Connecting building block

Abstract

The present invention relates to a connecting building block and has a body, at least one engaging element, and at least one connection area. The body is a hollow structure and has an opening formed through the body. Each one of the at least one engaging element is mounted on an external wall of the body around the opening. Each one of the at least one connection area is formed on a top wall opposite to the opening and through another one of the external walls near to the engaging element. When combining multiple connecting building blocks, the engaging element of a connecting building block is connected pivotally to the connection area of another connecting building block. The connecting building blocks can be rotated to change the connecting direction, so the connecting variations of the building block can be expanded.

1 . A connecting building block comprising:
 a body being a hollow structure and having
 an opening formed through a bottom of the body; and 
 multiple external walls formed around the opening of the body; 
   at least one engaging element mounted on one of the external walls of the body, and each engaging element having
 an extending bar being circular and formed on and extending perpendicularly from one of the external walls of the body; 
 a holding block being circular and formed on an extending end of the extending bar, and an outer diameter of the holding block being larger than an outer diameter of the extending bar; and 
   at least one connection area formed on an edge of a top wall of the body opposite to the opening and through the external wall of the body, and each connection area having
 an inner groove formed in the edge of the top wall of the body that is opposite to the opening, a bottom side of the inner groove being curved; and 
 a rotation groove formed through one of the external walls of the body and communicating with the inner groove, a bottom side of the rotation groove being curved, and the rotation groove having a width and a depth respectively smaller than a width and a depth of the inner groove; 
   wherein a diameter of the extending bar is equal to the width of the rotation groove, a diameter of the holding block is equal to the width of the inner groove, and an area of the holding block is bigger than an area of the extending bar.   
     
     
         2 . The connecting building block as claimed in  claim 1 , wherein the connecting building block has multiple engaging elements formed on and protruding from the body. 
     
     
         3 . The connecting building block as claimed in  claim 1 , wherein the connecting building block has multiple connection areas formed on the body and through the external walls of the body. 
     
     
         4 . The connecting building block as claimed in  claim 2 , wherein the connecting building block has multiple connection areas formed on the body and through the external walls of the body. 
     
     
         5 . The connecting building block as claimed in  claim 3 , wherein the body is a hollow square structure. 
     
     
         6 . The connecting building block as claimed in  claim 4 , wherein the body is a hollow square structure. 
     
     
         7 . The connecting building block as claimed in  claim 1 , wherein the connecting building block has at least one fastening block extending perpendicularly on the top wall of the body. 
     
     
         8 . The connecting building block as claimed in  claim 2 , wherein the connecting building block has at least one fastening block extending perpendicularly on the top wall of the body. 
     
     
         9 . The connecting building block as claimed in  claim 4 , wherein the connecting building block has at least one fastening block extending perpendicularly on the top wall of the body. 
     
     
         10 . The connecting building block as claimed in  claim 8 , wherein the body is a hollow rectangular structure; and the connecting building block has multiple fastening blocks formed perpendicularly on and protruding from the top wall of the body. 
     
     
         11 . The connecting building block as claimed in  claim 9 , wherein the body is a hollow rectangular structure; and the connecting building block has multiple fastening blocks formed perpendicularly on and protruding from the top wall of the body. 
     
     
         12 . The connecting building block as claimed in  claim 1 , wherein the body is a triangular structure, and the at least one engaging element and the at least one connection area are respectively formed on two adjacent external walls of the body. 
     
     
         13 . The connecting building block as claimed in  claim 2 , wherein the body is a triangular structure, and the at least one engaging element and the at least one connection area are respectively formed on two adjacent external walls of the body. 
     
     
         14 . The connecting building block as claimed in  claim 3 , wherein the body is a triangular structure, and the at least one engaging element and the at least one connection area are respectively formed on two adjacent external walls of the body. 
     
     
         15 . The connecting building block as claimed in  claim 4 , wherein the body is a triangular structure, and the at least one engaging element and the at least one connection area are respectively formed on two adjacent external walls of the body.