Article grouping device/method

Abstract: Device for conveying a series of spaced apart articles (17) to a processing machine, in particular these articles being formed to groups (17') of a specific number comprising a drivable conveyor belt system (2) with a run running essentially horizontally which can accommodate the series of articles (17), and which runs parallel to and at a distance from an endless chain (5) on which a number of equally spaced drivers (8) are mounted said drivers (8) being movably mounted in such a way that they are placed only after passing a control element (9) in a position projecting relative to of the conveyor belt system (2) between articles (17) lying thereon, which control element (9) is fitted so that it can move to and fro over at least a portion of said run of the endless chain (5) parallel thereto and is coupled to first means (12) which can give a signal for each passing or incoming article (17), and near the downstream end of the chain fixed second means (16) are present which for every passing group of articles (17') can give a multiple "p" of these signals, so that these signals are a measure of the number of outgoing articles (17), and a comparison device (31) is present, to which the signals of said first (12) and second (16) means can be fed, by which device (31) the speed of the endless chain (5) and the position of the control element (9) are controlled, said position being dependent on the ratio "N" between the number of incoming and the number of outgoing articles (17), and it being possible for "N" to vary between a value of zero and a value of at least 1.

Description: The invention relates to an article grouping method according to the preamble of Claim 1, and an article grouping device according to the preamble of Claim 4, said preambles being based on a prior art which is represented by US-A-28841-15. In said document the problem of keeping a constant pitch between the articles moving in a stream is solved in that, every n-th article is removed from that stream, such that the pitch is locally increased. For this purpose, the articles are slowed down after passage of a specific position, the place of which is determined by an actuating means. Said actuating means is controlled in dependence of the movement of the conveying device, which is directly correlated to the position of the articles upstream from said position, if the pitch is indeed constant and if removal of each n-th article from the stream is reliable. Thus with a constant speed of the conveyor, said position is periodically moved up- and downstream along the conveyor, according to a periodic control of said actuating means. To retard the speed of the articles, use is made of a chain with drivers, running with a lower speed compared to the speed of the main conveyor. Along the upper run of the chain, the drivers can be moved from an inactive to an active position by said actuating means at the predetermined position. For a reliable operation of the solution according to US-A-288-4115, a constant pitch ahead of said position, as well as a reliable removal of each n-th article is essential. Deviation from these parameters leads to malfunctioning of the process, since the activating means is controlled in dependence of merely the movement of the conveyor. Thus, the known process and the known device for carrying out said process are not suitable for the purpose of the present application, which is directed to the manipulation of articles fed with a random pitch, and to be manipulated such that groups of one or more articles with a constant pitch are formed, in phase with a downstream device for further processing the articles. From US-A-4660350 an article manipulating device is known which is suitable in particular for use in a plant for the production of so-called multi-packs, in other words, packs each containing a number of individually packed articles, so that such a plant comprises a single-pack machine for the production of packed single articles, a transfer device which is also a group former of the type mentioned in the preamble, and a multi-pack machine for the production of multi-packs. The single-pack machine produces a continuous stream of packed articles which are transferred by the transfer device to the multi-pack machine, so that the speeds of these machines and those of the transfer machine have to be synchronized. The stream of packed articles produced by the single-pack machine is, however, not always constant, since this machine has a facility for blowing rejected packs out of the stream of packed articles and the production speed of this machine depends on the supply thereto of single articles to be packed. The speeds of the transfer device and of the multi-pack machine will therefore have to be capable of varying. However, sudden changes in speed from a specific speed to zero speed and vice versa are not possible in this case. The transfer device therefore also serves as a buffer in which articles can be buffered when the stream of articles coming out of the single-pack machine suddenly begins or decreases with gradually increasing speed of the multi-pack machine, and from which articles can be drawn for supplying the multi-pack machine at gradually decreasing speed whenever a gap occurs in the article supply steam, until this gap is filled up again by the single-pack machine which continues to supply packed articles at full speed. In the device known from US-A-4660350 the above-mentioned run of the endless chain is guided in such a zigzag manner that between every two drivers a sag is present in the chain, said sags meaning an additional length of this run. In this case the endless chain is driven at one side by the producing machine and at the other side by the processing machine, said drives being synchronized by means of regulating devices. If a gap now occurs in the stream of articles supplied by the producing machine, then the drive of the endless chain is stopped by the producing machine, so that the sags are pulled approximately straight over a period of time by the other drive of the endless chain, with the result that the processing machine remains supplied, during which time the gap is filled up by the producing machine. The disadvantage of this known device is that it cannot operate at relatively high speeds, since the masses of the chain and moving parts are too great for this. Moreover, in order to obtain great enough extra length of the endless chain, a relatively large number of sags must be present, as a result of which the straight length of the zigzag-shaped run of the endless chain becomes unacceptably great. The object of the invention is to provide an improved method and device of the above-mentioned type. This object is achieved by providing a method/device which is characterized by the features indicated in the independent Claims. The invention will be explained in greater detail with reference to the drawing, in which: Figure 1 shows in side view an embodiment of the device according to the invention; Figure 2 shows this device in top view; Figure 3 shows two drivers on a larger scale; Figure 4 is a section along the line IV-IV in Figure 3; and Figure 5 shows a control diagram for the device according to the invention. As shown in Figures 1 and 2, the transfer device 1 extends between a packaging machine (not shown), to the right in the figures, delivering a stream of individually packed articles, and a packaging machine to the left in the figures, packing groups of three of these articles. The device 1 comprises two adjacent conveyor belts 2, each having an upper run 2′ and a lower run 2″. These conveyor belts are driven by means of the pulley 3 which is driven by means of the transmission 4 from the single-pack machine. The device 1 also comprises an endless chain 5, driven by means of the chain wheel 6 which is driven by means of the transmission 7 from the multi-pack machine. Fitted on this chain are drivers 8, which are situated at equal intervals and which can swing between two positions, i.e. the position shown by reference number 8, in which position the drivers project upwards through the space between the conveyor belts until they are past the upper runs 2′ of the conveyor belts, and the position shown by the reference number 8′, in which position the drivers do not project past the top parts 2′. The drivers are taken out of the position 8′ into the position 8 by means of the pawl 9, which is provided with a camming 9′ up on which the follower roller 8″ of a driver 8 runs. The pawl 9 can be moved to and fro, by means of the toothed belt or endless chain 10, parallel to the conveyor belts 2 and the chain 5 in the direction of the double arrow A. The toothed belt 10 is driven here by the motor 11. Fitted above the conveyor belts 2 is a photoelectric cell 12 which together with the pawl 9 is moved to and fro in the direction of the double arrow B, for which purpose the pawl 9 is mounted on an endless chain 13 which is driven by means of the pulley 14, this pulley 14 being driven by means of the transmission 15 by the motor 11. The photoelectric cell 12 is situated at a distance in front of the pawl which is approximately equal to half the length of an object 17. A scanning device 16 is also fitted at a fixed point below the top part of the endless chain 5. In Figure 5 M1 and M2 indicate the motors which respectively drive the single-pack machine and thereby the endless belts 2, and the multi-pack machine, and thereby the endless chain 5, while the motor M3 corresponds to the motor 11. M1 and M2 are linked to the pulse emitters B1 and B2 respectively, B1 producing, for example, 1,000 pulses per single produced, singly packed article, and B2 producing, for example, 3,000 pulses per group of three articles. B3 is a position-measuring element for the pawl 9. G2 and G3 are tacho-generators. Reference number 30 indicates an increment counter which passes on 1,000 incrementing pulses given by B1 to a counter register 31 each time a signal is given by the photoelectric cell 12 as the result of an article passing it, while 32 indicates a decrement counter which passes on 3,000 decrementing pulses given by B2 to the counter register 31 each time a signal is given by the scanning device 16 as the result of a driver 8 in the operating position passing it. Reference number 33 indicates a positioning unit for positioning the pawl 9, while 34 is a synchronization regulator, 35 a transducer, and 36 a digital/analogue converter. When the device is in operation a stream of individually packed articles 17 is produced by the single-pack machine, said articles then being transferred by the transverse conveyor 18 to the conveyor belts 2. When the photoelectric cell 12 is passed, said photoelectric cell gives for each article which has passed a signal or a number of pulses which increment the counting register 31. If, for example, each group of articles has to be made up of three of these articles, then after the passing of every three articles moving along the conveyor belts 2 a driver 8 is raised through said driver running along the pawl 9. Due to the fact that the endless chain 5 and thereby the drivers 8 move along at a speed which is lower than that of the conveyor belts 2, three articles 17 are always collected to a combined group 17 behind the drivers 8. At the end of the conveyor belts 2 the groups 17′ are slid onto a table 19, so that a group 17′ formed behind a driver is pushed forward over the table 19 by the following driver, following which these groups of articles 17′ are transferred by the conveyor 20 to the multi-pack machine. When a driver 8, in its raised position, passes the scanning element 16, said element in the example of an embodiment selected gives three signals or three times a number of pulses which decrement the above-mentioned counting register. The signals incrementing and decrementing the counting register 31 determine the value of the counting register, which value is proportional to the ratio N between the number of incoming articles, i.e. the articles which have passed the photoelectric cell 12, and the number of outgoing articles, i.e. the articles formed into groups which pass the scanning element 16. In addition, N is directly proportional to the place where the pawl 9 is situated, while N can vary between 0 and, for example, 1, 2, so that in the case of the first-mentioned value the pawl 9 is fully downstream, at the scanning element 16, and in the case of the second value the pawl 9 is fully upstream. When the device shown starts operating from a standstill position, then a driver 8 in the operating position is near the scanner 16. The single-pack machine is then put into operation, so that the production speed thereof increases from zero to the set capacity of, for example, 540 articles per minute. The stream of articles fed in by the conveyor belts then passes the photoelectric cell 12, in which case 1,000 incrementing pulses are given to the counting register 31 each time one article passes, the result of which is that first of all the pawl 9, after three times 1,000 incrementing pulses, is moved over one chain pitch in the upstream direction, which places the next upstream driver in the operating position behind the first three articles and that, secondly, the multi-pack machine gradually goes into operation and the endless chain is thereby set in motion, so that outgoing articles are produced and decrementing pulses are fed into the counting register 31. Since the value N = 1 is being striven for, so long as per unit time the number of incoming articles is greater than the number of outgoing articles, the pawl 9 will be moved further upstream, while after every 3,000 incrementing pulses a driver is placed in the working position, until the multi-pack machine is running as fast as the single-pack machine, so that per unit time the number of incoming articles is equal to the number of outgoing articles. As shown in Figures 3 and 4, each driver 8 is formed by an approximately L-shaped element, with a first leg 21 and a second leg 22. This element is rotatably connected to the chain 5 at 23, an elongated aperture 24 engaging around a pin 25 forming a limit for the swinging movement about the point 23 of the element. A follower roller 26 is also connected to the legs 21 and 22 and can run up against the run-on face 9′ of the pawl 9, causing the element 21, 22 to be swung from the non-operating position shown on the left into the operating position shown on the right, in which position the leg 21 projects past the conveyor belts 2. In order to fix these two positions of the element 21, 22 a member 28 loaded by the pressure of a spring 27 is provided, the member 28 being pressed against a bush 29, so that during swinging of the element 21, 22 the member 28 passes a dead point on the periphery of the bush 29.

Claims: Article grouping method, wherein: articles are successively moved in a downstream direction on a conveyor system having an overlapping portion; the articles have a first speed upstream and a second speed downstream of said overlapping portion in which the articles are engaged by engagement means; actuating means for actuating said engagement means is provided in said overlapping portion, said actuating means being controlled in its reciprocating movement parallel to the moving direction of the articles in dependence of the pitch of the articles upstream said portion, in order to manipulate said pitch, characterized by a first sensor means, sensing the passage of the articles at said first speed, said first sensor means being reciprocatively moved with said actuating means; and a second sensor means, sensing the passage of a single article or a group of articles at said second speed; the first signals from said first sensor means and the second signals from said second sensor means being compared, on the basis of said comparison said second speed and the positioning of said actuating means are controlled, such that the actuating stroke and the cycle of engagement of said engagement means are dependent from said upstream article pitch. Method according to claim 1, wherein downstream of said overlapping portion the articles are grouped together, each group containing "p" articles, the second signals being a multiple "p" of the first signals, said second speed and the movement of the reciprocating actuating means being controlled dependent on the ratio "N" between said first and second speed. Method according to claim 1 or 2, characterized in that said first speed is higher than said second speed, and that due to an increase of the ratio "N" said actuating means is moved upstream with respect to the moving article stream and said second speed is increased. Article grouping device for manipulating articles, positioned between a product feeder (18) and a product discharge (20), comprising an endless conveying belt (2); an overlapping endless chain (10) with equally spaced drivers (8) movable between an active and an inactive product engagement position at the upper run such that only after passing an actuating means (9) a driver is placed into its active position, the actuating means (9) being reciprocatively movable with respect to at least a portion of the upper run of the chain (10) parallel thereto by means of regulating means (33) connected thereto such that the drivers are activated at a manipulating position selected in accordance with the position of a product (17) on said conveyor, the upper runs of both said belt and said chain extending closely parallel with respect to each other, such that the active drivers (8'') project between products to be carried on said belt (2), characterized in that there is provided a first sensor means (12) which is controllable in its reciprocating movement parallel to the moving direction of said run (2) and which is adapted for signalising the passage of an infed article (17), said first sensor means being positioned upstream of the actuating means (9) and being connected to said regulating means for movement in correspondence with said actuating means (9); and a second sensor means (16) being positioned to sense the articles substantially at the end of the upper run of the chain (10) and being adapted for signaising the passage of a driver (8), the first and second sensor means being connected to a comparison device (34) for receiving said first signals from the first sensor means and for receiving said second signals from the second sensor means, the second signals being a multiple "p" of the first signals, to derive a ratio "N" from both said signals, said comparison device being controllably connected to both the endless chain (10) and the regulating means (33) to control the speed of said chain and the position of said actuating means (9) and said first sensor means (12), depending on the value "N". Device according to claim 4, wherein the endless conveying belt (2) is divided into two spaced portions, forming two spaced runs extending in one horizontal plane, the drivers (8) projecting between the portions when in their active position. Device according to claim 4 or 5, wherein each driver (8) includes a substantially L-shaped member, which is rotatably connected to the endless chain (10) at a point (23) on one leg (22), such that the L-shaped member is rotatable between two extreme inclined positions, a position limiting member (25) to cooperate with said L-shaped member in its two extreme positions for limiting the rotational movement thereof, the L-shaped member having a spring-loaded element (28), the free end of which is pressed against a curved surface (29), such that during rotation of the member between said positions, the spring-loaded element (28) passes the highest point of said surface (29), and a follower roller (26) fitted near the interconnection of the two legs (21, 22). Device according to one of the preceding claims 4 to 6, wherein the actuating means (9) is formed by a pawl. Device according to claims 6 and 7, wherein the pawl (9) is formed by a run-on face (9'), forming a ramp for the follower roller (26).

Inventors: FRANSEN ADRIANUS ANTONIUS JOSE, FRANSEN, ADRIANUS ANTONIUS JOSEPH
Applicants: KLOECKNER HAENSEL TEVOPHARM, KLOECKNER HAENSEL TEVOPHARM B.V.
Application year: 1990
Main classification: B65G47
IPC codes: B65G47, B65G19