Abstract:
There is provided a blind operating device for transmitting a rotation in both directions from an operation portion to a driving axis of the blind capable of making a diameter of a clutch spring smaller, and then capable of reducing operation load without breaking the clutch spring. The blind operating device includes an input shaft into which a rotation from a pulley is inputted, and a rotation axis that is provided coaxially with the input axis and is capable of transmitting the rotation to the driving axis. A clutch spring is wound around a fixed spring winding axis of a case and a rotation spring winding axis of the rotation axis Linking and de-linking of the rotation axis and the case is made possible utilizing tightening and loosening of the clutch spring and one end of the clutch spring is linked to the rotation axis. When the rotation in one direction is inputted to the input axis, a part of the clutch spring wound around the fixed spring winding axis loosens starting from a rotation spring winding axis side, whereby the rotation axis is allowed to rotate with the input axis.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a blind operating device that is used for a blind, in which a rotation in both directions is transmitted from an input axis to a rotation axis while a rotation from the rotation axis is blocked. 
       BACKGROUND ART 
       [0002]    Conventionally, as a blind operating device of this type, one described in Japanese Utility Model Application Publication (JP-Y) No. 4-22713 is known. In the blind operating device described in JP-Y No. 4-22713, a rotation axis is divided into a driven axis and a driving axis for rotating the driven axis, a driving axis body provided with a circular arch protrusion is fixed to an end portion of the driving axis and the driving axis body is rotatably received in an axis hole of a fixed brake drum. A coil spring is fitted on an outer peripheral surface of the brake drum while both end portions of the coil spring extend in radial directions. A driven axis body provided with a split sleeve is fixed to the driven axis, the circular arch protrusion of the driving axis is inserted into a slit of the split sleeve of the driven axis body so as to leave gaps on both sides of the circular arch protrusion, and the both end portions of the coil spring are inserted in the gaps. 
         [0003]    When the driving axis is rotated, the circular arc protrusion presses either one of the both end portions of the coil spring in a direction causing the coil spring to expand, and thus, the coil spring rotates together with the driving axis so as to rotate the split sleeve, whereby a rotation is transmitted to the driven axis. On the other hand, when slat are affected by wind or the like and ready to rotate the driven axis, the slit sleeve presses one of the both end portions of the coil spring in a direction causing the coil spring to contract, and thus, the inner peripheral surface of the coil spring is tightly contacted to the outer periphery surface of the brake drum, whereby a rotation of the split sleeve and then of the driven axis can be blocked. 
       SUMMARY OF INVENTION 
     Technical Problem 
       [0004]    However, the operating device described in the Japanese Utility Model Application Publication No. 4-22713 is configured in such a manner that when the split sleeve presses one of both end portions of the coil spring, the coil spring contracts and tightly contacts the fixed brake drum. Therefore, there is a problem that the operating device has a risk that the end portion of the coil spring may be broken if the driven axis rotates to cause the split sleeve to strongly push the end portion of the coil spring with even for a moment or if weight of the blind is large. 
         [0005]    It is considered that such problem of the coil spring breakage can be avoided by making a diameter of the coil wire larger, however, this requires a force for expanding a coil spring having a large diameter coil wire to rotate the driving axis in order to operate the blind, resulting in a problem of increasing operation load. 
         [0006]    The present invention is made in view of the problem and the object thereof is to provide a blind operating device capable of making a diameter of a clutch spring small, and then capable of reducing operation load without breaking the clutch spring. 
       Solution to Problem 
       [0007]    To accomplish the above object, a blind operating device for respectively transmitting a rotation in both directions from an operation portion to a driving axis of the blind, according to a first aspect of the present invention includes: 
         [0008]    an input axis into which the rotation from the operation portion is inputted; 
         [0009]    a rotation axis that is provided coaxially with the input axis and is capable of transmitting the rotation to the driving axis; and 
         [0010]    a fixed body, wherein 
         [0011]    the rotation axis includes a rotation spring winding axis and the fixed body includes a fixed spring winding axis which is aligned with the rotation spring winding axis, 
         [0012]    a clutch spring is wound around the fixed spring winding axis and the rotation spring winding axis for allowing switching of linking and de-linking of the rotation axis and the fixed body by utilizing tightening and loosening of the clutch spring, 
         [0013]    one end of the clutch spring is linked to the rotation axis, 
         [0014]    when the rotation in one direction is inputted to the input axis, the input axis presses the rotation axis and presses the one end of the clutch spring so that the clutch spring loosens whereby the rotation axis is allowed to rotate with the input axis, and 
         [0015]    when the rotation in the other direction is inputted to the input axis, the input axis presses the other end of the clutch spring so that the clutch spring loosens, whereby the rotation axis is allowed to rotate with the input axis. 
         [0016]    A blind operating device for respectively transmitting a rotation in both directions from an operation portion to a driving axis of the blind, according to a second aspect of the present invention includes: 
         [0017]    an input axis into which the rotation from the operation portion is inputted; 
         [0018]    a rotation axis that is provided coaxially with the input axis and is capable of transmitting the rotation to the driving axis; and 
         [0019]    a fixed body, wherein 
         [0020]    the rotation axis includes a rotation spring winding axis and the fixed body includes a fixed spring winding axis which is aligned with the rotation spring winding axis, 
         [0021]    a clutch spring is wound around the fixed spring winding axis and the rotation spring winding axis for allowing switching of linking and de-linking of the rotation axis and the fixed body by utilizing tightening and loosening of the clutch spring, 
         [0022]    when the rotation in one direction is inputted to the input axis, a part of the clutch spring wound around the fixed spring winding axis loosens starting from a rotation spring winding axis side, whereby the rotation axis is allowed to rotate with the input axis, and 
         [0023]    when the rotation in the other direction is inputted to the input axis, a part of the clutch spring wound around the fixed spring winding axis loosens starting from an opposite side to the rotation spring winding axis, whereby the rotation axis is allowed to rotate with the input axis. In this case, it is preferable that when the rotation in the one direction is inputted to the input axis, the rotation is firstly transmitted to a part of the clutch spring wound around the rotation spring winding axis. 
         [0024]    It is preferable that the blind operating device further includes a clutch spring receiver which is provided rotatably on a peripheral surface of the fixed spring winding axis and to which the other end of the clutch axis is linked, wherein when the rotation in the other direction is inputted to the input axis, the input axis presses the clutch spring receiver so that the clutch spring loosens. Since the input axis does not directly presses the other end of the clutch spring, stress concentration on the clutch spring can be avoided. 
         [0025]    A blind operating device for transmitting a rotation in both directions from an operation portion to a driving axis of the blind, according to a third aspect of the present invention includes: an input axis into which the rotation from the operation portion is inputted; 
         [0026]    a rotation axis that is provided coaxially with the input axis and is capable of transmitting the rotation to the driving axis; and 
         [0027]    a fixed body, wherein 
         [0028]    the rotation axis includes a rotation spring winding axis and the fixed body includes a fixed spring winding axis which is aligned with the rotation spring winding axis, 
         [0029]    a clutch spring is wound around the fixed spring winding axis and the rotation spring winding axis for allowing switching of linking and de-linking of the rotation axis and the fixed body by utilizing tightening and loosening of the clutch spring, and 
         [0030]    when a rotation is transmitted from the driving axis to the rotation axis, a part of the clutch spring wound around the fixed spring winding axis tightens the fixed spring winding axis starting from the rotation spring winding axis side, whereby a rotation of the rotation axis can be blocked. 
         [0031]    The clutch spring is wound around over the fixed spring winding axis and the rotation spring winding axis. Accordingly, when a force, particularly a force for the clutch spring to tighten, is inputted to the clutch spring, the clutch spring can tighten starting from a middle portion in a portion wound around the fixed spring winding axis, whereby stress concentration on one end of the clutch spring can be avoided. In this manner, the blind operating device can be configured unlikely to cause a breakage of the clutch spring. Therefore, a diameter of the clutch spring wire can be made small. And making the clutch spring wire have a small diameter, operation load can be reduced. 
         [0032]    In addition, when the clutch spring loosens, the clutch spring can loosen starting from a middle portion in a portion wound around the fixed spring winding axis. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0033]      FIG. 1  is a perspective view of a blind operating device of a first embodiment of the present invention. 
           [0034]      FIG. 2  is an exploded perspective view of a substantial part of the blind operating device of  FIG. 1 . 
           [0035]      FIG. 3  is a partial sectional view of the blind operating device of  FIG. 1 . 
           [0036]      FIG. 4  is a plan view of the blind operating device of  FIG. 1  without illustrating a part thereof. 
           [0037]      FIG. 5A  is a plan view of the blind operating device upon lifting a shielding member without illustrating a part of the blind operating device, in which a pressing member is shown with a broken line to help illustration. 
           [0038]      FIG. 5B  is a plan view of the blind operating device upon lowering the shielding member without illustrating a part of the blind operating device, in which the pressing member is shown with a broken line to help illustration. 
           [0039]      FIG. 5C  is a plan view of the blind operating device when the shielding member is stopped without illustrating a part of the blind operating device, in which the pressing member is shown with a broken line to help illustration. 
           [0040]      FIG. 6A  is a perspective view of the blind operating device upon lifting the shielding member without illustrating a part of the blind operating device, in which an input axis is not shown to help illustration. 
           [0041]      FIG. 6B  is a perspective view of the blind operating device upon lowering the shielding member without illustrating a part of the blind operating device, in which the input axis is not shown to help illustration. 
           [0042]      FIG. 7  is an elevation view of a blind to which the blind operating device of  FIG. 1  is adopted. 
       
    
    
     REFERENCE SIGNS LIST 
       [0000]    
       
           10 : Blind operating device 
           14 : Second case (fixed body) 
           14   b : Fixed spring winding axis 
           20 : Pulley (Operation portion) 
           22 : Operation Cord (Operation portion) 
           30 : Input axis 
           32 : Rotation axis 
           32 C: Rotation spring winding axis 
           34 : Clutch spring 
           34   a : One end of clutch spring 
           34   b : The other end of clutch spring 
           44 : Driving axis 
       
     
       DESCRIPTION OF EMBODIMENTS 
       [0055]    An embodiment of the present invention is described referring to the drawings.  FIG. 1  is a perspective view of a blind operating device of an embodiment of the present invention,  FIG. 2  is an exploded perspective view of a substantial part thereof,  FIG. 3  is a partial sectional view thereof, and  FIG. 4  is a plan view thereof without illustrating a part thereof. 
         [0056]    The operating device can be applied to arbitrary kinds of blind. In this example, the operating device is applied to a Venetian blind as shown in  FIG. 7 . However, its applicable scope is not limited thereto and the operating device can be applied to arbitrary blind, in which arbitral shielding member is lifted/lowered or is opened/closed, such as a pleated screen, a roman shade, a roll screen. 
         [0057]    In an operating device  10  shown in the figures, a fixed outer housing is configured by assembling together a first case  12  on input side, a second case (fixed body)  14  on output side, and a cover  16  for closing an open end of the second case  14 . The operating device  10  is integrally assembled together with an operation portion that is manually operated. More specifically, the operation portion includes a pulley  20  and an operation cord  22  wound around the pulley  20 . In addition, the operating device  10  incorporates a planetary gear mechanism  24  in the second case  14  as a reduction gear provided on output side; however the operating device  10  does not necessarily incorporate such a planetary gear mechanism and the planetary gear mechanism  24  can be eliminated. 
         [0058]    The operating device  10  further includes an input axis  30 , a rotation axis  32  that is provided coaxially with and in parallel to the input axis  30 , a clutch spring  34 , and a spring receiver  36 . These components are described hereinafter. 
         [0059]    The input axis  30  is received in the first case  12  and includes a central axis portion  30   a  for supporting the pulley  20  without allowing a relative rotation between them, a flange portion  30   b  having a larger diameter than that of the central axis portion  30   a , and a pressing member  30   c  extending from an outer peripheral portion of a part of the flange portion  30   b  toward the output side in an axis direction. Thus, the input axis  30  is configured in such a manner that a rotation of the pulley  20  is transmitted to the input axis  30 . 
         [0060]    The rotation axis  32  includes a smaller diameter portion  32   a  inserted in the central axis portion  30   a  of the input axis  30 , a spring receiving portion  32   b  having a larger diameter than that of the smaller diameter portion  32   a , a rotation spring winding axis  32   c  which is provided on the output side of the spring receiving portion  32   b  and around which a part of the clutch spring  34  is wound, and an output axis portion  32   d  that has a smaller diameter than that of the rotation spring winding axis  32   c  and is received in the second case  14 . 
         [0061]    A cutout portion  32   f  is formed on outer peripheral portion of the spring receiving portion  32   b  and the pressing member  30   c  of the input axis  30  passes through the cutout portion  32   f . Then, pressing portions  32   h ,  32   h , to which the pressing member  30   a  can abut, are formed on both sides of the cutout portion  32   f  of the spring receiving portion  32   b . In addition, a locking groove  32   g  for locking one end  34   a  of the clutch spring  34  is formed in a central part of the cutout portion  32   f  of the spring receiving portion  32   b.    
         [0062]    A sun gear  32   e  of the planetary gear mechanism  24  is formed on an output side tip end of the output axis portion  32   d . As shown in  FIG. 3 , the planetary gear mechanism  24  includes the sun gear  32   e , a planetary gear  40  meshing with the sun gear  32   e , internal teeth  14   a  formed on internal peripheral surface of the second case  14 , and an output axis  42  for supporting the planetary gear  40 . The output axis  42  is coupled with a driving axis  44  that moves in conjunction with the movement of the shielding member. That is to say, the rotation axis  32  is linked with the output axis  42  and the driving axis  44  via the planetary gear mechanism  24 . 
         [0063]    A cylindrical fixed spring winding axis  14   b  is formed in the second case  14 . The fixed spring winding axis  14   b  having the same outer diameter with the rotation spring winding axis  32   c  is provided in parallel to the rotation spring winding axis  32   c . The clutch spring  34  is wound around the rotation spring winding axis  32   c  and the fixed spring winding axis  14   b . In a boundary part of the rotation spring winding axis  32   c  and the fixed spring winding axis  14   b , a rib and a cutout portion formed thereon, which are disclosed in Japanese Patent Application Laid-Open (JP-A) No. 2002-115729, are preferably formed on at least one of the rotation spring winding axis  32   c  and the fixed spring winding axis  14   b , whereby the clutch spring  34  can be prevented from falling into a boundary portion and biting into the axes. 
         [0064]    The spring receiver  36  is rotatably fitted on the outer peripheral surface of the fixed spring winding axis  14   b  of the second case  14  on the opposite side of the rotation spring winding axis  32   c . A cutout  36   a  is formed on the spring receiver  36  and the pressing member  30   c  of the input axis  30  passes through the cutout portion  36   a . Then, pressing portions  36   c ,  36   c , to which the pressing member  30   c  can abut, are formed on both sides of the cutout portion  36   a  of the spring receiver  36 . In addition, a plurality of locking grooves  36   b  are formed around the spring receiver  36  and one of the locking grooves  36   b  is selected to lock the other end  34   b  of the clutch spring  34 . 
         [0065]    The positions in the circumferential direction of the cutout portion  32   f  of the spring receiving portion  32   b  and the cutout portion  36   a  of the spring receiver  36  do not exactly match and are shifted from each other as shown in  FIG. 4 . 
         [0066]    The operation of the blind operating device  10  configured as described above is described hereinafter. 
         [0067]    In order to lift the shielding member of the blind, the operation cord  22  is operated and a rotation in a lifting direction is inputted to the input axis  30  via the pulley  20 . Accordingly, as shown in  FIGS. 5A and 6A , pressing member  30   c  (shown with a broken line in  FIG. 5 ) of the input axis  30  moves in the cutout portion  32   f  of the spring receiving portion  32   b  of the rotation axis  32  and in the cutout portion  36   a  of the spring receiver  36  so as to firstly abut the pressing portion  32   h  of the cutout portion  32   f  of the rotation axis  32  thereby pressing the rotation axis  32 . When the rotation axis  32  rotates in the lifting direction through this operation, the one end  34   a  of the clutch spring  34  is pressed so that the clutch spring  34  loosens and is allowed to rotate. Then, the rotation axis  32  is allowed to rotate with the clutch spring  34  and the driving axis  44  rotates in the lifting direction, whereby the shielding member is lifted. 
         [0068]    On the other hand, in order to lower the shielding member, the operation cord  22  is operated and a rotation in a lowering direction is inputted to the input axis  30  via the pulley  20 . Accordingly, as shown in  FIGS. 5B and 6B , pressing member  30   c  of the input axis  30  moves in the cutout portion  32   f  of the spring receiving portion  32   b  of the rotation axis  32  and in the cutout portion  36   a  of the spring receiver  36  so as to firstly abut the pressing portion  36   c  of the cutout portion  36   a  of the spring receiver  36 , thereby pressing the pressing portion  36   c . When the spring receiver  36  rotates in the lowering direction through this operation, the other end  34   b  of the clutch spring  34  is pressed so that the clutch spring  34  loosens and is allowed to rotate. Then, the rotation axis  32  is allowed to rotate with the clutch spring  34  and then the driving axis  44  rotates in the lowering direction, whereby the shielding member is lowered. 
         [0069]    Next, in a state where the operation cord  22  is not operated, the rotation in the lowering direction due to own weight of the shielding member is transmitted from the driving axis  44 . This rotation is transmitted to the rotation axis  32  to make the spring receiving portion  32   b  ready to rotate in the lowering direction, and thus the one end  34   a  of the clutch spring  34  is pressed in a direction opposite to that shown in  FIG. 5A . However, because the clutch spring  34  tightens the fixed spring winding axis  14   b , which is fixed, the clutch spring  34  is not allowed to rotate, and thus a rotation of the rotation axis  32  can be blocked. Therefore, the shielding member can remain in a stopped state ( FIG. 5C ). 
         [0070]    The operations of the clutch spring  34  as described above, more specifically, loosening of the clutch spring  34  upon lifting the shielding member and tightening of the clutch spring  34  when the shielding member is in the stopped state do not occur in vicinity of the one end  34   a  of the conventional clutch spring  34  but occur from the peripheral surface of the fixed spring winding axis  14   b  in the vicinity of the boundary part of the rotation spring winding axis  32   c  and the fixed spring winding axis  14   b , which is on middle position away from the one end  34   a  as indicated by R 1  and T in the  FIGS. 5 and 6 . The reason is described below. The force transmitted to the clutch spring  34  is inputted from the one end  34   a  and transmitted from a part of the clutch spring  34  wound around the rotation spring winding axis  32   c  to a part of the clutch spring  34  wound around the fixed spring winding axis  14   b . At this time, the rotation spring winding axis  32   c  is ready to move with the part of the clutch spring  34  wound around the rotation spring winding axis  32   c , and thus the rotation spring winding axis  32   c  and the part of the clutch spring  34  wound around the rotation spring winding axis  32   c  are integrated so as to generate no force therebetween. Instead, loosening and tightening occur on the fixed spring winding axis  14   b , which is fixed, starting from the rotation spring winding axis  32   c  side of the fixed spring winding axis  14   b . As described above, the vicinity of the one end  34   a  of the clutch spring  34  operates integrally with the rotation spring winding axis  32   c . Therefore, stress concentration on the one end  34   a  of the clutch spring  34  upon tightening, which is one reason of breakage of the conventional clutch spring, can be avoided. Consequently, a configuration, in which the clutch spring  34  is unlikely to be broken, can be realized, and thus, it is possible to make the clutch spring  34  having a smaller diameter wire and accordingly possible to decrease operation load that is required when operating the clutch spring  34 . 
         [0071]    In addition, the loosening of the clutch spring  34  occurs starting from the vicinity R 2  of the other end  34   b  of the clutch spring  34  upon lowering the shielding member. That is to say, the loosening occurs on the fixed spring winding axis  14   b , which is fixed, starting from an opposite side to the rotation spring winding axis  32   c  side of the fixed spring winding axis  14   b . At this time, the input axis  30  does not directly press the other end  34   b  but directly presses the spring receiver  36 , whereby stress concentration of the clutch spring  34  can be prevented. However, it should be noted that a force for the clutch spring  34  to be tightened is not inputted to the other end  34   b  of the clutch spring  34  on the fixed spring winding axis  14   b  and only a force for the clutch spring  34  to be loosened is inputted so that stress concentration in the vicinity of the other end  34   b  is not large enough to break the clutch spring  34 . Therefore, spring receiver  36  may be arbitrarily eliminated and the other end  34   b  of the clutch spring  34  may be bent on the fixed spring winding axis  14   b  so that the input axis  30  may directly press the other end  34   b.