Abstract: A drilling device used for drilling into ground, rock or for reaming a predrilled hole includes several hammering bits in a circular shape and equipped with hammers, whereupon they together drill a hole which has a larger diameter. A casing tube can be pulled out of the hole/pushed into the drilled hole. A tubular, rotatable drill rod tube resides in the casing tube. The hammers are located in a circular shape and are each attached to the outer surface of the drill rod tube by joint/hinge attachments lying essentially in the drilling direction. Rotation of the drill rod tube in a first direction turns the hammers and associated bits outwardly from the drill rod tube, and rotation in another direction turns the hammers with their bits inwardly towards the drill rod tube so that they can be pulled away with the drill rod tube from inside the casing tube.

Abstract: Drilling device for drilling into ground, rock or for reaming a predrilled hole which drilling device comprises, if needed, a bit (2) which drills the central part of the hole and a hammer (1) for it, or the mentioned bit (2) is at least partly replaced with an endpiece which takes control of the predrilled hole whereupon in both cases the drilling device additionally comprises several hammering bits (4) placed in a circular shape and equipped with their own hammers (3) whereupon they together drill a hole which has a larger diameter and the drilling device comprises a casing tube (6) which can be pulled out of the hole/pushed into the hole which is created during drilling and belongs to the drilling device and also essentially in the middle of the drilling device residing tubular, rotatable drill rod tube (16).

Abstract: A bit assembly for a hammering and rotating drill, in which a main drill body (1) is arranged to drill essentially a middle portion of the hole and in the main drill body (1) there is mounted one or more outer bits (2),(3) arranged to drill an outer circle of the hole. The outer drilling bits (2),(3) are arranged to drill an outer drilling surface which is located behind a middle drilling surface of the main drill body in the drilling direction. The outer bits (2),(3) are further mounted in the drill body (1) in formed counter cavities (7), the axial directions (S) of which are either the same direction as the drilling direction or which deviate outwards from the drilling direction. The outer bits can be moved at least a part of the way out of the counter cavities, in order to be moved in a direction which deviates from the axial direction (S) of the counter cavity.

Abstract: A bit assembly for a hammering and rotating drill, in which assembly the drill body (1) is arranged to drill essentially the middle portion of the hole and in the drill body (1) mounted one or more hammering bit (2), (3) is arranged to drill the outer circle of the hole. The outer circle of the hole drilling bits (2), (3) are arranged to drill a drilling surface, which locates further behind in the drilling direction than for the drill body (1) meant drilling surface (L1) and that the mentioned bits (2), (3) are further mounted in a drill body (1) formed counter cavities (7), the axial directions (S) of which have either the same direction as the drilling direction has or deviate outwards from it and mentioned bits can at least a part of their way out of the counter cavities be transported out in the direction which deviates from the axial direction (S) of the counter cavity.

Abstract: A method for mounting hard metal buttons in a drill bit and a drill bit. In the method, a hole (4) is worked into a drill (1) before the drill bit is tempered. Subsequently, a hard metal button (3a) surrounded by brazing material is positioned into the hole (4) of the drill bit (1). The assembly is positioned into a tempering space, in which the brazing material spreads around the hard metal button (3a) into a space between the walls of the hole (4) and the hard metal button (3a) under the influence of heat. When the drill bit (1) is cooled after this, the brazing material (5) solidifies, and simultaneously, the body portion (2) of the drill bit (1) having a higher thermal expansion coefficient presses the hard metal button (3a) through the brazing material (5).