Patent Publication Number: US-11638479-B2

Title: Weight supporting collapsible structures

Description:
FIELD AND BACKGROUND OF THE INVENTION 
     The present invention, in some embodiments thereof, relates to collapsible structures and, more particularly, but not exclusively, to a weight supporting collapsible structures. 
     Foldable play structures are known in the art. However they are generally not suitable for children to climb on; and if they are suitable for children to climb on they generally fold into several parts and/or fold into large sizes which are generally heavy and not easily portable. 
     For example, the collapsible slide disclosed in EP 1348472 A1 is suitable for children to climb on, but employs structures which are large, heavy and not easily portable. The cardboard play structure disclosed in US 20110281495 A1 disassembles into several parts. 
     For another example, the pop-out play structure disclosed in US 20110281496A1 comprising a foldable pop up play structure; this structure is portable but not suitable for kids to climb on. 
     SUMMARY OF THE INVENTION 
     According to an aspect of some embodiments of the present invention there is provided a collapsible structure with opposite support panels and tab panels, comprising: a first and a second structure panels; at least two support panels, each one of the support panels is connected to the first and second structure panels via two support folding lines at opposite sides of the support panel; and at least two tab panels, each of the tab panels is connected to the first and to the second structure panels via two tab folding lines at opposite sides of the tab panel, each of the at least two tab panels contains at least two internal folding lines perpendicular to the tab folding lines; wherein when the structure is in a collapsed position, the first and second structure panels, the at least two support panels and the at least two tab panels are adjacent and generally parallel to each other, the first and second structure panels are folded; and wherein when the structure is in an erected position, the at least two support panels are perpendicular to the first and second structure panels and the at least two tab panels are folded by the at least two internal folding lines, each of the at least two tab panels is partially adjacent to one of the at least two support panels to shape a fixed rod supporting the at least two internal folding lines and inserted to support a rigid distance between the first structure panel and the second structure panel. 
     Optionally, the two support folding lines are parallel for at least one of the at least two support panels. 
     Optionally, when the structure is in a collapsed position, each of the first and second structure panels are folded along a divide folding line wherein a length of the collapsed structure is half a length of the first structure panel and one of the tab panels. 
     Optionally, the at least two tab folding lines are parallel to the at least two support folding lines. 
     Optionally, when the structure is in a collapsed position, the at least two tab panels are folded along at least one of the at least two internal folding lines. 
     Optionally, when the structure is in erected position, at least one of the at least two tab panels is used as a seat. 
     Optionally, the collapsible structure further comprises: a cross panel connected to the first structure panel via a cross folding line perpendicular to the at least two support folding lines; wherein when the structure is in erected position, the cross panel is perpendicular to the first structure panel and to the second structure panel. 
     More optionally, when the structure is in erected position, the cross panel is horizontal and used as a table. 
     More optionally, the collapsible structure further comprises: a ground support panel connected to the cross panel via a ground support cross folding line perpendicular to the cross folding line; wherein when the structure is in erected position, the ground support panel is perpendicular to the cross panel and the ground to provide more structural strength. 
     Optionally, each of the at least two tab panels includes a longitudinal folding line perpendicular to the at least two internal folding lines; and wherein when the structure is in collapsed position, the at least two tab panels are folded along the longitudinal folding lines. 
     According to some embodiments of the invention there is provided a method for erecting the collapsible structure, comprising: providing the collapsible structure in a collapsed position; unfolding the first and second structure panels; separating between the first structure panel and the second structure panel; increasing the distance between the first structure panel and the second structure panel so the at least two support panels are perpendicular to the first and second structure panels; folding each of the at least two tab panels by the at least two internal folding line; and inserting each of the at least two tab panels between the first structure panel and the second structure panel to support the rigid distance between the first structure panel and the second structure panel. 
     According to an aspect of some embodiments of the present invention there is provided a collapsible structure with crossing tab panels, comprising: a first and a second structure panels; at least two support panels, each one of the support panels is connected to the first and second structure panels via two support folding lines at opposite sides of the support panel; and a first and a second tab panels, each connected to the first and second structure panels respectively via a tab folding line at a top side of each the respective first and second structure panels, each of the tab panels contains at least one internal folding line parallel to the tab folding line; wherein when the structure is in a collapsed position, the first and second structure panels, the at least two support panels and the first and second tab panels are adjacent and generally parallel to each other, the first and second structure panels are folded; and wherein when the structure is in an erected position, the at least two support panels are perpendicular to the first and second structure panels and the at least two tab panels are folded by the respective at least one internal folding line, each partially adjacent to an opposing of the respective first and second structure panels. 
     Optionally, the two support folding lines are parallel for at least one of the at least two support panels. 
     Optionally, when the structure is in a collapsed position, each of the first and second structure panels are folded along a divide folding line wherein a length of the collapsed structure is half a length of the first structure panel and one of the support panels. 
     Optionally, the at least one tab folding line is perpendicular to the at least two support folding lines. 
     Optionally, when the structure is in a collapsed position, the at least two tab panels are folded along at least one of the at least two internal folding lines. 
     Optionally, when the structure is in erected position, at least one of the at least two tab panels is used as a seat. 
     Optionally, each of the at least two support panels includes a longitudinal folding line parallel to the two support folding lines; and wherein when the structure is in collapsed position, the at least two support panels are folded along the longitudinal folding lines. 
     Optionally, the collapsible structure further comprises: a cross panel connected to the first tab panel via a cross folding line perpendicular to the tab support folding line; wherein when the structure is in erected position, the cross panel is perpendicular to the first structure panel and to the first tab panel. 
     Optionally, the collapsible structure further comprises: at least one tab panel connected at a bottom side of one of the first and second structure panels. 
     According to some embodiments of the invention there is provided a method for erecting the collapsible structure, comprising: providing the collapsible structure in a collapsed position; unfolding the first and second structure panels; separating between the first structure panel and the second structure panel; increasing the distance between the first structure panel and the second structure panel so the at least two support panels are perpendicular to the first and second structure panels; folding the first and second tab panels by the at least one internal folding line; and inserting each of the first and second tab panels to be partially adjacent to an opposing of the respective first and second structure panels. 
     According to an aspect of some embodiments of the present invention there is provided a collapsible structure with parallel cells, comprising: a first and a second structure panels; a first and a second outer support panels and a middle support panel, each one of the outer and middle support panels is connected to the first and second structure panels via two support folding lines at opposite sides of the support panel; a first and a second inner support panels; and at least two foldable panels, each of the at least two foldable panels is connected to the middle support panel and connected to at least one of the first and second inner support panels at opposite sides of the foldable panel; wherein when the structure is in a collapsed position, the first and second structure panels, the at least two support panels and the at least two tab panels are adjacent and generally parallel to each other; and wherein when the structure is in an erected position, all the support panels are perpendicular to the first and second structure panels and the first and a second inner support panels are adjacent to first and a second outer support panels respectively. 
     Optionally, the at least two foldable panels includes a top foldable panel and a bottom foldable panel, each of the foldable panels is connected to the middle support panel via an internal folding line in the middle of the foldable panel, and connected to the first and to the second inner support panels via two inner support folding lines at opposite sides of the foldable panel. 
     More optionally, when the structure is in a collapsed position the top and bottom foldable panels are folded by the internal folding line, and when the structure is in an erected position the top and bottom foldable panels are unfolded. 
     Optionally, the support folding lines are parallel for at least one of the outer and middle support panels. 
     Optionally, the first structure panel includes at least one cut to create an opening to the structure. 
     Optionally, the collapsible structure further comprises: at least one intermediate panel connected to the middle support panel and one of the first and second inner support panels. 
     More optionally, the intermediate panel is horizontal and used as a shelf. 
     More optionally, two of the at least two foldable panels and one of the first and second inner support panels are included in one panel having two folding lines each connecting one of the foldable panels to the inner support panel; and wherein the panel is connected to the middle support panel via two folding lines at opposite sides of the panel. 
     According to some embodiments of the invention there is provided a collapsible structure comprising at least two units of the described collapsible structure, the units are connected via a support folding line of each of the units. 
     According to some embodiments of the invention there is provided a collapsible structure comprising at least two units of the described collapsible structure, the units include a mutual outer support panel. 
     According to some embodiments of the invention there is provided a method for erecting the collapsible structure, comprising: providing the collapsible structure in a collapsed position; separating between the first structure panel and the second structure panel; increasing the distance between the first structure panel and the second structure panel so the first and second outer support panels are perpendicular to the first and second structure panels; separating between the first inner support panel and the middle support panel and between the second inner support panel and the middle support panel; increasing the distance between the first inner support panel and the second inner support panel; and unfolding the top foldable panel and a bottom foldable panel to support a rigid distance between the first structure panel and the second structure panel. 
     Unless otherwise defined, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the invention, exemplary methods and/or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       Some embodiments of the invention are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of embodiments of the invention. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the invention may be practiced. 
       In the drawings: 
         FIGS.  1 A,  1 B,  1 C,  1 D,  1 E,  1 F and  1 G  are schematic illustrations of a collapsible structure with opposite support panels and tab panels at different collapsing states, according to some embodiments of the present invention; 
         FIG.  2 A  is a schematic illustration of a collapsible structure with opposite support panels and tab panels and a cross panel, according to some embodiments of the present invention; 
         FIG.  2 B  is a schematic illustration of a collapsible structure with opposite support panels and tab panels, a cross panel and a ground support panel, according to some embodiments of the present invention; 
         FIG.  2 C  is a schematic illustration of a collapsible structure with multiple opposite foldable support panels and tab panels, according to some embodiments of the present invention; 
         FIG.  2 D  is a schematic illustration of a collapsible structure with opposite support panels and tab panels, according to some embodiments of the present invention; 
         FIG.  3    is a flowchart schematically representing a method for erecting the collapsible structure of  FIGS.  1 A-G , according to some embodiments of the present invention; 
         FIG.  4 A  and  FIG.  4 B  are schematic illustrations of an exemplary collapsible cardboard play table, according to some embodiments of the present invention; 
         FIG.  4 C  is a schematic illustration of a process of building the collapsible cardboard play table of  FIG.  9 A  and the spread parts of the collapsible cardboard play table of  FIG.  9 A , according to some embodiments of the present invention; 
         FIGS.  5 A,  5 B,  5 C,  5 D and  5 E  are schematic illustrations of a collapsible structure with crossing tab panels at different collapsing states, according to some embodiments of the present invention; 
         FIGS.  6 A,  6 B,  6 C and  6 D  are schematic illustrations of exemplary collapsible structures with crossing tab panels, according to some embodiments of the present invention; 
         FIG.  7    is a flowchart schematically representing a method for erecting the collapsible structure of  FIGS.  5 A-E , according to some embodiments of the present invention; 
         FIGS.  8 A,  8 B and  8 C  are a schematic illustrations of an exemplary collapsible cardboard play sitting storage structure with crossing tab panels, according to some embodiments of the present invention; 
         FIG.  8 D  is a schematic illustration of a process of building the cardboard play sitting storage structure of  FIG.  8 A  and the spread parts of the cardboard play sitting storage structure of  FIG.  8 A , according to some embodiments of the present invention; 
         FIGS.  9 A,  9 B,  9 C,  9 D and  9 E  are schematic illustrations of a collapsible structure with parallel cells at different collapsing states, according to some embodiments of the present invention; 
         FIGS.  10 A,  10 B,  10 C,  10 D and  10 E  are schematic illustrations of exemplary collapsible structures with parallel cells, according to some embodiments of the present invention; 
         FIG.  11    is a flowchart schematically representing a method for folding the collapsible structure of  FIGS.  9 A-E , according to some embodiments of the present invention; and 
         FIGS.  12 A and  12 B  are schematic illustrations of an exemplary collapsible cardboard play kitchen structure with interlocking slit, according to some embodiments of the present invention; and 
         FIG.  12 C  is a schematic illustration of the spread parts of the cardboard play kitchen structure of  FIG.  12 A  and its construction, according to some embodiments of the present invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
     The present invention, in some embodiments thereof, relates to collapsible structures and, more particularly, but not exclusively, to a weight supporting collapsible structures. 
     For foldable play structures to be suitable for children to climb on, they must have general structural strength and specifically structural strength for weight put on top of the structure and/or on top of parts of the structure. According to some embodiments of the present invention, there are provided collapsible structures that are relatively strong to external forces, for example, carrying weight, and may be used to build play structures that are foldable as well as safe from breaking and/or crushing when climbed by children. For example, a play structure may withstand carrying weight of up to 150 kilograms. 
     The collapsible structures may also be used to construct other structures, such as furniture and/or any other structure that requires capability of being folded up to a straightened structure and stored as well as structural strength. 
     The collapsible structures are made of panels connected by folding lines. The panels may be made, for example, from cardboard, corrugated material, corrugated plastic, paper, paperboard, honeycomb material, plastic sheet, plastic film, metal sheet, compound material sheet and/or any other material according to the size and required structural strength. The folding lines may be made by folding the sheets, when relatively soft material is used. For some rigid materials, etching may be required before folding. For hard materials, the folding lines may be made by using flexible connections between the panels, such as hinges. Also, the folding lines may be made by differences in thickness, for example thinner material along a line. 
     The panels may be of any thickness, according to the size and required structural strength. For example, two-layer cardboard of thickness of 5 millimeters (mm), three-layer reinforced cardboard of thickness of between 5 mm and 15 mm, plastic sheets of thickness of between 0.5 mm and 1.5 mm and/or any other thickness. 
     According to some embodiments of the present invention, there is provided a collapsible structure with opposite support panels and tab panels. The structure contains two structure panels, at least two support panels each connected to both structure panels via two support folding lines at opposite sides of the foldable support panel, and at least two foldable tab panels each connected to both structure panels via two tab folding lines. The foldable tab panel contains at least two internal folding lines perpendicular to the tab folding lines. 
     When the structure is in a collapsed position, the panels are adjacent and generally parallel to each other, while the structure panels are folded. When the structure is in an erected position, the structure panels are straightened and the tab panels are folded by the internal folding lines to shape a fixed rod which supports the internal folding lines and inserted to support a rigid distance between the structure panels. 
     According to some embodiments of the present invention, there is provided a collapsible structure with crossing tab panels. The structure contains two structure panels, at least two support panels each connected to both structure panels via two support folding lines at opposite sides of the foldable support panel and two foldable tab panels each connected one of the structure panels via a tab folding lines. The foldable tab panel contains at least one internal folding line parallel to the tab folding lines. 
     When the structure is in a collapsed position, the panels are adjacent and generally parallel to each other, while the structure panels are folded. When the structure is in an erected position, the structure panels are straightened and each tab panel is folded by the internal folding lines to be partially adjacent to the structure panel opposite to it. 
     According to some embodiments of the present invention, there is provided a collapsible structure with parallel cells. The structure contains two structure panels, two outer support panels and a middle support panel, two inner support panels and at least two (top and bottom) foldable panels. The outer and middle support panels are each connected to both structure panels at opposite sides of the foldable support panel. The foldable panels are each connected to the middle support panel and to one or more of the inner support panels. 
     When the structure is in a collapsed position, the panels are adjacent and generally parallel to each other, while the foldable panels are folded. When the structure is in an erected position, the foldable panels are straightened. All of the support panels are then perpendicular to the structure panels and to the foldable panels. 
     The structures have structural strength for external force applied on the structure panels from all sides and specifically for weight put on top of the structures. 
     Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not necessarily limited in its application to the details of construction and the arrangement of the components and/or methods set forth in the following description and/or illustrated in the drawings and/or the Examples. The invention is capable of other embodiments or of being practiced or carried out in various ways. 
     Referring now to the drawings,  FIGS.  1 A,  1 B,  1 C,  1 D,  1 E,  1 F and  1 G  are schematic illustrations of a collapsible structure with opposite support panels and tab panels at different collapsing states, according to some embodiments of the present invention. 
     The collapsible structure  100  contains a first structure panel  101  and a second structure panel  102 . Collapsible structure  100  also contains at least two support panels  103  and  104  each connected to first structure panel  101  and second structure panel  102  via two support folding lines, optionally parallel, at opposite sides of the foldable support panel,  111  and  112 . Collapsible structure  100  also contains at least two tab panels  105  and  106  connected to structure panels  101  and  102  via tab folding lines such as  113  and  114 , optionally parallel to support folding lines  111  and  112 . Tab panels  105  and  106  contain at least two internal folding lines such as  115  and  116  parallel to tab folding lines  113  and  114 . 
     When collapsible structure  100  is in a collapsed position, as shown at  FIG.  1 G , panels  101 - 106  are adjacent and generally parallel to each other, while structure panels  101  and  102  are folded along a main folding line, for example made by divide folding lines  119  and  120 . Optionally, structure panels  101  and  102  are folded so the length of the collapsed structure is half the length of a structure panel and a tab panel. Optionally, tab panels  105  and  106  are folded by one or more of internal folding lines  115 ,  116 ,  117  and  118 . 
     When collapsible structure  100  is in an erected position, as shown at  FIG.  1 A , structure panels  101  and  102  are straightened and tab panels  105  and  106  are folded by internal folding lines  115 ,  116 ,  117  and  118  respectively to a shape fixed rod and inserted to support a rigid distance between first structure panel  101  and second structure panel  102 . The fixed rods may be used for example as seats, as they have structural strength. 
     Reference is now made to  FIGS.  2 A,  2 B,  2 C and  2 D  which are schematic illustrations of exemplary collapsible structures with opposite support panels and tab panels, according to some embodiments of the present invention. 
     Optionally, the collapsible structure include a cross panel  201 , as shown at  FIG.  2 A . Cross panel  201  may be connected to structure panel  101  via a cross folding line  211  perpendicular support folding lines  111  and  112 . When collapsible structure  100  is in an erected position, cross panel  201  is perpendicular the structure panels. Cross panel  201  may be horizontal and may be used for example as a table. 
     Optionally, the collapsible structure includes a ground support panel  202 , as shown at  FIG.  2 B . Ground support panel  202  is connected to cross panel  201  via a ground support cross folding line  212  which is perpendicular to cross folding line  211 . When collapsible structure  100  is in an erected position, ground support panel  202  is perpendicular to cross panel  201  and the ground to provide more structural strength. 
     The collapsible structure may also include any number of extra support panel(s)  204 , as shown at  FIG.  1 C . The extra support panel(s) provide more structural strength. 
     Optionally, as shown at  FIG.  2 D , support panels  103  and  104  may each include a longitudinal folding line  205  and  206  perpendicular to internal folding lines  115  and  116 . When collapsible structure  100  is in a collapsed position, support panels  103  and  104  are folded by longitudinal folding line  205  and  206 . The foldable support panels may fold in any way, using any pattern of longitudinal folding lines. For example, the foldable support panels may fold by three parallel folding lines. 
     Optionally, the structure is made by one sheet of material, as described above. 
     Reference is now made to  FIG.  3   , which is a flowchart schematically representing a method for erecting the collapsible structure of  FIGS.  1 A-G , according to some embodiments of the present invention. 
     First, as shown at  301 , collapsible structure  100  is provided in a collapsed position. In this position, first structure panel  101  and second structure panel  102  are adjacent and folded. Optionally, tab panels  105  and  106  are also folded. 
     Then, as shown at  302 , the main folding line is opened from its folded state and structure panels  101  and  102  are unfolded. Optionally, tab panels  105  and  106  are also unfolded. 
     Then, as shown at  303 , first structure panel  101  and second structure panel  102  are separated. 
     Then, as shown at  304 , the distance between first structure panel  101  and second structure panel  102  is increased. In the maximal distance between first structure panel  101  and second structure panel  102 , support panels  103  and  104  are perpendicular to structure panels  101  and  102 . 
     Then, as shown at  305 , tab panels  105  and  106  are folded by internal folding lines  115  and  116 . 
     Finally, as shown at  306 , tab panels  105  and  106  are inserted between first structure panel  101  and second structure panel  102  to support a rigid distance between them. 
     Reference is now made to  FIG.  4 A  and  FIG.  4 B , which are a schematic illustrations of an exemplary collapsible cardboard play table, according to some embodiments of the present invention. The structure is made so a child  401  may use tab panels  402  and  403  as a seats. Cross panel  404  is used as a table. Tab panels  402  and  403  are rolled into place when erecting the structure. Reference is also made to  FIG.  4 C  which is a schematic illustration of a process of building the collapsible cardboard play table of  FIG.  4 A  and the spread parts of the collapsible cardboard play table of  FIG.  4 A , according to some embodiments of the present invention. Optionally, the structure is made by one sheet of material, for example, by plastic injection, as described above. After the construction of the structure, it stays in one piece and may be folded and erected easily. 
     Reference is now made to  FIGS.  5 A,  5 B,  5 C,  5 D and  5 E , which are schematic illustrations of a collapsible structure with crossing tab panels at different collapsing states, according to some embodiments of the present invention. 
     The collapsible structure  500  contains a first structure panel  501  and a second structure panel  502 . Collapsible structure  500  also contains at least two support panels  503  and  504  each connected to first structure panel  501  and second structure panel  502  via two support folding lines, optionally parallel, at opposite sides of the foldable support panel, such as  511  and  512 . Collapsible structure  500  also contains at least two foldable tab panels  505  and  506  connected to structure panels  501  and  502  at an upper side via tab folding lines  513  and  514 , perpendicular to support folding lines  511  and  512 . Tab panels  505  and  506  contain at least one internal folding line such as  515  and  516  parallel to tab folding lines  513  and  514 . 
     When collapsible structure  500  is in a collapsed position, as shown at  FIG.  5 E , panels  501 - 506  are adjacent and generally parallel to each other, while structure panels  501  and  502  are folded along a main folding line, for example made by divide folding lines  517  and  518 . Optionally, structure panels  501  and  502  are folded so the length of the collapsed structure is half the length of a structure panel and a support panel. Optionally, tab panels  505  and  506  are folded by tab folding lines  513  and  514  and/or internal folding lines  515  and  516 . 
     When collapsible structure  500  is in an erected position, as shown at  FIG.  5 A , structure panels  501  and  502  are straightened and tab panels  505  and  506  are folded by tab folding lines  513  and  514  and internal folding lines  515  and  516 . Each of tab panels  506  and  506  is partially adjacent to an opposing structure panel. 
     Reference is now made to  FIGS.  6 A,  6 B,  6 C and  6 D , which are schematic illustrations of exemplary collapsible structures with crossing tab panels, according to some embodiments of the present invention. 
     Optionally, as shown at  FIG.  6 A , support panels  503  and  504  may each include a longitudinal folding line  601  and  602  perpendicular to internal folding lines  515  and  516 . When collapsible structure  500  is in a collapsed position, support panels  503  and  504  are folded by longitudinal folding line  601  and  602 . The foldable support panels may fold in any way, using any pattern of longitudinal folding lines. For example, the foldable support panels may fold by three parallel folding lines. 
     Optionally, the structure include a cross panel  603 , as shown at  FIG.  6 B . Cross panel  603  may be connected to tab panels  505  or  506  via a cross folding line  611  perpendicular to tab folding lines  513  and  514 . When collapsible structure  500  is in an erected position, cross panel  603  is perpendicular the structure panels and adds structural strength. 
     The collapsible structure may also include any number of extra support panel(s) such as  604  and  605 , as shown at  FIG.  6 C . The extra support panel(s) provide more structural strength. Optionally, tab panels  505  and/or  506  include an interlocking slit in which extra support panel(s)  604  and/or  605  are inserted when collapsible structure  500  is in an erected position, for reinforcement. 
     The collapsible structure may also include any number of extra tab panel(s) such as  606 , as shown at  FIG.  6 D . The extra tab panel(s) may be connected to structure panels  501  and  502  at bottom side. The extra tab panel(s) may provide more structural strength and/or be used as a bottom of the structure to allow storage inside the structure. 
     Optionally, the structure is made by one sheet of material, as described above. 
     Reference is now made to  FIG.  7   , which is a flowchart schematically representing a method for erecting the collapsible structure of  FIGS.  5 A-E , according to some embodiments of the present invention. 
     First, as shown at  701 , collapsible structure  500  is provided in a collapsed position. In this position, first structure panel  501  and second structure panel  502  are adjacent and folded. Optionally, tab panels  505  and  506  are also folded. 
     Then, as shown at  702 , the main folding line is opened from its folded state and structure panels  501  and  502  are unfolded. Optionally, tab panels  505  and  506  are also unfolded. 
     Then, as shown at  703 , first structure panel  501  and second structure panel  502  are separated. 
     Then, as shown at  704 , the distance between first structure panel  501  and second structure panel  502  is increased. In the maximal distance between first structure panel  501  and second structure panel  502 , support panels  503  and  504  are perpendicular to structure panels  501  and  502 . 
     Then, as shown at  705 , tab panels  505  and  506  are folded by tab folding lines  513  and  514  and internal folding lines  515  and  516 . 
     Finally, as shown at  706 , tab panels  505  and  506  are inserted to be partially adjacent to an opposing structure panel  101  or  102  to support a rigid distance between them. 
     Reference is now made to  FIGS.  8 A,  8 B and  8 C  are a schematic illustrations of an exemplary collapsible cardboard play sitting storage structure with crossing tab panels, according to some embodiments of the present invention. The structure is made so a child  801  may use tab panels  802  and  803  as a seats. Tab panels  802  and  803  may be opened in order to store items  804  inside the structure, as shown at  FIG.  8 B . Reference is also made to  FIG.  8 D  is a schematic illustration of a process of building the cardboard play sitting storage structure of  FIG.  8 A  and the spread parts of the cardboard play sitting storage structure of  FIG.  8 A , according to some embodiments of the present invention. Optionally, the structure is made by one sheet of material, for example, by plastic injection, as described above. After the construction of the structure, it stays in one piece and may be folded and erected easily. 
     Reference is now made to  FIGS.  9 A,  9 B,  9 C,  9 D and  9 E , which are schematic illustrations of a collapsible structure with parallel cells, according to some embodiments of the present invention. 
     The collapsible structure  900  contains a first structure panel  901  and a second structure panel  902 . Collapsible structure  900  also contains a first outer support panel  903 , a second outer support panel  904  and a middle support panel  905 , each connected to first structure panel  901  and second structure panel  902  via two support folding lines, optionally parallel, at opposite sides of the foldable support panel, such as  911  and  912 . Collapsible structure  900  also contains a first inner support panel  906  and a second inner support panel  906 . Collapsible structure  900  also contains at least two foldable panels connected to middle support panel  905  and to one or more of first and second inner support panels  906  and  907 . 
     Optionally, the foldable panels include a top foldable panel  908  and a bottom foldable panel  909 . Each of foldable panels  908  and  909  is connected to middle support panel  905  via an internal folding line  913  in the middle of the foldable panel, and connected to first and second inner support panels  906  and  907  via two inner support folding lines  914 ,  915  at opposite sides of the foldable panel. 
     When collapsible structure  900  is in a collapsed position, as shown at  FIG.  9 E , panels  901 - 909  are adjacent and generally parallel to each other. Optionally, foldable panels  908  and  909  by folded by internal folding line(s)  913 . 
     When collapsible structure  900  is in an erected position, as shown at  FIG.  9 A , support panels  903 - 907  are perpendicular to structure panels  901  and  902 . First inner support panel  906  is adjacent to first outer support panel  903  and second  907  is adjacent to second outer support panel  904 . Optionally, top foldable panel  908  and bottom foldable panel  909  are unfolded. 
     Reference is now made to  FIGS.  10 A,  10 B,  10 C,  10 D and  10 E , which are schematic illustrations of exemplary collapsible structures some of which being with parallel cells, when each shown cell may be seen at different collapsing states, according to some embodiments of the present invention. 
     Optionally, first structure panel  901  and/or second structure panel  902  include one or more cuts to create one or more opening(s) to said structure, as shown at  FIG.  10 A  that exhibits a structure(s) with parallel cells. The cuts may create a flap of the structure panel to be used as a door, such as doors  1001  and  1002 . 
     Optionally, the collapsible structure includes one or more intermediate panel(s)  1003  connected to auxiliary support panel  905  and one of the inner support panels  906  or  907 , as shown at  FIG.  10 B  that exhibits a structure with parallel cells. Intermediate panel(s)  1003  may be horizontal and used as one or more shelves inside the structure. 
     Optionally as seen in  FIG.  10 C  that exhibits a single cell structure, two foldable panels  1004 ,  908  and  1005 ,  909  and one inner support panel  1006 ,  906  are included in one panel having two folding lines  914 ,  915  each connecting one of said foldable panels to said inner support panel. The panel is connected to an auxiliary support panel  1007  via two folding lines  913  at opposite sides of the panel. 
     Optionally, two or more units of collapsible structure  900  may be connected. For example, the units may be connected by a mutual outer support panel  1008 , as shown at  FIG.  10 D . For example, the units may be connected via a support folding line  1009  of each of the units, as shown at  FIG.  10 E . 
     Optionally, the structure is made by one sheet of material, as described above. 
     Reference is now made to  FIG.  11   , which is a flowchart schematically representing a method for folding the collapsible structure of  FIGS.  9 A-E , according to some embodiments of the present invention. 
     First, as shown at  1101 , collapsible structure  900  is provided in a collapsed position. 
     Then, as shown at  1102 , first structure panel  901  and second structure panel  902  are separated and the distance between them is increased. In the maximal distance between first structure panel  901  and second structure panel  902 , support panels  903 - 907  are perpendicular to structure panels  901  and  902 . 
     Then, as shown at  1103 , first inner support panel  906  and middle support panel  905  are separated and second inner support panel  907  and middle support panel  905  are separated and the distance between all these panels is increased. 
     Finally, as shown at  1104 , top foldable panel  908  and a bottom foldable panel  909  are unfolded to support a rigid distance between first structure panel  901  and second structure panel  902   
     Reference is now made to  FIGS.  12 A and  12 B , which are schematic illustrations of an exemplary collapsible cardboard play kitchen structure with interlocking slit, according to some embodiments of the present invention. Reference is also made to  FIG.  12 C , which is a schematic illustration of the spread parts of the cardboard play kitchen structure of  FIG.  12 A  and its construction, according to some embodiments of the present invention. Optionally, the structure is made by one sheet of material, for example, by plastic injection, as described above. After the construction of the structure, it stays in one piece and may be folded and erected easily. 
     The descriptions of the various embodiments of the present invention have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein. 
     It is expected that during the life of a patent maturing from this application many relevant collapsible structures will be developed and the scope of the term collapsible structure is intended to include all such new technologies a priori. 
     The terms “comprises”, “comprising”, “includes”, “including”, “having” and their conjugates mean “including but not limited to”. This term encompasses the terms “consisting of” and “consisting essentially of”. 
     The phrase “consisting essentially of” means that the composition or method may include additional ingredients and/or steps, but only if the additional ingredients and/or steps do not materially alter the basic and novel characteristics of the claimed composition or method. 
     As used herein, the singular form “a”, “an” and “the” include plural references unless the context clearly dictates otherwise. For example, the term “a compound” or “at least one compound” may include a plurality of compounds, including mixtures thereof. 
     The word “exemplary” is used herein to mean “serving as an example, instance or illustration”. Any embodiment described as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments and/or to exclude the incorporation of features from other embodiments. 
     The word “optionally” is used herein to mean “is provided in some embodiments and not provided in other embodiments”. Any particular embodiment of the invention may include a plurality of “optional” features unless such features conflict. 
     Throughout this application, various embodiments of this invention may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range. 
     Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range. The phrases “ranging/ranges between” a first indicate number and a second indicate number and “ranging/ranges from” a first indicate number “to” a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numerals therebetween. 
     It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements. 
     Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. 
     All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting.