Boring or penetrating the earth – Bit or bit element – Rolling cutter bit or rolling cutter bit element
Reexamination Certificate
1997-03-06
2001-06-19
Tsay, Frank (Department: 3625)
Boring or penetrating the earth
Bit or bit element
Rolling cutter bit or rolling cutter bit element
C175S398000
Reexamination Certificate
active
06247544
ABSTRACT:
I. BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to directional boring machines. More particularly, this invention pertains to a directional boring machine with a novel duckbill for facilitating penetration of the earth.
2. Description of the Prior Art
Directional boring machines are well known. An example of such a machine is shown in U.S. Pat. No. 4,953,638.
In directional boring machines, a plurality of pipe segments are threadedly interconnected to form a drill string. A terminal end of the drill string is provided with a drill head. An above-ground end of the drill string is rotated and longitudinally advanced by a boring machine. Through manipulation of the boring machine, the drill head can be forced through the earth to form a bore. Drill heads come in a variety of shapes and configurations.
The '638 patent shows a particular design of a drill head which includes a metal plate (item 72 in
FIG. 6
) attached to a drill head where the metal plate extends forwardly from the drill head. In the industry, such a metal plate is referred to as a duckbill. The duckbill assists in penetrating the earth as the drill string is rotated. Further, the angled inclination of the duckbill relative to the axis of rotation of the drill head encourages the drill string to be moved in a curved direction when the drill head is being longitudinally advanced without rotation.
Underground directional boring machines are used to form bores through a wide variety of soil conditions. Flat duckbills such as that shown in
FIG. 6
of the '638 patent are adequate for soft soil conditions. However, such drill heads may not be satisfactory for rock or other hard soil conditions. In such conditions, it would be desirable to provide additional cutting teeth on the duckbill to facilitate cutting through the soil conditions. An example of a duckbill with cutting members is shown in U.S. Pat. No. 5,148,880 in
FIGS. 29-31
.
II. SUMMARY OF THE INVENTION
According to a preferred embodiment of the present invention, a directing blade for a directional boring machine is disclosed. The directing blade includes a blade body which extends along the longitudinal axis from an attachment end to a free end. The attachment end is attachable to a blade attachment surface of a drill head. The terminal end of the blade body includes a plurality of cutting teeth secured thereto. The teeth are disposed in a non-symmetrical pattern relative to a longitudinal axis of the blade body.
REFERENCES:
patent: 2701126 (1955-02-01), McClennan
patent: 2815933 (1957-12-01), Dionisotti
patent: 4953638 (1990-09-01), Dunn
patent: 5067262 (1991-11-01), Stiffler et al.
patent: 5148880 (1992-09-01), Lee et al.
patent: 5242026 (1993-09-01), Deken et al.
patent: 5341887 (1994-08-01), Deken et al.
patent: 5392868 (1995-02-01), Deken et al.
patent: 5526886 (1996-06-01), Jenne
patent: 5597046 (1997-01-01), Fisk
patent: 5647448 (1997-07-01), Skaggs
patent: 5687807 (1997-11-01), Woods et al.
patent: 5778991 (1998-07-01), Runquist et al.
patent: 5799740 (1998-09-01), Stephenson et al.
patent: 5899283 (1999-05-01), Cox
patent: 5941322 (1999-08-01), Stephenson et al.
patent: 5950743 (1999-09-01), Cox
patent: WO 97/33065 (1997-09-01), None
Exhibit 1, photo of prior art cutting blade (admitted prior art).
“4th Generation Drill Head Assembly”. Straightline Directional Tooling—Training Seminar, 1 p., Jun. 14, 1996.
“Barbco Directional Tooling for All Makes, All Models, All Soil Conditions”, Barbco, Inc., 1 p., (undated).
Merchant & Gould P.C.
Tsay Frank
Vermeer Manufacturing Company
LandOfFree
Duckbill with cutting teeth does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Duckbill with cutting teeth, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Duckbill with cutting teeth will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2530398