Note: Descriptions are shown in the official language in which they were submitted.
BEAD-BUILDING COMPONENT ~OR
PNEUMATIC VEHICLE TIRES
Background of the Invention
The present invèntion relates to an annular bead-
buildin~ component for pne~lla~ic vehicle tires, and
has a pull-resistant and/or compression resistant
bead core of load-carriers of metal or a material of
similar high streng~h, and also has a profiled rubber
member whlcil at least predominantly surrounds the bead
core. The present invention also relates to a pneumatic
vehicle tire equipped with such a bead-buil~in~ compon-
ent.
A vehicle wheel and tire assembly has been pro-
posed according to which the beads of a tire are mounte~
on the raclially inner periphery of a one-piece rim, and
according to which, in order to eliminate a deep mount-
ing bed, the bead cores are eccentrically disposed in
the tire beads in such a way that when the tire is
mounted, ~he distance Erom the center of a core
cross-section to the radially outer edge of the bead is
greater than the di~tance to the axially inner edge oE
the bead,
Since ~ the manufacture of such a tire is a
question o~ ex~remely smAll tolerances with regard to
the exact dispositiorl of the bead core in the tire bead,
it is an object of the present invention ~o set forth
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a way in which this can be reliably achieved.
Brief Description of ~he Drawings
This object, and other objects and advantageso the present inven~ion, will appear more clearly
fron ~he ollowing speciication in conjunction wi~h
the accompanying drawings, in which:
Figure 1 is a perspective view o~ a
portion of one inventive embodiment o a bead-building
component;
Figure 2 is a radial partial section of
an inventive bead-building component in a vulcanizing
rnold;
Figure 3 is a partial radial section of
a bead-building component in which is embedded a
spiral spring;
Figure 4 shows a ~ilament with balls on
it which serves as a spacer element;
Figure S is a radial par~ial sec~ion
showing a tire which is in the vulcanizing position
and in which is installed an inventive bead-building
component; an~
Figure 6 is a yartial radial section of
a vehicle wheel and tlre assembly.
Summary oE the Invention
By one aspect of this invention, there is pro-
vicled an annular bead-building component or
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pneumatic vehicle tires, said component comprising
a pull~resistant and/or compression resistant bead
core of load-carriers made of ~etal or some other
material of similar hi~h strength, and also corn-
prising a profiled rubber member which at least pre-
dominantly surrounds said bead core; the improvement
wherein said bead-building component is a component
which, prior to its installation into an unfinished
tire, has been prevulcanized in a vulcanizing mold;
and wherein spacer elements are provided in at least
one of said profiled rubber member and said vulcan-
izing mold for fixing the position of said bead
core relative to said profiled rubber member during
said prevulcanization.
Due to the inventive utilization of a pre-
vulcanized bead-building component, an already formed
component is inserted durin~ the process of ~inishing
the tire; as a resuLt oE its inherent stability, this
component predetermines the contour of the tire beads
after the vulcanLzation of the entire tire. Pursuant
to one advanta~eous embodiment o~ the present invention,
the bead-building component, which has an essentially
round cross-section, is provided at one location with
a circumEerential fixin~ rib which during the finishing
of the tire is disposed betweerl the carcass and the
looped-around carcass end. As a result, the bead-
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building component can no longer alter its position
in ~he ~ire vulcanizin~ mold during vulcanization, so
that the position of the bead core within the final
tire bead is also fixed.
The manufacture of the inventive bead-building
component is advantageously carried out in a separate
vulcanizing mode, with a bead core irst being placed
therein, and the space then being filled by disposing
or spraying rubber therein. It is particularly impor-
tant that measures be taken in order to precisely fixthe positon of the bead core within the cross-section
of the profiled rubber member. Such rQeasures can, on
the one hand, comprise provicling the vulcanizing mold
with spacer elements in the fornl of pins or cross-
pieces; on the other hand, spacer elements such as
circumferential spiral springs can be permanently
embedded in the profiled rubber member o~ the bead-
buil~ing corrlponent.
Pursuant to further specific embodirnents of tlle
present lnven~ion, a textile Eabric may be disposed be-
tween the profiled rubber member and the bead core
in or~er to provida for a relative pivotabili~y o~
the two. Such a relative pivotability can also
be provided by permanentlY disposing spacer elements
in the proiled rubber mernber.
The bead core can be eccentrically disposed in
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the profiled rubber member in such a way that when
the tire is mounted, the distance from the cen~er
of the core to that edge of the profiled rubber
rnember which faces the rim seating surface is con-
siderably greater than is the distance fro~ the
center of the core to the axially inwardly dis-
posed edge of the profiled member, with four times
this difference in length corresponding approximate-
ly to the height of a rim flange.
A pneumatic vehicle tire which is equipped
with the inventive bead-building component is
characterized in that the tire carcass is anchored
in the tire bead by being looped around the bead-
building component, and in that the fixing rib of
the bead-building component extends into the space
between the tire carcass and the looped-around car-
cass end.
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Description of Preferred Embodiments
Rererring now to the drawings in detail, the
annular bead-building component oE Fig. 1 comprises
a profiled rubber member 1, and a bead core 2 which
is embedded therein. The bead core 2 princlpally
comprises a cable core having a plurality of metal
cables 3 which are grouped about an inner core 4. The
cable core 2 is covered with a textile Eabric 5 which
is embedded with an intentionally slight adhesion to
the adjacent portions of the bea~-building component.
There thus results a consi~erable ability oE the pro-
filed rubber member 1 to pivot about the bead core 2,
so that a so-called pivoting bead results after the
bead-building component is inserted into the tire.
The building component illus~rated in Fig. 1 has
an essentially round cross sectional shape, from which
the only deviation i9 at a downward angle, i.e. on the
radially inner side, due to a circum~erential, pointed
fixi.n~ rib 6 o the rnaterial o~ the proEiled rubber
rnember 1. IE necessary, the Eixin~ rib 6 can also com-
pr:ise a rubber havin~ a different Shore har~nes~. A
hardness Oe about 90 Shore A (aEter the vulcanization
of the complete kire) has proven to be expedient for
the profile~ rubber member 1, As will become clear
from the subsequent description o~ the vehicle wheel
and tire assembly, the bead-building component of
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Fig, 1, provides a tire, the beads o~ which are mounted
under pretension on the rim in such a way that it can
pivot on its own into another position when pressure
is los~.
Fig. 2 shows a bead-building component which
is still located in a vulcanizing mold 7. Since it
is very importan~ that the bead core 2 assume a very
specific position with as slight a tolerance as
possible within the cross-sectional area of the pro-
~iled rubber member 1, and that it also ~aintains thisposition during the preliminary vulcaniæation, spacer
elements 8 in the form of holding pins or at least
partially circumferential holding ribs are disposed
in the bottom half o~ the vulcanizin~ mold 7. ~uring
the preliminary vulcanization, the bead core 2, due to
its great weight, rests upon ~he spacer elements ~ of
the rnold 7, so that it cannot "swim away" in the so~t
rubber which surrounds it, The openings which remain
due to the holding pins or holding ribs 8 after the
mold has been rernoved are closed off by pushing ru~er
into them prior to insertlng the bead-building corrlponent
into the tire, or during vulcanization of the tire.
I~ should also ba noted that with the bead-build-
ing component o~ Fig. 2, the tip of the ~ixing rib 6 is
directed upwardly, and the shortest distance from the
bead core 2 to the edge of the bead-building component
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is disposed at the opposite side in the lower re~ion.
As a result, after insertion into the tire, and
af~er the tire is mounted, the Eixillg rib is directed,
free of tension, pret~y much exactly axially outwardly,
so that the bead region of the tire is mounted on the
rim without pretension.
In ~he bead-building cornponent of Fig, 3, a
circumferential spiral sprin~, 9 is disposed within tlle
profiled rubber member 1, The spiral spring ~ also
serves as a spacer element ~or tlle exact positioning f
the bead core ~, and can either be used in addition ~o
the holding pins or holding ribs 8 of the vulcanizing
mold 7, or in place thereof. The interior of the
spiral spring 9 shoul~ be filled with rubber. It is
important to use a spiral spring 9 rather than a some-
what similarly shaped metal ring, so that the relative
ability of the profiled rubber member 1 to pivot about
the bead core 2 is maintained (the axes of rotation
are, in sections, portions oE thc bead core 2). In
place oE the spiral s~ring 9, a fil~ment 10 with balls
11 on it, such as shown in Fl~, 4, can also be used;
the balls 11 also serve as spacer elements, and can
comprise a prevulcani.zed rub~er or some other material.
Since the important thing is the spacing function o~ the
"balls",and not the geometric shape thereof, quite
differently shaped elements 11 can also be used which
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effect an even be~ter keying or wedging o the bead
core 2 i-n the vulcanizing mold.
Fig 5 shows a portion of a tire in which a
bead-building component has been installed. The tip
of the fixing rib 6, in the relaxed state, is directed
axially i~lwardly relative to the axial direction of a
winding drum. In this position, the tip of the fixing
rib 6 extends into the space between the tire carcass
12 and the looped-around carcass end 13, so that a
twisting or turning of the profiled rubber member 1
relative to the carcass 12 is no~ possible. This tire
is vulcanized with the walls 14 disposed laterally
outwar~ly, as can be seen rom the indicated axial
~irection o~ the heatin~ or vulcanizing mold. This
achieves an easier molding oE the bead portions dis-
posed within the tire. To mount the tire, the tire
walls 14 are turned inwardly, In so doing, the tire
beads 15 with the proEiled rubber members l carry out
a pivo~ing movement about their respective bead core
2 while buildin~ up a pretension; at the same time, they
carry out an axially inward movement. The result o~
this pretension isthatthe tire, i.n the mounted state,
presses with its beads lS against the rim ~langes even
before the tire is inflated with air, t~us achieving a
scaling and simplifying inflation. The ribs 16 shown
on the outside of the tire of Fig. 5 serve to simpliEy
Mounting of the tire.
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Fig. 6 illus~rates a vehicle wheel on which a
tire is completely mounted. Shown is a bel~ed tire
having a radial carcass 12, though a bias carcass
could also be used. By being looped around the bead-
building components, the ends of the carcass 12 are
anchored in the beads 15. The tire also has a
customary belt 17. The tire is mounted on the rim
18 in such a way that the bead seating surfaces are
located on sea~ing surfaces disposed radially inwardly
of the rim ring 19 next to the inwardly extendin~
; rim flanges 20 on the rim 18.
The tire beads 15, in a Eo~n ~itting manner,
substantially fill a space delimited by the rim flanges
20, the rim seating surfaces, and parts 21 of the
rim rinK 19 which in cross section extend essentially
vertically. As a result of the vertical parts 21,
a standard drop-well 22 is formed on the radially outer
side of the rim 1~. For very wide tires, this dro~-
well 22 can help during mounting in more easily moving
the tire over the one~piece rim 18. In order to even
be able to mount the tire at all on the one-piece rim
18, which in contrast to known rims has no deep mounting
bed~next to the rim seatin~, sur~aces ~or the beads 15,
it is important that the bead core 2 be eccentrically
mounted in the predominantly round profiled rubber rnernber
1, an~ hence in the tire bead 15, in such a way that
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when the tire is mounted, the distance from the center
of the cross-section of the core to the radially
ou~er edOe of the bead is greater than the dis~ance
to the axially inner ed~e of the bead. Furthen.lore,
the aforementioned ability o~ the tire bead 15 to pivot
abou~ the core 2 is necessary.
In order to mount the tire, the axis of
rotation of the rim 18 is first disposed a~ right
angles to the axis o rotation of the tire, whereupon
the rim is moved into the interior of the tire, where
it is rotated by 90, so that the two tire beads 15 are
disposed laterally outwardly next to the rim flan~es 20.
One of the beads 15 is subsequently pivoted or twisted
inwar~ly to such an extent that the region where the
bead core 2 i5 closest to the edge of the bead is dis-
posed radially outwardly. At one location, this region
is then pushed over ~he rim Elange 20 onto the rim
seating surface; the process is then repeated in sections
alon~ the entire ~erlphery. Finally, the tire bead 15
is pivo~ed bac~ into the operating position o~ the tire,
whereby the e~Eective diameter of the tire in the radial-
ly outer portion of the tire bead 15 is increase~ to
such an extent that the tire obtains a rig:Ld seat on
the rim 18.
Dependin~ upon the design of the bead-buildin~
component, the tire bead 15 can, in the operating state,
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be free o tensîon, have a twisting moment in the
closing sense (pressing against the rir.l flange 20~,
or have a twis~ing moment in the opening sense (turn-
ing into the mounting position). It is readily
apparent that the first situation occurs during
installation of a bead-building component of the type
shown in Figs. 2 and 3, while the second situation
occurs for a component of the type shown in Fig, 5.
The third situation occurs for a component of the type
shown in Fig. 1 if the bead-building components of
Figs 1 to 5 are represented in a tension-free state.
In Fig. 1, the fixing rib 6 is directed radially in-
wardly, in Fi~s. 2 and 3 it is directed axially out-
wardly, and in Fig, S it is directed axially inwardly,
whereas in the operating position of the tire it is
always ~irected axially outwardly.
It should be noted that the present invention is
applicablc not only for eccentrically ~isposed bea~
cores 2, but also in tires which are mounted radially
outwardly on the rim.
The present invention is, o~ course, in no way
restricted to the specific disclosure of the specifi-
ca~ion and drawlngs, but also encompasses any modifi-
ca~ions within the scope o~ the appended claims.
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