in the figures, fixing of the supporting
sectional elements 12 to the transverse supporting element 20 is
made by means of screws 30 that engage aligned holes 32, 34 formed
in the side portions 28 and in the ribbing 18 in an area
corresponding to the seat portion 12a of each supporting sectional
element 12. The transverse supporting element 20 is preferably made
of metal material, for example die-cast aluminium.
[0032] With reference to FIGS. 2 and 2A, the supporting sectional
elements 12 are moreover connected to one another by means of a
dorsal transverse element 36, the side ends of which are inserted
in the internal grooves 16 of the two supporting sectional elements
12, at the top ends of the respective backrest portions 12b. The
ends of the transverse element 36 are preferably fixed to the
sectional elements 12 by means of screws 38, which engage holes 40
provided on the rear part of the sectional elements 12.
[0033] With reference to FIGS. 1 to 3, the chair 10 comprises a
sheet 42 of flexible material that is tensioned between the two
lateral supporting sectional elements 12. The sheet of flexible
material 42 is preferably constituted by a single piece of fabric,
mesh or the like, which is held by the lateral supporting sectional
elements 12 in the configuration illustrated in FIGS. 1 and 2,
where the sheet 42 has a seat portion 42a, a backrest portion 42b,
and an arched radiusing portion 42c, in an area corresponding to
the respective portions 12a, 12b and 12c of the supporting
sectional elements 12.
[0034] As illustrated in particular detail in FIGS. 3 and 3A, the
sheet of flexible material 42 has two side edges 44, which are
inserted and fixed in the respective external grooves 14 of the
supporting sectional elements 12. Preferably, the side edges 44 are
sewn so as to form a loop in order to present a tubular seat in
which a flexible lamina 46 is inserted. The side parts of the sheet
of flexible material 42 wrap around the top part of the supporting
sectional elements 12, and the side edges 44 are anchored to the
supporting sectional elements 12 in the external grooves 14. Fixing
of the side edges 44 to the supporting sectional elements 12 can be
completed by means of screws. As may be noted in FIG. 3, the sheet
of flexible material 42 remains tensioned between the side supports
12.
[0035] With reference to FIGS. 4 to 7, the ribbing 18 of each
supporting sectional element 12 is provided with a plurality of
through notches 48 set at a distance from one another along the
longitudinal axis of the ribbing 18. The ribbing 18 of each
supporting sectional element 12 extends in a vertical plane of
symmetry of the respective supporting sectional element 12. If the
ribbing 18 were continuous, each supporting sectional element 12
would be basically rigid as regards bending in the vertical plane
of symmetry The notches 48 form respective points of localized
bending of the supporting sectional elements 12. In an area
corresponding to each notch 48, the supporting sectional element 12
is able to perform a movement of bending. The notches 48 are
distanced from one another in a longitudinal direction by stretches
50 in which the ribbing 18 is continuous. The supporting sectional
element 12 in an area corresponding to the stretches 50 is
basically rigid for the movements of bending in the vertical plane
of symmetry. The notches 48 form hinge points between substantially
rigid contiguous sections of the supporting sectional element
12.
[0036] With reference to FIG. 4, each notch 48 comprises a
substantially drop-shaped through hole 52 made in the internal part
of the ribbing 18. Each notch 48 has two divergent walls 54 facing
one another, which extend from the hole 52 to the outer edge of the
ribbing 18. The walls 54 form an angle a that represents the
maximum amplitude of the movement of bending in each point of
localized bending. In fact, the movement of bending of the
supporting sectional element 12 produces a mutual approach of the
facing surfaces 54. When the surfaces 54 are in contact with one
another as illustrated in FIG. 5, the supporting sectional element
12 becomes rigid in regard to a further deformation of bending.
Each point of localized bending of the sectional element 12 is
hence self-limiting, with a maximum amplitude of bending defined by
the geometry of the respective notch 48.
[0037] FIGS. 4 and 5 show in side view a stretch of a supporting
sectional element 12 in the resting position and in the position of
maximum inclination backwards, respectively. As may be noted, in
the position of maximum inclination backwards illustrated in FIG. 5
the walls 54 of each notch 48 are in contact with one another,
i.e., each point of localized bending is in the position of maximum
bending. The fact that the points of localized bending are
self-limiting is particularly important in so far as it prevents
the risk of an excessive bending from causing yielding of the
supporting sectional element 12.
[0038] FIG. 6 shows the radiusing portion 12c of a supporting
sectional element 12 in the resting position (solid line) and in
the position of maximum inclination backwards (dashed line). In the
position of maximum inclination, the backrest is inclined by
approximately 22.degree. with respect to the resting position. The
stiffness of the movement of bending of the supporting sectional
element depends upon the geometry of the notches 48. As illustrated
by way of example in FIG. 7 notches 48' can be provided, which
extend throughout the width of the ribbing 18 and notches 48'',
which extend only through a part of the height of the ribbing 18.
The notches 48'' could for example be arranged in the areas in
which it is desired to obtain a movement of bending with a higher
stiffness. The notches 48'' could for example have a maximum
inclination .alpha.'' in the region of 3.degree., whilst the
notches 48' could have a maximum inclination .alpha.' in the region
of 4.degree.. By varying the geometry of the notches it is possible
to vary the flexural stiffness and the maximum angle of inclination
in an area corresponding to each point of localized bending.
Furthermore, by varying the distance between the contiguous
notches, it is possible to vary the geometry of deflection of the
supporting sectional elements 12.
[0039] In the embodiment illustrated in FIGS. 1 to 3, the ribbing
18 has a rectangular cross section. The ribbing 18 can have a
thickness (dimension in the transverse direction) comprised between
2 and 20 mm. The ribbing 18 can have a height (extension in a
vertical plane) comprised between 10 and 60 mm.
[0040] Illustrated in FIGS. 8 and 9 is an alternative embodiment of
the cross section of the supporting sectional element 12. In this
case, the ribbing 18 has a substantially parabolic shape with a
maximum width equal to the width of the sectional element 12, which
can be in the region of 15-40 mm. The height of the ribbing 18 can
be comprised between 10 and 60 mm.
[0041] Each notch 48 can have a height comprised between 5 mm and
60 mm. The angle between the divergent walls 54 of each notch 48
can be comprised between 1.degree. and 22.degree.. In general, the
angle between the walls 54 is in the region of 3.degree.-4.degree.
so that the notches 48 are very narrow. Consequently, closing of
the notches 48 during bending of the supporting sectional elements
12 does not entail the risk of pinching of the user's fingers.
Whenever necessary, the notches 48 can be protected by means of
co-moulded compressible elastomer elements that close the side and
front outer edges of each notch 48 partially or completely.
[0042] Return from the deflected position to the resting position
occurs as a result of the elastic return of the material
constituting the supporting sectional elements 12, thanks to the
particular elasticity of the plastic material constituting the
sectional elements. As illustrated in FIGS. 2 and 3, to increase
the characteristics of elastic return of the supporting sectional
elements 12, each of said sectional elements can be provided with
at least one elastic member 56. Said elastic member can
advantageously be constituted by a small bar of metal material with
high elasticity, for example spring steel, inserted in the internal
groove 16 (FIG. 3) of each supporting sectional element 12. If
necessary, there may be provided an elastic member 56 in each of
the grooves 14, 16 of each supporting sectional element 12. The
elastic member 56 can be arranged in the radiusing portion 12c of
each supporting sectional element 12 and in any other area in which
it is desired to increase the characteristics of elastic return of
the sectional element.
[0043] Illustrated in FIGS. 10 to 13 is a second embodiment of the
chair according to the present invention. The elements
corresponding to the ones previously described are designated by
the same reference numbers.
[0044] In this embodiment of the invention, the two ribbed
supporting sectional elements 12 are connected to one another by
two transverse elements 58, 60 formed integrally by moulding with
the supporting sectional elements 12. As illustrated in FIG. 11,
the two supporting sectional elements 12, connected to one another
by the transverse elements 58, 60, constitute a framework formed by
a single piece of injection-moulded plastic material.
[0045] The first transverse element 58 is set in an area
corresponding to the top ends of the backrest portions 12b. The
second transverse element 60 is set in an area corresponding to the
front end of the seat portions 12a. In this variant, each
supporting sectional element 12 can be provided with just one
groove (the external groove 14), serving for anchorage of the side
edges 44 of the sheet of flexible material 42. The two supporting
sectional elements 12 are fixed, in a way similar to that of the
embodiment previously described, to a transverse supporting element
20 of metal material, which is fitted on the central column 22 of
the base 24.
[0046] This second embodiment enables simplified assembly of the
sheet of flexible material 42 on the supporting sectional elements
12. For insertion of the side edges 44 of the sheet of flexible
material 42 into the external grooves 14 of the supporting
sectional elements 12 the flexibility of the transverse elements
58, 60 is exploited, which enables approach of the supporting
sectional elements 12 to one another. After insertion of the side
edges 44 in the external grooves 14, the supporting sectional
elements 12 are brought back into their resting position by the
elastic return of the transverse elements 58, 60, by setting the
sheet of flexible material 42 in tension between the supporting
sectional elements 12. The structure is definitively stiffened in a
transverse direction by fixing of the ribbed supporting sectional
elements 12 to the transverse supporting element 20, as illustrated
in FIG. 12. The elastic members 56 can be inserted in the same
external grooves 14 in which the side edges of the flexible sheet
42 are inserted (see FIG. 12). Alternatively, there could be
provided seats for the elastic members 56 on the internal sides of
the supporting sectional elements 12.
[0047] FIGS. 14 to 16 illustrate a third embodiment of the chair 10
according to the present invention. In this case, the chair 10
comprises a shaped thin plate 62 made of injection-moulded plastic
material having a seat portion 62a, a backrest portion 62b and an
arched radiusing portion 62c. The plate of plastic material 62 has
two integral ribbings 64 that project in a vertical plane from the
bottom or rear surfaces of the portions 62a, 62b, 62c. The ribbings
64 with the corresponding portions of the plate 62 constitute two
lateral supporting sectional elements 12, between which the
flexible plastic material forming the seat and the backrest of the
chair extends. As in the variants described previously, the
ribbings 64 are provided with through notches 48, which form points
of localized bending of the supporting sectional elements 12.
[0048] The ribbings 64 are fixed to a transverse supporting element
20 carried by a central column 20, in a way similar to what was
described previously. In the rear surface of the plate 62, in an
area corresponding to the radiusing portion 62c, there are
preferably made two integral seats 66 for housing elastic members
56 (see, in particular FIGS. 15 and 16). The seats 66 can be
positioned on the inner side of the ribbings 64 (as illustrated in
the figures) or else on the outer side.
[0049] The plate of plastic material 62, in order to be able to
bend backwards, must not have a concave curvature on the surfaces
of the seat and of the backrest since said curvature would stiffen
the backrest, preventing it from bending backwards. For this
reason, in this embodiment the chair 10 is preferably provided with
padded panels (not illustrated) fixed to the surfaces of the seat
and backrest of the plate of plastic material 62.
[0050] Also in this embodiment, the ribbings 64 of the supporting
sectional elements 12 can have different shapes in cross section.
For example, illustrated in FIGS. 17 and 18 is an alternative
embodiment, in which the ribbings 64 have a substantially parabolic
shape in cross section.
[0051] Illustrated in FIG. 19 is a variant of the chair of FIG. 14.
Also in this case, the ribbings 64 are formed integrally with a
plate 62 of plastic material. The problem of the impossibility of
providing concave resting surfaces of the seat and backrest is
solved by forming in the plate 62 a plurality of transverse
openings 68 that extend between the ribbed supporting sectional
elements 12. The height of the openings 68 must be sufficiently
wide so as not to constitute a hazard for the fingers of the user
during bending backwards of the plate 62. In this embodiment, the
seat and the backrest of the chair are formed by two ribbed
supporting sectional elements 12 arranged laterally and extending
between which is a plurality of transverse slats 70 parallel to one
another and set at a distance from the transverse openings 68. The
slats 70 can have a concave sectional element so as to provide
concave resting surfaces in an area corresponding to the seat
portion 62a and the backrest portion 62b.
[0052] In the version illustrated in FIGS. 14 and 19, the ribbings
64 do not necessarily need to be positioned in an area
corresponding to the side edges of the plate 62. In a possible
variant illustrated in FIG. 20, the ribbings 64 can be displaced
laterally towards the median plane of the chair.
[0053] The chair according to the present invention enables
provision of a flexible seat formed by a fabric or by an elastic
mesh or, alternatively, by a sheet of injection-moulded plastic
material. The supporting sectional elements 12 can be provided with
a large number of points of localized bending distributed along a
substantial part of the ribbed sectional elements. In particular,
the present invention enables positioning of the points of start of
bending in a very advanced position (approximately half of the
seat). This characteristic increases comfort for the user
considerably as compared to a chair in which the movement of
bending backwards regards just the backrest or a portion thereof.
The most advanced notch can be set in the immediate vicinity of the
area of fixing of the supporting sectional elements 12 to the
transverse supporting element 20.
* * * * *