Rock drilling apparatus

Rock drilling apparatus comprising:

• a pressure fluid driven rock drilling machine (10) having a percussive motor and a rotation chuck (44) arranged in a housing (43);
• a drill rod (18) connectable to said housing (43) and having a drill bit (16) at one end of said drill rod (18) and a shank (21) at the other end of said drill rod (18), said drill bit (16) being spaced from said housing;
• a tube (20) surrounding said drill rod (18) and extending from said drill bit (16) to said housing (43), said tube (20) having a rear adapter (24) nonrotatably attached to said tube (20);
• the percussive action needed for the drilling being transmitted from said percussive motor to said drill bit (16) by said drill rod (18);
• a collar (22) projecting from said drill rod (18) in front of said shank (21), said tube (20) extending between said collar (22) and said drill bit (16);
• guiding means (33) on said drill bit (16) for maintaining said tube (20) rotatably between said drill bit (16) and said collar (22);
• socket means (42) on said drilling machine (10) for receiving said rear adapter (24) therein with said rear adapter centered in a position radially spaced around said drill rod (18);
• said shank (21) non-rotatably extending into said rotation chuck (44);
• a disconnectable coupling device (46;
• 57) for maintaining said rear adapter (24) in said socket means (42);
• and
• means (31;
• 55) for preventing relative rotation between said socket means (42) and said rear adapter (24) during operation of said percussive motor.