A flexible material rolling machine

Abstract

A flexible material rolling machine comprises a driven first material storage spool or roller 105 and a supply of a flexible support layer 103 wound thereon during operation. An area of the flexible s

Description

Field The invention relates to a flexible material rolling machine. More particularly, but not exclusively, the invention relates to a flexible material rolling machine arranged to pick up, move / store and place a piece of flexible material. More particularly, but not exclusively the invention relates to a flexible material rolling machine arranged to pick up, move / store and place while protecting the piece of flexible material which term includes woven sheets and non-woven sheets of material. Background Within the aerospace industry, several new aircraft have entered production that use large-scale carbon fibre elements in their construction, especially in the wings. This allows for the use of much lighter wing structures while maintaining the strength needed for a commercial aircraft. To ensure the integrity of the components in the new generation of airliners, it is imperative that the carbon fibre material that makes up the wing is not subject to any activity that may compromise the structural integrity of the material by creasing, stretching, crushing, tearing, or otherwise permanently deforming the material. Large sheets of material are used to build each component, and handling these sheets of material can result in the aforementioned damage. Therefore, a process of rolling the material, including the raw material from the manufacturer, is used to transport it between assembly lines or even factories. The process of rolling is also fraught with difficulty and if not done so with the upmost care can result in substandard material whose integrity is compromised. Due to the high cost of the material, it is also important to limit waste, therefore the material is cut to exact dimensions prior to being assembled onto mould tools. When placed on tooling, extremely accurate placement is required to ensure full coverage of the component area in order to maintain high quality requirements and minimise waste. A further challenge is to meet the required number of components to satisfy a supply chain, and to achieve this, an improvement in manufacturing time is required. Therefore, a process that allows large areas of bulk flexible material to be deposited quickly, carefully, and accurately is required. One aim of the present invention is to provide a machine for picking up, moving / storing and placing sheets of flexible material which avoids material damage, reduces material waste and decreases manufacturing time. Prior Art An example of a flexible material rolling machine is disclosed in published international patent application number WO 2019 / 123209 (Loop Technology limited) which discloses a system for handling sheets of flexible material. The system comprises a first roller which has a plurality of first releasable connectors and a second roller which has a plurality of second releasable connectors. An array of third releasable connectors is displaceable between at least the first and second rollers. The first, second and third releasable connectors releasably attach to a sheet of flexible material in use. Although successful, the aforementioned flexible material rolling machine disclosed is rather complex with a high operating cost, is limited to handling relatively simple material shapes, only one piece of material at a time, with a limited process speed. Further objects of the invention are to provide a flexible material rolling machine which protects the material during a picking stage, a rolling stage, a placing stage, when rolled for long term storage, as well as improving placement accuracy and process speeds. The present invention arose to solve the aforementioned problems of, only a single piece of material can be moved / stored at one time, the complexity and operating cost of system, the relatively simple material shapes that can be processed and the slow process speeds associated with the aforementioned flexible material rolling machine. Summary of the Invention According to a first aspect of the invention there is provided a flexible material rolling machine comprising a drive means which is operative to drive a first material storage spool or roller and a supply of a flexible support layer which is wound onto the first material storage roller or spool when the drive means is operational; and an area of the flexible support layer receives and supports a sheet of flexible material to be rolled, whereby the sheet of flexible material is sandwiched between the flexible support layer, on which it is supported, and an underside of the flexible support layer that is already wound on the first material storage roller or spool. In some embodiments the first material storage roller or spool is cylindrical. However, the storage roller or spool may also be oval, or a closed shape bounded with straight sides in cross-section. In some embodiments, the first material storage roller or spool can be made up of a number of hollow drums, rollers or elements onto which the flexible material is wrapped or wound. Preferably the supply of the flexible support layer is provided by a second storage roller or spool. Ideally at least one drive means is provided for driving the second storage roller or spool. In some embodiments the drive means is performed by the first drive means. The material storage roller or spool may be removed from the machine to allow the flexible material to be transported either within a factory, from a preparation area to a final placement area, or from a manufacturer to a customer for example. Further embodiments may contain additional functionality such as a material control stage for controlling a physical characteristic of the flexible material as it is loaded / unloaded into the storage stage, including but not limited to tensioning, debulking, cutting, inspection, motion and positional control. An advantage of the invention is that it provides a system for picking, storing and accurate placement of a wide range of sizes of fabric with the option of material manipulation where appropriate. The fabric is sandwiched between the flexible support layer, around the effective roller circumference, between previously wound flexible support layer, and therefore the fabric is trapped to resist movement and protected from damaged during the winding process due to minimal and careful material interaction. The system also enables multiple sheets of material to be processed at one time. Another advantage is that implementation of backing support material backing support material significantly improves material support on the storage roller. Loose edges of fabric are prevented from flapping or being creased when rolled, rotation of the storage roller or spool which significantly reduces the opportunity for damage to the fabric. A further advantage of the backing support material backing support material is that it also limits slippage of the material during rolling of the material onto the storage roller. This advantage also applies to the unrolling of the material when it comes to be laid out in manufacturing (for example in a mould). Consequently, when the fabric comes to be laid down, the location of material features, such as the leading edge, is repeatable for the material placement process. It is also possible to store multiple pieces of material onto a single storage roller. Existing systems can only pick and store one piece of material regardless of size. Use of the backing support material backing support material allows a user to pick as many pieces as necessary. This has a further advantage that, when the fabric is unrolled, the multiple pieces of fabric are provided in a particular order, predetermined by the rolling process. Further advantages of the invention are described below. There is improved material leading edge handling / control and material placement accuracy using an intelligent pick / place stage. During placement, the pick / place stage utilises a plurality of releasable connectors to pick the material from a surface, which may be within the machine, and then accurately to place the material onto a final placement surface. The movement and activation of the plurality of releasable connectors on the pick / place stage can be individually controlled to manage complex material shapes and leading edges as well as to form final placement surface form to control material integrity and placement accuracy. There is a significantly lower compressed air requirement which is more efficient and reduces cost because the number of releasable connectors is reduced. In some embodiments electrically powered connectors may be used, such as motorised connectors, connectors powered by one or more fans and electrostatic devices. Material deposition rates are faster, more efficient, and reduce costs because the pick place process carried out has been simplified significantly. Multiple pieces of fabric can also be rolled up and moved / stored effectively in one process. The system weighs less and results in a reduced load capacity requirement for the deployment system, such as a robotic actuator and consequently less control devices are required. Another advantage is there is reduced system complexity and cost. According to another aspect of the invention there is provided a method of operating a flexible material rolling machine according to any preceding claim comprising the steps of: operating a drive means to drive a first storage spool or roller; operating a second storage spool or roller which has a flexible support layer wound thereon, unwinding the flexible support layer from the second storage spool or roller and winding the flexible layer onto the first storage spool or roller when the drive means is operational; deploying an area of the flexible support layer and supporting a sheet of flexible material to be rolled, on a support surface thereof and sandwiching the sheet of flexible material between an underside of the flexible support layer, that is already wound on the first storage spool or roller and the support surface of the flexible support layer. A further advantage is that with the addition of cutting elements, there is the capability of continuous material feed using bulk material. For large area requirements, a full roll of bulk / uncut material can be loaded onto the machine and accurately placed onto a surface. Brief Description of the Figures The present invention will now be described by way of example, with reference to the drawings, in which: Figure 1 shows a side elevation of a first embodiment of the present invention; Figure 2 is a perspective view of the first embodiment; Figure 3 shows the first embodiment of the present invention with the material handling stage in a retracted position; Figure 4 shows a side elevation of a second embodiment of the present invention with a recirculating material handling stage; Figure 5 shows a perspective view of the second embodiment; Figure 6 NOT SHOWN Figure 7 NOT SHOWN; Figure 8 NOT SHOWN; Figure 9 shows a fourth embodiment of the present invention; Figure 10 is a side view of the fourth embodiment; Figure 11A is a diagram showing the present invention prior to material being loaded; Figure 11B is a diagram showing the present invention with material loaded into a storage stage; Figure 12 is a diagram showing three stages of the present invention, a material handling stage, a material transfer stage and a material storage stage; and Figure 13 is a diagram of the present invention showing the process of the material handling stage picking the flexible material and transitioning over to the material transfer stage. Detailed Description of Embodiments of the Invention In overview, Figure 1 shows a side elevation of a system for handling varying sizes of flexible material, such as a fabric 1101. A flexible support layer 103 is wound off a backing support material storage roller 104 and reversed in direction at a slender roller 110 before the flexible support layer 103 is wound onto a storage roller 105. Between point 110 and the storage roller 105, the flexible support layer 103 presents a substantially flat surface 102, supported by a conveyor support system 111. Material handling stage 101 picks the flexible material 1101 from the surface and places it on top of the support layer 103. Rotation of the storage roller 105 and backing support material storage roller 104 commences and the support layer 103 and fabric 1101 are drawn onto the storage roller 105 together. The fabric 1101 is thus sandwiched between the portion of support layer 103 upon which it was placed and the roller 105 or a portion of the support layer 103 that was already wound on the storage roller. The system comprises a material handling stage 101, also known as a pick / place stage, a material transfer stage 1202 and a storage stage 1203. The material handling stage 101 (pick / place stage) comprises an array of releasable connectors 112 that make up discrete implements for supporting a piece of fabric to be rolled or placed onto a final placement surface. Material stabilisation units 109 are used to bond material layers together once placed onto the final placement surface, in order to stabilise / fix the position of the placed material. Figure 1 shows the material handling 101 stage in a first position in which a piece of fabric may be picked up, for example from a preparation surface 1302 or cutting table, ready for rolling. The releasable connectors may be, as shown here, suction cups that suck the fabric upwards. However, they may equally comprise vacuum connectors, needle connectors, cryogenic connectors, electromagnetic connectors or electrostatic connectors. The connectors are preferably independently controllable and independently positionable with respect one to another. Figure 13 shows an example of operation, where releasable connectors 112 are lowered by a raising / lowering mechanism 113 and are activated to attach to the piece of fabric to be rolled 1101 which is typically supported on a preparation surface 1302 such as a cutting table. The releasable connectors 112 are preferably arranged to be individually controllable so that only the appropriate connectors are activated for a particular piece of material. The raising / lowering mechanism 113 is then activated to raise the piece of fabric 1101 upwards A mechanism or robot 114 is then activated to move the entire material handling stage to a second position above the material support layer 103. Figure 3 shows the material handling stage 101 in this second position. The raising / lowering mechanism 113 is then activated to lower the piece of material 1101 onto the material support layer 102 and the releasable connectors are deactivated. The piece of material and the material support layer are then ready to be rolled. Means may be provided in the materials handling stage (also referred to as a pick / place stage) to vary at least one of the orientation and / or location of the releasable connectors whilst attached to a sheet of fabric material so as to deform the sheet to a new shape. This is generally done when the piece of material is removed from the storage roller as part of the place phase, rather than during the storage phase, unless the system is picking from a non-flat surface. Although a rectilinear array of connectors are shown, different arrangements of connectors may be utilised for different applications. While an array of releasable connectors that can be moved between a first and second position are shown, they may alternatively be provided in a continuous recirculating feed. A continuous feed mechanism (as shown in Figures 4 and 5) may consist of either a walk beam (not shown) type arrangement, whereby a stepped feed is implemented as either a ‘sequential movement and pause’ using one linear feed action, or as linked stepped linear feed sets, so that the motion is continuous due to one set of linear actuators advancing through the feed stoke, whilst the other feed set(s) move towards the start of a feed stoke type arrangement to provide continuous loading / unloading from planar to planar or double curvature formation. Alternatively, a recirculating track (Figures 4 and 5) or wheel provides continuous recirculation of forming splines and associated releasable connectors transitioning between being tangential to the storage load / in-load plane and tangential to the application surface. Optionally tacking or other such means of material (ply) stabilisation may be employed at the point of or shortly thereafter placement. The material transfer stage consists of a moving transfer bed which moves the combination of support layer and fabric towards the storage roller 105. The storage roller is driven by a motor such as a stepper or a servo motor. In an embodiment in which pieces of fabric are recovered from the storage roller, the support material storage roller is also driven by a motor. Control of the storage roller 105 and the support material storage roller 104 is carried out by controller 108. Whether the apparatus is being used to store or recover pieces of material, the flexible support layer effectively creates a conveyor belt (or similar) arranged between the rollers 104, 110 and 105 and supported by a conveyor support system, 111. Optionally a solid sheet may be deployed to support the material rather than relying on the two rollers. A solid sheet backing support may be used to improve backing support material (conveyor) stability and associated ply stability and positional accuracy. The solid sheet backing support may be a roller bed or sheet of rigid or semi-rigid backing material. However, if the span between rollers is small or flexible backing support material tension is high, or if there is an application specific benefit, then a solid sheet backing support structure may not be required. Pinch / grip rollers 107 are provided to control the progress of material onto the storage roller 105. In alternative embodiments the pinch / grip rollers may be material bulk control or debulking, material (ply) stabilisation at the point of or shortly thereafter placement onto the machine replaced or supplemented by a material support system to ensure that the fabric and the support layer do not suffer any relative movement before they are wound onto the storage roller. Such a material support system may comprise a mechanical arrangement, or a vacuum or pressurised air arrangement to maintain material positioning during transfer. Additional functionality can be employed, depending on the complexity of the desired process, such as material cutting, debulking, material manipulation and tacking. An optional cutting stage (such as that shown as area 107 in Figure 1, may be provided. As the fabric is rolled onto or off the machine, a cutting method, such as a roller knife or ultrasonic knife, can be used to cut the material into the desired final shape. Waste material can be collected by a hopper, such as the dynamic pick place stage and disposed of during the process. A viewing or vision stage 106 is provided to monitor movement of the fabric and detect details in the material such as edges or defects. The viewing or vision stage 106 can also be applied to material feature monitoring, such as monitoring of the leading edge of the fabric to increase pick / place accuracy. The vision stage 106 may also be utilised to monitor the backing support material and for maintenance. The vision stage is coupled to a controller 115 that will implement corrective action and / or sound an alarm if the fabric is determined to be misplaced or damaged. The third, storage, stage consists of the roller 105 to store the material in use. The roller or spool utilises a backing or support material to aid rolling, support, and storage of the material. The flexible support material or backing support material can be used as part of the transfer mechanism. The storage roller or spool can be detached from the system to enable longer term storage (that is anything longer than immediate reuse) options of the material in use. The storage system is designed to not limit the length of fabric to be stored although the maximum size of the storage roller does place an implicit limit. Once the leading edge of a fabric being loaded has been transferred onto the flexible backing support material then feed onto the storage roller or spool can begin and continue until to storage capacity limits of the storage roller are reached. The storage roller size can be designed to suit the length required using a common design architecture and following all of the same, previously discussed principles. Additional leading edges or other such features that may require transfer onto the stage loading surface may require pick and place, but this does not require continuously recirculating transfer connections unless the pitch between features presents a limit to transfer or speed and continuity of transfer requires multiple edges or other such features to be simultaneously handled. The three stages can be operated independently or combined depending on the complexity of the operation. It is envisaged to pick and place the flexible material 1101 in a form which reduces distortions and creases. For simple high radius curvatures, gravitation deposition has been found to be sufficient. However, lower radius curvature or features with complex curves or small radii of curvature tend to require greater control when depositing the material. In these cases, active formation of a deposited ply may be beneficial. The material handling stage 101 may be a rigid rectilinear construction, as shown in figure 4 and 5, or a conformal material handling stage 101, to control transfer between planar presentation from the material handling stage 1202 to a complex form such as double curvature to match the final placement surface. The Process As shown in Figure 13, the system moves above the leading edge of the flexible material in use 1101. A vision stage 106 can be used to monitor material location and integrity while it is positioned on the preparation surface 1302. The material handling stage 101 lifts the flexible material 1101, utilising the releasable connectors 112, away from the preparation surface such as a cutting table 1302. The flexible material 1101 is then positioned over the material transfer stage 1202 of the machine, the material handling stage 101 lowers and releases the flexible material onto the transfer stage 1202. The flexible material 1101 is then supported by the material transfer stage 1202 and its associated mechanisms, as it moves towards an interaction point with the first material storage roller or spool 105 in the material support and storage stage 1203. The flexible material 1101, now supported by the flexible support material 103, is then rolled around the first material storage roller or spool 105. This process is carried out in reverse to place accurately the material onto the final placement surface, such as a mould. Depending on the process requirements further stages can be used. For example, a vision stage 106 and material control stage 107 can be used to track and control material features to improve pick / place accuracy, material cutting and waste collection, and material debulking. Equally, stages can be removed, such as the material handling stage 101, as the process dictates. In this instance the flexible material will be loaded onto the material transfer stage 1202 by an external system, and then simply dropped onto the final placement surface. The material handling stage storage roller or spool 101 can also be operated separately to the main machine to load / unload flexible material onto this machine or in another process depending on the application. Figures 9 and 10 shows the system with the material handling stage 101 removed. Where the flexible material 1101 is to be stored for a prolonged periods, it is loaded into the material support and storage stage or spool 1203 as previously described. Once loaded, the support and storage stage or spool 1203 is detached from the machine and removed for storage or transport. The machine can then be loaded with either an empty material support and storage stage 1203, or one that has previously been loaded with a flexible material 110 and continue to be used in the manufacturing process. As there is reduced interaction with the material during the pick / store / place process, this significantly reduces the potential for material damage. The invention has been described by way of example only and it will be appreciated that variation may be made to the aforementioned embodiment without departing from the scope of protection as defined by the claims. For example, although reference has been made to carbon fibre, it is appreciated that the flexible material rolling machine may be used to roll other flexible or woven material including, glass fibre, Kevlar (RTM) and other technical textiles. Parts List Material handling stage Material conveyor Flexible support layer Second material storage roller or spool First material storage roller or spool Vision stage Material control stage Roller control stage Material stabilisation units Conveyor leading edge Conveyor support system Releasable connectors Releasable connector control mechanism Material handling stage transfer and control mechanism Pick and place continuous recirculating feed. Flexible material, technical textile, or fabric. Material handling / pick and place stage Material transfer stage Material support and storage stage or spool Machine control stage Flexible material rolling machine. Preparation surface

Claims

1. A flexible material rolling machine comprises a drive means which is operative to drive a first material storage spool or roller and a supply of a flexible support layer which is wound onto the first material storage roller or spool when the drive means is operational; and an area of the flexible support layer receives and supports a sheet of flexible material to be rolled, whereby the sheet of flexible material is sandwiched between the flexible support layer, on which it is supported, and an underside of the flexible support layer that is already wound on the first material storage roller or spool.

2. A flexible material rolling machine according to claim 1 wherein the first storage spool or roller is cylindrical.

3. A flexible material rolling machine according to claim 1 or 2 wherein the supply of the flexible support layer is stored on a second roller.

4. A flexible material rolling machine according to claim 3 wherein at least one drive means is provided for driving the second roller.

5. A flexible material rolling machine according to any preceding claim wherein at least one tensioner is provided for varying tension imparted to the flexible support layer.

6. A flexible material rolling machine according to claim 5 wherein the at least one tensioner is a guide around which the flexible support layer is folded.

7. A flexible material rolling machine according to any preceding claim includes pinch rollers for controlling tension or position of the flexible material during loading and unloading.

8. A flexible material rolling machine according to any preceding claim includes a grip roller which is operative to maintain a consistent tension across a width of the flexible material during loading and unloading.

9. A flexible material rolling machine according to any preceding claim wherein an air entrainment means is used to displace the flexible material.

10. A flexible material rolling machine according to any preceding claim wherein one or more debulking rollers are deployed during loading and unloading of the flexible material in order to remove air and reduce occupied volume of the material.

11. A flexible material rolling machine according to any preceding claim wherein an imaging system is used for monitoring a characteristic of the flexible material.

12. A flexible material rolling machine according to claim 11 wherein the imaging system is used for material position monitoring.

13. A flexible material rolling machine according to any preceding claim wherein a controller is operative to control pick / place elements.

14. A flexible material rolling machine according to any preceding claim wherein the, or each, the storage spool or roller, on which wound material is stored, is removable to enable remote storage of the flexible material.

15. A flexible material rolling machine according to any preceding claim wherein the flexible material includes carbon fibre.

16. A flexible material rolling machine according to any preceding claim includes at least one passive leading-edge or active leading-edge stage sensor which provides feedback signals for controlling at least the speed of the drive means during a pick / place step.

17. A flexible material rolling machine according to any of claims 5 to 16 wherein the at least one tensioner grips an edge of the material.

18. A flexible material rolling machine according to any preceding claim wherein the flexible support layer comprises a chain of small rigid sections of material.

19. A flexible material rolling machine according to any preceding claim wherein a grip roller or edge gripping mechanism is operative to maintain tension within the flexible material during loading and unloading.

20. A flexible material rolling machine according to any preceding claim wherein a vacuum system is used to control the flexible material during loading and unloading.

21. A flexible material rolling machine according to any preceding claim wherein an imaging system is used for path correction.

22. A flexible material rolling machine according to any preceding claim includes a means for cutting the flexible material.

23. A method of operating a flexible material rolling machine according to any preceding claim comprising the steps of: operating a drive means to drive a first storage spool or roller; operating a second storage spool or roller which has a flexible support layer wound thereon, unwinding the flexible support layer from the second storage spool or roller and winding the flexible layer onto the first storage spool or roller when the drive means is operational; deploying an area of the flexible support layer and supporting a sheet of flexible material to be rolled, on a support surface thereof and sandwiching the sheet of flexible material between an underside of the flexible support layer, that is already wound on the first storage spool or roller and the support surface of the flexible support layer.

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