Patent ID: 8147173

Claim:
An adapter for operating a keyhole saw ( 10 ) on a driving machine, in particular an electric hand-held drill, comprising a driving element section ( 17 ; 117 ) for absorbing torque, and a threaded section ( 18 ; 118 ) to be screwed into a threaded hole ( 20 ) in the keyhole saw ( 10 ), and comprising at least one driving segment ( 16 ; 116 ) which is offset radially relative to the adapter axis, and which is inserted in a form-fit manner into at least one receiving hole ( 21 ) present in the keyhole saw ( 10 ), wherein the at least one driving segment ( 16 ; 116 ) is located in an axially extending manner on the end—which faces the keyhole saw ( 10 )—of a driving element ( 12 ; 112 ) which includes the driving element section ( 17 ; 117 ), the threaded section ( 17 ; 117 ) is formed on a threaded mandrel ( 13 ; 113 ) which is situated in the driving element ( 12 ; 112 ) and is non-detachably connected thereto, and the threaded mandrel ( 13 ; 113 ) is held in the driving element ( 12 ; 112 ) in a rotatable manner and such that it is axially displaceable to a limited extent, wherein the driving element ( 12 ; 112 ) includes a driving element body ( 14 ; 114 ) on which the driving segment ( 16 ; 116 ) is formed, and a driving flange ( 15 ; 115 ) which extends the driving segment ( 16 ; 116 ) as a single piece, and the flange surface of which that faces away from the driving element body ( 14 ; 114 ) forms a mating surface for the keyhole saw ( 10 ), wherein the threaded mandrel ( 13 ; 113 ) extends, via the threaded section ( 18 ; 118 ) and on the flange-side end of the driving element ( 12 ; 112 ), beyond the driving element ( 12 ; 112 ); and the displacement path of the threaded mandrel ( 13 ; 113 ) in the driving element ( 12 ; 112 ) is designed to be at least so great that the end—which faces away from the flange-side end of the driving element ( 12 ; 112 )—of the threaded section ( 18 ; 118 ) may be slid back behind the exposed front end of the driving segment ( 16 ; 116 ).