Patent Publication Number: US-7220024-B1

Title: Disposable work light

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to a portable work light and more particularly, to a disposable work light having a protective and reflectorized housing permanently mounted on the housing lamp. 
   2. Description of Prior Art and Advantages 
   Traditionally, trouble lights, such as that disclosed in U.S. Pat. No. 4,275,435 issued to Henry M. Dora on Jun. 23, 1981; U.S. Pat. No. 2,861,175 issued to O. W. Schweikle on Nov. 18, 1958; U.S. Pat. No. 2,677,753 issued G. W. Heinz on May 4, 1954; and U.S. Pat. No. 4,141,062 issued to Raymond L. Trueblood on Feb. 20, 1979, include incandescent lamps which are threadedly received in a complementally formed electrically conductive, threaded, metal light bulb socket that is disposed in, and transversely moveable relative to, a surrounding rubber handle in which the socket is disposed. Incandescent lamps are fragile. If the traditional trouble light is dropped or bumped, the incandescent lamp filament is easily broken. It is an advantage of the present invention to provide a portable work light which will resist lamp breakage due to drops and bumps. 
   A substantial amount of heat radiates from incandescent bulbs causing the bulbs to be very hot and subject the user to being burned. The generated heat can also ignite certain inflammable gases and liquids, if inadvertently introduced to the heated incandescent lamp. A hot incandescent lamp can explode if splashed with even one drop of water. 
   To overcome these problems, trouble lights have been made with linear fluorescent light sources, such as that disclosed in U.S. Pat. No. 5,975,719 issued to Paul J. Reiff, et al on Nov. 2, 1999; U.S. Pat. No. 6,386,736 issued to Paul J. Reiff, et al on May 14, 2002; U.S. Pat. No. 2,489,686 issued to J. L. Suter on Nov. 29, 1949; U.S. Pat. No. 3,815,080 issued to Frank Summa on Jun. 4, 1974 and U.S. Pat. No. 2,874,270 issued to H. E. Douglas, et al on Feb. 17, 1959. Such elongate, linear light bulbs are bulky, clumsy and limited in their light output. Linear light sources are not concentrated in a short length for a given voltage as are spiral fluorescent bulbs, such as that disclosed in U.S. Pat. No. 2,279,635 issued to J. Morley on Apr. 14, 1942 and U.S. Pat. No. 3,953,761 issued to Thomas Lo Giudice on Apr. 27, 1976. For example, a 15 watt fluorescent bulb is as bright as a 75 watt incandescent bulb which is generally the upper acceptable recommended watt limit for most trouble light fixtures. 
   A typical trouble light socket includes a curvilinear metal reflector, fixed to the trouble light handle, extending on one lateral side of the incandescent lamp and a hinged, wire cage along the laterally opposite side of the lamp to protect the lamp from breakage. The prior art housing is mounted on a rubber handle and moveable therewith relative to the bulb subjecting the bulb to breakage. It is an advantage of the present invention to provide a trouble light having a housing which is inseparably fixed to the base of the bulb to limit relative movement therebetween. 
   It is another advantage of the present invention to provide a reflector housing of the type described which has a relatively short reflectorized portion and a reduced diameter section mounted on the base of the lamp. 
   Yet another advantage of the present invention is to provide a portable work light including a partially reflectorized protective housing cantileverly inseparably mounted to the lamp. 
   The housing, constructed according to the present invention, contemplates a pair of semi-cylindrical halves which are permanently mated to each other and to laterally opposite sides of the base of a fluorescent light bulb with one of the semi-cylindrical halves including a light reflecting portion on one lateral side of the bulb and the other half including a translucent section on the laterally opposite side of the bulb for transmitting the reflected light rays emanating from the light source. 
   The present invention contemplates a new and novel work lamp which has a fluorescent light with an electrically non-conductive base, including a ballast and starter, and a rotary electrically conductive base for being detachably rotatably received in a complementally formed electrical socket and an elongate cylindrical housing fixed to the base for disposal with the lamp when the lamp has outlived its useful life. 
   Existing trouble lights include an annular gap between the electrically conductive rotary base of the light source and the electrically non-conductive handle, which provides a ready ingress window for flammable gases and liquids that can be ignited. The present invention contemplates a resilient annular guard received by the base of the lamp and projecting radially outwardly therefrom to provide a cover which will span the gap between the lamp and the handle and thus, eliminates inadvertent passage of liquid, such as water, and/or explosive gases therebetween. The radially outer portion of the resilient vibration dampening guard is a resilient seal clamped between the terminal end of the electrically non-conductive handle and the opposing end of the cantileverly supported lamp housing. When the spiral fluorescent light bulb incorporated in the present invention exceeds it useful life and is disposed, the resilient shield and housing will be disposed therewith. Accordingly, it is another advantage of the present invention to provide a disposable work light including a resilient annular safety shield having a bore therethrough received on the base of a fluorescent lamp bulb and spanning the gap the between the bulb and the electrically nonconductive portion of the handle surrounding the base of the bulb. 
   It is another advantage of the present invention to provide an annular resilient shield which is resiliently mounted on the base of the light source and bears against the end of the electrically non-conductive light mounting handle for stabilizing the bulb and absorbing any shock or force that would otherwise be transmitted from the handle to the bulb. 
   It is another advantage of the present invention to provide a resilient safety ring which mounts on the base of a lamp and seals to the mounting handle for keeping gas and/or fumes out of electrical contact with the handle supported electrical socket. 
   It is a further advantage of the present invention to mount a housing and a reflector on the light source as opposed to mounting the reflector on the handle in which the light source is threadedly mounted. 
   Another advantage of the present invention is to provide a replacement for an incandescent light bulb used in a mechanic&#39;s work light and to provide an enhanced versatile work light that is safe to use and provides a variety of light intensities in a compact arrangement. 
   These and other advantages of the present invention will become more readily apparent as the descriptions hereof proceeds: 
   SUMMARY OF THE INVENTION 
   A portable work light including a lamp having a rotary base; an elongate partially reflectorized housing having an axially inner end cantileverly mounted on a base of the lamp for disposal therewith; and a vibration dampener and seal for vibrationally isolating the lamp from a handle into which the lamp is detachably mounted and for sealing the electrical connections within the handle from ambient liquids and ignitable gases. 

   
     DESCRIPTION OF THE DRAWINGS 
     The invention may be more readily understood by referring to the accompanying drawings, in which: 
       FIG. 1  is a front elevational view of a disposable work light constructed according to the present invention; 
       FIG. 2  is a sectional side view thereof, taken along the section line  2 — 2  of  FIG. 3 , 
       FIG. 3  is a top plan sectional view of the reflector housing only, taken along the section line  3 — 3  of  FIG. 1 ; 
       FIG. 4  is an exploded view illustrating the various components of the work light prior to assembly; and 
       FIG. 5  is a slightly enlarged, top plan sectional view of the base, taken along the line  5 — 5  of  FIG. 1 . 
   

   DESCRIPTION OF PREFERRED EMBODIMENT 
   A disposable work light, generally designated  10 , constructed according to the present invention includes a fluorescent lamp or light source, generally designated  12 , including an electrically non-conductive, open top hollow one piece base, generally designated  14 , which may comprise any electrically non-conductive material, such as plastic. The open top is closed via an electrically non-conductive cap  26  which is press fit into the open top and has a pair of bulb receiving apertures  13 A therethrough. The fluorescent light bulb  12  includes a pair of upstanding glass legs  12 A and  12 B received in the apertures  13 A, coupled to a spiral glass configuration  12 C having a relatively short axial length  12 D. The base  14  has a cavity  17  which receives a ballast or transformer  22 , a starter  24  and other assundry electronic circuitry  28  electrically coupled, via line  23 , between one terminal  32  of the fluorescent bulb  12  and a central terminal  19  insulated from an electrically conductive rotary metal screw shell or base  20  via a strip of insulation  21 . The electrically non-conductive housing  14  includes a hollow cylindrical sidewall  14 A integrally coupled to a frustoconically shaped, axially inner wall portion  14 B having a radially inwardly extending inverted integral L-shaped flange  14 C provided with a transversely extending annular base leg  14 D and an axially inwardly extending, annular terminal leg  14 E. 
   The rotary metal screw shell or base  20 , which is threaded at  25 , is coupled in circuit to the other terminal  32 A of the fluorescent bulb  12  via a wire  29 . The light source  12  could also comprises a series of light emitting diodes (not shown) which emit light that is conducted from the diodes to a work area via a plurality of glass rods. It should be understood that rather than the screw shell or base  20 , an electrically conductive bayonet base could be substituted. Also, rather than threads  25 , the base  20  could include a bayonet connection which includes linear projections that are inserted into a complementally formed electrical socket and then turned or rotated about the rotational axis a. 
   A plurality of circumferentially spaced, radially outwardly extending ribs  30  are integrally formed with the outer surface of the annular side wall  14 A for a purpose to become more apparent hereinafter. 
   Cantileverly permanently mounted on the base  14  of the fluorescent light bulb  12  is an electrically non-conductive, cylindrical housing  40 . The housing  40  is fabricated from a pair of confronting, elongate, semi-cylindrical housing portions  42  and  44  including complementally formed, circumferentially spaced, male and female, mating edges or ends  46  and  48 , respectively, which are sealed together, as illustrated in  FIG. 3 , by adhesive, sonic welding, a threaded coupling and/or suitable fasteners to form a hollow cylinder  41 . The housing portion  42  is fabricated from clear translucent material such as Lexane® plastic which will readily transmit light emitted by the light source  12  in the direction of the arrow  31 . If the work light is merely threaded into a complementally threaded electrical socket embedded in an insulated handle without a reflector, the other semi-cylindrical portion  44  comprises opaque plastic material and includes a layer  50  of reflectorized material, such as tin, aluminum, painted metal, or a coating of reflective material that is bonded to the inside of the semi-cylindrical half  44  for reflecting, concentrating and intensifying the light and directing it from one lateral side of the lamp to the laterally opposite side of the lamp as represented by the arrows  33  ( FIG. 3 ). For commercial applications, the semi-cylindrical portion  44  may also be constructed of metal. If the work light  10  is utilized as a replacement for a conventional incandescent light bulb of a conventional trouble light having a reflector, the housing portion  42  may also be fabricated from clear translucent plastic material. 
   The semi-cylindrical housing portions  42  and  44  have an identical radius of curvature R, about the longitudinal axis a, and cooperate to form the cylindrical housing  40  which includes a longitudinally intermediate light emitting and reflecting portion  66  having a predetermined diameter  67  and an axial length  67 A and axially outer and inner cylindrical end portions  68  and  70 , respectively, having reduced diameters  69 . The semi-cylindrical portions  42  and  44  cooperate to form the axially outer cylindrical portion  68  including a relatively short cylindrical side wall  74  having axially outer end wall portions cooperating to define the axially outer end wall  52  defining an aperture  54  therethrough for rotatably receiving the shank  55  of a hook  56  which is operative to suspend the portable light  10  on any fixture. A pair of axially spaced apart plates  58  are integrally formed with the shank  55  for rotatably securing the suspension hook  56  to the end wall  52 . 
   The axially inner cylindrical end portion  70  has a side wall  71  is axially longer than the axially outer end portion  68  and includes an axially inwardly converging end wall  72  terminating in a rigid, transversely inwardly extending annular flange or ring  63  abutting the axially inner end of the flange  14 D of the base  14  and defines an opening  65  which receives the terminal flange  14 E. The side wall  71  and the axially inwardly converging frustoconically shaped wall  72  include a plurality of circumferentially spaced apart, radially inwardly projecting ribs  77  which mount the walls  71  and  72  in radially spaced relation with the walls  14 A and  14 B to provide a gap G therebetween ( FIG. 5 ). The ribs  77  radially bear against the outer circumferential surface of base  14  and circumferentially bear against the ribs  30  of the rotary base  14  for insuring that the rotary base and cylinder housing  40  will rotate about the axis a in unison. The side walls  70  and  71  include a plurality of circumferentially spaced apart elongate slots  62  therethrough disposed between the ribs  77  for communicating ambient air to the gap G which allows inlet cooling air to enter in the direction of the arrow X to pass along the lamp  12  and thence outwardly through the slots  68 A in the opposite end  68  in the direction of the arrows Y. The elongate gap G, formed circumferentially between the confronting ribs  30  and  77  and in radial alignment with the slot  62  in housing  70 , allows ambient air to longitudinally axially longitudinally outwardly in the direction of the arrows S and Y to cool the lamp  12 . The circumferentially spaced vent slots  68 A provide outlet ventilation for any heat that may be generated by the fluorescent lamp  62 . 
   Compared to linear fluorescent lights, the axial length  34  of the spiral lamp light portion  12 C is relatively short and thus, the arial length  35  of housing mid portion  66  is also axially relatively short. Only the inner curvilinear half surface  66 A of mid-portion  60  is reflectorized with a reflectorized coating  50 . A layer of adhesive may be applied to the ribs  30  and the confronting ribs  77  and the inside surfaces of the housing to further seclude relative turning of a house  70  and the base  14  of the light bulb  12 . 
   The electrically conductive rotary metal screw shell or base  20  of unit  10  is threaded about the elongate rotary axis a into a complementally formed electrical light terminal  81  having a complementally and electrically conductive light socket  80  mounted in an electrically non-conductive housing handle  82 . The threaded electrically conductive socket  80  is electrically coupled to a source of electrical power via leads  88  and threadedly receives the rotary shell base  20 . The user may easily thread the entire assembly  10  into the socket handle  80  by merely gripping the housing  40  and concurrently rotating it and the fluorescent bulb  12  about the longitudinal axis a. The housing handle  82  is radially spaced from the base  14  by a gap G 1 . 
   A vibration dampener and seal, generally designated  84 , is provided and includes an annular flat ring or plate of resilient material, such as rubber, having a central aperture  85  snugly receiving the radially outer surface of the terminal base flange  14 E so as to preclude the passage of liquid, such as ignitable and/or flammable gases or fluids or water therebetween. The resilient washer or vibration dampener and seal  84  projects radially outwardly a sufficient distance to cover the gap G 1  between the non-conductive housing handle  82 , and the rotary base  14 . When the work light  10  is fully threaded into the socket  80 , the radially outer portion  84  of the seal  84  is axially sandwiched between the flange  14 D of the axially inner end of rotary base  14  and more particularly sandwiched between and abutting the flange  63  of the cantileverly supported housing  40  and the axially outer end  87  of the confronting annular housing handle  82  to absolutely preclude any ambient fluids from passing to the electrical socket  80 . 
   The present invention may also be applied to existing light sockets having electrically conductive bayonet receptacle which receive a bayonet plug that can thereafter be rotated to its final operating position. 
   METHOD AND OPERATION 
   The apparatus constructed according to the present invention is manually rethreaded about the axis a into a socket  80  by merely gripping the housing  40  and concurrently turning it and the rotary metal screw shell  20  so that the screw base  20  is threadedly received in the complementally formed handle socket  80 . When fully threaded into the socket, the radially outer portion  84 A of the vibration dampener and seal  84  is sandwiched between the terminal end  87  of the housing handle  82  and the confronting rim  63  of the insulated housing  40  to close the gap G and preclude fluids, such as gas fumes and liquid from entering the gap G and coming into contact with the electrically conductive handle socket contact  80 . 
   The slots  62  in the cylindrical wall  71 , provide an air inlet for ambient air to be drawn inwardly, in the direction of the arrow X, over the fluorescent lamp  12 , in the direction of the arrow  5 , and then outwardly through the vent slots  68 , in the direction of the arrow Y, via a so-called “chimney effect”. 
   With the housing  40  secured to the base  14 , the housing  40  will not move relative to the bulb  12  whereby breakage of the bulb  12  is minimized. In addition, the resilient shield  84  will absorb shock which would otherwise be transmitted from the handle  82  to the bulb  12 . 
   When the fluorescent bulb  12  is no longer operative, the entire replacement light  10  is unthreaded from the handle socket  8  and the bulb  12 , along with the reflector  50 , protective housing  40 , light source  12 , base  14  including the electronic components  22 ,  24  and  28 , mounting hook  56 , and resilient shock absorber and seal  84  are concurrently discarded and a duplicate replacement installed. 
   It is to be understood that the drawings and descriptive matter are in all cases to be interpreted as merely illustrative of the principles of the invention, rather than as limiting the same in any way, since it is contemplated that various changes may be made in various elements to achieve like results without departing from the spirit of the invention or the scope of the appended claims.