U.S. patent number 3,635,105 [Application Number 04/862,111] was granted by the patent office on 1972-01-18 for power tong head and assembly.
This patent grant is currently assigned to Byron Jackson Inc.. Invention is credited to John L. Dickmann, Howard S. Flick.
United States Patent |
3,635,105 |
Dickmann , et al. |
January 18, 1972 |
**Please see images for:
( Certificate of Correction ) ** |
POWER TONG HEAD AND ASSEMBLY
Abstract
A power tong in which the rotary head has opposed jaws slidably
mounted in jaw guides and shiftable radially outwardly by springs
and radially inwardly by cam surfaces and cam followers, the cam
surfaces being compound so as to move the jaws inwardly upon
rotation of an outer drive ring in either direction relative to an
inner jaw supporting ring.
Inventors: |
Dickmann; John L. (Whittier,
CA), Flick; Howard S. (Long Beach, CA) |
Assignee: |
Byron Jackson Inc. (Long Beach,
CA)
|
Family
ID: |
27101425 |
Appl.
No.: |
04/862,111 |
Filed: |
July 22, 1969 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
675843 |
Oct 17, 1967 |
3483774 |
|
|
|
Current U.S.
Class: |
81/57.18 |
Current CPC
Class: |
E21B
19/164 (20130101) |
Current International
Class: |
E21B
19/16 (20060101); E21B 19/00 (20060101); B25b
017/00 () |
Field of
Search: |
;81/57,57.18,57.2,57.21 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Jones, Jr.; James L.
Parent Case Text
This application is a division of application Ser. No. 675,843,
John L. Dickmann et. al., filed Oct. 17, 1967, now issued U.S. Pat.
No. 3,483,774.
Claims
We claim:
1. A tong head for use in a power tong assembly having power
transmission means for driving an output gear in opposite
directions, said head comprising: a case having a gear therein
adapted to receive a shaft driven by the output gear of said
transmission means, said case having means including a wall for
connecting said case to said transmission means, said case having a
bull gear therein driven by the first mentioned gear provided with
an internal circumferentially extended U-shaped channel, a tubular
guide having a central opening extending axially thereof, said
guide having means including selectively reversible reverse release
stop means revolvably supporting the guide on said bull gear, jaw
guides carried by said guide and extending radially therefrom into
said channel, gripping jaws reciprocable in said jaw guides into
and out of said opening, and cam and follower means in said channel
and on said jaws for forcing said jaws into said opening upon
relative revolution of said guide and said bull gear,
2. A tong head as defined in claim 1, wherein brake means are
provided on said frame to initially hold said guide against
revolution with said bull gear.
3. A tong head as defined in claim 1, wherein said jaw guides and
said jaws are provided with opposing spring seats, and including
springs normally biasing said jaws out of said opening.
4. A tong head as defined in claim 1, wherein a pair of plates is
connected with said arms, said jaw guides being connected between
said plates.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
The present invention involves a tong head assembly applicable to
and adapted to be driven by a power means such as claimed in U.S.
Pat. No. 3,481,228, and operated by control means as claimed in
U.S. Pat. No. 3,481,299.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to power tongs, or wrenches, of the
general type employed for the purpose of making up or breaking out
the joints of pipe or rods as lengths of such pipe or rods are
connected in or disconnected from a string being run into or
retrieved from a well, such as an oil or gas well.
More particularly the invention involves an improved tong head
adapted to be operated by a power system so as to grip or engage
the couplings of a length of pipe or rods, hereinafter for
simplicity referred to generically as pipe, to rotate the same,
while the adjacent pipe is held stationary by a "backup" tong or
wrench which may be for expediency made a part of the power tong
assembly or may be a separate tong or wrench. By driving the
gripped pipe in one direction or the other the joints between the
pipe "stands" or lengths may be made up or broken out.
Such tongs must be durable and effective in operation in order to
facilitate the running in of long strings of pipe or the removal of
such long strings of pipe from a well; such pipe strings being
thousands of feet in length and being composed of short stands or
lengths of pipe which may be conveniently handled in a derrick.
Moreover, the joints, particularly old joints, may require the
application of a number of thousands of foot pounds of torque when
the joints are being broken out. Thus, a problem exists in respect
of deformation of the joints due to the application of high
compressive forces thereto to enable gripping of the pipe in dies
driven by the power system.
Since the pipe is run or pulled by a hoist system of substantial
strength on speed of operation, the jaw system which carries the
gripping dies should be operable in such a fashion as to be fully
retracted or out of the way when disengaged from the pipe so as to
allow longitudinal movement of the pipe through the tong head
without requiring that the tong be shifted laterally out of the
way, thus enabling more rapid running or pulling of pipe strings,
and yet the jaws should properly engage and centralize the pipe
upon engagement therewith.
SUMMARY OF THE INVENTION
Accordingly, among the objects of the invention is the provision of
a power tong assembly having a tong head comprising the
characteristic outer drive ring and a relatively rotatable inner
ring including retractable pipe gripping jaws which are shiftable
along a line extended diametrically of the pipe opening in the
head, said jaws having opposing die elements which will engage and
center the pipe upon engagement therewith so as to efficiently
transmit torque to the pipe upon operation of the tong in either
direction.
Another object is to provide a power tong assembly including a head
having retractable jaws, as aforesaid, each jaw having die carriers
which may be easily changed to enable handling of the pipe
efficiently over a wide range of pipe sizes.
Still another object is to provide a pipe tong assembly having a
tong head in which radially movable jaws are provided with cam
followers and are slidably supported in an inner ring assembly and
spring loaded away from one another, the outer ring being composed
of a large bull gear revolvable in either direction by power means
and having opposite cams operable upon the followers of the
respective jaws to force the jaws toward one another upon rotation
of the bull gear.
Still another object of the invention is to provide a tong assembly
including a tong head which is a self-contained unit adaptable to
various power mechanisms.
Other objects and advantages of the invention will be hereinafter
described or will become apparent to those skilled in the art, and
the novel features of the invention will be defined in the appended
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view in perspective illustrating a tong assembly made
in accordance with the invention;
FIG. 2 is a fragmentary top plan view of the assembly of FIG. 1,
showing the tong head and transmission subassemblies;
FIG. 3a is a fragmentary longitudinal section through the tong
assembly as taken on the line 3--3 of FIG. 2, and showing the tong
head;
FIG. 3b is a continuation of FIG. 3a, showing the power
transmission;
FIG. 4 is a horizontal section taken on the line 4--4 of FIG.
3a;
FIG. 5 is a transverse section taken on the line 5--5 of FIG.
4;
FIG. 6 is a fragmentary view partly in section and partly in plan
showing the reverse stop mechanism of the tong head;
FIG. 7 is a view taken on the line 7--7 of FIG. 6;
FIG. 8 is a horizontal sectional view as taken on the line 8--8 of
FIG. 3b;
FIG. 9 is a horizontal sectional view as taken on the line 9--9 of
FIG. 3b;
FIG. 10 is a horizontal sectional view as taken on the line 10--10
of FIG. 3b;
FIG. 11 is a fragmentary view in side elevation showing the
manifold and control means for the motors, the case being broken
away;
FIG. 12 is a view in rear end elevation of the structure of FIG.
11;
FIG. 13 is a view in section as taken on the line 13--13 of FIG.
12, showing the compound control rock shaft assembly;
FIG. 14 is a view in section on the line 14--14 of FIG. 12;
FIG. 15 is a view in section on the line 15--15 of FIG. 12;
FIG. 16 is a fragmentary view in side elevation showing the
connection of the actuator lever to the operating means for the
motor control valves;
FIG. 17 is a fragmentary view in section as taken on the line
17--17 of FIG. 16; and
FIG. 18 is a fragmentary view in section as taken on the line
18--18 of FIG. 17.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIGS. 1 and 2, a tong assembly embodying the
invention will be seen to comprise three separate and distinct
subassemblies comprising a pipe gripping or tong head assembly 1
adapted to grip a joint and rotate the same relative to another
joint, which joints together compose a threaded connection or joint
between stands of well tubing or pipe or sucker rods, all of which
are generically referred to herein as pipe, an illustrative length
of which is generally illustrated at 2 and includes a joint or
coupling 3. Also included in the tong assembly is a power
transmission subassembly generally denoted at 4 which contains
drive means for effecting rotation of the pipe gripping mechanism
included in the tong head. Included in the power transmission
subassembly is a plurality of motors, designated M1 and M2 in the
illustrative embodiment, these motors, as will hereinafter be more
fully described, being adapted to drive the transmission mechanism
at a relatively high speed and low torque, on the one hand, and at
a relatively low speed and high torque, on the other hand, and in
opposite directions. Further, the composite assembly includes a
control subassembly generally denoted at 5 whereby an operator of
the tong, in the making up and breaking out of pipe or rod joints,
will be enabled to cause the motor M2 to operate in either selected
direction, while motor M1 remains idle so as to drive the pipe
gripping mechanism at a relatively high rate of speed but at low
torque, such as would be desirable when a joint is being initially
made up and offers little resistance, such relatively high speed
initial making up of the joint being generally referred to in the
field as "spinning." Thereafter it is desired that the joint be
finally made up by the application of relatively high-torque forces
which the tong operator may accomplish by causing, through the
manipulation of the control mechanism 5, the simultaneous operation
of motors M1 and M2 in such a manner that the transmission
mechanism will impart to the gripping mechanism high-torque loads
but at low speed, so as to shoulder or finally tighten up the
joint. Alternatively, in the breaking out of a joint the gripping
mechanism must impose high-torque loads on the joint in order to
initiate its rotation so that the control mechanism 5 is adapted to
enable the reverse rotation of both of the motors M1 and M2 in such
a manner as to cause high torque, low-speed rotation of the pipe
gripping mechanism to initially break out the joint, and ,
thereafter, the control mechanism may be manipulated to allow the
motor M1 to idle as the motor M2 continues to drive the pipe
gripping mechanism at a relatively high speed under the reduced
torque requirements for spinning the joint out.
Referring now more specifically to the tong head assembly 1, as
best illustrated in FIGS. 3a through 7, it will be seen that this
subassembly comprises a split case including an upper case section
6 and a lower case section 7 joined on substantially a median plane
by suitable fasteners 8, the case defines a generally circular head
end 9 which houses a pipe gripping mechanism generally denoted at
C; and in a longitudinally extended, substantially rectangular case
section 10 there is housed gear mechanism or other suitable drive
means, to be hereinafter described, for effecting rotation of the
pipe gripping means G.
The pipe gripping means G comprises an outer ring 11 which is of
generally U-shape in cross section providing an inwardly opening
channel 12. The outer ring 11 is provided about its outer periphery
with drive elements in a specifically illustrated form of gear
teeth 13, so that the outer ring may be said to constitute a bull
gear. Suitable bearing means are provided for supporting the outer
ring 11 for revolution within the case section 9, such bearing
means being shown as ball bearings 14 engaging in annular races 15
formed about the outer wall of the outer ring 11 and riding in
races 16 provided within the case section 9. Suitable seal rings 17
may be provided between the case and a confronting portion of the
outer ring 11 to prevent the entry of well fluids or other
materials into the case section 9 which might otherwise cause
damage to the drive mechanism for the outer ring 11.
As best seen in FIG. 4, the outer ring 11 is provided with
diametrically opposing compound cam sections, each including a
central low region 18 and oppositely extending rising surfaces 19,
these rising surfaces each being formed on an arc or progressively
decreasing radii from said low region, and the rising surfaces of
the opposing cam sections, in the illustrative embodiment, meeting
one another at a diametrical plane at right angles to a diametrical
plane of the outer ring 11 extending through the low regions 18 of
the camming sections. This is to say that the portion of the rising
cam surfaces 19 adjacent the low region 18 of the cam sections is
formed on an arc having a greater radius than an intermediate
portion of the rising surfaces, and the intermediate portions of
the rising surfaces are struck on an arc of greater radius than the
portions of the rising surfaces nearest the end thereof remote from
the low region.
Revolvably disposed within the outer ring 11 is what may be
typified as the inner ring assembly generally denoted at 20.
Included in the inner ring assembly 20 (see FIGS. 3a, 4 and 5) is a
pair of guide members, including an upper tubular guide 21 and a
lower tubular guide 22, respectively having diametrically opposed,
axially extended arms 23 and 24 which confront one another
substantially at the midplane of the tong head. These arms define
therebetween lateral openings 25 of rectangular form and in
diametrically opposed relation, these openings leading into the
central axially extended opening through the composite guides 21
and 22, this latter central opening constituting an opening through
which pipe or rods may be extended as they are being run into or
pulled from a well by the usual hoist equipment in the derrick, all
as is well known in the art and in order to facilitate movement of
couplings into and through the central opening of the guides, the
upper guide 21 has a beveled or flared wall 26, and the lower guide
22 has a beveled or flared wall 27.
Means are provided for joining the guide sections in assembled
relation, as well as for supporting in the lateral openings 25 a
pair of hollow jaw guides 28, 28. Such means, in the illustrative
embodiment, includes a pair of jaw guide clamps or plates 29, 29
which, as best seen in FIGS, 4 and 5, have a series of axially
spaced grooves 30 and ribs 31 formed in an arcuate inner midsection
of the plates 29 complementally with grooves 32 and ribs 33 formed
in the arms 23 and 24 of the respective upper and lower guides 21
and 22. It will be understood that these complemental and coengaged
ribs and grooves not only support the jaw guide clamps or plated 29
on the composite guides, but also that these ribs and grooves hold
the composite guide assembly together in the relationship as shown
in FIG. 3a.
The jaw guides 28 constitute boxlike hollow members having
sidewalls 34 provided with vertically extended external ribs 35
disposed in complemental vertical grooves 36 in the plates 29,
suitable fastening means, such as screws 37, extending through the
jaw guide walls 34 and into the clamp plates 29 so as to maintain
all of the components, including the guides 21 and 22, the clamp
plates 29, and the jaw guides 28, in an integrated assembly, with
the jaw guides 28 extending radially outwardly into the channel 12
formed in the outer ring 11, as previously described. This
integrated assembly, constituting the inner ring 20, is adapted to
be supported for rotation relative to the outer ring 11, and,
illustratively, it will be noted that the upper guide 21 has an
outwardly extended flange 38 which supports the inner ring assembly
on the upper outer wall of the outer ring 11, while the
corresponding flange 39 of the guide 22 is slightly downwardly
spaced from the corresponding lower outer wall of the outer ring
11. Thus, the inner ring 20 is disposed within the outer ring 11
for relative rotation thereof.
The gripping mechanism G further includes a pair of jaws 40, 40
slidably disposed within the jaw guides 28 for radial movement into
and out of the central opening through the guides 21 and 22.
Included in each of he jaws 40 is a die carrier 41 adapted to be
removably retained in a seat 42 as by means of fasteners 43. At the
outer end of each of the jaws 40 cam follower means in the form of
a roller 44 supported on a vertical shaft 45 are provided in each
jaw, these rollers 44 being engageable with the cam sections
previously described in the outer ring 11. Means are provided for
normally biasing the jaws 40 outwardly to cause engagement of the
rollers 44 with the cam sections, and such means (see FIG. 4) may
comprise a suitable number of coiled compression springs 46 seated
at one end in bores 47 in the sidewalls 34 of the jaw guides and
abutting at their other ends against a foot provided on an L-shaped
spring seat 48, a leg of which is disposed in a slot 49 in the jaw
40 and retained therein as by a pin 50.
It will now be apparent that with the structure as thus far
described, relative revolution of the outer ring 11 about the inner
ring 20 will cause movement of the cam sections relative to the
followers 44, so that the latter will be cammed inwardly by one of
the rising surfaces 19, depending upon the direction of rotation of
the outer ring 11. In order to assure that such relative rotation
will occur when the outer ring 11 is driven, brake means are
provided for applying a drag to the inner ring 20. Illustratively,
such brake means comprised a brake band 51 having friction material
52 thereon and engageable with the outer peripheral surface of the
flange 39 of the lower guide 22, the brake band 51 being retained
against downward displacement from the flange 39 by means of a
bottom plate 53 secured to the case section 7 as by fasteners 54
and extending into underlying relation to the brake band. In order
to anchor the brake and against rotation with the inner ring 20,
anchor means are provided and, in the illustrative embodiment, such
anchor means comprise ears 55 formed on the extremities of the
brake band and extending downwardly through a slot 56 in the plate
53. These ears 55 are joined together in a suitable state of
tension adjustment about the inner ring flange 39 by means of a
suitable adjuster screw 57; and it will be understood that the ears
55 respectively constitute anchoring abutments engageable with the
extremities of the slot 56 to anchor the brake band.
In order to grip a joint disposed within the gripping means G when
the jaws 40 are moved toward one another responsive to relative
rotation between the outer ring 11 and the inner ring 20, the die
holders 41, previously referred to as constituting a part of the
jaws 40, are provided with suitable die means, including a pair of
similar dies 58, each having along vertical edges thereof teeth 59
adapted to bite into the coupling on engagement therewith. These
dies 58 are disposed in dovetail slots 58a extending vertically in
the die carriers 41 and generally disposed at an angle relative to
the diametrical lines extending across the central opening through
the guides, so that the dies will engage with one or another of the
teeth 59 a substantial range of joint diameters without requiring
changing of the dies 58 or the die carriers 41. The vertically
toothed dies 58 herein illustrated may be, moreover, replaced by
arcuate toothed dies which more particularly are designed to fit
with a particular joint diameter, as is well known in the art.
Following the gripping and rotation of a joint part by the gripping
means G, it is desired that the gripping means be released from the
joint part in response to reversal of the direction of rotation of
the outer ring 11 to cause return movement of the followers 44 to
the low regions 18 of the camming sections within the outer ring.
Means are provided to prevent the continued relative rotation
between the outer ring 11 and the inner ring 20 to prevent the
gripping means from again being actuated into gripping engagement
with the joint part as a result of reversal of the rotation. Such
means is best illustrated in FIGS. 3a, 6 and 7 wherein it will be
noted that a flange 60 is provided in overlying relation to the
seal means 17, this flange 60 being secured to the upper wall of
the outer ring 11 as by a suitable number of fasteners (not
shown).
Within the flange 60 there is provided an annular seat 62 in which
is rotatably disposed a ring 63. At at least one location about the
ring 63 is a downwardly extended lug 64 which extends into an
upwardly opening slot 65 in a sliding block 66 having upstanding
end lugs 67, 67. Coiled springs 68, 68 are interposed between the
opposing end lugs 67 and the intermediate lug 64 of the ring 63,
and means are provided for causing rotation of the ring 63 relative
to the flange 60, for example, a pair of outwardly extended lever
arms 69 projecting outwardly from the ring 63 for manual
engagement. The relative angular position of the ring 63 is adapted
to be adjusted within the limits of elongated arcuate slots 70
provided in the flange 60, locking screws 71 carried by the ring 63
extending through the slots 70 and into threaded engagement with
the outer ring 11.
It is now apparent that the outer ring 11, when rotating, carries
with it the flange 60 and the ring 63, and, in order to prevent
reverse actuation of the gripping means G into engagement with the
joint part as aforementioned, stop elements are provided on the
guide 21, these stop elements being in the form of rollers 72
mounted in the outer peripheral wall of the flange 38 of guide 21
in angularly spaced relation and selectively engageable by floating
rollers 73, one of which is adapted to be cammed inwardly for
engagement with one of the rollers 72, depending upon the relative
adjusted position of the ring 63. As best seen in FIG. 6, these
floating rollers 73 are adapted to be cammed inwardly by wedge
surfaces 74 at the opposite ends of the floating block 66, these
wedge surfaces 74 being opposed by wedge surfaces 75 formed in the
inner periphery of the flange 60.
As will now be apparent, the floating block 66 is biased by one of
the springs 68, depending upon the position of ring 63, to a
position at which the opposing wedge surfaces 74 and 75 will hold
one of the rollers 73 in a radially inwardly displaced position for
engagement with one of the rollers 72. In FIG. 6 it will be noted
that the outer ring assembly is free for counterclockwise rotation
relative to the inner ring guide 21, but clockwise rotation will be
prevented. Thus, the tong head assembly may be employed to turn a
joint part in a counterclockwise direction, but the gripping means
G will be prevented from reverse actuation when the outer ring 11
is rotated in the reverse direction, so that the inner ring 20 will
be caused to rotate along with the outer ring 11 when the followers
44 are at the low regions 18 of the camming sections.
As seen in FIGS. 1, 2, 3a and 3b, the tong head case sections 6 and
7 extend outwardly from the generally circular head end 9 thereof
so as to form the boxlike section 10 of the case in which is
disposed the illustrative gearing by which the bull gearlike outer
ring 11 is to be driven. This gearing includes a large ring gear 76
having a hub 77 journaled in bearings 78 supported between the case
sections 6 and 7. The ring gear 76 is in mesh with a pinion 79
which is journaled in bearings 80 mounted in the case sections 6
and 7 and adapted to be driven by a lower splined section 81 of a
short splined shaft 82 which extends through an opening 83 in the
upper case section 6, and, more particularly, through a
horizontally extended wall 6a thereof which constitutes a portion
of means, including the wall 6a, for connecting the tong head case
to the power transmission mechanism 4 now to be described.
This transmission means or section 4 of the assembly also comprises
a longitudinally split case having an upper case section 85 and a
lower case section 86 having a wall 86a mating with the wall 6a of
head assembly 1 and suitably joined thereto as by fasteners 87,
this wall 86a having an opening 88 aligned with opening 83 in head
case wall 6a. Journaled in the opening 88 is the hub 89 of a large
ring gear 90 constituting the driven gear of the gearing means of
the transmission. The short splined shaft 82 previously described
has a splined end 91 engaged in the hub 89 so that power is
transmitted from the gear 90 to the head gearing 79, 76, 11.
The motors M1 and M2 previously referred to are adapted to drive
the ring gear 90, and, accordingly, these motors are mounted
beneath a portion of the transmission case which extends rearwardly
from the head case. The motor M1 is preferably a hydraulic or other
reversible fluid motor having an output shaft 92 on which is a
pinion 93 engaged with ring gear 90 within the transmission case,
so as to drive the ring gear 90 in opposite directions at a speed
dependent upon the gear ratio and the flow of fluid through the
motor M1.
Motor M2 is also mounted beneath the transmission case adjacent
motor M1 and has an output shaft 94 adapted to drive the ring gear
90 in opposite directions through double acting, self-energizing,
overrunning clutch means C interposed between the drive pinion 95
and the motor shaft 94. This clutch means is illustrated in FIGS.
3b and 8-10 as including a power input or drive part 96 splined to
the motor shaft 94 and a power output or driven part 97 journaled
in the transmission case and integral with, or otherwise made a
part of, the pinion 95.
More particularly, this overrunning clutch means includes camming
surfaces 98 arranged in equidistantly spaced relation about the
drive part 96 and engageable with a like number of rollers 99 to
urge the latter outwardly into driving relation with the inner
periphery of a wall 100 formed as a part of the driven clutch part
97 (see FIG. 8). These rollers 99 are supported in a carrier ring
101 which also supports a plurality of equidistantly spaced
additional rollers or balls 102 engaged with he camming surfaces
98. These balls 102 are normally biased inwardly into engagement
with the camming surfaces 98 by a resilient spring ring 103
disposed about the balls; and this spring ring functions to
normally tend to centralize the balls 102 with respect to the
camming surface 98, thereby also centralizing the rollers 99 with
respect to the surfaces 98. Fixed drag brake means are provided so
that when the drive part 96 is rotated in either direction relative
to the driven part 97, the clutch will be engaged. This brake means
comprises a cuplike brake drum 104 supported within the case
section 86 between a pair of snap rings 105. Within the brake drum
104 is a discontinuous drag ring 106, the ends of which are spaced
apart (see FIG. 10).
The roller carrier 101 has an outward projection or abutment 107
extending into the space between the ends of the drag ring 106.
When the drive part 96 is rotated, the camming surfaces 98 will
force the balls 102 outwardly from their centralizing position
transmitting the rotation to the roller carrier 101 until the pin
107, just referred to, engages one of the drag ring ends, depending
upon the direction of rotation, whereupon further rotation of the
roller carrier 101 will be resisted by frictional engagement of the
drag ring 106 in the brake drum 104, and thus the rollers 99 will
be forcibly cammed outwardly into engagement with the wall 100 of
the driven part 97. Rotation of the brake drum 104 along with the
drag ring 106 is prevented by provision of a suitable stop, such as
a pin 108, engaging the drum 104 and fixed in the case 86.
From the foregoing, it will now be understood that in operation the
motor M1 may drive the ring gear 90 in either direction and, unless
the motor M2 is also operating to drive the clutch drive part 96,
the clutch driven part 97 will idle along with the ring gear 90;
however, when the motor M2 is operated to cause rotation of the
clutch drive part 96, then both of the motors will be effective to
drive the ring gear 90 in either direction, such selective
operation of the motors M1 and M2 is adapted to be controlled by
control means for the flow of fluid to the respective motors from a
source, as will now be described.
The control section 5 of the tong assembly, as generally
illustrated in FIG. 1, includes a cover or case 109 which, as seen
in FIG. 11, is adapted to be connected to the rear end of the
transmission subassembly 4 on a supporting bracket 110 having ears
111 secured by fasteners 112 to the transmission case. Within the
cover 109 and supported on the bracket 110, as at 113, is a fluid
manifold and valve assembly generally denoted at V, whereby to
control the flow of power fluid from a source (not shown) to the
respective motors M1 and M2. Schematically illustrated in the valve
and manifold assembly V, as seen in FIG. 12, is a first valve means
V1 and a second valve means V2, respectively adapted to control the
flow of motor fluid to the motors M1 and M2 under the influence of
operating means generally denoted at O, which operating means is
operable by actuator means generally denoted at A. Accordingly,
valve V1 is adapted to control the flow of fluid from the source
leading into the manifold at an inlet 114 and leading from the
manifold at an outlet 115 from the motor M1 in such a manner that
fluid will flow from the inlet 114 through a valve passage 116 to
motor M1 and from that motor through a conduit 117 and a valve
passage 118 through the valve and to the outlet 115, so as to drive
the motor M1, say in a left-hand direction, when the valve is in a
first position, the valve V1 is operable when it is in a second
position to cause a reversal of the direction of flow so that the
motor M1 will be driven in the opposite or right-hand direction.
Likewise, the valve V2 is adapted to control the flow of fluid
through the motor M2 in reverse directions by causing the flow of
fluid from the inlet 114 through a valve passage 119 and from the
motor through a conduit 120 and thence a valve passage 121, whereby
the motor M2 will rotate in a left-hand direction; and, when the
valve V2 is adjusted to a second position, the flow of fluid will
be reversed, causing the operation of the motor in a right-hand
direction. It will be understood that the arrangement of the valves
and the flow passages is merely illustrative and that any desired
four-way valves or other valve means may be employed to accomplish
the reversal of fluid flow through the two motors, but it is
preferred that the operating means O be so constructed as to move
the valve V1 to its first position or to its second position while
the valve V2 remains closed, but, when it is desired, the valve V2
may be moved either simultaneously with, or after movement of, the
valve V1 to its first and second positions.
This operating means comprise a rock shaft 122 rotatably mounted in
transversely extended relation by a pair of arms 123 depending from
the bracket 110. The rock shaft 122 is a hollow shaft within which
is revolvably disposed a second rock shaft 124. As seen in FIGS. 13
and 14, the inner rock shaft 124 has a lever arm 125 connected
thereto and extending laterally through an opening 126 in the
hollow rock shaft 122, this opening 126 being extended angularly so
as to provide clearance space between end walls 127 and 128
thereof. As seen in FIGS. 13 and 15, the inner rock shaft 124 also
has a lever arm 129 projecting therefrom and through an opening 130
providing angularly spaced abutments 131 and 132 engageable with
the lever arm in a manner hereinafter to be described. Carried by
the lever arm 125 is a valve operating linkage means 133 adapted to
be connected to the valve V1 so as to move the latter between its
first and second positions from its off position; and connected to
the lever arm 129 is linkage means 134 adapted to be connected to
the valve V2 to cause its operation between its first and second
positions from its off position.
The actuating means A for the operating means O, just described, is
located at one end of the rock shafts 122 and 124, but preferably
at each end of said rock shafts, so as to enable operation of the
tong assembly from either side thereof. As best seen in FIGS. 12,
16 and 17, the actuator means comprises a lever 135, the lever
being pivotally supported on pins 136 which are carried by a member
137 which is connected to the hollow rock shaft 122, the pins 136
extending into the hollow rock shaft so as to effect rotation of
the latter when the lever 135 is moved between a normal position in
either direction. The rock shaft 124 extends endwise from the
hollow shaft 122 and has secured to its outer end a lever 138
having an arm extending lengthwise of the lever 135 between upper
and lower walls 139 and 140 of the lever 135. Between these walls
139 and 140 are camming means generally denoted at 141 and
including an upper wedge surface 142 and a lower wedge surface 143
defining therebetween a central slot 144. These wedge surfaces and
slot are adapted to cooperate with an end 145 on the actuator lever
138 only when the lever 135 is pivoted to a laterally displaced
outer position as shown in broken lines in FIG. 17, so that when
the lever 135 is in its normal position, shown in full lines in
FIG. 17, and is moved either upwardly or downwardly, it will effect
corresponding rotative movement of the hollow rock shaft 122; but
when the lever 135 is pivoted about pins 136 to the angular
position shown in broken lines in FIG. 17, the end 145 of lever 138
will be engaged in the slot 144 within lever 135 so that the two
levers will move simultaneously, thereby effecting simultaneous
rocking movement of the hollow rock shaft 122 and the internal rock
shaft 124. Thus it will be understood that the actuator lever 135
is effective to cause either movement of the outer rock shaft 122
along, or together with the inner rock shaft 124, in opposite
directions so as to effect either the operation of valve V2 upon
abutment of either of the abutments 131 and 132 with the lever 129
or the simultaneous actuation of valve V1.
In addition, it will also be noted that when the outer rock shaft
122 is rotated in either direction so as to effect operation of
valve V1, the spaced end walls 127 and 128 of the opening 126,
through which the operating lever 125 for valve V2 projects, will
allow the rock shaft 122 to move to a first position without
operating valve V2. Thereafter, depending upon the direction of
movement of the actuator lever 135, one of the end walls 127 or 128
just referred to will engage the valve operating lever 125 to cause
it to move in a corresponding direction so as to operate the valve
V2 when the actuator lever 135 is in a second position. Thus, by
the simple manipulation of the actuator lever 135, the tong may be
driven at a high speed and low torque through the operation of the
valve V1 upon movement of the lever 135 to a first position; upon
movement of the lever 135 in the same direction to a second
position, the valve V2 will be operated to cause operation of motor
M1 which, through the clutch means previously described, will now
work with motor M2 so that the tong will be driven at a lower speed
and higher torque, as would be desirable when making up a joint.
However, when breaking out a joint, and it is desired that the tong
be first operated at low speed and high torque, the actuator lever
135 may be pivoted about pins 136 to effect coengagement of the
lever 138 in the slot 144 of the actuator lever 135 so that, when
the lever is pivoted to actuate the valve mechanism, both valves V1
and V2 will be initially opened. To initiate operation of the tong,
and when the joint has been broken out, the lever 135 may be moved
inwardly to the full line position of FIG. 17 so that the valve V2
will close, thereby allowing the tong to operate at high speed and
low torque to spin out the joint.
While the specific details of an illustrative embodiment of the
invention have been herein shown and described, changes and
alterations may be made without departing from the spirit of the
invention.
* * * * *