EP1058668A1

EP1058668A1 - Conveyor

Info

Publication number: EP1058668A1
Application number: EP99902930A
Authority: EP
Inventors: Wouter Balk
Original assignee: AMBAFLEX BV
Current assignee: Ambaflex International BV
Priority date: 1998-01-30
Filing date: 1999-01-28
Publication date: 2000-12-13
Also published as: NL1008166C2; JP2002501869A; AU2301899A; WO1999038787A1

Abstract

A conveyor for conveying piece goods and the like through a path comprises a frame (1), and an endless conveyor belt (8) supported by the frame, driven by driving means and having a conveying part and return path. The conveyor belt includes a plurality of transversely elongated, substantially rigid slats (9) which are interconnected directly or indirectly and which are relatively pivotable at least about an axis parallel to the conveying surface and perpendicular to the direction of conveyance. The frame comprises support sections (10) for slidably supporting the slats in the conveying part, as well as a plurality of rollers (5, 6) around which the conveyor belt is guided and deflected and with which the support sections are linked up. The support sections, preferably those at the leaving side of at least one roller, comprise a damping element (12) which is positioned such that it supports the slats when they leave a roller.

Description

Conveyor

The present invention relates to a conveyor for conveying piece goods, for example, and the like through a path, comprising a frame, an endless conveyor belt supported by said frame and driven by driving means, which conveyor belt including a conveying part and a return part and which is provided with a plurality of elongated, seen in transverse direction, substantially rigid carrying elements, which are directly or indirectly interconnected and which are relatively pivotable, at least about an axis parallel to the conveying surface and perpendicularly to the direction of conveyance, wherein the frame comprises supporting sections for slidably supporting said carrying elements in the conveying part, as well as a plurality of pulleys for guiding and deflecting the conveyor belt, to which the supporting sections are adjacent.

Although conveyors of this kind are satisfactory for various uses in practice, it has become apparent that the amount of noise which is produced increases in particular at higher speeds. One of the causes of this phenomenon is that noise is produced at the connection between the driving, reversing or deflecting elements and the supporting sections for the carrying elements, which is caused by the transition from a curvilinear path with moving support for the carrying elements at the location of a pulley to a straight path with stationary support for the carrying elements at the location of the supporting sections. The carrying elements may slam down on the supporting sections in that case, in particular if the high speeds lead to deformations of the carrying elements. The object of the invention is to provide an improved conveyor, wherein the above problem is at least partially overcome.

In order to accomplish that object, the conveyor according to the invention is characterized in that the supporting sections are provided with a damping element on the leaving side of at least one pulley, which element is positioned such that it supports the carrying elements when they leave the pulley. The damping element according to the invention effectively deadens the noise produced by the hard carrying elements landing on the hard supporting sections. Also any vibrations that are produced can be eliminated by the damping element. It is preferred to use a rubbery material or another material having damping properties as the material for the damping element.

In a very advantageous embodiment, the damping element can move along with the conveyor belt, for example in that the damping element is a circulating endless element. In this manner, the occurrence of friction between the damping element and the carrying elements or parts which are connected thereto is avoided.

It is advantageous thereby if the damping element is passed over the pulley in question, for example in that the damping element is an elastic cord or the like, which is passed over the pulley in question and over at least one further pulley in a path which extends slightly above the supporting surface of the supporting sections, at least on the leaving side of the pulley, and which extends in spaced- apart relationship with respect to the pulley to below the supporting surface of the supporting sections.

In this manner, the moving support of the carrying elements from the respective pulley is taken over by the damping element until the damping element has reached a position under the supporting surface of the supporting sections, at which point the support of the carrying elements is taken over very gradually, without noise being produced, by the supporting sections. Noise and vibrations are thus damped in a very effective manner.

In one embodiment of the conveyor according to the invention, wherein the carrying elements are guided in a convex path so as to take care of any excess length, it is advantageous if the damping element is guided in a straight path at the location of said convex path, in such a manner that the damping element extends slightly above said supporting sections and that it will be capable of biassing said carrying elements.

It is noted that if vibrations or movements of the carrying elements cause noise in the conveyor at other locations that at the pulleys, it is possible to use the damping elements at places some distance away from the pulleys. The invention is suitable not only for slat-type conveyors comprising slats which are linked together by a chain, but also for other conveyor types wherein open and interconnected carrying elements are used.

The invention will be explained in more detail hereafter with reference to the drawing, which shows an embodiment of a conveyor according to the invention. Fig. 1 is a general, very schematic side view of the embodiment of the conveyor according to the invention.

Fig. 2 is a plan view of the frame of the conveyor of Fig. 1.

Fig. 3 is a larger-scale view of detail III in Fig. 1.

Figs. 4a, 4b and 4c are sectional views along lines IVa-IVa, IVb-IVb and IVc-IVc, respectively, in Fig. 3.

Fig. 5 is a side view of the end pulley of Fig. 1. 4

Fig. 6 is a larger-scale view of detail 6 in Fig. 5.

Fig. 7 is a larger-scale view of detail 7 in Fig. 5. Fig. 8 is a side view of a 90° deflection pulley equipped with a damping element, which is intended for use in another embodiment of a conveyor.

The drawing shows a conveyor which is capable of transporting goods, in particular piece goods, in vertical direction via a helical path. Conveyors of this kind are also known as spiral conveyors or winding conveyors. Said conveyors are capable of conveying products in a continuous flow, wherein said flow of products may be intended for vertical transport or for buffering during a process stage. Applications are for example the foodstuffs industry, distribution centers, the graphical industry and the like. The invention may also be used in a conveyor comprising a conveyor belt which is guided in a straight, a horizontal or a sloping path, however. The illustrated conveyor comprises a frame 1, which is provided in the present case with a central column 2 with bases 3 and a helical guide chute 4, which winds round column 2 and which is secured thereto. Various other frame constructions are conceivable, of course. An end pulley 5, 6 is provided at the upper end and at the lower end of guide chute 4, and a return chute 7 of frame 1 extends between said ends of helical guide chute 4. In the present case, the conveyor belt 8 supported by frame 1 is guided along different paths in the conveying part and in the return part. Also embodiments wherein the conveying part is returned along the underside of guide chute 4 are possible, however.

In the illustrated case, helical guide chute 4 comprises four windings, but this number may be larger or smaller, depending on the intended use. In the illustrated case, the driving motor is capable of engaging the end pulley at the end of the conveyor path, that is, at end pulley 5 or 6, whilst it is furthermore possible to use auxiliary driving elements at other locations in the conveyor. Also linear drive of the conveyor belt 8 is a possibility. The conveyor may be connected to other conveyors at the location of upper and lower end pulleys 5, 6. Conveyor belt 8 is provided with a large number of carrying elements in the form of slats 9 (see Figs. 3 - 7), which are interconnected, either directly or via an endless connecting element. Slats 9 have an upper, flat conveying surface, and the spacing between the slats in the direction of conveyance is so small that products can be supported by a number of adjoining slats 9. As already mentioned before, slats 9 are pivotally interconnected, either directly, or, in the present embodiment, via an endless connecting element (not shown) , in such a manner that slats 9 are capable of pivoting movement with respect to each other, both about a first axis extending parallel to their conveying surface and perpendicularly to the direction of conveyance, and about a second axis extending perpendicularly to the conveying surface and perpendicularly to the direction of conveyance. Said latter pivoting movement makes it possible to use a spiral path, whilst the former pivoting movement makes it possible to pass conveyor belt 8 over end pulleys 5 and 6. Since slats 9 are slightly tapered near their ends, in a direction away from their axis, slats 9 do not interfere with each other in bends. Also other shapes, such as a diamond shape, a V-shape or a toothed shape, as well as overlaps or a combination thereof are possible. In a special embodiment, slats 9 may be segmented, in which case the conveyor belt is indeed only capable of movement in a fully curved path, but in which case a fully closed surface of the conveyor belt 8 is effected.

As is shown in particular in Fig. 2, guide chute 4 of frame 1 comprises helical supporting sections 10 having an upper supporting surface 11 (see Figs. 4 - 7), on which slats 9 rest with their undersides, so that slats 9 are slidably supported by supporting surface 11 during their movement. The amount of friction and wear can be limited by suitably selecting the materials of supporting sections 10 and the (plastic) slats.

Especially if the container is used for purposes which require a very high conveying speed of up to 120 m/min., noise may be produced, for example at the location of the transition from a support by end pulleys 5, 6 to the support by supporting sections 10, because the ends of slats 9 deform slightly upwards, as it were, at the transition from the circular path over pulley 5, 6 to the straight path over supporting sections 10, and subsequently they slam down on the supporting surface 11 of supporting sections 10. The invention copes with this problem by providing a damping element, in this case consisting of a rubber elastic cord 12 which has been formed into an endless element and which is partially passed over end pulley 5 in this case and subsequently guided in such a path that the two cords 12 (in this case) are capable of catching the ends of slat 9 at the leaving side of end pulley 5 in order to prevent noise.

Fig. 5 shows the trajectory of cord 12 over end pulley 5 and two further pulleys 13, 14. The trajectory of the cord and the use of pulleys for said cord can be adapted in dependence on the case in question, of course.

As is shown in particular in Fig. 3, each cord 12 is guided in a groove 15 in the respective part of end pulley 5, whereby cord 12 extends slightly above the surface of end pulley 5, in such a manner that slat 9 is kept under 7 a slight tension. Each slat 9 is held in position in outward direction in its centre, at the location of a chain (not shown) , by supporting sections 10, so that the wings of slat 9 are under a slight tension when passing over end pulley 5. This very measure already prevents deformation of slat 9 by the centrifugal forces.

As is shown in Fig. 6, the trajectory of cord 12 on the upper side of end pulley 5 is such that cord 12 extends slightly obliquely with respect to the supporting surface 11 of the respective supporting section 10, whereby it extends above supporting surface 11 adjacent to end pulley 5 and gradually disappears under supporting surface 11 as a result of said oblique trajectory. As a result of this trajectory of cord 12, the transfer of the respective end of slat 9 from end pulley 5 to supporting surface 11 of supporting section 10 takes place very gradually, as a result of which hardly any noise is produced. This gradual transfer, which is effected by the selected trajectory of cord 12, is illustrated in Figs. 4a, 4b, 4c, which are sectional views along the trajectory of cords 12 and supporting sections 10. If end pulley functions as a driving pulley and the direction of conveyance of the conveyor is the upward direction, the pulling force on conveyor belt 8 will drop out after end pulley 5, as a result of which a possible excess length of the driving chain will collect at the leaving side of end pulley 5, whilst the drop out of the tension on conveyor belt 8 and/or of the chain thereof may also lead to rattling noises caused by movement or vibration of slats 9. In order to provide guidance for the conveyor belt on the leaving side of driving end pulley 5, the middle portion of conveyor belt 8 is moved in a convex path, whereby also supporting sections 10 follow a convex path. Also in this case, cord 12 may be of assistance as a damping element for damping noise and/or vibrations in that cord 12 is guided in a straight path, which extends slightly outside the path for the chain of the slats and the path of supporting surface 11, as a result of which cord 12 biases the respective end of slats 9, thus damping or preventing movements of the slats either in the plane of conveyance or in a direction perpendicularly thereto, as a result of which the amount of noise produced by said movements is decreased to a considerable degree. Fig. 8 shows another variant of the invention, wherein cord 12 is used with a pulley 16 which is used for guiding conveyor belt through a 90° arc. Also a deflection of conveyor belt 8 of this kind may cause noise, due to variations in the tension of conveyor belt 8, so that also in this case the biassing of parts, for example the ends of the slats or other carrying elements, may lead to a decreased noise production. Of course a great many other variations in the trajectory of cord 12 are conceivable, which can be selected in dependence on the path of the conveyor belt or on the construction of the frame or the like. Instead of using two cords for every pulley, it is also possible to use more than two cords, for example four, with conveyor belts having a greater width.

From the foregoing it will be apparent that the invention provides a conveyor wherein a considerable noise reduction is achieved, using simple means, with a conveyor comprising a number of interconnected, rigid carrying elements .

The invention is not limited to the embodiments as shown in the drawing and discussed in the foregoing, which can be varied in several ways within the scope of the invention. Thus, the damping element may also be a stationary element or one or more elements which rotate about an axis, such as a roller or a wheel. In the embodiment wherein an endless element makes up the damping element, said endless element may also be a belt or the like, of course. Instead of acting on the ends of the carrying elements, the damping element may also act on another part of the carrying elements, which may be positioned under the supporting surface of the supporting sections. The term pulleys for driving, deflecting or reversing the conveyor belt is understood to include elements such as wheels or polygonal drums or the like.

Claims

10CLAIMS

1. A conveyor for conveying piece goods and the like along a selected path, comprising a frame (1) , an endless conveyor belt (8) supported by said frame and driven by driving means, which conveyor belt including a conveying part and a return part and being provided with a plurality of elongated, seen in transverse direction, substantially rigid carrying elements (9), which are directly or indirectly interconnected and which are relatively pivotable, at least about an axis parallel to the conveying surface and perpendicularly to the direction of conveyance, wherein the frame comprises supporting sections (10) for slidably supporting said carrying elements (9) in the conveying part, as well as a plurality of pulleys (5, 6) for guiding and deflecting the conveyor belt, to which the supporting sections (10) are adjacent, characterized in that said supporting sections (10) are provided with a damping element, preferably on the leaving side of at least one pulley (5, 6) , which element is positioned such that it supports the carrying elements (9) when they leave the pulley (5, 6) .

2. A conveyor according to claim 1, wherein said damping element (12) can move along with the conveyor belt (8) .

3. A conveyor according to claim 2, wherein said damping element (12) is a circulating endless element.

4. A conveyor according to claim 3, wherein said damping element (12) is passed over the pulley (5, 6) in question.

5. A conveyor according to claim 3, wherein said damping element (12) is an elastic, preferably rubbery cord 11 or the like, which is passed over the pulley (5, 6) in question and over at least one further pulley (13, 14) in a path which extends slightly above the supporting surface of the supporting sections (10), at least on the leaving side of the pulley (5, 6) , and which extends in spaced-apart relationship with respect to the pulley (5), preferably in a straight path, to below the supporting surface (11) of the supporting sections (10) .

6. A conveyor according to claim 5, wherein said cord (12) is guided in a groove (15) in said pulley (5, 6), and wherein said cord (12) preferably extends slightly above the surface of the pulley for the purpose of biassing the carrying elements (9).

7. A conveyor according to any one of the preceding claims, wherein said carrying elements (9) are slats which are linked together by means of a roller chain or the like.

8. A conveyor according to claim5 or 6 and claim 7, wherein at least two cords (12) are provided at the pulley

(5, 6) in question, which cords guide the ends of said slats (9).

9. A conveyor according to claims 4 and 6, wherein said carrying elements (9) are guided in a convex path on the leaving side of a driving pulley (5), whilst the damping element (12) is guided in a straight path at the location of said convex path, in such a manner that the damping element extends slightly above said supporting sections (10) and that it will be capable of biassing said carrying elements

(9) .

10. conveyor according to any one of the preceding claims, wherein said damping element (12) is guided along said supporting sections both on the winding side and on the leaving side of a pulley (5, 6) .