Patent Publication Number: US-6217111-B1

Title: Foldable chair assembly

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a foldable chair assembly, more particularly to a foldable chair assembly which has a significantly reduced thickness and which occupies a relatively small amount of storage space when folded. 
     2. Description of the Related Art 
     FIG. 1 illustrates a conventional chair assembly  1  which includes a seat member  2 , a backrest member  3 , a pair of elongated armrest members  13  (only one is visible) a pair of front leg members  11  (only one is visible), and a pair of rear leg members  12  (only one is visible). The backrest member  3  has a lower end connected pivotally to a rear end portion of the seat member  2  by means of a pair of pivot plates  20  disposed on lateral sides of the chair assembly  1  and by means of pivot pins  201 ,  202  that extend through the pivot plates  20  such that the seat member  2  is foldable toward the backrest member  3  and is stretchable from the backrest member  3 . The armrest members  13  have rear ends extending respectively to lateral sides of the backrest member  3  above the pivot plates  20  and connected pivotally to the backrest member  3  by means of pivot pins  133 . The front and rear leg members  11 ,  12  are disposed respectively on lateral sides of the seat member  2 . Each of the front leg members  11  has an upper end connected pivotally to a front end of a respective one of the armrest members  13  by means of a pivot pin  131 , a lower end to be supported on a ground surface, and an intermediate portion connected pivotally to the seat member  2  by means of a pivot pin  21 . Each of the rear leg members  12  is disposed rearwardly of a respective one of the front leg members  11 , and has an upper end connected pivotally to an intermediate portion of a respective one of the armrest members  13  by means of a pivot pin  132 , a lower end to be supported on the ground surface, and an intermediate portion connected to an adjacent one of the pivot plates  20  by means of a pivot pin  22 . Referring to FIG. 2, to fold the chair assembly  1 , the seat member  2  and the armrest members  13  are turned rearwardly to pivot toward the backrest member  3 . After the chair assembly  1  is folded, the seat member  2  is folded on and is disposed in front of the backrest member  3 , the armrest members  13  are disposed respectively on the lateral sides of the backrest member  3 , and the front leg members  11  are disposed in front of and adjacent to the rear leg members  12 , respectively. The chair assembly  1 , in its folded state, has a thickness which is measured between front and rear sides of the chair assembly  1  in the folded state and which is generally equal to the combined thickness of the backrest member  3  and an adjacent pair of the first and second leg members  11 ,  12 . It is desirable to further reduce the thickness of the chair assembly in its folded state so as to reduce the storage space occupied thereby. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to provide a foldable chair assembly which has a significantly reduced thickness in its folded state such that the chair assembly occupies a relatively small amount of storage space when folded. 
     Accordingly, the foldable chair assembly of the present invention includes a backrest member, a seat member, a pair of elongated armrest members, a pair of front leg members, a pair of rear leg members, and a pair of pivot members. The backrest member has a lower end, an upper end, and an intermediate portion between the upper and lower ends. The seat member has a rear end portion connected pivotally to the lower end of the backrest member, and a front end portion extending forwardly from the rear end portion. The armrest members are disposed respectively on two opposite lateral sides of the seat member. Each of the armrest members has a rear end which extends to a respective one of the two opposite lateral sides of the backrest member and which is connected pivotally to the intermediate portion of the backrest member. Each of the armrest members further has a first portion which is proximate to the respective one of the lateral sides of the seat member, and a second portion which is distal to the respective one of the seat member in a transverse direction transverse to a longitudinal direction of the armrest member. The front leg members are disposed respectively at the lateral sides of the seat member. Each of the front leg members has an upper end mounted pivotally on the first portion of a respective one of the armrest members, a lower end which is adapted to be disposed on a ground surface, and an intermediate portion extending between the upper and lower ends and connected pivotally to the front end portion of the seat member. The rear leg members are disposed respectively at the lateral sides of the seat member, and are disposed rearwardly of the front leg members, respectively. Each of the rear leg members has an upper end mounted pivotally on the second portion of a respective one of the armrest members, a lower end adapted to be disposed on the ground surface, and an intermediate portion extending between the upper and lower ends of the rear leg member. The pivot members are disposed respectively at the lateral sides of the backrest member. Each of the pivot members has a first end mounted pivotally on the lower end of the backrest member, and a second end mounted pivotally on the intermediate portion of a respective one of the rear leg members. The chair assembly is movable between an unfolded state, in which the backrest member and the front and rear leg members are substantially upright, and the seat member and the armrest members are substantially horizontal, and a folded state, in which the backrest member, the seat member, the armrest members and the front and rear leg members are substantially upright and in which the front leg members are disposed between the rear leg members and are generally parallel to the rear leg members. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, of which: 
     FIG. 1 is a side view of a conventional chair assembly in an unfolded state; 
     FIG. 2 is a side view of the conventional chair assembly in a folded state; 
     FIG. 3 is a perspective view of a first preferred embodiment of the foldable chair assembly of the present invention in an unfolded state; 
     FIG. 4 is a side view of the first preferred embodiment; 
     FIG. 5 is a fragmentary perspective view of the first preferred embodiment to illustrate a folding operation thereof; 
     FIG. 6 is a side view of the first preferred embodiment in a folded state; 
     FIG. 7 is a front elevational view of the first preferred embodiment in the folded state; 
     FIG. 8 is a side view of a second preferred embodiment of the foldable chair assembly of the present invention in an unfolded state; and 
     FIG. 9 is a fragmentary perspective view of the second preferred embodiment, illustrating how a front leg member and a rear leg member are connected to an armrest member. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIGS. 3 and 4, the first preferred embodiment of the foldable chair assembly  4  of the present invention is shown to include a seat member  5 , a backrest member  6 , a parallel pair of front leg members  41 , a parallel pair of rear leg members  42 , a pair of elongated armrest members  43 , and a pair of pivot members  50 . 
     The backrest member  6  has an upper end, a lower end and an intermediate portion extending between the upper and lower ends. The lower end of the backrest member  6  is formed with a pair of lateral extensions  62  that project laterally from the backrest member  6 . The seat member  5  has a rear end portion connected pivotally to the lower end of the backrest member  6  by means of a pair of pivot connectors  53 (only one is visible in FIG. 3) such that the seat member  5  is foldable rearwardly toward the backrest member  6  and is stretchable forwardly from the backrest member  6 . 
     The front leg members  41  are disposed respectively on two opposite lateral sides of the seat member  5 . Each of the front leg members  41  has a lower end adapted to be disposed on a ground surface, an upper end connected pivotally to a respective one of the armrest members  43 , and an intermediate portion which extends between the upper and lower ends and which is connected pivotally to a front end portion of the seat member  5  by means of a pivot pin  51 . A pair of front linking rods  411  are disposed below the seat member  5 , and extend transversely between the front leg members  41  to interconnect the front leg members  41 . 
     The rear leg members  42  are disposed rearwardly of the front leg members  41  and are disposed respectively on the lateral sides of the seat member  5 . A rear linking rod  421  is disposed below the backrest member  6 , and extends transversely between the rear leg members  42  to interconnect the rear leg members  42 . Each of the rear leg members  42  has a lower end adapted to be disposed on the ground surface, an upper end connected pivotally to a respective one of the armrest members  43 , and an intermediate portion which extends between the upper and lower ends and which is mounted pivotally to the lower end of the backrest member  6  by means of a respective one of the pivot members  50 . Each of the pivot members  50  has an upper end connected pivotally to a respective one of the lateral extensions  62  at the lower end of the backrest member  6  by means of an upper pivot pin  55 , and a lower end pivoted to the intermediate portion of a respective one of the rear leg members  42  by means of a lower pivot pin  52 . 
     The armrest members  43  are disposed respectively on the lateral sides of the seat member  5 , and have rear ends extending respectively to two opposite lateral sides of the backrest member  6  and connected pivotally to the intermediate portion of the backrest member  6  by means of pivot pins  433 . Referring to FIG. 5, each of the armrest members  43  has a longitudinal first side wall  434  proximate to the respective one of the lateral sides of the seat member  5  and a longitudinal second sidewall  435  opposite to and spaced apart from the first side wall  434  and distal to the respective one of the lateral sides of the seat member  5  in a transverse direction transverse to a longitudinal direction of the armrest member  43 . Each of the armrest members  43  has a bottom side formed with a downwardly extending partition wall  436  between the first and second side walls  434 ,  435 . The partition wall  436  extends in the longitudinal direction of the armrest member  43  for dividing the armrest member  43  into a first portion proximate to first side wall  434 , and a second portion proximate to the second side wall  435 . The upper end of each of the front leg members  41  extends to the bottom side of the respective one of the armrest members  43 , and is disposed proximate to the first side wall  434 . The upper end of each front leg member  41  is connected pivotally to the respective armrest member  43  by means of a pivot pin  431  that extends between the first and second side walls  434 ,  435  of the respective armrest member  43 . A stop member  437 , in the form of a sleeve, is sleeved on the pivot pin  431  and is disposed between the upper end of the respective front leg member  41  and the second side wall  435  of the respective armrest member  43  so as to retain the upper end of the respective front leg member  41  in the first portion and to prevent the upper end of the respective front leg member  41  from moving toward the second side wall  435 . The upper end of each of the rear leg members  42  extends to the bottom side of the respective one of the armrest members  43 , and is disposed between the second side wall  435  and the partition wall  436 . The upper end of each rear leg member  42  is connected pivotally to the respective armrest member  43  by means of a pivot pin  432  which extends transversely between the second side wall  435  and the partition wall  436 . 
     As shown in FIG. 4, when the chair assembly  4  is in an unfolded state, the seat member  5  and the armrest members  43  are substantially horizontal, and the backrest member  6  and the front and rear leg members  41 ,  42  are substantially upright. 
     Referring to FIGS. 5 to  7 , when the chair assembly  4  is folded, the seat member  5  pivots rearwardly for folding on the backrest member  6 , the armrest members  43  pivot rearwardly so as to be disposed respectively on the lateral sides of the backrest member  6 , and the front leg members  41  are moved rearwardly with the seat member  5  and the armrest members  43  toward the corresponding one of the rear leg members  42 . When the chair assembly  4  is in a folded state, as shown in FIGS. 6 and 7, the seat member  5 , the backrest member  6 , the armrest members  43 , and the front and rear leg members  41 ,  42  are substantially upright. In this situation, each of the front leg members  41  is disposed between the first side wall  434  and the partition wall  436  of the respective one of the armrest members  43 , and each of the rear leg members  42  is disposed between the second side wall  435  and the partition wall  436  of the respective one of the armrest members  43 . The pair of front leg members  41  are thus disposed between and are parallel to the pair of rear leg members  42 . As shown in FIG. 6, the thickness of the chair assembly  4  measured between front and rear sides thereof is significantly reduced when compared with the conventional chair assembly  1  shown in FIG.  2 . This results in a significant reduction in the storage space occupied by the chair assembly  4  when folded. 
     It is noted that, the rear linking rod  421 , which interconnects the rear leg members  42 , is disposed at a position to allow the front leg members  41  and the front linking rods  411  to extend between the rear leg members  42  without contacting the rear linking rod  421  when the chair assembly  4  is folded. 
     Referring to FIGS. 8 and 9, the second preferred embodiment of the chair assembly  7  of the present invention is shown to also include a seat member  75 , a backrest member  76 , a pair of armrest members  73  (only one is shown), a pair of front leg members  71  (only one is shown), and a pair of rear leg members  72  (only one is shown). The structure of the chair assembly  7  is similar to that of the first preferred embodiment, except for the connection among the armrest members  73  and the front and rear leg members  71 ,  72 . Each of the armrest members  73  has a first side wall  731  proximate to a respective lateral side of the seat member  75 , and a second side wall  732  which is opposite to and spaced apart from the first side wall  731  and which is distal to the respective lateral side of the seat member  75  in a transverse direction transverse to a longitudinal direction of the armrest member  73 . Each of the armrest members  73  has a bottom side provided with a cylindrical pivot shaft  74  which extends transversely between the first and second side walls  731 ,  732 . The pivot shaft  74  has a first section proximate to the first side wall  731 , and a second section proximate to the second side wall  732 . The upper end  711  of each of the front leg members  71  is provided with a first tubular sleeve  712  which is sleeved rotatably on the first section of the pivot shaft  74  of the respective one of the armrest members  73 . The upper end  721  of each of the rear leg members  72  is provided with a second tubular sleeve  722  which is sleeved rotatably on the second section of the pivot shaft  74 . 
     Each of the first and second side walls  731 ,  732  has an inner surface  733  confronting the other one of the first and second side walls  731 ,  732  and formed with a retaining groove  730  which includes a slide groove portion  735  that extends in the longitudinal direction of the armrest member  73 , and a series of engaging groove portions  734  that are communicated with the slide groove portion  735  and that extend upwardly from the slide groove portion  735 . The pivot shaft  74  has two opposite ends which extend respectively into the retaining grooves  730  in the inner surfaces  733  of the first and second side walls  731 ,  732 , and which are slidable along the slide groove portions  735  for extension into a selected confronting pair of the engaging groove portions  734 , thereby permitting adjustment of the inclination of the backrest member  76 . When the chair assembly  7  is in an unfolded state, the pivot shaft  74  of each armrest member  73  engages a selected pair of the engaging groove portions  734  in the armrest member  73  for positioning the backrest member  76  at a desired inclination. 
     Similarly, when the chair assembly  7  is folded, the front leg members  71  are disposed between the rear leg members  72  and are parallel to the rear leg members  72  so as to result in a significant reduction in the thickness of the chair assembly  7  in the folded state, thereby reducing the storage space occupied by the chair assembly  7  when folded. 
     While the present invention has been described in connection with what is considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.