member 24 comprises a press portion 24 a which extends over the surface of the grip section 5 a a hook 24 b engaged with a recess 19 is disposed at a rear end of the second grip section 5 b the locking member 24 is biased by a spring 25 which is located in the main body 2 for supporting the locking member 24 to move upwardly and downwardly the sliding unit 22 has a protruding shoulder 22 a disposed in the intermediate portion and a stop portion 22 b disposed at its upper end the sliding unit 22 is biased by a spring 23 which is disposed under the sliding unit 22 in addition an extending block 18 is disposed on the second grip section 5 b of the nozzle attachment 10 shown in fig2 for selectively engaging the protruding shoulder 22 a of the sliding unit 22 referring to fig5 a when the elongate nozzle attachment 10 disengages the main body 2 the sliding unit 22 biased by the spring 23 is located at its first position the stop portion 22 b of the sliding unit 22 engages the stop portion 21 b of the actuating member 21 for preventing the movement of the actuating member 21 the locking member 24 is located at its first position biased by the spring 25 referring to fig5 b when the elongate nozzle attachment 10 is.