JP2006160496A - Load transferring system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a load transferring system capable of maximally securing a load storage space on a rack to increase the storage efficiency of the rack by performing carry-in and -out operations without allowing a pair of forks extending and retracting at the sides of a load to come into contact with the parts of the rack. <P>SOLUTION: A pair of right and left side arrangement type forks 40 are used to transfer a receiving box 50 in which the load is stored between the lift table 33 of a stacking crane 30 and the rack 10. When the receiving box 50 is transferred, a distance between the pair of forks 40 holding the receiving box 50 is changed to engage the engagement part of the forks 40 with the engaged part of the receiving box 50 or brought into contact with the longitudinal end part of the receiving box 50, and the forks 40 are extended and retracted to slidably move the receiving box 50 relative to the rack 10 and the lift table 33. Thus, the receiving box can be properly transferred to any of the longitudinal storage parts 15 and 16 of the rack 10, and the storage space can be maximally secured on the rack 10 without allowing the parts of the rack 10 to come into contact with the forks 40. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a load transfer system capable of loading and unloading a stacker crane equipped with a load transfer device and a shelf for storing the load, and more particularly to reducing the dead space of the shelf and transferring the load. The present invention relates to a load transfer system in which a method is improved to improve load storage efficiency.

  In an automatic warehouse system, in order to secure a large number of storage spaces, storage units are set in front and rear of a shelf, and loads are loaded and unloaded using forks on a lifting platform provided in a stacker crane. An example of such a conventional automatic warehouse system is described in Japanese Patent Application Laid-Open No. 2003-486048.

  In such a conventional automatic warehouse system, it is possible to store a large amount of loads on a shelf and efficiently carry in and out, but the fork as used in such a conventional automatic warehouse system is brought into contact with the lower side of the load. This type of load transfer device that loads and unloads a load on the fork secures a space for loading and unloading the fork directly under the load, and lifts and loads the load with the fork above the load. Since it is necessary to secure enough space for the work, there is a problem that the storage efficiency of the shelf is lowered due to the occurrence of such dead space above and below the load. In addition, the lifting platform stop position for each storage position of the load transfer device must be in the vertical direction when loading and unloading loads, such as the upper surface of the fork needs to be positioned above when loading the shelf and below when loading. There is also a problem that the control of the stop position of the lifting platform becomes complicated.

  In recent years, as a solution to these problems of the unloading fork insertion type load transfer device used in this conventional automatic warehouse system, a fork is placed on the side of the cradle on which the load or load is loaded from the side. There has been proposed a load transfer device of a type in which a part is engaged and a fork is extended and reduced, and a load and a cradle are slid and carried in and out. Examples of such conventional load transfer devices include those described in JP-A-11-208816, JP-A-2004-203528, and JP-A-2004-224484.

Such a conventional load transfer device has a pair of forks that operate on the side of the load with respect to the load stored in the shelf, and takes out and puts the pair of forks on the side of the load, By changing the distance between the forks, it is possible to switch between a state where a part of the fork is engaged with the load side and a state where the fork is disengaged. It is a mechanism that allows loading and unloading of loads, and it has the feature that it is not necessary to secure the space for the fork to move above and below the load, and the storage efficiency can be improved without causing dead space above and below the load on the shelf.
JP 2003-48604 A Japanese Patent Laid-Open No. 11-208816 JP 2004-203528 A JP 2004-224484 A

  Various systems for transferring conventional loads were configured in the above-mentioned patent documents. However, as in Patent Document 1, two loads can be stored on the shelf before and after, and the storage amount on the shelf is reduced. Fork structure for carrying in / out operation from the side to the load as described in Patent Documents 2, 3 and 4 in order to use the shelf efficiently by reducing the vertical dead space in the shelf as much as possible while greatly increasing However, there are many problems that cannot be applied simply. In other words, in order to carry in / out a load that is in the back with respect to the front of the shelf among the two pieces arranged in front and rear in each part of the shelf, it is necessary to deeply enter the fork into the shelf side. In order to mechanically establish loading and unloading of the fork without making contact between the vertical column that supports the plate from the side and the fork that expands and contracts back and forth on the side of the load, the range of motion of the fork is on the inside of the vertical column Therefore, there is a problem that the space for loading the load on the shelf board is reduced by that amount, and the adoption of the fork of the above method does not simply reduce the dead space of the shelf. Was.

  The present invention has been made in order to solve the above-described problems, and can carry out a loading / unloading operation without causing a pair of forks and shelves that extend and contract on the side of the load to contact each other, thereby maximizing the load storage space on the shelf. An object of the present invention is to provide a load transfer system that can improve the storage efficiency of the shelf by securing the limit and can carry in and out the load quickly by appropriately operating the fork.

  The load transfer system according to the present invention has a shelf structure in which a large number of storage spaces in which a plurality of storage items can be placed in the depth direction with respect to the shelf front are arranged vertically and horizontally, and the shelf front is opposed to each other at a predetermined interval. And a stacker crane that is disposed in the middle of the two sets of shelves and moves along the respective shelves and is capable of carrying in and out the storage object. The stacker crane is mounted on or near the elevator platform that can reach the front of the shelf front of a predetermined storage space by moving the stacker up and down, and extends or contracts in the longitudinal direction of the shelf In the load transfer system comprising a fork for carrying the stored items into and out of the storage space and handling one or a plurality of loads as one of the stored items, the load is one or more. In a state where it is stored in the specified box Each box is handled as one stored item, and the receiving box has a predetermined hooking portion on the side of the shelf parallel to the shelf depth direction, at least on the shelf front side near the shelf front in the shelf storage state. A pair of the forks are disposed on or near the lifting platform at positions facing the receiving box on the side of the receiving box, and can reach the position farthest from the lifting platform in the extended state. A convex hooking portion that can be hooked to the hooked portion is formed at the leading end portion, and at least a predetermined range portion including the hooking portion can be brought close to and separated from the other pair. The shelf includes a plurality of support portions on which the bottom portion of the receiving box is placed and forms a bottom surface of the storage space, and a plurality of vertical columns that support the support portions, and the vertical columns are at least the forks Placed outside the reach of The fork is driven to extend and contract in a state in which the hooking part is brought into contact with the hooked part of the receiving box or the front or rear end surface of the receiving box, and the receiving box is placed in each depth direction of the storage space. And between the lifting platform.

  Thus, according to the present invention, as a fork for transferring the receiving box in which the load is stored between the lifting platform and the storage space of the shelf in the stacker crane, a pair of left and right positions that are positioned laterally with respect to the receiving box In addition to using a mold fork, a hooked portion is provided in the receiving box, and when the receiving box is transferred, the distance between the pair of forks facing each other with the receiving box being changed is changed to When the fork is expanded and contracted after engaging the hook-shaped hooking part with the hooked part of the receiving box, or by bringing the hooking part into contact with the front and rear ends of the receiving box, the hooking part moves back and forth along with this expansion and contraction. By pushing or pulling the receiving box and sliding it to the shelf or lift, the transfer can be executed, so that the receiving box can be placed at any position in the front and rear direction in the storage space of the shelf while suppressing the amount of extension of the fork. With proper holding and low driving force On possible mounting, without contact between the shelves each part and the fork, maximum can be secured storage space in the shelf space required for the operation of the fork becomes minimum necessary, it can be effectively utilized for storage space.

  Further, in the load transfer system according to the present invention, if necessary, the shelf support portion is formed so that two receiving boxes can be placed side by side in the depth direction of the shelf, and the vertical column is When two receiving boxes are placed side by side on the support part, they are located on the rear side of the hooked part position in the front part of the receiving box on the rear side of the shelf.

  As described above, according to the present invention, the shelf support portion can mount two receiving boxes, and the vertical column of the shelf is the farthest part where the fork tip reaches the hooked portion of the rear receiving box. Since the fork does not come into contact with the vertical column even if the fork is driven to extend and retract on the front side of the vertical column, the space for expansion and contraction in the state where the fork is not held can be reduced. It can be secured on the front side of the vertical column, and the area other than the actual receiving box mounting space can be minimized, and the shelf can be made compact, and the dead space can be eliminated. Space can be further increased.

  Further, in the load transfer system according to the present invention, if necessary, a stopper that protrudes upward in a convex shape is provided at the foremost portion of the shelf support portion facing the stacker crane and serving as a shelf opening. In the unloading process from the shelf by the fork, the fork is contracted and the receiving box is placed in each storage space in a state where the fork engaging part is engaged with the engaged part on the front side of the receiving box. When the front end of the receiving box reaches the stopper, the fork and the lifting base are raised until the load receiving surface of the lifting base and the lower end of the front of the receiving box are positioned at least above the stopper. When the fork is reduced again, the entire receiving box is slid onto the lifting platform, and in the process of loading into the shelf by the fork, the lifting platform is placed with the load receiving surface of the lifting platform positioned at least above the stopper. The rack is extended to move the receiving box from the lifting platform to the shelf side.When most of the receiving box is transferred to the support, the fork and the lifting table are connected to the upper surface of the shelf and the receiving surface of the lifting platform. It is lowered until the height is substantially the same, and the receiving box is moved to the respective mounting positions by extending the fork again.

  As described above, according to the present invention, a convex stopper is arranged at the front end of the support portion of the shelf, and it is extremely difficult to slide the stopper forward from the stopper with respect to the receiving box placed on the support portion. At the time of loading and unloading, the fork and the lifting platform are operated so that the receiving box can be transferred by passing over the stopper, so that natural vibrations such as earthquakes and false human vibrations are Even if it is added, it is possible to prevent the receiving box from moving freely from the support part to the front side, and to prevent the receiving box from falling off the shelf. There is no impact or noise caused by hitting, and there is no need to increase the fork driving force or secure the receiving box strength by moving the stopper forcibly while sliding, and setting the optimal driving force and strength Reduce costs That.

  Further, in the load transfer system according to the present invention, if necessary, the hooking portion is also disposed at a position farthest from the shelf among the movable parts of the fork, and the receiving portion is in the process of carrying the shelf by the fork. When the box is transferred from the lifting platform to the shelf support until most of the receiving box is transferred, the fork is extended with the front hooking part away from the shelf in contact with the front end of the receiving box. On the other hand, when the entire receiving box is finally moved to each placement position of the storage space, after the hooking portion and the receiving box are once separated and the fork is reduced, the rear side closer to the shelf is placed. The fork is extended in a state where the hooking portion is in contact with the front end of the receiving box.

  As described above, according to the present invention, the hooking portions are arranged before and after the movable portion of the fork, respectively, and the receiving box is initially pushed into the state of pushing the receiving box at the hooking portion on the side away from the shelf. In the rest of the carry-in process, by pushing the receiving box at the hooking part near the shelf, the hooking part is properly used and the movement of the fork in the opposite direction and the shelf front-rear direction can be minimized respectively. The delivery of the receiving box can be completed in a short time, and the entire system is excellent in handling the load.

  In addition, the load transfer system according to the present invention moves the receiving box from each placement position of the storage space to the front side of the shelf in the process of carrying out from the shelf by the fork as necessary, and a part of the receiving box Until the fork is transferred onto the lifting platform, the fork is reduced with the hooked portion on the rear side of the fork engaged with the hooked portion on the front side of the receiving box, while the rest of the receiving box continues. When the part is completely moved onto the lifting platform, the hooking portion on the rear side of the fork is detached from the hooked portion of the receiving box, the fork is once extended, and then the hooking portion on the rear side is moved to the receiving box. The fork is reduced in a state where it is in contact with the rear end.

  Thus, according to the present invention, at the beginning of the receiving box unloading process from the shelf, the engaging part of the fork is hooked to the hooked part of the receiving box to pull the receiving box, while in the remaining unloading process, the engaging part is By bringing the receiving box into contact with the receiving box end surface and pushing the receiving box, the fork and receiving box can be connected more securely by engaging the hooked part and the hooked part, and the front part of the receiving box can be lifted appropriately. On the other hand, when a part of the receiving box reaches the lifting platform, the force is efficiently transmitted to the receiving box by pushing from the end in the direction of travel at the engaging part, and on the receiving surface of the lifting platform located above the supporting part. The receiving box can be moved quickly and the entire movement beyond the upper side of the stopper of the receiving box can be performed smoothly and in a short time, and the hooks can be used properly to move the fork in the opposite direction and the shelf front-rear direction. Carrying out the inbox in a shorter time with minimum required It is completed, and excellent in handling properties of the luggage system as a whole.

  An embodiment of the present invention will be described below with reference to FIGS. In the present embodiment, an example of a system that loads and unloads books in a library library will be described. 1 is a side view of a load transfer system according to the present embodiment, FIG. 2 is a front view of a stacker crane in the load transfer system according to the present embodiment, and FIG. 3 is a load transfer system according to the present embodiment. FIG. 4 is a sectional view of the main part of the fork in the load transfer system according to the present embodiment, and FIG. 5 is a side view of the fork in the extended state in the load transfer system according to the present embodiment. FIGS. 6 and 6 are a side view and a front view of a receiving box in the load transfer system according to the present embodiment, and an enlarged view of a fork claw. FIG. 7 is a main part of a shelf in the load transfer system according to the present embodiment. FIG. 8 is a cross-sectional view, a side view of the support portion, and an enlarged view of the stopper. FIG. 8 is a diagram illustrating each state of the fork separation state, the claw engagement state, and the claw receiving box end surface contact state in the load transfer system according to the present embodiment. 9 and 9 are related to this embodiment. FIG. 10 is a first half explanatory view of a receiving box carrying-out process to the shelf front side storage unit according to the present embodiment, and FIG. FIG. 12 is a partial explanatory view of the receiving box carry-out process to the rear shelf storage unit in the load transfer system according to the present embodiment. FIG. 12 shows the receiving box carry-in to the front shelf storage unit in the load transfer system according to the present embodiment. 13 is an explanatory diagram of the first half of the process, FIG. 13 is an explanatory diagram of the latter half of the process of loading the box into the storage unit on the front side of the shelf in the load transfer system according to the present embodiment, and FIG. 14 is the rear side of the shelf in the load transfer system according to the present embodiment. It is a partial explanatory view of a receiving box carrying-in process to a storage part.

  In each of the drawings, the load transfer system 1 according to the present embodiment has a shelf structure in which a large number of storage spaces in which two stored items can be placed in the depth direction with respect to the shelf opening are arranged in the vertical and horizontal directions. Two shelves 10 are arranged in such a manner that each shelf front is opposed to each other at a predetermined interval, and each shelf 10 is disposed between the shelves 10 so as to be linearly movable along each shelf front facing each other. And a stacker crane 30 that performs a loading / unloading operation, and the loading / unloading of the book 60 as one or a plurality of the loads as a single stored item in the receiving box 50 in a state where the book 60 is stored in the predetermined receiving box 50. Is to be handled. Note that the load transfer system 1 is not limited to the handling of the receiving box 50 in which the books 60 are stored. For example, after all the books 60 originally stored are taken out from the receiving box 50, When only the receiving box 50 is returned to the original storage position of the shelf 10 or when the book 60 is scheduled to be stored later, only the receiving box 50 is stored in the shelf 10 in advance and the book 60 is actually stored. It is also intended to handle only the empty receiving box 50 that may occur transiently, such as when unloading 50 from the shelf 10, and the receiving box 50 is carried in as one of the stored items regardless of the state in the receiving box 50. The features of the configuration related to carrying-in / out of the receiving box during handling such as taking out are included in the scope of the present invention.

  The shelf 10 is formed by fixing a plurality of support portions 12 having a length capable of supporting two receiving boxes 50 to a plurality of vertical columns 11 that are erected, and each support portion 12 between the vertical columns 11. The upper space portion and an intermediate region sandwiched between them are arranged as a storage space in many vertical and horizontal directions, and the support portion 12 forms a bottom surface of the storage space and the receiving box 50 is placed thereon. Of the storage space on the support portion 12, the front receiving box 50 mounting position is the front storage section 15 and the rear receiving box 50 mounting position is the rear in the state where the two receiving boxes 50 are placed side by side. It becomes the side storage part 16, and the receiving box 50 is mounted in one of each storage part, and it is not set as the mounting state which straddled two storage parts. When loading / unloading the receiving box 50 to / from the rear storage unit 16, when the front storage unit 15 is empty, the loading / unloading is executed as it is, and when it is not empty, it is always stored in the front storage unit 15 in advance. Carrying in / out is performed after the process of once transferring the receiving box 50 to the temporary storage space. In addition, grasping | ascertaining the presence or absence of the receiving box 50 in all the storage parts 15 and 16 of the shelf 10 controls all the load handling apparatuses including a load transfer system, and puts in and out the book 60 with respect to the receiving box 50. The central control unit (not shown) that consistently manages the movement state of the receiving box 50 from the loading / unloading port to the shelf 10 is performed based on the fact that the receiving box 50 is carried into and out of the shelf 10. The load management system including the storage status of is known and will not be described.

  The support portion 12 has a substantially L-shaped cross-sectional portion located at one side end of one storage space and a symmetrical L-shaped cross-sectional portion located at the other end of the adjacent storage space in the middle. It is a structure integrated through a plate-shaped portion, and is fixedly disposed in an arrangement in which two vertical columns 11 are sandwiched between two substantially L-shaped cross-sectional portions. With such an arrangement, each side end of the bottom surface of the receiving box 50 is received by the separate support parts 12 and one receiving box 50 is supported by the two support parts 12. Moreover, the position of the support part 12 with respect to the two vertical pillars 11 to be attached is the rear receiving box 50 when the two receiving boxes 50 are placed side by side on the support part 12, that is, the rear side. The positional relationship is such that the storage unit 16 is positioned on the side of the two vertical columns 11 (see FIG. 7). Convex stoppers 13 and 14 are formed at the tip of the support portion 12 to prevent the receiving box 50 from being displaced outward from the support portion 12.

  In the stacker crane 30, a lifting platform 33 that moves up and down a moving object between a pair of masts 32 erected on a traveling platform 31 that can travel on a linearly arranged rail 30 a moves up and down. It is a publicly known crane device that can be arranged. The entire traveling mechanism and the lifting mechanism of the lifting platform 33 are the same as those in the prior art, and detailed description thereof is omitted. A pair of forks 40 that can be extended and reduced in the depth direction of each shelf 10 is disposed on the lifting platform 33 as a transfer mechanism. Further, a portion between the forks 40 on the lifting platform 33 is provided with a substantially flat load receiving surface 34 on which the receiving box 50 as the storage object to be transferred is placed. After the elevating platform 33 moves up and down by placing the receiving box 50 on the cargo receiving surface 34 and reaches the front of the shelf front of the predetermined storage space in the shelf 10, the fork 40 on the elevating platform 33 is expanded or contracted and stored. This is a mechanism for carrying the receiving box 50 into and out of the space. For detecting the position of the receiving box 50 on the shelf 10 or the cargo receiving surface 34 and the position where the tip of the fork 40 is reached in order to operate the fork 40 appropriately, a known detection method using various sensors and switches is used. The detailed description is omitted.

  The fork 40 is mounted on the elevating platform 33 so as to be slidable in the lateral direction with the load receiving surface 34 interposed therebetween, and is slidably mounted in parallel to the depth direction of the shelf 10 on each of the lower steps 41. It consists of three components: a middle step portion 42 and an upper step portion 43 that is slidably assembled in the same direction in the middle step portion 42, and is provided at the lower end of the lower step portion 41 and at the lower end of the middle step portion 42. The middle stage 42 is driven with respect to the lower stage 41 and the gear 42b provided at the upper center of the middle stage 42 and the racks 43a and 41b provided on the upper stage 43 and the lower stage 41, respectively, Are engaged in a differential gear train, and when the drive gear 41a of the lower step portion 41 is rotated, the middle step portion 42 protrudes from the lower step portion 41 or in the reverse direction. The upper stage 43 moves with a displacement larger than the middle stage part 42 in the same direction as the middle stage part 42 with respect to the lower stage part 41 by the action of the differential gear train, and in the protruding state from the lower stage part 41, the upper stage part 43 is always in the middle stage part. It is a mechanism located farther than 42.

  The fork 40 is expanded and contracted by displacing the upper step portion 43 and the middle step portion 42 with respect to the lower step portion 41, and the operation speed when the receiving box 50 is moved accordingly is as follows. Corresponding speed control is performed. That is, when the book 60 is unevenly distributed in the receiving box 50 and the load center position of the entire receiving box 50 is greatly deviated from the center of the receiving box 50, the movement of the receiving box 50 and the receiving box 50 of the book 60 are moved. In order to prevent the behavior of the fork 40 from destabilizing, the speed control such as reducing the expansion / contraction operation speed of the fork 40 and reducing the change rate of the operation speed is executed, so that the receiving box 50 can stably move on the support portion 12. On the other hand, when the book 60 is properly stored in the receiving box 50 and the shift of the load center is small, the operating speed of the fork 40 is set as much as possible within a range in which the receiving box 50 and the book 60 do not become unstable. Faster and shorter cycle time for loading and unloading operations. In addition, acquisition of information such as the degree of uneven distribution of the book 60 in the receiving box 50, which serves as a reference for speed control, is received by a measuring means separately provided at a loading / unloading port or the like for loading / unloading the book 60 into / from the receiving box 50. In the case of automatic acquisition based on the measurement result of 50 load balances and the like, the management operator manually inputs a parameter indicating the storage state of the book 60 in the receiving box 50 into the control system at the same entrance / exit. Can be any of the following.

  The lower step portion 41 is mounted on the lifting platform 33 via a linear motion guide 41c, and a rack 41d parallel to the linear motion guide 41c is integrally mounted, and is disposed on the lower side of the load receiving surface 34. By driving the gear 35, the middle stage part 42 and the upper stage part 43 can be moved in a predetermined range in the lateral direction, whereby each fork 40 can be moved toward and away from the other pair.

  The upper step portion 43 is configured to include claws 44 and 45 as the engaging portions that protrude toward the other opposing forks 40 at the end portions in the front-rear direction. The end surface portion on the front end side of the fork 44 of the claw 44 and the end surface portion on the rear end side of the fork 40 of the claw 45 are formed in a shape in which corner portions are obliquely chamfered, and the chamfered positions of the claw 44 and 45 are inclined. The surfaces 44 a and 45 a come into contact with the receiving box 50 and push the receiving box 50 when the receiving box 50 is carried into the shelf 10. The upper step portion 43 and the middle step portion 42 form a portion that advances to the shelf 10 side in the fork 40, but the combined thickness of the upper step portion 43 and the middle step portion 42 is smaller than the widthwise dimension of the vertical column 11, and the upper step portion 43 and the middle stage 42 are expanded and contracted in a state where they are not in contact with the receiving box 50, the movable range will be accommodated in the space in front of the vertical column 11 adjacent to both sides of the storage space where the receiving box 50 is located, The area where the receiving box 50 can actually be placed can be secured to the maximum extent.

  The receiving box 50 is formed as a shallow box-like body with an upper open state that can accommodate a plurality of books 60 inside, and a partition plate 50a whose position can be adjusted as needed is disposed inside, and shelves Recessed portions 51 and 52 as the hooked portions to which the claws 44 and 45 of the fork 40 can enter and engage with the lower portions of the front end portion and the rear end portion of the side surface parallel to the shelf depth direction in the installed state. The claws 44 and 45 are disposed over a predetermined range, and are handled as one loading / unloading unit when loading / unloading into / from the shelf 10. When the fork 40 is telescopically driven while the claws 44 and 45 of the fork 40 are engaged with the recesses 51 and 52 of the receiving box 50 or in contact with the lower end of either the front or rear of the receiving box 50, the receiving box 50 is stored in the storage space. This is a mechanism to be transferred between the storage units 15 and 16 and the lifting platform 33 before and after the depth direction.

  In the receiving box 50, the recesses 51 and 52 are installed on either side of the side of the receiving box 50, so that the carry-in / out operation can be performed as it is even if the order of the receiving box 50 is changed with respect to the shelf 10. Yes. Note that the hooked portion of the receiving box 50 is not limited to the recesses 51 and 52, but can have other shapes that allow the claws 44 and 45 to be hooked, for example, within a range where the receiving box 50 can be accommodated in the storage portions 15 and 16. It does not matter even if it protrudes from the receiving box body part to the side.

  In addition, the receiving box 50 has a shape in which the lower corners of the front and rear end surfaces are partly cut out, and the claws 44 and 45 of the fork 40 are brought into contact with this portion. As a result, the distance between the abutted surfaces at the lower part of the front and rear end surfaces is smaller than the distance between the claws 44 and 45, and when one of the claws abuts the receiving box, it does not accidentally contact the other claw. .

  In addition, the vertical column 11 of the shelf 10 is located behind the front end side recess 51 of the receiving box 50 in the rear storage unit 16 when the two receiving boxes 50 are placed side by side on the support unit 12. When the claw 45 of the fork 40 is engaged with the recess 51 of the receiving box 50 in the rear storage portion 16 and the receiving box 50 is transferred, the fork 40 and each of the vertical columns 11 are moved. Contact cannot occur (see FIG. 7A).

  Next, the transfer operation of the load transfer system according to the present embodiment will be described. As a premise, the receiving box 50 to be handled corresponds to one of the storage units 15 and 16 in the predetermined storage space of the shelf 10 in a one-to-one correspondence according to the size and type of the book 60 stored therein. It is assumed that no loading / unloading operations are performed except for the storage unit. In both cases of carrying in and out, the fork 40 is separated from the receiving box 50 at a predetermined interval when the fork 40 performs the expansion / reduction operation as it is in the initial state.

  First, the carrying-out process of the receiving box 50 stored in the front storage unit 15 will be described. First, the entire stacker crane 30 is moved and the lifting platform 33 is moved up and down to target the cargo receiving surface 34 and the fork 40. It is made to oppose the front side of the receiving box 50, and the load receiving surface 34 height is positioned so that it may become substantially the same height as the support part 12 in which the receiving box 50 is mounted. At this position, the fork 40 is extended to the receiving box 50 side, the claw 45 at the tip is made to reach a position facing the concave portion 51 on the side of the receiving box 50, and then the fork 40 is moved in the proximity direction. The recess 51 is engaged (see FIG. 9A). Even when the receiving box 50 is mistakenly shifted from the normal position of the front storage portion 15 at the time of loading, even when the claw 45 is partly detached from the side of the concave portion 51 to the rear side at the normal arrival position of the claw 45. Since the claw 45 has the inclined surface 45a, when the pair of forks 40 are brought close to each other, the movable part of the fork 40 including the claw 45 is moved forward by the guide by the inclined surface 45a in contact with the rear edge of the recess 51. The claw 45 can be inserted into the recess 51 while shifting or the recess 51 portion of the receiving box 50 is shifted backward, and a certain engagement state of the claw 45 is obtained while allowing a slight displacement of the receiving box 50. It is a mechanism that can be.

  When the claw 45 is engaged with the recess 51, the front end of the receiving box 50 is immediately behind the stopper 13. Even if the fork 40 is moved in the direction in which the fork 40 is contracted by the stopper 13, the receiving box 50 is moved to the lifting platform 33 side. Since it cannot be pulled, the elevator base 33 is once raised, and the front end portion of the receiving box 50 is lifted by the claws 45 of the fork 40 that rises simultaneously (see FIG. 9B). When the front end of the receiving box 50 reaches the upper side of the stopper 13, the raising and lowering of the lifting platform 33 is stopped, the fork 40 starts to be reduced, and the receiving box 50 is pulled in until it partially rests on the load receiving surface 34 ( (See FIG. 9C).

  Thereafter, the forks 40 are once separated from each other to separate the claws 45 from the recesses 51 of the receiving box 50, and the forks 40 are extended again so that the leading pawls 45 reach the rear end side of the receiving box 50 (FIG. 10). (See (A)), the forks 40 are moved toward each other so that the claw 45 and the lower part of the rear end face of the receiving box 50 can come into contact with each other. In this state, the fork 40 is shrunk and the receiving box 50 is pushed by the claw 45 so that the entire receiving box 50 is completely moved onto the load receiving surface 34 to be accommodated in the lifting platform 33 and at the same time, the fork 40 is placed on the lifting platform 33. Is returned to the initial position, the transfer is completed (see FIG. 10B).

  In the process of transferring the receiving box 50 onto the cargo receiving surface 34, not only the lateral movement of the receiving box 50 is restricted by the standing part of the substantially L-shaped cross-sectional part of the support part 12, but also the fork Since the receiving box 50 is sandwiched from the side by the wide plate-like upper stage 43 in 40, the moving posture of the receiving box 50 can be reliably maintained in a constant state. Depending on the size of the book 60, the book 60 is partially exposed above the receiving box 50 (see FIG. 6). The upper stage 43 of the fork 40 is also located on the side of the book 60. Thus, it is possible to prevent the book 60 from dropping from the receiving box 50.

  The carrying-out operation of the receiving box 50 after the completion of the transfer to the lifting / lowering table 33 is performed by raising or lowering the lifting / lowering table 33 while the fork 40 is completely accommodated and running the entire stacker crane 30 as before. 33 is temporarily moved or moved to the front of the exit space (not shown). The temporary storage space and the leaving space are configured in substantially the same manner as the storage space of the shelf 10, but the area for storing the receiving box 50 is set to one receiving box because of the necessity, and the receiving box 50 is dropped. Since there is a separate structure in consideration of safety, such as prevention, there is no stopper at the tip of the support portion (not shown) forming the bottom surface of each space, and the receiving box 50 is placed between the lifting platform 33 and It can be moved by sliding as it is.

  The receiving box 50 is temporarily placed or carried into the unloading space. First, the load receiving surface 34 and the fork 40 are made to face the temporary placing or unloading space to be loaded, and the height of the receiving surface 34 forms the bottom of the space. It is made to substantially coincide with the height of (not shown). At this position, the forks 40 are moved toward each other toward the receiving box 50 on the cargo receiving surface 34 so that one claw 44 of the fork 40 and the front end side surface of the receiving box 50 can be brought into contact with each other. In this state, the fork 40 is extended, the receiving box 50 is pushed, and these are moved from the load receiving surface 34 to the temporary placement or delivery space side, and the entire receiving box 50 is temporarily placed from the initial position of the other claw 45 or the delivery space side. Transfer until it reaches the condition. Thereafter, the forks 40 are once separated from each other so that the claws 44 are separated from the receiving box 50, and the forks 40 are contracted so that the other claw 45 reaches the front side of the receiving box 50 (rear side in the direction of travel of the receiving box 50). 40 is moved toward each other to a predetermined interval so that the inclined surface 45a of the claw 45 and the front end side surface of the receiving box 50 can come into contact with each other.

  In this state, the fork 40 is extended, and the receiving box 50 is pushed to be completely placed on a temporary placement or a storage space support (not shown), and the receiving box 50 reaches a predetermined position in the space. 50 is in the retracted state, and the forks 40 that have completed the carrying-in operation are separated from each other, the claw 45 is separated from the receiving box 50, the fork 40 is contracted again and returned to the initial position on the lifting platform 33, and the transfer is completed.

  Further, the carrying-out process of the receiving box 50 stored in the temporary placement or unloading space will be described. Similarly, the load receiving surface 34 and the fork 40 are opposed to the temporary placing or unloading space to be unloaded, and the load receiving surface 34 is made from the beginning. It matches with the level of the support part which makes the bottom face of the space. At this position, the fork 40 is extended to the receiving box 50 side, the claw 45 at the front end is made to reach the rear end side of the receiving box 50, and then the fork 40 is moved toward each other so that the claw 45 and the receiving box 50 It is possible to contact the rear end surface. In this state, the fork 40 is shrunk and the entire receiving box 50 is completely drawn onto the load receiving surface 34 so as to be accommodated. At the same time, the fork 40 is returned to the initial position on the lifting platform 33 to complete the transfer.

  Next, a process of carrying out the receiving box 50 stored in the rear storage unit 16 will be described. As a premise, it is assumed that the receiving box 50 is not placed in the front storage unit 15. Similarly to the above, the cargo receiving surface 34 and the fork 40 are positioned on the front side of the target receiving box 50. At this position, the fork 40 is extended to reach the position where the claw 45 is opposed to the recess 51 of the receiving box 50, and then the fork 40 is moved toward each other to engage the claw 45 and the recess 51 (FIG. 11 ( A)). At this time, since the tip of the fork 40 is always in front of the vertical column 11 of the shelf 10, the two do not contact each other. If the nail | claw 45 and the recessed part 51 are made into the engagement state, it moves to the direction which shrinks the fork 40, and draws the receiving box 50 near the raising / lowering stand 33 (refer FIG. 11 (B)). Thereafter, the receiving box 50 is carried out in the same procedure as in the case of the front storage unit 15 (see FIGS. 9 and 10).

  On the other hand, as for the process of loading the receiving box 50 into the front storage unit 15, as described above, the entire stacker crane 30 is first traveled and the lifting platform 33 is moved up and down so that the cargo receiving surface 34 and the fork 40 are to be loaded. It is located in front of the front storage portion 15 (see FIG. 12A). In the case of this carry-in, the cargo receiving surface 34 is positioned higher than the stopper 13 at the tip of the shelf support portion 12. At this position, the forks 40 are moved closer to each other with respect to the receiving box 50 on the cargo receiving surface 34 so that the claw 44 far from the shelf 10 and the front end side surface of the receiving box 50 can come into contact with each other. In this state, the fork 40 is extended, and the receiving box 50 is pushed to move them from the load receiving surface 34 to the shelf 10 side, and the entire receiving box 50 moves away from the load receiving surface 34 and moves to the support portion 12 side of the shelf 10. (See FIG. 12B).

  Thereafter, the forks 40 are once separated from each other and the claws 44 are separated from the receiving box 50, and the forks 40 are contracted again so that the claws 45 closer to the shelf 10 are placed on the front side of the receiving box 50 (the rear side in the direction of travel of the receiving box 50). Then, the elevator 33 is lowered, and the heights of the cargo receiving surface 34 and the shelf support 12 are substantially matched (see FIG. 12C). Then, the fork 40 is moved in a direction close to each other, the fork 40 is set at a predetermined distance slightly wider than the case where the claw 45 and the recess 51 are engaged, and the inclined surface 45a of the claw 45 and the front end side surface of the receiving box 50 Can be brought into contact with each other (see FIG. 8C). In this state, the fork 40 is extended, the receiving box 50 is pushed by the claw 45, and is moved completely onto the support portion 12 behind the stopper 13 to reach the front storage portion 15 (see FIG. 13A). ), The receiving box 50 is in the retracted state. By pressing the receiving box 50 between the inclined surfaces 45a of the claws 45 of the pair of forks 40, the receiving box 50 can be securely held between the tips of the forks 40, and the pushing can be appropriately performed without causing a shake or the like. Yes. The forks 40 that have completed the carrying-in operation are separated from each other, the claw 45 is separated from the receiving box 50, the fork 40 is contracted again and returned to the initial position on the lifting platform 33, and the transfer is completed (FIG. 13B). reference).

  Further, the procedure for carrying the receiving box 50 into the rear storage unit 16 will be described. From the same procedure as described above to the state where the receiving box 50 is transferred from the load receiving surface 34 to the support unit 12 side of the shelf 10. After the transfer, the elevator 33 is further lowered, and the heights of the load receiving surface 34 and the shelf support 12 are substantially matched (see FIG. 14A), and then the inclined surface 45a of the claw 45 with the fork 40 as a predetermined interval. The fork 40 is extended and the receiving box 50 is pushed by the claw 45 while contacting the surface of the receiving box 50 with the front end side surface. The fork 40 is extended and the receiving box 50 is pushed in, so that the receiving box 50 reaches the rear storage portion 16 (see FIG. 14B). Note that the operating speed of the fork 40 is slowed down before the receiving box 50 reaches the rear storage portion 16 so that the impact due to the sudden stop is not applied to the book 60 in the receiving box 50 when the receiving box 50 is stopped. Thereafter, the forks 40 are separated from each other in the same manner as described above, and when the forks 40 are contracted and returned to the initial position on the lifting platform 33, the transfer is completed (see FIG. 14C).

  In this way, the claws 44 and 45 of the fork 40 are engaged with or abutted with predetermined positions of the receiving box 50, and the fork 40 is expanded and contracted, so that the receiving box 50 is securely placed between the lifting platform 33 and the storage parts 15 and 16. Can be moved to. Further, by using a pair of forks 40 that are engaged or abutted with the receiving box 50 from the lateral direction, the dead space in the shelf 10 is reduced as compared with the case of using a conventional fork supported from the lower side. The capacity of the shelf 10 can be increased. In addition, even when the book 60 is unevenly distributed in the receiving box 50 and the load balance is not good (see FIG. 6) during the loading / unloading process, the receiving box 50 can be controlled by appropriately controlling the speed of the fork extension / contraction operation. It is possible to reliably prevent the movement of the book from becoming unstable or the book 60 from being displaced in the receiving box 50 or from being ejected from the receiving box 50.

In actual load transfer, even when the receiving box 50 exists in the front storage unit 15 of the shelf 10, the receiving box 50 in the rear storage unit 16 can be carried out, or can be transferred to the vacant rear storage unit 16. Since it may be necessary to carry in the receiving box 50 or the like, in such a case, after the receiving box 50 in the front storage unit 15 is once carried out of the shelf 10 in the above procedure and transferred to the temporary storage space, the rear side An unloading operation is performed on the receiving box 50 in the storage unit 16, or the receiving box 50 is carried into the vacant rear storage unit 16. After this is completed, the receiving box 50 previously placed in the temporary storage space is unloaded and loaded into the original position of the shelf 10 to restore the original state of the shelf 10 other than the receiving box 50 unloaded to the shelf 10 to a restored state. deep.
In addition, although the carrying-in / out process of the receiving box 50 was demonstrated only about one shelf 10, the operation | work can be performed similarly about the shelf of the opposite direction about the stacker crane 30 travel route. In that case, the work process is the same only by changing the front-rear relationship of the fork 40.

Thus, in the load transfer system according to the present embodiment, the receiving box 50 in which the books 60 are stored between the elevator platform 33 and the front and rear storage units 15 and 16 of the shelf 10 in the stacker crane 30 is provided. As the fork to be transferred, a pair of left and right forks 40 positioned laterally with respect to the receiving box 50 is used, and when the receiving box 50 is transferred by disposing the recesses 51 and 52 in the receiving box 50. The gap between the pair of forks 40 facing each other across the receiving box 50 is changed, and the claws 44 and 45 provided on the fork 40 and the recesses 51 and 52 of the receiving box 50 are engaged with each other, or the claws 44 and 45 are received. When the fork 40 is expanded and contracted after being brought into contact with the front and rear end portions of the box 50, the receiving box 50 is pushed or pulled by the claws 44 and 45 that move back and forth in accordance with the expansion and contraction to the shelf 10 and the lifting platform 33. The slide is moved and the transfer is As a result, it is possible to transfer the storage box 15 and 16 in the front-rear direction of the shelf 10 while holding the receiving box 50 appropriately with a small driving force while suppressing the amount of extension of the fork 40, and each part of the shelf 10 and the fork 40. Therefore, the space necessary for the operation of the fork 40 is minimized and the storage space in the shelf 10 can be secured to the maximum, so that the storage space can be effectively used.
In addition, although the load transfer system according to the above-described embodiment is configured to load and unload books in the library library as a load, the present invention is not limited to this and is applied to a system such as an automatic warehouse that handles other articles as loads. It can also be configured.

  In the load transfer system according to the embodiment, when the receiving box 50 is carried into the shelf 10, the fork 40 is moved from the receiving box 50 to the support 12 side by moving the receiving box 50 toward the support portion 12. The fork 40 and the lift 33 are lowered to change the contact position of the claw 45 of the fork 40 with the receiving box 50, and then the receiving box 50 is pushed out with the fork 40, so that the receiving box 50 is moved from the stopper 13. Although it is configured to transfer to the rear side, not limited to this, it can be configured to move the receiving box 50 by engaging the claw 45 with the recess 51 of the receiving box 50 at the time of carrying in as well as at the time of carrying out, After the fork 40 is once separated from the receiving box 50 moved to the support portion 12 side, the claw 45 on the side close to the shelf 10 is made to enter the recessed portion 51 on the front side of the receiving box 50 and the fork 40 is further extended. And press the receiving box 50 to receive the receiving box 50 With the side held above the stopper 13, the entire receiving box 50 is positioned behind the stopper 13, and the fork 40 and the lifting platform 33 are lowered together with the front side part of the receiving box 50, so that the receiving box 50 is stored in the front side of the support portion 12. Thus, the receiving box 50 beyond the position of the stopper 13 suddenly drops on the support part 12 and no impact or noise is generated, and the book 60 in the receiving box 50 is shocked. It is possible to reliably prevent the adverse effects caused by.

  Further, in the cargo transfer system according to the embodiment, when the receiving box 50 is present in the front storage unit 15 when the receiving box 50 is carried into and out of the rear storage unit 16, the front receiving box is provided. 50 is temporarily transferred to the temporary storage space, and then the carry-in / out of the rear receiving box 50 is executed. In addition to this, around the storage position of the receiving box 50 to be carried in / out on the shelf 10. Then, it is determined from the management information of the shelf whether there is another storage space that is vacant in the front storage unit 15, and if it exists, the empty space closest to the storage position of the loading / unloading target receiving box 50, It is also possible to adopt a mechanism for transferring the front receiving box 50, and it is possible to reduce the cycle time for loading and unloading the rear receiving box 50 by omitting the movement of the lifting platform 33 to the temporary storage space. Further, when a management method is adopted in which the receiving box 50 does not necessarily have to be stored in a predetermined storage space determined for each receiving box 50 of the shelf 10, for carrying in / out the receiving box 50 on the rear side. The management information may be changed with the storage location of the destination of the receiving box 50 unloaded from the front storage unit 15 as a new storage position of the receiving box 50, and the moved receiving box 50 is returned to the original storage position. There is no need to return, the movement of the stacker crane 30 for the return stroke and the expansion / contraction operation of the fork 40 can be omitted, and the cycle time when the plurality of receiving boxes 50 are continuously carried in / out can be shortened.

  Further, in the load transfer system according to the embodiment, the claws 44 and 45 are integrally fixed to the upper stage 43 of the fork 40 and are directly engaged or abutted with the receiving box 50 to hold the receiving box 50 between the forks 40. However, the present invention is not limited to this, and the predetermined shock absorbing member includes the claws 44 and 45 and the upper stage portion. 43, or the claws 44, 45 themselves may be formed of a material that absorbs shock. When the claws 44, 45 come into contact with the receiving box 50 during the loading / unloading process of the receiving box 50, and The impact generated when the receiving box 50 moving by the expansion and contraction of the fork 40 stops by hitting the stoppers 13 and 14 can be absorbed by the claws 44 and 45, thereby preventing the book 60 in the receiving box 50 from being adversely affected. .

  Furthermore, in the cargo transfer system according to the above-described embodiment, there may be a situation in which the receiving box 50 is stored only in the front storage unit 15, and an attempt is made to carry the receiving box 50 into the vacant rear storage unit 16. In this case, the receiving box 50 stored in the front storage unit 15 is temporarily transferred to the temporary storage space and then carried into the rear storage unit 16. If the storage position of each receiving box 50 can be properly grasped and managed without having to correspond one-to-one with each receiving box 50 to be handled before and after the receiving box 50 in the rear box, Is carried into the front storage unit 15 only after it has been carried in, that is, when there is only one receiving box 50 for the storage space, it is always stored in the rear storage unit 16 so that the front side is vacant. It is also possible to adopt a configuration that adopts the method of , Eliminates the need of the transfer to the carry-in at the time of the temporary storage space, can shorten the stacker crane 30 moves worth of work time.

1 is a side view of a load transfer system according to an embodiment of the present invention. It is a front view of the stacker crane in the load transfer system concerning one embodiment of the present invention. It is the top view and front view of a raising / lowering stand in the load transfer system which concerns on one embodiment of this invention. It is principal part sectional drawing of the fork in the load transfer system which concerns on one embodiment of this invention. It is an extension state side view of a fork in a load transfer system concerning one embodiment of the present invention. It is the side view and front view of a receiving box in the load transfer system which concerns on one embodiment of this invention, and the nail | claw enlarged view of a fork. It is the principal part cross-sectional view of the shelf in the load transfer system which concerns on one embodiment of this invention, the side view of a support part, and a stopper enlarged view. It is each state explanatory drawing of the separation state of a fork, a nail hooking state, and the receiving box end surface contact state of a nail | claw in the load transfer system which concerns on one embodiment of this invention. It is explanatory drawing the first half of the receiving box carrying-out process to the shelf front side storage part in the load transfer system which concerns on one embodiment of this invention. It is a latter half explanatory drawing of the receiving box carrying-out process to the shelf front side storage part in the load transfer system which concerns on one embodiment of this invention. It is a partial explanatory view of a receiving box carrying-out process to the shelf rear side storage part in the load transfer system concerning one embodiment of the present invention. It is explanatory drawing the first half of the box receiving process to the shelf front side storage part in the load transfer system which concerns on one embodiment of this invention. It is a latter half explanatory drawing of the receiving box carrying-in process to the shelf front side storage part in the load transfer system which concerns on one embodiment of this invention. It is a partial explanatory view of a receiving box carrying-in process to the shelf rear side storage part in the load transfer system concerning one embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Load transfer system 10 Shelf 11 Vertical column 12 Support part 13,14 Stopper 15 Front side storage part 16 Rear side storage part 30 Stacker crane 30a Rail 31 Traveling base 32 Mast 33 Lifting base 34 Load receiving surface 35 Drive gear 40 Fork 41 Lower stage Part 41a drive gear 41b rack 41c linear motion guide 41d rack 42 middle stage part 42a rack 42b gear 43 upper stage part 43a rack 44, 45 claw 44a, 45a inclined surface 50 receiving box 50a partition plate 51, 52 concave part 60 load

Claims (5)

A shelf structure in which a plurality of storage spaces in which a plurality of stored items can be placed in the depth direction with respect to the shelf front are arranged in a number of directions, up and down, left and right, and two sets of shelves arranged at predetermined intervals with the shelf front facing each other, A stacker crane disposed in the middle of the two sets of shelves and moving along the respective shelves, and capable of carrying in and out the stored items, and the stacker cranes store the stored items. A lifting platform that can be mounted and moved up and down to reach the front of the shelf front of a predetermined storage space, and is disposed on or near the lifting platform, and extends or contracts back and forth in the depth direction of the shelf to store the stored items in the storage space. In a load transfer system having a fork for carrying in and out, and handling one or a plurality of loads as a single stored item,
The load is handled as one stored item for each receiving box in a state in which one or more are stored in a predetermined receiving box,
The receiving box is provided with a predetermined hooked portion on the side of the shelf parallel to the shelf depth direction, at least on the shelf front side near the shelf front in the shelf storage state,
A pair of the forks are disposed on or near the lifting platform at positions facing the receiving box on the side of the receiving box, and in a stretched state, the tip can reach the position farthest from the lifting platform, A convex hooking portion that can be hooked to the hooked portion is formed, and at least a predetermined range portion including the hooking portion can be brought close to and separated from the other pair.
The shelf includes a plurality of support portions on which the bottom portion of the receiving box is placed and forms a bottom surface of the storage space, and a plurality of vertical columns that support the support portions, and the vertical columns are at least the forks Placed outside the reach of
The fork is telescopically driven in a state where the hooking portion is engaged with the hooked portion of the receiving box or the front or rear end surface of the receiving box, and the receiving box is moved up and down in the depth direction of the storage space. A loading and unloading system characterized in that it is transferred to and from the platform. In the cargo transfer system according to claim 1,
The shelf support part is formed so that the receiving box can be placed side by side in the shelf depth direction,
When the two columns are placed side by side on the support portion, the vertical column is positioned on the rear side of the hooked portion position on the front portion of the receiving box on the rear side of the shelf. system. In the cargo transfer system according to claim 2,
A stopper that protrudes upward in a convex shape is disposed at the foremost part of the shelf support portion facing the stacker crane and serving as a shelf opening,
In the unloading process from the shelf by the fork, the fork is contracted in a state where the fork hooking portion is hooked with the hooked portion on the front side of the receiving box, and the receiving box is placed in each mounting position of the storage space. When the front end of the receiving box reaches the stopper, the fork and the lifting base are raised until the load receiving surface of the lifting base and the lower end of the front of the receiving box are at least above the stopper. Slide the entire receiving box onto the lifting platform by reducing the fork,
In the process of carrying into the shelf by the fork, the fork is extended with the load receiving surface of the lifting platform positioned at least above the stopper, and the receiving box is moved from the lifting platform to the shelf side. Once it has been transferred to the support section, lower the fork and the lifting platform until the upper surface of the support section of the shelf and the load receiving surface of the lifting platform are approximately the same height, and then move the receiving box to each mounting position again by extending the fork. A cargo transfer system characterized by In the cargo transfer system according to any one of claims 1 to 3,
The hooking part is also arranged at a part of the movable part of the fork farthest from the shelf,
In the process of carrying in the shelf by the fork, when transferring the receiving box from the lifting platform to the supporting part of the shelf until most of the receiving box is transferred, the front hooking part away from the shelf is placed at the front end of the receiving box. While the fork is extended in the contacted state, when the entire receiving box is subsequently moved to the storage space placement position, the hooking portion and the receiving box are once separated and the fork is reduced. After that, the fork is extended in a state where the rear side hooking portion close to the shelf is in contact with the front end portion of the receiving box. In the cargo transfer system according to claim 3,
In the process of unloading from the shelf by the fork, the receiving box is moved to the front side of the shelf from each placement position of the storage space, and a part of the receiving box is moved forward on the lifting platform until the front of the receiving box. When the fork is contracted with the hook on the rear side of the fork engaged with the hook on the side, the remaining portion of the receiving box is moved completely onto the lifting platform. The rear hooking part is detached from the hooked part of the receiving box, and once the fork is extended, the rear hooking part is brought into contact with the rear end of the receiving box to reduce the fork. A featured cargo transfer system.

Images