Modular material storage

Abstract

A modular storage system for temporary storage of surface mount technology (SMT) material, comprises a fully modular system, enabling extension in both horizontal and vertical directions. Each module

Description

This invention relates to a storage system for temporary storage of SMT material and a transport system fortransporting a load carrier. Background and Prior Art In various industries, for example the semiconductor industry and in particular those using surface-mount technology (SMT), it is necessary to effectively handle tape reels. For example, in SMT it is standard to store electrical and electronics components in discrete pockets provided in plastics tapes, which tapes are stored on respective reels. Since an SMT process may involve many different components, it follows in consequence that many tapes, and hence reels, must be accessibly stored. With the prevailing trend being towards fully-automated factories, such reel storage must be not only space-efficient, but also permit automatic loading of reels to the storage and retrieval of reels from that storage. This loading and retrieval should also be fast, to ensure uninterrupted processing. In the SMT field, such storage may be known as a "material tower", and an example of this is the Material Tower produced by ASMPT, which is schematically shown in FIG. 1. This Material Tower 1 can receive and dispense both individual reel cassettes (via a cassette opening 2) and cassette magazines (via a magazine portal 3), and has automatic location and retrieval systems within the tower. In particular, each Tower is provided with a movable gantry which can move SMT material within the tower. Individual reel cassettes can be transferred to and from storage slots using a transport system such as that described in CN112124876B. It is clearly preferable for material towers to be able to store as much material as possible in as compact a space as possible, and ideally to use the available space (for example within a production area of an SMT factory) in an efficient manner. Furthermore, there are advantages to linking different material towers, so that SMT material may be transferred between them as required. ASMPT's Material Tower 1 achieves such transfer by providing an integrated, retractable transfer arm 4 within each tower, which can pick up an individual reel cassette and transfer it to an adjacent Material Tower via dedicated 'windows' 5 in an upper part of the Tower. This system is known as 'daisychaining'. However, such a daisychaining solution is relatively slow, since it involves taking a reel cassette from the internal transport system of one Tower, transferring it with the transfer arm, then giving it to the transport system of an adjacent Tower. In addition, the transfer arm is only capable of transferring a single reel cassette at a time, i.e. it is unable to transfer a cassette magazine. It is an aim of the present invention to provide a reliable, fast and space-efficient means to store items such as reels, and permit fully automatic loading and unloading of these items. It is an additional aim to provide a more efficient mechanism for transferring SMT material between storage units. However, it is recognised that many of the approaches of the present invention are also applicable to storage and item transfer in other industries. In accordance with the present invention this aim is achieved by providing a fully modular system, in which storage modules may be connected both horizontally and vertically, and in which a single gantry may travel freely between horizontally-arranged modules. It is a further aim to provide an improved transport system for a material tower, which permits loading / unloading of material such as component reels to / from storage slots in a robust and reliable manner. Summary of the Invention In accordance with a first aspect of the present invention there is provided a storage system for temporary storage of SMT material, comprising: a first module and a second module, the first module and the second module being configured for releasable and repeatable engagement, a gantry for supporting an engagement tool, and a drive means for moving the gantry, the first module comprising: a first rail configured to guide the gantry during movement thereof, and the second module comprising: a second rail configured to guide said the gantry during movement thereof, wherein, when the first module and the second module are engaged, the first rail and second rail align, so that the gantry may be moved between the first module and the second module. In accordance with a second aspect of the present invention there is provided a transport system fortransporting a load carrier, the transport system comprising: a track delimited at each end thereof by first and second rotatable axles, the first axle being rotatably drivable about its axis, a shuttle movable along the track between the first and second ends, a carriage movable along the track, an engagement tool having an engagement section for engaging with a load carrier in use, an arm with first, second and third engagement points sequentially arranged spaced along its length, the arm engaging with the shuttle at the first engagement point, engaging with the carriage at the second engagement point, and engaging with the engagement tool at the third engagement point, a shuttle belt mounted to the first axle at a shuttle driving wheel, such that rotation of the first axle drives the shuttle belt, the shuttle belt driving the shuttle along the track, and a carriage belt mounted to the first axle at a carriage driving wheel, such that rotation of the first axle drives the carriage belt, the carriage belt driving the carriage along the track, wherein the shuttle driving wheel and the carriage driving wheel have different radii, such that rotation of the first axle causes the carriage and the shuttle to move along the track at different speeds, and thereby rotate the arm, the arrangement being such that, when the shuttle is located proximate the first end of the track, the arm is in a first rotational position in which the engagement tool projects outwardly beyond the first end of the track, and when the shuttle is located proximate the second end of the track, the engagement tool projects outwardly beyond the second end of the track. Other specific aspects and features of the present invention are set out in the accompanying claims. Brief Description of the Drawings The invention will now be described with reference to the accompanying drawings (not to scale), in which: FIG. 1 schematically shows, in oblique view, a known material tower; FIG. 2 schematically shows, in oblique view, two storage modules of a storage system in accordance with the present invention; FIG. 3 schematically shows, in oblique view, a storage system in accordance with the present invention comprising the modules of FIG. 2; FIG. 4 schematically shows, in oblique view, a storage system in accordance with the present invention comprising four storage modules; FIGs. 5 to 8 schematically show, from above, a transport system for transporting a load carrier, in accordance with the present invention; and FIGs. 9 and 10 schematically, from above, show a second embodiment of a transport system in accordance with the present invention. Detailed Description of the Preferred Embodiments of the Invention FIG. 2 schematically shows, in oblique view, two storage modules of a storage system 20 in accordance with the present invention, which are shown transparently so that internal features are visible. A first module 10 and a second module 11 are shown, in an unengaged configuration. As shown, the first and second modules are substantially cuboid, and of identical height, width and depth. Although not clear from FIG. 2, the lateral sides of each of the first and second modules 10, 11 is at least partially open. Each of the first second modules 10, 11 is configured to temporarily store SMT material, such as component reels in cassettes (not shown). Optionally, a plurality of cassettes may be located within a magazine (not shown), and such a magazine may also be temporarily stored within either of the first and second modules 10, 11. Although not shown in FIG. 2, a cassette opening and / or magazine portal, similar to those shown in FIG. 1, may for example be provided for this purpose. Also not shown are engaging mechanisms which help to releasably lock the first and second modules 10,11 together in an engaged configuration (see FIG. 3). The first module 10 is shown as including a movable gantry 18 within it (again shown transparently), with this gantry 18 being operable to transfer cassettes and / or magazines to storage locations (not shown for clarity) within the first module 10. The first module 10 comprises a first rail 12A extending laterally across the bottom floor of the first module 10, which first rail 12A provides guidance for the gantry 18 and allows it to move laterally within the first module 10. The gantry 18 is moved by drive means, which may for example comprise a rotary actuator (not shown) located on the gantry 18 arranged to drive a pinion (not shown) arranged for meshing engagement with a first rack 14A mounted on a rear wall of the first module 10. The gantry 18 and its drive means draws electrical power and communications from a first conductive track 16A mounted at a ceiling of the first module 10, which receives power from a first module power unit (not shown) and transfers communications signals with a first module control unit (not shown). Both the first conductive track 16A and the first rack 14A extend laterally across the interior of the first module 10, but, in this embodiment, do not extend to the very edge of the first module 10. In contrast, the first rail 12A does extend across the entire width of the first module 10. As noted above, the lateral sides of each of the first and second modules 10,11 is at least partially open, and the opening is sufficiently large to receive the gantry 18 and allow it to pass through, as will be described in more detail below. However, with the first module 10 unengaged from the second module 11 as shown, the first module 10 is provided with end modules 19, 19', attached via the engagement mechanisms, which respectively block the openings in the lateral sides of the first module 10. The end modules 19, 19' are configured for releasable and repeatable engagement with the first module 10 via the engagement mechanisms, and serve to close off the interior of the first module 10, so that it may function as a self-contained storage, resistant to the ingress of dust and other contaminants. The second module 11 is similar to the first module 10, having a similarly configured second rail 12B, second rack 14B and second conductive track 16B, although this latter is optional. In particular, if the second module 11 is not desired to operate as a self-contained storage (i.e. while disengaged to any other module), then the second conductive track 16B may be omitted. In such a case, it is also unnecessary to provide an associated gantry or a cassette opening and / or magazine portal, and in addition it may not be necessary to provide a power unit, assuming that the power unit of the first module 10 is sufficient to provide operating power to both the first and second modules 10,11 when engaged. FIG. 3 schematically shows, in oblique view, the storage system 20 comprising the modules of FIG. 2 in an engaged configuration. The end module 19' has been removed from the rightmost lateral side of the first module 10, and attached to the rightmost end of the second module 11 via its engagement mechanisms. The second module 11 and first module 10 are connected together directly via the engagement mechanisms. When thus engaged, the first rail 12A is aligned with the second rail 12B, and may directly engage with it. For example, the rightmost end of the first rail 12A may comprise a male conical projection (not shown), while the leftmost end of the second rail 12B may comprise a female conical recess (not shown) sized to accommodate the conical projection. In the storage system 20 shown, the first rack 14A and second rack 14B align and are caused to engage using an alternative technique since they do not extend the entire width of their respective modules. A rack bridging section 14Z is connected between the proximal ends of the first rack 14A and the second rack 14B which aligns with both, configured such that the first rack 14A, rack bridging section 14Z and second rack 14B together comprise a continuous rack with regularly spaced teeth provided therealong. The first conductive track 16A and, if provided, the second conductive track 16B are removed, and replaced by a single replacement conductive track 16Z which is over double the length of the first conductive track 16A, such that it spans both the first and second modules 10, 11. Communications signals to or from each of the first and second modules 10, 11 are transferred from or to the replacement conductive track 16Z, for example by multiplexing, while power may be received either from the power unit of the first module 10 alone, or from the power unit of each of the first and second modules, for example by multiplexing. When the modules 10,11,19,19' are engaged in this way, the gantry 18 is able to travel freely between the first and second modules 10,11, guided by the rails 12A, 12B and driven along the composite rack 14A, 14Z, 14B, while receiving power and communications from the replacement conductive track 16Z. With such an arrangement, SMT material may be delivered to orfrom any part of the storage system 20, without requiring a transfer arm as with the material tower shown in FIG. 1. Naturally, the storage system 20 may be extended as required in the horizontal direction by adding more modules, with the only restraint being that correspondingly longer replacement conductive tracks 16Z may be required. In alternative embodiments, the conductive tracks may also be formed in a modular way to avoid the need for a replacement conductive track 16Z, as long a power and communications signals can be effectively transmitted along the track. For relatively short storage systems, it is considered that supplying a replacement conductive track 16Z may be a more cost-effective and reliable solution. Similarly, the racks 14A, 14B could be made to extend the entire width of a module, so that it is not necessary to use a bridging section during engagement. Conversely, it is possible that the rails 12A, 12B need not extend for the entire width, and instead a rail bridging section may be used. Furthermore, alternative or additional guidance / drive means, such as an additional rail proximate the top of each of the respective modules and an additional rack proximate the base of each of the respective modules, may be provided which are similarly modular. Such additional guidance / drive means may improve the stability of the gantry 18. FIG. 4 schematically shows, in oblique view, a storage system 21 in accordance with an embodiment of the present invention comprising four storage modules 10, 11, 22 and 24, which demonstrates how the system may be extended vertically. A first module 10 and an adjacent second module 11 are as previously described, and in an engaged configuration, such that a gantry 18 may freely move therebetween in association with a rail 12, rack 14 and replacement conductive track 16Z. A third storage module 24, which may be substantially identical to either of the first or second modules 10, 12, is mounted on top of the second module 11. This is provided with an additional gantry 30, movable laterally in association with a rail 12, rack 14 and conductive track 16. End modules 19,19” are provided at the leftmost ends of the first and third modules 10, 24. In addition, a fourth storage module in the form of a vertical transfer module 22 is located adjacent the second and third modules 12, 24 and in engagement therewith via respective engagement mechanisms. The vertical transfer module is substantially double the height of the first, second and third modules 10,11, 24, and comprises a lifting means in the form of a rising magazine 28 which is drivable along a vertical rack 26. For clarity, associated guide rails and power / communications supply means for the rising magazine 28 are not shown, however these may be of similar form to those for the gantries 18 for example. At its lowest position, the rising magazine 28 is configured to transfer SMT material with the gantry 18 when it is located in the second module 11, while at its highest position, the rising magazine 28 is configured to transfer SMT material with the gantry 30 of the third module 24. It can be seen therefore that SMT material input to the first module 10 can readily be transferred to any other module. If it is desired to add additional storage, a further module may be placed on top of the first module 10. This could be a storage module similar to the second or third modules, or even an additional vertical transfer module similar to vertical transfer module 22, which would allow the storage system to be stacked even higher. In alternative embodiments, the gantries 18, 30 could be configured to at least partially enter the vertical transfer module 22, to aid transfer of SMT material between those gantries and the rising magazine 28. To effect this, the vertical transfer module 22 may be provided with rails, racks and, optionally, a conductive track which all align with those of the adjacent modules. FIGs. 5 to 8 schematically show, from above, a transport system 30 for transporting a load carrier, in accordance with the present invention. Such a transport system 30 may for example be carried by a gantry 18 of the storage system previously described, and used to transfer reel cassettes between storage slots in a storage module. In these Figures, the transport system 30 is arranged to transfer a load carrier between storage locations (not shown) located to the left and to the right of the transport system 30. The transport system 30 comprises a frame 32, which supports the rest of the assembly. Preferably, the frame 32 is supported by a gantry (not shown) so as to be movable in the vertical direction. The frame 32 supports first and second rotatable axles 34, 36, rotatable about parallel axes, with the first axle 34 at least being drivable about its axis by a motor 38. The first and second axles 34, 36 delimit, at each end thereof, a track running between the left and right sides of the transport system 30 as shown. Mounted to the first axle are a first shuttle driving wheel 40 and a second shuttle driving wheel 44, near respective ends of the first axle 34, as well as a carriage driving wheel 48 mounted between the first and second shuttle driving wheels 40,44. The second axle 36 has corresponding first and second shuttle driving wheels 40', 44' and carriage driving wheel 48'. A first shuttle belt 42 is carried by the first shuttle driving wheels 40, 40', a second shuttle belt 46 is carried by the second shuttle driving wheels 44, 44', and a carriage belt 50 is carried by the carriage driving wheels 48, 48', so that all of these belts 42, 46, 50 are reversibly drivable parallel to the track. A shuttle 52 is carried by the first and second shuttle belts 42, 46 so as to be drivable along the track between the first and second ends. A carriage 54 is carried by the carriage belt 50 so as to be drivable along the track. Two arms 56, 56' are provided which each engage with the carriage 54, shuttle 52 and a boom or engagement tool 58 at respective first, second and third engagement points 60, 62, 64 sequentially arranged spaced along their lengths. In the embodiment shown, the first engagement point 60 is a pivot which is pivotably connected to the carriage 54. The second and third engagement points 62, 64 are pins which are constrained to travel within respective races 66, 68 of the shuttle 52 and engagement tool 58, which races 66, 68 comprise elongate slots extending parallel to the first and second axles 34, 36. The shuttle driving wheels 40, 40', 44, 44' all have the same radius, while the carriage driving wheels 48, 48' have a radius different to that of the shuttle driving wheels 40, 40', 44, 44', in this example a smaller radius. With this configuration, rotation of the first axle 34 causes the carriage 54 and the shuttle 52 to move along the track at different speeds. This differential movement in turn causes arms 56, 56' to rotate about the first engagement points 60, which rotation in turn causes the engagement tool 58 to move parallel to the track with a sinusoidal speed profile along its range of travel. The engagement tool 58 thereby moves relative to both the carriage 54 and the shuttle 52. For example, if the shuttle driving wheels 40,40' are provided with 24 teeth, while the carriage driving wheels 48, 48' are provided with 18 teeth, then the carriage 54 will only move 75% of the distance of the shuttle 52 over the same time. FIGs. 5 to 8 show the relative positions of the carriage 54, shuttle 52 and engagement tool 58 for various displacements of these components along the track. FIG. 6 shows the shuttle 52 at its maximum extent of travel to the right, i.e. proximate a first end of the track, and it can be seen that in this configuration the arms 56, 56' are in first rotational positions in which the engagement tool 58 projects outwardly beyond the first end of the track. Importantly, the arms 56, 56' do not reach a fully parallel configuration, to prevent stalling in this position. FIG. 7 shows the carriage 54, shuttle 52 and engagement tool 58 in the middle of their ranges of travel. FIG. 8 shows the shuttle 52 at its maximum extent of travel to the left, i.e. proximate a second end of the track, and it can be seen that in this configuration the arms 56, 56' are in second rotational positions in which the engagement tool 58 projects outwardly beyond the second end of the track. FIG. 5 shows an intermediate position. It can be seen that in the positions shown in FIGs. 5 and 7, the engagement tool 58 does not project beyond the end of the track or frame 32, and therefore the frame 32 can be moved vertically without risk of collision with load carriers stored in adjacent storage slots. When the frame 32 is moved to the desired height, the engagement tool 58 can be moved to an extended position as shown in FIG. 6 or 8, in which it can 'reach over' and engage with a load carrier, via an engagement section (not shown) provided on the engagement tool 58. The engagement tool 58 can then be retracted, pulling the load carrier with it, back within the footprint of the frame. performed as required. the desired storage slot. Vertical movement of the frame 32 and load carrier may then be The engagement tool 58 may then pull / push the load carrier into The symmetrical nature of the first and second shuttle belts 42, 46, and first and second arms 56, 56' ensures reliable operation without deviating from the left right direction shown. Those skilled in the art will recognise that, since the first and second arms 56, 56' are caused to rotate through differential driving between the carriage 54 and the shuttle 52, the first and second arms 56, 56' need to engage with both the carriage 54 and the shuttle 52, however to permit their rotation the arms 56, 56' can only be mounted to one of these at a fixed location. In the embodiment described above, this fixed location is the first engagement point 60 which is pivotably connected to the carriage 54. The second engagement point 62 therefore cannot be fixed, and instead engages with the shuttle 52 via a race 66. However, in alternative embodiments it is equally possible to reverse this configuration. Such an embodiment is schematically shown in FIGs. 9 and 10, which illustrate such a transport system 70 in configurations corresponding to those of the transport system 30 shown in FIGs. 5 and 6. For consistency, similar items retain the reference numerals used in those Figures. As shown, the arms 56, 56' are pivotably connected to the shuttle 52 at the second engagement point 62, while the first engagement point 60 engages with the carriage 54 via a race 72. In this type of embodiment, the arms 56, 56' might not rotate to the near parallel position shown in FIGs. 6 and 8, but would remain more angled at their most extreme positions. Otherwise, the functioning of the transport system 70 remains identical to that of transport system 30. The above-described embodiments are exemplary only, and other possibilities and alternatives within the scope of the invention will be apparent to those skilled in the art. Reference numerals used: 1 - Material tower 2 - Cassette opening 3 - Magazine portal 4 - Transfer arm 5 - Window 10 - First module 11 - Second module 12-Rails 12A - First rail 12B - Second rail 14 - Racks 14A - First rack 14B - Second rack 14Z - Rack bridging section 16A - First conductive track 16B - Second conductive track 16Z - Replacement conductive track 18, 30 - Gantries 19,19', 19” - End modules 20, 21 - Storage system 22 - Vertical transfer module 24 - Third module 26 - Vertical rack 28 - Rising magazine 30, 70 - Transport system 32 - Frame 34 - First axle 36 - Second axle 38 - Motor 40, 40' - First shuttle driving wheels 42 - First shuttle belt 44, 44' - Second shuttle driving wheels 46 - Second shuttle belt 48, 48' - Carriage driving wheels 50 - Carriage belt 52 - Shuttle 54 - Carriage 56, 56' - Arms 58 - Engagement tool 60, 62, 64 - Engagement points 66, 68, 72 - Races

Claims

1. A storage system for temporary storage of SMT material, comprising:a first module and a second module, the first module and the second module being configured for releasable and repeatable engagement,a gantry for supporting an engagement tool, anda drive means for moving the gantry,the first module comprising:a first rail configured to guide the gantry during movement thereof, andthe second module comprising:a second rail configured to guide said the gantry during movement thereof, wherein, when the first module and the second module are engaged, the first rail and second rail align, so that the gantry may be moved between the first module and the second module.

2. The storage system of claim 1, wherein, when the first module and the secondmodule are engaged, the first rail and the second rail are directly engaged.

3. The storage system of claim 1, comprising a rail bridging section which directlyengages with the first rail and the second rail when the first module and the second module are engaged.

4. The storage system of any preceding claim, wherein the first module comprisesa first rack for driving engagement with the gantry and the second module comprises a second rack for driving engagement with the gantry, and wherein, when the first module and the second module are engaged, the first rack and the second rack align, so that the gantry may be driven between the first module and the second module.

5. The storage system of any preceding claim, which, when the first and secondmodules are engaged, comprises a conductive track which spans the first and second modules for supplying electrical power to the gantry.

6. The storage system of any preceding claim, comprising an end moduleconfigured for releasable and repeatable engagement with each of the first and second modules.

7. The storage system of any preceding claim, comprising at least one additionalmodule configured for releasable and repeatable engagement with the first module, the second module, or the first and second module.

8. The storage system of any preceding claim, wherein the first module has a firstheight and the second module comprises a vertical transfer module, the vertical transfer module comprising lifting means for moving SMT material within the vertical transfer module to a height greater than the first height.

9. The storage system of claim 8, comprising a third module which is arrangedvertically above the first module, and wherein the vertical transfer module is configured to transfer SMT material to the third module.

10. The storage system of any of claims 1 to 9, wherein the first module comprises an input / output port for receiving or dispensing SMT material, the first module comprising first and second conveyors configured so that SMT material is transferrable to the input / output port via either of the first and second conveyors.

11. A transport system for transporting a load carrier, the transport system comprising:a track delimited at each end thereof by first and second rotatable axles, the first axle being rotatably drivable about its axis,a shuttle guided by the track and movable along the track between the first and second ends,a carriage guided by the track and movable along the track,an engagement tool having an engagement section for engaging with a load carrier in use,an arm with first, second and third engagement points sequentially arrangedspaced along its length, the arm engaging with the shuttle at the first engagement point, engaging with the carriage at the second engagement point, and engaging with the engagement tool at the third engagement point,a shuttle belt mounted to the first axle at a shuttle driving wheel, such that rotation of the first axle drives the shuttle belt, the shuttle belt driving the shuttle along the track, anda carriage belt mounted to the first axle at a carriage driving wheel, such that rotation of the first axle drives the carriage belt, the carriage belt driving the carriage along the track,wherein the shuttle driving wheel and the carriage driving wheel have different radii, such that rotation of the first axle causes the carriage and the shuttle to move along the track at different speeds, and thereby rotate the arm,the arrangement being such that, when the shuttle is located proximate the first end of the track, the arm is in a first rotational position in which the engagement tool projects outwardly beyond the first end of the track, and when the shuttle is located proximate the second end of the track, the engagement tool projects outwardly beyond the second end of the track.

12. The transport system of claim 11, comprising an additional shuttle belt mounted to the first axle at a second shuttle driving wheel, such that rotation of the first axle drives the shuttle belt, the shuttle belt driving the shuttle along the track, wherein the carriage belt is arranged to lie between the shuttle belt and the additional shuttle belt.

13. The transport system of either of claims 11 and 12, comprising an additional arm engaging with the shuttle, the carriage and the engagement tool.

14. The storage system of any of claims 1 to 10, comprising the transport system of any of claims 11 to 13.s