Patent Publication Number: US-7216840-B2

Title: Supporting framework for a swivel chair or swivel table

Description:
BACKGROUND OF THE INVENTION 
   1. Field of Invention 
   The present invention relates to an improved supporting framework for a swivel chair, table or the like , with the supporting framework being adapted to lock after a component (e.g., gas spring) thereof rotates a desired angle (i.e., the supporting framework has been positioned). 
   2. Related Art 
   Supporting framework for swivel chairs, tables or like office furniture is well known. However, such prior supporting frameworks are typically relatively complex in constructions, costly to manufacture, trouble-prone, and unreliable in use. Thus, continuing improvements in the exploitation of supporting framework for swivel chairs, tables or like office furniture are constantly being sought. 
   SUMMARY OF THE INVENTION 
   It is therefore an object of the present invention to provide a supporting framework for a piece of swivel furniture including a sleeve, a cylinder, a gas spring, a ring and a hollow can. The cylinder is put on the gas spring and includes two opposite holes, a top annular flange, and a plurality of equally circumferentially spaced longitudinal apertures open to the flange. A plurality of post are spring loaded in a first group of said apertures. A plurality of lock bars are spring loaded in a second group of said apertures. The number of apertures in the second group is equal to that in the first group. The lock bars are shorter than the posts. The ring rests upon the cylinder, with the gas spring projected through the ring and fastened thereby. The ring includes a plurality of equally circumferentially spaced openings having a diameter less than a diameter of the posts such that the posts are urged upward against the openings but slightly larger than a diameter of the lock bars such that the lock bars are adapted to enter into the openings. The sleeve is put on the cylinder and includes two opposite lock holes. The hollow cap with the gas spring projected therethrough includes two opposite channels of an inverted L-shape on its peripheral wall. Two lock pins are inserted through the channels and the lock holes and into the holes for fastening the cap, the sleeve, and the cylinder together. Thus moving the lock pins from upper second positions to lower first positions in the channels will enable the gas spring to rotate or vice versa will lock the same. 
   In one aspect of the present invention, the piece of swivel furniture is a swivel chair or a swivel table. 
   The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded view of a preferred embodiment of a supporting framework according to the invention; 
       FIG. 2  is a side view, in part section, of the assembled supporting framework in  FIG. 1 , where the supporting framework is adapted to rotate when a lock pin is disposed in a first position; 
       FIG. 3  is a side view of the assembled supporting framework in  FIG. 1 , where the supporting framework is adapted to rotate when the lock pin is disposed in the first position; 
       FIG. 4  is a perspective view, with a portion broken away, of the assembled supporting framework in  FIG. 1 , where the supporting framework is adapted to rotate when the lock pin is disposed in the first position; 
       FIG. 5  is a view similar to  FIG. 2 , where the supporting framework is locked when the lock pin is disposed in a second position; 
       FIG. 6  is a view similar to  FIG. 3 , where the supporting framework is locked when the lock pin is disposed in the second position; and 
       FIG. 7  is a view similar to  FIG. 4 , where the supporting framework is locked when the lock pin is disposed in the second position. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to  FIGS. 1 and 2 , there is shown a supporting framework  9  mounted under a seat of a swivel chair or under a swivel table in accordance with a preferred embodiment of the invention. The supporting framework  9  includes a gas spring  6 , and a cylinder  2  put on the gas spring  6 . The cylinder  2  includes two opposite holes  21  on its upper portion, and a plurality of longitudinal apertures (six are shown)  22  equally circumferentially spaced on its upper portion. Each longitudinal aperture  22  has an opening on a top annular flange. A plurality of springs (six are shown)  3  is disposed in the longitudinal apertures  22 . One of a plurality of posts (three are  4  and a plurality of lock bars (three are shown)  5  are provided in each of the longitudinal apertures  24 , with each having a bottom end urged by the spring  3 . The lock bars  5  are shorter than the posts  4 . A ring  7  rests upon the cylinder  2 . The ring  7  includes a central opening  71 , with the gas spring  6  projected therethrough and fastened thereby due to conforming shapes. Thus, the gas spring  6  and the ring  7  are adapted to rotate together. The ring  7  further includes a plurality of equally circumferentially spaced peripheral openings  72 , having a diameter less than a diameter of tops of the posts  4  but slightly larger than a diameter of the lock bars  5 . Thus, the top of each post  4  is urged against the opening  72 , and the top of each lock bar  5  is adapted to enter into the opening  72 . A sleeve  1  includes two opposite lock holes  11  on its upper portion, with the sleeve  1  being put on the cylinder  2  with the lock holes  11  aligned with the holes  2 l. A cap  8  rests upon the ring  7  and includes a central opening with the gas spring  6  projected therethrough. Two opposite channels  81  of an inverted L-shape are on the peripheral wall of the can  8 . Two lock pins  84  are inserted through the channels  81  and the lock holes  11  and into the holes  21  for fastening the cap  8 , the sleeve  1 , and the cylinder  2  together. 
   Referring to  FIGS. 3 and 4  in conjunction with  FIG. 2 , a user may rotate the cap  8  a small angle and then lift the same to move the lock pins  84  to lower first positions  82  of the channels  81 . The posts  4  are adapted to push the ring  7  and the cap  8  upward due to expansion of the springs  3  while the lock pins  84  are in the lower first positions  82  of the channels  81 . The openings  72  of the ring  7  then separate from the lock bars  5 . The gas spring  6  is, thus, able to rotate freely for adjusting orientation of a chair or table. 
   Referring to  FIGS. 5 ,  6 , and  7 , and for locking the supporting framework  9  after the chair or table has been positioned in the desired orientation, a user may first press the cap  8  to cause the lock pins  84  to move against the upper edges of the lower first positions  82 . At that time, can  8  can be rotated to move the lock pins  84  from the lower first positions  82  to upper second positions  83  in the channels  81 . The downward movement of the cap  8  causes the posts  4 , the lock bars  5  inside the ring  7  and the cylinder  2  to move downwardly. The gas spring  6  can then be rotated a small angle to align the openings  72  of the ring  7  with the lock bars  5 . The lock bars  5 , thus, hoist to enter into the openings  72  of the ring  7  (i.e., the gas spring  6  is locked) due to expansion of the springs  3 . 
   While the invention herein disclosed has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims.