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US 2003/0141114 A1Published application
Drill bit for trenchless drilling
AssigneeSandvik Rock Tools, Inc.
InventorsGary A. Fuller, Kenneth Monyak, Thomas J. Maechler
Life of this patent
Estimating the term…
Abstract
A drill bit for trenchless drilling includes a bit body defining a longitudinal axis about which the drill bit is rotated during a trenchless drilling operation. Two sets of cutting teeth are mounted at a front end of the bit body, the sets disposed on opposite sides of the axis. The first and second sets are brazed into respective slots formed in the first and second side surfaces of the bit body. The slots on each side surface communicate with a common groove, wherein the groove forms a shoulder against which rear ends of the cutting teeth abut.
Claims11
A drill bit for trenchless drilling comprising:
- a generally flat bit body including first and second side surfaces separated from one another by a thickness of the bit body, the bit body further including a front cutting end, and a rear mounting end adapted to be mounted to a rotary drill string, the bit body defining a longitudinal center axis extending through the mounting end and the cutting end;
- the cutting end including a front edge, and first and second grooves formed in the first and second side surfaces, respectively, each groove defining a generally forwardly facing shoulder spaced rearwardly from the front edge and being exposed to the front edge by a plurality of slots formed in the respective first and second side surfaces, each slot extending from the front edge of a respective groove in a direction oriented generally radially with reference to the front edge, the slots associated with each groove being spaced apart from one another along the front edge by lands formed by the bit body, each land including a rear end spaced forwardly from and facing the respective shoulder, the grooves and the slots extending only partially through the thickness of the bit body from the respective first and second side surfaces, wherein the bit body defines a floor extending from each shoulder to the front edge;
- and
- first and second sets of cutting teeth mounted to respective ones of the first and second side surfaces and disposed on opposite sides of the axis, each tooth including a front cutting end, and a rear mounting portion mounted in a respective one of the slots, wherein each mounting portion rests upon the floor associated with the respective slot, and a rear end of each tooth abuts against a respective one of the shoulders, the first set of teeth being arranged asymmetrically relative to the second set of teeth with reference to the axis.
1 more element
A method of manufacturing a drill bit for trenchless drilling, the method comprising the steps of:
- A) providing a bit body having first and second side surfaces, a rear mounting end, a front cutting end, and defining a longitudinal center axis extending from the mounting end to the cutting end;
- B) milling a groove into the first side surface of the bit body, wherein the groove is spaced rearwardly from a front edge of the bit body and forms a forwardly facing shoulder;
- C) milling a plurality of slots in the first side surface, wherein each slot extends from the front edge to the groove in a direction generally radially with reference to the front edge, the slots spaced apart along the front edge, wherein the bit body forms lands disposed between adjacent slots, each land including a rear end spaced forwardly from and facing the shoulder, the slots and the groove forming a floor extending from the front edge to the shoulder;
- D) positioning cutting teeth in respective ones of the slots such that each tooth includes a front cutting portion, and a rear end abutting the shoulder;
- E) securing the teeth to the bit body;
- and
- F) performing steps A-D with respect to the second side surface, wherein the teeth associated with the first side surface define a first set of teeth disposed on a first side of the axis, and the teeth associated with the second side surface define a second set of teeth disposed on a second side of the axis, the first set of teeth arranged asymmetrically relative to the second set of teeth with reference to the axis.
4 more elements
Dependencies are inferred from the claim text.