Patent Publication Number: US-11659931-B1

Title: Foldable chair

Description:
FIELD 
     The disclosure relates to a chair, and more particularly to a foldable chair. 
     BACKGROUND 
       FIGS.  1  to  3    illustrate a conventional foldable chair. The conventional foldable chair includes a backrest unit  11 , two side leg units  12  spaced apart from each other in a left-right direction and pivotally connected to the backrest unit  11 , a chair cover unit  13  secured to the backrest unit  11  and the side leg units  12 , and a front leg unit  14  disposed in front of the backrest unit  11 . 
     The backrest unit  11  includes two backrest posts  111  that are spaced apart from each other in the left-right direction and extending in a top-bottom direction perpendicular to the left-right direction, and two back scissor legs  112  that are arranged in the front-rear direction and that are crossed over and pivotally connected to each other. Each of the side leg units  12  includes two side scissor legs  121  that are arranged in the left-right direction and that are crossed over and pivotally connected to each other. The front leg unit  14  includes two front scissor legs  141  that are arranged in the front-rear direction and that are crossed over and pivotally connected to each other. 
     As shown in  FIGS.  1  to  4   , the conventional foldable chair can be operated between a stretched state (see  FIGS.  1  to  3   ) and a folded state (see  FIG.  4   ). 
     However, to operate the conventional foldable chair to change between the stretched and folded states, a user has to move the backrest unit  11 , the side leg units  12 , and the front leg unit  14  respectively for folding or unfolding the back scissor legs  112 , the side scissor legs  121 , and the front scissor legs  141 , and this is rather inconvenient. 
     SUMMARY 
     Therefore, an object of the disclosure is to provide a foldable chair that can alleviate the drawback of the prior art. 
     According to the disclosure, a foldable chair includes a chair back unit, two side leg units, a chair cover unit, a foldable rod unit, and at least one linking rod unit. 
     The chair back unit includes two back rod sets spaced apart from each other in a left-right direction. Each of the back rod sets has a back rod that extends in a top-bottom direction perpendicular to the left-right direction, an upper sleeve that is slidably sleeved on the back rod, and a lower sleeve that is sleeved on a bottom end of the back rod. 
     The side leg units are spaced apart from each other in the left-right direction. Each of the side leg units includes first and second scissor legs that are arranged in the left-right direction and that are crossed over and pivotally connected to each other, a bottom pivot seat that is disposed in front of the lower sleeve of a respective one of the back rod sets, and an upper pivot seat that is disposed in front of the upper sleeve of the respective one of the back rod sets. The first scissor leg has opposite top and bottom ends that are pivotally and respectively connected to the upper sleeve of the respective one of the back rod sets and the bottom pivot seat. The second scissor leg has opposite top and bottom ends that are pivotally and respectively connected to the upper pivot seat and the lower sleeve of the respective one of the back rod sets. 
     The chair cover unit includes a seat cover that has left and right front ends respectively secured to the upper pivot seats of the side leg units, and left and right rear ends respectively disposed above the upper sleeves of the back rod sets and respectively and slidably sleeved on the back rods of the back rod sets. 
     The foldable rod unit is pivotally connected between the back rods of the back rod sets and is operable to move the back rods of the back rod sets toward or away from each other. 
     The at least one linking rod unit has an end that is pivotally connected to the foldable rod unit, and another end that is pivotally connected to the chair back unit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the disclosure will become apparent in the following detailed description of the embodiments with reference to the accompanying drawings, of which: 
         FIG.  1    is a perspective view illustrating a conventional foldable chair; 
         FIG.  2    is a perspective view of the conventional foldable chair viewed from a different angle; 
         FIG.  3    is a rear view of the conventional foldable chair in a stretched state; 
         FIG.  4    is a rear view of the conventional foldable chair in a folded state; 
         FIG.  5    is a perspective view illustrating a foldable chair according to a first embodiment of the disclosure in a stretched state; 
         FIG.  6    is another perspective view of the first embodiment viewed from a different angle in the stretched state; 
         FIG.  7    is a side view of the first embodiment in the stretched state; 
         FIG.  8    is a rear view of the first embodiment in the stretched state; 
         FIG.  9    is a side view of the first embodiment in a folded state; 
         FIG.  10    is a rear view of the first embodiment in the folded state; 
         FIG.  11    is a rear view illustrating a foldable chair according to a second embodiment of the disclosure in a stretched state; 
         FIG.  12    is a rear view of the second embodiment in a folded state; and 
         FIG.  13    is a rear view illustrating a foldable chair according to a third embodiment of the disclosure in a stretched state. 
     
    
    
     DETAILED DESCRIPTION 
     Before the disclosure is described in greater detail, it should be noted that where considered appropriate, reference numerals or terminal portions of reference numerals have been repeated among the figures to indicate corresponding or analogous elements, which may optionally have similar characteristics. 
       FIGS.  5  to  7    illustrate a foldable chair according to a first embodiment of the disclosure placed on a support surface  2  such as a floor. 
     In this embodiment, the foldable chair includes a chair back unit  3 , two side leg units  4 , a front leg unit  5 , a foldable rod unit  6 , two linking rod units  7 , and a chair cover unit  8 . 
     The chair back unit  3  includes two back rod sets  31  that are spaced apart from each other in a left-right direction, and two back legs  32 . 
     Each back rod set  31  has a back rod  311  that extends in a top-bottom direction perpendicular to the left-right direction, an upper sleeve  312  that is slidably sleeved on the back rod  311 , and a lower sleeve  313  that is sleeved on a bottom end of the back rod  311 . 
     The back legs  32  are arranged in a front-rear direction perpendicular to the left-right direction and the top-bottom direction, and are crossed over and pivotally connected to each other. Each of the back legs  32  has a top end that is pivotally connected to the upper sleeve  312  of a respective one of the back rod sets  31 , and a bottom end that is pivotally connected to the lower sleeve  313  of another one of the back rod sets  31 . 
     The side leg units  4  are disposed in front of the chair back unit  3 , and are spaced apart from each other in the left-right direction. Each of the side leg units  4  includes first and second scissor legs  41 ,  42  that are arranged in the left-right direction and that are crossed over and pivotally connected to each other, a bottom pivot seat  43  that is disposed in front of the lower sleeve  313  of a respective one of the back rod sets  31 , and a upper pivot seat  44  that is disposed in front of the upper sleeve  312  of the respective one of the back rod sets  31 . 
     For each side leg unit  4 , the first scissor leg  41  extends diagonally and has opposite top and bottom ends that are pivotally and respectively connected to the upper sleeve  312  of the respective one of the back rod sets  31  and the bottom pivot seat  43 . The second scissor leg  42  extends diagonally and has opposite top and bottom ends that are pivotally and respectively connected to the upper pivot seat  44  and the lower sleeve  313  of the respective one of the back rod sets  31 . 
     As shown in  FIG.  7   , the bottom pivot seats  43  of the side leg units  4  and the lower sleeves  313  of the back rod sets  31  are disposed on the support surface  2  such that the chair back unit  3  and the side leg units  4  can stand on the support surface  2  when the foldable char is in use. 
     The front leg unit  5  includes two front legs  51  that are arranged in the front-rear direction and that are crossed over and pivotally connected to each other. Each front leg  51  has a top end that is pivotally connected to the upper pivot seat  44  of a respective one of the side leg units  4 , and a bottom end that is pivotally connected to the bottom pivot seat  43  of another one of the side leg units  4 . 
     It is noted that those pivot connections between the back legs  32  and the upper sleeves  312 , between the back legs  32  and the lower sleeves  313 , between the first scissor legs  41  and the upper sleeves  312 , between the first scissor legs  41  and the bottom pivot seats  43 , between the second scissor legs  42  and the lower sleeves  313 , between the second scissor legs  42  and the upper pivot seats  44 , between the front legs  51  and the bottom pivot seats  43 , and between the front legs  51  and the upper pivot seats  44  may be implemented in various known ways, and are not limited by the disclosure. 
     The foldable rod unit  6  is pivotally connected between the back rods  311  of the back rod sets  31 , is operable to move the back rods  311  of the back rod sets  31  toward or away from each other, and includes a hinge seat  61  and two connecting rods  62 . 
     The hinge seat  61  is disposed between the back rods  311  of the back rod sets  31 . Each connecting rod  62  has a first end portion  621  that is pivotally connected to the hinge seat  61 , a second end portion  622  that is opposite to the first end portion  621  and that is pivotally connected to the back rod  311  of a respective one of the back rod sets  31 , and an intermediate portion  623  that is connected between the first and second end portions  621 ,  622 . 
     Each of the linking rod units  7  has an end that is pivotally connected to the foldable rod unit  6 , and another end that is pivotally connected to the chair back unit  3 . Specifically, each of the linking rod units  7  includes a linking rod  71  that has a top end pivotally connected to the hinge seat  61 , and a bottom end pivotally connected to the upper sleeve  312  of a respective one of the back rod sets  31 . 
     It is noted that the pivot connections between each linking rod  71  and the upper sleeve  312  of the respective one of the back rod sets  31  may be implemented in different ways, and specific ways of implementing the pivot connections therebetween are not limited to the disclosure. For example, as shown in  FIG.  6   , in the left side of the foldable chair (viewed from the rear side), the corresponding linking rod  71 , the corresponding back leg  32 , and the corresponding upper sleeve  312  are sequentially arranged from rear to front, and are interconnected via a pivot pin  721  extending therethrough. Alternatively, in the right side of the foldable chair, the corresponding linking rod  71 , the corresponding upper sleeve  312 , and the corresponding back leg  32  are exemplified to be sequentially arranged from rear to front, and are interconnected via another pivot pin  721  extending therethrough, with a pad  722  sandwiched between the corresponding linking rod  71  and the corresponding upper sleeve  312 . 
     The chair cover unit  8  includes a seat cover  81  and a backrest cover  82 . The seat cover  81  has left and right front ends that are respectively secured to the upper pivot seats  44  of the side leg units  4 , and left and right rear ends that are respectively disposed above the upper sleeves  312  of the back rod sets  31  and that are respectively and slidably sleeved on the back rods  311  of the back rod sets  31 . The backrest cover  82  is integrally connected to the seat cover  81  and is connected to the back rods  311  of the back rod sets  31 . 
     The foldable chair of the disclosure is operable to change between a stretched state (see  FIGS.  7  and  8   ) and a folded state (see  FIGS.  9  and  10   ). 
     As shown in  FIGS.  6  to  8   , in the stretched state, the hinge seat  61  and the connecting rods  62  extend in a line in the left-right direction between the back rods  311  of the back rod sets  31 ; the linking rods  71  of the linking rod units  7  are inclined relative to the top-bottom direction; each pair of the back legs  32 , the first and second scissor legs  41 ,  42 , and the front legs  51  are orthogonally and respectively crossed; and each of the upper sleeves  312  is approximately located at a midpoint of the corresponding back rod  311 . 
     To operate the foldable chair from the stretched state to the folded state, a user may pull the hinge seat  61  downwardly to move the back rods  311  of the back rod sets  31  toward each other and to fold the back legs  32 . 
     Referring to  FIGS.  9  and  10   , in the folded state, the hinge seat  61  and the connecting rods  62  cooperate with each other to form an inverted U-shaped structure; the linking rods  71  of the linking rod units  7  extend in the top-bottom direction and are parallel to each other; each pair of the back legs  32 , the first and second scissor legs  41 ,  42 , and the front legs  51  are respectively crossed with an angle between upper portions thereof being at an acute angle less than 30°; and each of the upper sleeves  312  is located between the midpoint and a top end of the corresponding back rod  311 . 
     According to the foldable chair of the disclosure, by virtue of the cooperation among the foldable rod unit  6 , the linking rod units  7 , and the chair back unit  3 , the user can easily and smoothly operate the foldable chair to change between the stretched state and the folded state. 
       FIGS.  11  and  12    illustrate a foldable chair according to a second embodiment of the disclosure, which has a structure generally similar to that of the first embodiment. However, in this embodiment, the intermediate portion  623  of each connecting rod  62  is pivotally connected to the back rod  311  of a respective one of the back rod sets  31 , such that the second end portion  622  of each connecting rod  62  protrudes outwardly from the back rod  311  of the respective back rod set  31 . The linking rods  71  of the linking rod units  7  are not directly connected to the connecting rods  62 . Specifically, in this embodiment, each of the linking rod units  7  further includes a connecting member  73  having a top end that serves as the top end of the linking rod unit  7 , and that is pivotally connected to the second end portion  622  of the corresponding connecting rod  62 . The linking rod  71  of the linking rod unit  7  is connected pivotally to a bottom end of the connecting member  71 , and has a bottom end serving as the bottom end of the linking rod unit  7 . The linking rod  71  has a length that is longer than that of the connecting member  73 . 
     As shown in  FIG.  11   , in the stretched state, the hinge seat  61  and the connecting rods  62  extend in a line in the left-right direction; and the linking rod  71  and the connecting member  73  of each linking rod unit  7  extend in the same direction that it is inclined relative to the top-bottom direction. 
     To operate the foldable chair from the stretched state to the folded state, the user may pull the hinge seat  61  downwardly to move the back rods  311  of the back rod sets  31  toward each other and to fold the back legs  32 . 
     Referring to  FIG.  12   , in the folded state, the hinge seat  61  and the connecting rod  62  cooperate with each other to form a substantially V-shaped structure; the linking rods  71  of the linking rod units  7  are inclined relative to the top-bottom direction; and the connecting members  73  of the linking rod units  7  are also inclined relative to the top-bottom direction, but the inclinations are different between the linking rods  71  and the connecting members  73 . 
       FIG.  13    illustrate a foldable chair according to a third embodiment of the disclosure, which has a structure generally similar to that of the first embodiment. However, in this embodiment, the foldable chair includes only one linking rod unit  7 . Because the foldable chair includes only one linking rod unit  7 , the foldable chair of this embodiment can be made more lightweight and economical compared to the foldable chair of the first embodiment. 
     In the description above, for the purposes of explanation, numerous specific details have been set forth in order to provide a thorough understanding of the embodiments. It will be apparent, however, to one skilled in the art, that one or more other embodiments may be practiced without some of these specific details. It should also be appreciated that reference throughout this specification to “one embodiment,” “an embodiment,” an embodiment with an indication of an ordinal number and so forth means that a particular feature, structure, or characteristic may be included in the practice of the disclosure. It should be further appreciated that in the description, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of various inventive aspects, and that one or more features or specific details from one embodiment may be practiced together with one or more features or specific details from another embodiment, where appropriate, in the practice of the disclosure. 
     While the disclosure has been described in connection with what are considered the exemplary embodiments, it is understood that this disclosure 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.