Explosive discharge actuated tool for driving fasteners

An explosive discharge actuated tool for driving fasteners, comprising:

• a tubular housing extending in a longitudinal direction, and having an opening which extends in a first transverse direction transverse to the longitudinal direction to define a mounting surface, and a plurality of retaining recesses which are disposed on said mounting surface, and which are displaced from each other in the longitudinal direction;
• a barrel mounted in and movable relative to said tubular housing in the longitudinal direction, and including
• a rear segment defining an accommodation chamber for receiving an explosive cartridge, and
• a barrel body extending from said rear segment forwardly and defining a barrel bore which is in fluid communication with said accommodation chamber, said barrel body having an exhaust port which is located proximate to said rear segment and downstream of said accommodation chamber for discharging a combustion gas;
• a piston disposed in said barrel bore and to be driven by the combustion gas so as to exert a striking power to strike a fastener out of said barrel, said piston having a trailing end disposed forwardly of said accommodation chamber to define, in a pre-firing position, a combustion chamber in said barrel bore so as to generate the combustion gas when the explosive cartridge detonated;
• and
• a power adjusting unit including
• an adjusting pin which has a blocking region and which is disposed to be movable relative to said barrel in the longitudinal direction so as to permit said blocking region to completely or partially close said exhaust port,
• a latch spindle having an actuated end and a latch end which is opposite to said actuated end in the first transverse direction, and which is disposed to be movable relative to said adjusting pin in the first transverse direction between a shiftable position where said latch spindle is movable with said adjusting pin in the longitudinal direction, and a non-shiftable position where said latch spindle is prevented from moving with said adjusting pin in the longitudinal direction, and
• an engaging block sleeved on and movable with said latch spindle in the first transverse direction and having a protuberance which is configured to be movable between an engaged position where said protuberance is engaged in a selected one of said retaining recesses so as to prevent said latch spindle from moving away from the non-shiftable position, and a disengaged position where said protuberance is disengaged from the selected one of said retaining recesses to place said latch spindle in the shiftable position.