Extensible tool handle
BACKGROUND OF THE INVENTION 
     This is a continuation of application Ser. No. 651,898 filed Sept. 19, 1984, now abandoned. 
    
    
     The present invention relates to extensible handles for tools such as cleaning tools which are required for use in remote locations. 
     Household cleaning tools such as feather dusters and vacuum cleaning tools, and gardening tools such as clippers and pruning shears often need to be used in relatively inaccessible locations such as the corners of ceilings. The household cleaning tools like the feather dusters normally have fairly short handles and it is difficult to reach ceilings with them. Vacuum cleaner tubes are often provided with extensible flexible hoses and separate extension tubes with locking arrangements which are relatively difficult to use, and cannot readily be extended. 
     Other types of tools which are also often needed in inaccessible locations are paint brushes, pruning shears, and the like. Such locations are often reached using ladders, and these tools could be used more safely if provided with an easily extensible, secure handle. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an extensible handle for tools to allow the tools to reach otherwise inaccessible locations. 
     It is a further object of the invention to provide such a handle which can be readily changed in length. 
     According to the present invention, an extensible handle for a tool is provided which comprises at least two telescoping inner and outer cylinders of elliptical cross-section. When the elliptical axes of the cylinders are aligned, they can be telescoped in and out of each other to the desired length. The cylinders are then rotated out of alignment so that the opposing elliptical surfaces bind and secure and substantially seal the cylinders together. 
     In a preferred embodiment of the invention, several telescoping elliptical cylinders or tubes are provided to allow a large variation between the maximum and minimum lengths of the handle. A tool such as a feather duster or pruning shears may be secured to one end of the handle. 
     Thus the length of the handle can be quickly and easily adjusted according to the location in which the tool is to be used by simply rotating the elliptical cylinders into alignment, sliding them relative to one another until a desired length is reached, and then rotating them out of alignment to bind their relative position together. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above described in other objects, advantages and features of the present invention will become more readily apparent from a review of the following specification when taken in conjunction with the drawings, wherein: 
     FIG. 1 is a perspective view of a feather duster having an extensible handle according to a preferred embodiment of the invention; 
     FIG. 2 is a view similar to FIG. 1 showing the handle collapsed with a saw tool attached to the handle; 
     FIG. 3 is a sectional view of the handle on the line 3--3 of FIG. 2, showing a vacuum hose attachment; 
     FIG. 4 is a horizontal cross-section on the line 4--4 of FIG. 1; 
     FIGS. 5A and 5B are exaggerated cross-sectional views through two of the tubes to depict the locking action between the elliptically shaped tubes; 
     FIGS. 6A and 6B are exaggerated cross-sectional views through two tubes to depict the locking action between slightly triangularly shaped tubes; 
     FIGS. 7A and 7B are exaggerated cross-sectional views through two of the tubes to depict the locking action between rectangularly shaped tubes; and 
     FIGS. 8A and 8B are exaggerated cross-sectional views through two of the tubes to depict the locking action between pentangonally shaped tubes. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The drawings show a preferred embodiment of an extensible handle according to the invention. Clearly, the extensible handle may be used for many types of tools, including cleaning tools, gardening tools, decorating tools, and the like. Some examples are showin in the drawings. In FIG. 1, the extensible handle is shown as used for a feather duster, and in FIG. 2 it is attached to a saw tool. In FIG. 3 a vacuum hose attachment is shown. 
     As shown in FIG. 1, a feather duster 1 is secured to one end of an extensible handle 2 comprising a series of telescoping tubes or cylinders 3, 4, 5, and 6 of generally elliptical cross-section. As shown in FIG. 4, each tube is of gradually reduced cross-sectional size so that each one is a close but slidably fit within the next. Although in FIG. 4 all the cylinders are shown as tubes, the innermost cylinder 6 could be of solid cross-section. 
     Each tube engages telescopically into the next tube in the handle. Adjacent tubes are rotatable relative to one another between a release position in which their elliptical axes are aligned and they are telescopically slidable relative to one another to change the length of the handle, and a locked position in which their axes are out of alignment and they are held against relative axial movement by the binding engagement between their opposing elliptical surfaces. With proper selection of elliptical cross-sections, the engagement provides a substantial seal for adjacent tubes. FIG. 4 shows all tubes with their elliptical axes aligned. 
     FIGS. 5A and 5B show two of the tubes 30 and 31 with their ellipses exaggerated so that the sealing action is clear. In FIG. 5A the two tubes 30 and 31 have their elliptical axes aligned. In FIG. 5B the innermost tube 31 has been rotated out of alignment so that it binds against the outer tube 30 at points 7 and 8. 
     The tubes may be made of any suitable, relatively rigid material, such as plastic or aluminum, for example. 
     When the feather duster 1 is to be used to clean debris such as dust and cobwebs from remote locations, adjacent tubes of the handle can be adjusted until the necessary length is reached. Thus adjacent tubes are twisted into alignment, telescoped in or out to a desired length, and twisted out of alignment until they are locked together. This can be repeated for each adjacent pair of tubes in the handle until the overall desired length is reached. In the preferred embodiment, the handle 2 has four tubular sections, but more or less sections of selectable lengths may be provided according to the maximum extension desired. 
     In FIG. 2, the tubes are shown collapsed or telescoped to their minimum length. A sawing tool or head 9 is attached to the handle 2 in this example, which may be used for pruning, for example. Thus the handle can be adjusted to the necessary length to reach the branches of trees to be pruned. 
     When adjacent tubes are twisted until they bind together, the opposing elliptical surfaces will be substantially sealed. Thus the handle may also be used to form an extensible hose connector for a vacuum cleaner, as illustrated in FIG. 3. If the seal is insufficient for a vacuum hose, an extra seal such as an O-ring may be provided at each interconnection between adjacent tubes, as shown in FIG. 3. 
     FIG. 3 shows the seals between the telescoping ends of the end two tubes 3 and 4 of the handle. All the other engaging tube ends will be provided with similar seals. An inner seal 10 is provided on the end 11 of the tube 4 which engages inside the tube 3 to provide a seal between the end and the adjacent surface of the tube 3. An outer seal 12 is provided on the end 13 of the tube 3 which engages over the tube 4. The seals may be of any suitable material, such as foam rubber, rubber or foamed plastic, and allow the relative rotation between the elliptical tubes to provide the locking action. 
     The free end 14 of the tube 3 is provided with a rubber grommet 15 for connection to a flexible vacuum hose 16 of the type found on vacuum cleaners. The opposite end (not shown) of the sealed extension tube 20 is conventionally mounted on a vacuum cleaner attachment connecting device. The vacuum cleaner is thus provided with an extensible attachment handle for reading into remote corners and raised areas. 
     FIGS. 6A and 6B show an alternate embodiment of two tubes 40 and 41 having slightly triangularly shaped noncircular cross-sections. In FIG. 6A the tubes 40 and 41 are shown having their respective axes aligned and in FIG. 6B the innermost tube 41 is rotated out of alignment so that it binds against the outer tube 40. 
     FIGS. 7A and 7B and FIGS. 8A and 8B show similar structures for noncircular tube structures with generally rectangular and pentagonal cross-sectional structures. In FIG. 7A the tubes 50 and 51 are shown having their respective axes aligned and in FIG. 7B the innermost tube 51 is rotated out of alignment so that it binds against the outer tube 50. 
     Similarly, in FIG. 8A, the two tubes 60 and 61 have their respective axes aligned and in FIG. 8B the innermost tube 61 has been rotated out of alignment so that it binds against the outer tube 60. 
     Clearly, the handle may be used for any type of cleaning tool having a handle, and may be used for other types of handled tools. Gardening tools such as pruning shears often have to be used in relatively remote locations, and if these tools were provided with extensible handles as described above, they could be used in remote locations without a ladder. In another application, a clamp could be secured at one end of the extensible handle for passing things to people in out-of-reach locations, e.g. on roofs, building sites, airplanes and the like. 
     The extensible handle is relatively inexpensive, easy to adjust and allows ready access to places which are otherwise out of normal reach. 
     While a preferred embodiment of the present invention has been described above, it will be understood that modifications and changes may be made to the disclosed embodiment which are within the scope of the invention, which is defined by the appended claims.