Arrangement in a belt conveyor

A belt conveyor with at least one endless belt (1,1') has two tensile force (longitudinal)-absorbing members (3,4,3',4') which extend throughout the entire length of the belt conveyor and which are each connected to a respective edge portion of the belt and project from the plane of that edge portion. The belt conveyor is sealed at a longitudinal edge throughout at least part of its length. One edge portion of the belt overlaps and extends outside the other edge portion of the belt along the sealed part of the length of the belt conveyor, more specifically with its tensile force (longitudinal)-absorbing member (3,3') projecting in the same direction as the tensile force (longitudinal)-absorbing member (4',4) of the other edge portion of the belt. When the belt conveyor has a single belt (1), the two tensile force (longitudinal)-absorbing members (3,4) of the belt project from opposite sides of the belt (1) in the straightened state thereof. When in the case of a two-belt conveyor, each belt has two tensile force (longitudinal)-absorbing members, these may project either from the same side or from opposite sides of the belt in the straightened state thereof.

The present invention relates to an arrangement in a belt conveyor having 
at least one endless belt and two tensile force (longitudinal)-absorbing 
members extending throughout the entire length of the belt conveyor and 
being each connected to a respective edge portion of the belt and 
projecting from the plane of said portion for cooperation with guide 
rollers determining the path of travel of the belt conveyor which is 
sealed over at least part of its length at a longitudinal edge thereof. 
A belt conveyor of this type is previously known, e.g. from GB patent 
specification No. 970,253 describing a single-belt conveyor having two 
V-belt-shaped tensile force (longitudinal)-absorbing members which in the 
straightened state of the belt project from one and the same side of the 
belt at the longitudinal edges thereof. This prior-art belt conveyor 
confers substantial advantages, for instance in that the goods conveyed 
can be transported in a protected fashion on a central part of the belt 
depending in a bag-like manner between the tensile force 
(longitudinal)-absorbing members. This belt conveyor is however 
disadvantageous in so far as it allows no vertical conveyance of the goods 
and especially no easy transition from a horizontal direction of 
conveyance to a more or less vertical direction of conveyance, and vice 
versa. Furthermore, this known belt conveyor construction necessitates 
guide rollers for holding together or sealing a longitudinal edge. 
The object of the present invention is to overcome the above-mentioned 
shortcomings inherent in the known belt conveyor construction. The 
inventive arrangement should thus allow easy transition from a horizontal 
direction of conveyance to a substantially vertical direction of 
conveyance, and vice versa. It should also provide for improved and less 
expensive sealing of one longitudinal edge of the belt conveyor. 
According to the present invention, these and other objects are achieved in 
an arrangement of the type stated in the introduction to this 
specification, in that one edge portion of the belt, along the sealed part 
of the length of the belt conveyor, overlaps and extends outside the other 
edge portion of the belt, with its tensile force (longitudinal)-absorbing 
member projecting in the same direction as the tensile force 
(longitudinal)-absorbing member of the other edge portion of the belt. 
The arrangement according to the invention can be used both in a 
single-belt conveyor and in a two- or multi-belt conveyor. In a 
single-belt conveyor, the inventive arrangement is achieved in that the 
two tensile force (longitudinal)-absorbing members of the belt are so 
designed as to project from opposite sides of the belt when in its 
straightened state. This particular belt is also usable in a two- or 
multi-belt conveyor. The two-belt conveyor may use two identical belts 
which are offset in relation to each other transversely of the direction 
of travel of the conveyor a distance which corresponds at least to the 
width of one tensile force (longitudinal)-absorbing member. A two-belt 
conveyor may however also use two belts, each having two tensile force 
(longitudinal)-absorbing members which project from the same side of the 
respective belt in the straightened state thereof. In accordance with the 
invention, the width of one belt must then exceed the width of the other 
belt by at least the total width of its two tensile force 
(longitudinal)-absorbing members. 
A single-belt conveyor using the inventive arrangement is particularly 
advantageous in that the two tensile force (longitudinal)-absorbing 
members along a vertical part of the path of travel of the belt conveyor, 
can be twisted about each other between two of the guide rollers of the 
belt conveyor which determine the path of travel thereof. By twisting the 
tensile force (longitudinal)-absorbing members about each other, such 
reliable sealing is obtained as to allow vertical conveyance of goods. In 
a two-belt conveyor, vertical conveyance can be performed without the 
belts being twisted about each other, although this alternative is also 
possible. 
To conclude, by the special positioning of the tensile force 
(longitudinal)-absorbing members side by side, these members may be of the 
same length in each belt without causing any increased wear of the belt by 
the belt edge portions sliding on each other. Further, the arrangement of 
the invention allows easy transition from horizontal conveyance to more or 
less vertical conveyance of goods, and vice versa. The goods may consist 
of materials ranging from coarse particles to fine powder and even liquids 
or more or less liquid products. The invention also ensures tighter 
sealing along a longitudinal edge of the belt conveyor as compared with 
previously known constructions. 
By the length of and the distance to a tensile force 
(longitudinal)-absorbing member is here meant the length of the member in 
the neutral plane thereof and the distance to the neutral plane of the 
member, respectively, this plane being defined as the plane in the 
transverse section of the member where neither elongation nor compression 
appears when the member is bent.

A belt 1, shown in cross-section in FIG. 1, consists of a web 2 of flexible 
and elastic material, preferably a polymer material, and two tensile force 
(longitudinal)-absorbing members 3 and 4. The members 3, 4 are each 
connected to an edge portion 6 and 5, respectively, of the belt, i.e. the 
longitudinal portion of the belt closest to the respective edge, and 
project from the plane thereof. The height of the member 3 equals the sum 
of the height of the member 4 and the thickness of the belt edge portion 
5. The tensile force (longitudinal)-absorbing members 3 and 4 extend 
throughout the entire length of the belt conveyor and may, as shown in 
FIG. 1, have the profile of a V-belt, other profiles being however also 
conceivable. The two tensile force (longitudinal)-absorbing members 3, 4 
are but little extensible in the longitudinal direction, for instance by 
being provided with some type of reinforcement, e.g. in the form of wires 
as shown in the member 4, or in the form of strips as shown in the member 
3. 
The tensile force (longitudinal)-absorbing members 3 and 4 may be connected 
to the web 2, e.g. by vulcanization, heat welding or gluing. They may also 
be extruded integrally with the rest of the belt so as to produce a 
complete belt in a single operation, for instance of polyurethane. The web 
2 extending between the members 3, 4 is flexible in the transverse 
direction and may suitably consist of an easily extensible and elastic 
material. In the use of the belt 1 in a two-belt conveyor, the web 2 may 
however in some cases consist of a material which is more rigid in the 
transverse direction but yet flexible and extensible for adaptation to the 
goods conveyed. 
The belt 1 shown in FIG. 1, whose two tensile force 
(longitudinal)-absorbing members 3, 4 project from opposite sides of the 
belt, may be used in a two-belt conveyor together with a similar belt 1', 
as schematically illustrated in FIG. 2. The belts 1, 1' are offset 
transversely of their direction of travel a distance corresponding at 
least to the width of one tensile force (longitudinal)-absorbing member. 
The two-belt conveyor may be sealed throughout part of its length, more 
particularly along one longitudinal edge by means of the members 3, 4' and 
along its other longitudinal edge by means of the members 3', 4. Highly 
safe and reliable sealing is achieved in accordance with the invention in 
that the edge portion of the belt 1 joined to the member 3 overlaps and 
extends outside the edge portion of the belt 1' joined to the member 4', 
the tensile force (longitudinal)-absorbing member 3 of the belt 1 
projecting in the same direction as the tensile force 
(longitudinal)-absorbing member 4' of the belt 1'. The same applies to the 
members 3', 4 at the other longitudinal edge of the belt conveyor. 
In a two-belt conveyor, the invention also makes it possible to use the 
belt configuration shown in FIG. 4 where two belts 7, 7' are disposed 
adjacent each other to permit conveying goods between them. Also in this 
case, each belt 7, 7' has two tensile force (longitudinal)-absorbing 
members 8, 9 and 8', 9', respectively, which are of the same type as the 
members 3, 4 and 3', 4' but which project from the same side of the belt 7 
and 7', respectively. Further, the width of the belt 7 exceeds the width 
of the belt 7' by at least the total width of the two tensile force 
(longitudinal)-absorbing members 8 and 9 of the belt 7. 
The belt shown in FIG. 1 is most useful in a single-belt conveyor and is 
then given the configuration shown in FIG. 3 along the sealed part of the 
belt conveyor. By the illustrated location of the tensile force 
(longitudinal)-absorbing members 3, 4 over each other and projecting in 
the same direction from the respective edge portion of the belt, excellent 
sealing is obtained along the upper longitudinal edge of the belt conveyor 
where the member 3 ensures complete sealing by engaging the member 4. 
The profile of the member 3 may also be such that the gap between the 
members 3 and 4 in FIG. 3 is filled. As a result, the belt edge with the 
member 3 will hook onto the member 4. This presupposes that the angle 
between the outer side of the member 4 and the belt edge portion 5 is 
acute. In order to further enhance the engagement between the members 3 
and 4 in this case, the longitudinal tension in the member 4 may be made 
greater than that in the member 3. 
FIGS. 5 and 6 show examples of two guide rollers for a single-belt conveyor 
having the belt configuration of FIG. 3. In FIG. 5, there is shown a 
roller 10 rotatably mounted on a vertical shaft 11 depending from an arm 
12 mounted in a frame (not shown). The roller 10 has two axially offset 
grooves for engagement with a respective one of the tensile force 
(longitudinal)-absorbing members 3 and 4. On a vertical shaft 13, also 
mounted in the arm 12, a pressure roller 14 is rotatably mounted. The 
pressure roller 14 is intended, by suitable means (not shown), to be 
pressed against the outwardly facing sides of the tensile force 
(longitudinal)-absorbing members 3 and 4. The pressure exerted on the 
member 4 is transmitted by part of the belt edge portion 6 and acts so as 
to maintain the members 3 and 4 in the grooves of the roller 10. 
The construction of a guide and support roller 10 as shown in FIG. 5 can be 
used in such portions of the path of the belt conveyor where the belt 
conveyor is travelling substantially linearly or curves through a lesser 
angle. The roller 10 may also be used as a driving roller. 
In FIG. 6, there is shown a deflecting roller 15 having the same groove 
design in its periphery as the roller 10 but a larger diameter than this. 
The roller 15 is mounted for rotation about a vertical shaft 16 which is 
mounted in an arm 17 supported by a frame (not shown). The belt 1 can 
change its direction of travel about the roller 15 up to about 180.degree. 
and the roller 15 then is well suited as a driving roller. If the change 
of the direction of travel of the belt 1 about the roller 15 is not very 
small, there is no need for such a pressure roller as normally required 
for the roller 10 in FIG. 5. 
Along parts of the path of travel of the belt conveyor, the belt 1 can be 
advanced in a substantially straightened state, either depending between 
two rollers similar to the roller 10 in FIG. 5 or on a roller as is shown 
in FIG. 7. FIG. 7 more specifically shows a roller 18 having a groove 19 
at one end and rotatably mounted on a shaft 20 which is supported in arms 
21 and 22 mounted on a frame (not shown). The groove 19 of the roller 18 
engages with the tensile force (longitudinal)-absorbing member 4, while 
the member 3 is facing away from the roller 18. The roller 18 is so 
designed that the members 3 and 4 when passing over the roller 18 are at 
the same distance from the centre of rotation of the roller 18. 
As an alternative to the roller 18, a roller having a constant radius may 
be used or two separate rollers. 
The inventive arrangement allows easy transition of the single-belt 
conveyor from a horizontal direction of travel to a more or less vertical 
direction of travel, and vice versa. In FIG. 8, there is shown an example 
of a roller construction for permitting transition from a horizontal to a 
vertical direction of travel. More precisely, a roller 23 is rotatably 
mounted on a horizontal shaft 24 which is mounted in an arm 25 supported 
by a frame (not shown). The roller 23 has a substantially constant radius 
and cooperates with a pressure roller 26 having grooves for engagement 
with the tensile force (longitudinal)-absorbing members 3 and 4. The 
pressure roller 26 thus serves to guide the tensile force 
(longitudinal)-absorbing members 3 and 4 into engagement with the lower 
part of the roller 23 and is rotatably mounted on a shaft 27 which is 
fixedly mounted in the arm 25. The transition from e.g. the belt 
configuration according to FIG. 5 to the belt configuration according to 
FIG. 8 may be carried out stepwise by means of a plurality of 
progressively inclined pairs of rollers of the type shown in FIG. 5. The 
guide roller 26 ensures that the belt 1 is firmly held in position also 
underneath the roller 23, such that the belt 1 will not run off it. In the 
part of the path of travel of the belt conveyor vertically ascending from 
the roller 23, sealing of the longitudinal belt edge can be further 
improved in that the tensile force (longitudinal)-absorbing members 3 and 
4 are twisted about each other, i.e. such that the entire conveyor belt 1 
follows a helical path in its vertical extent. Alternatively or 
additionally, the distance between the guide rollers for the conveyor belt 
1 may be reduced along the more or less vertical parts of the path of 
travel of the conveyor belt. In these parts, the guide rollers may have a 
shape conforming to the shape assumed by the twisted tensile force 
(longitudinal)-absorbing members 3, 4, as illustrated in FIG. 9. 
One application of the two-belt configuration of FIG. 4 is shown in FIG. 
10. On a shaft 28, which is mounted in arms 29 and 30 supported by a frame 
(not shown), a guide roller for the belt is rotatably mounted. This guide 
roller consists of three axially offset sections 31-33. The sections 31 
and 33 each have two grooves for engagement with the tensile force 
(longitudinal)-absorbing members 8, 8' and 9, 9', respectively. Although 
not shown, pressure rollers may be provided for cooperating with the 
roller sections 31 and 33 in order to improve the sealing of the belt edge 
and/or to increase the friction between the tensile force 
(longitudinal)-absorbing members and the respective roller section. 
Alternatively, the sections 31-33 may be disengaged from each other or the 
section 32 may be dispensed with. 
FIG. 11, like FIG. 10, illustrates a two-belt configuration using a belt 
according to FIG. 2. More specifically, two axially offset roller sections 
34 and 35 are rotatably mounted on a shaft 36 which is mounted in two arms 
37 and 38 supported by a frame (not shown). The roller section 34 has 
grooves for cooperating with the tensile force (longitudinal)-absorbing 
members 3' and 4. Similar cooperation takes place between the tensile 
force (longitudinal)-absorbing members 3, 4' and the roller section 35, 
however without any grooves. As in FIG. 10, pressure rollers may be 
provided for each roller section 34 and 35, the pressure roller 
cooperating with the roller section 35 suitably having grooves for 
engagement with the tensile force (longitudinal)-absorbing members 3 and 
4'. This also applies to the embodiment in FIG. 7. 
Although the guide rollers shown in FIGS. 10 and 11 are rotatable about 
horizontal shafts, it is of course also possible to arrange these shafts 
with a vertical extent. In this manner, the two-belt conveyor can also be 
moved over rollers similar to the roller 15 in FIG. 6. Naturally, the 
two-belt conveyor may also have a more or less vertical extent along part 
of its length. 
Modifications of the embodiments described above are of course possible 
within the scope of the invention. Thus, the shaft 11 in FIG. 5 may be 
horizontal and located below the shaft 13. According to a particularly 
suitable alternative, the belt 1 or each of the belts 1, 1' and 7, 7', 
respectively, consists of two separately manufactured belt edge portions 
and one separately manufactured central part, which are joined to each 
other, e.g. by vulcanization, so as to form the respective belts. A 
standard belt may be used as central part. The load-contacting surface of 
each central part should then merge smoothly into the corresponding 
surfaces of the adjoining belt edge portions. Further, the invention is 
useful e.g. in a three-belt conveyor which may use three belts according 
to FIG. 1. Finally, it should be pointed out that the above-mentioned 
guide rollers may be backing rollers, terminal rollers, deflecting 
rollers, support rollers, grooved rollers, pressure rollers etc.