CA1109411A

CA1109411A - Belt conveyor

Info

Publication number: CA1109411A
Application number: CA315,977A
Authority: CA
Inventors: Einar Karlsson
Original assignee: BELTLINE AB
Current assignee: BELTLINE AB
Priority date: 1977-11-08
Filing date: 1978-11-08
Publication date: 1981-09-22
Also published as: JPS5475773A; NO154459B; ES474882A1; NO783739L; AT369708B; DE2848270A1; AU531216B2; GB2007178B; FI67820B; FI67820C; NL7810976A; FR2407876A1; DK494478A; JPS6122642B2; PL114226B1; IT1119710B; PL210783A1; NO154459C; IT7829582A0; CH634526A5

Abstract

ABSTRACT
This invention relates to a belt conveyor comprising a convey-ing belt suspended in a plurality of suspension points in a stand, which belt includes energy-absorbing elements and a flex-ible belt portion located therebetween and has the object to bring about such a belt conveyor, which renders it possible to transport therewith goods not only in an open but also in a closed way. This object is achieved by the present invention substantially in that rollers are arranged in the conveyor stand to co-operate with the energy-absorbing elements and to carry the belt in an endless path, in which the belt is driven by driv-ing rollers arranged in the stand, and the energy-absorbing ele-ments are designed with the same section as a V-belt, while every roller co-operating with such a V-belt section of the belt ex-tends with its axle substantially in parallel with that side of the V-belt section, to which the roller abuts with its running surface, and every driving roller for driving the belt includes at least one V-belt groove for driving engagement with one of the V-belt sections of the belt, which is held in this driving engagement by means of at least one pressing roller.

Description

This invention relates to a belt conveyor, more precisely to a conveyor of the kind which comprises a convey-ing belt supported in a stand, for example, in the form of spaced-apart posts, and comprising energy-absorbing elements designed integrally with the belt in spaced relationship to each other, and a flexible intermediate member between the energy-absorbing elements, and with carrier rollers provided in the conveyor stand and cooperating with the energy-absorbing elements to carry the belt in an endless path, and with drive rollers provided in said stand for driving the belt in said path.
At belt conveyors of the aforesaid kind, and also at conventional belt conveyors consisting of a reinforced rubber belt running on slightly V- or U-shaped roller stands of tight relationship, it is difficult, and at some construc-tions entirely impossible to guide the conveying belt in a path, which is curvy in horizontal projection, and especially in narrow curves, without subjecting the conveying belt, which usually consists of an elastomer, for example, rubber, to exceptionally heavy wear or destroying the belt in some other way relatively rapidly. As one consequence thereof, known belt conveyors could not be given a path leading about an obstacle and, therefore, not be utilized for transporting goods over long distances, as it is possible, for example, with a cable overhead conveyor, unless a plurality of reload-ing stations were provided. The belt conveyor, therefore, has been used only for short-distance goods transport.
At belt conveyors of the kind disclosed, for example, in the patent specification Great Britain 1,351,132, the goods are transported more or less enclosed in the upper load-carrying run of the conveying belt, because the run is suspended bag-shaped on carrying rollers. This implies a ~1~94~L~

great advantage as the goods are held enclosed during its transport, but in spite of this advantage, belt conveyors of this ~ind are used to a very limited extent and, as mentioned above, only for goods transported over very short distances.
One reason, which has contributed to said limited utilization, has been the failure in so~ving the problems of driving the conveying belt so that no sliding will arise between the belt and drive rollers. This problem has not been solved in said British patent specification either, where instead a compli-cated drive system with separate drive wires is used, whichrenders the conveyor substantially more expensive and limits its possibilities of utilization and application.
The present invention, therefore, has the object to solve these and other problems involved with the use of the type of belt conveyor concerned and to bring about such a belt conveyor, at which the driving power efficiently and slide-proof is transferred directly from the drive rollers to the conveying belt, and which further can be used for the transport of goods even over long distances and along curved paths.
According to the invention, a conveyor is proposed which comprises a conveying belt with energy-absorbing ele-ments carried in a stand, the elements being integral with the belt and spaced apart from each other and including a flexible intermediate portion therebetween. The conveyor stand rollers are arranged to cooperate with the energy-absorbing elements and to carry the belt in an endless path, and also driving rollers are arranged in the stand for driving the belt in the path. The energy-absorbing elements have a section projecting at least from the lower surface of the belt with a width preferably increasing to the belt, and at least one driving roller for driving the belt includes at least one groove for 11~9~11 driving engagement with one of the sections of the belt.
These and other characterizing features of the present invention are explained in greater detail in the following descriptive part where reference is made to the accompanying drawings, which show some embodiments of the invention, but only by way of example:
Fig. 1 is a section in a schematic manner through the conveying belt of the present belt conveyor and through a roller stand for carrying the belt substantially horizontally, Fig. 2 is a similar section as in Fig. 1, but through a possible return run of the endless conveying belt of the conveyor, Fig. 3 shows a roller stand for carrying the belt in a closed bag-shaped way, Fig. 4 shows a roller stand for carrying the belt vertically suspended at one of its edges, Fig. 5 is a vertical section in a schematic manner through a drive station for the conveying belt, Fig. 6 is a horizontal view in a schematic manner of a second drive station for the conveying belt, Fig. 7 is a section along the line VII-VII in Fig. 8, Fig. 8 is a schematic view from above of a portion of a belt curve for a substantially horizontally located belt, Figs. 9 and 10 are sections in a schematic manner along the line IX-IX and, respectively, X-X
in Fig. 8, Figs. 11 and 12 are views substantially along the line XI-XI and, respectively, XII-XII in 41~

Fig. 8;
Fig. 13 is a lateral view in a schematic manner of a belt conveyor according to the invention with at least one terminal drive station of the type shown in Fig. 5;
Fig. 14 shows schematically a slightly modified embodiment of the present conveyor with a supporting wire for carrying the conveying belt between posts;
Fig. 15 is a vertical section along substantially the line XV-XV in Fig. 14; and Fig. 16 shows an intermediate drive station for the conveying belt at any one of the embodiments shown.
In the drawings, the numeral 1 designates an endless conveying belt comprised in the belt conveyor according to the invention, which belt consists of a flexible cloth of a dense, loose or network-like fabric, or of elastomer material, for exam~le, synthetic or natural rubber, and is provided with longitudinal energy-absorbing elements or runs 2 in the form of V-belt sections. Said sections 2, which are provided with a reinforced core 3, are formed integral with the cloth and located in spaced relationship to each other at the lower surface of the belt. The V-belt sections 2 can be located at and form the longitudinal edges of the belt, as shown in the Figures, but they may also be located at some distance from the same and form sealing lips at the outside of the sections 2. The reinforced V-belt sections 2 of the belt are capable to entirely take up the forces required for driving and supporting the belt, while it is the object of the flexible intermediate portion 4 of the belt located between the energy-absorbing sections to carry the goods 5 to be transported. Owing to the flexibility of said inter-mediate portion, the belt also can be folded or bent to closed shape, as shown in Fig. 3, so that it encloses the goods in a substantially dust-proof way.
The belt 1 is supported by the belt conveyor accor-ding to the present invention in a closed or endless path by means of one or several roller stands 6 in each of mutually spaced suspension points 30 in the belt conveyor stand, which may comprise posts, columns, poles or the like 31, as, for example, shown in Fig. 13. In this Figure, the conveying belt 1 is shown by way of example only to extend in an end-less path between a driven roller 16 in a drive station of the type shown in greater detail in Fig. 5 and also shown designed as a delivery station 32, and an idle roller 33, which, how-ever, may be driven and comprised in a drive station of said type, in connection thereto a loading station 34 associated with the conveyor is shown.
~ ach roller stand 6 supporting the conveying belt 1 comprises two rollers. Each roller has a running surface 8 substantially in parallel with the axle 7 of the roller and is either a carrying roller 9 and a pressing roller 10 (see, for example, Figs. 1 and 2) or two carrying rollers 9 (see, for example, Fig. 3), depending on how the belt is to be - supported in the path between driving stations arranged in the path and required for driving the belt.
Fig. 1 shows roller stands 6, which are located directly in front of each other and provided with carrying and guide rollers 9, 10. Said stands carry between themselves the conveying belt 1 in a substantially plane state in such a manner that their carrying rollers 9 abut the inside 11 of the respective V-belt sections and cooperate therewith, and their pressing rollers 10 abut the upper surface 12 of the ~1~9~1 respective V-belt sections and cooperate therewith. The load on the belt 1 caused by goods possibly lying on the belt is taken up by the carrying rollers 9, while the pressing rollers lO prevent the V-belt sections 2 of the belt to slide upward from the running surface 8 of the carrying rollers. In order to prevent the intermediate portion 4 of the belt to contact the carrying rollers, said rollers can be designed with thrust collars 14 to cooperate with the lower surface 13 of the respective V-belt sections.
In Fig. 2 the same roller stand arrangement is shown as in Fig. 1, which, however, is intended for a possible return run of the endless conveying belt 1 in the present belt conveyor. Also in this case, the carrying rollers 9 cooperate with the inside ll of the respective V-belt section, and the pressing rollers lO cooperate with the upper surface 12 of the respective V-belt section which here faces downward and rests against the underlying pressing roller lO. By reducing the distance between the roller stands 6, the belt both in its return run or load-carrying run can be given a more or less deep trough or groove shape.
As already mentioned, the belt l, due to its flexible intermediate portion 4, can be folded or bent to a closed or substantially closed bag-shaped cross-section. For supporting the belt l in this shape, each roller stand as shown in Fig. 3 and also in Fig. 15 comprises two carrying rollers 9, each carrying one of the V-belt sections 2 of the belt abutting or substantially abutting each other, the said intermediate portion 4 of the belt suspending down like a bag between the carrying rollers 9 due to the fact that the rollers with their running surfaces 8 cooperate with the inside ll of the respective V-belt section. The load arising on the belt owing to the goods 5 enclosed therein also tends ~13~

to draw the V-belt sections toward each other, because the contact surfaces between the running surfaces 8 of the carry-ing rollers and the V-belt sections 2 of the belt are inclined relative to the vertical plane. Thus, a certain locking is obtained therebetween by increased friction, which prevents a certain relative movement between the V-belt sec-tions facing toward each other, and at the same time the possible pressure is reduced which the V-belt sections with their bottom surface 13 may exert on the thrust collar 14 of the carrying rollers. This has a certain importance especial-ly in narrow curves where the load on the carrying rollers located on the inside of the curve is greater than in straight portions of the path.
In order to render it possible to empty the belt 1 from the goods 5 enclosed therein at any place where necessary along the path, and not only at the terminal positions of the path, at least one roller stand 6 of the type shown in Fig. 4 is provided in the direction of movement of the path in suit-ably spaced relationship after a suspension point comprising one or more roller stands of the type shown in Fig. 3.
Through said roller stand 6 the belt 1 runs only with one V-belt section 2, the second V-belt section being allowed to move downward with the belt and thereby opening the belt.
Thereafter said second V-belt section is re-united with the V-belt section 2 carrying the belt in a subsequent roller stand of, for example, the type shown in Fig. 3. Also in this case, the carrying roller 9 takes up the load from the belt, while the pressing roller 10 with its substantially vertical axle prevents the V-belt section 2 supported by the carrying roller 9 from sliding off its carrying roller 9. By this roller stand, thus, a very simple emptying device for the belt conveyor in question is obtained, which device in an easy way ~1~9~1 can be arranged at any place desirecl along the path. Roller stands of the type shown in Fig. 4 can be used, besides their use as emptying or discharge device, for carrying the convey-ing belt, and preferably its possible return run suspending vertically from one V-belt section, as shown in Fig. 4. The return run of the belt arranged in this way results in that the return run need not be located beneath the load-carrying run of the conveying belt, but can be suspended to the side of and on the same or on a higher or lower level than the load-carrying run, for example, at 36 in Fig. 15, along longer or shorter portions of its extension, and that the belt conveyor can be laid with considerably narrower curves than would be possible with a planely supported return run. In curves the pressing roller 10 of each such roller stand must be located on the inside of the curve, so that the tension in the belt caused by the curving of the belt is taken up by the pressing roller 10 and not by the thrust collar 14 of the carrying roller, which is the case if the carrying roller is located on the inside of the curve.
For supporting the return run of the conveying belt in plane state, the run, instead of being supported by the roller stand arrangement shown in Fig. 2, can be supported by a roller 37 (Fig. 15) provided at least in every suspension point 30, on which roller the belt 1 is fixed by means of guide rollers 39, which are provided with grooves 38 corres-ponding to the V-belt section 2 of the belt, in which grooves 38 the V-belt sections 2 of the belt run.
All roller stands 6 of the present belt conveyor have in common, that their rollers 9, 10 are arranged so that the axle 7 of each roller is in parallel with that side of the V-belt section, to which the roller abuts with its running surface 8. It is hereby ensured that the energy-absorbing 941.~

or more rollers 16 of the type shown in Fig. 5, i.e., rollers with grooves formed for the V-belt sections 2 of the belt and pressing rollers 18 for maintaining the V-belt sections engaged with the grooves of the ro7ler during the movement of the belt thereover.
When the goods consist of bulk goods or the like, the belt can be loaded also by means of a pipe inserted down-ward between V-belt sections of the belt with thrust rollers arranged diametrically for keeping the V-belt sections 2 of the belt apart and for preventing sliding movement between the same and the charging pipe (not shown).
At long and/or steeply ascending belt transports, an intermediate driving station can be provided in one or more of the suspension points 30 of the conveying belt and prefer-ably in the poles 31, instead of roller stands. Such an intermediate driving station 40 is shown in Fig. 16 and may comprise a driving roller 43 driven by a driving unit 41 and provided with V-belt grooves 42, and a counter-hold roller 44 located directly in front of said driving roller 43 and pro-vided with V-belt grooves 42, which counter-hold roller may but need not be driven. Between the rollers 43, 44, the belt in bag-shaped state is supported in the same way as by the rollers 20, 22 in Figs. 6 and 7 and runs with its V-belt sections 2 in driving engagement with the grooves 42 of the rollers, whereby driving power is transferred to the V-belt sections 2 from each driven roller 43, 44.
At least the roller stands supporting the conveying belt in bag-shape, like each intermediate driving station, should be hingedly suspended. An example thereof is shown in Figs. 3 and 15 where the carrying rollers 9 of the roller stand are hingedly suspended about an axle 46 in a console 47, which in its turn is suspended pivotally about an axle 48, vertically suspended position, as shown in Fig. 4, whereby the risk of belt damages caused by objects following with the return run is completely eliminated. Due to the elasticity of the intermediate portion 4 of the belt, also the risk of belt damages caused by objects possibly following with the return run in between the same and the driving roller is reduced.
In Figs. 6 and 7 a modified driving station is shown, which comprises a driving wheel 20 driven by a motor (not shown) and having a vertical axle 19, which wheel has a relatively large diameter and is formed with a peripheral V-belt groove 21 and with a plurality of non-driven pressing rollers 22 located outside the driving wheel 20 and also formed with V-belt grooves 23. This station, thus, is arranged to drive the belt 1 in its closed bag-shaped state with the V-belt sections 2 abutting each other. Of these V-~ belt sections, thus, one is caused to drivingly engage with ;~ the V-belt groove 21 of the driving wheel by means of the pressing rollers 22 coacting with the other V-belt section of the belt and pressing against the same, which rollers 22 are not driven but only follow along and can be radially attached to the driving roller for control of the forces, by which the V-belt sections are pressed against each other, and into the groove 21 of the driving roller. From this driving station the belt passes out also in bag-shaped state and thus can take along its load through the driving station. When the belt is emptied from its load before such a driving station, the belt can be utilized also after this station for the return trans-- port of goods, which can be supplied to the belt, because the belt during a certain distance is supported and maintained entirely or partially spread, for example, by means of a roller stand of the type shown in Fig. 1 or by means of one 11~9411 or more rollers 16 of the type shown in Fig. 5, i.e., rollers with grooves formed for the V-belt sections 2 of the belt and pressing rollers 18 for maintaining the V-belt sections engaged with the grooves of the roller during the movement of the belt thereover.

s When the goods consist of bulk goods or the like, the belt can be loaded also by means of a pipe inserted down-, ward between V-belt sections of the belt with thrust rollers arranged diametrically for keeping the V-belt sections 2 of the belt apart and for preventing sliding movement between the same and the charging pipe (not shown).
At long and/or steeply ascending belt transports, an intermediate driving station can be provided in one or more of the suspension points 30 of the conveying belt and prefer-ably in the poles 31, instead of roller stands. Such an s intermediate driving station 40 is shown in Fig. 16 and may comprise a driving roller 43 driven by a driving unit 41 and , provided with V-belt grooves 42, and a counter-hold roller 44 !F located directly in front of said driving roller 43 and pro-vided with V-belt grooves 42, which counter-hold roller may but need not be driven. Between the rollers 43, 44, the belt in bag-shaped state is supported in the same way as by the rollers 20, 22 in Figs. 6 and 7 and runs with its V-belt sections 2 in driving engagement with the grooves 42 of the rollers, whereby driving power is transferred to the V-belt sections 2 from each driven roller 43, 44.
At least the roller stands supporting the conveying belt in bag-shape, like each intermediate driving station, should be hingedly suspended. An example thereof is shown in Figs. 3 and 15 where the carrying rollers 9 of the roller stand are hingedly suspended about an axle 46 in a console 47, which in its turn is suspended pivotally about an axle 48, ~ fl~ i :.
which need not be in parallel with the axle 46, but especially in curves should be arranged perpendicularly in relation to the axle 46. In Fig. 15 the console 47 is shown suspended in a structure 49, in which also the rollers 37 and 39 for the return run of the belt are shown provided. Said structure 49, as shown in Fig. 14, may be suspended on a wire 50, which is secured on a carrying wire 51 extending between the poles 31.
With such a carrying wire 51, the poles 31 can be positioned at great distance from each other, with one or more suspension points between the poles. When the tensile stress is concen-trated to the V-belt sections 2 of the belt, and said sec-tions in their turn run on rollers, a long distance also can be held between the suspension points 30, thereby rendering possible a belt conveyor of low cost compared with conven-tional belt conveyors.
According to the present invention, it is also possible to drive the belt 1 in entirely or partially plane `j state through a curve, as illustrated in Fig. 8. The outer ` V-belt sections 2 of the belt are for this purpose supported ' ~ 20 in roller stands 25 of the type shown to the left in Fig. 1, I ~
which stands are located in substantially the same plane, and at which the carrying roller 9 abuts the inside of the V-belt section, while the pressing roller 10 of each roller stand acts on the upper surface 11 of the V-belt section. In a similar way, corresponding roller stands 24 (Fig. 10), i.e., roller stands of about the type shown to the right in Fig. 1, are arranged at the inner edge of the belt, and length adjust-ing means are provided at the belt edge facing toward the inside of the curve to balance the difference in length between the outer and the inner edge of the belt. Said means consists of every second roller stand at the inner edge of the belt being located on a higher or lower level than the adjacent roller stand, which in its turn can be located on the same or on a higher or lower level than the roller stands at the outer edge of the belt. The belt thus is caused to move with its inner edge along a substantially sinus-shaped path, and in this way the difference in length and speed between the outer and the inner edges of the belt are compen-sated for. The belt hereby can be caused to move through a curve also in spread state and in this state can be used as loading and discharge station.
The present invention is not restricted to what is described above and shown in the drawings, but can be modi-fied, changed and completed in many different ways within the ~-` invention idea as it is defined in the accompanying claims.
~, A belt conveyor according to the invention, thus, may comprise one or more of the details described above and shown in the drawings and by means of these details be so varied, that substantially all objects desired with respect to goods transports of the kind concerned can be achieved.
The term V-belt section is to be understood here as every section having a width increasing to the belt and which can be formed with teeth for meshing engagement with the driving rollers.

, ':

Claims

The embodiments of the invention in which an exclu-sive property or privilege is claimed are defined as follows:

1. A conveyor comprising an endless conveyor belt driven by driving rollers in an endless path, said conveyor belt including two tractive force absorbing elements spaced from each other and being integral with the belt along the length thereof and a flexible intermediate portion between said elements, support rollers cooperating with said elements for supporting a portion of the conveyor belt between said driving rollers, with said intermediate belt portion hanging down bag-like between the force absorbing elements of the belt, each of said elements having inclined sides so as to have in cross-section a truncated wedge shape with a width decreasing from the belt, and each driving roller having at least one groove mating with one such element for drive engagement therewith, each support roller having a running surface cooperating with a portion of the cross-section of the respective element, each said support roller being arranged to have the running surface thereof abutting an inclined side of said respective element and the axis of rotation of said roller being substantially parallel with the respective side of the element.

2. A conveyor according to claim 1, characterized in that the conveyor belt portion intended for the transport of goods is suspended by support rollers arranged in pairs, with the absorbing elements of the belt in abutment to each other.

3. A conveyor according to claim 2, characterized in that the inclined sides of the rollers press the sides of the elements facing toward each other against each other.

4. A conveyor according to claim 1, characterized in that a counterpressure-roller is provided adjacent the drive roller, which rollers have substantially vertically extending axles and the counterpressure-roller has a groove, and between which rollers the conveying belt runs with the elements abutting each other with one side and in engagement with the grooves of the rollers for transferring driving power from the driving roller to the conveying belt.

5. A conveyor according to claim 4, characterized in that the counterpressure-roller is displaceable toward and from the driving roller to change the distance between the rollers and thereby the pressure between the elements abutting each other.

6. A conveyor according to claims 4 and 5, characterized in that the counterpressure-roller is also driven.

7. A conveyor according to claim 1, characterized in that a terminal driving roller is provided which is driven about a substantially horizontal axis, the roller having an axial length exceeding the width of the conveying belt in planar state and the roller includes two grooves adapted to receive the elements when the conveyor belt runs in spread state.

8. A conveyor according to claim 7, charac-terized in that at least one pressing roller is provided at each groove of the drive roller to press and maintain the elements of the belt in driving engagement with grooves of the driving roller.

9. A conveyor according to claim 1, charac-terized in that the driving roller rotates about a vertical axis with the groove extending peripherally of the roller for a driving engagement enclosing between 90° and 180°
with one of the elements of the conveying belt abutting each other, the other element of the belt running in and being supported by a number of pressing rollers located radially outside the driving roller, the flexible inter-mediate portion of the belt suspending bag-like between the driving and the pressing rollers.

10. A conveyor according to claim 1, charac-terized in that the support rollers are arranged in pairs and co-operating with the absorbing element of the conveying belt to carry the return run of the belt in a vertically suspended position.

11. A conveyor according to claim 1, charac-terized in that for carrying the conveying belt in substantially plane state in cooperation with the inside of the elements of the belt rollers are arranged, to which the elements are held in abutment by pressing rollers located directly in front of said rollers and acting against the side of the elements lying in the plane of the conveying belt.

12. A conveyor according to claim 11, characterized in that for guiding the conveying belt in plane state through a curve the said support roller pairs cooperating with the inner section of the belt are arranged to guide said section in a substantially sinus-shaped path for compensating for the difference in length between the inner and outer portions of the belt through the curve.