Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02777281 2012-05-16
IMPROVED CUSHIONING AND SELF-COOLING OF A SEMI-SOLID TIRE
Field of the Invention
This invention relates to a tire, and more particularly to an improved
cushioning and self-cooling
of a semi-solid tire.
Background of the Invention
There have been various proposals for tires of vehicles. Typically, such tires
comprise an
annular body formed of elastomeric material such as rubber. There have also
been various
proposals for attachments of the annular body to a wheel rim, including
moulding the annular
body of a tire on to the rim portion of the wheel or forming the annular body
separately (either as
a one-piece unit or in segments) and then releaseably fastening the annular
body to the rim
portion of the wheel.
The solid and semisolid tire were created primarily for eliminating the danger
of
explosion and downtime due to punctures in the pneumatic tire.
The first response was a solid tire, which was then followed by a rubber/foam
filled
pneumatic tire. These are heavy puncture proof tires that in time damage the
axles and
transmission of the vehicles.
The next advancement was a light semi-solid tire, which eliminates the danger
to the
vehicle. This will improve the cushioning somewhat, however, one problem is
that heat
accumulates in the rubber with the repeated deformation.
It has also been found that welding should not occur close to the rubber
bonding agent,
because it is found to unstitch the rubber.
It is against this background, and the problems and difficulties associated
therewith, that
the present invention has been developed.
CA 02777281 2012-05-16
Summary of the Invention
According to a first aspect of the present invention there is provided a tire
system to be
mounted on a wheel rim, the tire system comprising a tire having a pair of
sides, a radially inner
portion engageable with the wheel rim, a plurality of voids impressed into the
both the front side
and the back side, and a plurality of bosses which correspond to the plurality
of voids, wherein
the plurality of voids each include a larger outer chamber and a smaller inner
chamber.
Preferably, the plurality of voids vary in size, and the plurality of bosses
include bosses of
varying size which do not completely fill the plurality of voids.
The bosses of varying size may include bosses which only fill the larger outer
chamber.
In one embodiment, a plurality of secondary voids is located radially outwards
from the
plurality of voids. A plurality of secondary bosses may correspond to the
plurality of secondary
voids.
In another embodiment, the system includes a plurality of tunnels, wherein
each tunnel
extends between two of the plurality of voids.
In a further embodiment, each tunnel extends between one of the plurality of
voids in one
of the pair of sides and another of the plurality of voids in the other of the
pair of sides. As well,
each tunnel may extend between the smaller inner chamber of one of the
plurality of voids and
the larger outer chamber of another of the plurality of voids.
In another embodiment, each of the smaller inner chambers includes two tunnels
which
each extend to a different one of the larger outer chambers.
According to another aspect of the invention, there is provided a tire system
comprising a
modified rim, which includes a disk having a radially outer portion, a flat
rim ring welded to the
radially outer portion of the disk, and a plurality of flat gussets welded to
the disk and the flat rim
ring. The tire system also includes a tire having a rubber layer having a
radially inner portion and
a pair of sides, a flat tire ring glued to the radially inner portion of the
rubber layer, a plurality of
voids impressed into both of the pair of sides, and a plurality of bosses
which correspond to the
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CA 02777281 2012-05-16
plurality of voids, wherein the plurality of voids each include a larger outer
chamber and a
smaller inner chamber. The flat tire ring is mounted on the flat rim ring by
slight interference
pressing, and a plurality of anti-slippage dowels is inserted through the flat
rim ring, the flat tire
ring, and slightly into the rubber layer.
The invention will be better understood by reference to the following
description of one
specific embodiment thereof as shown in the accompanying drawings.
Brief Description of the Drawings
Figure 1 is a half cross-sectional view of the tire according to the first
embodiment of the
invention.
Figure 2 is a half cross-sectional view of the tire according to another
embodiment of the
invention.
Figure 3 is a side view of a cross-section of the tire.
Figure 4 shows the varying shapes and sizes of the bosses.
Figure 5 is a side view of the portion of the tire according to another
embodiment of the
invention.
Figure 6 is a perspective view of a portion of the tire according to another
embodiment of the
invention.
Figure 7 is a half cross-sectional view of the tire according to another
embodiment of the
invention.
Description of Preferred Embodiment
Figures 1 and 2 show a semi-solid tire 10 according to a first embodiment. The
tire 10
includes a pair of sides and a radially inner portion, which is adapted to be
fitted onto a
conventional wheel rim 12 designed for tires, such as pneumatic tires. The
wheel rim 12 has a
tire support surface 14 incorporating a seat 16 on each side of the rim 12
adjacent the rim edge
18.
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In the wheel rim design shown in Figure 1, a layer of low quality rubber 20 is
glued with
adhesive to the pneumatic rim 12. A layer of high quality rubber 22 is laid
on, then tread rubber
24 is laid on the top.
In the wheel rim design shown in Figure 2, a flat sheet ring 32 is welded
inside the rim
12, then a flat band 34 is welded on the top of rim 12 at the sides. For
stopping the internal ring
to slip aside under pressure, holes 36 are drilled and filled up with spot-
welding. This way, a
strengthened rim is obtained, and the rest of rubber casting procedure
continues.
In the preferred embodiment, through the moulding process, a plurality of
voids 26 is
impressed into both sides of the rubber. In this preferred embodiment, each of
the plurality of
voids 26 include a larger outer chamber 28, and a smaller inner chamber 30.
These voids can be
used to tune the cushioning of the wheel.
A cross-section of a plurality of voids 26 is shown in Figure 3.
Figure 4 shows the flexibility of the varying shapes and sizes of the bosses
38. As
illustrated, the bosses 38 include a larger base portion 46, and a smaller tip
portion 48, which
correspond to the shape of the main voids 26. As shown in Figure 4, the
smaller tip portion may
be of variable length L and diameter D, as the wheel user requests. As well,
the edges of the
larger base portion can be rounded, or angled, as shown. If a tougher wheel is
needed, the smaller
inner chamber 30 can be closed/eliminated by filling the smaller tip portion
48 with plug 40.
A further preferred embodiment is shown in Figure 5, where the cushioning can
be
improved further by additional side voids 42. These side voids 42 offer the
advantage of
becoming part of the tread when the tread band had worn to their level, and
the wheel is still in
ride-able condition. These side voids 42 may also include corresponding side
bosses (not
shown), which are also variable, like bosses 38.
There are cases when the contact area with the ground must be increased. A
method to
further soften the cushioning is providing variable sized communicating
tunnels 44 between the
main voids 26. As can be seen in Figure 6, the preferred embodiment includes
two of the
communicating tunnels 44 extending from each of the smaller inner chambers 30,
with each of
the two tunnels 44 extending to a different larger outer chamber 28.
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The present invention improves the cushioning for various applications, by
applying more
or less bosses into the voids in the load bearing rubber. For a more rigid
tire to be used in
applications such as mining, one would use more bosses and less voids. For a
softer tire, used in
applications such as sand, the less bosses and more voids. A well-balanced
rubber semi-solid tire
can be used for 4-wheel drive, and military types, as primarily puncture-
proof.
The combination of the main voids 26, the side voids 42, and the communicating
tunnels
44 contributes to the self-venting of the tire 10.
For heavier loads and expected rapid wearing of the tread, it is easier to
change the rubber
part of the wheel, install a new rubber, than to spend time to retread the
worn rubber.
While a conventional wheel rim 12 is shown in Figures 1 and 2, Figure 7 shows
another
embodiment of the invention which includes a special rim 50. The modified rim
50 is fabricated
of a rolled flat rim ring 58 welded on a disk 54, strengthened with flat
gussets 56. The rim 50 is
machined on top to leave an axial anti-slippage shoulder. The tire portion
includes a flat tire ring
60, with high quality rubber 22 bonded to it. This is typically done with
glue. Tread 24 is then
glued on top. Similar to the embodiment described above, a plurality of voids
26 is impressed
into both sides of the rubber. The flat rim ring 52 and the flat tire ring 60
are mounted together
by slight interference pressing. Holes are drilled through both plates,
slightly protruding into the
high quality rubber 22, for anti-slippage headed dowels 62. The dowels 62 are
fastened by spot
welding, and dismounted by grinding the welding away. The anti-slippage dowels
62 are against
axial (side) slippage, and radial slippage due to the traction torque load.
This embodiment allows for the tire to be held in place on the rim, without
the use of
welding.
The scope of the claims should not be limited by the preferred embodiments set
forth in
the examples, but should be given the broadest interpretation consistent with
the description as a
whole.
