Other

Teijo Hulkkonen

Hannu I Paasonen

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.

Drilling device for drilling and reaming of a hole

A bit assembly for a hammering and rotating drill, in which a main drill body () is arranged to drill essentially a middle portion of the hole and in the main drill body () there is mounted one or more outer bits (),() arranged to drill an outer circle of the hole. The outer drilling bits (),() 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 (),() are further mounted in the drill body () in formed counter cavities (), 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.

Growing community of inventors

Tampere, Finland

Teijo Hulkkonen