Note: Descriptions are shown in the official language in which they were submitted.
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DRAPER BELT HAVING IMPROVED DURABILITY
This invention relates to conveyor belts, and more particularly, concerns wide-
aspect conveyor belts known as draper belts having improved durability and
service life.
Conveyor belts have been long been used in industry to rapidly move large
amounts of materials. Conveyor belts are used to move logs, pulp, paper, sand,
gravel,
aggregate, food, mine ore, construction materials, packages, grain, and the
products of
various manufacturing processes.
One important conveyor belt market involves the agricultural business. Wide-
aspect belts are extensively used in farm machinery, especially harvesting
implements.
See U.S. Patents 4,371,580 and 4,518,647. For example, a farm implement known
as a
swather may be provided with an elongated cutter bar to cut grass, wheat,
oats, barley,
rice, canola or other grains. Conveyor belts known as draper belts are located
immediately behind the cutter bar to convey the cut materials to crimp rollers
or other
processing subsystems, or to the ground.
These draper belts must operate for long periods of time under adverse
environmental conditions. Heat, cold, dirt, vibration and equipment
misalignment can
strain these belts and substantially shorten their service life.
It is accordingly an object of the present invention to provide draper belting
having improved durability and consequently lengthened service life.
It is a more specific object of the invention to provide a draper belt having
improved construction at its edges so as to increase its durability and
lengthened service
life.
It is another specific object of the invention to provide draper belting
having an
improved cleat design so as to increase the belting durability and lengthening
its service
life.
Other objects and advantages of the invention will become apparent upon
reading
the following detailed description and upon reference to the drawings.
Throughout the
drawings, like reference numerals refer to like parts.
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Brief Description of the Drawings
Figure 1 is a plan view of selected portions of a swather farm implement
having a
set of draper or material conveyor belts.
35 Figure 2 is a side elevational view showing, in schematic form, portions of
the
swather farm implement shown in figure 1.
Figure 3 is a perspective view of portions of the swather shown in figures 1
and 2.
Figure 4 is a side elevational view, showing in schematic form, a portion of a
draper belt constructed in accordance with the prior art.
40 Figure 5 is a perspective view showing a portion of the prior art draper
belt shown
in figure 4 as it can appear after having been torn or damaged.
Figure 6 is a perspective view showing a portion of the novel draper belt of
the
present invention.
Figure 7 is an isometric view of the novel draper belt of the present
invention
45 shown in figure 6.
Figure 8 is a schematic diagram of the belt suggesting the belt plies and ply
arrangements.
Detailed Description
50 Turning more particularly to the drawings, there is shown in figures 1- 3,
a
swather farm iinplement 10 of the sort used to harvest hay. This swather
(presumed to be
moving in the direction of travel T as indicated by the arrows in figures 1
and 2) includes
a cutter bar 12, behind which conveyor belts or draper canvases 14 and 15
receive the cut
and fallen material from the cutter bar 12. These draper belts 14 and 15
convey the cut
55 material in the direction indicated by the arrows M in figure 1 to a center
portion of the
machine 10 where the material is received and conveyed rearwardly by another
belt 16.
The material can be passed through crimping rollers 18 and is ejected from the
machine
as indicated in figure 2 or it can be discharged directly to the ground.
Alternatively, the
cut material may be conveyed to the either side of the header for discharge.
60 To discourage material from slipping on the belts 14 and 15, the belts 14,
15 and
16 are each provided with cleats 20 at regularly spaced intervals. These
cleats are
attached to the belt by any known means such as an adhesive whicll, is spread
entirely
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through and over the belt - cleat interface area. Alternatively, the cleats
can be integrally
molded with the belt.
65 As indicated in figures 4 and 5, the prior art draper belts 30 are prone to
damaging
separation or tearing. This separation often occurs adjacent a prior art cleat
31 because
the belt is subject to stress spikes at the cleat leading edge. Relatively
large amounts of
stress are imparted to the belt adjacent the cleat 31 as the belt and cleat
travel over the
belt-mounting roller 32 which has a constricted diameter.
70 To discourage this damage or tearing and to enhance durability and belt
edge
regidity in accordance with the invention, the novel belt of the present
invention 40 is
provided. As shown in figures 6,7, and 8, the novel belt comprises a first ply
41 formed
of synthetic/natural rubber; a second ply 42 formed of synthetic/natural fiber
woven
fabric; and a third ply 43 formed of synthetic/natural rubber. This third ply
43 can be
75 about twice as thick at the belt edges as it is at the belt mediate
portion.
To reinforce the belt edges in accordance with the invention, a reinforcing
fourth
ply 44 formed of synthetic/natural fiber woven fabric and a fifth ply 45
formed of
synthetic/natural rubber each extend span wise inwardly from the outer belt
edges by an
amount preferably about 15% on each side, for a total of both sides of about
20% to 40%,
80 and preferably about one-third, of the belt span dimension. Belt tearing is
discouraged by
providing different material in the belt base ply and in the side
reinforcement laminate.
The synthetic/natural rubber is used to protect the synthetic/natural fiber
woven fabric
from damage arising from the material being conveyed, and from the roller or
other
structure of the equipment. The synthetic/natural rubber is also used to bond
the plies of
85 synthetic/natural fiber woven fabric.
To extend the region of the belt which is subjected to stress and strain as
the cleat
51 and belt turn over a mounting roller 32 as shown in figure 6, the novel
cleat 51 is
provided with a longitudinally extended base 53. Here, this base 53 includes
an
intennediate portion 54 of gradually diminishing thickness, arid a terminal
formation 55
90 extending from the intermediate portion 54, as particularly shown in figure
6. The cleat
51 can be formed of any suitable material such as styrene butadyrene or acrylo-
nitrile
material and includes a reinforcing fiberglass bar 56, preferably of diainond
shape as
also suggested in figure 6.
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The'novel belt 40 and its cleats 51 are shown in further detail in figures 7
and 8.
95 To discourage wear and tear and to further strengthen the belt edges in
accordance with
the invention, the belt 40 includes a protective rubber base 41 and an
overlying ply of
protective rubber reinforcing material 42. This reinforcing material 42 can
consist of a
flexible tensile reinforcing material such as Nylon, Polyester, Cotton or
other load
bearing tensile member and may, if desired, include a substrate of filament or
spun
100 polyester, nylon, cotton, or other materials, obtainable from any of a
number of known
sources. The upper layer of spun or filament fabric 42 extends the full width
of the belt
or draper. The fabric includes a great number of individual fibers of finite
length which
have been previously woven into a yarn, in known manner. The bottom substrate
or ply
41 of the belt 40 includes a styrene butadyrene or acrylonitrile butadyrene
material, or it
105 can include a suitable natural rubber.
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