Side buffer for a transport vehicle that travels along the ceiling, and transport vehicle system

A side buffer includes a bottom portion on which a FOUP may be placed, a restriction portion, an article receiving portion, and a link portion. The restriction portion is movable between a restricting position and a retracted position. At the restricting position, the restriction portion restricts an inclination of the FOUP on the bottom portion. At the retracted position, the restriction portion allows the FOUP to move between the bottom portion and a position directly above the bottom portion. The article receiving portion is disposed so as to receive a force from the FOUP placed on the bottom portion. The link portion moves the restriction portion from the retracted position to the restricting position with the received force.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a side buffer for a conveying vehicle traveling along a ceiling and a conveying vehicle system.

2. Description of the Related Art

A semiconductor manufacturing plant includes a conveying system for conveying a container, in which substrates are contained, between processing apparatuses.

For example, the conveying system is provided with a rail suspended from a ceiling, and a conveying vehicle supported by the rail so as to be suspended therefrom. The conveying vehicle conveys a front opening unified pod (FOUP), in which substrates are contained.

Moreover, a side buffer is disposed adjacent to the rail so as to be able to adjust the timing for conveying the FOUP to the processing apparatus (See, for example, Japanese Patent Application Laid-Open No. 2009-196748).

The side buffer described in Japanese Patent Application Laid-Open No. 2009-196748 is described below. Note that, in the following descriptions about the technology described in Japanese Patent Application Laid-Open No. 2009-196748, reference numerals assigned to components are those used in Japanese Patent Application Laid-Open No. 2009-196748, and are not related to reference numerals which are illustrated in the drawings of the present application.

The side buffer described in Japanese Patent Application Laid-Open No. 2009-196748 includes an anti-tip member350in order to prevent a FOUP from falling from a placement table300due to shock caused by an earthquake, and the like.

The anti-tip member350has an angular U-letter shape. The anti-tip member350is constituted of a tilting restriction portion350a, a connecting portion350b, and a fixing portion350c. The tilting restriction portion350a, the connecting portion350b, and the fixing portion350care integrally formed. The fixing portion350cis a plate-shaped portion and is screwed to a beam360of the placement table300. The connecting portion350bis a plate-shaped portion extending upward from the fixing portion350c. The tilting restriction portion350ais a plate-shaped portion extending perpendicular to the connecting portion350b. In other words, the tilting restriction portion350ais displaced above a position where an article is placed on the placement table300.

In Japanese Patent Application Laid-Open No. 2009-196748, an article500is the FOUP and includes a protruding portion510at the lowermost portion of aside portion. An abutment surface portion510ais disposed on an upper surface of the protruding portion510. When the article500is to be placed onto the placement table300, the article500is moved by a conveying vehicle3in a substantially horizontal direction toward the placement table300. During this movement operation, the position of the abutment surface portion510aof the article500in a height direction is lower than the position of the tilting restriction portion350ain the height direction. The article500is conveyed above the placement table300by this movement operation, and then is lowered so as to be placed onto the placement table300.

When the article500tilts while having been placed on the placement table300, the abutment surface portion510aabuts against the tilting restriction portion350a. Accordingly, the range of tilting of the article500placed on the placement table300is restricted.

In the above-mentioned placement table300, the tilting restriction portion350ais disposed above the portion where the article500is placed on the placement table300. Therefore, the article cannot be moved in upward and downward directions between a position above the tilting restriction portion350aand the placement table300.

In a conveying system described in Japanese Patent Application Laid-Open No. 2009-196748, the taking-in and taking-out of the article500are performed at only one side of the placement table. This is because an edge of a lid of the FOUP protrudes from the side surface so that the lid of the FOUP would make contact with the tilting restriction portion when the taking-in and taking-out of the article500is performed at the opposite side of the placement table. Accordingly, the technology described in Japanese Patent Application Laid-Open No. 2009-196748 cannot be applied to a conveying vehicle system in which a FOUP having a lid protruding from the side surface is taken-in and taken-out at both sides of the placement table.

SUMMARY OF THE INVENTION

Preferred embodiments of the present invention enhance flexibility of directions in which an article may be taken-in and taken-out in a case of a side buffer including an anti-tip mechanism.

Various aspects, features, characteristics, etc. of preferred embodiments of the present invention described below can be optionally combined according to need or preference.

A side buffer according to a first preferred embodiment of the present invention is a side buffer disposed in a conveying vehicle system having a conveying vehicle traveling along a ceiling. The side buffer includes a placement portion on which an article may be placed; a suspension member which suspends the placement portion from the ceiling; a restriction portion movable between a restricting position, where an inclination of the article on the placement portion is restricted, and a retracted position, where the article is allowed to be moved among the placement portion, a position directly above the placement portion and above the restriction portion, and a position directly above the placement portion and below the restriction portion; an article receiving portion disposed so as to receive a force from the article placed on the placement portion; and a link portion which moves the restriction portion from the retracted position to the restricting position with the received force.

When the restriction portion is at the restricting position, the tilting of the article is restricted so that the tipping of the article can be prevented. On the other hand, when the restriction portion is at the retracted position, the article can be moved between the placement portion and the position directly above the placement portion so that the amount of flexibility in transferring the article can be enhanced. For example, the article can be placed onto the placement portion from the position directly above the placement portion.

Moreover, the link portion uses the force from the article to move the restriction portion from the retracted position to the restricting position, so that no special driving member is needed.

The restriction portion may be disposed at each of two sides of the article in a traveling direction of the conveying vehicle when the restriction portion is at the restricting position. Moreover, the article receiving portion may be disposed such that, when the article is placed on the placement portion, portions of the article near its end portion in a horizontal direction and perpendicular or substantially perpendicular to the traveling direction may be placed on the article receiving portion.

In this case, when the article is placed on the article receiving portion, the link portion moves the restriction portion from the retracted position to the restricting position. Therefore, the operation of placing the article onto the placement portion can result in the movement of the restriction portion from the retracted position to the restricting position.

The side buffer may be further provided with a biasing portion which presses the restriction portion toward the retracted position. In this case, when the above-mentioned force is removed, the restriction portion is positively moved to the retracted position.

The side buffer may include a first plate as the restriction portion, a second plate as the article receiving portion which is opposite to the first plate, and a third plate as the link portion which connects the first plate with the second plate.

The first plate, the second plate, and the third plate may be configured to have a U-letter shape.

The restriction portion, the article receiving portion, and the link portion may be integral with each other so as to define a single unit.

The side buffer may further include a rotation shaft, and the restriction portion may be disposed so as to be rotatable about the rotation shaft.

The article may include a protrusion on its surface. The restriction portion may be disposed such that an inclination of the article is restricted by restricting a range of movement of the protrusion at the restricting position.

The side buffer may include a first unit including the restriction portion, the article receiving portion, and the link portion. Moreover, the side buffer may include a second unit including another restriction portion, another article receiving portion, and another link portion. The first unit is disposed on one side of the placement portion, and the second unit is disposed on the other side which is opposite to the one side where the first set is disposed. In this case, the tilting of the article is restricted by the restriction portions from both sides, so that the position of the article can be more stably maintained even when a shock is applied thereto.

A conveying vehicle system according to another preferred embodiment of the present invention is provided with any one of the above-mentioned side buffers, and a conveying vehicle which moves the article in upward and downward directions between the placement portion and the position directly above the placement portion and higher than the restriction portion.

In the side buffer according to various preferred embodiments of the present invention, the restriction portion can be moved between the restricting position and the retracted position so that the flexibility of directions in which the article may be taken-in and taken-out can be enhanced.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

1. First Preferred embodiment

1-1. Configuration of FOUP

Referring toFIG. 1, a description is given of a configuration of a FOUP6which is conveyed by a conveying vehicle system1described below.

As illustrated inFIG. 1, the FOUP6includes a pod main body61, a lid62, an upper flange63, a handle64, and a lower flange65.

The pod main body61, which preferably is a container in the shape of a substantially rectangular parallelepiped, can contain semiconductor substrates therein, for example.

The upper flange63is disposed substantially at the center of an upper surface of the pod main body61. The upper flange63includes a plate parallel to the upper surface of the pod main body61, and a support portion which connects the plate with the pod main body61and projects upward from the pod main body61.

The handle64has a shape that is elongated in one direction. Each of the side surfaces, which are opposite to each other, of the pod main body61is preferably provided with the handle64. The “side surface” here means a surface, among the surfaces of the pod main body61, which abuts against both the upper surface of the pod main body61and the lid62. The handle64is disposed so as to be inclined with respect to the lower side of the side surface. Specifically, the handle64is disposed such that one end portion, which is closer to the lid62, of the end portions in a longitudinal direction of the handle64, is positioned closer to the upper surface of the pod main body61, and the other end portion is positioned to be farther from the upper surface of the pod main body61.

The lower flange65is disposed along the lower side (i.e. the side between the side surface and the lower surface of the pod main body61) of the same side surface as that on which the handle64is disposed. The lower flange65projects in a direction that is perpendicular or substantially perpendicular to the side surface, namely, in a direction parallel or substantially parallel to the lower surface of the pod main body61.

1-2. Configuration of Conveying Vehicle System

Referring toFIG. 2, the configuration of a conveying vehicle system is described.

The conveying vehicle system1according to the present preferred embodiment may be applied to a semiconductor manufacturing system, for example. The conveying vehicle system1conveys the FOUP6between a plurality of processing apparatuses9.

1-3. Configuration of Conveying Vehicle System

Referring toFIG. 2, the configuration of the conveying vehicle system1is described. Note that, an X-axis direction is a horizontal direction inFIG. 2, a Y-axis direction is a longitudinal direction inFIG. 2(i.e., a vertical direction), and a Z-axis direction is a direction perpendicular to the sheet ofFIG. 2.

The conveying vehicle system1is a system in which a plurality of conveying vehicles3travel along a given route. As illustrated inFIG. 2, the conveying vehicle system1includes the conveying vehicle3, a traveling rail30, and a supporting column31.

As illustrated inFIG. 2, the traveling rail30is suspended from a ceiling5of a clean room via the supporting column31. The traveling rail30includes a traveling rail main body32and a power supply rail33. The traveling rail30is disposed such that its longitudinal direction is parallel or substantially parallel to the Z-axis. A clean room is not the only place where the conveying vehicle system may be disposed. Even in the case where the conveying vehicle system is disposed in a room other than a clean room, the traveling rail may be suspended from the ceiling of the room.

The conveying vehicle3preferably is a suspension-type conveying vehicle. As illustrated inFIG. 2, the conveying vehicle3includes a base34, a traveling drive portion35, a power receiving portion36, two covers37, a lateral movement mechanism39, a lifting drive portion40, and a lifting table41. The traveling drive portion35is connected with the base34and can travel in the traveling rail main body32. The power receiving portion36can receive power from the power supply rail33. The two covers37are fixed to the base34so as to sandwich the FOUP6therebetween in the traveling direction of the conveying vehicle3(the longitudinal direction of the traveling rail30).

The lateral movement mechanism39can move the lifting drive portion40, lifting table41, and the FOUP6in the X-axis direction. The lifting drive portion40can move the lifting table41up and down in the Y-axis direction via a suspension member, such as a belt, a wire, or a rope, and the like. The lifting table41can clamp the upper flange63of the FOUP6with its hand, and release the clamping of the same.

1-4. Configuration of Side Buffer

Entire Configuration

Referring to FIGS .2to5, the configuration of a side buffer2is described. Note that, inFIG. 5, the portions disposed in front of the cross-section are illustrated with alternate long and short dash lines.

The side buffer2is a mechanism disposed adjacent to the traveling rail30. The side buffer2is configured such that the FOUP6can be temporarily placed thereon.

As illustrated inFIGS. 2 to 5, the side buffer2is provided with a frame member20, a beam21, a supporting column22, and an anti-tip mechanism29.

The beam21has a shape that is elongated in the Z-axis direction. Two beams21are used as one set.

The supporting column22(suspension member) is fixed at its first end to the beam21, and at its second end to the ceiling5. Thus, the supporting column22suspends the beam21and other members fixed to the beam21from the ceiling5. Note that, inFIG. 2, the each two supporting columns22are positioned in front of and behind the FOUP6and the bottom portion23so that the two supporting columns22are illustrated with alternate long and short dash lines for convenience of explanation.

The frame member20is supported by the beam21. The frame member20is provided with the bottom portion23(placement portion), side panels24, a front panel251, and a rear panel252.

As illustrated inFIG. 3, the bottom portion23is a plate-shaped member having a substantially X-letter shape. The bottom portion23is fixed to the beam21via a screw, or other suitable fixing member.

As illustrated inFIG. 3, the four side panels24are disposed such that the surfaces thereof become parallel or substantially parallel to the Z-axis. Two of the four side panels24are disposed at the right edge of the bottom portion23(the edge on the upper side inFIG. 3) so as to be aligned in the Z-axis direction. The other two side panels24are disposed at the left edge of the bottom portion23(the edge on the lower side inFIG. 3) so as to be aligned in the Z-axis direction. As illustrated inFIG. 4, the side panel24is disposed so as to protrude from the bottom portion23in the upward direction (the positive Y-axis direction).

As illustrated inFIG. 3, the front panel251and the rear panel252are disposed so as to be opposite to each other in the Z-axis direction. As illustrated inFIG. 5, the front panel251and the rear panel252are disposed so as to be perpendicular or substantially perpendicular to the surface of the bottom portion23. In other words, the front panel251and the rear panel252are disposed so as to be parallel or substantially parallel to the X-Y plane. Two ends of the front panel251in the X-axis direction are respectively connected with the front end of the right front (upper left inFIG. 3) side panel24and the front end of the left front (lower left inFIG. 3) side panel24. Two ends of the rear panel252in the X-axis direction are respectively connected with the rear end of the right rear side panel24(upper right inFIG. 3) and the rear end of the left rear side panel24(lower right inFIG. 3).

According to such an arrangement, gaps exist between the front panel251and the bottom portion23, and between the rear panel252and the bottom portion23. A restriction member290described below is disposed in this gap.

The frame member20may be integrally formed as a whole with a resin, or may be formed by assembling a plurality of components.

Configuration of Anti-Tip Mechanism

Referring toFIGS. 3 to 5, the configuration of the anti-tip mechanism29is described. The anti-tip mechanism29is a mechanism that prevents the FOUP6from tipping, even when the side buffer2is shaken. Note that, inFIG. 3, the positions of the components included in the anti-tip mechanism29are the positions when the FOUP6has been placed on the side buffer2.

As illustrated inFIGS. 3 to 5, one anti-tip mechanism29is disposed adjacent to each of the two ends of the bottom portion23in the Z-axis direction. The two anti-tip mechanisms29are symmetrically disposed with respect to the X-Y plane passing through the center of the bottom portion23. The anti-tip mechanism29is provided with a restriction member290, a rotation shaft295, and springs296.

The restriction member290can prevent the FOUP6from tipping by restricting the inclination of the FOUP6contained in the side buffer2. The restriction member290is provided with a restriction portion291(first plate), an article receiving portion292(second plate), and a link portion293(third plate).

The restriction portion291, the article receiving portion292, and the link portion293, are substantially rectangular plate-shaped members. The restriction portion291extends at aright angle from one side of the rectangular link portion293. The width of the restriction portion291in a direction perpendicular or substantially perpendicular to the surface of the link portion293is shorter than the width of the article receiving portion292in the same direction.

The angle defined by the surface of the restriction portion291and the surface of the link portion293is substantially a right angle.

The article receiving portion292has an elongated shape and is disposed so as to be opposite to the restriction portion291across the link portion293. The article receiving portion292is disposed, through the rotation shaft295described below, such that its longitudinal direction is parallel or substantially parallel to the X axis. The length of the article receiving portion292is determined according to the length in the X-axis direction of the FOUP6, the shape and the width in the Z-axis direction of the lower flange65, the distance between the restriction portion291and the article receiving portion292, the width in the Z-axis direction of the restriction portion291, and the like. The relationship between the length of the article receiving portion292and the length of the FOUP6when brought into the side buffer2is described later.

The link portion293extends at an angle perpendicular or substantially perpendicular to the surface of the article receiving portion292from the end of the article receiving portion292in the short direction. In other words, the link portion293connects the restriction portion291with the article receiving portion292.

In the longitudinal direction of the article receiving portion292, the length of the restriction portion291and the length of the link portion293are shorter than the length of the article receiving portion292. The link portion293and the restriction portion291are disposed not at the center of the article receiving portion292in the longitudinal direction of the article receiving portion292, but at a position closer to one end portion of the article receiving portion292(see figures). However, the shapes, numbers, and positions of the link portion and the restriction portion can be changed. Also, the magnitude correlations between the length of the restriction portion291, the length of the link portion293, and the length of the article receiving portion292can be changed.

As illustrated inFIG. 5, in a cross section (A-A cross section) which crosses through the restriction portion291and the link portion293and is parallel or substantially parallel to the Y-Z plane, the restriction member290has a U-letter shape, and specifically an angular U-letter shape. As illustrated inFIG. 5, the restriction portion291and the article receiving portion292are the portions which are opposite to each other in the cross section of the U-letter shape. The link portion293corresponds to the bottom portion of the U-letter shape. As mentioned above, in this cross section, in the direction perpendicular or substantially perpendicular to the surface of the link portion293, the width of the restriction portion291is shorter than the width of the article receiving portion292.

The restriction member290may be formed by folding a cross-sectional metal plate, through casting, or formed with materials such as a resin, for example.

The rotation shaft295is disposed in the corner between the article receiving portion292and the link portion293of the restriction member290in the longitudinal direction of the article receiving portion292. Two ends of the rotation shaft295are held in the bearing holes (not shown) respectively disposed in the side panels24. The bearing holes are disposed at lower portions of the side panels24(portions close to the bottom portion23), and are adjacent to the front end and the rear end of the bottom portion23. Thus, the rotation shaft295is disposed so as to be parallel or substantially parallel to the X-axis. In other words, the restriction members290are disposed at both sides of the bottom portion23in the Z-axis direction such that their longitudinal directions become parallel to the X-axis. The restriction member290can be rotated about the rotation shaft295. By this rotation, the restriction portion291can be rotated about the rotation shaft295.

As illustrated inFIG. 7, while incorporated into the side buffer2, one end of the article receiving portion292in the longitudinal direction is disposed adjacent to one end of the FOUP6in the X-axis direction. The other end of the article receiving portion292is disposed adjacent to the other end of the FOUP6. Moreover, inFIG. 7, both ends of the article receiving portion292in the X-axis direction are disposed inside with respect to both ends of the FOUP6in the X-axis direction. However, as other preferred embodiments, the ends of the article receiving portion292in the X-axis direction may be located at the same positions as those of the ends of the FOUP6in the X-axis direction, or located outside with respect to the same.

As illustrated inFIGS. 3 to 5, the springs296are disposed adjacent to both ends of the rotation shaft295. More specifically, the springs296are disposed closer to both ends of the rotation shaft295than the link portion293and the article receiving portion292. The spring296is wound around the rotation shaft295. A first end of each spring296abuts against the bottom portion23, and the other end is fixed to the restriction member290.

The springs296bias the restriction members290toward the directions in which the restriction members290are opened (i.e., the directions in which the distance between the restriction portions291of the two restriction members290is made longer).

In other words, the restriction member290on the front side receives a force from the springs296which causes the link portion293to be inclined toward the front panel251. However, the inclination of this restriction member290with respect to the bottom portion23(with respect to the Z-X plane) is restricted by the front panel251. As a result, the article receiving portion292of this restriction member290is disposed at a position where it may be pressed down by the FOUP6, namely, a position where the article receiving portion292may receive a force from the FOUP6.

Moreover, the restriction member290on the rear side (the right side inFIG. 5) receives a force from the spring296which causes the link portion293to be inclined toward the rear panel252. However, the inclination of this restriction member290with respect to the bottom portion23is restricted by the rear panel252. As a result, the article receiving portion292of this restriction member290is disposed at a position where it may be pressed down by the FOUP6, namely, a position where the article receiving portion292may receive a force from the FOUP6.

In other words, as illustrated inFIG. 5, with the rotation shaft and the front panel251, the article receiving portion292is disposed closer to the center of the bottom portion23in the Z-axis direction than the link portion293. In other words, the restriction member290is disposed such that the recess portion of its U-letter shape cross section is facing the inside of the frame member20in the Z-axis direction.

When the FOUP6is not placed on the side buffer2, the restriction portion291is disposed at a retracted position due to the biasing by the spring296(FIG. 5). As will be describer later, when the FOUP6is placed onto the side buffer2, by the placement operation of the lifting drive portion40, the FOUP6is moved down along the vertical direction (Y-axis direction) from a position above the restriction member290to the bottom portion23. The “retracted position” means a position which is out of the moving path of the FOUP6during the placement operation. In other words, it is a position where the restriction portion291is not pressed down by the FOUP6during the placement operation. Further, in other words, it is a position where the restriction portion291does not receive a force from the FOUP6during the placement operation (FIG. 5).

As will be described later, the article receiving portion292receives a force from the FOUP6when the FOUP6is placed onto the side buffer2. The link portion293, by transmitting this force to the restriction portion291, moves the restriction portion291. Specifically, when the FOUP6is placed onto the article receiving portion292, the article receiving portion292receives force in the downward direction (the negative direction of Y-axis). Because the restriction member290can be rotated about the rotation shaft295, the article receiving portion292moves downward due to this force. Because the link portion293is connected with the article receiving portion292, the link portion293is also rotated about the rotation shaft295. Because the link portion293is also connected with the restriction portion291, the restriction portion291is also rotated about the rotation shaft295. Thus, the restriction portion291is moved from the retracted position to a restricting position (FIG. 6). That is, the link portion293moves the restriction portion291from the retracted position to the restricting position based on the force received by the article receiving portion292. The details of the movement of the restriction portion291are described later with reference toFIG. 6.

1-5. Operation of Conveying Vehicle System1

Referring toFIG. 2, the operation of the conveying vehicle system1is described.

In the conveying vehicle system1, according to an instruction from a host controller, the conveying vehicle3is loaded with a FOUP6from a processing apparatus9, and is moved along the traveling rail30, thereby conveying the FOUP6to another processing apparatus9.

As illustrated inFIG. 2, the processing apparatus9is provided with a load port91and a gateway92.

The FOUP6is placed onto the load port91of the processing apparatus9as the destination by the conveying vehicle3. A substrate in the FOUP6is taken out by a robot and processed by the processing apparatus9. After the completion of the processing, the substrate is returned to the FOUP6. The conveying vehicle3then conveys the FOUP6to a next destination.

The FOUP6may be placed onto the side buffer2by the conveying vehicle3. By placing the FOUP6onto the side buffer2, the timing of conveyance to the processing apparatus9maybe adjusted.

1-6. Placement on Side Buffer

Referring toFIG. 2andFIGS. 5 to 7, the placement of the FOUP6onto the side buffer2is described. InFIG. 6, similar toFIG. 5, the FOUP6is illustrated with two-dot chain lines, and the portions disposed in front of the cross section are illustrated with alternate long and short dash lines. InFIG. 7, the FOUP6placed on the side buffer2is illustrated with solid lines, and the FOUP6removed from the side buffer2is illustrated with dotted lines. InFIG. 7, some components, such as the front panel251and the rear panel252, are omitted from the figure.

As illustrated inFIG. 5, when the FOUP6is not placed on the side buffer2, the two restriction members290are kept in the opened state (the state in which the distance between the restriction portions291of the two restriction members290is large) due to the biasing by the springs296. In this state, the distal end of the article receiving portion292is disposed at a position higher than the bottom portion23at the region where the FOUP6may be placed. Moreover, in this state, the restriction portion291is located at the retracted position, which is out of the region where the FOUP6may be placed, thereby enabling the FOUP6to move between the bottom portion23and a position directly above the bottom portion23.

As illustrated inFIG. 7, by lowering the FOUP6in the vertical direction from above the restriction member290, the FOUP6is placed onto the side buffer2. Specifically, the FOUP6is moved to a position above the bottom portion23and the restriction portion291by moving the FOUP6in X-axis direction with the lateral movement mechanism39while being held by the lifting table41(horizontal movement operation). Next, the FOUP6is lowered in the vertical direction by the lifting drive portion40(lowering operation). The moving directions of the FOUP6are also designated by arrows D1and D2inFIG. 2.

As illustrated inFIG. 6, the article receiving portion292is pressed down by the FOUP6that is being lowered. When the article receiving portion292is pressed down, the restriction member290is rotated about the rotation shaft295. Specifically, when the link portions293transmit the force received by the article receiving portions292to the restriction portions291, the restriction portion291of the restriction member290on the front side (the left side inFIG. 6) is rotated clockwise inFIG. 6, and the restriction portion291of the restriction member290on the rear side (the right side inFIG. 6) is rotated counter-clockwise inFIG. 6.

Finally, the article receiving portion292is pressed down by the FOUP6to the same height as that of the bottom portion23(FIG. 6). Asa result, the link portion293takes an upright position such that it is parallel or substantially parallel to the Y-axis. Moreover, the restriction portion291is moved to the restricting position. The “restricting position” means a position directly above the lower flange65of the FOUP6. Thus, the restriction members290are brought into a closed state (the state in which the distance between the restriction portions291of the two restriction members290is small). The lower flange65is sandwiched between the restriction portion291and the article receiving portion292in the Y-axis direction.

The function of the restriction member290when the FOUP6is inclined due to an earthquake, and the like, is described with reference toFIG. 8. InFIG. 8, the FOUP6, which is shaken and inclined with respect to the side buffer2, is illustrated with dotted lines. The components of the side buffer2other than the restriction member290are omitted from the figure.

As illustrated inFIG. 8, even when the FOUP6is inclined toward the left or right direction (in the X-Y plane direction), tipping of the FOUP6can be prevented by the restriction member290. This is because the positions of the restriction portions291hardly change even when the FOUP6is inclined. In other words, even when the FOUP6is inclined, the restriction portion291can restrict the range of movement of the lower flange65. As a result, the inclination of the FOUP6is restricted with respect to the side buffer2.

Next, the reason why the positions of the restriction portions291hardly change even when the FOUP6is inclined is described. Because the restriction member290is disposed in a way such that the FOUP6is placed on the article receiving portion292, even when the FOUP6is inclined, the range of movement of the article receiving portion292(the rotation angle of the restriction member290) is restricted by the weight of the FOUP6.

Thus, even when the FOUP6is inclined, the range of movement of the article receiving portion292is restricted so that the range of movement of the restriction portion291is also restricted, thereby restricting the movement of the lower flange65.

In other words, the restriction portion291is disposed in a way such that its restricting position can be maintained even when the FOUP6is inclined. More specifically, factors such as the distance between the restriction portion291and the article receiving portion292, the position of the end portion of the restriction portion291with respect to the lower flange65in the X-axis direction, the length of the article receiving portion292in the X-axis direction, and the position of the end portion of the article receiving portion292with respect to the end portion of the FOUP6in the X-axis direction, are set such that the restriction portion291abuts against the lower flange65when the FOUP6is inclined. In other words, when the FOUP6is inclined, the lower flange65abuts against the restriction portion291at the upper limit within the movable range of the restriction portion291which is restricted by the FOUP6.

1-8. Movement of FOUP from Side Buffer

When the FOUP6is moved from the side buffer2to another location by the conveying vehicle3, the FOUP6is held by the lifting table41, and moved upward in the vertical direction by the lifting drive portion40(FIG. 5andFIG. 7). Then, FOUP6is housed between the two covers37by the lateral movement mechanism39. After that, the FOUP6is conveyed to the next destination by the conveying vehicle3.

In this manner, the anti-tip mechanism29does not interfere with the placement and the taking-out of the FOUP6from the side buffer2in the vertical direction. In other words, the tipping of the FOUP6is effectively prevented, and the FOUP6can also be smoothly taken-in and taken-out with respect to the side buffer2.

The FOUP6can be taken-in and taken out not only in the direction D1ofFIG. 2, but also in the direction D2. In other words, the FOUP6can be taken-in and taken-out from both the positive and negative directions of the X-axis with respect to the side buffer2. The reason why such taking-in and taking-out operations in the two directions can be performed is that, because the restriction portion291is moved to the retracted position, it does not interfere with the taking-in and taking-out operations of the FOUP6.

The taking-in and taking-out operations in the two directions can be implemented by, for example, disposing rails on both sides of the side buffer2in the X-axis direction. By disposing the rails in this manner, the FOUP6may be taken-in and taken-out with respect to the side buffer2at both left and right sides inFIG. 2by the conveying vehicle3.

Note that, the FOUP6may be taken-in in the direction D1and taken-out in the direction D2, or may be taken-in in the direction D2and taken-out in the direction D1.

Moreover, according to the side buffer2, because the restriction member290is provided, there is no need to increase the heights of the side panels24, the front panel251, and the rear panel252in order to prevent the FOUP6from tipping. Therefore, the lifting distance of the FOUP6during taken-in and taken-out with respect to the side buffer2can be reduced. Accordingly, when the FOUP6is transferred by the vehicle3from the lifting table41to the side buffer2and vice versa, the operation time of the conveying vehicle3which is transferred can be shortened.

As described above, the restriction members290can take the first position illustrated inFIG. 5and the second position illustrated inFIG. 6by rotating about the rotation shafts295. In the first position, the restriction members290are opened outward in the Z-axis direction, and the restriction portions291are located at the retracted positions. Therefore, the restriction portions291do not interfere with the placement of the FOUP6onto the bottom portion23. Moreover, in the second position, the restriction members290are closed inward in the Z-axis direction, and the restriction portions291are located at the restricting positions. Therefore, even when the FOUP6is inclined with respect to the side buffer2as illustrated inFIG. 8, the inclination of the FOUP6is restricted. Note that, when the FOUP6is moved upward by the conveying vehicle3, the FOUP6separates from the article receiving portion292so that the restriction members290are brought into the first position from the second position by the springs296. Therefore, the restriction portions291do not interfere with the lifting movement of the FOUP6. As described above, the restriction members290provide restriction against an inclination of the FOUP6, but do not provide restriction against the movement of the FOUP6in the upward and downward directions.

2. Second Preferred Embodiment

Referring toFIG. 9, a side buffer according to a second preferred embodiment is described. The side buffer according to the second preferred embodiment preferably includes the same configuration as that of the side buffer2of the first preferred embodiment, except that the springs296are replaced with weights297as the biasing portions. Therefore, the components which have already been described are omitted from the following description and from the figure.

As illustrated inFIG. 9, an anti-tip mechanism298of the side buffer according to this preferred embodiment is provided with the weights297. The weight297is fixed to the outer surface of the bottom of the U-letter shaped restriction member290. In other words, the weight297is fixed to the outer surface of the link portion293. The weight297may integral with the restriction member290, for example, so as to define a single unit.

As illustrated inFIG. 9, when the FOUP is not placed on the side buffer, the restriction member290on the front side is inclined toward the front panel251due to the weight297, and the restriction member290on the rear side is inclined toward the rear panel252due to the weight297. Thus, the restriction portion291is disposed at the retracted position. That is, the center of gravity of the anti-tip mechanism298(the restriction member290and the weight297) is set such that the restriction member290is biased toward the retracted position.

As described in the first preferred embodiment, when the FOUP is placed onto the side buffer, the FOUP is lowered from directly above the side buffer. As a result, the article receiving portion292is pressed down by the FOUP6. When the restriction member290is rotated about the rotation shaft295, the restriction portion291is moved to the restricting position.

3. Other Preferred Embodiments

Preferred embodiments of the present invention has been described above, but the present invention is not limited to the above preferred embodiments, and can be variously modified within the scope without departing from the gist of the present invention.

In the first and second preferred embodiments, the restriction portion291, the article receiving portion292, and the link portion293preferably are integrally included in the restriction member290. However, the restriction portion291, the article receiving portion292, and the link portion293may be formed as individually separable members.

In the first and second preferred embodiments, the movement of the restriction portion291preferably is restricted by the front panel251and the rear panel252when the FOUP6is not placed. However, any other members for restricting the movement of the restriction portion291may be disposed, and an additional member that restricts force of the spring296(biasing portion) may be provided.

In the first and second preferred embodiments, the restriction member290and the rotation shaft295are separate members. However, the restriction member290and the rotation shaft295may be integral with each other to define a single unit. Moreover, when the restriction portion291preferably is a member separable from the article receiving portion292and the link portion293, the rotation shaft295may be attached to the restriction portion291, and the restriction portion291and the rotation shaft295may be integral with each other to define a single unit.

In the first and second preferred embodiments, when the FOUP6, which is an article, is placed on the side buffer2, the bottom of the FOUP6is preferably supported by mainly the bottom portion23of the frame member20. However, the bottom portion23of the frame member20may be omitted if the bottom portion of the article can be supported by the article receiving portion292by appropriately setting the size and strength of the article receiving portion292. In other words, the article receiving portion may also function as the placement portion.

In the first and second preferred embodiments, the restriction portions291are preferably disposed so as to abut against both ends of the FOUP6in the Z-axis direction (first position). Moreover, the article receiving portions292are preferably disposed such that portions of the FOUP6near the two ends in the X-axis direction (second directions) are placed on the article receiving portions292. The X-axis is perpendicular to the Z-axis.

However, the configurations in these preferred embodiments are merely examples of the configuration “when the restriction portions are positioned on two sides of the article in a first direction, and the article is placed on the placement portion, the article receiving portion is disposed such that portions of the article near the end portion in a second direction transverse to the first direction are placed on the article receiving portion”. That is, the second direction is not necessarily perpendicular to the first direction. Moreover, the article receiving portion is not necessarily disposed such that both ends of the article are placed on the article receiving portion, but may be disposed such that only a portion of the article near one end is placed thereon.

Preferred embodiments of the present invention have been described above, but the present invention is not limited to the above preferred embodiments, and can be variously modified within the scope without departing from the gist of the invention. Specifically, the plurality of preferred embodiments and their modified examples described herein can be optionally combined with one another based on the need or preference.

Preferred embodiments of the present invention are applicable to a placement table and a conveying vehicle system.