Patent Publication Number: US-6983991-B2

Title: Removable anatomic seat

Description:
The present invention refers to a removable anatomic seat. 
   In the field of seats, the ergonomic characteristics have an ever greater importance in their design. These aspects are especially accentuated in the case of seats intended for users who have to remain seated for a long time. 
   These activities which involve sitting for long periods bring risks as far as backache and other muscular-skeletal difficulties are concerned. 
   If the posture taken up on the seat is not physiologically correct, there is an increase in pressure on the disks of the spinal cord with respect to standing position, due to the fact that the pressure is associated with a prolonged static load on the lumbar column. 
   The most frequent symptoms which come from this are: lumbago, cervical vertebra ache and pectoral girdle pains. 
   Therefore, some seats are equipped with adjustment devices which can adapt to the morphology of the user, in particular as far as the position of the seat and backrest are concerned. 
   The position of the pelvis is essential in determining the posture of the rest of the body. 
   If the pelvis is tilted forwards it is easier to keep the correct head-trunk-pelvis alignment. 
   In the field special seats do exist, realised for the purpose of allowing the user to have the correct back position, which must be as close as possible to upright position. 
   Generally, they foresee a seat tilted forwards and devices for supporting the lower part of the user&#39;s legs, for example for knees. 
   The tilted seat helps a correct posture of the back to be taken up. Moreover, the support devices allow part of the weight which would weigh down upon the spinal cord to be discharged onto the lower limbs of the user. Nevertheless, such seats are quite heavy, and therefore are difficult to transport. 
   Moreover, the adjustment of the inclination of the seat is not very accurate, and the lower limbs are forced to remain in a predetermined position. U.S Pat. No. 5,918,936 discloses a removable anatomic seat according to the preamble of claim  1 . 
   The purpose of the present invention is therefore that of avoiding the drawbacks mentioned previously and in particular that of realising a removable anatomic seat which allows to improve the ergonomics of any chair. Another purpose of the present invention is that of realising a removable anatomic seat which allows an accurate adjustment of the best inclination for the morphological characteristics of the user. 
   Another purpose of the present invention is that of realising a removable anatomic seat which is particularly reliable, simple, and functional at a relatively low cost. 
   These and other purposes according to the present invention are achieved by realising a removable anatomic seat as outlined in claim  1 . 
   Further characteristics are foreseen in the subsequent claims. 

   
     The characteristics and advantages of a removable anatomic seat according to the present invention shall become clearer from the following description, given as an example and not for limiting purposes, referring to the attached schematic drawings in which: 
       FIG. 1  is a side view of a chair equipped with a removable anatomic seat, according to the present invention, in a horizontal position; 
       FIG. 2  is a front view of  FIG. 1 ; 
       FIG. 3  is a side view of the chair equipped with the removable anatomic seat of  FIG. 1 , where the seat exhibits a tilted position; 
       FIG. 4  is a front view of  FIG. 3 ; 
       FIG. 5  is a plan section view from above of the chair equipped with the removable anatomic seat of  FIG. 1 , taken according to the line V—V of  FIG. 1 , in which an anatomic seating recess has been removed. 
   

   It should be noted that the following description, regarding a preferred embodiment, refers to an application of the removable anatomic seat, according to the invention, on a chair. 
   Alternatively and neither more nor less advantageously, the removable anatomic seat, object of the present invention, can also be used for other types of furniture, such as armchairs and stools. 
   With reference to the figures, a removable anatomic seat, wholly indicated with  10 , is shown, which is rested on top of a horizontal seat  12  of a chair  14 , equipped at the rear with a backrest  16 . 
   In the illustrated example, according to the present invention, the anatomic seat  10  comprises an anatomic seating recess  20 , supported by a structure  22 . 
   The anatomic recess  20  is shaped to allow comfortable seating to the user. It is equipped with an element protruding upwards or raised portion  21 , in a front and central position of the recess  20  itself. 
   In the example shown in the figures, the structure  22  comprises a base  23 , for example four-sided, which covers the seat  12  of then chair  14 . 
   Four supports  25 , for example, are arranged on the base  23  in correspondence with four legs  13  of the chair  14 . The two front supports  25 , which are on an opposite side to the backrest  16  of the chair  14 , are rotatably connected to the seating recess  20  at  24 . 
   Moreover, the structure  22  is fixed to the chair  14  through stable positioning elements such as belts  26 , generally in a closed loop with buckles  28  below the seat  12  of the chair  14 . 
   The seating recess  20  can be tilted with respect to a horizontal support thereof on the structure  22 , through lifting elements. 
   Such a lifting takes place with the displacement of a shaft  30 , rotatably connected centrally at a lower end  32  to the anatomic recess  20 , and more precisely in a central zone or in any case not close to the front supports  25 . Such a connection can advantageously be quickly removable, for example through a pin. 
   The shaft  30  is rotatably connected at an opposite end  34  to a small block  36 . Such a connection can advantageously be quickly removable, for example through a pin. 
   As can be seen in  FIG. 5 , such a small block  36  can slide on a guide  38 , inside the structure  22 , and which extends according to a direction X perpendicular to the backrest  16 . Moreover, the small block  36  has a threaded bore  40 , realised in the direction X, matching a screwing  42 , also arranged along the direction X. The screw  42  is equipped with a handle  44  arranged at the front of the anatomic seat  10 . 
   The operation of the removable anatomic seat according to the invention is clear from that which is described above with reference to the figures, and in brief is the following. 
   The base  23  of the structure  22  is fixed to the seat  12  of the chair  14 . 
   The seating recess  20 , hinged at  24  to the two front supports  25 , is rested horizontally on the two rear supports  25 . 
   As can be seen in  FIG. 1 , the small block  36  is arranged on one side near to the two front supports  25 , so that the shaft  30 , connected to the small block  36  itself, is in a substantially horizontal position. By rotating the handle  44  of the screw  42 , the small block  36  is displaced towards the backrest  16 . In this way the shaft  30  pushes the anatomic recess  20  upwards, tilting it with respect to a horizontal plane. 
   Advantageously, an inclination of about 30° is reached, with the possibility of practically infinite variations in inclination. For example, the inclination can be progressively varied by rotating the handle  44  day by day. 
   The seating recess  20  has high friction coefficient zones at the top to limit the user slipping forwards. Moreover, the suitably upholstered central raised portion  21  is also used for the same purpose. 
   The front and side edges of the seating recess  20  are suitably sanded. 
   The removable connection realised between small block  36  and shaft  30  and/or between shaft  30  and recess  20  allows passage at any time from the optimal inclination which has been achieved to the horizontal position, or vice-versa, precisely by simply removing, or reapplying, respectively, the connection between shaft  30  and small block  36  and/or recess  20 . 
   From the description which has been carried out the characteristics of the removable anatomic seat object of the present invention are clear, just as the relative advantages are clear, amongst which we recall:
         simple and reliable use;   small size and weight;   adaptability to practically all conventional seats;   ease of transportation;   possibility of a very accurate adjustment of the inclination;   ability to keep the obtained inclination, even after possible dismounting;   possibility of immediately passing from the position obtained to horizontal position, and vice-versa, to suit the needs of the user;   freedom of movement for the lower limbs;   low costs, with respect to the prior art, in relation to the advantages obtained.       

   Finally, it is clear that the removable anatomic seat thus conceived is susceptible to numerous modifications and variants, all of which are covered by the invention; moreover, all of the details can be replaced by technically equivalent elements. In practice, the materials used, as well as the shapes and sizes, can be whatever according to the technical requirements. 
   The scope of protection of the invention is therefore set out by the attached claims.