Patent Publication Number: US-10787859-B2

Title: Retracting means for retracting curtain cord and retractable curtain

Description:
TECHNICAL FIELD OF THE INVENTION 
     The present disclosure relates to the curtain field and in particular to a retractor for retracting a curtain cord and a retractable curtain. 
     BACKGROUND OF THE INVENTION 
     Retracting of retractable curtains such as Roman curtains is generally achieved via cords at two sides of the curtain bodies at least, and the cords are wound or unwound by a retractor. In the prior art, the retractor comprises synchronizing wheels and winding shafts for winding the cords, the winding shaft and one of the synchronizing wheels are coaxially provided, a coil spring is wound around the synchronizing wheels to provide reset force, the cords are stacked and wound on the winding shaft, pass through the curtain body from the upper end to the lower end, and are stacked and wound on the winding shaft via several line guiding wheels after passing through the upper end of the curtain body. In actual use, uneven problem occurs on the cords at two sides, diameters of the turns on the winding shaft will gradually change and cause the unbalance of the two sides of the curtain body; the cords on the winding shaft are very easy to get intertwined and tied, and retracting the curtain takes too much effort, or can not be achieved due to completely getting stuck, which is inconvenient for use; the structure is not rational and compact enough. 
     SUMMARY OF THE INVENTION 
     To solve the above mentioned problems, it is an object of the present disclosure to provide a retractor for retracting a curtain cord and a retractable curtain, which avoids stacking or intertwining of the cord and has a compact structure. 
     According to a first aspect of the present disclosure, a retractor for retracting a curtain cord is provided, which comprises a synchronizing wheel group and transmission assemblies located at two sides of the synchronizing wheel group for changing the transmission direction, and the transmission assembly at each side is connected with a winding assembly; 
     the synchronizing wheel group comprises at least one coil spring and at least two synchronizing wheels, and two ends of each coil spring are fixedly connected to two synchronizing wheels respectively so as to be wound on the two synchronizing wheels in opposite winding directions; 
     each transmission assembly comprises a first bevel gear and a second bevel gear which are engaged with each other, and the first bevel gears of the two transmission assemblies are connected with at least one synchronizing wheel; 
     each winding assembly comprises a fixing seat, and a winding shaft and a transmission shaft which are rotatably provided on the fixing seat, the transmission shaft is connected with a corresponding second bevel gear, the transmission shaft passes though and is coaxial with the winding shaft, the outer wall of the winding shaft tilts outward gradually along the axis of the transmission shaft, and a threading hole for the cord to pass through is opened on a part of the fixing seat corresponding to one end of the winding shaft with a larger outer diameter; 
     the extending directions of the rotating axis of the synchronizing wheel and the axis of the transmission shaft are different. 
     According to a second aspect of the present disclosure, a retractor for retracting a curtain cord is provided, which comprises a synchronizing wheel group, transmission assemblies located at two sides of the synchronizing wheel group for changing the transmission direction, and winding assemblies connected with the transmission assemblies at the two sides, and the transmission assembly at at least one side of the synchronizing wheel group is connected with at least two winding assemblies; 
     the synchronizing wheel group comprises at least one coil spring and at least two synchronizing wheels, and two ends of each coil spring are fixedly connected to two synchronizing wheels respectively so as to be wound on the two synchronizing wheels in opposite winding directions; 
     each transmission assembly comprises a first bevel gear and a second bevel gear which are engaged with each other, and the first bevel gears of the two transmission assemblies are connected with at least one synchronizing wheel; 
     each winding assembly comprises a fixing seat, and a winding shaft and a transmission shaft which are rotatably provided on the fixing seat, the transmission shaft is connected with a corresponding second bevel gear, the transmission shaft passes though and is coaxial with the winding shaft, the outer wall of the winding shaft tilts outward gradually along the axis of the transmission shaft, and a threading hole for the cord to pass through is opened on a part of the fixing seat corresponding to one end of the winding shaft with a larger outer diameter; the transmission shafts at the same side are coaxial; 
     the extending directions of the rotating axis of the synchronizing wheel and the axis of the transmission shaft are different. 
     According to a third aspect of the present disclosure, a retractor for retracting a curtain cord is provided, which comprises a plurality of synchronizing wheel groups and a plurality of winding assemblies, two sides of each of the synchronizing wheel groups are provided with transmission assemblies for changing the transmission direction, and the transmission assemblies at two sides of each of the synchronizing wheel groups are connected with at least one winding assemblies, respectively; 
     the synchronizing wheel group comprises at least one coil spring and at least two synchronizing wheels, and two ends of each coil spring are fixedly connected to two synchronizing wheels respectively so as to be wound on the two synchronizing wheels in opposite winding directions; 
     each transmission assembly comprises a first bevel gear and a second bevel gear which are engaged with each other, and the first bevel gears of the two transmission assemblies are connected with at least one synchronizing wheel; 
     each winding assembly comprises a fixing seat, and a winding shaft and a transmission shaft which are rotatably provided on the fixing seat, the transmission shaft is connected with a corresponding second bevel gear, the transmission shaft passes though and is coaxial with the winding shaft, the outer wall of the winding shaft tilts outward gradually along the axis of the transmission shaft in a gradually outward manner, and a threading hole for the cord to pass through is opened on a part of the fixing seat corresponding to one end of the winding shaft with a larger outer diameter; 
     the extending directions of the rotating axis of the synchronizing wheel and the axis of the transmission shaft are different. 
     Preferably, the synchronizing wheel and the first bevel gear are uncoaxial, and the first bevel gear and the synchronizing wheel are connected via a cylindrical gear. The size of the retractor in the thickness direction is reduced to cause a compact structure. 
     Preferably, the synchronizing wheel group comprises at least two groups of synchronizing wheels and at least one coil spring, each group of synchronizing wheels comprises at least two synchronizing wheels, all synchronizing wheels in each group of synchronizing wheels are coaxial and are successively arranged along the rotating axis thereof, and one end of the coil spring is connected to one synchronizing wheel in one group of the synchronizing wheels, and the other end is connected to one synchronizing wheel in another group of the synchronizing wheels. The numbers of each group of the synchronizing wheels and the number of the coils may be increased or reduced according to the weight of the curtain body. 
     Preferably, the synchronizing wheel group comprises at least a pair of synchronizing wheels, and one coil spring is wound on each pair of synchronizing wheels. The numbers of the synchronizing wheels and the number of the coils may be increased or reduced according to the weight of the curtain body. 
     More preferably, the synchronizing wheels comprise at least three synchronizing wheels, at least the synchronizing wheel located in the middle is stacked and wounded with two coil springs to drive the synchronizing wheels at two sides thereof respectively. The numbers of each group of the synchronizing wheels and the number of the coils may be increased or reduced according to the weight of the curtain body. 
     Preferably, the outer wall of the synchronizing wheel is provided with a circle of gear teeth, and the synchronizing wheels are engaged with each other via the gear teeth, and two synchronizing wheels at two sides are connected with the first bevel gears at corresponding sides, respectively. 
     Preferably, the rotating axis of the synchronizing wheel and the axis of the transmission shaft are perpendicular to each other. 
     Preferably, the section of the transmission shaft is a polygon, the winding shaft has a hole matched with the polygon, and the transmission shaft passes through the hole. 
     Preferably, the fixing seat is opened with a plurality of guiding holes, the plurality of guiding holes are opened at different positions of the fixing seat, and the threading hole is located between the guiding holes and the outer wall of the winding shaft. 
     Preferably, the extending directions of the rotating axes of the transmission shafts of the respective winding assemblies are the same. 
     More preferably, the retractor further comprises a support for connecting to the curtain body and a mounting base for mounting the synchronizing wheels and the transmission assemblies, the mounting base and the fixing seat are fixedly provided on the support, the support is opened with a position-limit slot, the extending directions of the center line of the position-limit slot and the axis of the transmission shaft are the same, the mounting base and the fixing seat have position-limit protrusions thereon respectively cooperating with the position-limit slot, and each of the position-limit protrusions is stuck within the position-limit slot so as to arrange both the mounting base and the fixing seat along the center line of the position-limit slot. 
     According to a fourth aspect of the present disclosure, a retractable curtain comprises a curtain body and a cord for retracting the curtain body is provided, wherein the retractable curtain further comprises the retractor, and the cord is connected to the other one end of the winding shaft with a smaller outer diameter. 
     The present disclosure has the following advantages over the prior art: the winding shaft is provided at the two sides of the synchronizing wheel groups, the synchronizing wheels are connected with the transmission shaft via bevel gear groups engaged with each other, the winding shaft is driven by the transmission shaft to rotate, and the outer wall of the winding shaft is a slant surface, and the turns wound around the winding shaft earlier are pushed forwards by the turns wound later successively during rolling up to form single-layer winding, which avoids intertwining or tying occurring due to stacking of the cords and results in smooth retracting; the transmission direction is changed by the transmission assemblies, and the retractor has a reasonable arrangement and a compact structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic front view of a curtain after being opened of Embodiment 1 of the present invention; 
         FIG. 2  is a schematic side view of the curtain after being opened of Embodiment 1 of the present invention; 
         FIG. 3  is a schematic front view of the curtain after being rolled up of Embodiment 1 of the present invention; 
         FIG. 4  is a schematic side view of the curtain after being rolled up of Embodiment 1 of the present invention; 
         FIG. 5  is a schematic diagram of a retractor of Embodiment 1 of the present invention; 
         FIG. 6  is a sectional view of the retractor in  FIG. 5 ; 
         FIG. 7  is a schematic exploded diagram of a winding assembly of Embodiment 1 of the present invention; 
         FIGS. 8 and 9  are schematic diagrams of a synchronizing wheel of Embodiment 1 of the present invention from two viewing angles; 
         FIGS. 10-13  are schematic diagrams of another kinds of synchronizing wheels of the present invention; 
         FIG. 14  is a schematic diagram of a retractor of Embodiment 2 of the present invention; 
         FIG. 15  is a schematic diagram of a retractor of Embodiment 3 of the present invention. 
     
    
    
     In the above drawings,
       100 —curtain body;  200 —cord;  300 —support;  301 —position-limit slot;  400 —mounting base;  401 —position-limit protrusion;     1 —synchronizing wheel group;  11 —synchronizing wheel;  12 —coil spring;  13 —gear teeth;     2 —transmission assembly;  21 —cylindrical gear;  22 —first bevel gear;  23 —second bevel gear;     3 —winding assembly;  31 —fixing seat;  310 —threading hole;  311 —guiding hole;  312 —position-limit protrusion;  32 —winding shaft;  33 —transmission shaft.   

     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     In the following, the preferable embodiments of the present invention are explained in detail combining with the accompanying drawings so that the advantages and features of the present invention can be easily understood by the skilled persons in the art. 
     Embodiment 1 
       FIGS. 1-8  show a retractable curtain of the present invention, and in particular a retractable Roman curtain. Referring to  FIGS. 1-8 , the retractable curtain comprises a curtain body  100 , cords  200  for retracting the curtain body  100 , and a retractor for retracting the curtain cords  200 . The cords  200  pass through the curtain body  100 , and the lower ends of the cords  200  are fixedly connected with the lower end of the curtain body  100 , the upper ends thereof are fixedly connected with the retractor. The upper end of the curtain body  100  is connected with a support  300  extending horizontally, and the retractor comprises the support  300 , a mounting base  400  mounted on the support  300 , synchronizing wheel group(s)  1 , transmission assemblies  2  and winding assemblies  3 , the left and right sides of each synchronizing wheel group  1  are respectively connected with one transmission assembly  2  for changing the transmission direction, and each winding assembly  3  is connected with at least one synchronizing wheel group  1  via at least one transmission assembly  2 , respectively. The retractor has the following three configurations: 
     there is one synchronizing wheel group  1 , the transmission assembly  2  at the left side of the synchronizing wheel group  1  is connected with one winding assembly  3 , and the transmission assembly  2  at the right side of the synchronizing wheel group  1  is connected with another winding assembly  3 ; the present embodiment employs Configuration A, referring to  FIGS. 1-6 ; 
     there is one synchronizing wheel group  1 , the transmission assembly  2  at the left side and/or at the right side of the synchronizing wheel group  1  is connected with at least two winding assemblies  3 ; 
     there are several synchronizing wheel groups  1 , and also several winding assemblies  3 , the transmission assemblies  2  at the left and right sides of each synchronizing wheel group  1  are respectively connected with at least one winding assembly  3 , wherein at least one winding assembly  3  is located between two adjacent synchronizing wheel groups  1 . 
     The synchronizing wheel group  1  comprises at least one coil spring  12  and at least two synchronizing wheels  11 , and the synchronizing wheels  11  are rotatably disposed on the mounting base  400 . Two ends of each coil spring  12  are fixedly connected to two synchronizing wheels  11  respectively so as to be wound on the two synchronizing wheels  11  in opposite winding directions. Each of the transmission assemblies  2  comprises a first bevel gear  22  and a second bevel gear  23  which are engaged with each other, and the first bevel gears  22  of two transmission assemblies  2  at two sides of the synchronizing wheel group  1  are connected with at least one synchronizing wheel  11 , wherein the first bevel gear  22  and the second bevel gear  23  are rotatably disposed on the mounting base  400 , and the rotating axes of the first bevel gear  22  and the second bevel gear  23  are perpendicular to each other. Referring to  FIG. 7 , each of the winding assemblies  3  comprises a fixing seat  31  fixedly disposed on the upper end of the curtain body  100 , and a winding shaft  32  and a transmission shaft  33  which are rotatably disposed on the fixing seat  31 , the transmission shaft  33  is connected with a corresponding second bevel gear  23 , and the extending directions of the rotating axes of all the winding assemblies are the same. The transmission shaft  33  passes though and is coaxial with the winding shaft  32 , the outer wall of the winding shaft  32  tilts outward gradually along the axis of the transmission shaft  33 , the upper end of the cord  200  is fixedly connected with the end of the winding shaft  32  with a smaller outer diameter, and one end of the fixing seat  31  corresponding to the winding shaft  32  with a larger outer diameter is opened with a threading hole  310  thereon for the cord  200  to pass through. And in the above Configuration B, if there are multiple winding assemblies  3  at the same side of the synchronizing wheels  11 , the transmission shafts  33  of the multiple winding assemblies  3  may be the same shaft, and may also be multiple shafts connected successively. 
     Referring to  FIGS. 5 and 6 , the rotating axis of the synchronizing wheel  11  and the axis of the transmission shaft  33  are perpendicular to each other, and the axis of the transmission shaft  33  extends in a left-right direction. Specifically in the present embodiment, the rotating axis of the synchronizing wheel  11  and the axis of the transmission shaft  33  are both horizontal, and the rotating axis of the synchronizing wheel  11  extends in a front-rear direction. 
     Referring to  FIG. 7 , the fixing seat  31  is further opened with a plurality of guiding holes  311  located at different positions of the fixing seat  31 , the threading hole  310  is located between the guiding holes  311  and the outer wall of the winding shaft  32 , the upper end of the cord  200  is connected to the end of the winding shaft  32  with a smaller outer diameter after passing through one guiding hole  311  and the threading hole  310  successively, the cord  200  has different tensile force when passing through different guiding hole  311 , such that the tensile force of the cord  200  may be adjusted according to the weight of the curtain body. 
     The section of the transmission shaft  33  is a polygon, and in particular a regular hexagon, the winding shaft  32  has a hole matched with the regular hexagon, and the winding shaft  32  is sleeved on the transmission shaft  33 . And a hole matched with the regular hexagon is also opened on the second bevel gear  23 , one end of the winding shaft  32  is inserted into the hole of the second bevel gear  23 , and the second bevel gear  23 , the transmission shaft  33  and the winding shaft  32  are coaxial. 
     The synchronizing wheels  11  and the coil spring  12  have many kinds of combinations, for example: 
     Referring to  FIGS. 8 and 9 , there are two synchronizing wheels  11 , the outer wall of each of the synchronizing wheels  11  is provided with a circle of gear teeth  13 , the two synchronizing wheels  11  are engaged with each other via the gear teeth  13 , one coil spring  12  is wound on the two synchronizing wheels  11 , and each synchronizing wheel  11  is respectively connected with one first bevel gears  22 . 
     Referring to  FIG. 10 , there are two groups of synchronizing wheels  11 , each group of synchronizing wheels  11  has two synchronizing wheels  11 , the two synchronizing wheels  11  in each group of synchronizing wheels  11  are coaxial and arranged along the axis thereof successively, the outer wall of at least one synchronizing wheel  11  in each group of synchronizing wheels  11  is provided with a circle of gear teeth  13 , the two groups of synchronizing wheels  11  are engaged with each other via the gear teeth  13 , one synchronizing wheel  11  in each of the two groups of synchronizing wheels  11  is connected with the two ends of the first coil spring  12  and the first coil spring  12  is wound on the two synchronizing wheels  11 , the two ends of the second coil spring  12  are respectively fixedly connected with the other synchronizing wheels  11  in the two groups of synchronizing wheels  11  and the second coil spring  12  is wound on the two synchronizing wheels  11 , the first bevel gear  22  at the left side is connected with one synchronizing wheel  11  of the left group of synchronizing wheels  11 , and the first bevel gear  22  at the right side is connected with one synchronizing wheel  11  of the right group of synchronizing wheels  11 ; 
     Referring to  FIG. 11 , there are three synchronizing wheels  11 , the outer walls of the three synchronizing wheels  11  are each provided with a circle of gear teeth  13 , the three synchronizing wheels  11  are engaged with each other via the gear teeth  13  successively, the synchronizing wheel  11  at the leftmost is connected with the first bevel gear  22  at the left side correspondingly, and the synchronizing wheel  11  at the rightmost is connected with the first bevel gear  22  at the right side correspondingly; there are two coil springs  12 , two ends of one of the coil springs  12  are respectively fixedly connected with the synchronizing wheel  11  in the middle and the synchronizing wheel  11  at the left side, two ends of the other one of the coil springs  12  are respectively fixedly connected with the synchronizing wheel  11  in the middle and the synchronizing wheel  11  at the right side, and the two coil springs  12  are stacked and wound on the synchronizing wheel  11  in the middle; 
     Referring to  FIG. 12 , there are three groups of synchronizing wheels  11 , each group of synchronizing wheels  11  has two synchronizing wheels  11 , the two synchronizing wheels  11  in each group of synchronizing wheels  11  are coaxial and arranged along the axis thereof successively, at least one synchronizing wheel  11  in each group of synchronizing wheels  11  is provided with gear teeth  13 , the three groups of synchronizing wheels  11  are engaged with each other via the gear teeth  13 , there are four coil springs  12  wound on the three groups of synchronizing wheels  11 , and wound manner is the same as shown in  FIG. 11 ; 
     Referring to  FIG. 13 , the difference between the manners in it and  FIG. 12  is that there are three coil springs  12  wound on the three groups of synchronizing wheels  11 , wherein no coil spring  12  is wound on two synchronizing wheels  11  respectively belonging to two groups of synchronizing wheels  11 ; 
     By adjusting the number of the synchronizing wheels and the number of the coil springs, the above mentioned several manners may be suitable for curtain bodies with different weights, that is, the weight of the curtain body may be adjusted. 
     The synchronizing wheel  11  and the first bevel gear  22  are uncoaxial, the rotating axis of the synchronizing wheel  11  and the axis of the first bevel gear are parallel to each other, and the synchronizing wheel  11  and the first bevel gear  22  are connected via a cylindrical gear  21 . Specifically, the synchronizing wheel  11  is engaged with the cylindrical gear  21  via gear teeth, and the cylindrical gear  21  is coaxial with the first bevel gear  22 , and specifically in the present embodiment, the cylindrical gear  21  and the first bevel gear  22  are plastic injection molded integrally or cast formed integrally. In the present embodiment, the first bevel gear  22  and the second bevel gear  23  are both 90 degree bevel gears. 
     Referring to  FIGS. 6, 7 and 9 , the upper surface of the support  300  is opened with a position-limit slot  301  extending along the left-right direction of the curtain, the extending directions of the center line of the position-limit slot  301  and the axis of the transmission shaft  33  are the same, the position-limit slot  301  is a rectangular slot, the lower surface of the mounting base  400  has a position-limit protrusion  401  cooperating with the width of the position-limit slot  301 , the lower surface of the fixing seat  31  also has a position-limit protrusion  312  cooperating with the width of the position-limit slot  301 , the mounting base  400  and the fixing seat  31  are fixedly connected to the support  300  via screws, and each of the position-limit protrusions  401  and  312  is just stuck within the position-limit slot  301  so as to arrange both the mounting base  400  and the fixing seat  31  along the center line of the position-limit slot  301 , to avoid the shift of the transmission shaft  33  and the transmission assemblies  2 . 
     The working process of the retractable curtain is as follows: drawing the curtain body  100  downwards, unwinding the cord  200 , driving the winding shaft  32  to rotate, rotating the transmission shaft  33 , changing the transmission direction by 90 degrees via the transmission assembly  2 , driving the synchronizing wheels  11  to rotate, gradually unwinding the coil spring  12  from one of the synchronizing wheels  11  and winding it onto the other synchronizing wheel  11  in an opposite direction, and deformation happens to generate an elastic force, due to that this elastic force is not enough to overcome the gravity of the curtain body  100 , the curtain body  100  is in an opened state, as shown in  FIGS. 1 and 2 . 
     By holding or pushing the curtain body  100  upwards, that is, by applying a small thrust on the curtain body  100 , a resultant force of this thrust and the elastic force of the coil spring  12  is enough to overcome the gravity of the curtain body  100 , the coil spring is reset, the synchronizing wheels  11  rotate in an opposite direction, the winding shaft  21  rotates to roll up the cord  200 , and the curtain body is rolled up with it, as shown in  FIGS. 3 and 4 . 
     Due to that the outer wall of the winding shaft  32  is a slant surface, and the turns wound around the winding shaft  32  earlier are pushed forwards by the turns wound later successively during rolling up to form single-layer winding, which avoids intertwining or tying occurring due to stacking of the cords  200  and results in smooth retracting; meanwhile, by changing the transmission direction via the transmission assemblies  2 , the retractor has a reasonable arrangement and a compact structure. 
     Embodiment 2 
     Referring to  FIG. 14 , the distinction between the present embodiment and Embodiment 1 is only that: the rotating axis of the synchronizing wheels are vertical, that is, extends along a up-down direction. 
     Embodiment 3 
     Referring to  FIG. 15 , the distinction between the present embodiment and Embodiment 1 is only that: the retractor is disposed according to the above Configuration C, that is, there are several synchronizing wheel groups  1 , and also several winding assemblies  3 , the transmission assemblies  2  at the left and right sides of each synchronizing wheel group  1  are respectively connected with at least one winding assembly  3 , wherein one or more winding assembly(s)  3  is located between two adjacent synchronizing wheel groups  1 . 
     Specifically in the present embodiment, one winding assembly  3  is respectively disposed at the left and right sides of each synchronizing wheel group  1 , wherein the two ends of the transmission shaft  33  of the winding assembly  3  located between the opposite transmission assemblies  2  of two synchronizing wheel groups  1  are respectively connected with the second bevel gears  23  of these two transmission assemblies  2 . 
     The embodiments described above are only for illustrating the technical concepts and features of the present invention, are preferred embodiments, and are intended to make those skilled in the art being able to understand the present invention and thereby implement it, and should not be concluded to limit the protective scope of this invention. Any equivalent variations or modifications according to the present invention should be covered by the protective scope of the present invention.