GB2263264A

GB2263264A - A device and a method for the lateral alignment against an abutment surface of products advancing in a flow.

Info

Publication number: GB2263264A
Application number: GB9224724A
Authority: GB
Inventors: Renzo Francioni
Original assignee: Cavanna SpA
Current assignee: Cavanna SpA
Priority date: 1992-01-17
Filing date: 1992-11-25
Publication date: 1993-07-21
Also published as: NL9300012A; DE4300729A1; IT1256766B; ITTO920032A0; GB9224724D0; ITTO920032A1

Description

2263264 1 A DEVICE AND A METHOD FOR THE LATERAL ALIGNMENT AGAINST AN

ABUTMENT SURFACE OF-PRODOCTS-ADVANCING'IN!A7FOW The present invention relates in general to the problem of the lateral alignment against an abutment surface of products advancing in a flow.

The invention has been developed with particular attention to its possible use in machines for the automatic handling of products, for example, in machines for the automatic packaging of food products, for example confectionery products such as biscuits or the like.

In this area of application there is often a need for products advancing in a continuous or substantially continuous flow on a conveyor device such as a belt conveyor to be aligned accurately.

For this purpose, the conveyor in question, on which the products are generally supported as they advance, may be associated with two side-wall structures, constituted, for example, by two belt 'conveyors with respective active passes which entrain the products and, together with the main conveyor, define a path which confines the products as they advance and thus aligns them.

However, a solution of this type is satisfactory only when, the variations of the dimensions (widths) of the products concerned, measured in the direction in which the alignment is to be carried out (that is, in practice, transverse their direction of advance) are minimal from one product to the next.

On the other hand it is not satisfactory when the 2 widths of the products concerned are liable to vary within fairly wide limits; for example, this is the case with some types of food products such as biscuits or the like, the dimensions of which may vary widely from one product to the next, in dependence on different production conditions (leavening, baking etc).

Even if the problem caused by variations in widths of the products processed does not arise, the products may reach the station where the alignment is to be carried out in orientations which make them difficult to insert between the two side-wall formations used to define the confinement and alignment path. For example, the products concerned may be quadrate or rectangular food products, such as biscuits or the like, which may arrive with their longer sides generally inclined both to the direction of advance of the flow, and to the direction in which they are to be aligned laterally.

The aforementioned problems may very well cause the products to jam within the alignment means, with a consequent risk of the interruption of the operation of,.he cquipment, particularly when the high rates of operation of the automatic packaging equipment currently in use (600 items/minute or more) are involved.

It appears preferable, moreover, to be able to check the dimensions of the products and/or their orientations simultaneously with the lateral alignment operation, so that any products with undesirable dimensions and/or orientations, can be ejected from the system.

3 The object of the present invention is to provide means for the lateral alignment against an abutment surface of products advancing in a flow so that the aforementioned problems do not arise, even when the flow of products is quite dense and rapid, as is currently the case in automatic product-handling machines.

According to the present invention, this object is achieved by means of a device having the specific characteristics recited in the following claims.

A further subject of the invention is employing the device.

a method The invention will now be described, purely by way of non-limiting example, with reference to the appended drawings, in which:

- Figure 1 is a general perspective view showing the structure of a device according to the invention, and - Figure 2 is a front view, showing the portion of Figure 1 indicated by the arrow 11, on a slightly enlarged scale.

In the drawings, a conveyor, generally indicated 1, for products p - such as biscuits - may be inserted in a line for the automatic handling of such products; for example, this may be a line for automatically packaging the products P.

In general, it is assumed that the device 1 is designed to receive the products P in a continuous or substantially continuous flow from an input conveyor I, 4 Figure 2 is a front view, showing the portion of Figure 1 indicated by tne arrow II, on a slightly enlarged scale.

In the drawings, a conveyor, generally indicated 1, for products P - such as biscuits - may be inserted in a line for the automatic handling of such products; f or example, this may be a line for automatically packaging the products P.

in general, it is assumed that the device 1 -11s designed to receive the products P in a continuous or substantially continuous flow from an input conveyor I, 1 1 1 in order to transfer them to an output conveyor 0 after the device I has aligned them laterally (possibly ejecting products considered unsuitable owing to their dimensions and/or orientations).

The characteristics of the invention and the manner in which it is put into effect are largely unaffected by the functioning and nature of the conveyors 1 and 0, which may, for example, consist of motor-driven belt conveyors.

Essentially, the device 1 includes a conveyor which, in the embodiment illustrated, is constituted by a conveyor of the type including an endless belt 2, disposed around return rollers; the belt 2 thus has an upper, generally horizontal pass which extends between the input conveyor 1 and the output conveyor 0 and can transfer the products P between the two conveyors longitudinally of the upper pass of the belt. Moreover, the use of these conveyors in the field of the automatic handling of products, particularly food products, is well known and therefore they do not need to be described specifically herein.

In particular, the upper pass of the belt 2 extends between two end rollers 3, 4 which have horizontal axes and define the upstream and downstream ends of the conveyor pass of the belt 2, respectively.

Naturally, the terms "upstream" and "downstream" refer to the normal direction of movement of the upper pass of the belt 2 which is intended to take place from left to right with reference to the layout illustrated in Figures 1 and 2.

Further return rollers (also with horizontal axes), around which the belt 2 passes below the upper pass defined by the end rollers 3 and 4, are indicated 5.

A further roller, indicated 6, cooperates with the upper surface of the conveyor pass of the belt 2, within a U- or, more specifically, inverted CL-shaped loop in the conveyor pass of the belt 2, in the manner which will be described in further detail below.

With reference to the layout shown in Figures 1 and 2, the roller 6 rotates anticlockwise, in order to advance the upper pass of the belt 2 generally from left to right.

The belt 2 is also associated with further return rollers, tensioning rollers, etc. (not shown), for ensuring that the belt moves correctly; all of the above is according to criteria which are well-known in the art and need not be described herein.

In general, according to the terminology used below in the present description and', where approptiate, in the following claims, it is assumed that the products P are supported on the upper conveyor pass of the belt 2, so as to be able to slide, at least sideways. This means that the products P are simply placed on the belt 2, and there are no elements which could prevent them from sliding on the surface of the belt, at least sideways, (this expression meaning transverse the direction of advance of the products on the belt 2). In the embodiment illustrated, the belt 2 has a completely smooth. surface, and the products P are therefore also free to slide along the belt longitudinally; in any case, in order to implement the invention, the belt 2 could be replaced by a conveyor of a different type (for example, a motor-driven chain conveyor with teeth or dogs for entraining the products P longitudinally), but on which the products P can still slide or move sideways, that is, transverse the conveyor.

In the embodiment illustrated, the products P are constituted by generally square or rectangular bodies (for example, biscuits) which are to be aligned laterally against an abutment surface; in the embodiment shown the latter consists of a further belt conveyor 8, also comprising an endless belt passing around respective end pulleys 9, 10. In particular, the belt 8 has an active pass facing the upper conveyor pass of the belt 2 (also in correspondence with the loop 7) and thus forms a kind of vertical side-wall located on one side of the conveyor surface defined by the upper pass of the belt 2.

According to known criteria, the belt 8 is associated with various drive members 11 constituted, for example, by a mechanical transmission driven by the members which rotate the drive roller 6 in order to move the belt 2. The forward movement of the upper pass of the belt 2 and of the active pass of the belt 8 can thus be synchronised precisely by the selection of the transmission ratio of the element 11, so that any undesirable turning of the products P transported is prevented.

For reasons which will become clearer from the following, the active pass of the conveyor 8 does not reach a position of alignment with the path along which the products P advance an the belt 2 immediately in correspondence with its upstream return roller 9. it reaches this position, however, only in correspondence with a further return roller 9a (the profile of which is indicated in broken outline in Figure 1), located a certain distance downstream of the upstream return roller 9. By virtue of this arrangement of the rollers, the active pass of the belt 8 has an intake portion 8a, with, so to speak, a ramp-like shape. In practice, if the upper pass of the belt 2 is viewed from above, this shape corresponds to the fact that the portion 8a of the active pass of the belt 8 starts from a generally peripheral position (on the left-hand side, with reference to the layout shown in Figure 1) relative to the belt 2 and gradually approaches a line of movement which reaches in correspondence with the roller 9a; this line of movement is kept almost constant until the belt passes around the downstream roller 10.

This shape of the active pass of the belt 8 is designed to facilitate the handling of products which, as in the case of the product P shown furthest to the left in Figure 1, arrive on the device 1 askew, that is, with their longer sides (assuming that the products P are square or rectangular in plan) aligned neither with the general path of advance on the belt conveyor 2, nor at right-angles thereto. The ramp portion 8a is intended to ensure gradual cooperation between the products P and the belt 8 which is intended to constitute the (moving) abutment surface against which the alignment is carried out.

In the device according to the invention, the required alignment with this surface is achieved by means of gravity anl, more specifically, as a result of the Ck upper pass of the belt 2 being directed by means of bracket support elements, indicated 12, in a manner such that, at least in correspondence with the abutment surface defined by the belt 8, the conveyor pass of the belt 2 does not extend horizontally but is inclined to 0 the vertical by an angle of approximately 15 This inclination is shown in Figure 1, in which the imaginary linear path which the right-hand side of the upper pass of the belt 2 would follow if the elements 12 for bringing about its sideways inclination were not present is shown by a broken line. In practice, therefore, at least in correspondence with the side-wall belt 8, the products P advance on a conveyor surface which, instead of being horizontal, is inclined sideways (towards the left, with reference to the direction of advance to which Figure 1 refers), at an angle of approximately 15 0 to the horizontal.

t_ In these conditions, if the products P (which - as has been seen - are free to slide at least sideways on the upper pass of the belt 2), are not already in lateral contact with the surface of the belt 8, they slide by gravity towards this position, and are therefore aligned automatically with the ideal abutment surface defined by the active pass of the belt 8 downstream of the roller ga.

Similarly, instead of being oriented vertically, the axes of rotation of the various rollers, around which the belt 8 passes (the axes X9, X9a and x10 in Figure 1 of the rollers 9, 9a and 10 are shown in particular), are also inclined to the vertical - again towards the left with reference to the layout shown in. Figure 1 - by an angle (> 0) the size of which (about 15 1 t) corresponds to the angle of inclination of the upper pass of the belt 2 to the horizontal. The inclined arrangement of the roller axes in question ensures that instead of extending vertically, the active pass of the belt 8 is inclined to the vertical by an angle OC and is therefore perpendicular to the inclined conveyor surface of the belt 2.

A unit or station, generally indicated 13, for detecting the dimensions and orientations of the products P with a view to their possible ejection from the device is preferably located in correspondence with the loop 7 defined by the roller 6.

t_ The unit 13 comprises, generally upstream of the roller 6, a photoelectric emitter-receiver unit (14, 15), whose observation or detection line (which is identified by the line on which the elements 14 and 15 are aligned) is oriented approximately vertically and is located approximately in correspondence with the outer edge (the right-hand edge, in the example shown) of the belt 2. More specifically, the detection line of the emitter-receiver pair 14, 15, is spaced from the plane defined by the pass of the side-wall conveyor 8 by a distance equal to the expected transverse dimensions (the widths) of the products P, the sides of which abut the pass.

The photoelectric unit 14-15 can therefore detect, and indicate to the general control device, (for example, a PLC) which supervises the operation of the device, a condition in which a product P has a transverse dimension (a width) greater than the maximum tolerance value permissible for subsequent handling in the system (for example, for subsequent insertion into "flow-pack" ( 1 type packages).

Preferably (and according to known criteria, see, for example, British Application GB-A-2 244 806 in the name of the present Applicant), the photoelectric unit 14-15 comprises an emitter of radiation (typically infra-red radiation), and a pair of detectors 15 arranged side by side on the line of advance of the products. The availability of two detectors side by side is intended to enable the dimensional characteristics and the positions of the products to be detected more accurately and reliably.

Preferably, the photoelectric detector unit 14-15 is operated in a pulsed manner, so as to take several "readings" or measurements for each product (f or example, fifteen readings for each product P). This solution enables products in the f low which are too wide throughout their lengths to be distinguished from those which intercept the optical beam between the emitter 14 and the detector 15 only for short portions of their lengths, for example, owing to incorrect positioning. The different results of the detection thus enable a decision to be made as to whether or not to eject the product P from the device.

The ejection is achieved by means of two nozzles 19, 20 located respectively above and below the plane of movement of the products P in correspondence with the loop 7 defined by the roller 6.

More specifically (in this respect see Figure 2), the top of the loop ia defined by two so-called "feathers" 21 which face one another, and around which the belt 2 passes downwards in order to pass around the drive 12roller 20. A gap 22 is defined between the two feathers 21 which, whilst enabling the products P to be transferred safely between the two successive portions of the plane of movement defined by the feathers 21, also enables the nozzle 20 which is below this plane of movement to propel from the device the products which are to be ejected because, for example, as with the product P' shown in Figure 1, their transverse dimensions are not acceptable for the further handling of the products.

Preferably, the two nozzles 19 and 20 are inclined to one another and slightly offset sideways so that whereas the nozzle 20 in the lower position produces an air jet directed upwardly and outwardly of the device 1J. the nozzle 19, which is mounted so as to project slightly outwardly of the plane of movement defined by the belt 2, produces a jet of air which is directed downwardly. The products to be ejected are thus lifted from the plane of movement by the lower nozzle 20, which also pushes them sideways out of the device, and are then tipped downwards by the nozzle 19 which is in the upper position.

The nozzles 19 and 20 are connected to respective compressed-air sources (not shown in the drawings), with the interposition of control means (for example, solenoid valves - likewise not shown) governed by the general control unit of the device 1. This unit causes the solenoid valves to open, and jets of compressed air correspondingly to be emitted, whenever it is decided to eject a product P which is considered unsuitable.

This operation is usually synchronised with the advance of the products P on the belt 2 so that the eject4ncr 1 13 air jets are emitted precisely when the product to be ejected is astride the crap 22. For th-JS purpose, immediately upstream of the gap 22, there may be a further photoelectric de4Lector unit, also comprising an emitter 23 and a receiver 24, which can accurately detect when a product P to be ejected is approaching the gap 22, so that the nozzles 19 and 20 are activated at the required moment.

The products which are not ejected from the device in any case leave the belt 8, the active pass of which L acts - as an abutment surface for the products P, precisely in alignment with the line along which that pass of the belt extends.

Downstream of the output end of the belt 8, the upper pass of the belt 2 gradually resumes a horizontal position, as it approaches the end ruller 4, so that the products P reach a corresponding orientation for transfer onto the output convevor 0.

Claims

1. A device for the lateral alignment against an abutment surface (8) of products (P) advancing in a flow, including conveyor means (2, 8) forming a surface (2) for transporting and supporting the products (P), so that they can slide at least sideways, one side of the conveyor surface being defined by the abutment surface (8), characterised in that the conveyor means (2, 8) are associated with support means (12) for keeping the conveyor surface, substantially inclined to the horizontal and towards the abutment surface at least in correspondence with the abutment surface (8), so that the products advancing on the conveyor surface (2) slide sideways against the abutment surface (8) by gravity and are aligned therewith.

2. A device according to Claim 1 characterised in that the abutment surface (8) is movable in synchronism with the movement of the conve or surface (2).

y

3. A device according to Claim 1 or Claim 2, characterised in that the abutment surface (8) extends along P precise a1-4g-rLment, line (9a, 10), and reaches this alignment line along a generally ramp-like approach path (8a), in a direction corresponding to the direction of advance of the flow of products (P).

4. A device according to any one of the preceding claims, characterised in that the conveyor surface (2) is kept inclined at about 15 0 to the horizontal.

5. A device according to any one of the preceding claims! characterised in that the abutment surface (8) is also kept generally inclined so as to be is substantially perpendicular to the conveyor surface (2).

6. A device according to any one of the preceding claims, characterised in that the conveyor means include a belt conveyor (2), one pass of which defines the conveyor surface for the products (P).

7. A device according to any one of the preceding claims, characterised in that it includes a further belt conveyor (8), at least one active pass of which defines the abutment surface.

8. A device according to any one of the preceding claims, characterised in that it includes detector means (14, 15) for detecting at least one dimension and/or the orientation of the products (P).

9. A device according to Claim 8, characterised in that the detector means (14, 15) are sensitive to the dimensions of the products (P), transverse the line along which they are aligned.

10. A device according to Claim 8 or Claim 9, characterised in that it includes ejection means (19, 20), for selectively ejecting from the flow products (P) identified according to at least one dimension and/or their orientations.

11. A device according to any one of Claims 8 to 10, characterised in that the detector means (14, 15) comprise a photoelectric gate (14, 15).

12. A device according to Claim 10, characterised in that the ejection means comprise at least one nozzle (19, 20) for projecting a jet of compressed air towards the products (P) to be ejected from the flow.

13. A device according to Claim 10 or Claim 12, characterised in that the ejection means (19, 20) operate in correspondence with a loop (7) formed by a portion of the conveyor surface (2) which bends downwardly.

14. A device according to Claim 6 and Claim 13, characterised in that the loop is formed by a portion of the belt (2) which passes around a return roller (6).

15. A device according to Claim 13, characterised in that the roller (6) is a drive roller.

16. A device according to Claim 10 or Claim 12, characterised in that it includes further detector means (21, 22) for detecting the advance towards the ejection means of a product (P') to be ejected.

17. A device according to Claim 15, characterised in that the further detector c a L S comprise a photoelectric gate (23, 24).

18. A method of aligning laterally against an abutment surface (8) products (P) advancing in a flow, including the step of forming a surface for transporting and supporting the products (P) so that they can slide at least sideways, and the step of defining one side of the conveyor surface with the abutment surface (8), characterised in that it also includes the step of keeping the conveyor surface (2) substantially inclined to the horizontal and towards the abutment surface, at 1-7 least in correspondence with L-he abutment'- surface (8), so that the products (P) advancing on t.he conveyor t (8) by surface slide against the abutment surface gravity and are aligned therewit-h.

19. A device for the lateral alignment against an abutment surface of products advancing in a flow substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

20. A method of aligning laterally against an abutment surface products advancing in a flow substantially as hereinbefore described.

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