Field of the art
[0001] The present invention relates to a chair comprising a seat and a backrest, in which
the backrest is tiltable backwards relative to the seat under a backward thrust applied
by the user.
Description of the prior art
[0002] In the state of the art, many chairs are known with backrests that are tiltable under
a backward thrust applied by the user. The document
EP-A-14196090.6 by the same Applicant describes a chair comprising a fixed support structure including
a pair of front legs and a pair of rear legs, a seat, fixed to the fixed support structure,
and a backrest with a backrest panel with an arcuate shape connected in an oscillating
manner to the fixed support structure. The backrest comprises two side connecting
elements of plastic material, each of which comprises a cylindrical sleeve fixed to
an upper portion of a respective rear leg. The side connecting elements of the backrest
have respective bellows-shaped deformable portions, integrally formed with the respective
cylindrical sleeve. The bellows-shaped deformable portions are connected in a fixed
manner to respective side portions of the backrest panel.
[0003] Monocoque chairs are characterized by a monolithic structure in which the seat and
backrest are formed as a single molded panel of plastic material. Monocoque chairs
do not usually have backwardly-tiltable backrests.
Object and summary of the invention
[0004] The present invention aims to provide a monocoque chair equipped with a tiltable
backrest.
[0005] According to the present invention, this object is achieved by a chair having the
characteristics forming the subject of claim 1.
[0006] The claims form an integral part of the disclosure provided here in relation to the
invention.
Brief description of the drawings
[0007] The present invention will now be described in detail with reference to the attached
drawings, given purely by way of non-limiting example, wherein:
- Figure 1 is a perspective view of a monocoque chair according to the present invention,
- Figure 2 is a rear perspective view of the chair of Figure 1,
- Figure 3 is a perspective view on an enlarged scale of the part indicated by the arrow
III in Figure 1,
- Figure 4 is a cross-section along the line IV-IV of Figure 1,
- Figures 5 and 6 are longitudinal cross-sections of the chair of Figure 1, in the rest
position and in the backward-tilted position, respectively, and
- Figure 7 is a perspective view illustrating a variant of the chair of Figure 1.
Detailed description
[0008] With reference to the figures, numeral 10 designates a chair according to the present
invention. The chair 10 comprises a base 12, which carries a monocoque structure 14
in which a seat 16 and a backrest 18 are formed as a single panel of injection-molded
plastic material essentially in the shape of an L.
[0009] In the illustrated example, the base 12 has two front legs 20 and two rear legs 22
fixed to each other by an upper structure 24 to which the monocoque structure 14 is
fixed. Alternatively, the base 12 could have a rotatable central column. In general,
the base 12 can be of any type.
[0010] The monocoque structure 14 including the seat 16 and the backrest 18 is obtained
as a single piece of injection-molded plastic material, for example nylon. The monocoque
structure 14 comprises a bellows-shaped deformable transverse band 26, which extends
in the transverse direction between two opposite side edges 28 of the seat 18. The
deformable transverse band 26 is integrally formed with the monocoque structure 14
during the injection-molding step and is formed as one piece with the backrest 18.
The deformable transverse band 26 divides the backrest 18 in the transverse direction
into a lower backrest portion 18a and an upper backrest portion 18b. The lower backrest
portion 18a is connected as a single piece with the rear portion of the seat 16.
[0011] The upper backrest portion 18b is movable backwards with respect to the lower backrest
portion 18a between a rest position and a backward-tilted position. The backward movement
of the upper backrest portion 18b under a backward thrust applied by the user's back
is possible thanks to the elastic deformation of the deformable transverse band 26.
[0012] With reference in particular to Figures 3 and 4, the deformable transverse band 26
comprises a plurality of transverse ribs 30 with C-shaped cross-sections, each of
which extends in the transverse direction between the opposite side edges 28 of the
backrest 18. The transverse ribs 30 are connected to each other at their ends and
alternately face towards the front part and towards the rear part of the chair. In
the example shown, the deformable transverse band 26 comprises three transverse ribs
30. The upper rib and the lower rib have the respective concave part facing towards
the front of the chair and a central rib that joins together the upper rib and the
lower rib, and has the concave part facing the rear part of the chair.
[0013] Figures 5 and 6 are longitudinal cross-sections showing the chair 10 in the rest
position and in the backward-tilted position, respectively. The deformable portion
26 allows the backward tilt of the upper backrest portion 18b relative to the lower
backrest portion 18a. When the backward thrust applied by the user ceases, the deformable
transverse band 26 elastically returns to its undeformed position and returns the
backrest 18 to the rest position illustrated in Figure 5. The same deformable transverse
band 26 also forms a stop which prevents any further backward movement of the upper
backrest portion 18b beyond the position of maximum backward inclination illustrated
in Figure 5. In fact, as shown in Figure 6, when the upper backrest portion 18b is
tilted backwards, the outer side parts of the bellows-shaped deformable transverse
band 26 open, or rather the distance between the transverse ribs 30 increases, while
the central part of the deformable transverse band 26 closes, that is, the ribs 30
come into contact with each other. In particular, when the convex parts of the upper
rib and the lower rib are compressed into contact with each other, further elastic
deformation of the deformable transverse band 26 is prevented. Therefore, in this
condition, further backward inclination of the upper backrest portion 18b is prevented.
[0014] In the embodiment illustrated in the figures, the backrest 18 comprises a single
deformable transverse band 26. Alternatively, more deformable transverse bands could
be provided, spaced apart in the vertical direction. If the deformable transverse
bands are of a number greater than one, they could be distributed along the backrest
18.
[0015] It is not strictly necessary that the deformable transverse band 26 extends continuously
between the opposite side edges 28 of the backrest 18. In fact, as shown in Figure
7, the backrest 18 could be provided with a through-opening 32, which interrupts the
deformable transverse band 26 in the transverse direction. The opening 32 visually
separates the backrest 18 from the seat 16 and provides a visually lighter chair,
with an elastic behavior more easily deducible by the user.
[0016] Of course, without prejudice to the principle of the invention, the details of construction
and the embodiments can be widely varied with respect to those described and illustrated,
without thereby departing from the scope of the invention as defined by the claims
that follow.
1. A chair with a tilting seat, comprising a monocoque structure (14) including a seat
(16) and a backrest (18) formed as a single piece of injection-molded plastic material,
wherein the monocoque structure (14) comprises at least one bellows-shaped deformable
transverse band (26) formed as one piece in the backrest (18), so as to divide the
backrest (18) into a lower backrest portion (18a) fixed relative to the seat (16)
and an upper backrest portion (18b) movable relative to the lower backrest portion
(18a) between a rest position and a tilted position.
2. A chair according to claim 1, wherein the deformable transverse band (26) extends
between two opposite side edges (28) of the backrest (18).
3. A chair according to claim 1, wherein said deformable transverse band (26) comprises
a plurality of transverse ribs with a C-shaped cross-section (30), parallel to each
other, with respective concavities alternately facing towards the front and towards
the rear of the chair.
4. A chair according to any one of the preceding claims, wherein said deformable transverse
band (26) forms a stop that prevents a further backward motion of the backrest (18)
in a position of maximum backward inclination.
5. A chair according to any one of the preceding claims, comprising at least one opening
(32) in the backrest (18), which interrupts said at least one deformable transverse
band (26) in a transverse direction.
REFERENCES CITED IN THE DESCRIPTION
This list of references cited by the applicant is for the reader's convenience only.
It does not form part of the European patent document. Even though great care has
been taken in compiling the references, errors or omissions cannot be excluded and
the EPO disclaims all liability in this regard.
Patent documents cited in the description