John D Duke

US Patent:

43066267, Dec 22, 1981

Filed:

May 21, 1980

Appl. No.:

6/151865

Inventors:

John W. Duke - Stockbridge GA
John A. Duke - Stockbridge GA

International Classification:

E21C 510
E21C 900

US Classification:

173 35

Abstract:

A hydraulic earth boring machine for forming conduit passageways beneath established surfaces such as roadways, walkways, or the like. The boring machine includes a hydraulic cylinder having an open axial passageway for receiving a boring shaft. A drive cylinder surrounds the boring shaft and is driven by the hydraulic cylinder. A gripping assembly is mounted upon a trailing end of the drive cylinder and selectively couples the drive cylinder to the boring shaft. An elevating and vertical aiming assembly is mounted upon the hydraulic cylinder for facilely providing positioning of the boring machine, in situ, within an earth trench. In addition, an axial bracing and horizontal angling assembly is mounted upon the cylinder for mounting the boring machine within the trench adjacent an established surface.

US Patent:

43846246, May 24, 1983

Filed:

Feb 25, 1981

Appl. No.:

6/238028

Inventors:

John W. Duke - Stockbridge GA
John A. Duke - Stockbridge GA

International Classification:

E21C 900

US Classification:

175 19

Abstract:

An earth boring head comprising a generally conical earth boring member having a forward portion and a rearward portion. At least one aperture is fashioned in a forward portion of the earth boring member for liberating a lubricating fluid around the rearward portion of the conical member as the member is moved through an earth formation. In a preferred embodiment the conical earth boring member is fitted with a generally conical pilot member coaxially mounted in front of the conical earth boring member.