WO1997013712A1

WO1997013712A1 - Conveyor

Info

Publication number: WO1997013712A1
Application number: PCT/DK1996/000426
Authority: WO
Inventors: Uffe Lykkegaard
Original assignee: Crisplant A/S
Priority date: 1995-10-10
Filing date: 1996-10-09
Publication date: 1997-04-17
Also published as: AU7210596A

Abstract

In an endless conveyor, in particular of the sorting conveyor type, having pivotably coupled carrier elements, a horizontally curved conveying path will give rise to wedge shaped gaps between the carrier elements, which may condition a fall-down of conveyed objects through the gaps as well as a squeezing of objects present in the gaps when the conveyor resumes a straight path. According to the invention, these difficulties are remedied with the use of generally triangular cover plates arranged in a fan like manner so that in straight or inwardly directed runs these plates may be stowed together in an overlapping manner, while in outwardly directed curves they may unfold like a fan so as to widely cover the said gaps.

Description

Conveyor

The present invention concerns a conveyor of the kind having a supporting frame for an annular row of pivotably coupled carrying elements appearing in the same plane and mutually separated. The carrying elements may be fixed wagon units or carrying plate parts or - as preferably discussed now - elements with cross-moving conveyor belts for laterally unloading items in connection with sorting conveyors. Hereby a common feature will be that between successive elements in the chain formation in question there will appear separations between the single carrying elements, which se¬ parations are necessary for permitting the elements to be mu¬ tually pivotable when running through curved passages. The laterally extended front and rear edges thus cannot come close to each other since this would make impossible a mutual pivoting of the elements. The necessary matching sepa¬ rations appear as "apertures" which at least in the case of sorting conveyors imply distinct disadvantages as supplied items which are not unloaded quite precisely may fall down in the said apertures and thereby give rise to appreciable prob¬ lems, and they may also be destroyed.

For capacity considerations the rectangular carrying ele¬ ments have to be coupled together with a small mutual dis- tance, though in such a way that by moving through curves they will meet with a certain security distance at the cor¬ ners facing inwardly in the curve, wherefrom the adjacent end edges of the elements then will radiate in a diverging way. As shown on fig. 1 it is hereby a possibility that protruding curved plates covering most of the gap may be fastened at the ends of the elements though it will appear that this covering will leave triangular apertures at the outer side of the curve.

By certain types of conveyors, e.g. for baggage claim in airports, it is known to avoid similar problems by using pro¬ truding plate parts which may stick in under the succeeding or the previous carrying element, but the invention has to do with the kind of conveyors where this solution at the outset is impossible or unwanted. Different solutions have been tried, e.g by using foldably deformable plates, but until now without an acceptable result.

The invention is based on the conception that because a certain minimum distance between the element corners situated innermost in the curve is necessary anyway it is possible correspondingly to arrange a filling in of the said gap with the aid of triangular plate parts with cut-off tips, and be¬ cause in every gap it is possible to put several such plates on top of each other, then by a suitable device it will be possible to let this plurality of triangular plates fold out like a fan when the gap is expanded at the transition to a straight course, or to be further expanded by a transition to an oppositely curved course, respectively. This requires such a control of the plates that they automatically are placed in mutually different positions with an even distribution over the gap so that they together may cover the expanded gap in the best way. Even by use of completely sharply pointed tri- agular plates a perceptible covering of the expanded gap will be obtained, since only a lesser, external notch in the plate covering will be left which may be acceptable. However, the condition is bettered perceptibly by the fact that the outer plate end as indicated before may have a certain width, whereby e.g. it is obtainable to have the expanded gap com- pletely covered after transition to a straight course, while it is covered with only insignificant notches at the outer side when running in a curve to the opposite side. This will be achievable by the use of covering plates in a small num¬ ber. By a preferred arrangement according to the invention there is not used a special control for the filling plates as they are placed in such a way, that they each are elastically movable between a pushed-in position against the carrying element belonging to it and a free position swung-out there- from as the conditions may be so adjusted that the different cover plates automatically take mutually different positions in their free positions for achieving a maximum coverage of the expanded gap. In practice it has also been found possible to use only two movable plates for each of the gaps in question, which also may be realized by putting a single movable plate on each of the two oppositely placed ends of the elements. By the invention it has also been advantageous to let the said plates consist of an elastically resilient material which is connected with the respective carrying elements through an elastically twistable connection so that the plates during a narrowing movement may give way in such cases where they otherwise create a squeezing action of an item ac- comodated between them, whereby both the item and the plates will avoid destruction.

The invention will be explained in more detail in the following with reference to the drawing, where Fig. 1 is a schematic, elevated view of the progress of a conveyor according to the invention,

Fig. 2 is an elevated view of a pair of mutually facing ends of carrying elements in this conveyor and shown separa¬ ted from each other, Fig. 3 is a corresponding perspective view of one end of an element,

Fig. 4 is an elevated view of the assembly of two of these carrying elements as seen when the conveyor is running in a straight course, Fig. 5 is a corresponding view as seen when the conveyor is running through a curve, and

Fig. 6 is picture corresponding to fig. 3, but of an amended embodiment .

As already discussed fig. 1 shows that a series of linked carrying elements 2 in a conveyor appear with a certain mutu¬ al distance so that they have the possibillity of being mutu¬ ally pivoted when running through curves. The gaps between the elements can be covered to a wide extent by means of tri¬ angular or curved plate parts 4 protruding from the ends of the elements 2, but the requirement for pivotability in curves will result in the appearance of perceptible, free notches 6 at the outer sides of these coverings. In a certain curved course these notches will disappear at the inner side of the curve, while they will increase to larger notches 8 at the outer side of the curve.

Especially the notches 6 appearing in a straight course are unwanted since normally in connection with such straight sections appearing in connection with feeding station there may occur unsuccesful deliveries of transported items to the gaps between the carrying elements 2. The notches 8, however, are also unwanted, since they possibly may open up under an item which may fall down into the notch. In fig. 2 and 3 the principle of a preferred embodiment according to the invention is shown. On a curved plate 4 for mounting on each of the ends of the elements 2 there is pro¬ vided a partly protruding plate element 10 at each side with an outwardly tapered shape, though with a tip width approxi- mately corresponding to the minimum distance between the ele¬ ment corners inside in a curved course; this will correspond to the width of the lateral tip parts 12 of the plate 4. The plates 10 are inwardly provided with curved plate shanks 14 ending in extensions 16, which by suitable means are fastened to the bottom plate 4. The shanks 14 consist of an elastic material making it possible to push the plate 10 inwardly to a position in which it mainly merges with the underlying outer part of the bottom plate 4. The shank 14 extends through a flat brace 18 standing up from the bottom plate 4 and having the purpose of stabilizing the plate 10 against being twisted by an occuring pushing action.

As it appears directly from fig. 2 the whole element 10,14,16 may be made in one piece, i.e. of a material like polyurethane, which may give the plate shank 14 the required elasticity without perceivably weakening the firm plate char¬ acteristic of the plate 10.

Furthermore, it is positively desired that the plate body 10 is elastically bendable by itself as it then by an occur¬ ring squeeze situation may yield in order to avoid damage to the plate covering system as well as the item possibly being squeezed between the relevant plate parts.

In fig. 3 there is shown two such equipped element ends placed opposite each other and separated, while fig. 4 shows the same parts mutually connected, whereby it is clearly seen that the plate parts 10 selectively will cover the mentioned notches 6 in the straight courses of the conveyor because their outer wide ends completely fill up the occurring gaps between the elements 2.

Fig. 5 shows how the plate elements 10 are behaving in a curved course of the conveyor. It will be seen that the plates 10 at the inward course will be squeezed between the elements 2 so that all four of the plate parts 4 and 10 will be placed as in a stack. By the outer side the plates 10 will stay in their respective free positions whereby they to a large extent wil cover the notch 8 between the plates 4. By the shown embodiment only smaller notches 20 will be left, though so small as to be found acceptable. By conveyors only to be pivoted unilaterally in service, e.g. in a regular four sided or flat oval course, the plate parts at the outer side may be furnished with an extended width whereby the notches 20 may disappear completely.

It will also be possible that by each side of the plates 4 there may be provided two or even more cover plates 10 in mutually deviating free positions, wherefrom they may be pushed together to a common position by an inwardly curved course and may be spread out like a handful of playing cards by an outwardly curved course. In principle both or all of these cover plates may be located on only one of the adjacent plates 4.

The plate shanks 14 may be substituted by other kinds of elastic means, e.g. stiff arms fastened rotatably on fixed pins (journals) on the plates 4 and with inserted separate spring means, which possibly together with fixed stops keep the plates 10 in their respective unfolded positions from which they may be pushed in elastically. A further possibil¬ ity is to let the plate parts 10 be suspended in a freely pivotable way so that they will be freely pushed together by inside course running, while they by means of special tappets or connections will pull each other outwardly at the transi¬ tion to a straight running and further on at the transition therefrom to curved running at the opposite side. In fig. 6 there is shown an alternative location of the plate parts 10 as compared to fig. 2. Here the plate parts 10 are placed at a level just below the plate 4 on respective elastic arms 14' fastened with 15, and the overlapping areas between the plates 4 and 10 are removed by providing the plate 4 with recesses 22 corresponding to the inwardly facing contour of the plate parts 10.

Claims

P A T E N T C L A I M S:

1. A conveyor, especially a sorting conveyor, of the kind having a supporting frame for an endless row of pivotably coupled carrying elements of which adjacent, pivotably linked ends appear in the same plane and with a certain mutual, slotlike separation which makes possible running through ho¬ rizontal curves while deforming the separating slot to a wed¬ ge shape, whereby there is provided cover means for a more or less extensive covering of the separating slot, which cover means mainly comprise triangular cover plates which from res¬ pective ends protrude against each other in a partly over¬ lapping way and so that they by at least one side occur with mutual distance during running a straight course, together with further cover means for a more or less extensive cover¬ ing of the triangular gaps appearing thereby, characte ¬ ri zed in that the further cover means are constituted by generally triangular or preferably tapered rhomboid cover plate parts which at every pair of adjacent carrying elements are located on one or both of these elements in such a way that they in a generally overlapping way and according to need may fold in or out as a fan in a controlled or elastic self-controlled way depending on the turns occurring between successive carrying elements for a more or less extensive coverage of the said triangular areas.

2. A conveyor according to claim 1, charact eri zed i n that the said cover plate parts are placed alone as sing¬ le, mutually overlapping and elastically, outwardly swingable parts, or parts capable of being pushed inwardly, respective- ly, on each of the adjacent ends of the carrying elements.

3. A conveyor according to claim 1, characteri zed i n that the cover plate parts are made or suspended in such a way that they by occurring squeezing actions in the gaps between them may give way or capsize in order to avoid sub- stantial squeezing forces.

4. A conveyor according to claim 3, characteri zed i n that the cover plate parts are made of an elastomeric ma- terial and/or are twistably connected with their fastening locations.

5. A conveyor according to claim 1, characteri zed i n that the cover plate parts are designed as triangular or tapered rhombic plates which at their base side are integra¬ ted with a protruding plate shank consisting of elastomeric material .

6. A conveyor according to claim 5, charact eri zed i n that the plate shank extends through a guiding slot in a protruding part of the bottom plate so that the plate shank may perform a horizontal, lateral displacement while being stabilized against a twisting movement.

7. A conveyor according to claim 1, characteri zed i n that the area of the bottom plate covered by the cover plate parts i their swung-out position is removed for creat¬ ing corresponding recesses in the bottom plate.