Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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5729
~ETHOD OF MANUFACTURING A CURED TIRE
This invention relates to a method of manufacturing a cured
,.,
tire. I
Heretofore, it has been common to form raised lettering on a
5 tire by utili~ing a mold having recesses which form the raised
letters on the tire, and the raised letters are cured integrally with
the tire when the tire is cured. Tires have also been made with
recessed lettering thereon formed during curing by raised portions
of the mold. Such molds, however, are expensive to manufacture.
10 Tires have also been made which have recessed markings placed
thereon after curing by hot or cold brandin~ techniques which
generally do not provide sufficiently accurate markings.
It is an object of the present invention, therefore, to provide
a new and improved method of manufacturing a cured tire which
~;15 avoids one or more of the above-mentioned disadvantages and limita-
3tions of prior methods of manufactùring tires.
In accordance with the invention, the method of manufacturing
a cured tire comprises classifying the tire after curing, exposing
the cured tire to a laser beam after classification, and changing the
20 relative positions of the laser beam and the tire in such manner as
to cause the laser beam to engrave the surface of the tire after
classification in accordance with the classification.
For a better understanding of the present invention, together
with other and further obj ects thereof, reference is made to the
2 5 following description, taken in connection with the accompanying
drawings, and its scope will be pointed out in the appended claims.
Referring now to the drawings:
Fig. 1 is a perspective view, partly diagrammatic, of apparatus
useful in the method of the present invention;
30Fig. 2 i6 an enlarged, fragmentary view of an engraved letter
- on a cured tire;
Fig. 3 i6 an enlarged, fragmentary, sectional view, partly
diagrammatic, of the Fig. 1 apparatus engraving a tire;
Fig. 3a is an enlarged, fragmentary, sectional view, partly
35 diagrammatic, of a laser beam from the Fig. 1 apparatus engraving
a tire; "~"
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Fig. 4 is an enlarged, sectional view of a portion af a cured
tire having a groove laser-engraved therein; and
Fig. 5 is a fragmentary, perspective view, partly diagramma-
tic, of apparatus usef~l in the method of engraving the tread
surface o~ a cured ~ire I in accordance with the present invention.
Referring IlOW more particularly to Fig. 1 of the drawings, a
cured pneumatic tire 10 of standard construction is mounted by
means of a conventional chuck mechanism 10a shown in simplified
form, on the shaft of a motor 11. The motor 11 preferably i6
mounted on a conventional 3 axis mill 12 for motion in the x, y,
and z directions. The mill 12 may, for example, be a 3~axis numer-
ical control tape controlled mill of a type so]d by Boston Digital
Corporation, Holliston, Massachusetts under the trademark Bosto-
t Matic.
A commeraally available industrial laser 13, for example, of
the Everlase 150, a trademark, CO2 type sold by Coherent Radiation
-~ Co., Palo Alto, California, is positioned for volatilizing the surface
of the tire with its laser beam.
The method of engraving the cured tire 10 comprises exposing
2 the cured tire to a laser beam and changing the relative positions
of the laser beam and the tire in such manner as to cause the laser
beam to engrave the surface of the tire. The mill 12 and motor 11
of Fig. 1 preferably are controlled to change the position of the
tire relative to the laser beam to cause the laser beam to engrave
2 5 the sidewall surface of the tire .
In Fig. 1 the laser beam has engraved the indicia U N in the
form of recessed letters on the sidewall as part of the brand name
UNIROYAL, a registered trademark of Uniroyal, Inc.
The letter N is shown in enlarged view in Fig. 2, where it will
- 3 be seen that the border 14 of the letter is a groove of the cross-
sectional shape generally represented in Fig. 4. The groove may,
for example, be .060 inch deep and .050 inch wide at the top of the
i~ groove. As represented in Fig. 2 the portion 15 of the letter N
enclosed within the grooved border 14 is not recessed. However,
35 the width and depth of the groove may be readily controlled as
represented in Fig. 3 by adjustably positioning the tube 16 which
holds lens 17 of the laser to change the position of the ~ocal point
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18 of the laser beam 19 and thereby control the size of the beam
which strikes the surface of the tire. In some cases, the enffre
surface of the letter N may be recessed.
The cured tire may be marked with the brand name after
5 classification for unliforlLity or for blemishes or the like. The
brand name may be selected in accordance with the classification of
the tire. Tires from the same mold and with a similar appearance
may be given different brand names, if desired.
Laser engraving of the cured tire may also form, for example,
0 a logo, a signature, a picture or decorative recessed pattern in the
sidewall surface. Also, a brand name may be modified by, for
example, molding a one-word portion of the name and adding a
second word by laser engraving after the tire has been cured.
The depth of recessed letters on the sidewall of the tire may
15 be controlled, for example, by appropriate control of pulsed opera-
- tion of the laser beam or control of the relative speed of motion of
the tire. Color contrast between the recessed letters and the
background may be provided by, for example, engraving through a
black cover strip over a white sidewall layer to expose recessed
20 white letters against a black background. As represented in Fig.
3a, the laser beam 19 has a focal point 18 adjusted to cause the
beam to engrave through a black cover strip 24 over a white side-
wall layer 25 to expose a recessed white border 14a similar to the
border 14 of a letter such as represented in Fig. 2.
Referring now to Fig. 5 of the drawings, the cured tire may
be classified for uniformity, blemishes or the like and after classifi-
cation the cured tire 21 may be mounted for rotation by a suitable
chuck mechanism 21a, shown in simplified form, on the shaft of a
motor 20 mounted on a 3-axis numerical control tape-controlled mill
3 23. The method includes the step of exposing the tread surface of
the tire to a laser beam and the step of changing the relaffve
positions of the laser beam and the tire in such manner as to cause ~ t
i ~ the laser beam to cut the tread surface of the tire. As representedin Fig. 5, the laser beam may engrave slits 22 or sipes in the tread
35 surface, thereby giving the tire a different appearance and perfor-
mance. The laser beam may also be adjusted to engrave wider
grooves in the tread surface. Thus, an existing tread surface
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pattern may be modified, after dassification of the tire, in accor
dance with the classification or a tread having no pattern thereon
may be laser-engraved with a pattern after classification o~ the
tire, in accordance with the classification.
The method of mahufacturing a plurality of tires comprises
.` curing a plurality of tires in one or more molds of the same prede-
termined configuration. The method comprises exposing individually
a first group of selected cured tires to a laser beam and changing
the relative positions of the laser beam and the individual selected
10 tires of the first group to engrave an indicium representative of the
first group of selected tires into the individual selected tires.
Indicia representative of the first group of selected tires may be a
first brand name.
T he method also comprises exposing individually a second
15 group of selected cured tires to a laser beam and changing the
relative positions of the laser beam and the individual selected tires
of the second group to engrave an indicium representative of the
second group of selected tires into the individual selected tires of
the second group. Indicia representative of the second group of
20 selected tires may be a second brand name.
While there have been described what are at present believed
to be the preferred embodiments of this invention, it will be obvious
to those skilled in the art that various changes and modifications
may be made therein without departing from the invention, and it
25 is, therefore, aimed to cover all such changes and modifications as
fall within the true spirit and scope of the invention.
