Patent ID: 7014086

Claim:
An ignition device for igniting a foil cartridge ( 10 ) in an explosion-operated power tool, comprising; a displaceable support ( 8 ); an electrical insulator ( 24 ) arranged in the displaceable support ( 8 ); a pin-shaped electrode ( 25 ) located in the electrical insulator and having a tip ( 30 ) that communicates with surrounding environment via a channel ( 32 ) formed in the electrical insulator ( 24 ) and extending from the tip ( 30 ) in a longitudinal direct ion of the pin-shaped electrode ( 25 ); and an electrically conducting annular electrode ( 27 ) supported on the support ( 8 ) in a region of the channel ( 32 ), the annular electrode ( 27 ) tightly surrounding the insulator ( 24 ), leaving the channel ( 32 ) free, whereby an electrical arc is formed that extends from the tip ( 30 ) of the pin-shaped electrode ( 25 ) and longitudinally through the channel ( 32 ) to the annular electrode ( 27 ), the annular electrode ( 27 ) being displaceable together with the support ( 8 ), between a first position in which the annular electrode ( 27 ) is spaced from a cover ( 11 a ) of the foil cartridge ( 10 ), and a second position in which the annular electrode ( 27 ) contacts the cover of the foil cartridge.