EP2212222A1

EP2212222A1 - Helical conveyor

Info

Publication number: EP2212222A1
Application number: EP08850602A
Authority: EP
Inventors: Lothar Pasch
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-11-16
Filing date: 2008-11-13
Publication date: 2010-08-04
Also published as: NL2001010C2; WO2009064184A1

Abstract

The invention relates to a helical conveyor comprising a frame for supporting a helical path having a first number of windings or storeys placed above one another, a modular conveyor belt sitting on the helical path and able to slide over it, a drive mechanism (17) engaging a side of the modular conveyor belt at a second number of windings or storeys placed above one another, wherein the second number is lower than or equal to the first number, wherein the helical conveyor comprises a freely rotatable support roller (16) positioned within the helical path, for having a side of the modular conveyor belt facing the inner side of the helical path supporting against it, and wherein the drive mechanism is placed on an outer side of the helical path.

Description

Helical conveyor

BACKGROUND OF THE INVENTION

The invention relates to a helical conveyor comprising a frame for supporting a helical path having a number of windings or storeys placed above one another, a modular conveyor belt sitting on the helical path and able to slide over it, a drive mechanism engaging a side of the modular conveyor belt at a number of windings or storeys placed above one another. The invention furthermore relates to a drive mechanism for such a helical conveyor.

Dutch patent application 8702276 describes a helical conveyor for during a certain period of time under conditioned circumstances having products circulate, particularly food products such a dough products. Within the helical path a rotatable drum is positioned for driving the conveyor belt using friction. The peripheral velocity of the drum is slightly higher than the speed of locomotion of the conveyor belt. Slight slippage will therefore occur. The conveyors in question however are exposed to temperature changes and sometimes the products will soil. The friction coefficient between drum and the modular conveyor belt may as a result acquire a different value which may lead to problems.

The known helical conveyor is furthermore provided with a rotatable drum, in the shape of a stainless steel pipe. Said pipe forms a costly element of the helical conveyor and, in view of the dimensions of the known helical conveyors, has large dimension which may give rise to problems when transporting or building up the helical conveyor. It is an object of the present invention to at least partially solve one or more of the above-mentioned problems.

SUMMARY OF THE INVENTION

According to a first aspect the invention provides a helical conveyor comprising a frame for supporting a helical path having a first number of windings or storeys placed above one another, a modular conveyor belt sitting on the helical path and able to slide over it, a drive mechanism engaging a side of the modular conveyor belt at a second number of windings or storeys placed above one another, wherein the second number is lower than or equal to the first number, wherein the helical conveyor comprises a freely rotatable support roller positioned within the helical path, for having a side of the modular conveyor belt facing the inner side of the helical path supporting against it, and wherein the drive mechanism is placed at an outer side of the helical path. Instead of the rotatable drum positioned within the helical path according to the state of the art, the helical conveyor according to the invention is provided with a freely rotatable support roller, which is positioned within the helical path for having a side of the modular conveyor belt facing the inner side of the helical path supporting against it, particularly near the location where the drive mechanism is placed at the outer side of the helical path and engages onto the outer side of the modular conveyor belt. The modular conveyor belt is thus passed between the support roller at the inner side of the conveyor path and the drive mechanism at the outer side of the conveyor path. As the freely rotatable support roller in the helical conveyor according to the invention is only used for having the conveyor belt supporting against it, and not for driving the conveyor belt using friction, it can be designed much more lightweight, the conveyor belt will substantially not slip along the support roller, and the diameter of the support roller can be smaller than an inner diameter of the helical path.

Due to substantially avoiding slippage between the conveyor belt and the support roller, the modular conveyor belt will be less prone to wear which may lead to reduction of pollutions by wearing products and/or the life span of particularly the conveyor belt will be extended. In one embodiment the diameter of the support roller may be smaller than the inner diameter of the helical path. The diameter of the support roller may be adapted for only giving support at the location of the drive mechanism. In one embodiment the drive mechanism is placed such with respect to the support roller that the support roller is able to suitably absorb possible radial forces exerted by the drive mechanism on the conveyor belt. In one embodiment the drive mechanism is placed substantially radial with respect to the support roller.

In one embodiment the helical conveyor may be provided with a number of support rollers that are distributed within the helical path preferably in a regularly spaced apart manner.

In one embodiment several drive mechanisms can be placed around the helical conveyor, in connection with maximum belt forces.

Placing a drive mechanism at an outer side of the helical path of a helical conveyor is known pre se from US patent 5,454,467. Particularly figure 7 of said US patent shows a drive mechanism that is operationally connected to a side of the conveyor belt facing the outer side of the helical path. Also to ensure that the drive mechanism properly contacts the conveyor belt, the path of the conveyor belt is entirely or partially provided with guides (reference numbers 32 and 33} which counteract a lateral sliding of the conveyor belt. A drawback of said guides 32, 33 is that they cause extra friction and/or pollutions as the conveyor belt constantly slides along said guides. Due to the freely rotatable support roller in the helical conveyor according to the invention, said guides are not necessary.

In one embodiment the drive mechanism, for each of the second number of windings placed above one another, comprises a drive element for operational connection to a side of the modular conveyor belt facing the outer side of the helical path. In that way the forces exerted on the modular conveyor belt by the drive mechanism can be distributed over a number of locations along the length of the helical path, particularly over a number of locations along the helical path that are situated above one another. in one embodiment the drive element comprises a first confining element placed above the drive element, which first confining element extends at least partially above an edge area of the modular conveyor belt. In this embodiment the conveyor belt is confined in the vertical sense near the drive element between the helical path at the lower side and the first confining element at the upper side. The first confining element ensures that the conveyor belt at least near the drive element cannot fold upwards, as a result of which the operational connection between the drive element and the conveyor belt is guaranteed.

In one embodiment the drive element further comprises a second confining element placed below the drive element, which second confining element extends at least partially below an edge area of the modular conveyor belt. In this embodiment the modular conveyor belt, at least at the location of the drive element, is confined between the first and second confining element.

In one embodiment the first and/or second confining element are parts of the drive element, and thus will fixate the conveyor belt only locally at least near the drive element. In this embodiment the first and/or the second confining element comprises a piloting edge facing the drive element. As a result the side of the modular conveyor belt facing the outer side of the helical path, near the drive element is guided to said drive element by means of the piloting edge.

In one embodiment the drive element comprises a toothed wheel that is operationally connected to the side of the modular conveyor belt facing the outer side of the helical path. Preferably at the side facing the outer side of the helical path, the modular conveyor belt is provided with a series of cams for engagement onto the toothed wheel. The teeth of the toothed wheel are thus able to mesh with recesses between the series of cams for driving the conveyor belt.

In one embodiment the first and/or second confining element comprises a disk placed adjacent to the toothed wheel, wherein the diameter of the disk is larger than the diameter of the toothed wheel. The disk- shaped first and/or second confining element is placed above and/or below the toothed wheel respectively, wherein the disk or disks preferably are placed on the drive shaft of the toothed wheel. In this embodiment the first and/or the second confining element will be able to be rotated together with the toothed wheel. Due to these rotatable confining elements, on the one hand the friction between the confining elements and the conveyor belt can be reduced and on the other hand brake forces the conveyor belt is subjected to due to stationary confining elements can substantially be avoided.

In a further embodiment the drive element comprises a first and second toothed wheel placed adjacent to each other and around which a drive chain is placed for operational connection to the side of the modular conveyor belt facing the outer side of the helical path. Here again the modular conveyor belt preferably at the side facing the outer side of the helical path is provided with a series of cams for meshing with the drive chain. Contrary to the embodiment discussed above wherein use is made of a toothed wheel for driving the modular conveyor belt, which toothed wheel substantially engages onto a point of the helical path, the drive element according to this embodiment, that means with a drive chain, will engage along a trajectory of the helical path, wherein the length of the trajectory is defined by the distance between the first and second toothed wheel. The drive power exerted by the drive element on the conveyor belt, particularly the drive powers at the location of a winding or storey where the drive element in question engages onto the conveyor belt, can be distributed over the trajectory.

In order to ensure that due to an upward movement of the conveyor belt the coupling between the conveyor belt and the drive element might get lost, at least temporarily, a first embodiment including drive chain comprises a first and/or second confining element. Said confining elements are designed as a disk placed adjacent to the first and/or second toothed wheel, wherein the diameter of the disk is larger than the diameter of the toothed wheel with the drive chain placed around it. Thus the disk will be able to extend above and/or below an edge area of the conveyor belt in order to ensure that the drive element remains continually coupled to the conveyor belt.

In a second embodiment including drive chain, the drive chain is provided with first and/or second confining elements that may extend above and/or below an edge area of the conveyor belt at the moment that the drive chain is situated near the conveyor belt.

In one embodiment the drive chain comprises a number of substantially vertically extending pins for operational connection to the side of the modular conveyor belt facing the outer side of the helical path. The pins may in that case mesh with the recesses between the cams.

The drive chain may furthermore be provided with links placed above and below the pins for forming the drive chain. Preferably the vertically extending pins are placed substantially centrally in the drive chain. Said embodiment has the advantage that substantially no moment is exerted on the drive chain, contrary to the drive chain provided with teeth as shown in figure 7 of US patent 5,454,467.

In one further embodiment the top links comprise the first confining elements. In one embodiment at least one of the top links is integrally formed with at least one of the confining elements. In one embodiment the bottom links comprise the second confining elements, wherein in one embodiment, at least one of the bottom links is integrally formed with at least one of the second confining elements. In these embodiments the links thus have a twofold function, on the one hand to form the drive chain, on the other hand to confine the conveyor belt near the drive element.

According to a second aspect the invention provides a drive mechanism for a helical conveyor comprising a frame for supporting a helical path having a first number of windings or storeys placed above one another, a modular conveyor belt sitting on the helical path and able to slide over it, and a freely rotatable support roller positioned within the helical path for having a side of the modular conveyor belt facing the inner side of the helical path supporting against it, wherein the drive mechanism is placed at an outer side of the helical path, substantially radially opposite the support roller, for operational connection of the drive mechanism to a side of the modular conveyor belt at a second number of windings or storeys placed above one another, wherein the second number is lower than or equal to the first number. In one embodiment said drive mechanism is provided with one or more of the above- mentioned measures or aspects named in the various embodiments.

The aspects and measures described in this description and the claims of the application and/or shown in the drawings of this application may where possible also be used individually. Said individual aspects, such as the first and/or second confining elements and the drive chain with a number of substantially vertically extending pins, and other aspects may be the subject of divisional patent applications relating thereto. This particularly applies to the measures and aspects that are described per se in the sub claims.

SHORT DESCRIPTION OF THE DRAWINGS

The invention will be elucidated on the basis of a number of exemplary embodiments shown in the attached drawings, in which:

Figure 1 shows a view of an embodiment of a helical conveyor according to the state of the art;

Figure 2 shows a view in cross-section of the helical conveyor according to figure 1 ;

Figure 3 shows a schematic top view of an exemplary embodiment of a helical conveyor according to the invention;

Figure 4 shows a schematic top view of a second exemplary embodiment of a helical conveyor according to the invention;

Figures 5A and 5B show a schematic side view of exemplary embodiments of the helical conveyor according to the invention;

Figures 6 and 7 show a view in cross-section of an exemplary embodiment at the location of a winding or storey of a helical conveyor with drive by a toothed wheel according to the invention; Figure 8 shows a view in cross-section of an exemplary embodiment at the location of a winding or storey of a helical conveyor with drive by a drive chain according to the invention; and

Figures 9A and 9B show detailed views of the drive chain and its engagement onto a conveyor belt.

DETAILED DESCRIPTION OF THE DRAWINGS

Figure 1 shows a helical conveyor according to the state of the art consisting of a frame of girders 1 and posts 2. Onto the posts 2 that have been positioned according to a polygonal, inwardly oriented holders 3 are disposed which by means of a helical path 4 offer support to a modular conveyor belt 5. Within the helical path 4 a drum 6 is positioned which can rotatably be driven about a vertical axis 7 by means of a motor (not shown). The drum 6 is covered with spaced apart substantially vertical beams 9. When the modular conveyor belt 5 is kept at the right tension, the rotating drum 6 takes along the conveyor belt 5. Some intentional slippage occurs in the process. In figure 2, the known helical conveyor is shown in cross-section, along a plane substantially transverse to the vertical axis 7.

Figure 3 shows a first exemplary embodiment of a helical conveyor 10 according to the invention. Figure 3 shows a top view that extends substantially transverse to the axis of symmetry of the helical conveyor 10. The helical conveyor 10 according to this first exemplary embodiment comprises a frame comprising girders 11 and posts 12. On the posts 12 outwardly oriented outriggers 13 are disposed, which by means of guides 14 that are placed in a helical path on the outriggers 13, offer support to the conveyor belt 15.

Within the helical path a number, in this example four, freely rotatable support rollers 16 are disposed for having a side 151 of the modular conveyor belt 15 facing the inner side of the helical path supporting against it. The support rollers 16 are placed along a substantially vertical axis so as to be freely rotatable. The support rollers 16 are for instance connected at their upper and lower sides to further girders (not shown) of the frame. The view of figure 3 shows a further advantage of the device according to the invention. The frame namely can be substantially situated within the helical path. As outside of the helical path vertical posts 12 substantially need not be present, the modular conveyor belt 15 can easily be placed on the guides 14 of the helical path. In one embodiment, the modular belt lies unfastened, particularly detached on the guides 14 of the helical path.

The helical conveyor 10 according to this first exemplary embodiment is provided with a drive mechanism in the form of a toothed wheel 17 which engages at an outwardly facing side 152 of the modular conveyor belt 15. The toothed wheel 17 is placed substantially radially opposite one of the support rollers 16, as shown in figure 3. The side of the modular conveyor belt 15 facing the outer side of the helical path is provided with openings 154 that offer room for engagement of teeth 171 of the toothed wheel 17. The toothed wheel 17 is rotatably driven about a vertical axis by a motor M1 , as schematically shown in figure 5A.

Figure 4 shows a second exemplary embodiment of a helical conveyor 20 according to the invention. This second exemplary embodiment also comprises a frame provided with girders 21 and posts 22. On the posts 22 outwardly oriented outriggers 23 are disposed, which are provided with guides 24 forming a helical path for having the conveyor belt 25 supporting against it. At the location of the conveyor belt 25, the posts 22 situated near the helical path are provided with freely rotatable support rollers 26. In this embodiment the freely rotatable support rollers 26 substantially do not extend over the full height of the helical conveyor 20, but only at the location of the helical path are the posts 22 provided with support rollers of a limited height that are adapted for adequately having a side 251 of the modular conveyor belt 25 facing the inner side of the helical path supporting against them. Said combination of vertical posts 22 with support rollers 26 placed thereon is schematically shown in figure 5B.

In the second exemplary embodiment, as shown in cross-section of figure 4, a support roller 261 is placed opposite the drive mechanism 27. The drive mechanism 27 according to said second exemplary embodiment comprises two spaced apart toothed wheels 28 and a drive chain 29 placed around them. In this exemplary embodiment as well a side of the conveyor belt 25 facing the outer side of the helical path is provided with recesses or openings 254 for accommodating vertically extending pins 291 of the drive chain 29 therein. As the first and second toothed wheels 28 are spaced apart along the outer side of the helical path, a number of the pins 291 will continually be placed in the recesses 254, as a result of which a drive takes place along the trajectory situated between the first and second toothed wheels 28. By coupling one or both toothed wheels 28 to a drive mechanism M2, such as an electromotor, the helical conveyor can be driven.

The support roller 261 placed opposite the drive mechanism 27 is placed substantially radially with respect to a plane of symmetry 271 of the drive mechanism 27. In this exemplary embodiment the first and second toothed wheels 28 are placed substantially mirror symmetrical with respect to the plane of symmetry 271 .

For absorbing forces exerted radially on the conveyor belt 25 by the drive mechanism 27, the support roller 261 placed substantially radially opposite the drive mechanism 27, can be designed having a larger diameter such as the support roller 261 of figure 4. The other support rollers 26 can be designed lighter, optionally having a smaller diameter.

Instead of the use of a large number of support rollers 16, 26, as shown in figures 3 and 4, a further exemplary embodiment of the helical conveyor according to the invention may also comprise a single freely rotatable support roller. That means a comparable drum 6, as known in the art, wherein the drum 6 according to an embodiment of the invention, is positioned so as to be freely rotatable, in combination with a drive mechanism placed at the outer side of the helical path.

In a further exemplary embodiment, the conveyor belt 15, 25 lies detached on top of the guides 13, 23, that have been placed in a helical path. This situation is schematically shown in figures 6, 7 and 8. The freely rotatable support roller 16, 26 is placed at a side of the modular conveyor belt 15, 25 situated within the helical path. Radially opposite the support roller 16, 26 the drive mechanism 17, 28 is placed that is operationally coupled to a side of the conveyor belt 15, 25 facing the outer side of the helical path, as described above.

In the exemplary embodiment as shown in figure 6, the conveyor belt 15, 25 near its end facing the outer side of the helical path, is supported by a guide 13, 23. The drive mechanism 17, 28 is furthermore provided with a first confining element 31 extending radially above the end 152, 252 of the conveyor belt 15, 25 situated towards the outer side of the helical path. Because of said first confining element it can be prevented that the conveyor belt 15, 25 is able to fold upwards as a result of which the operational connection between the conveyor belt 15, 25 and the drive element 17, 28 might get lost. In one embodiment the first confining element 31 can rotate along with the drive mechanism 17, 28. In a further exemplary embodiment the first confining element 31 is provided with an inclined piloting edge 31 1 for passing the side 152, 252 of the conveyor belt 15, 25 under the first confining element 31 . In a further exemplary embodiment the first confining element 31 is spaced apart from the drive element 17, 28 to offer room to the conveyor belt 15, 25 running inclined in its helical path.

In a further exemplary embodiment, as shown in figure 7, the drive mechanism 17, 28 and particularly its toothed wheels, is provided with a first confining element 31 as well as a second confining element 32. Both confining elements 31 , 32 extend radially over the side 152, 252 of the conveyor belt 15, 25, so that the side 152, 252 is confined between the first and second confining element 31 , 32. Both confining elements 31 , 32 are provided with an inclined edge 31 1 , 321 for guiding the side 152, 252 of the conveyor belt 15, 25 towards the drive element 17, 28. Here as well the confining elements 31 , 32 are spaced apart from the drive element 17, 28 in order to offer room to the conveyor belt 15, 25 running inclined in its helical path.

In a further exemplary embodiment, provided with a drive chain, as described above and shown in figure 4, the drive chain is provided with substantially vertically extending pins 291 that are connected one to the other by means of links. Said links also serve as first confining element 41 and second confining element 42 for confining the side 252 of the conveyor belt 25, as shown in figure 8, therebetween.

This is shown in more detail in the side view of figure 9A and the top view of figure 9B. In this exemplary embodiment the conveyor belt 25 is a link belt, as for instance known from international patent application WO 2003/093147. Herewith the individual modules 251 are coupled in series by means of connection rods 252. The modules 251 can be moved with respect to each other so that the modules 251 on the one hand are placed substantially parallel to each other when going through a substantially straight part of the conveyor path, and on the other hand are placed at an angle to each other when going through a curved part of the conveyor path, particularly when going through the helical part of the conveyor path. In the helical part of the conveyor path the modules 251 are placed at a small angle to each other, as a result of which openings 254 arise at the outer curve into which openings the pins 291 of the drive chain 29 can be placed.

In the exemplary embodiment as shown in figure 9A the links 41 , 42 of the drive chain 29 are placed at such a distance from each other, that between the links 41 , 42 sufficient room is offered to the conveyor belt 25 running inclined in its helical path.

The above description is included to illustrate the operation of preferred embodiments of the invention and not to limit the scope of the invention. Starting from the above explanation many variations that fall within the spirit and scope of the present invention will be evident to an expert.

For instance the helical conveyor according to the invention may be provided with several drive mechanisms that are placed at a periphery. In addition a drive mechanism placed adjacent to a first helical conveyor can also drive a further adjacently placed second helical conveyor.

(octrooi/184327/PCTP184327A des BP/NG 4326)

Claims

1. Helical conveyor comprising a frame for supporting a helical path having a first number of windings or storeys placed above one another; a modular conveyor belt sitting on the helical path and able to slide over it; a drive mechanism engaging a side of the modular conveyor belt at a second number of windings or storeys placed above one another, wherein the second number is lower than or equal to the first number; wherein the helical conveyor comprises a freely rotatable support roller positioned within the helical path, for having a side of the modular conveyor belt facing the inner side of the helical path supporting against it, and wherein the drive mechanism is placed at an outer side of the helical path.

2. Helical conveyor according to claim 1 , wherein the support roller and the drive mechanism are placed on either side of the modular conveyor belt.

3. Helical conveyor according to claim 1 or 2, wherein the drive mechanism is placed substantially radially opposite the support roller.

4. Helical conveyor according to any one of the preceding claims, wherein the drive mechanism, for each of the second number of windings placed above one another, comprises a drive element for operational connection to a side of the modular conveyor belt facing the outer side of the helical path.

5. Helical conveyor according to any one of the preceding claims, wherein the drive element comprises a first confining element placed above the drive element, which first confining element extends at least partially above an edge area of the modular conveyor belt.

6. Helical conveyor according to any one of the preceding claims, wherein the drive element further comprises a second confining element placed below the drive element, which second confining element extends at least partially below an edge area of the modular conveyor belt.

7. Helical conveyor according to claim 5 or 6, wherein the first and/or the second confining element comprises a piloting edge facing the drive element.

8. Helical conveyor according to any one of the preceding claims, wherein the drive element comprises a toothed wheel for operational connection to a side of the modular conveyor belt facing the outer side of the helical path.

9. Helical conveyor according to claim 8, wherein the first and/or the second confining element comprises a disk placed adjacent to the toothed wheel, wherein the diameter of the disk is larger than the diameter of the toothed wheel.

10. Helical conveyor according to any one of the claims 1 -7, wherein the drive element comprises a first and second toothed wheel placed adjacent to each other and around which a drive chain is placed for operational connection to the side of the modular conveyor belt facing the outer side of the helical path.

1 1 . Helical conveyor according to claim 10, wherein the first and/or the second confining element comprises a disk placed adjacent to the first and/or second toothed wheel, wherein the diameter of the disk is larger than the diameter of the toothed wheel with the drive chain placed around it.

12. Helical conveyor according to claim 10, wherein the drive chain is provided with first and/or second confining elements.

13. Helical conveyor according to claim 12, wherein the drive chain comprises a number of substantially vertically extending pins for operational connection to the side of the modular conveyor belt facing the outer side of the helical path, and links placed above and below the pins for forming the chain.

14. Helical conveyor according to claim 13, wherein the top links comprise the first confining elements.

15. Helical conveyor according to claim 14, wherein at least one of the top links is integrally formed with at least one of the first confining elements.

16. Helical conveyor according to claim 13, 14 or 15, wherein the bottom links comprise the second confining elements.

17. Helical conveyor according to claim 16, wherein at least one of the bottom links is integrally formed with at least one of the second confining elements.

18. Helical conveyor according to any one of the claims 8-17, wherein the modular conveyor belt at the side facing the outer side of the helical path is provided with a series of recesses or openings for the drive element to mesh with.

19. Helical conveyor according to any one of the preceding claims, wherein the diameter of the support roller is smaller than an inner diameter of the helical path.

20. Drive mechanism suitable and intended for a helical conveyor according to any one of the preceding claims.

21. Drive mechanism for a helical conveyor comprising a frame for supporting a helical path having a number of windings or storeys placed above one another, a modular conveyor belt sitting (freely) on the helical path and able to slide over it, and a freely rotatable support roller positioned within the helical path for having a side of the modular conveyor belt facing the inner side of the helical path supporting against it, wherein the drive mechanism can be placed at an outer side of the helical path, substantially radially opposite the support roller, for operational connection of the drive mechanism to a side of the modular conveyor belt at a second number of windings or storeys placed above one another, wherein the second number is lower than or equal to the first number.

22. Drive mechanism according to claim 21 , provided with one or more of the measures as described per se in claims 2-19.

23. Helical conveyor provided with one or more of the characterising measures described in the attached description and/or shown in the attached drawings.

24. Drive mechanism provided with one or more of the characterising measures described in the attached description and/or shown in the attached drawings.

25. Method provided with one or more of the characterising measures described in the attached description and/or shown in the attached drawings.