Abstract:
A device for disabling a window treatment operated by a cord includes at least one member with a gear engaging the cord. When the cord is not tensioned correctly, the gear of the member intermeshes with teeth on another member impeding movement of the cord along its length. In one embodiment, two gears engage different sections of the cord and intermesh with each other. In another embodiment, a stationary member intermeshes with the gear of member selectively pivoted by the cord in accordance with the tension on the cord.

Description:
RELATED APPLICATIONS 
     This application claims priority to U.S. provisional application Ser. No. 61/426,560 and 61/426,564 filed on Dec. 23, 2011 and to U.S. Design Pat. D647,342 based on U.S. application Ser. No. 29/381,573 filed on Dec. 21, 2010, all incorporated herein in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     A. Field of Invention 
     This invention pertains to a window treatment operated by a cord, wherein a disabling device is provided to disable the window treatment if the cord is not tensioned properly. The device includes one or more gears engaged by the cord and blocked from rotation when the cord is not tensioned properly. 
     B. Description of the Prior Art 
     In the present application the term ‘window treatment’ refers to an apparatus for selectively covering a door, a window or other architectural feature in a building. Typical window treatments include window shades or blinds, venetian blinds, roman shades, vertical blinds, pleated blinds, and so. Window treatments can be operated either manually, using one or more cord, or automatically using an electric motor to activate the shade and a remote controller coupled to the electric motor either via a wired or wireless connection. The remote controller may respond to commands from a user or may operate autonomously. However, automatic window treatments are very expensive and complex, and by and large, the majority of window treatments are operated manually. Most of these latter types of window treatment include a built-in control mechanism that is used to operate the window treatment, e.g., raise or lower a fabric sheet, a plurality of slats, etc., with an elongated member such as a cord engaging the control mechanism. For example, the control mechanism may be a clutch such as one manufactured by Rollease, Inc. of Stamford, Conn. 
     It has been found that it is advantageous to tension the cord after the window treatment has been installed, and to disable the control mechanism and immobilize the cord if the free portion of the cord is not tensioned properly, but it is left loose adjacent to the window treatment. Mechanisms for disabling window treatment control mechanisms have been previously proposed, however, they were not found to be convenient to make and are not always effective. 
     SUMMARY OF THE INVENTION 
     A device for disabling a window treatment operated by a cord includes at least one member with a gear engaging the cord. When the cord is not tensioned correctly, the gear of the member intermeshes with teeth on another member impeding movement of the cord along its length. In one embodiment two gears engage different sections of the cord and intermesh with each other. In another embodiment, a stationary member intermeshes with the gear of member selectively pivoted by the cord in accordance with the tension on the cord. More particularly, in one embodiment, a device for disabling a window treatment including a control mechanism operated by a cord movable in a longitudinal direction along its length, includes 
     a first member having a cord engaging element, said first member rotating about an axis, said cord engaging member engaging said cord to transfer a motion of said cord along said longitudinal direction into a rotation of said first member, said first member moving laterally with respect to said longitudinal direction between a first and a second position in response to tension on said cord; and 
     a second member; 
     said first member and said second member cooperating to block movement of said cord in the longitudinally direction when said first member is in said first position. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  shows a somewhat diagrammatic front view of a device for disabling a window treatment constructed in accordance with this invention using two gears; 
         FIG. 1A  shows an alternate position for the gears of the device of  FIG. 1 ; 
         FIG. 2  shows a cross-sectional view of a first embodiment of a pulley for the device of  FIG. 1 ; 
         FIG. 3  shows a side view of the second embodiment of the pulley; 
         FIG. 4  shows a front view of a third embodiment of a pulley for the device of  FIG. 1 ; 
         FIG. 5  shows an orthogonal view for a tensioning device; 
         FIG. 6  shows an orthogonal view of the base of the tensioning device of  FIG. 5 ; 
         FIG. 7  shows a perspective view of a hasp in the tensioning device of  FIG. 5 ; 
         FIG. 8  shows a perspective view of a segment in the tensioning device of  FIG. 5 ; 
         FIG. 9  shows a perspective view of a bottom plate for the tensioning device of  FIG. 5 ; 
         FIG. 10  shows a perspective view of a biasing spring for the tensioning device of  FIG. 5 ; 
         FIG. 11  shows a side view of the tensioning device of  FIG. 5  in the installed configuration and receiving the cord  20 ; 
         FIG. 12 , shows a side view of the tensioning device of  FIG. 6  in the closed position; 
         FIG. 13  shows another cross-sectional view of the tensioning device similar to  FIG. 11 ; 
         FIG. 14  shows another cross-sectional view of the tensioning device similar to  FIG. 12 ; 
         FIG. 15  shows a side view alternate embodiment of the device of  FIG. 1 ; and 
         FIG. 16  shows a side view yet another alternate embodiment of the device of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A device for disabling a window treatment constructed in accordance with this invention is shown in  FIG. 1 . In this Figure the device  10  includes two stationary gears  10 A,  10 B, mounted on a base  11  and two pivoting gears  12 A and  12 B. Each gear  12 A,  12 B is mounted on a first end of a respective rod  14 A,  14 B. 
     In the embodiment shown, the other ends of rods  14 A,  14 B are mounted coaxially with pulleys  10 A,  10 B. In another embodiment (not shown), the other ends of rods  14 A,  14 B are secured to base  11  at a location space at a predetermined distance from the gears  12 A,  12 B. 
     The device  10  further includes two biasing springs  16 A,  16 B. Each spring  16 A,  16 B includes a first end attached to the base  11  and a second end attached to the respect rod  14 A,  14 B as shown in  FIG. 1 . The two springs  16 A,  16 B are tensioned to cause the two arms  14 A,  14 B to pivot toward each other in directions A, A′. 
     Each  12 A,  12 B gear has a respective large diameter toothed wheel  22 A,  22 B with a plurality of radial teeth  23 ; and a respective smaller diameter pulley  24 A,  24 B. Each pulley is attached to the respective gear and they are rotationally interlocked so that they can rotate round a common axis. In the figures, teeth  23  are shown with a triangular cross-section, however, they could also have rectangular, square, trapezoidal or other shapes as well. 
       FIG. 2  shows a cross sectional view of one embodiment of the pulleys  10 A,  10 B,  24 A,  24 B. Pulleys  10 A,  10 B can but need not have the same dimensions as pulleys  24 A,  24 B. In this embodiment, each pulley includes two radial rims  30 ,  32  and central surface  34  having a toroidal cross-section as shown. The two rims  30 ,  32  can be the same size, or one of them may have a larger diameter then the other. The rims  30 ,  32  are spaced from each other sufficiently to receive a cord  20  therebetween. The surface  34  has about the same or a slightly smaller cross-sectional radius of curvature as the radius of cord  20 . In an alternate embodiment, surface  34  is cylindrical. 
     The cord  20  can be a rope, a single or multifilament thread, a wire, a twine, a chain or can be formed of a plurality of beads that are either interconnected directly to each other, or are mounted on a common thread  21 . 
       FIG. 3  shows another embodiment for the pulleys. In this embodiment, each pulley includes two radial rims  30 ,  32  like in the embodiment of  FIG. 2 , the two rims having the same diameter, or one having a larger diameter then the other. In this embodiment, instead of having a continuous surface, the intermediate section between the rims is formed with a plurality of pockets spherical pockets  34 A. This embodiment is best suited for a cord  20  made of beads  21 , each bid fitting, preferably snugly, within one of the pockets  34 A. In this embodiment, the rims  30 ,  32  may be omitted. 
     In both embodiments, the pulleys are preferably made of, or are covered with a high friction material such as rubber to insure that the longitudinal movement of cord  20  is translated into rotational movement of pulleys. Moreover, if the pulleys, and in particular pulleys  24 A,  24 B, are not rotating, friction between the pulleys and the cord prevents the cord  20  from moving longitudinally. In one embodiment, e.g., embodiment of  FIG. 2 , the pulleys are shaped to pinch or otherwise create an interference fit with the cord  20  so that when the pulleys are free to rotate, longitudinal movement of the cord causes the pulleys to rotate about their respective axes, however if pulleys  24 A,  24 B are prevented from rotating, the cord interference fit prevents the cord from moving longitudinally. 
     The device  10  is installed by either mounting it on a wall or attaching it to the window treatment itself, as shown somewhat diagrammatically in  FIG. 1 . The cord  20  includes a right portion  20 A, a left portion  20 B and an intermediate portion  20 C. The right portion  20 B is threaded partially around pulleys  24 B and  10 B and the intermediate portion  20 C is positioned so that it engages a control mechanism  18  of a window treatment. The left portion  20 A is trained partially around pulleys  10 A and  24 A. 
     The two sections  20 A,  20 B then extend down towards a tensioning device  200 . Before the cord  20  is tensioned, the cord  20  cannot apply any considerable force on gears  12 A,  12 B and as a result, these gears are biased toward each other by springs  16 A,  16 B and their teeth are intermeshed, as shown in  FIG. 1A . As previously described, frictional forces prevent cord  20  from moving unless pulleys  24 A,  24 B are free to rotate about their respective axes. As a result, if either cord segment  20 A or cord segment  20 B is pulled down, the intermeshed teeth  12 A,  12 B do not allow the cord  20  to move in either direction and, hence, the window treatment control mechanism  18  cannot be operated. Pulleys  10 A,  10 B are used to direct the cord  20  into and out of the control mechanism  18 . 
     Tensioning the cord  20  causes the cord segments  20 A,  20 B to move downward. This causes pulleys  24 A,  24 B pivot arms  14 A,  14 B away from each other in directions B, B′ and against the forces applied by springs  16 A,  16 B. This action causes the gears  12 A,  12 B to separate from each other. The gears  12 A,  12 B remain separated as long as the cord  20  remains tensioned. With the gears  12 A,  12 B separated, the pulleys  24 A,  24 B are free to rotate about their axes and either segment  20 A,  20 B can be pulled thereby operating mechanism  18  of the window treatment. 
     Preferably the cord sections  20 A,  20 B are continuous and form a lower cord loop  20 D that is tensioned using the tensioning device  200 . 
     A cord tensioning device  200  that can be suitable for the purposes discussed above is now described. As shown in  FIGS. 5-14 , preferably cord tensioning device  200  includes a body  202 . Body  202  includes two mounting holes  204 ,  206 , that can be used to mount the device  200  on a window seal a side wall or other similar surfaces, and a central hole with an inner cylindrical wall  208 . The inner wall is formed with a downwardly oriented lip  209  (see  FIG. 11 ). 
     Tensioning device  200  further includes a u-shaped hasp  210  having a central curved portion  212  and two parallel leg  214 ,  216  terminating in respective enlarged portions  218 . 
     Tensioning device  200  further includes a segment  220  having two opposed wails  222 ,  224  that are concave and are sized to contact the inner surfaces of the legs  214 ,  216 . The segment  220  has two further opposite walls  226 ,  228  having approximately the same curvature as the hole  208  to allow the segment  220  to rotate within the hole. 
     Tensioning device  200  further includes a bottom plate  230  having two side walls  232 ,  234  sized and shaped to fit over the enlarged portions  218  and two other sides  236 ,  238  formed with a respective lip  240 ,  242 . 
     Finally, the tensioning device includes a compression spring  250  with a top  252  and a bottom  254 . 
     The assembled tensioning device is shown in two configurations in  FIGS. 11-14 . The hasp  210  fits into hole  208  and is axially movable therethrough. The segment  220  and bottom plate  230  are mounted on the hasp between its legs. The compression spring  250  is disposed with its top  252  in contact with lip  209  and its bottom  254  resting on top of plate  230 . The force of the spring  250  causes the plate  230  to be positioned downwardly of and away from the bottom of body  202 , Importantly the cord portion  20 D passes through the hasp  210  and as the hasp is urged downwardly as well, the hasp  210  and the body engage and pinch the cord segment  22 C between them and any movement of the cord causes the cord tensioning device  200  to move with the cord. 
     Once a window treatment is installed (or even before if so desired) the cord tensioning device  200  is attached to any straight surface (a wall, a window sill, etc.) by using screws, nails, etc., through the holes  204 ,  206 . As the cord tensioning device is so installed, its bottom plate  230  is pushed inwardly against the force of spring  250  moving the hasp  210  upwardly at the same time. When the cord tensioning device is fully installed, the hasp  210  is in its final position shown in  FIGS. 11 ,  13 . In this configuration, the cord section  20 D can move freely through the hasp. The cord is tensioned by the position of the cord tensioning device. Moreover, the cord can be tightened or loosened by rotating the hasp around the axis of hole  208 . 
     A device  300  constructed in accordance with an alternate embodiment of the invention is shown in  FIG. 15 . In this Figure, a window treatment system  300  includes two gears  312 A,  312 B having gears and being constructed in a manner similar to gears  12 A,  128  with the exceptions noted below. The gears  312 A,  312 B include respective pulleys  324 A  3248 . The device  300  further includes a base  311  formed with two horizontal slots  340 A,  340 B. The gears  312 A,  312 B are rotationally mounted on shafts that are trapped in and slide in respective slots  340 A,  340 B. Two springs  316 A,  316 B are used to bias the two gears toward each other. In an alternate embodiment, instead of slots  340 A,  340 B, arms (not shown) are used that are similar to arms  14 A,  14 B. 
     Between the two gears  312   a ,  312 B, there is a central member  344  having two sides  344 A,  344 B with teeth having the same size as the teeth on gears  312 A,  312 B. Member  344  is stationary and is attached to base  311 . 
     The cord  20  includes a section  20 A at least partially trained around in touch with pulley  340 A, a section  20 B at least partially trained around, or in touch with pulley  340 B. The cord  20  further includes an upper portion  20 A trained around a window treatment control mechanism  18 , and is tensioned by device  200 . 
     As with the previous embodiments previously discussed, it has been found that it is advantageous to install the system  300  in such a manner that the cord  20  is tensioned. The cord  20  and slots  340 A,  340 B are arranged so that when the cord  20  is under tension, the teeth of gears  312 A,  312 B are spaced away from the teeth of member  344  and the gears and their pulleys are free to turn about their respective axes. As a result, the cord  20  can be moved up and down by pulling on  20 A,  20 B thereby activating the mechanism  18  either in one direction or the other. 
     However, if the cord  20  is no longer tensioned by device  200 , it cannot counteract the forces of springs  316 A,  316 B. Therefore the springs pull or push the two gears  312 A,  312 B toward each other until their teeth engage and intermesh with the teeth of sides  344 A,  344 B respectively, as shown in  FIG. 15 . 
     The central member  344  is fixed and cannot move or rotate. Once the gears  312 A,  312 B come into contact with the teeth of sides  344 A,  344 B, the gears are immobilized and prevented from rotation by member  344 . In this manner the cord  20  is disabled and cannot be used to operate control mechanism  18 . 
     In the embodiments discussed above, means are provided to lock both sides of the cord by training the cord about the pulleys of gears and selectively immobilizing the gears to prevent each side or portion of the cord from moving. In another alternate embodiment, a single gear is provided to immobilize the cord only on one side. 
       FIG. 16  shows yet another embodiment similar to the embodiment of  FIG. 15 . The main difference is that in this embodiment, the central member  444  is not fixed to plate  11  but is slidable vertically and it has at the top a tip  446 . Moreover, the control mechanism  18  includes a gear  19  with a plurality of teeth  19 A. The central member  444  is arranged so that when cord portion  20 B is pulled downward, member  444  moves up until the tip  446  is pushed between two of the teeth  19 A and engages the gear  19  so that the gear  19  cannot rotate about its axis. A latch (not shown) interlocks with the member  444  and holds it while the tip  446  engages the teeth  19 A. The latch must be reset manually before the device  10  disengages from the gear  19  and allows to rotate about its axis once more. 
     As with the previous embodiments, device  300  or  400  can be provided separately or can be incorporated into the window treatment. 
     Numerous modifications may be made to this invention without departing from its scope as defined in the appended claims.