GB2582122A

GB2582122A - Controlling manufacture of articles

Info

Publication number: GB2582122A
Application number: GB1718987.9A
Authority: GB
Inventors: Wageck Frederico
Original assignee: C & J Clark Overseas Ltd
Current assignee: C & J Clark Overseas Ltd
Priority date: 2017-11-16
Filing date: 2017-11-16
Publication date: 2020-09-16
Also published as: GB201718987D0

Abstract

A method for controlling the manufacture of articles comprising the steps of a) halting the conveyor 12 based on the presence of articles 3 at a workstation 1 and then allowing processed articles to be returned to the conveyer 12 b) restarting the conveyor in response to a sensor 14 detecting articles have been returned to the conveyor and that articles to be processed have been removed c) moving the returned articles on the conveyer until it is again stopped in response to a sensor that signals the articles have reached the next workstation. Ideally the conveyor is an endless belt conveyor.

Description

Controlling manufacture of articles The disclosure relates to manufacturing of articles. More particularly, methods and apparatuses for controlling flow of articles through a multistage manufacturing system comprising a plurality of successive workstations are disclosed.

Manufacture of an article can comprise a multiple of stages. For example, a multiple of components may need to be produced, often in o multiple stages and joined together, again possibly in multiple of stages.

Finishing of the joined article may also require several stages. Examples of such articles comprise articles of footwear.

Controlling multistage manufacturing process where various different tasks are performed at different workstations can be difficult. A common problem is in timing of the various operations. This can cause problems in synchronising the "flow' of the articles through the manufacturing system. For example, some stages may cause bottlenecks to which the system cannot react, leaving later parts and workstations idle due to lack of articles to be processed from earlier workstations. The bottlenecks may be occasional, or even symptomatic. In either case there may not be enough visibility to the system to even realise where the real problem is and to react and resolve the issue. Sometimes problems are simply due to lack of proper and correctly timed transport between workstations.

The embodiments aim to address one or more of problematic issues z in relation to multistage manufacture of articles.

According to an aspect there is provided a method for controlling manufacture of articles in a system where articles are moved by a conveyor between workstations adapted for performing successive manufacturing stages, the articles are removed from the conveyor for processing at the 3u workstations, and processed articles are returned to the conveyor for movement to the next workstation, the method comprising: halting the conveyor based on information from a sensor arrangement configured to sense presence of articles relative to the workstations for enabling returning of processed articles from the workstations to the conveyor and removal of tte next articles to be processed from the conveyor to the workstations, restarting the conveyor in response to information from the sensor arrangement indicating that the processed articles have been returned to the conveyor and the next articles to be processed have been removed from the conveyor, moving the returned processed batches until the conveyor is stopped in response to information from the sensor arrangement that the returned processed articles have reached the next workstations, and repeating the steps.

According to an aspect there is provided a manufacturing system for manufacture of articles, the system comprising workstations adapted for performing successive manufacturing stages, a conveyor for conveying the articles between successive workstations such that the articles can be removed from the conveyor for processing at the respective workstations and processed articles can be returned to the conveyor for movement to the next workstation, a sensor arrangement associated with the workstations configured to sense presence of articles in predefined Locations, and a control apparatus for controlling movement of the articles between the workstations, zc the control apparatus being configured to halt the conveyor based on information from the sensor arrangement for enabling returning of processed articles from the workstations to the conveyor and removal of the next articles to be processed from the conveyor to the workstations, start the conveyor to move the returned processed articles to the next workstations in response to zs information from the sensor arrangement indicating that processed articles have been returned to the conveyor from the workstations and the next ailicles to be processed have been removed from the conveyor, stop the conveyor in response to information from the sensor arrangement that the returned processed articles have reached the next workstations, and repeat the above operation during manufacture of the articles.

In accordance with a more detailed aspect the conveyor comprises a belt conveyor. The conveyor may be arranged to provide an endless loop.

Articles can be arranged in batches of articles. Each workstation can he associated with at least one sensor for detecting presence of a next batch of articles to be processed and a returned batch of processed articles. The articles may be placed on carriers arranged for moving a batch of articles on the conveyor, from the conveyor to the workstation, and returning the processed batch of articles to the conveyor.

Articles may be moved from the conveyor to the workstation and/or returned to the conveyor by a human operator of the workstation. Alternatively, articles may be moved from the conveyor to the workstation in and/or returning to the conveyor by a manipulator. The manipulator may be operated in response to information from the sensor arrangement. Articles may be moved from and/or to the conveyor by a robot or by an apparatus arrange to push, drag or lift the articles from and/or to the conveyor.

Articles may be moved in at least one of the workstations by a robot or another manipulator.

Articles may comprise articles of footwear. Articles of footwear may be separated into two types of batches depending whether the articles of footwear are for the right foot or the left foot. The type of the batch may be indicated by a visual coding, for example by colour. Two types of batches may be fed alternately to the conveyor.

Various exemplifying embodiments of the invention are described below with reference to the attached drawings. Steps and elements explained herein may be reordered, omitted, and combined to form different embodiments and any step indicated as performed may be caused to be performed in another order. In the drawings: Figure 1 is a schematic view of an exemplifying multistage manufacturing system; Figure 2 -5 show steps of a cycle according to an example; Figure 6 is a flowchart in accordance with an example; Figures 7 -9 show example of manipulator apparatuses for a Figure 10 shows example of control apparatus.

In the following certain detailed examples of controlling manufacture of articles will be described with reference to the drawings. The like numbers in, the drawings refer to like components.

Figure 1 shows an example of a manufacturing system 10 comprising successive workstations 1. in the example two continuous conveyors 12, 22 are arranged for moving articles 3 relative to the successive workstations 1, The direction of movement of articles / flow of articles is indicated by arrows 11. Each workstation provides a given stage of manufacture of the articles 3.

lo To enable this each workstation 1 is provided with appropriate equipment, tooling, and other features to enable operators 2 to work and complete the given stage.

In the example of Figure 1 the system is arranged for manufacture of footwear and the workstations are labelled according to the various stages of Is footwear manufacture. Stages of manufacturing footwear as such are known and therefore will not be explained in any greater detail here. In view of understanding the invention all that is needed to note is that is that the stages are performed in a predefined order and that the stages are planned such that each stage associated with a conveyor takes about the same time to perform, For example, producing of eyelets at a workstation follows a labelling workstation, arid from the eyelet workstation the articles of footwear are moved to a first stitching workstation.

According to a possibility the conveyor comprises a belt conveyor arranged to provide an endless loop. An endless loop can provide a carousel type conveyor, this being shown in the non-liming example of Figure 1, Another example is a tubular belt conveyor moving articles in substantially one direction. It is also possible to have e.g. S-shaped or otherwise shaped conveyors arranged to move articles between workstations. The shape of the conveyor may be arranged to take into account the available space and 0 restrictions by it.

11 is noted that the type, design and number of conveyor(s) can he selected based on the application, and that the conveyor does not necessarily need to be of a looped type. What is important in view of operation of the invention is that a flow or articles from a workstation to the other can be provided as described herein.

Figure 1 shows further a plurality of sensors of a sensor arrangement 14. In Figure 1, two sensors are associated with each workstation 1. The sensors are arranged to detect presence of articles relative to the workstations. Appropriate sensors can comprise any sensor suitable for detecting the presence of the articles. For example, touch sensitive sensors, infrared sensors, sound sensors, light sensor, radio transmission sensors and so forth can be used for presence detection. Purpose and operation of the sensor arrangement will be described in more detail in the following description with reference to Figures 2 -5 illustrating in more detail one example of a system for manufacturing of articles where successive manufacturing stages by successive workstations are synchronised.

The articles can be arranged in batches, the minimum batch size being one article. According to a possibility articles can be conveyed as such, without any carrier means, by the conveyor. According to another possibility. articles can be conveyed through the manufacturing system on specific carriers, for example in carrier baskets, pallets, trays. plates or the like. A carrier may containing one or more pieces of the articles. Thus in this specification the term batch can refer to a single piece of article or a plurality of articles grouped to form a batch of articles and the terms article and batch can be used interchangeably, where appropriate. Both terms refer to an item moved between workstations and taken off from the conveyor for the purposes of performing manufacturing operations at the workstations and subsequently returned to the conveyor.

Figures 2 -5 illustrate various steps of an operational cycle of a system comprising workstations 1 adapted for performing the successive manufacturing stages and a conveyor 12 for conveying batches 5, 6 on the 3t) conveyor between the successive workstations. For the purposes of the illustrative example of Figures 2 -5 the shown successive batches in various stages and locations are labelled N, N4-2, N-+ 3. N-44, N+5, and N+6, the labelling indicating the order in which the batches are fed on the conveyor. The conveyor may comprise a continuous conveyor, for example a belt, a chain or an overhead conveyor. The conveyor is arranged such that can be removed from the conveyor for processing at the respective workstations 1. Likewise, batches 6 that have finished the respective processing stages at workstations 1 can he returned to the conveyor 12 for ovement to the next workstation.

A sensor arrangement 14 is associated with the workstations. The rob sensor arrangement is configured to sense presence of a batch in a predefined location. The sensor apparatus 14 is connected to a control apparatus 18 configured for controlling movement of the batches 5, 6 between the workstations 1 based on signals from the sensor arrangement. The connection can be provided by means of a bus 16, or another appropriate signalling connection. The connection can be wired or vvireless connection.

The control apparatus 18 can be configured to control the operation of e conveyor 12 based on information from the sensor arrangement 14 through control of a drive 13. The control apparatus can stop the conveyor 12 for enabling returning of processed batches 6 from the workstations 1 to zo the conveyor and removal of the next batches 5 to be processed from the conveyor to the workstations. The controller can further cause restart of the conveyor from the halted state to move the returned processed batches 6 in response to information from the sensor arrangement indicating that all processed batches 6 have been returned to the conveyor and all next batches 5 to be processed have been removed from the conveyor. The controller can stop the conveyor in response to information from the sensor arrangement that the returned processed batches have reached the next workstations.

In more detail, Figure 2 shows a step where batches 4 are placed in respective work stations 1. The batches taken into the workstations are having order labelling N, N+2, and N+4. At the same time, the conveyor has been halted and next batches 5 labelled N+1, N+3, and N+5 are waiting to be taken into the respective workstation. The instruction to halt the conveyor is generated based on signals from sensors 14 indicative that the next batches 5 are in the predetermined pick-up locations.

Figure 3 shows the step where work on batches labelled N, N+2, and N+4 has finished and they all have been returned on the conveyor from respective work stations 1. At this stage the sensors 14 can indicate to the control apparatus 18 that the batches have been returned to the predefined locations on the conveyor. The next batches 5 labelled N+1, N+3, and N+5 are still waiting to be taken into the respective workstation. The conveyor is not restarted as long as batches 5 remain on the conveyor.

Figure 4 shows the next step where batches 4 placed in respective work stations 1 are those with order labelling N+1, N+3, and N+5. Sensors 14 have indicated that batches labelled N+1, N+3, and N+5 have been removed from the conveyor and thus are in the respective workstations. Instruction to start the conveyor can now be generated based on signals from the sensors 14 indicative that the processed batches 6 are in the predetermined return locations and the next batch locations are empty. Thus the conveyor 12 starts to move the processed batches 6 forwards in the system as indicated by arrow 11.

Figure 5 shows the next step where batches 4 labelled N+1, N+3, and N+5 are in the workstations 1. The conveyor is again in the halted state, instruction to halt the conveyor having been generated based on signals from sensors 14 indicative that the next batches 5 labelled N+2, N+4, and N+6 are in the predetermined pick-up locations waiting to be taken into the respective workstations 1. The operation has now gone through a full cycle, the situation corresponding to that of Figure 2.

Figure 6 shows a flowchart according to an example of controlling manufacture of articles arranged in batches of articles, the batches of articles being moved by a continuous conveyor between successive workstations adapted for performing of successive manufacturing stages, as explained above. Articles waiting to be processed can be removed from the conveyor for processing at the successive workstations such that all articles go via all workstations. Once processed, the articles are returned from the respective workstations to the conveyor movement to the next workstation.

Controlling of the synchronised movement of the articles between the workstations comprises step 100 for detecting by a sensor arrangement that the next batches of articles to be processed are in predefined locations s Jative to the workstations. The sensor arrangement can comprise sensors arranged to detect position of the batches of articles relative to the workstations. Information indicating the presence of the next batches of icles is signalled at 102 to a controller. The controller stops the conveyor at 104 based on information from the sensor arrangement. The conveyor is to halted to enable easy returning of the processed articles from the workstations to the conveyor and removal of the next batches of articles to be processed from the conveyor to tie workstations at 106.

The sensor arrangement then detects at 108 that all processed articles have been returned to the conveyor. The conveyor is restarted at 110 in response to said information from the sensor arrangement indicating return of all processed articles to the conveyor and that all next articles to be processed have been removed from the conveyor. At the same time the articles removed from the conveyor to the workstations are processed. The processed articles are moved at 112 by the conveyor to the next zo respective workstations. The processed articles and new articles to be processed are moved ahead at en the production line until the conveyor is stopped again at 100 in response to information from the sensor arrangement that the articles have reached the next respective workstations. The cycle can then be repeated.

Figure 7 shows a manipulator apparatus for a workstation according to a further embodiment where a manipulator is used in at least one workstation to move articles from a conveyor to a workstation and/or to return processed articles to the conveyor. More particularly, Figure 7 example shows a robot 50 controlled by a control unit 51. An article of footwear 4 brought to the workstation 1 is attached by a gripping tool 54 to the robot. The robot 50 is arranged to move the article of footwear in three dimensional space relative to one or more tools 52. Tool(s) 52 can also be controlled by the control unit 51 so that they operate in synchrony with the robot 50.

In addition, the robot can be arranged to pick article 5 from the conveyor 12 and place the article back on the conveyor after having ended its work cycle. The work cycle can be started in response to a signal from sensor apparatus 14 that the next article 5 and the processed article are in predefined positions. The work cycle can be arranged to be started only after signals from all relevant workstations that this condition is satisfied in all of the relevant workstations.

to Figure 8 shows another example of a manipulator apparatus for a workstation. Articles can be removed from a conveyor to the workstation and/or returned to the conveyor by manipulator apparatus comprising a hydraulic or pneumatic mechanism arranged to push or drag the articles from and/or to the conveyor. More particularly. in the example a hydraulic or pneumatic cylinder 80 is provided for pushing an incoming batch of articles N+3 from a conveyor 12 to a work table 83 of a workstation 1, as denoted by the arrow next to the cylinder. The work table 83 ban be positioned relative to the conveyor 12 such that a carrier of the batch of articles can be smoothly pushed on the table. Appropriate guides may be provided, if necessary.

The cylinder can be operated in response to information from the sensor arrangement 14. For example, the controller 18 of Figures 2 -5 can control the push operation via the bus 16. The cylinder 80 can be retracted before a next batch N+4 of articles 6 arrives.

The apparatus can further comprise a second hydraulic or pneumatic cylinder 82 arranged to push a processed batch N+2 of articles back on the conveyor 12, as denoted by the arrow next to the cylinder 81. This cylinder can also be operated in response to information from the sensor arrangement 14. For example, the controller 18 of Figures 2 -5 can control operation of the cylinder 81 via the bus 16.

Figure 8 shows a stage when the batch N+3 of articles 4 has been pushed on the worktable 83 it can be processed by the operator. Figure 9 in turn shows a stage where the batch N+3 of articles is moved on the table 83 by a third pneumatic or hydraulic cylinder 82 to a position vvherefrom cylinder 81 can push the batch back on the conveyor 12. In this stage the conveyor 12 is running and the next batch N+4 of articles is about to arrive the workstation. The previous processed batch N+2 of articles has already left the workstation 1.

The arrival of the next batch can be detected by the sensor apparatus 14. The cycle can begin again after it has been detected that the processed batch N+3 is in a predefined position on the conveyor 12.

Instead of pushing the articles from and/or to the conveyor, the to apparatus may be arranged to drag or lift the articles from and/or to the conveyor. For example, an appropriate gripping element can be provided to grip on a basket or another carrier and drag o, to a desired posilon. Also it is possible to use e.g. looped belt or wheeled conveyor arrangements for moving the articles from and to the conveyor and within the workstation.

The batches of articles may be separated based on the type pf the articles. For example, articles of footwear may be separated into two typos of batches, depending wnether the articles of footwear are for the right foot or the left foot. The type of the batch can be indicated by a visual coding scheme, for example by colouring baskets or other carriers based on the type of the articles. The different types can be fed in a predetermined order on the conveyor. For example, the two types of batches of articles of footwear (left, right) can be fed alternately to the conveyor. The finished articles of footwear can be paired at the end of the production line by taking one item from two successive batches The operation of the conveyor, such as operation and movement of a belt conveyor relative to the workstations in response to signals from a sensor apparatus can be controlled by a controller apparatus. Figure 10 shows an example of control apparatus. The control apparatus 70 can be for example integrated with, coupled to and/or otherwise controlling a drive apparatus of sl the conveyor, For this purpose the control apparatus comprises at least one memory 71, at least one data processing unit 72, 73, and an input/output interface 74. Via the interface the control apparatus can be coupled to the 1 I sensor apparatus and devices it is indented to control and/or a communication system for communication with other data processing apparatus, for example a manufacturing, measurement data and/or stock management control system and so forth. The control apparatus can be configured to execute an appropriate software code to provide control functions required by the process described herein.

While certain aspects of the invention may be illustrated and described as block diagrams, flow charts, or using some other schematic pictorial representation, it is well understood that these blocks, apparatus, systems, techniques and control methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The foregoing description provides by way of exemplary and non-limiting examples a full and informative description of exemplary embodiments of the invention. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. All such and similar modifications of the teachings of this invention will still tall within the spirit and scope of this invention. l2

Claims

Claims 1. A method for controlling manufacture of articles in a system where articles are moved by a conveyor between workstations adapted for performing successive manufacturing stages. the articles are removed from the conveyor for processing at the workstations, and processed articles are returned to the conveyor for movement to the next workstation, the method comprising: a) halting the conveyor based on information from a sensor arrangement to configured to sense presence of articles relative to the workstations for enabling returning of processed articles from the workstations to the conveyor and removal of the next articles to be processed from the conveyor to the workstations, b) restarting the conveyor in response to information from the sensor is arrangement indicating that the processed articles have been returned to the conveyor and the next articles to be processed have been removed from the conveyor, c) moving the returned processed batches until the conveyor is slopped in response to information from the sensor arrangement that the returned 20 processed articles have reached the next workstations, and d) repeating steps a) to c).
2. A method according to claim 1, wherein the conveyor comprises a belt conveyor.
3. A method according to claim 1 or 2, wherein the conveyor is arranged to provide an endless loop.
4. A method according to any preceding claim, wherein the articles are arranged in batches of articles, and wherein each workstation is associated with at least one sensor for detecting presence of a next batch of articles to be processed and a returned batch of processed articles, the method comprising: stopping the conveyor based on information from each of said at least one sensor confirming presence of a next batch of articles to be processed by the respective workstation, and restarting the conveyor after receiving information from each of said at least one sensor confirming presence of a processed batch of articles returned from the respective workstation and removal of the next batch of articles from the conveyor.
5. A method according to any preceding claim, comprising moving the articles in carriers arranged for moving a batch of articles from the conveyor to the workstation and returning the processed batch of articles to the conveyor.
6. A method according to any of claims 1 to 5, comprising moving articles from the conveyor to the workstation and/or returning to the conveyor by a human operator of the workstation.
7. A method according to any of claims 1 to 5, comprising moving articles from the conveyor to the workstation and/or returning to the conveyor by a manipulator in response to information from the sensor arrangement.
8. A method according to claim 7, comprising moving the articles from and/or to the conveyor by a robot.
9. A method according lo claim 7, comprising moving the articles from and/or to the conveyor by an apparatus arrange to push, drag or lift the articles from and/or to the conveyor.
10. A method according to any preceding claim, comprising moving, in at least one of the workstations, the articles by a robot.
11. A method according to any preceding claim, wherein the articles comprise articles of footwear.
12. A method according to claim 11, comprising separating the articles of footwear into two types of batches depending whether the articles of footwear are for the right foot or the left foot, indicating the type of the batch by a visual coding and feeding the two types of batches alternately to the conveyor.
13. A manufacturing system for manufacture of articles, the system lo comprising: workstations adapted for perfonniftg successive manufacturing stages, a conveyor for conveying the articles between successive workstations such that the articles can be removed from the conveyor for processing at the respective workstations and processed articles can he returned to the conveyor for movement to the next workstation, a sensor arrangement associated with the workstations configured to sense presence of articles in predefined locations, and a control apparatus for controlling movement of the articles between r.2.c.i the workstations, the control apparatus being configured to a) halt the conveyor based on information from the sensor arrangement for enabling returning of processed articles from the workstations to the conveyor and removal of the next articles to be processed from the conveyor to the workstations, h) start the conveyor to move the returned processed articles to the next workstations in response to information from the sensor arrangement indicating that processed articles have been returned to the conveyor from the workstations and the next articles to be processed have been removed from the conveyor, c) stop the conveyor in response to information from the sensor arrangement that the returned processed articles have reached the next workstations, and d) repeat a) to c) during manufacture of the articles.
14. A manufacturing system according to claim 13, wherein the conveyor comprises a belt conveyor.
15. A manufacturing system according to claim 13 or 14, wherein the conveyor is arranged to provide an endless loop.
16. A manufacturing system according to any of claims 13 to 15, arranged JO to convey the articles in batches of articles, wherein each workstation is associated with at least one sensor for detecting presence of a next batch of articles to be processed and a returned batch of processed articles.
17. A manufacturing system according to claim 16, configured to move the batches of articles in one of a basket, a pallet, a fray, and a plate.
18. A manufacturing system according to any preceding claim, comprising a manipulator configured to move the articles from the conveyor to at least one workstation and/or return the articles to the conveyor.
19. A manufacturing system according to claim 18, wherein the manipulator is configured to operate in response to information from the sensor arrangement.
20. A manufacturing system according to claim 18 or 19, wherein the manipulator comprises a robot.
21. A manufacturing system according to claim 18 or 19, wherein the manipulator comprises a hydraulic or pneumatic mechanism arranged to push, drag, or lift the articles from and/or to the conveyor.
22. A manufacturing system according to any of preceding claims 13 to 21. configured for manufacture of articles of footwear.
23. A computer readable media comprising program code for causing an apparatus comprising a processor to perform a method according to any of claims 1 to 12.