Abstract: The invention relates to a shield structure of a rock drilling apparatus for dampening noise, the rock drilling apparatus comprising a feed beam whose one end is a drilling end, whereby the drilling end of the feed beam comprises a first shield part mounted immovably relative to the feed beam, and a second shield part mounted movably relative to the feed beam. A tubular shield flexible at least in its longitudinal direction is mounted between the shield parts, the shield being tightly attached by its ends to the first and the second shield part.

Abstract: The invention relates to a sound dampening housing for a rock drill which moves along a feed beam in a longitudinal direction thereof, the sound dampening housing being attachable to the feed beam of the rock drill on its both sides so that together with the feed beam the sound dampening housing constitutes a substantially closed space. The sound dampening housing is double-shelled, and an airspace is provided between its inner shell and its outer shell.

Abstract: The invention relates to a shield structure of a rock drilling apparatus for dampening noise, the rock drilling apparatus comprising a feed beam whose one end is a drilling end, whereby the drilling end of the feed beam comprises a first shield part mounted immovably relative to the feed beam, and a second shield part mounted movably relative to the feed beam. A tubular shield flexible at least in its longitudinal direction is mounted between the shield parts, the shield being tightly attached by its ends to the first and the second shield part.

Abstract: The invention relates to a sound dampening housing for a rock drill which moves along a feed beam in a longitudinal direction thereof, the sound dampening housing being attachable to the feed beam of the rock drill on its both sides so that together with the feed beam the sound dampening housing constitutes a substantially closed space. The sound dampening housing is double-shelled, and an airspace is provided between its inner shell and its outer shell.

Abstract: The invention relates to a method of generating a control signal and to an arrangement comprising a D/A converter for receiving a digital signal and converting the received signal into an analog control signal. The arrangement comprises measuring means for measuring the operating voltage of the D/A converter, means for generating a difference signal from the measurement result obtained from the measurement of the operating voltage, and the nominal value of the operating voltage, whereby the difference signal is used to change the control signal when the operating voltage differs from a nominal value preset for the operating voltage of the D/A converter.

Abstract: A rock drilling rig includes a movable carrier with a boom attached to it and movable in various ways. The free end of the boom is provided with drilling equipment. The drilling equipment is enclosed in a casing that prevents noise generated during drilling from spreading to the surroundings. The casing is arranged to move together with a feed beam and relative to the cradle mounted on the end of the boom. A flexible noise attenuating skirt projects forwardly from a front end of the casing for forming a sealed chamber around a drilling head.

Abstract: An arrangement for controlling the oscillation of a rock drilling equipment, comprising oscillation cylinders acting between a body and two crawlers, an oscillation selector valve allowing the oscillation cylinders to be interconnected. Locking valves are mounted in the oscillation cylinders, which valves prevent the flow of pressure fluid from the oscillation cylinders e.g., in the case of a hose damage, thus locking the crawlers and the body against movement relative to each other.