U.S. patent application number 13/635310 was filed with the patent office on 2013-01-10 for drilling apparatus with shutter.
This patent application is currently assigned to Vermeer Manufacturing Company. Invention is credited to Stuart Harrison, Keith Allen Hoelting, Andis Salins.
Application Number | 20130008723 13/635310 |
Document ID | / |
Family ID | 44649491 |
Filed Date | 2013-01-10 |
United States Patent
Application |
20130008723 |
Kind Code |
A1 |
Hoelting; Keith Allen ; et
al. |
January 10, 2013 |
DRILLING APPARATUS WITH SHUTTER
Abstract
The present disclosure relates to a drilling apparatus including
a cutting unit defining at least one through-hole that provides
fluid communication between a distal side and a proximal side of
the cutting unit. The cutting unit includes a plurality of cutting
elements at the distal side of the cutting unit. The cutting unit
also includes a shutter for selectively opening and blocking the
through-hole of the cutting unit.
Inventors: |
Hoelting; Keith Allen;
(Dallas, IA) ; Salins; Andis; (Footscray, AU)
; Harrison; Stuart; (Clyde, AU) |
Assignee: |
Vermeer Manufacturing
Company
Pella
IA
|
Family ID: |
44649491 |
Appl. No.: |
13/635310 |
Filed: |
March 15, 2010 |
PCT Filed: |
March 15, 2010 |
PCT NO: |
PCT/US2010/027302 |
371 Date: |
September 14, 2012 |
Current U.S.
Class: |
175/317 |
Current CPC
Class: |
E21B 3/02 20130101; E21B
21/01 20130101; E21B 7/046 20130101; E21B 21/10 20130101; E21B
10/62 20130101; E21B 47/024 20130101; E21B 10/60 20130101 |
Class at
Publication: |
175/317 |
International
Class: |
E21D 9/11 20060101
E21D009/11 |
Claims
1. A drilling apparatus comprising: a rotational cutting component
including a front cutting side and a back side, the rotational
cutting component defining a plurality of through-holes that extend
through the rotational cutting structure from the front cutting
side to the back side; a shutter mounted adjacent to the back side
of the rotational cutting component, the shutter and the rotational
cutting component being rotationally movable relative to one
another about an axis between a first orientation where the shutter
blocks the through-holes and a second orientation wherein the
through holes are open, the shutter including a torque transfer
interface aligned with the axis for transferring torque from a
drive shaft to the shutter to rotate the shutter about the axis;
and a connection arrangement between the shutter and the rotational
cutting component for transferring torque from the shutter to the
rotational cutting component to rotate the rotational cutting
component about the axis, the connection arrangement also allowing
a range of relative rotational movement between the rotational
cutting component and the shutter about the axis, the range of
relative rotational movement allowing the rotational cutting
component and the shutter to be moved between the first and second
orientations.
2. The drilling apparatus of claim 1, wherein the connection
arrangement includes slide elements that extend through curved
slots that curve about the axis.
3. The drilling apparatus of claim 2, wherein the slide elements
include slide pins affixed to the rotational cutting component, and
wherein the curved slots are defined by the shutter.
4. The drilling apparatus of claim 3, wherein the curved slots do
not extend completely through the shutter.
5. The drilling apparatus of claim 1, wherein the shutter is at
least partially recessed within the back side of the rotational
cutting component.
6. The drilling apparatus of claim 1, wherein a thrust bearing is
mounted between the rotational cutting component and the
shutter.
7. The drilling apparatus of claim 1, wherein cutters are mounted
at the front cutting side of the rotational cutting component.
8. The drilling apparatus of claim 7, wherein the cutters can be
mounted to the front side of the rotational cutting component with
mounting blocks, wherein the cutter mounting blocks are secured to
the rotational cutting component adjacent to the through-holes, and
wherein different sized mounting blocks can be used to vary maximum
open sizes of the through-holes.
9. A drilling apparatus comprising: a rotational cutting component
including a front cutting side and a back side, the rotational
cutting component defining a plurality of through-holes that extend
through the rotational cutting structure from the front cutting
side to the back side, the rotational cutting component being
rotated about an axis during drilling; and a blocking component
mounted adjacent to the back side of the rotational cutting
component for blocking at least portions of the through-holes, the
blocking component being mountable to the rotational cutting
component in different rotational positions about the axis, wherein
the blocking component provides a different through-hole blockage
percentage at each rotational position.
10. The drilling apparatus of claim 9, wherein the blocking
component is secured in the rotational positions by fasteners.
11. The drilling apparatus of claim 10, wherein the fasteners
extend through curved slots defined by the blocking component.
12. The drilling apparatus of claim 11, wherein the curved slots
have curvatures centered about the axis.
13. A drilling apparatus comprising: a cutting unit defining at
least one through-hole that provides fluid communication between a
distal side and a proximal side of the cutting unit, the cutting
unit including a plurality of cutting elements at the distal side
of the cutting unit; and a shutter for selectively opening and
blocking the through-hole of the cutting unit.
14. A drilling apparatus comprising: a cutting unit defining at
least one through-hole that provides fluid communication between a
distal side and a proximal side of the cutting unit, the cutting
unit including a plurality of cutting elements at the distal side
of the cutting unit; and a shutter used to at least partially cover
the through-hole.
Description
[0001] This application is being filed on 15 Mar. 2010, as a PCT
International Patent application in the name of Vermeer
Manufacturing Company, a U.S. national corporation, applicant for
the designation of all countries except the US, and Keith Allen
Hoelting, a citizen of the U.S., Andis Salins and Stuart Harrison,
both citizens of Australia, applicants for the designation of the
US only.
TECHNICAL FIELD
[0002] The present disclosure relates generally to trenchless
drilling equipment. More particularly, the present disclosure
relates to drilling equipment capable of maintaining a precise
grade and line.
BACKGROUND
[0003] Modern installation techniques provide for the underground
installation of services required for community infrastructure.
Sewage, water, electricity, gas and telecommunication services are
increasingly being placed underground for improved safety and to
create more visually pleasing surroundings that are not cluttered
with visible services.
[0004] One method for installing underground services involves
excavating an open trench. However, this process is time consuming
and is not practical in areas supporting existing construction.
Other methods for installing underground services involve boring a
horizontal underground hole. However, most underground drilling
operations are relatively inaccurate and unsuitable for
applications on grade and on line.
[0005] PCT International Publication No. WO 2007/143773 discloses a
micro-tunneling system and apparatus capable of boring and reaming
an underground micro-tunnel at precise grade and line. While this
system represents a significant advance over most prior art
systems, further enhancements can be utilized to achieve even
better performance.
SUMMARY
[0006] One aspect of the present disclosure relates to a drilling
apparatus including a cutting unit defining at least one
through-hole that provides fluid communication between a distal
side and a proximal side of the cutting unit. In use, spoils
generated by the cutting unit can be drawn through the through-hole
by a vacuum of the drilling apparatus. The cutting unit also
includes a flow-control shutter. In certain embodiments, the
shutter is movable between a first position where the through-hole
is blocked/closed and a second position where the through-hole is
open/unblocked. In other embodiments, the shutter can be used to
only partially block the through-hole. By selecting the
portion/percentage of the through-hole that is blocked by the
shutter it is possible to enhance drilling performance by
customizing the open transverse cross-sectional area of the
through-hole to match the type of geologic material in which the
drilling apparatus is being used.
[0007] Another aspect of the present disclosure relates to a
drilling apparatus (i.e., a tunneling apparatus) adapted for use in
flowable conditions (e.g., drilling environments below the water
table). In certain embodiments, the drilling apparatus includes a
drill string having a proximal end and a distal end. A cutting unit
is mounted at the distal end of the drill string. The cutting unit
is powered by a drive mechanism at the proximal end of the drill
string. The drive mechanism is adapted to provide torque for
rotating a cutting component of the cutting unit and is also
adapted for applying thrust to the drill string to drive the drill
string and the cutting unit distally into the ground. The drill
string defines a vacuum passage for evacuating spoils generated by
the cutting component within a bore being drilled. The drill string
also defines an air passage for providing air down the bore during
drilling to reduce the likelihood of plugging of the vacuum
passage. The cutting component defines through-holes that provide
fluid communication between the vacuum passage and a cutting side
(i.e., a distal side) of the cutting component. The through-holes
also provide fluid communication between the air passage and the
cutting side of the cutting component. The cutting unit further
includes a shutter for selectively opening and closing the
through-holes. During normal drilling operations in flowable
conditions, the through-holes are open thereby allowing: a) spoils
generated at the cutting side of the cutting component to readily
be drawn through the through-openings and into the vacuum passage;
and b) air from the air passage to flow to the cutting side of the
cutting component. When drilling operations are stopped, the
shutter is used to close (i.e., block, cover, etc.) the
through-holes to prevent flowable material at the cutting side of
the cutting component from filling the vacuum passage and/or the
air passage.
[0008] A variety of additional aspects will be set forth in the
description that follows. The aspects can relate to individual
features and to combinations of features. It is to be understood
that both the foregoing general description and the following
detailed description are exemplary and explanatory only and are not
restrictive of the broad inventive concepts upon which the
embodiments disclosed herein are based.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a schematic depiction of a drilling apparatus
having features in accordance with the principles of the present
disclosure;
[0010] FIG. 2 is a side view of a drill head in accordance with the
principles of the present disclosure;
[0011] FIG. 3 is a perspective view of the drill head of FIG. 2
showing a cutting side (i.e., a distal side) of a rotational
cutting component located at a distal end of a cutting unit of the
drill head;
[0012] FIG. 4 is a perspective view showing a shutter located at a
proximal end of the cutting unit of FIG. 3, the shutter and
rotational cutting component are shown in a first relative position
in which fluid communication between the distal end and the
proximal end of the cutting unit is open;
[0013] FIG. 5 is a perspective view showing the shutter and the
rotational cutting component of the cutting unit of FIG. 3 in a
second relative position in which fluid communication between the
distal end and the proximal end of the cutting unit is open;
[0014] FIG. 6 is a front, exploded perspective view of another
cutting unit in accordance with the principles of the present
disclosure;
[0015] FIG. 7 is a rear, exploded perspective view of the cutting
unit of FIG. 6;
[0016] FIG. 8 is a cross-sectional view of an assembled version of
the cutting unit of FIG. 6;
[0017] FIG. 9 is a front view of the cutting unit of FIG. 6 in a
fully-open flow orientation;
[0018] FIG. 10 is a rear view of the cutting unit of FIG. 6 in the
fully-open configuration;
[0019] FIG. 11 is a front view of the cutting unit of FIG. 6 in a
partially open flow configuration;
[0020] FIG. 12 is a rear view of the cutting unit of FIG. 6 in the
partially open flow configuration;
[0021] FIG. 13 is a front, perspective, exploded view of a further
cutting unit in accordance with the principles of the present
disclosure;
[0022] FIG. 14 is a rear, perspective, exploded view of the cutting
unit of FIG. 13; and
[0023] FIG. 15 is a cross-sectional view of an assembled version of
the cutting unit of FIG. 13.
DETAILED DESCRIPTION
A. Overview of Example Drilling Apparatus
[0024] FIG. 1 shows a drilling apparatus 20 having features in
accordance with the principles of the present disclosure.
Generally, the apparatus 20 includes a plurality of pipe sections
22 that are coupled together in an end-to-end relationship to form
a drill string 24. Each of the pipe sections 22 includes a drive
shaft 26 rotatably mounted in an outer casing assembly 28. A drill
head 30 is mounted at a distal end (i.e., a front end) of the drill
string 24 while a drive unit 32 is located at a proximal end (i.e.,
a back or rear end) of the drill string 24. The drive unit 32
includes a torque driver adapted to apply torque to the drill
string 24 and an axial driver for applying thrust or pull-back
force to the drill string 24. Thrust or pull-back force from the
drive unit 32 is transferred between the proximal end and the
distal end of the drill string 24 by the outer casing assemblies 28
of the pipe sections 22. Torque is transferred from the proximal
end of the drill string 24 to the distal end of the drill string 24
by the drive shafts 26 of the pipe sections 22 which rotate
relative to the casing assemblies 28. The torque from the drive
unit 32 that is transferred through the apparatus 20 by the drive
shafts 26 is ultimately used to rotate a cutting unit 34 of the
drill head 30.
[0025] The pipe sections 22 can also be referred to as drill rods,
drill stems or drill members. The pipe sections are typically used
to form an underground bore, and then are removed from the
underground bore when product (e.g., piping) is installed in the
bore.
[0026] The drill head 30 of the drilling apparatus 20 can include a
drive stem 46 rotatably mounted within a main body 38 of the drill
head 30. The main body 38 can include a one piece body, or can
include multiple pieces or modules coupled together. A distal end
of the drive stem 46 is configured to transfer torque to the
cutting unit 34. For example, the distal end of the drive stem 46
can include a male torque driver 49 (e.g., a hexagonal driver) that
fits within a torque driver receptacle 51 of the cutting unit 34
(e.g., a hexagonal female socket of the cutting unit 34). A
proximal end of the drive stem 46 couples to the drive shaft 26 of
the distal-most pipe section 22 such that torque is transferred
from the drive shafts 26 to the drive stem 46. In this way, the
drive stem 46 functions as the last leg for transferring torque
from the drive unit 32 to the cutting unit 34. The outer casing
assemblies 28 transfer thrust and/or pull back force to the main
body 38 of the drill head. The drill head 30 preferably includes
bearings (e.g., axial/thrust bearings and radial bearings) that
allow the drive stem 46 to rotate relative to the main body 38 and
also allow thrust or pull-back force to be transferred from the
main body 38 through the drive stem 46 to the cutting unit 34.
[0027] In certain embodiments, the drilling apparatus 20 is used to
form underground bores at precise grades. For example, the drilling
apparatus 20 can be used in the installation of underground pipe
installed at a precise grade. In some embodiments, the drilling
apparatus 20 can be used to install underground pipe or other
product having an outer diameter less than 600 mm or less than 300
mm.
[0028] It is preferred for the drilling apparatus 20 to include a
steering arrangement adapted for maintaining the bore being drilled
by the drilling apparatus 20 at a precise grade and line. For
example, referring to FIG. 1, the drill head 30 includes a steering
shell 36 mounted over the main body 38 of the drill head 30.
Steering of the drilling apparatus 20 is accomplished by generating
radial movement between the steering shell 36 and the main body 38
(e.g., with radially oriented pistons, one or more bladders,
mechanical linkages, screw drives, etc. positioned between the
steering shell 36 and the main body 38). Further details about
suitable steering systems are provided in U.S. Provisional Patent
Application No. 61/246,616, filed Sep. 29, 2009, that is hereby
incorporated by reference in its entirety.
[0029] Steering of the drilling apparatus 20 is preferably
conducted in combination with a guidance system used to ensure the
drill string 24 proceeds along a precise grade and line. For
example, as shown at FIG. 1, the guidance system includes a laser
40 that directs a laser beam through a continuous axially extending
air passage 43 defined by the outer casing assemblies 28 of the
pipe sections 22 to a target located adjacent the drill head 30.
The air passage extends from the proximal end to the distal end of
the drill string 24 and allows air to be provided to the cutting
unit 34. An air pressure source 45 can be used to force air
distally through the passage 43.
[0030] The drilling apparatus 20 also includes an electronic
controller 50 (e.g., a computer or other processing device) linked
to a user interface 52 and a monitor 54. The user interface 52 can
include a keyboard, joystick, mouse or other interface device. The
controller 50 can also interface with a camera 60 such as a video
camera that is used as part of the steering system. For example,
the camera 60 can generate images of the location where the laser
beam hits the target. It will be appreciated that the camera 60 can
be mounted within the drill head 30 or can be mounted outside the
drilling apparatus 20 (e.g., adjacent the laser 40). If the camera
60 is mounted at the drill head 30, data cable can be run from the
camera through a passage that runs from the distal end to the
proximal end of the drill string 24 and is defined by the outer
casing assemblies 28 of the pipe sections 22. In still other
embodiments, the drilling apparatus 20 may include wireless
technology that allows the controller to remotely communicate with
the down-hole camera 60.
[0031] During steering of the drilling apparatus 20, the operator
can view the camera-generated image showing the location of the
laser beam on the target via the monitor 54. Based on where the
laser beam hits the target, the operator can determine which
direction to steer the apparatus to maintain a desired line and
grade established by the laser beam. The operator steers the drill
string 24 by using the user interface to cause a shell driver 39 to
modify the relative radial position of the steering shell 36 and
the main body 38 of the drill head 30. In one embodiment, a radial
steering force/load is applied to the steering shell 36 in the
radial direction opposite to the radial direction in which it is
desired to turn the drill string. For example, if it is desired to
steer the drill string 24 upwardly, a downward force can be applied
to the steering shell 36 which forces the main body 38 and the
cutting unit 34 upwardly causing the drill string to turn upwardly
as the drill string 24 is thrust axially in a forward/distal
direction. Similarly, if it is desired to steer downwardly, an
upward force can be applied to the steering shell 36 which forces
the main body 38 and the cutting unit 34 downwardly causing the
drill string 24 to be steered downwardly as the drill string 24 is
thrust axially in a forward/distal direction.
[0032] To assist in drilling, the drilling apparatus 20 can also
include a fluid pump for forcing drilling fluid from the proximal
end to the distal end of the drill string 24. In certain
embodiments, the drilling fluid can be pumped through a central
passage defined through the drive shafts 26. The central passage
defined through the drive shafts 26 can be in fluid communication
with a plurality of fluid delivery ports provided at the cutting
unit 34 such that the drilling fluid is readily provided at a
cutting face of the cutting unit 34. Fluid can be provided to the
central passage though a fluid swivel located at the drive unit 32.
In other embodiments, a drilling fluid line can be routed from the
proximal end to the distal end of the drill string through a
separate channel defined by the drill string.
[0033] The drilling apparatus 20 can also include a vacuum system
for removing spoils and drilling fluid from the bore being drilled.
For example, the drill string 24 can include a vacuum passage 47
that extends continuously from the proximal end to the distal end
of the drill string 24. The proximal end of the vacuum passage can
be in fluid communication with a vacuum 65 and the distal end of
the vacuum passage is typically directly behind the cutting unit 34
adjacent the bottom of the bore. The vacuum 65 applies vacuum
pressure to the vacuum passage 47 to remove spoils and liquid from
the bore being drilled. At least some air provided to the distal
end of the drill string 24 through the air passage 43 is also
typically drawn into the vacuum passage to assist in preventing
plugging of the vacuum passage. In certain embodiments, the liquid
and spoils removed from the bore though the vacuum passage can be
delivered to a storage tank 67.
B. Example Cutting Units
[0034] FIG. 2 is a side view of a distal portion of the drill head
30 of the drilling apparatus 20 of FIG. 1. Specifically, FIG. 2
shows the steering shell 36 and the cutting unit 34 of the drill
head 30. The cutting unit 34 includes a proximal end 70 (i.e., a
back or rear end) positioned directly adjacent to a distal end of
the steering shell 36 and a distal end 72 (i.e., a front end)
distally offset from the steering shell 36.
[0035] Referring to FIG. 3, the cutting unit 34 includes a
rotational cutting component 74 that is rotated about a central
longitudinal axis 75 (see FIGS. 4 and 5) of the cutting unit 34 to
facilitate cutting a bore with the drilling apparatus 20. The axis
75 can be co-axially aligned with the central longitudinal axis
defined by the drive shafts 26 of the pipe sections 22.
Specifically, the rotational cutting component 74 is rotated about
the axis 75 via torque transferred from the drive unit 32 by the
drive shafts 26. During drilling operations, the rotational cutting
component 74 is typically rotated about the axis 75 relative to the
steering shell 36 of the drill head 30, the main body 38 of the
drill head 30 and the casing assemblies 28 of the pipe sections
22.
[0036] Referring to FIGS. 3 and 4, the rotational cutting component
74 includes an outer rim 76 (e.g., a cylindrical outer rim) that
extends generally from the distal end 72 to the proximal end 70 of
the cutting unit 34. The rotational cutting component 74 also
includes a front cutter mounting plate 78 (e.g., an annular
mounting plate) non-rotationally connected to the outer rim 76
adjacent the distal end 72 of the cutting unit 34. The phrase
"non-rotationally connected" means that the connection does not
allow relative rotation between the interconnected pieces. For
example, the front cutter mounting plate 78 can be welded to the
outer rim 76. Alternatively, the front cutter mounting plate 78 can
be unitarily cast with the outer rim 76, machined as an integral
part with the outer rim 76 or attached to the outer rim 76 with
fasteners. As shown at FIG. 3, an outer peripheral portion 77 of
the front cutter mounting plate 78 is non-rotationally connected to
the outer rim 76.
[0037] Referring to FIG. 4, the rotational cutting component 74
also includes an inner hub 80 that is non-rotationally connected to
an inner portion of the front cutter mounting plate 78. The inner
hub 80 defines the torque driver receptacle 51 adapted for
receiving the male torque driver 49 provided at the distal end of
the drive stem 46 of the drill head 30. Thus, the inner hub 80 is
configured to allow torque to be readily transferred from the drive
stem 46 of the drill head 30 to the rotational cutting component 74
of the cutting unit 34.
[0038] The rotational cutting component 74 of the cutting unit 34
also includes a plurality of cutting elements mounted at a cutting
side 82 (i.e., a distal side) of the front cutter mounting plate
78. The cutting elements include cutting teeth 84 and cutting
blades 86a attached to the cutting side 82 of the front cutter
mounting plate 78. The cutting blades 86a are mounted adjacent to
through-holes 88 that extend through the front cutter mounting
plate 78 in a distal-to-proximal direction. The cutting blades 86a
are secured to mounting blocks 89 that are secured by fasteners
within pockets defined by the front cutting side 82 of the
rotational cutting component 74. The cutting blades 86a and/or the
mounting blocks 89 can be configured to cover at least portions of
the through-holes 88. In this way, by using different cutting
blades 86a or different sized mounting blocks 89, the maximum
available size of the open portions of the through-holes 88 can be
varied to customize the cutting unit 34 to the type of material
through which the cutting unit 34 is drilling.
[0039] The through-holes 88 allow spoils generated by the cutting
elements of the cutting unit 34 to pass in a distal-to-proximal
direction through the cutting unit 34. Once the cuttings have
passed through the through-holes 88, the cuttings are drawn into
the vacuum passage 47 and removed from the bore being drilled. In
certain embodiments, the through-holes 88 can also allow air to
pass in a proximal-to-distal direction through the cutting unit 34
where the air mixes with the cuttings and is then drawn along with
the cuttings back through the through-holes 88 in a
distal-to-proximal direction to the vacuum passage 47.
[0040] When drilling in flowable conditions (e.g., below water
table conditions), it may be desirable to be able to selectively
open and close the through-holes 88. When the through-holes 88 are
closed, fluid communication between the distal end 72 and the
proximal end 70 of the cutting unit 34 is blocked so that material
on the distal side of the front cutter mounting plate 78 is
prevented from flowing through the through-holes 88 and filling the
vacuum passage 47 and/or the air passage 43.
[0041] Referring to FIGS. 4 and 5, the cutting unit 34 also
includes a shutter 90 for selectively opening and closing the
through-holes 88. FIGS. 4 and 5 show the shutter 90 as an annular
plate mounted at the proximal end 70 of the cutting unit 34. The
shutter 90 includes through-holes 91 that are circumferentially
separated from one another by blocking portions 92. The shutter 90
also defines arcuate slots 93 that are defined through the blocking
portions 92. The slots 93 define radiuses of curvature that are
swung about a center line that extends along the axis of rotation
75. Fasteners 94 (e.g., shoulder bolts or pins) extend through the
slots 93 and function to attach the shutter 90 to the proximal side
of the front cutter mounting plate 78. The shutter 90 is mounted
inside the proximal end of the outer rim 76. The fasteners 94 and
slots 93 allow the shutter 90 and the rotational cutting component
74 to rotate relative to one another about the axis 75 between a
first relative position shown in FIG. 4 and a second relative
position shown in FIG. 5. In the first relative position of FIG. 4,
the through-holes 91 of the shutter 90 align with the through-holes
88 of the rotational cutting component 74 such that fluid
communication is open between the proximal and distal ends 70, 72
of the cutting unit 34. In the second relative position of FIG. 5,
the blocking portions 92 of the shutter 90 cover the through-holes
88 of the rotational cutting component 74 such that fluid
communication is blocked between the distal and proximal ends 72,
70 of the cutting unit 34.
[0042] The cutting unit 34 also includes a retention assembly 23
for retaining the cutting unit 34 on the drive shaft 46 by
preventing the cutting unit from sliding distally off of the torque
driver 49. The retention assembly 23 includes a retaining cap 25, a
fastener 27 and a central cutting blade 86b. The central cutting
blade 86b is attached to a head of the fastener 27. The fastener 27
extends through the retaining cap 25 and connects to the end of the
drive shaft 46. For example, the fastener 27 can include a bolt
having a threaded shaft that threads into an internally threaded
axial opening defined by the male torque driver 49 of the drive
stem 46. When the fastener 27 threads into a threaded opening of
the male torque driver 49 (see FIG. 1), the fastener 27 causes the
back side of the retaining cap 25 to compress/abut against the
front side of the rotational cutting component 74 thereby
preventing the cutting component 74 from sliding axially off of the
male torque driver 49.
[0043] During normal drilling operations, the cutting unit 34 is
rotated in a first rotational direction 95 about the axis of
rotation 75. Rotation of the rotational cutting component 74 in the
first rotational direction 95 causes the fasteners 94 to slide
within the slots 93 to first ends 96 of the slots 93. With the
fasteners 94 located at the first ends 96 of the slots 93, the
shutter 90 and the rotational cutting component 74 are in the first
relative position in which fluid communication is provided between
the distal and proximal ends 72, 70 of the cutting unit 34 (see
FIG. 4). As the rotational cutting component 74 continues to be
rotated in the first rotational direction 95 while the fasteners 94
are located at the first ends 96 of the slots 93, torque is
transferred from the rotational cutting component 74 through the
fasteners 94 to the shutter 90. In this way, the shutter 90 rotates
in unison with the rotational cutting component 74 such that the
through-holes 88 remain open.
[0044] When drilling operations stop, it may be desirable to close
fluid communication between the distal and proximal ends 72, 70 of
the cutting unit 34. To accomplish this, the rotational cutting
component 74 is rotated in a second rotational direction 97 about
the axis of rotation 75. As this occurs, the slots 93 and the
fasteners 94 allow the rotational cutting component 74 to rotate
relative to the shutter 90 about the axis 75 from the first
relative position of FIG. 4 to the second relative position of FIG.
5. In the second relative position of FIG. 5, the fasteners 94
engage second ends 98 of the slots 93 and the blocking portions 92
of the shutter 90 cover the through-holes 88 of the rotational
cutting component 74. To reopen the through-holes, the rotational
cutting component 78 is merely rotated in the first direction 95
about the axis of rotation 75 causing the rotational cutting
component 74 to move back to the position of FIG. 4.
[0045] In alternative embodiments, rather than being used to open
and close through-holes, shutters in accordance with the principles
of the present disclosure can be used to adjust the size (e.g., the
open transverse cross-sectional area) of cutter through-holes to
customize the through-holes to accommodate drilling in a particular
type of material. For example, FIGS. 6-12 show a cutting unit 134
including a rotational cutting component 174 and a shutter 190. The
rotational cutting component 174 has a front cutting side 182
positioned opposite from a back side 183. A plurality of cutting
teeth are provided at the front cutting side 182, and a plurality
of through-holes 188 extend through the rotational cutting
component 174 from the front cutting side 182 to the back side 183.
The back side 183 of the rotational cutting component 174 includes
a hub 180 defining a torque driver receptacle 151 adapted for
receiving the male torque driver 49 provided at the distal end of
the drive stem 46 of the drill head 30. The hub 180 is configured
to allow torque to be readily transferred from the drive stem 46 of
the drill head 30 to the rotational cutting component 174 of the
cutting unit 134. In the depicted embodiment, the torque driver
receptacle 151 is shown as a torque transfer socket including a
plurality of flats. A retention assembly 123 fastens to the torque
driver 49 to prevent the cutting unit 134 from sliding distally off
of the torque driver 49. The retention assembly 123 includes a
retaining cap 125 and a fastener 127. The fastener 127 extends
through the retaining cap 125 and is adapted to connect to the
torque driver 49. When the fastener 127 is tightened, a back side
of the retaining cap 125 clamps against the front side of the
rotational cutting component 174.
[0046] The shutter 190 of the cutting unit 134 is secured to the
back side 183 of the rotational cutting component 174 by a
plurality of fasteners 161. As shown at FIG. 6, the fasteners 161
are depicted as bolts that are threaded into tapped openings
provided at the back side 183 of the rotational cutting component
174. The fasteners 161 extend through slots 193 defining radiuses
of curvature that are swung about a centerline that extends along
an axis of rotation 175. When the fasteners 161 are loosened, the
slots 193 allow the rotational cutting component 174 and the
shutter 190 to be rotated relative to one another about the axis of
rotation 175. In contrast, when the fasteners 161 are tightened,
the rotational cutting component 174 and the shutter 190 are locked
in position relative to one another such that relative rotational
movement between the rotational cutting component 174 and the
shutter 190 about the axis of rotation 175 is prevented.
[0047] The shutter 190 includes through-holes 191 and blocking
portions 192. By rotating the rotational cutting component 174 and
the shutter 190 relative to one another about the axis of rotation
175, the relative position between the through-holes 188 of the
rotational cutting component 174 and the through-holes 191 of the
shutter 190 can be altered. In this way, the amount of open
transverse cross-sectional area provided by the through-holes 188
can be adjusted. For example, the rotational cutting component 174
and the shutter 190 can be locked in a first relative rotational
position (i.e., a fully closed position) (not shown) in which the
blocking portions 192 of the shutter 190 fully block the
through-holes 188 such that material is prevented from passing
through the rotational cutting component 174. The rotational
cutting component 174 and the shutter 190 can also be locked in a
second rotational position (a fully open position) (see FIGS. 9 and
10) in which the through-holes 188 fully align with the
through-holes 191 so that no portions of the through-holes 188 are
blocked. In this position, a maximum open transverse
cross-sectional area is provided by the through-holes 188 for
allowing material to pass through the rotational cutting component
174.
[0048] The rotational cutting component 174 and the shutter 190 can
also be locked at intermediate positions between the fully open
position and the fully closed position. In an intermediate
position, the shutter 190 only partially blocks the through-holes
188, thereby providing a reduced transverse cross-sectional area
through which material can flow as compared to the fully open
position. In certain embodiments, the shutter 190 blocks 10-90
percent of the transverse cross-sectional area of the through-holes
188, or 20-80 percent of the transverse cross-sectional area of the
through-holes 188, or 20-60 percent of the transverse
cross-sectional area of the through-holes 188 when in selected
intermediate relative rotational positions. It will be appreciated
that the intermediate relative rotational position can be selected
by the operator so that the open portions of the transverse
cross-sectional areas of the through-holes 188 are selected to
match the type of material through which the drilling apparatus is
intended to be drilled, thereby customizing the drilling head to
the material intended to be drilled. The fasteners 161 allow the
rotational cutting component 174 and the shutter 190 to be locked
at an infinite number of intermediate relative rotational
positions. Once the intermediate relative rotational position has
been set, the fasteners maintain the rotational cutting component
174 and the shutter 190 in the selected intermediate relative
rotational position during drilling. FIGS. 11 and 12 show the
rotational cutting component 174 and the shutter 190 locked in an
example intermediate relative rotational position in which the
through-holes 188 are partially blocked by the shutter 190.
[0049] The cutting unit 134 is shown including a nut 135 for
securing the retention assembly 123 to the rotational cutting
component 174 during storage and shipping. It will be appreciated
that the nut 135 is removed and discarded when the cutting unit 134
is mounted to the drill head 30.
[0050] FIGS. 13-15 show still another cutting unit 234 in
accordance with the principles of the present disclosure. The
cutting unit 234 includes a rotational cutting component 274 and a
shutter 290. The rotational cutting component 274 includes a front
cutting side 282 positioned opposite from a back side 283.
Through-holes 288 extend through the rotational cutting component
274 from the cutting side 282 to the back side 283. Cutter mounting
pockets 285 are provided at the front side 282 of the rotational
cutting component 274 adjacent to the through-holes 288. The cutter
mounting pockets allow cutter mounting blocks 289 to be readily
mounted to the rotational cutting component 274 adjacent to the
through-holes 288. Cutters such as elongated blades are secured to
the cutter mounting blocks 289. By selecting different sizes of
cutter mounting blocks and/or cutters, the maximum possible open
areas of the through-holes 288 can be modified. For example, the
through-holes 288 have a maximum open transverse cross-sectional
area when the cutter mounting blocks and the cutters attached
thereto do not overlap the through-holes 288. By selecting cutter
mounting blocks and/or cutters with a predetermined amount of
overlap with respect to the through-holes 288, the maximum open
transverse cross-sectional area provided by the through-holes 288
can be adjusted.
[0051] The shutter 290 of the cutting unit 234 includes a hub 235
defining a torque driver receptacle 251 adapted for receiving the
male torque driver 49 provided at the distal end of the drive stem
46 of the drill head 30. The torque driver receptacle 251 is
configured to allow torque to be readily transferred from the drive
stem 46 of the drill head 30 to the shutter 290. In the depicted
embodiment, torque driver receptacle 251 includes a socket
configuration including a plurality of flats. A retention assembly
223 is used to prevent the rotational cutting component 274 and the
shutter 290 from sliding distally off of the torque driver 49. The
retention assembly 223 includes a retaining cap 225, a fastener 227
and a central cutting blade 286b. The central cutting blade 286b is
attached to a head of the fastener 227. The fastener 227 extends
through the retaining cap 225 and connects to the end of the drive
shaft 46. For example, the fastener 227 can include a bolt having a
threaded shaft that threads into an internally threaded axial
opening defined by the male torque driver 49 of the drive stem
46.
[0052] The retaining cap 225 is configured to retain the rotational
cutting component 274 and the shutter 290 on the drive shaft 46
without clamping the rotational cutting component in place relative
to the shutter 290. For example, the retaining cap 225 includes a
hub portion 221 and a flange portion 219 that projects radially
outwardly from a front end of the hub portion 221. The rear end of
the hub portion 221 defines a shutter clamping surface 221a that
engages a front face of the hub 235 of the shutter 290 when the
fastener 227 is threaded into the drive shaft 46 to retain the
shutter 290 on the drive shaft 46. The rear side of the flange
portion 219 defines a rotational cutting component retention
surface 219a that opposes the front side of the rotational cutting
component 274 to prevent the rotational cutting component 274 from
disconnecting from the drive shaft 46. The hub portion 221 defines
an offset 217 between the shutter clamping surface 221a and the
rotational cutting component retention surface 219a. The offset 217
extends in a front-to-rear direction and provides a gap between the
surfaces 221a, 219a in which an inner portion 290i of the shutter
290 is received. The gap provided by the offset 217 is larger than
then thickness of the inner portion 290i and prevents the inner
portion 290i from being clamped by the retaining cap 225 when the
fastener 227 is tightened. In this way, the retention assembly 223
does not interfere with the ability of the rotational cutting
component 274 to rotate relative to the shutter 290 about an axis
of rotation 275.
[0053] The cutting unit 234 also includes slide pins 294 (e.g.,
dowel pins) having front ends inserted within openings defined by
the back side 283 of the rotational cutting component 274 (see FIG.
15). Rear ends of the slide pins 294 fit within corresponding
arcuate slots 293 defined by the shutter 290. The arcuate slots 293
have curvatures defined by radiuses swung about a centerline that
extends along the axis of rotation 275. The slide pins 294 serve
two primary functions. First, the slide pins 294 allow torque to be
transferred from the shutter 290 to the rotational cutting
component 274 when torque is applied to the shutter 290 by the
drive stem 46 of the drill head 30. Thus, during drilling, torque
for rotating the rotational cutting component 274 about the axis of
rotation 275 is provided by the drive stem 46 and is transferred
from the shutter 290 to the rotational cutting component 274
through the slide pins 294. The rotational cutting component 274
and the shutter 290 are rotated in unison about the axis of
rotation 275 by the drive shaft 46 during drilling operations. The
slide pins 294 and the slots 293 also allow the shutter 290 and the
rotational cutting component 274 to be rotated relative to one
another about the axis of rotation 275. In this way, similar to the
first embodiment described herein, the rotational cutting component
274 and the shutter 290 can be moved to a first relative rotational
position in which through-holes 291 of the shutter 290 align with
the through-holes 288 of the rotational cutting component 274 such
that the through-holes 288 are open to allow material to pass in a
front-to-back direction through the cutting unit 234. The slide
pins 294 and the slots 293 also allow the rotational cutting
component 274 and the shutter 290 to be moved to a second relative
rotational position in which the shutter 290 blocks the
through-holes 288 by preventing material from passing through the
cutting unit 234 in a front-to-back action.
[0054] The cutting unit 234 further includes a bearing member 211
that mounts between the rotational cutting component 274 and the
shutter 290. The bearing member 211 includes a radial bearing
portion 211a that fits over the hub 235 of the shutter 290 and
provides a radial bearing between a outwardly radially facing
surface of the shutter hub 235 and an inwardly radially facing
surface of the rotational cutting component 274. The bearing member
211 also includes an axial/thrust bearing structure 211b that forms
a bearing between a front side of the shutter 290 and the back side
283 of the rotational cutting component 274.
[0055] The cutting unit 234 is shown including a nut 213 for
securing the retention assembly 223 to the rotational cutting
component 274 and the shutter 290 during storage and shipping. It
will be appreciated that the nut 213 is removed and discarded when
the cutting unit 234 is mounted to the drill head 30.
[0056] In the embodiment of FIGS. 13-15, drilling ideally takes
place when the cutting unit 234 is rotated in a rotational
direction 297 about the axis of rotation 275. Rotation of the
shutter 290 by the drive shaft 46 in the rotational direction 297
causes the slide pins 294 to slide within the slots 293 to ends 298
of the slots 293. With the slide pins 294 located at the ends 298
of the slots 293, the shutter 290 and the rotational cutting
component 274 are in the open position in which fluid communication
is provided between the front and back sides of the cutting unit
234. As the shutter 290 continues to be rotated in the rotational
direction 297 while the slide pins 294 are located at the ends 298
of the slots 293, torque is transferred from the shutter 290 to the
rotational cutting component 274 by the slide pins 294. In this
way, the rotational cutting component 274 rotates in unison with
the shutter 290 such that the through-holes 288 remain open.
[0057] When drilling operations stop, it may be desirable to close
fluid communication between the front and the back sides of the
cutting unit 234. To accomplish this, the shutter 290 is rotated by
the drive shaft 46 in a rotational direction 295 about the axis of
rotation 275. As this occurs, the slots 293 and the slide pins 294
allow the shutter 290 to rotate relative to the rotational cutting
component 274 from the open position to the closed position. In the
closed position, the slide pins 294 engage ends 296 of the slots
293 and blocking portions of the shutter 290 cover the
through-holes 288 of the rotational cutting component 274. To
re-open the through-holes 288, the shutter 290 is merely rotated in
the direction 297 about the axis of rotation 175, causing the
shutter 290 to move relative to the rotational cutting component
274 back to the open position. One advantage of this version of the
cutting unit is that contact between the cutting teeth of the
rotational cutting component 274 and the ground provides resistance
that prevents the shutter 290 and the rotational cutting component
274 from rotating in unison with one another when it is intended or
desired to close the through-holes by rotating the shutter 290 in
the direction 295 relative to the rotational cutting component
274.
[0058] From the foregoing detailed description, it will be evident
that modifications and variations can be made in the devices of the
disclosure without departing from the spirit or scope of the
invention.
* * * * *