Abstract:
A lift Venetian blind lift using a lift lock to lock/unlock the lift cord, a receiving tube to receive the end of the lift cord and to keep the lift cord from sight and reach of children, and a swinging device to couple the receiving tube to the lift lock for enabling the receiving tube to be turned forwards/backwards and leftwards/rightwards relative to the headrail in two perpendicularly intersected directions to control locking/unlocking of the lift lock conveniently.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to Venetian blinds and, more specifically, to such a Venetian blind that keeps the lift cords from sight and reach of children.  
           [0003]    2. Description of the Related Art  
           [0004]    A regular Venetian blind is generally comprised of a top rail, a bottom rail, a plurality of slats arranged in parallel between the top rail and the bottom rail, a lift control mechanism for controlling lifting and positioning of the bottom rail to adjust the extending area of the Venetian blind, and a tilting control mechanism for controlling the tiling angle of the slats to regulate the light. The lift control mechanism comprises a lift cord suspended from the top rail at one side for operation by hand to control the elevation of the bottom rail. Because the lift cord is exposed to the outside, it destroys the sense of beauty of the Venetian blind. Further, because a child can easily reach the exposed lift cord, an accident may occur when a child pulling the lift cord for fun.  
           [0005]    In order to eliminate the aforesaid problems, Venetian blinds with concealed lift cords are developed. There is known a commercially available Venetian blind with concealed lift cords, which comprises a receiving tube suspended from the headrail to hold the operating ends of the lift cords. The receiving tube keeps the lift cords from sight and reach of children. However, because the receiving tube is directly fastened to the headrail, it can only be tilted within a very limited angle. Because of limited tilting angle of the receiving tube, it is difficult to manipulate the lift cords as desired. Furthermore, the receiving tube cannot be adjusted to different elevations to fit different users. In general, this structure of Venetian blind is not orthopedically engineered for convenient use.  
         SUMMARY OF THE INVENTION  
         [0006]    The present invention has been accomplished to provide a Venetian blind, which eliminates the aforesaid drawbacks. It is the main object of the present invention to provide a Venetian blind having lift cords kept from sight, which is orthopedically engineered for convenient use.  
           [0007]    It is another object of the present invention to provide a Venetian blind having lift cords kept from sight, which is simple and inexpensive to manufacture.  
           [0008]    To achieve these objects of the present invention, the Venetian blind comprises a headrail extended in transverse direction, the headrail having a first end; a bottom rail extended in transverse direction and spaced below the headrail; a plurality of slats arranged in parallel between the headrail and the bottom rail; a receiving tube vertically suspended from the first end of the headrail; at least one lift cord, the at least one lift cord each having a first end fixedly fastened to the bottom rail and a second end upwardly extended through the slats into the inside of the headrail and then transversely extended to the first end of the headrail and then extended vertically downwards from the first end of the headrail into the inside of the receiving tube; a lift lock mounted inside the first end of the headrail and controlled by the receiving tube to lock/unlock the lift cords; and a swinging device coupled between the lift lock and the receiving tube for enabling the receiving tube to be turned back and forth in a predetermined direction relative to the headrail, the swinging device comprising a top hanging portion coupled to the headrail, and a bottom track portion pivoted to the receiving tube for enabling the receiving tube to be moved along the bottom track portion. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    [0009]FIG. 1 is a schematic drawing of a first preferred embodiment of the present invention, showing the Venetian blind extended out.  
         [0010]    [0010]FIG. 2 is a sectional view in an enlarged scale of a part of FIG. 1, showing the lift lock in the locking position.  
         [0011]    [0011]FIG. 3 is similar to FIG. 2 but showing the receiving tube turned leftwards relative to the headrail, the lift cords disengaged from the lift lock.  
         [0012]    [0012]FIG. 4 is a sectional view in an enlarged scale of a part of the first embodiment of the present invention, showing the receiving tube turned forwards relative to the headrail.  
         [0013]    [0013]FIG. 5 is a sectional view of a part of a second preferred embodiment of the present invention, showing the lift lock in the locking position.  
         [0014]    [0014]FIG. 6 is similar to FIG. 5 but showing the receiving tube turned leftwards, the lift cords disengaged from the lift lock.  
         [0015]    [0015]FIG. 7 is similar to FIG. 5 but showing the receiving tube turned forwards relative to the headrail. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0016]    Referring to FIGS. 1 and 2, a Venetian blind  10  is shown comprising a headrail  11  fixedly transversely fastened to the top side of the window, the headrail  11  having a first end  12  (the right end) and an opening  13  in the bottom side of the first end  12 , a bottom rail  14  extended in transverse direction and spaced below the headrail  11 , a number of slats  15  arranged in parallel between the headrail  11  and the bottom rail  14 , a lift lock  20  installed in the first end  12  of the headrail  11  above the opening  13 , a hanger  30 , a receiving tube  40 , and two lift cords  50 . The lift lock  20  is comprised of a transverse guide rod  21 , an oblique rack  23 , a movable ratchet wheel  22  meshed with the oblique rack  23 , and a stop rod  24  extended over the opening  13  below the oblique rack  23  and adapted to limit downward movement of the movable ratchet wheel  22 . When the movable ratchet wheel  22  moved upwards, the movable ratchet wheel  22  is engaged into the periphery of the lift cords  50  against the guide rod  21 , and therefore the lift cords  50  are locked. On the contrary, when the movable ratchet wheel  22  moved downwards, the lift cords  50  are unlocked.  
         [0017]    The hanger  30  is made of a rigid wire rod, having a hanging portion  31  and a track portion  32 . The two distal ends of the wire rod are bent into a respective hooked portion  311 , forming the hanging portion  31 . The hanging portion  31  is hung on the stop rod  24  of the lift lock  20 . The track portion  32  is comprised of straight rail  321  formed of a middle part of the wire rod between the hooked portions  311  of the hanging portion  31 .  
         [0018]    The receiving tube  40  is a straight round tube having a top open end and a bottom close end. The top open end of the receiving tube  40  is provided with a swinging ring  41 , which is hung on the straight rail  321  of the track portion  32  for deflection. Therefore, the receiving tube  40  can be swung back and fro and rotated relative to the headrail  11 . Further, the receiving tube  40  defines a longitudinal receiving space  42 .  
         [0019]    The lift cords  50  have a respective first end symmetrically fixedly fastened to the bottom rail  14 , and a respective second end upwardly inserted through a respective through hole (not shown) in each slat  15  and then inserted into the inside of the headrail  11  and then extended in the same direction toward the first end  12  of the headrail  11  and then extended over the transverse guide rod  21  of the lift lock  20  and then turned downwards through the gap between the transverse guide rod  21  and the movable ratchet wheel  22  to the outside of the headrail  11  via the opening  13  (the two lift cords  50  are separated by the stop rod  24  when passing through the opening  13 ). When extended out of the opening  13  of the headrail  11 , the second ends of the lift cords  50  are inserted into the inside of the longitudinal receiving space  42  of the receiving tube  40  and then fastened to a pulling device, which can be a telescopic tube, spiral spring, etc. Because the pulling device is of the known art and not within the scope of the present invention, no further detailed description in this regard is necessary. Subject to the size of the Venetian blind, one or more lift cords can be installed in the Venetian blind.  
         [0020]    The Venetian blind  10  further comprises a tilting control mechanism adapted for controlling the tilting angle of the slats. Because the tilting control mechanism is of the known art and not within the scope of the claims of the present invention, no further detailed description in this regard is necessary.  
         [0021]    When the Venetian blind receives no external force, the lift lock  20  locks the lift cords  50 . The gravity weight of the bottom rail  14  and the slats  15  pulls the lift cords  50  downwards (i.e., the lift cords  50  are pulled leftwards in the headrail  11 ), thereby causing the movable ratchet wheel  22  to be rotated upwards along the oblique rack  23  by the lift cords  50 . When the movable ratchet wheel  22  rotated upwards along the oblique rack  23 , it forces the lift cords  50  against the periphery of the guide rod  21 , thereby causing the lift cords  50  to be jammed in between the movable ratchet wheel  22  and the guide rod  21  to hold the bottom rail  14  at a particular elevation.  
         [0022]    Referring to FIG. 3, when wishing to lift the blind, the user can bias the lift cords  50  leftwards. Because the swinging member  41  of the receiving tube  40  is hung on the track portion  32  of the hanger  30  and the hanging portion  31  of the swinging member  30  is hung on the stop rod  24 , the receiving tube  40  is moved leftwards along the straight rail  321  of the track portion  32  to disengage the movable ratchet wheel  22  from the lift cords  50 , for enabling the lift cords  50  to be moved back and forth relative to the lift lock  20  to adjust the elevation of the bottom rail  14 .  
         [0023]    When the bottom rail  14  adjusted to the desired elevation, the user can then pull the receiving tube  40  rightwards along the straight rail  321  of the track portion  32  and then release the lift cords  50 . At this time, the gravity wait of the bottom rail  14  and the slats  15  impart a downward force to the first ends of the lift cords  50  and the lift cords  50  are partially obliquely disposed in contact with the bottom side of the movable ratchet wheel  22 . Therefore, when the lift cords  50  received a pulling force from the first ends, the movable ratchet wheel  22  is immediately forced to rotate in clockwise direction along the rack  23  toward the left upper end, thereby causing the lift cords  50  to be jammed in between the movable ratchet wheel  23  and the guide rod  21 , i.e., the bottom rail  14  is positively maintained at the elevation when released the lift cords  50 .  
         [0024]    As indicated above, the receiving tube  40  is coupled to the headrail  11  by the hanger  30 . The receiving tube  40  can be turned back and forth relative to the headrail  11  within an angle to control locking/unlocking of the lift cords  50 . Further, because the hooked portions  311  of the hanging portion  31  of the hanger  30  are hooked on the stop rod  24  of the lift lock  20  and the swinging ring  41  of the receiving tube  40  is hung on the straight rail  321  of the track portion  32  of the hanger  30 , the receiving tube  40  can be moved horizontally forwards/backwards relative to the headrail  11  within the distance between the hooked portions  311  of the hanging portion  31  of the hanger  30  and then turned leftwards/rightwards to lock/unlock the lift cords  50 , for enabling the bottom rail  14  (and the slats  15 ) to be adjusted to the desired elevation. Because of orthopedically engineered, the user can operate the Venetian blind with less effort.  
         [0025]    It is to be understood that the structure and action of the aforesaid lift lock  20  is of the known art. Various lift lock designs (the arrangement of a guide rod and an eccentrically pivoted ratchet wheel) are known and can be selectively used to substitute for the aforesaid lift lock  20 .  
         [0026]    FIGS.  5 ˜ 7  show a Venetian blind according to the second preferred embodiment of the present invention. According to this embodiment, the lift Venetian blind comprises:  
         [0027]    a headrail  61  (FIG. 7 shows only the first end of the headrail);  
         [0028]    a bottom rail (not shown) spaced below the headrail  61 ;  
         [0029]    a set of slats (not shown) arranged in parallel between the headrail  61  and the bottom rail;  
         [0030]    a lift lock  62  mounted in the first end of the headrail  61 , the lift lock  62  comprising a fixed guide rod  66 , an oblique rack  69 , a movable ratchet wheel  67  meshed with and moved along the oblique rack  69 , and a stop rod  68  provided below the oblique rack  69  and adapted to limit downward movement of the movable ratchet wheel  67 ;  
         [0031]    a swinging device  63 , the swinging device  63  comprising a hanging portion  64  and a track portion  65 , the hanging portion  64  comprising two top lugs  644  bilaterally upwardly extended from the track portion  65 , each top lug  644  having a pivot hole  642  respectively coupled to the stop rod  68  of the lift lock  62 , the track portion  65  comprising two downward lugs  651  arranged in parallel, each downward lug  651  having a substantially horizontally extended and smoothly arched sliding slot  652 ;  
         [0032]    a receiving tube  70 , the receiving tube  70  being a straight round tube having a top open end pivotally connected between the two sliding slots  652  of the swinging device  63  by a pivot pin  90 , and a longitudinal receiving space  71 ; and  
         [0033]    two lift cords  80 , the lift cords  80  each having a first end fixedly fastened to the bottom rail, and a second end inserted through the slats into the inside of the headrail and then extended sideways to the first end of the headrail and then turned downwards through the gap between the fixed guide rod  66  and the movable ratchet wheel  67  and extended downwards to the inside of the longitudinal receiving space  71  of the receiving tube  70 .  
         [0034]    The operation of this second embodiment is similar to the aforesaid first embodiment. Because the receiving tube is coupled to the headrail by the swinging device, the receiving tube can be moved along the sliding slots of the swinging device and then turned leftwards/rightwards to lock/unlock the lift cords (see FIGS. 6 and 7).