Patent Publication Number: US-2023134094-A1

Title: Refrigerator

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Divisional Application of U.S. patent application Ser. No. 16/582,755 filed Sep. 25, 2019, which claims priority under 35 U.S.C. § 119 to Korean Application No. 10-2019-0084452, filed Jul. 12, 2019, whose entire disclosures are hereby incorporated by reference. 
    
    
     BACKGROUND 
     1. Field 
     The present disclosure relates to a refrigerator having a drawer. 
     2. Background 
     A refrigerator is a home appliance that is provided to store various foods or beverages for a long time by cold air generated by circulation of a refrigerant according to a refrigeration cycle. 
     The refrigerator may be divided into two types of refrigerators: a common refrigerator that can store storage items a user wants to store regardless of a type of food or drink; and an exclusive-use refrigerator that varies in size or function based on a type of storage item to be stored. 
     The exclusive use refrigerator may include a kimchi refrigerator, a wine refrigerator, and so on. 
     The refrigerator may be classified into various types depending on a door opening and closing method of a storage chamber in a cabinet, such as a swinging door-type refrigerator, a drawer-type refrigerator, and a hybrid-type refrigerator having both doors and drawers. The hybrid-type refrigerator has a structure in which a swinging door is provided in an upper portion of the cabinet and a drawer is provided in a lower portion thereof. 
     The drawer provided in the drawer refrigerator or the hybrid-type refrigerator may open, by a user&#39;s operation, from an inside space of the cabinet in a sliding manner. The drawer may close by being pushed into the inside space of the cabinet by user&#39;s pushing operation, thereby allowing an open front portion of the cabinet to be closed. 
     The drawer may include a front panel and a storage bin (or storage room), the front panel forming a front surface of the refrigerator and being moved forward and rearward, thereby allowing the inside space of the cabinet to be opened/closed and the storage bin being provided in rear of the front panel and received in the inside space of the cabinet. By pulling the front panel, the storage bin may be pushed out from the inside space of the cabinet, thus various foods can be stored in and taken out from the storage bin. 
     The drawer provided in the drawer refrigerator or the hybrid-type refrigerator is mainly provided in the lower portion of the cabinet. This is because, due to weight of storage items stored in the storage bin of the drawer, the drawer may be removed from the cabinet and fall down when the drawer is opened. 
     However, when the drawer is provided in the lower portion of the cabinet, the user may bend over at the waist while keeping away from the front panel by an appropriate distance for opening of the drawer. 
     Korean Patent Application Publication No. 10-2009-0102577, Korean Patent Application Publication No. 10-2009-0102576, Korean Patent Application Publication No. 10-2013-0071919, and Korean Patent Application Publication No. 10-2018-0138083, the subject matters of which are incorporated herein by reference, may disclose features of a refrigerator in which a drawer may be automatically opened. 
     A rack and a pinion may be used for automatic opening of the drawer. 
     That is, as the rack and the pinion may be respectively installed in the drawer and the storage chamber opposed thereto in the cabinet, and the drawer can be moved forward automatically. 
     However, the drawer may be configured of a structure in which guide racks are respectively provided at opposite walls in the cabinet and pinions are respectively provided at opposite walls (e.g., opposite sides of rear surface) of the storage bin (constituting the drawer) to move the drawer forward and rearward. Therefore, there may be a limit to a pushing-distance of the drawer. 
     That is, considering that the pushing-out distance of the drawer is proportional to a length of a guide rack, when the guide rack is not provided outwards from inside of the cabinet, the storage bin of the drawer can not be fully exposed from the inside of the cabinet, and it may be inconvenient to take storage items out of the storage bin. 
     In an example of the drawer of the refrigerator, when a rack gear of any one side guide rack is engaged with any one pinion before a rack gear of the other side instead of rack gears of the opposite guide racks being engaged with the opposite pinions in a process of closing the drawer, the drawer may not precisely close into the storage chamber. 
     In the above example, the pinion and the rack gear of the guide rack may not be precisely engaged, thereby causing malfunction, and the front panel and the cabinet may not be in close contact with each other and a gap may occur therebetween. Accordingly, an opening operation may not be easily performed when the drawer is later re-opened. 
     If engagement between the rack gear (of each rack gear) and the pinion is not performed horizontally but rather is performed obliquely, the pinion and the rack gear may be damaged. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Arrangements and embodiments may be described in detail with reference to the following drawings in which like reference numerals refer to like elements, and wherein: 
         FIG.  1    is a perspective view showing a refrigerator according to an embodiment of the present disclosure; 
         FIG.  2    is a front view showing the refrigerator according to an embodiment of the present disclosure; 
         FIG.  3    is a side view showing the refrigerator according to an embodiment of the present disclosure; 
         FIG.  4    is a main part view showing schematically the refrigerator according to the embodiment of the present disclosure, wherein a drawer of the refrigerator is opened; 
         FIG.  5    is a main part view showing schematically the refrigerator according to the embodiment of the present disclosure, wherein a container is raised upward when the drawer of the refrigerator is opened; 
         FIG.  6    is a side view showing the drawer of the refrigerator according to the embodiment of the present disclosure, the drawer being equipped with a cable guide module; 
         FIG.  7    is an exploded-perspective view showing the cable guide module of the refrigerator according to the embodiment of the present disclosure; 
         FIG.  8    is a perspective view showing a coupled state of the cable guide module of the refrigerator according to the embodiment of the present disclosure; 
         FIG.  9    is a perspective view showing an installation state of the cable guide module installed in a storage chamber; 
         FIG.  10    is a perspective view showing the drawer taken at the rear side, wherein the cable guide module of the refrigerator according to the embodiment of the present disclosure is connected to the drawer; 
         FIG.  11    is a bottom view of the refrigerator showing a state in which a rack gear assembly is installed therein; 
         FIG.  12    is a perspective view showing the rack gear assembly according to the embodiment of the present disclosure is installed in the refrigerator, the view being taken at a lower portion thereof; 
         FIG.  13    is an exploded-perspective view showing the rack gear assembly of the refrigerator from above; 
         FIG.  14    is an enlarged view of “A” part in  FIG.  13   ; 
         FIG.  15    is an exploded-perspective view from the bottom, the view showing the rack gear assembly according to the embodiment of the present disclosure; 
         FIG.  16    is an enlarged view of “B” part in  FIG.  15    for showing an idle gear of the refrigerator according to the embodiment of the present disclosure; 
         FIG.  17    is an enlarged view of “C” part in  FIG.  15   , the view showing a confining module of the refrigerator according to the embodiment of the present disclosure; 
         FIG.  18    is a perspective view showing the rack gear assembly being overturned for showing a lower surface structure thereof; 
         FIG.  19    is an enlarged view of “D” part in  FIG.  18   ; 
         FIG.  20    is a bottom view showing the lower surface structure of the rack gear assembly of the refrigerator according to the embodiment of the present disclosure; 
         FIG.  21    is an enlarged view of “E” part in  FIG.  20   ; 
         FIG.  22    is an enlarged view of “F” part in  FIG.  20   ; 
         FIG.  23    is a main part perspective view showing installation of the idle gear of the refrigerator according to the embodiment of the present disclosure; 
         FIG.  24    is a main part perspective view showing installation of a cover body in  FIG.  23   ; 
         FIG.  25    is a main part side view showing installation of the idle gear of the refrigerator according to the embodiment of the present disclosure; 
         FIG.  26    is an exploded-perspective view showing a confining protrusion part of the refrigerator according to the embodiment of the present disclosure; 
         FIGS.  27 ,  29 ,  31 , and  33    are views showing operational states of the rack gear assembly during a process of opening the storage bin of the refrigerator according to the embodiment of the present disclosure; 
         FIG.  28    is an enlarged view of “G” part in  FIG.  27   ; 
         FIG.  30    is an enlarged view of “H” part in  FIG.  29   ; 
         FIG.  32    is an enlarged view of “I” part in  FIG.  31   ; and 
         FIG.  34    is a view showing schematically position compensation by the idle gear when the drawer of the refrigerator according to the embodiment of the present disclosure is closed. 
     
    
    
     DETAILED DESCRIPTION 
     An exemplary embodiment with respect to a refrigerator of the present disclosure may be described in detail with reference to accompanying  FIGS.  1  to  34   . 
       FIG.  1    is a perspective view showing a refrigerator according to an embodiment of the present disclosure.  FIG.  2    is a front view showing the refrigerator according to an embodiment of the present disclosure.  FIG.  3    is a side view showing the refrigerator according to an embodiment of the present disclosure. 
     As shown in the drawings, a refrigerator according to an example embodiment of the present disclosure may include a cabinet  100 , a drawer  200 , a driving part  400  (or driving device), and rack gear assemblies  601  and  602 . At least any one rack gear assembly of the rack gear assemblies  601  and  602  is provided with an idle gear  630  (referring to  FIG.  11   ). The idle gear may engage with gear teeth of a pinion  410  of the driving part, and may allow the pinion  410  to be idle. 
     The cabinet  100  may constitute an outer appearance of the refrigerator. 
     The cabinet  100  may include an upper wall or a roof  110  forming an upper side wall, a bottom  120  forming a lower side wall, two side walls  130  forming opposite side walls, and a rear wall  140  forming a rear side wall, and the cabinet may be configured as a box-shaped body which is opened forward. An inside space of the cabinet  100  may be used as a storage space. 
     A plurality of partition walls  150  may be provided inside the cabinet  100 . The partition walls  150  may divide the storage space in the cabinet  100  into a plurality of spaces, so that the storage space is provided as a plurality of vertically separated storage chambers ( 1 ,  2 , and  3 ). 
     In other implementations, the partition walls  150  may be provided to partition the storage space in the cabinet  100  into storage chambers that are horizontally positioned. 
     The refrigerator according to an embodiment of the present disclosure is provided with three storage chambers partitioned up and down. An upper storage chamber  1  may be a refrigerator chamber, and a center storage chamber  2  and a lower storage chamber  3  may be a refrigerator chamber or a freezer chamber, or a separate space. 
     Each of storage chambers ( 1 ,  2 , and  3 ) of the cabinet  100  is configured to be separately opened and closed by a door thereof. The upper storage chamber  1  may be opened and closed by a swinging door  4 , and the center storage chamber  2  and the lower storage chamber  3  may be opened and closed by the drawer  200 . The center storage chamber  2  may be configured to be opened and closed by the swinging door  4 . 
     The swinging door  4  may be hingedly coupled to the cabinet  100  in a swinging manner, and the swinging door  4  may rotate to open or close an opening of the upper storage chamber  1 . 
     A display part  5  (or display) may be provided on a front surface of the swinging door  4  for outputting information. A variety of different information such as an operational state of the refrigerator or temperatures of each storage chamber ( 1 ,  2 , and  3 ) may be displayed on the display part  5 . 
     The display part  5  may include at least one of LCD, LED, and so on. 
     The drawer  200  may open and close in a sliding manner. In an embodiment described below, the drawer  200  may be provided at the lower storage chamber  3  and may open in a drawer manner. 
     The drawer  200  may include the front panel  210  and a storage bin  220  (or storage room). 
     The front panel  210  may be pushed into the storage chamber so that the open front of the lower storage chamber  3  is closed and shielded, and the front panel  210  may be an installation space therein. 
     The front panel  210  may be formed such that a metal thin plate is folded into multiple stages so as to have each wall surface (upper surface, opposite side surfaces, front surface, and lower surface). The front panel  210  may be provided with an inner frame therein. The inner frame  211  may be formed of resin for reducing a weight of the front panel and improving productivity thereof. The front panel  210  may be formed of a material having metal texture. 
     The storage bin  220  may be provided at a rear of the front panel  210  and is received in the lower storage chamber  3 . 
     The storage bin  220  may be formed in a box-shaped body that is open upward, and a front surface of the storage bin  220  may be fixed to a rear surface of the front panel  210  in a close contact state therewith. The storage bin  220  and the front panel  210  may be coupled to each other by hook or bolt fastening, screw fastening, gearing, fitting, and so on. 
     Guide rails  230  may be respectively provided on opposite outside walls of the storage bin  220  and on opposite inner side walls of the lower storage chamber  3  (referring to  FIG.  3   ). The inner side walls of the lower storage chamber  3  may face the outer side walls of the storage bin  220 . The guide rails of the storage bin  220  and the guide rails of the lower storage chamber  3  are engaged with each other and support forward and rearward movement of the storage bin  220 . 
     Although not shown, the guide rails  230  may be respectively provided on a lower surface of the storage bin  220  and a bottom surface in the lower storage chamber  3 , and the guide rails may be engaged with each other, where the bottom surface in the lower storage chamber  3  face the lower surface of the storage bin  220 . The guide rails  230  may also be configured to extend into multiple stages. 
     A separate container  240  may be provided in the storage bin  220 . That is, a variety of food may be stored in the storage bin  220 , but the container  240  is in the storage bin  220  so that the food may be stored in the container  240 . The container  240  may be a kimchi container or a basket to be opened upwardly. 
     When the storage bin  220  is pushed out from the lower storage chamber  3 , the container  240  may move upward in the storage bin  220 . 
     In order for a user to raise the container  240  in the storage bin  220 , it is necessary to form a gap in which fingers of the user are inserted between the storage bin  220  and the container  240 , so a size of the container  240  should be reduced by a size of the gap. Accordingly, the container  240  may be automatically separated from the storage bin  220  in order that the size of the container  240  is maximized. When the container  240  is automatically separated from the storage bin  220 , the user can easily take out the container  240 . 
     A raising/lowering module  300  (or lift module) may be provided in the storage bin  220  to automatically raise the container  240  (referring to  FIGS.  4  and  5   ). 
     The raising/lowering module  300  may be embodied in various forms. For example, the raising/lowering module  300  may be formed in a scissors linkage structure, such that when the raising/lowering module is folded, a height is minimized, and when the raising/lowering module is unfolded, the height thereof is maximized. 
     Electrical parts  310  (for example, drive motor, etc.) supplying a driving force for raising movement of the raising/lowering module  300  may be provided in the installation space in the front panel  210 . 
     When the raising/lowering module  300  is operated before the storage bin  220  of the drawer  200  is fully pushed out, the container  240  or the cabinet  100  may be broke. Therefore, a control program may be programmed to operate the raising/lowering module only when the storage bin  220  is fully pushed out, and the control program being programmed to control movement of the raising/lowering module  300 . 
     The driving part  400  may provide a driving force for forward and rearward movement of the drawer  200 . 
     The driving part  400  may be provided on the bottom  120  of the cabinet  100 , and may include a pinion  410  and a driving motor  420 . 
     The pinion  410  may penetrate partially through the bottom surface (upper surface of the bottom) in the lower storage chamber  3  and may be exposed to the inside of the lower storage chamber  3  (referring to  FIG.  9   ). The driving motor  420  may supply power to the pinion  410  while being fixed at the bottom  120  of the cabinet  100 . 
     In an embodiment of the present disclosure, two pinions  410  may be respectively provided one by one on opposite sides of the bottom surface of the lower storage chamber  3 . The two pinions  410  may be connected to each other by a power transmission shaft  411 . The driving motor  420  may be connected to the power transmission shaft  411  by a belt, a chain, or a gear for supplying power thereto. The two pinions may be called a first pinion and a second pinion. 
     By the driving of the driving motor  420 , the two pinions  410  may rotate at the same time with the same speed and direction. 
     A reduction gear (or reducer) may be provided in a connecting portion between the power transmission shaft  411  and the driving motor  420 . 
     The two pinions  410  may be positioned at foremost sides of the bottom surface in the lower storage chamber  3 . Thus, the drawer may open to the maximum. 
     The driving motor  420  may operate when proximity of the user is sensed, or may operate when a button  6  is manipulated by the user. 
     The button  6  may be a touch-type button provided on the display part  5  of the swinging door  4 . The button  6  may also be a pressure-type button provided on a separate position from the display part  5 . 
     A cable guide module  500  may be connected to the bottom surface (upper surface of the bottom) in the lower storage chamber  3  and to the front panel  210  (referring to  FIG.  6   ). 
     The cable guide module  500  may protect a power line and cables (hereinafter referred to as cables), which are connected to the electrical parts in the front panel  210  among various power lines and cables connected along the inside of the bottom  120 . 
     The cable guide module  500  may be configured to guide the cables to be moved with forward and rearward movements of the drawer  200 , and to prevent the cables from being damaged due to twisting and scraping. 
     The cable guide module  500  may include a cover plate  510 , a guiding head  520 , a plurality of connecting members  530 , a swinging connection member  540  (or swinging connection base), and a mounting plate  550 , as shown in  FIGS.  7  to  10   . 
     The cable guide module  500  may be described in detail on a per component basis. 
     The cover plate  510  of the cable guide module  500  may be a part coupled to the upper surface of the bottom  120 . 
     A part of a front upper surface of the bottom  120  may be formed to be open, and the cover plate  510  may be coupled to the bottom  120  and cover the open part thereof. 
     Two pinion exposure holes  511  may be respectively provided on opposite sides of the cover plate  510  in a penetrating manner so that the pinions  410  of the driving part  400  are exposed (referring to  FIGS.  7  and  8   ). 
     The cover plate  510  may be provided with a motor receiving part  512  that receives the driving motor  420  (included in the driving part  400 ) (referring to  FIG.  7   ). The motor receiving part  512  may protrude from a part of the cover plate  510  that protrudes upward, or may be formed separately from the cover plate  510  and then coupled to the cover plate  510 . Although not shown, the motor receiving part  512  may be formed in different forms or manners. 
     Two protrusion passing holes  513  may be respectively formed through opposite sides in the rear of the cover plate  510 , and each protrusion passing holes  513  may be for installation of a confining protrusion part  650 , which may be described below. An upper end of the confining protrusion part  650  may be exposed toward the inside of the lower storage chamber  3  while the confining protrusion part  650  is accommodated in the protrusion passing hole  513 . The confining protrusion part  650  may be described again in a description about rack gear assemblies  601  and  602  to be described below. 
     An open/close sensing part  514  (or sensing device) may include components provided at a bottom in the storage chamber and the drawer that is opposed thereto to sense opening and closing of the drawer  200  (referring to  FIGS.  4    and  5 ). That is, as the open/close sensing part  514  is provided, it may check accurately whether the drawer  200  is fully closed or partially opened. 
     The open/close sensing part  514  may include a sensor  514   a  and a sensing member  514   b.  The sensor  514   a  may be a hall sensor, and the sensing member  514   b  may be a magnet that is sensed by the hall sensor. The open/close sensing part  514  may be provided as various structures such as an optical sensor, a switch, and so on. 
     The sensor  514   a  (of the open/close sensing part  514 ) may be provided at the bottom in the lower storage chamber  3 . The sensing member  514   b  may be provided at the lower surface of the storage bin  220  (constituting the drawer  200 ). Although not shown, the sensing member  514   b  may be provided at the bottom in the lower storage chamber  3  and the sensor  514   a  may be provided at the lower surface of the storage bin  220 , or the sensor  514   a  may be provided at any one side wall surface in the lower storage chamber  3  and the sensing member  514   b  may be provided at a wall surface of the storage bin  220 , the wall surface of the storage bin faces the sensor. 
     The sensor  514   a  may be provided at the cover plate  510  positioned at the bottom in the lower storage chamber  3 , so that maintenance of the cover plate  510  can be performed through removal thereof. 
     In an end of a lower surface of the rack gear assembly  600 , a separate sensing member  514   c  may be provided so that the sensor  514   a  senses the full opening of the drawer  200  when the rack gear assembly  600  is fully pushed out. 
     The open/close sensing part  514  may be configured to influence operation control of the driving part  400 . 
     When the open/close sensing part  514  (or sensing device) senses the closing of the drawer  200 , the open/close sensing part  514  is configured so that the driving motor  420  constituting the driving part  400  may perform additional operation from the sensing time by a predetermined time or a predetermined number of rotations and then deactivates the operation. 
     When the open/close sensing part  514  (or sensing device) senses the closing of the drawer  200 , the driving motor  420  is programmed to perform additional drive by at least one pitch of a rack gear  611  of a first rack member  610  and then to deactivate the driving. 
     When left and right sides of the drawer  200  are moved obliquely instead of parallel so that any one side of the drawer  200  reaches a closing position thereof earlier than the other side, although the other side is not closed, the sensor  514   a  (of the open/close sensing part  514 ) may determine that the drawer  200  is closed. 
     Even when one side of the drawer  200  is closed earlier than the other side, the other side is moved further by a distance of at least one pitch of the rack gear  611  from this time, so that opposite sides of the drawer  200  may be closed. 
     The pinion  410  is rotated additionally by only two rotations or less, more preferably, the pinion  410  is rotated additionally by only one rotation. This may prevent damage to the pinion  410  or the rack gear  611  caused when the pinion  410  is excessively rotated more than necessary. 
     Even when the pinion  410  is rotated one or two rotations, the pinion  410  or the rack gear  611  may be damaged. 
     However, considering that a packing member is provided between contact surfaces of the drawer  200  and the cabinet  100 , even when the pinion  410  is rotated additionally by a buffering distance of the packing member, the pinion  410  and the rack gear  611  are not damaged. After that, when deactivation of the driving motor  420  operating the pinion  410  is performed, as the pinion  410  is reversibly rotated by additional rotation by a buffering force of the packing member and a movement force by excessive rotation, the opposite sides of the drawer  200  may be closed precisely without gear damage. 
     The guiding head  520  of the cable guide module  500  is a part coupled to the front panel  210 . 
     An installation hole  212  may be provided on a center lower portion of the rear surface of the front panel  210  (referring to  FIG.  10   ), and the guiding head  520  may pass partially into the installation hole  212 , and may be coupled to the rear surface of the front panel  210 . 
     Each of the connecting members  530  of the cable guide module  500  may connect the swinging connection member  540  and the guiding head  520  to be moveable. 
     The connecting member  530  may be configured as a hollow tubular body and may be connected to another connecting member  530  continuously. The cables may pass sequentially inside the connecting members  530  in order. The connection structure of the connecting member  530  may be a chain linkage structure. 
     A connected portion between each of the connecting members  530  may be provided to swing in a horizontal direction. A first end of the connecting member  530  may be connected to the swinging connection member  540  in a swinging manner, and a second end of the connecting members  530  may be connected to the guiding head  520  in a swinging manner. Through the structure, when the drawer  200  is moved forward and rearward, the connecting members  530  may move in conjunction with movement of the drawer  200  to move the cables. 
     The swinging connection member  540  of the cable guide module  500  may be rotatably connected to the cover plate  510 . 
     A cable through-hole  515  may be provided on the cover plate  510  so that the cables pass therethrough, and the swinging connection member  540  may have a pipe structure and one end thereof is in close contact with an upper surface of the cover plate  510 . On an end of the swinging connection member  540 , an extension end  541  may have a dome structure extending gradually toward the end. 
     An extension hole  516  may be provided at a predetermined position on a circumference of the cable through-hole  515 . On a circumference of the extension end  541  constituting the swinging connection member  540 , a confining protrusion  542  may protrude outwards and pass through the extension hole  516 . 
     The extension hole  516  may have a width through which only the confining protrusion  542  may pass. That is, as the confining protrusion  542  passes through the extension hole  516  and then a manipulation in which the swinging connection member  540  is partially rotated, the swinging connection member  540  may be maintained in a state of preventing separation from the cable through-hole  515  of the cover plate  510 . 
     The mounting plate  550  (of the cable guide module  500 ) may prevent the swinging connection member  540  connected to the cover plate  510  from being separated from the cover plate  510 . 
     The mounting plate  550  may be fixedly coupled to the cover plate  510 , and may have a communicating hole  551  and a covering end  552 . The communicating hole  551  is provided on a portion corresponding to the cable through-hole  515 , and with the covering end  552  may protrude from a circumference of the communicating hole  551  to cover the extension end  541  of the swinging connection member  540 . An inner surface of the covering end  552  may have the same spherical surface as an outer surface of the extension end  541  so that the covering end  552  and the extension end  541  are in close contact with each other. 
     The rack gear assemblies  601  and  602  of the refrigerator according to an embodiment of the present disclosure may be described. 
     The rack gear assemblies  601  and  602  are provided to allow the drawer  200  to be moved forward and rearward by a driving force of the driving part  400  provided in the cabinet  100 . 
     The rack gear assemblies  601  and  602  may be respectively provided on opposite sides of the lower surface of the storage bin  220  constituting the drawer  200 . As the rack gear assemblies  601  and  602  have rack gears  611  and  621  on lower surfaces thereof, the rack gear assemblies  600  are installed to be engaged with the pinions  410  that are exposed to the inside of the lower storage chamber  3 . 
     The rack gears  611  and  621  (of the rack gear assemblies  601  and  602 ) extend from a front side of the lower surface of the storage bin  220  to a rear side thereof. Thus, the drawer  200  provided with the rack gear assemblies  601  and  602  may be pushed out and pushed in from the lower storage chamber  3  while being moved forward and rearward by rotation movement of the pinions  410 . 
     The pinions  410  and the rack gear assemblies  601  and  602  may be respectively made in pairs of at least three pinions and at least three rack gear assemblies. 
     As an automatic pushing-out distance of the storage bin  220  is increased, usability of the drawer  200  may improve. 
     That is, as a storage space in the storage bin  220  is maximally moved in the opposite direction from the lower storage chamber  3 , the drawer  200  may be provided such that it is easy to store the container  240  in the storage bin  220 , or to store items and food in the storage space. 
     The container  240  may be automatically raised by the raising/lowering module  300  when the drawer  200  is opened. Thus, it is preferable that the storage bin  220  is maximally separated from the lower storage chamber  3 . 
     The two pinions  410  may be positioned on a portion of the front side of the lower storage chamber  3 , and lengths of the rack gears  611  and  621  may be maximally long. 
     That is, as the two pinions  410  are positioned close to a portion of the front side of the lower storage chamber  3  and the rack gears  611  and  621  have the long lengths, the pushing-out distance of the storage bin  220  may increase. 
     A front to rear length of the lower surface of the storage bin  220  may be shorter than that of an open upper surface of the storage bin  220 . In view of that, the rack gears  611  and  621  may have limited lengths. 
     Accordingly, the rack gear assemblies  600  according to an embodiment may be configured to extend in lengths thereof, thereby increasing the pushing-out distance of the storage bin  220 . 
     That is, even when the front to rear length of the storage bin  220  is short, lengths of the rack gear assemblies  601  and  602  extend, thereby allowing the storage bin  220  to be farther pushed out. 
     Therefore, in an embodiment of the present disclosure, the rack gear assemblies  601  and  602  may include a first rack member  610  (or first rack) and a second rack member  620  (or second rack), a first rack cover  614 , a second rack cover  624 , the idle gear  630 , the confining protrusion part  650 , and a confining module  670  that are pushed out while being moved forward in order. 
     The rack gear assembly  600  may be described in detail by each part as follows. 
     The first rack member  610  (or first rack) may perform forward and rearward movement of the storage bin  220  by rotation of the pinion  410 , and the first rack member  610  may have a rack gear  611 . 
     The first rack member  610  may be provided such that an upper surface thereof is fixed to the lower surface of the storage bin  220  while being in close contact thereto. A plurality of coupling holes  612  may be provided on the first rack member  610 , and the first rack member  610  may be attached to the storage bin  220  by screw fastening (or other connections) through the coupling holes  612 . 
     The second rack member  620  (or second rack) may be at a lower surface of the first rack member  610 , and thus the first rack member  610  may have a movement guiding groove  613  that is formed in a depressed manner and supports sliding movement of the second rack member  620 . 
     The movement guiding groove  613  may be provided in the depressed manner from a front end portion of the first rack member  610  and formed by penetrating through a rear surface of the first rack member  610 . That is, the second rack member  620  received at the movement guiding groove  613  may be exposed to the rear of the movement guiding groove  613 . 
     The rack gear  611  of the first rack member  610  may be provided on any one side (one side in the opposite direction between two rack gear assemblies) of the movement guiding groove  613  along a longitudinal direction of the first rack member  610  in which the rack gear  611  is included. 
     The rack gear  611  may be further forward than the movement guiding groove  613 . 
     The first rack member  610  may include a first rack cover  614 . 
     The movement guiding groove  613  provided in the first rack member  610  has an inside portion that is open vertically so that a holder  672  and a locking member  673  (or latch), which are included in the confining module  670 , may pass through the movement guiding groove  613 . The first rack cover  614  may cover the upper surface of the first rack member  610  by being coupled thereto, so that a lower surface of the first rack cover  614  covers an open portion of the movement guiding groove  613  provided on the first rack member  610 , and may be provided as an upper surface of the movement guiding groove  613 . 
     The first rack cover  614  may be formed of a metal plate to reinforce insufficient strength of the first rack member  610 . 
     The lower surface (upper surface in the movement guiding groove) of the first rack cover  614  may include receiving grooves  614   a  and  614   b  in which the holder  672  and the locking member  673  of the confining module  670  are respectively received. 
     The receiving grooves  614   a  and  614   b  may include a first receiving groove  614   a  for receiving the holder  672  and a second receiving groove  614   b  for receiving the locking member  673 . The two receiving grooves  614   a  and  614   b  may be spaced apart from each other in a moving direction of the first rack member  610 . A spaced distance between a rear surface of the first receiving groove  614   a  and a rear surface of the second receiving groove  614   b  may be longer than a spaced distance between a rear surface of the holder  672  and a rear surface of the locking member  673 . 
     The receiving grooves  614   a  and  614   b  are configured such that the holder  672  is firstly received into the first receiving groove  614   a  and then the locking member  673  is received into the second receiving groove  614   b.    
     Unlike the above-described embodiment, the first rack cover  614  and the first rack member  610  may be provided as a single body through an injection molding manner. 
     However, when the first rack member  610  and the first rack cover  614  are configured as the single body, it may be difficult for the injection molding thereof. That is, the first rack member  610  and the first rack cover  614  are different in shapes and directions at uneven portions thereof, so that the injection molding thereof may be difficult. 
     Accordingly, as shown in the embodiment, the first rack member  610  and the first rack cover  614  may be separately manufactured and then coupled to each other. 
     The second rack member  620  may perform the forward and rearward movement of the storage bin  220  together with the first rack member  610 . 
     The second rack member  620  may be inserted in the movement guiding groove  613  of the first rack member  610 . When the first rack member  610  is moved by a preset distance, the second rack member  620  is moved forward by leading of the first rack member  610  and may receive rotational force of the pinion  410 . As the second rack member  620  is continuously moved forward by the rotational force of the pinion  410 , the first rack member  610  is further pushed out even when the rack gear  611  of the first rack member  610  is separated from the pinion  410 . 
     The first rack member  610  may lead the second rack member  620  through a linkage part  680  so that the second rack member  620  is moved. 
     The linkage part  680  may include a linkage protrusion  681  and a linkage step  682 , where the linkage protrusion  681  is provided on the lower surface (lower surface in the movement guiding groove) of the first rack cover  614  and the linkage step  682  is provided on an upper surface of the second rack member  620 . When the first rack member  610  is moved forward by the preset distance, the linkage protrusion  681  and the linkage step  682  are in contact with each other to perform forward movement of the second rack member  620 . 
     The linkage protrusion  681  may also be provided on the first rack member  610 . The linkage protrusion  681  may also be provided on the upper surface of the second rack member  620  and the linkage step  682  may be provided on a lower surface of the first rack member  610 . 
     When the second rack member  620  is fully inserted into the movement guiding groove  613  of the first rack member  610 , a spaced distance between the linkage protrusion  681  and the linkage step  682  is configured as a distance that is set such that the first rack member  610  is moved forward without affecting the second rack member  620 . The preset distance may be determined based on a size or a total pushing-out distance of the storage bin  220 . 
     The second rack member  620  may be provided with a rack gear  621 . The rack gear  621  is formed alongside a side portion of the rack gear  611  of the first rack member  610 . A front end of the rack gear  621  is provided to be further rearward than a front end of the rack gear  611  of the first rack member  610 , and a rear side end thereof may further extend to the rear side than a rear side end of the rack gear  611  of the first rack member  610 . 
     The rack gears  611  and  621  of the first rack member  610  and the second rack member  620  may easily receive the driving force of the pinions  410 , respectively. That is, since the pinions  410  are formed to have the width that is a size of adding a width of the rack gear  611  of the first rack member  610  and the rack gear  621  of the second rack member  620 , each of the rack gears  611  and  621  may efficiently receive the driving force of the pinions  410 . 
     A motion groove  622  may be provided on a front lower surface of the second rack member  620  in a depressed manner. The motion groove  622  may provide a motion space in which a stopper member  671  of the confining module  670  is moved forward and rearward in a mounted state. 
     The motion groove  622  may be provided with a plurality of through holes  622   a  and  622   b  in an upward penetrating manner. The through holes  622   a  and  622   b  may include a first through hole  622   a  through which the holder  672  passes and a second through hole  622   b  through which the locking member  673  passes. The holder  672  and the locking member  673  are included in the confining module  670  and may be described below. 
     The second through hole  622   b  may be formed as a horizontally long hole so that forward and rearward movement of the locking member  673  may be performed. 
     A second rack cover  624  may be provided at a lower surface of the second rack member  620 . The second rack cover  624  may cover the lower surface of the second rack member  620 . 
     The second rack cover  624  may prevent the stopper member  671 , mounted to the motion groove  622  (of the second rack member  620 ) from being separated to the outside. 
     The second rack cover  624  may be formed of a metal plate and may cover the lower surface of the second rack member  620 . Thus, deformation such as torsion or bending of the second rack member  620  may be prevented. The second rack cover  624  may be provided with a partially open portion for reducing the weight thereof. 
     The second rack cover  624  may be provided with folded ends  624   a  in a folded manner on opposite side surfaces and a rear surface thereof. The folded ends  624   a  cover parts of the opposite side surfaces and the rear surfaces of the second rack member  620  to prevent flexural deformation of the second rack member  620 . 
     The second rack cover  624  may include a stopper exposure hole  624   b  on a front end portion thereof, and the stopper member  671  may be partially exposed through the stopper exposure hole  624   b.    
     The idle gear  630  is provided so that the opposite sides of the drawer  200  are fully closed even when the drawer  200  is closed obliquely instead of horizontally. 
     The idle gear  630  may include a gear that is configured to be engaged with the pinion  410  and to allow the pinion  410  to idle. The idle gear  630  may be provided at any one rack gear assembly of the rack gear assemblies  601  and  602 . 
     In an embodiment of the present disclosure, the idle gear  630  is provided only at the rack gear assembly  602  (hereinafter referred to as release rack gear assembly) that is positioned on a right side when the drawer  200  is viewed from the bottom. 
     Although not shown, the idle gear  630  may be provided at the left side rack gear assembly  601  (hereinafter referred to as general rack gear assembly). 
     However, considering that the driving motor  420  constituting the driving part  400  is operated such that the rack gear assembly is further moved by a predetermined distance when closing of the drawer  200  is sensed, even when the idle gear  630  is provided in either side, the opposite sides the drawer  200  may be closed horizontally. 
     The two rack gear assemblies  601  and  602  may be configured as follows. In the general rack gear assembly provided at a portion where the open/close sensing part  514  is positioned, the rack gear  611  of the first rack member  610  is formed continuously to a front end of the first rack member  610 . On the other side, in the release rack gear assembly, the rack gear  611  of the first rack member  610  is not formed to a front end of the first rack member  610  and is formed relatively shorter than the rack gear  611  of the general rack gear assembly, and the idle gear  630  is provided in front of the release rack gear assembly, as shown in  FIG.  11   . 
     That is, the idle gear  630  may be provided at the position where the idle gear  630  is engaged with the pinion  410  when the drawer  200  is in the closed state. 
     The idle gear  630  has at least one gear tooth  631  and  632  (referring to  FIGS.  16 ,  19 , and  22  to  25   ). The gear tooth may be engaged with the gear teeth of the pinion  410 . 
     The idle gear  630  may have two gear teeth  631  and  632 , and the two gear teeth  631  and  632  has a pitch p 2  same as the pitch P 1  of the rack gear  611 . That is, the idle gear  630  may be formed in the substantially same structure as the rack gear  611  of the first rack member  610  and to be engaged with the pinion  410 . 
     A spaced distance L between the rack gear  611  and a rear side gear tooth  631 , which is positioned relatively close to the rack gear  611 , of the two gear teeth  631  and  632  of the idle gear  630  may be formed longer than a pitch of each gear tooth (pitch between gear teeth of idle gear or pitch between gear teeth of rack gear). 
     Even when the release rack gear assembly provided with the idle gear  630  is pushed into the storage chamber relatively less than the general rack gear assembly of the other side (normally one pitch), the gear teeth  631  and  632  of the idle gear  630  are engaged with the pinion  410 , thereby being pulled by the distance difference. Thus, the release rack gear assembly may be positioned alongside the general rack gear assembly while performing the forced forward movement thereof. 
     When the spaced distance L between the gear teeth  631  and  632  of the idle gear  630  and the rack gear  611  is excessively far from each other, the pinion  410  may not engage with the gear teeth  631  and  632  of the idle gear  630 . Accordingly, the spaced distance L between the gear teeth  631  and  632  of the idle gear  630  and the rack gear  611  may be formed longer than the one pitch (1*P 1  or 1*P 2 ) and formed shorter than a distance between three gear teeth of the rack gear  611  (two pitch, 2*P 1 ). That is, the pinion  410  may engage with the idle gear  630  at a moment when the rack gear  611  of the first rack member  610  passes over the pinion  410 . 
     The idle gear  630  may be installed to be elastically moveable up and down. Thus, although the release rack gear assembly may no longer be moved rearward, the idle gear  630  may eliminate a rotation force of the pinion  410  by being elastically moved up and down even when the pinion  410  is rotated. That is, the pinion  410  idles and may not transmit power. 
     For the up and down movement of the idle gear  630 , in the rack member  610 , a first seating step  633  may be provided at an upper side of the idle gear  630 , and an elastic member for up and down movement  634  may be provided between opposed surfaces on the first seating step  633  and the idle gear  630 . This may be shown in  FIG.  23   . 
     The elastic member for up and down movement  634  may be positioned at a portion of an upper surface of the idle gear  630 , the portion being the upper side between the two gear teeth  631  and  632  or the upper side of a rear side gear tooth  631 . That is, the elastic member for up and down movement  634  pressurizes the portion so that it is possible that the idle gear  630  is prevented from being turned front to back when the pinion  410  is rotated. 
     The idle gear  630  may be installed to be elastically moveable back and forth. Thus, even when the idle gear  630  does not have the same pitch as the rack gear  611  of the first rack member  610 , the pinion  410  may be engaged precisely with the idle gear and the damage caused when the gear teeth  631  and  632  of the idle gear  630  are forcibly engaged with the pinion  410  may be prevented. 
     For the back and forth movement of the idle gear  630 , in the first rack member  610 , a second seating step  635  is provided at a position blocking the front of the idle gear  630  and an elastic member for back and forth movement  636  is provided between opposed surfaces on the second seating step  635  and the idle gear  630 . 
     The first rack member  610  may be further provided with a cover body  637  surrounding the exterior of the idle gear  630 . That is, the cover body  637  may prevent that various foreign materials enters the idle gear  630 , thereby preventing malfunction of the idle gear  630  due to the foreign materials. 
     The cover body  637  may prevent a problem in that the idle gear  630  is displaced to the side. 
     A supporting protrusion  638  may be provided at a side wall of the idle gear  630 , the supporting protrusion  638  may be configured to support by passing through the cover body  637 . This may be shown in  FIG.  24   . 
     Lower ends of the two gear teeth  631  and  632  constituting the idle gear  630  may be positioned lower than a lower end of the rack gear  611 . 
     That is, since the idle gear  630  is installed to be elastically moveable up and down, the idle gear  630  is positioned lower than the rack gear  611  so that initial engagement between the idle gear  630  and the pinion  410  may be performed precisely and stably. 
     The confining protrusion part  650  may confine the second rack member  620 . 
     The confining protrusion part  650  may be a single body in which an upper surface is closed and a lower surface is opened, and may be installed on a front upper surface (bottom surface in storage chamber) of the bottom  120  constituting the cabinet  100 . 
     More particularly, the confining protrusion part  650  may be inserted in the protrusion passing hole  513  that is formed through the cover plate  510 . When the cover plate  510  is not provided, the protrusion passing hole  513  is formed through the upper surface (bottom surface in storage chamber) of the bottom  120  of the cabinet  100  so that the confining protrusion part  650  is provided therein. 
     An inner width of the protrusion passing hole  513  may be larger than an outer width of the confining protrusion part  650 , and a confining holder  654  may prevent outward exposure of a gap between the protrusion passing hole  513  and the confining protrusion part  650 , the gap being generated by width difference between the protrusion passing hole  513  and the confining protrusion part  650 . This may be shown in  FIG.  26   . 
     The confining holder  654  may be coupled to the upper surface (e.g., upper surface of bottom) of the cover plate  510 . The confining holder  654  may be configured of a protrusion through hole  654   a  at the center thereof and a circumference portion, the protrusion through hole  654   a  may be provided so that the confining protrusion part  650  passes therethrough and the circumference portion of the confining holder  654  blocks the gap between the protrusion passing hole  513  and the confining protrusion part  650  and may be coupled to the cover plate  510 . 
     A coupling end  656  may protrude outwards from a circumferential surface of the confining protrusion part  650 , and a raising guide  654   b  is formed by protruding from a lower surface of the confining holder  654  to pass through the coupling end  656  from the top to the bottom. Coupling ends  656  are respectively formed by protruding from opposite sides of the confining protrusion part  650 , and raising guides  654   b  are formed at opposite sides of the confining holder  654  to pass through the coupling ends  656 , respectively. 
     The raising guide  654   b  may support up and down movement of the confining protrusion part  650 . 
     The confining protrusion part  650  may be installed to be elastically moved up and down in the protrusion passing hole  513  by an elastic member  651 . 
     That is, when pressure is applied to the confining protrusion part  650 , the confining protrusion part  650  is moved downward into the protrusion passing hole  513 , and when the confining protrusion part  650  is not under pressure, the confining protrusion part  650  is moved upward from the protrusion passing hole  513  so that a part thereof is exposed (protrude) to the inside of the lower storage chamber  3 . 
     The elastic member  651  may be a coil spring, and a spring engagement protrusion  652  may protrude downward from the inside of the confining protrusion part  650 . The elastic member  651  is configured such that an upper end thereof passes through a lower surface of the confining protrusion part  650  and then is engaged with the spring engagement protrusion  652  of the confining protrusion part  650 . 
     The confining protrusion part  650  is in rear of the pinion  410 , and is provided to be as close as possible to the pinion  410 . 
     At a center portion of an upper surface of the confining protrusion part  650 , a slope  653  is inclined upward such that the front is low and the rear is high. As the locking member  673  of the confining module  670  is moved backward along the slope  653 , the confining protrusion part  650  is moved backward. 
     The confining module  670  may confine the second rack member  620  before the first rack member  610  is fully pushed out. 
     The confining module  670  may include the confining protrusion part  650 , the stopper member  671 , the holder  672 , and the locking member  673 . 
     The stopper member  671  may be installed in the motion groove  622  of the second rack member  620 , and may function to restrict the rearward movement of the second rack member  620 . A length (from the front to the rear) of the stopper member  671  may be shorter than a length (from the front to the rear) of the motion groove  622 , so that the stopper member  671  is installed to be moveable in forward and rearward directions within the motion groove  622 . 
     The stopper member  671  may include a confining hook  671   a  at a lower surface of a front end thereof, the confining hook  671   a  protruding downward. When the drawer  200  is closed to enter the preset distance, the confining hook  671   a  is hit at a front surface of the confining protrusion part  650  to prevent the stopper member  671  and the first rack member  610  from being moved backward. 
     A holder groove  671   b  may be provided on a front upper surface of the stopper member  671 , and a locking member through hole  671   c  may be provided on a rear side portion of the stopper member  671 . 
     The holder groove  671   b  may be gradually inclined downward such that the front is high and the rear is low. Therefore, when the holder  672  received inside the holder groove  671   b  is moved forward, the holder  672  may be easily separated from the holder groove  671   b.    
     The holder  672  may restrict the forward and rearward movement of the stopper member  671 . 
     A lower end of the holder  672  is received in the holder groove  671  b of the stopper member  671 , and an upper end of the holder  672  is installed to pass through a first through hole  622   a  of the second rack member. Thus, the first rack member  610  may be pushed out by the preset distance to lead the second rack member  620 , the holder  672  moved forward with the second rack member  620  is separated from the holder groove  671   b  and is received in the first receiving groove  614   a  of the first rack cover  614 . 
     The holder  672  may have inclined front upper and lower edges, and a front lower edge of the holder  672  may be inclined at the same slope as the holder groove  671   b.  Thus, the holder  672  may be easily separated from the holder groove  671   b.    
     The holder  672  has a cut groove  672   a  that is cut in forward and rearward direction on an upper surface of the holder  672 , and an insert protrusion  633  received in the cut groove  672   a  is provided on a lower surface of the first rack cover  614 , the lower surface thereof facing the upper surface of the holder  672 , the insert protrusion  633  is formed from a front end of the first rack cover  614  to the first receiving groove  614   a.  Due to a structure between the cut groove  672   a  and the insert protrusion  633 , during movement of the first rack member  610 , the holder  672  is prevented from being moved laterally so as to be precisely received in the first receiving groove  614   a.  The cut groove  672   a  and the insert protrusion  633  may be provided in plural. 
     The locking member  673  may prevent the forward movement of the second rack member  620  by being locked in a position of the rear of the confining protrusion part  650  until the first rack member  610  is pushed out by the preset distance. 
     The locking member  673  may move upward when the first rack member  610  and the first rack cover  614  are pushed out by the preset distance and may move with the second rack member  620  and the second rack cover  624 . The locking member  673  is inserted in the second receiving groove  614   b  of the first rack cover  614  positioned above the locking member to be operated for releasing the engagement with the confining protrusion part  650 . 
     An extending step  673   a  may be provided at an upper end of the locking member  673  in a shape of extending laterally, and a raising guide step  623  may be provided on opposite side portions of the second through hole  622   b  at a front upper surface of the second rack member  620 . The raising guide step  623  may have a rounded shape (or inclined shape) so as to raise the extended step  673   a  when the first rack member  610  and the first rack cover  614  are pushed out by the preset distance and moved with the second rack member  620  and the second rack cover  624 . 
     When the first rack member  610  and the first rack cover  614  are pushed out by the preset distance and moved with the second rack member  620  and the second rack cover  624 , the raising guide step  623  provided on the second rack member  62  raises the extended step  673   a  of the locking member  673 , thus the locking member  673  rises up to a height where the locking member  673  is not hit from the confining protrusion part  650 . 
     The raising guide step  623  may be rounded or inclined upward such that the front is low and the rear is high. The raising guide step  623  may be gradually inclined upward such that the front (at the center of the opposite side portions of second through hole  622   b ) is low and the rear is high. That is, the raising guide step  623  may be provided so that the locking member  673  is not affected by the raising guide step  623  when it is positioned in the front of the second through hole  622   b,  and is gradually moved upward by affecting by the raising guide step  623  when the locking member  673  is moved to the rear of the second through hole  622   b  by the forward movement of the second rack member  620 . 
     The extended step  673   a  of the locking member  673  is preferably rounded or inclined like the raising guide step  623 . 
     A lower surface of the locking member  673  is inclined upward such that the front is low and the rear is high. A slope of the lower surface of the locking member  673  is the same as the slope  653  formed at the center of the upper surface of the confining protrusion part  650 . 
     According to an embodiment of the present disclosure, operation of the refrigerator may be described with reference to  FIGS.  27  to  34   . 
     The drawer  200  is maintained in a closed state unless otherwise manipulated. This may be shown in  FIGS.  27  and  28   . 
     In the closed state, when a manipulation is performed to open the drawer  200  at the user&#39;s need, the driving motor  420  may operate while power is supplied to the driving part  400 . 
     The manipulation for opening the drawer  200  may be a manipulation of a button  6  (touch or pressure type) or an operation control of a control program that senses proximity of the user. 
     When the driving motor  420  is operated by the manipulation, the two pinions  410  may simultaneously rotate, and thus the drawer  200  may open forward while the rack gears  611  and  621  (of the two rack gear assemblies  601  and  602 ) engaged with the pinions  410  are operated. 
     The first rack member  610  (or first rack) and the first rack cover  614  are preferentially pushed out while being operated simultaneously, and then the second rack member  620  (or second rack) and the second rack cover  624  are subsequently pushed out. 
     While the first rack member  610  and the first rack cover  614  are simultaneously operated and pushed out, the locking member  673  is maintained in a confined state to the confining protrusion part  650 , so that the second rack member  620  (or second rack) and the second rack cover  624  are maintained in an initial position. 
     When the first rack member  610  and the first rack cover  614  are pushed out by the preset first distance and the linkage protrusion  681  comes into contact with the linkage step  682 , the second rack member  620  and the second rack cover  624  move forward with the first rack member  610  from the contact point. This process may be shown in  FIGS.  29  and  30   . 
     However, the locking member  673  may be confined to the confining protrusion part  650 , so the stopper member  671  through which the locking member  673  passes is maintained in place while the second rack member  620  moves forward. In the above process, the extended step  673   a  of the locking member  673  may gradually climb to the raising guide step  623  provided in the second rack member  620 , and the locking member  673  is moved upward and is separated from the confining protrusion part  650 . This process may be shown in  FIGS.  31  and  32   . 
     After that, the stopper member  671  may move forward with the second rack member  620  while contacting a rear surface in the motion groove  622  and passing the confining protrusion part  650 . 
     While the second rack member  620  and the second rack cover  624  move following the first rack member  610  and the first rack cover  614 , the rack gear  621  (of the second rack member  620 ) is engaged with the pinion  410  just before the rack gear  611  (of the first rack member  610 ) is separated from the pinion  410 . As the rack gear  611  (of the first rack member  610 ) is separated from the pinion  410  by rotation of the pinion  410  and at the same time only the rack gear  621  (of the second rack member  620 ) is moved by being engaged with the pinion  410 , and the drawer  200  may be further moved forward. This process may be shown in  FIG.  33   . 
     After movement of the second rack member  620  is finished, the storage bin  220  (of the drawer  200 ) is in a maximum opened state. When the maximum opened state of the storage bin  220  is checked (for example, the maximum opened state is sensed by open/close sensing part), the raising/lowering module  300  (or lift module) is operated to raise up the container  240  in the storage bin  220 . 
     Accordingly, the user can take the container  240  out of the storage bin, take storage items out from the container  240 , and/or put items into the container  240 . 
     When closing operation of the drawer  200  is performed as the user completes use thereof, the driving motor  420  (constituting the driving part  400 ) may drive such that the pinion  410  is reversibly rotated, and thus the rack gear  621 , engaged with the pinion  410 , may operate such that the second rack member  620  is moved backward. 
     The first rack member  610  is moved rearward with the second rack member  620  by being moved in conjunction with the second rack member  620  by the linkage part  680 . 
     After that, when a front end of the (second) rack gear  621  (of the second rack member  620 ) is positioned to be engaged with the pinion  410 , a rear end of the (first) rack gear  611  of the first rack member  610  is also positioned to be engaged with the pinion  410 . The (second) rack gear  621  of the second rack member  620  is then separated from the pinion  410 , and only the first rack member  610  is moved rearward by the (first) rack gear  611  thereof. 
     When just before the second rack member  620  is fully moved rearward, the confining hook  671   a  of the stopper member  671  is blocked by the confining protrusion part  650 , thereby no longer being moved rearward. Even though the stopper member  671  is hit, as the second rack member  620  is further moved by a moveable distance provided in the motion groove  622 , the extended step  673   a  of the locking member  673  is separated from the locking member  673  so that the locking member  673  is moved downward. 
     After that, the second rack member  620  is also no longer moved backward by the stopper member  671 , and the confining protrusion part  650  is positioned between the confining hook  671   a  of the stopper member  671  and the locking member  673  and confines the second rack member  620 . 
     Accordingly, only the first rack member  610  is further moved rearward and returned to an initial position (position where storage bin is fully pushed in). When completion of the return movement is sensed, driving of the driving motor  420  is stopped and the closing movement of the drawer ends. 
     When opening and closing operation of the drawer  200  is performed, the drawer  200  may be closed obliquely such that opposite sides of the drawer are not in a horizontal state but rather one side is further forward than the other side. 
     That is, although a rack gear of any one rack gear assembly of the rack gear assemblies  601  and  602  is engaged with the pinion  410  one pitch later than a rack gear of the other rack gear assembly by user carelessness, when the two pinions  410  are rotated at the same time by operation of the driving motor  420 , the drawer  200  is inserted into the lower storage chamber  3  with oblique opposite sides. 
     In this process, when any one side (for example, a side where open/close sensing part is provided) of the drawer  200  is closed before the other side of the drawer, the open/close sensing part  514  may sense the closing and then additional operation of the driving motor  420  may be controlled. 
     That is, the driving motor  420  may be controlled to be further operate by the predetermined time or the predetermined number of rotations from when the closing of the drawer  200  is sensed. Therefore, the release rack gear assembly, which relatively less closed among the rack gear assemblies  601  and  602  that are engaged with the pinion  410 , may be engaged with the pinion  410  to the portion where the idle gear  630  is provided. 
     The idle gear  630  may be provided with a pulling force by the pinion  410  by the spaced distance (higher than one pitch and less than two pitch) from the rack gear  611 , whereby the release rack gear assembly  602  may easily move. 
     The engagement between the pinion  410  and the idle gear  630  may be performed stably and precisely by the elastic member  634  and  636 . 
     On the other hand, when the other side (for example, the side opposite to a side where the open/close sensing part is provided) of the drawer  200  is closed before the one side of the drawer  200 , the two pinions  410  may continuously rotate until the open/close sensing part  514  senses the closing of any one side of the drawer  200 . 
     Since the idle gear  630  provided in the release rack gear assembly that is closed before the other rack gear assembly is engaged with the pinion  410 , and the idle gear  630  receives a horizontal movement force by the rotational force of the pinion  410  and the idle gear performs additional rearward movement of the release rack gear assembly. 
     Since the drawer  200  has the packing member on the contact surface between the front panel  210  and the cabinet  100 , a side of the drawer  200  where the release rack gear assembly is provided may be further moved rearward by a compressive force of the packing member. 
     However, when the drawer  200  is moved until the packing member is in a maximum compressed state, the idle gear  630  engaged with the pinion  410  is moved upward (referring to  FIG.  34   ) and temporarily released from engagement with the pinion  410 , whereby the pinion  410  idles. 
     The other pinion  410  may continuously move the general rack gear assembly rearward while being engaged with the rack gear  611  of the general rack gear assembly, so that the side, which corresponds to the other pinion, of the drawer is closed later. 
     When the closing of the drawer is sensed, the driving motor  420  is controlled from this time to perform the additional operation by the predetermined time or the predetermined number of rotations and then the operation is deactivated. 
     Accordingly, even when any one side of the drawer  200  is closed before the other side of the drawer, the opposite sides of the drawer  200  may be fully closed by the additional operation of the driving motor  420  and providing the idle gear  630 . 
     The refrigerator of example embodiments is not limited to the structure of the embodiments described above. 
     That is, the rack gear assemblies  601  and  602  may be provided only with the first rack member  610  (or first rack). In this example, the idle gear  630  may be installed in front of the (first) rack gear  611  (of the first rack member  610 ), and an installation structure thereof may also be provided to be capable of back and forth elastic movement and up and down elastic movement same as the above-described embodiment. 
     The rack gear assemblies  601  and  602  may also be formed by including at least three rack members. In this example, the idle gear  630  is provided in front of the (first) rack gear  611  of a rack member that is positioned at the front of the rack members based on the movement direction of the drawer  200 , and an installation thereof may be provided to be capable of back and forth elastic movement and up and down elastic movement same as the above-described embodiment. 
     The idle gear  630  constituting the refrigerator of the present disclosure may be embodied in various shapes. 
     As described above, the refrigerator of the present disclosure is provided with the rack gear assembly  601  that includes the idle gear  630 . The idle gear  630  may idle the pinion  410  by being engaged with the gear teeth of the pinion  410 , so that the drawer  200  can be fully closed even when the opposite sides of the drawer  200  are not moved parallel. 
     In the refrigerator of the present disclosure, the driving motor  420  (of the driving part  400 ) is configured to perform additional operation from when the closing of the drawer  200  is sensed and then to deactivate the operation, so that the drawer  200  can be fully closed even when the opposite sides of the drawer  200  are not moved parallel. 
     In the refrigerator of the present disclosure, the open/close sensing part  514  is provided at the opposed surfaces on the drawer  200  and the cabinet  100  to sense opening and closing of the drawer  200 , so that operational control of the driving motor  420  can be performed precisely. 
     In the refrigerator of the present disclosure, the open/close sensing part  514  is provided with the sensor  514   a  and the sensing member  514   b,  and the sensor  514   a  and the sensing member  514   b  are respectively provided at the opposed portions between the storage chamber  3  and the drawer  200 , so that opening and closing of the drawer  200  can be sensed accurately. 
     In the refrigerator of the present disclosure, the sensor  514   a  is provided at the bottom in the storage chamber  3  and the sensing member  514   b  is provided at the lower surface of the storage bin  220  (constituting the drawer  200 ), so that installation and maintenance thereof can be performed easily. 
     In the refrigerator of the present disclosure, the sensor  514   a  is the hall sensor and the sensing member  514   b  is the magnet, so that the user can accurately recognize opening and closing of the drawer  200 . 
     In the refrigerator of the present disclosure, the (first) rack gear  611  is operated to be further moveable by at least one pitch from when closing of the drawer  200  is sensed, the drawer  200  can be closed accurately. 
     In the refrigerator of the present disclosure, the pinion  410  is provided to be rotated only two rotations or less from when closing of the drawer  200  is sensed, so that damage to the pinion  410  or the rack gear  611  can be prevented (or reduced). 
     In the refrigerator of the present disclosure, the idle gear  630  is provided at at least one of the rack gear assemblies  601  and  602 , so that damage to the (first) rack gear  611  and the pinion  410  can be prevented (or minimized) even when the one side of the drawer  200  (where the rack gear assembly with the idle gear is provided) is closed before the other side of the drawer  200 . 
     In the refrigerator of the present disclosure, the idle gear  630  is provided in front of the (first) rack gear  611  of the first rack member  610 , so that the idle gear  630  can engage with the pinion  410  only when the drawer  200  is closed. 
     In the refrigerator of the present disclosure, the idle gear  630  is provided with at least one gear tooth, so that the idle gear  630  can engage with the pinion  410 . 
     In the refrigerator of the present disclosure, the idle gear  630  is provided with two gear teeth  631  and  632  and is formed to have the same pitch as the rack gear  611 , so that the idle gear  630  can be precisely engaged with the pinion  410 . 
     In the refrigerator of the present disclosure, the distance L between the idle gear  630  and the rack gear  611  is formed longer (or greater) than the pitch P 1  of the rack gear  611 , so that the idle gear  630  can be provided with the pulling force by the pinion  410  for easily forced movement. 
     In the refrigerator of the present disclosure, the distance L between the idle gear  630  and the rack gear  611  is formed shorter than the distance between three rack teeth of the rack gear  611 , so that engagement between the idle gear  630  and the pinion  410  can be precisely performed. 
     In the refrigerator of the present disclosure, lower ends of the two gear teeth  631  and  632  (included in the idle gear  630 ) is positioned lower than a lower end of the rack gear  611 , so that engagement between the idle gear  630  and the pinion  410  can be precisely performed. 
     In the refrigerator of the present disclosure, the idle gear  630  is elastically moveable up and down, so that the idle gear  630  can be released from engagement with the pinion  410  when the drawer  200  is closed and the opposite sides of the drawer  200  can be fully closed. 
     In the refrigerator of the present disclosure, the idle gear  630  is elastically moveable back and forth, so that the idle gear  630  can be stably engaged with the pinion  410  and may be provided efficiently with the pulling force by the pinion  410 . 
     In the refrigerator of the present disclosure, the idle gear  630  is elastically moveable up and down by the elastic member for up and down movement  634 , so that the idle gear  630  can be engaged with the pinion  410  or be released from the engagement with the pinion easily. 
     In the refrigerator of the present disclosure, the elastic member for up and down movement  634  is positioned at the portion of the upper surface of the idle gear  630 , the portion being the upper side between the two gear teeth  631  and  632  or the upper side of the gear tooth relatively close to the rack gear  611 , so that malfunction such as overturning of the idle gear  630  may be prevented. 
     In the refrigerator of the present disclosure, the idle gear  630  is elastically moveable back and forth by the elastic member for back and forth movement  636 , so that back and forth movement of the idle gear  630  may be performed. 
     In the refrigerator of the present disclosure, the first rack member  610  is further provided with the cover body  637  for surrounding the exterior of the idle gear  630 , so that malfunction due to damage to the idle gear or entering of foreign material may be prevented. 
     It will be understood that when an element or layer is referred to as being “on” another element or layer, the element or layer can be directly on another element or layer or intervening elements or layers. In contrast, when an element is referred to as being “directly on” another element or layer, there are no intervening elements or layers present. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     It will be understood that, although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section could be termed a second element, component, region, layer or section without departing from the teachings of the present disclosure. 
     Spatially relative terms, such as “lower”, “upper” and the like, may be used herein for ease of description to describe the relationship of one element or feature to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “lower” relative to other elements or features would then be oriented “upper” relative to the other elements or features. Thus, the exemplary term “lower” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     Embodiments of the disclosure are described herein with reference to cross-section illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of the disclosure. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the disclosure should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
     Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments. 
     Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.