Abstract:
A folding chair having a reversible seat wherein the two faces of the seat are preferably made of different materials. At the inner side of each long leg of the chair there is a a sliding groove to facilitate up and down sliding movement of the chair seat during the process of changing the chair seat and the chair back. A leaf spring is provided in the chair back for adjusting it an appropriate angle to fit the user wherein the chair back is automatically restored to its original position upon removal of pressure thereon.

Description:
THE BACKGROUND OF THE INVENTION 
     All conventional folding chairs are of one-direction folding and unfolding type having only one seat surface which can be made of rattan, wood, foam rubber, or sponge, etc. Since the two former materials exhibit better ventilation qualities, they are preferred for making chair seats for summer time use. Since the latter two materials exhibit warming qualities, they are preferred for making chair seats for winter time use. Once a conventional folding chair is manufactured, its use is fixed for either summer time use or winter time use. In other words, its use is limited and is unable to meet the requirements in an area having different seasonal modes. 
     BRIEF SUMMARY OF THE INVENTION 
     In view of the facts mentioned above, the inventor has developed the present invention, a folding chair having a seat made of two different materials. The chair seat and back are reversible to expose the material desired by the user by folding the chair seat along a sliding groove defined along the inner side of the two long legs of the chair. Further, on the chair back, a leaf spring is provided so as to adjust the chair back at an appropriate and comfortable angle for user, the chair back being restored to its original position automatically upon pressure thereagainst being removed. The main object of this invention is to provide a folding chair with a reversible seat having two chair seat surfaces made of different materials so as to meet the requirements of both summer time and winter time use. A further object of this invention is to provide a folding chair which can be folded up into a flat and small form to facilitate handling and storage. 
     A still further object of this invention is to provide a folding chair wherein the chair back can be automatically adjusted at an appropriate and comfortable angle for the user. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Reference will be hereinafter made to the drawings wherein: 
     FIG. 1 is a perspective view of the present invention; 
     FIG. 2 shows the gradual steps utilized to reverse the chair seat and back; 
     FIG. 3 is a perspective view showing the structure of the chair seat, wherein both seat faces are made of wood; 
     FIG. 4 is another embodiment of this invention wherein the long and short legs are made of metal pipe; 
     FIG. 5 shows an embodiment of the sleeve ring according to this invention being fitted to the long leg; 
     FIG. 6 shows an embodiment of the clamping sleeve of this invention being fitted to the long leg; 
     FIG. 7 shows an embodiment of a rotary sleeve ring of this invention fitted to the long leg; and 
     FIG. 8 shows an embodiment of the leaf spring fitted to the chair back of this invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As shown in FIG. 1, the lower section of the two long legs (1) (1&#39;) form the front face of the chair while the upper section of legs (1) (1&#39;) is used for fixing the chair back (2). 
     Short legs (3) (3&#39;) are connected inside the long legs (1) (1&#39;) at each side thereon, both the long legs and the short legs being mounted on an axle rod (4) for pivotal movement thereabout. The lower section of the two short legs (3) (3&#39;) form the rear feet of the chair. A cross bar (5) is located between the two rear feet. The upper end of the two short legs are mounted to the left and right foot edge of chair seat (6) by projected bar (61) so as to establish a loose joint to permit pivotal movement between the short legs (3) (3&#39;) and chair seat (6). A long sliding groove (11) is defined along the inner side of said two long legs (1) (1&#39;) and in which is fitted the projected stud (62) attached to the left and right rear sides of chair seat (6) to permit reciprocal sliding movement of stud (62) in groove (11). 
     In the upper section of the short legs (3) (3&#39;), there are provided moveable clamping pieces (31) attached near the axle rod (4). The two faces of the chair seat (6) and chair back (2) may be constructed of different materials in different colors; in other words, if one face of the chair seat and back is constructed of rattan or wood which has a better ventilation quality for summer time use, the other side of the chair seat and back should be made of sponge or foam rubber which has a better warming quality for winter time use. Of course, the chair seat (6) may also be constructed of same material on both faces as shown in FIG. 3. 
     FIG. 2 shows the gradual steps used when reversing the chair seat and back. The rear feet of the chair are used as the fulcrum in folding or unfolding the chair. When folding the chair, one pulls the rear edge (a) of chair seat (6) upwards to point (b). The front edge (a) of the chair seat can then be pivoted to its reverse direction at point (d) by pushing edge (c) through the separated long legs and by so doing to reverse the seat portions. Thereafter, one continues to pull the front edge (c) from point (d) to point (e). It should be noted that the chair back is simultaneously changed to another face which is of a similar material as the exposed chair seat. When pulling the rear edge of the chair seat (6) upwards, the projected stud (62) slides upwards in the sliding groove (11) on the long legs (1) (1&#39;) . When stud (62) is moved almost to the top end of groove (11), the seat reversing process for the chair is completed. Thereafter, by allowing the projected stud 62) to slide downwards to the bottom of groove 11, the chair seat (6) will be flatly disposed ready for use. 
     For storing purposes, one simply folds the long legs (1) and short legs (3) so that they are parallel, and the clamping piece (31) on the short legs is pivotably moved so as to retain both the long legs (1) and short legs (3) thereby preventing them from being unfolded. Thus, when the chair is not in use, it may be folded by aligning the long legs (1), (1&#39;) and the short legs (3), (3&#39;) in parallel. By moving the pivotable clamping piece (31) on the short legs (3), (3&#39;) at an angle of e.g. 90° as shown in FIG. 1, the long and short legs are retained in the parallel position. Before the long legs and the short legs can be set in a cross position, the pivotable clamping piece (31) is moved out of clamping engagement and aligned with the short legs, i.e., the only function of said moveable clamping piece is to retain the long legs (1), (1&#39;) and short legs (3), (3&#39;) in a folded position. 
     What has been mentioned above is considered to be merely a preferred embodiment, but not as a limitation of this invention. The long legs (1) and short legs (3) in the chair may also be constructed of metal pipe or other material as shown in FIG. 4. Moreover, the chair seat (6) of this invention may not be limited to a square shape but may also be round, semi-oval or other shapes. 
     Further, the long legs (1) of the chair may not be furnished with sliding grooves (11) and instead, its functions could be provided by a sleeve ring (7) as shown in FIG. 5, which is particularly well suited for a chair with metal pipe legs. In addition, the sleeve ring (7) may include a projected lug (71) toward one side of the chair seat, which is designed to be inserted into a mortise-like hole on the side of chair seat on a loose joint basis. In order to minimize the friction between projected lug (71) and the mortise-like hole, the hole is preferably fitted with a bush (63). 
     At a suitable point along the long legs (1), there can be provided a flange (12) which is used for stopping the sleeve ring (7) when it reaches the lowest limit during sliding, e.g., when the chair seat is flatly disposed ready for use. 
     Moreover, the aforesaid means may be replaced with a clamping sleeve (8) as shown in FIG. 6, which is preferred for long legs which are round, square, or other multi-angle shapes, etc. 
     In this invention, when the long leg (1) is a round shape, the sliding groove as a guide way on the long legs (1) for reversing the chair seat does not need to be utilized. Instead, a round channel around a suitable section on the long legs can be furnished so as to fit the rotary sleeve ring (10) in the round channel. On the sleeve ring (10), a supporting lug (101) is furnished for supporting the bottom of the chair seat (6) when the sleeve ring (10) on the long legs (1) is rotated to the right position. 
     When reversing the chair seat face, the sleeve ring (10) is first rotated so as to turn supporting lug (101) away from said chair seat (6) bottom, and then the chair seat (6) can be turned over. The chair is then ready for use. 
     The chair back (2) of this invention may be designed in such a way that it is flexible so as to fit the user at a self-adjusted angle. As shown in FIG. 8, the chair back (2) is attached to the cross bar (21) with spring (9). At the upper side section of chair back (2), a stud (22) is furnished. Also, at the lower side of chair back (2), a U-shaped retainer (23) is furnished in operative association with stud (14). At corresponding points on the long legs (1) (1&#39;), a hole (13) is provided for mating with stud (22) and stud (23), respectively. When the user sits upon the chair and against the chair back, back (2) will be urged backwards to a desired angle as a result of spring (9) until the stud (14) is stopped by the U-shaped retainer (23). As soon as the person removes pressure against the chair back (2), it will be restored to its original position automatically as a result of the biasing effect of spring (9).