Patent Publication Number: US-6659560-B1

Title: Office chair

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an office chair, more particularly to an office chair, which has a back, and armrests detachable from a seat thereof and adjustable in position for suiting the needs of different sitters. 
     2. Brief Description of the Prior Art 
     Referring to FIG. 7, a conventional office chair consists of an upper part  2 , and a lower part (not shown), which includes a base, a leg, and connecting means, and other elements. The upper part  2  includes a seat  21 , a back  23 , and a pair of armrests  25 ; extending from lower ends of the back  23 , and the armrests  25  are bent support plates  24 , and  26 , and the support plates  24 ,  26  are fixedly joined to a lower side of the seat  21  by means of screws  22 . Such office chair can provide a sitter with relatively much comfort but it is also found to have disadvantages as followings: 
     1. Because it takes relatively much labor to screw the screws  22  into the seat  21 , the back  23  and the armrests  25  are usually joined to the seat  21  in factories. Therefore, the office chair can only be separated into two parts, i.e. the upper and the lower parts, and will occupy relatively big space in packing. Consequently, the cost of storage and transportation would be very high, and become a problem of the manufacturers. 
     2. The back  23  and the armrests  25  are firmly fixed in position therefore they can&#39;t be adjusted in position relative to the seat. In other words, both the space between the armrests  25  and the depth of the chair can&#39;t be changed to suit sitters of different body sizes; when a big sitter sits on the chair, he/she might feel very uncomfortable because the small space is too small. 
     3. The owner can&#39;t dismantle the upper part of the chair easily, either. Consequently, when the owner of the chair has to move home, carrying the chair might become a problem because of the size of the chair can&#39;t be effectively reduced. And, the various parts of the chair upper part, when damaged, can&#39;t be replaced with a new one individually. 
     SUMMARY OF THE INVENTION 
     It is a main object of the present invention to provide an office chair, which has a back, and armrests that can be easily detached from, and joined to, the seat thereof. 
     It is another object of the present invention to provide an office chair, of which the back and the armrests are adjustable in position for suiting the needs of different sitters. 
     It is yet another object of the present invention to provide an office chair, of which the back and the armrests can be securely fitted in position after adjustment. 
     The office chair includes three connecting element fixedly to the bottom of the seat; each of the back and the armrests has a support plate having aligned locating holes; the support plates can&#39;t move up to separate from the connecting elements after having been slid onto the latter. Each of the connecting elements has a spring-loaded locating pin fitted thereto capable of engaging one of the locating holes of respective support plates; thus, the back and the armrests can be adjusted in position and can be easily detached from, and joined to, the seat. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be better understood by reference to the accompanying, wherein: 
     FIG. 1 is a partial exploded perspective view of the office chair according to the present invention, 
     FIG. 2 is another partial exploded perspective view of the office chair according to the present invention, 
     FIG. 3 is a cross-sectional view of a connecting element and a support plate of the office chair of the present invention, before assembly, 
     FIG. 4 is a cross-sectional view of a connecting element and a support plate of the office chair of the present invention, after assembly, 
     FIG. 5 is another cross-sectional view of a connecting element and a support plate of the present office chair; after assembly, 
     FIG. 6 is a partial view of the present office chair under assembly; and, 
     FIG. 7 is a perspective view of the upper part of the conventional office chair as described in the Background. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIGS. 1, and  2 , an office chair of the present invention includes three connecting elements  1 , which are respectively fixed to a rear end, a left edge, and a right edge of a lower side of a seat  21  of the office chair. 
     Each of a back, a left armrest, and a right armrest of the office chair has a support plate  26 ,  24 ,  24  extending down therefrom; each of the support plates  26 ,  24 ,  24  has several locating holes  263 ,  243 ,  243  formed on a bent insertion portion  262 ,  242 ,  242  thereof and has a rounded-off portion  261 ,  241 ,  241  at an inward end thereof 
     Referring to FIGS. 2, and  3 , each of the connecting elements  1  of the office chair includes a main body  11 , a locating pin  12 , a spring  13 , and a control member  14 ; each of the main bodies  11  has two wings  11 , a middle recess  116  between the wings  111 , a projecting base part  114  on the opposite side of the middle recess  116 , a stopping plate  118  sticking tip at an inward end of the middle recess  116 , and several retaining blocks  117  sticking above two opposite edges of the middle recess  116  to define a holding space between them and the middle recess  116  for allowing a respective support plate  24  ( 26 ) to be held therein. The retaining blocks  117  are provided for preventing the support plates  24 ,  26  from moving up to separate from the connecting elements  1  after the support plates  24 ,  26  are slid onto tile middle recesses  116 . 
     Each of the wings  111  has through connecting holes  112  so that fixing elements  113  such as screws can secure the connecting elements  1  to the seat of the chair by means of passing the fixing elements  113  through the holes  112  and then screwing the same into the lower side of the seat. 
     Each of the locating pins  12  has an tipper portion, and a lower portion  121 , which is thinner than the tipper one, and which has a transverse pin hole  122 , and threads  124  formed a lower end thereof. Each of the control members  14  has a screw hole  141 , and a through hole  142  across a lateral side thereof 
     Respectively formed on the middle recess  116 , and the projecting base part  114  of each connecting element  1  are through holes  115 , and  115 ′ aligned with each other; the through holes  115  are big enough for the thicker tipper portions of the locating pins  12  to pass through; each spring  13  is fitted around respective locating pin&#39;s thinner lower portion  121 , and is supported by the projecting seat part  114  to bias the pin  12  upwards when the lower portion  121  is passed through the through hole  115 ′; after the lower portions  121  of the locating pins  12  are passed through the holes  115 ′, they are screwed into respective control members  14 , and fixing pins  123  are inserted into the through holes  142  of the control members  14  and the transverse pin holes  122  to prevent the control members  14  from getting loose. Thus, the locating pins  12  normally stick up from corresponding middle recesses  116  to a locking position capable of engaging the locating holes of corresponding support plates  24  ( 26 ), and can be moved down to a disengaged position, in which they are lower than corresponding middle recesses  116 , by means of pulling the control members  14  downwards. 
     After the support plates  24 ,  26  are inserted between the spaces defined by the retaining blocks  117  and the middle recesses  116  of respective connecting elements  1 , and adjusted in position relative to the middle recesses  116 , the locating pins  12  can engage one of the locating holes  243 ,  263  of the support plates  24 ,  26  to securely fix the support plates  24 ,  26  to the connecting elements  1 . The rounded-off inward ends  241 ,  261  of the support plates  24 .  26  can help corresponding locating pins  12  to move downwards from the locking position to allow the support plates  24 ,  26  to slide onto respective connecting plates  1  easily. And, the stopping plates  118  can prevent the support plates  24 ,  26  from sliding past the ends of the connecting elements  116 . 
     From the above description, it can be easily understood that the present office chair has advantages as followings: 
     1. The armrests and the back are detached from the seat while being packed in factories, therefore various parts of the office chair can be arranged in a packing case in such a way that they occupy less space. Consequently, the cost of storage and transportation can be reduced. 
     2. The consumers can join the armrests, and the back to the seat easily, and have the fun of DIY after buying the office chair. 
     3. The back and the armrests can be adjusted in position relative to the seat therefore both the space between the armrests and the depth of the chair can be changed to suit sitters of different body sizes; when a big sitter is sitting on the chair, he/she won&#39;t feel any discomfort caused by narrow space of the seat. 
     4. The owner of the chair can substitute a back and armrests of different colors and designs for the original ones so that the chair is more attractive and fancy. 
     5. The locating pins  12  and the locating holes  243 ,  263  form a relatively secure locking connection of the back and the armrests with the seat, of which an accidental unlocking is rarely possible. Therefore, the chair is safe to use.