Alan F Lang

US Patent:

48238902, Apr 25, 1989

Filed:

Feb 23, 1988

Appl. No.:

7/159358

Inventors:

Alan F. Lang - Sandy UT

Assignee:

Longyear Company - Salt Lake City UT

International Classification:

F21B 2110
F21B 2112

US Classification:

175318

Abstract:

A reverse circulation deep hole rock bit that includes a drill bit connector tube telescopically extended into a drill bit housing to cooperatively form a part of a radial inner fluid channel for cuttings to flow axially outwardly and a radial outer annular clearnace space, a plurality of angularly spaced pressurized fluid passage that open to the annular space and a check valve in each fluid fluid passage to permit inward flow of fluid, but to block fluid flow in the opposite direction. A plurality of angularly spaced cutter arms have arcuate tubular segments secured to axial and radial outer portions of the arms while a radially inner tubular skirt is secured to or abuts against the axial outer portions of the arms. The combination of segments, arms and skirt are secured to the housing to extend inwardly thereof with the skirt forming part of the radial inner return channel while each passage opens to a separate chamber angularly between adjacent arms to direct pressurized fluid to flow between the rotary cutters that are mounted by the arms and convey cuttings outwardly through the radial inner fluid channel.