Abstract: Collection device for connecting a drilling tool, such as a bit, to the end of a drilling column, in which the connection device comprises a first element, with a first end, intended to be connected to the end of the drilling column, and a second element, with a second end, intended to be connected to the drilling tool, in which the second element is fixed to the first element so as to allow a translational movement in a longitudinal direction in order to make it possible to change the distance between the first end and this second end, characterized in that the connection device comprises a “pusher” structure for transmitting a thrust force from this first element towards the second element, comprising a set of “Belleville” washers making it possible to ensure that said thrust force, from the first element toward the second element, is substantially constant in any position of the second element with respect to the first element.

Abstract: Two-centre rotary boring bit for boring wells, comprising, on the one hand, a pilot tool (1) comprising a body of revolution with an axial core (3) and radial blades (4) bearing cutting elements (5) and, on the other hand, an enlarging tool (2) fitted behind the pilot tool and laterally offset therefrom, the pilot tool having, on its front face, a central region (11) that has no cutting elements in order to allow the creation of a core sample (12), said central region being in communication with a cavity (13) situated between two blades (4) of the pilot tool (1) and serving to remove the core sample toward the periphery of the boring bit.