Note: Descriptions are shown in the official language in which they were submitted.
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Background of t}-e Invention
The instant invention relates to a run-flat,
tubeless, pneumatic tire and more particularly to a
toroidal, reinforced insert for such a run-flat tire.
Flat tires or tires with minimum inflation have
long posed serious problems for drivers o~ vehicles equipped
with pneumatic tires. Flat tires usually require that they
be changed before the vehicle can proceed, and such a change
requires that there be a spare tire situated somewhere on
the vehicle, usually in the trunk of a car. A spare tire
conæumes valuable storage space, and it has therefore become
an ob;ective of the automobile and tire industries to provide
a tixe which would be able to perform, although at reduced
speeds, in a flat condition so that the vehicle may be able
to proceed to a service center and obtain permanent repairs
or replacement, thereby eliminating the need for a spare tire.
There have been many prior art attempts to provide a
run-flat tire utilizing inserts in the cavity created by the
tire and wheel rim. However, none of these attempts has met
with commercial success. The reasons for the failures of
the prior art inserts consist of one or more of the following:
1. The insert has proved too difficult to install.
2. The insert, such as a solid rubber buffer, takes
up too much enclosed air space and prevents the iron rim from
radiating heat from the enclosed air caused by tire flexing,
especially at high speed, and the resulting high temperature
o~ enclosed air melts the rubber and vulcanization of the
enclosing tire, causing the enclosing tire to wear out in a
few hundred or less mlles.
3. The insert, such as a steel buffer, though it
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would run cool, would be too rigid and would bend permanently
and cut through the enclosed tire casing if, for example, it
were run over a steel railroad rail.
The instant invention overcomes the aforementioned
problems of the prior art by providing a novel insert structure
for a pneumatic tire.
Summary of the Invention
Accordingly,~the instant invention provides a toroidal
insert for an inflated, tubeless, pneumatic tire. The insert
comprises a torus-like core, tire cord radially wound around the
core, and at least one load bearing member having tire cord
therein, said member being circumferentially wound around
substantially the middle one third of the radially outer surface
of the radially wound tire cord. The insert, when situated
within the inflated tire, includes a cross-section having a
thick, substantially oval, central portion extending between the
beads of the inflated tire and a pair of thin end portions each
extending from its respective side of the thick, substantially
oval, central portion along the adjacent sidewall of said
inflated tire to about the midpoint of said adjacent sidewall,
whereby, when the tire is deflated, the thick, substantially
oval, central portion of the insert supports the tread portion of
the deflated tire and each of the thin end portions of the
insert lies between and supports the adjacent, collapsed
sidewall of the deflated tire.
In accordance with one broad aspect, the invention
relates to a toroidal insert ~or an inflated, tubeless,
pneumatic tire having a tread and sidewalls, said insert
comprising: a preformed substantially noninflatable
substantially nonexpandible, substantially nondeflatable and
substantially noncompressible torus-like core having a central
axis; tire cord radially wound around said core; and at least
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one belt-like load bearing member having tire cord therein,
said belt-like member being circumferentially wound with
respect to the central axis of said core around substantially
the axially middle one third portion of the radially outermost
surface of the radially wound tire cord on said torus like
core wherein the insert, when situated within said inflated
tire, has a substantially U-shaped cross-section with a
relatively thick, substantially oval middle portion extending
between the beads of said inflated tire and a pair of relatively
thin leg portions each extending from its respective side of the
substantially oval middle portion along the adjacent sidewall of
said inflated tire to about the midpoint of said adjacent
sidewall, whereby, when the tire is deflated while supporting a
rated load the tread and sidewalls collapse to render the insert
with a substantially I-shaped cross-section with the
substantially oval middle portion of the insert supporting the
tread portion of the deflated tire and each of the end portions
of the insert lying between and supporting the adjacent,
collapsed sidewalls of the deflated tire.
In accordance with another aspect, the invention relates
to a tire rim, a tubeless pneumatic tire mounted on said rim,
said tire having a tread and sidewalls, and a toroidal insert
lying within and adjacent the sidewalls of said tire, said
insert comprising a preformed substantially noninflatable
substantially nonexpandible, substantially nondeflatable and
substantially noncompressible torus-like core having a central
axis, tire cord radially wound around said core, and at least
one belt-like load bearing member having tire cord therein,
said belt-like member being circumferentially wound with respect
to the central axis of said core around substantially the
axially middle one third portion of the radially outermost
surface of the radially wound tire cord, and wherein, when
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said tire is inflated, said insert has a substantially U-shaped
cross-section with a relatively thick substantially oval
portion extending between the beads of said tire and a pair of
relatively thin leg portions each extending from its respective
side of the substantially oval middle portion along the adjacent
sidewall of said tire to about the midpoint of said adjacent
sidewall, and whereby, when the tire is deflated while
supporting a rated load the tread and sidewalls collapse to
render the insert with a substantially I-shaped cross-section
with the substantially middle oval portion of the insert
supporting the tread portion of the tire and each of the end
portions of the insert lying between and supporting the adjacent,
collapsed sidewalls of the tire.
Brief Description of the Drawings
Figure 1 is a vertical, sectional view of an inflated,
tubeless, pneumatic tire having a toroidal insert according to
the instant invention:
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Figure 2 is the æame as Fig. 1 except that the tire
iB deflated and supported by the insert;
Figure 3 is a perspective vlew showing the torus-
like core of the insert being radially wound by tire cord;
Figure 4 is a perspective view of the insert after
it i8 radially wound and in the process of being circumferen-
tially wou~d;
Figure ~ is an axial, sectional view of the core
shown in Fig. 3 but after the core has been completely
radially wound,
~igure 6 is an axial, sect~onal view of the insert
shown in Fig. 4 but after the insert has been completely
circumferentially wound.
Descri~ion of the Preferred Embodiment
In describing the preferred embodiment of the
instant invention, reference is made to the drawings, wherein
there is seen in Figs. 1 and 2 a tubeless, pneumatic tire 10
having a pair of beads 12 and 14, a tread portion 16, a pair
of sidewalls 18 and 20, and a rein~orcing belt 22. The tire
10 is mounted on a wheel rim 24.
A toroidal insert 26 ls situated within the space
defined by the tire 10 and the wheel rim 24. When the
tire 10 is inflated, as seen in Fig. 1, the insert 26 includes
a cross-section ha~ing a thick, substantially oval central
portion 28 which extends between the beads 12 and 14 and a
pair of thin end portions 30 and 32, each of which extends
from its respective side of the substantially oval central
portion 28 along the adjacent sidewall 18 and 20 respectively
o~ the inflated tire 10 to about the midpoint M of the
adjacent sidewall.
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The insert 26 comprises a torus-like core 34
(see Fig 3) which may be formed from a cellular or foam
material, tire cord 36 which is radially wound around the
torus-li~e core 34, and two load bearlng members 38 and 40
which consist of tire cord 42 encased in rubber 43. The load
bearing members 38 and 40 are cir~umferentially wound
around substantially the middle one third of the radially
outer surface 44 of the radially wound tire cord 36 (see
Figs. 4 and ~. The tire cord 42 in the load bearing members
38 and 40 are preferably oriented at right angles to the
radially wound tire cord 36. Although the load bearing
members 38 and 40 are shown as being arcuate, in cross-section,
said members may be wound so that they are essentially flat
in cross-section. The term "substantially oval central
portion" is intended to include both flat and arcuate windings
of the load bearing members 38 and 40.
The torus-like core 34 is preferably fo~med ~rom an
open or closed celled foam, the most preferred foams being
polyurethane and polyethylene. The preferred materials for
the radially wound tire cord 36 are fiberglass, nylon,
polyester, and steel wire, with steel wire being the most
preferred. The preferred and most preferred materials for
the tire cord 42 in the load bearing members 38 and 40 are
the same as those ~or the radially wound tire cord 36, although
in any given insert the same or different materials may be
used to form the radially wound tire cord 36 and the load
bearing member tire cord 42.
The preferred method o~ manufacturing the toroidal
~nsert ~6 comprises molding or cutting the foam core to the
desired d~nensions, winding radial cords around the foam core,
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and then wrapping clrcumferential cords around the
circumference of the core at the proper diameter to compress
the core sufficiently to provide the central portion 28 and
the end portions 30 and 32.
In using the toroidal insert 26, one would first
place the insert 26 with~n the unmounted tire 10 so that the
central portion 28 and end portions 30 and 32 were aligned
within the tire 10 substantially as shown in Fig. 1. The
tire 10 and insert 26 are then mounted on the wheel rim 24
in conventional manner. The pneumatic tire 10 may then be
lnflate~.
Should the pneumatic tire 10 deflate, as seen ~n
Fig. 2, the thick, substantially oval, central portion 28
of the toroidal insert 26 supports the tread portion 16 of
the deflated tire 10 and each of the end portions 30 and 32
of the insert 26 lies between and supports the ad~acent,
collapsed sidewall 18 and 20 respectively of the deflated
tire 10. The insert 26 effectively stabilizes the tire 10 on
the rim 24, reduces heat buildup and allows the vehicle to
proceed.
The invention disclosed will have man~ modifications
which will be apparent to those skilled in the art in view of
the teachings of the specification. It is intended that all
modifications whlch fall within the true spirit and scope
of this invention be included within the scope o~ the
appended claims.
