Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates to conveyor belts
and especially to belts having load-retaining walls a-t the
edges.
In most belt conveyors the belt is manufactured
in a flat configuration but is troughed for retaining the
conveyed material by rollers set at an angle and engaging
the edge portions. Belts have also been molded in a
U-shape such as the belt of my U.S. Patent No. 4,061,223.
In another case it was proposed to transversely prestretch
the upper ply of a belt prior to curing so tha-t after curing
it would contract and cause the belt edges to curve upwardly.
It has also been proposed to make the plies at the edges of
the belt of materials having different coefficients of
expansion so that during operation in a low temperature
environment the edge portions will be curled upward and
retain a fluid material. Other belts have been proposed
having hinged edge portions which are supported by special
brackets between a supporting power belt and the load-carrying
container belt.
In some cases it is desirable to enclose the space
over the load-carrying surface and belts have been made with
retaining walls which have connecting edges. These belts
have usually required elaborate mechanical equipment for
connecting and disconnecting the edges.
According to the present invention, there is pro-
vided a conveyor belt which is longitudinally stretchable at
least 5 percent, said belt embodying belt narrowing means
responsive to longitudinal s-tretching of said belt, and
means resisting narrowing of said belt, said belt narrowing
means being closer to -the load-carrying surface of said belt
than said means resisting narrowing, whereby -tension on the
belt genera-tes transverse forces bending the edges of the
belt to form retaining walls for the load carried by the belt.
The present invention is directed to a conveyor
belt which is stretchable a predetermined amount upon ins-
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tallation.
As abobe mentioned the belt edge portions curl
up during the stretching and provide load-re-taining walls.
These walls may curl a greater or lesser amount depending
on the belt construction and, where desired, may curl
enough to connect the edges and enclose the material being
conveyed. The belt edge portions curl up upon longitudi-
nal stretching of the belt due to the interaction of belt
narrowing means responsive to stretching of the belt and
means resisting narrowing of the belt.
The belt narrowing means can be one or more
layers of bias cords which pantograph upon elongation of
the belt.
The means resisting narrowing can be a layer
of transversely ex-tending cords or the elastomeric material
of the belt.
It is usually desirable to have a belt cover a-t
the load-carrying surface to protect the belt narrowing
cords but the means resisting narrowing under the narrowing
means must be sufficient to overcome the resistance of the
elastomeric material of the cover and provide a sufficient
net resistance in the desired direction to produce the
curvature needed.
Since the edges of the belt in the present
invention are under sufficien-t tension to hold the load
without distortion, simple flat rollers may be used to
support the load-carrying belt run.
Another advantage is derived from the minimum
tension required to stretch the belt a predetermined amount
upon installation. This minimum tension is more or less
maintained throughout the belt length providing a built-in
take-up action distributed along the entire belt conveyor
rather than concentrating this action at a single point on
the conveyor which may be a considerable distance from
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where the take-up action is needed.
The novel construction thus provides a more
uniform distribution of s-tresses and makes possible a
conveyor which may have rollers spaced apart a greater
distance than rollers for a conventional conveyor.
Preferred embodiments will now be described as
example only, without limitative manner, with reference to
the drawings, wherein: -
Fig. 1 is a schematic side elevation of a
stretchable belt embodying the invention mounted on a
conveyor in the stretched condition, parts being broken
away, and the unloading and loading conveyors being shown
in chain-dotted lines.
Fig. 2 is a schematic plan view of the belt and
conveyor shown in Fig. 1.
Fig. 3 is a fragmentary enlarged sectional view
taken along the line 3-3 in Fig. 1.
Fig. 4 is an enlarged cross-sectional view of
the belt of Figs. 1-3 in the unstretched condition showing
the position of the reinforcing cords.
Fig. 5 is a cross-sectional view of the stret-
chable belt of Fig. 4 showing the belt in the stretched
condition.
Fig. 6 is a fragmentary cutaway plan view of
the belt of Fig. 4 showing -the position of the reinforcing
cords and plies.
Fig. 7 is a cross-sectional view of a modifi-
cation of the belt construction embodying the invention.
Fig. B is a fragmentary cutaway view of the
belt of Fig. 7.
Fig. 9 is a cross-sectional view of another
modification of the invention.
Fig. 10 is a fragmentary cutaway view of the
belt of Fig. 9.
Plg~ a cros~-~ectional view o~ a belt
construction simllar to the belt of Figs. 9 and 10.
Fig. 12 ~8 ~ cros~-sec:tlonnl vlew of ~ modi~i-
cation ~hown in the unstretched condition in whlch the
belt i~ adapted to be trained around curve~.
Fig. 13 iB A frag~entary cutaw~y plan vlew o~
the belt of Flg. 12 in the unstretched conditio~.
Fig. 14 is a partially schematlc cro~-eectional
view of the belt of Figs. 12 and 13 ~howing the belt in
the stratched conditlon.
Fig. 15 i~ a cro~ ection~l view of a belt
simllar to the belt of ~iy8. 12, 13 nnd 14.
Fig. 16 i8 A fragmentary cutaway plan view o~
th~ belt of Fig. 15.
Fig. 17 15 a schemAtic plan view of ~ conveyor
includlng a further belt modification h~ving ~dge~
which are connected for enclo~ing the materlal conveyed.
~ lg. 18 i8 n fragmentary cro~ ection~l vlew
of the helt of ~ig. 17 taken along the line 18-18 in
Fig. 17.
Fig. 19 18 a cro~ ection~l view of the belt
of Fig. 17 ~hown ln the unstretched conditionO
Fig. 20 i~ an enl~rged fragmen~ry sectlon~l
vlew taken along the line 20-20 in Fig. 17,
Pig. 21 i~ an enl~rged ~r~gme~tary soctlonal
view taken along the line 21-21 in ~ig. 17,
Fig. ~2 le a sectional vlo~ o~ ~nother b~lt
similar to the belt o~ Flgn. 17-20.
~eferrlng to Fig~. 1 and 2, z conveyor 10 ~8
shown located ln a horlzont~l posltion for conv~ying
bulk materlals such as coal ~rom a loadlng belt 11 at
one end to an unlo~dlng b~lt 12 ~t the other end. The
convayor 10 h~a a ~tr~tchable conveyor belt 13 extending
over termlnal pulleys 8uch as tail pulley 14 and
di.~charge pulley 15 located at the ends of the con-
veyor. A ~uitable be~t drive 16 include6 an electric
motor 17 or ~ther ~uitable power means connected to
the dl.scharge pulley 15 by a flexlble chain or belt
drive assen~ly 18.
With reference to F:Lgs. 1 and 3, a load-
carrying upper run 19 of the conveyor ~elt 13 is
supported by support rollers 22 mounted on roller
frame~ 23 spaced longltudlnally ~long the conveyor 10.
A lower run 24 of the conveyor belt 13 is supported on
split rollers 25 rotatably ~ounted on cent~r supports
26 which are ~tened to the roller frn~es 23.
As ~hown ln ~igs. 4 and 6, the conveyor belt
13 include~ an elongated elastomer~c ~ody o rubber or
other rubberlike material with spac~d-apar~ ~dges 27
snd 28. A load-carrying belt surface 31 extends between
the edge~ 27 and 28 and i~ located at the top side of
the ~elt when in the load-carrying upper xun 19 of the
conveyor 10.
The conveyor bslt 13 i8 stretchable at least
5 percent when sub~e~ted to lo~gitudlnal forces ln
tenslon and ~ mounted in ten~ion on the conveyor 10.
In this embodim~nt the conveyor belt 1~ 1~ spliced a~
a length such that th~ b~lt ls elongated at lea~t 5
percent when 'n the mounted po~ition on the aonveyor 10.
Belt narrowing me~ns re~pon01ve to ~etching
of the ~elt 13 ~uch a~ fir~t and second layers 32 ~nd
33 o~ bl~s cord r~in~orcing makerial g~nerate pxedetoro
30 mined transverse orces in a dlrection to reduce the
width of the belt upon stretchlng durlng the lniti~l
installation on the convoyor 10. Slnce the transverse
force~ generat~ by the layera 32 and 33 are closest ~o.
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the upper belt surface 31 and are resisted by the stiffness
of the underlying material, the edges 27 and 28 and edge por-
tions 29 and 30 of the belt 13 are caused to curl or bend
upwardlyr as shown in Fig. 5, and thereby provide re-taining
walls 34 and 35 at the edges for retaining material on the
belt surface.
In other words, the first and second layers 32 and
33 are positioned closer to the belt surface 31 carrying the
load than they are to the surface on the other side of the
belt and this is believed to contribute further to bending of
the edge portions 29 and 30 upwardly along the belt surFace
31. Also, as shown in Fig. 4, the first and second layers 32
and 33 separate the resilient material of the conveyor body
into an upper portion 36 between said layers and the belt sur-
face 31 and a lower portion 37 on the other side of the firstand second layers. Accordingly when the belt 13 is stretched
the reduction in width of the belt surface 31 between the
edges 27 and 28 is greater than the reduction in width of the
belt at the lower portion 37 which further contributes to the
curling or bending of the edges upwardly and away from the
belt surface 31.
The belt 13, shown in detail in Figs. 4, 5 and 6,
has a top cover 38 which may be of the same resilient material
as the rest of the belt, or may be of a more wear-resistant
material, because the belt surface 31 over this cover is
exposed to abrasion from the material to be conveyed. The
elastic material of the belt 13 is highly stretchable and has
a hardness on the durometer scale from about 60 to 80. For
installations in coal mines the material may be a flame-
resistant elastomer. For above-ground operation, the material
of the belt 13 may be any convent ~
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resistant rubber. The first and second layers 32 and 33
have reinforcing cords 39 and 40 laid on a bias of about 55
degrees and may be at angles in the range of from about 40
degrees to about 60 degrees relative to a transverse axis
A-A of the belt shown in Fig. 6. The first layer 32 extends
from edge 27 to edge 28 and the second layer 33 is coexten-
sive with and positioned under the first layer, but with
the cords 40 laid at an opposite bias angle to the cords 39
of the first layer.
10A third layer 43 of reinforcing cords is coexten-
sive with and positioned under the second layer 33 and is
formed of parallel cords 44 extending substantialIy trans-
versely of the belt 13. A fourth layer 45 of reinforcing
cords 46 is positioned under the third layer 43 with layer
15edges 47 and 48 spaced from the edges 27 and 28 or the belt
13. The cords 46 of the fourth layer 45 are laid on a bias
at substantially the same angle as the cords 39 of the first
layer 32. A fifth layer 49 of reinforcing cords 50 is
coextensive with and positioned under the fourth layer 45
and has the cords laid on a bias at substantially the same
angle as the cords 40 or the second layer-33.
The presence of the narrow band consisting of
layers 45 and 49 of reinforcing material on the other side
of the midplane balances the forces so that the reduction
in width when the belt is stretched does not curl the center
of the belt.
In the belt 13 of this embodiment, the cords 39,
40, 44, 46 and 50 of the first through fifth layers 32, 33,
43, 45 and 49 are of polyester and are spaced at about 22
ends per inch with each layer having a total thickness of
about 0.05 inches. Separating or
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cushioning components 51 of elastomeric material are provided
between the layers 32, 33, 43, 45 and 49 so that there can be
relative angular movement of the cords 39 and 40, 40 and 44,
44 and 46, and 46 and 50. The relative movement of the cords
contributes to the stretching of the belt 13 in the longitu-
dinal direction and can be increased or decreased by changing
the thickness of the cushioning components 51. In building
the belt 13, the cords 39~ 40, 44, 46 and 50 may be covered
by a skim coat of elastomeric rubber and after vulcanization
the skim coats of overlapping layers form the cushioning com-
ponents 51.
In the belt 13, shown in Figs. 4, 5 and 6, the
cords 39, 40, 44, 46 and 50 have a thickness of about 0.03
inches and a skim coat of from about O.Ol to 0.02 inches is
calendered or otherwise applied to each side of the cords
resulting in each of the cushioning components 51 having a
thickness of from about 0.02 to 0.04 inches. When the belt
13 is vulcanized the thickness of the cushioning components
51 will be reduced because of the removal of air and compact-
ing of the elastomeric material. The top cover 38 has a
- thickness of about 0.06 inches and a bottom layer or bottom
cover 53 of the belt 13 has a thickness of about 0.06 inches
at the center portion. The total thickness of the belt 13 in
- the vulcanized condition is about 0.37 inches. The belt 13
-of this embodiment has a total wid-th of about 38 inches. The
width of the fourth and fifth layers is about 20 inches and
the width of each of the edge portions 29 and 30 of the belt
is about 9 inches. The thickness of the bottom cover 53 is
greater by 0.1 inches or 0.16 inches at the edge portions 29
and 30. This compares with the thickness of the top cover
38 of only 0.06 inches. It is therefore believed that the
greater thickness of the bottom cover 53 adjacent the edges
27 and 28 of the belt 13 as co~ared with the thickness of the
top cover 38 contributes to the curling or bending of the
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edge portions 29 and 30 away fr~m the bottom cover and
towards the top cover. In fact lt has been found that the
greater the difference in thickness between the top cover 38
and the bottom cover 53 the greater is the tendency of the
edge portions 29 and 30 to curl.
The belt 13 is built and vulcanized in a ~lat con-
dition, as shown in Figs. 4 and 6, and then installed in a
stretched condition as shown in Figs. 1, 2, 3 and 5. The
initial stretching of the belt 13 of at least 5 percent and
preferably in the range of from 5 to 15 percent causes the
cords 39 and 40 of the first and second layers 32 and 33 and
the cords 46 and 50 of the fourth and fifth layers 45 and 49
to pantograph and progressively resist further elongation as
the belt is stretched. It has been found that with the cord
angles of around 55 degrees relative to the transverse axis
A-A the belt 13 may be stretched between 5 and 15 percent
after which the resistance to stretching is substantial and
sufficient for load-carrying operation of the conveyor 10.
It has also been found that the pantographing of the cords
39 and 40 in the first and second layers 32 and 33 generates
a substantial transverse force which interacts with the
resistance of the resilient material of the belt 13 and bends
the edge portions 29 and 30 upwardly to function as retaining
walls 34 and 35 as shown in Fig. 5. The cords 46 and 50 of
the fourth and fifth layers 45 and 49 neutrali~e the action
of the cords 39 and 40 of the first and second layers 32 and
33 at the center portion of the belt 13, thus maintaining a
relatively flat surface 31 between the curled side edge
portions 29 and 30. The transverse cords 44 of the third
layer 43 further resist a reduction in width or narrowing of
the belt 13 and accordingly con-tribute to the curling or
bending of the edge portions 29 and 30. Nevertheless, when
the belt 13 passes over the tail pulley 14 and discharge
pulley 15 it will flatten out as shown in Figs. 1 and 2. -
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In the return lower run 24 the belt 13 is in the
stretched condition and retaining walls 34 and:35 extend
downwardly at each side of the split rollers 25. As shown
in Fig. 3, if the belt 13 in the lower run Z4 travels to
either side, it wi-ll-be prevented from running of:E the split
rollers 25 by engagement of the retaining walls 34 and 35
with the ends of the split rollers.
As described hereinabove, when the belt 13 is
subjected to a sufficient tension, the walls 34 and 35 will
be retained in the operating condition for containiny the
bulk material so tha-t the rollers 22 may be cylindrical. The
substantial tension maintained throughout the leng-th of the
- belt 13 also makes possible a greater spacing between the
support rollers 22 than is possible with a conventional con-
veyor belt.
Referring to Figs. 7 and 8, a modified constructionof a conveyor belt 54 is shown having an elongated elastomeric
body of resilient material with spaced edges 55 and 56. A
first layer 57 has reinforcing cords 58 laids on a bias of
about 45 degrees to transverse axis B-s of the belt and
ex'~ends between the edges 55 and 56 of the belt 54. The belt
54 has a load-carrying belt surface 59 on a top cover 62 under
which the first layer 57 is located. A second layer 63 of
reinforcing cords 64 is positioned under said first layer,57
- with the cords laid at an opposi-te bias angle of 45 degrees
to the angle of the cords 58 of -the first layer. The second
layer 63 has edges 65 and 66 whi.ch are spaced from the edges
55 and 56 of the belt 54 providing a center portion between
the edges 65 and 66. Edge portions 67 and 68 are also pro-
vided between the edges 55 and 65 and the edges 56 and 66.
A bottom cover 69 is positioned under the second
layer 63 and has a thickness of about 0.07 inches at the
center portion. The top cover 62 also has a thickness of
about 0.07 inches and the first layer 57 and second layer 63
each have a thickness of about 0.05-inches. A cushioning
component 70 is located between the cords 58 and 64 of the
first and second layers 57 and 63 and may have a -thickness
of about 0.01 to 0.02 inches prior to vulcanization of the
be-lt 54. As shown in Figs. 7 and 8, the thickness of the
bottom cover 69 at the edge portions 67 and 68 is greater
than the thickness at the center portion which further con-
tributes to the curling or bending upwards of the edge por-
tions.
The cords 58 and 64 of the first and second layers
57 and 63 are of a suitable textile material such as polyester
and may be spaced at about 22 ends per inch. The width of
the belt is about 34 inches with the center portion having a
width of 10 inches and the edge portions 67 and 68 each having
a width of about 12 inches in the unstretched condition. The
belt 54 is stretchable at least 5 percent and when stretched
decreases in width a proportional amount. Also the edge por-
tions 67 and 68 bend upwardly to provide retaining walls at
the sides of the belt surface 59 in the stretched condition
in a similar manner to that described hereinabove for the
embodiment of Figs. 4, 5 and 6. The cords 64 of the second
layer 63 neutralize the curling action of the cords 58 of the
first layer 57 and provide a relatively flat surface 59 between
the curled side edges 55 and 56.
Another modification is shown in Fiys. 9 and 10 in
which a belt 71 has an elongated elastomeric body with edges
72 and 73 and a belt surface 74 extending between the edges.
The belt 71 has a center portion 75 with margins 76 and 77
spaced from the edges 72 and 73 providing edge portions 78
and 79. The belt surface 74 is on a top cover 82 which has a
thickness of about 0.07 inches. The top cover 82 may be of a
resilient material having good wear characteristics as indi-
cated above. Under the top cover 82 is a first layer 83 of
reinforcing cords 84 and 85 in the edge portions 78 and 79,
~L~6~75
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respectively. The irst layer 83 extends from the eclges
72 and 73 of the belt 71 to the margins 76 and 77 of the
central portion 75 in the edge portions 78 and 79. The
cords 84 in the edge portion 78 are laid on a bias to the
transverse axis C-C at an angle of 45 degrees in one direc-
tion. The cords 85 of the edge portion 79 are laid at an
angle of 45 degrees to the transverse axis C-C and at an
opposite bias angle -to the cords 84 of the other edge portion
78. Under the first layer 83 is a second layer 86 of.re-
inforcing cords 87 and 88 in edge portions 78 and 79 laid at
an angle of 45 degrees to the transverse axis C-C but at an
- opposite bias angle direction to the cords 84 and 85 of the
first layer.
Under the second layer 86 is a third layer 89 of
square woven stretch fabric 90.
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~L~6Za~S
The third layer 89 extends from one edge 72 of the belt 71to the other edge 73. The stretch fabric 90 of the third
layer 89 has the property of stretching a predetermined
distance when subject to tension during the initial stretch-
ing of the belt 71 and then its resistance to further elon-
gation increases rapidly to resist any appreciable stretching
of the belt in operation.
In this modification, the top cover 82 has thick-
ness of about 0.07 inches. The first layer 83 is of poly-
ester cords spaced at about 22 ends per inch with the firstlayer having a thickness of about 0.05 inches. The second
layer 86 also has a thickness of about 0.05 inches and
polyester cords spaced at about 22 ends per inch. A bottom
cover 93 under the third layer 89 has a thickness of about
0.07 inches. Cushioning components 92 are located between
the cords 89 and 85 of the first and second layers 83 and
86 and between the cords 87 of the second layer 86 and the
stretch fabric 90 of the third layer 89. The cushioning
components 92 may have a thickness of about 0.01 to 0.02
inches prior to vulcanization.
In operation the belt 71 is built and vulcanized
in the flat condition as shown in Figs. 9 and 10 with the
stretch fabric 90 of the third layer 89 in the unstretched
condition. Upon installation of the belt 71 on a conveyor,
the belt is initially stretched a predetermined amount of
at least 5 percent, at which point further stretching of the
belt is stronlgy resisted. During the stretching process,
the cords 84, - - -
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85, 87 and 88 of the first and second layers 83 and 36
pantograph and bend the edge portions 78 and 79 upwardly at
the sides of the belt surface 74 providing retaining walls
such as those shown in Figs~ 3 and 5. With the stretch
fabric 90 of the third layer 89 -the longitudinal force neces-
sary for initial stretching of the belt 71 is less than it
would be if the stretching of the belt was limited by layers
of reinforcing cord laid on a bias such as that shown in the
modifications of Figs. 4 through 8. Also -transverse cords oE
the stretch fabric 90 resist reduc-tion in width of the belt
71 and contribute to -the bending of the edge por-tions 78 and
79.
Referring to Fig. 11, a belt 71' is shown which is
identical to the belt of Figs. 9 and 10 except that in the
second layer 86' a center portion 94 has been added to fill
the space between the margins 76' and 77'. The center portion
94 of the second layer 86' is of square woven stretch fabric
95 having the property of being stretchable upon initial
stretching of the belt 71' during installation on the con-
veyor and then having a high resistance to further stretchingof the belt in operation. The stretch fabric 95 of the center
portion 94 of the second layer 86' may have the same charac-
teristics as the stretch fabric 90 of the third layer 89 of
the belt 71 sho~n in Figs. 9 and 10. The cushioning component
92' between the cords of the second layer 86' and the stretch
fabric of the third layer 89' also extends between the stretch
fabric of the second and third layers. In operation, the belt
of Fig. 11 is stretchable and will provide upstanding re-tain-
ing walls in a similar manner to the belt of Figs. 9 and 10:
however, the belt of Fig. 11 may have greater strength in the
longitudinal direction in the s-tretched condition.
- A belt 96 adaptable for movement around curves is
shown in Figs. 12, 13 ancl 14. 'l'l~e belt 96 has an elonga-ted
elastomeric body with a top portion 97 and a bottom portion
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98 connected at a center portion 99. As shown in FicJs. 12
and 13, the top portion 97 has a top cover 102 extending
between edges 103 and 104 which may be of a resilien-t
material having good wear characteristics. Under the top
cover 102 is a first layer 105 of reinforcing cords 106 in
eage portions 108 and 109 extending inward from edges 103 and
104 to the center portion 99. The cords 106 in the edge por-
tions 108 and 109 are laid at a bias angle of about 45 degrees
to the transverse axis D-D.
Under the first layer 105 is a second layer 112 of
reinforcing cords 113 coextensive with the cords 106 of the
first layer 105. The reinforcing cords 113 are laid at an
angle of about 45 degrees to the transverse axis D-D and at
an opposite bias angle to the cords 106 of the first layer
105.
Under the second layer 112 is a third layer 115 of
transversely extending cords 116 between the edges 103 and
104 of the belt 96. Under the third layer 115 is a middle
cover 118 which is connected at the center portion 99 to a
middle cover 119 of the bottom portion 98. As shown in Figs.
12, 13 and 14, the bottom portion 98 in the unstretched con-
dition preferably has a width less than the width of the top
portion 97.
Under the middle cover 119 is a fourth layer 122 of
reinforcing cords 123 extendiny -transversely between the
edges 103 and 104 of the bottom portion 98 of the bel-t 96.
Preferably the reinforcing cords 123 are of a high modulus
material such as steel.
Under the fourth layer 122 is a fifth layer 124 of
reinforcing cords 125 positionecl at a bias angle substantially
the same as the bias angle of the cords 106 of the first layer
105 and extending from edge-to-edge of the center portion 99.
Under the fifth layer 124 and coextensive therewith is a
sixth layer 126 of reinforcing cords 127 laid on a ~ias at an
~1~2~75
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angle similar to the angle of cords 113 of the second layer
112.
Under the sixth layer 126 is.a seventh layer ].28
of reinforcing cords 129 extending transversely between the
edges 103-and 104. The cords 129 are preferably of high
modulus material such as steel. Under the seventh layer 128
is a bottom cover 130 which e~tends from edge 103 to edge 104
of the bottom portion ~8. The transverse cords 129 of -the
seventh layer 128 and cords 123 of the fourth layer 122 are
spaced longitudinally of the belt 96 sufficiently to permit
longitudinal stretching of the belt 96 by an initial amount
of at least 5 percent. During this stretching the cords 106
and 113 of the first and second layers 105 and 112 interact
with the transverse cords 116 of the third layer 115 and with
the elastomeric material of the belt 96 causing the upper
surface of the edge portions 108 and 109 to contract laterally
and bend upwardly forming retaining walls 131 and 132 for con-
taining material being conveyed on a load-carrying belt sur-
face 133. Cushioning com~onents 139 are located between the
cords of the first and second layers 105 and 112, the second
and third layers 112 and 115, the fourth and fifth layers
122 and 124, the fifth and sixth layers 124 and 126, and the
sixth and seventh layers 126 and 128.
. The belt 96 is-fabricated and molded in the flat
condition shown in Figs. 12 and 13 with the edge portions 108
and 109 of the top portion 97 and bottom portion 98 separated
by a sheet or plate of material to form slots 134 and 135
- extending to the center portion 99. In operation the belt 96
is stretchable an initial amount of from 5 to 15 percent due
to the pantographing of the reinforcing cords 106 of the
first layer 105, reinforcing cords 113 of the second layer
112, cords 125 of -the fifth layer 124, and cords 121 of the
sixth layer 126. The in-teraction of the cords 106 of the
f~rst layer 105 and the cor~s 113 of the second layer 112
7~i
- 17 -
- with the elastomeric material of the belt 96 and the trans-
verse cords 116 of the third layer 115 during the stretching
of the belt causes the edge portlons 108 and 109 to bend
upwardly and form -the walls 131 and 132.
In this embodiment the top cover 102 has a thick-
ness of about 0.07 inches a-t the edge portions 108 and 109
and about 0.13 inches at the center portion 99. The re-
inforcing cords 106 of the first layer 105 and cords 113 of
the second layer 112 may be of polyester and be spaced at
about 22 ends per inch. The thickness of the first and
second layers 105 and 112 may be about 0.05 inches each. The
third layer 115 may also have reinforcing polyester cords 116
spaced at about 22 ends per inch and have a thickness of about
0.05 inches. The middle cover 118 for the top portion 97 may
have a thickness of about 0.07 inches.
The middle cover 119 of the bottom portion 98 may
also have a thickness of about 0.07 inches. The transverse
reinforcing cords 123 and 129 of the Eourth and seventh layers
122 and 128 may be steel strands spaced at eight ends per inch
and having a thickness of about 0.1 inches. The fifth and
sixth layers 124 and 126 may have reinforcing polyester cords
125 and 127 spaced at about 22 ends per inch with a thickness
of about 0.05 inches for each layer. The bottom cover 130 may
-have a thickness of 0.07 inches. The cushioning components
139 may have a thickness depending on the thickness of the
skim coat on the cords. The cords of polyester have a skim
coat of a thickness oE from about 0.01 to 0.02 inches and the
- cords of steel have a skim coat of from about 0.01 to 0.03
inches. Therefore the to-tal thickness of the cushioning com-
ponents 139 may be from about 0.02 to 0.05 inches.
In operation when the bel-t 96 is clirected around a
curve the bottom portion 98 resists transverse deflection of
the belt and supports the top portion 97 which has the walls
131 and 132 for re-taining the material on the belt surface
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133. Due to the stretching of the,walls 131 and 132 they
will be maintained in position even though the elongation of
the belt 96 varies across -the wicl-th of the bel~. Normally
pulleys (not shown) are positioned around the edges 103 and
104 of the bottom portion 98 and also under the bottom cover
130 to maintain the configuration of the belt 96 around curves.
- A belt 136 is shown in Figs. 15 and 16 which is
similar to the belt 96 shown in Figs. 12, 13 and 14. However~
instead of the fifth and sixth layers 124 and 126 of re-
inforcing cords 123 and 125 being positioned at a bias angle
to the transverse axis D-D, a separating layer 137 oE square
woven stretch fabric 138 extending between the edges of the
center portion 99' is positioned between the fourth and
seventh layers 122' and 128'. The stretch fabric 138 of the
separating layer 137 has the property of stretching a pre-
determined distance upon initial stretching during installa-
tion of the belt 136 from about 5 to 15 percent and then has
a high resistance to further stretching of the belt in opera-
tion. In other respects the construction of belt 136 of Figs.
15 ancl 16 is the same as the construction of the belt 96
except there is one less cushioning component 139'. In
operation the transverse cords of the stretch fabric 138 and
the elastomeric material of the belt 136 interact with the
reinforcing cords 106' of the first layer 105' and the cords
113' of the second layer 112' to bend the edge portions 108'
and 109' of the top portion 97' upwardly into the shape shown
in Fig. 14.
Referring to Figs. 17, 18, 19, 20 and 21 a further
modification is shown in which a belt 142 having a construc-
tion shown in greater detail in Fig. 19 has edge portiQns 143
and 144 and a center portion 145. The edge portions 143 and
144 are located between the center portion 145 and edges 146
and 147 of the belt 142. The eclge portions 143 and 144 may
be divided into outer margins 148 and 149 ad~acent the edges
.... . .. . .. . ....... . ... .. . . .
- 19 -
146 and 147 and inner margins 152 and 153 adjacent the
center portion 145. The bel-t 142 may be of an elastomeric
material and have a construction similar to the construction
described hereinabove for the belt 13 shown in Figs. 4 and 5
except that the belt 142 shown in Fig. 19 has edge portions
143 and 144 of greater wid-th than the edge portions of the
belt 13 by the width of the outer margins 148 and 199. Also
the third layer 43' extends beyond the ends of the first and
- second layers 32' and 33' so that when the belt 142 is in
the stretched condition as shown in Fig. 18 the edye portions
143 and 144 will overlap to enclose the space above the load-
carrying belt surface 31l. With the construction of the belt
142 the thickness of the belt at the outer margins 148 and
149 is reduced which also reduces the weight at the edges
146 and 147.
As shown in Figs~ 19 and 20 connecting means such
as channels 154 and 155 are mounted on the bottom cover 53'
at the outer margin 149 and ribs 156 and 157 are mounted on
the surface 31' of the top cover 38' at the other outer
margin 148 for matching engagement upon pressing of the
margin 148 against the margin 149 by suitable means such as
rollers 158 and 159. As shown in Fig. 17 the rollers 158
and 159 may be mounted on a frame 162 at one end of a con-
veyor 163 close to the tail pulley 164. After the load is
applied to the belt surface 31' and the belt 142 takes the
configuration shown in Fig. 18 the ribs 156 and 157 may be
pushed into engagement with the channels 154 and 155 provid-
ing a sealed chamber within the belt for conveying material.
At the discharge end of the conveyor 163, discharge pulley
165 tends to spread the walls 34' and 35' and as shown in
Fig. 21 separating rollers 166 and 167 may be used to assist
in this ac-tion and pull the ribs 156 and 157 out oE the
channels 154 and 155 so that the material conveyed on the
surface 31 may be discharged and the return run 168 carried
75~
-- 20 --
back to the tail pulley 164 by suitable rollers 169 as
shown in Fig. 18. The upper run 170 may be supported by
support rollers 172. As shown in Fig. 18 a roller frame 173
mounted on a supporting surface such as the ground or hung
from the roof supports the rollers 169 and 172.
In operation the belt 142 is mounted on the con-
veyor 163 under tension in a similar manner to that described
hereinabove for the other modifications. As the belt 142 is
driven from the tail pulley 164 to the discharge pulley 165
the rollers 158 and 159 will urge the ribs 156 and 157 into
engagement with the channels 155 and 154. Then at the dis-
charge end the discharge pulley 165 spreading -the walls 34'
and 35' and supplemented by the separating rollers 166 and
167 will pull the ribs 156 and 157 out of the channels 154
and 155 and permit the discharge of the material at the dis-
charge pulley 165. The elastomeric material of the belt 142
and the reinforcing cords may be the same as that described
hereinabove for the belt 13 of Figs. 4, 5 and 6. The channels
154 and 155 and ribs 156 ana 157 may be of a resilient ma-
terial such as nylon which is adhered to the belt 142 by a
suitable adhesive.
Referring to Fig. 22 a belt 174 has a construction
similar to the construction of the belt 71' shown in Fig. 11
except that the first layer 83 " and second layer 86 " extend
over only inner margins 175 and 176 adjacent the central
portion 75 " . Outer margins 177 and 178 extend beyond the
ends of the first and second layers 83 " and 86 " and are
adjacent the edges- 72 " and 73 " of the belt 174. Also con-
necting means such as channels 179 and 182 are mounted on the
bottom cover 93 " at the outer margin 178 and ribs 183 and
184 are mounted on the surface 74 " of the top cover 82 " at
the outer margin 177 for matching engagement upon pressing of
the margin 177 against the margin 178 by suitable means such
as the rollers 158 and 159 shown in Fig. 20.
- 21 -
In operation the belt 174 is mounted on a conveyor
similar to the conveyor 163 shown in Fig. 17 and operated
under tension in the same manner as that described for the
belt 142 shown in Figs. 17, 18, 19 and 20.
In Figs. 19 and 21 the belts 142 and 174 have outer
margins 148, 149, 177 and 178 which are shown substantially
equal in width to the corresponding inner margins 152, 153,
176 and 175. I-t is evident that the outer margins may have a
width substantially greater than the width of the inner
margins and be in relation to the wid-th of -the center por-
tions 145 and 75" so that the edges will overlap to enclose
the load carried by the belts.
While certain representative embodiments and details
have been shown for the purpose of illustrating the inven-tion
it will be apparent to those skilled in the art that various
changes and modifications may be made therein without depart-
ing from the invention.
