Abstract:
A folding chair is disclosed. The chair includes a plurality of legs, including front and back legs, a seat, and a folding unit. The folding unit is attached to the legs and the seat, and it is configured to fold the legs using a force applied to at least one of the legs. The front legs nest beside the back legs.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority under 35 U.S.C. § 119(e) to provisional U.S. Patent Application No. 60/890,812 filed on Feb. 20, 2007, the disclosure of which is expressly incorporated by reference herein in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The invention is directed to foldable furniture, and more particularly to a foldable chair having a unique folding frame structure with a push handle. 
         [0004]    2. Related Art 
         [0005]    Various folding chairs are and have been commercially available. A foldable chair or the like is intended to reduce space when arranged in a storage position. However, as discussed below, most prior art folding chairs suffer from one or more drawbacks such as being bulky, trouble-prone, unreliable in use, visually unattractive and in particular suffer from difficult to operate mechanisms and less rigid construction. 
         [0006]    U.S. Pat. No. 1,981,387 by J. Kovats discloses a folding chair construction, in which the back, legs and seat member can be easily and quickly folded together into a minimum space, and in which the back and leg members can be folded and unfolded at the same time and in a single operation. Also, in the U.S. Pat. No. 1,981,387 patent, the back member and the legs are locked in the upright or unfolded position by locking means, such as a locking plate having a notch configured to engage a pin attached to the back leg. A wire connection is coupled between the locking plate and a slidably mounted bar located at the front of the seat member. By pushing the pressing bar, the locking plate is disengaged from the pin and the back member and legs are unlocked. 
         [0007]    U.S. Pat. No. 2,225,306 by J. Kovats discloses a simplified folding chair structure, in which the back rest and legs are interconnected by a pair of link members on both sides of the chair, respectively. Each link member is connected to the front leg, the rear leg and the back rest so that they all move together in opening and closing operations of the chair. A releasable latch member is provided to prevent accidental collapse of the chair and securely hold the chair when the chair is unfolded. The latch member is operated by a spring member, which is pulled down when it is desired to fold the chair. 
         [0008]    U.S. Pat. No. 1,946,082 by J. Kovats discloses a folding chair wherein the back of the chair may be collapsed against one side of the chair seat while one pair of chair legs are collapsed against the other side of the chair seat member and the other pair of chair legs are swung to a position in or approximately in the plane of the seat member. Further shown therein is a single frame structure for a seat member having a front portions and side portions. 
         [0009]    U.S. Pat. No. 2,224,399 by J. Kovats discloses locking means that securely locks the actuating mechanism for a folding chair in an extended position. The locking means includes a latch configured to automatically engage keeper means mounted on the underside of the seat member when the chair is moved to the extended position. 
         [0010]    Each of the prior art chairs suffer from at least difficult to operate mechanisms and less rigid construction. Accordingly, there is a need for an improved folding chair. 
       SUMMARY OF THE INVENTION 
       [0011]    The invention meets the foregoing need and other advantages apparent from the discussion herein. Accordingly, in one aspect of the invention, a folding chair has legs, a mechanical unit attached to the legs and configured to selectively prevent the legs from being folded, and a seat covering the mechanical unit. The mechanical unit may include a folding unit for folding legs using a force applied to at least one of the legs, and a handle mechanically engaged to the folding unit to allow the legs to be folded upon being activated. 
         [0012]    Accordingly, in one aspect of the invention, a folding chair includes a plurality of legs, including a front leg and a back leg, a seat, and a folding unit. The folding unit is attached to the legs and the seat, and it is configured to fold the legs using a force applied to at least one of the legs. In addition, the front legs nest beside the back legs. 
         [0013]    The folding chair may include a back support, which may also be folded by the folding unit. The folding unit may include a locking mechanism that prevents the legs from being folded when the locking mechanism is engaged. The locking mechanism may include a hook and a pin that engage each other when the chair is unfolded. The locking mechanism may include either a push bar or a handle to disengage the mechanism so that the legs may be folded. 
         [0014]    According to another aspect of the invention, a folding chair includes a plurality of legs, including a front leg and a back leg, a seat, and a mechanical unit. The mechanical unit is attached to the legs and the seat, and it is configured to fold the legs using a force applied to at least one of the legs. In addition, the front legs nest beside the back legs. 
         [0015]    The folding chair may include a back support, which may also be folded by the mechanical unit. The mechanical unit may include a locking mechanism that prevents the legs from being folded when the locking mechanism is engaged. The locking mechanism may include a hook and a pin that engage each other when the chair is unfolded. The locking mechanism may include either a push bar or a handle to disengage the mechanism so that the legs may be folded. 
         [0016]    In yet another aspect of the invention, a mechanical unit for folding a chair includes a frame, a hinge, at least one leg connected to the frame by the hinge, a first link connected to the frame, a swing link connected to the first link and the frame, and a second link connected to the swing link. Movement of the second link causes the leg to rotate relative to the hinge as a result of movement of the swing link and the first link. 
         [0017]    The mechanical unit may include a first bracket connected to the frame and a second bracket connected to both the second link and a second leg. A force applied to the second leg moves the second link, causing the first leg to rotate, and rotates the second leg. The mechanical unit may include a third bracket connected to both the first and second brackets, as well as a back support. When the force is applied to the second leg, it also rotates the third bracket and the back support. The mechanical unit may include a locking mechanism that prevents the legs from being folded when the locking mechanism is locked. The locking mechanism may include either a push bar or a handle that disengages the locking mechanism so that the chair can be folded. A folding chair may be constructed with the mechanical unit. 
         [0018]    Additional features, advantages, and embodiments of the invention may be set forth or apparent from consideration of the following detailed description, drawings, and claims. Moreover, it is to be understood that both the foregoing summary of the invention and the following detailed description are exemplary and intended to provide further explanation without limiting the scope of the invention as claimed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The accompanying drawings, which are included to provide a further understanding of the invention, are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the detailed description serve to explain the principles of the invention. No attempt is made to show structural details of the invention in more detail than may be necessary for a fundamental understanding of the invention and the various ways in which it may be practiced. In the drawings: 
           [0020]      FIG. 1  shows a perspective view of a folding chair constructed according to the principles of the invention; 
           [0021]      FIG. 2  shows a side view of the folding chair of  FIG. 1  in a folded position; 
           [0022]      FIG. 3  shows a bottom view of the folding chair of  FIG. 1  in a folded position; 
           [0023]      FIG. 4  shows a perspective view of a frame structure of the folding chair of  FIG. 1 ; 
           [0024]      FIG. 5  shows an exploded perspective view of the frame structure of  FIG. 4 ; 
           [0025]      FIG. 6  shows a side view of the frame structure of  FIG. 5  in an unfolded position; 
           [0026]      FIG. 7  shows the frame structure of the frame structure of  FIG. 6  in a folded position; 
           [0027]      FIG. 8  shows another perspective partial view of the frame structure of  FIG. 4 ; 
           [0028]      FIG. 9  shows another exploded partial perspective view of the frame structure of  FIG. 8 ; 
           [0029]      FIG. 10  shows another perspective view of the frame structure of  FIG. 4  with an unlocking unit; and 
           [0030]      FIG. 11  shows a perspective side/bottom view of the frame structure of  FIG. 10  with a push handle. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0031]    The embodiments of the invention and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments and examples that are described and/or illustrated in the accompanying drawings and detailed in the following description. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale, and features of one embodiment may be employed with other embodiments as the skilled artisan would recognize, even if not explicitly stated herein. Descriptions of well-known components and processing techniques may be omitted so as to not unnecessarily obscure the embodiments of the invention. The examples used herein are intended merely to facilitate an understanding of ways in which the invention may be practiced and to further enable those of skill in the art to practice the embodiments of the invention. Accordingly, the examples and embodiments herein should not be construed as limiting the scope of the invention, which is defined solely by the appended claims and applicable law. Moreover, it is noted that like reference numerals represent similar parts throughout the several views of the drawings. 
         [0032]      FIG. 1  shows a perspective view of a folding chair  10  constructed according to the principles of the invention. The folding chair  10  includes a seat  12 , legs, such as front legs  14  and rear legs  16 , and a back support, such as vertical bars  20  and a panel  22 . The folding chair  10  further includes a novel more rigid construction as shown in the figures and described below. Additionally, the folding chair  10  includes an improved novel mechanism to initiate folding as shown in the figures and described below. 
         [0033]    The folding chair  10  may include other components such as links  18  bridging the rear legs  16  or the like.  FIG. 2  shows a side view of the folding chair  10  in a folded position, and  FIG. 3  shows a bottom view of the folding chair  10  in the folded position. As shown in  FIG. 3 , a distance between the rear legs  16  may be less than a distance between the front legs  14  such that the rear legs  16  are arranged between the front legs  14  when the folding chair  10  is folded. 
         [0034]    A mechanical unit  24  may be arranged at a bottom side of the seat  12  to establish folding and locking of the various chair parts. The mechanical unit  24  may be configured to be substantially covered by the seat  12  although certain parts may not be covered to provide structural rigidness. A push handle  25  may be provided at the bottom side of the seat  12  to unlock the folding mechanism of the folding chair  10  to achieve the unfolded position, which will be explained below in detail. 
         [0035]      FIG. 4  shows a perspective view of the mechanical unit  24 , and  FIG. 5  shows an exploded view of the mechanical unit  24 . As shown therein, the mechanical unit  24  may be divided into two parts: a frame  26  and linkage  28  attached to the frame  26 . Although  FIGS. 4 and 5  show only one linkage  28  provided on one side of the frame  26 , as would have been obvious to one of ordinary skill in the art, another linkage may be provided on the opposite side of the frame  26  for the purpose of this invention as shown in  FIG. 4 . 
         [0036]      FIG. 6  shows a side view of the linkage  28  when the folding chair  10  is in the unfolded position. As shown in  FIG. 6 , the linkage  28  may be an assembly of various parts to establish the folding mechanism. The front leg  14  is pivotally attached to the frame  26  by a hinge  30 . A swing link  34  is coupled between the leg  14 , link  36 , and a link  38 . Specifically speaking, one end of the swing link  34  is pivotally connected to the leg  14 , and the other end is pivotally connected to the link  38 . Similarly, the link  36  is provided between the swing link  34  and frame  26 , and both ends may be pivotally connected to the swing link  34  and frame  26 , respectively. The link  38 , pivotally connected to the swing link  34  at its one end, may also be pivotally connected to a bracket  44  at the other end. The bracket  44  is pivotally connected to a bracket  42  at a pivot  41 . The rear leg  16  is attached to the bracket  44 , and the vertical bar  20  may be connected to the bracket  42 . The bracket  42  may also be pivotally connected to a bracket  40  at a pivot  43 . The bracket  40  is connected to the frame  26 . A link  46  is pivotally coupled to the bracket  44  and the bracket  40 . As shown in  FIG. 6 , when the folding chair  10  is in the unfolded position, the swing link  34  and link  42  may be visible but other components of the frame  26  and linkage  28  may not be visible. 
         [0037]      FIG. 7  shows a side view of the linkage  28  when the folding chair  10  is in the folded position. Upon folding the rear leg  16 , the bracket  44  is rotated counter-clock wise with respect to the pivot  41 . Since the link  46  maintains the same distance between the bracket  40  and bracket  44 , the pivot  41  is pushed in the direction of arrow A. This results in pulling the link  38  and swing link  34  in the direction of arrow B while the link  36  enables the link  38  and swing link  34  to pull the legs  12  under the bottom surface of the seat  12 . Thus, a force applied to fold the rear leg  16  is transferred to the hinge  30 , resulting in folding the front legs  16 ,  16 . Also, since the bracket  42  is pivotally connected to the bracket  40 , the bracket  42  rotates clockwise with respect to the pivot  41  when the rear leg  16  is folded and the pivot  41  is moved in the direction of arrow A. Thus, the force applied to fold the rear leg  16  is transferred to turn the bracket  42 , resulting in folding the vertical bar  20 . 
         [0038]      FIG. 8  shows a perspective view of the frame  26  and the brackets  40  and hinges  30  attached to the frame  26 .  FIG. 9  shows an exploded perspective view of the structure shown in  FIG. 8 . As shown therein, the frame  26  may be formed by assembling side panels  48 , a front panel  66 , and a rear panel  67 . The panels  48 ,  66 ,  67  may be formed of metal or any other material that has sufficient structural rigidity. The panels  48 ,  66 ,  67  may also have a stamped construction. 
         [0039]      FIG. 10  shows a locking/unlocking mechanism that may be added to the folding chair  10  constructed according to the principles of the invention. The folding chair  10  may be further equipped with a post  52  formed on the bracket  44  and a hook  53  pivoted on the bracket  40 . The hook  53  may be operatively connected to a rod  54  extending to a push bar  56 . The push bar  56  may be pivotally connected to the frame  26  with a pivot  58 . A spring or the like may be coupled between the push bar  56  and the front panel  66  to maintain engagement between the post  52  and hook  53 . The post  52  and hook  53  are configured such that they are automatically locked to each other when the folding chair  10  is fully unfolded. Also, once the post  52  and hook  53  are locked to each other, they may stay locked and the folding chair  10  may not be folded until the push bar  56  is pushed and the hook  53  is unlocked from the post  52 . As shown in  FIG. 11 , a push handle  25  may be provided to provide a better grip on operating surface for users. The push handle  25  may be provided to cover or actuate the push bar  56  or may replace the push bar  56 . This makes unlocking the chair (to fold) easier. 
         [0040]    While the invention has been described in terms of exemplary embodiments, those skilled in the art will recognize that the invention can be practiced with modifications in the spirit and scope of the appended claims. These examples given above are merely illustrative and are not meant to be an exhaustive list of all possible designs, embodiments, applications or modifications of the invention.