Abstract:
The adjustable tension shade includes a spring motor, an axle, and a shade roller. The spring motor is mounted to the axle and drives the shade roller. The axle has an adjustable telescoping shaft and the free ends of the axle are spring-biased outwardly away from each other. The shade roller has a tubular body that surrounds the axle and the spring motor and serves as a mounting point and storage unit for a shade. A pair of feet is connected to each end of the axle and each has a soft rubber gripping surface thereon.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention generally relates to window shades. More specifically, the present invention relates to spring tension mounted window shades. 
   2. Background of the Related Art 
   In the home improvement and construction industries, there is a desire to make a window more pleasing to the eye, to provide some type of shade to the sun and to provide privacy, as needed. Windows are available in many different sizes thereby necessitating that the window shade be fit to the window casement at hand. As a result, numerous sizes of window shades must be available to fit a given window. This is particularly problematic in connection with the sale of such shades because different sizes of shades must be available for purchase to fit the different sizes of windows. Windows of uncommon sizes require custom built shades. 
   In the prior art, there have been many attempts to address the problem of fitting a shade to a window. U.S. Pat. No. 473,990 (Wilkinson) provides such a spring tension shade that includes spring-loaded pads on opposing ends of the shade to frictionally grip the facing sides of a window casement. However, the main body must generally fit within the width of the casement thereby. This device is not intended to fit to a wide range of window sizes. The focus of this invention is simply to removably attach a window shade to a window casement without the use of tools or mounting hardware. U.S. Pat. No. 4,373,569, issued to Barretella, similarly provides for a window shade assembly that can be easily installed and which is held in place by friction. 
   These prior art assemblies, however, suffer from the disadvantage of being of a substantially fixed length. The play in the spring-biased pads on the opposing ends of the assembly is minimal. As a result, the prior art assemblies are specifically made for installation into a specific sized window casement. 
   Therefore, there is a desire to provide a single spring tension shade assembly that can be installed into windows of a wide range of sizes. There is a desire to provide to the consumer with a single shade assembly that can be easily adjusted to fit a given window 
   Another disadvantage of prior art shade rollers is that the holding force exerted by the ends of the assembly is through the roller itself. This means that there is increased friction that keeps the roller from turning freely. As the holding force increases, the force necessary to operate the roller thereby increases making it harder to furl or unfurl the shade. The increase in the force necessary to operate the shade necessitates that the holding force must be increased to keep the shade assembly secure within the window casement. 
   Therefore, there is a need for a tension shade assembly that minimizes or reduces the forces exerted on the roller itself to prevent the jamming or the rotation of the roller or the dislodgment of the tension shade assembly from the window casement. 
   SUMMARY OF THE INVENTION 
   The present invention solves the problems associated with the prior art shade assemblies. The adjustable tension shade of the present invention includes a shade roller having a tubular body and a telescoping spring-biased axle. The shade roller has a first portion that slidably resides within a second portion to form the shade roller. The axle has a axle body portion and an adjustment rod portion that is received therein. The axle body portion has an adjustment spring contained therein. The adjustment rod portion has a raised shoulder that cooperates with the adjustment spring contained in the axle body portion to position the adjustment rod therein. The adjustment spring urges the free ends of the axle away from each other. As a result, the axle body member can be retained within a window casement by friction in similar fashion to a standard spring tension curtain rod. The ends of the axle have cushioned footings attached thereon to retain the entire assembly in place without damaging the window casement walls. 
   Unlike a curtain rod, the second (outer) portion of the tubular body member is also fitted with a spring motor. Thus, a shade can be attached thereto so it can be rolled in similar fashion to a typical spring tension shade, such as that depicted in the Wilkinson &#39;990 patent discussed above. 
   However, the shade assembly of the present invention can be adjusted in width across a wide range to accommodate window casements of different sizes. The shade assembly is fit to a given window and then the shade itself is selected to fit to the adjusted to length. The shade member can be cut to the size and then attached directly onto the second (outer) tubular member so that it can be wound thereabout, as desired. However, it is also possible to provide a window shade member that can be sized by the user without cumbersome cutting. As seen in U.S. Pat. No. 4,438,799, issued to Comeau and commonly owned with the instant invention, a shade of adjustable width, using tear-way strips, can be used in conjunction with the present invention to facilitate the sizing of the shade member. Using the easy-adjusting shade member of Comeau &#39;799, the shade assembly can be provided in a single kit for a consumer to custom install and fit a shade assembly into a wide range of window casement sizes. 
   Accordingly, it is an object of the present invention to provide an adjustable tension shade rod that can be easily adjusted to fit a range of window sizes. 
   Another object of the present invention is the provision for an adjustable tension shade rod that can be mounted to a window casement without the need for special mounting hardware. 
   Yet another object of the present invention is the provision for an adjustable tension shade that can be mounted to a window casement without damaging the window casement. 
   Yet another object of the present invention is the provision for an adjustable tension shade that minimizes the lateral forces on the roller of the tension shade thereby preventing jamming or dislodgment of the tension shade from the window casement. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description, appended claims, and accompanying drawings where: 
       FIG. 1  is a perspective view of the preferred embodiment of the tension shade assembly of the present invention; 
       FIG. 2  is a perspective view of the preferred embodiment of the tension shade assembly of the present invention with the shade member removed; 
       FIG. 3  is a exploded view of the preferred embodiment of the tension shade assembly of the present invention; 
       FIG. 4  is a side cross-section view through line  1 — 1  of  FIG. 1 ; 
       FIG. 5  is a close-up side cross-section view of the adjustable end of the preferred embodiment shown in  FIG. 4 ; 
       FIG. 6  is a close-up side cross-section view of the middle portion of the preferred embodiment shown in  FIG. 4 ; and 
       FIG. 7  is a close-up side cross-section view of the spring-motor end of the preferred embodiment shown in  FIG. 4 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The adjustable tension shade rod of the present invention is shown generally at  10  in  FIGS. 1–7 . As will hereinafter be more fully described, the present invention provides an inexpensive adjustable tension shade rod that can be adjusted to fit many windows of varying dimensions without the need for additional mounting hardware and without damaging the window casement walls. 
   Referring first to  FIG. 1 , a front perspective view of the spring tension rod assembly  10  of the present invention is shown to include a telescoping shade roller  26  with a foot  28  on each opposing sides thereof. As will be described in detail below, the shade roller  26  is rotatably mounted relative to each foot  28 . A grip surface  30  is provided on the ends of each foot  28  is a grip surface for communicating with a mount surface, such as a window casement. A shade  33  is wound about the shade roller  26 .  FIG. 1  illustrate the shade  33  fully would about the shade roller  26 . 
   Turning now to  FIG. 2 , the spring tension rod assembly of  FIG. 1  is shown without shade  33  for ease of discussion. As will be described in detail below, first portion  32  and second portion  34  of shade roller telescope relative to one another while still being able to carry shade  33 , as seen in  FIG. 1 . Thus, as seen in  FIG. 4 , the spring tension shade assembly  10  can be easily compressed laterally so that it may clear past the sides of a window casement, then positioned as desired and then released so it may be frictionally, yet removably, retained in place. 
   Turning now to  FIG. 3–7  further details of the invention are set forth. The adjustable tension shade assembly  10  of the present invention has an axle  12  that has an adjustable telescoping shaft. The axle  12  includes an axle body portion  14  and an adjustment rod portion  16 . The axle body portion  14  is preferably an open seam roll-formed tube, but other construction techniques could be used. The axle body portion  14  has an adjustment spring  18  contained therein that extends the length of the axle body portion  14 . The adjustment spring  18  is retained within the axle body portion  14  by selectively crimping the axle body portion  18 , but other techniques could be used equally effectively. The adjustment rod portion  16  includes a raised shoulder  20  on one end, which can best be seen in  FIG. 6 . The raised shoulder  20  can be formed, preferably of metal, by a number of methods that one skilled in the art would appreciate, including stamping, integrally molding or turning upwardly one end of the adjustment rod portion  16  among others. Other materials and manufacturing techniques may be used for the adjustment rod portion  16 . Most preferably, the raised shoulder  20  is formed by stamping the adjustment rod portion  16  near one end, leaving a small portion  22  extending beyond the raised shoulder  20 . 
   As seen in  FIG. 6 , the adjustment rod portion  16  is slidably received into the axle body portion  14  and threaded into the adjustment spring  18  contained therein. The raised shoulder  20  serves a guide within the coils of the adjustment spring  18  to keep the adjustment rod portion  16  from moving freely within the axle body portion  14  or becoming dislodged entirely. By turning the adjustment rod portion  16 , it can be threaded in or out of the axle body portion  14  to the length that is desired to fit the entire assembly  10  into a particular window casement  21 . The small portion  22  of the adjustment rod portion  16  extending beyond the raised shoulder  20  serves to stabilize the adjustment rod portion  16  within the adjustment spring  18  and axle body portion  14  of the axle  12  and prevents the raised shoulder  20  from jumping the coils of the adjustment spring  18 . The adjustment spring  18  also urges the adjustment rod portion  16  out and away from the axle body portion  14  and thus urges the free ends of the axle  12  away from each other. A metal coil spring is preferably used to spring-bias the axle to an extended telescoped condition. Other spring-biasing structures may be used for this purpose. 
   Turning now to  FIG. 7 , a spring motor  24  is connected to one end of the axle body portion  14  of the axle  12  and serves to drive the shade roller  26 , described below, during operation of the adjustable tension shade assembly  10 . In particular, the spring motor  24  is coupled to the axle body portion  14  of the axle  12  by interfitting the spring motor  24  into and over one end of the tube formed by the axle body portion  14 . The axle  12  remains stationary while the spring motor  24  furls and unfurls the shade  33  on the shade roller  26 . Spring motors  24  are well-known in the art and one skilled in the art would be capable of selecting or constructing an appropriate spring motor  24  to drive the adjustable tension shade assembly  10  of the present invention. Therefore, the spring motor  24  need not be discussed in further detail herein. 
   Referring back to  FIGS. 1 and 4 , attached to each end of the axle is a foot  28 . Each foot  28  serves to secure the adjustable tension shade assembly  10  against the window casement  21  without the use of additional mounting hardware. Although optional, each foot  28  preferably includes a soft rubber, or rubber-like, grip surface  30  to prevent damage to the underlying wall of the window casement  21 . Each grip surface  30  enhances the friction fit of the adjustable tension shade assembly  10  in the window casement  21  and prevents its slippage therefrom. Optionally, each foot  28  may further be pivotally mounted to the axle  12  to allow the adjustable tension shade assembly  10  to be fit into a window casement  21  that has walls that are not plumb or otherwise have uneven surfaces. 
   As best seen in  FIGS. 3–6 , received over the axle  12  is a shade roller  26  that has a tubular body. The shade roller  26  includes a first portion  32  and a second portion  34 . The second portion  34  is slidably received into the first portion  32  and enables the shade roller  26  to be adjusted to the desired length of the axle  12 . After the axle  12  has been adjusted to the desired length as described above, the shade roller  26  is extended or retracted as appropriate to correspond to the length of the axle  12 . A shade  33 , shown in  FIG. 1  but omitted from the other figures for ease of description, is attached to the shade roller  26  and is furled and deployed as desired. 
   Once the tension shade assembly  10  is sized to a given window casement  21  or other mounting structure, the shade  33  of the appropriate width can be secured to the shade roller  26 . As described above, the appropriate width may be achieved by cutting the shade, for example. 
   Referring back to  FIG. 2 , the shade roller  26  further includes a groove  36  on the first portion  32  that engages a tongue  38  on the second portion  34 . The engagement of the tongue  38  with the groove  36  prevents the rotational movement of either portion  32 ,  34  relative to the other. This feature is commonly referred to as “keying.” This keying the portions  32 ,  34  of the shade roller  36  prevents the adjustable tension shade assembly  10  from malfunctioning during its operation. As would be appreciated by one skilled in the art, the use of a tongue  38  and a groove  36  are but one implementation that one could use to “key” the portions  32 ,  34  of the shade roller  26  together. 
   In  FIGS. 3 and 4 , an end cap  40  is frictionally fit into the free end of the second portion  34  of the shard roller  26  and serves to support the shade roller  26  on the adjustment rod portion  16  of the axle  12 . 
   It can therefore be seen that the present invention provides a simple, yet inexpensive, adjustable tension shade that can be mounted in a variety of window casements and without damaging the window casement or the need for additional hardware. For these reasons, the instant invention is believed to represent a significant advancement in the art that has substantial commercial merit. 
   While there is shown and described herein certain specific structure embodying the invention, it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited to the particular forms herein shown and described except insofar as indicated by the scope of the appended claim.