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 is:  
     
         1 . A spanner comprising a box end having an inner periphery consisting of a plurality of wall faces to define a first polygonal receiving space, each said wall face including a groove defined therein, the grooves of the wall faces together defining a second polygonal receiving space, at least one of the grooves including a closed first end, at least one of the grooves including an open first end and each of the grooves having an open second end.  
     
     
         2 . The spanner as claimed in  claim 1 , wherein each said groove includes a closed first end and an open second end.  
     
     
         3 . The spanner as claimed in  claim 1 , wherein each said groove is triangular.  
     
     
         4 . A spanner comprising a box end having a first end, a second end, and an inner periphery consisting of first, second and third, planar wall faces extending between the first end and the second end to define a first polygonal receiving space, with the first and second, the second and third, and the first and third wall faces being interconnected at first, second and third corners, respectively, with the first polygonal receiving space having a triangular shape at the first and second ends, each said wall face including a groove defined therein, the grooves of the wall faces together defining a second polygonal space of a triangular shape at the second end, at least one of the grooves including a closed first end, with each of the grooves having an open second end.  
     
     
         5 . The spanner as claimed in  claim 4 , wherein the first polygonal receiving space has an angular positional difference of 60° from the second polygonal receiving space.  
     
     
         6 . The spanner as claimed in  claim 1 , wherein the first polygonal receiving space and the second polygonal space are square.  
     
     
         7 . The spanner as claimed in  claim 6 , wherein the first polygonal receiving space has an angular positional difference of 45° from the second polygonal receiving space.  
     
     
         8 . The spanner as claimed in  claim 1 , wherein the first polygonal receiving space and the second polygonal space are hexagonal.  
     
     
         9 . The spanner as claimed in  claim 8 , wherein the first polygonal receiving space has an angular positional difference of 30° from the second polygonal receiving space.  
     
     
         10 . The spanner as claimed in  claim 1 , wherein the first polygonal receiving space and the second polygonal space are octagonal.  
     
     
         11 . The spanner as claimed in  claim 10 , wherein the first polygonal receiving space has an angular positional difference of 22.5° from the second polygonal receiving space.  
     
     
         12 . A spanner having a box end and a drive member rotatably mounted in the box end, the drive member comprising an inner periphery consisting of a plurality of wall faces to define a first polygonal receiving space, each said wall face including a groove defined therein, the grooves of the wall faces together defining a second polygonal receiving space, at least one of the grooves including a closed first end, at least one of the grooves including an open first end and each of the grooves having an open second end.  
     
     
         13 . The spanner as claimed in  claim 12 , wherein each said groove includes a closed first end and an open second end.  
     
     
         14 . The spanner as claimed in  claim 12 , wherein each said groove is triangular.  
     
     
         15 . The spanner as claimed in  claim 12 , wherein the drive member has a first end and a second end, with a plurality of wall faces including first, second and third, planar wall faces extending between the first end and the second end, with the first and second, the second and third, and the first and third wall faces being interconnected at first, second and third corners, respectively, with the first polygonal receiving space having a triangular shape at the first and second ends, wherein the second polygonal space has a triangular shape at the second end.  
     
     
         16 . The spanner as claimed in  claim 15 , wherein the first polygonal receiving space has an angular positional difference of 60° from the second polygonal receiving space.  
     
     
         17 . The spanner as claimed in  claim 12 , wherein the first polygonal receiving space and the second polygonal space are square.  
     
     
         18 . The spanner as claimed in  claim 17 , wherein the first polygonal receiving space has an angular positional difference of 45° from the second polygonal receiving space.  
     
     
         19 . The spanner as claimed in  claim 12 , wherein the first polygonal receiving space and the second polygonal space are hexagonal.  
     
     
         20 . The spanner as claimed in  claim 19 , wherein the first polygonal receiving space has an angular positional difference of 30° from the second polygonal receiving space.  
     
     
         21 . The spanner as claimed in  claim 12 , wherein the first polygonal receiving space and the second polygonal space are octagonal.  
     
     
         22 . The spanner as claimed in  claim 21 , wherein the first polygonal receiving space has an angular positional difference of 22.5° from the second polygonal receiving space.