U.S. patent application number 12/103592 was filed with the patent office on 2008-10-16 for method and apparatus for folding of sheet materials.
This patent application is currently assigned to Industrial Origami, Inc.. Invention is credited to Max W. Durney.
Application Number | 20080250837 12/103592 |
Document ID | / |
Family ID | 39852493 |
Filed Date | 2008-10-16 |
United States Patent
Application |
20080250837 |
Kind Code |
A1 |
Durney; Max W. |
October 16, 2008 |
METHOD AND APPARATUS FOR FOLDING OF SHEET MATERIALS
Abstract
A method and apparatus for folding of sheet materials for
forming a three-dimensional structure from a substantially
two-dimensional sheet material includes a restraint assembly for
restraining a work piece from movement in one direction, a low
flange assembly movably mounted on the frame for biasing the work
piece against the restraint assembly and effecting folding along
the low-flange fold line, a high flange assembly movably mounted on
the frame to effect folding along the high-flange fold line, and a
control assembly for sequentially operating the low flange assembly
and the high flange assembly. A method of using the method and
apparatus for folding of sheet materials, and the structure created
thereby, is also disclosed.
Inventors: |
Durney; Max W.; (San
Francisco, CA) |
Correspondence
Address: |
MORGAN, LEWIS & BOCKIUS, LLP
ONE MARKET SPEAR STREET TOWER
SAN FRANCISCO
CA
94105
US
|
Assignee: |
Industrial Origami, Inc.
San Francisco
CA
|
Family ID: |
39852493 |
Appl. No.: |
12/103592 |
Filed: |
April 15, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60911905 |
Apr 15, 2007 |
|
|
|
Current U.S.
Class: |
72/319 ;
52/648.1; 72/379.2 |
Current CPC
Class: |
B21D 51/52 20130101;
B21D 5/16 20130101 |
Class at
Publication: |
72/319 ;
72/379.2; 52/648.1 |
International
Class: |
B21D 11/00 20060101
B21D011/00; B21D 31/00 20060101 B21D031/00; E04H 12/00 20060101
E04H012/00 |
Claims
1. A folding tool system for forming a three-dimensional structure
from a substantially two-dimensional sheet material which includes
a predetermined low-flange fold line defining a low flange and a
predetermined high-flange fold line defining a high flange, said
system comprising: a frame including a restraint assembly for
restraining a work piece from movement in one direction; a low
flange assembly movably mounted on the frame for biasing the work
piece against the restraint assembly and effecting folding along
the low-flange fold line, the low flange assembly including a
low-flange applicator for applying force against the low flange to
effect low-flange folding; a high flange assembly movably mounted
on the frame to effect folding along the high-flange fold line, the
high flange assembly including a high-flange actuator for applying
force against the high flange to effect high-flange folding; and a
control assembly for sequentially operating the low flange assembly
and the high flange assembly.
2. A system according to claim 1, wherein the restraint assembly
includes a restraining block movable between a first position
remote from the work piece and a second position for engaging the
high flange of the work piece.
3. A system according to claim 2, wherein the restraint assembly
further includes a restraining plate movable between a retracted
position and an extended position adjacent the low-flange fold line
for restraining the work piece as the low flange assembly applies
force against the low flange.
4. A system according to claim 1, wherein the low-flange applicator
includes an applicator bar to apply substantially continuous force
along a majority of the low flange to effect substantially uniform
folding along the low-flange fold line.
5. A system according to claim 4, wherein the applicator bar is
pivotally mounted to provide over-90.degree. action to accommodate
for spring-back of the low flange.
6. A system according to claim 1, wherein the high-flange actuator
includes at least one arm pivoting about an axis substantially
parallel to an adjacent the high-flange fold line.
7. A system according to claim 6, wherein the arm includes a
shoulder corresponding to a desired final shape of the work piece
along the high-flange fold line.
8. A system according to claim 1, wherein the control system
comprises a controller for controlling the actuation sequence and
dwell time of the low flange assembly and the high flange
assembly.
9. A system according to claim 8, wherein the control system
includes a first pneumatic actuator controlling movement of the low
flange assembly and a second pneumatic actuator controlling
movement of the high flange assembly.
10. A system according to claim 9, wherein the first pneumatic
actuator is an air bag dimensioned and configured to move the low
flange assembly upward toward the restraining assembly.
11. A system according to claim 9, wherein the second pneumatic
actuator is an pneumatic cylinder dimensioned and configured to
move the high flange assembly to pivot along the high-flange fold
line.
12. A system according to claim 9, wherein the first pneumatic
actuator operates in the range of approximately 50 psi and 150
psi.
13. A system according to claim 9, wherein the second pneumatic
actuator operates in the range of approximately 50 psi and 150
psi.
14. A folding tool system for forming a three-dimensional structure
from a two-dimensional sheet material which includes a plurality of
predetermined low-flange fold lines defining low flanges, a
plurality of predetermined lateral high-flange fold lines defining
lateral high flanges, and a plurality of predetermined end
high-flange fold lines defining end high flanges, said system
comprising: a frame including a restraint assembly for restraining
a work piece from movement in one direction; a low flange assembly
movably mounted on the frame for biasing the work piece against the
restraint assembly and effecting folding along the low-flange fold
lines, the low flange assembly including a plurality of low-flange
applicators for applying force against the low flanges to effect
low-flange folding along each of the low-flange fold lines; a high
flange assembly movably mounted on the frame to effect folding
along the high-flange fold lines, the high flange assembly
including a plurality of lateral high-flange actuators for applying
force against the lateral high flange to effect high-flange folding
along each of the lateral high-flange fold lines, the high flange
assembly further including a plurality of end high-flange actuators
for applying force against the end high flanges to effect high
flange folding along each of the end high-flange fold lines; and a
control assembly for sequentially operating the low flange
applicators, the lateral high-flange actuators, and the end
high-flange actuators.
15. A system according to claim 14, wherein the restraint assembly
includes a restraining block movable between a first position
remote from the work piece and a second position for engaging the
end high flanges.
16. A system according to claim 15, wherein the restraint assembly
further includes a restraining plate movable between a retracted
position and an extended position adjacent the low-flange fold
lines for restraining the work piece as the low flange assembly
applies force against the low flanges.
17. A system according to claim 14, wherein the low-flange
applicator includes a plurality of applicator bars to apply
substantially continuous force along a corresponding one of the low
flanges to effect substantially uniform folding along a
corresponding one of the low-flange fold lines.
18. A system according to claim 17, wherein the applicator bars are
pivotally mounted to provide over-90.degree. action to accommodate
for spring-back of the low flanges.
19. A system according to claim 14, wherein the high-flange
actuators include at least one arm pivoting about an axis
substantially parallel to an adjacent and corresponding one of the
high-flange fold lines.
20. A system according to claim 19, wherein the arm includes a
shoulder corresponding to a desired final shape of the work piece
along the corresponding high-flange fold line.
21. A system according to claim 14, wherein the control system
comprises a controller for controlling the actuation sequence and
dwell time of the low flange assembly, the lateral high-flange
assembly, and the end high-flange assembly.
22. A system according to claim 21, wherein the control system
includes a first pneumatic actuator controlling movement of the low
flange assembly and a second pneumatic actuator controlling
movement of the high flange assembly.
23. A system according to claim 22, wherein the first pneumatic
actuator is an air bag dimensioned and configured to move the low
flange assembly upward toward the restraining assembly.
24. A system according to claim 22, wherein the second pneumatic
actuator includes a plurality of pneumatic cylinders dimensioned
and configured to selectively move the lateral high-flange
actuators and the end high-flange actuators.
25. A system according to claim 22, wherein the first and second
pneumatic actuators operate in the range of approximately 50 psi
and 150 psi.
26. The system according to claim 1 configured to be operated at
force levels selected based on the properties of the work piece, to
substantially eliminate the danger of damaging the work piece in
the event of operator error.
27. The system according to claim 1 configured to be operated at
force levels to substantially eliminate the danger of harming a
human operator in the event of operator error.
28. The system according to claim 1 configured for folding along at
least one of the fold lines is achieved by using at least one of
the restraint assemblies to contact the work piece at a location
proximal to the fold line rather than substantially along the fold
line.
29. The system according to claim 1 configured to be deployed in an
assembly environment, rather than exclusively in a fabrication
environment.
30. A method for forming a three-dimensional structure from an
approximately two-dimensional sheet material, the sheet material
including a predetermined low-flange fold line defining a low
flange and a predetermined high-flange fold line defining a high
flange, said method comprising the steps of: restraining a work
piece from movement in one direction; positioning a low flange
assembly against the low flange to bias the work piece against the
restraint assembly, the low flange assembly including a low-flange
applicator contacting the low flange to effect folding along the
low-flange fold line; and moving a high flange assembly against the
high flange, the high flange assembly including a high-flange
actuator contacting the high flange to effect folding along the
high-flange fold line.
31. A method according to claim 30, wherein the restraining step is
accomplished by moving a restraining block between a first position
remote from the work piece and a second position for engaging
against one or more high flanges of the work piece.
32. A method according to claim 31, wherein the restraining step is
accomplished by moving a restraining plate between a retracted
position and an extended position adjacent one or more low-flange
fold lines for restraining the work piece as the low flange
assembly applies force against the low flanges.
33. A method according to claim 31, wherein the positioning step is
accomplished by positioning an applicator bar against one or more
low flanges to apply substantially continuous force along a
majority of one or more low flanges to effect substantially uniform
folding along each corresponding low-flange fold line.
34. A method according to claim 33, wherein positioning step is
accomplished by moving the applicator bar to an over-90.degree.
position to accommodate for spring-back of the one or more low
flanges.
35. A method according to claim 31, wherein the moving step is
accomplished by pivoting one or more arms pivoting about a
corresponding axis substantially parallel to a corresponding
high-flange fold line.
36. A method according to claim 31, wherein the positioning and
moving steps are accomplished by providing pneumatic pressure to
control positioning of the low flange assembly and movement of the
high flange assembly.
37. A method according to claim 36, wherein the provided pneumatic
pressure is in the range of approximately 50 psi and 150 psi.
38. A three-dimensional structure formed by operation of the method
of claim 30.
39. The method according to claim 30 operated at force levels
selected based on the properties of the work piece, to
substantially eliminate the danger of damaging the work piece in
the event of operator error.
40. The method according to claim 30 operated at force levels to
substantially eliminate the danger of harming a human operator in
the event of operator error.
41. The method according to claim 30, wherein folding along at
least one of the fold lines is achieved by using at least one of
the restraint assemblies to contact the work piece at a location
proximal to the fold line rather than substantially along the fold
line.
42. The method according to claim 30 deployed in an assembly
environment, rather than exclusively in a fabrication environment.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent
Application No. 60/911,905 filed Apr. 15, 2007, entitled METHOD AND
APPARATUS FOR FOLDING OF SHEET MATERIALS, the entire contents of
which is incorporated herein for all purposes by this
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates, in general, to tool systems for
folding of sheet materials and methods for their use.
[0004] 2. Description of Related Art
[0005] Bending two-dimensional (2D) sheet materials to form
three-dimensional (3D) structures is known. Machinery and tooling
for effecting bends in 2D sheet materials is also known. For
example, U.S. Pat. No. 4,133,198 to Huda et al. discloses an
apparatus for bending large area construction units. U.S. Pat. No.
4,230,058 to Iwaki et al. shows an apparatus that is configured to
manufacture box-shaped structures from metal sheet. U.S. Pat. No.
5,105,640 to Moore discloses an apparatus for forming box-shaped
sheet metal ducts from sheet material.
[0006] Known apparatuses generally have presses and/or clamping
members provided to clamp the sheet material which may operate
under similar levels of forces that are used to stamp, punch or
otherwise work the sheet material into the desired shapes. The
relatively high force levels mean that the presses and/or clamping
members may present severe physical harm to an operator whom
inadvertently catches a finger or limb within such componentry or
between such componentry and the sheet material during the clamping
or bending process.
[0007] A further disadvantage of known apparatuses is that they
generally require the use of hardened steels and other metals that
are highly machined with close tolerances in order to produce a 3D
structure from a 2D sheet material. For example, known apparatuses
which stamp or punch narrow peripheral flanges into a sheet
material generally require hardened surfaces with close tolerances
in order to accurately form the peripheral flanges with their
desired dimensions.
[0008] Sheets of material with non-uniform, non-symmetrical flanges
and bend lines present manufacturing complexities. A set of tools
may be provided each of which accommodates bending of flanges of a
particular scale, size, dimension, or configuration. With such
conventional apparatus, bending along a bend line with a large
flange portion often requires changing the tool or configuration
than when bending flange portions on a smaller scale. The time and
complexity increases as the number and variety of bend lines and
flanges increase.
[0009] In light of the foregoing, it would be beneficial to have a
folding system which overcomes the above and other disadvantages of
known apparatuses for bending sheet materials.
BRIEF SUMMARY OF THE INVENTION
[0010] One aspect of the present invention is directed to a folding
tool system for forming a three-dimensional structure from a
substantially two-dimensional sheet material which may include a
predetermined low-flange fold line defining a low flange and a
predetermined high-flange fold line defining a high flange. The
system may include one or more of a frame including a restraint
assembly for restraining a work piece from movement in one
direction, a low flange assembly movably mounted on the frame for
biasing the work piece against the restraint assembly and effecting
folding along the low-flange fold line, the low flange assembly
including a low-flange applicator for applying force against the
low flange to effect low-flange folding, a high flange assembly
movably mounted on the frame to effect folding along the
high-flange fold line, the high flange assembly including a
high-flange actuator for applying force against the high flange to
effect high-flange folding, and a control assembly for sequentially
operating the low flange assembly and the high flange assembly.
[0011] The restraint assembly may include a restraining block
movable between a first position remote from the work piece and a
second position for engaging the high flange of the work piece. The
restraint assembly may further include a restraining plate movable
between a retracted position and an extended position adjacent the
low-flange fold line for restraining the work piece as the low
flange assembly applies force against the low flange.
[0012] The low-flange applicator may include an applicator bar to
apply substantially continuous force along a majority of the low
flange to effect substantially uniform folding along the low-flange
fold line. The applicator bar may be pivotally mounted to provide
over-90.degree. action to accommodate for spring-back of the low
flange.
[0013] The high-flange actuator may include at least one arm
pivoting about an axis substantially parallel to an adjacent the
high-flange fold line. The arm may include a shoulder corresponding
to a desired final shape of the work piece along the high-flange
fold line.
[0014] The control system may include a controller for controlling
the actuation sequence and dwell time of the low flange assembly
and the high flange assembly. The control system may include a
first pneumatic actuator controlling movement of the low flange
assembly and a second pneumatic actuator controlling movement of
the high flange assembly. The first pneumatic actuator may be an
air bag dimensioned and configured to move the low flange assembly
upward toward the restraining assembly. The second pneumatic
actuator may be an pneumatic cylinder dimensioned and configured to
move the high flange assembly to pivot along the high-flange fold
line. The first pneumatic actuator operates in the range of
approximately 50 psi and 150 psi. The second pneumatic actuator
operates in the range of approximately 50 psi and 150 psi.
[0015] Another aspect of the present invention is directed to a
folding tool system for forming a three-dimensional structure from
a two-dimensional sheet material which may include a plurality of
predetermined low-flange fold lines defining low flanges, a
plurality of predetermined lateral high-flange fold lines defining
lateral high flanges, and a plurality of predetermined end
high-flange fold lines defining end high flanges. The system may
include one or more of a frame including a restraint assembly for
restraining a work piece from movement in one direction, a low
flange assembly movably mounted on the frame for biasing the work
piece against the restraint assembly and effecting folding along
the low-flange fold lines, the low flange assembly including a
plurality of low-flange applicators for applying force against the
low flanges to effect low-flange folding along each of the
low-flange fold lines, a high flange assembly movably mounted on
the frame to effect folding along the high-flange fold lines, the
high flange assembly including a plurality of lateral high-flange
actuators for applying force against the lateral high flange to
effect high-flange folding along each of the lateral high-flange
fold lines, the high flange assembly further including a plurality
of end high-flange actuators for applying force against the end
high flanges to effect high flange folding along each of the end
high-flange fold lines, and a control assembly for sequentially
operating the low flange applicators, the lateral high-flange
actuators, and the end high-flange actuators.
[0016] The restraint assembly may include a restraining block
movable between a first position remote from the work piece and a
second position for engaging the end high flanges. The restraint
assembly may further include a restraining plate movable between a
retracted position and an extended position adjacent the low-flange
fold lines for restraining the work piece as the low flange
assembly applies force against the low flanges.
[0017] The low-flange applicator may include a plurality of
applicator bars to apply substantially continuous force along a
corresponding one of the low flanges to effect substantially
uniform folding along a corresponding one of the low-flange fold
lines. The applicator bars may be pivotally mounted to provide
over-90.degree. action to accommodate for spring-back of the low
flanges.
[0018] The high-flange actuators may include at least one arm
pivoting about an axis substantially parallel to an adjacent and
corresponding one of the high-flange fold lines. The arm may
include a shoulder corresponding to a desired final shape of the
work piece along the corresponding high-flange fold line.
[0019] The control system may include a controller for controlling
the actuation sequence and dwell time of the low flange assembly,
the lateral high-flange assembly, and the end high-flange assembly.
The control system may include a first pneumatic actuator
controlling movement of the low flange assembly and a second
pneumatic actuator controlling movement of the high flange
assembly. The first pneumatic actuator may be an air bag
dimensioned and configured to move the low flange assembly upward
toward the restraining assembly. The second pneumatic actuator may
include a plurality of pneumatic cylinders dimensioned and
configured to selectively move the lateral high-flange actuators
and the end high-flange actuators. The first and second pneumatic
actuators operate in the range of approximately 50 psi and 150
psi.
[0020] The system may be operated at force levels selected based on
the properties of the work piece, to substantially eliminate the
danger of damaging the work piece in the event of operator error.
The system may be operated at force levels to substantially
eliminate the danger of harming a human operator in the event of
operator error. The system may be configured for folding along at
least one of the fold lines may be achieved by using at least one
of the restraint assemblies to contact the work piece at a location
proximal to the fold line rather than substantially along the fold
line. The system may be deployed in an assembly environment, rather
than exclusively in a fabrication environment.
[0021] Another aspect of the present invention is directed to a
method for forming a three-dimensional structure from an
approximately two-dimensional sheet material, the sheet material
including a predetermined low-flange fold line defining a low
flange and a predetermined high-flange fold line defining a high
flange. The method may include one or more of the steps of:
restraining a work piece from movement in one direction;
positioning a low flange assembly against the low flange to bias
the work piece against the restraint assembly, the low flange
assembly including a low-flange applicator contacting the low
flange to effect folding along the low-flange fold line; and moving
a high flange assembly against the high flange, the high flange
assembly including a high-flange actuator contacting the high
flange to effect folding along the high-flange fold line.
[0022] The restraining step may be accomplished by moving a
restraining block between a first position remote from the work
piece and a second position for engaging against one or more high
flanges of the work piece. The restraining step may be accomplished
by moving a restraining plate between a retracted position and an
extended position adjacent one or more low-flange fold lines for
restraining the work piece as the low flange assembly applies force
against the low flanges.
[0023] The positioning step may be accomplished by positioning an
applicator bar against one or more low flanges to apply
substantially continuous force along a majority of one or more low
flanges to effect substantially uniform folding along each
corresponding low-flange fold line. The positioning step may be
accomplished by moving the applicator bar beyond a targeted final
bend angle, e.g. to an over-90.degree. position, to accommodate for
spring-back of the one or more low flanges.
[0024] The moving step may be accomplished by pivoting one or more
arms pivoting about a corresponding axis substantially parallel to
a corresponding high-flange fold line.
[0025] The positioning and moving steps may be accomplished by
providing pneumatic pressure to control positioning of the low
flange assembly and movement of the high flange assembly. The
provided pneumatic pressure may be in the range of approximately 50
psi and 150 psi.
[0026] A three-dimensional structure may be formed by operation of
the above-mentioned methods.
[0027] The method may be operated at force levels selected based on
the properties of the work piece, to substantially eliminate the
danger of damaging the work piece in the event of operator error.
The method may be operated at force levels to substantially
eliminate the danger of harming a human operator in the event of
operator error.
[0028] Folding along at least one of the fold lines may be achieved
by using at least one of the restraint assemblies to contact the
work piece at a location proximal to the fold line rather than
substantially along the fold line. The method may be deployed in an
assembly environment, rather than exclusively in a fabrication
environment.
[0029] The method and apparatus for folding of sheet materials of
the present invention has other features and advantages which will
be apparent from or are set forth in more detail in the
accompanying drawings, which are incorporated in and form a part of
this specification, and the following Detailed Description of the
Invention, which together serve to explain certain principles of
the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1A is an isometric view of an exemplary apparatus for
folding of sheet materials, and FIG. 1B is an end elevational
schematic view of the apparatus of FIG. 1A.
[0031] FIG. 2A is an isometric view of a sheet of material that is
configured for folding with the apparatus of FIG. 1, and FIG. 2B,
FIG. 2C and FIG. 2D are enlarged isometric views of the sheet of
material of FIG. 2A during progressive stages of folding.
[0032] FIG. 3A is an enlarged partial isometric view of the
apparatus of FIG. 1 during an initial stage of folding the sheet of
material of FIG. 2A, and FIG. 3B and FIG. 3C are partial
elevational views of FIG. 3A.
[0033] FIG. 4A is an enlarged partial isometric view of the
apparatus of FIG. 1 during another stage of folding the sheet of
material of FIG. 2A, and FIG. 4B and FIG. 4C are partial
elevational views of FIG. 4A.
[0034] FIG. 5A is an enlarged partial isometric view of the
apparatus of FIG. 1 during another stage of folding the sheet of
material of FIG. 2A, and FIG. 5B and FIG. 5C are partial
elevational views of FIG. 5A.
[0035] FIG. 6A is an enlarged partial isometric view of the
apparatus of FIG. 1 during another stage of folding the sheet of
material of FIG. 2A, and FIG. 6B and FIG. 6C are partial
elevational views of FIG. 6A.
[0036] FIG. 7A is an enlarged partial isometric view of the
apparatus of FIG. 1 during another stage of folding the sheet of
material of FIG. 2A, and FIG. 7B and FIG. 7C are partial
elevational views of FIG. 7A.
[0037] FIG. 8A is an enlarged partial isometric view of the
apparatus of FIG. 1 during another stage of folding the sheet of
material of FIG. 2A, and FIG. 8B and FIG. 8C are partial
elevational views of FIG. 8A.
[0038] FIG. 9A is an enlarged partial isometric view of the
apparatus of FIG. 1 during another stage of folding the sheet of
material of FIG. 2A, and FIG. 9B and FIG. 9C are partial
elevational views of FIG. 9A.
[0039] FIG. 10A is an enlarged partial isometric view of the
apparatus of FIG. 1 during another stage of folding the sheet of
material of FIG. 2A, and FIG. 10B and FIG. 10C are partial
elevational views of FIG. 10A.
[0040] FIG. 11A is an enlarged partial isometric view of the
apparatus of FIG. 1 during another stage of folding the sheet of
material of FIG. 2A, and FIG. 11B and FIG. 11C are partial
elevational views of FIG. 11A.
[0041] FIG. 12A is an enlarged partial isometric view of the
apparatus of FIG. 1 during another stage of folding the sheet of
material of FIG. 2A, and FIG. 12B and FIG. 12C are partial
elevational views of FIG. 12A.
[0042] FIG. 13 is an enlarged elevational view of a leveling device
of the apparatus of FIG. 1.
[0043] FIG. 14 an enlarged elevational view of the leveling device
of FIG. 14 in which the leveling device is in a leveling
position.
[0044] FIG. 15 an enlarged elevational view of the leveling device
of FIG. 14 in which the leveling device is in another leveling
position.
[0045] FIG. 16A, FIG. 16B, FIG. 16C, FIG. 16D and FIG. 16E are
schematic views of another restraint assembly that may be used with
the apparatus of FIG. 1.
[0046] FIG. 17A is an enlarged partial isometric view of another
apparatus similar to that shown in FIG. 1, while FIG. 17B, FIG.
17C, FIG. 17D and FIG. 17E are isometric views of the apparatus in
successive stages of folding the sheet of material similar to that
shown in FIG. 2A.
[0047] FIG. 18A is a schematic view of an apparatus similar to that
shown in FIG. 1, while FIG. 18B, FIG. 18C, FIG. 18D, FIG. 18E, FIG.
18F, FIG. 18G and FIG. 18H are schematic views of the apparatus of
FIG. 18A in successive stages of folding the sheet of material in a
manner similar to that shown in FIG. 2A.
DETAILED DESCRIPTION OF THE INVENTION
[0048] Reference will now be made in detail to various exemplary
embodiments of the present invention, examples of which are
illustrated in the accompanying drawings and described below. While
the invention will be described in conjunction with several
exemplary embodiments, it will be understood that present
description is not intended to limit the invention to those
exemplary embodiments. On the contrary, the invention is intended
to cover not only the exemplary embodiments, but also various
alternatives, modifications, equivalents and other embodiments,
which may be included within the spirit and scope of the invention
as defined by the appended claims.
[0049] Turning now to the drawings, wherein like components are
designated by like reference numerals throughout the various
figures, attention is directed to FIGS. 1A and 1B, which illustrate
an exemplary folding tool system generally designated by the
numeral 30 that may be used to fold two-dimensional (2D) sheet
materials into three-dimensional (3D) shapes. The folding tool
system designed to be used with sheet materials having engineered
fold lines which facilitate bending along predetermined fold
lines.
[0050] The bending tool systems in accordance with the present
invention are particularly suited for bending 2D sheet materials
having engineered fold lines utilizing various fold geometries and
configurations including, but not limited to, those disclosed by
U.S. Pat. No. 6,481,259, U.S. Pat. No. 6,877,349, U.S. Pat. No.
7,152,449, U.S. Pat. No. 7,152,450, U.S. patent application Ser.
No. 10/821,818 (now U.S. Patent Application Publication No.
2005/0005670 A1), and U.S. Pat. No. 7,032,426, U.S. patent
application Ser. No. 10/931,615 (now U.S. Patent Application
Publication No. 2005/0097937 A1), U.S. patent application Ser. No.
10/985,373 (now U.S. Patent Application Publication No.
2005/0061049 A1), U.S. patent application Ser. No. 11/357,934 (now
U.S. Patent Application Publication No. 2006/0261139 A1), U.S.
patent application Ser. No. 10/952,357 (now U.S. Patent Application
Publication No. 2005/0064138 A1), U.S. patent application Ser. No.
11/384,216 (now U.S. Patent Application Publication No.
2006/0207212 A1), U.S. patent application Ser. No. 11/080,288 (now
U.S. Pat. No. 7,350,390 B2), U.S. patent application Ser. No.
11/374,828 (now U.S. Patent Application Publication No.
2006/0213245 A1), U.S. patent application Ser. No. 11/180,398 (now
U.S. Patent Application Publication No. 2006/0021413 A1, U.S.
patent application Ser. No. 11/290,968 (now U.S. Patent Application
publication No. 2006/0075798 A1, and U.S. patent application Ser.
No. 11/411,440, the entire contents of which patents and patent
applications are incorporated herein for all purposes by this
reference.
[0051] The folding tool system of the present invention is designed
to take advantage of various aspects of manufacturing with
engineered fold lines. For example, accurate machine tool
tolerances are relatively less critical because the locations of
the bends necessary are engineered into the sheets of material.
Accordingly, the folding tool system of the present invention can,
but need not, take the form of a light-duty machine formed of mild
steel which may be capable of millions of duty cycles due to
relatively minimal wear and tear. Special metals, expensive and
time-consuming machining, hardening and other heat treatments may
be reduced or avoided because the need for precise machine tool
tolerances is reduced: the tolerances are built into the sheet of
material whereby a less expensive and lighter duty folding tool may
be utilized to fold a 2D sheet of material into its final shape, or
in some cases its intermediate shape. As such, the folding tool
system may be constructed with milder steel, laser cut parts and
other relatively inexpensive components such as including plastic,
composite and other materials typically considered to be too soft
to be built from metal forming equipment, as well as die cast and
other relatively less precise componentry. Of course, the foregoing
does not necessarily preclude heavy-duty construction using
hardened steels. Rather, it allows enhanced flexibility depending
on factors such as duty cycle, economy, weight, and the like.
[0052] In addition, some aspects of the folding tool system are
similar to those disclosed in U.S. patent application Ser. No.
10/938,170 (now U.S. Pat. No. 7,296,455 B2), and U.S. Patent
Application No. 60/840,810 (now U.S. patent application Ser. No.
11/846,134 and U.S. Patent Application Publication No. US
2008/0048366 A1), the entire contents of which patent applications
are also incorporated herein for all purposes by this
reference.
[0053] One will appreciate, however, that the folding tool system
is also suited for bending other types of sheet materials about a
fold line including, but not limited to, the above-mentioned
engineered fold lines, predetermined fold lines defined by scoring
and/or other suitable means, or intended bend lines in which the
sheet materials do not have any physical structure extending along
the bend line for promoting bending along the bend line.
[0054] Returning to FIG. 1A, folding tool system 30 is configured
to fold a 2D sheet material blank into a 3D sheet material product.
For the purposes of the following description, the sheet material
will be generally designated by the numeral 32 regardless of its
state of manufacture. In particular, whether with the sheet of
material is in the flat as shown in FIG. 2A and FIG. 2B, in an
intermediate state of manufacture as shown in FIG. 2C, or in a
final state of manufacture as shown in FIG. 2D, the reference
numeral 32 will be used. In fact, both the 2D and 3D states of the
sheet material are illustrated in FIG. 1A.
[0055] In the illustrated embodiment, the sheet of material is
provided with a plurality of fold lines 33, 35, 37 and 39 which
dimensioned and arranged to facilitate folding into a 3D product
having peripheral low flanges or narrow peripheral flanges 40,
latching low flanges or narrow latching flanges 42, lateral high
flanges or deep side walls 44, and end high flanges or deep end
walls 46, as best seen in FIG. 2A. The illustrated 3D product is a
household load center or primary distribution box, one that is in
the form of an open box having self-latching side walls and a
peripheral flange defining the primary opening of the box. One will
appreciate that a number of other 3D products may be formed which
include both low flanges and high flanges. For example, the 3D
products may include, but are not limited to, electronic component
chassis, automotive components, appliance components, transport
components, construction components, RF shields, HVAC components,
aerospace, aerospace components, and the like.
[0056] The terms "low" and "high", "shallow" and "deep", and
"narrow" and "wide" are used in a relative sense. For example, what
is low in one application may be high in another, or vice versa.
Also, as between a "very low" and "low" pair of flanges, the former
may be regarded as "low" and the latter as "high." For the purposes
of convenience, and without limiting the generality of the
foregoing, the term "low flange" may be referred to herein a
shallow or narrow flange, and the term "high flange" may be
referred to herein as a deep or wide flange or side wall.
Generally, low flanges require relatively more, and often
significantly more, support to bend uniformly along a desired fold
line as less material is present to distribute bending force. On
the other hand, high flanges require relatively less, and often
significantly less, support to bend uniformly along a desired bend
line, as will be discussed in greater detail below. In part, the
size of the flange determines the size of the "lever arm" and
accordingly the force required for bending.
[0057] Returning to FIG. 1A, folding tool system 30 generally
includes a frame 47 that supports a restraint assembly 49, a low
flange assembly 51, and a high flange assembly 53. Unlike
conventional hard tooling solutions, the folding tool system can be
configured to fold 2D sheet materials of varying size to form 3D
products of varying size. In the illustrated embodiment, the
restraint assembly may be longitudinally repositioned in the
direction of arrow "L" in order to accommodate distribution boxes
of varying lengths, which lengths are indicated by numeral 54. One
will also appreciate that the folding tool system such that the
restraint assembly may be configured to lateral repositioning in
directions laterally transverse and/or vertically perpendicular to
arrow "L" in order to accommodate distribution boxes of varying
widths and heights.
[0058] In the illustrated embodiment, the restraint assembly is
located above the work piece. As shown in FIG. 3A the restraint
assembly includes a restraining bar 56 that pivots down and abuts
against each side wall to restrain upward motion of the work piece.
Each restraining bar is configured to contact the side wall
adjacent the low-flange peripheral fold line 33 to facilitate
bending along the fold line
[0059] In the illustrated embodiment, the restraining bar extends
continuously along a majority of the peripheral flange. One will
appreciate, however, that the restraining bar need not be
continuous but may instead be segmented. Preferably, the
restraining bar contacts a sufficient portion of the peripheral
flanges to facilitate substantially uniform bending along the
corresponding fold line.
[0060] The restraint assembly also includes a restraining block 58
that pivots down and abuts against end high flange 46 and restrains
upward motion of the work piece in a manner similar to the
restraining bar discussed above. In the illustrated embodiment, the
restraining block has a shape and dimensions that substantially
conform with the end wall. One will appreciate that other
configurations may be utilized such as restraining arms or other
more localized restraints.
[0061] The primary purpose of the restraints is to limit upward
motion. Since the sheet of material includes engineered fold lines,
the fold lines will dictate where the sheet of material bends. As
such, the restraining bar and the restraining blocks need only
contact the side and end walls proximal the peripheral fold lines
and not precisely along the fold lines. The precise locations of
the restraining bar and block are relatively less critical. As
relatively more precise tolerances are necessary, these components
may also be constructed with milder steel, laser cut parts and
other relatively inexpensive components such as including plastic,
composite and other materials typically considered to be too soft
to be built from metal forming equipment, as well as die cast and
other relatively less precise componentry, as noted above.
[0062] The restraining bars and the restraining blocks are movable
between upper retracted positions and lower deployed positions, the
significance of which positions will become apparent below.
Preferably, but not necessarily, double-acting pneumatic actuators
60, 61 are provided to control their respective movement, however,
one will appreciate that other suitable actuators may be utilized
such as single-acting pneumatic cylinders, a combination of single-
and double-acting pneumatic cylinders, single- and/or double-acting
hydraulic cylinders, electric motors, linear actuators and other
suitable means.
[0063] The low flange assembly is mounted on the frame and is
preferably configured to bend all narrow flanges at substantially
the same time to minimize cycle time. In the illustrated
embodiment, low flange assembly 51 is mounted on a pair of
pneumatic air bags 63 serve to lift the low flange assembly upward
relative to the main frame 47, as indicated by the arrow "U" in
FIG. 1B. Platform 65 of the low flange assembly rises to bias sheet
of material 32 against the retraining bar and blocks 56 and 58, and
rises further to effect bending all of the narrow flanges
substantially simultaneously. The sequence of bending a plurality
of flanges of varying size may be modified depending on the
application. In various embodiments, only one or a portion of the
narrow flanges are bent substantially simultaneously and thereafter
one or a portion of other flanges are bent. In various embodiments,
all flanges of a similar size or in proximity to each other on the
sheet are bent substantially simultaneously.
[0064] With reference to FIG. 3A, the low flange assembly further
includes a number of force applicators 67, 68, 70 which abut
against and apply force to "wipe" the corresponding narrow flanges
40, 42 upwardly past the lower surfaces of the restraining bars and
blocks 56, 58. As the applicators wipe the narrow flanges past the
restraining bars and blocks, the applicators effect bending along
the corresponding fold line and actually form the narrow flanges.
In the illustrated embodiment, the actuators are in the form of
cylindrical bars mounted on platform 65, which bars extend
substantially the length of the narrow flanges and thus apply a
substantially continuous force against the narrow flanges. One will
appreciate that the bars need not be continuous but instead may be
segmented, provided that the bars contact a majority of the length
of the narrow flanges in order to promote substantially uniform
bending along the corresponding fold line.
[0065] Also, the force applicators may be provided with a contact
roller that is free to roll along the surface of the narrow flange
during bending. Such a contact roller may prevent sliding contact
of the applicator bar along the narrow flange and thus minimize
scratching, wear or other damage to the work piece.
[0066] The force applicators may be provided with a cam actuator 72
such that an inward force may be applied inwardly to bend the
narrow flanges over 90.degree. as the assembly reaches the end of
its upward stroke, as shown in FIG. 6B and FIG. 6C. Such a cam
actuator may thus accommodate for spring-back in the narrow flange
in an otherwise conventional manner.
[0067] In the illustrated embodiment, each applicator bar is
dedicated to a single corresponding narrow flange. One will
appreciate, however, that a single applicator bar may be utilized
to fold a plurality of narrow flanges and, conversely, a plurality
of applicator bars may be utilized to fold a single narrow
flange.
[0068] The dimensions and configuration of the force applicators
will dictate the particular angle bend imparted on the work piece.
For example, in the illustrated embodiment, low flange applicators
67, 68, 70 are configured to impart a desired bend angle (e.g.
approximately 90.degree.), however, the actuators may be adjustable
such that the bend angle may be adjusted by adjusting the throw of
the applicators. Also, the bend angle may be adjusted to
accommodate for spring back to achieve a desired final bend
angle.
[0069] Turning now to the high flange assembly, it is also movably
mounted on the frame and is configured to effect folding along the
high-flange fold lines. In the illustrated embodiment, high flange
assembly 53 including a plurality of lateral high-flange actuators
74, 75 which are configured to apply force against corresponding
lateral and end high flanges 44, 46 to effect high-flange folding
along the corresponding lateral high-flange fold lines. In the
illustrated embodiment, the high-flange actuators are mounted on
platform 65 and thus rise along with the low flange assembly,
however, one will appreciate that the high-flange actuators may be
otherwise movably mounted on frame 47.
[0070] Each high-flange actuator is provided with a double-acting
pneumatic cylinder 77. As is the case with the retraining bar and
block actuators discussed above, other suitable actuation means may
be utilized instead of, or in addition to double-acting pneumatic
cylinders. Also, one will appreciate that one or more cylinders may
be provided for each actuator and, conversely, a cylinder may be
provided for one or more actuators.
[0071] In the illustrated embodiment, the high-flange actuators
include at least one arm 79 that pivots about an axis substantially
parallel to a corresponding high-flange fold line. Preferably, the
arm pivots directly below a bottom 81 of the work piece and
includes a shoulder 82 which corresponds to a desired final shape
of the work piece. Such configuration forms a cradle as the arms
are pivoted upwardly, which cradle provides a self-centering effect
on the work piece and also allows the deep flanges to be bent with
little or no restraint from the restraining assembly. In
particular, the light duty folding of the deep flanges, coupled
with gravity and/or frictional forces allow the deep flanges to be
bent with the work piece merely resting on and between the
high-flange actuators.
[0072] Turning now to the operation of the above-mentioned
pneumatic actuators, may be controlled by suitable means to control
the pressure and dwell time of each actuator, as well as the
actuation sequence of the actuators. For example, a programmable
logic controller 84 having a multi-channel valve assembly may be
provided to control the actuators in any desired combination,
duration, and/or sequence. The controller may be configured with a
manual override to activate any one or more actuators as desired,
and/or with appropriate safety and/or off switches. One will
appreciate that other suitable controllers may be utilized.
[0073] The pneumatic cylinders, or other actuation means, may be
adjusted such that the force applied to the work piece is
sufficient to bend the work piece along the engineered fold lines,
while reducing or eliminating the risk of injury to the operator in
the event that the operator inadvertently pinches a finger or limb.
Similarly, the actuation means may be adjusted such that the tool
system uses forces that are sufficiently low that there is less
danger of damaging the work piece in the event of misalignment or
other operator error. In various embodiments, the pneumatics are
configured to operate in the range of approximately 10 psi to 200
psi. In various embodiments, the pneumatics operate in the range of
approximately 50 psi to 150 psi. One will appreciate, however, that
the operating pressures will depend on the product gauge of the
material, the material strength, and/or other material
characteristics including, but not limited to the usual commercial
range for pneumatic equipment. For example, hydraulics or other
higher force means may be appropriate for bending thick-gauge
materials and/or with higher strength materials. While hydraulics
and other higher force means may be utilized, it is preferable that
pneumatics be used as pneumatics may be less messy and
environmentally cleaner in use than hydraulics.
[0074] An exemplary method of using folding tool system 30, and an
exemplary product resulting from use of the method, will now be
described. Although the following describes with particular detail
the process of folding one corner of the work piece, one will
appreciate that all four corners may be similarly and
simultaneously processed. With reference to FIG. 3A, work piece 32
is placed into the appropriate location while the restraining bar
and block 56, 58 are in their retracted positions. As can be seen
in FIG. 3B and FIG. 3C, the work piece is placed such that it is
resting on applicator bars 67, 68, 70. In various embodiments, the
cam actuators 72 are configured such that upper protrusions 86
locate the work piece within the tool system.
[0075] Next, the restraining bar and block 56, 58 swing down into
their deployed positions as shown in FIG. 4A, and more
particularly, as shown by the arrows in FIG. 4B and FIG. 4C. The
restraining bar is positioned proximal the lateral peripheral
low-flange fold line 33 while the restraining block is positioned
adjacent the fold line 35. As such, the restraint assembly is now
in place to restrain upward motion of the work piece.
[0076] As shown in FIGS. 5A, B and C, and in FIGS. 6A, B and C, the
low flange assembly 51 is moved upwardly such that low flange
applicators 67, 68, 70 wipe the corresponding narrow flanges
upwardly above lower edges of the restraining bar and block 56, 58.
In various embodiments, the targeted bend angle is approximately
90.degree.. As the low flange assembly approaches the extent of its
upward stroke, actuators 72 pivot and bias the narrow flanges
inwardly past 90.degree. to accommodate for spring back. The amount
of such "overbending" depends in part on the characteristics of the
material and bending process.
[0077] With reference to FIGS. 7A, B and C, restraining bar 56
swings toward its retracted position while the restraining block 58
remains in its downward deployed position. This allows restraint of
the work piece while bending commences by the lateral high-flange
actuators 74, as indicated by the arrow in FIG. 8B
[0078] Next, the lateral high-flange actuators complete 74 their
stroke and bend lateral high flange or side wall 44 into its final
position, as indicated by the arrow in FIG. 9B. As can be seen in
FIG. 9B, restraining bar 56 is configured for double duty in that
in its upper retracted position, the restraining also abuts against
narrow flange 40 and thus serves to restrain upward motion of work
piece 32. Such restraint is beneficial in holding the work piece in
place as restraining block retracts upwardly (FIG. 10C), and as the
end high-flange actuators 75 commence and progress through their
stroke (FIG. 11C).
[0079] As shown in FIG. 2A, the work piece is provided with a latch
assembly 88 of the type described in U.S. patent application Ser.
No. 11/386,463 (now U.S. Patent Application Publication No.
2006/0277965 A1), the entire contents of which application is
incorporated herein for all purposes by this reference. One will
appreciate that additional force may be required to engage the
latch assembly during bending. In which case, the high-flange end
actuators 75 may be configured to provide more force than the other
actuators. Also, the double-duty of the restraining bar 56 in its
upper retracted position (FIG. 10B) serves to keep the work piece
in position as the high-flange end actuators 75 pivot upwardly as
shown in FIG. 10C. The restraining bar may abut against the lateral
narrow flanges 40 during the entire stroke of the high-flange end
actuator. However, and as noted above, due to the low duty bending
afforded by engineered fold lines, it is may not be necessary to
restrain the work piece during the entire stroke of the end
actuators, in which case, the low flange assembly 51 may lower, as
indicated by the arrow in FIG. 12B, while the end actuator
completes its stroke as indicated by the arrow in FIG. 12C.
[0080] Turning to FIG. 13, the folding tool system may include a
leveling device 89 in the form of an off-center cam lever provided
on the base of frame 47. One or more leveling devices may be
provided on the frame. For example, a leveling device may be
provided at each corner of the folding tool system's footprint.
Preferably, the frame includes at least three leveling devices to
allow, and more preferably, one at each corner of the frame.
[0081] In the illustrated embodiment, the leveling device includes
a body 91 and an adjustment lever 93. The body is pivotally mounted
to frame 47 by a pivot assembly 95. In the illustrated embodiment,
the pivot assembly includes a through bore and is pivotally mounted
to the frame by a fastener such as a bolt, carriage screw, or other
suitable means. Two or more pivot assemblies may be provided to
vary the degree of adjustability afforded by the leveling device.
For example, two or more bores may be provided at varying distance
from the center of body 91. The further the bore is located from
the center of the body, the greater the vertical adjustment may be
realized.
[0082] As shown in FIG. 14, pivotally mounting leveling device 89
to frame 47 through one bore affords a certain degree of
adjustability as the leveling device is pivoted approximately
75.degree. as compared to its original position shown in phantom.
Mounting the device to the other bore located further from the
center of body 91 affords a greater degree of adjustability as the
leveling device is pivoted approximately 75.degree., as shown in
FIG. 15. One will appreciate that the pivot range of the leveling
device may vary.
[0083] In the illustrated embodiment, body 91 is substantially
circular; however, one will appreciate that other shapes may be
utilized. For example, the body may have a nautilus-like profile in
which the portion which contacts the ground or floor is located
substantially directly below the pivot assembly in which case, the
device is effectively self-locking, that is, does not have any
significant propensity to rotate from its desired position.
[0084] The exemplary folding tool system described herein may
provide a simpler and safer method of defining 3D objects from 2D
sheet materials, than known devices. Additionally, the tool system
may be used in the assembly environment instead of, or in addition
to, the fabrication environment as it takes advantage of engineered
fold lines and thus may reduce the necessity of press brakes,
progressive dies and other heavy machinery. The folding tool system
may also be readily located in an assembly line after or between
various fabrication stations on which a profiling, punching, laser
cutting or other operation takes place. Furthermore, the folding
tool system may also be located in an assembly line before or after
various finishing stations.
[0085] Also, the folding tool system allows 2D sheet material parts
to be transported directly to the assembly space, and thus allows
the product to the shipped in the flat through much of the
manufacturing and assembly process as possible. Various methods can
be utilized to feed the work piece to the folding tool system
including either manual labor, or automated machinery, or a
combination thereof.
[0086] In another exemplary embodiment of the present invention,
restraint assembly 49a is similar to restraint assembly 49
described above but includes a wipe bar 96 as shown in FIG. 16A.
The configuration of restraint assembly 49a allows for forming an
outwardly extending peripheral flange, which results in an S-shaped
or Z-shaped side wall. Also, the configuration of restraint
assembly allows for a single actuator to fold both a peripheral low
flange, and a lateral high flange. For example, the lateral high
flange applicator may be utilized to fold both the peripheral low
flange and the lateral high flange as will become evident below.
One will appreciate that a single actuator may similarly be
utilized to form both a peripheral low flange and an end high
flange.
[0087] Like reference numerals have been used to describe like
components of restraint assembly 49a and restraint assembly 49. In
this embodiment, the restraint assembly includes a restraining bar
56a that is configured for pivotal movement in a manner similar to
that described above. In this embodiment, wipe bar 96 is mounted on
a pivoting restraining bar mount 98 as shown in FIG. 16A. As the
lateral high flange actuator (not shown) begins to fold lateral
high flange 44a in a manner similar to that described above,
peripheral low flange 40a moves toward wipe bar 96, as shown in
FIG. 16B, and contacts the wipe bar to cause folding of the
peripheral low flange about the peripheral fold line, as shown in
FIG. 16C. Preferably, restraining bar mount 98 is shaped to
accommodate the folded low flange 40a as it continues to move
inward as folding of high flange 44a is completed, as shown in FIG.
16D. Once folding is completed, the restraining bar mount 98 pivots
upwardly about pivot 100 thereby swinging both restraining bar 56a
and wipe bar 96 out of the way, as shown in FIG. 16E, thereby
allowing access for ready removal of the folded sheet of
material.
[0088] In another exemplary embodiment of the present invention,
folding tool system 30b is similar to high-flange assembly 30
described above but includes modified low-flange and high-flange
actuators, as shown in FIG. 17A. In this embodiment, the relative
positioning of latch flange 42b and lateral flange 44b are
controlled by single action, that is, by movement of the lateral
high flange actuator 74b. In this embodiment, low flange
applicators 67b, 68b are similar to those described above.
Applicators 67b, 68b abut against and apply force to "wipe" the
corresponding narrow flanges 40b upwardly in a manner similar to
that described above. Latch flange applicator 70b, however, does
not cam inwardly and outwardly in the manner of applicator 70
described above. Instead, latch flange applicator 70b holds
latching flange 42b in a substantially right angle position, even
as high flange actuator 74b begins to fold lateral high flange 44b
about its corresponding fold line, as shown in FIG. 17B.
[0089] In the illustrated embodiment, latch flange applicator 70b
is in the form of a block, however, other suitable shapes and
configurations may be utilized. Preferably, the latch flange
applicator has a chamfered top to facilitate "wiping" the latching
flange upwardly. Also, latch flange applicator 70b may be provided
with an latch flange adjuster 102 to fine tune the position of the
latching flange.
[0090] High flange actuator 74b is configured to contact and fold
lateral high flange 44b in a manner similar to that described
above. In this embodiment, the high flange actuator also includes a
tuned swing plate 74b'. The tuned swing plate is positioned just
beyond the end of the high flange to contact latching flange 42b,
as shown in FIG. 17C, and properly position the latching flange as
the end flange 46b is folded upwardly, as shown in FIG. 17D.
Preferably, the contact surface of swing plate 74b' is offset
approximately, or slightly greater than the material thickness of
sheet 32b. Such configuration of the swing plate will bias the
outside surface of latching flange 42b slightly inside of the
inside surface of lateral flange 44b to provide proper clearance
for folding end flange 46, while properly aligning the latching
flange for proper engagement of latching assembly 88b as the
folding operation is completed, as shown in FIG. 17E.
[0091] The swing plate may include a ramped or chamfered surface
103, or be otherwise configured to facilitate the latching flange
sliding across the swing plate and inward of the lateral flange.
One will also appreciate that suitable adjustment means may be
provided to fine tune the position of the swing plate with respect
to the remainder of lateral high flange actuator.
[0092] In another exemplary embodiment of the present invention,
folding tool system 30c is similar to folding tool system 30
described above and is configured for a method of "overbending" to
accommodate for material spring-back without a rocker assembly
(e.g., cam actuator 72), as is shown in FIGS. 18A-H. Like reference
numerals have been used to describe like components of the folding
tool system. Folding tool system 30c includes a platform 65c with a
riser 106 and a bend applicator 108 fixedly mounted with respect to
the riser and positioned on the platform spaced from the riser. The
bend applicator is configured to engage the sheet of material and
apply an opposing force to the underside of the sheet.
[0093] In the illustrated embodiment, the bend applicator is a rod,
however, one will appreciate that in various embodiments the bend
applicator may have other configurations which include a chamfered,
ramped or curved surface to promote sliding of the material along a
bend line into the space between the bend applicator and the
inclined portion of the platform. In the illustrated embodiment,
the riser is a stepped riser block, however, one will appreciate
that in various embodiments the riser may have other configuration
which include a chamfered, ramped or other geometry to provide
suitable clearance for elastic bending as described below.
[0094] In operation, the sheet of material 32c is placed on the
platform and bend applicator while they remain substantially
stationary as shown in FIG. 18B, and the platform and bend
applicator is moved upwardly against a restrainer as discussed
below. In various embodiments, the tool system may be configured
such that the sheet moves with the platform and bend applicator,
while in other embodiments, the tool system may be configured such
that the sheet moves relative to the platform and/or bend
applicator. By designing the system for movement of the sheet
rather than the platform parts, the system may achieve greater
flexibility and simplicity of moving parts.
[0095] As shown in FIGS. 18C and 18D, an end of the sheet of
material engages bend applicator 108 as the bend applicator moves
toward the sheet and "wipes" along the undersurface of the sheet.
As such, bend applicator 108 imparts bending along a bend line 110
while a restrainer 111 restrains the sheet from upward movement. In
various embodiments, the sheet of material includes bend-inducing
structures to facilitate bending at the intended bending location
as described above (e.g. bend line 110).
[0096] After engaging the bend applicator, the sheet of material is
restrained downwardly until a portion of the sheet engages riser
106, as shown in FIG. 18D. At this time, the end of the sheet
material is provided with a desired angle .alpha., which provides a
substantially 90.degree. flange in the exemplary embodiment.
[0097] As shown in FIG. 18E, the combination of the bend applicator
and riser provides a geometry which causes the sheet of material to
bend beyond the desired angle .alpha. to an over-bend angle .beta.,
which is slightly over 90.degree. (e.g., approximately 89.degree.
to 85.degree., or more) in the illustrated embodiment. In part, the
bend angle is determined by the direction of application force on
the sheet and angle of incidence of an inclined portion of the
sheet as riser 106 moves above the bottom edge of restrainer 111.
As can be seen in FIG. 18e, a flange 32c' of the sheet of material
is folded such that it extends in a direction coincident with the
line of application on the sheet. Along bend line 110, however, the
sheet of material is forced into a void between the riser 106 and
bend applicator 108. In this fully engaged position, a portion of
the sheet of material is pushed toward platform 65c such that the
sheet of material temporarily bends along two bend lines, bend line
110 and bend line 110'. Whereas bending along bend line 110 is
effected by bend applicator 108, bend line 110' is determined by an
inflection point 112 formed by an edge of the riser.
[0098] The riser 106, and in particular the edge thereof, is
configured and dimensioned to minimally bend the sheet such that
only elastic deformation of the sheet of material occurs along bend
line 110'. In contrast, bend applicator 108 is dimensioned and
configured to effect significant bending which causes the sheet of
material to plastically deform along bend line 110. Elastic bending
means that the sheet of material is bent such that the bending is
within the elastic region of the material or is less than the yield
point. The bending is not severe enough to plastically or
permanently deform the material.
[0099] As shown in FIG. 18F, platform 65c and sheet of material 32c
are lowered during which time, the sheet of material is allowed to
"spring back" such that material has substantially a 90.degree.
bend along bend line 110 and is substantially unbent along bend
line 110'. In particular, the sheet will "spring back" to a
substantially planar form along bend line 110' as shown in FIG.
18F. Further, the sheet of material will also experience some
spring back along bend line 110. This is due to the material
characteristics of the sheet which determine that part of the
bending is within the elastic region.
[0100] Next, platform 65c and bend applicator 108 are further
lowered such that restrainer 111 disengages the sheet of material,
as shown in FIG. 18G, and the sheet of material is removed
altogether from the platform, as shown in FIG. 18H. As shown in
FIG. 18H, the sheet of material in the final state has a 900 bend
along bend line 110 and substantially no bending in the region of
inflection point 112.
[0101] Although apparatus 30c is designed to produce a 90.degree.
bend after spring back, the apparatus may be modified to produce
any number and type of bends and bend angles. For example, the
platform may include inflection points of varying size, number,
shape, and location which define a plurality of inclined portions.
The slope of one or more of the inclined portions may be configured
to impart bending beyond the yield point of the material to cause
some plastic deformation. The inflection point angle and length of
the inclined portion may also be modified to adjust the final bend
angle of the sheet of material. The platform may also include a
variety of applicator configurations including, but not limited to,
a plurality of applicators of varying shapes and sizes. The use of
a plurality of applicators and other modifications of the platform
working surface allows the system to perform several processes in a
substantially singular step as the sheet is forced against the
platform. The platform may be modified in many other ways depending
on the application to accommodate and utilize the deformation
properties of the sheet of material.
[0102] For convenience in explanation and accurate definition in
the appended claims, the terms "up" or "upper", "down" or "lower",
"inside" and "outside", "lateral" and "end" are used to describe
features of the present inventions with reference to the positions
of such features as displayed in the figures.
[0103] In many respects various modified features of the various
figures resemble those of preceding features and the same reference
numerals followed by subscripts "a" and "b" designate corresponding
parts.
[0104] The foregoing descriptions of specific exemplary embodiments
of the present invention have been presented for purposes of
illustration and description. They are not intended to be
exhaustive or to limit the invention to the precise forms
disclosed, and obviously many modifications and variations are
possible in light of the above teachings. The exemplary embodiments
were chosen and described in order to explain certain principles of
the invention and their practical application, to thereby enable
others skilled in the art to make and utilize various exemplary
embodiments of the present invention, as well as various
alternatives and modifications thereof. It is intended that the
scope of the invention be defined by the Claims appended hereto and
their equivalents.
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