Abstract:
The invention is related to connecting the edges of surface components by joining the extension flap created from one edge and the buffer flap with opening slot created from the other edge. It comprises mathematical formulas to define the geometry of the flaps so that a connection of the edges of surface components can be accomplished.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    Various connection methods for three-dimensional (3D) puzzles have been developed for years. Some adopt traditional tab and recess cut, others apply adhesives, and still others use different types of hinges to achieve the connection among puzzle pieces. This invention provides a new mechanism to connect two surface components that are most common in 3D puzzles. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0002]    Various embodiments of the invention are disclosed in the following detailed description and the accompanying drawings. 
           [0003]      FIG. 1A  illustrates an embodiment of two surface components (i.e. part  100  and part  200 ) with edge  102  and edge  202 . 
           [0004]      FIG. 1B  extends from  FIG. 1A  and illustrates an embodiment of the buffer flap  104  with opening slot  106  created from edge  102 , and the extension flap  204  created from edge  202 . The opening slot  106  is created along the edge  102 . The extension flap comprises of two folding lines ( 206  and  208 ). The areas extending from the folding lines to the edge of the flap are the tabs ( 210  and  212 ). 
           [0005]      FIG. 2  illustrates the geometry of the extension flap and the buffer flap with opening slot. 
           [0006]      FIG. 3A  illustrates the original condition of part  100  and part  200  before connection. 
           [0007]      FIG. 3B  illustrates the folding of tab  210  and tab  212  before connection. 
           [0008]      FIG. 3C  illustrates the insertion of the extension flap  204  into the opening slot  106 . 
           [0009]      FIG. 3D  illustrates the unfolding of tab  210  and tab  212  after connection. 
       
    
    
     DETAILED DESCRIPTION 
       [0010]    This invention provides a simple mechanism to connect the edges of surface components. The connection is achieved by first creating the extension flap from one edge and the buffer flap with opening slot from the other edge. The extension flap and the buffer flap with opening slot are then joined to connect the two edges. 
         [0011]    The details of the invention are described below with figures that illustrate the geometry and the assembly process of the connection. 
         [0012]      FIG. 1A  illustrates an embodiment of two surface components (i.e. part  100  and part  200 ) with edge  102  and edge  202 . To connect edge  102  and edge  202 , the buffer flap with opening slot is created from edge  102 , and the extension flap is created from edge  202 .  FIG. 1B  extends from  FIG. 1A  and illustrates an embodiment of the buffer flap  104  with opening slot  106  created from edge  102 , and the extension flap  204  created from edge  202 . The opening slot  106  is created along edge  102 . The extension flap comprises of two folding lines ( 206  and  208 ). The areas extending from the folding lines to the edge of the flap are the tabs ( 210  and  212 ). 
         [0013]    The geometry of the extension flap and that of the buffer flap with opening slot is defined in  FIG. 2 . The geometry of the flaps should be constrained by the following mathematic formulas to reliably perform their functions.
       β≧½ (180°−α)   α&lt;90°   a&gt;0   d&gt;0       
 
         [0018]    As shown in  FIG. 2 , angle β defines the folding lines on the extension flap. Angle β has to follow the constraint of β≧½ (180°−α), where α is the leading angle of edge  214 . 
         [0019]    The major function of edge  214  in the extension flap is for creating the stoppage to prevent the extension flaps from slipping out of the opening slot. To perform this function, α has to be smaller than 90 degree, i.e. α&lt;90°, and the length of edge  214  has to be at least larger than zero, i.e. a&gt;0. 
         [0020]    With the opening slot created along edge  102  of the original surface component, the function of the buffer flap  104  is to create an area for the opening slot  106  to reside in. As a result, the distance between the original edge  102  of the surface component and the leading edge  108  of the buffer flap has to be greater than zero, i.e. d&gt;0. 
         [0021]    As shown in  FIG. 2 , the area created by edge  214 , edge  216 , edge  218 , and the folding line is defined as the tab. While edge  218  is an extension of the leading edge of the extension flap, edge  216  plays the role of cutting off the tip that would be formed by edge  214  and edge  218  so that the sturdiness of the tab can be increased. 
         [0022]      FIG. 3A  to  FIG. 3D  demonstrate the assembly process of the extension flap and the buffer flap with opening slot.  FIG. 3A  illustrates the original condition of the two parts before connection. As shown in  FIG. 3B , the two tabs ( 210  and  212 ) on the extension flap  204  are folded along the folding line before inserting into the opening slot  106 . After folding the two tabs ( 210  and  212 ),  FIG. 3C  illustrates the insertion of the extension flap  204  into the opening slot  106 . After inserting the extension flap  204  into the opening slot  106 ,  FIG. 3D  illustrates the unfolding of the two tabs ( 210  and  212 ) to create a stoppage to prevent the extension flap  204  from slipping out of the opening slot  106 . Therefore, the connection between the two edges is formed.