Belt conveyor supporting arrangement

A belt conveyor supporting arrangement includes three main components for preventing the belt from being damaged. The first component is a backing bed apparatus comprising a smooth slidable top plate having plural air flow channels at the surface thereof which is supported by a cushion plate. The second component is a skirt plate device for shutting the opening between the surface of the belt and the chute with little contact friction. The third component is a bending tension return-roller apparatus M3 comprising a pair of rollers inclined like the symbol [ ] and having a device for adjusting the angles thereof.

This invention relates to a supporting arrangement for a belt conveyor 
which is used to convey bulk materials, such as ore, stone, coal, etc.; 
especially to one which is arranged at a position where bulk materials are 
transferred to a driven belt from a chute or feeder. 
BACKGROUND OF THE INVENTION 
When bulk materials such as ore, coal and stone are transferred from a 
chute or feeder to a belt conveyor, the belt tends to be damaged. 
Therefore, the chute or feeder is developed so as to lower the dropping 
energy onto the conveyor belt. For instance, a ladder or stone box L is 
mounted on the inside of the chute as shown in FIG. 11 so that the drop 
distance of bulk materials becomes shorter. Alternatively, the chute is 
usually designed with a throat portion and a pair of plates SC as the bulk 
materials tend to jump off the belt and lodge between carrier roller C and 
the belt B as shown in FIG. 12, in which R is a return roller. 
The portion of the belt positioned where bulk materials are transferred 
from the chute is supported by plural carrier rollers C, spaced from each 
other, so that the dropping materials jump about on the belt and engage 
between the belt and the rollers C. In this manner, the belt tends to be 
damaged. Therefore, as shown in FIG. 13, it is proposed that the carrier 
roller is covered by rubber materials, the rollers are supported by rubber 
liners RL and also a carrier table T is supported by coil springs or an 
air cushion device SP. However, such remodeling is unwieldy and such a 
roller supporting system fails to alleviate dropping impact between the 
carrier rollers. 
To avoid such problems, a proposed supporting arrangement for a belt 
conveyor comprises a top plate P, made of high molecular polyethylene, 
which comes into contact with a running belt and an elastic plate R, made 
of natural or synthetic rubber, through which the top plate P is mounted 
on a supporting frame so as to support the conveyor belt B on a lubricous 
surface of the top plate and absorb the dropping impact by the elastic 
plate P (Japanese Utility Model KOUKAI 137711/1985 and 190106/1988). 
In such cases, however, there are some problems such that the top resin 
plate P becomes badly worn in a short time because it comes into constant 
surface contact with the running belt and thus the friction area is larger 
than that in a conventional roller supporting system, so that the resin 
plate tends to soften and wear out owing to friction heat. Furthermore, it 
is difficult to bend a resin plate having sufficient rigidity and 
thickness into the arc troughed shape, which is necessary to convey the 
bulk materials without excessive jumping on the belt surface. Therefore, 
as shown in FIG. 14, the resin plate is divided into at least 3 parts so 
that the belt enters into the opening D between the inclined support 
plates and the horizontal support plate and thus is worn away or cut down. 
In the worst cases, the supporting system itself is damaged. Besides, the 
dropping impact can be lessened only to a limited extent with the elastic 
plate, so that the dropping materials still tend to jump or flow out 
through the opening between the chute S and the belt B, causing sanitation 
problems. It is proposed, therefore, that the opening must be closed by a 
rubber skirt plate, but it is inevitable that the plates and belt are cut 
down and wear unevenly because the bulk materials such as ores enter into 
the small opening between the skirt and belt (which widens with abrasion). 
Additionally, the bulk materials drop down from the chute onto the running 
belt at random, so that material cannot be loaded uniformly onto the 
receiving surface of the belt and thus the belt tends to run zigzag. Such 
zigzag running causes the belt to be worn locally. To avoid this problem, 
attempts have been made to adjust the tension of the endless belt by 
tension pulleys, but is is difficult to avoid zigzag running. 
OBJECT OF THE INVENTION 
Accordingly, it is a primary object of the invention to provide an improved 
rollerless supporting arrangement for prolonging belt-life, and especially 
for improving the durability of a lubricous backing top plate as well as 
the belt. 
Another objective of the invention is to provide a skirt shutting device, 
without damaging the belt, for avoiding outflow of dust or fine particles 
of bulk materials, in the proposed system. 
A further objective of the present invention is to provide a return tension 
roller apparatus for avoiding zigzag running of the belt at the side for 
receiving bulk materials in the proposed system. 
SUMMARY OF THE INVENTION 
To accomplish the above objectives, it was found that, providing a top 
lubricous plate with plural channels extending in the running direction of 
a belt at the plate surface, which is in contact with the belt, (1) the 
contact area with the belt is diminished and thus the heat of friction can 
be decreased between the belt and the top plate, and (2) simultaneously an 
air flow in the running direction of the belt occurs in the plural 
channels owing to the running of the belts, and thus, cools the top plate 
in contact with the belt, so that the top plate can be maintained in good 
condition for a long time. Also, we have found that it is easy to bend the 
top stiff plate into the desired arc troughed shape owing to the plural 
channels on the surface thereof, without any joint spaces, as shown in 
FIG. 14. 
On the basis of the above knowledge, this invention can be completed. 
In accordance with this invention, there is provided a belt conveyor 
supporting arrangement positioned where bulk materials are transferred 
from a chute or feeder comprised of a supporting frame, a cushioning 
device mounted on the supporting frame for relieving dropping impact owing 
to bulk materials dropped onto a conveyor belt and the contact backing top 
plate which surface is lubricous for smoothly supporting the conveyor 
belt; the improvement comprising the contact backing top plate's contact 
surface being provided with plural parallel channels extending in the 
running direction of the belt arranged to diminish a contact area between 
the belt and the top plate and generate an air flow in the channels along 
the running direction of the belt. 
In a preferred configuration, the supporting frame has an arc sectional 
shape in a cross direction of the belt and can be attached on a 
conventional stand for rollers. 
The cushioning device can be formed to have a dropping impact lowering 
function and is preferably made of a rubber plate mounted in an arc shape 
along the arc surface of the supporting frame. In this case, the rubber 
plate tends to hang down to some extent between spaced frame members of 
the supporting frame owing to receiving repeat impact thereon. Therefore, 
it is preferred that the spaced frame members are covered at the upper 
side by a mesh plate in order to prevent the rubber plate from hanging 
down, thereby maintaining the cushioning function thereof. 
As a backing plate, a slotted resin plate can be used. As shown in FIG. 10, 
long bar members 35 may be inserted and mounted into the slotted channels 
31 to be detached in a longitudinal direction therefrom when desired but 
not to be detached upwardly therefrom by accident. The long bar members 
have a rectangular cross section and are made of lubricous heat-resist 
material so that the upper surfaces of the bar members serve as a contact 
backing surface to the belt. In such a preferred case, the bar members can 
be replaced with new ones after abrasion, this is beneficial to lower the 
product cost of the backing plate if they are made of high cost resin 
materials. 
The contact backing plate may be preferably made of a synthetic resin plate 
having a superior heat resistance, such as teflon resin, ultra molecular 
polyethylene resin (brand name: ULMOLAR made by TAKIRON Co., Ltd. in 
Japan), heat resisting nylon resin (brand name: MC-NYLON made by NIHON 
POLYPENKO Co., Ltd.). MC-NYLON is best among them for the backing 
material. Such materials in a plate having a desired thickness are 
difficult to bend into an arc shape having a desired curvature. 
According to this invention, the backing plate is provided at the upper 
surface with plural parallel channels in a cross direction thereof, so 
that it is easy to bend the plate into an arc shape in such a direction 
and thus mount it on the rubber plate along the arc surface thereof. 
For achieving the second object in the above supporting arrangement 
comprised of a supporting frame; a cushioning device on the frame; a 
contact backing top plate on the device, there is a provided a skirt plate 
device M2 for shutting the opening between the belt conveyor and the 
chute, comprised of a pair of plates made of lubricous resin material 
which are extending in a running direction of the belt and positioned in a 
spaced relation at both sides of the belt and are supported upstream of 
the belt by a pivoted means so as to automatically descend by its own 
weight and contact the belt surface with little friction. 
In a preferred embodiment, as with the lubricous resin materials for 
production of the skirt plate, the use of high molecular polyethylene 
resin, teflon resin or heat resisting nylon resin mentioned above, 
especially heat resisting nylon resin, for example MC-NYLON, is 
recommended. 
In such a device, the skirt plate tends to lower by its own weight so that 
no gap occurs between the plate and belt even as the lower part thereof 
wears. It is preferred, however, to adjust a weight of the skirt plate by 
arranging a balance-weight G, thereon, so as to prevent the skirt plate 
from jumping on the belt. 
For achieving the third objective in the above supporting arrangement 
comprised of a supporting frame, a cushioning device mounted on the frame, 
and a contact backing top plate on the device, a bending tension roller 
apparatus comprised at least of a pair of rollers inclined in the opposite 
direction just like the symbol [ ] are provided. The two rollers are 
linked with each other pivotably at one end axis thereof and at the other 
end axis thereof are connected to the supporting table by means of a 
slidable connector, whereby the angle between the opposite inclined 
rollers can be adjusted to such a desired extent that the belt can be 
prevented from zigzag running. 
In such an apparatus, it is preferred that a pair of the inclined rollers 
is connected pivotably with a center connecting roller at both end axes 
thereof. 
The above first arrangement M1, of this invention, includes a top contact 
plate provided with plural parallel channels at the surface thereof, 
thereby the surface area contact with the running belt is decreased and 
the air flow occurring in the channels cools the surface of the contact 
plate. Additionally, the channels on the upper surface thereof permit the 
plate to be deformable into an arc troughed shape although it is made of a 
stiff material. 
Further, the above second arrangement M2, of this invention, provides an 
automatically lowering lubricous skirt plate for shutting the opening 
above the belt, thereby bulk materials tend not to flow out from the belt 
surface and no cutting or local wearing problems caused by the entering of 
ores between the belt and the skirt plate occur. 
Furthermore, according to the above third arrangement M3, of this 
invention, a pair of the inclined rollers permits the belt at the return 
side to be forced into a desired arc troughed shape, so that no problem of 
abrasion caused by zigzag running of the belt owing to random loading 
occurs. 
According to this invention, the belt for conveying bulk materials can be 
completely prevented from damage by the combination of the above three 
arrangements M1, M2 and M3, and the service life of the conveyor belt can 
be greatly extended. 
Many other features, advantages, and additional objects of the present 
invention will become apparent to those skilled in the art upon making 
reference to the detailed description which follows and the accompanying 
sheet of drawings. However, it should be understood that the detailed 
description and specific examples, while indicating preferred embodiments 
of the invention, are given by way of illustration only, since various 
changes and modifications within the spirit and scope of the invention 
will become apparent to those skilled in the art from this detailed 
description. 
The present invention will become more fully understood from the detailed 
description given hereinbelow and the accompanying drawings which are 
given by way of illustration only, and thus, are not limitative of the 
present invention, and wherein:

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In FIG. 1, a belt conveyor arrangement is shown comprised of an endless, 
arc troughed belt B which is supported in the running direction by means 
of a tension pulley TP and sustained by means of carrier table T mounted 
on a conveyor frame F. The belt can run in the arrow direction for 
conveying bulk material such as ore. On the carrier table T which is 
positioned where bulk materials is transferred from a chute S, a belt 
supporting apparatus M1 is mounted. This is comprised of a supporting 
frame 1 made of steel constructed by plural arc lateral members 11, 11 
spaced in a parallel relation connected with both side longitudinal 
members 12, 12 (FIG. 5) and a cushioning plate 2 mounted along the upper 
surface of the frame 1, which may be made of a natural or synthetic rubber 
plate which is designed to a proper thickness, for example about 30 mm, 
considering the impact load thereonto. Therefore, such a cushioning plate 
works as a resilient surface support for the belt receiving bulk material, 
thereby absorbing the dropping energy of bulk material at any position on 
the belt. 
On the above cushioning plate, a contact top plate 3 is mounted. This plate 
3 is made of lubricous material provided with plural channels 31 extending 
in the running direction of the belt and parallel-spaced in a lateral 
direction thereof. As the lubricous material, it is preferred to use 
materials having little friction such as heat resisting nylon resin (Brand 
name: MC-NYLON made by Nihon Polypenco Co., Ltd. in Japan). 
The contact plate 3 is preferably designed to have 10-20 mm thickness and 
channels 31 spaced out at 20-40 mm intervals on the surface thereof which 
has 5-10 mm depth and 10-20 mm width. 
It is necessary to preform the contact top plate 3 into an arc troughed 
shape. The plural parallel channels make the plate itself easy to deform 
into the determined shape, as shown in FIG. 3. The deformed plate can 
thereby bend along the arc troughed surface of the cushioning plate 2. 
A method for attaching the contact top plate on the supporting frame 1 can 
be carried out in the following manner. 
Firstly, both side edges 32 of the top plate 3 are cut out along the 
longitudinal parts thereof, on which cut portions are abutted and fixed 
detachably by means of flush bolt 42. Pressing members 41' are provided 
within a corresponding cut portion 41 of the top plate 3 as shown in FIG. 
7. 
In such a case, it is preferred to attach side longitudinal members 12, of 
the supporting frame 1 on a carrier table T by means of rubber ring (not 
shown) for preventing the attaching portion from fatigue failure. On the 
other hand, as shown in FIG. 6(b), the contact top plate 3 is fixed at the 
front and back end by plural short pieces 34 which extend downward from 
inclined parts 33 connected to the belt and contacting the short pieces 
detachably fixed on front and back arc members 11, 11. Such an arrangement 
permits the belt contact plate to have some lateral flexibility against 
belt lateral sliding and also sufficient cushioning function against the 
shock of dropped bulk material. Additionally, by means of plural parallel 
channels extending in the longitudinal direction, the belt contact area is 
decreased by half or two thirds of the total and cooling air flows along 
the channels accompanied by the belt running thereon, so that the cooling 
effect is larger than in the case of total contact. 
As shown in FIGS. 8 and 9, between the chute S and the running belt B 
supported by the transfer apparatus M1, an opening O extending in the 
running direction is inevitably formed. This opening O can be closed by 
means of the skirt plates 5 with little friction, if the weight that 
presses the plates 5 into contact with the belt surface at the lower edge 
5a is adjusted properly. 
The skirt plate 5 is slidably arranged between the lower portion of the 
chute S and adverse L shape members pivoted thereon and spaced from each 
other in a manner to lower downwardly by its own weight. Also, the skirt 
plate 5 is supported pivotably at the upstream side by an arm member 8, 
expandable through an adjuster 83, where the arm member 8 is connected at 
one end 81 to a fan-shaped projection part 71 of a supporting member 7 in 
a manner that the connecting angle can be adjusted by means of bolt B1 as 
well as bolt B2 inserted in an arc cutting hole 72. The other end 82 is 
connected to a supporting pole 91 and both ends are pivotably supported by 
a pair of stands 9, 9 spaced out over the belt B positioned behind the 
transfer apparatus M1. From the supporting pole 91, protruded in a 
diagonally upward direction, is a supporting member 92, on a selected 
position of which through plural attaching holes 92a, is attached a 
balance weight G to adjust the contact pressure against the belt surface. 
In such an arrangement, the skirt plate 5 automatically lowers and rests 
on the belt with a predetermined contact pressure at the lower end 
thereof, this pressure is adjusted by means of attaching the balance 
weight at a selected position. Further, the skirt plate 5 is cut out at 
the lower corner of the upstream side thereof to abut smoothly against the 
belt. 
As shown in FIG. 9, at a return side opposite to the transfer position, a 
tension return roller M3 is arranged for preventing zigzag running of the 
belt. In this roller apparatus, at both ends of the axis on which a center 
tension roller TR1 is rotatably mounted, a pair of rotatable right and 
left rollers TR2, TR3 are pivotably linked. The axes of these rollers TR2, 
TR3 are arranged to form a pivotably linked return roller system just like 
the symbol [ ]. As shown in FIG. 9, the site of joint portion J1 can be 
selected, while the rollers TR2, TR3 are jointed and slidably adjusted 
along the axis thereof by means of a screw adjuster at the remaining end 
thereof, so that the cross angles between the rollers TR2, TR3 and the 
center roller TR1 can be changed by means of adjustment of the joints J1 
and J2. Thereby, the portion of the belt at the return side can be 
corrected to be larger in the curve extent that at the receiving side 
thereof. 
In such an apparatus, the side rollers TR2, TR3 may be linked by a suitable 
means in place of the above center roller TR1. 
As apparent from the above description, according to the above embodiments, 
the dropping energy of bulk material can be absorbed and thus alleviated 
by the arrangement for receiving bulk materials comprised of the 
cushioning device made of elastic material such as rubber which is 
curvedly arranged in a lateral direction on the supporting frame extending 
in the running direction of the belt. Further, the contact area between 
the belt and the top plate is reduced by about half or two thirds, and 
thus, the friction resistance therebetween is reduced by half compared to 
that when the belt runs in total contact with the top plate. This 
reduction is achieved by the top plate having a surface with plural 
parallel channels extending in the running direction of the belt. Besides, 
along the plural parallel channels, cooling air flows as the belt runs in 
contact with the channels. This air flow thereby cools the contact surface 
thereof. For instance, it has been found that the surface temperature of 
the belt decreases 5.degree. C. below the ambient temperature in an 
unloaded condition, i.e. when no bulk material is loaded. It is apparent 
that the service life of the belt is greatly prolonged compared to a total 
contact supporting system. 
According to the arrangement comprised of the skirt plate device M2 for 
shutting the opening extending between the chute and the transfer 
apparatus M2 by means of a low friction material plate which automatically 
lowers by its own weight, there is no excessive friction and little 
opening occurs between the skirt plate and the belt. Therefore, the 
dropping bulk material is prevented from jumping out, even if it jumps on 
the receiving surface of the belt, so that all the bulk material can be 
completely conveyed to the determined place. 
Furthermore, according to the arrangement comprised of the tension return 
roller system M3 for correcting a deformable troughed belt, the return 
side of the running belt is tensed by means of a pair of rollers TR2, TR3 
opposite each other and inclined just like the symbol [ ], as well as the 
belt being adjusted to a determined tension by a pair of tension pulleys, 
so that the belt can run without zigzag or lateral sliding even if local 
loading onto the receiving surface of the belt, thereby preventing 
excessive contact between the belt B and the transfer apparatus M1. 
These above functions and effects, such as the cushioning of the impact 
energy onto the belt, the diminishing of the contact frictional belt, 
forced cooling of the belt, the closing of the opening between the belt 
and the chute as well as avoiding the zigzag running of the belt, etc. 
work together to prevent the belt from 5 being damaged and wearing 
locally, and thus insure long belt service life. 
The invention being thus described, it will be obvious that the same may be 
varied in many ways. Such variations are not to be regarded as a departure 
from the spirit and scope of the invention, and all such modifications as 
would be obvious to one skilled in the art are intended to be included 
within the scope of the following claims.