GB2197278A - Method and apparatus for conveying tipping and diverting articles - Google Patents

Abstract

Can conveying apparatus 10 comprises a drive cable 12 and side guides 16 and 18 for cans 14. Magnets 38 normally hold the cans in their upright straight-through configuration. When it is desired to divert the cans, a diverter arm 32 tips the cans sideways against guides 20 and 22, and magnets 40 hold them in this position. Drive is maintained at all times by magnets 38 and 40 between the cans 14 and the cable 12. From their tipped configuration the cans are removed from the conveyor by a variety of means. <IMAGE>

Description

SPECIFICATION Method and apparatus for conveying articles This invention relates to a method and apparatus for conveying articles. In particular, but not exclusively, the invention relates to a method and apparatus for conveying cans such as may be used in a canning factory in which partially made or completed cans are transported from place to place within the factory. In such a conveying system, typically the cans are carried on a conveying cable and supported by fixed side guides, though other conveying systems may be used.

In modern conveying systems of this sort the throughput of cans is considerable. For example, a conveyor may handle up to about 1,200 cans per minute, which corresponds to a can speed of about 300 feet per minute.

Accordingly, it will be readily appreciated that there are considerable problems in controlling a flow at this speed. For example, if a blockage of any sort occurs in the conveying system there is immediately a need to divert the flow of cans to palletizing and depalletizing apparatus which can temporarily store the flow of cans while the blockage is cleared and then can discharge the stored cans. There are other reasons for wishing to divert the flow of cans from one track of the conveyor to another, such reasons relating to the general need for control of the manufacturing and canning process. Whatever the reason, in view of the considerable can flow rate, there always has been considerable difficulty in efficiently changing over the can flow from one direction to another without causing jamming or other problems.When a jam occurs, it has very significant cost and efficiency implications for a canning factory.

Previously proposed equipment for diverting a flow of cans from one path to another has not been entirely satisfactory. For example, there have been gate type devices incorporating pneumatically operated mechanical gate members which are caused to move into the can flow path. These are complex and expensive. Moreover, since they require the gate member to physically move into the can flow path, there is a need to briefly impede the can flow'while the gate moves. At a can flow speed of about 5 feet per second, even a very brief interruption in can flow for this purpose is of significance and causes problems upstream from the gate.

In short, previoulsy proposed can diverting apparatus is by no means sufficiently efficient and generally tends to cause blockages.

Accordingly, there is a considerable need for improved conveying apparatus providing means whereby a flow of cans or other articles can be diverted from one path to another, and it is an aim of the present invention to provide improvements in one or more of these respects, or generally.

According to the invention there is provided article conveying apparatus, and a method of conveying articles as defined in the accompanying claims.

The invention also provides article conveying apparatus and a method of conveying articles not limited by all features of any claim hereof but comprising any novel feature or novel combination of features disclosed herein.

In an embodiment described below article conveying apparatus is in the form of a can conveyor. Conveying means comprises a driven cable on which the cans rest, together with associated fixed side guide members to support the cans in a generally upright position. For diverting the cans from the main stream of the conveyor, there is provided diverting apparatus. The diverting apparatus comprises tipping means actuable to tip the cans to one side of their normal upright position, through an angle of between 30 degrees and 60 degrees from the vertical, and preferably about 45 degrees.

Article holding means is provided in the form of a permanent magnet or an electromagnet which holds the cans in conveying relationship with the cable as they proceed in their normal upright position. A first and generally horizontal portion of the magnet is provided for this purpose. A second portion of the magnet and suitably inclined with respect to the first portion is provided to hold the cans in conveying relationship with the cable when they have been tipped by the tipping means. When no can diversion is occurring, the cans merely proceed through the apparatus in their upright condition. Where the article holding means is a permanent magnet, it simply acts to hold the cans more firmly in their upright position against the cable during the period of their travel over which it acts.

When can diversion is initiated by the tipping means, the second magnet firmly holds the cans against the cable in their tipped position whereby they are positively conveyed in that attitude.

In the embodiments, the tipping means may comprise a mechanically actuated tipping member, for example a pneumatically actuated arm. Alternatively, the tipping means may comprise electro-magnetic means which may also provide the article holding means. By energising the electro-magnet of the inclined article holding means, the cans can be caused to tip magnetically to their inclined position, without mechanical intervention.

In the embodiment, the article holding means serves to provide positive drive to the cans or other articles as they are conveyed in either the tipped or untipped mode. If untipped, the positive drive given to the cans by the permanent or electro-magnet or other means serves to positively assist taking the cans past the zone where they can be optionally diverted. In this zone there is a gap at one side or both of the conveyor in the side support guide members for the can, so as to permit can diversion. In the absence of such positive conveying action, there is a tendency for the cans, particularly light-weight unfilled cans to jostle each other sideways and to cause jamming. In the embodiment, the positive drive provided by the conveyor and the article holding means avoids such jamming.

In the case of the cans which are tipped for diversion, once they are tipped and nevertheless still firmly conveyed by the cable, they are in a condition where they can be readily removed. Removal can be effected in various ways. For example, the row of tipped cans be intercepted by a guide member which imparts a lateral movement to the cans with respect to the cable or other conveyor member, whereby the cans are slid off the cable and are thereby removed. It will be understood that by virtue of the positive holding and driving action of the cable and the magnets, the guide member can be positioned somewhat downstream from the location at which the cans are initially tipped, whereby the guide member intercepts a row of cans which is well positioned and in a stable condition for being smoothly guided in the desired direction.

In this way, the tendency for jams to occur in the diversion zone is greatly reduced.

Alternative means can be provided for removing the cans from the conveyor. For example, a rotary magnetic wheel could be employed, or a variety of other means.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows a cross-section through conveying apparatus according to the invention, the section being taken in a direction transverse to the conveying direction; Figure 2 shows, on a smaller scale, a plan view of the conveying apparatus of Fig. 1 showing cans passing through the apparatus in their untipped configuration; and Figure 3 shows a second view of the apparatus of Fig. 2 showing a stream of cans which has been diverted to a tipped configuration and has been removed from the conveying means.

As shown in Fig. 1, article conveying apparatus in the form of a can conveyor 10 comprises conveying means 12 in the form of an endless cored cable 12 on which are carried a plurality of cans 14 which are shown in Fig. 1 in their upright configuration (in full lines) and in their tipped configuration (in dotted lines).

The cans are conveyed by cable 12 between guides comprising side guides 16, 18 for the upright position and 22, 24 for the tipped position. The guides are mounted on a guide rail support bracket 26 which likewise also carries a generally triangular section centre guide rail 28.

Cable or rope 12 has a wire core with a nylon covering and runs in a groove formed in a polymeric track 30 and is driven by a drive (not shown) so as to circulate continuously around its endless track. The track 30 is formed of a relatively low friction polymeric material.

For tipping the cans while conveyed on cable 12 there is provided tipping means in the form of a tipping arm 32 pivoted for movement towards and away from the cans 14 about a pivot axis 34.

Article holding means 36 is provided which is capable of holding the cans in conveying relationship with cable 12 both in their tipped and untipped positions. The article or can holding means comprises ceramic magnets 38, 40 arranged as shown so as to be aligned with the cans respectively in their untipped and tipped position. The magnets are located directly below the cans in the region of their laterally outer side edges. The magnets extend along a continuous portion of the conveying apparatus throughout the portion thereof where diversion is to take place.

Figs. 2 and 3 show the conveying apparatus in operation. In Fig. 2, the cans 14 are all proceeding in the normal travel direction D and the diverter arm 32 extends parallel to direction D so as to complement the guides 16 and 18. The cans 14 are firmly held by mangets 38 and 40 against cable 12, whereby even if the cans jostle each other they do not break away and hence have the chance to become jammed on the guides 20, 22 of the diversion track 42. As clearly shown in Figs. 2 and 3, centre guide 28 has a pair of lateral guide members 42, 44 projecting at approximately 45 degrees with respect to direction D. These lateral guide members serve to divert the cans from their linear flow path indicated in dotted lines in Fig. 1 and thus to cause them to slide laterally off cable 12 as clearly indicated in Fig. 3. They then enter a further conveyor system for disposal as required.

Fig. 1 shows further details of the article holding means 36. Magnets 38, 40 are mounted on a pressed section mild steel back bone 46 and provided with a stainless steel cover 48 serving to provide a smooth but magnetically permeable cover for the assembly whereby the magnetic effect is exerted on the cans and no mechanical impediment is offered to the smooth flow of the cans through the diversion zone.

The embodiment operates substantially as described above. When diverter arm 32 is in the Fig. 2 position, the cans pass through the diversion zone in upright configuration and are held thus by magnets 38. Magnets 40 are, in this configuration of the cans, too remote to exert significant magnetic effect. When diverter arm 32 is moved to the Fig. 3 posi tion, the cans contacted immediately tip over and make contact with guides 20 and 22 and largely disengage from the magnetic field of magnets 30 and engage with that of magnets 40, as shown in dotted lines in Fig. 1. In both configurations, the cans are firmly conveyed by cable 12 and no hesitation in the conveying action occurs so that there is no impediment to the free flow of the cans through the diversion zone.When the first diverted can reaches centre guide 28, it is well placed to pass below the guide and the latter normally has little to do by way of guidance.

When it is desired to revert to the normal flow of Fig. 2, diverter arm 32 is returned to the Fig. 2 position and the first can 14 which is not diverted by the arm then forms the first can of the straight-ahead flow.

The above embodiment provides automatic means for a multi-outlet discharge from a single line in feed of cans or other articles. Obviously, in the above embodiment the diversion track 42 can be on either side and of course also there can be two or more diversion tracks at longitudinally spaced intervals along the main conveyor run. The diversion apparatus may be controlled by sensors from downstream equipment so that, for example, when one piece of downstream equipment has sufficient cans or has sustained a blockage, the can flow can be diverted to alternative apparatus or a palletizer/depalletizer.

The above embodiment has been found to be more successful than prior art devices, being much less susceptible to jamming. Moreover, the requirement for instantaneous gate switching as in prior art devices is substantially removed. The apparatus is capable of dealing with can flow speeds in excess of 1000 units per minute. Also, the apparatus is not appreciably sensitive to can shape and can readily handle distorted and damaged cans or other articles, whereas prior art magnetic diverters have required substantially undistorted cans.

The plurality of the magnets is indicated in Fig. 1. By the position of opposite poles at the upper surfaces of the magnets, a co-operation of the magnetic fields is produced whereby the desired uniform and low profile field is produced.

A particular feature of the above embodiment is that the cans are not diverted across an adjacent central divider, and in this way the potential for jamming at this location is greatly reduced.

Among modifications which could be made in the above embodiment while remaining within the scope of the invention, are the following: 1. The conveying apparatus may comprise alternative conveying means such as a slat type conveyor or other endless conveyor member, or indeed any conveying arrangement whereby the cans or other articles may be tipped laterally, for example over one side edge of the conveyor.

2. Alternative tipping means may be employed to act on the cans or other articles.

3. For the article holding means, in the case of aluminium cans and other non-ferrous articles, suction means may be provided for holding purposes, or other means for holding the article in conveying relationship with the conveyor. In this connection, it is to be noted that it may be possible to operate the apparatus in attitudes other than the normally upright position in view of the holding action provided by the article holding means. In some instances, an upside down flow of cans can even be contemplated.

4. For the purpose of tipping the cans or articles, means may be provided for raising and lowering one or more of the magnets, where permanent magnets are provided.

5. After the cans or other articles have been diverted, they may be conveyed elsewhere by any suitable means, including a gravity discharge apparatus or a magnetic lowerator, or other means.

6. In the above embodiment, the disposition of the cans in their straight through and diverted modes has been chosen for the purpose of unfilled and therefore lightweight cans. For a conveyor in which the cans or other containers are full, it would be preferred to realign the diverted and undiverted modes so as to be equally inclined with respect to the vertical. The preferred inciination is 30 degrees on each side of the vertical. The inclination between the can centre lines 50 and 52, and the centre guide centre line 54 is 30 degrees in each case, as shown in Fig. 1. For use with full cans, the apparatus is simply realigned so that centre line 54 is vertical.

Claims (14)

1. Article conveying apparatus comprising: conveying means; tipping means actuable to tip articles conveyed by said conveying means; characterised by article holding means capable of holding articles in conveying relationship with said conveying means both in said tipped and untipped configurations, whereby said articles may be conveyed by said conveying means after being tipped, and then removed from said conveying means.

2. Apparatus according to claim 1 characterised in that said article holding means comprises magnetic means.

3. Apparatus according to claim 2 characterised in that said magnetic means comprises first and second magnetic means extending in the travel direction of said conveying means.

4. Apparatus according to claim 3 characterised in that said first and second magnetic means are inclined with respect to each other to an extent corresponding to said tipped and untipped configurations of said articles.

5. Apparatus according to claim 4 characterised in that said magnetic means comprises inclined permanent magnets whereby articles are held thereby in their untipped configuration, and when tipped are held in their tipped configuration.

6. Apparatus according to claim 5 characterised in that said magnetic means comprises a ceramic permanent magnet.

7. Apparatus according to claim 4 characterised in that said magnetic means comprises an inclined electromagnet energisable selectively to provide both said tipping means and said article holding means.

8. Apparatus according to claim 4 characterised in that said magnetic means comprises a permanent magnet or magnets movable towards and away from said conveying means to provide both said tipping means and said article holding means.

9. Article conveying apparatus substantially as described herein with reference to the accompanying drawings.

10. A method of conveying articles comprising providing conveying means, tipping means actuable to tip articles conveyed by said conveying means, and conveying articles on said apparatus and then diverting articles from said conveying means by a method comprising the step of actuating said tipping means to tip said articles, characterised by the step of providing article holding means capable of holding said articles in conveying relationship with said conveying means both in said tipped and untipped configurations, and causing said article holding means to hold a first series of said articles in said conveying relationship, and then causing said article holding means to hold a further series of said articles in said tipped configuration after actuation of said tipping means, and removing said tipped articles from said apparatus.

11. A method of conveying articles substantially as described herein with reference to the accompanying drawings.

12. Apparatus according to any one of claims 1 to 9 characterised in that in said untipped configuration of said articles, the articles are substantially upright.

13. Apparatus according to any one of claims 1 to 9 characterised in that in said tipped and untipped configurations of said articles, the articles are inclined with respect to the vertical.

14. A method according to claim 10 characterised in that in said tipped configuration of said articles, the articles are inclined with respect to the vertical.