Patent ID: 7992652

Claim:
A fluid distributor cylinder for a percussive drill assembly, the drill assembly including a casing having an inner circumferential surface defining a central bore, a first central axis extending through the central bore, a bit movably coupled to the casing, and a piston movably disposed within the central bore, the distributor cylinder comprising: a generally tubular body disposeable within the central bore of the casing, the body including first and second ends, a second central axis extending generally between the first and second ends, an outer circumferential surface, at least a portion of the outer surface being configured to engage the inner surface of the casing to form an interference fit between the body and the casing, and an exterior thread configured to releasably engage the inner surface of the casing to substantially prevent axial displacement of the body with respect to the casing; wherein the inner surface of the casing has an inside diameter and substantially the entire outer surface of the body has an outside diameter, the body being sized such that the outside diameter is greater than the inside diameter when the distributor cylinder is separate from the casing.