Pivoting/locking mechanisms, multi-fold foldable frames and frame assemblies

Abstract

A foldable frame includes a front section, a rear section, a front support, a rear support, and a middle support. The front section includes a first front subsection and a second front subsection foldable relative to each other, and the rear section includes a first rear subsection and a second rear subsection foldable relative to each other. The front support is pivotally connected to the first front subsection, and the rear support is pivotally connected to the first rear subsection. The second front subsection and second rear subsection are pivotally connected to the middle support. When folded, the first front and rear subsections are disposed between the second front and rear subsections, with the front support disposed between the first and second front subsections and the rear support disposed between the first and second rear subsections.

1 . A foldable frame comprising:
 a middle support;   a front section pivotally connected to the middle support at a front side of the middle support, where the front section comprises a first front subsection, a second front subsection, and a front pivoting/locking mechanism that pivotally connects the first and second front subsections to allow folding and unfolding of the first and second front subsections relative to each other and selectively locks the first and second front subsections to prevent accidental folding of the first and second front subsections relative to each other;   a front support pivotally connected to the first front subsection of the front section;   a rear section pivotally connected to the middle support at a rear side of the middle support, wherein the rear section comprises a first rear subsection, a second rear subsection and a rear pivoting/locking mechanism that pivotally connects the first and second rear subsections to allow folding and unfolding of the first and second rear subsections relative to each other and selectively locks the first and second rear subsections to prevent accidental folding of the first and second rear subsections relative to each other; and   a rear support pivotally connected to the first rear subsection of the rear section;   wherein when the foldable frame is in a folded state, the first front subsection and the first rear subsection are disposed between the second front subsection and the second rear subsection, with the front support disposed between the first and second front subsections, and the rear support disposed between the first and second rear subsections; and   wherein when the foldable frame is in an unfolded state, the second front subsection and the second rear subsection are disposed between the first front subsection and the first rear subsection, and the front section and the rear section are supported by the front, middle and rear supports.   
     
     
         2 . The foldable frame of  claim 1 , wherein:
 the middle support comprises a left middle coupling piece at a left side of the middle support and a right middle coupling piece at a right side of the middle support;   each of the left and right middle coupling pieces comprises a first segment and a second segment;   each of the second front subsection and the second rear subsection comprises a left peripheral bar pivotally connected to the first segment of the left middle coupling piece and a right peripheral bar pivotally connected to the first segment of the right middle coupling piece; and   when the foldable frame is unfolded and in an upright position, the second segment of the left middle coupling piece abuts upwardly the left peripheral bars of the second front subsection and the second rear subsection, and the second segment of the right middle coupling piece abuts upwardly the right peripheral bars of the second front subsection and the second rear subsection.   
     
     
         3 . (canceled) 
     
     
         4 . The foldable frame of  claim 1 , wherein:
 the front support is pivotally connected to the first front subsection of the front section through a lateral bar disposed at the first front subsection of the front section; or   the rear support is pivotally connected to the first rear subsection of the rear section through a lateral bar disposed at the first rear subsection of the rear section.   
     
     
         5 . The foldable frame of  claim 4 , further comprising:
 one or more front adjustable bars, each having an end pivotally connected to the front support and another end pivotally connected to the first front subsection of the front section to control rotation of the front support with respect to the first front subsection of the front section; and   one or more rear adjustable bars, each having an end pivotally connected to the rear support and another end pivotally connected to the first rear subsection of the rear section to control rotation of the rear support with respect to the first rear subsection of the rear section.   
     
     
         6 - 7 . (canceled) 
     
     
         8 . The foldable frame of  claim 1 , wherein a respective pivoting/locking mechanism in the front and rear pivoting/locking mechanisms comprises:
 a first coupling piece fixed at a proximal end of a first bar, wherein the first bar is a peripheral bar of one of the first front subsection, second front subsection, first rear subsection and second rear subsection;   a second coupling piece fixed at a proximal end of a second bar and pivotally coupled with the first coupling piece, wherein the second bar is a peripheral bar of another of the first front subsection, second front subsection, first rear subsection and second rear subsection and adjacent to the first bar; and   a control unit operable to selectively restrict the first and second coupling pieces from rotating with respect to each other.   
     
     
         9 . The foldable frame of  claim 8 , wherein:
 the first coupling piece comprises a first slot elongated in a first direction;   the second coupling piece comprises a second slot with a closed bottom and an open top, wherein the second slot is shorter than the first slot of the first coupling piece in the first direction; and   the control unit comprises:   a third coupling piece comprising a third slot with a closed bottom and a closed top, wherein the third slot is elongated in the first direction;   a first rod disposed, cross-sectional-wise, in the third slot of the third coupling piece and movable along the third slot of the third coupling piece, wherein the first and second coupling pieces are pivotally coupled with each other by the first rod; and   a second rod integrally formed or coupled with a top portion of the third coupling piece, the second rod disposed, cross-sectional-wise, in the first slot of the first coupling piece and movable along the first slot of the first coupling piece;   wherein when the first and second coupling pieces are aligned with each other and the open top of the second slot of the second coupling piece faces downwardly, the third coupling piece together with the second rod moves by gravity to a first position where the second rod is disposed outside of the second slot of the second coupling piece, thereby allowing the first and second coupling pieces to rotate with respect to each other around the first rod; and   wherein when the first and second coupling pieces are aligned with each other and the open top of the second slot of the second coupling piece faces upwardly, the third coupling piece together with the second rod moves by gravity to a second position where the second rod is disposed in the second slot of the second coupling piece, thereby restricting the first and second coupling pieces from rotating with respect to each other around the first rod.   
     
     
         10 . The foldable frame of  claim 9 , wherein the first rod is disposed adjacent to the bottom of the third slot of the third coupling piece at the first position, and adjacent to the top of the third slot of the third coupling piece at the second position. 
     
     
         11 - 14 . (canceled) 
     
     
         15 . The foldable frame of  claim 8 , wherein the first and second coupling pieces are pivotally coupled with each other by a first rod through a first hole formed at the first coupling piece and a second hole formed at the second coupling piece. 
     
     
         16 . The foldable frame of  claim 8 , wherein:
 the first coupling piece comprises a hole;   the second coupling piece comprises a slot with an opening, a receiving portion, and a contraction at or adjacent to the opening; and   the control unit comprises:
 a bolt disposed, cross-sectional-wise, in the hole of the first coupling piece, and movable along an axis of the hole of the first coupling piece, wherein the bolt comprises a first bolt segment larger than the contraction of the slot of the second coupling piece, and a second bolt segment smaller than the contraction of the slot of the second coupling piece; 
 a button connected to an end of the bolt; and 
 an elastic member sleeved on the bolt and having an end abutting the first or second coupling piece and another end abutting the button such that when the first and second coupling pieces are aligned with each other, the first bolt segment is retained in the receiving portion of the slot by the contraction of the slot of the second coupling piece, thereby restricting the first and second coupling pieces from rotating with respect to each other. 
   
     
     
         17 . The foldable frame of  claim 16 , wherein pushing the button toward the first coupling piece moves the bolt along the axis of the hole of the first coupling piece, thereby pushing the first bolt segment of the bolt out of the receiving portion of the slot of the second coupling member and allowing the first and second coupling pieces to rotate with respect to each other. 
     
     
         18 . (canceled) 
     
     
         19 . The foldable frame of  claim 8 , wherein:
 the first coupling piece comprises a hole;   the second coupling piece comprises a slot with an opening, a receiving portion, and a contraction at or adjacent to the opening; and   the control unit comprises:
 a bolt disposed, cross-sectional-wise, in the hole of the first coupling piece, and movable along an axis of the hole of the first coupling piece, wherein the bolt comprises a first bolt segment, and a second bolt segment, wherein the first bolt segment is larger than the contraction of the slot of the second coupling piece, and the second bolt segment smaller than the contraction of the slot of the second coupling piece; 
 a first button piece disposed at the first coupling piece and comprising a first surface; and 
 a second button piece connected to the bolt and comprising a second surface facing the first button piece, wherein the second button piece is rotatable relative to the first button piece, 
 wherein the first surface of the first button piece and the second surface of the second button piece are configured such that rotation of the second button piece relative to the first button piece moves the bolt along the axis of the hole of the first coupling piece, thereby selectively moving the first bolt segment of the bolt into the receiving portion of the slot of the second coupling piece to restrict the first and second coupling pieces from rotating with respect to each other or moving the first bolt segment of the bolt out of the receiving portion of the slot of the second coupling piece to allow the first and second coupling pieces to rotate with respect to each other. 
   
     
     
         20 . The foldable frame of  claim 19 , wherein the control unit further comprises:
 an elastic member sleeved on the bolt and having an end abutting a ridge on the bolt and another end abutting the first coupling piece, the second coupling piece or the first button piece to facilitate smooth rotation of the second button piece relative to the first button piece around the axis of the hole of the first coupling piece.   
     
     
         21 . The foldable frame of  claim 19 , wherein the second button piece is connected to an end of the bolt by a pin through a hole formed at the second button piece and a hole formed at the end of the bolt. 
     
     
         22 . The foldable frame of  claim 19 , wherein each of the first and second button pieces includes a hole or a slot to receive, cross-sectional-wise, the bolt. 
     
     
         23 . The foldable frame of  claim 19 , wherein the second button piece is rotatable relative to the first button piece around the axis of the hole of the first coupling piece. 
     
     
         24 . The foldable frame of  claim 19 , wherein the second button piece is rotatable relative to the first button piece around an axis substantially perpendicular to the axis of the hole of the first coupling piece. 
     
     
         25 . (canceled) 
     
     
         26 . The foldable frame of  claim 1 , further comprising:
 one or more connection sections, wherein:
 a first side of a respective connection section in the one or more connection sections is pivotally connected to a peripheral bar of a corresponding subsection in the first front subsection, second front subsection, first rear subsection and second rear subsection, thereby allowing the respective connection section to fold and unfold with respect to the corresponding subsection; 
 a second side of the respective connection section is configured to be detachably coupled with a structure when the respective connection section is unfolded with respect to the corresponding subsection; and 
 the respective connection section is disposed substantially within an interior defined by the corresponding subsection when the respective connection section is folded with respect to the corresponding subsection. 
   
     
     
         27 . The foldable frame of  claim 26 , wherein the one or more connection sections comprise a first connection section connected to the first front or rear subsection and a second connection section connected to the second front or rear subsection. 
     
     
         28 . (canceled) 
     
     
         29 . The foldable frame of  claim 26 , wherein the respective connection section comprises:
 one or more first connectors at the first side of the respective connection section to pivotally couple the respective connection section with the peripheral bar of the corresponding subsection; and   one or more second connectors at the second side of the respective connection section to detachably couple the respective connection section with the structure.   
     
     
         30 . The foldable frame of  claim 29 , wherein each of the one or more first connectors is disposed at an interior side of the peripheral bar of the corresponding subsection when the foldable frame is folded. 
     
     
         31 - 39 . (canceled) 
     
     
         40 . A foldable structure comprising:
 two or more foldable frames of  claim 1  to be disposed side by side and removably connected to each other.   
     
     
         41 - 50 . (canceled)