Key-coupler for coupling key to key-holder

Abstract

A key-coupler for coupling a key with a key-holder includes a first closed ring to which the key-holder is connected and a second closed ring to which the key is connected. The key-coupler is integrally made of a single spring wire and includes a pair of circular portions and a portion connecting the pair of circular portions. Both closed rings are formed by overlapping the pair of circular portions with each other. The key-coupler is easily opened by simply separating one circular portion from the other, and is closed by its own spring action upon removing a force separating the circular portions.

What is claimed is:  
     
         1 . A key-coupler for coupling a key to a key-holder, the key-coupler comprising: 
 a first circular portion;    a second circular portion;    a connecting portion connecting the first circular portion to the second circular portion;    a first closed ring formed by overlapping the first circular portion with the second circular portion; and    a second closed ring defined by the connecting portion and the first closed ring, the second closed ring being formed by overlapping the first circular portion with the second circular portion, wherein: 
 the first closed ring and the second closed ring are opened by applying a force forcibly separating the first circular portion from the second circular portion, and both rings are closed by removing the forcibly separating force.  
   
     
     
         2 . The key-coupler as in  claim 1 , wherein: 
 the first circular portion includes a first opening that is closed by the second circular portion when both circular portions are overlapped with each other; and    the second circular portion includes a second opening that is closed by the first circular portion when both circular portions are overlapped with each other.    
     
     
         3 . The key-coupler as in  claim 2 , wherein: 
 the connecting portion is made of a material having a spring action.    
     
     
         4 . The key-coupler as in  claim 2 , wherein: 
 the first circular portion, the second circular portion and the connecting portion are all integrally made of a single spring wire.    
     
     
         5 . The key-coupler as in  claim 4 , wherein: 
 the first and the second circular portions include respective angled portions that form a gap therebetween when both circular portions are overlapped with each other.    
     
     
         6 . The key-coupler as in  claim 4 , wherein: 
 both of the first closed ring and the second closed ring are formed so that both rings are positioned substantially on a same plane.    
     
     
         7 . The key-coupler as in  claim 6 , wherein: 
 the first ring is formed in a circle shape on the plane.    
     
     
         8 . The key-coupler as in  claim 6 , wherein: 
 the first ring is formed substantially in a triangular shape on the plane.    
     
     
         9 . The key-coupler as in  claim 8 , wherein: 
 the second ring is formed substantially in a trapezoidal shape on the plane.    
     
     
         10 . The key-coupler as in  claim 5 , wherein: 
 the gap is formed on the first closed ring at a position opposite to the second closed ring.    
     
     
         11 . The key-coupler as in  claim 5 , wherein: 
 the gap is formed on the first closed ring at a position facing the second closed ring.