Adhesive bonding and miscellaneous chemical manufacture – Surface bonding means and/or assembly means therefor – Tire body building type
Reexamination Certificate
2001-06-05
2004-05-25
Knable, Geoffrey L (Department: 1733)
Adhesive bonding and miscellaneous chemical manufacture
Surface bonding means and/or assembly means therefor
Tire body building type
C156S414000, C156S417000
Reexamination Certificate
active
06739366
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a tire building apparatus, and more particularly to tire building apparatus laminating uncured materials such as a belt material, a tread rubber material and the like onto a green case for a radial ply tire and capable of particularly positioning an accurate centering of a green case transferred from another building apparatus.
2. Description of Related Art
A tire building apparatus conducting the building at two stage is as follows.
That is, a tire building apparatus of a first stage laminates an innerliner rubber material, a radial carcass ply material, a bead core material and rubber materials surrounding them (a bead filler rubber or a stiffener rubber, and a chafer rubber) and, if necessary, a sidewall rubber material together to form a cylindrical green case. In this case, all materials are uncured materials and so forth on.
Then, outlines of two conventional tire building apparatuses
50
,
50
A of a second stage are described with reference to
FIGS. 5 and 6
, wherein such apparatuses are shown as a right-half section of their main part in
FIGS. 5 and 6
, respectively. Each of the building apparatuses
50
,
50
A comprises a pair of grasping members
52
,
53
airtightly grasping an expandable cylindrical bladder
51
, and a group of many segments
54
each slidably engaging with the outer grasping member
53
. They form a building drum.
And also, each of the building apparatuses
50
,
55
A comprises a pair of ring-shaped pistons
55
,
55
A engaging with the group of these segments
54
and enlarging each segment
54
by its inward movement along a rotating axial line X, and a pair of opposed double-wall cylinders
56
slidably housing the pistons
55
,
55
A therein. Each of the segments
54
is provided on a side of an outer periphery with a flange
54
f
located inward in the direction of the rotating axis X.
In the apparatuses
50
,
50
A shown in
FIGS. 5 and 6
, the piston
55
,
55
A locates at an operating standby position. The cylinder
56
has a space
56
S at a back side of the piston
55
,
55
A. The space
56
S is connected to a supply means of a pressurized gas such as pressurized air or the like (not shown) and a vacuum means (not shown). The piston
55
,
55
A is provided with a slant face
55
s
,
55
As taperingly extending toward an inward top in the direction of the rotating axis. On the other hand, each of the segments
54
has a disc
54
d
rotatably contacting with the slant face
55
s
,
55
As.
The tire building using the apparatuses
50
,
50
A will be described simply below. At first, a green case GC is transferred by a ring-shaped grasping device (shown by a phantom line) grasping the green case from its outside to an outer peripheral side of the bladder
51
and subjected to a centering with respect to the group of the segments
54
. At a state of holding the green case, the piston
55
,
55
A is moved inward in the rotating axial direction by supplying the pressurized gas to the space
56
S.
The disc
54
d
rises on the slant face
55
s
,
55
As accompanied with the above movement. Thus, the group of the segments
54
is enlarged in the radial direction, whereby each of the flanges
54
f
is located inward in the vicinity of each bead portion Bp of the green case GC. In this case, the outer peripheral face
54
os
of each segment
54
is separated away from the inner face of the bead portion Bp. This is a first stage of enlarging the segments
54
.
Thereafter, the group of the segments
54
is moved outward in the direction of the rotating axis X to enlarge the segments in the radial direction and hence widen a width of the building drum, whereby each of the flanges
54
f
is pushed onto the inside of the bead portion Bp in the green case GC. Then, the group of the segments
54
is further enlarged in the radial direction to push the outer peripheral face
54
os
of the segment
54
to the inner face of the bead portion Bp, whereby the pair of the bead portions Bp are engaged with the group of the segments
54
. This is a final stage of enlarging the segments
54
in the radial direction. As such a state, the green case GC is released from the grasping device
60
and moved into a subsequent building step.
In case of the apparatus
50
shown in
FIG. 5
, however, even if a pressure of the pressurized gas to be supplied to the space
56
S is adjusted by any processes in a gas supplying source, a space required between the outer peripheral face
54
os
of the segment
54
and the inner face of the bead portion Bp can not be ensured due to the scattering of the adjusted pressure and the scattering of slide resistance of the piston
55
and hence both faces are at a state of contacting with each other. When the width of the building drum is widened at such a state, there is caused a large change in the centering of the green case GC with respect to the building drum through the grasping device
60
.
In this connection, the apparatus
50
A shown in
FIG. 6
has a merit that the change in the centering is made smaller than that in the apparatus
50
. That is, the piston
55
A of the apparatus
50
A has such a structure that the slant face
55
As is divided into two slant face portions
55
As-
1
and
55
As-
2
and a flat face portion
55
Asf is positioned between the slant face portions. Thus, it is intended to control a quantity of each segment
54
enlarged to a given value on the flat face portion
55
Asf. Even in this case, however, it can not be avoided to have an influence by the scattering of the adjusted pressure and the scattering of slide resistance of the piston
55
, so that it is not ensured to stay the rotatably contacting disc
54
d
on the flat face portion
55
Asf. As a result, there is caused a big change of the centering, which is said to be smaller than that of the apparatus
50
but can not overlook at all.
Such a change of the centering brings about the occurrence of poor uniformity in a tire after an uncured tire is subjected to tire building through vulcanization. This type of the centering change occurs over all tires. Particularly, in case of a tire having a structure that a carcass ply is not arranged in at least a central region of a tread portion, an elongation of a portion not existing the carcass ply in the direction of the rotating axis X becomes large and hence the change of the centering is considerably large, which is a serious problem.
SUMMARY OF THE INVENTION
It is, therefore, an object of the invention to provide an apparatus eliminating all of the aforementioned problems, concretely a tire building apparatus capable of accurately and easily holding a centering of a green case transferred to a given position and positioned once to a building drum even if there are existent various scattering factors in the operation of the building apparatus and completely eliminating poor tire uniformity due to the change of the centering.
According to the invention, there is the provision of a tire building apparatus comprising a group of many segments enlarging a size in a radial direction to pushingly lock a bead portion of a green tire, a ring-shaped inner piston engaging with the segments of such a group and moving inward in a direction of an axial line to enlarge the size of each of the segments, a ring-shaped outer piston contacting and engaging with a back face of the inner piston to move the inner piston inward in the direction of the axial line, a cylinder slidably housing the inner piston and the outer piston in its double wall, a pair of gas pressure acting means moving each of the inner piston and outer piston housed in the double wall inward or outward in the direction of the axial line, and a stopper formed in the cylinder for stopping the inward movement of the outer piston at a given position before the completion of the inward movement of the inner piston.
In a preferable embodiment of the invention, the inner piston has a slant face taperingly extending toward its inner top end and contacting and engaging with each of the se
Bridgestone Corporation
Knable Geoffrey L
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