Note: Descriptions are shown in the official language in which they were submitted.
l~SSOS
CONSTRUCTION MAT FORMED FROM DISCARDED
TIRE BEADS AND METHODS FOR ITS U
BACKGROUND OF THE INVENTION
In the construction, farming and logging
industries, for example, it is sometimes necessary to
build a temporary road over an unstable ground
surface, such as that found in swamps or formed of
muskeg. Methods such as that shown in United States
Patent No. 3,880,538 have been devised for building
roads over unstable ground surfaces wherein a mat of
rigid polyurethane is laid over the unstable ground
surface and then covered with a particulate material
or earth fill, the mat acting to distribute the weight
of a vehicle traveling over the particulate material
and prevent it from sinking into the unstable ground
beneath. This method, however, is disadvantageous in
that it is expensive in requiring the use of
relatively costly plastic materials.
Mats are also used in the construction and
mining industries as blasting mats. Here, again, the
mats are relatively expensive. In certain cases, for
example, the mats are formed from steel cables woven
together. A mat of this type is relatively heavy and
a crane is required at the construction site to put it
in place prior to the blasting operation. Further-
more, inasmuch as the mat is formed from steel, there
is always the possibility of a short between the
detonation wires.
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SUMMARY OF THE INVENTION
In accordance with the present invention, a
mat construction is provided for applications of the
type described above which is exceedingly low in cost,
inasmuch as it uses only discarded and otherwise
useless materials.
Specifically, the invention contemplates the
use of tire beads, a useless by-product of tire
recycling, which are tied together with strips of used
tire casings to form a mat which can be used as a
blasting mat and as a substrate for roads built on
unstable ground surfaces.
In the case where the mat is used as a
substrate for roads, it is placed over the unstable
ground surface and earth fill or particulate matter is
thereafter placed over the top of the mat which acts
to reduce the penetration of road bed into the
substrate as a result of vehicle loads by transferring
vertical forces into horizontal pull on the tire
beads. In effect, this acts as a force virtually
pulling the beads through an earthen mass. The loads
which tend to push the road bed down also act to
increase the resistance to horizontal movement of the
tire beads until penetration of the road bed stops.
In the case where the mat is used as a
blasting mat, preferably several rectangular arrays of
tire beads are superimposed one above the other such
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that arcuate portions of one array will extend over
and cover the openings in lower or higher beads to
prevent the escape of rocks or other drebis when the
blast occurs.
A distinct advantage of the present
invention is that the tire beads, which are relatively
light-weight, can simply be transported to the site
where they are to be used and then tied together
manually, thereby obviating the need for a crane or
the like as is required with heavy mats previously
used.
The above and other ob~ects and features of
the invention will become apparent from the following
detailed description taken in connection with the
accompanying drawings which form a part of this
specification and which:
Figure 1 is a top of plan view of a mat
constructed from discarded tire beads in accordance
with the invention;
Figure 2 is an elevational view of a mat as
applied to an unstable ground surface for the purpose
of distributing a load more or less evenly over the
ground surface; and
Figure 3 is a plan view of a typical
blasting mat configuration utilizing the principles of
the invention.
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With reference now to the drawings, and
particularly to Figure 1, a top view of the mat of the
present invention is shown. It is formed from tire
beads which are otherwise discarded from a tire
recycling process. In this regard, the tire casing is
initially cut from the tire bead, which contains an
annular steel ring, prior to the casings being cut
into strips or the like. Ordinarily, the beads must
be discarded.
In accordance with the present invention,
however, tire beads, identified by the reference
numeral 10 in Figure 1, are formed in a two-
dimensional array arranged in linear rows 12 extending
from left to right in Figure 1 and linear columns 14
which are at right angles to each other. Fastening
means secure the tire beads together in the array
shown in Figure 1 at their peripherally facing
surfaces. The fastening means may, for example,
comprise tire casing strips 15 which encircle the tire
beads at their peripherally facing surfaces, each
strip having its ends tied together in a square knot,
for example, to form a loop. In the case where the
mat is used as a flexible underlayment for succeeding
layers of road base courses, the tightness of the
casting strips looped around facing edges of the tire
beads is not particularly critical. However, in the
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case where the mat is used in blasting operations, the
fastening means should be as tight as possible.
Figure 2 illustrates a typical application
of the present invention as an underlayment for road
base courses. The mat, generally indicated by the
reference numeral 16, is initially formed at the site
by low-cost laborers which place the tire beads 10 in
position and then tie them together by means of the
tire strips 15. The unstable ground surface, which
may be swampy ground or muskeg as explained above, is
identified by the reference numeral 18 in Figure 2.
Earth fill 20 or other suitable road base course
material is then poured over the mat 16. In this way,
when a vehicle, for example, travels over the fill 20,
its weight will be distributed over the entire area of
the mat and will effectively prevent wheels of the
vehicle from sinking into the unstable ground surface.
The fill 20 also creates a resistance to lateral
movement. It will be understood that the width of the
mat is a function of the width of the desired roadway
and its length is a function of the length of the
roadway. Concentrated loads at the center of the fill
area place the beads in tension as well as
compression.
Figure 3 illustrates an application of the
invention to blasting operations wherein three mats
22, 24 and 26 are placed one above the other such that
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the arcuate portions of one mat overlap the central
opening of the tire beads above and below. The mat
shown in Figure 3 can be formed by simply carrying the
light-weight tire beads to the blasting site and then
tieing them together and superimposing one mat above
the other without the necessity for using a crane.
Although the invention has been shown in
connection with certain specific embodiments, it will
be readily apparent to those skilled in the art that
various changes in form and arrangement of parts may
be made to suit requirements without departing from
the spirit and scope of the invention.
