Patent Publication Number: US-6669282-B2

Title: Chair with writing table

Description:
The present invention relates to a chair with a writing table. Chairs of the above type are normally used as seating places for people participating at meetings, congresses, lessons, and the like. The writing table is normally mounted in an articulated way on the supporting structure of the chair and can be displaced between a lowered, inoperative, position, and a raised, operative, position, in which it forms a resting surface that enables the occupant to write or work on a portable computer. 
     One of the requirements that must be met by chairs designed for being used at meetings and the like is the need to enable one chair to slide into another chair so as to occupy as little space as possible when the chairs are stacked away out of use. There are already known chairs for meetings, congresses, and the like without writing tables, which can be set against one another when out of use in a longitudinal direction. The presence of an integral writing table generally makes it impossible for the chairs to slide into one another. 
     The purpose of the present invention is to provide a chair of an improved type which will enable the above problem to be overcome. 
     According to the present invention, the above and other purposes are achieved by a chair having the characteristics that form the subject of the ensuing claims. 
    
    
     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: 
     FIG. 1 is a side view of a chair according to the invention, with the writing table in the lowered position; 
     FIG. 2 is a side view of the chair illustrated in FIG. 1, with the writing table in the raised position; 
     FIGS. 3 and 4 are plan views of the chair according to the invention, with the writing table in the raised position and in the lowered position, respectively; 
     FIG. 5 is a side view illustrating two chairs according to the invention, which are slid into one another in a longitudinal direction; 
     FIG. 6 is a plan view of the part indicated by the arrow VI in FIG. 3; 
     FIG. 7 is a cross section taken along the line VII—VII of FIG. 6; 
     FIG. 8 is a cross section taken along the line VIII—VIII of FIG. 7; 
     FIGS. 9 and 10 are cross sections taken, respectively, along the lines IX—IX of FIG.  4  and X—X of FIG. 3; 
     FIG. 11 is a cross-sectional plan view of the part indicated by the arrow XI in FIG. 4; 
     FIGS. 12 and 13 are cross sections taken, respectively, along the lines XII—XII and XIII—XIII of FIG. 11; 
     FIG. 14 is a cross section taken along the line XIV—XIV of FIG. 15; 
     FIG. 15 is a cross section taken along the line XV—XV of FIG.  14 ; 
    
    
     With reference to FIGS. 1 to  4 , the reference number  20  designates a chair comprising a base structure  22 , which includes a pair of front legs  24  and a pair of rear legs  26 , each of said legs carrying at its bottom end a wheel  28 , preferably of an orientable type. The base structure  22  comprises a transverse element  30 , about which there is mounted, so that it can turn, a seat  32 , which can move between a raised, inoperative, position, and a lowered, operative, position. A supporting structure for supporting the backrest  34  is mounted on the transverse element  30  in an oscillating way and co-operates with elastic means (not illustrated) which counter the action of backward thrust exerted by the occupant against the backrest  36 . 
     The base structure  22  comprises a tubular supporting element  38 , which carries, at its top, an articulation element  40 , to which there is connected, in the way described in what follows, a writing table  42 . The table  42  can move between a lowered, inoperative, position, illustrated in FIGS. 1 and 4, and a raised, operative, position, illustrated in FIGS. 2 and 3. According to the present invention, in the lowered, inoperative, position, the writing table  42  is inclined by an angle α with respect to a vertical plane A parallel to a longitudinal plane of symmetry of the chair  20 . The angle α is an acute angle, preferably of between 5° and 20°, for example approximately 14°. The above arrangement of the writing table  42  enables two or more chairs of the same type to slide into one another in the longitudinal direction, as illustrated in FIG.  5 . To make it possible for the chairs  20  to slide into one another, it is necessary for the external legs  24  and the internal legs  26  to be staggered with respect to one another in a transverse direction, as illustrated in FIGS. 3 and 4, so that, when two chairs slide into one another, the front legs  24  of the chair located in the rear position pass between the rear legs  26  of the front chair that is immediately adjacent to it. As illustrated in FIG. 5, in the position where one set of chairs  20  of the same type are slid into one another, the seat  32  of each chair is raised in a substantially vertical position, so that the backrest  36  of the chair set in front is substantially adjacent to the transverse element  30  of the chair that is in a position immediately behind it. 
     With reference to FIG. 4, the articulation mechanism  40  is built in such a way as to enable two movements of rotation about the two mutually orthogonal axes  44 ,  46 . The first axis of rotation  44  is orthogonal to the plane of the writing table  42 , whilst the second axis of rotation  46  is parallel to the plane of the writing table  42 . To pass from the inoperative position of FIG. 1 to the operative position of FIG. 2, it is necessary first to make a rotation about the axis  44  and then a rotation about the axis  46 . With reference to FIG. 3, when the table is in the raised, operative, position, the articulation mechanism  40  enables a further movement of oscillation of the table  42  about a vertical axis  48  orthogonal to the plane of representation of FIG.  3 . This movement of rotation about the axis  48  enables the table  42  to be displaced between the position indicated by the solid line and the position indicated by the dashed line. This movement is advantageous for enabling the user to get up from the chair without having to lower the table  42 . Consequently, the user can get up from the chair without having to remove any objects that may be resting on the surface of the table  42 . 
     The constructional characteristics of the articulation mechanism  40 , which enable the movements about the axes  44 ,  46 , and  48  to be obtained, will be described in what follows with reference to FIGS. 6 to  14 . With initial reference to FIGS. 11 to  14 , the articulation mechanism  40  comprises a base body  50  fixed at the top of the tubular support  38  forming part of the base structure  22  of the chair. The base body  50  carries a pin  52 , the axis of which defines the first axis of rotation  44 . A rotating body  54  is mounted so that it can turn about the pin  52 . With reference to FIGS. 14 and 15, the body  50  has an arched groove  56  with an angular extension of approximately 180°, within which an end stretch of a pin  58  carried by the rotating body  54  engages with play. The ends of the arched groove  56  define the limit positions of end of travel of the rotating body  54  with respect to the base body  50 . Preferably, in a position corresponding to one of the ends of the arched groove  56 , there is positioned a wad of elastomeric material  60 . With reference to FIGS. 11,  12 , and  13 , a spring-type retention mechanism is set between the basic body  50  and the rotating body  54 , in order to withhold the rotating body  54  in a stable position corresponding to the lowered position of the table. The said retention mechanism comprises a pair of pins  62 , slidably mounted within respective seats of the base body  50  and pushed by springs  64  in compression against a front surface  66  of the rotating body  54 . On the surface  66  of the rotating body  54 , a pair of engagement seats  68  are formed with a part  70  shaped like a ramp, within which end portions of the pins  62  engage, as illustrated in FIG. 13, in order to withhold the body  54  in the stable retention position. 
     With reference to FIGS. 8,  9 , and  10 , the rotating body  54  carries a pin  72 , which defines the second axis of oscillation  46 . Articulated on the pin  72  is a U-shaped bracket  74 , which is able to perform an oscillation with an amplitude of approximately 90° about the pin  72 . With reference to FIGS. 7,  8 , and  10 , the U-shaped bracket  74  is fixed to a disk  76 , which carries a pivot pin  78  defining the third axis of oscillation  48 . A metal plate  80 , which forms the supporting structure of the writing table  42 , is mounted so that it can turn about the pin  78 . With reference to FIG. 6, the metal plate  80  has a shaped opening  82 , the walls of which co-operate with the U-shaped bracket  74  to define two end-of-travel positions of oscillation of the table  42 , which correspond to the positions illustrated in FIG. 3 with a solid line and with a dashed line. Shells made of plastic material  82 ,  84 , forming the outer part of the writing table  42 , are fixed to the plate  80  by means of screws designated by  86  in FIG.  8 . 
     Of course, without prejudice to the principle of the invention, the details of construction and the embodiments may vary widely with respect to what is described and illustrated herein, without thereby departing from the scope of the present invention as defined in the ensuing claims.