Patent Publication Number: US-2023154779-A1

Title: Parallel transfer apparatus

Description:
CROSS-REFERENCE TO THE RELATED APPLICATION 
     This application claims priority under 35 U.S.C. § 119 from Korean Patent Application No. 10-2021-0158372, filed on Nov. 17, 2021, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. 
     BACKGROUND 
     1. Field 
     The exemplary embodiments of the disclosure relate to a transfer apparatus. In particular, the exemplary embodiments of the disclosure relate to a parallel transfer apparatus. 
     2. Description of the Related Art 
     In a process of processing a semiconductor substrate, a carrier, in which a plurality of substrates is received, is provided to a substrate processing apparatus, and is unloaded from the substrate processing apparatus. The carrier, which receives a plurality of substrates, may be, for example, a front opening unified pod (FOUP) or a front opening shipping box (FOSB). 
     Generally, such a carrier may be transferred by a transfer apparatus. The transfer apparatus may not only transfer a carrier, in which substrates before processing by a substrate processing apparatus are received, to provide the carrier to the substrate processing apparatus, but also may transfer a carrier, in which substrates having been processed by the substrate processing apparatus are received, to unload the carrier from the substrate processing apparatus. 
     SUMMARY 
     The exemplary embodiments of the disclosure achieve an enhancement in transfer speed and installation space efficiency of a transfer apparatus. 
     A transfer apparatus according to some exemplary embodiments of the disclosure may include a mast portion including a base portion, a protrusion portion protruding from the base portion, and a plurality of shuttles configured to move along the mast portion, thereby transferring a carrier. The mast portion may include a first magnet track fixed to a first sidewall of the protrusion portion, and a second magnet track fixed to a second sidewall of the protrusion portion. Each of the plurality of shuttles may include a first coil portion adjacent to the first magnet track in a horizontal direction, and a second coil portion adjacent to the second magnet track in the horizontal direction. The protrusion portion, the first magnet track, and the second magnet track may be disposed between the first and second coil portions. 
     A transfer apparatus according to some exemplary embodiments of the disclosure may include a mast portion, a first shuttle and a second shuttle configured to move along the mast portion, thereby transferring a carrier, a first belt coupled to the first shuttle, to move together with the first shuttle, and a second belt coupled to the second shuttle while extending through the first shuttle, to move together with the second shuttle. The first shuttle may include a belt through hole through which the second belt extends. 
     A transfer apparatus according to some exemplary embodiments of the disclosure may include a mast portion including a base portion, a protrusion portion protruding from a first sidewall of the base portion, a first shuttle and a second shuttle configured to move along the first sidewall of the base portion, thereby transferring a carrier, a first counterweight and a second counterweight configured to move a second sidewall of the base portion, a first belt interconnecting the first shuttle and the first counterweight, and a second belt interconnecting the second shuttle and the second counterweight. The first and second shuttles may overlap each other in a vertical direction. The first and second counterweights may be spaced apart from each other in a horizontal direction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS.  1  and  2    are perspective views schematically showing a transfer apparatus according to some exemplary embodiments of the disclosure. 
         FIG.  3    is a view explaining a mast portion and a belt-pulley structure of the transfer apparatus according to  FIGS.  1  and  2   . 
         FIG.  4    is a view explaining a rail structure and counterweights of the transfer apparatus according to  FIGS.  1  and  2   . 
         FIG.  5    is a side view of the transfer apparatus according to  FIGS.  1  and  2   . 
         FIG.  6    is a view explaining a first shuttle of the transfer apparatus according to  FIGS.  1  and  2   . 
         FIG.  7    is a view explaining the relation between the first shuttle and the mast portion in the transfer apparatus according to  FIGS.  1  and  2   . 
         FIG.  8    is an enlarged perspective view of an upper portion of the transfer apparatus according to  FIGS.  1  and  2   . 
         FIG.  9    is a view explaining a pulley support portion and a belt-pulley structure in the transfer apparatus according to  FIGS.  1  and  2   . 
     
    
    
     DETAILED DESCRIPTION 
     Example embodiments will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which like numerals refer to like elements throughout. 
       FIGS.  1  and  2    are perspective views schematically showing a transfer apparatus according to some exemplary embodiments of the disclosure. 
     Referring to  FIGS.  1  and  2   , the transfer apparatus according to the exemplary embodiments of the disclosure may include a mast frame  100 . 
     The mast frame  100  may include a mast support portion  110  and a mast portion  120 . The mast portion  120  may be provided on the mast support portion  110 . The mast portion  120  may be attached to the mast support portion  110 . The mast support portion  110  may have the form of a plate extending along a plane defined by a first direction D 1  and a second direction D 2 . The first direction D 1  and the second direction D 2  may intersect each other. For example, the first direction D 1  and the second direction D 2  may be horizontal directions perpendicularly intersecting each other. The mast support portion  110  may support the mast portion  120 . The mast portion  120  may extend in a third direction D 3 . The third direction D 3  may intersect the first direction D 1  and the second direction D 2 . For example, the third direction D 3  may be a vertical direction perpendicularly intersecting the first direction D 1  and the second direction D 2 . 
     The mast frame  100  may further include a pulley support portion  130 . The pulley support portion  130  may be provided on the mast portion  120 . The pulley support portion  130  may have the form of a plate extending along a plane defined by the first direction D 1  and the second direction D 2 . 
     A first shuttle  200  and a second shuttle  300  may be provided. The first shuttle  200  and the second shuttle  300  may be vertically movable along the mast portion  120  of the mast frame  100 . The first shuttle  200  and the second shuttle  300  may move in the third direction D 3  and in a direction reverse to the third direction D 3 . The first and second shuttles  200  and  300  may overlap each other in the third direction D 3 . The first and second shuttles  200  and  300  may be arranged along the mast portion  120 . In the exemplary embodiments of the disclosure, the number of the shuttles  200  and  300  is not limited to two. In some embodiments, the number of shuttles  200  and  300  may be three or more. 
     A rail structure  410  connected to the mast portion  120  of the mast frame  100  may be provided. A first counterweight  420  and a second counterweight  430 , which vertically move along the mast portion  120  of the mast frame  100 , may be provided. The first counterweight  420  may function to reduce a force required for vertical movement of the first shuttle  200 . The second counterweight  430  may function to reduce a force required for vertical movement of the second shuttle  300 . The first counterweight  420  and the second counterweight  430  may move in the third direction D 3  and in a direction reverse to the third direction D 3 . The rail structure  410  may define paths along which the first and second counterweights  420  and  430  move. The first and second counterweights  420  and  430  may move along the paths defined by the rail structure  410 . For example, the first and second counterweights  420  and  430  may move within the vertical paths defined by the rail structure  410 . The first and second counterweights  420  and  430  may be spaced apart from each other in the first direction D 1 . 
     The number of the counterweights  420  and  430  may be equal to the number of the shuttles  200  and  300 . In the exemplary embodiments of the disclosure, the number of the counterweights  420  and  430  is not limited to two. In some embodiments, the number of counterweights  420  and  430  may be three or more. 
     A first belt  510  interconnecting the first shuttle  200  and the first counterweight  420  may be provided. A second belt  520  interconnecting the second shuttle  300  and the second counterweight  430  may be provided. The first shuttle  200 , the first counterweight  420 , and the first belt  510  may be coupled together to move together. For example, when the first shuttle  200  moves upwards, the first counterweight  420  may move downwards. The second shuttle  300 , the second counterweight  430 , and the second belt  520  may be coupled together to move together. For example, when the second shuttle  300  moves upwards, the second counterweight  430  may move downwards. The second belt  520  may extend through the first shuttle  200 . A portion of the second belt  520  may be surrounded by the first shuttle  200 . The second belt  520  and the first shuttle  200  may move independently of one another. 
     Belt-pulley structures  600  may be provided on the pulley support portion  130  of the mast frame  100 . The belt-pulley structures  600  may support the first and second belts  510  and  520 . In some embodiments, the belt-pulley structures  600  may surround each of the first and second belts  510  and  520 , and the first and second belts  510  and  520  may move through the belt-pulley structures  600 . Each of the first and second belts  510  and  520  may be supported by two belt-pulley structures  600 . The first belt  510  may move on the belt-pulley structures  600  such that the first shuttle  200  and the first counterweight  420  may vertically move. The second belt  520  may move on the belt-pulley structures  600  such that the second shuttle  300  and the second counterweight  430  may vertically move. 
     In the transfer apparatus according to the exemplary embodiments of the disclosure, carriers  10  disposed at the first and second shuttles  200  and  300  may be transferred upwards and downwards in accordance with vertical movement of the first and second shuttles  200  and  300 . The carriers  10  may be transferred from one floor to another floor by the transfer apparatus. 
       FIG.  3    is a view explaining the mast portion and the belt-pulley structure of the transfer apparatus according to  FIGS.  1  and  2   .  FIG.  4    is a view explaining the rail structure and the counterweights of the transfer apparatus according to  FIGS.  1  and  2   .  FIG.  5    is a side view of the transfer apparatus according to  FIGS.  1  and  2   . For convenience of description, the belts and the shuttles are omitted from  FIG.  3   . 
     Referring to  FIG.  3   , the mast portion  120  of the mast frame  100  may include a base portion  121  and a protrusion portion  122 . The base portion  121  and the protrusion portion  122  of the mast portion  120  may extend lengthwise in the third direction D 3 . The protrusion portion  122  may protrude from a first sidewall  121 _ 1  of the base portion  121 . The protrusion portion  122  may include a first sidewall  122 _ 1 , a second sidewall  122 _ 2 , and a third sidewall  122 _ 3 . The third sidewall  122 _ 3  of the protrusion portion  122  may be parallel to the first sidewall  121 _ 1  of the base portion  121 . The first sidewall  122 _ 1  of the protrusion portion  122  may be connected to the third sidewall  122 _ 3  of the protrusion portion  122  and the first sidewall  121 _ 1  of the base portion  121 . The second sidewall  122 _ 2  of the protrusion  122  may be connected to the third sidewall  122 _ 3  of the protrusion portion  122  and the first sidewall  121 _ 1  of the base portion  121 . The first sidewall  122 _ 1  and the second sidewall  122 _ 2  of the protrusion portion  122  may be parallel to each other. The first sidewall  122 _ 1  and the second sidewall  122 _ 2  of the protrusion portion  122  may be sidewalls opposing each other. The first and second shuttles  200  and  300  may vertically move along the first sidewall  121 _ 1  of the base portion  121  and the protrusion portion  122 . 
     The mast portion  120  of the mast frame  100  may further include a guide  123 , a first magnet track  124 , a second magnet track  125 , and a bumper  126 . The guide  123  may be fixed to the third sidewall  122 _ 3  of the protrusion portion  122  of the mast portion  120 . The guide  123  may guide vertical movement of the first and second shuttles  200  and  300 . The first and second shuttles  200  and  300  may move along the guide  123 . The guide  123  may extend lengthwise in the third direction D 3 . 
     The first magnet track  124  may be fixed to the first sidewall  122 _ 1  of the protrusion portion  122 . The second magnet track  125  may be fixed to the second sidewall  122 _ 2  of the protrusion portion  122 . The first and second magnet tracks  124  and  125  may be parallel to each other. The first and second magnet tracks  124  and  125  may be disposed at opposite sides of the protrusion portion  122 . The first and second magnet tracks  124  and  125  may extend lengthwise in the third direction D 3 . Each of the first and second magnet tracks  124  and  125  may include a magnet. Each of the first and second magnet tracks  124  and  125  may be a constituent element of a linear motor configured to drive the first and second shuttles  200  and  300 . The first and second magnet tracks  124  and  125  may be spaced apart from each other in the first direction D 1 . The protrusion portion  122  may be disposed between the first and second magnet tracks  124  and  125 . The guide  123  may be disposed between the first and second magnet tracks  124  and  125 . 
     The bumper  126  may be connected to an upper end of the guide  123 . The bumper  126  may be provided on the third sidewall  122 _ 3  of the protrusion portion  122 . The bumper  126  may define a movement limit of the first shuttle  200  moving along the guide  123 . The bumper  126  may be disposed on a movement path of the first shuttle  200  and, as such, upward movement of the first shuttle  200  beyond the bumper  126  may be limited. Although not shown, a bumper may be connected to a lower end of the guide  123 , similarly to the bumper  126  connected to the upper end of the guide  123 . The bumper connected to the lower end of the guide  123  may define a movement limit of the second shuttle  300 . 
     The mast portion  120  of the mast frame  100  may further include a communication antenna  129 , power cables  127 , and power cable supports  128 . The communication antenna  129  may communicate with the first and second shuttles  200  and  300  in a wireless manner. The communication antenna  129  may transmit and receive radio signals with the first and second shuttles  200  and  300 . The communication antenna  129  may extend lengthwise in the third direction D 3 . The communication antenna  129  may be provided on the first sidewall  121 _ 1  of the base portion  121 . 
     The power cable supporters  128  may support the power cables  127 . The power cable supports  128  may be arranged in the third direction D 3 . For example, the power cable supports  128  may be arranged to be parallel to one another in the third direction D 3 . The power cables  127  may be disposed at opposite sides of the power cable support  128 . The power cable supports  128  may be provided on the first sidewall  121 _ 1  of the base portion  121 . 
     The power cables  127  may supply electric power to the first and second shuttles  200  and  300 . In some embodiments, the power cables  127  may supply electric power to the first and second shuttles  200  and  300  in a wireless manner. The power cables  127  may extend lengthwise in the third direction D 3 . A plurality of power cable supports  128  may support one power cable  127 . 
     Each of the belt-pulley structures  600  on the pulley support portion  130  may include belt-pulley supports  610 , a belt pulley  620 , and a cover  630 . The belt-pulley supports  610  may be provided on the pulley support portion  130 . Two belt-pulley supports  610  may support one belt pulley  620 . The belt-pulley supports  610  may be disposed at opposite sides of the belt pulley  620 . 
     The belt pulleys  620  may support the first and second belts  510  and  520 . The belt pulleys  620  may rotate in accordance with movement of the first and second belts  510  and  520 . The belt pulleys  620  may be rotatably connected to the belt-pulley supports  610 . 
     The cover  630  may be provided on the belt-pulley supports  610 . The cover  630  may interconnect two belt-pulley supports  610 . 
     Referring to  FIGS.  4  and  5   , the rail structure  410  may include fixed plates  411 , rail supports  412 , and rails  413 . The fixed plates  411  may be provided on the second sidewall  121 _ 2  of the base portion  121 . The second sidewall  121 _ 2  of the base portion  121  may be a sidewall opposing the first sidewall  121 _ 1  of the base portion  121 . The first and second counterweights  420  and  430  may vertically move along the second sidewall  121 _ 2  of the base portion  121 . The fixed plates  411  may extend lengthwise in the first direction D 1 . The fixed plates  411  may be arranged in the third direction D 3 . For example, the fixed plates  411  may be arranged to be parallel to one another in the third direction D 3 . 
     The rail supports  412  may be disposed on the fixed plates  411 . A plurality of rail supports  412  may be connected to one fixed plate  411 . The plurality of rail supports  412  connected to one fixed plate  411  may be arranged in the first direction D 1 . For example, the plurality of rail supports  412  connected to one fixed plate  411  may be arranged to be parallel to one another in the third direction D 3 . The rail supports  412  may protrude from a sidewall of the fixed plate  411  in a direction reverse to the second direction D 2 . 
     One rail  413  may be connected to a plurality of rail supports  412 . The plurality of rail supports  412  connected to one rail  413  may be arranged in the third direction D 3 . The rail  413  may extend lengthwise in the third direction D 3 . Opposite sides of the rail support  412  may be connected to the fixed plate  411  and the rail  413 , respectively. The rail support  412  may be disposed between the fixed plate  411  and the rail  413 . 
     Weight movement paths  414  may be defined by the rail structure  410 . The weight movement paths  414  may extend in the third direction D 3 . Each of the weight movement paths  414  may be defined by the fixed plates  411 , the rail supports  412 , and the rails  413  of the rail structure  410 . The weight movement path  414  may be a space defined between the fixed plate  411  and the rails  413  spaced apart from each other in the second direction D 2 . The weight movement path  414  may be a space defined between the rails  413  spaced apart from each other in the first direction D 1 . The weight movement path  414  may be a space defined between the rail supports  412  spaced apart from each other in the first direction D 1 . In the exemplary embodiments of the disclosure, the number of weight movement paths  414  defined by the rail structure  410  may be four, without being limited thereto. In some embodiments, the number of weight movement paths  414  may be three or less, or five or more. 
     Each of the first and second counterweights  420  and  430  may move along the weight movement path  414  defined by the rail structure  410 . Movement in the horizontal direction of each of the first and second counterweights  420  and  430  may be restricted by the fixed plates  411 , the rail supports  412 , and the rails  413  of the rail structure  410 . Each of the first and second counterweights  420  and  430  may be disposed between the rail supports  412  spaced apart from each other in the first direction D 1 . For example, the rail supports  412  may be provided on opposite outer sidewalls of each of the first and second counterweights  420  and  430 . Each of the first and second counterweights  420  and  430  may be disposed between the fixed plate  411  and the rails  413  spaced apart from each other in the second direction D 2 . For example, the fixed plate  411  and the rails  413  may be provided on front and back sides, respectively, of each of the first and second counterweights  420  and  430 . The first and second counterweights  420  and  430  may be disposed in a part of the weight movement paths  414 , and may not be disposed in another part of the weight movement paths  414 . 
     The first and second counterweights  420  and  430  may include respective bodies  421  and  431 , and respective rail rollers  422  and  432 . The rails  413  may be disposed to face outer sidewalls of respective bodies  421  and  431  of the first and second counterweights  420  and  430  and, as such, may restrict horizontal movement of the first and second counterweights  420  and  430 . The rail rollers  422  and  432  may be disposed on the outer sidewalls of the bodies  421  and  431 , respectively. When the first and second counterweights  420  and  430  move, the rail rollers  422  and  432  may rotate along the rails  413 . The rail rollers  422  and  432  may contact the rails  413 . 
     The first belt  510  may be coupled to an upper end of the body  421  of the first counterweight  420 . The second belt  520  may be coupled to an upper end of the body  431  of the second counterweight  430 . 
     Referring to  FIG.  5   , the first shuttle  200  may include a shuttle frame  210 , a first electronic device case  220 , a second electronic device case  230 , and bedplates  240 . 
     The shuttle frame  210  may be connected to the first belt  510 . The first and second electronic device cases  220  and  230  may be disposed on a first sidewall  213  of the shuttle frame  210 . The first and second electronic device cases  220  and  230  may include electronic devices. In some embodiments, the first and second electronic device cases  220  and  230  may include regulators  221  and  231 , respectively. The regulators  221  and  231  may be, for example, constituent elements for driving of the first shuttle  200 . In some embodiments, the first electronic device case  220  may include a communication module  222 . The communication module  222  may have a wireless communication function. The communication module  222  may communicate with the communication antenna  129  in a wireless manner. Each of the first and second electronic device cases  220  and  230  may include an empty space therein. 
     The bedplates  240  may be connected to a sidewall of the first electronic device case  220 . Each of the bedplates  240  may support a carrier  10  in which substrates are received. In accordance with vertical movement of the first shuttle  200 , carriers  10  disposed on the bedplates  240  may be transferred upwards and downwards. The carrier  10  may be transferred from the outside to the bedplate  240 , and may be transferred from the bedplate  240  to the outside. 
       FIG.  6    is a view explaining the first shuttle of the transfer apparatus according to  FIGS.  1  and  2   .  FIG.  7    is a view explaining the relation between the first shuttle and the mast portion in the transfer apparatus according to  FIGS.  1  and  2   .  FIG.  8    is an enlarged perspective view of an upper portion of the transfer apparatus according to  FIGS.  1  and  2   .  FIG.  9    is a view explaining the pulley support portion and the belt-pulley structure in the transfer apparatus according to  FIGS.  1  and  2   . 
     Referring to  FIGS.  5 ,  6 ,  7 , and  8   , the first shuttle  200  may include pick-up portions  252 , guide clamps  254 , guide blocks  256 , a first coil portion  257 , a second coil portion  258 , a belt clamp  262 , belt guide rollers  264 , and a braking portion  266  which are connected to the shuttle frame  210 . 
     The pick-up portions  252 , the guide clamps  254 , the guide blocks  256 , the first and second coil portions  257  and  258 , and the braking portion  266  may be fixed to a second sidewall  214  of the shuttle frame  210 . The second sidewall  214  of the shuttle frame  210  may be a sidewall opposing the first sidewall  213  of the shuttle frame  210 . The second sidewall  214  of the shuttle frame  210  may face the mast portion  120 . 
     The pick-up portions  252  may be disposed adjacent to the power cables  127 . The pick-up portions  252  may overlap with the power cables  127  in the second direction D 2 . The pick-up portions  252  may receive electric power required for driving of the first shuttle  200  from the power cables  127  in a wireless manner. In some embodiments, the pick-up portions  252  and the power cables  127  may constitute a non-contact power supply device (HID). The pick-up portions  252  may be spaced apart from each other in the third direction D 3 . 
     The guide clamps  254  may be disposed adjacent to the guide  123 . The guide clamps  254  may overlap with the guide  123  in the second direction D 2 . The guide clamps  254  may clamp the guide  123 . When the guide clamps  254  clamp the guide  123 , movement of the first shuttle  200  may be restricted, whereas, when the guide clamps  254  release clamping of the guide  123 , movement restriction of the first shuttle  200  may be released. The guide clamps  254  may be spaced apart from each other in the third direction D 3 . 
     The guide blocks  256  may be disposed adjacent to the guide  123 . The guide blocks  256  may overlap with the guide  123  in the second direction D 2 . The guide blocks  256  may engage with the guide  123  to allow the first shuttle  200  to move along the guide  123 . In accordance with movement of the first shuttle  200 , the guide blocks  256  may slide on the guide  123 . Accordingly, the first shuttle  200  may move in the third direction D 3  or in a direction reverse to the third direction D 3  while maintaining a predetermined distance from the mast portion  120 . As the guide blocks  256  engage with the guide  123 , movement in the horizontal direction of the first shuttle  2000  may be restricted. The guide blocks  256  may be arranged in the third direction D 3 . The guide blocks  256  may be disposed between the guide clamps  254 . 
     The first and second coil portions  257  and  258  may extend lengthwise in the third direction D 3 . The first coil portion  257  may be disposed adjacent to the first magnet track  124 . For example, the first coil portion  257  may be adjacent to the first magnet track  124  in the horizontal direction. The first coil portion  257  may be spaced apart from the first magnet track  124  in the first direction D 1 . The second coil portion  258  may be adjacent to the second magnet track  125 . For example, the second coil portion  258  may be adjacent to the second magnet track  125  in the horizontal direction. The second coil portion  258  may be spaced apart from the second magnet track  125  in the first direction D 1 . The first and second magnet tracks  124  and  125 , the protrusion portion  122 , the guide  123 , and the guide blocks  256  may be disposed between the first and second coil portions  257  and  258 . 
     The first coil portion  257  and the first magnet track  124  may constitute one linear motor, and the second coil portion  258  and the second magnet track  125  may constitute one linear motor. The first shuttle  200  may be driven by two linear motors spaced apart from each other in the first direction D 1 . Each of the first and second coil portions  257  and  258  may include an electromagnetic coil. When current flows through the electromagnetic coils of the first and second coil portions  257  and  258 , the linear motors may be driven and, as such, the first shuttle  200  may move vertically. 
     The distance between the first coil portion  257  and the first magnet track  124  spaced apart from each other in the first direction D 1 , may be defined as a first distance L 1 . The distance between the second coil portion  258  and the second magnet track  125  spaced apart from each other in the first direction D 1  may be defined as a second distance L 2 . As two linear motors are symmetrically disposed at opposite sides of the protrusion portion  122 , attractive forces generated by the linear motors may offset each other. Accordingly, the first distance L 1  and the second distance L 2  may be maintained to be constant during vertical movement of the first shuttle  200 . For example, the first distance L 1  and the second distance L 2  may be maintained at 0.5 mm. 
     In the transfer apparatus according to the exemplary embodiments of the disclosure, the distance between a coil portion and a magnet track may be maintained to be constant during vertical movement of a shuttle and, as such, stability of vertical movement of the shuttle may be enhanced. As stability of vertical movement of the shuttle is enhanced, the vertical movement speed of the shuttle may become relatively high. 
     Referring to  FIGS.  6 ,  7 , and  8   , the belt clamp  262  may be provided on a top surface  215  of the shuttle frame  210 . The belt clamp  262  may clamp the first belt  510 . The first shuttle  200  may be coupled to the first belt  510  by the belt clamp  262 . As the belt clamp  262  couples the first shuttle  200  to the first belt  510 , the first shuttle  200  may move together with the first belt  510 . 
     The shuttle frame  210  may include a belt through hole  216 . The belt through hole  216  may extend through the shuttle frame  210  in the third direction D 3 . The belt through hole  216  may be an empty space extending in the third direction D 3 . The belt through hole  216  may extend through the top surface  215  of the shuttle frame  210  and a bottom surface  217  of the shuttle frame  210 . 
     The belt guide rollers  264  may guide the second belt  520 . The belt guide rollers  264  may be disposed adjacent to the top surface  215  and the bottom surface  217  of the shuttle frame  210 . The belt guide rollers  264  may overlap with the belt through hole  216 . The belt guide rollers  264  may guide the second belt  520  to extend through the belt through hole  216 . A portion of the second belt  520  may be disposed in the belt through hole  216  and be surrounded by the shuttle frame  210 . When the second belt  520  moves, the belt guide rollers  264 , which contact the second belt  520 , may rotate. The first shuttle  200  may not be influenced by movement of the second belt  520  by virtue of the belt guide rollers  264 . 
     In the exemplary embodiments of the disclosure, the number of belt through holes  216  included in the first shuttle  200  is not limited to one. In some embodiments, the first shuttle  200  may include two or more belt through holes. In this case, the belt guide rollers may be configured to correspond to the belt through holes. 
     In the transfer apparatus according to the exemplary embodiments of the disclosure, the second belt  520  may be connected to the second shuttle  300  while extending through the belt through hole  216  of the first shuttle  200  and, as such, the first shuttle  200  and the second shuttle  300  may be disposed in parallel along one mast portion  120 . As a plurality of shuttles is disposed in parallel, the space occupied by the transfer apparatus may be relatively small. 
     The braking portion  266  may restrict movement of the first shuttle  200 . In some embodiments, the braking portion  266 , which is physically spaced apart from the base portion  121 , may be brought into contact with the base portion  121  in accordance with driving thereof, thereby restricting movement of the first shuttle  200 . 
     The second shuttle  300  may have a structure similar to the structure of the first shuttle  200  described with reference to  FIGS.  5  to  8   . 
     Referring to  FIGS.  8  and  9   , the pulley support portion  130  may include recesses  131 . The recesses  131  may be defined as a sidewall of the pulley support portion  130  that is recessed. The first and second belts  510  and  520  supported by the belt-pulley structures  600  may be connected to respective shuttles  200  and  300  and respective counterweights  420  and  430  while extending through corresponding ones of the recesses  131 , respectively. 
     The recesses  131 , through which the first and second belts  510  and  520  do not extend, may be defined as preliminary recesses. When it is desired to install an additional shuttle and an additional counterweight, an additional belt and an additional belt-pulley structure may be installed to correspond to a preliminary recess and, as such, the additional shuttle and the additional counterweight may be installed. In the exemplary embodiments of the disclosure, the number of recesses  131  is not limited to that of the case shown above. 
     In the transfer apparatus according to the exemplary embodiments of the disclosure, attractive forces generated by linear motors may be offset each other and, as such, stability of vertical movement of a shuttle may be enhanced. Accordingly, the vertical movement speed of the shuttle may become relatively high. 
     In the transfer apparatus according to the exemplary embodiments of the disclosure, shuttles and counterweights may be disposed in parallel and, as such, the space occupied by the transfer apparatus may be relatively small. 
     While the embodiments of the disclosure have been described with reference to the accompanying drawings, it should be understood by those skilled in the art that various modifications may be made without departing from the scope of the disclosure and without changing essential features thereof. Therefore, the above-described embodiments should be considered in a descriptive sense only and not for purposes of limitation.