U.S. patent application number 11/109005 was filed with the patent office on 2005-10-20 for multi-ram press and method of metal forming.
Invention is credited to Lanczy, Geza T..
Application Number | 20050229669 11/109005 |
Document ID | / |
Family ID | 35094876 |
Filed Date | 2005-10-20 |
United States Patent
Application |
20050229669 |
Kind Code |
A1 |
Lanczy, Geza T. |
October 20, 2005 |
Multi-ram press and method of metal forming
Abstract
A method of forming a workpiece, including the steps of:
providing a center ram, a first outside ram, a second outside ram,
and a die; pressing the center rain against the workpiece and
toward the die to a first predetermined die depth; trapping the
workpiece between the center ram and the die; pressing the first
outside ram and the second outside ram against the workpiece and
toward the die to a second predetermined die depth; and stretching
the workpiece beyond a yield tensile strength of the workpiece
material. The die surface has a die center surface which includes
at least part of a first arcuate surface, a first planar surface,
and at least part of a second arcuate surface. The center ram
surface is complimentary in shape to the die center surface.
Inventors: |
Lanczy, Geza T.; (Auburn,
IN) |
Correspondence
Address: |
TAYLOR & AUST, P.C.
142 SOUTH MAIN STREET
P. O. BOX 560
AVILLA
IN
46710
US
|
Family ID: |
35094876 |
Appl. No.: |
11/109005 |
Filed: |
April 19, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60564010 |
Apr 20, 2004 |
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Current U.S.
Class: |
72/353.2 |
Current CPC
Class: |
B21D 5/01 20130101; B21D
22/02 20130101 |
Class at
Publication: |
072/353.2 |
International
Class: |
B21D 028/00 |
Claims
What is claimed is:
1. A method of forming a workpiece, comprising the steps of:
providing a center ram, a first outside ram, a second outside ram,
and a die, said die including a die surface having a first arcuate
surface, a first planar surface and a second arcuate surface, said
first planar surface being interposed between said first arcuate
surface and said second arcuate surface, said die surface having a
die center surface including at least part of said first arcuate
surface, said first planar surface, and at least part of said
second arcuate surface, said center ram having a center ram surface
including a center ram first arcuate surface, a center ram planar
surface, and a center ram second arcuate surface, said center ram
planar surface being interposed between said center ram first
arcuate surface and said center ram second arcuate surface, said
center ram surface being complimentary in shape to said die center
surface; pressing said center ram against the workpiece and toward
said die to a first predetermined die depth; trapping the workpiece
between said center ram and said die; pressing said first outside
ram and said second outside ram against the workpiece and toward
said die to a second predetermined die depth; and stretching the
workpiece beyond a yield tensile strength of the workpiece material
using said die, said center ram, said first outside ram and said
second outside ram.
2. The method of claim 1, further including the step of forming the
workpiece in a shape complimentary to a surface of said die.
3. The method of claim 2, further including the step of eliminating
a spring-back in the workpiece.
4. A forming tool for forming a workpiece, said forming tool
comprising: a die including a die surface having a die center
surface, a die first outer surface and a die second outer surface,
said die center surface in between said die first outer surface and
said die second outer surface; a center ram including a center ram
surface complimentary in shape to said die center surface; a first
outside ram including a first outside ram surface complimentary in
shape to said die first outer surface; and a second outside ram
including a second outside ram surface complimentary in shape to
said die second outer surface.
5. The forming tool of claim 4, wherein said die surface includes a
first arcuate surface, a first planar surface and a second arcuate
surface, said first planar surface interposed between said first
arcuate surface and said second arcuate surface, said die center
surface includes at least part of said first arcuate surface, said
first planar surface, and at least part of said second arcuate
surface.
6. The forming tool of claim 5, wherein said die surface includes a
first edge planar surface connected to said first arcuate surface,
and a second edge planar surface connected to said second arcuate
surface.
7. The forming tool of claim 6, wherein said die surface includes a
third edge planar surface extending from said first edge planar
surface, and a fourth edge planar surface extending from said
second edge planar surface.
8. The forming tool of claim 4, wherein said center ram surface
includes a center ram first arcuate surface, a center ram planar
surface, and a center ram second arcuate surface, said center ram
planar surface interposed between said center ram first arcuate
surface and said center ram second arcuate surface.
9. The forming tool of claim 8, wherein said first outside ram
surface includes a first outside ram arcuate surface connected to a
first outside ram edge surface.
10. The forming tool of claim 9, wherein said second outside ram
surface includes a second outside ram arcuate surface connected to
a second outside ram edge surface.
11. A press for forming a workpiece, said press comprising: at
least one guidepost; a forming tool actuatable along said at least
one guidepost, said forming tool comprising: a die including a die
surface having a die center surface, a die first outer surface and
a die second outer surface, said die center surface in between said
die first outer surface and said die second outer surface; a center
ram including a center ram surface complimentary in shape to said
die center surface; a first outside ram including a first outside
ram surface complimentary in shape to said die first outer surface;
and a second outside ram including a second outside ram surface
complimentary in shape to said die second outer surface.
12. The press of claim 11, wherein said die surface includes a
first arcuate surface, a first planar surface and a second arcuate
surface, said first planar surface interposed between said first
arcuate surface and said second arcuate surface, said die center
surface includes at least part of said first arcuate surface, said
first planar surface, and at least part of said second arcuate
surface.
13. The press of claim 12, wherein said die surface includes a
first edge planar surface connected to said first arcuate surface,
and a second edge planar surface connected to said second arcuate
surface.
14. The press of claim 13, wherein said die surface includes a
third edge planar surface extending from said first edge planar
surface, and a fourth edge planar surface extending from said
second edge planar surface.
15. The press of claim 11, wherein said center ram surface includes
a center ram first arcuate surface, a center ram planar surface,
and a center ram second arcuate surface, said center ram planar
surface interposed between said center ram first arcuate surface
and said center ram second arcuate surface.
16. The press of claim 15, wherein said first outside ram surface
includes a first outside ram arcuate surface connected to a first
outside ram edge surface.
17. The press of claim 16, wherein said second outside ram surface
includes a second outside ram arcuate surface connected to a second
outside ram edge surface.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a non-provisional application based upon U.S.
provisional patent application Ser. No. 60/564,010, entitled
"MULTI-RAM PRESS AND METHOD OF METAL FORMING", filed Apr. 20,
2004.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to metal forming, and, more
particularly, to the forming of a reflector or reflector housing of
a light fixture.
[0004] 2. Description of the Related Art
[0005] Robert Hooke articulated in his 1678 treatise ut tensio sic
vis a relationship between elastic deformation and load which is
now known as Hooke's law, and which states, in its simplest form,
that stress is proportional to strain where stress is the force per
unit area in a body and strain is the axial deformation per unit
length of the same body. The constant of proportionality is known
as the modulus of elasticity, or Young's modulus, where
strain=stress/Young's modulus. For common metal materials such as
many steels, Hooke's law describes the elastic region of the
stress-strain curve associated with a particular steel where a
steel body at normal temperature regains its original shape, or
springs-back, upon the removal of the stress causing load.
[0006] Hooke's law holds up to a point where the material becomes
plastic (the point where the deformation (strain) of the material
is unrecovered) and this point is called yield tensile strength.
The plastic region terminates at the ultimate tensile strength of a
material which is the limit stress at which the material actually
breaks. In many steel constructions, the maximum allowable tensile
stress at any point in the construction is 2/3 of the yield
strength of the particular steel in order to provide a margin of
safety relative to potential fracture of the material.
[0007] In metal forming, there is known an apparatus for a method
of bending a channel section workpiece whereby a center projection
is moved with a counter pressure plate, with the workpiece in
between, against side formations which constrain the piece. A
desired double bending or joggle is created with no crinkling or
rippling of the member flanges and the extent of displacement of
the center section can be selectively adjusted to allow for
"spring-back" so that the final shape, when released from the
press, is within required tolerances even though the specification
of the metal, in particular its yield strength, may vary. However,
disadvantages of this apparatus include that it requires seven
rams, and a center projection is moved with a counter pressure
plate.
[0008] Also known is an apparatus for securing a piece of flat
sheet metal between two sets of outer vice plates, and center
pressure and counterpressure plates whereby the center plates move
vertically and the outer plates move horizontally to avoid
stretching the piece. A disadvantage of this apparatus is that it
is complicated by requiring center plates which move vertically and
outer plates which move horizontally.
[0009] In another known apparatus there is disclosed a molding die
of irregular-shape between a male die and a female die whereby a
pin in a male die extend to hold the sheet piece against the female
die while side parts shape the piece. Just before the end of the
molding, the pins go into the male die and mold the sharply bent
parts, and as a result, the sharply bent parts are molded. A
disadvantage of this apparatus is that it requires a pin in the
male die.
[0010] Another known metal forming system includes multiple die
forming stations in order to achieve a required final shape of the
formed part. Disadvantages of this kind of system include a high
capital cost for the multiple die forming stations, increased
manufacturing cycle time required by the transferring of the formed
part to the multiple stations, and a potential for quality problems
in the formed part due to the additional handling and multiple die
forming stations.
[0011] What is needed in the art is a metal forming apparatus and
method which forms a metal part with a minimum of die forming
stations, rams and operations, and relatively simple and
inexpensive dies and rams.
SUMMARY OF THE INVENTION
[0012] The present invention provides a single station method of
forming a reflector or reflector housing of a light fixture, or
other formed parts, which effectively eliminates spring-back in the
formed part.
[0013] The invention comprises, in one form thereof, a method of
forming a workpiece, including the steps of: providing a center
ram, a first outside ram, a second outside ram, and a die; pressing
the center ram against the workpiece and toward the die to a first
predetermined die depth; trapping the workpiece between the center
ram and the die; pressing the first outside ram and the second
outside ram against the workpiece and toward the die to a second
predetermined die depth; and stretching the workpiece beyond a
yield tensile strength of the workpiece material. The die includes
a die surface which has a first arcuate surface, a first planar
surface and a second arcuate surface, where the first planar
surface is interposed between the first arcuate surface and the
second arcuate surface. The die surface has a die center surface
which includes at least part of the first arcuate surface, the
first planar surface, and at least part of the second arcuate
surface. The center ram has a center ram surface which includes a
center ram first arcuate surface, a center ram planar surface, and
a center ram second arcuate surface where the center ram planar
surface is interposed between the center ram first arcuate surface
and the center ram second arcuate surface. The center ram surface
is complimentary in shape to the die center surface.
[0014] The invention comprises, in another form thereof, a forming
tool for forming a workpiece. The forming tool includes a die which
has a die surface with a die center surface, a die first outer
surface and a die second outer surface. The die center surface is
in between the die first outer surface and the die second outer
surface. The forming tool further includes a center ram, a first
outside ram and a second outside ram. The center ram has a center
ram surface complimentary in shape to the die center surface. The
first outside ram includes a first outside ram surface
complimentary in shape to the die first outer surface. The second
outside ram includes a second outside ram surface complimentary in
shape to the die second outer surface.
[0015] The invention comprises, in another form thereof, press for
forming a workpiece. The press includes at least one guidepost and
a forming tool actuatable along the at least one guidepost. The
forming tool includes a die which has a die surface with a die
center surface, a die first outer surface and a die second outer
surface. The die center surface is in between the die first outer
surface and the die second outer surface. The forming tool further
includes a center ram, a first outside ram and a second outside
ram. The center ram has a center ram surface complimentary in shape
to the die center surface. The first outside ram includes a first
outside ram surface complimentary in shape to the die first outer
surface. The second outside ram includes a second outside ram
surface complimentary in shape to the die second outer surface.
[0016] An advantage of the present invention is that the formed
workpiece is formed at a single workstation, which forming
operation previously required multiple workstations, and/or
multiple die forming stations in a single workstation.
[0017] Another advantage of the present invention is that, by
eliminating the need for multiple workstations, and/or multiple die
forming stations in a single workstation, which each include a
press and forming tool, the capital expense is reduced.
[0018] Yet another advantage of the present invention is that the
manufacturing cycle time for the formed workpiece is reduced.
[0019] Yet another advantage of the present invention is that the
manufacturing cost of the formed workpiece is reduced.
[0020] Yet another advantage of the present invention is that, by
eliminating the need for multiple workstations, and/or multiple die
forming stations in a single workstation, which each can include a
press and forming tool, extra handling of the formed workpiece and
transportation of the formed workpiece between workstations is
eliminated.
[0021] Yet another advantage of the present invention is that, by
minimizing the handling of the formed workpiece and transportation
of the formed workpiece, the quality of the formed workpiece
increases and the quality of the formed workpiece is also more
easily controllable.
[0022] Yet another advantage of the present invention is that, by
eliminating the need for multiple workstations, and/or multiple die
forming stations in a single workstation, which each can include
manufacturing tolerances and errors associated therewith, the
quality of the formed workpiece increases and the quality of the
formed workpiece is also more easily controllable.
[0023] Yet another advantage of the present invention is that, by
eliminating the need for multiple workstations, fewer operators are
needed to form the workpiece and/or the operator(s) can spend more
time monitoring tooling trends and product quality in order to
prevent product defects, for example.
[0024] Yet another advantage of the present invention is that press
operator training costs are reduced.
[0025] Yet another advantage of the present invention is that
energy costs associated with forming the workpiece are reduced.
[0026] Yet another advantage of the present invention is that
overhead expenses associated with forming the workpiece are
reduced.
[0027] Yet another advantage of the present invention is that work
in process inventory associated with forming the workpiece is
reduced.
[0028] Yet another advantage of the present invention is that
required manufacturing maintenance costs associated with forming
the workpiece are reduced.
[0029] Yet another advantage of the present invention is that
maintenance, repair and operations (MRO) inventory costs associated
with forming the workpiece are reduced.
[0030] Yet another advantage is that the forming tool of the
present invention is relatively simple and inexpensive to
manufacture and maintain.
[0031] Yet another advantage of the present invention is that, by
reducing the manufacturing cycle time associated with forming the
workpiece, finished goods inventory can be reduced since the
manufacturing system is now more responsive to customer demand.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The above-mentioned and other features and advantages of
this invention, and the manner of attaining them, will become more
apparent and the invention will be better understood by reference
to the following description of embodiments of the invention taken
in conjunction with the accompanying drawings, wherein:
[0033] FIG. 1 is a perspective view of an embodiment of a press and
forming tool according to the present invention;
[0034] FIG. 2 is a perspective view of an embodiment of a formed
workpiece formed using the press and forming tool of FIG. 1;
[0035] FIG. 3 is a front, partially fragmentary view of the press
and forming tool of FIG. 1 with the workpiece sheetmetal blank
inserted between the rams and die of the forming tool;
[0036] FIG. 4 is a front, partially fragmentary view of the press
and forming tool of FIG. 1 with the workpiece inserted between the
rams and die of the forming tool, and with the center ram engaging
the workpiece; and
[0037] FIG. 5 is a front, partially fragmentary view of the press
and forming tool of FIG. 1 with the workpiece inserted between the
rams and die of the forming tool, and with the center ram and the
outside rams engaging the workpiece.
[0038] Corresponding reference characters indicate corresponding
parts throughout the several views. The exemplifications set out
herein illustrate one preferred embodiment of the invention, in one
form, and such exemplifications are not to be construed as limiting
the scope of the invention in any manner.
DETAILED DESCRIPTION OF THE INVENTION
[0039] Referring now to the drawings, and more particularly to
FIGS. 1 and 2, there is shown a press 10 for forming a workpiece
12. Press 10 generally includes at least one guidepost 14 and a
forming tool 16 actuatable along the at least one guidepost 14.
[0040] Workpiece 12 is shown in its formed or finished state in
FIG. 2. Workpiece 12 can be of any bendable material, and
particularly can be of a metal material such as steel or aluminum,
but the material of workpiece 12 is not limited to metals. In the
embodiment shown in FIG. 2, workpiece 12 is in the form of a
reflector or reflector housing such as is used in a light fixture,
particularly a fluorescent light fixture, but is not limited to
such a form.
[0041] Shown particularly in FIGS. 3-5, forming tool 16 includes a
die 18 with a die surface 20 which has a die center surface 22, a
die first outer surface 24 and a die second outer surface 26. Die
center surface 22 is in between die first outer surface 24 and die
second outer surface 26. A center ram 28 includes a center ram
surface 30 complimentary in shape to die center surface 22. A first
outside ram 32 has a first outside ram surface 34 complimentary in
shape to die first outer surface 24. A second outside ram 36 has a
second outside ram surface 38 complimentary in shape to die second
outer surface 26.
[0042] In one embodiment, die surface 20 further includes a first
arcuate surface 40, a first planar surface 42 and a second arcuate
surface 44. First planar surface 42 is interposed between first
arcuate surface 40 and second arcuate surface 44. Die center
surface 22 includes at least part of first arcuate surface 40,
first planar surface 42, and at least part of second arcuate
surface 44. Die surface 20 further includes a first edge planar
surface 46 connected to first arcuate surface 40, and a second edge
planar surface 48 connected to second arcuate surface 44. Die
surface 20 can also have a third edge planar surface 50 which
extends from first edge planar surface 46 at an angle of
approximately 90.degree., for example, but other angles are
possible. Fourth edge planar surface 52 extends from second edge
planar surface 48, also at an angle.
[0043] Center ram surface 30 includes a center ram first arcuate
surface 54, a center ram planar surface 56, and a center ram second
arcuate surface 58. Center ram planar surface 56 is interposed
between center ram first arcuate surface 54 and center ram second
arcuate surface 58. First outside ram surface 34 includes a first
outside ram arcuate surface 60 connected to a first outside ram
edge surface 62. Similarly, second outside ram surface 38 includes
a second outside ram arcuate surface 64 connected to a second
outside ram edge surface 66.
[0044] All of the arcuate surfaces of forming tool 16 can have
profiles which are circular, parabolic, elliptical, some
combination thereof, and/or other complex curvatures.
[0045] Guideposts 14 are as known in the forming processes' art as
related to press apparatus.
[0046] In use, the method of the present invention is generally
shown sequentially in FIGS. 3-5 where FIG. 3 shows the blank of
workpiece 12, which can be a sheet metal such as steel, or other
bendable materials. The blank of workpiece 12 is placed between die
18 and rams 28, 32 and 36. In FIG. 4, center ram 28 is pressed
against workpiece 12 and toward die 18 to a first predetermined die
depth 68, which is approximately die center surface 22 plus the
thickness of the material of workpiece 12. In FIG. 5, while center
ram 28 traps workpiece 12 against die 18, outside rams 32, 36 are
pressed against workpiece 12 and toward die 18 to a second
predetermined die depth 70, which is approximately die first outer
surface 24 or die second outer surface 26, plus the thickness of
the material of workpiece 12.
[0047] More particularly, the present invention discloses a method
of forming a workpiece, including the steps of: providing center
ram 28, first outside ram 32, second outside ram 36, and die 18,
and particularly with center ram surface 30 being complimentary in
shape to die center surface 22; pressing center ram 28 against
workpiece 12 and toward die 18 to first predetermined die depth 68;
trapping workpiece 12 between center ram 28 and die 18; pressing
first outside ram 32 and second outside ram 36 against workpiece 12
and toward die 18 to second predetermined die depth 70; and
stretching workpiece 12 beyond a yield tensile strength of the
workpiece 12 material using die 18, center ram 28, first outside
ram 32 and second outside ram 36.
[0048] The method of the present invention can further include the
steps of forming workpiece 12 in a shape complimentary to surface
20 of die 18; and eliminating a spring-back in workpiece 12.
[0049] While the yield tensile strength of the material of
workpiece 12 is exceeded, the ultimate tensile strength of the
material of workpiece 12 is not exceeded, thereby avoiding both
spring-back in workpiece 12 after forming, and fracture of the
material of workpiece 12 thereby achieving the form of workpiece 12
as shown in FIG. 2, for example, in a single press 10 workstation
with a single die forming station.
[0050] While this invention has been described as having a
preferred design, the present invention can be further modified
within the spirit and scope of this disclosure. This application is
therefore intended to cover any variations, uses, or adaptations of
the invention using its general principles. Further, this
application is intended to cover such departures from the present
disclosure as come within known or customary practice in the art to
which this invention pertains and which fall within the limits of
the appended claims.
* * * * *