Spacing conveyor mechanism

Abstract: There is provided a mechanism 10 for conveying cans 11 along a path 12. The mechanism has a drive chain 14 to which are pivotally attached carriages 17 having conveyors 18 with recessed pockets 19. Each carriage also has a fixed cog 20 which meshes with a second sprocket 21 which is rotated at a different speed to the main sprockets 15 of the drive chain 14. Selection of the relative speeds and teeth ensure that the conveyors 18 remain parallel to each other throughout their path.

Description: This invention relates to spacing conveyor mechanisms for article packaging machines and in particular but not exclusively for can or bottle multi-pack packaging machines. GB-A-2079235 discloses an article transfer system which utilises pendulant buckets for transferring articles vertically as well as horizontally having stabilising means comprising a circular stabilising member mounted on each bucket which engages with a separate stabiliser chain spaced from main drive conveyor chains, the stabiliser chain being driven at the same linear speed as the drive chains. EP-A-0450915 discloses a spacer and conveyor mechanism for use in a packaging machine in which articles are conveyed along a feed path and formed into groups for subsequent packaging. A series of spacer and conveyor elements are mounted on an endless chain by means of a connector adjacent one end of said element, and a guide element is provided at the opposite end of said element, said endless chain, connector and guide elements cooperating with sprockets sets at opposite sides of said mechanism comprise superposed sprockets. According to a first aspect of the present invention there is provided a spacing conveyor mechanism for an article packaging machine having an article feed path, said mechanism comprising a number of article conveyors mounted on a single endless drive means comprising a single endless drive element extending in a circuitous path between a number of drive members which define where the circuitous path changes direction, a part of which circuitous path is in use adjacent the feed path of the articles and during which part of its path each conveyor engages the articles in the feed path, each conveyor comprising a carriage pivotally attached to the drive means each carriage incorporating an article engaging member, a number of further drive means being provided each being associated solely with one of said drive members for cooperation with the carriages so as to rotate the carriages relative to the endless drive element when there is a change in direction in the path of the single endless drive so that the conveyors remain substantially parallel to each other throughout their circuitous paths, guide means being provided which assist in maintaining the conveyors in said substantially parallel position along the path between the drive members. Preferably said endless drive means comprises a chain and each drive member comprises a sprocket. In a further embodiment said further drive means comprises a drive wheel associated with each sprocket, said wheels engaging corresponding cogs fixed relative to the carriages and being driven at a predetermined speed relative to the single endless drive means so as to ensure said parallel movement. It is a preferred feature that said drive wheels are coaxial with their associated sprockets and are driven in rotation with the sprockets by way of gearing. Conveniently, the article engaging members are removably attached to their respective carriages and have a number of recessed pockets each for a separate article. Normally the carriages and their associated cogs are attachable at any location along the length of the single endless drive chain and preferably the carriages are, in use, equispaced along the chain. A preferred feature is that two sprockets are provided such that the chain path has two straight sections and two semi circular sections, one of the straight sections being adjacent the feed path. Preferably still, the guide means comprises a cover member having a guide groove of the same shape as the path of the single endless drive element, a pin being provided on each carriage coaxially with its pivotal connection to the single endless drive element, said pins engaging in the guide groove. According to a second aspect of the present invention there is provided a spacing conveyor arrangement comprising two such spacing conveyor mechanisms located parallel to each other on both sides of an article feed path, each set of article conveyors in use engaging separate lines of articles. An embodiment of the present invention will now be described in more detail. The description makes reference to the accompanying drawings in which: Figure 1 is a plan view with a part cut away portion of a mechanism according to the present invention, Figure 2 is a sectional view on line II-II of Figure 1. In the figures there is shown a spacing conveyor mechanism 10 for a packaging machine. The embodiment shown is for spacing and conveying multiples of cans or bottles 11 but it could be for other articles. The mechanism 10 is, in use, positioned adjacent a feed path 12 defined by a moving belt, for example, which conveys the cans or bottles in groups to an area (not shown) where they are automatically packed into boxes, sleeves etc. A feed mechanism (not shown) which may be in the form of a star wheel arrangement feeds cans or bottles to the mechanism 10 at a rate equal to the rate required. The mechanism 10 groups the cans or bottles on to a conveyor means, such as the moving belt, which transports the groups to the packing section of the packaging machine. Quite frequently a similar mechanism 10 will be provided in parallel so as to space and convey articles in one or two rows, the moving belt having space for said row or rows of articles to pass between the two mechanisms 10. Each mechanism 10 comprises a drive chain 14 which is positioned in a horizontal plane between two sprockets 15 (represented as broken lines without teeth in figure 1). Pivotally connected to the chain 14 at equally spaced locations 16 are carriages 17 each carrying a conveyor 18. The conveyors 18 have a number of recessed pockets 19 for receiving a chosen number of individual bottles or cans, which number of course determines the size of the multi-packs being produced. In the embodiment shown there are five pockets 19 in each of four conveyors 18 so that for every full revolution of the chain, twenty cans 11 will be moved to the packing area in groups of five. Similarly the star wheel (not shown) will feed twenty cans to the mechanism 10 in the same time period. The drives of the star wheel and the chain 14 can be the same or separate drives can be used as long as they are controlled so as to work on the same number of can in a given time period. To ensure smooth movement of the cans 11 through the mechanism 10, it is important that the conveyors 18 approach and separate from the cans 11 substantially parallel to the feed path 12. The conveyors 18 and carriages 17 are therefore kept parallel to each other all the time and in particular as they approach the cans and separate from the cans 11. In order to achieve this parallel movement of the conveyors 18 and carriages 17, each carriage is provided with a cog 20 which is fixedly located relative to the carriage 17, coaxially with the pivotal connection to the chain 14. The cog 20 is shown in figure 1 on only one of the carriages 17 which is partially cut away. Coaxially mounted relative to each sprocket 15 is a second sprocket 21 which is driven at a different speed to the main sprocket 15 by way of suitable gearing 22. As each carriage 17 passes around a sprocket 15 in its circuitous path, the cog 20 meshes with the second sprocket 21 and this causes the carriage 17 to rotate relative to the chain 14. It will be appreciated that the movement of the carriages 17 about the sprockets is dependent on various factors namely the relative speeds of the two sprockets 15,21 and the teething ratios of the cogs 20 and second sprocket 21. There are numerous combinations which will maintain the parallel condition. For example, taking the configuration of the figures let us assume that da, na, wa: are the diameter, number of teeth and angular velocity of sprocket 15. db,nb: are the diameter and number of teeth of cog 20 dc,nc,wc: are the diameter, number of teeth and angular velocity of second sprocket 21. The geometry of the system requires that da = dc + db and d = nP (Where P is the pitch between teeth) For a 5/8" (15.9 mm) drive chain and 1/2" (12.7 mm) pitch teeth on the cog 20 and second sprocket 21 we have 5.na 4 = nb + nc Such that if na = 32 teeth, nb = 12 teeth then nc = 28 teeth Also, the required drive ratio is: Wc Wa = nc + 0.5 nb nc in order to maintain the parallel nature of the carriages around their circuitous path. It will be apparent that other drive systems could be used instead of the chains/sprockets and cogs/sprockets. For example toothed belts could be used on even frictional drives. Other configurations could be provided. For example, more carriages/conveyors 17,18 could be provided on each chain and the number of pockets 19 per conveyor 18 can be changed. Depending on the changes made, adjustments may be necessary in the drive ratio between the feed mechanism and the spacing conveyor mechanism 10. Also, more than two main sprockets 15 may be provided for each mechanism 10, each main sprocket 15 having a coaxial second sprocket as mentioned above. Also shown in figure 1 is an optional cover member 25 in which there is a guide groove 26 of identical shape to the path of the chain 14. An upstanding pin 27 is provided on each carriage 17, coaxially with its pivotal connections at 16. The pins 27 engage in the groove 26 and can assist in maintaining the integrity of the mechanism 10. Suitable, low friction materials are of course best for the pins 27 and groove 26.

Claims: A spacing conveyor mechanism (10) for an article packaging machine having an article feed path (12), said mechanism comprising a number of article conveyors (18) mounted on a single endless drive means comprising a single endless drive element (14) extending in a circuitous path between a number of drive members which define where the circuitous path changes direction, a part of which circuitous path is in use adjacent the feed path (12) of the articles and during which part of its path each conveyor (18) engages the articles in the feed path (12), each conveyor (18) comprising a carriage (17) pivotally attached to the drive means each carriage (17) incorporating an article engaging member (19), a number of further drive means being provided each being associated solely with one of said drive members for cooperation with the carriages (17) so as to rotate the carriages relative to the endless drive element (14) when there is a change in direction in the path of the single endless drive so that the conveyors (18) remain substantially parallel to each other throughout their circuitous paths, guide means being provided which assist in maintaining the conveyors (18) in said substantially parallel position along the path between the drive members. A mechanism as claimed in claim 1 wherein said single endless drive comprises a chain (14) and each drive member comprises a sprocket (15). A mechanism as claimed in claim 2 wherein each further drive means comprises a drive wheel associated with each sprocket (21), said drive wheels engaging corresponding cogs (20) fixed relative to the carriages (17) and being driven at a predetermined speed relative to the single endless drive means so as to ensure said parallel movement. A mechanism as claimed in claim 3 wherein said drive wheels are coaxial with their associated sprockets (21) and are driven in rotation with the sprockets by way of gearing (22). A mechanism as claimed in claim 4 wherein the article engaging members (19) are removably attached to their respective carriages (17) and have a number of recessed pockets (19) each for a separate article (11). A mechanism as claimed in claim 5 wherein the carriages (17) and their associated cogs (20) are attachable at any location along the length of the single endless drive chain (14) and preferably the carriages (17) are, in use, equispaced along the chain (14). A mechanism as claimed in claim 6 wherein two sprockets (21) are provided such that the chain path has two straight sections and two semi circular sections, one of the straight sections being adjacent the feed path (12). A mechanism as claimed in any one of claims 1 to 7 wherein the guide means comprises a cover member (25) having a guide groove (26) of the same shape as the path of the single endless drive element, a pin being provided on each carriage coaxially with its pivotal connection (16) to the single endless drive element, said pins engaging in the guide groove (26). A spacing conveyor arrangement comprising two spacing conveyor mechanisms (10) as claimed in any one of claims 1 to 8 located parallel to each other on both sides of an article feed path (12), each set of article conveyors in use engaging separate lines of articles.

Inventors: MUELLER ROLF, MUELLER, ROLF, Müller, Rolf 
Applicants: RIVERWOOD INT CORP, RIVERWOOD INTERNATIONAL CORPORATION
Application year: 1995
Main classification: B65G17
IPC codes: B65G17