Abstract:
The illuminated retractable leash is an animal tethering device which uses electroluminescent wire and a DC to AC inverter to illuminate not only the extendable and retractable physical tether to the animal, but also to illuminate the leash housing. Electroluminescent wire wound on a rotating spool is supplied power by an inverter circuit powered by an on board battery. A transparent spool and an at least partially transparent housing provides the capability for illuminating the housing, as well as the electroluminescent wire leash.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to pet leashes, and more particularly to an illuminated, retractable pet leash. 
   2. Description of the Related Art 
   Retractable leashes for pets are well known. U.S. Patent Publication No. 2003/0029388, published in February 2003, and U.S. Patent Publication No. 2003/0145803, published in August 2003, both disclose a housing having a spring-biased spooling assembly for automatically taking up the slack in the leash. Similarly, illuminated pet leashes have also been available for several years. Not only do they increase the safety of both the pet and the owner when walking at night, but also present an attractive ornamental appearance. In addition, retractable leashes that extend the length of the leash and then retract, taking up the slack as the length is shortened, have also been available. 
   U.S. Pat. No. 5,967,095, issued to K. Greeves in October 1999, discloses a leash having a relatively flat and flexible light source provided along one side of the leash for illuminating the leash. The leash is a strap made from leather, plastic, nylon, or other similar material. The light source is preferably at least one strip of electroluminescent material attached to one or both sides of the strap by C-clips, hook and loop fasteners, etc., or is embedded into the strap. The electroluminescent material is powered by a battery and inverter, the power source being either permanently or temporarily attached to the strap. A second embodiment incorporates electroluminescent material to, illuminate the handle portion of a leash retractor, but does not incorporate means to illuminate the leash itself. Greves does not show or suggest a retractable illuminated leash, nor does Greves show or suggest that the leash may be made from electroluminescent wire itself, without a supporting strap of leather, plastic, nylon or the like. 
   U.S. Pat. No. 4,513,692, issued to Kuhnsman et al. in April 1985, discloses an illuminated pet leash comprising a non-opaque tube that contains one or more bundles of optical fibers. A light bulb is connected adjacent to the leash handle to shine light into the tube and illuminate the optical fibers in the tube. 
   U.S. Pat. No. 4,887,552, issued to James Hayden in December 1989, discloses an electrically lighted pet leash that is composed of a transparent, flexible tube containing a string of small electric light bulbs mounted in parallel between two insulated wires. The leash is looped at one end to form a choker collar and at a second end to form a handle. The string of lights extends throughout the leash to illuminate both the collar and the handle. A small rechargeable battery is mounted adjacent to the handle for operating the lights. 
   U.S. Pat. No. 5,850,807, issued to Russell Keeler in December 1998, discloses an illuminated leash for allowing a pet owner to easily and remotely locate the pet leash. The device includes an encoding/transmitting device for encoding and transmitting output signals, an elongated non-opaque tube having a bundle of optical fibers longitudinally disposed therein, a housing, a receiving/decoding device disposed within the housing for receiving and decoding the output signals from the transmitter and a light source disposed in the housing adjusted to illuminate the bundle of fibers. 
   The related art does not describe or suggest incorporating an illuminated, retractable leash within a leash retractor housing. Rather, the related art has been directed towards illuminated handles. In addition to the &#39;095 patent heretofore discussed, U.S. Pat. No. 5,558,044, issued to Nassar, Jr. et al. in September 1996, discloses an illuminated dog leash handle and U.S. Pat. No. 5,887,550, issued to Anthony H. Levine, in May 1999, discloses a combined retractable pet leash and flashlight. 
   Although less relevant to the present invention, U.S. patent application Ser. No. 10/406,448, filed Apr. 4, 2003 by G. Woodruff, discloses a portable light spool system adapted to store and dispense electro-luminescent wire. The light system comprises a housing containing a rotatably mounted cylindrical hub around which the wire is wound. The cylindrical hub is hollow and is adapted to accommodate a battery and inverter. A switch disposed on the hub is operative to impress the high frequency A.C. output voltage of the inverter upon the electroluminescent wire. 
   None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus an illuminated leash retractor solving the aforementioned problems is desired. 
   SUMMARY OF THE INVENTION 
   The illuminated retractable leash is a roll of electroluminescent wire mounted on a retractable reel in a handheld housing, the wire being attachable to a pet collar. Included in the housing is a battery, an inverter supplying power to the electroluminescent wire and a switch to illuminate the wire. 
   Electroluminescent (EL-wire) is a cool to the touch, bendable, vinyl coated wire that emits a pleasant 360-degree softly glowing neon light. EL-wire is a flexible wire cable having a solid copper center conductor surrounded by a material, which is luminescent in an electric field. Two thin filaments or wires, which are shorted together and helically wound around the luminescent material. The assembly is covered with one or two layers of vinyl or other plastic insulating material. 
   When an alternating current is conducted through the center conductor and the two filaments, the alternating electromagnetic field between the conductors causes the luminescent material to glow. The color emitted by the cable may vary with the frequency of the A.C. voltage or current. The brightness intensity level depends on the voltage and frequency applied to it, and usually must exceed a minimum threshold voltage before the EL-wire will glow. The higher the voltage and frequency, the brighter the EL-wire illuminates. The present invention utilizes a DC to AC inverter designed to generate a certain voltage and frequency, optimized for a specific length of EL-wire wound on the spool. 
   EL technology is relatively new and only within the past few years has EL-wire become available in consumer products, specifically applications requiring lengths of glowing lights, applications which previously employed LED or other lamp technologies. 
   The illuminated retractable leash has an at least partially transparent housing utilizing an extendible roll of EL-wire as the leash material wound around a rotatably supported spring-biased spool or reel. Not only is the EL-wire illuminated as it extends from the housing, but by virtue of the transparent spool and housing, the housing itself is illuminated, providing a further measure of nighttime safety. 
   The housing includes a spring-biased spool winding and unwinding mechanism commonly found in automatic leash retractors. A battery powered DC to AC inverter circuit is mounted on a printed circuit board disposed in the housing, the output of the circuit connected to the innermost end of the EL-wire. Operated by a housing mounted switch, the inverter provides the required electric signal to illuminate the entire length of the EL-wire. The spool is transparent, thereby allowing the EL-wire wound on the spool to illuminate the at least partially transparent leash housing. 
   Accordingly, it is a principal object of the invention to provide an illuminated, pet leash in a retractable handheld housing. 
   It is another object of the invention to provide an illuminated, retractable leash having a leash housing at least partially made of transparent plastic, whereby the housing itself is illuminated by virtue of the spool of EL-wire, thereby increasing the safety of the user when walking his or her pet at night. 
   It is a further object of the invention to provide improved elements and arrangements thereof for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes. 
   These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a first embodiment of an illuminated retractable leash according to the present invention. 
       FIG. 2  is an exploded, perspective view of the illuminated retractable leash according to  FIG. 1 . 
       FIG. 3  is a side view of the illuminated retractable leash according to  FIG. 1  with half of the housing removed to show the interior of the housing. 
       FIG. 4  is a representative block diagram of the illuminated retractable leash according to  FIG. 1 . 
       FIG. 5  is a perspective view of an alternate embodiment of an illuminated retractable leash according to the present invention having the battery compartment in the handle grip and the inverter circuit mounted in the leash housing. 
       FIG. 6  is an exploded, perspective view of the illuminated retractable leash according to  FIG. 5 . 
       FIG. 7  is a side view of the illuminated retractable leash according to  FIG. 5  with half of the housing removed to show the interior of the housing. 
       FIG. 8  is a perspective view of the wire spool of the leash of  FIG. 5 , illustrating the conductive rings defined on the lateral surface of the spool. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The present invention is an illuminated retractable leash, designated generally as  100  in the drawings. The retractable leash material consists of electroluminescent wire (EL-wire), which illuminates when supplied with an operative voltage supplied by a DC to AC inverter disposed in the leash housing. When switched on, not only is the EL-wire visible as it extends from the housing, but by virtue of the EL-wire wound on the transparent spool, the glow from the EL-wire is visible through the transparent housing. 
   Referring first to  FIG. 1 , a first embodiment of the illuminated retractable leash  100  comprises an at least partially transparent plastic housing  103  having two halves  104 ,  104 ′, a grip portion  114 , a stop mechanism trigger  112 , a battery cover  106  that snaps into the center of housing half  104 , and a length of electroluminescent wire  102  extending from housing  104 . At least one portion  110  of each housing half  104 ,  104 ′ is transparent to allow light generated from within the housing  103  to be visible from the exterior of the retractable leash  100 . The free end of the electroluminescent wire  102  is equipped with a snap hook or other connector adapted for attachment to a pet collar. 
   Leash retractor mechanisms are well known, and a mechanism similar to that disclosed in U.S. Patent Application Publication No. 2003/0029388, published in February 2003, and U.S. Patent Application Publication No. 2003/0145803, published in August 2003, the disclosure of which is hereby incorporated by reference, may be utilized to provide for extension and retraction of the electroluminescent wire  102  in the leash  100  of the present invention. As shown in  FIGS. 2–3 , the illuminated retractable leash  100  includes a coiled spring  204  biasing a spool  202  formed of transparent plastic, around which a length of EL-wire  102  is wound. The spring  204  is received within a cavity  224  in the lateral surface of spool  202 , the inner end of the spring  204  being fastened to a non-rotating portion of the housing  103 , and the outer end of the spring being fastened to the rotating spool  202 . When the EL-wire  102  is played out, the spool  202  rotates, increasing spring tension, whereby any slack generated in the EL-wire  102  is automatically rewound on the spool  202 . A stop mechanism, not shown but disclosed in both the incorporated &#39;388 and &#39;803 Patent Application Publications, is activated by a grip mounted button  112 , and serves to stop the extension or winding up of the EL-wire  102  about spool  202 . 
   The snap-fitting circular battery compartment cover  106 , formed of molded plastic, provides a snug fit within an opening in housing half  104 . Cover  106  provides access to a printed circuit board  208  mounted to the center of spool  202  by a pair of screws  214  received by a pair of bosses  212  defined within the lateral side of the spool  202 . The periphery of the battery cover  106 , substantially thicker than the central portion  108  of the cover, has plastic tabs disposed thereon, allowing the cover  106  to snap securely in place. A rubber gasket  218 , or other waterproofing seal, placed within a recess  220  defined within the outer perimeter of an opening in the housing-half  104  provides a waterproof seal protecting the printed circuit board  208  disposed within. 
   With the battery cover  106  removed, a pair of batteries  210  is removably retained within battery clips  216  mounted on printed circuit board  208 . The printed circuit board  208 , mounted to the center of spool  202  by screws  214 , contains a DC to AC inverter circuit not uncommon in the field of electronics and is powered by the board mounted batteries  210 . The batteries  210 , as well as the other components deposed on the printed circuit board  208 , are uniformly distributed by weight about the center of the printed circuit board  208  in order to enable the spool  202  to rotate evenly about its axis when mounted on spool hub or support  226 . 
   A miniature push button switch  222 , mounted in the center of the printed circuit board  208 , operates to supply an effective voltage to the DC to AC inverter circuit. The abutment portion of switch  222  is in contact with the interior surface of the thin center portion  108  of the battery cover  106 , whereby depressing the center  108  of the exterior portion of the battery cover  106  operates to illuminate or extinguish the glow from the EL-wire  102 . 
     FIG. 4  shows a representative block diagram of the electrical circuit for the illuminated retractable leash  100  and shows at least one battery  210  supplying a DC voltage to the inverter circuit mounted on printed circuit board  208  through switch  222 . The ends  206  of the EL-wire are soldered, or otherwise connected, to the output of the inverter. 
     FIGS. 5–8  illustrate an alternate embodiment of the illuminated retractable leash  100 , which removes the added mass of the printed circuit board and batteries from the rotating spool, thereby directing the full force of the spring towards retracting the EL-wire. As with the embodiment of  FIGS. 1–4 , the illuminated retractable leash of  FIGS. 5–8  contains a leash housing  502  having two halves  504  and  504 ′, transparent housing portions  506  in each half, a leash retractor mechanism including a stop mechanism and trigger  112 , and a spool biasing spring  204  disposed within a recess  616  in the right lateral side  618  of transparent spool  606 . However, in this second embodiment, a screw  610  or other suitable hardware secures the printed circuit board  608  to a non-rotating portion of the housing  504 ′. Furthermore, the “on/off” switch  508  and batteries  604  are disposed in the handgrip  514 , the batteries  610  being accessible by removing battery cover  512 . Similar to the previous embodiment a rubber gasket  602  or other waterproofing seal protects the printed circuit board  608  mounted inverter circuit from water damage. 
   Although the heretofore-mentioned embodiments have been silent as to the type of battery used to supply the power for the inverter circuit, the present invention is not limited to a specific battery technology. Lead acid, nickel-cadmium or Lithium ion batteries may be incorporated as seen fit. Should rechargeable batteries be employed, a grip mounted external DC jack  510  as shown in  FIGS. 5 and 7  is provided to recharge the batteries. 
   In positioning the inverter circuit and battery outside of the spool  606 , the difficulty to be overcome is how to deliver inverter output to the rotating ends  620  of the EL-wire  102  wound on spool  606 . This problem is solved by a pair of electrical contacts  612  mounted to the inner lateral surface  506  of housing  504 ′, connected by a pair of wires  614  to the inverter circuit on the printed circuit board  608 . As best seen in  FIG. 8 , the inner ends  620  of the EL-wire  102  are soldered, or otherwise electrically connected to a pair of concentric electrically conductive surfaces  802  defined in the left lateral side  618 ′ of the rotating spool  606 . The housing mounted contactors  612  are so aligned to make continuous contact with the rotating conductive plates  802 , thereby providing a continuous supply of alternating current to illuminate the EL-wire  102 . 
   In conclusion, the inventor has disclosed two embodiments of an illuminated retractable leash  100 , in which electroluminescent wire, serving as the leash material, illuminates both the housing and the extended leash. 
   It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.