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Class Information
Number: 175/398
Name: Boring or penetrating the earth > Bit or bit element > Nonsymmetrical bit
Description: Apparatus in which the external physical form or shape of the bit is such that the bit has (1) no more than one plane of bilateral symmetry passing through a line coinciding with the longitudinal axis of the drive shaft for the bit and (2) no radial symmetry about an axis coinciding with the longitudinal axis of the drive shaft for the bit.
Sub-classes under this class:
Patents under this class:
| Patent Number |
Title Of Patent |
Date Issued |
| 4932484 |
Whirl resistant bit |
Jun. 12, 1990 |
| 4867255 |
Technique for steering a downhole hammer |
Sep. 19, 1989 |
| 4817741 |
Rotary drill |
Apr. 4, 1989 |
| 4815543 |
Activated rock cutting assembly |
Mar. 28, 1989 |
| 4770259 |
Drill tool |
Sep. 13, 1988 |
| 4635738 |
Drill bit |
Jan. 13, 1987 |
| 4620600 |
Drill arrangement |
Nov. 4, 1986 |
| 4456075 |
Weeding auger with U-shaped blade |
Jun. 26, 1984 |
| 4440244 |
Drill tool |
Apr. 3, 1984 |
| 4294319 |
Cutter head for rotary percussion drills |
Oct. 13, 1981 |
| 4202421 |
Impact bit having circumferential inserts of differing combination |
May. 13, 1980 |
| 4202420 |
Rock drill with hard metal drilling head |
May. 13, 1980 |
| 4196783 |
Device for boring |
Apr. 8, 1980 |
| 4074780 |
Earth auger |
Feb. 21, 1978 |
| 4002214 |
Drilling tool, especially for hammer drills |
Jan. 11, 1977 |
| 3960223 |
Drill for rock |
Jun. 1, 1976 |
| 3951220 |
Archimedes spiral drill bit |
Apr. 20, 1976 |
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