Material handling device with carrier track for reducing carrier damage

Abstract

A method and apparatus for delivering items to multiple storage locations are provided. The system includes multiple storage locations. The storage locations may be positioned to provide aisles, and multiple delivery vehicles can operate within the aisles to deliver items to the storage locations. The system may include tracks that guide the vehicles to the storage locations. Redirection components may be provided for redirecting the vehicles relative to the tracks to reduce misalignment between the vehicles and the tracks.

Description

[0001] Priority requirements

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 150,909, filed February 18, 2021, pursuant to 35 U.S.SC §119. The entire disclosure of U.S. Application No. 63 / 150,909 is incorporated herein by reference. Technical Field

[0003] This invention relates to material handling systems, and more particularly to systems utilizing multiple storage locations in one or more storage racks. More specifically, this invention relates to a material handling system that utilizes one or more automated delivery vehicles to deliver items to storage locations. Background Technology

[0004] The use of automated storage and retrieval significantly improves the efficiency of material handling. For example, in order fulfillment applications, automated storage and retrieval systems significantly reduce the time required to retrieve items needed to fulfill customer orders. Various automated storage and retrieval systems are currently known. One exemplary type of system utilizes one or more storage racks, multiple carriers, and tracks for guiding the carriers to storage locations on the racks. The carriers deliver items to storage locations or bins, from which operators can retrieve the items to fulfill orders. Over time, the carriers may become prone to jamming or damage due to interaction with the tracks. Therefore, it is desirable to provide a system with tracks that minimize wear and damage to the carriers traveling along the tracks. Summary of the Invention

[0005] According to one aspect, the present invention provides a material handling apparatus including multiple sorting locations for receiving articles. The system may include one or more vehicles for delivering articles to the sorting locations. The vehicles may travel along a track. The track may include sections for improving the interaction between the vehicles and the track. In one embodiment, the section includes portions that reduce engagement between drive elements on the vehicles and the track.

[0006] Optionally, the vehicle includes a drive mechanism that engages the track, and the track includes sections that allow a portion of the drive mechanism to disengage from a portion of the track.

[0007] The track may optionally include a profile configured to positively engage with the drive mechanism of the vehicle.

[0008] According to a preferred embodiment, the track may optionally include teeth or recesses that engage with mating elements of the vehicle's drive mechanism.

[0009] While methods and apparatuses have been described herein by way of example with several embodiments and illustrative drawings, those skilled in the art will recognize that the inventive methods and apparatuses for classifying articles using a dynamically reconfigurable classification array are not limited to the embodiments or drawings described. It should be understood that the drawings and their detailed description are not intended to limit the embodiments to the specific forms disclosed. Rather, they are intended to cover all modifications, equivalents, and substitutions falling within the spirit and scope of the methods and apparatuses for classifying articles using one or more dynamically reconfigurable classification arrays as defined by the appended claims. Any headings used herein are for organizational purposes only and are not intended to limit the scope of the specification or claims. As used herein, the word “may” is used in a permissive sense (i.e., meaning possible) rather than a mandatory sense (i.e., meaning must). Similarly, the words “comprising,” “including,” and “containing” mean including, but not limited to, the specific embodiments described. Attached Figure Description

[0010] The foregoing summary of the invention and the following detailed description of the preferred embodiments will be best understood when read in conjunction with the accompanying drawings, in which the same reference numerals will be used to denote the same or identical parts throughout the drawings:

[0011] Figure 1 This is a perspective view of a material handling apparatus incorporating aspects of the present invention.

[0012] Figure 2 yes Figure 1 A plan view of the illustrated material handling device.

[0013] Figure 3 yes Figure 1 A schematic side view of the track system of the illustrated material handling device.

[0014] Figure 4 yes Figure 1 An enlarged perspective view of a portion of the track system of the illustrated material handling device.

[0015] Figure 5 yes Figure 1 An enlarged plan view of the carrier of the illustrated material handling device.

[0016] Figure 6 yes Figure 5 Side elevation view of the illustrated vehicle.

[0017] Figure 7 yes Figure 1 An enlarged perspective view of the redirection component of the illustrated material handling device.

[0018] Figure 8 yes Figure 7 The side elevation view of the front component of the illustrated redirection component.

[0019] Figure 9 yes Figure 1 A second enlarged perspective view of the redirection component of the illustrated material handling device.

[0020] Figure 10 yes Figure 9 The side elevation view of the rear component of the illustrated redirection component.

[0021] Figure 11 yes Figure 7 An enlarged side view of a segment of the illustrated redirection component.

[0022] Figure 12 yes Figure 11 The exploded perspective view of the illustrated segment.

[0023] Figure 13 yes Figure 1 An enlarged perspective view of the alternative redirection component of the illustrated material handling device.

[0024] Figure 14 yes Figure 13 The side elevation view of the front component of the illustrated redirection component.

[0025] Figure 15 yes Figure 13 A partial plan view of the exemplified alternative redirection component.

[0026] Figure 16 It is along Figure 15 Enlarged sectional view taken from line 16-16 in the figure. Detailed Implementation

[0027] Certain portions of the following detailed description are presented in reference to the operation of binary digital signals stored in the memory of a particular device or dedicated computing device or platform. In the context of this particular specification, the term "particular device," etc., includes general-purpose computers programmed to perform specific functions according to instructions from program software. In this case, the operation or processing involves the physical manipulation of physical quantities. Typically, although not strictly necessary, such quantities may take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, or otherwise manipulated. For general reasons, referring to such signals as bits, data, values, elements, symbols, characters, items, numbers, etc., has proven convenient in some cases. However, it should be understood that all such or similar terms are associated with appropriate physical quantities and are merely convenient notations. Unless otherwise specifically stated, as will be apparent from the following discussion, it should be understood that throughout this specification, the use of terms such as "processing," "calculation," "analysis," "determination," etc., refers to the actions or processes of a particular device (such as a dedicated computer or similar dedicated electronic computing device). Therefore, in the context of this invention, a dedicated computer or similar dedicated electronic computing device is capable of manipulating or transforming signals, which are generally represented as physical electronic or magnetic quantities within the memory, registers, or other information storage, transmission, or display devices of the dedicated computer or similar dedicated electronic computing device.

[0028] Current overall reference Figures 1 to 6 And for specific reference Figures 1 to 2 The material handling device is represented as 10. System 10 can take any form incorporating multiple storage locations. In this example, the system includes a pair of spaced-apart storage racks 30, 32, with an aisle 35 formed between the racks. Multiple automated delivery vehicles 200 can operate within the aisle 35. Specifically, the delivery vehicles 200 can travel along tracks 100 positioned in the aisle, as further described below. Additionally, as Figures 7 to 16 As shown and described in more detail below, system 10 may include one or more mechanisms for improving the engagement between the track and the vehicle. For example, the track may optionally include sections for redirecting the vehicle relative to the track.

[0029] exist Figures 1 to 2In the illustrated exemplary system, the material handling device includes an optional station for supplying items into the system. This station is referred to as sensing station 20. Sensing station 20 can determine the identifying characteristics of the items to be supplied into the system. The identifying characteristics can be any of a variety of characteristics, such as a product number or UPC code. The identifying characteristics can be determined manually, such as by an operator. However, in this example, the sensing station includes scanning station 22, which may include multiple scanners, such as optical scanners in the form of barcode scanners, digital cameras, or others. The sensing station may include a conveyor for conveying items through the scanners, or the operator may manually scan the items before they are supplied into the system.

[0030] The sensing station 20 may optionally include a conveyor, such as a conveyor belt or multiple rollers, for continuously conveying items to a loading station, where the items are loaded onto a carrier 200. Multiple items may be loaded onto individual carriers. However, in this example, each item is loaded onto a separate carrier, which then delivers the item to one of the storage locations.

[0031] Although the construction of the sensing station may vary, details of an exemplary sensing station are provided in U.S. Patent No. 10,494,192. The entire description of U.S. Patent No. 10,494,192 is incorporated herein by reference. Furthermore, it should be noted that the sensing station is not an essential element, and aspects of the invention can be used in systems that do not include a sensing station.

[0032] Refer again Figures 1 to 4 The details of the storage components will be described in more detail below. The system includes multiple storage locations 40 for storing items so that they can be retrieved. In one configuration, items are delivered to the storage locations by multiple automated vehicles 200. Alternatively, the system can be configured such that items can be retrieved from the storage locations by automated vehicles. Alternatively, the storage locations can be used to accumulate items so that an operator or other automated retrieval device can retrieve items from the storage locations. For example, storage boxes 45 can be located in various storage locations 40, and the system can deliver items to different storage boxes to fulfill customer orders. Once the system has delivered all the items required for an order to a specific storage box, the operator removes the storage box 45 from the storage location 40 and replaces the full storage box with an empty one.

[0033] Storage locations can be arranged in any of a variety of orientations. For example, reference Figures 1 to 2The system includes two opposing racks: a front rack 30 and a rear rack 32. Racks 30 and 32 are spaced apart from each other, thus forming an aisle 35 between the racks. Optionally, racks 30 and 32 can be connected by multiple lateral supports of interconnecting racks. In particular, multiple top lateral supports can extend between the tops of the racks, and multiple lateral supports can extend between the bottoms of the racks, thereby connecting the racks and maintaining the racks spaced apart to provide the aisle 35.

[0034] Track 100 can follow any of a variety of configurations depending on the application. Figure 3 An exemplary embodiment is illustrated, which includes a closed loop with multiple columns. Similarly, the system can be constructed as a series of rows connected by vertical tracks. Alternatively, the system can be an open track rather than a closed loop. Therefore, it should be understood that the loop construction illustrated in the figure is merely an example, and the track can take any of many forms.

[0035] Refer again Figure 3 The track 100 optionally includes an upper horizontal guide rail 114 and a lower horizontal guide rail 116. Multiple vertical supports 112 extend between the upper horizontal supports 114 and the lower horizontal supports 116. During transport, the vehicle travels upward from the loading station along a pair of vertical supports to the upper guide rail 114. The vehicle then travels along the upper guide rail 114 in the direction of travel indicated by arrow T1 until it reaches a column with a suitable container or destination. The vehicle then travels downward along two front vertical posts and two parallel rear posts until it reaches a suitable container or destination, where the goods are unloaded into the container or destination area. The vehicle then continues downward along the vertical supports until it reaches the lower horizontal supports 116. The vehicle then returns towards the loading station following the lower guide rail.

[0036] refer to Figure 2 and Figure 5 Track 100 includes a front track 105 and a rear track 110. The front track 105 and the rear track 110 are parallel tracks that cooperate to guide the vehicle around the track. In the discussion of the tracks, the front track 105 and the rear track 110 are similarly constructed as opposing tracks supporting the front and rear wheels 220 of the vehicle. Specifically, in this embodiment, the rear track 110 is a mirror image of the front track 105. Therefore, unless otherwise stated below, the description of a portion of the front or rear track also applies to opposing front or rear tracks.

[0037] The details of the orbit can be broadly similar to those described in U.S. Patent No. 7,861,844. The entire disclosure of U.S. Patent No. 7,861,844 is incorporated herein by reference.

[0038] refer to Figure 4The track 100 includes a drive surface 120 that positively engages the vehicle to enable it to travel along the track. The drive surface 120 can be any of a variety of configurations engaging drive elements on the vehicle. Specifically, the drive surface can be configured to mate or engage with drive elements on the vehicle. One such example of the drive surface 120 is a series of teeth forming a rack that engages with the wheels of the vehicle, as described further below. Similarly, the track may include a series of recesses or pawls that cooperate with corresponding elements, such as sprockets or other elements projecting from the wheels. Thus, the term "positively engaging" refers to the engagement between the drive surface 120 and the drive elements of the vehicle 200, which prevents the drive elements from sliding along the track 100.

[0039] Optionally, the track may also include a guide surface 122, which is a generally flat surface adjacent to the drive surface 120. For example, the drive surface 120 may extend across approximately half of the track, and the guide surface 122 may extend across the other half of the track. Figure 4 As shown, the drive surface 120 can be formed on the inner wall of the track, and the opposite outer wall can be a generally flat surface of the guide surface 122 parallel to the inner wall.

[0040] As described above, the track may include a plurality of vertical legs 112 extending between a horizontal upper guide rail 114 and a lower guide rail 116. Intersections may be formed at various sections of the track, where one of the vertical legs intersects with one of the horizontal legs. For example, each intersection may include a pivotable door 125 having a smoothly curved inner seat and a flat outer seat, the outer seat having a drive surface corresponding to the drive surface 120 of the track. The door 125 may pivot between a first position and a second position. In the first position, the door 125 may be closed such that the straight outer seat of the door is aligned with the straight outer branch of the intersection. In the second position, the door 125 may be opened such that the curved inner seat of the door is aligned with the curved branch of the intersection.

[0041] In the above description, system 10 is described as having multiple output boxes 45. However, it should be understood that the system can include various types of destinations, rather than simply output boxes. For example, in some applications, it may be desirable to sort items into storage areas, such as areas on storage shelves. Alternatively, a destination can be an output device that transfers items to other locations. Thus, one type of destination is a box; a second type is a shelf or other location on which items are to be stored; and a third type of destination is an output device that can be used to transfer items to different locations. The system can include one or more of each of these types or other types of destinations.

[0042] Delivery vehicle

[0043] refer to Figures 5 to 6 The details of a delivery vehicle 200 will be described in more detail below. Each delivery vehicle 200 may be a semi-autonomous vehicle having an onboard drive system including an onboard power supply. Each vehicle may optionally include mechanisms for loading and unloading items for delivery. Exemplary vehicles are illustrated and described in U.S. Patent No. 7,861,844, which is incorporated herein by reference.

[0044] As discussed in further detail below, the vehicle includes a mechanism for driving the vehicle along track 200. The drive mechanism may include any of a variety of elements. In this example, the drive mechanism includes a plurality of wheels 220 that engage with track 100.

[0045] Additionally, the vehicle 200 may optionally incorporate mechanisms for loading items onto the vehicle and unloading items from the vehicle into a container. The loading / unloading mechanism 210 may be specifically tailored for a particular application. For example, the delivery vehicle 200 may include a platform on which items can be placed. The platform 210 may be a fixed platform, and the system may include elements operable to load items onto and unload items from the platform. Alternatively, the platform may be movable. For example, the platform may be one or more horizontal belts. The belts may be selectively operable to convey items onto the vehicle. Similarly, the belts may be selectively operable to unload items from the belts. In this example, the loading / unloading mechanism 210 is exemplified as one or more conveyor belts extending along the top surface of the vehicle. The conveyor belts are reversible. Driving the belts in a first direction displaces items toward the rear end of the vehicle; driving the belts in a second direction displaces items toward the front end of the vehicle.

[0046] The carrier may include a transmission motor mounted on its underside to drive the conveyor belt. The conveyor belt may be driven around a front roller at the leading edge of the carrier and a rear roller at the trailing edge of the carrier. The transmission motor may be connected to the front roller to drive the front roller, thereby operating the conveyor belt.

[0047] Vehicle 200 includes multiple wheels. For example... Figures 5 to 6 As shown, each vehicle may include four wheels 220: two front wheels and two rear wheels. The terms "front" and "rear" refer to the tracks in which the wheels travel in the opposite direction to the vehicle's direction of travel. Specifically, the front wheels 220a and 220c travel in the front track 105, while the rear wheels 220b and 220d travel in the rear track 110.

[0048] Wheels 220 are mounted on two parallel, spaced-apart axles 215 and 216, such that the two wheels are arranged along the front edge of the vehicle and the two wheels are arranged along the rear edge of the vehicle. Specifically, wheels 220a and 220b are mounted on the front axle 215, while wheels 220c and 220d are mounted on the rear axle 216. Axle 215 is referred to as the front axle because, when moving horizontally, the vehicle typically moves with axle 215 in front and axle 216 behind. However, it should be understood that the vehicle can be reversed, such that axle 216 becomes the front axle and axle 215 becomes the rear axle. Therefore, it should be understood that the terms "front" and "rear" do not imply any requirement or restriction on the orientation of the vehicle or its direction of travel.

[0049] Each wheel 220 may include a drive element 222 that cooperates with the drive surface of the track. The drive element can be any of a variety of elements configured to cooperate with the drive surface 120 of the track. For example, the drive element can be a rotatable element, such as a gear or sprocket. In this example, the drive element 222 is a gear, such as a pinion with multiple teeth.

[0050] In addition to drive element 222, each wheel optionally includes a guide element. The guide element guides the wheel along a section of track where the track transitions from one direction to another. The guide element may also carry some of the load of the vehicle. According to one embodiment, the guide element may be a roller, such as idler roller 224. Roller 224 may be coaxial with and positioned adjacent to drive element 222. Idler roller 224 may engage the track to roll along the track, while drive element 222 engages drive surface 120 to drive the vehicle along the track.

[0051] The drive element 222 can be fixed relative to the axle on which it is mounted. This allows rotation of the axle to drive the drive element, thereby driving the vehicle along the track 100. Alternatively, the roller 224 can rotate relative to the axle on which it is mounted, such that the roller does not provide driving force for forward-driving the vehicle.

[0052] Optionally, the drive elements of the vehicle are configured such that a first drive element on a first axle engages the front track, and a second drive element on the first axle engages the rear track. Similarly, a first drive element on a second axle engages the front track, and a second drive element on the second axle engages the rear track. Thus, two spaced-apart drive elements (such as gears 222a and 222c) engage the front track 105, and two spaced-apart drive elements (such as gears 222b and 222d) engage the rear track 110.

[0053] The vehicle includes an onboard motor for driving the wheels 220. More specifically, the drive motor is operatively connected to the axles to rotate the axles 215, 216, which in turn rotates the gears 222 of the wheels.

[0054] The vehicle 200 can be powered by an external power source, such as contacts along the guide rails, which provide the power required to drive the vehicle. However, in this example, the vehicle includes an onboard power source that provides the necessary power to both the drive motor and the transmission motor. Additionally, in this example, the power source is rechargeable. While the power source could include a rechargeable battery, in this example, the power source consists of one or more supercapacitors.

[0055] During operation, the engagement between the vehicle drive element 222 and the track 100 provides precise control over the position of the vehicle 200 along the track. Furthermore, since the rear track 110 is a mirror image of the front track 105, the opposing tracks control the position of the front wheels 220a, 220c relative to the rear wheels 220b, 220d. Specifically, the drive surfaces on the front track 105 are aligned with the drive surfaces on the rear track 110. For example, if the drive surface 120 is as follows... Figure 8 and Figure 10 The teeth shown are aligned such that the first tooth 120a along the front track 116 is aligned with the first tooth 120b along the rear track. Thus, when the front drive element 222a on the front axle engages the first tooth element 120a on the front track 105, the rear drive element 222b on the front axle 215 simultaneously engages the first tooth element 120b on the rear track 110. Similarly, when the front drive element 222c on the rear axle engages the first tooth element 120a on the front track 105, the rear drive element 222d on the rear axle 215 simultaneously engages the first tooth element 120b on the rear track 110.

[0056] Because the drive surfaces of track 100 tend to prevent the drive elements 222 of the vehicle from sliding relative to the track, the forced engagement between the drive surfaces and the drive elements tends to maintain the vehicle in a proper orientation relative to the track. Specifically, the aligned drive elements 222 and drive surfaces 120 tend to keep the axles 215, 216 parallel to each other and perpendicular to the direction of travel along the track. Although the vehicle forcibly engages with the track in a manner that limits slippage between the vehicle and the track, the drive elements of the vehicle may become misaligned over time, thereby generating stress on the vehicle, leading to vehicle wear and / or the vehicle becoming stuck within the track.

[0057] To limit wear, the system may incorporate a section for automatically redirecting the vehicle relative to the track. For example, the system may include a section that facilitates the alignment of the vehicle's drive elements with the drive surfaces of the track. The redirection section may have any of a variety of configurations; however, it is designed to provide a limited slip section in which engagement between the drive elements and the drive surfaces is reduced or interrupted.

[0058] Now for reference Figures 7 to 12The section used for the automatic redirection vehicle relative to the track is typically designated 140. In the illustrated embodiment, the redirection assembly 140 is configured to reduce the skew between the front and rear sides of the vehicle. For example, a front wheel (e.g., wheel 220a) may be offset from the opposite rear wheel (e.g., wheel 220b) such that the two wheels are not positioned at the same point along the length of the track. Specifically, the distance from wheel 220a to tooth 120a may be greater than the distance from wheel 220b to tooth 120b. This offset wheel may cause axle 215 to bend or angled relative to the direction of travel. For example, as described above, in the illustrated embodiment, when the vehicle is properly oriented, axles 215, 216 are oriented perpendicular to the direction of travel. When wheel 220 is offset, the axle may bend or skew to an angle not perpendicular to the direction of travel.

[0059] Depending on the configuration of vehicle 220, redirection segment 140 may include one or more segments. In one example, such as Figure 8 For example, redirection section 140 includes a first section 150 and a second section 160 spaced apart from the first section. Although the spacing between the first and second sections can vary, the first section 150 and the second section 160 are spaced along the track by a distance similar to the spacing between the front axle 215 and the rear axle 216. Thus, the wheel of the rear axle 216 can engage the first section 150, while the wheel of the front axle 215 engages the second section 160 (see [link to documentation]). Figures 7 to 8 ).

[0060] refer to Figures 7 to 12 The first segment 150 of the redirection segment 140 includes a front component 152 and a corresponding rear component 154. The front component 152 is positioned along the front track 105, and the rear component 154 is positioned along the rear track 110. As discussed further below, the front component 152 may be a mirror image of the rear component 154, such that the front and rear components are substantially identical. Alternatively, the front component 152 may be constructed differently from the rear component 154, as discussed further below.

[0061] refer to Figures 7 to 8 The first segment 150 includes the front component 152 and the rear component 154. The second segment 160 includes the front component 162 and the rear component 164. Different segments are designated according to the vehicle's direction of travel. For example, as... Figure 7 As shown, the typical direction of travel of the vehicle is indicated by arrow T. When the vehicle travels in direction T, the leading edge of the vehicle is conveyed through the first segment 150 of the redirection assembly 140. As the vehicle continues along the path in direction T, the leading edge is conveyed through the second segment 160. However, it should be understood that the placement of the segments of the redirection assembly 140 can vary depending on a number of factors, including but not limited to the main direction of travel of the vehicle along the track.

[0062] As described above, the first segment 150 and the second segment 160 of the redirection component 140 each include front components 152, 162 along the front track 105. (See reference) Figure 11 and Figure 12 The details of the front component 162 of the second segment 160 will be described in more detail. The front component includes a track segment 170. The track segment 170 has a generally C-shaped channel cross-sectional profile. Specifically, the bottom wall 180 of the track forms the first wall of the channel, and an opposing upper wall opposite the bottom wall forms the second wall. The upper and lower walls are connected by an elongated web extending between the upper and lower walls.

[0063] The upper wall of track segment 170 may optionally include multiple surfaces. For example, the upper wall may include a generally flat guide surface 171 opposite the lower wall and extending substantially the entire length of track segment 170. Guide surface 171 may form a recess extending the length of the upper wall. Additionally, guide surface 171 may be spaced from the lower wall 180 by a distance similar to the diameter of the guide wheel 224 of the carrier wheel. The guide wheel has a generally smooth surface that provides rolling engagement between the guide wheel and guide surfaces 171, 180.

[0064] The upper wall also includes a sliding surface 173 configured to facilitate sliding between the drive element 222 of the carrier and the track 100. For example, the sliding section 173 may be configured to provide a gap between the outer surface of the drive element 222 and the drive surface 120 of the track. The sliding surface 173 is aligned with the drive surface 120 of the track 100. In this way, the sliding surface forms a gap between the length of the drive surface 120 on a portion of the track and the individual length of the drive surface on a second portion separated from the first portion.

[0065] For example, refer to Figure 12 A first driving surface 172 may be formed on the upper wall at a first end of the track segment 170. The first driving surface 172 is formed similarly to the driving surface 120 of the track 100. For example, the first driving surface 172 may be a plurality of spaced teeth that mesh with the gear 222. Additionally, the track segment 170 may include a second driving surface 174 formed on the upper wall at a second end of the track segment 170. The second driving surface is formed similarly to the driving surface 120 of the track, such as a plurality of spaced teeth similar to the first driving surface 172. The second driving surface 174 is spaced apart from the first driving surface, thereby forming a gap between the two driving surfaces. A sliding surface 173 extends between the first driving surface 172 and the second driving surface 174.

[0066] As described above, the sliding surface 173 is configured to facilitate sliding between the track 100 and the drive element 222 of the carrier wheel 220. For example, the sliding surface 173 can be configured such that the sliding surface is spaced from the lower wall 170 by a distance greater than the outer diameter of the drive element 222. For example, the sliding surface 173 can be a smooth flat wall such that the drive element 222 of the carrier wheel does not forcibly engage with the sliding surface. In this way, the drive element 222 can slide relative to the sliding surface 173.

[0067] As described above, the sliding surface 173 of track segment 170 allows the vehicle's wheels to slide relative to the track. This allows the sliding surface to facilitate the realignment of wheels on one side of the track with respect to opposing wheels on the other side. For example, if the front wheel 222a skips one or more teeth in the front track 105, the front wheel 222a may be misaligned relative to the rear wheel 222b in the rear track 110. More specifically, a wheel at one end of axle 215 may be offset relative to a wheel at the second end of axle. When one wheel is misaligned or skewed relative to the second wheel, this misalignment or skew can lead to excessive wear and / or jamming between the vehicle and the track. As discussed further below, the sliding surface 173 allows the vehicle wheels to slide relative to the track to redirect the wheels, thereby reducing vehicle wheel misalignment and / or skew.

[0068] The redirection segment 160 provides an elongated section in which the drive surface 120 of the track is modified or interrupted, causing the drive element 222 of the vehicle to disengage from the drive element. For example... Figure 11 As shown, the redirection component may include one or more transition sections that transition the drive element of the vehicle from engagement with a drive surface to non-engagement with a drive surface and from non-engagement with a drive surface to engagement with a drive surface. For example, drive surface 172 is configured to have a first end that substantially matches the configuration of drive surface 120 of the track. The second end of the drive surface tapers from a full drive surface configuration to a reduced drive surface and / or to a non-drive surface. For example, in the illustrated embodiment, the drive surface is a tooth, such as a rack, and drive surface 172 tapers from a full-size tooth to a tooth with reduced height and then to toothless. Thus, the engagement between the gear teeth 222 on the vehicle 200 and drive surface 172 gradually disengages. Similarly, drive surface 174 tapers in the opposite direction to gradually engage with gear teeth 222 of the vehicle. Specifically, the second drive surface 174 tapers from toothless or reduced tooth height to a full tooth height that matches the configuration of drive surface 120 of track 100.

[0069] Although transition sections 172 and 174 are illustrated as integral with track section 170, it should be understood that transition sections 172 and 174 may be formed on adjacent sections of track 100, such that sliding surface 173 extends further along track section 170.

[0070] Optionally, the redirection component 140 may also include auxiliary redirection devices. For example, the redirection component may include a centering element for limiting the skewing of the vehicle relative to the desired direction of travel. Examples of such centering devices are... Figures 11 to 12 The example is illustrated as a deflector 195, which is configured to deflect the vehicle in a desired direction of travel. The deflector 195 can be any of a variety of elements designed to apply lateral forces on the side of the vehicle.

[0071] In this example, the deflector 195 includes one or more biasing elements that push the vehicle along the centerline between the front track 105 and the rear track 110. Specifically, the deflector includes a pivotable rod that pivots about a pivot pin 198. The pivot pin 198 extends through a bore 196 in the deflector 195. Thus, the pivot pin 198 forms a pivot axis, allowing the deflector to pivot about an axis preferably transverse to the direction of travel T (see [link to previous example]). Figures 7 to 10 ).

[0072] The deflector 195 protrudes through an opening or window 165 in the web of the track section 160. In this example, a biasing element, such as a spring 197, biases the deflector 165 toward the center of the aisle 35. In other words, the deflector 165 is biased to push against the side of the vehicle 200. Thus, when the vehicle passes through the redirection section, the deflector 195 redirects the vehicle toward the center of the aisle. Additionally, refer to... Figure 8 and Figure 10 The opposing deflectors 195 can be positioned in the rear track 110 such that they push against opposite sides of the vehicle 200. In this way, the two opposing deflectors push the sides of the vehicle towards the center of the aisle. For example, as... Figure 8 As shown, the deflector 195 in the front assembly 162 pushes against the front side of the vehicle, and the deflector 195 in the rear assembly 164 pushes against the rear side of the vehicle. Preferably, the opposing deflectors are balanced so that they provide approximately similar biasing forces, thereby pushing the vehicle toward the center of the aisle to guide or redirect the center of the vehicle toward the center of the aisle.

[0073] As described above, the redirection section 162 may include a housing 190 that accommodates the track section 170 and the deflector 195. For example, the housing may be a C-shaped channel with sufficient width and depth to allow the track section to be fitted within the housing. Figure 12 As shown, the track segment 170 may have an upper lip and a lower lip that are fitted onto the outer edge 191 of the housing 190. The track segment may be fixedly attached to the housing, such as by releasable fasteners (e.g., threaded fasteners) or by permanent means such as welding, epoxy resin, or adhesive.

[0074] The housing may optionally be deep enough to provide clearance for the deflectors 195. Specifically, all or substantially all of the deflectors 195 may be fitted inside the housing below the track, such that the deflectors do not protrude substantially into the track. In this way, the deflectors 195 can deflect or retract into the housing 190 to leave the path of the vehicle.

[0075] The pivot axis of deflector 195 may optionally be located below the surface of the web plate connecting the upper and lower legs of the track segment. For example, in this embodiment, pivot axis 196 is located in the gap between track segment 170 and housing 190. In particular, pivot pin 198 is located below track segment such that the pivot pin does not extend through track segment.

[0076] Optionally, the deflector 195 includes a biasing element 197 that biases the deflector inward toward the center of the passageway 35. Figure 12 An exemplary biasing element in the form of a helical spring is illustrated. The deflector may be configured to cooperate with the helical spring, such as a post extending into the helical spring or a recess receiving a first end of the helical spring. A second end of the spring may abut against an inner wall of the housing. Alternatively, an orifice may be formed in the wall of the housing, and a cover 199 may cover the orifice in the housing. The biasing element 197 may abut against an inner surface of the cover. The cover 197 may be releasably or substantially permanently attached to the housing 190.

[0077] Redirect component 140 may include one or more redirect segments 152 as described above. For example, such as Figure 8 and Figure 10 For example, the second redirection segment 160 may include a pre-redirection segment 162 along the preceding track 105 and a post-redirection segment 164 opposite to the pre-redirection segment 162. The post-redirection segment 164 may be constructed in a manner generally similar to that of the pre-redirection segment 160, wherein the post-redirection segment is approximately a mirror image of the pre-redirection segment.

[0078] A redirection segment may include one or more redirection elements. For example, the pre-redirection component 162 of the second segment 160 includes both a sliding surface 173 and a deflector 195. (See reference) Figure 8 and Figure 10 The first redirection segment 150 may similarly have a sliding surface for redirecting the vehicle and auxiliary redirection elements such as deflectors. Alternatively, the first redirection segment 150 may include a track segment constructed similarly to track segment 170, but the deflector 195 may be omitted from the first segment 150.

[0079] Refer again Figure 8 and Figure 10The first redirection segment 150 may include: a front segment 152 including a sliding surface 173; and a rear segment 154 including a track segment having a drive surface opposite the sliding surface 173. Specifically, the rear component 154 of the first redirection segment 150 includes a track having a drive surface 120 along substantially the entire length of the component. The drive surface 120 provides a forced drive mechanism throughout the entire length of the first segment.

[0080] Thus, the redirection assembly can be constructed in various variations that allow different components of the vehicle to slide relative to the track in different areas of the redirection assembly. As described above, the first redirection segment 150 has a first sliding surface on one side and a driving surface on the opposite portion of the track, such that the front wheels of the vehicle can slide relative to the track while the rear wheels remain engaged with the track.

[0081] In addition, the second redirection segment 160 has a first sliding surface on one side and a second sliding surface on the opposite side, so that the front wheel and the rear wheel can slide relative to the track simultaneously.

[0082] Optionally, the distance between the second redirection segment 160 and the first redirection segment 150 is similar to the distance between the front axle 215 and the rear axle 216. Thus, the redirection assembly 140 allows three of the four corners of the vehicle to slide relative to the track 100, while the fourth corner of the vehicle remains engaged with the track. For example, as described above, when the front wheels 220a and b engage the second redirection segment 160, the drive elements 222a and 222b align with the sliding surface 173, causing the drive elements 222a and 222b to disengage from the track. When the front wheels engage the second redirection segment, the rear wheels 220c and d engage the first redirection segment 150, causing the front drive element 222c to align with the sliding surface of the front segment, and the rear drive element 222d to align with the drive surface. Thus, the drive elements of a single wheel of the vehicle engage the drive surface of the track to drive the vehicle through the redirection segment, while the remaining wheels 222a, 222b, and 222c disengage from the drive surface of the track 100.

[0083] It should be understood that the configuration of the redirection assembly 140 can be varied depending on a variety of factors. For example, as described above, it may be desirable to incorporate supplemental or auxiliary redirection elements, such as deflector 195, into one or more redirection segments. However, the redirection assembly 140 may be configured without such auxiliary redirection elements. Similarly, in the foregoing example, the redirection assembly includes three segments that allow the three wheels of the vehicle to simultaneously disengage from the drive surface of the track.

[0084] It may be desirable to reduce the number of segments that allow wheels to disengage from the drive surface of the track. For example, a redirection assembly may include two segments that allow wheels to disengage from the drive surface of the track simultaneously. In one example, the two segments may be opposite each other such that the two wheels disengaging simultaneously are on the same axle. Alternatively, the two segments may be spaced apart along the length of the track such that the two wheels disengaging simultaneously are spaced apart along the length of the vehicle. For example, the two segments may be spaced apart by a distance similar to the spacing between the front axle 215 and the rear axle 216.

[0085] Now for reference Figures 13 to 16 An alternative embodiment of the skew correction component or redirection component 440 for use in the material handling device 10 is illustrated. The alternative redirection component 440 is similar to... Figures 7 to 12 The example shown is redirection component 140. However, as described below, alternative redirection component 440 may include alternative auxiliary redirection element 485. As stated above, Figures 7 to 12 The redirection component 140 may include an optional deflector 195, which operates as an auxiliary redirection element via a deflector vehicle to attempt to center the vehicle between the front track 105 and the rear track 110. An alternative redirection component 440 includes multiple track elements that are generally similar to... Figures 7 to 12 The system is illustrated in the example. However, Figures 13 to 16 The system includes a fixed element that provides an auxiliary redirection element 485 instead of a movable deflector 195.

[0086] like Figures 13 to 16 As shown, the alternative redirection component 440 allows all three wheels of the vehicle to slide along the track simultaneously. For example, the first redirection segment 450 may include a front component 452 and a rear component 456. The front component 452 may include components that... Figures 7 to 12 The rear component 154 has a similar drive surface 455 to the drive surface 120. Conversely, the rear component 494 may include a drive surface 455 similar to... Figures 7 to 12 The component 164 in the middle has a similar sliding surface 466. Similarly, the second redirection segment 460 may include opposing front components 462 and rear components 464, which are constructed in a manner generally similar to the rear component 164, such that the component has a sliding surface 466.

[0087] More specifically, the three components 456, 462, and 464 can be constructed to be substantially similar to each other. Each component may include a sliding section 466 formed in a track similar to the sliding surface 173, allowing the vehicle wheel to slide along the sliding section. Additionally, similar to... Figure 12 The components shown, 456, 462, and 464 may each include transition regions similar to transition elements 172 and 174, wherein the track segment transitions from the drive element to the sliding surface or from the sliding surface to the drive element.

[0088] Alternative auxiliary redirection element 485 includes an elongated guide or fence. Fence 485 includes a generally vertical wall extending along the inner edge of the track. Figures 13 to 14 In this illustration, the fence is shown attached along the inner edge of the front track 105; however, it should be understood that the fence may alternatively be positioned along the rear track.

[0089] Figure 16 A cross-sectional view of the front assembly 460 is shown. A guardrail 485 projects upward from the inner edge of the track, thus forming a lateral stop that prevents lateral displacement of the wheel relative to the track. In this case, the lateral displacement is a horizontal displacement transverse to the direction of travel.

[0090] The fence is positioned such that it is spaced from the inner surface of the track by a distance similar to the thickness of the wheel 220. For example, the distance from the inner surface of the fence 485 to the inner surface of the track is less than approximately 120% of the width of the wheel 220. Preferably, the distance from the inner surface of the fence 485 to the inner surface of the track is less than approximately 110% of the width of the wheel 220. In this way, the fence and the inner surface of the track form guides that restrict the lateral movement of the wheel transverse to the direction of travel T. Similarly, the inner surfaces of the fence and the track form guides that restrict the ability of the wheel to twist or deflect about a vertical axis.

[0091] The fence can be formed into a generally L-shaped structure, having lower legs 487 that form supports for attaching the fence to the track. In this way, the lower legs 487 can be fixedly connected to the lower surface of the track housing 490.

[0092] refer to Figure 14 Fence 485 extends along the length of redirection component 440. Fence 485 can be a single element, or multiple elements can be positioned along the length of redirection component 440. For example, as Figures 13 to 15 As shown, the fence can be a single guide extending along both the first redirection segment 450 and the second redirection segment 460. However, the fence can be separate guides, such as a first fence positioned along the first redirection segment 450 and a second fence spaced apart from the first fence and positioned along the second redirection segment 460. In either case, preferably, the fence is elongated, with a length at least as long as the shorter of the first redirection segment 450 and the second redirection segment 460. Further still, the length of the fence can be at least as long as the combined length of both the first and second redirection segments. Thus, when three of the four wheels disengage from the drive surface 120 of the track 100, the fence 485 is long enough to prevent lateral displacement of the vehicle 200.

[0093] How to use

[0094] System 10 provides an apparatus for automatically delivering and / or sorting multiple items using multiple vehicles 200. Items can be scanned at an input station 20 and loaded onto a vehicle at a loading station adjacent to the input station. From the loading station, the vehicle travels vertically and horizontally along a track to one of multiple destination areas, such as one or more sorting bins 40. At the appropriate sorting bin 40, the vehicle 200 can transfer the item into the sorting bin. After delivering an item, the vehicle continues along the track back to the loading station to receive another item. The vehicle can continue circling the track, picking up items at loading stations and delivering them to sorting bins.

[0095] As the carrier moves along the track, it is forcibly engaged with the track. Specifically, the track includes multiple drive surfaces, and the carrier includes multiple drive elements that mate with the drive surfaces of the track. The mating drive elements and drive surfaces prevent the carrier wheels from sliding relative to the drive surfaces along the track.

[0096] As the vehicle travels along the track, it can be redirected relative to the track. In other words, the vehicle is redirected as it moves. The vehicle can be redirected to correct various potential misalignments between the vehicle and the track that could lead to excessive wear or jamming. For example, the vehicle can be redirected to reduce or eliminate misalignment between wheels on opposite sides of the track. For instance, the drive element of the wheel on a first side of the vehicle can disengage from the drive surface on the track, while the drive element on a second side of the vehicle remains engaged with the drive surface on the track. When the drive element of the wheel on the first side disengages from the drive surface of the track, the wheel on the first side moves freely relative to the track, thereby reducing the misalignment between the wheel on the first side and the wheel on the second side.

[0097] Additionally, the vehicle can be redirected by simultaneously disengaging the drive elements of multiple wheels from the drive surfaces of multiple segments of the track. In this way, the drive elements of multiple wheels move freely relative to the track, while the drive element of at least one wheel remains forcibly engaged with the track to drive the vehicle forward.

[0098] For example, as the vehicle 200 travels along track 100, it may pass through redirection section 140. Front wheels 220a and 220b may pass through the first segment 150 of the redirection section, while rear wheels 220c and 220d engage teeth 120 in the front track 105 and the rear track 110. As the front wheels 220a and 220b pass through the first segment 150, drive elements (such as gear 222a of the first wheel 220a) are displaced along the sliding surface 173 of track 170. As gear 222a displaces along the sliding surface 173, it disengages from the track. If the front wheel 220a is skewed relative to the rear wheel 220b, the front wheel will tend to redirect to align with the rear wheel as the gear 222a of the front wheel disengages from the track along the sliding surface 173. If the front wheel 220a is aligned with the rear wheel 220b, the front axle 215 will tend to orient itself in a desired orientation, such as perpendicular to the direction of travel T. If the front and rear wheels are not aligned on the front axle 215, the front axle may deflect or skew relative to the desired orientation. When the leading edge of the vehicle passes through the first orientation section, and the front wheels are released while the rear wheels remain engaged, the deflection or skew of the front axle may displace the front wheel 220a relative to the rear wheel 220b.

[0099] After passing through the first redirection section 150, the front wheels 220a and 220b re-engage with the drive surfaces 120 of the track, forcing the front wheels into engagement with the track. The vehicle continues to move forward, causing the front wheels to move through the second redirection section 160. As the front wheels move through the second redirection section 160, the rear wheels move through the first redirection section 150. In this embodiment, the first and second redirection sections are configured such that three of the four drive wheels 220 disengage from the drive surfaces of the track, while a single wheel remains engaged with the drive surfaces to drive the vehicle forward. Thus, three of the vehicle's four wheels are released to correct for skew or misalignment between one or more wheels on the first side of the vehicle and one or more wheels on the second side of the vehicle, while also correcting for skew or misalignment of one or more front wheels relative to one or more rear wheels.

[0100] After the rear wheels 220c and 220d pass through the first redirection section 150, the vehicle continues forward, causing the rear wheels to enter the second redirection section 150. In the second redirection section, both rear wheels 220c and 220d disengage from the drive surface, allowing the two wheels to slide or translate relative to the track. When the rear wheels 220c and 220d disengage from the drive surface of the track, the front wheels 220a and 220b are forcibly engaged with the track to drive the vehicle along the track.

[0101] The method may also include steps to prevent torsional and / or lateral displacement of the vehicle as it passes through the redirection assembly. Specifically, according to one embodiment, the method may include steps to simultaneously apply forces to the sides of the vehicle as it passes through the redirection assembly. In particular, forces of similar magnitude and opposite direction may be applied to both sides of the vehicle, thereby pushing the vehicle toward the center of the aisle. For example, as described above, the second redirection segment 160 may include a deflector 195, a first deflector positioned along the front track 105, and a second deflector positioned along the rear track. The first deflector provides a force against the side of the vehicle in a direction toward the rear track. Similarly, the second deflector 195 provides a force against the opposite side of the vehicle in a direction toward the front track. The force of the deflector 195 may be provided by a biasing element such that the deflector provides substantially equal and opposite forces transverse to the direction of travel T.

[0102] Alternatively, instead of a displaceable element for applying lateral forces to the vehicle, the redirection assembly may include a fixed guide or stop that limits lateral displacement and / or torsion of the vehicle. Specifically, as described above, the method may include releasing multiple wheels from engagement with a drive surface to allow the multiple wheels to slide relative to a track, while one or more wheels remain engaged with the drive surface. The method may include the step of constraining lateral displacement of the vehicle when multiple wheels disengage from the drive surface. In one embodiment, the method includes the step of simultaneously releasing three wheels from the drive surface while maintaining wheel engagement with the drive surface. When the three wheels disengage from the drive surface, the method includes the step of engaging one or more of the three released wheels with a stop to prevent lateral displacement of the released wheels.

[0103] The method may also include the step of re-engaging one or more of the three released wheels to the drive surface. Additionally, the method may include the step of releasing one or more wheels from the stop after the re-engaging step.

[0104] In view of the foregoing, the present invention can provide a system in which multiple vehicles move along a track to deliver articles to multiple locations. Optionally, the track may include a loop, and the vehicles may circulate around the loop. The track may include a redirection component that redirects the vehicles relative to a drive surface on the track. The method may include the steps of repeatedly engaging and disengaging the drive surface of a selector wheel of the vehicle while repeatedly engaging and disengaging it. The track is configured to allow the wheel to slide relative to the track when it disengages from the drive surface. This displaces a drive element on the wheel relative to the drive surface of the track to align the drive element with the drive surface.

[0105] In the above description, redirection components 140 and 440 are described as having two separate segments 150 and 160 and 450 and 460. However, it should be understood that the number of segments in the redirection components can vary. For example, redirection component 140 may include only a single redirection segment 150. In this embodiment, the front wheels 220a and 220b are redirected as they pass through redirection segment 150, and the rear wheels 220c and 220d will be similarly redirected as they pass through the redirection segment. In this embodiment, the front component 152 and the rear component 154 of redirection segment 150 may both include sliding surfaces. Thus, as the front wheels 220 move through the redirection segment, both wheels disengage from the drive surface of the track, while the rear wheels 220c and 220d remain engaged with the drive surface of the track to drive the vehicle forward. After moving through redirection segment 150, the front wheels 220a and 220b re-engage with the drive surface of the track to drive the vehicle forward, while the rear wheels 220c and 220d move through the redirection segment and disengage from the drive surface of the track.

[0106] As described above, the number and location of the redirection segments can vary according to many variables, including but not limited to the vehicle's construction, the number of wheels on the vehicle, the construction of the track's drive surface, and the construction of the drive elements on the vehicle. Therefore, it should be understood that the redirection components 140, 440 are not limited to the specific number and / or construction of the redirection segments described above.

[0107] Similarly, in the above description, redirection components 140, 440 may include auxiliary redirection elements, such as deflector 195 or fence 485. Auxiliary redirection elements 195, 485 may form part of the second redirection segments 160, 460, while the first redirection segments 150, 450 may not include deflector 195 or guide element 485. Therefore, it should be understood that the number and location of auxiliary redirection elements can vary based on several variables. Additionally, it should be understood that redirection components 140, 440 may be configured without any auxiliary redirection elements, such as deflector 195 or fence 485.

[0108] In various embodiments, the methods described herein may be implemented in software, hardware, or a combination thereof. Furthermore, the order of the methods may be changed, and various elements may be added, reordered, combined, omitted, or otherwise modified. All examples described herein are presented in a non-limiting manner. Various modifications and changes will be apparent to those skilled in the art who benefit from this disclosure. Implementations according to embodiments have been described in the context of specific embodiments. These embodiments are illustrative and not restrictive. Many variations, modifications, additions, and improvements are possible. Thus, multiple instances may be provided for the components described herein as a single instance. The boundaries between various components, operations, and data storage are somewhat arbitrary, and specific operations are illustrated in the context of the particular illustrative construction. Other allocations of functionality are foreseeable and may fall within the scope of the appended claims. Finally, structures and functions presented as discrete components in the example constructions may be implemented as combined structures or components. These and other variations, modifications, additions, and improvements may fall within the scope of the embodiments as defined by the appended claims.

[0109] While the foregoing relates to embodiments of the present invention, other and additional embodiments of the present invention may be devised without departing from the basic scope of the present invention, and the scope of the present invention is defined by the appended claims.

Claims

1. A material handling apparatus for sorting items into multiple destination areas, comprising: Multiple destination areas for an item, wherein the destination areas are arranged as multiple columns or rows; Multiple vehicles for transporting goods to or from the destination area; and A track for guiding the vehicle to the destination area, wherein the track includes multiple columns or rows adjacent to the plurality of destination areas, and wherein the track includes engaging elements; At least one of the said vehicles includes: A motor, used to drive the vehicle to one of the destination areas; A drive system capable of cooperating with the track to guide the vehicle to one of the destination areas, wherein the drive system includes: First wheel axle; The first wheel is mounted on the first end of the first wheel axle; The second wheel is mounted on the second end of the first wheel axle; and Multiple drive elements for driving the first and second wheels and forcibly engaging with the engagement elements on the track; The track includes a redirection section configured to disengage at least the drive element of the first wheel from the engagement element of the track, thereby allowing the first wheel to slide relative to the second wheel along the track to redirect the first wheel relative to the second wheel.

2. The apparatus of claim 1, wherein, The drive element is formed separately from the first wheel and the second wheel.

3. The apparatus of claim 1, wherein, The track includes a front track and a rear track spaced apart from the front track to form a passageway between the front track and the rear track, wherein the vehicle moves within the passageway.

4. The apparatus of claim 3, wherein, The front track is configured to guide the first wheel of the vehicle, and the rear track is configured to guide the second wheel of the vehicle.

5. The apparatus of claim 3 or 4, wherein, The drive element includes a first drive element associated with the first wheel and a second drive element associated with the second wheel; and wherein the redirection section includes a track segment along the front track having a first gap formed between the engagement elements, such that the first drive element disengages from the engagement element while the second drive element forcibly engages the engagement element to drive the vehicle along the track.

6. The apparatus of claim 5, wherein, The vehicle includes: A first axle has a first wheel at a first end and a second wheel at a second end; The second axle has a third wheel at the first end and a fourth wheel at the second end; Wherein, the first wheel and the third wheel engage the front track; The second wheel and the fourth wheel engage the rear track; The drive element includes a third drive element associated with the third wheel and a fourth drive element associated with the fourth wheel; The redirection section includes a first segment and a second segment, the first segment having a first gap formed between the engaging elements, the second segment having a second gap formed between the engaging elements, and wherein the second segment is constructed and positioned relative to the first segment such that when the first driving element is positioned within the first gap, the third driving element and the fourth driving element are positioned within the second gap, such that the second wheel engages the engaging elements to drive the first driving element through the first gap, and drives the third driving element and the fourth driving element through the second gap.

7. The apparatus of claim 5, further comprising means for preventing lateral displacement of the first drive element and the second drive element as the first wheel passes through a portion of the redirection section.

8. The apparatus according to claim 7, wherein, The device for preventing lateral displacement of the first drive element and the second drive element is configured to prevent lateral displacement when the first wheel passes through the first gap.

9. The apparatus according to claim 7 or 8, wherein, The device for preventing lateral displacement of the first drive element and the second drive element includes a fence positioned along the edge of the front track or the rear track.

10. The apparatus according to claim 1, wherein, The drive system is operable to maintain the orientation of the vehicle relative to the horizon when the vehicle changes from a first direction of travel to a second direction of travel, wherein the first direction of travel and the second direction of travel form an angle.

11. The apparatus according to claim 10, wherein, The vehicle includes a transfer mechanism for transferring items between the vehicle and one of the destination areas, wherein the transfer mechanism is operable to transfer items between the vehicle and the destination area.

12. A method for classifying items into multiple category locations, comprising the following steps: Multiple sorting locations for receiving items are provided, such that aisles are formed between the multiple sorting locations; Load the items onto the vehicle; Driving the vehicle within the aisle to deliver items to one of the sorting locations, wherein the step of driving the vehicle within the aisle includes driving a first drive element along a first track having a plurality of first engagement elements, and driving a second drive element along a second track having a plurality of second engagement elements spaced apart from the first track. Disengaging the first drive element from the first engagement element while engaging the second engagement element with the second drive element allows the first drive element to slide relative to the second drive element along the first track, thereby redirecting the first drive element relative to the second drive element; and After the step of disengaging the first drive element from the first engagement element, the first drive element is engaged with the first engagement element so that the first drive element and the second drive element drive the vehicle along the first track and the second track.

13. The method of claim 12, further comprising the step of transferring articles from the vehicle to a storage box.

14. The method according to claim 12 or 13, wherein, The vehicle includes a third drive element and a fourth drive element, and the driving step includes engaging the third drive element with the first engagement element and engaging the fourth drive element with the second engagement element.

15. The method according to claim 14, wherein, The disengagement step includes disengaging the third drive element from the first engagement element and disengaging the fourth drive element from the second engagement element when the second drive element engages the second engagement element.

16. The method of claim 14, wherein, The first drive element and the third drive element include rotatable gears capable of cooperating with the first engagement element, and the second drive element and the fourth drive element include rotatable gears capable of cooperating with the second engagement element.

17. The method according to claim 12, wherein, The driving step includes driving the vehicle around the loop multiple times to deliver multiple items, and the method includes a step of disengaging each time the vehicle is driven around the loop.

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