JPH1143209A - Storage shelf - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the front end part of a truck on the lower side from being projected from the front side face of an object to be stored when a next object to be stored is stored while an object to be stored which is previously stored, is moved by pressing force in the direction in which the object is stored. SOLUTION: A storage part 10 in which an object A to be stored, which is supported on a pallet P is stored together with the pallet P, is provided with a pair of rails 2, 2 and plural trucks 3, 3a which are movably supported on the rails 2, 2 and which may be piled up one over the other when the object A to be stored is not stored. The length H1 of the trucks 3, 3a in the direction of movement is formed to be shorter than the length H of the pallet P. Thus, even when the object to be stored, is placed at the position at which the object is excessively moved relative to the truck on the lower side, an amount of excessive movement can be absorbed by the dimensional difference between the truck and the pallet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a storage shelf capable of storing an object to be stored supported by a pallet together with the pallet.

[0002]

2. Description of the Related Art As shown in FIGS. 11 to 13, for example, a storage shelf has a plurality of columns B opposed to each other at predetermined intervals in the left, right, front and rear directions, and a predetermined interval vertically between these columns B. A storage section D comprising a plurality of horizontal rails C to be erected and capable of storing three objects A to be stored in front and back between left and right columns.
Is provided. A pair of right and left rails E, E extending in the front and rear storage directions are disposed in the storage portion D so as to have an ascending gradient from the front end to the rear end.
In addition, a plurality of carts G1 and G2 that can vertically overlap when the storage object A is not stored are supported.

The upper bogie G1 is connected to the lower bogie G
2, a pair of front and rear wheels J are provided on the upper bogie G1 to be engaged with the widthwise outer portion of the rail E, and the lower bogie G2 is provided on the lower bogie G2. A pair of front and rear wheels J is provided to engage with the widthwise inner portion,
When the storage object A is taken out, each of the carts G1 and G2 has moved to the front storage position by its own weight and overlapped vertically.

[0004] When storing one storage object A, the first storage object A supported by the pallet P is lifted by a fork of a forklift F, as shown in FIG. In this state, the pallet P is placed on the upper cart G1. In the case of storing two stored objects A, as shown in FIG. 11B, the second stored object A raised by the fork of the forklift F is transferred to the first stored object A. The first stored object A is moved to the center storage position together with the upper carriage G1 and pressed to the front side surface of the object A, and the second stored object A is moved to the lower carriage G2 stopped at the front storage position. With the pallet P. In the case of storing three objects A, as shown in FIG. 12C, the third object A raised by the fork of the forklift F is stored in the second object A. The second stored object A is moved to the central storage position together with the lower carriage G2, and the first stored object A is further moved to the rear storage position together with the upper carriage G1. Then, the third storage object A is placed together with the pallet P on the starting ends of the rails E, E.

[0005]

The trolleys G1 and G2 of the storage shelf configured as described above are formed to have substantially the same size as the pallet P specified by JIS.
In addition, since the second storage object A supported by the fork of the forklift F is particularly placed on the upper carriage G1, the second storage object A supported by the fork of the forklift F is placed on the upper carriage G1 because the movement is independent of each other. When the second object A is placed on the lower truck G2 after the first container A is moved by the pressing force together with the upper bogie G1, the first In some cases, the second storage object A cannot be placed at an appropriate position on the cart G2.

In other words, the second storage object A is mounted on the lower bogie G2 when an operator who operates the forklift F sees the position of the forklift F with respect to the storage shelf and mounts the forklift F. Is inserted into the pallet in the sense of the driver, so that when the second object A is placed on the lower carriage G2, the second object A is moved too far with respect to the lower carriage G2. After being placed, the front end of the lower cart G2 protrudes from the front side surface of the second storage object A, and as shown in FIG. 12D, the front end of the lower cart G2 and the second A space may be generated between the storage object A and the front side surface.

Therefore, when the third storage object A is placed on the starting end of the rails E while moving the first and second storage objects in a state where this space is generated, the third storage object A 1 rides on the front end of the lower bogie G2, as shown in FIG.
As shown in FIG. 2 (d), there is a problem that the third transferred object A is inclined to the forward inclined posture, and the storage posture is unstable.

The present invention has been made in view of the above-mentioned circumstances, and the size of each of the carts is devised so that the length of the carts in the moving direction is shorter than the length of the pallet.
Alternatively, it is another object to provide a storage shelf capable of stably storing an object to be stored by providing engagement protrusions on the upper carriage and the lower carriage to restrict the movement of each other.

[0009]

According to a first aspect of the present invention, there is provided a storage shelf, wherein a storage part for storing an object to be stored supported by a pallet together with the pallet is supported by a rail and movably supported by the rail. In a storage shelf comprising a plurality of trolleys that can vertically overlap when not stored, each of the trolleys is formed to have a length in a moving direction shorter than a length of the pallet. .

In the first invention, the length of the bogie from the front end to the rear end is shorter than the length of the pallet without forming each bogie to the same size as the pallet specified by JIS. When the next object to be stored is placed on the lower bogie while being stored on the upper bogie while being moved by the pressing force in the storage direction, the stored object is stored on the upper bogie. Even if the stored object is placed at a position that has moved too far with respect to the lower bogie, the excessive amount of excessive movement can be absorbed by the dimensional difference between the bogie and the pallet. Objects can be stored with good stability. In the storage shelf according to the second invention, the upper bogie and the lower bogie during non-storage are provided with engaging projections that engage when an object to be stored is mounted on the bogie and moves. It is characterized by.

According to the second aspect of the present invention, when the next object to be stored is placed on the lower bogie while being moved while the object to be stored placed on the upper bogie is moved by the pressing force in the storage direction, Since the engagement protrusion provided on the upper carriage is engaged with the engagement protrusion provided on the lower carriage, the lower carriage can be forcibly moved by following the upper carriage. The stored items can be prevented from moving too far relative to the lower cart,
It is possible to stably store the next object to be stored, and even if the engaging protrusion of the upper dolly is attached to the front end of the dolly without being provided on the lower surface of the dolly, The object to be stored can be placed on the lower bogie without being hooked, and the vertical interval between the upper bogie and the lower bogie can be reduced, and in particular, the stability of the upper bogie can be improved.

A storage shelf according to a third aspect of the present invention has a rail and a rail movably supported by a storage part for storing an object to be stored supported by the pallet together with the pallet. In a storage shelf including a plurality of carts that can be overlapped, an upper cart and a lower cart when not stored are engaged with each other when an object to be stored is mounted on the carts and moves. The projection is provided.

According to the third aspect of the present invention, when the next object to be stored is placed on the lower bogie while being moved while the object to be stored placed on the upper bogie is moved by the pressing force in the storing direction, and stored. Since the engagement protrusion provided on the upper carriage is engaged with the engagement protrusion provided on the lower carriage, the lower carriage can be forcibly moved by following the upper carriage. The stored items can be prevented from moving too far relative to the lower cart,
The next object to be stored can be stored with high stability.

A storage shelf according to a fourth aspect of the present invention is characterized in that the engaging projection of the upper dolly is pivotally supported so as to be able to hang down by its own weight.

[0015] In the fourth invention, even if the rails are arranged uphill from the front end to the rear end, and the upper surface of each bogie is horizontal, When the object is stored while being moved together with the trolley by the pressing force in the storage direction, the upper trolley can be moved smoothly without engaging the engagement protrusion of the upper trolley with the lower trolley. Further, the engagement protrusion of the upper carriage can be securely engaged with the engagement protrusion of the lower carriage, and when the object to be stored is taken out, the engagement protrusion of the upper carriage is reduced in its own weight. Since it can be swung in opposition, the upper carriage can be reliably returned to its own weight.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing the embodiments. (A) and (b) of FIG. 1 and FIG.
(C) is an explanatory view of a storage stage for storing an object to be stored on a storage shelf, (d) of FIG. 2 is an explanatory view of a state in which the object and a lower cart are relatively moved, and FIG. FIG. 4 is an enlarged sectional view of a bogie portion, FIG. 5 is a side view, and FIG. 6 is an overall perspective view of a state in which an object is stored.

The storage shelf according to the first embodiment shown in FIGS. 1 to 6 has a plurality of columns 1... Facing each other at predetermined intervals in the left, right, front and back, and between the columns 1. A plurality of lower horizontal rails 11 and middle horizontal rails 1 that are vertically installed at predetermined intervals.
2. An upper horizontal rail 13 is provided, and a storage unit 10 is provided between the left and right columns 1... And between the horizontal rails 11, 12, 13 so as to be able to store three objects A to be stored in front and rear, respectively. Have been.

A pair of right and left rails 2, 2 extending in the front and rear storage directions are provided above the lower horizontal rail 11, the middle horizontal rail 12, and the upper horizontal rail 13 serving as floors of the storage unit 10 from the front end to the rear end. A plurality of trolleys 3 and 3a that are arranged so as to have an uphill slope and that can vertically overlap when the object A is not stored are supported by these rails 2 and 2.

As shown in FIG. 3, the carts 3 and 3a are rotatably supported by square frames 31 and 31a and four corners of the frames 31 and 31a. , 32a,... Further, leg pieces 33, 33 are protruded from left and right ends of the frame body 31 of the upper bogie 3, and these leg pieces 33, 33 are provided.
Each of the wheels 32 is pivotally supported. Also, the distance from the upper surface of the upper bogie 3 to each wheel 32... Is the same, and the distance from the upper surface of the lower bogie 3a to each wheel 32a is the same.
Are the same, and the upper surfaces of the carts 3 and 3a are parallel to the rails 2 and 2, respectively.

The upper bogie 3 is formed to have substantially the same width as the pallet P specified by JIS, while the lower bogie 3a is formed to be slightly smaller in width than the upper bogie 3 and the pallet P. Have been. As shown in FIG. 4, the interval between the left and right wheels 32, 32 of the upper bogie 3 is wider than the interval between the left and right wheels 32a, 32a of the lower bogie 3a. When the wheels 32a of the lower bogie 3a are engaged with the width-direction inner portions of the rails 2 and 2, respectively, when the storage object A is not stored, Each of the trolleys 3 and 3a is moved to the front storage position by its own weight so as to overlap vertically.

In addition, at the front end and the rear end of each of the rails 2, 2,
Movable pieces 21 and 22 for engaging with the wheels 32 and 32a to prevent the carts 3 and 3a from dropping out are protruded, and the rear end of the upper cart 3 is provided with a position shift of the pallet P. A shift prevention piece 34 for preventing the protrusion is provided.

Thus, the length of each of the carts 3 and 3a in the moving direction is originally formed so as to be substantially the same as the length H of the pallet P, however, in the first embodiment. In FIG. 2, as shown in FIG. 2C, the length H1 in the moving direction of each of the carts 3 and 3a is formed to be shorter than the length H of the pallet P by a predetermined length.

Therefore, as shown in FIGS. 1 (a) and 1 (b) and FIG. 2 (c), the first storage object A stored on the upper carriage 3 and stored first is stored. When the next second storage object A is stored while being moved by the pressing force in the direction, even if the second storage object A may move too much with respect to the lower carriage 3a, The excessive movement amount that has moved too much
a and the pallet P can absorb the difference.

That is, when one storage object A is stored in the storage shelf configured as described above, as shown in FIG. 1A, the first storage object A supported by the pallet P is The forklift F is placed on the upper carriage 3 together with the pallet P while being lifted by the fork of the forklift F. When two objects A are stored, as shown in FIG.
A second second object A lifted by the fork of the forklift F is pressed against the front side surface of the first object A, and the first object A is moved to the center with the upper carriage 3. The second storage object A is placed together with the pallet P on the lower carriage 3a that stops at the previous storage position.

In these cases, since the length H1 in the moving direction of the upper bogie 3 and the lower bogie 3a is shorter than the length H of the pallet P, the front ends of the upper and lower pallets P are 3 and protrude outward from the respective front ends of the lower carriage 3a. Therefore, the second storage object A is moved to the lower cart 3
a, the excessive amount of movement of the second object A is absorbed by the dimensional difference between the vehicle and the pallet, even if the second object A moves too much with respect to the lower carriage 3a. It is possible to prevent the front end of the lower cart 3a from protruding from the front side surface of the second storage object A.
When storing three objects to be stored A, FIG.
As shown in FIG. 3, the third third object A lifted by the fork of the forklift F is
To move the second storage object A to the central storage position together with the lower carriage 3a, and further move the first storage object A to the rear storage position together with the upper carriage 3 respectively. .

In this case, as shown in FIG. 2 (d), the third object A raised by the fork of the forklift F does not ride on the lower bogie 3a, and the starting ends of the rails 2, 2 are moved. Can be stably mounted together with the pallet P.

In the second embodiment, as shown in FIG.
As in the first embodiment, the lengths H1 in the moving direction are shorter than the length H of the pallet P by a predetermined length. The engagement protrusions 4 and 4a that engage when the robot is placed and moved are provided, and the lower carriage 3a is forcibly moved by following the upper carriage 3.

The engaging projection 4 of the upper bogie 3 projects downward at the front end of the bogie 3, and the engaging projection 4a of the lower bogie 3a projects upward at the rear end of the bogie 3a. Then, the upper engaging protrusion 4 is opposed to the moving direction of the carriage 3a, and when the upper carriage 3 moves backward, the engaging protrusions 4 and 4a are engaged with each other to follow the lower carriage 3a. I try to move it.

In the second embodiment, when the second second storage object A lifted by the fork of the forklift F is stored in the same manner as in FIG. A acts on the first storage object A,
The object A moves together with the upper carriage 3. At this time, when the second storage object A excessively moves with respect to the lower carriage 3a, the engagement protrusion 4 of the upper carriage 3 is moved to the lower carriage 3a.
a, the lower carriage 3a can be forcibly moved to follow the lower carriage 3a, so that the second object A can be surely moved too much with respect to the lower carriage 3a. Can be prevented. Therefore, the second storage object A raised by the fork of the forklift F can be placed without protruding the lower bogie 3a from the front side surface of the second storage object A. Therefore, the third storage object A can be stably mounted on the starting ends of the rails 2 and 2 together with the pallet P without riding on the lower bogie 3a.

The engaging projections 4 and 4a are provided at the front end or the rear end of each of the carts 3 and 3a having the length H1 in the moving direction shorter than the length H of the pallet P by a predetermined length. Therefore, even if the engagement protrusion 4 of the upper carriage 3 is not provided on the lower surface of the carriage 3 and is attached to the front end of the carriage 3 as shown in FIG. The stored item A can be placed on the lower cart 3a, and the vertical interval between the upper cart 3 and the lower cart 3a can be reduced, and the stability of the upper cart 3 can be particularly improved.

In the third embodiment, as shown in FIG.
The lengths H1 of the carts 3 and 3a in the moving direction are formed to be substantially the same as the length H of the pallets P, and the carts 3 and 3a are provided with the engaging projections 4 and 4a. Other configurations are the first and second shown in FIGS.
Since they are the same as those of the embodiment, the same reference numerals are given, and the detailed description thereof will be omitted.

In this case, in particular, the engaging projections 4 of the upper carriage 3 are provided on the lower surface of the carriage 3, and when the second storage object A is mounted on the lower carriage 3a, the second storage object A is prevented from being hooked on the engagement protrusion 4.

In the third embodiment configured as described above, as in the second embodiment, the second second storage object A raised by the fork of the forklift F is shown in FIG.
(B), the pressing force by the second storage object A acts on the first storage object A, and the first storage object A moves together with the upper carriage 3. At this time, when the second storage object A excessively moves with respect to the lower carriage 3a, the engagement protrusion 4 of the upper carriage 3 is changed to the engagement protrusion 4a of the lower carriage 3a.
, The lower truck 3a can be forcibly moved to follow, so that the second stored object A can be reliably prevented from moving too far with respect to the lower truck 3a. Therefore, the second storage object A raised by the fork of the forklift F can be placed without protruding the lower bogie 3a from the front side surface of the second storage object A. Therefore, the third storage object A can be stably mounted on the starting ends of the rails 2 and 2 together with the pallet P without riding on the lower bogie 3a.

In the first to third embodiments described above,
As shown in FIGS. 1 to 4, the upper surfaces of the carts 3 and 3 a are configured so as to be parallel to the rails 2 and 2.
As in the fourth embodiment, the upper surfaces of the carts 3 and 3a may be configured so as to be horizontal with respect to the rails 2 and 2, which have an ascending gradient from the front end to the rear end.

In this case, the upper bogie 3 and the first and second lower bogies 3a and 3b are used, as shown in FIG.
The length between the front wheels from the upper surface of each of the trucks 3, 3a, 3b is
It is formed to be longer than the length between the rear wheels from the upper surface, and when the storage object A is not stored, the carts 3, 3a, and 3b return and move by their own weights so that they overlap vertically. In this case, as shown in FIG.
With this arrangement, the upper and first lower trucks 3 and 3a are movably supported on the left and right rails, similarly to the first to third embodiments, and the remaining left and right one rails are provided. , The second lower truck 3b is movably supported.

In the fourth embodiment, similarly to the first embodiment, a configuration in which the length H1 in the moving direction of each of the carts 3, 3a and 3b is formed to be shorter than the length H of the pallet P by a predetermined length. And, similarly to the second embodiment, each of the carts 3, 3
Although it is possible to adopt a configuration in which the engagement projections 4 and 4a are provided on the a and 3b, however, in FIG.
The length H1 in the moving direction of each of the first lower truck and the second lower truck 3, 3a, 3b is substantially the same as the length H of the pallet P, and each of the trucks 3, 3a, 3b has Dolly 3,3
a, 3b are provided with engaging projections 4, 4a which engage when the object A is placed and move, so that the first lower truck 3a follows the upper truck 3 and the second lower truck 3a The lower bogie 3b is forcibly moved following the first lower bogie 3a, and the other configurations are the same as those of the first embodiment shown in FIGS. Therefore, the same reference numerals are given and the detailed description is omitted.

The engaging projections 4a provided at the rear ends of the lower carts 3a and 3b are the same as those of the third embodiment, but are provided at the distal ends of the upper cart 3 and the first lower cart 3a. As shown in FIG. 9, the engagement projection 4 is pivotally supported so that it can hang down by its own weight. In the case where the engaging protrusion 4 has a fixed structure as in the first to third embodiments, when the upper bogie 3 moves rearward, the upper bogie 3 and the lower bogies 3a and 3b are connected. In the fourth embodiment, since the vertical interval becomes large and the engagement protrusions 4 and 4a cannot be engaged with each other.
The engagement protrusion 4 is formed longer than in the first to third embodiments, and when the upper bogie 3 and the first lower bogie 3a move rearward, the upper bogie 3 that hangs down by its own weight. Engagement protrusion 4 is surely engaged with engagement protrusion 4a of first lower dolly 3a, and engagement protrusion 4 of first lower dolly 3a is surely engaged with engagement protrusion 4a of second lower dolly 3b. When the upper bogie 3 and the first lower bogie 3a move rearward, the engaging protrusion 4 and the lower bogies 3a, 3b
The contact resistance of the engaging projection 4 is reduced so that the engaging projection 4 can be reliably moved against the contact resistance due to its own weight.

The bogies 3 and 3a in the first to fourth embodiments described above support the upper and lower bogies 3 and 3a on a pair of rails with one pair on the left and right sides. 1
As shown in FIG. 0, the carts 3, 3a, 3b may be supported on the rails 2, 2 in which the two rails on the left and right are one set.

In the first to third embodiments,
In the fourth embodiment, three trolleys 3, 3a, 3b are used, but the number of trolleys 3, 3a, 3b in each embodiment is not particularly limited.

[0040]

As described above, according to the storage shelf according to the first aspect of the present invention, each bogie is formed from the front end to the rear end of each bogie without being formed in the same size as a pallet specified by JIS. Since the length is shorter than the length of the pallet, the next object to be stored is placed on the upper carriage while the next object to be stored is moved downward by the pressing force in the storage direction. When the object is stored on a trolley, even if the object to be stored is placed too far with respect to the lower trolley, the excessive amount of the excessive movement is determined by the dimensional difference between the trolley and the pallet. It is possible to absorb and store the next object to be stored with good stability.

According to the storage shelf according to the second aspect of the present invention, the next object to be stored is placed on the lower carriage while the object placed on the upper carriage is moved by the pressing force in the storage direction. In this case, the engagement protrusion provided on the upper carriage is engaged with the engagement protrusion provided on the lower carriage, and the lower carriage can be forcibly moved by following the upper carriage. Therefore, it is possible to prevent the object to be stored from being excessively moved with respect to the lower bogie, and to stably store the next object to be stored, and furthermore, to engage the engaging protrusion of the upper bogie with the bogie. Without being provided on the lower surface, even when attached to the front end of the bogie, the object to be stored can be placed on the lower bogie without being hooked on the engaging projection, and furthermore, between the upper bogie and the lower bogie. The vertical interval can be reduced, and particularly the stability of the upper bogie can be improved.

According to the storage shelf according to the third aspect of the invention, the next object to be stored is placed on the lower carriage while the object to be stored placed on the upper carriage is moved by the pressing force in the storage direction. In this case, the engagement protrusion provided on the upper carriage is engaged with the engagement protrusion provided on the lower carriage, and the lower carriage can be forcibly moved by following the upper carriage. Therefore, it is possible to prevent the object to be stored from being excessively moved with respect to the lower cart, and to stably store the next object to be stored.

According to the storage shelf according to the fourth invention, the rail is
Even if the upper surface of each trolley is configured to be horizontal from the front end to the rear end and is configured so that the upper surface of each trolley is horizontal, it is stored while moving the stored object with the trolley by the pressing force in the storage direction. In this case, the upper bogie can be moved smoothly without engaging the engaging lugs of the upper bogie with the lower bogie, and the engaging lugs of the upper bogie can be moved to the lower bogie. The engaging protrusion can be reliably engaged with the engaging protrusion, and when the object to be stored is taken out, the engaging protrusion of the upper carriage can be swung against its own weight. It is possible to reliably return to its own weight.

[Brief description of the drawings]

FIG. 1 is a side view of a storage shelf according to the present invention, in which a part of a storage shelf is omitted, and (a) and (b) are explanatory diagrams of a storage stage.

FIGS. 2A and 2B show a side view of a storage shelf according to the present invention, in which a part of the storage shelf is omitted, wherein FIG. 2C is an explanatory diagram of a storage stage, and FIG. FIG.

FIG. 3 is a front perspective view of a storage shelf according to the present invention.

FIG. 4 is an enlarged sectional view of a cart portion of the storage shelf according to the present invention.

FIG. 5 is a side view of the storage shelf according to the present invention.

FIG. 6 is an overall perspective view showing a state where an object to be stored is stored in a storage shelf according to the present invention.

FIG. 7 is an enlarged longitudinal sectional side view of a second embodiment of the storage shelf according to the present invention.

FIG. 8 is an enlarged vertical sectional side view of a third embodiment of the storage shelf according to the present invention.

FIGS. 9A and 9B show a storage shelf according to a fourth embodiment of the present invention, in which FIG. 9A is an explanatory diagram showing a non-storing state, and FIG. 9B is an explanatory diagram showing a storing state. .

FIG. 10 is an enlarged sectional view of a bogie portion of a storage shelf according to a fourth embodiment of the present invention.

FIGS. 11A and 11B show a conventional example, and FIGS. 11A and 11B are explanatory diagrams of a storage stage. FIGS.

FIG. 12 shows a conventional example, in which (c) is an explanatory diagram of a storage stage, and (d) is an explanatory diagram of a state where an object to be stored and a lower cart are relatively moved.

FIG. 13 is a side view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Storage part 2 Rail 3, 3a Truck 4, 4a Engagement protrusion A Stored object P Pallet

Claims (4)

[Claims] A plurality of rails which are movably supported by a rail and a rail in a storage section for storing an object to be stored supported by the pallet together with the pallet and which can vertically overlap when the object to be stored is not stored. A storage shelf comprising a cart, wherein each of the carts has a length in a moving direction shorter than a length of the pallet. 2. The vehicle according to claim 1, wherein the upper bogie and the lower bogie during non-storage are provided with engaging projections that engage when an object to be stored is mounted and moved on these bogies. Storage shelves. 3. A plurality of rails, which are movably supported by the rails and are movably supported by the rails, in a storage section for storing the object to be stored supported by the pallet together with the pallet and capable of vertically overlapping when the object to be stored is not stored. In a storage shelf provided with a trolley, the trolley on the upper side and the trolley on the lower side during non-storage are:
A storage shelf characterized in that an engagement protrusion is provided for engaging when an object to be stored is placed on the carriage and moves. 4. The storage shelf according to claim 3, wherein the engaging protrusion of the upper bogie is pivotally supported so that it can hang down by its own weight.