Abstract:
A light attachment that can be readily mounted on a variety of tools and tool support fixtures and other support structures includes a light portion supported on a mounting portion by a flexible gooseneck cable. The mounting portion includes a housing that defines a male-female attachment element configured to slidingly mate with a complementary attachment element formed on the body of the power tool. In a preferred embodiment, the attachment element has a dovetail shape for sliding engagement within a complementary shaped notch in the body of the tool. The housing contains a power source for the light portion. The light portion incorporates an on-off switch that is actuated by rotating a component that is threadedly engaged within the housing. The housing supports a printed circuit board to which the power supply wires are attached. The circuit board also carries a spring contact switch element that completes an electrical circuit to energize the light portion when the spring contact is pressed against the circuit board. Power is supplied through the circuit board and switch to an LED light element. The LED is disposed within the housing so that the rotatable component can push the base of the LED into the spring switch to close the electrical circuit.

Description:
This application is a continuation-in-part of both (i) co-pending application Ser. No. 10/680,513, filed on Oct. 7, 2003, and (ii) co-pending application Ser. No. 10/680,632, filed on Oct. 7, 2003. The disclosure of each of the above-identified utility patent applications is hereby totally incorporated by reference in its entirety. 
   Also, this application claims the benefit of U.S. Provisional Application Ser. No. 60/509,360, filed Oct. 7, 2003. The disclosure of this provisional patent application is hereby totally incorporated by reference in its entirety. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to a light assembly, and particularly to devices for shedding light on a workpiece during operation of a power tool, such as a hand-held rotary power tool. 
   Hand-held power tools have been used by individuals for many decades. Such individuals include craftsman, repairman, hobbyists, and woodworkers to name a few. From the day that the power drill replaced the brace and bit, hand-held tools have greatly simplified most craft and/or repair projects and, perhaps most significantly, brought such projects within the grasp of the non-professional. Throughout its development, the power drill has been adapted to a variety of tasks, nearly all predicated on replacing the drill bit with a specialized tool. For instance, special bits have been developed for creating different types of holes in a workpiece. Other attachments allow a power drill to act as a screwdriver or sander. Still other attachment bits convert the power drill to a router capable of producing intricate patterns and scrollwork in a workpiece. 
   Power tools have evolved from the bulky pistol grip type drill to a more compact, “pencil” type tool. Smaller hand-held tools are available for performing very intricate cuts in a workpiece. Other hand-held power tools and attachments have been developed to allow a held-held drill to function like a coping saw or jig saw. In all of these applications, the ability to see the workpiece is critical. The development of smaller hand-held tools and streamlined support jigs has helped provide as un-obstructed view of the workpiece as possible. However, a clear view may be insufficient if the workpiece is not adequately illuminated. 
   A well lighted work area is obviously desirable, but is only half the battle. Even with the best stationary lighting, shadows can plague the home craftsman or repairman. Moreover, not all craft and/or repair operations need to occur at a well-lighted workbench. Consequently, there is a need for a light source that can be associated with a power tool and that eliminates the lighting problems that are present with prior work area lighting solutions. There is also a need for a light source that can be readily associated with a number of tools in the work shop. 
   SUMMARY OF THE INVENTION 
   The present invention addresses these needs by a light attachment that can be readily mounted on a variety of tools and/or tool support fixtures and/or other support structures. In one embodiment of the invention, the light attachment includes a light portion supported on a mounting portion by a flexible cable or gooseneck-type cable. The flexible cable can be bent to virtually any configuration and hold its shape so that the light portion can be positioned exactly at the location that requires illumination. 
   The mounting portion includes a housing that defines an attachment element configured to mate with a complementary attachment element formed on the power tool. Alternatively, the attachment element may be formed on a case for a power tool, or other fixture, and may even be formed on a clip device. In a preferred embodiment, the attachment element has a dovetail shape for sliding engagement within a complementary shaped notch in the body of the tool. The attachment element also includes a knob disposed at the end of a resilient arm. The knob is sized to fit within a dimple defined in the notch in the tool body and the resilient arm is arranged to deflect as the attachment element slides into the notch. When the knob is aligned over the dimple, the resilient arm urges the knob into the dimple to help hold the mounting portion, and therefore the light attachment, to the tool or tool support fixture or other support structure. 
   The housing of the mounting portion is configured to contain a power source for the light portion. In the preferred embodiment, the power source includes a number of flat batteries, such as a lithium ion batteries, coupled to power supply wires housed within the flexible cable. 
   The light portion of the light attachment incorporates the on-off switch into the light guide. The light portion includes a housing mounted to the flexible cable. The housing supports a printed circuit board to which the power supply wires are attached. The circuit board also carries a spring contact switch element that completes the circuit when it is pressed against the circuit board. Power is supplied through the circuit board and switch to an LED light element. The LED is disposed within the housing. The light guide is in threaded engagement with internal threads of the housing so that the guide can bear against the LED light element as it is threaded into the housing. Pressure on the LED light element causes a terminal thereof to depress the spring contact switch element to energize the LED light element. An O-ring can be engaged between the light guide and the housing to increase the frictional resistance to movement of the light guide. 
   The LED preferably includes a built-in refraction lens so that a lens is not required on the light guide. The built-in lens, which has a defined angle of refraction, thus focuses the light emitted by the LED onto the workpiece. 
   One benefit of the present invention is that it provides a light attachment that can be attached to a variety of tools or fixtures or other support structures to provide direct illumination where it is needed most. Another benefit is that the light emitting portion is carried by a flexible cable that allows positioning the light in an infinite number of positions. 
   A further benefit achieved by the light attachment of the present invention is that certain heavy components of the light attachment are contained at the mounting end of the light attachment so that its weight does not interfere with the ability to position the light source and hold that position. Yet another benefit is that the on-off switch is with the light source, or immediately adjacent the workpiece. 
   Other benefits and certain objects of the invention will become apparent from the following written description taken together with the accompanying figures. 

   
     DESCRIPTION OF THE FIGURES 
       FIG. 1  is a perspective view of a hand-held tool with the light attachment mounted thereto in accordance with the principles of the present invention. 
       FIG. 2  is a side elevational view of the light attachment shown in  FIG. 1 , with the light attachment repositioned to assume a substantially linear orientation. 
       FIG. 3  is an end elevational view of the mounting portion of the light attachment shown in  FIG. 2 . 
       FIG. 4  is an enlarged partial perspective view of an attachment feature on the hand-held tool shown in  FIG. 1  for use with the light attachment of the present invention. 
       FIG. 5  is a side partial cross-sectional view of the light attachment shown in  FIG. 2 . 
       FIG. 6  is a cross-sectional view of the mounting portion housing of the light attachment shown in  FIG. 5 . 
       FIG. 7  is a top partial cut-away view of the light attachment shown in  FIG. 5 . 
       FIG. 8  is an enlarged exploded perspective view of the light portion of the light attachment shown in  FIG. 1 . 
       FIG. 9  is a side cross-sectional view of the light portion shown in  FIG. 8 . 
       FIG. 10  is a side elevational view of a tool support fixture configured for use with the light attachment in accordance with the principles of the present invention. 
       FIGS. 11–14  are various distinct perspective views of a clip device to which the light attachment of  FIG. 2  may be mounted in accordance with the principles of the present invention. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   For the purposes of promoting an understanding of the principles of the present invention, reference will now be made to the embodiments illustrated in the drawings and described in the following written specification. It is understood that no limitation of the scope of the invention is thereby intended. It is further understood that the present invention includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the invention as would normally occur to one skilled in the art to which this invention pertains. 
   The present invention is particularly suited for use with a hand-held tool, such as a rotary hand-held power tool  10  shown in  FIG. 1 . The power tool  10  includes a working end  12  that can be a collet for attachment of various rotary tool bits, such as bits for grinding, sharpening, routing, cutting, carving, engraving, cleaning, polishing, and sanding. The tool  10  includes a body  14  that houses drive and control components (schematically shown by reference numeral  11 ) for the tool. The distal end  15  (i.e., the end of the tool opposite the working end  12 ) is configured to support a light attachment  20  according to one embodiment of the present invention. 
   The light attachment  20  includes a light portion  22 , a flexible cable (or conduit)  24  and a mounting portion  26 . The flexible cable  24  is a gooseneck cable that can be bent to assume one of an infinite number of positions, and can maintain that position. The gooseneck cable  24  can be constructed in a known manner to exhibit this formable rigidity or stiffness. For instance, a typical gooseneck cable includes a pair of concentrically disposed spiral-wound tubes. The outer radius of the spirals of the inner tube is substantially equal to the inner radius of the spirals of the outer tube so that the static friction force between the inner and outer tubes tends to keep the gooseneck cable in a fixed position when no forces are being applied thereto. The cable  24  is hollow to allow passage of power wires  66  (see  FIGS. 8–9 ). 
   In the preferred embodiment, the mounting portion  26  includes three basic components. In particular, the mounting portion includes a top cover  30 , a battery cover  32  that snaps onto the top cover, and a bottom cover  34 . The top and bottom covers can snap together or, preferably, are affixed such as by sonic welding or use of an adhesive. Alternatively, screws may be used to affix such parts together. The bottom cover  34  includes an attachment element  36  that is configured to engage a complementary attachment feature  16  located at the distal portion  15  of the body  14  of the tool  10  (see  FIG. 4 ). The attachment components are male-female type attachment elements that can be positively engaged. For instance, as seen in  FIGS. 2 and 3 , the attachment element  36  is in the form of a dovetail  38  that slides in a friction fit manner within a complementary-shaped notch or cavity  17  defined in structure attached to the tool body  14 . Alternatively, such structure may be integrally formed as a part of the tool body  14 . In order to further hold the attachment element  36  to the attachment feature  16 , the dovetail is provided with a knob  40  formed at the end of a resilient arm  41 , as best seen in  FIGS. 5–6 . The arm  41  is biased to the position shown in the figures with the knob  40  extending below the dovetail structure  38 , although the arm can be resiliently deflected upward into a cavity  42  formed in the dovetail structure. When the dovetail structure  38  is slid into the notch  17 , the resilient arm deflects upward as the knob  40  bears on the surface of the tool body. When the dovetail is fully seated within the notch  17 , the knob  40  is aligned with a dimple  18  formed within the notch. The resilient arm  41  urges the knob into the dimple to further hold the attachment element  36  within the attachment feature  16  of the tool body  14 . The knob can be disengaged and the mounting portion  26  removed from coupling relationship with the tool  10  by a applying a slight force against the mounting portion. 
   The top and bottom covers  30 ,  34  cooperate to define a shackle  45  that surrounds the flexible cable  24  as it extends into the mounting portion  26 . A collar  47  surrounds the shackle to press the shackle about the cable to help hold the assembly together. In addition, the interior of the top and bottom covers can define a series of strain relief ridges  50 . These ridges  50  press into the exterior of the flexible cable disposed within the mounting portion to hold the cable within the covers. The ridges provide a strain relief function as they resist but don&#39;t prevent separation of the flexible cable from the mounting portion under sufficient force. 
   The bottom cover  34  defines supports  52  ( FIG. 6 ) for a printed circuit board  55  ( FIG. 5 ) mounted therein. The circuit board is connected to the power wires  66  ( FIGS. 8–9 ) that pass through the flexible cable and that are electrically connected to the light portion  22 . The circuit board  55  also electrically interfaces with a battery assembly  57  supported within the top cover  30 . The battery assembly is accessible for replacement through the battery cover  32 . The top cover and battery cover combine to support a positive terminal  59  ( FIG. 7 ) and a negative terminal  61  for electrical contact with the cathode and anode of the battery assembly. Preferably, the battery assembly  57  includes a disc shaped battery stack. For instance, the battery assembly can include two 3 volt lithium ion (CR2025) batteries. The circuit board  55  provides an electrical interface between the battery assembly and the power wires. 
   Referring to  FIGS. 8–9 , the light portion  22  includes a housing  63  that is affixed to the free end of the flexible cable  24 . The housing can include a shackle  64  similar to the shackle  45  of the mounting portion to firmly connect the housing to the cable. The shackle  64  may be crimped or swaged over the flexible cable. The housing is hollow to receive the wires  66  therethrough and to support the components of the light portion  22 . In the preferred embodiment, the light portion  22  includes a printed circuit board  65  that is electrically connected to the wires  66 . The circuit board  65  supports a leaf spring contact switch  67  that includes one end portion that is biased away from the circuit board. The circuit board  65  further supports a power lead  68  that is connected to the base  72  of an LED light  70 . The leaf spring contact switch  67  can be depressed toward the circuit board  65  so that the one end portion of the leaf spring contact switch makes electrical contact with a wire pad on the circuit board  65  while being in further electrical contact with a corresponding wire pad on the LED base  72  thereby completing an electrical circuit that includes the battery assembly  57  and the LED light  70 . The switch and circuit board is configured so that the leaf spring contact switch  67  is normally biased to a “break” (or open circuit) position, but can be depressed, as discussed above, to a “make” (or closed circuit) position. 
   The switch  67  is actuated by rotation of a light guide  75  that is threaded into the mouth of the housing  63 . The lower portion of the light guide  75  includes external threads that mate with internal threads  83  defined within the housing. The lower portion of the light guide  75  bears against the base  72  of the LED  70  with the LED projecting into a bore  77  of the light guide. As shown in  FIG. 9 , the bore  77  can be outwardly flared to widen the light beam leaving the light portion. In a preferred embodiment, the LED  70  includes a built-in refraction lens  71  that eliminates the need for a lens across the mouth of the light guide  75 . The built-in lens is preferably configured to focus the light emitted by the LED  70  to a relatively narrow beam so that the maximum candlepower can be focused on the workpiece. 
   As the light guide  75  is threaded into the housing  63 , the lower portion pushes down on the LED base  72 . As the base slides within the housing it pushes down on the spring switch  67  to close the switch and make the electrical circuit. As the light guide is threaded out of the housing, the pressure on the spring switch is relieved and the natural resilience of the switch causes it to deflect upward. 
   In one aspect of the invention, the interface between the light guide  75  and the housing  63  is such that the light guide resists unthreading under upward pressure from the spring switch  67 . In order to enhance this resistance, the light portion  22  includes an O-ring  84  disposed between the light guide and the housing, as shown in  FIG. 9 . The O-ring resists translation within the housing, which ultimately resists movement of the light guide into or out of the housing. The frictional resistance generated by the O-ring  84  is sufficient to hold the position of the light guide against the upward force of the spring switch, but not so great as to make manually threading the light guide into the housing too difficult. 
   The light attachment  20  beneficially retains the battery assembly in the mounting portion  26  so that the weight of the battery assembly can be easily borne by the tool itself. This arrangement eliminates the additional weight of the battery assembly in the light portion  22  which can compromise the ability of the flexible gooseneck cable  24  to hold the position of the light portion. On the other hand, the on-off switch is incorporated into the housing and light guide of the light portion  22  so that the light can be easily turned on or off near the location of the workpiece. 
   The light attachment  20  is configured to be mounted to wide range of tools and tool support fixtures and other support structures, provided they include an appropriate attachment feature, such as the feature  16  of (or on) the tool body  14 . For instance, as shown in  FIG. 10 , a tool support fixture  90  is provided for supporting a tool, such as the tool  10  shown in  FIG. 1 . The fixture includes an engagement nut  94  that fixes the tool to the fixture  90 . For instance, the tool  10  is provided with external threads on its body that mate with internal threads of the nut  94  to secure the tool  10  to the fixture  90 . A pair of handles  96  is provided to permit stable manipulation of the fixture and the tool mounted within the fixture. 
   The fixture includes several attachment features  98  which are identical to the attachment feature  16  described above. Thus, the fixture  90  provides multiple locations at which the light attachment  20  can be supported on the fixture. The flexible cable  24  can be manipulated so that the light portion  22  is optimally positioned to direct a light beam in a meaningful direction. Moreover, the multiple attachment features  98  can support several light attachments to illuminate the workpiece from multiple directions. 
   The light attachment tool  20  is also configured to be mounted to a clip device  150  that is shown in  FIGS. 11–14 . The clip device  150  includes a base (or support structure)  152  and a clip arm  154  pivotally mounted to the base  152 . The base  154  includes an attachment element  155  (see  FIGS. 13–14 ) that is configured to engage with the dovetail attachment element  36  of the light attachment  20  (see e.g.  FIGS. 2–3 ). The attachment element  155  is substantially identical to the attachment feature  16  described above. In particular, the attachment element  155  defines a dovetail shaped cavity  157  as shown in  FIGS. 13–14  that is configured to receive the dovetail structure  38  of the attachment element  36  in a friction fit manner so as to hold the light attachment  20  in fixed relation to the clip device  150 . The base  152  further has defined therein a dimple  159  that is configured to receive the knob  40  of the attachment element  36  (see  FIGS. 2–3 ) so as to enhance the integrity of the coupling between the light attachment  20  and the clip device  150 . 
   The base  152  further has a pair of spaced apart mounts  156 , each having a hole (not shown) defined therein. Similarly, the clip arm  154  has a pair of holes  158  respectively aligned with the holes defined in the pair of spaced apart mounts  156 . A rod  160  extends through the aligned holes of the mounts  156  and the clip arm  154  so as to provide a pivotal coupling therebetween as best shown in  FIG. 12 . A spring  162  is positioned around the rod  160  and arranged to bias the clip arm  154  to its closed position as best shown in  FIGS. 11–12 . However, upon application of force to the clip arm  154  at location  164 , the clip arm  154  pivots about the rod  160  so as to provide an opening between the end portion  166  of the spring arm  154  and the base  152 . Then, the clip device may be attached to any appropriate support object (e.g. a work bench) by simply locating a part of the support object in the opening, and thereafter, removing the application of force to the clip arm at the location  164 . 
   The clip device  150  may conveniently be packaged and sold together as a kit with the light attachment  20  and/or the power tool  10 . The clip device  150  provides significant benefits since it may be mounted on any appropriate structure in the vicinity of a workpiece to thereby provide a mount for receiving the mounting portion  26  of the light attachment  20 . Other benefits of the present invention are derived since both the power tool  10  and the clip device  150  possess a similarly configured dovetail cavity thereby providing the user the option to either mount the light attachment  20  directly to the power tool  10 , or alternatively mount the light attachment  20  to the clip device for custom mounting on any appropriate structure in the vicinity of the workpiece (e.g. a work bench). 
   While the invention has been illustrated and described in detail in the drawings and foregoing description, the same should be considered as illustrative and not restrictive in character. It is understood that only the preferred embodiments have been presented and that all changes, modifications and further applications that come within the spirit of the invention are desired to be protected.