U.S. patent application number 10/336269 was filed with the patent office on 2003-06-05 for composite blade.
This patent application is currently assigned to Goodyear Tire & Rubber Company. Invention is credited to Domange, Andre, Louis, Patrick.
Application Number | 20030101851 10/336269 |
Document ID | / |
Family ID | 25218749 |
Filed Date | 2003-06-05 |
United States Patent
Application |
20030101851 |
Kind Code |
A1 |
Domange, Andre ; et
al. |
June 5, 2003 |
Composite blade
Abstract
Method of manufacturing a composite blade (300 through 313)
having at least two blade portions (101, 201), for a tire curing
mold having the steps of providing a first strip (100) of metallic
material commonly used to form blades for tire curing molds;
stamping or punching out from the strip various shapes to make main
blade portions (101); providing a second strip (200) of metallic
material; stamping or punching out from the second strip (200) a
further set of blade portions (201) having a longitudinal and
lateral dimensions which are preferably at most equal to those of
the first blade portions (101), assembling at least one of the
first and at least one of the second blade portions (201); and
affixing the different blade portions (101, 201) together.
Inventors: |
Domange, Andre; (Etalle,
BE) ; Louis, Patrick; (Bastogne, BE) |
Correspondence
Address: |
The Goodyear Tire & Rubber Company
Patent & Trademark Department - D/823
1144 East Market Street
Akron
OH
44316-0001
US
|
Assignee: |
Goodyear Tire & Rubber
Company
|
Family ID: |
25218749 |
Appl. No.: |
10/336269 |
Filed: |
January 3, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10336269 |
Jan 3, 2003 |
|
|
|
09815754 |
Mar 23, 2001 |
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Current U.S.
Class: |
76/101.1 |
Current CPC
Class: |
B29D 2030/0613 20130101;
B29D 30/0606 20130101 |
Class at
Publication: |
76/101.1 |
International
Class: |
B21K 021/00 |
Claims
What is claimed is:
1. Method of manufacturing a composite blade having at least two
blade portions for a tire curing mold comprising the steps of:
providing a first strip of metallic material commonly used to form
blades for tire curing molds; stamping or punching out from the
strip various shapes to make main blade portions; providing a
second strip of metallic material; stamping or punching out from
the second strip a set of second blade portions having longitudinal
and lateral dimensions; assembling a main portion and at least one
of the second blade portions; and affixing the different blade
portions together to form the composite blade.
2. The method according to claim 1 wherein the blade portions are
affixed by the steps of welding or soldering the blade portions
together.
3. The method according to claim 1 comprising the further step of
providing further strips of metallic material; stamping or punching
out from the further strips sets of blade portions having a
longitudinal and lateral dimensions which are preferably at most
equal to those of the main blade portions; assembling a main and at
least one of the second blade portions together with at least one
of the further portions; and affixing the different blade portions
together.
4. A composite blade obtained through the method of any of claim
1.
5. The composite blade according to claim 4 wherein the second
strip of metallic material has the same thickness as the first
strip.
6. The composite blade according to claim 4 wherein the metal of
the second strip of metallic material has the same compositions as
the first strip.
7. The composite blade according to claim 4 wherein the composite
blades have any number of slots or cuts to form various
projections.
8. A mold including a blade according to claim 1.
9. Tire cured in a mold according to claim 1.
Description
TECHNICAL FIELD
[0001] The present invention relates to blades for curing molds.
More particularly to composite type blades that have thicknesses
which can easily be tailored to the tire tread property
requirements and a method of fabricating such composite blades.
BACKGROUND OF THE INVENTION
[0002] Blades for tire curing molds are well known in the art of
tire manufacture. Such blades are conventionally made from a
running length or strip of a metallic material such as steel,
stainless steel or brass. The strip is generally about 0.4 mm to 1
mm thick and has a length of about 10 to 40 mm. Sometimes the
strips are of solid form; other times perforated strips are used to
form the blades.
[0003] U.S. Pat. No. 3,880,020, a method and apparatus for making
blades, is disclosed which enables small quantity lots of a
multiplicity of different styles of blades to be made rapidly and
economically. The method and apparatus permits blades to be blanked
out from the stack of material by a plurality of punch and die sets
while the stock remains securely attached to an endless loop
carrier. If so desired, a plurality of sub-presses are used for
forming bends in the blade.
[0004] In U.S. Pat. No. 3,581,535, a similar method and apparatus
for making blades is disclosed. The method and apparatus for making
blades for use in tire molds includes piercing, notching, bending
or otherwise altering the shape of a free end of strip material by
successively positioning the free end and a plurality of shape
altering tools in operative engagement and cutting off the formed
blade from the free end. Bends, cuts, notches and holes are
possible.
[0005] WO 99/21701 discloses a method of fabricating a composite
blade employing the steps of forming a blade blank and
encapsulating at least one end in a second material by placing the
end in a die and molding an enlarged cross-section of a second
material around the end. Preferably, the second material is a
powdered metal.
[0006] The blades create sipes in a tread during the vulcanization
step of a green tire in a curing mold. A sipe is a narrow groove or
incision in the tread and closes when located in the footprint,
i.e., in the contact patch of the tire tread with a flat surface at
zero speed and under normal load and inflation pressure. The sipes
may extend circumferentially or laterally about the tread in a
straight, curved or zig-zag manner and may be as deep as the block
and rib defining grooves. The sipes may pass through or cut one or
both sides of the ribs and blocks or be confined to their interior.
It is also known to have the sipes lying in planes which are not
perpendicular to tangents to the surface of the tread at their
point of intersection. It is further known to use sipes having a
depth which varies along their length as well as sipes which have
varying thicknesses. However, the manufacturing of such blades is
expensive and lacks flexibility.
[0007] It is an object of the present invention to provide a
manufacturing process for making a set of blades having different
thicknesses.
[0008] It is a further object of the present invention to provide a
manufacturing process for making blades having varying thicknesses
along their length.
[0009] It is a further object of the present invention to provide a
manufacturing process for making blades having varying thicknesses
along their depth.
[0010] It is a still further object of the present invention to
provide a mold for vulcanizing a tire as well as tire vulcanized in
such mold.
SUMMARY OF THE INVENTION
[0011] The invention provides a method of manufacturing a composite
blade having at least two blade portions for a tire curing mold
comprising the steps of: providing a first strip of metallic
material commonly used to form blades for tire curing molds;
stamping or punching out from the strip various shapes to make main
blade portions; providing a second strip of metallic material;
stamping or punching out from the second strip a set of second
blade portions having longitudinal and lateral dimensions;
assembling a main portion and at least one of the second blade
portions; and affixing the different blade portions together to
form the composite blade.
[0012] Preferably, the blade portions are affixed by the step of
welding or soldering the blade portions together.
[0013] The method further may have the steps of providing further
strips of metallic material; stamping or punching out from the
further strips further sets of blade portions having a longitudinal
and lateral dimensions which are preferably at most equal to those
of the main blade portions; assembling a main and at least one of
the second blade portions together with at least one of the further
portions; and affixing the different blade portions together. A
composite blade obtained through the method is also disclosed.
[0014] In one embodiment the second strip of metallic material has
the same thickness as the first strip and the metal of the second
strip of metallic material has the same composition as the first
strip. The composite blades may have any number of slots or cuts to
form various projections.
[0015] A mold including the blade and a tire cured in the mold are
also disclosed.
[0016] To acquaint persons skilled in the art, most closely related
to the instant invention, certain preferred embodiments are now
described with reference to the annexed drawings. These embodiments
are illustrative and can be modified in numerous ways within the
scope of the invention defined in the claims.
BRIEF DESCRIPTION OF THE FIGURES
[0017] FIG. 1 is a view of a first strip used to form the main
portion of the composite blade according to the invention;
[0018] FIGS. 2 to 4 show various main portions of differing shapes
used in assembling the composite blades according to the
invention.
[0019] FIG. 5 is a view of a second strip used to form second
portions of the composite blade according to the invention;
[0020] FIGS. 6 to 10 show various second blade portions of
differing shapes used in assembling the blades according to the
invention;
[0021] FIGS. 11 to 17 are views of substantially flat composite
blades obtained by using the process according to the
invention;
[0022] FIGS. 18 to 20 are side views of composite blades having
varying depths obtained by using the process according to the
invention;
[0023] FIGS. 20 to 23 are top views on composite blades according
to the invention; and
[0024] FIGS. 24 to 25 are schematic sections across a block of
rubbery tread material.
DETAILED DESCRIPTION OF THE INVENTION
[0025] With reference to FIG. 1, a portion of a first strip (100)
of metallic material commonly used to form blades for tire curing
molds is shown. The resultant blades are stamped or punched out
from the strip (100) and take various shapes as shown in FIGS. 2 to
4. The blades may have any number of slots (120) or cuts (121) to
form the various projections (122). The blades may be wavy as shown
in FIG. 3 or have bends at their extremities (see FIG. 4). These
features are well known in the tire building art and such blades
are used as main portion of the composite blade according to the
invention.
[0026] According to the invention and with reference to FIGS. 5 to
10, a second strip (200) of metallic material commonly used to form
blades for tire curing molds is stamped or punched to form a second
set of blade portions out from the strip (200) which may take
various shapes as shown in FIGS. 6 to 10. This second strip (200)
of metallic material may have the same thickness as the first strip
(100), a somewhat higher or smaller thickness. Usually the
thickness of the first strip (100) ranges between 0.3 and 1 mm and
the thickness of the second strip (200) between 0.3 and 0.8 mm. The
metallic material of the second strip (200) may be the same as the
one of the first strip (100). Preferred metallic material is steel
because of its low cost. Further materials of interest are
aluminum, nickel alloy, and titanium. Combinations of carbon steel
constituting the first strip (100) with titanium or other metals
containing steel alloys constituting the second strip (200) would
allow a great flexibility in the choice of the blade portion
thicknesses.
[0027] The main blade portion (101) made out of the first strip
(100) is usually at least partly anchored in the mold by holes (21)
(see FIG. 2). This anchoring must be sufficient to insure that the
composite blades do not pull out when the tread is extracted from
the tire curing mold. The blade portion (201) made out of the
second strip (200) is or is not anchored in the mold, depending on
the design of the blade.
[0028] The second blade portions (201) made out of the second strip
(200) may take the shape of a rectangle (FIG. 6), parallelogram
(FIG. 7), triangle (FIG. 9), trapezoid (FIG. 10) and may basically
have any geometrical shape which is considered by a man skilled in
the art to confer favorable properties to the tire tread. They may
be flat as shown in FIGS. 6 and 7, or they may be given a curved or
wavy shape as shown in FIG. 8, depending on the fact that they will
be assembled to a corresponding flat, curved or wavy main portion
obtained out of the first strip (100). Alternatively the main
portion (101) and the second portion (201) may be given at first a
flat shape and after assembly stamped in order to obtain the
desired wavy, sinusoidal or crimped or similar shape.
[0029] After assembly, the main and second blade portions (101,
201) are affixed together. This may be done by gluing using a high
temperature epoxy adhesive or a high temperature cement. Another
possibility is to subject the assembled portions to a combined
compression and heat treatment. A still further possibility is to
braze or solder the two portions. The presently preferred way is to
weld the different portions together along their lateral adjacent
sides, or at multiple points called "spot welding".
[0030] The composite blades (300 through 312), according to the
invention, may be fabricated at low cost in a great variety of
shapes. FIGS. 11 through 23 illustrate a few of these exemplary
shapes, featuring different depths, widths and lengths. FIG. 11
shows a blade (300) providing a sipe having a greater width in its
radially middle portion, FIG. 12 shows a blade (301) having
substantially a width double to the one offered by single metallic
strips (100) or (200). FIGS. 13, 14 and 15 show blades (302, 303,
304) providing sipes with laterally stepped off widths, allowing to
tailor the elastomeric block stiffness to the requirements; such
sipes influence locally transverse deformation of the blocks they
are included in. FIG. 16 shows a blade (305) providing a sipe
having on part of its lateral length and on part of its radially
inner portion, a higher width. FIG. 17 shows a blade (306)
producing a sipe having on part of its length a higher width, which
length decreases towards the tread surface. FIG. 18 shows a blade
(307) providing a sipe having on both sides a higher width and a
depth decreasing from both sides towards the center. FIG. 19 shows
a blade (308) providing a sipe having a first side a higher width
and a depth decreasing towards the second side. FIG. 20 shows a
blade (309) providing a sipe having a lateral length decreasing
radially towards the tread bottom and a higher sipe width portion
with a width and length remaining constant.
[0031] It must be appreciated that some of the composite blades
obtained through the method according to the invention result in
rather complicated blade layouts despite the fact that the
manufacturing steps are simple.
[0032] As more specifically illustrated in FIGS. 21 and 22, the
blades (310, 311) obtained according to the method of the invention
may include the steps of bending. The bending step may take place
before or after assembly of the different blade portions. The
blades may further be crimped, notching or perforated before or
after assembly. In FIG. 23 a blade (312) is shown where only part
of the two metal sheets (101 and 201) overlap. The sheets (101) and
(201) can have the same height or different heights.
[0033] With reference to FIGS. 24 and 25, the possibility of making
interlocking sipes in the tread blocks is illustrated. For ease of
representation, only one sipe per block (241, 251) is shown and the
block and grooves are not to scale. It is understood that a block
includes usually several sipes. In the instant case, the further
sipes may have the same section than the one shown in the drawing.
In FIG. 24 a block (241) is defined by laterally and
circumferentially extending grooves (242), wherefrom only one kind
can be represented in this cross-section. The block (241) includes
sipe (245) which has in the case of the drawing throughout its
height, substantially uniform thickness. However, slightly above
half-height, the sipe (245) shows a protrusion (243) on one side
and a recess (247) on the other. Such sipe (245) is easily obtained
according to the inventive method by assembling to the radially
outer part of a first side of a main portion (101) as shown in FIG.
2, a second blade portion (201) as shown in FIG. 6; a further
similar second blade portion (201), as shown in FIG. 6 is assembled
to the radially inner part of main portion (101).
[0034] It can be easily seen that if there is block deformation as
indicated by arrow A, the protrusion (243) located on one side of
the sipe, advances towards recess (247) on the other side of the
sipe, until it is in contact with such. Once in contact, protrusion
(243) opposes any further deformation of the block (245). Opposite
deformation does not result in such interlocking and the two
adjacent sipe sidewalls may slide along each other as far as
allowed by the rigidity of the rubbery material and the forces
applied thereto. It appears that such sipe is directional. It
appears further that such interlocking stops when the tire is worn
down to the protrusion (243). At that time the stiffness of the
block has increased and a limiting of flexing is no more
desired.
[0035] With reference to FIG. 25, the possibility of making
bi-directional interlocking sipes (255) in the tread blocks (251)
is illustrated. Also, in this case only one sipe per block is shown
for ease of representation. Furthermore, the different elements are
not to scale. In FIG. 25, a block (251) is defined by laterally and
circumferentially extending grooves (252). The block includes sipe
(255) which has in the case of the drawing throughout its height,
substantially uniform thickness. However, slightly above
half-height, the sipe shows a protrusion (254) on one side and a
recess (253) on the other. Such sipe is easily obtained according
to the inventive method by assembling to a main portion (101) as
shown in FIG. 2, two blade portion as shown in FIG. 6, to one side,
and more specifically a first one (101) to its radially outer
portion and a second one (201) to its radially inner portion,
leaving a free portion in the middle of the main portion (101),
which free portion defines in the cured tire the protrusion (254).
On the middle portion of the other side of the main portion (101) a
blade portion (201) as shown in FIG. 6 is assembled, which blade
portion defines the recess (253) in the cured tire.
[0036] It can be easily seen that if there is block deformation in
a direction indicated by arrow A or in the opposite direction,
protruding rubbery material (254) will move towards recess (253) on
the other side of the sipe, until it nests into recess (253)
opposing any further deformation on the block (251). The amount of
deformation required to have such interlocking depends on the width
of the sipe and on the layout, mainly transverse dimensions, of the
recess and the protrusion. It appears that such sipe has no
directional effect in a new tire. Once the tire is about half worn
down, the sipe will have substantially a cross-section which can be
compared to that shown in FIG. 24 and its behavior will be, as
explained in connection with FIG. 24.
[0037] In case of the sipes shown in FIGS. 24 and 25, the loss due
to wear of the non-directional interlocking FIG. 24) or the change
from non-directional to directional of the interlocking (FIG. 25)
may be controlled by giving the recess (247, 253) and similarly the
protrusion (243, 254) a small inclination. This can easily be
implemented by assembling second blade portions (201), as shown in
FIG. 7 to the main portion (101) of the composite blade (300
through 312).
* * * * *