Abstract:
A flexible extension shaft comprises a flexible extension member having a length, and one end and an opposite end. A tool base connection member is secured to one end of the flexible extension member. A tool bit connection member is secured to the opposite end of the flexible extension member. A lighting unit is secured to the flexible extension shaft.

Description:
TECHNICAL FIELD 
       [0001]    The invention relates to flexible extension shafts for extending the reach of hand tools and power tools, such as screwdrivers. 
       CROSS REFERENCE TO RELATED APPLICATIONS 
       [0002]    (Not applicable) 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0003]    (Not applicable) 
       BACKGROUND OF THE INVENTION 
       [0004]    Many tools, such as screwdrivers, have a chuck which receives a tool bit, thus allowing the use of the tool for a plurality of functions. For example, many screwdrivers terminate in a hexagonal chuck which simply comprises a hexagonal hole configured to receive a standard bit having a hexagonal base. Such bits are commonly available, often featuring Phillips-type screwdriver heads of various size, slot-type screwdriver heads of various size, and other tools. 
         [0005]    Extension shafts for such tools are also well known, typically comprising a hexagonal base configured to be received in the hexagonal chuck of a standard tool. The hexagonal base is coupled to a flexible extension member which, in turn, is coupled to hexagonal chuck. The effect is to extend the reach of the tool by about the length of the flexible extension member. At the same time, the flexibility of the extension member allows a tool to perform a function in what might be otherwise an unreachable place, for example inside an item of machinery. 
       SUMMARY OF THE INVENTION 
       [0006]    In accordance with the invention, an improved flexible extension shaft featuring an illumination light is provided. 
         [0007]    More particularly, a flexible extension shaft comprises a flexible extension member having a length, and one end and an opposite end. A tool base connection member is secured to one end of the flexible extension member. A tool bit connection member is secured to the opposite end of the flexible extension member. A lighting unit is secured to the flexible extension shaft. 
         [0008]    The lighting unit may be slidingly mounted on the flexible extension member. 
         [0009]    The flexible extension member may comprise an outer sleeve and a central rotatable member which rotates within the outer sleeve. The tool base connection member and the tool bit connection member may be secured to the central rotatable member. 
         [0010]    Connection member may be included for securing the lighting unit to the flexible extension member. 
         [0011]    The connection member may be a closed loop extending around the flexible extension member. 
         [0012]    Alternatively, the connection member may be a clip. 
         [0013]    The lighting unit may incorporate a switch. 
         [0014]    The lighting unit a slide on the flexible extension member. 
         [0015]    The tool base connection member may comprise a hexagonal bit for mating with the output of a power or hand tool and the tool bit connection member may be a hexagonal socket chuck. 
     
    
     
       BRIEF DESCRIPTION THE DRAWINGS 
         [0016]    The operation of the invention will become apparent from the following description taken in conjunction with the drawings, in which: 
           [0017]      FIG. 1  is a perspective view of a flexible extension shaft in accordance with the present invention, illustrating the workpiece illuminating light positioned proximate to the work area, for example illuminating a screw being tightened by the shaft using a power or manual tool driver; 
           [0018]      FIG. 2  is a view similar to that of  FIG. 1  with the lighting unit in the rearward position; 
           [0019]      FIG. 3  is a detailed perspective of the lighting unit positioned adjacent the workpiece; 
           [0020]      FIG. 4  is a schematic diagram of an electrical circuit for use in a flexible extension shaft according to the present invention; 
           [0021]      FIG. 5  is a perspective view of an illumination device useful in the inventive extension shaft with the housing cap removed to exposing internal working parts, but showing the switch and batteries in a working position; 
           [0022]      FIG. 6  is a cross-sectional schematic illustration of the illuminating unit illustrated in Figures numerals  1 - 5  with the batteries removed; 
           [0023]      FIG. 7  is a view similar to  FIG. 6  with the batteries in place; 
           [0024]      FIG. 8  is a view similar to  FIG. 5  illustrating wiring of power from the switch to the light source; 
           [0025]      FIG. 9  is a perspective view illustrating the drive receiving end of the inventive flexible extension shaft; 
           [0026]      FIG. 10  is a view similar to  FIG. 9  with the illumination unit grippingly engaged by the shaft base collar; 
           [0027]      FIG. 11  illustrates the socket end of the flexible extension shaft; 
           [0028]      FIG. 12  is a view similar to that of  FIG. 8  illustrating an alternative embodiment of the invention which may be clipped onto an existing flexible or inflexible shaft; 
           [0029]      FIG. 13  illustrates an alternative embodiment of the present invention using a coiled contact spring structure; 
           [0030]      FIG. 14  illustrates the coiled contact spring structure; 
           [0031]      FIG. 15  illustrates the embodiment of  FIGS. 13 and 14  in an exploded cross-sectional, schematic view; 
           [0032]      FIG. 16  illustrates cap of the alternative embodiment of  FIG. 15  in a cross-sectional, schematic view; and 
           [0033]      FIG. 17  illustrates base of the alternative embodiment of  FIG. 15  in a cross-sectional, schematic view. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0034]    Turning to  FIG. 1 , an extension shaft  10  constructed in accordance with the present invention is illustrated. Extension shaft  10  comprises a hexagonal shaft base  12  and an illumination unit  14 . Hexagonal shaft base  12  is secured to a flexible extension member  16 . An extension shaft chuck  18  is secured to the other end of flexible extension member  16 . 
         [0035]    In  FIG. 1 , illumination unit  14  is illustrated on extension shaft  10  in the illuminating position. Optionally, illumination unit  14  may be positioned on extension member  16  of extension shaft  10  in the light storage position as illustrated in  FIG. 2 . Repositioning is done by simply sliding illumination unit  14  on extension member  16  until it is in the desired position, which in most cases it is the most scored position, as illustrated in  FIG. 1 . Alternatively, illumination unit  14  may be slid to the rearmost position illustrated in  FIG. 1 . 
         [0036]    Generally, illumination unit  14  comprises a tubular sleeve  20  configured to snugly fit around extension member  16 , as illustrated most clearly and  FIG. 3 . This enables illumination unit  14  to slide to any position along the extension member  16 . Slight curving of extension member  16  will result in snugly securing tubular sleeve  20 , thus maintaining it in any desired position. 
         [0037]    An illumination housing base  22  is secured to an integral with tubular sleeve  20 . An illumination housing cap  24  mates with illumination housing base  22 , and is secured debt to by, for example, screws  26 . Illumination is generated by a lamp  28 , at one end of the housing formed by illumination housing base  22  and illumination housing cap  24 . At the other end of the housing, a single pole single throw switch  30  forms of function of turning lamp  28  on and off. 
         [0038]    As illustrated in  FIG. 4 , lamp  28  is wired in series with switch  30  and batteries  32 . Lamp  28  may take any of various forms, but in accordance with a preferred embodiment of the invention, a light emitting diode is used. 
         [0039]    As can be seen in  FIG. 5 , when screws  26  are unscrewed, cap  24  may be removed, exposing batteries  32 . When needed, batteries  32  may thus be replaced and cap  24  put back in place and secured with screws  26 , which are received in holes  34 . 
         [0040]    Referring to  FIG. 6 , illumination unit  14  is illustrated in cross-section. For purposes of understanding the function of the various members, in this view, batteries  32  have been removed, exposing leaf spring battery contacts  36  in their relaxed or un-deflected positions. As illustrated in  FIG. 4 , leaf spring contacts  36  function as wires in the circuit through which batteries  32  drive lamp  28 . 
         [0041]    More particularly, current flows through a path comprising switch lead  38 , leaf spring contacts  36  lamp  28 , leaf spring contacts  36 ′ and switch lead wire  40 . That path forms a series circuit with voltages from batteries  32  being added to each other. 
         [0042]    As illustrated in  FIG. 7 , when it is desired to insert batteries into the illumination unit  14 , batteries are placed in volumes  44 , causing the deflection of leaf spring contacts  36  in the directions indicated by arrows  42  in  FIG. 6 . Alluded to above illumination housing cap  24  may be removed from illumination housing base  22 , resulting in exposure of volumes  44  to receive or accommodate replacement of batteries  32 , as illustrated in  FIG. 8 . 
         [0043]    As can be seen most easily in  FIG. 8 , light emitting diode lead  46  is positioned in a channel  48 . When illumination housing cap  24  is brought into engagement with illumination housing base  22 , light emitting diode lead  46  bears against lead  38  of switch  30 . 
         [0044]    In accordance with the invention, light emitting diode lamp  28  may be secured to illumination housing base  22 . Likewise, switch  30  may be secured to illumination housing cap  24 , for example by glue or a friction fit. 
         [0045]    Referring to  FIG. 9 , base  12  comprises a hexagonal member  50  configured to mate with a standard hexagonal tool socket. Based  12  also includes a collar  52 , which defines a cutaway portion  54 . As illustrated in  FIG. 10 , cutaway portion  54  receives switch housing portion  56 . Illumination unit  14  may be retained in the position illustrated in  FIG. 10 , by frictional engagement of switch housing portion  56  with the edges  58  of cutaway portion  54 . Alternatively, frictional engagement with the inside surface  60  of collar  52  may be used to achieve the same result. 
         [0046]    Referring back to  FIG. 9 , hexagonal shaft base  12  is secured to flexible extension member  16 , for example by being crimped, welded or by any suitable means. In accordance with a preferred embodiment, hexagonal member  50  is secured to a central rotatable member  62 , which rotates within flexible extension member  16 , having a structure which is generally, per se, taught in the prior art. Likewise, in accordance with the present invention, it is contemplated that a variety of coupling structures and coupling members may be used at both ends of extension shaft  10 . 
         [0047]    Illumination unit  14  is able to slide from the position illustrated in  FIGS. 2 and 10 , to the position illustrated in  FIGS. 1 and 3 . In use, it would be in the forward position illustrated in  FIG. 1 , likely, for most users, most of the time. However, under certain circumstances, it may be desirable to vice illumination unit  14  as illustrated in  FIG. 2 . This would keep illumination unit  14  out of the way, for example in the event that the space where the work is being done is relatively cramped. 
         [0048]    Referring to  FIG. 11 , an illustrative extension shaft chuck, comprising a hexagonal socket configured to receive standard hexagonal tool bits, such as Philips head tool bits, slot or standard screwdriver driver tool bits and drill tool bits. 
         [0049]    In accordance with the invention, any suitable chuck may be used, such as a Jacobs™ type chuck or the like. 
         [0050]    In accordance with the invention, collar  64  is secured to flexible extension member  16 . Central rotatable member  62  is secured, at the end opposite the end of which is secured to base  12 , to extension shaft chuck  18 , which includes a hexagonal socket  66 . 
         [0051]    An alternative embodiment of a flexible extension shaft illumination unit  114  of the invention is illustrated in  FIG. 12 . In this embodiment, structures are substantially identical to those illustrated in the embodiment of Figures and  1 - 11 , except that the cylindrical portion of illumination housing base  12  has been replaced by a pair of cylindrically contoured clamps  112 . 
         [0052]    Referring to  FIG. 13 , another alternative embodiment of the invention is illustrated. In this embodiment, illumination unit  214  uses a double-coiled spring  236  in place of the leaf springs  36  of the earlier embodiments. Such a spring  236  is illustrated  FIG. 14 . In this embodiment, a switch  230  is secured by a quantity of glue  268 . Referring to  FIG. 15 , the parts of illumination unit  214  are illustrated in exploded perspective. 
         [0053]    The replacement of batteries in accordance with the invention may be seen with reference to  FIGS. 16 and 17 .  FIG. 16  schematically in cross-section illustrates the cap portion of the illumination unit in the embodiment of  FIG. 12 .  FIG. 17  schematically in cross-section illustrates the base portion of the illumination unit in the embodiment of  FIG. 12 .