Abstract: A drill bit for drilling a borehole having a bit body with an axis of rotation, a leading face, and a plurality of blades upstanding from the leading face. At least one of the blades terminates in a gauge pad having a gauge surface arranged, in use, to face a wall of the borehole. The gauge surface being devoid of cutting elements and terminating at an end remote from the blade at a junction with a gauge pad end wall. The gauge pad carries a cutter having a face and a cutting edge located radially inward of the gauge surface, and the junction of the gauge surface and the gauge pad end wall crosses, radially, between the face of the cutter and the wall of the borehole. The gauge surface may be a substantially continuous surface, and may have at least one additional cutter located angularly between two adjacent blades of the drill bit.

Abstract: A drill bit for drilling a borehole, the drill bit comprising a bit body 10 having an axis of rotation 12, a leading face, a plurality of blades 26 upstanding from the leading face, at least one of the blades terminating in a gauge pad 28 having a gauge surface 29 arranged, in use, to face a wall 30 of the borehole 32, the gauge surface 29 being devoid of cutting elements, the gauge surface 29 terminating at an end thereof remote from the blade at a junction 58 with a gauge pad end wall 56, wherein the gauge pad 28 carries a single cutter 62 having a face 64 and a cutting edge 65 located radially inward of the gauge surface 29, and wherein the junction 58 of the gauge surface 29 and the gauge pad end wall 56 crosses, radially, between the face 64 of the cutter 62 and the wall 30 of the borehole 32.

Abstract: A drill bit for drilling a borehole, the drill bit comprising a bit body 10 having an axis of rotation 12, a leading face, a plurality of blades 26 upstanding from the leading face, at least one of the blades terminating in a gauge pad 28 having a gauge surface 29 arranged, in use, to face a wall 30 of the borehole 32, the gauge surface 29 being devoid of cutting elements, the gauge surface 29 terminating at an end thereof remote from the blade at a junction 58 with a gauge pad end wall 56, wherein the gauge pad 28 carries a single cutter 62 having a face 64 and a cutting edge 65 located radially inward of the gauge surface 29, and wherein the junction 58 of the gauge surface 29 and the gauge pad end wall 56 crosses, radially, between the face 64 of the cutter 62 and the wall 30 of the borehole 32.

Abstract: A drill bit for drilling a borehole having a bit body with an axis of rotation, a leading face, and a plurality of blades upstanding from the leading face. At least one of the blades terminates in a gauge pad having a gauge surface arranged, in use, to face a wall of the borehole. The gauge surface being devoid of cutting elements and terminating at an end remote from the blade at a junction with a gauge pad end wall. The gauge pad carries a cutter having a face and a cutting edge located radially inward of the gauge surface, and the junction of the gauge surface and the gauge pad end wall crosses, radially, between the face of the cutter and the wall of the borehole. The gauge surface may be a substantially continuous surface, and may have at least one additional cutter located angularly between two adjacent blades of the drill bit.

Abstract: A variable temperature portable cautery includes a housing configured to retain a voltage source, such as a plurality of batteries, and an electrically heated cautery tip carried by the front end of the housing in operative relation with each other. A manually operable switch is provided on the housing to allow selective energization of the cautery tip from the voltage source. A rotatably adjustable variable resistor is mounted on the rear end of the housing and is connected in circuit between the voltage source and heated tip to allow the temperature of the tip to be selectively varied. The movable contact of the switch and the wiper contact of the variable resistor are provided by the respective ends of a common conductor member extending longitudinally in the housing.