Boring bit and method of manufacture

Abstract

A boring bit has a shank, a head and teeth distributed around the head. The teeth have a root embedded within the head's core body, a tip extending out of the head, and a narrowing region between the root and the tip. More than approximately two-thirds of the tooth length is embedded in the core body, including a portion of the narrowing region. Stabilizing rods are welded to the tips of the teeth to form a temporary connection, and the core body is formed from a molten metal poured into a cavity of a cast mold. The rods are inserted into indentations in the cast to hold the teeth in place, and the molten metal heats the teeth and weld to substantially loosen the temporary connection. As the molten metal cools, it solidifies around the teeth and secures the root and narrowing region of the teeth within the core body.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority from U.S. Provisional Patent Application No. 61 / 786,516 filed on Mar. 15, 2013 which is hereby incorporated by reference.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH[0002]Not Applicable.APPENDIX[0003]Not Applicable.BACKGROUND OF THE INVENTION[0004]1. Field of the Invention[0005]The present invention relates to boring bits for the drilling heads of directional boring machines, and more particularly to the design and method of manufacture of the teeth used in the boring bits.[0006]2. Related Art[0007]Boring bits are used in a number of directional boring machines. Generally, directional boring or horizontal directional drilling (HDD) is a steerable trenchless method of installing pipes, conduits and cables along an underground route that is formed from a drilling rig at one end of the route. There are different types of heads used in the pilot-hole process, and they depend on the geological material.[000...

AI Technical Summary

Benefits of technology

[0011]In another aspect of the invention, stabilizing rods are welded to the tips of the teeth to form a temporary connection, and the core body is formed from a molten metal poured into a cavity of a cast mold. The stabilizing rods are inserted into indentations in the cast to hold the teeth in place, and the molten metal heats the teeth and the weld and substantially loosens the temporary connection. As the molten metal cools, it solidifies around the teeth and secures the root and narrowing region of the teeth within the core body.

Problems solved by technology

However, the fluid exits at multiple conduits at different angles which vary from the axis of the drill stem and beacon housing unit so the fluid does not provide any significant assistance in the steering of the head.

However, the carbide teeth are not typically formed in situ with the body of the bit during the casting process for current boring bits.

For those manufacturing methods which incorporate teeth into the cast while molten metal is poured into the cast's cavities, these methods do not provide a good way to temporarily hold the teeth to indentations in the cast while the molten metal fills around the teeth and loosen the hold on the teeth as the metal solidifies.

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