Patent Publication Number: US-2011048652-A1

Title: Safety mechanism for roman shade

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No(s). 098215682 filed in Taiwan, R.O.C. on 25 Aug. 2009, the entire contents of which are hereby incorporated by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to a safety mechanism for Roman shade, and more particularly to a safety mechanism for Roman shade that effectively prevents pull cords and raising cords of the Roman shade from endangering a small child. 
     BACKGROUND OF THE INVENTION 
     A Roman shade is one of many commercially available window shades, and usually includes a head rail, a lifting unit, and a shade cloth connected to and hung from the head rail. The lifting unit includes a plurality of pull cords and raising cords, and the shade cloth can include a plurality of horizontal strips sequentially connected from top to bottom. At least one row of through holes is formed on the vertically sequentially connected horizontal strips for the raising cord to extend therethrough. A lower end of the raising cord is fixedly tied to the lowest one of the through holes. When the pull cords are pulled, the raising cords are raised or lowered to thereby bring the shade cloth to lift or lower. 
     The pull cords are usually located at one lateral side of the shade cloth and exposed to the open environment. A small child playing around in the room nearby the Roman shade might curiously or unexpectedly wind the pull cord or the raising cord around his or her neck and is subject to the risk of being dangerously strangulated by the cord. That is, the exposed pull cords and raising cords of the Roman shade form a big potential threat to the safety of small children. 
     It is therefore desirable and tried by the inventor to develop a safety mechanism for Roman shade, so that the Roman shade is safer for use. 
     SUMMARY OF THE INVENTION 
     A primary object of the present invention is to provide a safety mechanism for Roman shade capable of preventing pull cords and raising cords of the Roman shade from winding around and endangering a small child, so that the Roman shade is safer for use. 
     To achieve the above and other objects, the safety mechanism for Roman shade according to the present invention includes a shade assembly having a head rail, a shade cloth connected at an end to the head rail, and a plurality of connecting members provided on the shade cloth; a lifting unit connected to the shade assembly and having pull cords and raising cords connected thereto; a plurality of butt-connecting devices separately connected to the pull cords and each having two detachably connected upper and lower sleeves; and a plurality of locking members associated with the raising cords and detachably engaged with the connecting members. 
     When a pull cord or a raising cord is subjected to a load excessively larger than a force needed to lift or lower the shade cloth, such as when a small child is wound around by and struggling against the cord, the upper and lower sleeves of the butt-connecting device on that pull cord will separate from each other and the locking members on that raising cord will disengage from the connecting members to release the child from the cord, making the Roman shade safer for use. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein 
         FIG. 1  is a perspective view showing a safety mechanism for Roman shade according to a first embodiment of the present invention; 
         FIG. 2  is an exploded perspective view of a butt-connecting device adopted in the safety mechanism for Roman shade of the present invention; 
         FIG. 3  is a perspective view of a locking member adopted in the safety mechanism for Roman shade of the present invention; 
         FIG. 4  shows the state of the safety mechanism for Roman shade of  FIG. 1  when any one of a plurality of pull cords and raising cords is subjected to an excessively heavy load; and 
         FIG. 5  is a perspective view showing a safety mechanism for Roman shade according to a second embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Please refer to  FIG. 1  that is a perspective view showing a safety mechanism for Roman shade according to a first embodiment of the present invention. As shown, the safety mechanism for Roman shade shown in  FIG. 1  includes a shade assembly  1 , a lifting unit  2 , a plurality of butt-connecting devices  3 , and a plurality of locking members  4 . 
     The shade assembly  1  includes a head rail  11 , a shade cloth  12  connected at an upper end to the head rail  11 , and a plurality of connecting members  13  connected to the shade cloth  12 . The connecting members  13  each can be in the form of a transverse bar extended across a full width of the shade cloth  12 . 
     The lifting unit  2  is connected to the shade assembly  1 , and has a plurality of pull cords  21  and a plurality of raising cords  22  connected thereto. 
     The butt-connecting devices  3  are separately connected to the pull cords  21 . As can be seen from  FIG. 2 , each of the butt-connecting devices  3  includes an upper sleeve  31  and a lower sleeve  32  detachably connected to the upper sleeve  31 . The upper sleeve  31  is internally provided around a lower end thereof with an annular groove  311 , and the lower sleeve  32  is externally provided around an upper end thereof with an annular rib  321  for fitly engaging with the annular groove  311 . Alternatively, the upper sleeve  31  is internally provided around the lower end thereof with an annular rib (not shown), and the lower sleeve  32  is externally provided around the upper end thereof with an annular groove (not shown) for fitly engaging with the annular rib in the upper sleeve  31 . 
     The locking members  4  are associated with the raising cords  22  and detachably connected to the connecting members  13 . Please refer to  FIG. 4 . Each of the locking members  4  is provided near an end with a vertically extended bore  41 , through which one raising cord  22  is extended to thereby associate with the locking member  4 . The locking member  4  is provided at an opposing end with a horizontally extended locking groove  42  for detachably engaging with the connecting member  13 . 
     Please refer to  FIG. 4  along with  FIGS. 2 and 3 . When the pull cords  21  are pulled, the butt-connecting members  3  on the pull cords  21  are brought to move along with the pull cords  21 ; meanwhile, through the action of the lifting unit  2 , the raising cords  22  and the locking members  4  associated therewith are raised or lowered by the pulled pull cords  21  to accordingly, lift or lower the shade cloth  12  connected to the locking members and the raising cords  22  via the connecting members  13 . 
     In the event a small child playing around in a room curiously or unexpectedly winds any one of the pull cords  21  or the raising cords  22  around one part of his or her body, such as the neck, and the pull cord  21  or the raising cord  22  winding around the small child is subjected to a load excessively larger than the pull force needed to raise the shade cloth  12 , the upper and the lower sleeve  31 ,  32  of the butt-connecting device  3  on the excessively loaded pull cord  21  will become separated from each other at the annular groove  311  and the annular rib  321 , and the locking grooves  41  of the locking members  4  on the excessively loaded raising cord  22  will become disengaged from the connecting members  13 , as shown in  FIG. 4 , so that the pull cord  21  or the raising cord  22  no longer tightly winds around the small child&#39;s body to endanger the child. When the dangerous condition is removed, the separated upper and lower sleeves  31 ,  32  can be connected to each other again by engaging the annular groove  311  with the annular rib  321 , and the locking members  4  can be connected to the shade cloth  12  by engaging the locking grooves  41  with the connecting members  13  again. Thus, the pull cord  21  and the raising cord  22  can work again to lift or lower the shade cloth  12 . 
       FIG. 5  shows a second embodiment of the present invention, which is generally structurally similar to the first embodiment, except for a plurality of connecting members  13   a  each being in the form of a holding seat sewn to predetermined positions on the shade cloth  12 . Each of the connecting members  13   a  is provided at one edge opposite to the shade cloth  12  with an engaging bar  131   a , with which the locking groove  41  on the locking member  4  is detachably engaged. Therefore, the second embodiment can provide the same safety effect as the first embodiment. 
     In the present invention, whenever the pull cord  21  or the raising cord  22  is subjected to a load excessively larger than a force needed to lift or lower the shade cloth of a Roman shade, the upper and lower sleeves of the butt-connecting member on the overloaded pull cord will become separated from each other and the locking member on the overloaded raising cord will disengage from the connecting member to avoid the cord from entangling with or strangulating a child, making the Roman shade safer for use. Therefore, the safety mechanism for Roman shade according to the present invention is novel, improved, and practical for use to fully satisfy the market demands. 
     The present invention has been described with some preferred embodiments thereof and it is understood that many changes and modifications in the described embodiments can be carried out without departing from the scope and the spirit of the invention that is intended to be limited only by the appended claims.