U.S. patent application number 14/236001 was filed with the patent office on 2014-06-05 for pneumatically actuated redirect surface.
This patent application is currently assigned to NORTH CUTTING SYSTEMS, LLC. The applicant listed for this patent is William J. Slyne. Invention is credited to William J. Slyne.
Application Number | 20140151493 14/236001 |
Document ID | / |
Family ID | 47668807 |
Filed Date | 2014-06-05 |
United States Patent
Application |
20140151493 |
Kind Code |
A1 |
Slyne; William J. |
June 5, 2014 |
PNEUMATICALLY ACTUATED REDIRECT SURFACE
Abstract
The present invention is directed to a pneumatically actuated
redirection surface guide tool for use in tape laying systems. In
the laying of unidirectional, pre-impregnated carbon fiber tapes,
for instance, a tape can be directed between a tape supply reel and
a tape laying head through use of one or more of the disclosed
guide tools. The surface of the guide tool includes small holes
that allow for positive and negative air pressure to be applied to
the surface to increase or decrease the friction between the tape
that is passing over and being redirected by the surface.
Inventors: |
Slyne; William J.; (Markman,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Slyne; William J. |
Markman |
|
CA |
|
|
Assignee: |
NORTH CUTTING SYSTEMS, LLC
Milford
CT
|
Family ID: |
47668807 |
Appl. No.: |
14/236001 |
Filed: |
August 1, 2012 |
PCT Filed: |
August 1, 2012 |
PCT NO: |
PCT/US2012/049125 |
371 Date: |
January 29, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61515473 |
Aug 5, 2011 |
|
|
|
Current U.S.
Class: |
242/615.1 |
Current CPC
Class: |
B29C 70/386 20130101;
B65H 23/24 20130101; B29C 70/388 20130101 |
Class at
Publication: |
242/615.1 |
International
Class: |
B65H 23/24 20060101
B65H023/24 |
Claims
1. A pneumatically actuated redirect surface for use in steering
and directing a tape web, the surface comprising: a guide tool
comprising a curved substantially smooth surface, wherein the
surface has perforations therein, and wherein the surface comprises
a tangent contact portion; the guide tool further comprising a
manifold therein, with the perforations in the surface in fluid
communication with the manifold; and a moveable tool mount, wherein
the mount carries the guide tool and is adapted to be movable,
whereby the tool is movable and the entry and exit points of a tape
web moving over the surface is able to be changed while a tape is
in motion.
2. A pneumatically actuated redirect surface as described in claim
1, wherein the tangent contact portion of the tool surface is a
straight line.
3. A pneumatically actuated redirect surface as described in claim
1, wherein the tangent contact portion of the tool surface is not a
straight line.
4. A pneumatically actuated redirect surface as described in claim
1, wherein the tool surface is comprised of a flexible sheet which
has the perforations therein, and wherein the tangent contact
portion of the tool surface is not a straight line.
5. A pneumatically actuated redirect surface as described in claim
1, wherein the tool mount is movable in a rotatable manner about an
axis of rotation, and wherein the axis of rotation is substantially
the center of the tangent contact portion of the surface.
6. A pneumatically actuated redirect surface as described in claim
1, wherein the tool surface is curved in the shape of a part of a
circle.
7. A pneumatically actuated redirect surface as described in claim
6, wherein the tool surface is curved in the shaped of a
semi-circle.
8. A method of steering and directing a tape web in its path of
travel from a supply roll to a work surface comprising the steps
of: providing a guide tool comprising a curved, substantially
smooth surface, wherein the surface has perforations therein, and
wherein the surface comprises a tangent contact portion; the guide
tool further comprising a manifold therein, with the perforations
in the surface in fluid communication with the manifold; providing
an air pressure pump in fluid communication with the manifold,
wherein the pump is adapted to provide positive air pressure to the
manifold; providing a tape web; moving the tape web, and
positioning the moving web over the surface of the guide tool;
wherein the direction of travel of the moving web changes between
an approach path toward the guide tool surface and a departure path
from the guide tool surface; and activating the pump to deliver
positive air pressure to the manifold, whereby air provided into
the manifold and forced out of the perforations provides a lifting
pressure between the guide tool surface and the tape web that
reduces the friction otherwise caused by movement of the web over
the surface.
9. A method as described in claim 8, wherein the pump is also
adapted to provide vacuum air pressure to the manifold.
10. A method as described in claim 8, wherein the guide tool is
rotatable about an axis of rotation, and the method further
comprising the step of moving the guide tool simultaneously with
moving the tape web across the surface of the guide tool; wherein
the tape web has a substantially zero Gaussian curvature as it
moves across the guide tool surface.
11. A method as described in claim 8, wherein the tangent contact
portion of the tool surface is a straight line.
12. A method as described in claim 8, wherein the tangent contact
portion of the tool surface is not a straight line.
13. A method as described in claim 8, wherein the tool surface is
comprised of a flexible sheet which has the perforations therein,
and wherein the tangent contact portion of the tool surface is not
a straight line.
14. A method as described in claim 8, wherein the tool surface is
curved in the shape of a part of a circle.
15. A method as described in claim 8, wherein the tool surface is
curved in the shaped of a semi-circle.
16. A method as described in claim 8, wherein the tape web
comprises a laminate of a pre-impregnated fiber tape on a backer
web.
17. A method as described in claim 16, wherein the fiber tape is a
carbon fiber tape and the backer web is silicone coated paper.
Description
[0001] This application claims the benefit of U.S. Provisional
Application Ser. No. 61/515,473, filed Aug. 5, 2011, entitled
"Pneumatically Actuated Redirect Surface (PARS)", which is
incorporated by reference herein in its entirety.
[0002] The present invention relates to a method and apparatus to
steer and direct a composite tape web as it travels from a supply
roll or reel unto a work surface or work piece.
BACKGROUND
[0003] In an apparatus that lays composite tape, the tape
redirection is normally accomplished by turning the tape around
redirect rollers. This is well known in the field of composite
manufacture such as utilized in the construction of laminated
composite parts for aerospace products. Redirect rollers are
commonly utilized within Automatic Tape Layers or ATLs such as
disclosed in U.S. Pat. No. 7,836,931 and U.S. Pat. No.
5,431,749.
[0004] FIGS. 1 and 2 are examples of a tape and rollers used in
existing ATLs. For instance, FIG. 1 shows a unidirectional
pre-impregnated carbon fiber tape 12, laminated to a silicone
coated paper backer web 13. The lamination bond is due to the
carbon fiber tape's impregnated adhesive. The laminated tape
assembly 11 is referred to as the tape.
[0005] This type of tape is well known in the field of composite
tape assembly where for example a tape would have a width of 1/2''
to 12'' and the paper backer would have a thickness of 0.001'' to
0.005'' and the carbon fiber tape would have a thickness between
0.0005'' and 0.0070'' and be 60% carbon fiber by volume and 40%
epoxy adhesive by volume. An example tape is T800H manufactured by
Toray USA.
[0006] FIG. 2 shows a prior art redirect roller 21 that rotates on
a shaft 22, where said shaft is concentric to the roller surface
23. A tape 11 is supported along its travel path by the roller
surface and the roller rotates with a surface speed equal to the
tape speed. The roller is rotated by the traction of the tape being
pulled tangent around the roller or by a drive motor connected to
the roller. The redirect roller effects a direction change to the
tape while maintaining the tape edge tangent to a plane that in
normal to the rotational axis of the roller. The tape 11 travels to
the roller in a straight line, makes tangent contact with the
roller, continues around the roller in tangent contact, then exits
the roller to continue traveling in a straight line.
[0007] Notwithstanding the wide use of rollers for redirection,
there are limitations in those roller systems relating to tape
handling and machine system design.
SUMMARY
[0008] Accordingly, it is an object of the present invention to
overcome the limitations of existing roller redirect systems. The
surface described herein includes a surface that is perforated with
small holes that are in fluid communication with a source of either
positive or negative air pressure. This surface may be used in tape
laying apparatuses and may solve some of the drawbacks and
limitations of existing roller systems.
[0009] In one example, a pneumatically actuated redirect surface is
used in steering and directing a tape web, the surface comprises a
guide tool comprising a curved substantially smooth surface,
wherein the surface has perforations therein, and wherein the
surface comprises a tangent contact portion. The guide tool further
comprises a manifold therein, with the perforations in the surface
in fluid communication with the manifold. A movable tool mount
carries the guide tool and is adapted to be movable. The tool is
movable and the entry and exit points of the tape web moving over
the surface are able to be changed while a tape is in motion. The
tangent contact portion of the tool surface maybe a straight line,
or alternatively, not a straight line. The tool surface may be
comprised of a flexible sheet which has the perforations therein,
in wherein the tangent contact portion of the tool surface is not a
straight line. The tool mount may be movable in a rotatable manner
about an axis of rotation wherein the axis of rotation is
substantially the center to the tangent contact portion of the
surface. The tool surface may be curved in the shape of a part of a
circle or in the shape of a semi-circle.
[0010] In another example, a method of steering and directing a
tape web in its path of travel from a supply reel to a work surface
comprises the steps of providing a guide tool comprising a curved
substantially smooth surface. The surface has perforations therein,
and comprises a tangent contact portion. The guide tool further
comprises a manifold therein, with the perforations in the surface
in fluid communication with the manifold. An air pressure pump is
in fluid communication with the manifold, wherein the pump is
adapted to provide positive air pressure to the manifold. A tape
web is provided and moved wherein the moving web is positioned over
the surface of the guide tool. The direction of travel of the
moving web changes between an approach path toward the guide tool
surface and a departure path from the guide tool surface. The pump
is activated to deliver positive air pressure to the manifold,
whereby air provided into the manifold and forced out of the
perforations provides a lifting pressure between the guide tool
surface and the tape web that reduces the friction otherwise caused
by movement of the web over the surface. Alternatively, the pump is
also adapted to provide vacuum air pressure to the manifold. The
guide tool may be rotatable about an axis of rotation. In this
alternative, the guide tool may be moved simultaneously with moving
the tape web across the surface of the guide tool. The tape web may
have a substantially zero Gaussian curvature as it moves across the
guide tool surface. The tangent contact portion of the tool surface
is a straight line or alternatively not a straight line. The tape
web may comprise a laminate of a pre-impregnated fiber tape on
backer web. The fiber tape may be a carbon fiber tape, and the
backer web may be silicone coated paper.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a perspective view of a unidirectional,
pre-impregnated carbon fiber tape laminated to a backer web.
[0012] FIG. 2 is a perspective view of the carbon fiber tape and
backer web moving around a roller.
[0013] FIG. 3 is a perspective view of a carbon fiber tape moving
around a pneumatically actuated redirect surface.
[0014] FIGS. 4A and 4B illustrate side elevation views of
alternative embodiments of a pneumatically actuated redirect
surface. FIG. 4C is a front elevation view of a pneumatically
actuated redirect surface.
[0015] FIG. 5A is a front elevation view of tape moving across a
pneumatically actuated redirect surface. FIG. 5B is a side
elevation view of the tape moving across of the surface as shown in
FIG. 5A.
[0016] FIGS. 6A and 6B illustrate the rotation of a pneumatically
actuated redirect surface to demonstrate a change of direction of
the tape moving across the surface.
[0017] FIG. 7 is a front elevation view of a tape moving across a
pair of pneumatically actuated redirect surfaces mounted adjacent
each other.
[0018] FIGS. 8A and 8B are side elevation views of a pneumatically
actuated redirect surface having a flexible sheet as the surface of
the tool
DETAILED DESCRIPTION
[0019] FIG. 3 shows an example of a guide tool that is also
referred to herein as the Pneumatically Actuated Redirect Surface
(PARS) 31. The PARS guide tool 31 is comprised of an outer surface
33 that is perforated with small holes 36 that are in fluid
communication with an inner manifold 34 that is in fluid
communication with a source 35 of air with either positive pressure
or negative pressure (vacuum).
[0020] A tape 11 approaches the PARS traveling in a straight line
until it is in tangent contact with the PARS surface 33. The tape
is oriented such that the paper backer side or face is adjacent to
the PARS surface. When positive pressure air 35 is forced into the
PARS manifold 34, the air creates a lifting pressure between the
PARS surface 33 and the tape backer surface of tape 11. The tape
experiences virtually no friction as it passes over the PARS
surface, thus effecting a redirection of the tape without the need
of a roller.
[0021] The surface perforations 36 are normally placed only at
location under where the tape 11 is known to be in tangent contact
with the PARS surface 33.
[0022] When a vacuum pressure is presented at the manifold port 35,
the perforations 36 remove air from the space between the tape 11
and the PARS surface 33 causing the tape backer to adhere to the
PARS surface. This effects an effective braking in the motion of
the tape.
[0023] FIGS. 4A and 4B show a side view from a perspective that is
normal to the plane of the tape travel. FIG. 4A shows a 90 degree
tape direction change while maintaining the tape in a constant
plane. FIG. 4 shows a 180 degree tape direction change while
maintaining the tape in a constant plane. FIG. 4C shows the rotated
view of the two PARS examples of 4A and 4B. In FIG. 4A and 4B, a
tape 11 approaches the PARS 31 and makes tangent contact at 41,
travels around the PARS surface 33 and exits the PARS surface at
42.
[0024] FIG. 5A and 5B show a tape 11 that is being simultaneously
redirected at two angles by a single PARS surface. The tape 11
approaches the PARS along an approach path 51 and is then
redirected by the PARS surface to exit along a departure path
52.
[0025] FIGS. 6A and 6B show a movable PARS surface where the entire
manifold 31 is rotated while the tape 11 is in motion across the
PARS surface 33. FIG. 6A shows a tape 11 approaching a PARS surface
31 with an approach path 51. The tape exits the PARS surface with a
departure path 61. As the PARS manifold is rotated by 90 degrees 65
about pivot axis 64 (normal to the page) the departure path of the
tape is rotated through 180 degrees until it exits at departure
path 62. One-half way through the rotation at 45 degrees from FIG.
6A, the PARS and tape would appear as shown in FIG. 4C.
[0026] All tapes referred to so for in this disclosure have zero
Gaussian curvature and would lay flat upon a flat surface. And,
accordingly all redirect means disclosed have a surface with zero
Gaussian curvature. Such surfaces may be cylindrical, conical, and
planar and may contain combinations or portions of such surfaces
joined so that the combined surface is continuous and smooth with
zero Gaussian curvature. All redirect means discussed here preserve
the tape's zero Gaussian curvature.
[0027] One could also produce a PARS surface that is comprised of a
flexible foil or sheet a section of which is shown in FIG. 8A and
FIG. 8B where the said foil or sheet would comprise the outer
surface 33 with perforations that are in fluid communication with a
source of pressurized air where the foil or sheet could have its
curvature adjusted for example between FIG. 8A to FIG. 8B while the
tape is in motion while maintaining zero Gaussian curvature. The
foil or sheet would have an integral network of flexible tubes 864
which supply pressurized air to manifold tubes 834 where each
manifold tube supplies pressurized air to a row of surface
perforations (disposed in a row normal to the plane of the page in
FIG. 8A and FIG. 8B where the network of flexible tubes allow the
flow of pressurized air 835 from the air pump to each of the
surface perforations, said tubes would be flexible enough so as not
to interfere with the bending of the foil or sheet. Such a foil or
sheet would be positioned and deformed by the controlled
displacement of its support attachment points.
[0028] It is required that the normal vector of the tape surface be
parallel to the normal vector of the PARS surface at the point of
the tape's tangent point of contact. The tape exit surface normal
vector will be parallel to the normal vector of the PARS surface at
the point of tape exit point of contact.
[0029] PARS surfaces may be fixed in a static position with respect
to a tape entry path, or the PARS surface may be able to
dynamically rotate such that the tape entry or exit or both be able
to be changed while the tape is in motion--see FIG. 6A and 6B. In
one example, a tape laying machine may be engineered to lay a
single type of tape onto a single, uniform surface. In this
example, the PARS may be fixed in a single position along the tape
path, and because of its single purpose, it will never move.
However, in many tape laying machines, the surface onto which a
tape is laid, and even the tape itself, will change. For this
purpose, the PARS guide tool will be attached to and carried by a
mount that is adapted to be moveable. This movement may be in a
rotating fashion as exemplified in FIGS. 6A and 6B where the PARS
31 rotates around the point 64. In another example, the point of
rotation may be at a different position along the PARS 31 tool.
Still further alternatively, and in order to achieve substantial
versatility, the tool mount on which the PARS guide tool 31 is
mounted may be moveable multidirectionally in two or three
dimensions in order to most favorably change the tape path for a
given tape and a particular surface onto which the tape is laid.
This moveable tool mount may be manually adjustable to change
positions of the mount and the tool on the mount. Alternatively,
this mount is guided through the use of various motors and by a
computer so that the movement of the PARS tool 31 can be accurately
monitored and managed.
[0030] The PARS surface 31 is positioned on a tool mount (not
shown). The tool mount is movable so that the PARS surface may be
moved to accommodate a moving tape. The tool mount is simple
hardware that supports the PARS surface. The tool mount may be a
component of a tape laying machine generally. The tool mount may be
on a tape supply reel system or on a tape laying system or
independently in between. One or more PARS surfaces may be used in
one or several locations in the larger apparatus.
[0031] As PARS surfaces are essentially replacing one or more
rollers to redirect a moving tape, their placement can be analyzed
by inspecting the desired tape path and the required redirect
points. To analyze the placement of a moveable (steerable) PARS
surface then the point along two alternative tape paths where the
tape path diverges between the two alternative tape paths is where
a moveable PARS would be located.
[0032] The two extreme alternate tape paths determine the extremes
of movement of the PARS such that the PARS placement in all
orientations between and including the extreme PARS orientations
follow the geometric constraints relating to the tape-PARS entry
and exit stated above.
[0033] The pump that supplies positive and/or negative air pressure
to the manifold need only supply a nominal pressure for the example
application below. The pressure in imperial units would be on the
order of 10 inches of H2O and 200 CFM. Such a pump would be a
centrifugal fan with less than 1 horsepower.
EXAMPLE
[0034] An example configuration as shown in FIG. 5A and FIG. 5B
would have the following quantities in imperial units: [0035]
Outside diameter--8.0 inches [0036] Inside diameter--6.5 inches
[0037] Holes spacing--0.5 inches [0038] Hole diameter-- 1/16 inches
[0039] Tape width--5.0 inches [0040] Tape Entry Angle in FIG.
5A--135 degrees (East equals 0 degrees) [0041] Tape Exit Angle in
FIG. 5A--225 degrees (East equals 0 degrees) [0042] PARS length
required to support the tape--apron 19.64 inches. (length of the
perforation matrix)
[0043] FIG. 7 shows a typical use for a PARS surface. It is desired
to reverse the direction of a moving composite prepreg tape on a
backer, but maintain the direction in which the composite tape is
facing. Two PARS surfaces are inserted at appropriate positions and
angles as shown in FIG. 7.
Methods and Benefits of Use
[0044] A PARS surface can have a variety of non-cylindrical shaped
surfaces that effect a significant change in tape travel direction
and tape plane of travel. During use, and especially in a machine
design, the combination of multiple PARS surfaces and the
movability of those surfaces means that a tape can be moved
dynamically during the tape laying process while moving across the
strategically deployed PARS surfaces.
[0045] Additionally, when the size and speed of tape are known,
then the proper amount of positive air pressure that is applied to
the manifold in the PARS surface can mean that there is effectively
zero friction as a result of the movement of a tape over the
surface. In the alternative example, when it is important in the
tape laying process that the tape be braked or stopped all
together, then the pump can be modified to instead draw varying
degrees of vacuum on the surface of the PARS tools to facilitate
and better manage the slowing down of a tape moving over the PARS
surfaces. Accordingly, with proper positive and negative air
pressure control, the tape redirection and management can be
achieved while adding essentially zero mass to the tape's motion.
This facilitates instant stopping and starting without exerting
destructive or degrading sheer forces to, for instance, a carbon
fiber tape with a paper backer web.
[0046] Additionally, the PARS surface provides a large radius
redirection in smaller space than a redirect roller. Only the
surface of tape contact needs to be present. A large radius roller
takes up substantial space in an apparatus. In the situation of a
large radius, it is important to reduce the delaminating of the
fibers and the backer prior to the fibers being deposited onto a
work surface.
[0047] While unidirectional pre-impregnated carbon fiber tape with
a silicone tape or backing web is disclosed herein in substantial
detail, other types of tapes and webs can also be redirected by the
PARS apparatus without deviating from the scope of the
invention.
[0048] Other embodiments of the present invention will be apparent
to those skilled in the art from consideration of the
specification. It is intended that the specification and Figures be
considered as exemplary only, with a true scope and spirit of the
invention being indicated by the following claims.
* * * * *