United States Patent [19] [in Patent Number: 4,974,688
Helton [45] Date of Patent: Dec. 4, 1990
[54] STEERABLE EARTH BORING DEVICE
[75] Inventor: Gary B. Helton, Danville, Ind.
[73] Assignee: Public Service Company of Indiana, Inc., Plainfield, Ind.
[21] Appl. No.: 378,065
[51] Int. a.5 E21B 7/08; E21B 10/44
[52] U.S. a 175/73; 175/61;
175/323; 175/382; 175/394
[58] Field of Search 175/74, 73, 61, 62,
175/323, 382, 384, 394
[56] References Cited
U.S. PATENT DOCUMENTS
3,326,008 6/1967 Baran et al 175/73
3,526,285 9/1970 Adkins et al 175/73
3,565,190 2/1971 Ishii 175/171
3,743,034 7/1973 Bradley 175/73
4,013,134 3/1977 Richmond et al 175/73
4,026,371 5/1977 Takada et al 175/73 X
4,342,346 8/1977 Capoccia 175/73
4,374,547 2/1983 Nguyen et al 175/45
4,396,073 8/1983 Reichman et al 175/74
4,571,122 2/1986 Yamamoto et al 175/62 X
4,655,299 4/1987 Schoeffler 175/38
4,674,579 6/1987 Geller et al 175/45
4,714,118 12/1987 Baker et al 175/26
4,787,463 11/1988 Geller et al 175/45
Primary Examiner—Hoang C. Dang
Attorney, Agent, or Firm—Woodard, Emhardt,
Naughton Moriarty & McNett
[57] ABSTRACT
A steerable earth boring device comprises a compaction auger rotatably mounted to a housing at one end of the auger such that the compaction auger is substantially externally exposed. A steering tip is pivotably disposed at the other end of the compaction auger for providing steering control for the earth boring device. An internally housed steering mechanism is provided for pivoting the steering tip relative to the compaction auger while the auger is rotating. The steering mechanism includes a non-rotatable cam disposed within and pivotably connected to the housing and a follower rotatable with and pivotable relative to the compaction auger. The cam and follower contact at a bearing surface so that pivoting motion of the cam is transmitted to the rotatable follower. A control member is connected between the follower and the steering tip, extending through the compaction auger, to transmit pivoting of the follower to pivoting of the steering tip.
12 Claims, 4 Drawing Sheets
