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US 5,372,209 AGranted
Polycentric reamer
AssigneeDCD, Ltd.
InventorsLudvig A. Raihert, Takov A. Edelman, Alexey G. Messer, Abeksandr N. Sorokin, Sergej P. Krivonenkov, Rudolf S. Alikin, Yaroslaw S. Gavrilov
Life of this patent
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Abstract
A polycentric reamer having a body thrust unit and reaming unit is especially useful for locally reaming a borehole beneath a casing string. By asymmetrically positioning a reaming unit within a body formed from non-coaxial mated cylinders, superior results are achieved. These results include minimizing wear on the casing string.
Claims15
A polycentric reamer for reaming bore holes, which comprises:
- (a) a body with an upper connection thread, said thread having an axis, and a longitudinal channel, said longitudinal channel having an axis, formed by several non-coaxial cylinders mated to each other, each of said cylinders having an axis;
- (b) a thrust unit;
- (c) a reaming unit positioned asymmetrically within the body, the reaming unit including at least one cone mounted on a supporting shaft, said supporting shaft having an axis, so that in a plane perpendicular to the thread axis and passing through the cone point furthest from the thread axis, (i) the distance from the thread axis to the furthest point of the body's circumference surpasses the distance from the thread axis to the cone point furthest from the thread axis, and (ii) a circle drawn around the body and centered beyond the thread axis intersects a circle drawn around the reamer at the cone point furthest from the thread axis and centered at the thread axis, so that a portion of the body inscribing circle extends beyond the reamer inscribing circle.
Dependencies are inferred from the claim text.