U.S. patent application number 09/912977 was filed with the patent office on 2002-01-31 for directional drilling apparatus with shifting cam.
Invention is credited to Chandler, Roy L., Webb, Charles T..
Application Number | 20020011359 09/912977 |
Document ID | / |
Family ID | 22827714 |
Filed Date | 2002-01-31 |
United States Patent
Application |
20020011359 |
Kind Code |
A1 |
Webb, Charles T. ; et
al. |
January 31, 2002 |
Directional drilling apparatus with shifting cam
Abstract
The apparatus includes an annular cam rotatably located in a
housing with a drill shaft extending through the cam and housing.
The shaft can be rotated for drilling purposes and be moved
longitudinally in the housing for shifting purposes. The cam has
grooves in its outer surface for receiving a cam follower carried
by the shaft which rotates the cam as the shaft is moved
longitudinally for shifting purposes. The shaft may be moved
longitudinally in one direction to a position to engage members of
a clutch such that when the shaft rotates, it rotates the housing.
The shaft is movable in an opposite direction to disengage the
clutch members and then is movable to locate the cam follower in
the groove at different positions to allow the operator to control
the longitudinal position of the shaft for turning purposes or for
drilling straight.
Inventors: |
Webb, Charles T.; (Burleson,
TX) ; Chandler, Roy L.; (Arlington, TX) |
Correspondence
Address: |
DECKER, JONES, MCMACKIN, MCCLANE, HALL &
BATES, P.C.
BURNETT PLAZA
801 CHERRY STREET, SUITE 2000
FORT WORTH
TX
76102-6836
US
|
Family ID: |
22827714 |
Appl. No.: |
09/912977 |
Filed: |
July 25, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60221413 |
Jul 28, 2000 |
|
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Current U.S.
Class: |
175/73 ; 175/413;
175/421; 175/61 |
Current CPC
Class: |
E21B 17/1064 20130101;
E21B 7/067 20130101 |
Class at
Publication: |
175/73 ; 175/61;
175/413; 175/421 |
International
Class: |
E21B 007/08; E21B
010/42; E21B 010/62 |
Claims
1. An apparatus for drilling a borehole in the earth, comprising: a
housing having a front end and a rear end, a shaft extending
through said housing, said shaft being rotatable relative to said
housing and movable longitudinally between forward and rearward
positions relative to said housing, said shaft having front end for
receiving a drill means, an annular cam located in said housing,
said annular cam being rotatable relative to said housing, a groove
formed in said annular cam and which extends between rearward and
forward positions, a cam follower being located in said groove of
said annular cam, means for preventing rotation of said cam
follower relative to said housing, said cam follower being movable
longitudinally relative to said annular cam, moving means for
moving said cam follower relative to said annular cam, said cam
follower being movable longitudinally in said groove relative to
said annular cam to rotate said annular cam to cause said cam
follower to be moved to different positions in said groove, said
cam follower being movable rearward in said groove to said rearward
position by said moving means, said cam follower being movable
forward in said groove from said rearward position by said moving
means.
2. The apparatus of claim 1, comprising: a clutch located in said
housing and comprising a first clutch member coupled to said shaft
for rotation with said shaft and a second clutch member coupled to
said housing for rotating said housing when engaged by said first
clutch member and when said first clutch member is rotated by said
shaft, said first clutch member being movable longitudinally
relative to said annular cam.
3. The apparatus of claim 1, wherein: said groove comprises a stop
zone located between said two positions, said cam follower being
movable in said groove to said stop zone at which point said first
and second clutch members are engaged to allow said shaft to rotate
said housing when said shaft is rotated and to drill straight.
4. The apparatus of claim 3, wherein: said cam follower is movable
to a position forward of said stop zone to disengage said first and
second clutch members to allow said shaft to rotate relative to
said housing for turning purposes, first and second pad means
coupled to the exterior of said housing about 180 degrees apart
with said first pad means being coupled to said front end on one
side of said housing and said second pad means being coupled to
said rear end of said housing on a side opposite said one side, at
least one of said pad means extends outward beyond the radius of
said drilling means to apply pressure to the wall of the borehole
in directions to enhance turning of the drill means in the earth,
and friction means coupled to said housing for engaging the wall of
the borehole for resisting rotation of said housing in the
borehole.
5. The apparatus of claim 1, wherein said housing is defined as an
elongated rear housing, said apparatus comprises: an elongated
front housing having a front end and a rear end, said shaft extends
through said front and rear housings, means for pivotally coupling
said rear end of said front housing to said front end of said rear
housing for pivotally movement relative to each other and to said
shaft, said shaft being rotatable relative to said front and rear
housings and movable longitudinally between forward and rearward
positions relative to said front and rear housings, said front end
of said shaft extends out of said front end of said front housing
for receiving a drill means, a main cam fixedly secured in said
rear housing, slot mean formed in said main cam, a main cam
follower coupled to said shaft in said rear housing such that said
shaft may rotate relative to said main cam follower, means for
preventing longitudinal movement of said main cam follower relative
to said shaft such that forward and rearward movement of said shaft
causes said main cam follower to move in said slot means and said
cam follower of said annular cam to move in said groove of said
annular cam to rotate said annular cam and to allow said groove and
said cam follower of said annular cam to control longitudinal
movement of said shaft and hence of said main cam follower in said
slot means.
6. The apparatus of claim 5, comprising: pad means coupled to said
rear end of said front housing on one side thereof such that
rearward movement of said shaft causes said main cam follower to
move in said slot means and to cause said rear and front ends of
said front and rear housings respectively to pivot relative to each
together and to said shaft to move said pad means away from said
shaft against the wall of the borehole to allow said apparatus to
change its direction of drilling.
7. An apparatus for drilling a borehole in the earth, comprising: a
housing having a front end and rear end, a shaft extending through
said housing for rotational and longitudinal movement, said shaft
having a front end extending out of said front end of said housing
for receiving a drill means, said shaft being movable
longitudinally in a first direction relative to said housing for
engaging a clutch means for rotating said housing when said shaft
is rotated and movable longitudinally in a second direction
opposite said first direction for disengaging said clutch means for
allowing said shaft to rotate relative to said housing, a rotatable
cam located in said housing rotatable relative to said housing and
surrounding said shaft, a cam follower located in said housing and
movable longitudinally with said shaft for rotating said rotatable
cam for controlling longitudinal movement of said shaft relative to
said housing, engaging means coupled at least to one end of said
housing on one side for engaging the wall of the bore being drilled
for urging the drill means against the wall of the bore when said
shaft is disengaged from said clutch means and located in a given
position for allowing said apparatus to turn while drilling is
being carried out.
8. An apparatus for drilling a borehole in the earth, comprising:
front and rear housings each having a front end and a rear end, a
shaft extending through said front and rear housings for rotational
and longitudinal movement, said shaft having a front end extending
out of said front end of said front housing for receiving a drill
means, means for pivotally coupling said rear and front ends of
said front and rear housings together for pivotal movement of said
front and rear housings relative to each other and relative to said
shaft, said shaft being movable longitudinally in a first direction
relative to said housings for engaging a clutch means for rotating
said housings when said shaft is rotated and movable longitudinally
housings for disengaging said clutch means and for allowing said
shaft to rotate relative to said housings, a fixed cam fixedly
located in one of said housings and fixedly coupled to said one
housing, a first cam follower coupled to said shaft in said one
housing for longitudinal movement with said shaft for engaging said
fixed cam and for causing said first and second housings to pivot
relative to each other and relative to said shaft when said shaft
is moved longitudinally relative to said housings, a rotatable cam
located in said one housing rotatable relative to said one housing
and surrounding said shaft, a second cam follower located in said
one housing and movable longitudinally with said shaft for rotating
said rotatable cam for controlling longitudinal movement of said
shaft relative to said housings.
9. A drill bit comprising: a drill bit body having front end and a
rear end with a central axis extending between said front and rear
ends and being connectable to a shaft for rotating with said shaft,
a plurality of angularly spaced apart slots formed in the exterior
of said drill bit body which extend outward relative to said
central axis and between said front and rear ends, each slot having
a lip extending from each of its said front and rear ends
respectively, a cutting means for each of said slots with each said
cutting means comprising a connecting portion with a forward end
and a rearward end which is located in one of said slots, each
connecting portion comprising a hook near its said front and rear
ends respectively for connection to said lips of said slot in which
it is located, a removable stop positioned to prevent longitudinal
movement of said connecting portion of each said cutting means
relative to its said slot.
10. A drilling apparatus for drilling a borehole in the earth
comprising: a housing, a shaft extending through said housing, said
shaft being movable relative to said housing, a first clutch member
coupled to said shaft, a second clutch member located within said
housing, said first clutch member being engageable with said second
clutch member when said shaft is moved in a first linear direction
relative to said housing to a given position to cause said housing
to rotate with said shaft when said shaft is rotated, said first
clutch member being disengagable from said second clutch member
when said shaft is moved in a second linear direction opposite to
said first linear direction to a second position to allow said
shaft to rotate relative to said housing, said first clutch member
comprising a first annular member having a plurality of angularity
spaced apart teeth extending outward from said annular member, said
second clutch member comprising a second annular member rotatable
in said housing and movable in said housing in said first and
second linear directions, a clutch stop located in said housing for
stopping movement of said second clutch member in said second
linear direction when said second clutch member is moved in said
second linear direction and engages said clutch stop, said clutch
stop comprising at least one lug having a cam surface thereon which
extends from an inner position away from said clutch stop to an
outer position, a lug pin coupled to said lug, said second clutch
member having at least one gap formed in its outer surface, a cam
follower extending from said gap for engaging said surface of said
cam, an elastic member coupled to said cam follower and to said lug
pin for normally urging said second clutch member in a first
rotational direction to normally locate said cam follower against
said inner position of said cam surface for urging said second
clutch member in said second linear direction against said clutch
stop, said second clutch member having a central opening with a
plurality of angularity spaced apart teeth extending inward, such
that said first clutch member may be moved by said shaft within
said second clutch member with each tooth of said first clutch
member located between adjacent teeth of said second clutch member
to allow said shaft and said first clutch member to rotate said
second clutch member for rotating said housing, said second clutch
member being movable in said first linear direction in the event
that said teeth of said first clutch member engage said teeth of
said second clutch member when said shaft is moved in said first
linear direction to cause said cam follower to engage and move
along said cam surface to rotate said second clutch member in a
second rotational direction opposite said first rotational
direction to increase the tension on said elastic member and to
allow surfaces of said teeth of said first clutch member to engage
surfaces of said teeth of said second clutch member to rotate said
second clutch member further in said second rotational direction to
allow said teeth of said second clutch member to be located between
said teeth of said second clutch member.
Description
[0001] This application claims the benefit of U.S. Provisional
Patent Application No. 60/221,413, filed Jul. 28, 2000.
BACKGROUND OF THE INVENTION
[0002] 1. Field of The Invention
[0003] The invention relates to a directional drilling system for
drilling a borehole in the earth.
[0004] 2. Description of The Prior Art
[0005] U.S. Pat. Nos. 4,281,723, 4,953,638, 5,423,388, 5,490,569,
5,957,222, 6050,350, and 6,082,470 disclose drilling apparatus with
directional control systems.
SUMMARY OF THE INVENTION
[0006] It is an object of the invention to provide a drilling
apparatus with a new and useful directional control system. The
apparatus is particularly useful in the utility industry for
drilling shallow, generally horizontal holes for placing conduits
and cables in the ground without forming trenches.
[0007] The apparatus comprises an annular cam rotatably located in
a housing with a drill shaft extending through the cam and housing.
The shaft can rotate for drilling purposes and be moved
longitudinally in the housing for shifting purposes. The cam has
grooves in its outer surface for receiving a cam follower carried
by the shaft, which rotates the cam as the shaft is moved
longitudinally for shifting purposes. The shaft may be moved
longitudinally in one direction with the cam follower in the groove
to a position to engage members of a clutch such that when the
shaft rotates, it rotates the housing. The shaft is movable in an
opposite direction with the cam follower in the groove to disengage
the clutch members and then is movable to locate the cam follower
in the groove at different positions to allow the operator to
control the longitudinal position of the shaft for turning purposes
or for drilling straight.
[0008] In one embodiment, the apparatus comprises a single housing.
For turning purposes the cam follower is located in a position in
the groove to disengage the clutch members to allow the drill bit
to rotate relative the housing and to allow wear pads to cause the
housing to move in a turning mode. Straight drilling is carried out
with the clutch members engaged such that the complete apparatus
rotates while drilling straight.
[0009] In another embodiment the apparatus comprises front and rear
housings with a shaft extending therethrough. The rear of the front
housing and the front of the rear housing are pivotally coupled
together. The annular cam and its follower are located in the rear
housing. A main cam having a slot is fixedly secured in the rear
housing. A main cam follower is carried by the shaft such that
longitudinal movement of the shaft causes the main cam follower to
move in the slot and to cause the rear and front ends of the front
and rear housings respectively to pivot relative to each other and
to the shaft in directions dependent on the position of the main
cam follower in the slot for turning or straight drilling purposes.
The grooves in the annular cam are formed such that they will allow
regulation of the amount of longitudinal movement of the shaft and
hence of the main cam follower relative to the main cam to allow
regulation of straight and turn drilling and the degree of turning
that the drilling means will undergo.
[0010] Also provided are a new and useful drill bit and a new and
useful clutch assembly.
BRIEF DESCRIPTION OF DRAWINGS
[0011] FIG. 1 illustrates the top view of the drilling apparatus of
the invention in the straight drilling mode.
[0012] FIG. 2 illustrates the side view of the drilling apparatus
of the invention in the straight drilling mode.
[0013] FIG. 3 is a side cross sectional view of the parts of the
apparatus that are locked longitudinally with the guide
housings.
[0014] FIG. 4 is a top cross sectional view of the parts of the
apparatus that are locked longitudinally with the guide
housings.
[0015] FIG. 5 is a side cross sectional view of the parts of the
apparatus that are locked longitudinally with the shaft.
[0016] FIG. 6 illustrates the top cross sectional view of the parts
that are locked longitudinally with the shaft.
[0017] FIG. 7 is a cross sectional view of FIG. 1 taken along the
lines 7-7 thereof.
[0018] FIG. 8 is a cross sectional view of FIG. 1 taken along the
lines 8-8 thereof.
[0019] FIG. 9 is a top view of the drilling apparatus of the
invention in the shifting mode.
[0020] FIG. 10 is a side view of the drilling apparatus of the
invention in the shifting mode positioned in a curved hole.
[0021] FIG. 11 is a cross sectional view of FIG. 9 taken along the
lines of 11-11 thereof.
[0022] FIG. 12 is the cross sectional view of FIG. 9 taken along
the lines of 12-12 thereof.
[0023] FIG. 13 is a cross sectional view of FIG. 10 taken along the
lines of 13-13 thereof.
[0024] FIG. 14 is a cross sectional view of FIG. 7 taken along the
lines of 14-14 thereof.
[0025] FIG. 15 is a cross sectional view of FIG. 8 taken along the
lines of 15-15 thereof.
[0026] FIG. 16 is a cross sectional view of FIG. 11 taken along the
lines of 16-16 thereof.
[0027] FIG. 17 is a cross sectional view of FIG. 12 taken along the
lines of 17-17 thereof.
[0028] FIG. 18 is a cross sectional view of FIG. 12 taken along the
lines of 18-18 thereof when the clutch is in the neutral
position.
[0029] FIG. 19 is a cross sectional view of FIG. 12 taken along the
lines of 18-18 thereof, which is the same lines as FIG. 18 was
taken from but when the shaft has been rotated in order to rotate
the drilling apparatus.
[0030] FIG. 20 is a top view of the drilling apparatus of the
invention in the major turn mode.
[0031] FIG. 21 is a side view of the drilling apparatus of the
invention in the major turn mode.
[0032] FIG. 22 is a cross sectional view of FIG. 20 taken along the
lines of 22-22 thereof.
[0033] FIG. 23 is a cross sectional view of FIG. 20 taken along the
lines of 23-23 thereof.
[0034] FIG. 24 is a cross sectional view of FIG. 22 taken along the
lines of 24-24 thereof.
[0035] FIG. 25 is a cross sectional view of FIG. 23 taken along the
lines of 25-25 thereof.
[0036] FIG. 26 is a top view of the drilling apparatus of the
invention in the minor turn mode.
[0037] FIG. 27 is a side view of the drilling apparatus of the
invention in the minor turn mode.
[0038] FIG. 28 is a cross sectional view of FIG. 26 taken along the
lines of 28-28 thereof.
[0039] FIG. 29 is a cross sectional view of FIG. 26 taken along the
lines of 29-29 thereof.
[0040] FIG. 30 is a top view of the drilling apparatus of the
invention in the partially pulled back mode.
[0041] FIG. 31 is a side view of the drilling apparatus of the
invention in the partially pulled back mode.
[0042] FIG. 32 is a cross sectional view of FIG. 30 taken along the
lines of 32-32 thereof.
[0043] FIG. 33 is a cross sectional view of FIG. 30 taken along the
lines of 33-33 thereof.
[0044] FIG. 34 is an isometric view of the shifting cam.
[0045] FIG. 35 is 360-degree flat view of the exterior of the
shifting cam
[0046] FIG. 36 is a 180-degree flat view of the shifting cam and
the shifting cam follower in the straight drilling mode.
[0047] FIG. 37 is a 180-degree flat view of the shifting cam lug
contacting the shifting cam groove intersection.
[0048] FIG. 38 is a 180-degree flat view of the shifting cam with
the shifting cam followers in fall rearward position.
[0049] FIG. 39 is a 180-degree flat view of the shifting cam with
the shifting cam follower lug contacting an intersection of the
shifting cam grooves.
[0050] FIG. 40 is a 180-degree flat view of the shifting cam with
the shifting cam follower in transition between the full rearward
position and the full forward position.
[0051] FIG. 41 is a 180-degree flat view of the shifting cam with
the shifting cam follower in the fully forward position.
[0052] FIG. 42 is a 360-degree flat view of the shifting cam with
the shifting cam follower lugs contacting an intersection of the
shifting cam grooves.
[0053] FIG. 43 is a 360-degree flat view of the shifting cam with
the shifting cam followers in transition between the major turn
position and the rearward position before drilling straight.
[0054] FIG. 44 is a 360-degree fiat view of the shifting cam with
the shifting cam followers by-passing the by-pass groove of the
shifting cam.
[0055] FIG. 44A is a 180-degree flat view of the shifting cam with
the shifting cam follower lug stopped by the end of the shifting
cam groove.
[0056] FIG. 44B is a 180-degree flat view of the shifting cam with
the shifting cam follower lug contacting the intersection of the
grooves in the shifting cam.
[0057] FIG. 44C is a 180-degree flat view of the shifting cam with
the shifting cam follower in the straight position.
[0058] FIG. 44D is a 180-degree flat view of the shifting cam with
the shifting cam follower contacting an intersection of the
shifting cam grooves.
[0059] FIG. 44E is a 180-degree flat view of the shifting cam with
the shifting cam follower in the full rearward position.
[0060] FIG. 44F is a 180-degree flat view of the shifting cam with
the shifting cam follower lug contacting an intersection of the
shifting cam grooves.
[0061] FIG. 44G is a 180-degree flat view of the shifting cam with
the shifting cam follower's forward displacement halted in
preparation to start the minor turn sequence.
[0062] FIG. 44H is a 180-degree flat view of the shifting cam with
the shifting cam follower contacting an intersection of the
shifting cam grooves.
[0063] FIG. 44(I) is a 180-degree flat view of the shifting cam
with the shifting cam follower fully rearward in the minor turn
sequence.
[0064] FIG. 44J is a 360-degree flat view of the shifting cam with
the shifting cam followers in transition from the fully rearward
position to the minor turn position.
[0065] FIG. 44K is a 360-degree fiat view of the shifting cam with
the shifting cam followers exiting the by-pass groove.
[0066] FIG. 44L is a 360-degree flat view of the shifting cam with
the shifting cam followers heading toward the minor turn stop.
[0067] FIG. 44M is a 360-degree flat view of the shifting cam with
the shifting cam follower lugs stopped by the minor turn stop.
[0068] FIG. 44N is a 180-degree flat view of the shifting cam with
the shifting cam follower in transition between the minor turn and
the rearward stop before going straight. This view shows the
shifting cam follower missing the by-pass groove.
[0069] FIG. 44(0) is a 180-degree flat view of the shifting cam
with the shifting cam follower in transition between the minor turn
and the rearward stop before going straight.
[0070] FIG. 44P is a 180-degree flat view of the shifting cam with
the shifting cam follower in the fully rearward position before
going straight.
[0071] FIG. 45 is an isometric view of the clutch stop.
[0072] FIG. 45A is an enlargement of the clutch stop lug.
[0073] FIG. 46 is an isometric view of the front of the female
clutch member.
[0074] FIG. 47 is an isometric view of the rear of the female
clutch member.
[0075] FIG. 48 is an isometric view of the rear of the male clutch
member.
[0076] FIG. 49 is a cutout section of the guide housing showing the
clutch members in a relaxed position.
[0077] FIG. 50 is a cutout section of the guide housing showing the
clutch members engaging each other.
[0078] FIG. 51 is a front view of the shaft retainer cut to hold
the rotational cutting means.
[0079] FIG. 52 is a side view of the shaft retainer.
[0080] FIG. 53 is a rear view of the shaft retainer.
[0081] FIG. 54 is a cross sectional view of FIG. 52 taken along the
line 54-54 thereof.
[0082] FIG. 55 is a side view of the assembled rotational cutting
means.
[0083] FIG. 56 is a front view of the assembled rotational cutting
means.
[0084] FIG. 57 is a rear view of the assembled rotational cutting
means.
[0085] FIGS. 58-65 shows the coupling procedure of the rotational
cutting means.
[0086] FIG. 66 is a cross sectional view of the front end of the
drilling apparatus showing the magnetic displacement device in
use.
[0087] FIG. 67 is a cross sectional view of FIG. 66 taken along the
line 67-67 thereof.
[0088] FIG. 68 is an isometric view of the transmitter housing with
magnetic sensitive wires positioned to indicate longitudinal
displacement of the shaft.
[0089] FIG. 69 is a cross sectional view of the rear of the
apparatus using a longer clutch means.
[0090] FIG. 70 is a top view of the drilling apparatus with a third
housing attached.
[0091] FIG. 71 is a side view of the drilling apparatus with a
third housing attached.
[0092] FIG. 72 is a cross sectional view of FIG. 70, using a
standard transmitter, taken along the lines 72-72 thereof.
[0093] FIG. 73 is a cross sectional view of FIG. 70, using a
Wireline transmitter, taken along the lines 73-73 thereof.
[0094] FIG. 74 is an illustration of the alternative drilling
apparatus using a percussion type cutting means in the straight
drilling mode.
[0095] FIG. 75 is an illustration of the alternative drilling
apparatus using a percussion type cutting means in the shifting
mode.
[0096] FIG. 76 is an illustration of the alternative drilling
apparatus using a percussion type cutting means in the turning
mode.
[0097] FIG. 77 is an illustration of the alternative drilling
apparatus using a rotational type cutting means in the straight
drilling mode.
[0098] FIG. 78 is an illustration of the alternative drilling
apparatus using a rotational type cutting means in the shifting
mode.
[0099] FIG. 79 is an illustration of the alternative drilling
apparatus using a rotational type cutting means in the turning
mode.
[0100] FIG. 80 is a cross sectional view of FIG. 74 and FIG. 77
taken along the lines of 80-80 thereof.
[0101] FIG. 81 is a cross sectional view of FIG. 75 and FIG.78
taken along the lines of 81-81 thereof.
[0102] FIG. 82 is a cross sectional view of FIG. 76 and FIG. 79
taken along the lines of 82-82 thereof.
[0103] FIG. 83 is a cross sectional view of FIG. 79 taken along the
lines of 83-83 thereof.
[0104] FIG. 84 is a 180-degree flat view of the
alternative-shifting cam with the alternative-shifting cam follower
in the fully forward position.
[0105] FIG. 85 is a 180-degree flat view of the
alternative-shifting cam with the alternative-shifting cam follower
contacting an intersection of the alternative shifting cam
grooves.
[0106] FIG. 86 is a 180-degree flat view of the
alternative-shifting cam with the alternative-shifting cam follower
in transition between fully forward and fully rearward
positions.
[0107] FIG. 87 is a 180-degree flat view of the
alternative-shifting cam with the alternative-shifting cam follower
in the fully rearward position.
[0108] FIG. 88 is a 180-degree view of the alternative-shifting cam
with the alternative-shifting cam follower contacting an
intersection of the alternative-shifting cam grooves.
[0109] FIG. 89 is a 180-degree flat view of the
alternative-shifting cam with the alternative-shifting cam follower
in transition between the fully rearward position and the straight
position.
[0110] FIG. 90 is a 180-degree flat view of the
alternative-shifting cam with the alternative-shifting cam follower
in the straight position.
[0111] FIG. 91 is a 180-degree flat view of the
alternative-shifting cam with the alternative-shifting cam follower
in contact with an intersecting groove.
[0112] FIG. 92 is a 180-degree flat view of the
alternative-shifting cam with the alternative-shifting cam follower
in transition from the straight position to the fully rearward
position.
[0113] FIG. 93 is a 180-degree flat view of the
alternative-shifting cam with the alternative-shifting cam follower
in the fully rearward position.
[0114] FIG. 94 is a 180-degree flat view of the
alternative-shifting cam with the alternative-shifting cam follower
contacting an intersection of the grooves.
[0115] FIG. 95 is a 270-degree flat view of the
alternative-shifting cam with the alternative-shifting cam follower
in transition between fully rearward and fully forward
positions.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0116] Referring to FIGS. 1-65 of the drawings, the apparatus
comprises a shaft 101 having a rear end 101R connectable to a
drilling system 103 and a rotational cutting means 105 connectable
to the front end 101F. The shaft 101 extends through a front
housing 111 and a rear housing 113. The drilling system is a
conventional system that can rotate and push the shaft 101 forward
for drilling purposes and it can also pull the shaft 101 rearward.
Additional stem members can be attached to the rear 101R of the
shaft 101 and to the drilling system 103 as the hole being drilled
gets longer or deeper. The shaft 101 can rotate within each of
units 111 and 113, and can move forward a small distance to a
drilling position and rearward a small distance to a shifting
position relative to units 111 and 113. Units 111 and 113 cannot
rotate relative to each other, but they can bend or pivot
lengthwise relative to each other. As shown in FIGS. 21-23 and
27-29.
[0117] A front ball joint 115 with pivot pins 117 located at the
front of unit 111 supports unit 111 on the front of the shaft 101F.
A middle ball joint 119 with a rear end 119R connects the rear of
unit 111 with the front of unit 113. A rear ball joint 121 with
pivot pins 121A similar to the front ball joint 115 supports the
rear of unit 113 on the rear of shaft 101R.
[0118] A main cam 123 and a main cam follower 163 are employed in
unit 113 to cause the apparatus to drill straight as shown in FIGS.
1 and 2 or to tilt or pivot units 111 and 113 relative to the shaft
101 as shown in FIGS. 21-23 and 27-29 to cause the front of the
shaft 101F to turn up, down, left, or right or any fraction thereof
while drilling operations are being carried out. A shifting cam 145
is also located in unit 113 for the purpose of regulating the
straight and turn drilling by regulating the amount of longitudinal
displacement between the main cam 123 and the main cam follower
163.
[0119] For reference, in the drawings, the top of the drilling
apparatus is on the inside of the radius being drilled, such that
if the hole is being turned up relative to the earth, the top of
the drilling apparatus is up relative to the earth. Likewise if the
bore is being turned downward relative to the earth, the drilling
apparatus is turned upside down, and so on. Referring to FIG. 3 and
FIG. 4, the front housing 111 has fixedly attached to it, a front
socket 127, a transmitter case 129, a middle socket 131, and a
front wear pad 133. The front socket 127 encases the front ball 115
so that the front housing 111 may pivot relative to the shaft 101.
The transmitter case 129 is accessible through a cutout 135 in the
side of the front housing 111. The door 129D covers the transmitter
137. The transmitter case 129 holds the compartment for the
transmitter 137 employed by the drilling apparatus. The middle
socket 131 encases the middle ball 119 so that the front housing
111 may pivot relative to the rear housing 113. The middle socket
131 and the middle ball 119 are pinned together so that they cannot
rotate relative to each other, such that the two housings 111 and
113 cannot rotate relative to each other. The front wear pad 133 is
located on the bottom of the drilling apparatus, such that it
pushes against the bore wall 179 to cause the drilling apparatus to
turn. The rear of the middle ball 119R is fixedly attached to the
front of the rear housing 113. The rear housing 113 has fixedly
attached to it a main cam 123, a stop plate 141, a shifting cam
bushing 143, a stop bushing 167B, a clutch stop 147, a rear socket
149, and a rear wear pad 151. The shifting cam bushing 143 supports
a shifting cam 145. The shifting cam 145 is free to rotate, but is
locked longitudinally relative to the rear housing 113. The clutch
stop 147 is fixedly attached to the housing 113 and limits the
rotational and forward movement of a female clutch member 153. The
rear socket 149 limits the rearward movement of the female clutch
member 153. The female clutch member 153 is free to rotate relative
to the rear housing 113 only enough to allow the male clutch member
171 to engage with female clutch member 153 without regards to
their starting rotational orientation.
[0120] Referring to FIGS. 5 and 6 the shaft 101 has attached to it
a shaft retainer 155 upon which; in this case, a rotational cutting
means 105 is mounted. The cutting means 105 may be a conventional
rotary type as shown or it may be a hammering system that is
commonly employed in harder strata and illustrated in FIGS. 74-76.
Behind the shaft retainer 155 are two sleeves 157 and 159 that
rotate with the shaft 101 and hold the other components
longitudinally in place. Behind the sleeves 157 and 159 are a
thrust bearing 161, a main cam follower 163, a cam follower spacer
165, a thrust bearing 169, and a male clutch member 171. The cam
follower 163 and cam follower spacer 165 are free to rotate
relative to the shaft 101, but are tied longitudinally to the shaft
101 by the shaft retainer 155, the two sleeves 157 and 159, the
thrust bearings 161 and 165 and the shoulder 101S of the shaft 101.
The shaft 101 can rotate relative to the cam follower 163 and
spacer 165. Mounted on the rear of the shaft 101R is a rearward
cutter 173. The rearward cutter 173 contains threads for accepting
a thread adapter 175 that joins the drilling apparatus to the drill
string and ultimately the drilling system 103. Two shifting cam
followers 177A and 177B are mounted 180 degrees from each other and
90 degrees from the cam follower lugs 163S and 163L on the outside
of the cam follower 163. The shifting cam followers 177A and 177B
are free to pivot relative to the cam follower 163, but are locked
longitudinally to the cam follower 163 by pins 163P. The shifting
cam followers 177A and 177B are locked rotationally to the housing
113 but are free to move longitudinally relative to the housing
113. The followers 177A and 177B cannot rotate relative to the
housing 113.
[0121] Referring to FIGS. 3-44 the main cam 123 has two slots cut
into it, 180 degrees apart. The bottoms of the slots stay
relatively parallel to each other. The bottom of the slots start
out in the rear of the main cam 123 close to the bottom of the
drilling apparatus and progress in several stages close to the top
of the drilling apparatus as they progress to the front. The slots
accept the main cam follower lugs 163S and 163L. The sides of slots
keep the main cam follower 163 rotationally engaged to the rear
housing 113 for rotation with the rear housing 113 as well as
giving support for side loaded pressure placed on the drilling
apparatus. The large cam follower lug 163L is located on the bottom
of the drilling apparatus, while the small cam follower lug 163S is
located on the top of the drilling apparatus. As the main cam
follower 163 is displaced forward relative to the main cam 123, the
main cam follower lugs 163S and 163L follow the slots in the main
cam 123. This causes the front of the rear housing 113 and the rear
of the front housing 111 to pivot downward away from the shaft 101,
such that the bore wall 179 is pushed on by the wear pad 133 and
the drilling apparatus is caused to change directions. When the
main cam follower 163 is displaced fully rearward, the front of the
rear housing 113 and the rear of the front housing 111 are pivoted
upward toward the shaft 101. This causes the wear pad 133 to be
pulled in as close as possible to the shaft 101.
[0122] Referring to FIGS. 34-44P, the shifting cam 145 and shifting
cam followers 177A and 177B regulate the amount of longitudinal
displacement that the main cam 123 and main cam follower 163
undergo. In FIGS. 35-44P the exterior surface of the cam 145 is
shown laid out flat. The two cam followers 177A and 177B are
located 180 degrees apart. In FIGS. 35, 42-44, and 44J-44M, 360
degrees of the cam is shown and in FIGS. 42-44 and 44J-44M both cam
followers 177A and 177B are shown. In FIGS. 36-41, 44A-44(I) and
44N-44P only 180 degrees of the cam 145 is shown and only one cam
follower 177B is shown although it is to be understood that the
complete cam of FIGS. 34 and 35 and both followers 177A and 177B
will be employed. In FIGS. 36-44P the horizontal arrows depict the
direction of longitudinal travel of the followers 177A and 177B and
the vertical arrows next to the cam 145 depict the direction of
rotation of the cam 145. In FIGS. 36-44P, rearward movement of the
followers 177A and 177B is to the right and forward movement of the
followers 177A and 177B is to the left. The lugs 177AL and 177BL of
the cams 177A and 177B can be moved between positions displaced
fully rearward as shown by follower 177B in FIG. 38 and to
positions fully displaced forward as shown by follower 177B in FIG.
41 and to intermediate positions. Grooves 145A-145E are cut into
the outside of the shifting cam 145 at an angle such that when the
shifting cam followers 177A and 177B are displaced longitudinally
they contact the walls of the grooves 145A-145E, which rotate the
shifting cam 145. Furthermore, the lugs 177AL and 177BL on the
shifting cam followers 177A and 177B are shaped in such away as to
ride along the walls of the grooves 145A-145E and to enter into an
intersecting groove 145AB-145DE when the appropriate displacement
and rotational positioning is achieved.
[0123] FIG. 36 shows the shifting cam follower 177B in the straight
drilling position. In this position the shifting cam followers 177A
and 177B, and thus the main cam follower 163, cannot progress any
further forward relative to the shifting cam 145, and thus the main
cam 123, because the shifting cam follower lugs 177AL and 177BL are
in contact with end of the shifting cam grooves 145E. Displacing
the shifting cam followers 177A and 177B rearward causes them to
contact the next set of intersecting grooves 145DE (FIG. 37). When
the shifting cam followers 177A and 177B are displaced further
rearward the shifting cam 145 is forced to rotate by the shifting
cam follower lugs 177AL and 177BL pushing on the walls of the
shifting cam grooves 145D. The contact of the main cam follower
lugs 163S and 163L and the stop ring 141 halt the rearward
longitudinal displacement of the shifting cam followers 177A and
177B relative to the shifting cam 145 (FIG. 38 and FIG. 12). In
this longitudinal position the clutch members 153 and 171 are
engaged and the housing 113 may be rotated with the shaft 101. When
the desired rotational position is achieved, the shifting cam
followers 177A and 177B can be moved forward relative to the
shifting cam 145 until they contact the next set of intersecting
grooves 145AD (FIG. 39). As the shifting cam followers 177A and
177B are further displaced forward relative to the shifting cam
145, the shifting cam follower lugs 177AL and 177BL push on the
wall of the shifting cam grooves 145A forcing the shifting cam 145
to rotate relative to the housing 113 (FIG. 40). The shifting cam
followers 177A and 177B do not rotate relative to the housing 113
because they are held rotationally locked to the housing 113 by the
shifting cam bushings 143. The contact of the stop washer 167 and
the stop bushing 167B halts the further forward displacement of the
shifting cam followers 177A and 177B relative to the shifting cam
145 as well as the forward displacement of the main cam follower
163 relative to the main cam 123 (FIG. 41 and FIG. 23). In this
position the tightest radius is being drilled. Displacing the
shifting cam followers 177A and 177B rearward causes them to
contact yet another set of intersecting grooves 145AC (FIG. 42).
Further rearward displacement causes the shifting cam follower lugs
177AL and 177BL to push on the walls of shifting cam grooves 145C,
forcing the shifting cam 145 to rotate relative to the housing 113
(FIG. 43). FIG. 44 shows the shifting cam followers 177A and 177B
moving passed the by-pass groove 145B without entering it. This is
possible by the widening of the grooves 145C in this location. The
contact of the end of the shifting cam grooves 145C and the
shifting cam follower lugs 177AL and 177BL stops the rearward
displacement of the shifting cam followers 177A and 177B relative
to the shifting cam 145 (FIG. 44A). In this embodiment the clutch
members 171 and 153 are not engaged in this position, allowing the
operator to know that upon pushing forward he will be drilling
straight because the next intersecting groove leads to the straight
position. Displacing the shifting cam followers 177A and 177B
forward causes the shifting cam follower lugs 177AL and 177BL to
contact the intersections of yet another set of shifting cam
grooves 145CE (FIG. 44B). Further forward displacement of the
shifting cam followers 177A and 177B causes the shifting cam
follower lugs 177AL and 177BL to push on the shifting cam groove
walls, which causes the shifting cam 145 to rotate relative to the
housing 113. The contact of the shifting cam follower lugs 177AL
and 177BL and the end of the shifting cam grooves 145E stops the
forward displacement of the shifting cam followers 177A and 177B
relative to the shifting cam 145 and thus, the forward displacement
of the main cam follower 163 relative to the main cam 123 (FIG.
44C). In this position the housings 111 and 113 are virtually
parallel with the shaft 101, thus causing zero effect on the
direction of travel, which allows the drilling apparatus to drill
straight. In this embodiment the clutch members 171 and 153 are not
engaged, which allows the shaft 101 to rotate without rotating the
housing 113. While drilling straight the housings 111 and 113 slide
through the bore being drilled. Rearward displacement of the
shifting cam followers 177A and 177B causes them to contact the
next set of intersecting grooves 145DE (FIG. 44D). Further rearward
displacement causes the shifting cam 145 to rotate relative to the
housing 113. Contact between the main cam follower lugs 163S and
163L and the stop plate 141 stops the rearward displacement between
the shifting cam followers 177A and 177B and the shifting cam 145
(FIG. 44E and FIG. 12). Forward displacement of the shifting cam
followers 177A and 177B causes the shifting cam follower lugs 177AL
and 177BL to contact the next set of intersecting grooves 145AD
(FIG. 44F). Further forward displacement of the shifting cam
followers 177A and 177B causes the shifting cam follower lugs 177AL
and 177BL to push on the shifting cam groove walls causing the
shifting cam 145 to rotate relative to the housing 113. By halting
the forward displacement of the shifting cam followers 177A and
177B relative to the shifting cam 145 before the shifting cam
follower lugs 177AL and 177BL are displaced enough to enter the
intersecting grooves 145AC, but after they have passed the entrance
of the by-pass grooves 145AB, the operator has a choice to either
drill straight or at least drill a lesser deviated hole (FIG. 44G).
The forward displacement of the shifting cam followers 177A and
177B may be stopped by the operator or by the hard surface of the
bore wall. For example, if the cutting means 105 or 247 is not
activated, by either the rotation of the shaft or the supply of a
compressed medium, such as air or water, after the main cam
follower 163 is displaced forward enough to put sufficient pressure
on the housing 113 to deflect it against the bore wall, the
apparatus will not cut off to the side and thus the pressure from
the wear pads 151 and 133 and the non-activated cutting means 105
or 247 will halt the forward displacement of the main cam follower
163 relative to the main cam 123 and thus the shifting cam
followers 177A and 177B relative to the shifting cam 145. Rearward
displacement of the shifting cam followers 177A and 177B relative
to the shifting cam 145 causes the shifting cam follower lugs 177AL
and 177BL to contact the shifting cam groove walls causing the
shifting cam 145 to rotate. This time the shifting cam 145 is
rotating in the opposite direction from what it normally rotates.
Further rearward displacement causes the shifting cam follower lugs
177AL and 177BL to contact the intersections of the bypass grooves
145AB (FIG. 44H). Still more rearward displacement of the shifting
cam followers 177A and 177B causes the shifting cam 145 to rotate
in its normal direction. The contact of the main cam follower lugs
163S and 163L and the stop ring 141 halts the rearward displacement
(FIG. 44(I) and FIG. 12). In this position the clutch members 153
and 171 are engaged and the housing 113 may be rotated if desired.
Forward displacement of the shifting cam followers 177A and 177B
causes the shifting cam follower lugs 177AL and 177BL to contact
the next set of intersecting grooves 145BA. Further forward
displacement of the shifting cam followers 177A and 177B causes the
shifting cam 145 to rotate in its normal direction (FIG. 44J and
FIG. 44K). The shifting cam 145 is rotated until the shifting cam
follower lugs 177AL and 177BL exit the by-pass grooves 145B (FIG.
44L). The continued forward displacement of shifting cam followers
177A and 177B causes the shifting cam follower lugs 177AL and 177BL
to enter into a set of short grooves 145M, which stops the forward
displacement of the shifting cam followers 177A and 177B relative
to the shifting cam 145 (FIG. 44M). In this position the main cam
follower 163 is displaced forward relative to the main cam 123
enough to deflect the housings 111 and 113 only part of their total
deflection capabilities (FIGS. 27-29). If the operator chooses to
drill forward the drilling apparatus will turn at a lesser degree
than would otherwise be possible. If the operator chooses not to
drill forward he can continue to manipulate the drill stem in order
to position the drilling apparatus in the desired mode. Rearward
displacement of the shifting cam followers 177A and 177B causes the
shifting cam follower lugs 177AL and 177BL to contact the walls of
shifting cam groove 145C on the other side of the by-pass groove
145B thus allowing the shifting cam 145 to be rotated in the normal
direction (FIG. 44N). Further rearward displacement of the shifting
cam followers 177A and 177B relative to the shifting cam 145 causes
the shifting cam follower lugs 177AL and 177BL to push on the
shifting cam groove wall, which causes the shifting cam 145 to
rotate relative to the housing 113 (FIG. 44(0)). Contact between
the shifting cam follower lugs 177AL and 177BL and the end of the
shifting cam grooves 145C stops the rearward displacement of the
shifting cam followers 177A and 177B relative to the shifting cam
145 (FIG. 44P). Further longitudinal displacement causes this
sequence to repeat.
[0124] Referring to FIGS. 1, 2, 7, 8 and 36, when the shifting cam
followers 177A and 177B are stopped by shifting cam grooves 145E
the drilling apparatus is drilling with the main cam follower 163
only partially displaced relative to the main cam 123, such that a
straight bore is produced.
[0125] Referring to FIGS. 9-13, 38, 44E, and 44(I) when the
shifting cam followers 177A and 177B are allowed to regress
backward without hindrance from the shifting cam 145 the
longitudinal displacement of the main cam follower 163 relative to
the main cam 123 is stopped by the main cam follower lugs 163S and
163L and the stop plate 141. In this position all of the parts of
the drilling apparatus are rotationally locked by the engagement of
the clutch means 171 and 153.
[0126] Referring to FIG. 10 the bore illustrated is curved
downwards while the drilling apparatus is in the shifting position
and oriented to drill upwards. The rear of the front housing 111
and the front of the rear housing 113 are bent upward allowing the
drilling apparatus to be rotated a full 360 degrees in a tighter
radius bore than might otherwise be possible. This allows the
drilling apparatus to be with drawn through a smaller radius bore
without becoming stuck.
[0127] Referring to FIGS. 20-25 and 41 when the shifting cam
followers 177A and 177B are allowed to progress forward unimpeded
by the shifting cam 145 the forward displacement of the main cam
follower 163 relative to the main cam 123 is stopped by the contact
of the stop washer 167 and the stop bushing 167B. In this position
the drilling apparatus is producing the tightest turn possible.
[0128] Referring to FIGS. 21-23 and 27-29 the middle wear pad 133
is mounted on the rear of the front housing 111 such that when the
rear of the front housing 111 is bent downward the wear pad 133 is
forced against the bottom of the bore 179, which pushes laterally
on the drilling apparatus until the rear wear pad 151 hits the
opposite side of the bore 179, then the front of the drilling
apparatus is pivoted toward the opposite side changing the
direction of travel.
[0129] Referring to FIGS. 26-29 and 44M, when the shifting cam
followers 177A and 177B are stopped by shifting cam groove 145M the
drilling apparatus is drilling with the main cam follower 163 only
partially displaced relative to the main cam 123, such that a
larger radius is drilled.
[0130] Referring to FIGS. 30-33, 44A and 44P, when the shifting cam
followers 177A and 177B are stopped by shifting cam groove 145C the
male clutch member 171 is halted from engaging the female clutch
member 153 such that the housing 113 cannot be rotated when the
shaft is rotated. This lets the operator know that upon pushing
forward he will be drilling straight.
[0131] Referring to FIGS. 18,19 and 45-50 the clutch stop 147 has
two lugs 147L protruding toward the rear of the drilling apparatus.
Each lug is identical. Each has a cam groove 147C cutout of it that
acts like a cam and a pin 147P protruding radially outward. The pin
147P is designed to hold the end of one of the elastic bands 153R
or 153S whose other end is attached to one of two cam follower pins
153P, that are attached to the clutch ring 153. The elastic bands
may be o-rings made from a suitable elastomer. The clutch ring 153
has two cutouts 153C cut into its outer edge. Within these cutouts
153C are mounted the two cam follower pins 153P that act as cam
followers. The interior of the ring 153 has teeth 153T protruding
toward the center. Each tooth 153T has a beveled surface 153B on
its forward face. Cut radially around the clutch rings 153 outer
edge is a groove 153G that is wide enough and deep enough for the
unobstructed acceptance of the elastic bands 153R and 153S. A male
clutch member 171 is mounted fixedly on the shaft 101. On the outer
edge of the male clutch member are mounted teeth 171T. Each tooth
171T has a beveled surface 171B facing rearward.
[0132] FIG. 49 shows the clutch assembly in a relaxed state. The
housing 113 supports the clutch ring 153 and the clutch stop 147.
The male clutch member 171 is forward of the clutch ring 153. The
clutch ring 153 is positioned so that the lugs 147L on the clutch
stop 147 are located in and engaged with the cutouts 153C on the
clutch ring 153. The cam pins 153P are positioned in the cam groove
147C. The elastic bands 153R and 153S are position so that one end
is held by a cam pin 153P and stretches through the groove 153G to
the pin 147P that is mounted on the opposite lug 147L. In this
relaxed state, the elastic bands 153 R and 153S keep the clutch
ring 153 rotated clockwise as seen from the rear of the drilling
apparatus. Being fully rotated clockwise the cam follower pins 153P
are positioned in the apex of the cam grooves 147C and the clutch
ring 153 is fully forward, resting against the face of the clutch
stop 147.
[0133] When the male clutch member 171 is pulled rearward, it will
either enter into the clutch ring 153 without any interference, or
the respective teeth 153T and 171T will hit. If the teeth 153T and
171T hit, the clutch ring 153 will be forced rearwards. This will
cause the cam follower pins 153P to contact the cam grooves 147C,
which will force the clutch ring 153 to rotate counter-clockwise as
seen from the rear. As the counter clockwise rotation is taking
place the elastic bands 153R and 153S are stretching and gaining
potential energy. The rearward displacement of the clutch ring 153
is stopped when it contacts the rear ball socket 149. By the time
the clutch ring 153 has been displaced fully rearward the cam
groove 147C has exhausted its influence on the cam follower pin
153P (FIG. 50). In this position the beveled surfaces 153B and 171B
on the clutch rings teeth 153T and the male clutch members teeth
171T will be rotationally aligned so that any further rearward
displacement of the male clutch member 171 relative to the clutch
ring 153 will cause these surfaces 153B and 171B to push on each
other, which will continue the counter-clockwise rotation of the
clutch ring 153 relative to the clutch stop. The counter-clockwise
rotation will stop when the clutch ring 153 and the male clutch
member 171 are located such that each tooth 171T is located between
adjacent teeth 153T.
[0134] In this position, the male clutch member 171 may be rotated
in either direction to rotate the clutch ring 153 and hence the
housing 113 in either direction. If it is rotated counter
clockwise, the clutch ring 153 will be rotated relative to the
housing 113 until the clutch stop lugs 147L contact the edges of
the cutouts 153C on the clutch ring 153. Further counter-clockwise
rotation of the clutch ring 153 will rotate the housing 113
counter-clockwise. If the male clutch member 171 is rotated
clockwise, the cam follower pins 153P will contact the cam grooves
147C, which will force the clutch ring 153 forward. The clutch ring
153 will stop being rotated relative to the housing 113 when the
edges of the cutouts 153C in the clutch ring 153 contacts the
clutch stop lugs 147L. In this position the clutch ring 153 is back
in its starting position. Further clockwise rotation of the clutch
ring 153 will rotate the housing 113 clockwise. If the male clutch
member 171 has moved forward enough to disengage with the clutch
ring 153 but has not rotated the clutch ring 153 clockwise enough
to reposition the clutch ring 153 in its starting position, the
elastic bands 153R and 153L will contract. This will rotate the
clutch ring 153 clockwise causing the cam follower pin 153P to
contact the cam groove 147C. As the cam follower pin 153P is
rotated clockwise it is being forced forward by the cam groove
147C. The rotation and the forward travel relative to the housing
113 stop when the edges of the cutouts 153C on the clutch ring 153
contact the clutch stop lugs 147L, in this position the clutch ring
153 is in its starting position.
[0135] Referring to FIGS. 51-65 the rotational cutting means 105
are individual wings positioned on the shaft retainer 155 in radial
positions to form a drill bit. Three slots 155S are cut lengthwise
into the shaft retainer 155. On the front and rear of the shaft
retainer 155 are cut six slots perpendicular to the slots 155S such
that they leave behind a lip 155L corresponding to the front and
rear of each slot 155S. Two dowel-pin holes 155P are drilled
perpendicular to each slot 155S such that the are in a position to
allow dowel-pins 155D to lock the rotational cutting wings 105 in
place. The dowel-pin holes 155P are drilled so that the dowel-pins
155D can be inserted and extricated from the direction of rotation
such that upon rotation in the proper and common direction, the
dowel-pins 155D will not be pushed out of the dowel-pin holes 155P.
A smaller diameter hole is positioned to allow the dowel-pins to be
pressed out. On the front of the shaft retainer are three openings
155H that allow water or other medium to escape from inside the
shaft 101. The individual cutting wings 105 have a section behind
the actual cutting area 105C that is called the shank 105S. The
shank 105S is of a shape that will fit into one of the slots 155S
with little clearance. On the front is a front hook 105F. On the
rear is a rear hook 105R. A second cutting surface 105B faces
toward the rear. Two dowel-pin holes 105D are drilled in the middle
of the shank 105S. FIGS. 58-65 show the rotational cutting means
105 being mounted onto the shaft retainer 155 in steps. First the
shank 105S is held in line with the slot 155S, then lowering the
rear end of the shank 105S so that the rear hook 105R is engaged
with the rear lip 155L of the shaft retainer 155. Then the
rotational cutter 105 is rotated downwards into the slot 155S until
it comes to rest in the bottom of the slot 155S. In this position
the rotational cutting means 105 can be pulled rearwards. This
engages the front hook 105F with the front lip 155L and lines up
its dowel-pin holes 105D with the dowel pin holes 155P in the shaft
retainer 155. Then dowel-pins 155D are inserted into each dowel-pin
hole 155P.
[0136] Referring to FIGS. 66-68, a magnet 183 is magnetically
isolated from but locked onto the shaft 101 in a position which
allows it to pass longitudinally in the area of the transmitter
case 129 when the shaft 101 is displaced longitudinally relative to
the front housing 111. The transmitter case 129 is made of
non-magnetic material and has a number of magnetic conducting
strips 185 isolated from each other. Each strip 185 has an end
positioned in a different longitudinal position with its other end
positioned in a different radial position around the transmitter
cavity 135. A special transmitter 137B such as the Digitrac Eclipse
produced by Digital Control Inc. has to be used. This transmitter
137B is built with magnetically sensitive switches 187 that when
activated send signals to the receiver to be viewed by the locator
and ultimately by the operator Referring to FIG. 69 the female
clutch member 153 and the clutch stop 147 of FIGS. 1-68 are
replaced in the drilling apparatus by a longer female clutch member
153L and a corresponding clutch stop 147B. This makes the housings
111 and 113 of the drilling apparatus of FIGS. 1-68 rotate while
the bore is being drilled straight as well as when it is in the
shifting mode. The clutch will be disengaged when the drilling
apparatus is in the turning mode.
[0137] Referring to FIG. 70-72 a third housing 189 maybe attached
to the rear of the drilling apparatus via the rear ball 121 such
that it is rotationally and longitudinally locked to the drilling
apparatus. A third housing shaft 101H is attach to the rear end of
the shaft 101R via a standard collar 191 such that the third
housing' axis is parallel to the shaft 101 and the third housing
shaft 101H is fixedly attached to the shaft 101. The rear of the
third housing 189 is supported on the third housing shaft 101H via
a bearing compartment 189B. The third housing 189 is designed to
hold a larger transmitter 137L than can be held in the normal
transmitter compartment 135, which is sometimes needed or preferred
to produce a bore. One such transmitter is the Subsite produced by
Charles Machine Works Incorporated.
[0138] Referring to FIG. 73 in the third housing 189 a ring collar
191R can be used, instead of the standard collar 191, to attach the
rear of the shaft 101 and the front of the third housing shaft
101H. On the inside of the ring collar 191R is attached a wire 193.
The wire 193 is fed back through the shaft 101H and ultimately to
the drilling rig 103 and onto a receiver. The wire 193 is spliced
and made longer upon the addition of each new drill stem. A brush
195 is provided to transmit a signal from a wireline transmitter
137W that is housed in the third housing 189. The brush 195 is
touching but not solidly attached to the ring collar 191R such that
a constant connection is achieved even when the shaft 101 is
rotating or moving longitudinally relative to the third housing
189. Wireline transmitters are special but not uncommon for longer
and/or deeper bores.
[0139] Operation
[0140] After the crew foreman has determined the bore path, the
crew sets up the drill rig, in this case a Vermeer 24/40 produced
by Vermeer Manufacturing Incorporated. With the lead drill stem
already on the drill rig, the crew threads the drilling apparatus
onto it. The crew will then insert transmitter 137 and calibrate it
with the receiver located at the surface. The foreman has chosen to
use a cutting means/wear pad ratio that would allow the drilling
apparatus to rotate 360-degrees about its own axis when in the
shifting position even in a curved hole. He could have chosen a
number of different ratios, anywhere from barely turning for sewer
bores, to a 1/1 ratio which would give him the tightest turn, but
would not allow the drilling apparatus to rotate about its own axis
in a curved hole. Although, rotating about it's own axis in a
curved hole is not necessary to its operation, at times it can be
handy. Starting at a 15-degree angle with the horizon and the
drilling apparatus set to drill straight, the operator of the drill
rig begins the bore.
[0141] Initially, the operator of the system will start out with
the followers 177A and 177B in the groove positions 145E as shown
in FIG. 36 in order to drill straight. The operator drills straight
until the drilling apparatus is about 4' deep. At this time, he
pulls back on the drill stem. This causes reactions in the drilling
apparatus, 1) the clutch engages 171 to 153, 2) the shifting cam
follower 177A and 177B pulls back spinning the shifting cam 145,
and 3) the cam follower lugs 163S and 163L slide rearward relative
to the guide housings 111 and 113.
[0142] The operator can now rotate the drilling apparatus to the
desired orientation, in this case 12:00. This places the front wear
pad 133 on the bottom of the drilling apparatus and the rear wear
pad 151 on the top of it. The operator can now push the drill stem
forward. This causes 1) the clutch to disengage 171 from 153, 2)
the shifting cam followers 177A and 177B are pulled forward
rotating the shifting cam 145, and 3) the cam follower lugs 163S
and 163L ride up the main cam 123 which causes the guide housings
111 and 113 to bend or pivot relative to each other and the shaft
101 so that the front wear pad 133 pushes against the bottom of the
bore 179, in the middle of the drilling apparatus, while the rear
wear pad 151 pushes on the top of the bore. This reaction forces
the cutting means 105, located on the front of the drilling
apparatus upward, changing the direction of travel. When the
drilling apparatus has reached its full deflection using the chosen
cutting means/wear pad ratio, the turning radius is approximately
110 feet. (Note: choosing other cutting means/wear pad ratios will
change the radius of the bore.)
[0143] The operator can continue turning until he has achieved his
desired degree of deviation or until he has to add another drill
stem. While adding another drill stem, it is a good time for the
crew's locator to check the position of the drilling apparatus,
which includes its inclination, and its X, Y and Z position, with
the receiver. For a consistent reading the drilling apparatus needs
to be positioned in the same clock position every time. For the
best reading, the drilling apparatus needs to be in a 3:00
rotational position, as indicated by the receiver. To do this the
operator pulls back on the drill stem approximately 5 inches, then
pushes forward approximately 2 inches, and finally pulls back
approximately 3 inches. This causes the lugs of followers 177A and
177B to be located in the cam groove positions 145C as depicted in
FIG. 44A, 145E as depicted in FIG. 44C, and 145D as depicted in
FIG. 44E respectively. In this position the clutch is engaged and
the drill stem can rotate the drilling apparatus until the receiver
indicates a 3:00 position. While the drill stem is being changed
the locator can take his reading.
[0144] After adding a new drill stem and calculating his heading
the foreman chooses to drill straight. To do this the operator
needs to push forward approximately 2 inches and then pull back
approximately 2 inches and then forward approximately 4 inches and
then back ward approximately 2 inches. This causes the lugs of the
cam followers 177A and 177B to be located in the cam groove
positions 145A as depicted in FIG. 44G, 145B as depicted in FIG.
44(I), 145M as depicted in FIG. 44M, and 145C as depicted in FIG.
44P respectively. In this position he should be able to rotate the
drill stem without rotating the drilling apparatus. This indicates
that the next time he pushes forward he will be drilling straight.
Then pushing forward, he can drill straight for as long as he
wants. After drilling for a short distance he notices that the
drilling apparatus has drifted slightly off course. Since he is
installing steel casing and does not want a major bend in the bore
where the pipe will be place, he decides to use the minor turn
feature of the drill head. To do this the operator moves the drill
stem back approximately 2 inches, then forward approximately 1
inches, then backward approximately 1 inches, and then pushing
forward he can start to drill. This locates the lugs of the
followers 177A and 177B in the groove positions 145D as depicted in
FIG. 44E, 145A as depicted in FIG. 44G, 145B as depicted in FIG.
44(I), and 145M as depicted in FIG. 44M respectively. This will
cause the drilling apparatus to change directions, but not as
quickly as when using the major turn feature.
[0145] By oscillating or moving the shaft 101 in and out relative
to the drilling apparatus the operator has the choice of a major
turning radius, a minor turning radius, or drilling straight. The
foreman continues to manipulate the drilling apparatus to achieve
his goal of installing steel casing in a directional bore.
Furthermore, the foreman has control of the degree of turn that
each turning radius gives him by adjusting the diameter of the
cutting means in relation to the diameter of the front wear pad
and/or the diameter of the rear wear pad before the bore is even
started. In this embodiment, while the drilling is being carried
out the housings 111 and 113 slide along the bore hole being
drilled by the cutting means 105.
[0146] FIGS. 74-83 refer to another embodiment of the invention.
This embodiment has a single housing 201. A shaft 203 passes
through the housing 201 such that its forward end 203F passes out
of the front of the housing 201 and its rear end 203R passes out of
the rear of the housing 201. On the shaft's front end 203F is
mounted a cutting means. The cutting means may be a rotary type 245
as shown in FIGS. 77-79 or a percussion type 247 as shown in FIGS.
74-76. In this embodiment the housing 201 rotates with the shaft
203 while straight drilling is being carried out and the housing
201 does not rotate with the shaft while turn drilling is being
carried out. The housing 201 is supported on both ends by bearings
205 and is sealed by seals 207. The shaft 203 is free to rotate and
move longitudinally relative to the housing 201. The housing
supports a front wear pad 209 and a rear wear pad 211. The two wear
pads 209 and 211 are 180 degrees from each other and on opposite
ends of the housing 201. The resulting central axis of the housing
201 is offset from the central axis of the shaft 203 which allows
the wear pads 209 and 211 to influence the direction of travel by
contacting the bore wall outside of the cutting diameter. The
outside of at least one of the wear pads lies outside of the
cutting diameter of the cutting means. On the outside of the
housing 201 are three spring-loaded friction arms 219 that add
resistance to rotation.
[0147] Inside of the housing 201, from front to back, is a front
housing support 213, a transmitter housing 215, a forward stop 217,
a rearward stop 221, a shifting cam bushing 223 which supports a
shifting cam 225 and ties the shifting cam follower 235
rotationally to the guide housing 201, a female clutch member 227,
and a rear housing support 229. All of these parts, except the
shifting cam 225, are fixedly attached to the housing 201. The
shifting cam 225 is longitudinally locked to, but is free to rotate
relative to, the housing 201. The cam 225 has grooves formed in its
outer surface.
[0148] On the shaft is a front sleeve 231, a front thrust bearing
233, a shifting cam follower body 235 supported on the shaft by
bearings 235B, a rear thrust bearing 237, a rear spacer 239, and a
male clutch member 241. The shifting cam follower body 235 has two
shifting cam follower arms 235D and 235A positioned 180 degrees
from each other. The shifting cam follower lugs 235L on the
shifting cam follower arms 235D and 235A ride in the grooves
225A-225D of the shifting cam 225. All of the parts except the
shifting cam follower body 235 which holds arms 235 D and 235A are
locked to the shaft 203. The shifting cam follower 235 is
longitudinally locked to the shaft 203 but is free to rotate
relative to the shaft 203. The shifting cam follower 235 is free to
move longitudinally with the shaft 203 relative to the housing 201
but is tied rotationally to the guide housing 201, such that it
cannot rotate relative to the guide housing 201.
[0149] FIGS. 84-95 shows the shifting cam follower 235 being
longitudinally displaced relative to the shifting cam 225. Since
the shifting cam follower 235 is locked rotationally to the housing
201 by the shifting cam bushings 223, the shifting cam 225 is
rotated by the lugs 235L of the shifting cam follower 235 pushing
on the walls of the shifting cam grooves 225A-225D.
[0150] In FIGS. 84-95, the exterior surface of the cam 225 is shown
laid flat. The two cam followers 235A and 235D are located 180
degrees apart. In FIG. 95, 270 degrees of the cam 225 is shown and
in FIG. 95 both cam followers 235A and 235D are shown. In FIGS.
84-94, only 180 degrees of the cam 235 is shown and only one cam
follower 235D is shown although it is to be understood that the
complete cam 225 and both followers 235A and 235D will be employed.
In FIGS. 84-95 the horizontal arrows depict the direction of
longitudinal travel of the followers 235A and 235D and the vertical
arrows next to the cam 225 depict the direction of rotation of the
cam 225. In FIGS. 84-95, rearward movement of the followers 235A
and 235D is to the right and forward movement of the followers 235A
and 235D is to the left. The lugs 235L of the followers 235A and
235D can be moved between positions displaced fully rearward as
shown by follower 235D in FIG. 87 and to positions fully displaced
forward as shown by follower 235D in FIG. 84 and to intermediate
positions.
[0151] FIG. 84 shows the shifting cam follower arm 235D in the
fully forward or turning position. Shifting cam follower arm 235A
is not pictured in any of the FIG. 84-94, but is understood to
exist. In this position the clutch means is not engaged. Pulling
back on the shifting cam follower arm 235D causes it to contact the
shifting cam groove intersection 225AB (FIG. 85). Further rearward
displacement causes the shifting cam 225 to be rotated by the
shifting cam follower lugs 235L pushing on the wall of the shifting
cam groove 225B (FIG. 86). Rearward displacement is stopped when
the shifting cam follower body 235 contacts the rearward stop 221
(FIG. 87 and FIG. 82). In this position the clutch means is
engaged. Forward displacement of the shifting cam follower arm 235D
causes the shifting cam follower lug 235L to contact the shifting
cam groove intersection 225BC (FIG. 88). Further forward
displacement of the shifting cam follower arm 235D causes the
shifting cam follower lug 235L to push on the wall of the shifting
cam groove 225C (FIG. 89). This causes the shifting cam 225 to
rotate. Forward displacement of the shifting cam follower arm 235D
is halted when the shifting cam follower lug 235L contacts the end
of the shifting cam groove 225C (FIG. 90). This is the straight
drilling position. In this position the clutch means is still
engaged and the whole drilling apparatus, including the housing
201, is being rotated as the hole is drilled (FIG. 80). Rearward
displacement of the shifting cam follower arm 235D causes the
shifting cam follower lug 235L to contact the shifting cam groove
intersection 225CD (FIG. 91). Further rearward displacement of the
shifting cam follower arm 235D causes the shifting cam follower lug
235L to push on the wall of the shifting cam groove 225D (FIG. 92).
This causes the shifting cam 225 to rotate relative to the housing
201. Again the rearward displacement of the shifting cam follower
arm 235 relative to the shifting cam 225 is halted when the
shifting cam body 235C contacts the rearward stop 221 (FIG. 93 and
FIG. 82). In this position the housing 201 can be rotated to a
desired clock position in preparation for drilling a curved hole in
the chosen direction. Forward displacement of the shifting cam
follower arm 235D causes the shifting cam follower lug 235L to
contact the shifting cam groove intersection 225DA. Further forward
displacement of the shifting cam follower arms 235D and 235A causes
the shifting cam follower lugs to push on the walls of the shifting
cam grooves 225A (FIG. 95). This causes the shifting cam 225 to
rotate. Forward displacement is halted when the shifting cam body
235C contacts the forward stop 217 (FIG. 81 and FIG. 84). In this
position the clutch means is disengaged and the housing 201 is held
from rotating by friction on the walls of the bore. While the drill
stem is rotating and thrusting forward the cutting means 245 or
247, the drilling apparatus is drilling a curved hole. Further
manipulations of the drill stems allow the operator to control the
direction of travel.
[0152] When using a rotary type cutting means 245 with this
embodiment a hole-opener 243 is to be employed directly behind
housing 201. The hole-opener 243 is fixedly attach to the shaft 203
and is designed to enlarge the bore enough to allow the entire
drilling apparatus to rotate around its own axis, even in a curved
hole. If the drilling apparatus is not positioned in a sufficiently
large void to allow the drilling apparatus to be rotated about its
own axis without hindrance from the bore walls, undue strain and
stress will be placed on the drilling apparatus. Further more the
complete rotation of the drilling apparatus may not be possible in
a non-enlarged bore, thus hindering the ability to control the path
of the bore.
[0153] To use this embodiment with a percussion type cutting means
247, the drilling crew would first thread the drilling apparatus
onto the lead drill stem. Then they would mount the percussion head
247 on the front of the drilling apparatus. Next, the transmitter
137 would be inserted under the front wear pad 209. With these
things done the bore is ready to begin. Starting with the drilling
apparatus in the straight drilling mode and the percussion bit 247
pressed up against the ground, the fluid medium usually either
compressed air or water is switched on. This causes the bit 247 to
vibrate in and out pulverizing even the hardest rock. As the
drilling apparatus is advanced, it is rotated. This makes the bit
247 move in a circular motion with the center of the bore off
center from the center of the bit 247. The resultant bore diameter
is larger than the cutting bit diameter. As long as the apparatus
is moved forward and rotated with the percussion cutting means 247
activated it will drill relatively straight. When the operator
wants to change direction, he pulls back on the drill stem. This
causes the shifting cam follower 235 to rotate the shifting cam
225. The rearward displacement ceases when the shifting cam
follower 235 encounters the rearward stop 221. The drill stem can
now rotate the drilling apparatus to the desired rotational
position. Once in the desired position, the drill stem can be
pushed forward causing the shaft 203 to be forwardly displaced
relative to the housing 201. This disengages the clutch means 241
from 227 and causes the shifting cam follower 235 to rotate the
shifting cam 225. The forward displacement is halted when the
shifting cam follower 235 hits the forward stop 217. The bit 247 is
pressed against the earth and the fluid medium is switched on. This
causes the bit 247 to vibrate in and out pulverizing the rock. The
drill stem can be rotated allowing the bit 247 to impact various
spots on the face of the rock being drilled. The bit 247 is rotated
about its own center. While turning, the housing 201 is held from
rotating by the friction arms 219 that are contacting the wall of
the bore. Since the housings wear pads 209 and 211 lay outside of
the cutting radius of the percussion means 247, they push on the
wall of the bore which in turn pushes on the drilling apparatus
moving the cutting means 247 in the opposite direction. The bore
can be drilled in the turning mode as far as needed. To drill
straight again the drill stem is pulled back, this causes the
shifting cam follower 235 to rotate the shifting cam 225 and
engages the clutch means 241 to 227. The drill stem is then pushed
forward causing the shaft 203 to be displaced relative to the
housing 201 until the grooves 225C (FIG. 90) in the shifting cam
225 stops the shifting cam follower 235. In this position the
clutch means 241 to 227 is still engaged such that when the drill
stem rotates the shaft 203 the entire drilling apparatus, including
the housing 201, is rotated. Since the curved hole that the
drilling apparatus is now in is too small to allow the rotation of
the drilling apparatus about its axis at first, the percussion
means 247 is activated and slowly rotated along with the housing
201 which enlarges the bore diameter. After one revolution, normal
drilling can be resumed. The operator can choose between straight
and curved drilling at any time. The operator knows that he is
drilling straight when he is drilling and the transmitter is
showing that the drilling apparatus is rotating, likewise he knows
when he is drilling a curved hole when he is drilling and the
transmitter is showing that the drilling apparatus is not
rotating.
[0154] To use this embodiment with a rotary type cutting means 245.
The drilling crew would first thread the drilling apparatus onto
the lead drill stem. Then the crew would mount the rotary drill bit
245 on the front of the drilling apparatus. Next, the transmitter
137 would be inserted under the front wear pad 209. Starting with
the drill head in the straight drilling mode, the drill stem is
rotated and then thrust forward. This makes the drilling apparatus,
including the housing 201, as well as the rotary drill bit 245 to
do the same, which drills a straight hole.
[0155] When the operator wants to turn, he pulls back on the drill
stem, which pulls back on the shaft 203 causing it to be displaced
relative to the housing 201. At the same time the shifting cam
follower 235 rotates the shifting cam 225. The drill stem can be
rotated which rotates the shaft 203, which in turn rotates the
drilling apparatus until the desired rotational direction is
reached. Then pushing forward the shifting cam follower 235 rotates
the shifting cam 225 and the clutch means 241 is disengaged from
227. The forward displacement is stopped when the shifting cam
follower 235 hits the forward stop 217. With the housing held
rotationally in place by the friction arms 219, the drill stem, the
shaft 203, and rotary drill bit 245 are rotated and thrust forward
cutting the hole. Since at least one wear pad 209 and/or 211 lies
outside of the cutting diameter of the rotary bit 245, the
protruding wear pad 209 and/or 211 contacts the wall causing the
drilling apparatus to be deflected in the opposite direction. While
the curved hole is being drilled a hole opener 243 on the rear of
the drilling apparatus is enlarging the hole, which is also true
when a straight hole is being drilled, but to a lesser extent,
because a straight hole is bigger than a curved hole. The curved
hole can be cut until the operator chooses to drill straight. When
he does desire to drill straight, he pulls back on the drill stem
for at least five feet, which positions the entire drilling
apparatus in the enlarged hole. While pulling back the shaft 203
and shifting cam follower 235 are displaced relative to the housing
201 and the shifting cam 225. This causes the shifting cam follower
235 to rotate the shifting cam 225 and the clutch means 241 and 227
to engage. The drill stem is then pushed forward which causes the
shaft 203, the shifting cam follower 235 and the male clutch means
241 to be displaced relative to the housing 201, the shifting cam
225 and the female clutch member 227. The shifting cam follower 235
hitting the grooves 225C (FIG. 90) in the shifting cam 225 stops
the forward displacement. In this position the clutch members 241
to 227 are still engaged which causes the housing 201 to rotate and
the bore to be drilled straight. The drill stem is now thrust
forward and rotated which causes the entire drilling apparatus to
be rotated and thrust forward. The resulting bore is relatively
straight and of a larger diameter than the diameter of the rotary
drill bit 245. The operator knows that he is drilling straight, if
while he is drilling the transmitter is indicating that the housing
201 is rotating and conversely he is turning if the transmitter
indicates that the housing 201 is not rotating.
* * * * *