Patent Publication Number: US-7581579-B2

Title: Operating device for a window covering

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This application claims priority to Great Britain patent application No. GB 0512576.0, filed 21 Jun. 2005, which is hereby incorporated by reference as if fully disclosed herein. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to an operating device for imparting movement to a window covering, such as a roller blind, vertical blind and/or curtain. 
   2. Description of the Related Art 
   Various operating devices and mechanisms are known for imparting movement to a window covering. Common arrangements for roller blinds and vertical blinds, by way of example, provide an endless loop of cord or chain which, when pulled in one direction, draws or unfurls the blind, and when pulled in the other direction, reverses the movement. Curtains can have similar arrangements. 
   However, the use of an endless loop of cord or chain presents a recognised hazard. A number of children each year are killed or injured by accidentally entangling themselves with the loop of cord or chain, resulting in hanging. 
   A further problem presents itself in that, concerning vertical blinds, often a second endless loop of cord or chain is provided for operating the orientation of the slats. However, this second loop of cord or chain often becomes entangled with the other loop of cord or chain, making operation difficult. It can often be problematic, especially for an elderly or infirm person, to disentangle the loops of cord or chain. 
   The present invention seeks to provide a solution to these problems. 
   SUMMARY OF THE INVENTION 
   According to a first aspect of the invention, there is provided an operating device for a window covering, the device comprising a telescopically extendable and retractable handle and means for converting linear telescopic movement of the handle to rotational movement for moving the window covering. 
   Preferable and/or optional features of the first aspect of the invention are set forth in claims  2  to  4 , inclusive. 
   According to a second aspect of the invention, there is provided an operating device, in accordance with the first aspect of the invention, in combination with a window covering. 
   Preferably, the window covering is a blind or curtain. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will now be more particularly described, by way of example only, with reference to the accompanying drawings, in which: 
       FIG. 1  is a perspective view of a first embodiment of an operating device, in accordance with the first aspect of the invention; 
       FIG. 2  is an exploded view of the operating device shown in  FIG. 1 ; 
       FIG. 3  is an enlarged view of a gear housing of the operating device shown in  FIG. 1 , with part of the housing removed; 
       FIG. 4  is a view similar to that of  FIG. 3 , but with a rack guide removed for clarity; and 
       FIG. 5  is an enlarged perspective view from below of a second embodiment of an operating device, in accordance with the first aspect of the invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to the drawings, there is shown an operating device  10  for a window covering, which comprises a telescopically extendable and retractable handle  12 , a gear housing  14  to which a proximal end  16  of the telescopic handle  12  is connected via a ball-joint assembly  18 , and a tubular rack housing  20  which extends from one side of the gear housing  14  transversely to the telescopic handle  12 . 
   As shown, the telescopic handle  12  includes three parts  112 ,  212 ,  312  which are slidable coaxially relative to each other. However, the handle  12  can have two parts, or more than three parts, as necessity dictates. 
   As best seen in  FIG. 2 , an elongate flexible rack element  22  is provided which is, typically detachably, attached at one end  24  to the internal end  26  of the smallest diameter part  312  of the telescopic handle  12 . The flexible rack element  22  extends coaxially inside the telescopic handle  12 , passes into the gear housing  14  through the ball-joint assembly  18 , and exits the gear housing  14  so as to be received in the rack housing  20 . 
   The flexible rack element  22  is formed from metal or plastics material and, as can best be seen in  FIG. 4 , has a circular lateral cross-section. The flexible rack element  22  includes a multitude of ring shaped teeth  28  spaced from each other along the longitudinal extent of the rack element  22 . 
   As can be seen in  FIG. 3 , the gear housing  14  includes a pinion gear  30  mounted for rotation on one internal side of the gear housing  14 , adjacent to the ball-joint assembly  18 . The rack element  22  and pinion gear  30  together form a rack and pinion mechanism. 
   A spur gear  32  is also mounted for rotation in the gear housing  14  and meshes with the pinion gear  30 . The spur gear  32  is connected to an output shaft  34  ( FIG. 2 ), which extends externally of the gear housing  14  in parallel or substantially in parallel with the rack housing  20 . 
   A rack guide  36  is also located within the gear housing  14  to guide the rack element  22  from the ball-joint assembly  18  to the opening  38  of the rack housing  20 . The rack guide  36  is J-shaped or substantially J-shaped allowing the rack element  22  to deviate through 90 degrees before passing into the rack housing  20 . A portion  40  of the back of the J-shaped rack guide  36  is open to enable the rack element  22  to mesh and thus drive the pinion gear  30 . 
   The rack guide  36  is supported by the rack housing  20  and is spaced from the ball-joint assembly  18  to allow angular displacement of the handle  12 . 
   From an extended condition, as the handle  12  of the operating device  10  is pushed into a retracted condition, the flexible rack element  22  is urged to pass through the gear housing  14  and into and along the rack housing  20 . As the rack element  22  moves through the rack guide  36  in the gear housing  14 , the pinion gear  30  rotates, which in turn drives the spur gear  32 , causing the output shaft  34  to rotate. The output shaft  34  is connected to, for example, a roller blind mounting cylinder, thereby allowing the roller blind material to be unfurled or wound up, or to a movement mechanism of a vertical blind or curtain, thereby moving the blind or curtain(s) to cover or uncover a respective window. 
   When the handle  12  is extended from its retracted condition, the operation described above is reversed, and the blind or curtain(s) is/are moved in the other direction. 
   It will be realised that the spur gear can be dispensed with, as shown in a second embodiment of an operating device  110 , shown in  FIG. 5 . In this case, the pinion gear  130  directly rotates the output shaft  134 , due to movement imparted by the rack element  122 . 
   More than one spur gear can be provided, and the rack element can be of non-circular lateral cross-section. Any suitable teeth can be provided on the rack element, for example, the teeth can be non-circular instead of ring-shaped. Alternatively, a single tooth in the form of a screw-thread or helical thread can be provided. 
   The gear housing could be replaced by any suitable support member, for example, simply being a plate. 
   The rack housing can be at any orientation to the gear housing/support member. 
   Conveniently, the operating device described above can be provided as a kit of parts to allow self- or home-assembly. 
   The operating device described above is particularly advantageous, since the rack housing can be located in parallel with, and hidden by, a blind or curtain track or mechanism extending across a window. The gear housing is unobtrusive, and can be easily be mounted to the surface adjacent the window. 
   It is thus possible to provide a window covering operating device which dispenses with the need for a loop of cord or chain in order to furl or unfurl the window covering. Safety is thus greatly improved, and ease of operation is simplified, especially for a user with low or reduced dexterity. It is also possible to provide an operating device which coverts linear movement of the handle into rotational movement for moving the window covering via a telescopic handle. 
   The embodiments described above are given by way of examples only, and other modifications will be apparent to persons skilled in the art without departing from the scope of the invention as defined by the appended claims.