Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to a machine having multiple
functions, particularly designed for preliminarily treating
pneumatic tyres having worn-out treads and for applying
subsequently thereto pre-molded annular tread rings.
As is well known, pneumatic tyres having a worn out
tread the carcass of which is still in good condition are
advantageously rebuilt, especially if they involve large
dimensions, by the application on their perimetral portion of
a new annular tread ring. In this specification, the expression
"tyre càrcass" means the tyre wlthout the tread.
More in detail, the portion of the pneumatic tyre
whereat the original tread was formed is removed and there
is glued thereon by means of suitable adhesive layers a
pre-molded annular tread ring.
The above-mentioned operation requires at present the
use of several machines with subsequent transfers of the
pneumatic tyre and annular tread ring and a consequent wasted
production time and increased cost.
It is, therefore, an object of this invention to
provide a machine capable of performing the entire operating
re-covering cycle so that the pneumatic tyre need not be ~ -
removed from its original position on the machine until after
it has been covered with the new tread ring.
More particularly, it is the object of this inven-
tion to provide a machine capable of performing in a sequence -`
the surface peeling operation of the pneumatic tyre to remove
the worn out tread and the placing on the thus peeled off
pneumatic tyre to be re-covered the new pre-molted tread ring.
In accordance with the invention there is provided
a machine which comprises in combination, a support on which
a chuck is rotably mounted and is operative for supporting a
tyre to be retreaded thereon and means for inflating the tyre.
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The machine further has means for selectively rotating the
tyre;means for peeling the worn-out tread from the tyre to
obtain a tyre carcass which include a cutting element mounted
on the support for displacement toward and away from the tyre
in a path along a plane normal to the rotation axis of the
chuck; means for preparing the peeled outer peripheral surface
of the carcass for application of a new annular tread thereto ~-
which include at least one brush mounted on the support across
: the chuck from the peeling means for displacement toward and
1~ away from the carcass substantially along the above said
plane; means for expanding the new annular tread for position-
ing the same on the prepared outer peripheral surface of the - ;
carcass which include a plurality of expanding arms; means ;
i for mounting the expanding arms on the support axially of
the chuck for simultaneous movement parallel to and radially of
the chuck rotation axis which inciudes rails located at one ~:~
side of the above said plane and extending parallel to the
,1~ rotation axis; a carriage movable over the rails toward and
away from said chuck; a cylindrical body mounted on the carriage
and having a central axis coincidlng with the rotation axis;
a sleeve mounted on the cylindrical body for axial displacement
: relative thereto, and first links articulated to the sleeve
: ~ and to the expanding arms and forming a parallelogram linkage ` ~`
therewith. There are urther provided means for sequentially
moving the expanding arms relative to the support between a
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;~ retracted position in which the expanding arms are located
:~ axially adjacent the chuck and axially spaced therefrom and
at a radial distance from one another at which the new
annular tread can be placed onto the expanding arms in ` .
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unstressed condition, a fully expanded position in which the
new annular tread is fully expanded and positioned over the
outer peripheral surface of the carcass with spacing therefrom,
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and a partially expanded position in which the inner surface
of the new annular tread contacts the outer peripheral surface
of the carcass between the expanding arms and adheres thereto,
the adhesion of the surface permitting the return of the
expanding arms toward the retracted position without entrain-
ment of the new annular tread, including a cylinder-and-piston
unit accommodated in the cylindrical body and having a shank
extending axially outwardly of the latter, a disc-shaped body
connected to the shank, and second links pivoted on the disc-
shaped body and on the first links; and means for pressing
the new annular tread against the outer peripheral surface
of the carcass, including at least one pressing roller mounted
on the support at the peeling means for displacement between ^
a retracted position outside the path and an extended position
in which the pressing roller contacts the outer surface of
the new annular tread and presses the same against the carcass.
A preferred embodiment of the invention is herein-
; after described by way of example with reference to the
accompanying drawingsr in which
- Fig. 1 shows, in a schematic front view, a machine
of this invention for the treatment of a pneumatic tyre having ~ -
a worn-out tread and for the application of a pre-molded -~
annular tread ring to the tyre carcass;
- Fig. 2 represents, in a schematic top view, the
; machine of this invention as illustrated in Fig. 1 but with
"~ the finishing treatment device omitted;
- Fig. 3 and Fig. 4 show, in a schematic view, the
expanding unit in the phases of picking up the tread ring and
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~ its placing on the carcass of the pneumatic tyre, respectively;
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- Fig. 5 represents, 1n a perspective schematic
view, the detail of the rough peeling of the worn-out tread
~ from the-pneumatic tyre;
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- Fig. 6 shows, in a schematic view, the phase of
brushing the inner face of the new tread ring to be applied
~ on the pneumatic tyre;
; - Fig. 7 represents, in a schematic form, the
pressing operation of the new tread ring against the carcass
of the pneumatic tyre;
- Figs. 8 and 9 show, in a schematic form, the two
positions relating to the said tread ring mounted on the
expanding unit relative to the pneumatic tyre to be recovered
.
1~ - Fig. 10 represents, in a schematic form, the
slip-off phase of a tread ring support arm from a tread ring ~-
mounted on the pneumatic tyre,
- Fig. 11 shows a front view of one of the tread
ring support arms provided with rows of rollers;
- Fig. 12 represents, in a schematic form, a second
embodiment of the tread ring support arms of the expanding
u~it,
- Fig. 13 shows, in a schematic form, a third embodi-
ment of the tread ring support arms of the expanding unit;
- Fig. 14 represents, in a perspective schematic
form, the~arm of Flg. 13;
- Fig. 15~shows an arm similar to the arm of Fig. -~
13, but having one less ~air of rollers, in a schematic side
view, and
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'~ - Fig. 16 represents the cross section of the arm
shown in Fig. 13, 14 and 15.
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Referring now particularly to the various figures
of the accompanying drawings, the machine shown includes an
expansible self-centering chuck 1, consisting of a plurality
30 of sectors, which are movable in radial directions. The
chuck is provided w~th a valve 2 (see Figs. 3 and 4) for
the inflation of the pneumatic tyre 3 to be treated, the
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tyre being mounted on the self-centering chuck preferably
with the aid of a small-sized platform (not shown), whish may
lift the tyre by pedal control.
The self-centering chuck 1 is rotatable either on,
or with, a shaft 4 and has peripheral beads 5, adapted to
embrace the beads of the pneumatic tyre 3, the chuck beads
being formed on the radially-movable section of the chuck.
At one side of the said self-centering chuck there
is situated a platform 6 supporting a pair of cylindrical
structures 7 and 7', arranged side-by-side to each other
(see Fig. 7) which are rotatable about their own vertical axes
due to the action of an automatically controlled hydraulic
circuit.
To the cylindrical structures 7 and 7', there are
connected two arms 8 and 8', respectively, inclined relative
; to the vertical, these arms serving as support means for
double acting cylinders 9 and 9'.
To the piston rod of the aforesaid double acting
; cylinders 9,9' there is fixed a bracket 11, supported via a
~; 20 small bar 12 by a guide 13, integral with the cylinders
themselves. On each bracket 11 a roller 14 is journalled.
On the platform 6 there is further mounted a bracket
15 to which an arm 17 is pivotally coupled via a pin 16.
Such arm 17 is also articulated to the platform 6 via a
double acting cylinder 18, adapted to cause the arm itself
, to take up either a vertical or an oblique position inclined
; to the vertical as shown in Fig. 1.
To the upper end of the said arm 17 there is fixed
a rectangular frame 19 for supporting a pair of parallel guides
` 30 20 and 20', and piston rods 21 and 21' of a double-ended
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cylinder 22. The rods 21 and 21' are aligned with each other
and are disposed between the said guides 20 and 20'.
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The piston rods 21 and 21' act in opposite senses so
that the cylinder 22 is moved alternately from right to left
and left to right as viewed in Fig. 2 when the machine is
operating.
Orthogonally to the cylinder 22 and the guides 20
and 20' there is disposed a second double-ended cylinder 23,
fastened to the body of the cylinder 22 itself and to two
slides 24 and 24', slidable along the guides 20 and 20'.
~ The piston rod of cylinder 23 has two rod ends 25
and 25' which carry a gouge 26 and a small wheel 27, respect-
ively. The gouge presses against the tyre for the rough
peeling-off of the worn tread and the wheel en~ages the
profile of a template 28, fastened to the frame 19. The
template 28 is in~erchangeable with other templates having
a different profile corresponding to the profile of the tyre
to be retreaded.
In particular, the piston of the cylinder 23 presses
; on the piston rod carrying the gouge 26 and the wheel 27
so that due to the alternating translatory motion of the
body of the cylinder 22, the gouge follows an arcuate trajecto-
ry, defined by the curved profile of the template 28.
The translatory speed of the cylinder 22 and
therefore of the piston of the cylinder 23 can be conveniently
varied as a function of the supply of pressure fluid to the
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cylinder 22 itself.
. From a functional standpoint it should be stressed
here that durlng the peeling operation of the worn out tread
of the pneumatic tyre 3 carried out by the gouge 26 the arm
17 supporting the frame 19 is disposed vertically and the
two arms 8 and 8', supporting the rollers 14 are so rotated
as to lie on the same vertical plane and to show a diverging
position as shown in Fig. 2.
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Once the peeling operation of the pneumatic tyre
has been completed, the cylinder 18 draws the arm 17 downwardly,
thereby causing the tilting of the frame 19 with the consequent
retraction of the gouge 26.
The same arm 17 engages further in its maximum
inclination position a micro-switch 10, which controls the
timed rotation of the two arms 8 and 8' which thus set in
side-by-side positions on orthogonal planes to the axis of the
self centering chuck 1 as shown in Fig. 7.
On the structure 29 supporting the self-centering
chuck carrying shaft 4, there is rotatably mounted an arm 30, `
supporting a bearing 31, In the bearing 31 the shaft of a
motor 32 rotates and at the end of the shaft there is fastened
a roller 33.
; The roller 33 by pressing on the peripheral portion
of the pneumatic tyre 3 causes its rotation with the chuck,
thereby allowing the treatment of the pneumatic tyre itself
;~ (Fig. 5)-
On the opposite side of the chuck 1 relative to the
~$~ 20 platform 6, as shown in Fig. l,there is situated a hollow
~; column 34, mounted on a base pin 35 which is displaceable
at will over the floor surface via two couplings 36 and 37
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having vertical rotations axes, the coupling 37 being fixed
to one side of the structure 29. ~-
At the top of the said hollow column 34 there is `~
arranged a motor 38, provided with a through-shaft at the
'J ends of which there are fixedly secured two brushes 39 and
`~ 39' having metal bristles. The brushes are disposed inside
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box-like enclosures 39a having one side open as shown in
; 30 Fig. 6.
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~ The said enclosures 39a communicate via the ducts
`.7 ~ 40 and 41' with the hollow column 34, which through the
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tubular member 41 and 42 provides for discharge of the rubber
particles removed by the brushes from the surfac~ on the
pneumatic tyre 3.
Such brushes are placed in contact with the rough
peeled surface of the pneumatic tyre by suitably handling
the column 34 by means of the knobs 43 and 43' and perform
a surface finishing treatment of the pneumatic tyre.
The same brushes 39 and 39' serve further to subject
the inner face of the tread ring 44 to be applied on the
pneumatic tyre 3 to an identical finishing treatment as
shown in Fig. 6.
Said operation is in practice carried out prior
to starting the treatment cf the pneumatic tyre already
fixed on the self-centering chuck by spreading the ring 44
between the pneumatic tyre and the driving roller 33.
On the inner face of the said ring 44 there is
spread a layer of adhesive means, whereas on the treated
surface of the pneumatic tyre 3 there is similarly spread a
layer of adhesive means and also a rubber sheet as sub-layer
; 20 is placed on the adhesive layer on the tyre.
The machine of this invention includes further an
expanding unit mounted by means of slides 45 on a pair of
fixed rails 46 situated in front of the self-centering chuck 1
and parallel to the axis thereof.
Said expanding unit consists essentially of upright
number 47, supporting a horizontal cylinder 48 having a
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- piston rod 49a connected to a disQ 49.
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Six rods 50 are pivotally conne~ted to the disc
49 at equi-angularly spaced points around the disc periphery, -;
these rods in turn being connected to respective ones of six
rods 51. The rods 51 are journalled at one end to a sleeve
S2 slidable on the cylinder 48 and are journalled at the
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other end to respective ones of six tread ring support arms 53.
A second rod 54 is pivotally connected between each arm 53
and the sleeve 52 to form a parallelogram linkage.
Although six rods 50 are preferred, as shown, it
is to be understood that only three rods may be provided or
any other number of rods greater than three may be used.
The articulations 55 connecting the arms 53 to
the rods 54 slide in a guide 56 formed at the end of corres-
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ponding ones of six rods 57 disposed radially of the cylinder 48
I0 and fixed thereto. -
The arms 53 carry adjustable shoulders 58 for
centering the tread ring 44 on the tyre carcass and have end
portions beyond the shoulders 58 for supporting the tread
ring. As shown particularly in Figs. 10 and 11, the arm ~ '~
end portions support rows of frusto-conical rollers 60 and
cylindrical rollers 59 rotatable on parallel axis. The two
rows of rollers 60 provide first surfaces facing upwardly,
as viewed in Figs. lO and 11, for engaging the inner surface
of the annular tread ring 44, and the ~wo rows of rollers 55
provide second surfaces facing downwardly for engaging the
periphery of the type carcass. ' ;i
Such particular configuration of the rollers 59
and 60 allows the profile of the arms 53 to better suit
` the profile taken by the ring 44 when it is stretched and
superposed on the carcass of the pneumatic tyre 3 (Figs.
8 and 9).
The configuration of the rollers 60 promotes the
slipping of the arms from underneath the ring 44, when it
has been at least partially stuck to the pneumatic tyre
' 30 (Fig~ 11).
Alternatively (Fig. 12) the arms 53, instead of
having rollers, are provided with a pair of flexible blades
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61, which may be slipped off the tyre to the side by retrac- '
tion of the arms.
According to another alternative form as schematically
shown in Figs. 13 through 16, the arms 53 comprise a framé 62,
supporting a plurality of pairs of cylindrical rollers 63.
; The frame 62 is bevelled off on the sides and at
its free end 64 so as not to have sharp edges in contact with
the ring 44.
The rollers 63 project from oppositely-facing
surfaces of the frame 62 in order to ensure the slip-off of
such frame from the tyre without causing displacement of
the ring 44. This ensures that the tread ring sets correctly
the tyre carcass The ring 44 arranged on the pne~matic tyre on
3 is finally compressed against the same by the action of the
two rollers 14 as shown in Fig. 7.
;; ~ From the foregoing description and from perusal of
the various figures on the accompànying drawings it is possible
to easily see the great functional character and practical
application of the machine according to this invention for re-
covering pneumatic tyres having worn-out treads.
When putting into effect the machine of this inven-
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~' tion several changes and modifications as to shape, construc- ;
tion and dimension may be introduced without departing from
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the scope of this invention as set forth in the following
t claims.
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