Abstract: A chuck for a drill head of a rotation rock drilling rig, wherein a plurality of jaws are equally angularly distributed around a grip position axis, wherein the jaws co-operate with actuator means for radial movements of the jaws, and wherein the chuck includes urging means being arranged for influencing the jaws into the release position. The urging means is a partially annular jaw spring surrounding said axis and having two spring ends adjacent to each other. The jaws together form an inside seat for the jaw spring and the jaw spring is arranged for fixing engagement with one of the jaws. The invention also relates to a drill head, a rig and a jaw spring.

Abstract: A method for fitting a cylinder assembly into an internal combustion cylinder housing includes the steps of gripping the connected rod-pin-piston assembly with a gripper or clamp and lowering the connected rod-pin-piston assembly, gripped by the gripper or clamp, onto the head surface of the engine cylinder. The connected rod-pin-piston assembly is then inserted into the engine cylinder being thrust by an actuator passing through the gripper or clamp.

Abstract: In an apparatus for cutting a tubular film into an elongated strip wherein the tubular film is fed at a given velocity in flattened form from a supply reel to an expansion zone where the film is expanded into a tube, advanced after such expansion along a mandrel, cut into a flat strip while advancing along the mandrel, and the flat strip is removed from the mandrel at an angle to the mandrel axis, the mandrel is hollow and air is introduced into the hollow mandrel under sufficient pressure that the flattened film is expanded into a relatively stiff cylindrical tube that makes a sliding fit with the mandrel and resists deformation while being supported thereon, Improved positive control over the film during its expansion and advance to the mandrel is achieved by means of moving surfaces, e.g. endless belts or roller arrays, that define a diverging expansion zone and are driven at a velocity equal to the velocity at which the film is fed.

Abstract: Flexible tubular film is helically cut into a flat strip by feeding the tubular film in flattened form from a supply source to a film feeding means advancing the flat film tube at a predetermined velocity to a tube expansion zone in which the flat tube is expanded into a generally cylindrical tube and passed axially over a hollow mandrel slightly less in external diameter than the diameter of the expanded tube to be cut helically while on the mandrel into a flat strop that is removed at an angle to the mandrel axis. The tube is expanded in the zone by inflation with air fed through the mandrel in a direction countercurrent to the direction of tube movement and under a pressure sufficient to render the expanded tube stiff as it slides over the mandrel and resistant to deformation while being helically cut.