Patent Publication Number: US-8522854-B2

Title: Operating device for rotating a winding roller of a window blind

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a window blind, more particularly to an operating device for rotating a winding roller of a window blind to wind up a window covering. 
     2. Description of the Related Art 
     A conventional window blind generally includes a winding roller, a window covering extending downwardly from the roller, and a ring chain (or cord) disposed on an end portion of the roller and extending downwardly. A user can pull the ring chain to rotate the winding roller such that the window covering can be raised or lowered. However, such ring chain poses choking or strangulation hazards to young children. Another window blind such as those disclosed in EP Application No. 10157918.3 and U.S. patent application Ser. No. 12/696,173, is provided with an operating rod to replace the ring chain. The operating rod extends vertically and has an upper end coupled with a winding roller by a rotation transmitting mechanism such that vertical rotation of the operating rod results in horizontal rotation of the winding roller, and a lower end coupled with a hinged handle which can be manipulated to rotate the operating rod. Since the hinged handle is disposed remote from the winding roller, it is hard for a force applied to the hinged handle to be transmitted to the rotation transmitting mechanism, thereby rendering operation of the operating rod laborious and inefficient. 
     In a co-pending U.S. patent application Ser. No. 13/036,066, entitled “Operating Device for Rotating a Winding Roller of a Window Blind,” filed by the applicant, there is disclosed an upright rotating shaft which is operated to rotate by means of engagement between a sleeve shell and one of upper and lower coupling members. 
     It is desirable to improve the aforesaid operating device to simplify the structure thereof. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide an operating device which is operable easily and smoothly and which has a simple construction to facilitate manufacture. 
     According to this invention, the operating device includes a rotating shaft having a shaft end which is adapted to be coupled with a winding roller such that a rotation of the rotating shaft about an upright axis results in horizontal rotation of the winding roller for winding up or winding down a window covering, and a shaft body which extends from the shaft end along the upright axis and which has a thread segment formed on an outer shaft surface thereof. A sleeve shell is disposed to surround and permit the shaft body to be rotatable relative thereto so as to cooperatively define an accommodation space. The sleeve shell has a surrounding wall that extends in a direction of upright axis to terminate at first and second peripheral ends, and that includes first and second surrounding segments respectively proximate to the first and second peripheral ends. A carrier has an annular seat wall that surrounds the thread segment, and an actuated annular wall that surrounds the annular seat wall and that extends in the direction of upright axis to terminate at first and second actuated ends. The carrier is disposed in the accommodation space and is movable along the upright axis between a pressed position, where the first peripheral end is in pressing engagement with the first actuated end, and a non-pressed position, where the second actuated end rests on the second peripheral end. A force transmitting member is carried on the annular seat wall and is engaged with the thread segment. A rotation preventing unit is disposed between the first surrounding segment and the actuated annular wall such that, when the carrier is in the pressed position, an axially manual force applied to the surrounding wall is transmitted to move the actuated annular wall along the upright axis so as rotate the rotating shaft about the upright axis through engagement of the force transmitting member with the thread segment, thereby winding up the window covering. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment of the invention, with reference to the accompanying drawings, in which: 
         FIG. 1  is a fragmentary perspective view of the preferred embodiment of an operating device according to this invention incorporated in a window blind; 
         FIG. 2  is a fragmentary exploded perspective view of the preferred embodiment; 
         FIG. 3  is a fragmentary sectional view of the preferred embodiment when an actuating unit is in a non-pressed position; 
         FIG. 4  is a fragmentary sectional view of the preferred embodiment when the actuating unit is in a pressed position; 
         FIG. 5  is a cross-sectional view taken along line  5 - 5  of  FIG. 4 ; and 
         FIG. 6  is a cross-sectional view taken along line  6 - 6  of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1 to 3 , the preferred embodiment of an operating device  10  according to the present invention is shown to be mounted on a window blind  1  for rotating a winding roller  14  of the window blind  1 . The window blind  1  includes a horizontal extending headrail  11 , two mounts  12  (only one is shown in  FIG. 1 ) spacedly disposed on the headrail  11 , two rotary sleeves  13  (only one is shown in  FIG. 1 ) rotatably mounted between the mounts  12 , the winding roller  14  operatively coupled with the rotary sleeves  13  to be rotatable relative to the headrail  11  about a horizontal axis for winding up or winding down a window covering  15 , and a coupling mechanism  16  operatively coupled with one of the rotary sleeves  13 , and having a connecting end  161 . The operating device  10  of this invention is connected to the connecting end  161 , and is shown to comprise a rotating shaft  2 , a driving unit  3 , an actuating unit  4 , and a rotation preventing unit. 
     The rotating shaft  2  has a shaft end  22  which is adapted to be connected to the connecting end  161  of the coupling mechanism  16  such that a rotation of the rotating shaft  2  about an upright axis transverse to the horizontal axis results in a horizontal rotation of the winding roller  14 , and a shaft body  24  which extends from the shaft end  22  along the upright axis and which has a thread segment  21  formed on an outer shaft surface thereof. 
     The driving unit  3  includes first and second shell halves  31 ,  33  which are engaged with each other by a spline structure, such as a plurality of axially extending holes and protrusions  315 ,  335  so as to cooperatively form a sleeve shell. The sleeve shell is disposed to surround and permit the shaft body  24  to be rotatable relative thereto so as to cooperatively define an accommodation space  32 . The first and second shell halves  31 ,  33  respectively have first and second surrounding segments  312 ,  332  which cooperatively form a surrounding wall and which extend in a direction  20  of the upright axis to terminate at first and second peripheral ends  311 ,  331 , respectively. The first and second shell halves  31 ,  33  respectively define first and second penetrating holes  314 ,  334  formed at the first and second peripheral ends  311 ,  331  for passage of the shaft body  24 . 
     The actuating unit  4  is movably disposed in the accommodation space  32 , and includes a carrier  41  and a plurality of force transmitting members  42 . 
     The carrier  41  includes a bearing seat member  410  and an actuated cap member  411 . The bearing seat member  410  has an annular seat wall  416  that surrounds the thread segment  21  and that has a plurality of bearing surfaces  419  angularly displaced from each other and facing upward to respectively form a plurality of recesses  418 . The actuated cap member  411  has an actuated annular wall  412  which surrounds the annular seat wall  416  and which extends in the direction  20  of upright axis to terminate at first and second actuated ends  4121 ,  4122 , and an inner flange  413  which extends inwardly and radially from the first actuated end  4121 . The actuated annular wall  412  of the actuated cap member  411  is engaged with the annular seat wall  416  of the bearing seat member  410  by a spline structure, such as a plurality of recesses and protrusions  415 ,  417 . The carrier  41  is movable along the upright axis between a pressed position ( FIG. 4 ), where the first peripheral end  311  is in pressing engagement with the first actuated end  4121  and the inner flange  413 , and a non-pressed position ( FIG. 3 ) where the second actuated end  4122  rests on the second peripheral end  331 . 
     The force transmitting members  42  are in the form of balls  42  which are received in the recesses  418 , respectively, to be rotatably engaged on the bearing surfaces  419 , respectively, which are held by the inner flange  413 , and which are in rollable contact with the thread segment  21 . 
     Alternatively, the force transmitting members  42  may integrally formed with the carrier  41 . 
     The rotation preventing unit includes a plurality of blocking bars  313  which project radially and inwardly from the first surrounding segment  312  of the first shell half  31  and which are angularly displaced from each other, and a plurality of blocked protrusions  414  which are configured to be engageable and blocked by the blocking bars  313  in a circumferential direction about the upright axis when the carrier  41  is in the pressed position, as shown in  FIGS. 4 and 5 . 
     Referring to  FIGS. 3 to 5 , when an axially manual force is applied to the driving unit  3 , such as a downwardly pulling force, the sleeve shell is moved downwardly relative to the actuating unit  3  to the pressed position illustrated in  FIG. 4 . The downwardly pulling force is continued to apply to the driving unit  3  such that the actuating unit  4  is moved downward with the driving unit  3 . In the meantime, by virtue of the rotation preventing unit which can prevent rotation of the carrier  41  relative to the sleeve shell, the downwardly pulling farce is transmitted to move the actuating unit  4  along the upright axis so as to spirally rotate the rotating shaft  2  in a clockwise direction about the upright axis through the engagement of the force transmitting members  42  with the thread segment  21 , thereby winding up the window covering  15 . 
     Referring to  FIGS. 3 ,  4  and  6 , once the driving unit  3  and the actuating unit  4  are lowered to reach a relatively lower position while the winding-up action of the window covering  15  has yet to be completed, an opposite axially manual force is applied to the driving unit  3 , such as an upwardly lifting force, the sleeve shell is raised relative to the actuating unit  4  to the non-pressed position illustrated in  FIG. 3 . The upwardly lifting force is continued to apply to the driving unit  3  to move the actuating unit  4  upwardly with the driving unit  3  while leaving the rotating shaft  2  nonrotated because of the rollable contact of the force transmitting members  42  with the thread segment  21 . When the driving unit  3  and the actuating unit  4  are raised to reach a relatively higher position, the downwardly pulling force is further applied to the driving unit  3  so as to move the actuating unit  4  to the pressed position for further rotating the rotating shaft  2 . 
     When it is desired to wind down the window covering  15 , the rotating shaft  2  is rotated manually in a counterclockwise direction about the upright axis. By the weight of the window covering  15 , the user can rotate the rotating shaft  2  in the counterclockwise direction effortlessly. 
     Accordingly, the operating device of the embodiment has a simple construction, and is operable conveniently and effortlessly, particularly being used for winding a relatively long window covering. 
     While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretations and equivalent arrangements.