Abstract:
A chair includes a support assembly comprised of a first leg set having two space first leg bars and a second leg set having two space second leg bars that are located between and pivoted to the first leg bars. A backrest has lower ends pivoted to the second leg bars and is thus rotatable with respect to the support assembly to selectively change a tilting angle of the backrest with respect to the support assembly. A tubular slide is movably fit over a free end of each first leg bar and is pivoted to the backrest. The tubular slide has a fastening device to selectively secure the tubular slide with respect to the first leg bar thereby releasably securing the backrest with respect to the support assembly.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates generally to a chair, such as a deck chair, and in particular to a collapsible chair having an adjustable backrest.  
         [0003]     2. Related Art  
         [0004]     Chairs, such as deck chairs, that allow a person to sit and partially lie down on a backrest of the chair are known. Conventional deck chairs, although some featuring a folding or collapsible structure, have a fixed backrest that tilts at a fixed angle to allow a person to partially lie down. Such an angle is fixed and thus not adjustable. This may cause uncomfortable situations for different persons. In some designs of the deck chairs, the tilting angle of the backrest is too large to make a person comfortably lying thereon. It may sometimes cause troubles to the old to get up from the excessively tilting backrest or even fall down over the backside of the chair.  
         [0005]     Deck chairs with adjustable backrest are also known. However, complicated adjusting mechanisms are often involved in such deck chairs. Not only is the adjustment of the backrest complicated and troublesome, but also manfacturing costs of the deck chairs are significantly increased.  
         [0006]     Thus, it is desired to have a collapsible chair with an adjustable backrest that effectively eliminates the drawbacks encountered in the conventional designs of the collapsible chairs.  
       SUMMARY OF THE INVENTION  
       [0007]     Therefore, a primary object of the present invention is to provide a collapsible chair having an adjustable backrest that allows for easy adjustment of tilting angle of the backrest.  
         [0008]     Another object of the present invention is to provide a collapsible chair having an adjustable backrest that prevents over-tilting and thus causing falling of a person lying down on the backrest.  
         [0009]     A further object of the present invention is to provide a collapsible chair with adjustable backrest that is simple in structure and low in costs.  
         [0010]     Yet a further object of the present invention is to provide a collapsible chair that is selectively and movably mounted on a base to form a rocker chair.  
         [0011]     To achieve the above objects, in accordance with the present invention, there is provided a chair comprising a support assembly comprised of a front leg set having two space front leg bars and a rear leg set having two space rear leg bars that are located between and pivoted to the front leg bars. A backrest has lower ends pivoted to the rear leg bars and is thus rotatable with respect to the support assembly to selectively change a tilting angle of the backrest with respect to the support assembly. A tubular slide is movably fit over a free end of each front leg bar and is pivoted to the backrest. The tubular slide has a fastening device to selectively secure the tubular slide with respect to the front leg bar thereby releasably securing the backrest with respect to the support assembly. The support assembly is selectively mounted on a base and is supported above the ground. Swings arms are rotatably mounted to both the base and the support assembly to allow for to and fro movement of the support assembly with respect to the base.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     The present invention will be apparent to those skilled in the art by reading the following description of preferred embodiments thereof, with reference to the attached drawings, in which:  
         [0013]      FIG. 1  is a perspective view of a collapsible chair constructed in accordance with the present invention;  
         [0014]      FIG. 2  is a perspective view of the chair of the present invention mounted to a base to form a rocker chair;  
         [0015]      FIG. 3  is a perspective view of the chair with covering mounted thereon;  
         [0016]      FIG. 4  is a side elevational view of the collapsible chair of the present invention;  
         [0017]      FIG. 4A  is an enlarged view of encircled portion  4 A of  FIG. 4 , but shown in an exploded form;  
         [0018]      FIG. 4B  is a cross-sectional view taken along line  4 B- 4 B of  FIG. 4A ;  
         [0019]      FIG. 5  is a side elevational view showing a collapsing operation of the chair of the present invention; and  
         [0020]      FIG. 6  is a side elevational view of the chair in a collapsed condition. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0021]     With reference to the drawings and in particular to  FIGS. 1 and 4 , a collapsible chair constructed in accordance with the present invention, generally designated with reference numeral  10 , comprises a support assembly  12  and a backrest  14  movably mounted to the support assembly  12  whereby the backrest  14  selectively tilts with respect to the support assembly  12  at a tilting angle which is adjustable.  
         [0022]     The support assembly  12  comprises a front leg set  16  and a rear leg set  18  pivoted to each other. The front leg set  16  comprises two front bars  20 ,  22  spaced from and substantially parallel to each other. The front bars  20 ,  22  are fixed together by front crossbars  24  extending therebetween. Although in the embodiment illustrated, two front crossbars  24  are used to fix the front bars  20 ,  22  together, other numbers of front crossbars may also be used. For example, the front bars  20 ,  22  can be fixed together by a single front crossbar.  
         [0023]     The rear leg set  18  comprises two rear bars  26 ,  28  spaced from and substantially parallel to each other. The rear bars  26 ,  28  are fixed together by a rear crossbar  30  extending therebetween. Although in the embodiment illustrated, a single rear crossbar  30  is used to fix the rear bars  26 ,  28  together, other numbers of rear crossbars may also be used. For example, the rear bars  26 ,  28  are fixed together by two or more rear crossbars. The front and rear crossbars  24 ,  30  are of such lengths that the rear leg set  18  is received between the front bars  20 ,  22  of the front leg set  16  with the rear bars  26 ,  28  adjacent to the front bars  20 ,  22  whereby pivot pins  32 ,  34  extends through the rear bars  26 ,  28  and the associated front bars  20 ,  22  to pivot the rear leg set  18  to the front leg set  16 .  
         [0024]     Apparently, the lengths of the front crossbars  24  and the rear crossbar  30  can be selected so that the front leg set  16  is received between the rear bars  26 ,  28  and pivoted thereto.  
         [0025]     Each of the front and rear bars  20 ,  22 ,  26 ,  28  has an end  36 ,  38 ,  40 ,  42  positionable on a fixture surface (not shown), such as the ground, for supporting the support assembly  12  on the fixture surface. In the embodiment illustrated, the end  36 ,  38 ,  40 ,  42  has an expanded portion for soundly supporting the chair  10 . Preferably, the expanded portion is spherical, as illustrated in the drawings.  
         [0026]     The backrest  14  comprises two back bars  44 ,  46  spaced from and substantially parallel to each other. The back bars  44 ,  46  are fixed together by back crossbars  48 ,  49  extending therebetween. The back crossbars  48 ,  49  are so arranged that the back crossbars  48 ,  49  and the back bars  44 ,  47  form a rectangle with lower end sections  50 ,  52  of the back bars  44 ,  47  extending beyond the lower back crossbar  48 . The back crossbars  48 ,  49  have a length substantially corresponding to the length of the rear crossbar  30  so that the lower end sections  50 ,  52  of the back bars  44 ,  46  are respectively in alignment with the rear bars  26 ,  28  of the rear leg set  18 .  
         [0027]     Also referring to  FIGS. 4A and 4B , a joint member  54  connects the lower end section  50 ,  52  of each back bar  44 ,  46  of the backrest  14  to an associated rear bar  26 ,  28 . The joint member  54  comprises two spaced lugs  55  partially receiving the rear bar  26 ,  28  therein and a bolt  56  extends through both the lugs  55  and the rear bar  26 ,  28  to pivotally attach the joint member  54  to the rear bar  26 ,  28 . The joint member  54  comprises a cylinder  54 A removably fit into the lower end section  50 ,  52  of the back bar  44 ,  46 . In this respect, the back bar  44 ,  46  is preferably tubular and has a lower opening for receiving the cylinder  54 A. A spring biased pin  54 B sideways projects from the cylinder  54 A for releasably engaging a hole  50 A defined in the tubular wall of the back bar  44 ,  46  thereby releasably securing the backrest  14  to the rear leg set  18 . The pivot joint formed by the bolt  56  between the backrest  14  and the rear leg set  18  allows the backrest  14  to selectively tilt or lean with respect to the support assembly  12  at a tilting angle that is adjustable through rotation of the backrest  14  with respect to the support assembly  12 .  
         [0028]     Each back bar  44 ,  46  has a telescopic construction comprising an inner tube  441 ,  461  telescopically received in an outer tube  442 ,  462 . A pin (not labeled) is arranged in the inner tube  441 ,  461  and is resiliently biased to extend beyond the inner tube  441 ,  461  to engage holes  58  defined in the outer tube  442 ,  462  thereby selectively securing the position of the inner tube  441 ,  461  with respect to the outer tube  442 ,  462 . This provides the backrest  14  with an adjustable size by means of the telescopic displacement of the inner tubes  441 ,  461  with respect to the outer tubes  442 ,  462 , as indicated by arrow C of  FIGS. 4 and 5 .  
         [0029]     Preferably, the upper back crossbar  49  is integrally formed with the inner tubes  441 ,  461  to form a U-shaped configuration, while the lower back crossbar  49  is mounted between the outer tubes  442 ,  462 .  
         [0030]     The front leg set  16  comprises a tubular slide  60  having an end fit over a free end section  62  (shown in phantom lines) of each front bar  20 ,  22 . The tubular slide  60  telescopically receives the free end section  62  therein and movable along and with respect to the free end section  62  to change relative position therebetween. The tubular slide  60  is pivoted to the corresponding back bar  44 ,  46  of the backrest  14  for selectively imposing constraints to the rotation of the backrest  14  with respect to the support assembly  12 . Fastening means  66  is provided between the tubular slide  60  and the free end section  62  for selectively securing the tubular slide  60  with respect to the end section  62  of the front bar  20 ,  22  thereby fixing the backrest  14  with respect to the support assembly  12 .  
         [0031]     In the embodiment illustrated, the fastening means  66  comprises a collar  68  mounted to the tubular slide  60 , comprising deformable paws (not shown), which when actuated by an operation level  70 , impose a sufficient friction force to the end section  62  thereby securing the tubular slide  60  with respect to the end section  62 . The friction based fastening means is generally known to those having ordinary skills and thus no further details will be given herein. It is also noted that such a friction based fastening means can be replaced by other known fasteners, such as spring-biased pins.  
         [0032]     Flexible connection means, such as a rope and a wire  72 , is arranged inside the tubular slide  60  and has opposite ends (not labeled) attached to the tubular slide  60  and the end section  62  of the front bar  20 ,  22  respectively. The wire  72  has a length that is shorter than a maximum length of the end section  62  that can be received into the tubular slide  60  whereby the tubular slide  60  is prevented from sliding off the end section  62  of the front bar  20 ,  22  by the wire  72 . Apparently, other means performing the same function of preventing the tubular slide  60  from sliding off the end section  62  can be adapted to replace the wire  72 .  
         [0033]     In the embodiment illustrated, the front and rear bars  20 ,  22 ,  26 ,  28  are of convex arc configurations. This allows for a comfortable and sound support to a person sitting thereon. The arc configuration of the front bars  20 ,  22  also allows for the formation of armrests by portions of the front bars  20 ,  22  between the backrest  14  and the pivot joints  32 ,  34  of the front bars  20 ,  22  with respect to the rear bars  26 ,  28 .  
         [0034]     Also referring to  FIGS. 5 and 6 , collapse of the chair  10  is illustrated. Collapse of the chair  10  is easily carried out by releasing the fastening means  66  to allow the tubular slides  60  to move to a furthest location from the end sections  62 , as indicated by arrow A of  FIG. 5 , which rotates the backrest  14  with respect to the support assembly  12  about pivot pins  56 , as indicated by arrow B of  FIG. 6 . The furthest location is determined by the length of the wire  72 , which is such that the backrest  14  substantially overlies on the back leg set  18  and the front and back leg sets  16 ,  18  substantially coincident with each other as illustrated, thereby completing the collapse of the chair  10 .  
         [0035]     Also referring to  FIG. 3 , a seat member  74  comprises a flexible member, such as a fabric made of synthetic or natural fibers or simply a thin plastic sheet, mounted between the rear bars  26 ,  28  between the lugs  54  to which the backrest  14  is pivoted and free ends  76 ,  78  of the rear bars  26 ,  28  for supporting a person thereon. If desired, the seat member  74  may comprise a cushion or a pad mounted on a rigid base (both not shown), which is in turn mounted to the rear bars  26 ,  28 .  
         [0036]     A back support member  80  comprises a flexible member, such as a fabric made of synthetic or natural fibers or simply a thin plastic sheet, mounted between the back bars  44 ,  46 . Preferably, the back support member  80  is attached to the outer tubes  442 ,  462  to allow the movement of the inner tubes  441 ,  461  with respect to the support assembly  12 . A head pillow  81  is attached to the upper back crossbar  49  and partially overlaps an upper end of the back support member  80  whereby the head pillow  81  is firmly supported between the crossbar  49  and the back support member  80 . The overlapped portion of the head pillow  81  allows for displacement of the upper back crossbar  49  with respect to the backrest  14  without separating the head pillow  81  from the back support member  80 .  
         [0037]     Armrest pads  82  made of soft material surround the portions of the front bars  20 ,  22  that function as armrests. The soft pads  82  provide comfortable contact between the arms of a person that sits on the chair  10  and the armrests.  
         [0038]     Also referring to  FIG. 2 , the chair  10  of the present invention can be converted into a rocker chair  84  by mounting the chair  10  to a base  86 . The base  86 , which is positioned on a fixture surface (not shown), such as the ground, is sized to be accommodated under the chair  10  and partially received between the front bars  20 ,  22  and the rear bars  26 ,  28  for supporting the chair  10  above the fixture surface with a suitable distance between the chair  10  and the fixture surface.  
         [0039]     In the embodiment illustrated, the base  86  is made up of two inverted U-shaped bar members  88 ,  90  with crossbars  92  connected therebetween. Each U-shaped bar member  88 ,  90  has a top section  94 ,  96  extending substantially horizontally and two legs  94 A,  96 A depending from opposite ends of the top section  94 ,  96 . An elongate bar  98 ,  100  is mounted to and extends between the front bar  20 ,  22  and the associated rear bar  26 ,  28  at a position below the corresponding top section  94 ,  96  of the base  86  and is substantially parallel to the top section  94 ,  96 . Two swing arms  102  are connected between the elongate bar  98 ,  100  and the top section  94 ,  96  by having opposite ends (not labeled) rotatably mounted to the elongate bar  98 ,  100  and the top section  94 ,  96  by rotation joints  104 . The swing arms  102  are substantially parallel whereby the swing arms  102 , the top section  94 ,  96  and the elongate bar  98 ,  100  form a parallelogram, which together with the rotation joints  104  between the swing arms  102  and the top section  94 ,  96  and the elongate bar  98 ,  100 , allows the chair  10  to move to and fro with respect to the base  86 , functioning as a rocker chair.  
         [0040]     Each leg  94 A,  96 A comprises a tubular section telescopically receiving an inner leg member  94 B,  96 B. The inner leg member  94 B,  96 B is movable with respect to the leg  94 A,  96 A at least between upper and lower positions where the chair  10  is raised to and lowered down to high and low positions with respect to for example the ground. Releasable fastening means, such as spring-biased pin and hole pair, is provided between the inner leg member  94 B,  96 B and the leg  94 A,  96 A for selectively securing the chair  10  at the high and low positions.  
         [0041]     Although the present invention has been described with reference to the preferred embodiments thereof, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims.