Patent Publication Number: US-10321767-B2

Title: Supports, folding mechanisms and foldable supporting frames

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of Chinese Application No. 201520117011.8, filed Feb. 27, 2015, Chinese Application No. 201520117012.2, filed Feb. 27, 2015, Chinese Application No. 201520117014.1, filed Feb. 27, 2015, Chinese Application No. 201520117015.6, filed Feb. 27, 2015, and Chinese Application No. 201520117037.2, filed Feb. 27, 2015. 
     1. FIELD OF THE INVENTION 
     The present invention generally relates to supports, folding mechanisms and foldable supporting frames having the supports and folding mechanisms. More particularly, the present invention relates to supports, folding mechanisms and foldable supporting frames for supporting mattresses, cushions, box springs or the like. 
     2. BACKGROUND 
     Currently, mattresses, cushions, box springs or the like are arranged in two ways. One is for relatively shorter people such as Asians and the other is for relatively taller people such as Americans and Europeans. 
     In the first way, mattresses, cushions, or box springs are placed directly on bed frames. To hold and stabilize mattresses, cushions, or box springs, most of bed frames include crossbars. For comfort and luxury, bed frames are usually made of woods and in different colors. To ensure stability and maintain aesthetic appearance, these bed frames are not foldable. As bed frames are usually large, for example, typical standard sizes including 1.8 m by 1.8 m and 2.0 m by 2.0 m, packaging, moving and shipping such bed frames create a challenge. 
     In the second way, supporting frames are added to bed frames to increase the heights of beds. Supporting frames are placed on bed frames and mattresses, cushions, or box springs are then placed on the supporting frames. In such cases, there is no need to modify bed frames to accommodate relatively taller people or personal preferences. However, most of current supporting frames are not foldable and thus it is difficult to package, move and transport such supporting frames. Although some of current supporting frames are foldable, they generally have complex structures and irregular shapes when folded. Thus, it is difficult to use, package, move and transport these foldable supporting frames. 
     Given the above background, there is a need in the art for support frames and related components that are relatively simple, stable, easier to use, and configured for convenient packaging, shipping and transportation. 
     The information disclosed in this Background section is provided for an understanding of the general background of the invention and is not an acknowledgement or suggestion that this information forms part of the prior art already known to a person skilled in the art. 
     3. SUMMARY 
     Various aspects of the present invention provide supports, folding mechanisms and foldable supporting frames that are relatively simple, stable, and easier to use, package, move and transport. 
     In one aspect, the present invention provides a foldable supporting frame including a plurality of bent bars, a plurality of supports and a plurality of folding mechanisms. The plurality of bent bars includes first and second bent bars to form an upper frame, and third and fourth bent bars to form a lower frame. Each of the first, second, third and fourth bent bars include first and second free ends. Each support includes a supporting piece having an upper part pivotally connected to the upper frame and a lower part pivotally connected to the lower frame. The plurality of folding mechanisms includes first and second folding mechanisms. Each of the first and second folding mechanisms includes a first link having a left upper part pivotally connected to the first or second free end of the first bent bar, and having a right upper part pivotally connected to the first or second free end of the second bent bar. Each of the first and second folding mechanisms further includes one or more of the following: (i) a second link having a lower part coupled to the first or second free end of the third bent bar, and a third link having a lower part coupled to the first or second free end of the fourth bent bar, wherein the second and third links are pivotally connected to each other at upper parts thereof; and (ii) a fourth link having one end pivotally connected to a lower part of the first link and the other end pivotally connected to an adjacent support. 
     In another aspect, the present invention provides a foldable supporting frame including a plurality of bent bars, a plurality of folding mechanisms and a plurality of supports. The plurality of bent bars includes first and second bent bars to form an upper frame, and third and fourth bent bars to form a lower frame. Each of the first, second, third and fourth bent bars include first and second free ends. The plurality of folding mechanisms includes first and second folding mechanisms. The first folding mechanism pivotally connects the first free end of the first bend bar with the first free end of the second bent bar, and the second mechanism pivotally connects the second free end of the first bent bar with the second free end of the second bent bar, thereby forming an upper frame of the foldable supporting frame. The first folding mechanism pivotally connects the first free end of the third bend bar with the first free end of the fourth bent bar, and the second mechanism pivotally connects the second free end of the third bent bar with the second free end of the fourth bent bar, thereby forming a lower frame of the foldable supporting frame. Each support includes a supporting piece and a restraining piece. The supporting piece has an upper part pivotally connected to the upper frame of the foldable supporting frame and a lower part pivotally connected to the lower frame of the foldable supporting frame. The restraining piece is extended from the supporting piece and bent at a predetermined angle with respect to the supporting piece. The restraining piece has an upper surface and a lower surface. When the foldable supporting frame is unfolded, the upper surface of the restraining piece is below the upper frame of the foldable supporting frame and in direct contact with a lower surface of the upper frame, thereby preventing further unfolding of the foldable supporting frame. 
     In yet another aspect, the present invention provides a support for supporting a foldable supporting frame having an upper frame and a lower frame. The support includes a supporting piece and a restraining piece. The supporting piece has an upper part configured to be pivotally connected to the upper frame of the foldable supporting frame and a lower part configured to be pivotally connected to the lower frame of the foldable supporting frame. The restraining piece is extended from the supporting piece and bent at a predetermined angle with respect to the supporting piece. The restraining piece has an upper surface and a lower surface. When the foldable supporting frame is unfolded, the upper surface of the restraining piece is below the upper frame of the foldable supporting frame, and in direct contact with a lower surface of the upper frame. As such, the support prevents the upper frame from further and undesired unfolding. 
     In still another aspect, the present invention provides a folding mechanism for connecting a plurality of bent bars to form a foldable supporting frame. The plurality of bent bars includes first, second, third and fourth bent bars, each having a free end. The folding mechanism includes a first link having a left upper part configured to be pivotally connected to the free end of the first bent bar, and having a right upper part configured to be pivotally connected to the free end of the second bent bar. The folding mechanism further includes one or more of the following: (i) a second link having a lower part configured to be coupled to the free end of the third bent bar, and a third link having a lower part configured to be coupled to the free end of the fourth bent bar, wherein the second and third links are pivotally connected to each other at upper parts thereof; and (ii) a fourth link having one end pivotally connected to a lower part of the first link and the other end pivotally connected to an adjacent support of the foldable supporting frame. 
     In one embodiment, the supporting piece and the restraining piece are substantially perpendicular to each other. 
     In some embodiments, one of the upper and lower parts of the supporting piece includes a substantially horizontally extended first pivotal portion. The first pivotal portion is configured to match with a side surface of one of the upper and lower frames and be pivotally connected to the one of the upper and lower frames. The other of the upper and lower parts of the supporting piece includes a substantially vertically extended second pivotal portion. The second pivotal portion is configured to match with a side surface of the other of the upper and lower frames and be pivotally connected to the other of the upper and lower frames. In an embodiment, the restraining piece, the first pivotal portion and the second pivotal portion are substantially perpendicular to each other. 
     In some embodiments, the support further includes a connecting piece having an upper part pivotally coupled to the lower part of the supporting piece and a lower part configured to be fixedly coupled to the lower frame of the foldable supporting frame. In an embodiment, the connecting piece is substantially perpendicular to the lower frame of the foldable supporting frame. In a preferred embodiment, the connecting piece is bent in between the upper part and the lower part of the connecting piece. 
     In one embodiment, the second link and the third link are positioned substantially symmetrically with respect to each other. 
     In some embodiments, the second link is bent between the upper part and a lower part such that the upper part forms a recessed step with respect to the lower part of the second link. The third link is bent between the upper part and a lower part such that the upper part forms a recessed step with respect to the lower part of the third link. The second link and the third links are pivotally connected to each other within the recessed steps. In an embodiment, bending edges of the second and third links are slanted with respect to a horizontal line when the foldable supporting frame is unfolded. 
     In one embodiment, the lower part of the second link is configured to be pivotally connected to the free end of the third bent bar, and the lower part of the third link is configured to be pivotally connected to the free end of the fourth bent bar. In another embodiment, the lower part of the second link is configured to be fixedly connected to the free end of the third bent bar, and the lower part of the third link is configured to be fixedly connected to the free end of the fourth bent bar. 
     In some embodiments, the lower part of the first link and upper parts of the second and third links are pivotally connected to each other. In a preferred embodiment, pivot points, at which the first link connects with the first bent bar, with the second bar and with the second and third links, are positioned triangularly. In another preferred embodiment, a pivot point at which the first link connects with the first bent bar and a pivot point at which the first link connects with the second bar are positioned substantially symmetrically with respect to a pivot point at which the first link connects with the second and third links. 
     In some embodiments, the first, second, third and fourth bent bars are substantially the same as each other. In some embodiments, each of the first, second, third and fourth bent bars include a lateral part and two longitudinal parts. Each longitudinal part is extended longitudinally from one end of the lateral part. The plurality of supports are disposed between a longitudinal part of the first bent bar and a corresponding longitudinal part of the third bent bar, and between a longitudinal part of the second bent bar and a corresponding longitudinal part of the fourth bent bar. In a preferred embodiment, the supports are disposed evenly within a pair of the longitudinal part of the first and third bent bars or within a pair of the longitudinal part of the second and fourth bent bars. 
     In some embodiments, the foldable supporting frame further includes a plurality of crossbars, each crossbar having two ends connected to longitudinal parts of one of the first, second, third and fourth bent bars. In some embodiments, when the foldable supporting frame is unfolded, the upper frame and lower frame are substantially flat and are substantially parallel to each other. 
     The systems of the present invention have other features and advantages that will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention. 
    
    
     
       4. BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated into and constitute a part of this specification, illustrate one or more embodiments of the present application and, together with the detailed description, serve to explain the principles and implementations of the application. 
         FIG. 1  is a schematic perspective view illustrating a foldable supporting frame in an unfolded state in accordance with some embodiments of the present invention. 
         FIG. 1A  is an enlarged view of circle C 1  in  FIG. 1  illustrating a first exemplary folding mechanism in accordance with some embodiments of the present invention. 
         FIG. 1B  is an enlarged view of circle C 2  in  FIG. 1  illustrating a first exemplary folding mechanism in accordance with some embodiments of the present invention. 
         FIG. 1C  is a perspective view illustrating a first exemplary support in accordance with some embodiments of the present invention. 
         FIG. 1D  is an enlarged view of circle C 3  in  FIG. 1  illustrating a first exemplary support in accordance with some embodiments of the present invention. 
         FIG. 1E  is an enlarged view of circle C 4  in  FIG. 1  illustrating a first exemplary support in accordance with some embodiments of the present invention. 
         FIG. 2  is a schematic perspective view illustrating a foldable supporting frame in a first folded state in accordance with some embodiments of the present invention. 
         FIG. 2A  is an enlarged view of circle D in  FIG. 2  illustrating a first exemplary folding mechanism in accordance with some embodiments of the present invention. 
         FIG. 3  is a schematic perspective view illustrating a foldable supporting frame in a second folded state in accordance with some embodiments of the present invention. 
         FIG. 3A  is an enlarged view of circle E in  FIG. 3  illustrating a first exemplary folding mechanism in accordance with some embodiments of the present invention. 
         FIG. 4  is a schematic perspective view illustrating a foldable supporting frame in a third folded state in accordance with some embodiments of the present invention. 
         FIG. 4A  is an enlarged view of circle F in  FIG. 4  illustrating a first exemplary folding mechanism in accordance with some embodiments of the present invention. 
         FIG. 5  is a schematic perspective view illustrating a foldable supporting frame in a fourth folded state in accordance with some embodiments of the present invention. 
         FIG. 5A  is an enlarged view of circle G in  FIG. 5  illustrating a first exemplary folding mechanism in accordance with some embodiments of the present invention. 
         FIG. 6  is a schematic perspective view illustrating a foldable supporting frame in an unfolded state in accordance with some embodiments of the present invention. 
         FIG. 6A  is an enlarged view of circle C 1 ′ in  FIG. 6  illustrating a second exemplary folding mechanism in accordance with some embodiments of the present invention. 
         FIG. 6B  is an enlarged view of circle C 2 ′ in  FIG. 6  illustrating a second exemplary folding mechanism in accordance with some embodiments of the present invention. 
         FIG. 6C  is a perspective view illustrating a second exemplary support in accordance with some embodiments of the present invention. 
         FIG. 6D  is an enlarged view of circle C 3 ′ in  FIG. 6  illustrating a second exemplary support in accordance with some embodiments of the present invention. 
         FIG. 6E  is an enlarged view of circle C 4 ′ in  FIG. 6  illustrating a second exemplary support in accordance with some embodiments of the present invention. 
         FIG. 7  is a schematic perspective view illustrating a foldable supporting frame in a first folded state in accordance with some embodiments of the present invention. 
         FIG. 7A  is an enlarged view of circle D′ in  FIG. 7  illustrating a second exemplary folding mechanism in accordance with some embodiments of the present invention. 
         FIG. 8  is a schematic perspective view illustrating a foldable supporting frame in a second folded state in accordance with some embodiments of the present invention. 
         FIG. 8A  is an enlarged view of circle E′ in  FIG. 8  illustrating a second exemplary folding mechanism in accordance with some embodiments of the present invention. 
         FIG. 9  is a schematic perspective view illustrating a foldable supporting frame in a third folded state in accordance with some embodiments of the present invention. 
         FIG. 9A  is an enlarged view of circle F′ in  FIG. 9  illustrating a second exemplary folding mechanism in accordance with some embodiments of the present invention. 
         FIG. 10  is a schematic perspective view illustrating a foldable supporting frame in a fourth folded state in accordance with some embodiments of the present invention. 
         FIG. 10A  is an enlarged view of circle G′ in  FIG. 10  illustrating a second exemplary folding mechanism in accordance with some embodiments of the present invention. 
         FIG. 11A  is a schematic top view illustrating a foldable supporting frame in an unfolded state in accordance with some embodiments of the present invention. 
         FIG. 11B  is a schematic bottom view illustrating a foldable supporting frame in an unfolded state in accordance with some embodiments of the present invention. 
     
    
    
     5. DETAILED DESCRIPTION 
     Reference will now be made in detail to implementations of the present application as illustrated in the accompanying drawings. The same reference indicators will be used throughout the drawings and the following detailed description to refer to the same or like parts. Those of ordinary skill in the art will realize that the following detailed description of the present application is illustrative only and is not intended to be in any way limiting. Other embodiments of the present application will readily suggest themselves to such skilled persons having benefit of this disclosure. 
     In the interest of clarity, not all of the routine features of the implementations described herein are shown and described. It will, of course, be appreciated that in the development of any such actual implementation, numerous implementation-specific decisions must be made in order to achieve the developer&#39;s specific goals, such as compliance with application- and business-related constraints, and that these specific goals will vary from one implementation to another and from one developer to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of engineering for those of ordinary skill in the art having the benefit of this disclosure. 
     Many modifications and variations of this disclosure can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. The specific embodiments described herein are offered by way of example only, and the disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. 
     Embodiments of the present invention are described in the context of supporting frames that support mattresses, cushions, box springs or the like. The supporting frames can be of various sizes including but not limited to twin, full, queen and king sizes, and of various shapes including but not limited to rectangles and squares. Also, the supporting frames can be made of various materials including but not limited to metals such as steel, plastics and woods. The supporting frames can be used alone or in conjunction with bed frames. For example, the supporting frames can be placed on bed frames, before placing support mattresses, cushions, box springs or the like on the supporting frames, to increase the heights of the beds to accommodate users&#39; different heights or preferences. 
     Generally, a supporting frame of the present invention includes a plurality of bent bars pivotally and selectively connected to each other by folding mechanisms to form an upper frame and a lower frame of the supporting frame. The supporting frame of the present invention also includes a plurality of supports disposed between the upper and lower frames and pivotally connected to the upper and lower frames. Because the bent bars are connected to each other through the folding mechanisms and/or the supports, the foldable supporting frame of the present invention can be folded or unfolded by rotating any one of the bent bars. As such, the supporting frames of the present invention are easier to fold and unfold, and convenient for handling, packaging, storing, shipping and transportation. By way of example,  FIGS. 1-5A  illustrate folding of the supporting frame by rotating first bent bar  1  along a direction indicated by arrow M in  FIG. 1 , and  FIGS. 6-10A  illustrate folding of the supporting frame by rotating first bent bar  1 ′ along a direction indicated by arrow M′ in FIG.  6 . It should be understood that the foldable supporting frame of the present can be folded or unfolded by rotating other bent bars such as second, third or fourth bent bar or more than one bent bar at the same time. 
     The present application discloses two types of exemplary folding mechanisms, i.e., first exemplary folding mechanism  6  illustrated in  FIGS. 1-5A  and second exemplary folding mechanism  6 ′ illustrated in  FIGS. 6-10A . The present application also discloses two types of exemplary supports, i.e., first exemplary supports  5  illustrated in  FIGS. 1-5A  and second exemplary supports  5 ′ illustrated in  FIGS. 6-10A . First exemplary folding mechanism  6  can be used along with either first exemplary supports  5  or second exemplary supports  5 ′ or combination of first exemplary supports  5  and second exemplary supports  5 ′. Similarly second exemplary folding mechanism  6 ′ can be used along with either first exemplary supports  5  or second exemplary supports  5 ′ or combination of first exemplary supports  5  and second exemplary supports  5 ′. Further, first exemplary folding mechanism  6  and second exemplary folding mechanism  6 ′ can be used in the same supporting frame. By way of example only,  FIGS. 1-5A  depict a foldable supporting frame including first exemplary folding mechanisms  6  and first exemplary supports  5 , and  FIGS. 6-10A  depict a foldable supporting frame including second exemplary folding mechanisms  6 ′ and second exemplary supports  5 ′. 
     Referring now to  FIGS. 1-5A , in some embodiments, a foldable supporting frame of the present invention includes a plurality of bent bars, such as first bent bar  1 , second bent bar  2 , third bent bar  3  and fourth bent bar  4 . The plurality of bent bars are selectively and pivotally connected to each other by a plurality of first exemplary folding mechanisms  6  to form an upper frame such as upper frame  1 - 2  and a lower frame such as lower frame  3 - 4 . In various embodiments, the foldable supporting frame also includes a plurality of first exemplary supports  5  disposed between the upper and lower frames and pivotally connected to the upper and lower frames. 
     In some embodiments, for the purposes of master production, assembling convenience, easy packaging or the like, first bent bar  1 , second bent bar  2 , third bent bar  3  and fourth bent bar  4  are made to be the same or substantially the same as each other. In such embodiments, when unfolded, the supporting frame is substantially symmetric with first bent bar  1  substantially symmetric to second bent bar  2  and third bent bar  3  substantially symmetric to fourth bent bar  4 . When folded, first bent bar  1  coincides with second bent bar  2  and third bent bar  3  coincides with fourth bent bar  4 , with first bent bar  1  and second bent bar  2  in the middle as illustrated in  FIG. 5 . As a result, the folded supporting frame is more compact and of a regular shape, making it easier to handle, package, store, and transport. In some embodiments, each of the first, second, third and fourth bent bars includes lateral part  100  and two longitudinal parts  200  each extended longitudinally from one end of lateral part  100 . 
     In the illustrated embodiments, the supporting frame includes two first exemplary folding mechanisms  6 , one shown in circle C 1  and the other in circle C 2 . Enlarged views of these folding mechanisms  6  are shown in  FIGS. 1A and 1B . In one embodiment, the two folding mechanisms are identical or substantially identical to each other. In another embodiment, the two folding mechanisms are reflection-symmetric or mirror-symmetric to each other. It should be understood that a supporting frame of the present invention can include more than two exemplary mechanisms and more than four bars (bent or straight) connected by the exemplary mechanisms. 
     In various embodiments, folding mechanism  6  includes one or more links pivotally connected to a bent bar or an adjacent support. For example, as shown in  FIGS. 1A and 1B , folding mechanism  6  includes first link  61 . First link  61  has left upper part  611  pivotally connected to free end  11  of first bent bar  1  and right upper part  612  pivotally connected to free end  21  of second bent bar  2 . The connected first and second bent bars collectively form upper frame  1 - 2  of the foldable supporting frame. 
     In some embodiments, folding mechanism  6  includes optional or additional links to connect third and fourth bent bars to form the lower frame of the supporting frame. For example,  FIGS. 1A and 1B  illustrate second link  63  and third link  64 , with the lower part of second link  63  pivotally connected to the free end of third bent bar  3  and the lower part of third link  64  pivotally connected to the free end of four bent bar  4 . The upper parts of second link  63  and third link  64  are pivotally connected to each other. The connected third and fourth bent bars thus collectively form lower frame  3 - 4  of the foldable supporting frame. In one embodiment, second link  63  and third link  64  are positioned substantially symmetrically with respect to each other. It should be understood that second link  63  and third link  64  are not necessary since third bent bar  3  are pivotally coupled to fourth bent bar  4  through supports  5  and first link  61 . 
     In some embodiments, folding mechanism  6  further includes fourth link  62  pivotally connected to first link  61  and adjacent support  5 . For example, in the illustrated embodiments, fourth link  62  has one end  621  pivotally connected to right lower part  613  of first link  61  and another end  622  pivotally connected to an adjacent support  5  positioned between second bent bar  2  and fourth bent bar  4 . In a preferred embodiment, right lower part  613  of first link  61  is extended (e.g., portion  61   b  illustrated in  FIG. 2A ) toward the adjacent support to which fourth link  62  is pivotally connected. It should be understood that first link  61  and fourth link  62  can be configured (e.g., flipping first link  61 ) such that fourth link  62  is pivotally connected to a left lower part of first link  61  and an adjacent support positioned between first bent bar  1  and third bent bar  3 . 
     In some embodiments, pivot points, at which first link  61  connects with first bent bar  1 , with second bar  2  and with an adjacent support, are positioned triangularly. Such positioning of the pivot points ensures the coordination among the bent bars and prevents sways and offsets of the bent bars, and thus improves the stability of folding and unfolding the supporting frame. In some embodiments, first link  61  is configured to have a substantially rectangular main body (e.g.,  61   a  in  FIG. 2A ) to further improve the stability of folding and unfolding the supporting frame. The rectangular shape of main body  61   a  also enhances the aesthetic appearance of the supporting frame when it is folded as illustrated in  FIG. 5A . 
     Continuously referring to  FIGS. 1-5A  and in particular to  FIGS. 1A, 2A, 3A, 4A and 5A , in some embodiments, second link  63  is bent between the upper part and the lower part, creating one bending structure  65  in which the upper part forms recessed step  66  with respect to the lower part of second link  63 . Similarly, third link  64  is bent between the upper part and the lower part, creating another bending structure  65  in which the upper part forms recessed step  66  with respect to the lower part of third link  64 . In such embodiments, second link  63  and third link  64  are pivotally connected to each other at pivot point  67  located within the recessed steps of second link  63  and third link  64 . The recessed steps of second link  63  and third link  64  are in surface contact with each other. The contacting surfaces of the recessed steps guide and restrain rotation of second link  63  and third link  64 , and thence guide and restrain rotation of the first, second, third and fourth bent bars. This reduces or eliminates sway, offset or any undesired movement of bent bars when folding or unfolding the supporting frame, and thus increases effectiveness, efficiency and accuracy of folding and unfolding the supporting frame. In addition, bending structures  65  enhance the strength and prolong the lifetime of second link  63  and third link  64 . 
     In a preferred embodiment, bending edges  651  of second link  63  and third link  64  are slanted with respect to a horizontal line or corresponding bent bars when the foldable supporting frame is unfolded. Second link  63  and third link  64  are positioned and pivotally connected in such a way that bending edges  651  assist in guiding rotation of second link  63  and third link  64 . This further increases folding/unfolding effectiveness, efficiency and accuracy of the supporting frame. 
     Continuously referring to  FIGS. 1-5A , the plurality of first exemplary supports  5  are disposed between the upper frame and the lower frame of the foldable supporting frame formed by the plurality of bent bars. In some embodiments, the plurality of supports are disposed between longitudinal part  200  of first bent bar  1  and corresponding longitudinal part  200  of third bent bar  3 , and between longitudinal part  200  of second bent bar  2  and corresponding longitudinal part  200  of fourth bent bar  4 , as illustrated in  FIGS. 2 and 3 . In some embodiments, the supports are disposed evenly within one pair of longitudinal parts (e.g., one longitudinal part  200  of first bent bar  1  and one corresponding longitudinal part  200  of third bent bar  3 ) along the longitudinal direction of the supporting frame. 
     Referring in particular to  FIGS. 1A-1E , in some embodiments, first exemplary support  5  includes supporting piece  51  and restraining piece  52  extended from the supporting piece and bent at a predetermined angle with respect to the supporting piece. In a preferred embodiment, supporting piece  51  and restraining piece  52  are perpendicular or substantially perpendicular to each other. Restraining piece  52  can be formed on either side (e.g., left and right sides) of supporting piece  51 . For example, support  5  on the left hand side of  FIG. 1B  has restraining piece  52  formed on the right side of supporting piece  51  and support  5  on the right hand side of  FIG. 1B  has restraining piece  52  formed on the left side of supporting piece  51 . Restraining piece  52  includes first surface  521  and second surface  522 . 
     Supporting piece  51  has first part  511  and second part  512 . In a preferred embodiment, first part  511  includes a substantially horizontally extended first pivotal portion such as first pivotal portion  5111  illustrated in  FIG. 1C . Second part  512  includes a substantially vertically extended second pivotal portion  5121 . In some embodiments, restraining piece  52 , first pivotal portion  5111  and second pivotal portion  5121  are perpendicular or substantially perpendicular to each other. 
     In some embodiments, first part  511  is configured such that it can be pivotally connected to either the upper frame or the lower frame of the supporting frame through first pivotal portion  5111 . For instance,  FIGS. 1C and 1B  illustrate first part  511  of support  5  pivotally connected to the upper frame, and  FIGS. 1D and 1E  illustrate first part  511  of support  5  pivotally connected to the lower frame. Similarly, in some embodiments, second part  512  is configured such that it can be pivotally connected to either the upper frame or the lower frame of the supporting frame through second pivotal portion  5121  as illustrated in  FIGS. 1A, 1B, 1D and 1E . In one embodiment, supports  5  are oriented such that first parts  511  of all supports are connected to the upper frame and corresponding second parts  512  are connected to the lower frame of a supporting frame. In another embodiment, supports  5  are oriented such that first parts  511  of all supports are connected to the lower frame and corresponding second parts  512  are connected to the upper frame of a supporting frame. In still another embodiment, at least one support  5  is oriented with first part  511  connected to the upper frame and corresponding second part  512  connected to the lower frame; and at least one support  5  is oriented with first part  511  connected to the lower frame and second part  512  connected to the upper frame. 
     In a preferred embodiment, first pivotal portion  5111  and second pivotal portion  5121  of supporting piece  51  are in surface contact with side surfaces of the upper and lower frames and pivotally connected to the upper and lower frames. For instance, in the embodiments illustrated in  FIGS. 1D-1E , first pivotal portion  5111  of supporting piece  51  is in surface contact with side surface  204  of lower frame  4  and pivotally connected to lower frame  4 . Second pivotal portion  5121  of supporting piece  51  is in surface contact with side surface  203  of upper frame  3  and pivotally connected to upper frame  3 . As such, first pivotal portion  5111  and second pivotal portion  5121  of supporting piece  51  guide and restrain rotation of the bent bars. This reduces or eliminates sway, offset or any undesired movement of bent bars when folding or unfolding the supporting frame, and thus increases effectiveness, efficiency and accuracy of folding and unfolding the supporting frame. 
     When the foldable supporting frame is unfolded (e.g., when in use), one of the surfaces of the restraining piece (e.g., first surface  521  or second surface  522  depending on the orientation of the support) is below the upper frame of the foldable supporting frame and in direct contact with the lower surface of the upper frame. For instance, in the embodiments illustrated in  FIGS. 1D-1E , second surface  522  of the restraining piece is below upper frame  2  of the foldable supporting frame and in direct contact with lower surface  201  of the upper frame. As such, the plurality of first exemplary supports  5  supports the upper frame and prevents the upper frame from any undesired movement (e.g., further unfolding, collapsing, swaying) when the supporting frame is unfolded (e.g., in use). 
     In some embodiments, when unfolded, one of the surfaces of the restraining piece (e.g., first surface  521  or second surface  522  depending on the orientation of the support) is above the lower frame of the foldable supporting frame and in direct contact with the upper surface of the lower frame. For instance, in the embodiments illustrated in  FIGS. 1D-1E , first surface  521  of the restraining piece is above lower frame  4  of the foldable supporting frame and in direct contact with upper surface  202  of the lower frame. As such, the plurality of first exemplary supports  5  helps to maintain the upper and lower frames to be substantially flat and substantially parallel to each other when the supporting frame is unfolded. 
     On the other hand, as illustrated in  FIG. 5 , when the supporting frame is folded (e.g., for packaging), the plurality of first exemplary supports  5  and first exemplary folding mechanisms allow each of the first, second, third and fourth bent bar to fold toward each other, with the first and second bent bars in the middle. In some embodiments, when folded, third bent bar  3  and fourth bent bar  4  are parallel or substantially parallel to each other. As a result, the folded supporting frame is more compact and better for packaging, storing, shipping and transportation. 
     Turning now to  FIGS. 6-10A , in some embodiments, a foldable supporting frame of the present invention includes a plurality of bent bars, such as first bent bar  1 ′, second bent bar  2 ′, third bent bar  3 ′ and fourth bent bar  4 ′. First bent bar  1 ′, second bent bar  2 ′, third bent bar  3 ′ and fourth bent bar  4 ′ are the same or similar to first bent bar  1 , second bent bar  2 , third bent bar  3  and fourth bent bar  4  illustrated in  FIGS. 1-5A . In some embodiments, first bent bar  1 ′, second bent bar  2 ′, third bent bar  3 ′ and fourth bent bar  4 ′ are made to be the same or substantially the same as each other. In some embodiments, each of the first, second, third and fourth bent bars includes lateral part  100 ′ and two longitudinal parts  200 ′ each extended longitudinally from one end of lateral part  100 ′. 
     Similar to the embodiments illustrated in  FIGS. 1-5A , the plurality of bent bars are selectively and pivotally connected to each other by a plurality of second exemplary folding mechanisms  6 ′ to form an upper frame such as upper frame  1 - 2 ′ and a lower frame such as lower frame  3 - 4 ′. In various embodiments, the foldable supporting frame also includes a plurality of second exemplary supports  5 ′ disposed between the upper and lower frames and pivotally connected to the upper and lower frames. 
     In the illustrated embodiments, the supporting frame includes two second exemplary folding mechanisms  6 ′, one shown in circle C 1 ′ and the other in circle C 2 ′. Enlarged views of these folding mechanisms  6 ′ are shown in  FIGS. 6A and 6B . In one embodiment, the two folding mechanisms are identical or substantially identical to each other. In another embodiment, the two folding mechanisms are reflection-symmetric or mirror-symmetric to each other. 
     In various embodiments, folding mechanism  6 ′ includes first link  61 ′ having left upper part  611 ′ pivotally connected to free end  11 ′ of first bent bar  1 ′ and right upper part  612 ′ pivotally connected to free end  21 ′ of second bent bar  2 ′. The connected first and second bent bars collectively form upper frame  1 - 2 ′ of the foldable supporting frame. In some embodiments, first link  61 ′ includes link body piece  61   a ′ with left upper part  611 ′ and right upper part  612 ′. 
     In some embodiments, folding mechanism  6 ′ further includes second link  63 ′ and third link  64 ′, with the lower part  631 ′ of second link  63 ′ fixedly connected to the free end of third bent bar  3 ′ and the lower part  641 ′ of third link  64 ′ fixedly connected to the free end of fourth bent bar  4 ′. Unlike first link  61  of first exemplary folding mechanism  6 , the lower part  613 ′ of first link  61 ′ is pivotally connected to the upper part  632 ′ of second link  63 ′ and the upper part  642 ′ of third link  64 ′. The connected third and fourth bent bars thus collectively form lower frame  3 - 4 ′ of the foldable supporting frame. In one embodiment, second link  63 ′ and third link  64 ′ are positioned substantially symmetrically with respect to each other. 
     In some embodiments, pivot points, at which first link  61 ′ connects with first bent bar  1 ′, with second bar  2 ′ and with second link  63 ′ and third link  64 ′, are positioned triangularly, forming a triangular structure  62 ′. Such positioning of the pivot points ensures the coordination among the bent bars and prevents sways, offsets or other undesired movements of the bent bars, and thus improves the stability of folding and unfolding the supporting frame. In some embodiments, a pivot point at which first link  61 ′ connects with first bent bar  1 ′ and a pivot point at which first link  61 ′ connects with second bar  2 ′ are positioned substantially symmetrically with respect to a pivot point at which first link  61 ′ with second link  63 ′ and third link  64 ′. 
     In some embodiments, second link  63 ′ is the same as or similar to second link  63  and third link  64 ′ is the same as or similar to third link  64  of first folding mechanism  6  disclosed herein and illustrated in  FIGS. 1-5A . For example, referring to  FIGS. 6A, 7A, 8A, 9A and 10A , in some embodiments, second link  63 ′ is bent between the upper part and the lower part, creating one bending structure  65 ′ in which the upper part forms recessed step  66 ′ with respect to the lower part of second link  63 ′. Similarly, third link  64  is bent between the upper part and the lower part, creating another bending structure  65 ′ in which the upper part forms recessed step  66 ′ with respect to the lower part of third link  64 ′. In such embodiments, second link  63 ′ and third link  64 ′ are pivotally connected to each other at pivot point  67 ′ located within the recessed steps of second link  63 ′ and third link  64 ′. The recessed steps of second link  63 ′ and third link  64 ′ are in surface contact with each other. The contacting surfaces of the recessed steps guide and restrain rotation of second link  63 ′ and third link  64 ′, and thence guide and restrain rotation of the first, second, third and fourth bent bars. This reduces or eliminates sway, offset or any undesired movement of bent bars when folding or unfolding the supporting frame, and thus increases effectiveness, efficiency and accuracy of folding and unfolding the supporting frame. In addition, bending structures  65 ′ enhance the strength and prolong the lifetime of second link  63 ′ and third link  64 ′. 
     Like second link  63  and third link  64  disclosed herein and illustrated in  FIGS. 1-5A , in a preferred embodiment, bending edges  651 ′ of second link  63 ′ and third link  64 ′ are slanted with respect to a horizontal line or corresponding bent bars when the foldable supporting frame is unfolded. Second link  63 ′ and third link  64 ′ are positioned and pivotally connected in such a way that bending edges  651 ′ assist in guiding rotation of second link  63 ′ and third link  64 ′. This further increases folding/unfolding effectiveness, efficiency and accuracy of the supporting frame. 
     Continuously referring to  FIGS. 6-10A , the plurality of second exemplary supports  5 ′ are disposed between the upper frame and the lower frame of the supporting frame formed by the plurality of bent bars. In some embodiments, the plurality of supports are disposed between longitudinal part  200 ′ of first bent bar  1 ′ and corresponding longitudinal part  200 ′ of third bent bar  3 ′, and between longitudinal part  200 ′ of second bent bar  2 ′ and corresponding longitudinal part  200 ′ of fourth bent bar  4 ′, as illustrated in  FIGS. 6 and 7 . In some embodiments, the supports are disposed evenly within one pair of longitudinal parts (e.g., one longitudinal part  200 ′ of first bent bar  1 ′ and one corresponding longitudinal part  200 ′ of third bent bar  3 ′) along the longitudinal direction of the supporting frame. 
     Referring in particular to  FIGS. 6C-6E , in some embodiments, second exemplary support  5 ′ includes supporting piece  51 ′ and restraining piece  52 ′ extended from the supporting piece and bent at a predetermined angle with respect to the supporting piece. In a preferred embodiment, supporting piece  51 ′ and restraining piece  52 ′ are perpendicular or substantially perpendicular to each other. Supporting piece  51 ′ has first part  511 ′ and second part  512 ′. Restraining piece  52 ′ includes first surface  521 ′ and second surface  522 ′. 
     In some embodiments, second exemplary support  5 ′ further includes a connecting piece such as connecting piece  7 ′ illustrated in  FIGS. 6D and 6E . Connecting piece  7 ′ has upper part  72 ′ and lower part  71 ′. In such embodiments, first part  511 ′ of supporting piece  51 ′ is pivotally connected to upper frame  1 - 2 ′ of the supporting frame, and second part  512 ′ of supporting piece  51 ′ is pivotally connected to upper part  72 ′ of connecting piece  7 ′. Lower part  71 ′ of connecting piece  7 ′ is fixedly coupled to lower frame  3 - 4 ′ of the supporting frame. In a preferred embodiment, connecting piece  7 ′ is substantially perpendicular to lower frame  3 - 4 ′ of the supporting frame. In an embodiment, lower frame  3 - 4 ′ of the supporting frame has upper surface  3 - 4 - 1 ′ and side surface  3 - 4 - 2 ′. In an embodiment, lower part  71 ′ of connecting piece  7 ′ is fixedly coupled to side surface  3 - 4 - 2 ′ of lower frame  3 - 4 ′ of the supporting frame. 
     In some embodiments, connecting piece  7 ′ is bent between upper part  72 ′ and lower part  71 ′, creating bending structure  73 ′. Bending structure  73 ′ makes it easier to fix lower part  71 ′ of connecting piece  7 ′ on the lower frame of the supporting frame, and enhances the strength and prolongs the lifetime of connecting piece  7 ′. 
     In a preferred embodiment, first part  511 ′ of supporting piece  51 ′ is extended and/or bent in accordance with the upper frame, e.g., toward side surface  1 - 2 - 2 ′ of upper frame  1 - 2 ′, to form first pivotal portion  5111 ′. First pivotal portion  5111 ′ of supporting piece  51 ′ and side surface  1 - 2 - 2 ′ of upper frame  1 - 2 ′ are in surface contact with and pivotally connected to each other. As such, first pivotal portion  5111 ′ of supporting piece  51 ′ guides and restrains rotation of the bent bars of upper frame  1 - 2 ′. This reduces or eliminates sway, offset or any undesired movement of bent bars when folding or unfolding the supporting frame, and thus increases effectiveness, efficiency and accuracy of folding and unfolding the supporting frame. 
     In a preferred embodiment, second part  512 ′ of supporting piece  51 ′ is extended and/or bent in accordance with upper part  72 ′ of connecting piece  7 ′, e.g., toward a side surface of upper part  72 ′ of connecting piece  7 ′, to form second pivotal portion  5121 ′. Second pivotal portion  5121 ′ of supporting piece  51 ′ and the side surface of upper part  72 ′ of connecting piece  7 ′ are in surface contact with and pivotally connected to each other. Since lower part  71 ′ of connecting piece  7 ′ is fixedly connected to the lower frame of the supporting frame, second pivotal portion  5121 ′ of supporting piece  51 ′ guides and restrains rotation of the bent bars of lower frame  3 - 4 ′. This further reduces or eliminates sway, offset or any undesired movement of bent bars when folding or unfolding the supporting frame, and thus increases effectiveness, efficiency and accuracy of folding and unfolding the supporting frame. 
     When the foldable supporting frame is unfolded (e.g., when in use), first surface  521 ′ of the restraining piece is below upper frame  1 - 2 ′ of the foldable supporting frame and in direct contact with lower surface  1 - 2 - 1 ′ of upper frame  1 - 2 ′. As such, the plurality of second exemplary supports  5 ′ supports the upper frame and prevents the upper frame from any undesired movement (e.g., further unfolding, collapsing, swaying) when the supporting frame is unfolded (e.g., in use). In some embodiments, the plurality of s 71 ′ cond exemplary support  5 ′ helps to maintain the upper frame and lower frame to be substantially flat and substantially parallel to each other when the supporting frame is unfolded. 
     On the other hand, as illustrated in  FIG. 10 , when the supporting frame is folded (e.g., for packaging), the plurality of second exemplary supports  5 ′ and second exemplary folding mechanisms  6 ′ allow each of the first, second, third and fourth bent bar to fold toward each other, with the first and second bent bars in the middle. In some embodiments, when folded, third bent bar  3 ′ and fourth bent bar  4 ′ are parallel or substantially parallel to each other. As a result, the folded supporting frame is more compact and better for packaging, storing, shipping and transportation. 
     In some embodiments, the foldable supporting frames include additional or optional components. For example, as illustrated in  FIGS. 11A and 11B , a foldable supporting frame includes a plurality of crossbars  8 , each having two ends. In a preferred embodiment, crossbar  8  is disposed laterally with the two ends connected to longitudinal parts  200  of a bent bar. 
     Supports, folding mechanisms and foldable supporting frames of the present invention have a number of advantages. For instance, the foldable supporting frames of the present invention can be used alone or in conjunction with bed frames to increase the heights of the beds to accommodate users&#39; different heights or personal preferences. A foldable frame of the present invention includes a plurality of bent bars pivotally connected to each other through folding mechanisms and/or supports. Accordingly, the foldable frame can be folded or unfolded by rotating any one of the bent bars, making it easier to handle and use. Moreover, rotation of the bent bars are guided and restrained by the folding mechanisms and/or supports, effectively reducing or eliminating sway, offset or any undesired movement of the bent bars and improving efficiency and accuracy of folding/unfolding the supporting frame. Further, when the supporting frame is unfolded or in use, the supports hold the upper frame and prevent it from further unfolding, collapsing, swaying or any undesired movement. In various cases, the supports hold the upper frame and maintain the upper and lower frames substantially flat and substantially parallel to each other. Accordingly, the foldable frame is stable and comfortable to use. In addition, when folded, the folding mechanisms and supports allow the bent bars to move toward each other and fold onto each other tightly. As a result, the folded supporting frame is more compact and of a regular shape, making it easier to handle, package, store, and transport. 
     The terminology used herein is for the purpose of describing particular implementations only and is not intended to be limiting of the claims. As used in the description of the implementations and the appended claims, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be understood that the terms “upper” or “lower”, “left” or “right”, “horizontal” or “vertical”, “lateral” or “longitudinal” and etc. are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures. It will be understood that, although the terms “first,” “second,” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first link could be termed a second link, and, similarly, a second link could be termed a first link, without changing the meaning of the description, so long as all occurrences of the “first link” are renamed consistently and all occurrences of the “second link” are renamed consistently.