Abstract: Improved sealing means in rock drilling equipment of the kind comprising casing sections positioned between the drilling unit and the cutter head and housing the drill rod sections. A combined seal consisting of a metal part and a resilient part is positioned between the casing and the cutter head to prevent water and mud from penetrating into the casing. In addition, sealing means are provided to prevent drill water from flowing between the drill rod and the casing in the direction towards the drill chamber, and further means are provided to close off communication between the drill chamber and the annular chamber between the casing and the drill hole wall.

Abstract: A sound attenuating wall comprises a skeleton frame, surface layers secured thereto, skeleton frame members, and an insulation provided between the skeleton frame members and the surface layers, respectively. The skeleton frame members are formed by two elements which in point of strength act separately of each other and are interconnected by portions of material which are weak or slender in the direction of the plane of the wall. The insulation disposed in the wall fills out only part of the space therein.