Abstract: An apparatus for storing drill rods, comprising two drill rod cartridges each comprising a rotating rotor provided with finger boards, guides for guiding the drill rods into gaps formed by the finger boards circumferentially around the axis of the rotor. The rotors are arranged to rotate in opposite directions in such a way that projections in the finger boards of one rotor are positioned in alignment with gaps in the other rotor, the drill rods being positioned therebetween and then passed alternately with the rotor of the two cartridges along spirals to a circumference about the rotors.

Abstract: The invention relates to a method and an arrangement for adjusting the percussion and the feed of a rock drilling apparatus with respect to each other. In the method, the volume flow of pressure fluid to be supplied to a percussion device (7) and a feed motor (8) is adjusted on the basis of the feed pressure of the feed motor (11), a volume flow adjusted pump (1) being controlled so that the ratio of the pressure applied to the persussion device (7) to the pressure of the feed motor (11) is set by control valves (10, 14). In the arrangement, pressure fluid is supplied to the percussion device (7) and the feed motor (11) by means of a volume flow adjusted pump (1). The arrangement further comprises control valves (10, 14) by means of which the volume flow of the pressure fluid fed by the pump (1) is kept such that the ratio of the pressure of the percussion device and that of the feed motor (11) remains substantially constant.

Abstract: The invention relates to a travelling centralizer arrangement in a rock drill (2), comprising a travelling centralizer (5) movable along the feeding beam (1) during the drilling. The travelling centralizer (5) of the arrangement comprises two jaw halves (12a, 12b) mounted in a carriage (8) provided for the travelling centralizer so as to be pivoted about journals (13a, 13b) parallel to the feeding beam (1). Each jaw half (12a, 12b) comprises a wheel (9a, 9b) moving along the guideways (10) of the feeding beam (1) and keeping the jaw halves (12, 12b) pressed against each other during normal drilling so that jaws (14a, 14b) form a drill rod centralizer concentric with the drill rod (4). The guideways (10) comprises at the forward end of the feeding beam (1) a portion (L) which extends downward from the straight guideway portion.

Abstract: A supporting arrangement for a feed device for a drilling machine of a rock drilling unit (2) comprising a feed device (3) for a drilling machine (4), a cradle (5) supporting the feed device longitudinally displaceably and a supporting device (10) which is extendable in parallel with the feed device for supporting the feed device against a tunnel wall. The supporting device is supported by the cradle so that it remains stationary with respect to the cradle when the feed device is displaced.

Abstract: The present invention relates to a method and an apparatus for positioning a drilling apparatus with respect to a drilling plane formed by holes to be drilled in a rock in a tunnel. Light beams pointing in opposite directions are developed and fixed with respect to the drilling unit and are directed towards marks on the tunnel walls by adjusting the base of the apparatus in a horizontal plane.