WO1997019872A1

WO1997019872A1 - Article storage equipment

Info

Publication number: WO1997019872A1
Application number: PCT/JP1996/003466
Authority: WO
Inventors: Kanji Anno; Joji Hatanaka
Original assignee: Daifuku Co., Ltd.
Priority date: 1995-11-29
Filing date: 1996-11-25
Publication date: 1997-06-05
Also published as: AU7710496A; TW519109U

Abstract

The invention relates to the article storage equipment including a pair of fixed racks (A) spaced from each other, movable racks (B) arranged between the pair of fixed racks to be movable in one direction, a transfer vehicle (E) movable along a passage (C') formed by movement of the movable racks, and guides (7b) provided on the racks at opposite sides of the passage for supporting and guiding the transfer vehicle. Each of the fixed racks and movable racks are constructed such that the guides at opposite sides of a working passage formed have a proper space therebetween which is maintained by properly setting a space between adjacent racks lying close to each other, to enable the transfer vehicle to move smoothly inside the passage.

Description

SPECIFICATION

ARΗCLE STORAGE EQUIPMENT

[TECHNICAL FIELD]

This invention relates to article storage equipment having movable racks. More particularly, the invention relates to article storage equipment comprising a pair of fixed racks having a plurality of storage units open for allowing articles to be deposited and fetched in a first direction, and arranged with a space therebetween in said first direction; at least one movable rack disposed between said pair of fixed racks and extending in a second direction perpendicular to said first direction; a plurality of wheels arranged at intervals in said second direction in bottom regions of said movable rack; rack supporting rails extending in said first direction and disposed in positions in said second direction corresponding to said wheels for supporting said wheels and permitting said movable rack to move along said first direction within a predetermined running range; a running type transfer vehicle movable along said second direction in a working passage formed between a pair of racks set adjacent each other by movement of said movable rack, for depositing and fetching the articles in/from said fixed racks or said movable rack; running rails extending in said second direction for supporting said transfer vehicle; vehicle control means for controlling running of said transfer vehicle; and guides provided in regions of said fixed racks and movable rack where said working passage is formed, for guiding and supporting said transfer vehicle through contact with said transfer vehicle.

[BACKGROUND ART] This type of article storage equipment is typically used in an automated warehouse, an example of which is disclosed in Patent Laying-Open Publication No. H6-107307. This type of automated warehouse includes a plurality of racks, and a transfer apparatus having a transfer vehicle for depositing articles in and fetching articles from the racks. A large area of land is required if, for example, ten racks are installed with spaces for the transfer vehicle between all of the racks. Thus, instead of providing spaces for the transfer vehicle between each of the racks, eight racks, excluding two end racks, are designed to be movable in a direction of the arrangement of the racks. A space for the transfer vehicle to move through is opened only at a required rack by moving the racks. This way, an effective use of land may be made by requiring the thickness of ten racks and a space for a working passage of the transfer vehicle. The transfer vehicle is moved to a required rack by a carriage disposed at a lateral end of the racks and movable along the direction of the arrangement of the racks. Once the rack is moved to the required rack, it is moved parallel to the rack along a rail present in a working passage formed by moving the racks, thereby to fetch articles stored in any one of the racks. However, various problems arise when trying to move the racks having such a great weight.

One of the problems is that when a rack is moved to form a working passage for the transfer vehicle, one end of the movable rack and the other end thereof sometimes become displaced backward and forward in the running direction. That is, the movable rack sometimes moves at an oblique angle relative to the fixed racks where the movable racks are supposed to move in such way that they are parallel to the fixed racks. When a movable body is stopped in an oblique posture as noted above, at an end of a set running range, the working passage formed is broad at one end and narrow at the other end, making it diff icult for the transfer vehicle to run smoothly.

Figs. 15 and 16 show a prior art apparatus for solving this problem. Fig. 15 is a plan view of a storage apparatus, in which 03 denotes movable racks. A space is formed between a pair of movable racks 03, and a working rack C is formed for a transfer vehicle. To synchronize rotation of left and right drive wheels 01 and to prevent oblique movement of a movable rack, pinion gears 02 rotatable with the right and left drive wheels 01 are meshed with the gear receiving rails 05 fixed along opposite sides of support rails 04 of the movable racks 03. However, according to the above prior art, when a displacement in a running direction between one end and the other end in the sideways direction of the movable rack increases, the pinions 02 and the gear receiving rails 05 may not mesh well and the teeth of pinions 02 may run out of the teeth of the rails 05. When this happens, it may become impossible to run the movable rack 03 smoothly, or the movable racks 03 may not run properly as a result of displacement of meshing phases of pinions 02 and the gear receiving rails 05 between one end and the other end of the movable rack.

Further, the provision of pinions 02 and racks 05 complicates the construction, resulting in a disadvantage of requiring higher cost and labor for manufacture and installation of the storage system.

The following problem is noted as another problem arising from movement of the racks. A conventional movable rack is stopped at a stopping position using a limit switch. However, the movable rack sometimes does not stop at a position and moves further before finally coming to stop due to the inertia of the movable rack. Generally, the construction is such that moving racks are stopped such that there is distance between the racks so that frames of the racks are out of contact to avoid damage due to collisions between the racks. Therefore, when moving a movable rack to form a working passage for the transfer vehicle, a space formed between the racks is not sometimes accurate. As a result, the distance between guides provided on the sides of the racks facing the working passage is sometimes not the best distance for the transfer vehicle to run smoothly.

Furthermore, running rails for the transfer vehicle are fixed to the ground surface of the articles storage equipment. Therefore, when a running rail is not centered in the working passage for the transfer vehicle, the transfer vehicle can not be guided by the guides provided on the racks appropriately. This also prevents the vehicle from running in an optimal condition.

[DISCLOSURE OF THE INVENTION]

This invention has been made having regard to the state of the art noted above, and its object is to attain an optimum running condition of a transfer vehicle by properly maintaining a space between guides positioned on opposite sides of a working passage, while providing a simple construction for smooth running of movable racks.

Another object is to provide article storage equipment capable of precluding a situation where a transfer vehicle cannot run properly along a working passage when movable racks do not stop at proper positions.

To this end, article storage equipment according to this invention comprises a pair of fixed racks having a plurality of storage units open for allowing articles to be deposited and fetched in a first direction, and arranged with a space therebetween in said first direction; at least one movable rack disposed between said pair of fixed racks and extending in a second direction peφendicular to said first direction; a plurality of wheels arranged at intervals in said second direction in bottom regions of said movable rack; rack supporting rails extending in said first direction and disposed in positions in said second direction corresponding to said wheels for supporting said wheels and permitting said movable rack to move along said first direction within a predetermined running range; a running type transfer vehicle movable along said second direction in a working passage formed between a pair of racks set adjacent each other by movement of said movable rack, for depositing and fetching the articles in/from said fixed racks or said movable rack; running rails extending in said second direction for supporting said transfer vehicle; vehicle control means for controlling running of said transfer vehicle; and guides provided in regions of said fixed racks and movable rack where said working passage is formed, for guiding and supporting said transfer vehicle through contact with said transfer vehicle; wherein each of said fixed racks and said movable rack has contact elements contactable with each other for controlling a space in said first direction between adjacent racks lying close to each other when said working passage is formed, to maintain a proper space between the guides, opposed to said working passage, of said adjacent pair of racks forming said working passage.

When a working passage is formed, the contact elements contact each other to regulate a space between adjacent racks lying close to each other and to eliminate a displacement in a running direction between one end and the other end of the movable rack.

Thus, the movable rack may run smoothly with the simple construction not requiring pinions and gear receiving rails or the like. The distance between the guides provided at opposite sides of the work passage may be maintained at a proper distance for the transfer vehicle to run through.

In an embodiment of this invention, the article storage equipment preferably further comprises a pair of drive means for separately driving at least those wheels, among said wheels, disposed in opposite end regions in said second direction of said movable rack; drive control means for controlling operation of the drive means; and a pair of detecting means for separately detecting opposite ends in said second direction having approached one end of said fixed running range; wherein said drive control means is operable to start operation of said pair of drive means based on a start command, and when, with said pair of detecting means and said pair of drive means at the same end regions are made to correspond to each other, said detecting means detects an approach to one end of said fixed running range, to cause the drive means corresponding to that detecting means to continue operating for a predetermined time before stopping.

When a working passage is formed, the opposite ends in the second direction may be moved until the adjacent racks lying close to each other positively contact each other at the contact elements. The drive means are stopped after operating for the predetermined time. Thus, the drive means of the running wheels are never operated in an overload condition for a long time, with the rack standing still at one end of the fixed running range. There is little possibility of impairing durability of the drive means.

In an embodiment of this invention, the article storage equipment preferably further comprises first determining means for determining that said adjacent movable racks for forming said working passage have formed said working passage, and second determining means for determining that said running rail is in a proper position relative to said transfer vehicle, said vehicle control means permitting said transfer vehicle to move along said working passage when said first determining means determines that said adjacent pair of movable racks have formed said working passage and said second determining means determines that said running rail is in the proper position relative to said transfer vehicle. With this construction, the transfer vehicle runs along the working passage only when the working passage is formed and the rail is in a proper running position relative to the transfer vehicle. For example, unless the running rail is in the proper running position relative to the transfer vehicle, the transfer vehicle never runs along the work passage inadvertently, thereby precluding the disadvantage of the transfer vehicle becoming unable to run properly.

In a preferred embodiment of this invention, the transfer vehicle is a stacker crane movable in said working passage and in a position outside one end of said working passage, the article storage apparatus further comprising a transport carriage for moving this stacker crane along said first direction, said second determining means being mounted on said transport carriage.

The transport carriage moves in the first direction while supporting the stacker crane. Since the second determining means is mounted on the transport carriage, the transport carriage in a position corresponding to the running rail may stop at a proper position relative to the ninning rail. In a preferred embodiment of this invention, said first determining means is mounted on said transport carriage.

The stacker crane, since it moves in the working passage, must have a narrower construction than the width of the passage. The transport carriage, since it moves only outside of the racks, may have a broader construction than the width of the working passage. Therefore, the transport carriage and the racks situated at opposite sides of the working passage may be as close to each other as possible.

Since the first determining means is mounted on the transport carrier movable close to the storage racks at the opposite sides of the working passage, an accurate determination may be made whether it is in the proper relative position or not.

In an embodiment of this invention, said transfer vehicle preferably is operable to run as supported by supporting rails disposed on the ground; said transfer vehicle being prevented from turning over when transferring the articles, by causing rollers supported to be rotatable on vertical axes at opposite sides of said transfer vehicle in a direction of width of the working passage, to contact said guides in a direction toward the rack having the guides.

To prevent the transfer vehicle from toppling during a transfer of articles, the movable rack could be equipped with engaging elements for engaging the transfer vehicle while permitting its running. Where the engagement with the movable rack prevents the transfer vehicle from turning over, the movable rack may be pulled by the transfer vehicle to be displaced toward the working passage when the transfer vehicle leans away from the movable rack with which it is engaged. However, in this invention, the transfer vehicle is prevented from turning over when transferring the articles, by causing the rollers supported by the transfer vehicle to contact the guides in a direction toward the rack having the guides. Thus, when the transfer vehicle begins to tum over toward whichever rack, the movable rack is never pulled toward the working passage by the transfer vehicle beginning to turn over. There is no possibility of the movable rack shifting toward the working passage.

Thus, while preventing the transfer vehicle from tuming over during a transfer of the articles, the space between the guides disposed at the opposite sides of the working passage may be maintained at a proper space. It is possible to avoid a situation in which the movable rack starts moving in an oblique posture with one end and the other end in the sideways direction displaced forward and backward direction, and a situation in which the transfer vehicle becomes incapable of smooth ruining. In an embodiment of this invention, said contact elements preferably are disposed in at least two positions spaced apart in said second direction of each of said fixed racks and said movable rack.

Since the contact elements are disposed in at least two positions spaced apart in the second direction of each of the fixed racks and the movable rack, the contact between these contact elements regulates, with facility, the space between the adjacent racks lying close to each other when forming the working passage, even if the racks are somewhat deformed between the contact elements spaced apart.

It is possible to have said contact elements extend substantially over an entire length in said second direction of each of said fixed racks and said movable rack. Then, the space between the guides present at the opposite sides of the working passage may easily be maintained at a proper space substantially over the entire length of the working passage by placing the adjacent racks lying close to each other when forming the working passage, in contact with each other over the entire length in the sideways direction thereof.

In an embodiment of this invention, said guides may be used also as said contact elements. In this case, since separate contact elements need not be provided, thereby reducing the number of components, and simplifying and lightening the rack construction. Further, said contact elements may be provided for each of said fixed racks and said movable rack such that upper positions and lower positions thereof contact each other. Then, there is little possibility of the movable rack leaning in the direction of movement where, for example, the lower part of the movable rack moves further with only the upper part of the movable rack is in contact. Thus, the space between the guides may be maintained more properly.

In an embodiment of this invention, said detecting means preferably includes a photosensor, and a detected member for turning the photosensor on and off, wherein one of said photosensor and said detected member is mounted on said movable rack, and the other is fixed to a fixing device for said rack supporting rail. Then, the movable rack approaching one end of the fixed running range may be detected with high precision, compared with a case of detection by a limit switch turned on and off through contact with the movable rack or the ground. It is made still less likely to impair durability of the drive means by setting a reduced time for continuing to operate the drive means after the movable rack approaches one end of the fixed running range. Since one of the photosensor and the detected member is mounted on the movable rack, and the other is fixed to a fixing device for the rack supporting rail, it is unnecessary to provide an additional foundation for fixing the photosensor or the detected member to the ground, thereby simplifying the fixation structure.

Where said first and second determining means are optical sensors, these means have excellent response while being unlikely to be damaged through abrasion and the like and being highly durable, compared with a case of using contact sensors or the like.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a perspective view of entire article storage equipment according to this invention;

Fig.2 is a schematic plan view of the entire article storage equipment according to this invention;

Fig. 3 is a side view of a principal portion of the article storage equipment according to this invention;

Fig. 4 is a side view of a principal portion of the article storage equipment according to this invention;

Fig. 5 is a side view showing a lower portion of a transfer vehicle;

Fig. 6 is a front view of the lower portion of the transfer vehicle shown in Fig. 5;

Fig. 7 is a view, partly in section, showing a detecting device provided for a movable rack;

Fig. 8 is a plan view of the detecting device shown in Fig. 7;

Fig. 9(A) is a side view of the detecting device shown in Fig. 7;

Fig. 9(B) is a plan view showing detected members;

Fig. 10 is an explanatory view showing a control system of the article storage equipment;

Fig. 11 is an explanatory view showing a first and a second determining devices;

Fig. 12 is a side view of article storage equipment according to another embodiment of this invention; Fig. 13 is a side view of article storage equipment according to a further embodiment of this invention;

Fig. 14 is a plan view showing a first determining device in another embodiment;

Fig. 15 is a plan view showing the prior art; and

Fig. 16 is a view, partly in section, showing a principal portion of the prior art.

[BEST MODE FOR CARRYING OUT THE INVENTION] Figs. 1 and 2 show article storage equipment installed in an automated warehouse, in which a pair of fixed racks A are installed on a ground surface, and eight movable racks B are arranged between these fixed racks A. In Fig. 1, a first direction X and a second direction Y perpendicular to the first direction X are defined. Each of the fixed racks A and movable racks B has vertical frames Al arranged at intervals in the second direction, and horizontal frames A2 extending horizontally. The vertical frames Al define side planes of each rack.

A direction of putting articles in and out is a direction extending along the first direction X. Each of the fixed racks A and movable racks B is arranged in a posture elongated sideways which is along the second direction. Four rack supporting rails 1 are fixed to the ground surface to extend along the first direction. The article storage apparatus includes a stacker crane E acting as a transfer vehicle for depositing and fetching articles D in/from the fixed racks A or movable racks B. Further, a crane transport carriage (traverser) F is provided for transporting the stacker crane E along carriage rails 2 disposed adjacent one end of the fixed racks A and movable racks B, and a load receiving carriage G for temporarily receiving an article D to be stored or taken out. The stacker crane runs along the second direction in a working passage C formed between adjacent racks for depositing and fetching articles.

Each of the fixed racks A and movable racks B has article holders H arranged in the second direction and vertical direction for storing containers D having a shape of a square box as one example of articles. All the article holders H are open along the first direction. As shown in Figs. 3 and 4, each of the movable racks B is constructed such that two adjacent racks Bl in a back-to-back relationship are connected to each other, with bottoms thereof fixed to a support frame B2. The support frame B2 supports four sets of rack running wheels 3 corresponding to four rack supporting rails 1, respectively, each set including two wheels arranged forward and rearward in a running direction.

With rolling of the rack running wheels 3, the movable racks B are reciprocable within a fixed running range along the four rack supporting rails 1. Thus, a working passage C is selectively formed in one location between fixed rack A and movable rack B as shown in Fig. 3 or between adjacent movable racks B as shown in Fig. 4. A single crane supporting rail 5 is provided to correspond to each of the working passages C, for supporting the stacker crane G in a way to enable its running with rolling of crane running wheels 4 arranged in lower portions of the stacker crane E.

As shown in Fig. 5, the stacker crane E has four crane running wheels 4 attached to a vehicle body 6. These wheels 4 include two drive wheels 4a arranged at one end in the running direction along the second direction, and two idle wheels 4b arranged at the other end in the running direction. As shown in Figs. 1, 3 and 5, the vehicle body 6 further includes a lift deck 6a for moving a fork device J up and down, two supports 6b for vertically movably supporting the fork deck 6a, an electric propelling unit 6c for driving the drive wheels 4a, an electric raising and lowering mechanism 6d for raising and lowering the lift deck 6a, a square frame 6e for interconnecting upper ends of the two supports 6b, and four guide rollers 7a attached to opposite sides of the square frame 6e in a direction of width of the working passage to be rotatable about vertical axes. At least three crane running wheels 4 of the four crane running wheels 4 are supported on the crane running rail 5 to be capable of running. With running of the vehicle body 6, these guide rollers 7a roll along guide rails 7b each mounted on an upper end of the movable rack C or fixed rack E lying at each of the opposite sides of the working passage C, to guide the running thereof. The stacker crane E in transferring container D is prevented from tuming over by the guide rollers 7a contacting the guide rail 7b in the direction of fixed rack A or movable rack B to which that guide rail 7b is attached.

At intersections where the rack supporting rails 1 and the crane supporting rails 5 intersect each other in plan view, the rack supporting rails 1 and crane supporting rails 5 are fixed by common rail clamps 8 bolted to the floor surface. The rack supporting rails 1 are continuous through the intersections, and the crane supporting rails 5 are fixed at an interval across the rack supporting rails 1 in plan view, so that the rack running wheels 3 may pass through the intersections without interference of the crane supporting rails 5. The crane supporting rails 5 are at a higher level than the rack supporting rails 1, and the two drive wheels 4a and two idle wheels 4b of the stacker crane E are arranged at front and rear positions at a wider pitch than the interval of the crane supporting rails 5 across the rack supporting rails 1. When one of the crane running wheels 4 is lifted between the crane supporting rails 5 at the intersection, the remaining three crane supporting wheels 4 of the stacker crane E are supported to be capable of running, whereby it can pass through the intersection over the rack supporting rail 1, with the crane running wheels 4 free of interference by the rack supporting rail 1.

As shown in Fig. 6, each rack has a rack-side current feeding device 22 for supplying driving electric power to the stacker crane E. The stacker crane E has a current collecting device 23 for receiving electric power from the current feeding device 22 while maintaining a contact with the current feeding device 22 when running in the working passage C. The traverser F also has a current feeding device 22 for supplying electric power to the stacker crane E when contained in the traverser F. A rack-side support member 21 to which the current feeding device 22 is attached has a detected element 20c for detecting a stopping position of the stacker crane E, and speed adjusting plates 20a, 20b for regulating running speed of the stacker crane. A support arm 24 on the stacker crane to which the current collecting device 23 is attached has a transmission type photoelectric sensor 19c for detecting the detected element 20c, and transmission type photoelectric sensors 19a, 19b for detecting the speed adjusting plates 20a, 20b.

Contact elements according to this invention will be described next.

Each of the fixed racks A and movable racks B has contact elements 9 in two positions spaced apart in the second direction, i.e. at opposite ends in the sideways direction of the rack, for regulating, through contact, a spacing in the article depositing and fetching direction between adjacent racks lying close to each other when working passage C is formed selectively between fixed rack A and movable rack B or between movable racks B, in order to maintain a space between the guide rails 7b situated at opposite sides of the working passage C at a proper space.

Each fixed rack A has four contact elements 9 in positions at the opposite ends in the second direction opposed to the movable rack B. As shown with Fig. 3, two of them are disposed above the guide rail 7b of the fixed rack A, and the other two are disposed in lower positions of the fixed rack A opposed to the support frame B2 of the movable rack B.

Each movable rack B has eight contact elements 9 disposed in positions at opposite ends in the second direction opposed to adjacent racks. Four of them are disposed above the guide rails 7b of the fixed rack B, and the other four are disposed in lower positions of the fixed rack B on the support frame B2.

These contact elements 9 are hard stoppers 9a, which are metallic in this embodiment, but hard rubber, a resin or the like may be employed instead.

These stoppers 9a have contact surfaces 9b protruding to a greater extent than the guide rails 7b in the article depositing and fetching direction which is the first direction. When the movable racks B are moved to form work passage C between desired racks, with adjacent racks moving toward and relative to each other, four stoppers 9a opposed in the moving direction between these racks move into contact approximately at the same time, whereby a space between the guide rails 7b situated at opposite sides of the working passage C is maintained at a proper space.

As shown in Figs. 7, 9 and 10, two rack running wheels 3 supported in the front and rear positions corresponding to each rack supporting rail 1 are a drive wheel 3a and an idle wheel 3b. Drive wheels 3a adjacent each other in the sideways direction in opposite end regions of each movable rack B form a set interlocked through an axle 10. Each axle 10 has an electric motor M acting as drive means for driving the associated axle 10. Each movable rack B has a control device 11 acting as a drive control means for controlling operation of these electric motors M. These electric motors M are started based on a start command outputted from the control device 11.

As shown in Fig. 11, a control panel 26 is installed in fixed state outside a traverser moving track. The operator inputs operation control information at this control panel 26. The control device 11 provided for each movable rack B and the control panel 26 are interconnected, whereby the electric motors M of each movable rack B are controlled to form a working passage C in a position designated through the control panel 26.

As shown in Fig. 11, the stacker crane E has a control device 30 acting as vehicle control means for controlling operations of the traverser F, stacker cranes E and fork device J. Control information is transmitted in wireless mode by optical communication between the control panel 26 and control device 30.

That is, the control panel 26 and traverser F have first optical communication devices Kl in the form of light transmitter/receiver devices 31, 31 for communicating optical signals transmitted along the direction of movement of the traverser F. The traverser F and stacker crane E also have second optical communication devices K2 in the form of light transmitter/receiver devices 32,

32 for communicating optical signals transmitted along the direction of movement of the stacker crane E. Based on the control information communicated in this manner, a running electric motor FM on the traverser F and the electric propelling unit 6c on the stacker crane E are controlled.

Detecting devices for detecting ends of the movable rack B approaching stopping positions will be described next with reference to Figs. 7-10.

A pair of detecting devices 12 are provided along the fixed running range of the movable rack B for detecting positions of the opposite ends of the movable rack B in the second direction, and inputting the positions to the control device 11. Each of these detecting devices 12 includes three photo-interrupter type photosensors 13a, 13b, 14. These photosensors 13a, 13b, 14 are disposed in a middle position in the first direction of the support frame B2, and fixed through a bracket 12a extending in the second direction. The photosensors 13a and 13b are spaced from each other in the first direction.

These photosensors 13a, 13b, 14 are turned on and off by two detected plates 15a, 15b acting as detected members which are fixed to rail clamps 16 fixing the rack supporting rails 1 to the floor surface. The first detected plate 15a is provided to turn on and off the two first photosensors 13a, 13b arranged forward and rearward in the running direction. As shown in Fig. 9 (B), the second detected plate 15b has opposite ends thereof extending beyond ends of the first detected plate 15a in the running direction, to turn on and off the second photosensor 14 disposed laterally outwardly of the first photosensors 13a, 13b, in an intermediate position between the first photosensor 13a, 13b.

The two first photosensors 13a, 13b detect the end in the second direction of the movable rack for which the first photosensors 13a, 13b are provided, approaching one end of the fixed running range. As shown in Figs. 9 (A) and (B), the first photosensor 13b disposed rearward in the running direction is turned off by interruption of the first detected plate 15a, and the first photosensor 13 disposed forward in the running direction is turned on after leaving one end of the first detected plate 15a. When the control device 11 receives an ON signal from one of the two first photosensors 13 a, 13b and an OFF signal from the other, it is determined that the one end in the sideways direction of the movable rack has approached one end of the fixed running range. The control device 11 continues to operate the electric motor M for the drive wheels 3a arranged at the same end as the first photosensors 13a, 13b, for a predetermined time, e.g. about 1 second, and thereafter stops the electric motor M. It is desirable that this stopping position is a position where the racks contact each other at contact elements 9, but it may be a position before the contact elements make contact.

The second photosensor 14 is provided to stop the movable rack B forcibly when the two first photosensors 13a, 13b fail to operate normally and the movable rack B may not stop at the one end of the fixed running range. When the second photosensor 14 moves past one end of the second detected plate 15b and turns on, the control device 11 immediately stops the operation of electric motor M at the side where the second photosensor 14 is provided.

Further, for safety precautions, projections la are formed on the rack supporting rails 1 in the stopping position of movable rack b as shown in Fig. 9 (A), for contacting and stopping the rack running wheels 3.

Next, description will be made, with reference to Fig. 11, of a first determining device according to this invention for determining whether a working passage C is formed or not, and a second determining device for determining whether the running rail 5 is in a proper position relative to the stacker crane E.

The traverser F has a position detecting photosensor 33 as does each movable rack B. In a stopping position corresponding to a working passage C designated through the control panel 26, the photosensor 33 detects a detected plate 34 preinstalled in an appropriate position on the floor surface. Based on the detection information, the traverser automatically stops at the stopping position designated.

A pair of reflection type photoelectric sensors 36, 36 are provided as the first determining device S for determining whether a working passage C is properly formed or not.

This first determining device includes detection elements 35 disposed at corners of the fixed racks A and movable racks B opposed to the traverser F, and the reflection type photoelectric sensors 36 for determming whether a working passage C is properly formed or not, by emitting beams to the detection elements 35 and determining presence or absence of light reflected from the detection elements 35. The traverser F further includes a distance-measuring type optical sensor 37 acting as the second determining device for determining whether or not the running rail 5 in the working passage is in an appropriate position corresponding to the wheels of the stacker crane E. That is, the optical sensor 37 measures a distance to the running rail 5 by emitting a measuring beam and measuring time taken for the beam to return after being reflected by an end of the running rail 5. A sensor using a sound wave may be employed as this second determining device, or a reflection type photoelectric sensor 36 may be employed as in the first deterrnining device. The control device 30 causes the stacker crane E to start running after each of the reflection type photoelectric sensors 36, 36 confirms presence of the detection element 35, and the distance-measuring type optical sensor 37 confirms that the running rail 5 is in a proper position. The stacker crane E is not permitted to run toward the working passage unless the running passage is properly formed or the position of the running rail 5 is confirmed to be proper. At such time of abnormality, the control panel 26 gives an indication to that effect or an alarm operation is executed.

[DIFFERENT EMBODIMENTS] Fig. 12 shows an embodiment in which contact elements 9 extend substantially over an entire length in the sideways direction of each of the fixed racks A and movable racks B.

In each of the fixed racks A and movable racks B shown in the first embodiment, the contact elements 9 have the guide rails 7b contact each other, in place of the stoppers 9a provided in the opposite end regions in the sideways direction above the guide rails 7b, which guide rails 7b extend substantially over the entire length in the sideways direction of each rack. When a working passage C is formed selectively between fixed rack A and movable rack B or between movable racks B, a space in the article depositing/fetching direction between these racks is determined by the contact between the guide rails 7b of the racks lying adjacent and in close contact with each other.

The other aspects are the same as in the first embodiment. Fig. 13 shows contact elements 9 in a further embodiment. Here again, the contact elements 9 extend substantially over the entire length in the sideways direction of each of the fixed racks A and movable racks B.

In each of the fixed racks A and movable racks B shown in the first embodiment, the contact elements 9 have stoppers 9a disposed above the guide rails and extending substantially over the entire length in the sideways direction of each rack. When a working passage C is formed selectively between fixed rack A and movable rack B or between movable racks B, a space in the article depositing/fetching direction between these racks is determined by the contact between the guide rails 7b of the racks lying adjacent and in close contact with each other. The other aspects are the same as in the first embodiment.

In the foregoing embodiments, the first determining device is exemplified as comprising a pair of reflection type photoelectric sensors 36, 36 for detecting the detection elements 35, 35 provided for each storage rack. This construction may be replaced by light projectors BT, as shown in Fig. 14, which are installed on a floor surface opposite the location where the traverser is installed. In this case, one right and left pair is installed so that the light beams reach the traverser only when a working passage is properly formed between the racks. The traverser F may include light detectors 40 for detecting the light projected from these light projectors BT. When the light detectors 40, 40 detect the light, it is determined that a running passage is formed properly.

In the foregoing embodiments, the second determining device is exemplified as comprising the distance measuring type optical sensor 37. Instead, a reflection type photoelectric sensor may be used to detect the rails.

In the foregoing embodiments, the transfer apparatus for transporting articles includes a stacker crane, and the traverser moves the stacker crane along the first direction. This construction may be replaced by a fork device provided for a movable body movable in each of the first direction and second direction.

In the foregoing embodiments, the first determining device and second determining device comprise optical sensors, respectively. This construction may be replaced by various detecting devices such as by contact type position detecting sensors or magnetism detecting sensors.

In the foregoing embodiments, one running rail is provided in the middle of each working passage. However, each working passage may include a plurality thereof.

In the foregoing embodiments, the control device 30 is provided for the stacker crane E, but may be provided for the traverser F or may be provided for the control panel 26.

Furthermore, the foregoing embodiments include a plurality of movable racks. However, the article storage equipment may include a single movable rack disposed between one pair of fixed racks.

The movable racks may be moved by manual operating force.

Furthermore, one movable rack is driven by two drive devices in the above embodiments, but may be driven by a single drive device. The contact elements may be provided to extend substantially over the entire length in the sideways direction in the upper position and lower position of each of the fixed racks and movable racks, so that the racks contact each other in the upper positions and lower positions.

Claims

[CLAIMS]

1. Article storage equipment comprising: a pair of fixed racks having a plurality of storage units open for allowing articles to be deposited and fetched in a first direction, and arranged with a space therebetween in said first direction; at least one movable rack disposed between said pair of fixed racks and extending in a second direction perpendicular to said first direction; a pluraUty of wheels arranged at intervals in said second direction in bottom regions of said movable rack; rack supporting rails extending in said first direction and disposed in positions in said second direction corresponding to said wheels for supporting said wheels and permitting said movable rack to move along said first direction within a predetermined running range; a running type transfer vehicle movable along said second direction in a working passage formed between a pair of racks set adjacent each other by movement of said movable rack, for depositing and fetching the articles in/from said fixed racks or said movable rack; running rails extending in said second direction for supporting said transfer vehicle; vehicle control means for controlling running of said transfer vehicle; and guides provided in regions of said fixed racks and movable rack where said working passage is formed, for guiding and supporting said transfer vehicle through contact with said transfer vehicle; wherein each of said fixed racks and said movable rack has contact elements contactable with each other for controlling a space in said first direction between adjacent racks lying close to each other when said working passage is formed, to maintain a proper space between the guides, opposed to said working passage, of said adjacent pair of racks forming said working passage.

2. Article storage equipment as defined in claim 1, wherein said contact elements project farther than said guides in a direction along said first direction.

3. Article storage equipment as defined in claim 1, further comprising: a pair of drive means for separately driving at least those wheels, among said wheels, disposed in opposite end regions in said second direction of said movable rack; drive control means for controlling operation of the drive means; and a pair of detecting means for separately detecting opposite ends in said second direction having approached one end of said fixed running range; wherein said drive control means is operable to start operation of said pair of drive means based on a start command, and when, with said pair of detecting means and said pair of drive means at the same end regions are made to correspond to each other, said detecting means detects an approach to one end of said fixed running range, to cause the drive means corresponding to that detecting means to continue operating for a predetermined time before stopping.

4. Article storage equipment as defined in claim 1, further comprising first determining means for determining that said adjacent movable racks for forming said working passage have formed said working passage, and second determining means for determining that said running rail is in a proper position relative to said transfer vehicle, said vehicle control means permitting said transfer vehicle to move along said working passage when said first determining means determines that said adjacent pair of movable racks have formed said working passage and said second deterrnining means determines that said running rail is in the proper position relative to said transfer vehicle.

5. Article storage equipment as defined in claim 4, wherein said transfer vehicle is a stacker crane movable in said working passage and in a position outside one end of said working passage, the article storage apparatus further comprising a transport carriage for moving this stacker crane along said first direction, said second determining means being mounted on said transport carriage.

6. Article storage equipment as defined in claim 5, wherein said first deterrnining means is mounted on said transport carriage.

7. Article storage equipment as defined in claim 1, wherein said transfer vehicle is operable to run as supported by supporting rails disposed on the ground; said transfer vehicle being prevented from turning over when transferring the articles, by causing rollers supported to be rotatable on vertical axes at opposite sides of said transfer vehicle in a direction of width of the working passage, to contact said guides in a direction toward the rack having the guides.

8. Article storage equipment as defined in any one of claims 1 to 3, wherein said contact elements are disposed in at least two positions spaced apart in said second direction of each of said fixed racks and said movable rack.

9. Article storage equipment as defined in claim 1, wherein said contact elements extend substantially over an entire length in said second direction of each of said fixed racks and said movable rack.

10. Article storage equipment as defined in claim 9, wherein said guides are used also as said contact elements.

11. Article storage equipment as defined in any one of claims 1, 2, 8, 9, wherein said contact elements are provided for each of said fixed racks and said movable rack such that upper positions and lower positions thereof contact each other.

12. Article storage equipment as defined in claim 3, wherein said detecting means includes a photosensor, and a detected member for turning the photosensor on and off, wherein one of said photosensor and said detected member is mounted on said movable rack, and the other is fixed to a fixing device for said rack supporting rail.

13. Article storage equipment as defined in claim 4, wherein said first and second determining means are optical sensors.