GB2028751A

GB2028751A - Bucket elevator with digging wheel as lower reversing element

Info

Publication number: GB2028751A
Application number: GB7928723A
Authority: GB
Original assignee: STORK CONRAD BV
Current assignee: STORK CONRAD BV
Priority date: 1978-08-18
Filing date: 1979-08-17
Publication date: 1980-03-12
Also published as: FR2433474A1; DE2933392A1; NL7808584A; FR2433474B3; JPS5544493A

Abstract

A bucket elevator for taking up and conveying upwardly bulk material includes an upper reversing wheel (6), a lower digging wheel (7), two parallel flexible elastic belts (2), extending around both wheels and buckets (4) connected to the belts and disposed between them. The digging wheel (7) has scoops (8) each with an open bottom. As the belts with the buckets go round the digging wheel, one scoop goes between the belts and a pair of adjacent buckets, the open bottom of each scoop being aligned with the open top of the trailing bucket. Pulleys may be provided to vary the path of the flexible belts 2. <IMAGE>

Description

SPECIFICATION Apparatus for taking up and conveying upwardly bulk material This invention relates to an apparatus for taking up and conveying upwardly bulk material, comprising at least one continuous flexible element, said element being passed over at least two rotatable reversing means spaced one above the other, buckets which are secured to said flexible element and which are all equally spaced apart, and driving means for imparting a circulating movement in one direction to the flexible element and the buckets secured thereto make means being provided in the proximity of the upper reversing means for collecting the material elevated by the buckets. An apparatus of this kind is generally known by the name of bucket elevator.

In said known bucket elevator the continuous flexible elements are constituted by chains, to which the buckets consisting of a high grade metal are secured, said elements being reversed by sprocket wheels.

A bucket elevator is a comparatively expensive and heavy apparatus, also because the speed of rotation of the chains is limited. Consequently, in order to obtain a satisfactory elevating capacity, the buckets should have a reasonable large volume, which makes them heavy and, in addition, high maintenance costs may be involved mainly because of the large number of pivots and because of the fact that the buckets acting also as digging means are subjected to wear.In addition, the distance between the sprocket wheels cannot be altered in a simple and reliable manner, as a consequence of which the apparatus is not suitable for being used as transshipping means for unloading vessels since, in doing so, the apparatus as a whole unit will have to be lowered deeper and deeper into the hold of the vessel, whereby the means for taking up the material to be conveyed upwardly should move along with the apparatus and the total elevation height should be equal to the depth of the hold, so that initially, said elevation height is needless great. Furthermore, the buckets of a bucket elevator should act as digging elements and as elevating elements.The consequence of which is that the digging action can only be fulfilled satisfactorily when the complete apparatus travels in the horizontal direction, which corresponds with the direction in which the buckets circulate. For, during operation the entire apparatus should be moved horizontally over the material to be elevated, so that in practice, a bucket elevator is used with a working stroke in which material is being dug up and elevated and with a non-operative or idle return stroke, what means that the apparatus does not operate continuously. The idle return stroke may be avoided by turning the complete apparatus through 180 degrees about the vertical longitudinal axis, however, in that case, also the means for collecting the material elevated by the buckets should be turned, which causes a lot of difficulties.

Finally, the unloading of material which has been elevated, especially of sticky material, out of the buckets is a problem in the case of a bucket elevator.

It is an object of this invention to provide an apparatus of the aforementioned type, which is particularly suitable for being used as transshipping means for the unloading of vessels.

Said object is achieved in that in the apparatus in accordance with the present invention the flexible element is constituted by two parallel-extending belts or similar elements of a flexible, elastic material, e.g. rubber, with which the buckets are connected, said buckets being made of a light weight meterial, such as a light metal or a synethetic material, preferably also of a flexible elastic material, such as rubber, while the upper reversing means is constituted by a reversing disc and the lower reversing means is constructed as a digging wheel, the digging scoops of said digging wheel being also open at the bottom side and the distance between said scoops corresponding with the distance between the buckets, said digging scoops being shaped such that their bottom sides correspond with the open sides of the buckets, while the open spaces between said buckers are laterally confined by the belts so that the digging scoops project into said spaces when the belts pass over said lower reversing means.

By using belts of a flexible elastic material instead of chains, for reasons of dynamics it is possible to operate at considerably higher rotational speeds, so that for obtaining the same elevating capacity the buckets may be smaller and, thus, lighter. And since they are constructed of a comparatively light material, such as rubber, the buckets are already lighter by themselves, as a result of which per unit of belt-length less material needs to be elevated, at, in turn, leads to a reduction in load on the apparatus, so that the apparatus can be of a lighter construction, it will need less power and it will bring about a reduction in load on the supporting foundation, e.g.

a quay. In addition, the belts of a flexible elastic material are highly wear-resistant and the digging wheel may be constructed of a high-grade material, since it comprises only a modest number of digging scoops as compared with the number of buckets of the conventional bucket elevator. The digging scoops are only used for digging up the material and hence they can be constructed for an optimate digging action, permitting that material is dug up and elevated during both two horizontally directed strokes of the complete apparatus. By the fact that the buckets may be constructed of a flexible elastic material they can always be properly emptied, e.g.

by a slight deformation of the buckets, when needed.

The path of the belts made of flexible, elastic material, can easily be changed by means of one or more guide pulleys, comprising two radially projecting circumferential flanges, with which said belts are in contact, and a cavity constituted between said flanges for receiving the buckets. Thus, various possibilities are created for obtaining inclined belt portions which are highly advantageous for dumping the material out of the buckets.

In addition, two guide pulleys spaced apart in the vertical sense and at least a second reversing disc, seen in the direction of rotation located between said guide pulleys and laterally spaced apart therefrom may be provided, so that an essentially horizontal loop is formed in the belts, in which the second reversing disc is movable in horizontal direction and the distance between the digging wheel and the upper reversing disc can be changed, as a result of which a particularly favourable embodiment for unloading a vessel is obtained, since the elevating height can always be adapted to the depth of the hold at which lies the material to be elevated.

Consequently, the elevating height needs never be higher than is absolutely necessary.

The digging wheel may be mounted for a pivotal movement about an essentially vertical axis extend ing in the plane of the wheel, so that the digging wheel can be turned through angles of over 90 without any additional tension in the belts. Thus, in operation, the complete apparatus is movable in almost all horizontal directions.

The digging wheel construction may comprise a digging wheel having radially extending digging scoops all equally spaced apart along its circumference and a guide drum disposed around said digging wheel, said drum comprising two circular discs spaced apart and extending parallel to each other, over which the flexible belts are passed while the axis of rotation of said drum is disposed eccentrically relative to the axis of rotation of the digging wheel so that the circumference of the digging wheel is disposed inside the circumference of the discs and the digging scoops of the digging wheel project beyond said discs over a predetermined part of the circumference of said discs in order to register with the buckets.

It is, thus, achieved that less space is needed between the buckets for the digging scoops to move into and out of said space, so that the open spaces between the buckets may become smaller and more buckets can be used per unit of belt-length, as a result of which the elevating capacity of the device is increased.

In the case of the present digging wheel construction the drum may be arranged such that the axis of rotation of the drum may be rotated about the axis of rotation of the digging wheel, so that the radial direction in which the axis of rotation of the drum is displaced relative to the one of the digging wheel can be adjusted for changing said part of the circumference.

In this way, the position of the part of the circulating belt cooperating with the digging scoops can be altered in dependency on the direction of stroke of the complete device, so that for each direction of stroke the most favourable position for digging up the material can be obtained.

It is also possible to provide the circumference of the digging wheel and the one of the discs with engaging elements, such as teeth, said circumferences touching each other. In doing so, the discs of the drum may be connected with each other by bars extending between the circumferences of the discs, in which said coupling of the discs and the digging wheel guarantees that the digging scoops will always run free of said bars.

It is noted that a bucket elevator is known from Dutch Patent Application No. 67,06213, in which the lower reversing element is provided with radially extending digging elements which may cooperate with the buckets, so that during the digging up of the material said elements constitute the parts which are subjected most to wear.

The invention will now be described in more detail with reference to the accompanying drawing in which: Figure 1 is a diagrammatic side elevation of an embodiment of the apparatus in accordance with the invention; Figure 2 is a cross-sectional view taken on line Il-Il in Figure 1; Figure 3 is a side elevation of a different embodiment ofthe invention; Figure 4 is a side elevation of another embodiment; Figure 5 illustrates the apparatus according to Figure 4, located on a bridge; Figure 6 is a diagrammatic side elevation of a different embodiment of the digging wheel construction; Figure 7 is a longitudinal sectional view of the construction according to Figure 6; and Figure 8 and 9 are diagrammatic elevations of two positions of the digging wheel construction according to Figure 6 and 7.

As illustrated in Figure 1,the device according to the invention comprises a continuous flexible element 1 consisting of two belts 2 made of a flexible elastic material, such as rubber, in the form of V-belts which are connected with each other by plate-shaped parts 3 of a flexible elastic material, said parts being all equally spaced apart. Buckets 4 made of a flexible elastic material, such as rubber are formed over the plate-shaped parts 3, so that said plate-shaped parts 3 constitute a wall portion of said buckets 4; between the buckets 4, laterally confined by the belts 2, are open spaces 5. At the top, the belts 2 are passed over a rotatable reversing disc 6 and at the lower side they are passed over a reversing means 7 constructed as a digging wheel.

Said digging wheel 7 is provided with radially extending digging scoops 8 which are also open at the bottom sides 9; said scoops 8 being shaped such that their bottom sides 9 corresponds with the open sides of the buckets 4, while the scoops 8 project through the open spaces 5.

In addition, a guide pulley 10 is provided which is provided with two circumferential flanges 11, between which the buckets 4 can be accommodated.

By said guide pulley 10, an oblique part 12 in the path of the belts 2 is obtained, as a result of which the material which has been elevated can easily be dumped out of the buckets onto e.g. the conveyor belt 13. However, the material which has been elevated can also be discharged through the open spaces 5, as illustrated in Figure 4.

In the embodiment, as illustrated in Figure 3, corresponding parts are indicated by the same reference numerals as in Figure 1 and 2, but in Figure 3 they are marked with an accent. The reversing disc 6' and the digging wheel 7' are mounted in a frame 14 which is suspended by means of cable 15 and which is guided by guide means 16. The digging wheel 7' is connected to the frame 14 by means of the rotating gearing 17 for a rotating movement about a vertical axis. In addition, two guide pulleys 18 and 19, as well as a second reversing disc 20 are provided, all of which are rotatably mounted in a fixed position.Between guide pulley 18 and reversing disc 20, an oblique part 21 of the belts 2' is formed, as a result of which the material, which has been elevated, can easily be dumped out of the buckets 4' onto a transverse conveyor belt 22, by which the material is conveyed towards a longitudinal conveyor belt 23. Conveyor belts 22 and 23 are also mounted in a fixed position so that during the up-and-down-movement of the frame 14 the place of discharge will always remain at the same level.

In the embodiment shown in Figure 4, corresponding parts are indicated by the same reference numerals as in Figure 1 and 2, but in Figure 4they are marked with a double accent. In this embodiment, the digging wheel 7" is mounted on the lower end of a frame 25 though a rotating gearing 24, said frame 25 extending through guide means 26 which is connected to frame 28 by means of ball joint 27, said frame 28 being constructed as a carriage. The upper reversing disc 6" and guide pulleys 29 and 30 are mounted on said carriage 28.

In addition, a reversing disc 31, which is movable in horizontal direction, is provided, so that during the up-and-down-movement of the frame 25 and the movement of the reversing disc 31 corresponing to the movement of said frame 25, the distance between digging wheel 7" and reversing disc 6" can be changed. As illustrated in Figure 4, the material which has been elevated is dumped through the open space 5" onto a chute 32.

Figure 5 shows the embodiment according to Figure 4, in which the apparatus is disposed on the bridge 33 of a loading bridge capable to travel on the quay 34. The frame 28 is constructed as a carriage capable to travel along bridge 33; the reversing disc 31 is mounted on the carriage 28 for movement in horizontal direction. In addition, a conveyor belt 35 is shown, which is provided along bridge 33; the material which has been elevated can be conveyed by said belt towards the quay 34.

When the apparatus is in operation, frame 25 is lowered into the hold of vessel 36 and the belts 2" with buckets 4" are being circulated by means of driving members (not illustrated), said driving mem bers preferably driving the reversing disc 6" a well as the digging wheel 7", whereby the scoops 8 of the digging wheel 7" dig up the material lying in the hold, said material being subsequently forced into the buckets 4" and being elevated by said buckets.

The material is then dumped out of the buckets and discharged through conveyor belt 35.

As shown in Figure 6 and 7, the digging wheel construction 37 comprises digging scoops 38 which are also open at the bottom sides, said digging wheel being secured on shaft 39; the shaft 39 is mounted in bearings in frame 40 for being rotated by the motor 42 through the gear-wheel transmission 41. A drum 43 is provided around digging wheel 37, said drum comprising two circular discs 44 the belts 45 being passed over said discs; the belts 45 and the buckets 46 secured thereto correspond with belts 2 and buckets 4 of the devices described above. The discs 44 are rotatable about bushing 47 which is eccentrically journalled on shaft 39. The bushing 47 is retained in a certain position by means of rod 48 pivotably connected to the bushing, said rod 48 being connected to frame 40 through the rightangled lever 49 and the straight lever 50.The other end of the straight lever 50 is connected to the piston rod of a piston-cylinder assembly 51.

Furthermore, a support 52 is provided for supporting belts 45, said support 52 being rotatably connected to right-angled lever 49 at reference numeral 53 and to frame 40 by means of link 54.

Thus, the drum 43 is disposed eccentrically about digging wheel 37, so that during rotation of the drum 43 and the circulation of belt 45 with the buckets 46 secured thereto and during rotation of the digging wheel 37 the digging scoops 38 will need less space for moving in and out the space between the buckets, as a result of which said buckets 46 may be positioned closer to each other. When the piston cylinder unit 51 is operated, bushing 47 may be rotated about shaft 39, whereby the radial direction in which the axis of rotation of the drum is displaced relative to the one of the digging wheel can be adjusted, as illustrated in Figure 8 and 9, in which the axis of rotation of drum 43 is indicated by reference numeral 55.For the digging operation oftheappar- atus in both directions of stroke, the most favourable position of the drum relative to the digging wheel can thus be set by means of the piston-cylinder unit 51. For the direction of stroke A and B, said position is shown in Figure 8 and 9 respectively, in which the hatched part in said Figures indicates the area in which the digging scoops of the digging wheel cooperate with the circulating buckets.

It is noted that in Figure 6 up to 8 inclusive the extent to which the drum is disposed eccentrically with respect to the digging wheel is exaggerated for the sake of clarity.

Reinforcement bars 56 may be disposed between discs 44 of drum 43. In doing so, it is necessary that elements, such as teeth (not illustrated) are provided along the circumference of digging wheel 37 and of discs 44, which mesh in the region in which said circumferences touch each other; it is, thus, ensured that when the digging scoops 38 move into the spaces between the buckets 46, said scoops will always run free of the bars 56.

Claims

1. Apparatusfortaking up and conveying upwardly bulk material, comprising at least one continuous flexible element, said element being passed over at least two rotatable reversing means spaced one above the other, buckets which are secured to said flexible element and which are all equally spaced apart, driving means for imparting a circulating movement in one direction to the flexible element and the buckets secured thereto make means being provided in the proximity of the upper reversing means for collecting the material elevated by the buckets, characterized in that the flexible element is constituted by two parallel-extending belts or similar elements of a flexible, elastic material, e.g. rubber, with which the buckets are connected, said buckets being made of a light weight material, such as a light metal or a synthetic material, preferably also of a flexible elastic material, such as rubber, while the upper reversing means is constituted by a reversing disc and the lower reversing means is constructed as a digging wheel, the digging scoops of said digging wheel being also open at the bottom side and the distance between said scoops corresponding with the distance between the buckets, said digging scoops being shaped such that their bottom sides correspond with the open sides of the buckets, while the open spaces between said buckets are laterally confined by the belts so that the digging scoops project into said spaces when the belts pass over said lower reversing means.

2. Apparatus according to Claim 1, characterized in that the flexible belts are constituted by V-belts, said belts being connected with each other by plate-shaped parts, all equally spaced apart and forming a wall portion of the buckets.

3. Apparatus according to Claim 1 or 2, characterizedin that the flexible belts are passed over one or more guide pulleys, said pulleys comprising two radially projecting circumferential flanges, said belts being in engagement with said flanges, and a cavity between said flanges for receiving the buckets.

4. Apparatus according to Claim 3, characterized in that one guide pulley is disposed in the proximity of the part of the belts moving downwards.

5. Apparatus according to claim 3, characterized in that one guide pulley is disposed in the proximity of the part of the belts moving upwards and that there is at least a second reversing disc, which, seen in the direction of circulation, is disposed behind said guide pulley and being displaced in horizontal direction relative to said pulley.

6. Apparatus according to Claim 3, characterized in that two guide pulleys spaced apart in the vertical sense and at least a second reversing disc are provided which disc, seen in the direction of circulation is disposed between said guide pulleys and spaced apart therefrom sideways, so that an essentially horizontal loop is formed in the belts.

7. Apparatus according to Claim 6, characterized in that the second reversing disc is movable in horizontal direction and the distance between the digging wheel and the upper reversing disc is variable.

8. Apparatus according to Claims 1 to 7 inclusive, characterized in thatthe digging wheel is mounted for a pivotal movement about an essentially vertical axis extending in the plane of the wheel.

9. Apparatus according to Claims 1 to 8 inclusive, characterized in that the digging wheel construction comprises a digging wheel having radially extending digging scoops along its circumference, said digging scoops being all equally spaced apart, and a guide drum disposed around said digging wheel, said drum comprising two circular discs extending in spaced apart relation parallel to each other, said flexible belts being passed over said circular discs and the axis of rotation of said drum being eccentric ally disposed relative to the axis of rotation of the digging wheel so that the circumference of the digging wheel is disposed inside the circumference of the discs and the digging scoops of the digging wheel over a certain part of the circumference of said discs project beyond said discs in order to corres pond with the buckets.

10. Apparatus according to Claim 9, characterizedin that the axis of rotation of the drum if mounted for a rotational movement about the axis of rotation of the digging wheel, so that the radial direction in which the axis of rotation of the drum is displaced relative to the one of the digging wheel, can be altered, for changing said part of the circumference.

11. Apparatus according to Claim 9 or 10, char acterizedin that the circumference of the digging wheel and the one of the discs are provided with engaging elements, such as teeth, said circumferencestouching each other.

12. Apparatus according to Claim 11, characte rizedin that the discs of the drum are connected with each other by bars extending between the discs, said bars being connected to the discs in the proximity of their circumferences.

13. A bucket elevator comprising an upperre- versing disc, a lower digging wheel, two parallel flexible elastic belts extending around both wheels, and a plurality of buckets each connected to both belts and located between them, the buckets being evenly spaced along the belts, the digging wheel having a plurality of scoops each with an open bottom, the scoops being evenly spaced circumferentially and sized so that as the belts with the buckets go round the digging wheel, one scoop projects between the two belts and between two adjacent buckets, the open bottom of the scoop being aligned with the top of the trailing bucket.

14. Apparatusfortaking up and conveying upwardly bulk material substantially as herein described with reference to and as shown in Figures 1 and 2, or with reference to and as shown in Figure 3, or with reference to and as shown in Figures 4 and 5, or with reference to and as shown in Figures 6 to 9 of the accompanying drawings.