Spanner with prevention of disengagement of fasteners

Abstract

A spanner comprises a box end that has an inner periphery consisting of a number of wall faces to define a first polygonal receiving space. Each wall face includes a groove defined therein. The grooves of the wall faces together define a second polygonal receiving space. At least one of the grooves includes a closed first end and an open second end.

What is claimed:  
     
         1 . A spanner wrench comprising: 
 a. a handle;    b. a head attached to said handle that defines a box end having 
 an inner periphery having a plurality of wall faces connected by a first plurality of corners, said wall faces and said first plurality of corners defining a first polygonal receiving space bounded at the top by a first open end and at the bottom by a second open end, each said wall face including at least one groove formed therein,  
 a second polygonal receiving space defined by said grooves that is bounded at the top by said first open end and at the bottom by said second open end, and  
   c. a radially inward extending ledge located in a minority of said first plurality of corners proximate said first open end,    wherein, 
 when a work piece is received in said first polygonal receiving space, said radially inward extending ledges prevent said work piece from passing through said first open end, and  
 when said work piece is received in said second polygonal receiving space, said work piece can pass through said first open end.  
   
     
     
         2 . The spanner wrench of  claim 1 , wherein a cross-section of said grooves are triangularly shaped.  
     
     
         3 . The spanner wrench of  claim 1 , wherein said first polygonal receiving space and said second polygonal receiving space are triangular.  
     
     
         4 . The spanner wrench of  claim 3 , wherein said first corners have an angular positional difference of 60° from said grooves with respect to the centerline of said box end.  
     
     
         5 . The spanner wrench of  claim 1 , wherein said first polygonal receiving space and said second polygonal receiving space are square.  
     
     
         6 . The spanner wrench of  claim 5 , wherein said first corners have an angular positional difference of 45° from said grooves with respect to the centerline of said box end.  
     
     
         7 . The spanner wrench of  claim 1 , wherein said first polygonal receiving space and said second polygonal receiving space are hexagonal.  
     
     
         8 . The spanner wrench of  claim 7 , wherein said first corners have an angular positional difference of 30° from said grooves with respect to the centerline of said box end.  
     
     
         9 . The spanner wrench of  claim 1 , wherein said first polygonal receiving space and said second polygonal receiving space are octagonal.  
     
     
         10 . The spanner wrench of  claim 9 , wherein said first corners have an angular positional difference of 22.5° from said grooves with respect to the centerline of said box end.  
     
     
         11 . A spanner wrench comprising: 
 a. a handle;    b. a head attached to said handle and defining a hole therethrough;    c. a drive member rotatably received in said hole and having an inner periphery defining, 
 a plurality of wall faces connected by a first plurality of corners, said wall faces and said first plurality of corners defining a first polygonal receiving space bounded at the top by a first open end and at the bottom by a second open end, each said wall face including at least one groove formed therein,  
 a second polygonal receiving space defined by said grooves that is bounded at the top by said first open end and at the bottom by said second open end, and  
   d. a radially inward extending ledge located in at least one of said first plurality of corners proximate said first open end    wherein, 
 when a work piece is received in said first polygonal receiving space, said radially inward extending ledges prevent said work piece from passing through said first open end, and  
 when said work piece is received in said second polygonal receiving space, said work piece can pass through said first open end.  
   
     
     
         12 . The spanner wrench of  claim 11 , wherein said grooves are triangularly shaped.  
     
     
         13 . The spanner wrench of  claim 11 , wherein said first polygonal receiving space and said second polygonal receiving space are triangular.  
     
     
         14 . The spanner wrench of  claim 13 , wherein said first corners have an angular positional difference of 60° from said grooves with respect to the centerline of said drive member.  
     
     
         15 . The spanner wrench of  claim 11 , wherein said first polygonal receiving space and said second polygonal receiving space are square.  
     
     
         16 . The spanner wrench of  claim 15 , wherein said first corners have an angular positional difference of 45° from said grooves with respect to the centerline of said drive member.  
     
     
         17 . The spanner wrench of  claim 11 , wherein said first polygonal receiving space and said second polygonal receiving space are hexagonal.  
     
     
         18 . The spanner wrench of  claim 17 , wherein said first corners have an angular positional difference of 30° from said grooves with respect to the centerline of said drive member.  
     
     
         19 . The spanner wrench of  claim 11 , wherein said first polygonal receiving space and said second polygonal receiving space are octagonal.  
     
     
         20 . The spanner wrench of  claim 19  wherein said first corners have an angular positional difference of 22.5° from said grooves with respect to the centerline of said drive member.