U.S. patent application number 15/889866 was filed with the patent office on 2018-06-21 for wire screen manufacturing system and method.
This patent application is currently assigned to Delta Screen & Filtration, LLC. The applicant listed for this patent is Carl Cooper, Steven Mark Everritt, Richard Grifno, Art Parmely. Invention is credited to Carl Cooper, Steven Mark Everritt, Richard Grifno, Art Parmely.
Application Number | 20180169737 15/889866 |
Document ID | / |
Family ID | 54006320 |
Filed Date | 2018-06-21 |
United States Patent
Application |
20180169737 |
Kind Code |
A1 |
Everritt; Steven Mark ; et
al. |
June 21, 2018 |
Wire Screen Manufacturing System and Method
Abstract
An exemplary embodiment of wire wrap welding system generally
includes a headstock; a bed; a bed mounted tailstock linearly
moveable in relation to the headstock; a linear induction drive
system adapted to move the tailstock; a linear encoder system
having a series of position encoders disposed on the bed; a
servomotor adapted to rotate a headstock mounted spindle; a welding
system positioned on the headstock, a servomotor positioned on the
tailstock and adapted to rotate a tailstock mounted spindle; and a
control system. An exemplary embodiment of a method for controlling
slot openings between wire segments in a wire wrap welding process
generally includes controlling movement of a bed mounted tailstock
in relation to the rate of rotation of a headstock mounted spindle,
utilizing a linear induction drive system, a linear encoder system,
and a control system.
Inventors: |
Everritt; Steven Mark;
(Houston, TX) ; Cooper; Carl; (Houston, TX)
; Parmely; Art; (Houston, TX) ; Grifno;
Richard; (Houston, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Everritt; Steven Mark
Cooper; Carl
Parmely; Art
Grifno; Richard |
Houston
Houston
Houston
Houston |
TX
TX
TX
TX |
US
US
US
US |
|
|
Assignee: |
Delta Screen & Filtration,
LLC
Houston
TX
|
Family ID: |
54006320 |
Appl. No.: |
15/889866 |
Filed: |
February 6, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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14628633 |
Feb 23, 2015 |
9919354 |
|
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15889866 |
|
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61946266 |
Feb 28, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B01D 39/10 20130101;
B21F 27/18 20130101; B23K 11/008 20130101; B21F 27/10 20130101;
B21F 27/124 20130101 |
International
Class: |
B21F 27/10 20060101
B21F027/10; B21F 27/18 20060101 B21F027/18; B21F 27/12 20060101
B21F027/12; B01D 39/10 20060101 B01D039/10; B23K 11/00 20060101
B23K011/00 |
Claims
1. A manufacturing system for producing wire wrap screens for pipe
comprising: a headstock comprising a spindle; a welding apparatus
positioned on said headstock; a bed; a tailstock positioned on said
bed and comprising a spindle; a first rotary actuator adapted to
provide rotation of said headstock spindle; a second rotary
actuator adapted to provide rotation of said tailstock spindle; and
at least one component selected from the group consisting of: a
linear induction drive system adapted to provide linear movement of
said tailstock in relation to said headstock along said bed; and a
linear encoder system adapted to determine the location of said
tailstock in relation to said headstock along said bed.
2. The manufacturing system of claim 1, wherein said linear
induction drive system comprises: a motor assembly comprising one
or more motors; and one or more stators positioned on said bed.
3. The manufacturing system of claim 1, wherein said linear
induction drive system comprises: one or more roller tracks
positioned on said bed; and one or more guide rollers, each guide
roller adapted to cooperate with one of said roller tracks to
provide rolling movement of said motor assembly in relation to said
headstock along said bed.
4. The manufacturing system of claim 1, wherein: said bed comprises
one or more guide rails; and said tailstock comprises one or more
races comprising at least one bearing, each race adapted to
cooperate with one of said guide rails to provide low-friction
movement of said tailstock in relation to said headstock along said
bed.
5. The manufacturing system of claim 1, comprising an additional
drive system adapted to provide linear movement of said tailstock
in relation to said headstock along said bed.
6. The manufacturing system of claim 1, comprising a control system
adapted to control at least one said function is selected from the
group consisting of: rotation of said headstock spindle; rotation
of said tailstock spindle; linear movement of said tailstock in
relation to said headstock along said bed by said linear induction
drive system; and determination of the location of said tailstock
in relation to said headstock along said bed by said linear encoder
system.
7. The manufacturing system of claim 1, wherein said linear encoder
system is adapted to determine the location of said tailstock in
relation to said headstock along said bed, based at least in part,
on information provided, directly or indirectly thereto, by at
least one of one or more position encoders disposed on said
bed.
8. The manufacturing system of claim 6, wherein said determination
of the location of said tailstock in relation to said headstock
along said bed comprises utilizing, at least in part, information
provided, directly or indirectly to said control system, by at
least one of one or more position encoders disposed on said
bed.
9. A manufacturing system for producing wire wrap screens for pipe
comprising: a headstock comprising a spindle; a welding apparatus
positioned on said headstock; a bed; a tailstock positioned on said
bed and comprising a spindle; a first rotary actuator adapted to
provide rotation of said headstock spindle; a second rotary
actuator adapted to provide rotation of said tailstock spindle; a
linear induction drive system comprising: a motor assembly
comprising one or more motors; one or more stators positioned on
said bed; one or more roller tracks positioned on said bed; and one
or more guide rollers, each guide roller adapted to cooperate with
one of said roller tracks to provide rolling movement of said motor
assembly in relation to said headstock along said bed; a linear
encoder system comprising one or more position encoders disposed on
said bed; and a control system; wherein: said linear induction
drive system is adapted to provide linear movement of said
tailstock in relation to said headstock along said bed; said linear
encoder system is adapted to determine the location of said
tailstock in relation to said headstock along said bed; and said
control system is adapted to control at least one function of said
manufacturing system.
10. The manufacturing system of claim 9, wherein: said bed
comprises one or more guide rails; and said tailstock comprises one
or more races comprising at least one bearing, each race adapted to
cooperate with one of said guide rails to provide low-friction
movement of said tailstock in relation to said headstock along said
bed.
11. The manufacturing system of claim 9, wherein: said bed
comprises one or more guide rails; and said tailstock comprises one
or more races comprising at least one bearing, each race adapted to
cooperate with one of said guide rails to provide low-friction
movement of said tailstock in relation to said headstock along said
bed.
12. The manufacturing system of claim 9, wherein at least one said
function is selected from the group consisting of: rotation of said
headstock spindle; rotation of said tailstock spindle; linear
movement of said tailstock in relation to said headstock along said
bed by said linear induction drive system; and determination of the
location of said tailstock in relation to said headstock along said
bed by said linear encoder system.
13. The manufacturing system of claim 9, comprising an additional
drive system adapted to provide linear movement of said tailstock
in relation to said headstock along said bed.
14. A method for controlling the width of slot openings between
wire segments in a wire wrapped screen comprising: providing a
manufacturing system for producing wire wrap screens for pipe; and
operating said manufacturing system to produce said wire wrap
screens, wherein said operating comprises utilizing a linear
induction drive system to control, at least partially, said
width.
15. The method of claim 14, comprising utilizing a linear encoder
system to determine the relative location of at least one component
of said manufacturing system.
16. The method of claim 15, wherein said manufacturing system
comprises: a headstock comprising a spindle; a welding apparatus
positioned on said headstock; a bed; a tailstock positioned on said
bed and comprising a spindle; a first rotary actuator adapted to
provide rotation of said headstock spindle; and a second rotary
actuator adapted to provide rotation of said tailstock spindle;
wherein: said linear induction drive system is adapted to provide
linear movement of said tailstock in relation to said headstock
along said bed; and said linear encoder system is adapted to
determine the location of said tailstock in relation to said
headstock along said bed.
17. The method of claim 16, wherein said manufacturing system
comprises at least one component combination selected from the
group consisting of: one or more roller tracks positioned on said
bed, and one or more guide rollers, each guide roller adapted to
cooperate with one of said roller tracks to provide rolling
movement of a motor assembly comprising said one or more motors in
relation to said headstock along said bed; and one or more guide
rails provided on said bed, and one or more races positioned on
said tailstock and comprising at least one bearing, each race
adapted to cooperate with one of said guide rails to provide
low-friction movement of said tailstock in relation to said
headstock along said bed.
18. The method of claim 16, wherein said operating a manufacturing
system comprises operating a control system to control at least one
function selected from the group consisting of: linear movement of
said tailstock in relation to said headstock along said bed by said
linear induction drive system; and determination of the location of
said tailstock in relation to said headstock along said bed by said
linear encoder system.
19. The method of claim 18, comprising operating an additional
drive system adapted to provide linear movement of said tailstock
in relation to said headstock along said bed
20. The method of claim 18, comprising the steps of: providing a
support for a plurality of ribs; providing a wire to intersect each
said rib; providing a welding wheel, supported on a support
assembly, in contact with said wire at a point of intersection
between said wire and one said rib; rotating said headstock
spindle; moving said tailstock away from said headstock utilizing
said linear induction drive system; welding said wire to said one
said rib at said point of intersection; obtaining measurements,
continuously or intermittently, of at least one of the rotation
speed of said headstock spindle and the location of said tailstock;
and utilizing said control system to control, based at least in
part on said obtained measurements, at least one of: said first
rotary actuator; said second rotary actuator; said linear induction
drive system and; said linear encoder system.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of pending U.S. patent
application Ser. No. 14/628,633, filed on Feb. 23, 2015, which
claims the benefit of U.S. Provisional Application No. 61/946,266,
filed on Feb. 28, 2014, which applications are incorporated herein
by reference as if reproduced in full below.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
BACKGROUND OF THE INVENTION
Field of the Invention
[0003] The present invention relates to manufacture of wire screens
for oil, gas, and water well pipe. More particularly, the present
invention relates to a system and method for manufacturing wire
screens for pipes.
Description of the Related Art
[0004] Hydrocarbons are produced by drilling into subterranean
hydrocarbon-bearing formations. Unconsolidated formation walls can
result in sand, rock, or silt accumulating in a wellbore, which can
ultimately cause various problems in the drilling operation. Sand
control has become increasingly important in the industry.
[0005] Well screens (also called filters) used in sand control
applications can be of various types, including wire mesh and
continuous slot, wire wrapped. Continuous slot, wire wrapped
screens are composed of wire helically wrapped around multiple
support ribs to form a cylindrical screen with a continuous helical
slot there between. It is important that slot size (i.e., width
between adjacent segments of the wrapped wire) is maintained within
determined tolerances throughout the length of the screen.
[0006] Wire wrapped screens are typically manufactured using wire
wrapping machines that simultaneously wrap the wire around, and
weld the wire to, multiple support ribs, to form a hollow,
cylindrical well screen of a desired length. A headstock spindle
rotates the ribs causing wire to be wrapped around the set of ribs.
Typically, a precision lead screw progresses the work piece
laterally by driving the tailstock laterally away from the
headstock. Rate of rotation of the headstock spindle in relation to
advancement of the lead screw along the linear axis determines the
dimensions of slot openings between adjacent wire segments.
[0007] Commercially utilized wire wrap screen machines incorporate
computer based controls using servomotors for headstock spindle
rotation. Typically, a servomotor with a precision ball screw
controls linear movement of the driven tailstock. Alternative
commercially utilized machines incorporate a helical gear rack for
linear drive of the tailstock.
[0008] Some of the factors affecting the ability to maintain
required slot spacing and tolerance are the relatively long
sections of wire wrap screen necessary, and component wear over
time. Wire wrap pipe screen sections may be greater than forty feet
in length.
[0009] Linear induction drive technology has been previously
described. See, for example, U.S. Pat. No. 3,824,414 issued to
Laithwaite, et al., and U.S. Pat. No. 4,230,978 issued to Gardella,
Jr., et al., both of which are incorporated herein by reference in
their entirety to the extent not inconsistent herewith. Linear
encoder technology has been previously described. See for example,
U.S. Pat. No. 3,090,896 issued to Bowden, et al., and U.S. Pat. No.
3,427,518 issued to Cloup, both of which are incorporated herein by
reference in their entirety to the extent not inconsistent
herewith.
[0010] Embodiments of the present invention provide a wire wrap
screen system having a linear induction drive system and a linear
encoder system to controllably drive the tailstock, and a method
for operating the wire wrap system.
BRIEF SUMMARY OF THE INVENTION
[0011] Embodiments of a wire wrap welding system and method for a
wire wrapping system generally comprise providing a wire wrap
system having a headstock; a bed; a tailstock, wherein the
tailstock is mounted on the bed for linear movement in relation to
the headstock; a linear induction drive system for controlled
movement of the tailstock; a linear encoder system comprising a
series of position encoders disposed on the bed; a servomotor for
controlled rotation of a spindle on the headstock; a welding system
positioned on the headstock; a servomotor positioned on the
tailstock for controlled rotation of a spindle mounted on the
tailstock; and a control system for controlled rotation of the
headstock in relation to linear position of the tailstock.
[0012] Embodiments of a method for controlling wire slot openings
using a wire wrap welding system general comprise controlling
motion of a tailstock mounted on a bed in relation to a rate of
rotation of a headstock spindle utilizing a linear induction drive
system and a linear encoder system. Embodiments of the method
further comprise controlling pressure applied to weld faying
surfaces, and rate of rotation of a tailstock spindle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] For a more complete understanding of embodiments of the
invention, reference is now made to the following Detailed
Description of Exemplary Embodiments of the Invention, taken in
conjunction with the accompanying drawings, in which:
[0014] FIG. 1 is an illustrative view of an embodiment of a wire
wrapping system of the present invention.
[0015] FIG. 2 is a partial view of an embodiment of a welding wheel
assembly mounting structure of the present invention.
[0016] FIG. 3 is a partial side view of an embodiment of a welding
support assembly and mounting structure of the present
invention.
[0017] FIG. 3A is a partial side view of a rotating spindle of an
embodiment of the present invention.
[0018] FIG. 4 is a partial view of a tailstock, a linear induction
drive system, and a linear encoder system of an embodiment of the
present invention.
[0019] FIG. 5 depicts an embodiment of a method of the present
invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION
[0020] Referring now to the drawings, wherein like reference
characters designate like or similar parts throughout, FIG. 1
depicts a wire wrapping system 2 having a welding pressure control
assembly 10. Wire wrapping system 2 is used to manufacture wire
wrapped well screens 18. Wire wrapping system 2 includes a wire
feed assembly 4, bed 6, control module 8, welding pressure assembly
10, headstock 12, rotating headstock spindle 14, and tailstock
16.
[0021] A plurality of elongated support ribs 20 and a wire 22 are
used to form screen 18. Wire 22 is wrapped helically around the
support ribs 20 and is welded at each contact point 24 of
intersection between a rib 20 with wire 22. In this context,
welding includes fusion welding, such as, but not limited to,
electrical resistance welding. In an exemplary embodiment, welding
is performed by a rotating welding wheel electrode 46 provided
proximate headstock 12. The welding wheel electrode 46 welds wire
22 to corresponding ribs 20 at contact points 24 by electrical
resistance welding.
[0022] Headstock 12 is equipped with a rotating spindle 14. Spindle
14 rotates about axis A-A. Spindle 14 is driven by a rotary
actuator, such as a servomotor or stepper motor, 96. Spindle 14 has
a plurality of radially spaced rib openings 26 (shown in FIG. 2)
through which ribs 20 extend. Openings 26 are spaced from spindle
axis A-A at various distances and in various patterns to allow
multiple circular patterns of openings 26.
[0023] Openings 26 allow ribs 20 to extend generally along axis
A-A, but spaced therefrom prior to welding. Other supports (not
shown) intermediate headstock 12 and tailstock 16 support ribs 20
substantially parallel to, and equally spaced from, axis A-A after
welding, if a screen 18 is being formed without a pipe section
disposed there within.
[0024] Ribs 20 each have a first rib end 21 extending toward
tailstock 16. A tailstock spindle 30 grasps rib ends 21 with a
grasping mechanism (not shown), such as a pull ring or a chuck.
Tailstock spindle 30 rotates about axis A-A.
[0025] Headstock 12 and tailstock 16 each have axial openings to
allow pipe to be inserted axially along the bed 6 for applications
wherein the wire screen is to be applied directly to a pipe
section. Tailstock pipe opening 158 is depicted in FIG. 4. A like
opening 159 is provided in headstock 12. When screen 18 is
constructed on pipe, the grasping mechanism of tailstock 16 (not
shown) is applied to the pipe.
[0026] Referring to FIG. 4, tailstock spindle 30 (not shown in FIG.
4) is driven to rotate about axis A-A by a rotary actuator, such as
a servomotor or stepper motor, 36, connected to spindle drive
assembly 162. In an exemplary embodiment, servomotor 96 is
electronically connected to a processor 88 of a control panel 8.
Rate of rotation of spindle 14 may therefore be controlled by
processor 88. Servomotor 36 is controlled to rotate tailstock
spindle 30 at substantially the same rotation rate as headstock
spindle 14. In an exemplary embodiment, servomotor 96 and
servomotor 36 are each electronically connected to processor 88 and
are each controllable by processor 88.
[0027] A head 66 is fixedly attached to spindle 14 and extends
outward from spindle 14 in the direction of the tailstock 16. Head
66 is provided with cylindrical openings with milled longitudinal
slots 15 (shown in FIG. 3A) sized and located to support ribs 20
and maintain rib 20 spacing. Head 66 serves as a support for ribs
20 and wire 22 during welding and comprises an element of the
ground electrode of the welding process. Head 66 may be of
differing sizes for different screen 18 diameters.
[0028] Headstock 12 is disposed proximate first bed end 7 of bed 6.
Bed 6 is an elongate structure that extends along a longitudinal
axis substantially parallel to, but offset from, axis A-A.
Tailstock 16 is moveable along bed 6. In one embodiment, welding
assembly 10 is located proximate first bed end 7 of bed 6. Welding
assembly 10 comprises a welding assembly 44, which includes a
welding arm 38, positioned on welding support assembly 40, moveably
positioned above bed 6. As shown in detail in FIG. 2, a linear
actuator, such as a servomotor or stepper motor, 70 is provided on
a bracket 60 such that a motor shaft 72 extends vertically through
bracket 60. A coupler 74 is mounted below bracket 60, connecting
motor shaft 72 to a lead screw 64.
[0029] A force determination device, such as a load cell, 100 is
provided in the welding assembly 10 to determine forces applied by
the welding wheel electrode 46 to the wire 22 during a welding
process. The load cell 100 is positioned intermediate a mounting
structure 42 structure contact plate 57, and a support assembly 40
contact plate 59. In one embodiment, load cell 100 is a
commercially available, precision compression loading type load
cell. Specifically, load cell 100 measures pressure forces applied
to load cell 100 by structure contact plate 57 and support contact
plate 59.
[0030] In an exemplary embodiment, load cell 100 is electronically
connected to processor 88 of control panel 8 to provide continuous
or intermittent communication of measured pressure forces.
Accordingly, servomotor 70 may be operated in a closed loop process
wherein load cell 100 measured forces are processed with feedback
control of servomotor 70. Processor 88 control commands responsive
to measured forces are provided pursuant to predetermined
parameters to servomotor 70, thereby inducing operation of
servomotor 70 to move support assembly 40 in relation to mounting
structure 42 to increase or decrease applied force.
[0031] Welding wheel electrode 46 is supported in a fixed vertical
orientation on support assembly 40 during a welding process.
Spindle 14, on which head 66 is positioned, is in a fixed vertical
position in relation to mounting structure 42. Accordingly, head
66, together with ribs 20 and wire 22 supported thereon, are
positioned in a fixed vertical position in relation to mounting
structure 42. Accordingly, for any given welding process, welding
wheel electrode 46 may be positioned on the faying surfaces of ribs
20 and wire 22. Upon calibration, the applied pressure of welding
wheel 46 to faying surfaces of ribs 20 and wire 22 may be
determined. Applied pressure may then be adjusted by relative
movement of support assembly 40 in relation to mounting structure
42.
[0032] Cylinders 50, which in one aspect may be hydraulic and/or
pneumatic, dampen the movement of support assembly 40 in relation
to mounting structure 42, thereby allowing controlled pressure
application with self-correcting, dampening adjustments for
variations, such as variations resulting from rotation
eccentricities of the welding wheel and spindle, welding wheel
contact surface wear, and depth variations of faying surfaces.
[0033] In embodiments of the welding pressure control assembly 10
of the present invention which include a processor 88 in control
module 8, force readings from load cell 100 are transmitted to
processor 88. Processor 88 is programmable to operate servomotor 70
and accordingly adjust the position of support assembly 40
according to given conditions. Processor 88 is operable to,
continually or intermittently, receive load data from load cell 100
and to adjust the vertical position of support assembly 40, via
servomotor 70, to achieve a desired load level of welding wheel
electrode 46 on wire 22. Such force level is indicated by load cell
100.
[0034] Tailstock 16 is controllably moveable along bed 6 by a
linear induction drive system 120. Referring to FIG. 4, in one
embodiment, linear induction drive system 120 comprises a plurality
of stators 122 positioned along bed 6, collectively defining stator
bed 124, and a motor assembly (not separately labeled) comprising
at least one drive motor 126. Each stator 122 comprises a magnet
(not shown). Drive motor 126 comprises motor coils (not shown)
connected to a power source (not shown). In an exemplary
embodiment, two or more drive motors 126, positioned in a motor
housing 130, may be utilized. Guide rollers 132 are attached to
both sides of motor housing 130. Guide rollers 132 allow motor
housing 130 to roll linearly along bed 6 on roller tracks 134.
Roller tracks 134 are provided along bed 6 on each side of stator
bed 124 and extend parallel to each other.
[0035] Drive motors 126 are arranged and structured in relation to
stators 122 such that upon applying electrical power to motors 126,
a magnetic field is generated, inducing movement of drive motors
126 along stators 122. In an exemplary embodiment, the relative
positioning of drive motors 126 in relation to stator bed 124 is
such that the gap between a lower edge of motor housing 130, and an
upper surface of each respective stator 122, is substantially equal
along stator bed 124. In an exemplary embodiment drive motors 126
are 480 volt, three-phase motors.
[0036] Referring to FIG. 4, two tailstock guide rails 142 are
provided linearly along bed 6. Tailstock 16 guide rails 142 extend
parallel to each other. Tailstock 16 is constructed with parallel
races 144, each race 144 constructed to engage a corresponding
guide rail 142. Bearings (not shown) are provided along each race
144 to facilitate low-friction travel of races 144 along guide
rails 142.
[0037] Referring further to FIG. 4, a connector plate 140 is
fixedly attached to each of motor housing 130 and an attachment bar
146 of tailstock 6. Accordingly, linear movement of motor housing
130 along stator bed 124 produces corresponding movement of
tailstock 16 along guide rails 142. Tailstock races 144, guide
rails 142, motor housing 130, guide rollers 132, and roller tracks
134 are structured, sized, and located such that the weight of
tailstock 16 is substantially supported along guide rails 142,
allowing relatively low-friction, linear movement of tailstock 16
along bed 6, and such that movement of the motor assembly
comprising drive motors 126 along stator bed 124 produces
corresponding movement of tailstock 16 along bed 6.
[0038] Still referring to FIG. 4, one or more cover supports 148
are provided to support a stator bed 124 cover 138 (cutaway view in
FIG. 4). Cover 138, which may be replaceably removable, serves to
keep undesired airborne materials away from stator bed 124.
[0039] In one embodiment, an encoder system (not separately
labeled), such as a linear encoder system, utilizes a scale 128 for
determination of linear position of tailstock 16 along bed 6. The
linear encoder system may utilize optical, magnetic (active or
passive), capacitive, inductive, eddy current, or other suitable
technology. In one embodiment, scale 128 comprises a series of
position encoders 129 positioned on bed 6. In one embodiment, the
linear encoder system comprises one or more sensors (not shown),
such as a transducer, which are adapted to wirelessly receive
information from position encoders 129, to determine the location
of tailstock 16 along bed 6. In one embodiment, the sensors are
disposed within motor housing 130. In one embodiment, drives motors
126 may be equipped with one or more sensors. In one embodiment,
the encoder system is electronically connected to processor 88 to
allow for controlled movement of tailstock 16 along bed 6. In one
embodiment, linear drive motors 126 are electronically connected to
processor 88 to allow for control of motors 126 and,
correspondingly, to control position of tailstock 16 along bed
6.
[0040] In embodiments of the present invention, a second drive
system, such as drive motor 164, connected to tailstock 16 and
positioned in a second motor assembly 166, may be utilized to move
tailstock 16 along bed 6. In one embodiment, motor 164 utilizes a
chain or belt drive to move tailstock 16 along bed 6. In one
embodiment, second motor 164 is electronically connected to
processor 88 to allow for controlled movement of tailstock 16 along
bed 6. In one embodiment, either or both of motor 164 and linear
drive motor(s) 126 may be utilized to move tailstock 16 along bed
6. In one embodiment, only linear motor 126 is initially utilized
to move tailstock 16 along bed 6; however, if the load on one or
more linear motors 126 reaches or exceeds a predetermined setting,
motor 164 may be actuated to assist linear motor 126 in moving
tailstock 16 along bed 6. In one embodiment, second motor 164 is
controlled by processor 88 based at least partially on information
obtained from position encoders 129 by the linear encoder
system.
[0041] Referring again to FIG. 4, in an exemplary embodiment of the
present invention, pipe opening 158 is provided in tailstock 16.
Pipe opening 158 allows extension of a pipe section (not shown) to
extend through tailstock 16. In such embodiment, ribs 20 are
positioned proximate the pipe at headstock 12 in a commercially
practiced, direct wrap method. In such application, an alternative
tailstock spindle 30 is attached to the pipe section. Referring
still to FIG. 4, servomotor 36 and drive belt 156 are also depicted
for this embodiment. Motor 36 and drive belt 156 are operable to
rotate spindle 30 by rotating spindle 30 drive assembly 162.
Operation
[0042] In operation, ribs 20 are extended through openings 26 and
wire 22 is positioned on a rib 20. Each rib 20 and wire 22
comprises faying surfaces for welding by welding wheel electrode
46.
[0043] At the beginning of a welding process, welding wheel 46 is
positioned on wire 22. The indicated pressure forces applied to
load cell 100 are determined. Servomotor 70 is operated to provide
a load of support assembly 40 in relation to structure 42, thereby
providing a determined load of welding wheel 46 on faying surfaces
of wire 22 and ribs 20. As welding wheel 46 is fixedly attached to
support assembly 40, and wire 22 and rib 20 faying surfaces
supported on spindle 14 are in a vertically fixed orientation in
relation to mounting structure 42, the load applied by welding
wheel 46 to wire 22 and rib 20 is also a determined force.
[0044] Pressure applied within air cylinders 50 is electronically
controlled to maintain a determined cylinder pressure to offset at
least a portion of the weight load of support assembly 40. Cylinder
rods 58 are mounted on mounting structure 42, and cylinders 50 can
be adjusted to provide a determined load on load cell 100 as load
cell 100 measures load applied intermediate mounting structure 42
and support assembly 40. Accordingly, by application of appropriate
dampening force by air cylinders 50, the indicated load at load
cell 100 between structure contact plate 57 and support contact
plate 59 can be set to a determined force as low as zero.
[0045] With the determined initial position, processor 88 is
operated to control servomotor 70 to operate lead screw 64 to
vertically bias support assembly 40 in relation to mounting
structure 42 until a determined application load force is obtained.
Load cell 100 indicates the load applied by welding wheel 46 to the
faying surfaces of wire 22 and ribs 20.
[0046] As spindle 14 of headstock 12 is rotated, and welding wheel
electrode 46 is powered, the wire 22 is welded to successively
rotated ribs 20. Rotation of spindle 14 results in wire 22 being
drawn through a wire guide 34 from a spool 32 during a welding
operation.
[0047] In one embodiment, a control system (not separately
labeled), comprising processor 88 of control panel 8, is operated
during a welding process to rotate spindle 14, to control lateral
movement of tailstock 16, and to control pressure applied by
welding pressure assembly 10 during the welding process. In an
exemplary embodiment, processor 88 may be further utilized to
control rotation of tailstock spindle 30.
[0048] Referring to FIG. 5, a method 300 depicting an embodiment of
the present invention is disclosed for a wire wrap screen
manufacturing process, the method comprising the steps indicated
herein.
[0049] A rib support step 302 comprises providing a support for
ribs 20, said support comprising a head 66.
[0050] A wire feed step 304 comprises providing wire 22 to an
intersecting surface of a rib 20.
[0051] A welding wheel placement step 306 comprises providing a
welding wheel 46, supported on a support assembly 40, in contact
with a wire 22 supported on a rib 20.
[0052] A rotating step 308 comprises rotating spindle 14.
[0053] A linear drive step 310 comprises driving tailstock 16 along
axis A-A away from headstock 12 utilizing a linear induction drive
system 120.
[0054] A welding step 312 comprises welding a wire 22 to a rib 20
at each intersection of wire 22 and rib 20.
[0055] A feedback step 314 comprises continuous or intermittent
measurement of rotation speed of spindle 14 and location of
tailstock 16.
[0056] A control step 316 comprises continuous or intermittent
receipt of indicated welding wheel load data, processing the
received data, and output of control commands according to
predetermined parameters.
[0057] An adjustment step 318 comprises operation of induction
linear drive motors 126 and control of the rotation speed of
servomotor 96 to control rotation of spindle 14 as determined by
operation parameters, to control spacing of wire 22.
[0058] As is known in the art, rotating step 308, linear drive step
310, and welding step 312 are generally performed substantially
concurrently. In an embodiment of the present invention, feedback
step 314 comprises continuously or intermittently measuring various
data in relation to the wire wrapping system, including rotation
speed of spindle 14, rotation speed of spindle 30, and linear
travel of tailstock 16. In such an embodiment, control step 316
includes receipt of indicated load data and data related to spindle
14 rotation speed, spindle 30 rotation speed, and linear travel of
tailstock 16; processing the data; and output of control commands
according to predetermined parameters, and adjustment step 318
comprises adjustment of one or more of spindle 14 rotation speed,
spindle 30 rotation speed, and linear movement of tailstock 16.
More specifically, and as previously described, adjustment step 318
includes adjustment of the position of tailstock 16 at selected
time intervals in relation to rotation of spindle 14, to obtain
precise relative location of loops of wire 22 and slots formed
between adjacent segments of wrapped wire 22.
[0059] While the preferred embodiments of the invention have been
described and illustrated, modifications thereof can be made by one
skilled in the art without departing from the teachings of the
invention. Descriptions of embodiments are exemplary and not
limiting. The extent and scope of the invention is set forth in the
appended claims and is intended to extend to equivalents thereof.
The claims are incorporated into the specification. Disclosure of
existing patents, publications, and known art are incorporated
herein to the extent required to provide reference details and
understanding of the disclosure herein set forth.
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