Abstract: A feed beam, a rock drilling unit and to a method of manufacturing a feed beam is provided. The feed beam includes a basic profile element, which has two or more superimposed material layers. At least one of the material layers may be made of a composite material.

Abstract: A feed beam, a rock drilling unit and to a method of manufacturing a feed beam is provided. The feed beam includes a basic profile element, which has two or more superimposed material layers. At least one of the material layers may be made of a composite material.

Abstract: A rock drill includes a frame, a percussion member, an axial shank, and an axial sleeve provided within the frame and including a first pressure surface provided in a first pressure space and a second pressure surface provided in a second pressure space. A first channel is provided in the axial sleeve for providing a connection between the first pressure space and the second pressure space in at least one position of the axial sleeve in the frame. A second pressure channel connected to the second pressure space is connectable to external pressure. A pressure accumulator is connected to the first pressure space and the flow of the pressure medium outwards from the first pressure space is throttled.

Abstract: A rock drill includes a frame, a percussion member, an axial shank, and an axial sleeve provided within the frame and including a first pressure surface provided in a first pressure space and a second pressure surface provided in a second pressure space. A first channel is provided in the axial sleeve for providing a connection between the first pressure space and the second pressure space in at least one position of the axial sleeve in the frame. A second pressure channel connected to the second pressure space is connectable to external pressure. A iu pressure accumulator is connected to the first pressure space and the flow of the pressure medium outwards from the first pressure space is throttled.

Abstract: The invention relates to a percussion device comprising two percussion pistons alternately making a percussion motion and a control valve for controlling the percussion pistons. The control valve (7) comprises a slide (8) affected by a force so that the slide is generally in a first position, but moves at the end of the percussion motion of the first percussion piston from the first position to a second position and correspondingly back to the first position at the end of the percussion motion of the second percussion piston (4).

Abstract: An axial bearing includes a first piston and a second piston. Axial contact surfaces between the pistons are arranged in the same pressure space. The same pressure fluid fed to the axial bearing acts on the contact surfaces and on working pressure surfaces of the pistons. A rock drilling machine is also provided with such an axial bearing.

Abstract: The invention relates to an axial bearing and to a rock drilling machine pro-vided with an axial bearing. The axial bearing (100) comprises a first piston (20) and a second piston (21). Axial contact surfaces (60, 43a) between the pistons (20, 21) are arranged in the same pressure space (28). The same pressure fluid fed to the axial bearing acts on the contact surfaces and on working pressure surfaces of the pistons.

Abstract: An impact device for a rock drill. The rock drill includes a tool and a mechanism for delivering a stress pulse to the tool. That mechanism includes an impact element supported to a frame of the drill, and a mechanism for subjecting the impact element to stress and thereafter releasing the impact element suddenly from the stress, whereupon stored stress energy in the impact element is discharged in the form of a stress pulse directed at the tool.

Abstract: A method and an equipment for controlling the operation of a rock drilling apparatus, which rock drilling apparatus comprises a percussion device for producing impact energy to a tool of the rock drilling apparatus, a rotating device for rotating the tool in a drill hole, a feeding device for feeding the tool in the drill hole and a flushing device for supplying flushing agent through the tool and the bit for flushing loose drilling waste from the hole. The feed force and the percussion power are determined and the relation between the feed force and the percussion power is adjusted to a targeted operation area within an upper and a lower limit.

Abstract: A method and an equipment for controlling the operation of a rock drilling apparatus, which rock drilling apparatus comprises a percussion device for producing impact energy to a tool of the rock drilling apparatus, a rotating device for rotating the tool in a drill hole, a feeding device for feeding the tool in the drill hole and a flushing device for supplying flushing agent through the tool and the bit for flushing loose drilling waste from the hole. The feed force and the percussion power are determined and the relation between the feed force and the percussion power is adjusted to a targeted operation area within an upper and a lower limit.

Abstract: The invention relates to a percussion device comprising two percussion pistons alternately making a percussion motion and a control valve for controlling the percussion pistons. The control valve (7) comprises a slide (8) affected by a force so that the slide is generally in a first position, but moves at the end of the percussion motion of the first percussion piston from the first position to a second position and correspondingly back to the first position at the end of the percussion motion of the second percussion piston (4).

Abstract: An impact device for a rock drill or the like, comprising means for delivering a stroke, or a stress pulse, at a tool connected to the impact device. The means for delivering a stress pulse comprise an impact element (2) supported to a frame (1a) of the impact device, and means for subjecting the impact element to stress and correspondingly for releasing the impact element (2) suddenly from stress, whereupon the stress energy is discharged in the form of a stress pulse directed at the tool (3) that is directly or indirectly connected to the impact element.