Patent Publication Number: US-2013249367-A1

Title: Synchronizing device for synchronizing sliding movements of sliding rail units and a drawer, and spindle extension connector and anti-wobbling unit used for the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority of Taiwanese Application No. 101110371, filed on Mar. 26, 2012. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a synchronizing device, and more particularly to a synchronizing device that is adapted for synchronizing sliding movements of sliding rail units that are respectively disposed on two opposite sides of a drawer. The invention also relates to a synchronizing spindle extension connector and an anti-wobbling unit adapted to be applied to the synchronizing device. 
     2. Description of the Related Art 
     In order to smoothly slide a drawer in or out of a cabinet, a pair of sliding rail units are disposed on two opposite sides of the drawer so as to be positioned between the drawer and the cabinet, respectively. In addition, to prevent an uneven force from causing asynchronous sliding movements of the sliding rail units, a synchronizing device is generally provided to synchronize smooth movements of the sliding rail units. 
     Currently, a conventional synchronizing device includes a pair of rack members that are respectively mounted on a cabinet, a pair of pinion gears that are respectively rotatably mounted on two opposite sides of a drawer, and a spindle that interconnects and drives the pinion gears in synchronous rotation. In use, the pinion gears move along and mesh with the rack members, synchronously. Due to the synchronous rotation and equal travel of the pinion gears along the rack members, the drawer is smoothly slidable without swerving relative to the sliding rail units in the cabinet. 
     However, when the drawer has a relatively large dimension, the spindle of the conventional synchronizing device has to be correspondingly lengthened in order to interconnect the pinion gears. Some spindles may even have a length that ranges from 150 centimeters to 200 centimeters. Hence, there are great dimension differences among components of the conventional synchronizing device and the components are not suitable in a uniform packing. As shown in  FIG. 13 , in order to conveniently pack, transport, assemble, and store the components of the conventional synchronizing device, the spindle  9  is divided into two spindle sections  91 . When assembling on site, a spindle extension connector  92  is used for interconnecting the spindle sections  91  such that the spindle sections  91  are assembled to form the spindle  9 . If the spindle sections  91  are stretchable relative to each other to change the length of the spindle  9 , a connection between the spindle sections  91  may not be stable after being assembled. Since connection portions between the spindle extension connector  92  and the spindle sections  91  may respectively have relatively large rotation gaps, the synchronous rotation of the pinion gears of the conventional synchronizing device may be adversely affected. 
     Besides, since the spindle  9  of the conventional synchronizing device is relatively long and is formed by assembling the two spindle sections  91 , the rigidity of the spindle  9  is uneven and the spindle  9  may be deformed due to gravity. Hence, splits  90  may be formed between the spindle extension connector  92  and the spindle sections  91 . The spindle  9  may be gradually bent from two opposite end sides toward a central portion therebetween. When the spindle  9  is driven to rotate by the pinion gears, the spindle  9  may have wobbling rotation. Moreover, a relatively maximum deformation of the spindle  9  may occur at the connection between the spindle extension connector  92  and the spindle sections  91 . The wobbling of the spindle  9  may collide with the drawer to make noise. 
     SUMMARY OF THE INVENTION 
     Therefore, the present invention is to provide a synchronizing device that can alleviate at least one drawback of the aforementioned conventional synchronizing device. 
     According to one aspect of the present invention, a synchronizing device is adapted for synchronizing sliding movements of a pair of sliding rail units that are respectively disposed on two opposite sides of a drawer. The synchronizing device includes a pair of guiding units, a pair of rotating units, a synchronizing linking unit, and at least one anti-wobbling unit. The pair of guiding units are adapted to support and slide the sliding rail units thereon, respectively. Each of the guiding units has a longitudinal rack member. The pair of rotating units are adapted to be respectively and rotatably disposed on the two sides of the sliding drawer, and are able to rotate on the guiding units, respectively. Each of the rotating units includes a mounting seat and a pinion gear that is journeyed on the mounting seat and that meshes with and moves along the rack member of a corresponding one of the guiding units. The synchronizing linking unit interconnects the rotating units to synchronize movements of the pinion gears of the rotating units. The synchronizing linking unit includes at least one synchronizing spindle, and at least one synchronizing spindle extension connector connected to the synchronizing spindle. The synchronizing spindle extension connector has a connecting end portion including an annular contact surface that has a non-circular cross-section and that is able to interlock with the synchronizing spindle for simultaneous rotation. The anti-wobbling unit is mounted between the sliding drawer and the synchronizing linking unit, and includes a resilient anti-wobbling pad member to prevent wobbling of the synchronizing linking unit. 
     According to another aspect of the present invention, a synchronizing spindle extension connector is adapted to be connected axially to a synchronizing spindle of a synchronizing linking unit of a synchronizing device, and includes two opposite connecting end portions, at least one of which includes a contact surface that has a non-circular cross-section and that is adapted to interlock with the synchronizing spindle. 
     According to a further aspect of the present invention, an anti-wobbling unit is adapted for a synchronizing spindle of a synchronizing device of a drawer, and includes an anti-wobbling pad member that is made of a resilient material and that is adapted for preventing wobbling of the synchronizing spindle. 
     According to still another aspect of the present invention, there is provided an anti-wobbling unit of a synchronizing device. The synchronizing device includes a synchronizing spindle extension connector connected to at least one synchronizing spindle. The anti-wobbling unit includes an anti-wobbling pad member that is adapted to be mounted on the synchronizing spindle extension connector. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, of which: 
         FIG. 1  is a perspective view of a first preferred embodiment of a synchronizing device according to the present invention, illustrating a sliding drawer with the synchronizing device sliding out relative to a cabinet; 
         FIG. 2  is an exploded fragmentary perspective view, illustrating the first preferred embodiment; 
         FIG. 3  is a fragmentary longitudinal sectional view of the first preferred embodiment; 
         FIG. 4  is a fragmentary transverse sectional view of the first preferred embodiment; 
         FIG. 5  is an exploded fragmentary perspective view of the first preferred embodiment, illustrating the synchronizing device mounted on a rear side of the sliding drawer; 
         FIG. 6  is a fragmentary transverse sectional view of a second preferred embodiment of the present invention; 
         FIG. 7  is a fragmentary traverse sectional view, illustrating a third preferred embodiment of the present invention; 
         FIG. 8  is an exploded fragmentary perspective view, illustrating a fourth preferred embodiment of the present invention; 
         FIG. 9  is a fragmentary traverse sectional view of the fourth preferred embodiment; 
         FIG. 10  is an exploded fragmentary perspective view, illustrating a fifth preferred embodiment of the present invention; 
         FIG. 11  is a top view of the fifth preferred embodiment; 
         FIG. 12  is a fragmentary transverse sectional view of the fifth preferred embodiment; and 
         FIG. 13  is a fragmentary sectional view, illustrating a conventional spindle. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Before this invention is described in detail, it should be noted that, in the following description, similar elements are designated by the same reference numerals. 
     Referring to  FIG. 1 , the first preferred embodiment of a synchronizing device  9  according to the present invention is adapted to be positioned between a cabinet  1  and a sliding drawer  2 . The synchronizing device  9  is adapted for synchronizing sliding movements of a pair of sliding rail units  3  that are respectively disposed on two opposite sides of the sliding drawer  2 . By means of the sliding rail units  3 , the sliding drawer  2  is forward or backward slidable relative to the cabinet  1 . Each of the sliding rail units  3  includes a first slide rail  31  disposed on an interior side of the cabinet  1 , a second slide rail  32  disposed on one side of the sliding drawer  2  and slidable relative to the first slide rail  31 , and an intermediate slide rail  33  movably disposed between the first and second slide rails  31 ,  32  for lengthening the travel of the second slide rail  32  relative to the cabinet  1 . In actual implementation, the intermediate slide rail  33  may be omitted and each of the sliding rail units  3  may include only the first and second slide rails  31 ,  32  so as to be configured as a two-part slide rail structure. In use, when the drawer  2  is pulled to move forward or backward relative to the cabinet  1 , the second slide rails  32  are driven to respectively slide relative to the first slide rails  31 , and thus to direct the drawer  2  to have a smooth movement relative to the cabinet  1 . 
     Referring to  FIGS. 2 to 4 , the synchronizing device  9  includes a pair of guiding units  4 , a pair of rotating units  5 , a synchronizing linking unit  6 , and at least one anti-wobbling unit  7 . 
     The pair of guiding units  4  are adapted to support and slide the sliding rail units  3  thereon, respectively. Each of the guiding units  4  has a longitudinal rack member  41 . In this embodiment, the guiding units  4  are respectively mounted on top ends of the first slide rails  31 . However, the guiding units  4  may have various placements relative to the sliding rail units  3  depending upon the intended structural designs. Preferably, each of the guiding units  4  has two side walls  42  to retain a corresponding one of the rotating units  5  therebetween. 
     The rotating units  5  are adapted to be respectively and rotatably disposed on the two sides of the sliding drawer  2  and are able to rotate on the guiding units  4 , respectively. Each of the rotating units  5  includes amounting seat  53  and a pinion gear  51  that is journalled on the mounting seat  53  and that meshes with and moves along the rack member  41  of a corresponding one of the guiding units  4 . Preferably, each of the rotating units  5  includes a pinion shaft  52  that is integrally formed with the pinion gear  51  and that extends toward another rotating unit  5 . In this preferred embodiment, the mounting seat  53  is mounted on a corresponding one of the second slide rails  32  to be engaged with the pinion shaft  52 . Since each of the pinion gears  51  of the rotating units  5  is retained between the side walls  42  of the corresponding one of the guiding units  4 , the pinion gear  51  is able to move along the corresponding one of the guiding units  4  without swerving from the guiding unit  4  and is prevented from separating from the guiding unit  4 . Hence, the probability of malfunction can be reduced. Alternatively, as shown in  FIG. 5 , the mounting seat  53  of each rotating unit  5  is mounted on a rear side of the sliding drawer  2 . Therefore, the present invention should not be limited to the disclosure of this embodiment. In addition, there are other components between the pinion shaft  52  and the mounting seat  53 . Since the feature of this invention does not reside in the configuration of the other components between the pinion shaft  52  and the mounting seat  53 , which may be readily appreciated by those skilled in the art, details of the same are omitted herein for the sake of the brevity. 
     The synchronizing linking unit  6  interconnects the rotating units  5  to synchronize movements of the pinion gears  51  of the rotating units  5 . The synchronizing linking unit  6  includes at least one synchronizing spindle  61  and at least one synchronizing spindle extension connector  62  that is connected to the synchronizing spindle  61 . The synchronizing spindle extension connector  62  has a connecting end portion  621  including an annular contact surface that has a non-circular cross-section and that is able to be inserted into and interlocked with the synchronizing spindle  61  for simultaneous rotation. In this preferred embodiment, the synchronizing linking unit  6  includes two synchronizing spindles  61  that are respectively connected to the pinion shafts  52  of the rotating units  5 . However, the numbers of the synchronizing spindles  61  and the synchronizing spindle extension connectors  62  may vary depending upon the desired dimension and design of the sliding drawer  2 . Aside from the arrangement of two synchronizing spindles  61  and one synchronizing spindle extension connector  62  illustrated in this preferred embodiment, the arrangement may be modified to include three of the synchronizing spindles  61  in conjunction with two of the synchronizing spindle extension connectors  62 . Alternatively, the synchronizing spindle extension connector  62  may be configured to have one end connected to the spindle  61  and the other end axially connected to the corresponding rotating unit  5 . The numbers of the synchronizing spindles  61  and the synchronizing spindle extension connectors  62  may be varied and are not be limited to the disclosure of this preferred embodiment. 
     In this preferred embodiment, each of the synchronizing spindles  61  is hollow and has two opposite spindle end portions  611 . The synchronizing spindle extension connector  62  includes two opposite connecting end portions  621 , at least one of which includes an annular contact surface that has a non-circular cross-section and that is adapted to be inserted into and interlocked with a corresponding one of the synchronizing spindles  61 . In this preferred embodiment, both of the connecting end portions  621  are configured as insert rods that are respectively insertable into the corresponding ones of the spindle end portions  611  of the two synchronizing spindles  61 . Preferably, the synchronizing spindle extension connector  62  further includes a blocking portion  622  that is disposed between the two connecting end portions  621  and that is able to block the synchronizing spindles  61  so that the synchronizing spindles  61  do not extend beyond the blocking portion  622 . More preferably, each of the connecting end portions  621  has an inclined guide end  623  that is distal from the blocking portion  622  and that is outwardly tapered. The inclined guide end  623  facilitates the synchronizing spindle extension connector  62  to be inserted into the corresponding one of the synchronizing spindles  61 . In this preferred embodiment, the synchronizing spindles  61  are respectively connected to the pinion shafts  52 . When the number of the synchronizing spindles  61  is increased, only the synchronizing spindles  61  proximate to the pinion shafts  52  are respectively connected to the pinion shafts  52 . The other synchronizing spindles  61  are connected to each other through the synchronizing spindle extension connectors  62 . During assembling, each of the pinion shafts  52  is inserted into one of the spindle end portions  611  of the corresponding one of the synchronizing spindles  61 . The connecting end portions  621  of the synchronizing spindle extension connectors  62  are respectively inserted into two adjacent ones of the spindle end portions  611  of two adjacent ones of the synchronizing spindles  61  until the blocking portions  622  abut against end edges of the two adjacent synchronizing spindles  61 . 
     Specifically, in order to prevent the rotating units  5  and the synchronizing unit  6  from being asynchronous, the pinion shaft  52  of each rotating unit  5  has an annular surface that has a non-circular cross-section. Preferably, the annular contact surface of the connecting end portion  621  of the synchronizing spindle extension connectors  62  and the annular surface of the pinion shaft  52  of each rotating unit  5  are the same in shape. Each of the spindle end portions  611  of each synchronizing spindle  61  has an annular inner surface  612  that has a non-circular cross-section complementary to the annular contact surface of the connecting end portion  621  of the synchronizing spindle extension connectors  62  and the annular surface of the pinion shaft  52  of each rotating unit  5  in shape. The annular contact surfaces of the connecting end portions  621  of each synchronizing spindle extension connector  62  and the annular surface of the pinion shaft  52  of each rotating unit  5  may be configured to have different shapes, such as slotted contour, rectangular contour, triangular contour, polygonal contour, oval contour, etc., and the annular inner surfaces  612  of the spindle end portions  611  of each synchronizing spindle  61  are correspondingly configured to have a complementary contour. In this preferred embodiment, the annular contact surfaces of the connecting end portions  621  of the synchronizing spindle extension connectors  62  and the annular surfaces of the pinion shafts  52  of the rotating units  5  are configured to have a cross contour, and the annular inner surfaces  612  of the spindle end portions  611  of the synchronizing spindle  61  are correspondingly configured to have a complementary cross contour. However, the present invention is not limited in this respect. 
     In this preferred embodiment, the anti-wobbling unit  7  is mounted between the sliding drawer  2  and the linking unit  6  and includes a resilient anti-wobbling pad member  71  to prevent wobbling of the synchronizing linking unit  6 . Preferably, the anti-wobbling pad member  71  is made of a resilient material selected from rubber, plastics, foams, etc., thereby preventing wobbling of the synchronizing spindle  61 . In this preferred embodiment, the anti-wobbling pad member  71  is a ring that is sleeved around the synchronizing spindle extension connector  62  and that is situated between the sliding drawer  2  and the synchronizing linking unit  6  so as to prevent wobbling of the synchronizing spindle  61 . In actual implementation, length and thickness of the anti-wobbling pad member  71  are not limited to the disclosure of this embodiment. Alternatively, the number of the anti-wobbling unit  7  may be increased so as to be disposed on easily deformable portions of the synchronizing linking unit  6 . For example, the anti-wobbling pad member  71  is sleeved around easily deformable portions of the synchronizing spindle  61 , thereby prevent wobbling of the synchronizing spindle  61 . 
     Referring to  FIGS. 1 ,  3 , and  4 , when a user pulls the sliding drawer  2 , the sliding rail units  3  disposed on the sliding drawer  2  will move together therewith and drive the synchronizing linking unit  6  to synchronize movements of the rotating units  5 . When the pinion gears  51  engagingly move on the respective rack members  41 , revolutions or rotating angles of the two pinion gears  51  are substantially the same, thereby ensuring synchronous movements of the two second slide rails  32  on two sides of the sliding drawer  2 . Therefore, a swerving problem caused by an uneven force applied to the sliding drawer  2  can be avoided. Hence, the sliding drawer  2  is smoothly slidable relative to the cabinet  1 . 
     For the synchronizing linking unit  6  of this invention, the synchronizing spindle extension connector  62  is inserted into and interlocked with respective ones of the synchronizing spindles  61  for connection, thereby having a simple structure and being convenient to be assembled. Since each synchronizing spindle  61  has a uniform diameter, each synchronizing spindle  61  is able to be divided into different length sections. In order to conform to various sizes of the cabinet  1 , the different length sections of the synchronizing spindles  61  may be increased in number or varied in length. Therefore, the synchronizing linking unit  6  is convenient to be fabricated, assembled, and packed. Moreover, the synchronizing linking unit  6  is convenient and suitable for being assembled in correspondence with the size variation of the cabinet  1  on site. 
     When the sliding drawer  2  has a relatively large width, the synchronizing linking unit  6  is required to correspondingly have a relatively long length in its entirety to satisfy the width of the sliding drawer  2 . After assembly, the synchronizing linking unit  6  has an overall weight that sags from two opposite outermost spindle end portions  611  of the synchronizing spindles  61  to a central region of the synchronizing linking unit  6 . Therefore the overall weight deforms the synchronizing linking unit  6 . Since the anti-wobbling unit  7  is mounted between the sliding drawer  2  and the linking unit  6 , particularly in case that the anti-wobbling unit  7  covers a relatively large deformation region of the synchronizing linking unit  6 , the anti-wobbling pad member  71  frictionally contacts the sliding drawer  2  to prevent impact noise when the synchronizing linking unit  6  synchronously moves with the rotating units  5  in a wobbling state and thus achieves relatively better noise-proof effect. Besides, the anti-wobbling pad member  71  corrects the relatively large deformation region of the synchronizing linking unit  6  to reduce wobbling of the synchronizing linking unit  6 , so that the wobbling of the synchronizing linking unit  6  is allowable and does not affect rotation of the rotating units  5 . 
     In other words, according to the present invention, by virtue of inclusion of the plurality of the synchronizing spindles  61  having relatively shorter length, components of the synchronizing device are convenient during transport and packing. During assembling, the plurality of the synchronizing spindle extension connectors  62  are used for connection of the synchronizing spindles  61 . However, such connective structure causes the synchronizing linking unit  6  to sag and have wobbling rotation. As a result, the synchronizing linking unit  6  may result in the rotating units  5  easily jumping off the guiding units  4  when the rotating units  5  rotate on the guiding units  4 . Through a practical test, when the synchronizing spindle extension connectors  62  are specially increased to be interlocked with the synchronizing spindles  61 , the aforesaid circumstance is likely to be more severe. Hence, the anti-wobbling unit  7  is attributed to restrict wobbling of the synchronizing linking unit  6  and reduce noise. Therefore, the pinion gears  51  are prevented from disengaging from the rack members  41  because the synchronizing spindles  61  are prevented from swerving therebetween. 
     Moreover, according to this invention, the synchronizing linking unit  6  and other components of the synchronizing device  9 , as well as the sliding rail units  3  may have relatively similar packing volume scales and are prevented from being bent and deformed by gravity or other external force. In response to dimension standardizing in the global cabinet market to merge with modular design conception, the packing volume scales are based on 10 centimeter increments per length unit. The length of the synchronizing linking unit  6  conforms to the width of the cabinet  1 . When the width of the cabinet  1  ranges from 40 centimeters to 200 centimeters, the length of the synchronizing spindle  61  is configured to comply with the minimum width, 40 centimeters, of the cabinet  1  as a desired basic dimension. The synchronizing spindle  61  is divided into 10 centimeter sections in order to facilitate packing in a uniform multi-section standard, thereby having convenience of packing. When assembling on site, because the sections of the synchronizing spindles  61  are corresponding to the width of the cabinet  1  in desired quantities, it is not required to use measurement and cutting tools and the synchronizing spindles  61  are assembled in the cabinet  1  by a DIY method. According to the present invention, the synchronizing device  9  can be packed in the uniform multi-section standard to conform to various dimensions of the cabinet  1 , thereby resolving imbalance quantity between the synchronizing device  9  and the cabinet in stock. 
       FIG. 6  shows a second preferred embodiment of a synchronizing device  9  according to this invention, which has a structure generally similar to that of the first preferred embodiment. However, the anti-wobbling pad member  71  of the anti-wobbling unit  7  is configured as a plate body that is mounted on the sliding drawer  2  and that abuts against the synchronizing spindle  61 . In this preferred embodiment, the anti-wobbling pad member  71  abuts against a central portion of the synchronizing spindle extension connectors  62  of the synchronizing linking unit  6  so as to restrict wobbling of the synchronizing linking unit  6 . Therefore, the anti-wobbling unit  7  prevents the synchronizing linking unit  6  from impacting the sliding drawer  2 , thereby achieving the noise-proof effect. 
       FIG. 7  shows a third preferred embodiment of a synchronizing device  9  according to this invention, which has a structure generally similar to that of the second preferred embodiment. However, in the preferred embodiment, the anti-wobbling unit  7  further includes a supporting seat  72  that supports the anti-wobbling pad member  71 , and a fixture member  73  that fixes the supporting seat  72  to the sliding drawer  2 . In this preferred embodiment, the anti-wobbling pad member  71  is configured as a plate body that abuts against the synchronizing spindle  61 . The supporting seat  72  is configured as an L-shaped plate body. Preferably, the supporting seat  72  has a fixed portion  721  that is fixed on the rear side of the sliding drawer  2  through the fixture member  73  and a supporting portion  722  that extends horizontally and outwardly from a bottom end of the fixed portion  721 . In this preferred embodiment, the fixture member  73  is an adhesive. However, in actual implementation, the fixture member  73  may be a screw or a bolt. Furthermore, the number of the fixture member  73  may be increased. In this preferred embodiment, the anti-wobbling pad member  71  is mounted on the supporting portion  722 , and abuts against an outer surface of the synchronizing spindle extension connectors  62  of the synchronizing linking unit  6 . When the synchronizing linking unit  6  is stationary, the anti-wobbling unit  7  prevents the synchronizing linking unit  6  from sagging. 
       FIGS. 8 and 9  show a fourth preferred embodiment of a synchronizing device  9  according to this invention, which has a structure generally similar to that of the third preferred embodiment. However, in the preferred embodiment, the sliding drawer  2  has a mounting hole  21  formed in the rear side thereof. The supporting seat  72  of the anti-wobbling unit  7  is directly mounted on the sliding drawer  2 . In this preferred embodiment, the supporting seat  72  has a hollow plug head portion  723  that is plugged fixedly in the mounting hole  21  of the sliding drawer  2 , and a stem  724  that is disposed inside the plug head portion  723  and that is eccentric to a central axis of the plug head portion  723 . The anti-wobbling pad member  71  is a ring that is sleeved around the stem  724  and that abuts against the synchronizing spindle  61  of the synchronizing linking unit  6 . Therefore, the anti-wobbling pad member  71  is capable of achieving the noise-proof effect and preventing wobbling of the synchronizing linking unit  6 . During assembling the anti-wobbling unit  7 , by virtue of an eccentric design of the stem  724  relative to the plug head portion  723 , the plug head portion  723  is rotatable in the mounting hole  21  so that the stem  724  is driven thereby to abut against and prevent the synchronizing spindle extension connectors  62  of the synchronizing linking unit  6  from sagging. 
       FIGS. 10 to 12  show a fifth preferred embodiment of a synchronizing device  9  according to this invention, which has a structure generally similar to that of the first preferred embodiment. However, in the preferred embodiment, the synchronizing spindle extension connector  62  further includes a sleeve portion  624  that is disposed around the connecting end portions  621  and that is sleeved around the synchronizing spindles  61  and the blocking portion  622  of the synchronizing spindle extension connector  62 . The sleeve portion  624  cooperates with the connecting end portions  621  to de fine an insertion space  625  that accommodates the spindle end portions  611  of the synchronizing spindles  61 . The sleeve portion  624  has two opposite open ends and at least one opening  626  that is disposed between the two opposite open ends and that is adapted for viewing the synchronizing spindle  61  and examining whether the synchronizing spindle  61  is situated in a predetermined position inside the sleeve portion  624 . In this preferred embodiment, the sleeve portion  624  has two openings  626  that are respectively proximate to two sides of the blocking portion  622  of the synchronizing spindle extension connector  62  and that respectively communicate with the insertion space  625 . The openings  626  permit a worker to view whether the spindle end portions  611  of the synchronizing spindles  61  are respectively inserted into the insertion space  625  to abut against the blocking portion  622  of the synchronizing spindle extension connector  62 . In actual implementation, the openings  626  may communicate with each other to be merged into one opening. 
     Preferably, the sleeve portion  624  further has an inner periphery surface that has a non-circular cross-section, and two lengthwise grooves  627  that lengthwise extend from the openings  626  and that extend inwardly from the inner periphery surface of the sleeve portion  624 . The lengthwise grooves  627  respectively communicate with the insertion space  625 . Each of the spindle end portions  611  of the synchronizing spindles  61  has an outer periphery surface that has a non-circular cross-section, and a lengthwise protrusion  613  that is lengthwise formed on the outer periphery surface and that is received in a corresponding one of the lengthwise grooves  627 . In this preferred embodiment, by virtue of an engagement of the lengthwise protrusion  613  and the corresponding one of the lengthwise grooves  627 , the cross-sections of each of the spindle end portions  611  and the sleeve portion  624  are configured to have a key-keyhole-shaped engagement structure. However, the engagement structure formed between the cross-sections of each of the spindle end portions  611  and the sleeve portion  624  is not limited to the disclosure of this embodiment. For example, the engagement structure formed between the cross-sections of each of the spindle end portions  611  and the sleeve portion  624  may be circular. In this preferred embodiment, by virtue of installation of the sleeve portion  624 , a firm connection is enhanced between the synchronizing spindle extension connector  62  and the synchronizing spindles  61 . Alternatively, the anti-wobbling pad member  71  of the anti-wobbling unit  7  may be substituted for an anti-wobbling pad member that is exemplified in the second embodiment to the fourth embodiment. 
     To sum up, in order to alleviate drawbacks of the conventional synchronizing linking unit such as various packing dimensions, deformation during transport, and use of measurement and cutting tools on site, and to balance the number of other components in stock to coordinate various dimensions of the cabinet  1 , the synchronizing spindle extension connector  62  of the synchronizing device  9  according to the present invention is used to be interlocked with the synchronizing spindles  61 . When the numbers of the synchronizing spindle extension connectors  62  and the synchronizing spindles  61  are increased, a combined length of the synchronizing spindle extension connectors  62  and the synchronizing spindles  61  is relatively lengthened but results in wobbling thereof when driven to rotate. The anti-wobbling unit  7  is used to prevent the connection wobbling among the synchronizing spindle extension connectors  62  and the synchronizing spindles  61 , and thus prevent impact of the sliding drawer  2 . 
     While the present invention has been described in connection with what are considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.