Patent ID: 6427788
Filing Date: 2002-08-06
Classification: E21B

Abstract:
An underreaming tool comprising:a substantially hollow tubular body having at least one pivot pin bore and at least one pivot pin retaining cover slot formed therein, said at least one pivot pin bore located within said at least one pivot pin retaining cover slot; a mandrel mounted substantially within said hollow tubular body, said mandrel being axially movable between a blade retracting position and a blade extending position; at least one cutting blade pivotably mounted to said hollow tubular body, said at least one cutting blade being operatively associated with said mandrel for selective retraction and extension with respect to said substantially hollow tubular body, said cutting blade having a pivot pin bore formed therein; a pivot pin slidably insertable into said at least one pivot pin bore of said hollow tubular body and said pivot pin bore of said cutting blade for pivotably attaching said at least one cutting blade to said substantially hollow tubular body; and a pivot pin retaining cover operable to be received in said at least one pivot pin retaining cover slot to cover an end of said pivot pin.