US PATENT SUBCLASS 175 / 398
.~ Nonsymmetrical bit


Current as of: June, 1999
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175 /   HD   BORING OR PENETRATING THE EARTH

327  DF  BIT OR BIT ELEMENT {21}
398.~ Nonsymmetrical bit {2}
399  DF  .~.~> With bore wall engaging guide
400  DF  .~.~> Nonsymmetrical arrangement of opening for cuttings or fluid


DEFINITION

Classification: 175/398

(under subclass 327) 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.

(1) Note. For the purposes of this subclass an element has bilateral symmetry when each part thereof lying on one side of a plane passing therethrough has a corresponding part lying on the opposite side of the plane at an equal distance from the plane and on a line through the parts and perpendicular to the plane. An element has radial symmetry when it can be divided into a plurality of segments radially about the axis of symmetry each of which has the same shape and size and the sum of the radial angles of all the segments equals 360 degrees.

(2) Note. Patents in which the claims would meet the terms of the definition of this subclass because only a portion of a specifically described bit has been claimed are excluded if the entire bit as described would not meet the terms of the definition. Such patents have been classified on other features.

(3) Note. The external form of the bit is considered to include the configuration and location of cutter elements, cutting edges, fluid or cuttings conveying ports or the shape of the bit head, however, a lug or recess or opening for the purpose of connecting the parts of the bit or the bit to the drive shaft are not included, such as, for example, an opening for a single set screw or a flat on the bit head to be received in a socket. Also the internal shape of fluid, cuttings or core conveying passages are not included.

SEE OR SEARCH THIS CLASS, SUBCLASS:

376, for a nonsymmetrical roller type bit. 394+, for a bit having a helical conveying portion.

397, for a forked rotary nontracking bit.