Abstract: Rock drilling apparatus including a pressure fluid driven rock drilling machine (10) and a drill unit (11). The drill unit (11) includes a drill rod (18), a drill bit (16) and a tube (20) surrounding the drill rod (18). The drill rod (18) has a collar (22) in front of a shank (21), the collar (22) maintaining the tube (20) rotatably therebetween and between the drill bit (16). The rock drilling machine (10) includes coupling device (46; 57), a socket means (42) and a rotation chuck (44) for receiving and holding the tube (20) and shank (21) connected to the machine (10), the tube (20) being radially spaced around the drill rod (18) and non-rotatably connected to the socket means (42).

Abstract: Oil is supplied to the compressed air supply hose for a jack leg drill by means of a conventional in-line oiler. A substantial part of the oil is separated from the drive air by means of a wall flow separator at the drill and conveyed through internal passages in the drill to various parts to be lubricated such as a chuck and a ratchet mechanism for rotating the chuck.

Abstract: A rock drill is mounted on a cradle that is axially displaceably mounted on a feed beam. The drill has a front aperture for receiving the rear end of a drill string. The drill string is freely insertable into and retractable out of a rotation transmitting wear bushing in the aperture, and a drill string retainer is mounted on the cradle. The wear bushing is also freely retractable out of the drill, and it is also held in position by the drill string retainer. The rear end of the drill is mounted to the cradle by means of a hinge connection so that the front end of the drill can be swung up when the wear bushing is to be replaced.

Abstract: A rock drilling apparatus has a noise reducing drill rod cover which comprises a pair of elongated strips, each of which, when in an extended condition in the longitudinal direction thereof, form part-cylindrical members which matingly engage the other strip to form a generally cylindrical cover around the drill rod. Spool means is provided, preferably in the area of the centralizer, to selectively roll the elongated strips thereon, the strips being flattened when rolled onto the spool means. The elongated strips are rolled onto simultaneously driven spools, and comprise either metallic strips, metallic strips covered with rubber on one or both surfaces thereof, or elastic strips having spaced metallic inserts embedded therein.