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Class Information
Number: 175/391
Name: Boring or penetrating the earth > Bit or bit element > Bit with leading portion (e.g., pilot) forming smaller diameter initial bore > Plural larger diameter steps
Description: Apparatus in which the cutting edges of the bit are arranged so that the boring outline of the bit will describe at least two peripheral axial steps.
Patents under this class:
| Patent Number |
Title Of Patent |
Date Issued |
| RE32267 |
Process for drilling underground arcuate paths and installing production casings, conduits, or flow pipes therein |
Oct. 21, 1986 |
| 4478295 |
Tuned support for cutting elements in a drag bit |
Oct. 23, 1984 |
| 4448269 |
Cutter head for pit-boring machine |
May. 15, 1984 |
| 4391467 |
System for producing a uniform rubble bed for in situ processes |
Jul. 5, 1983 |
| 4380271 |
Earth auger with removable cutting tooth support structure |
Apr. 19, 1983 |
| 4373594 |
Rotary drill bit |
Feb. 15, 1983 |
| 4324300 |
Rotary drill bit |
Apr. 13, 1982 |
| 4319648 |
Process for drilling underground arcuate paths and installing production casings, conduits, or flow pipes therein |
Mar. 16, 1982 |
| 4207954 |
Core bit having axial conical core breaker |
Jun. 17, 1980 |
| 4116289 |
Rotary bit with ridges |
Sep. 26, 1978 |
| 4098363 |
Diamond drilling bit for soft and medium hard formations |
Jul. 4, 1978 |
| 4073354 |
Earth-boring drill bits |
Feb. 14, 1978 |
| 4049067 |
Cutter mounting extension apparatus |
Sep. 20, 1977 |
| 4046207 |
Earth drilling tools |
Sep. 6, 1977 |
| 4031974 |
Boring apparatus capable of boring straight holes |
Jun. 28, 1977 |
| 4010808 |
Expandable raise bit |
Mar. 8, 1977 |
| 3967689 |
Reaming apparatus |
Jul. 6, 1976 |
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