A pallet handling system and a method for handling pallets
Patent Information
- Application Number
- ES2022169033T
- Authority / Receiving Office
- ES · ES
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2022-04-20
- Publication Date
- 2026-09-15
- Estimated Expiration
- 2042-04-20
Smart Images
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Abstract
Description
A pallet handling system and a method for handling pallets Background of the invention The invention relates to a pallet rack comprising support means for supporting a pallet and an automated guided vehicle comprising a pallet lifting device. The invention also relates to a method for handling pallets using a pallet rack and an automated guided vehicle comprising a pallet lifting device. Description of the related technique Automated guided vehicles (AGVs) are increasingly used in industry, warehouses, and other settings to automate the handling of goods and products. An AGV is a portable, self-propelled robot that follows long lines or wires marked on the floor and / or uses radio waves, vision cameras, magnets, lasers, or similar technologies for navigation. AGVs with autonomous route replanning capabilities are also called autonomous mobile robots (AMRs). In other words, European patent application EP 3 656702 A1 discloses an AGV with a lifting device on its upper surface that allows the AGV to pick up and place EUR pallets (also known as Euro pallets or EPAL pallets [800 x 1200 mm]) on a pallet rack by lifting the pallets from the underside of the upper pallet deck boards (i.e., between the three parallel stringers supporting the pallet on the floor) and placing them on the pallet rack so that the lower deck boards of the two outer stringers are supported by parallel supports on the pallet rack. However, this pallet handling system has its limitations. First, it is difficult to use this system to handle both EUR pallets and the more common US pallet type.The most common type of US pallet measures 1016 x 1219 mm (40 x 48 inches), and the three bottom deck boards span 1016 mm. This means that if the US pallet is lifted by the bottom of the top deck boards between the bottom deck boards, the pallet measures 1219 mm across the direction of travel. This is undesirable due to space requirements and the risk of the pallet, including its load, tipping when moving around corners. Furthermore, to allow pallets to be lifted directly from the AGV by a forklift or similar equipment, the vertical travel of the lifting device must be relatively long to provide sufficient clearance. Developing a lifting device that is both compact and has sufficient travel and lifting capacity is expensive and complex. Therefore, an object of the invention is to disclose a pallet handling system and method that mitigate the aforementioned problems. Document JP2010211583A describes a system according to the preamble of claim 1 and a method according to the preamble of claim 10. The invention The invention discloses a pallet handling system comprising a pallet rack with three support means that are parallel in a longitudinal direction, wherein each of the three support means comprises one or more upper support surfaces substantially at the same horizontal level. The three support means are connected to one or more support structures arranged to suspend the three support means above ground level, wherein the three support means comprise first support means, second support means, and third support means, the second support means being arranged between the first and third support means.The second support means are formed as a lever having a second support connection end that is connected to at least one of the one or more support structures and a second free support end, and wherein the second support means have a width between 140 and 5 mm and, preferably, between 120 and 20 mm.The pallet handling system also includes an automated guided vehicle comprising a pallet lifting device having at least two upper lifting surfaces, wherein the at least two upper lifting surfaces are separated by a gap along a middle portion of the pallet lifting device, such that a first upper lifting surface of the at least two upper lifting surfaces fits between the first support means and the second support means, and such that a second upper lifting surface of the at least two upper lifting surfaces fits between the second support means and the third support means, and wherein the gap is arranged to accommodate the second support means.The pallet handling system is characterized in that the first support means and the third support means comprise one or more widthwise notches on the facing sides, and wherein the at least two upper lifting surfaces comprise one or more widthwise protrusions extending into the one or more widthwise notches. Forming the first and third support elements with notches along the inner side faces, corresponding to protrusions on the outer side faces of at least the two upper lifting surfaces, is advantageous because it allows the EUR pallet, in particular, to be supported more across the width of the outer stringers, both on the pallet rack and when being lifted by the pallet lifting equipment. This reduces the risk of local deformation or damage to the pallet, especially when the pallet is heavily loaded, and the pallet is supported closer to the periphery on the pallet lifting device, thus reducing the risk of the pallet tipping off the AGV during transport. Equipping pallet racking with three support elements is advantageous because it ensures that EUR pallets are supported by the racking in a way that provides better stability. The weight of the pallet, including the load on it, is supported along the two outer stringers by the first and third support elements, and along the middle stringer between them by the second support element. Furthermore, the middle stringer of a EUR pallet is typically approximately 145 mm wide. By forming the second support elements, which are between 140 and 5 mm wide, and preferably between 120 and 20 mm wide (narrower than the width of the middle stringer), the AGV can lift the EUR pallet from the racking by contacting the pallet along the underside of all three stringers.However, if the secondary support means are too wide, it becomes too difficult to ensure that at least one of the first and second upper lifting surfaces makes contact with the middle beam of the EUR pallet when lifting the pallet from the pallet rack. Conversely, if the secondary support means are too narrow, it will be difficult to guarantee that they are strong enough to adequately support a fully loaded pallet. Therefore, the current width ranges ensure an advantageous balance between functionality and durability. It should be noted that the term "width" in this context refers to the direction perpendicular to the longitudinal direction of the three support means.The pallet handling system according to the present invention also ensures that US pallets can be positioned on the pallet rack with the three bottom boards extending across the longitudinal length of the three support means, so that the pallet is better supported by the pallet rack and so that the AGV can lift the US pallet from the pallet rack with the narrowest part of the US pallet along the AGV's travel direction. Configuring the pallet rack and AGV so that both EUR and US pallets are lifted and supported from below by the lower pallet platforms is advantageous, since the pallets are designed to be supported on these surfaces, and the risk of the pallets becoming deformed or even broken due to being supported only in extreme positions is considerably reduced.Furthermore, configuring the pallet handling and lifting system so that both EUR and US pallets are lifted from the underside of the lower platforms is advantageous because it allows pallets to be lifted directly from the AGV without the pallet lifting device needing to retract. This results in a simpler and more economical pallet lifting system, simplified logistics (as pallets don't necessarily always have to be delivered to pallet racks), and faster repairs in case of AGV failure, since the pallet, including its load, can be easily removed by forklift. Additionally, configuring the secondary support elements as a lever is advantageous because it ensures they can be robust and rigid without obstructing the AGV as it moves in and out from under the pallet racking.Furthermore, forming the pallet lifting device on the AGV with a slot arranged to accommodate the second support means is advantageous, since in this way it is possible to lift the pallet from the pallet rack without interfering with the second support means and, at the same time, ensure that at least one of the upper lifting surfaces of the pallet lifting device comes into contact with the middle stringer of a EUR pallet when lifting it from the pallet rack by means of the AGV. It should be emphasized that the term "supporting means" shall be understood to mean any type of support capable of supporting a pallet placed on the pallet racking. That is, the term includes any type of rails, forks, bars, or the like. It should also be noted that the supporting means need not necessarily be arranged to support the pallet along their entire length. In one embodiment, the supporting means could comprise several individual support surfaces that are directly or indirectly interconnected along the length of the supporting means. Furthermore, in this context, the term "pallet lifting device" should be understood as any type of pallet lift capable of raising and lowering a pallet and which can be mounted on top of an automated guided vehicle. That is, the term includes any type of hydraulic lift, pneumatic lift, electrically driven lift, scissor lift, jack lift, etc., or any combination thereof. Furthermore, it should be noted that any reference to orientation in this document (i.e., up, down, top, bottom, width, etc.) is made in relation to the pallet handling system in normal use. In one aspect of the invention, the slot has a width that is between 5 and 140 mm wider, and preferably between 10 and 120 mm wider, than the second support means. If the gap is too wide relative to the width of the secondary support members, the probability of at least one of the two upper lifting surfaces of the pallet lifter coming into contact with the middle beam when lifting a EUR pallet is too low. However, if the gap is too narrow relative to the width of the secondary support members, it will be very difficult to remove the lifted pallet lifter from the pallet rack without it impacting the secondary support members or even becoming stuck during the process. Therefore, the current gap width ranges are advantageous with regard to the functionality of the pallet handling system. It should be noted that, in this context, width refers to the direction perpendicular to the longitudinal direction of the support members. In one aspect of the invention, the internal distance between the first and third support means is between 780 and 605 mm and, preferably, between 750 and 620 mm. If the internal distance between the first and third support members—that is, the distance perpendicular to the longitudinal direction of the three support members—is too long, it will be difficult to properly support an 800 mm wide EUR pallet on both the first and third support members of the pallet racking. Conversely, if the internal distance between the first and third support members is too small, it will be difficult to support both outer stringers of the EUR pallet using the AGV's pallet lifting device. Therefore, the specified distance intervals are advantageous for ensuring the proper support of the EUR pallet on both the pallet racking and the pallet lifting device. In one aspect of the invention, the length of the three support means is between 700 and 1600 mm and, preferably, between 800 and 1300 mm in the longitudinal direction. If the length of the three support elements is too short, the pallets will not be adequately supported on the pallet racking, increasing the risk of an unevenly loaded pallet tipping over. Conversely, if the length of the three support elements is too long, it becomes more difficult for a loaded AGV to move in and out of the pallet racking, and the cost of the pallet racking becomes excessively high. Therefore, the current length ranges are advantageous in relation to the functionality of the pallet handling system. It should be noted that the length is measured along the longitudinal direction of the support elements.In one aspect of the invention, each of the upper lifting surfaces is between 255 and 385 mm and, preferably, between 280 and 360 mm wide, and each of the upper lifting surfaces is between 200 and 1400 mm and, preferably, between 500 and 1200 mm long, wherein the length is measured in the longitudinal direction of the support means and the width is perpendicular to the length. If the upper lifting surfaces are too wide, the three support means must be very narrow to ensure the upper lifting surfaces can pass upwards between them, thus reducing the pallet support provided by the pallet rack. However, if the upper lifting surfaces are too narrow, the support provided by the upper lifting surfaces is reduced when lifting the pallet, and therefore the current width intervals are advantageous in relation to pallet support, both in the pallet rack and the pallet lifting device. Furthermore, if the upper lifting surfaces are too short, the risk of the pallet tipping over while supported by the pallet lifting device increases, and if the upper lifting surfaces are too long, the pallet lifting device becomes too large and expensive.Therefore, the current length ranges are advantageous in relation to pallet support and cost. In one aspect of the invention, the second support means are located in the middle between the first and third support means. Positioning the secondary support means midway between the primary and secondary support means is advantageous because it ensures that the EUR pallet can be supported symmetrically on the pallet rack. This also guarantees that the middle beam of the EUR pallet can be supported on both upper lifting surfaces on either side of the secondary support means, thus ensuring symmetrical support on the pallet lifting device. Symmetrical support of the EUR pallet is advantageous because it allows for more evenly distributed pallet support, reduces the risk of pallet tipping, and minimizes the risk of deformation or damage to the pallet. In one aspect of the invention, each of the at least two upper lifting surfaces is formed by a lifting plate disposed on a lifting pedestal, wherein a maximum width of the lifting plate is greater than a maximum width of the lifting pedestal. Typically, pallet racking is positioned against or even suspended from a wall, so the AGV must exit from underneath the pallet racking in the same direction it entered. However, when the AGV changes its travel direction by 180 degrees, it may sway slightly from side to side, increasing the risk of the pallet lifter striking the three support structures when reversing with a pallet on an elevated pallet lifter.Therefore, it is advantageous to form each of the at least two upper lifting surfaces by means of a lifting plate arranged on a lifting pedestal, wherein a maximum width of the lifting plate is greater than a maximum width of the lifting pedestal, since the lifting plate can be formed wide to ensure sufficient support of the pallet, while the narrower lifting pedestal ensures more clearance with respect to the three support means when the lifting plate is raised above the upper surface of the support means. In one aspect of the invention, the pallet lifting device comprises first lifting means arranged to actuate the first upper lifting surface and second lifting means arranged to actuate the second upper lifting surface. Forming the upper lifting surfaces with individual lifting devices is advantageous because it allows for more versatile pallet lifting equipment. It should be noted that this does not preclude the individual lifting devices from being powered by the same lifting unit (i.e., the same hydraulic pump, the same electric motor, or similar). In one aspect of the invention, the three support means are interconnected by one or more support structures. Forming the pallet racking in such a way that the three support means are connected to each other by one or more support structures is advantageous because it ensures a more stable construction and because the pallet racking is formed as a single unit that can be moved more easily. In one aspect of the invention, the three support means are integrally formed, and the one or more support structures comprise legs that suspend the three support means above ground level. Forming the three support elements as a single, coherent unit is advantageous because it simplifies manufacturing and subsequent handling. Supporting the three integrally formed support elements with legs ensures a simple design that is easy to handle and assemble. The invention further discloses a method for handling pallets, the method comprising the steps of: • arranging a pallet comprising three lower platforms on a pallet rack such that the three lower platforms are supported above ground level by three support means substantially at the same level as the pallet rack, wherein the three support means are parallel in a longitudinal direction of the three support means, wherein the three parallel support means comprise first support means, second support means and third support means, of which the second support means are arranged between the first and third support means, wherein the second support means are formed as a lever having a second support connection end that is connected to at least one of the one or more support structures and a second free support end, wherein the second support means have a width between 140 and 5 mm and, preferably, between 120 and 20 mm,and wherein the first support means and the third support means comprise one or more widthwise notches on their facing sides, and wherein the at least two upper lifting surfaces comprise one or more widthwise protrusions extending into the one or more widthwise notches, • guiding an automated guided vehicle comprising a pallet lifting device under the pallet supported by the pallet rack in a direction substantially parallel to the longitudinal direction, • raise a first upper lifting surface of the at least two upper lifting surfaces of the pallet lifting device between the first support means and the second support means and raise a second upper lifting surface of the at least two upper lifting surfaces of the pallet lifting device between the second support means and the third support means such that the first upper lifting surface and the second upper lifting surface come into contact with the three lower platforms of the pallet and raise the pallet from the first support means, the second support means and the third support means, and • guide the automated guided vehicle comprising the pallet lifting device and the pallet away from the pallet rack in a direction substantially parallel to the longitudinal direction. Positioning the pallet on the pallet rack so that the three lower platforms are supported by the three support means at the same level is advantageous because it provides better and more uniform support for the pallet. Lifting the pallet from the pallet rack using at least two upper lifting surfaces of the pallet lifter that extend upwards between the three support means to contact the three lower platforms is also advantageous because it provides better and more uniform support for the pallet on the lifter. Furthermore, lifting the pallet on the three lower platforms allows it to be lifted from the AGV, for example, using a forklift, without retracting the pallet lifter. Forming the first and third support elements with notches along the inner side faces, corresponding to protrusions on the outer side faces of at least the two upper lifting surfaces, is advantageous because it allows the EUR pallet, in particular, to be supported more across the width of the outer stringers, both on the pallet rack and when being lifted by the pallet lifting equipment. This reduces the risk of local deformation or damage to the pallet, especially when the pallet is heavily loaded, and the pallet is supported closer to the periphery on the pallet lifting device, thus reducing the risk of the pallet tipping off the AGV during transport. In one aspect of the invention, the pallet comprises a first stringer having a first stringer bottom platform extending along a first side of the pallet, a third stringer having a third stringer bottom platform extending along an opposite side of the pallet, and a second stringer having a second stringer bottom platform extending along a middle portion of the pallet parallel to the first stringer and the third stringer, wherein the pallet is arranged on the pallet rack with the second stringer bottom platform aligned with and on top of the support means. Positioning a EUR pallet so that the lower platform of the middle stringer, i.e., the second stringer, is aligned with and on top of the second support means is advantageous because the pallet is thus better supported on the pallet rack and because this allows the lower platform of the second stringer to be supported by both the first and second support means when the pallet lifting device raises the pallet from the pallet rack, thus ensuring better support of the pallet on the pallet lifting device. In one aspect of the invention, both the first upper lifting surface and the second upper lifting surface come into contact with the lower platform of the second stringer when the first upper lifting surface and the second upper lifting surface are raised. Supporting the lower platform of the second stringer by both the first upper lifting surface and the second upper lifting surface when the pallet lifting device raises the pallet from the pallet rack is advantageous because it ensures better and more uniform support of the pallet on the pallet lifting device, thus reducing the risk of local deformation or damage to the pallet. In one aspect of the invention, each of the at least two upper lifting surfaces is formed by a lifting plate disposed on a lifting pedestal, wherein a maximum width of the lifting plate is greater than a maximum width of the lifting pedestal, and wherein the first upper lifting surface and the second upper lifting surface are raised until a lower surface of the lifting plates is higher than the three support means before guiding the automated guided vehicle comprising the pallet lifting device and the pallet away from the pallet racking. Raising the lower surface of the lifting plates above the three support means before guiding the automated guided vehicle (AGV) away from the pallet racking is advantageous because it allows for more clearance between the pallet lifting device and the three support means, while also allowing for a larger contact surface between the lower pallet platforms and the lifting surfaces when the maximum width of the lifting plate is greater than the maximum width of the lifting pedestal. In one aspect of the invention, the method analyzed above serves to handle pallets by means of a pallet handling system according to any of the pallet handling systems described above. This achieves an advantageous embodiment of the invention. Figures The invention will be described below with reference to the figures in which Figure 1 illustrates a pallet handling system lifting a EUR pallet, in an isometric view, Figure 2 illustrates a pallet handling system lifting a US pallet, in an isometric view. Figure 3 illustrates a pallet rack, in an isometric view. Figure 4 illustrates a pallet rack, viewed from above, Figure 5 illustrates a pallet lifting device, in an isometric view, Figure 6 illustrates a pallet lifting device, viewed from above, Figure 7 illustrates a pallet handling system with a pallet lifting device in the raised position, in an isometric view, Figure 8 illustrates a pallet handling system with a pallet lifting device in the lowered position, in an isometric view, Figure 9 illustrates a pallet handling system with a EUR pallet in the lowered position, viewed from the front, and Figure 10 illustrates a pallet handling system with a EUR pallet in an elevated position, viewed from the front. Detailed description of the related technique Figure 1 illustrates a pallet handling system 1 lifting a EUR 21 pallet, in an isometric view. In this embodiment, the pallet handling system 1 comprises a pallet rack 2 having three parallel support means 3, 4, 5, each with an upper support surface 6 substantially at the same vertical level, i.e., the upper support surface 6 or surfaces 6 of each of the three support means 3, 4, 5 are arranged substantially at the same height above ground level.In this embodiment, an automated guided vehicle (AGV) 10, comprising a pallet lifting device 11, is about to descend and thereby place a standardized EUR 21 pallet on pallet rack 2, such that a lower platform 24 of the first stringer of a first stringer 23a of pallet 21 will rest on first support means 3 of pallet rack 2, a lower platform 28 of the second stringer of a second stringer 27a of pallet 21 will rest on second support means 4, and a lower platform 26 of the third stringer of a third stringer 25a of pallet 21 will rest on third support means 5.That is, in this embodiment, the second support means 4 are located substantially exactly in the middle between the first support means 3 and the third support means 5, so that the three support means 3, 4, 5 can provide regular and uniform support for a standard EUR 21 pallet, with the second stringer 27a located substantially exactly in the middle between the first stringer 23a and the third stringer 25a with the second stringer 27a when the second stringer 27a of the EUR 21 pallet is aligned with and disposed on top of the second support means 4 of the pallet rack 2. The nominal dimensions of a EUR 21 pallet are 800 mm wide, 1200 mm long, and 144 mm high, and it comprises three stringers 23a, 25a, and 27a, of which at least the lower platforms 24, 26, and 28 extend the entire longitudinal length of the pallet. The two outer stringers (i.e., the first stringer 23a and the third stringer 25a) are 100 mm wide, and the middle stringer (i.e., the second stringer 27a) is 145 mm wide. These are the standard dimensions for a EUR pallet; however, it is clear that these dimensions may vary at least slightly due to manufacturing inaccuracies, deformation during use, wear, thermal expansion, etc. Pallet 21 is typically made of wood, but it can also be made of plastic, metal, compressed cardboard, a composite material, or any combination thereof. Figure 2 illustrates the pallet handling system 1 described in Figure 1 lifting a United States pallet 21, in an isometric view. In this embodiment, the pallet lifting device 11 of the AGV 10 is about to lower a US pallet 21 onto the three support brackets 3, 4, and 5 of the pallet rack 2, so that the three lower platforms 24, 26, and 28 are each supported by the entirety of the three support brackets 3, 4, and 5. The standard US pallet 21, often also referred to as a North American pallet, is nominally 40 inches wide, 48 inches long, and 5.55 inches high, which is approximately equivalent to 1016 mm in width, 1219 mm in length, and 141 mm in height.The design of US pallets differs from the design of EUR pallets in several aspects, although one important difference is that, while the US pallet 21 comprises three stringers 23b, 25b, and 27b (often called "stingers," especially on US pallets) that extend the length of the pallet 21, the three lower decks 24, 26, and 28 are positioned perpendicular to the three stringers 23b, 25b, and 27b. The above measurements are the standard measurements for the most commonly used US pallet 21; however, it is obvious that these dimensions can vary at least slightly due to manufacturing inaccuracies, deformation during use, wear, thermal expansion, etc. Figure 3 illustrates a pallet rack 2, in an isometric view, and Figure 4 illustrates a pallet rack 2, viewed from the front. To allow a EUR pallet arranged with stringers 23a, 25a, 27a parallel to the three support means 3, 4, 5 in pallet rack 2 to be supported so that the lower platform 24 of the first stringer is in contact with the first support means 3, while the lower platform 26 of the third stringer is in contact with the third support means 5, the minimum internal ID distance between the first support means 3 and the third support means 5 is approximately 640 mm to allow the greater part of the two outer stringers 23a, 25a to be supported by the two outer support means 3, 5. However, in another embodiment, the ID width distance between the first 3 and the third 5 support media could be wider, such as 660 mm, 700 mm, 720 mm, or even higher, or smaller, such as 630 mm, 615 mm, 610 mm, or even lower. In this embodiment, the two outer support means 3 and 5 have the same SML length of approximately 1250 mm, while the second support means 4 are slightly shorter, i.e., approximately 1200 mm. However, in another embodiment, all three support means 3, 4, and 5 could have the same length, or the two outer support means 3 and 5 could have different SML lengths. Also in another embodiment, the two outer support means 3 and 5 and / or the second support means 4 could be shorter, such as 1100 mm, 1000 mm, 900 mm, or even shorter, and / or the two outer support means 3 and 5 and / or the second support means 4 could be longer, such as 1300 mm, 1350 mm, 1400 mm, or even longer, e.g., depending on the specific application, the accuracy of the AVG 10, etc. When the AGV 10 is transporting pallet 21, it is advantageous for the pallet lifting device 11 to support pallet 21 as close as possible to its outer periphery to reduce the risk of pallet 21 tipping off the AGV 10 when braking, accelerating, or cornering. Therefore, in this embodiment, the first support means 3 and the third support means 5 are each provided with three notches 17 across their inner edge.As can be seen more clearly in Figures 7 and 8, these notches 17 allow the two upper lifting surfaces 12, 13 of the pallet lifting device 11 to be provided with corresponding widthwise protrusions 18 extending into the widthwise notches 17, allowing the two outer stringers 23a, 25a to be supported by the two outer support means 3, 5 across almost the entire width of the stringers 23a, 25a, while ensuring that the two upper lifting surfaces 12, 13 of the pallet lifting device 11, in at least three areas, can support the EUR 21 pallet almost across the entire width of the stringers 23a, 25a.However, in another embodiment, the inner edge of the first support means 3 and the third support means 5 could be straight, i.e., without notches 17, or the first support means 3 and the third support means 5 could be provided with only one or two notches 17, or the first support means 3 and the third support means 5 could be provided with more than three notches 17, such as four, five, six or even more, and / or the notches could be provided with a different shape or size, e.g., depending on the specific use, pallet types, etc.If the first support means 3 and / or the third support means 5 are provided with a different number of notches 17 and / or notches 17 of a different size and / or shape, it is advantageous for the protrusions 18 across (see Figures 5-8) of the two upper lifting surfaces 12, 13 in the pallet lifting device 11 to be similarly altered to correspond substantially to the notches 17. In this embodiment, the three support means 3, 4, and 5 are interconnected by means of an end bar 30 extending through the pallet rack 2 at one end, such that the three support means 3, 4, and 5 are integrally formed. In this embodiment, the pallet rack 2 further comprises a support structure 7 in the form of four legs 19 that suspend the three interconnected support means 3, 4, and 5 above the floor.However, in another embodiment, the support structure 7 could comprise fewer or more legs 19 and / or the end bar 30 could be mounted on the wall, the outer support means could be individually connected to the underlying ground and the second support means 4 could comprise their own support structure 7 and / or the support structure 7 could be designed in numerous additional ways and / or the three support means 3, 4, 5 could be connected to the support structure 7 in numerous additional ways known to the skilled worker. In this embodiment, the second support means 4 are formed as a lever having a second support connection end 8 that connects to the support structure 7 via the end bar 30, such that the second support means 4 have a second unsupported end 9 at the opposite end that extends away from the end bar 30, allowing the AGV, including the lifting device 11, to enter and exit the pallet rack 2 with a pallet 21 without being obstructed by the support structure 7. In this embodiment, the second support means 4 have an SSW width of approximately 25 mm to ensure that the second stringer 27a of a EUR 21 pallet is sufficiently supported and, at the same time, to ensure that both upper lifting surfaces 12, 13 on the pallet lifting device 11 can contact the second stringer 27a on either side of the second support means 4 when lifting the EUR pallet from the pallet rack 2. However, in another embodiment, the SSW width of the second support means 4 could be smaller, such as 22 mm, 19 mm, 16 mm, or even smaller, or the SSW width could be larger, such as 30 mm, 40 mm, 50 mm, or even larger, and / or the SSW width of the second support means 4 could vary along the longitudinal extent of the second support means 4. Figure 5 illustrates a pallet lifting device 11, as seen in an isometric view, and Figure 6 illustrates a pallet lifting device 11, viewed from above. In this embodiment, the pallet lifting device 11 is a separate device connected to the top face of an AGV 10, although in another embodiment the pallet lifting device 11 could, at least to some extent, be integrally formed with the AGV 10. In this embodiment, the pallet lifting device 11 comprises first lifting means (not shown) arranged to actuate a first upper lifting surface 12 and second lifting means (not shown) arranged to actuate a second upper lifting surface 13, allowing the two upper lifting surfaces 12 and 13 to be actuated individually if required, although in another embodiment the two upper lifting surfaces 12 and 13 could be actuated by the same actuating means. In this embodiment, the actuating means comprise electric actuators, although in another embodiment the actuating means could also be, or instead be, hydraulic, pneumatic, etc.In this embodiment, each of the two upper lifting surfaces 12, 13 is formed by a wider lifting plate 15 arranged on a narrower lifting pedestal 16, such that the maximum width WPL of the lifting plate 15 is greater than the maximum width WPE of the lifting pedestal 16. In this embodiment, the width WPL of each of the lifting plates 15, and in this case the LSW of each of the upper lifting surfaces, is approximately 320 mm, and the width WPE of each of the lifting pedestals 16 is approximately 240 mm, although in another embodiment the lifting plates 15 and / or the lifting pedestals 16 could be wider or narrower, e.g., depending on the specific application, the specific design of the pallet racking, the specific pallet to be handled, etc.In another embodiment, the pallet lifting device 11 could be formed without the lifting plates 15, or the lifting plates 15 could be integrally formed with the lifting pedestals 16. In this embodiment, two upper lifting surfaces 12, 13 are separated by a slot 14 extending along the middle of the pallet lifting device 11, wherein the slot 14 is arranged to accommodate the second support means 4 (see Figures 1, 2, and 7-10). In this embodiment, the slot 14 has a width SLW of approximately 50 mm, and the width is constant along its entire length. However, in another embodiment, the slot 14 could be narrower, such as 45 mm, 35 mm, 25 mm, or even narrower, or the slot 14 could be wider, such as 60 mm, 70 mm, 80 mm, or even wider, and / or the width could vary along its entire length.Therefore, in this embodiment, the slit 14 is 25 mm wider than the second support means 4 described in Figures 3 and 4, although in another embodiment the slit 14 would only be 20 mm, 15 mm, 10 mm, or even less, wider than the second support means 4, or the slit would be 30 mm, 40 mm, 50 mm, or even more, wider than the second support means 4. In this embodiment, the LSW width of each of the upper lifting surfaces 12, 13 is approximately 320 mm and the LSL length of each of the upper lifting surfaces 12, 13 is approximately 850 mm, although in another embodiment the LSW width and / or the LSL length of one or both of the upper lifting surfaces 12, 13 could be larger or smaller, e.g., depending on the specific application, the specific AGV, the specific design of the pallet racking, etc. Or, in another embodiment, the upper lifting surfaces 12, 13 could be formed as more than two upper lifting surfaces 12, 13, such as four, six, eight, or even more. Figure 7 illustrates a pallet handling system 1 with a pallet lifting device 11 in the raised position, as seen in an isometric view, and Figure 8 illustrates a pallet handling system 1 with a pallet lifting device 11 in the lowered position, as seen in an isometric view. In this embodiment, the pallet handling system 1 is the same pallet handling system 1 as illustrated in all the other Figures, although in these illustrations it is more easily seen how the slot 14 accommodates the second support means 4 and how the protrusions 18 across each of the upper lifting surfaces 12, 13 extend into the corresponding notches 17 across the two outer support means 3, 5. Figure 9 illustrates a pallet handling system 1 with a EUR 21 pallet in the lowered position, viewed from the front, and Figure 10 illustrates a pallet handling system 1 with a EUR 21 pallet in the raised position, viewed from the front. In this embodiment, a pallet 21 (in this case, a EUR pallet) comprising three lower platforms 22 is first placed on pallet rack 2 to suspend the pallet 21 above floor level 20, such that the three lower platforms 22 are supported by the three support means 3, 4, 5 substantially at the same level as the pallet rack 2. After placing the pallet 21 on the rack 2, the automated guided vehicle 10 comprising the pallet lifting device 11 is guided under the pallet 21 supported by the pallet rack 2 in a direction substantially parallel to the longitudinal direction of the three support means 3, 4, 5.Once positioned beneath pallet 21, the upper lifting surfaces 12 and 13 of the pallet lifting device 11 are raised between the three support means 3, 4, and 5 so that the upper lifting surfaces 12 and 13 make contact with the three lower platforms 22 of pallet 21 and lift pallet 21 off the support means 3, 4, and 5, and so that the slot 14 of the pallet lifting device 11 accommodates the second support means 4 of the pallet rack 2. After this, the automated guided vehicle 10 that lifts pallet 21 is guided away from the pallet rack 2 by moving forward (i.e., through the pallet rack 2) or backward parallel to the direction in which it entered the pallet rack 2. The AGV 10 supporting pallet 21 can now move pallet 21 to a new location. Since pallet 21 in this embodiment is a EUR 21 pallet, pallet 21 is arranged in this embodiment such that the lower platform 28 of the second stringer is aligned with and positioned on top of the second support means 4 to allow the lower platforms 24, 26, 28 of all three stringers 23a, 25a, 27a to be supported by the three support means 3, 4, 5 when pallet 21 is placed on pallet rack 2 and by the upper lifting surfaces 12, 13 when the pallet is lifted from pallet rack 2 by the pallet lifting devices 11. Therefore, in this embodiment, both the first upper lifting surface 12 and the second upper lifting surface 13 come into contact with the lower platform 28 of the second stringer when the first upper lifting surface 12 and the second upper lifting surface 13 are lifted.However, in another embodiment, the second support means 4 and / or the slot 14 could be offset to one side, allowing only one of the first upper lifting surface 12 and the second upper lifting surface 13 to contact the lower platform 28 of the second stringer when the first upper lifting surface 12 and the second upper lifting surface 13 are raised. Furthermore, if the pallet were a US pallet 21 or another type of pallet 21, the pallet 21 could be arranged and aligned differently to allow maximum support on both the pallet rack 2 and the AGV 10. In this embodiment, the upper lifting surfaces 12, 13 of the pallet lifting devices 11 are formed by lifting plates 15, and in this embodiment, the upper lifting surfaces 13, 14 are raised until the lower surfaces 29 of the lifting plates 15 are higher than the three support means 3, 4, 5 at the same level before the automated guided vehicle 10 comprising the pallet lifting device 11 and the pallet 21 is guided away from the pallet rack 2 to allow for greater clearance between the lifting pedestals 16 (which are narrower than the lifting plates 15) and the second support means 4. However, in another embodiment, the pallet 21 could be raised to any height above the three support means 3, 4, 5 at the same level before the automated guided vehicle 10 is guided away from the pallet rack 2. In Figures 1, 2, 9, and 10, pallets 21 are empty. However, the purpose of pallets 21 is to provide a standardized base on which various types of goods can be placed, so that pallet 21, including the goods, can be transported using standardized pallet handling equipment such as forklifts, hand pallet trucks, pallet jacks, AGVs, and others. Therefore, it is clear that goods can be placed on pallets 21 during pallet handling using pallet handling system 1. The goods placed on pallets 21 could, in principle, be almost anything of a suitable size and weight for pallet storage and transport—that is, any type of boxes, merchandise, machine parts, food items, etc. The invention has been illustrated above with reference to specific examples of pallet racking 2, automated guided vehicles 10, pallet lifting devices 11, etc. However, it should be understood that the invention is not limited to the particular examples described above, but can be designed and altered into a multitude of variations within the scope of the invention as specified in the claims. List 1. Pallet handling system 2. Pallet racking 3. First means of support 4. Secondary means of support 5. Third-party support means 6. Upper support surface 7. Support structure 8. Second end of support connection 9. Second free end of support 10. Automated guided vehicle 11. Pallet lifting device 12. First upper elevation surface 13. Second upper elevation surface 14. Slit 15. Lifting plate 16. Lifting pedestal 17. Notch across the first and third support means. 18. Protrusions across the upper lifting surface. 19. Leg 20. Ground level 21. Pallet 22. Lower platform 23a. First stringer on EUR pallet 23b. First stringer on US pallet 24. Lower platform of the first stringer 25b. Third stringer on EUR pallet 25b. Third rail on US pallet 26. Lower platform of third stringer 27a. Second stringer on EUR pallet 27b. Second US pallet spar 28. Lower platform of second stringer 29. Lower surface of the lifting plate 30. End bar SSW. Width of the second media of support SLW. Slit width ID. Internal distance between the first and third SML support media. Length of support media LSW. Upper lifting surface width LSL. Length of the upper lifting surface WPL. Lifting plate width WPE. Width of the lifting pedestal
Claims
1. A pallet handling system (1), comprising a pallet rack (2) including three support means (3, 4, 5) that are parallel in a longitudinal direction of said three support means (3, 4, 5), wherein each of said three support means (3, 4, 5) comprises one or more upper support surfaces (6) substantially at the same horizontal level, wherein said three support means (3, 4, 5) are connected to one or more support structures (7) arranged to suspend said three support means (3, 4, 5) above the level (20) of the floor, wherein said three support means (3, 4, 5) comprise first support means (3), second support means (4), and third support means (5), of which said second support means (4) are arranged between said first and third support means (5),wherein said second support means (4) are formed as a lever having a second support connection end (8) that is connected to at least one of said one or more support structures (7) and a second unsupported end (9), and wherein said second support means (4) have a width (SSW) between 140 and 5 mm and preferably between 120 and 20 mm, and • an automated guided vehicle (10) comprising a pallet lifting device (11) having at least two upper lifting surfaces (12, 13), wherein said at least two upper lifting surfaces (12, 13) are separated by a gap (14) along a mid-portion of said pallet lifting device (11), such that a first upper lifting surface (12) of said at least two surfaces (12,13) upper lifting surfaces fit between said first support means (3) and said second support means (4) and such that a second upper lifting surface (13) of said at least two upper lifting surfaces (12, 13) fits between said second support means (4) and said third support means (5), and wherein said slot (14) is arranged to accommodate said second support means (4), characterized in that said first support means (3) and said third support means (5) comprise one or more notches (17) across their facing sides, and wherein said at least two upper lifting surfaces (12, 13) comprise one or more protrusions (18) across their width extending into said one or more notches (17) across their width.
2. A pallet handling system (1) according to claim 1, wherein said slot (14) has a width (SLW) that is between 5 and 140 mm wider and, preferably,between 10 and 120 mm wider than said second support means (4).
3. A pallet handling system (1) according to claim 1 or 2, wherein an internal distance (ID) between said first support means (3) and said third support means (5) is between 780 and 605 mm and, preferably, between 750 and 620 mm.
4. A pallet handling system (1) according to any of the preceding claims, wherein the length (SML) of said three support means (3, 4, 5) is between 700 and 1600 mm and, preferably, between 800 and 1300 mm in said longitudinal direction.
5. A pallet handling system (1) according to any of the preceding claims, wherein the width (LSW) of each of said upper lifting surfaces (12, 13) is between 255 and 385 mm and, preferably, between 280 and 360 mm, and wherein the length (LSL) of each of said upper lifting surfaces (12, 13) is between 200 and 1400 mm and, preferably,between 500 and 1200 mm in length, wherein the length (LSL) is measured in the longitudinal direction of said support means and said width (LSW) is perpendicular to said length.
6. A pallet handling system (1) according to any of the preceding claims, wherein said second support means (4) are located midway between said first and third support means (5).
7. A pallet handling system (1) according to any of the preceding claims, wherein each of said at least two upper lifting surfaces (12, 13) is formed by a lifting plate (15) disposed on a lifting pedestal (16), wherein a maximum width (WPL) of said lifting plate (15) is greater than a maximum width (WPE) of said lifting pedestal (16).
8. A pallet handling system (1) according to any of the preceding claims, wherein said three means (3, 4,5) support means are interconnected by said one or more support structures (7).
9. A pallet handling system (1) according to any of the preceding claims, wherein said three support means (3, 4, 5) are integrally formed, and wherein said one or more support structures (7) comprise legs (19) suspending said three support means (3, 4, 5) above said floor level (20).
10. A method for handling pallets (21), said method comprising the steps of: • arranging a pallet (21) comprising three lower platforms (22) on a pallet rack (2) such that said three lower platforms (22) are supported above the floor level (20) by three support means (3, 4, 5) substantially at the same level of said pallet rack (2), wherein said three support means (3, 4, 5) are parallel in a longitudinal direction of said three support means (3, 4, 5),wherein said three parallel support means comprise first support means (3), second support means (4), and third support means (5), wherein said second support means (4) are disposed between said first and third support means (3, 5), wherein said second support means (4) are formed as a lever having a second support connection end (8) that is connected to at least one of said one or more support structures (7) and a second unsupported end (9), wherein said second support means (4) have a width (SSW) between 140 and 5 mm and preferably between 120 and 20 mm, characterized in that said first support means (3) and said third support means (5) comprise one or more notches (17) across their facing sides, and wherein said at least two surfaces (12,13) upper lifting elements comprise one or more widthwise protrusions (18) extending into said one or more widthwise notches (17), the method further comprising the steps of: • guiding an automated guided vehicle (10) comprising a pallet lifting device (11) beneath said pallet (21) supported by said pallet rack (2) in a direction substantially parallel to said longitudinal direction,• raising a first upper lifting surface (12) of said pallet lifting device (11) between said first support means (3) and said second support means (4) and raising a second upper lifting surface (13) of said pallet lifting device (11) between said second support means (4) and said third support means (5) such that said first upper lifting surface (12) and said second upper lifting surface (13) come into contact with said three lower platforms (22) of said pallet (21) and raise said pallet (21) from said first support means (3), said second support means (4) and said third support means (5),and • guiding said automated guided vehicle comprising said pallet lifting device (11) and said pallet (21) away from said pallet rack (2) in a direction substantially parallel to said longitudinal direction.
11. A method according to claim 10, wherein said pallet (21) comprises a first stringer (23a, 23b) having a first stringer lower platform (24) extending along a first side of said pallet (21), a third stringer (25a, 25b) having a third stringer lower platform (26) extending along an opposite side of said pallet (21), and a second stringer (27a, 27b) having a second stringer lower platform (28) extending along a middle portion of said pallet (21) parallel to said first stringer (23a, 23b) and said third stringer (25a, 25b),and wherein said pallet (21) is disposed on said pallet rack (2) with said lower platform (28) of the second stringer aligned with and on top of said second support means (4).
12. A method according to claim 11, wherein both said first upper lifting surface (12) and said second upper lifting surface (13) come into contact with said lower platform (28) of the second stringer when said first upper lifting surface (12) and said second upper lifting surface (13) are raised.
13. A method according to any one of claims 10-12, wherein each of said at least two upper lifting surfaces (12, 13) is formed by a lifting plate (15) disposed on a lifting pedestal (16), wherein a maximum width (WPL) of said lifting plate (15) is greater than a maximum width (WPE) of said lifting pedestal (16),and wherein said first upper lifting surface (12) and said second upper lifting surface (13) are raised until lower surfaces (29) of said lifting plates (15) are higher than said three support means (3, 4, 5) before guiding said automated guided vehicle (10) comprising said pallet lifting device (11) and said pallet (21) away from said pallet rack (2).
14. A method according to any one of claims 10-13 for handling pallets (21) by means of a pallet handling system (1) according to any one of claims 1-9.