U.S. patent application number 11/840961 was filed with the patent office on 2008-02-21 for earth bit having a screen.
This patent application is currently assigned to ATLAS COPCO SECOROC LLC. Invention is credited to Gregory W. Peterson.
Application Number | 20080041633 11/840961 |
Document ID | / |
Family ID | 39100296 |
Filed Date | 2008-02-21 |
United States Patent
Application |
20080041633 |
Kind Code |
A1 |
Peterson; Gregory W. |
February 21, 2008 |
EARTH BIT HAVING A SCREEN
Abstract
An earth bit includes an earth bit body having a bore with a
bearing passageway in fluid communication therewith. A screen
extends through the bore and is repeatably moveable between rolled
and unrolled conditions. The screen is in the rolled condition when
extending through the bore. The screen screens a material flowing
between the bore and bearing passageway.
Inventors: |
Peterson; Gregory W.; (Fort
Worth, TX) |
Correspondence
Address: |
SCHMEISER OLSEN & WATTS
18 E UNIVERSITY DRIVE, SUITE # 101
MESA
AZ
85201
US
|
Assignee: |
ATLAS COPCO SECOROC LLC
Grand Prairie
TX
|
Family ID: |
39100296 |
Appl. No.: |
11/840961 |
Filed: |
August 18, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60822913 |
Aug 18, 2006 |
|
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|
Current U.S.
Class: |
175/339 ;
175/340 |
Current CPC
Class: |
E21B 10/18 20130101;
E21B 10/20 20130101; E21B 10/23 20130101 |
Class at
Publication: |
175/339 ;
175/340 |
International
Class: |
E21B 10/00 20060101
E21B010/00 |
Claims
1. An earth bit, comprising: an earth bit body having a bore with a
bearing passageway in fluid communication therewith; and a screen
extending through the bore, the screen being repeatably moveable
between rolled and unrolled conditions.
2. The earth bit of claim 1, wherein the screen is in the rolled
condition when extending through the bore.
3. The earth bit of claim 1, wherein the screen is biased against
the earth bit body when extending through the bore.
4. The earth bit of claim 1, wherein the screen covers the bearing
passageway when extending through the bore.
5. The earth bit of claim 1, wherein the screen screens a material
flowing between the bore and bearing passageway.
6. The earth bit of claim 1, wherein opposed ends of the screen are
proximate to each other when the screen is in the rolled
condition.
7. The earth bit of claim 1, further including a shroud carried by
the screen, the shroud being positioned proximate to the bearing
passageway.
8. An earth bit, comprising: an earth bit body having a bore with
nozzle and bearing passageways in fluid communication therewith;
and a screen which extends through the bore and between the nozzle
and bearing passageways.
9. The earth bit of claim 8, wherein the screen is repeatably
moveable between rolled and unrolled conditions.
10. The earth bit of claim 8, wherein the screen is in the rolled
condition when extending between the nozzle and bearing
passageways.
11. The earth bit of claim 10, wherein the screen is biased against
the earth bit body when extending between the nozzle and bearing
passageways.
12. The earth bit of claim 8, wherein the screen screens a material
flowing between the bore and the nozzle and bearing
passageways.
13. The earth bit of claim 8, further including a shroud positioned
to divert a material flow between the bore and bearing
passageway.
14. The earth bit of claim 13, wherein the shroud is carried by the
screen.
15. An earth bit, comprising: an earth bit body having a bore with
a bearing passageway in fluid communication therewith; a screen
which extends through the bore and screens a material flowing
between the bore and bearing passageway; and a shroud positioned to
restrict the flow of the material between the bore and bearing
passageway.
16. The earth bit of claim 15, wherein the shroud includes a shroud
opening that faces downstream from the material flow.
17. The earth bit of claim 16, wherein the screen screens the
material flowing through the shroud.
18. The earth bit of claim 15, wherein the screen covers an opening
of the bearing passageway that faces the bore.
19. The earth bit of claim 15, wherein the screen is repeatably
moveable between rolled and unrolled conditions.
20. The earth bit of claim 15, wherein the screen is biased against
the earth bit body.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims priority to U.S. Provisional
Application No. 60/822,913 filed in Aug. 18, 2006, the contents of
which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to earthboring tools for
boring a hole.
[0004] 2. Description of the Related Art
[0005] Earthboring tools are commonly used to bore holes by cutting
through earthen annulus. Such holes may be bored for many different
reasons, such as drilling for oil, minerals and water. One type of
earthboring tool used for boring is a rotary earth bit. Several
examples of rotary earth bits are disclosed in U.S. Pat. Nos.
3,550,972, 3,847,235, 4,136,748, 4,427,307, 4,688,651, 4,741,471
and 6,513,607. A rotary earth bit generally includes three lugs
coupled together to form an earth bit body having a bore extending
therethrough. A cutting cone is rotatably mounted to each lug with
a journal, which includes ball and roller bearings. The lug rotates
in response to the rotation of the earth bit. The cutting cones are
engaged with the roller and ball bearings and rotate about the
journal in response to contacting earthen annulus.
[0006] A drilling fluid, such as water and/or air, typically flows
through the bore. A portion of the drilling fluid is flowed through
a nozzle to spray material, such as earthen annulus, away from the
cutting cone. Another portion of the drilling fluid is flowed
through a bearing passageway and towards the cutting cone and
journal. The portion of the drilling fluid flowed through the
bearing passageway is used to cool the cutting cone and journal, as
well as the lubricating material. In this way, the earth bit
operates at a lower temperature. However, it is desirable to
control the flow of material through the bearing and nozzle
passageways.
BRIEF SUMMARY OF THE INVENTION
[0007] The present invention employs a screen for use with an earth
bit. The earth bit includes an earth bit body having a bore with
bearing and nozzle passageways in fluid communication therewith.
The screen is biased against the earth bit body when extending
through the bore. The screen extends through the bore and between
the nozzle and bearing passageways and screens a material flowing
between the bore and bearing and nozzle passageways. The material
is generally drilling fluid which includes water and air.
[0008] In some embodiments, a shroud is positioned to divert the
flow of the material between the bore and bearing passageway. The
flow of the material is diverted to reduce the amount of water that
enters into the bearing passageway. In this way, the shroud is
positioned to restrict the flow of the water between the bore and
bearing passageway. The shroud is carried by the screen and
includes a shroud opening that faces downstream from the fluid
flow. The material that flows between the shroud opening and
bearing passageway is screened by the screen.
[0009] Further features and advantages of the invention will be
apparent to those skilled in the art from the following detailed
description, taken together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a perspective view of an earth bit having a
screen, in accordance with the invention.
[0011] FIG. 2a is a cut-away view of the earth bit of FIG. 1 taken
along a cut-line 2-2.
[0012] FIG. 2b is a bottom view of the earth bit and screen of FIG.
1, in accordance with the invention.
[0013] FIGS. 3a and 3b are perspective views of a screen in
unrolled and rolled conditions, respectively.
[0014] FIGS. 4a and 4b are end views of the screen of FIG. 3b in
the rolled condition.
[0015] FIG. 5a is a perspective view of a shroud, in accordance
with the invention.
[0016] FIG. 5b is a partial cut-away view of a region of the earth
bit of FIG. 2a showing the shroud of FIG. 5a being carried by the
screen.
[0017] FIGS. 6 and 7 are flow diagrams of methods of assembly an
earth bit with a screen, in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] FIG. 1 is a perspective view of an earth bit 100 having a
screen, in accordance with the invention. FIG. 2a is a cut-away
view of earth bit 100 taken along a cut-line 2-2 of FIG. 1, showing
a bore 110 and screen 112. FIG. 2b is a view of screen 112 and bore
110 looking in a direction 128 of FIG. 2a. Earth bit 100 includes
several earth bit components assembled together. In this
embodiment, these components include three lugs 102 coupled
together to form an earth bit body 101 having a bore 110 (FIG. 2a)
extending therethrough. In this particular embodiment, earth bit
100 includes three cutting cones 103 rotatably mounted to
corresponding lugs 102 with journals 104, so that earth bit 100 is
a tri-cone earth bit. Journal 104 includes ball and roller bearings
106 and 107, respectively, which engage cutting cone 103 so that
cutting cone 103 is rotatably mounted thereto.
[0019] In this embodiment, bore 110 is in fluid communication with
a bearing passageway 108 and a nozzle passageway 111. Bore 110 is
in fluid communication with bearing passageway 108 and nozzle
passageway 111 through openings 110a and 110b, respectively.
Bearing passageway 108 extends through earth bit body 101 and
between bore 110 and journal 104. Nozzle passageway 111 extends
through earth bit body 101 and between bore 110 and a nozzle 105.
It should be noted that earth bit 100 generally includes one
bearing passageway for each lug it includes. Further, earth bit 100
generally includes one nozzle and nozzle passageway for each
cutting cone it includes, wherein the nozzle is directed at a
corresponding cutting cone.
[0020] In operation, lug 102 rotates in response to the rotation of
earth bit 100. Cutting cone 103 is engaged with ball and roller
bearings 106 and 107 and rotates, in response to contacting earthen
annulus, about journal 104. A drilling fluid, such as water and/or
air, is often flowed through bore 110. A portion of the drilling
fluid is flowed through nozzle passageway 111 and nozzle 105 to
spray material, such as earthen annulus, away from cutting cone
103. Earth bit 100 operates more efficiently if material is sprayed
away from cutting cone 103 with drilling fluid.
[0021] Another portion of the drilling fluid is flowed through
bearing passageway 108 and towards cutting cone 103 and journal
104. The portion of the drilling fluid flowed through bearing
passageway 108 is used to reduce the temperature of cutting cone
103 and journal 104. In this way, earth bit 100 operates at a lower
temperature. However, it is desirable to control the flow of
material through bearing passageway 108 and nozzle passageway
111.
[0022] In accordance with the invention, screen 112 is positioned
in bore 110 to cover openings 110a and 110b, as indicated by a
substitution arrow 129 in FIG. 2a. Screen 112 is repeatably
moveable between positions where it is away from bore 110 and where
it extends through bore 110. Screen 112 can be made of many
different materials, such as metal. The material included with
screen 112 is chosen so that screen 112 is flexible and it can be
repeatably moved between rolled and unrolled conditions.
[0023] When in the rolled condition, screen 112 is biased to move
to the unrolled condition. In this way, screen 112 applies a force,
denoted as force F, to earth bit body 101 when it extends through
bore 110 (FIG. 2b). An outer periphery 115 of screen 112
frictionally engages earth bit body 101 in response to force F. It
should be noted, however, that screen 112 can be engaged with bore
110 in many other ways, such as by welding or with fasteners.
[0024] Screen 112 extends between openings 110a and 110b and covers
them. In this way, screen 112 extends through bore 110 and between
bearing passageway 108 and nozzle passageway 111. Screen 110
includes openings which allow the drilling fluid to flow
therethrough. However, the openings of screen 110 are shaped and
dimensioned to restrict the flow of undesirable material through
openings 110a and 110b. The undesirable material can be of many
different types, such as abrasive material like earthen
annulus.
[0025] FIGS. 3a and 3b are perspective views of screen 112 in
unrolled and rolled conditions, respectively. It should be noted
that screen 112 is in the rolled condition when extending through
bore 110. In this embodiment, screen 112 is a rectangular piece of
material with openings extending through it. It should be noted
that screen 112 can be of many other shapes, but a rectangular
shape is shown here for illustrative purposes. Screen 112 has
opposed sides 113a and 113b, as well as opposed sides 113c and
113d. Sides 113a and 113b have a width dimension denoted as
W.sub.screen and sides 113c and 113d have a length dimension
denoted as L.sub.screen.
[0026] In the unrolled condition, sides 113a, 113b, 113c and 113d
extend linearly because screen 112 is a rectangular piece of
material. Further, in the unrolled condition, sides 113a and 113b
are away from each other, and sides 113c and 113d are away from
each other. In the rolled condition, sides 113a and 113b are away
from each other and sides 113c and 113d are towards each other. It
should be noted that sides 113a and 113b curve in response to
moving sides 113c and 113d towards each other. Sides 113c and 113d
extend linearly and, when they are proximate to each other, sides
113a and 113b define opposed openings 114a and 114b, respectively,
wherein openings 114a and 114b have a diameter d.sub.screen.
[0027] FIGS. 4a and 4b are end views of screen 112 in the rolled
condition. In this embodiment screen 112 is rolled so it has
diameter d.sub.screen. Diameter d.sub.screen is variable and
depends on the dimensions of screen 112 and the amount of overlap
between sides 113c and 113d, as indicated by an indication arrow
116 in FIG. 4a. Sides 113c and 113d generally overlap by a distance
D.sub.1 when they are proximate to each other and are engaged
together in a region 117. It should be noted that distance D.sub.1
and region 117 increase as the amount of overlap between sides 113c
and 113d increases. Further, distance D.sub.1 and region 117
decrease as the amount of overlap between sides 113c and 113d
decreases.
[0028] When sides 113c and 113d engage each other, but do not
overlap, they form an interface 119, as indicated by an indication
arrow 118 in FIG. 4b. It should be noted that sides 113c and 113d,
as shown in FIGS. 4a and 4b, can be held together, if desired.
Sides 113c and 113d can be held together in many different ways,
such as with a weld and a fastener.
[0029] FIG. 5a is a perspective view of a shroud 121, in accordance
with the invention. In this embodiment, shroud 121 includes an open
end 122 and a closed end 123, and opposed sides 126 and 127 which
extend therebetween. A shroud opening 124 extends through open end
122 and a shroud channel 125 extends between open and closed ends
122 and 123, as well as opposed sides 126 and 127.
[0030] FIG. 5b is a partial cut-away view of a region 119, as shown
in FIG. 2a, of earth bit 100. In this embodiment, shroud 121 is
carried by screen 112 within bore 110 and proximate to opening 110a
of bearing passageway 108. Shroud 121 is positioned so that open
end 122 and closed end 123 are positioned upstream and downstream,
respectively, relative to opening 110a. In this way, shroud opening
124 is positioned downstream from opening 110a and bearing
passageway 108. It should be noted that screen 112 extends between
open and closed ends 122 and 123, as well as opposed sides 126 and
127, so that it extends along shroud channel 125.
[0031] Shroud 121 can be carried by screen 112 in many different
ways. For example, it can be fastened to screen 112 using a
fastener, weld or an adhesive. In other examples, shroud 121
includes hooks which hook to screen 112. Shroud 121 can be
removably attached to screen 112 or it can be attached to screen
112 so it is repeatably removeable therefrom.
[0032] In operation, drilling fluid flows through bore 110 from
closed end 123 towards open end 122 of shroud 121. In this example,
the drilling fluid includes water and air. The water flows past
shroud 121 and a portion of the air is diverted through opening
124, where it flows upstream through channel 125 to opening 110a.
The air flows through screen 112 and into opening 110a and bearing
passageway 108 to the earth bit component discussed above. In this
way, shroud 121 diverts a material flow between bore 110 and
bearing passageway 108 and allows a portion of the drilling fluid
to flow upstream so it can enter bearing passageway 108.
[0033] The change in direction (i.e. diversion) of the flow of the
drilling fluid reduces the amount of water in the air that flows
into bearing passageway 108. It is useful to reduce the amount of
water that enters into bearing cavity 109 because this increases
bearing performance and bit life. The portion of the drilling fluid
that does not flow through shroud opening 124 generally flows
through nozzle passageway and nozzle 105, as shown in FIG. 2a.
[0034] FIG. 6 is a flow diagram of a method 200 of assembling an
earth bit, in accordance with the invention. Method 200 includes a
step 201 of providing lugs coupled together to form an earth bit
body with a bore extending therethrough. A first bearing passageway
extends through the lug and is in fluid communication with the
bore.
[0035] In a step 202, a screen is provided, wherein the screen is
repeatably moveable between rolled and unrolled conditions. In some
embodiments, the screen is provided in the rolled condition and, in
other embodiments, the screen is provided in the unrolled condition
and moved to the rolled condition.
[0036] In step 202, the screen is extended through the bore so it
covers an opening of the first bearing passageway that faces the
bore. In some embodiments, when the screen is in the rolled
condition, it is biased to move to the unrolled condition. The
screen engages the earth bit body in the bore when it extends
therethrough and is biased to move to the unrolled condition. In
other embodiments, the screen is held in the rolled condition. The
screen can be held in the rolled condition in many different ways,
such as with a fastener and weld.
[0037] It should be noted that, in some embodiments, a second
bearing passageway extends through the lug and is in fluid
communication with a nozzle. In these embodiments, the screen
covers an opening of the second bearing passageway that faces the
bore. The screen extends between the openings of the first and
second bearing passageways.
[0038] FIG. 7 is a flow diagram of a method 210 of assembling an
earth bit, in accordance with the invention. Method 210 includes a
step 211 of providing an earth bit with a bore extending
therethrough. In this embodiment, the earth bit includes a lug with
a first bearing passageway extending through the lug and in fluid
communication with the bore.
[0039] In a step 212, a screen is provided, wherein the screen is
repeatably moveable between rolled and unrolled conditions. In some
embodiments, the screen is provided in the rolled condition and, in
other embodiments, the screen is provided in the unrolled condition
and moved to the rolled condition.
[0040] In a step 213, a shroud is provided and attached to the
screen. In a step 214, the screen is extended through the bore so
it covers an opening of the first bearing passageway that faces the
bore. The screen is positioned so that the shroud is proximate to
the first bearing passageway. In some embodiments, when the screen
is in the rolled condition, it is biased to move to the unrolled
condition. The screen engages the earth bit body in the bore when
it extends therethrough and is biased to move to the unrolled
condition. In other embodiments, the screen is held in the rolled
condition. The screen can be held in the rolled condition in many
different ways, such as with a fastener and weld.
[0041] While particular embodiments of the invention have been
shown and described, numerous variations and alternate embodiments
will occur to those skilled in the art. Accordingly, it is intended
that the invention be limited only in terms of the appended
claims.
* * * * *