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(11) | EP 1 053 702 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | An improved chair structure |
| (57) An improved chair structure is described and comprises a body (1) which defines a
lower part (2) in turn including a seat (3), a lower backrest portion (5), and two
arms (4a, 4b), and an upper part including an upper backrest portion (6). The upper backrest portion is articulated to the lower portion (2) in the region of the arms (4a, 4b) so as to be movable between an operative position in which it constitutes an extension of the lower backrest portion (5) and an inoperative, transportation position in which it is arranged substantially parallel to the seat (3). |
[0001] The subject of the present invention is an improved chair according to the preamble to the main claim.
[0002] Within the specific technical field, chairs with bodies which can be dismantled, in which, in order to reduce transportation costs, the backrest and the seat are produced as separate pieces to be fixed together subsequently by the retailer or the final user are known, for example, from patent of industrial invention No. 1262148 in the name of Effezeta s.r.l.
[0003] In the technical solution proposed by this prior patent, the backrest and the seat are completely separate from one another and have respective engagement means and complementary engagement means for subsequently joining them together.
[0004] In practice, this technical solution has been found rather unsuitable for the proposed purpose because the backrest and the seat are completely separate.
[0005] The main object of the present invention is to provide a chair which is improved in comparison with the prior art.
[0006] Another object of the invention is to provide a chair in which the backrest and the seat are joined together, even during the transportation stage.
[0007] A further object of the invention is to render the conversion of the chair from the transportation condition to the condition of use reversible.
[0008] These and other objects are achieved by the invention by means of a chair formed in accordance with the following claims.
[0009] The characteristics and the advantages of the invention will become clearer from the detailed description of an embodiment thereof, described by way of non-limiting example with reference to the appended drawings, in which:
- Figure 1 is a perspective view of a chair formed in accordance with the present invention,
- Figure 2 is an exploded, perspective view of a detail of the chair of Figure 1,
- Figure 3 is a longitudinal section through the detail of Figure 2, in the assembled condition,
- Figures 4a and 4b are side elevational views of the chair of the previous drawings with the backrest in the operative position and in the inoperative position, respectively,
- Figure 5 is an exploded view of the detail of Figure 2 in accordance with a variant of the invention,
- Figure 6 is a section through a detail of Figure 5, rotated through 90°,
- Figures 7 and 8 are sections through the detail of Figure 5, in the assembled condition with the backrest in the operative and inoperative positions, respectively.
[0010] In the drawings, a chair according to the present invention, including a moulded body 1 made of rigid or semi-rigid plastics material, is generally indicated P.
[0011] The body 1 comprises a lower part 2, preferably formed as a unitary piece by injection moulding and including a seat 3, a pair of arms 4a, 4b, and a lower portion 5 of a backrest, generally indicated 8. The backrest 8 also comprises an upper portion 6 which is articulated to the lower part 2 about an axis X, in the region of the ends 7 of the arms 4a, 4b which are closest to the lower portion 5.
[0012] For the articulation between the backrest portion 6 and the arms 4a, 4b, a cylindrical seating 10, elongate along the axis X and having a through-window 11 in its wall, is formed in each arm. Each seating 10 is open at both of its axially opposed ends.
[0013] The upper portion 6 of the backrest has, in the region of its base 13, a rib 14 which can stiffen the base 13 and can constitute means for coupling with the free upper end 15 of the lower backrest portion 5. The upper backrest portion 6 is flanked on its two opposite sides by two, approximately parallel, coextensive flanges 18 each bearing, at its lower end, a tubular, cylindrical appendage 19. Each cylindrical appendage 19 has a pair of parallel and spaced-apart slits 20, between which there is a wall portion 20a bearing a projection 21 at its free end. Owing to the presence of the slits 20, the wall portion 20a is flexible radially so as to allow the appendage 19 to be inserted in the corresponding seating 10 of the respective adjacent arm. The appendage 19 is then restrained in the corresponding seating by snap-engagement of the projection 21 in the window 11.
[0014] The projection 21 is positioned angularly relative to the backrest and to the window 11 in the seating 10 in a mariner such that, when the upper backrest portion 6 is folded parallel to the seat 3 (the lowered position of Figure 4b), the projection 21 is in contact with the continuous inside wall of the seating 10 and keeps the appendage 19 in a radially retracted state. The positioning of the projection 21 is also such that, when the upper backrest portion 6 is set upright, perpendicular to the seat 3, in the operative position of Figure 4a, the projection 21 is engaged in the window 11, preventing further pivoting of the upper backrest portion 6 about the axis X.
[0015] In spite of the above-mentioned condition of engagement, the projection 21 is not subjected to stresses when the user leans on the backrest since, in this condition, the base 13 of the upper backrest portion 6 is in abutment with the upper end 15 of the lower backrest portion 5, defining a mechanical travel-limit stop for the relative pivoting between the upper backrest portion 6 and the lower backrest portion 5.
[0016] A plug 25 provided with a flange 26 having a diameter substantially corresponding to the inside diameter of the seating 10 and a cylindrical portion 27 having a diameter substantially corresponding to the inside diameter of the appendage 19 in the state in which it is not retracted radially is also provided for insertion in the appendage 19 in order to keep the latter in the radially extended state which corresponds to the engagement of the projection 21 in the window 11. In this condition, further radial retraction of the wall portion 20a and of the projection 21 is prevented, the projection 21 being restrained in the window 11 so that the upper backrest portion 6 is prevented from rotating relative to the lower backrest portion 5 and to the arms.
[0017] In each flange 18 of the upper backrest portion 6, in the region of the respective appendage 19, there is an opening 29 which is coaxial with the axis X and through which a tool 30 can be inserted to expel the plug 25 from the seating 10 and from the appendage 19 in order to allow the appendage 19 to be retracted radially again and the upper backrest portion 6 consequently to pivot to the inoperative, transportation position of Figure 4b, close to the seat 3.
[0018] A variant according to the present invention is described below with reference to Figures 5 to 8, in which details similar to those described in the previous embodiment are indicated by the same reference numerals.
[0019] In this variant, the appendage 19 comprises a window 31 which is intended to constitute a seat for a projection 34 formed at a free end of an element 35 projecting axially as an extension of the cylindrical portion 27 of the plug 25. The window 31 is generally L"-shaped and includes a first region 32 for axial sliding of the projection 34 and a second region for circumferential sliding thereof.
[0020] The plug 25 also has an outer cylindrical portion 36 coaxial with and radially spaced from the cylindrical portion 27, having an outside diameter substantially equal to the inside diameter of the seating 10, and extending axially for a distance equal to the difference between the axial dimension of the seating 10 and that of the appendage 19. The outer cylindrical portion 36 comprises a catch projection 37 which can engage for sliding axially in a guide 38 formed in the seating 10, thus preventing relative rotation of the plug 25 once it is inserted in the seating 10 of the respective arm.
[0021] When the assembled chair P is in the inoperative position of Figure 7, the projection 34 of the plug 25 is in abutment in the window 31 of the appendage 19 and the catch projection 37 is at least partially engaged in the guide 38 so that both axial and rotary movements of the plug 25 are prevented. Moreover, in this position, no part of the cylindrical portion 27 interferes with possible radial movements of the wall portion 20a.
[0022] The rotation of the backrest portion 6 about the axis X which enables the chair P to be brought to the operative position (Figure 8) brings about circumferential sliding of the projection 34 along the region 33 of the window 31. The window 31 and the projection 21 are positioned relative to one another on the appendage 19 in a manner such that the projection 21 snap-engages the window 11 at the moment at which the projection 34 of the plug 25 reaches the region 32 of the window 31. The plug 25 can thus be inserted fully in the seating 10, since the projection 34 can slide axially in the region 32 until the free end of the outer cylindrical portion 36 abuts the free end of the appendage 19, or the projection 34 abuts the edge of the region 32 of the window 31.
1. An improved chair structure comprising a body (1) with a lower part (2) including
a seat (3), a lower backrest portion (5), and two arms (4a, 4b), and an upper part
including an upper backrest portion (6), the upper backrest portion being movable
between an operative position in which it is connected to the lower part (2) as an
extension of the lower backrest portion (5) and an inoperative, transportation position,
characterized in that the parts are articulated to one another in the region of the
arms (4a, 4b) so that the upper backrest portion (6) can pivot from the inoperative
position, in which it is disposed substantially parallel to the seat (3), to the operative
position.
2. A chair structure according to Claim 1, in which the lower part (2) is moulded as
a unitary piece of plastics material.
3. A chair structure according to Claim 1 or Claim 2, in which a cylindrical seating
(10) is formed at the end of each of the arms (4a, 4b) closest to the lower backrest
portion, the upper backrest portion (6) having, for each seating, an associated cylindrical
appendage (19) which can engage rotatably in the corresponding seating in order to
permit a relative rotation between the body parts, snap-restraining means being provided
between each seating (10) and the corresponding appendage (19) for preventing the
said relative rotation.
4. A chair structure according to Claim 3, in which the restraining means comprise at
least one window (11) opening in each seating (10) and at least one projection (21)
on each appendage (19) for snap-engaging the corresponding window (11) when the body
parts are in the operative position.
5. A chair structure according to Claim 4, in which the projection (21) is resilient.
6. A chair structure according to Claim 4 or Claim 5, in which the projection (21) is
provided on a strip (20a) of the wall of the appendage (19), the strip (20a) being
able to pivot radially relative to the rest of the appendage wall.
7. A chair structure according to Claim 6, in which the strip (20a) of the wall is defined
between two slits (20) provided in the wall of the appendage (19), starting from its
free end.
8. A chair structure according to one or more of Claims 3 to 7, in which means are provided
for locking the snap-restraining means when the body is in the operative condition.
9. A chair structure according to Claim 8, in which the cylindrical appendages (19) are
tubular and the locking means comprise a cylindrical plug (25) which can be inserted
in the corresponding appendage (19) in order to prevent radial retraction of the strip
(20a).