Window shade

Abstract

A window shade includes an upper track, a lower track, a shade assembly, a lift cord means and a bead chain means. The lift cord means includes two boxes located in the upper track at two sides thereof and a flattened cord winding on the periphery of a jutting ring located in each box. By coupling a transmission axle with a transmission means located at one side of the bead chain means a concurrent transmission can be formed. Thereby the bead chain can aid retraction of the shade assembly through the transmission means to reduce transmission load of the bead chain means. The bead chain means of a suitable loading capability can be selected according to the weight of the shade assembly to reduce the load of the transmission means to facilitate extension of the shade assembly.

1 . A window shade, comprising:
 a hollow and elongate upper track which has openings at two ends wedged respectively by an anchor seat and a first latch hole, a second latch hole and a trough formed at the bottom thereof;   an elongate lower track which is spaced from the upper track at a lower side and has a wedge trough and openings at two ends thereof wedged respectively by an edge sealing element corresponding to the wedge trough;   a shade assembly which is located between the upper track and the lower track and has a beehive slat which has an upper end and a lower end formed respectively a first wedge plate and a second wedge plate to wedge respectively in the trough of the upper track and the wedge trough of the lower track to connect to the upper track and the lower track;   a lift cord means which is located in the upper track and run through by two sides of a transmission axle, and includes a box and a lid coupling with each other, a jutting ring located in the box and a flattened cord winding on the periphery of the jutting ring that has a latch element at one end latching on the jutting ring; the box having two corresponding elastic latch elements extended from the bottom thereof to wedge in the first latch hole and the second latch hole for anchoring and a threading slot between the two elastic latch elements to be threaded through by the flattened cord; and   a bead chain means located on the opening of another side of the upper track and includes a first box and a second box that are coupled together and a transmission means hinged in the first box and the second box; the transmission means including at least a barrel, an elastic element held in an inner lower half portion of the barrel that has two ends formed respectively a first lug and a second lug corresponding to each other, a coupling ring held in an inner upper half portion of the barrel above the elastic element, a movable element which has one end coupling with the first box, a hinge element held in the first box, a bead chain driving the transmission means and a rotary element located in the second box and wound by the bead chain.   
     
     
         2 . The window shade of  claim 1 , wherein the slat is selectively a beehive slat, a Venetian blind slat assembly or a pleated blind slat assembly. 
     
     
         3 . The window shade of  claim 1 , wherein the first wedge plate, the second wedge plate and the shade assembly have respectively an aperture corresponding to the first latch hole and the second latch hole of the upper track. 
     
     
         4 . The window shade of  claim 1 , wherein the box has a housing chamber at one side, a first opening at the bottom end of the housing chamber, a recess formed on the periphery and a latch cavity at each of corners thereof. 
     
     
         5 . The window shade of  claim 1 , wherein the lid has a latch flange on the periphery, a second opening on one end and a tenon at each of corners thereof. 
     
     
         6 . The window shade of  claim 1 , wherein the jutting ring is located in the box and has an inner round strut and an outer annular ring, the inner round strut having a hinge hole in the center, the outer annular ring having a latch slot formed on the periphery thereof. 
     
     
         7 . The window shade of  claim 1 , wherein the lift cord means has two ends coupled respectively with an anchor element which has an axle hole formed thereon to be fastened to the transmission axle to prevent the lift cord means from moving to a left side and a right side. 
     
     
         8 . The window shade of  claim 1 , wherein the first box has a first wedge flange and coupling holes on the periphery of one side, a strut which has a housing trough and a coupling hole at a front end thereof, and a second wedge flange on the periphery of another side thereof. 
     
     
         9 . The window shade of  claim 1 , wherein the second box has a housing compartment at one side that has a strut and a flattened strut and a coupling hub above the housing compartment. 
     
     
         10 . The window shade of  claim 9 , wherein the housing compartment has an inclined guiding trough. 
     
     
         11 . The window shade of  claim 1 , wherein the movable element has a round stem at one end that has a first axle hole and an arched strut extended from a distal end thereof, the arched strut having two ends formed respectively a plane. 
     
     
         12 . The window shade of  claim 1 , wherein the hinge element has an annular flange and an arched strut at one side, the arched strut having a second axle hole on another side. 
     
     
         13 . The window shade of  claim 1 , wherein the rotary element has a plurality of notches on the periphery, a stub shaft extended from one side and a cavity formed on another side thereof. 
     
     
         14 . The window shade of  claim 1 , wherein the bead chain means has a gear set pivotally coupled on one side of the transmission means located at one side of the first box and the second box. 
     
     
         15 . The window shade of  claim 14 , wherein the gear set has a first gear and a plurality of second gears that are engaged with each other, the second gears being engaged with teeth formed on a coupling member at one side of the first box to form concurrent transmission.