Abstract:
A miniature two or three cell flashlight as disclosed to comprise a barrel, a tailcap, a head assembly, and means for holding a miniature lamp bulb and for providing interruptible electrical coupling to dry cell batteries retained within the barrel and having a charger for charging the rechargeable batteries via conductors in the tailcap.

Description:
[0001]    This is a continuation of application Ser. No. 09/613,031, filed Jul. 10, 2000, which is a continuation of application Ser. No. 09/193,098, filed Nov. 16, 1998, now U.S. Pat. No. 6,086,219, which is a divisional application of Ser. No. 08/666,639, filed Jun. 18, 1996, now U.S. Pat. No. 5,836,672, which is a divisional application of Ser. No. 08/538,553, filed Oct. 3, 1995, now U.S. Pat. No. 5,528,472, which is a divisional application of Ser. No. 08/159,457, filed Nov. 30, 1993, now U.S. Pat. No. 5,455,752, which is a divisional application of Ser. No. 08/007,566, filed Jan. 22, 1993, now U.S. Pat. No. 5,267,130, which is a divisional application of Ser. No. 07/895,087, filed Jun. 8, 1992, now U.S. Pat. No. 5,193,898, which is a divisional application of Ser. No. 07/632,128, filed Dec. 19, 1990, now U.S. Pat. No. 5,121,308, which is a divisional application of Ser. No. 07/111,538, filed Oct. 23, 1987, now U.S. Pat. No. 5,008,785, the foregoing each being incorporated herein by reference. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates primarily to flashlights, and in particular, to miniature hand-held flashlights which may have their batteries recharged and a recharger therefor.  
           [0004]    2. Discussion of the Prior Art  
           [0005]    Flashlights of varying sizes and shapes are well known in the art. In particular, certain of such known flashlights utilize two or more dry cell batteries, carried in series in a cylindrical tube serving as a handle for the flashlight, as their source of electrical energy. Typically, an electrical circuit is established from one electrode of the battery through a conductor to a switch, then through a conductor to one electrode of the lamp bulb. After passing through the filament of the lamp bulb, the electrical circuit emerges through a second electrode of the lamp bulb in electrical contact with a conductor, which in turn is in electrical contact with the flashlight housing. The flashlight housing provides an electrical conduction path to an electrical conductor, generally a spring element, in contact with the other electrode of the battery. Actuation of the switch to complete the electrical circuit enables electrical current to pass through the filament, thereby generating light which is typically focused by a reflector to form a beam of light.  
           [0006]    The production of light from such flashlights has often been degraded by the quality of the reflector utilized and the optical characteristics of any lens interposed in the beam path. Moreover, intense light beams have often required the incorporation of as many as seven dry cell batteries in series, thus resulting in a flashlight having significant size and weight.  
           [0007]    Efforts at improving such flashlights have primarily addressed the quality of the optical characteristics. The production of more highly reflective, well-defined reflectors, which may be incorporated within such flashlights, have been found to provide a more well-defined focus thereby enhancing the quality of the light beam produced. Additionally, several advances have been achieved in the light emitting characteristics of flashlight lamp bulbs.  
           [0008]    Since there exists a wide variety of uses for hand-held flashlights, the development of the flashlight having a variable focus, which produces a beam of light having a variable dispersion, has been accomplished.  
           [0009]    Also, flashlights which may have their batteries recharged with a constant current recharger are known. However, such advances have heretofore been directed to “full-sized” flashlights.  
         SUMMARY OF THE INVENTION  
         [0010]    It is a primary object of the present invention to provide miniature hand-held flashlights having a recharging capability.  
           [0011]    It is another object of the present invention to provide miniature flashlights having three dry cell batteries as a power source.  
           [0012]    It is another object of the present invention to provide miniature flashlights having various tailcap constructions.  
           [0013]    It is another object of the present invention to provide miniature hand-held flashlights having improved optical characteristics.  
           [0014]    It is another object of the present invention to provide a rechargeable miniature hand-held flashlight which is capable of producing a beam of light having a variable dispersion.  
           [0015]    It is a further object of the present invention to provide a rechargeable miniature hand-held flashlight which is capable of supporting itself vertically on a horizontal surface to serve as an “ambient” unfocused light source.  
           [0016]    It is another object of the present invention to provide a rechargeable miniature hand-held flashlight wherein relative motions of components that produce the variation and the dispersion of the light beam provide an electrical switch function to open and complete the electrical circuit of the flashlight.  
           [0017]    These and other objects of the present invention, which may become obvious to those skilled in the art through the hereinafter detailed description of the invention are achieved by a miniature flashlight and battery charger comprising: a cylindrical tube containing one or more miniature dry cell batteries and preferably three AA sized batteries which, when used with the charger should be suitable for charging, disposed in a series arrangement, a lamp bulb holder assembly including electrical conductors for making electrical contact between terminals of a miniature lamp suitable for use with rechargeable batteries, and the cylindrical tube and an electrode of the battery, respectively, retained in one end of the cylindrical tube adjacent the batteries, a tail cap and spring member enclosing the other end of the cylindrical tube and providing an electrical contact to another electrode of the batteries and providing for charging of the batteries within the tube, and a head assembly including a reflector, a lens, a face cap, which head assembly is rotatably mounted to the cylindrical tube such that the lamp bulb extends through a hole in the center of the reflector within the lens and a charger housing which may be electrically coupled to the tube at the tailcap. In the preferred embodiment of the present invention, the batteries are of the size commonly referred to as AA batteries.  
           [0018]    The head assembly engages threads formed on the exterior of the cylindrical tube such that rotation of a head assembly about the axis of the cylindrical tube will change the relative displacement between the lens and the lamp bulb. When the head assembly is fully rotated onto the cylindrical tube, the reflector pushes against the forward end of the lamp holder assembly causing it to shift rearward within the cylindrical tube against the urging of the spring contact at the tailcap. In this position, the electrical conductor within the lamp holder assembly which completes the electrical circuit from the lamp bulb to the cylindrical tube is not in contact with the tube. Upon rotation of the head assembly in a direction causing the head assembly to move forward with respect to the cylindrical tube, pressure on the forward surface of the lamp holder assembly from the reflector is relaxed enabling the spring contact in the tailcap to urge the batteries and the lamp holder assembly in a forward direction, which brings the electrical conductor into contact with the cylindrical tube, thereby completing the electrical circuit and causing the lamp bulb to illuminate. At this point, the lamp holder assembly engages a stop which prevents further forward motion of the lamp holder assembly with respect to the cylindrical tube. Continued rotation of the head assembly in a direction causing the head assembly to move forward relative to the cylindrical tube causes the reflector to move forward relative to the lamp bulb, thereby changing the focus of the reflector with respect to the lamp bulb, which results in varying the dispersion of the light beam admitted through the lens.  
           [0019]    By rotating the head assembly until it disengages from the cylindrical tube, the head assembly may be placed, lens down, on a substantially horizontal surface and the tailcap and cylindrical tube may be vertically inserted therein to provide a miniature “table lamp”.  
           [0020]    The flashlights of the present invention preferably include three AA size batteries or smaller, suitable for charging when the charger is used. When the battery charger feature is used, a tailcap having the features shown and described herein provides a charging circuit for the batteries without removal of the batteries from the flashlight. When a charging feature is not desired, then any one of a variety of other tailcaps may be used. For example, a tailcap having a lanyard ring construction may be used. Alternatively, a tailcap having an insert and of the construction shown in co-pending application, Ser. No. 043,086, filed on Apr. 27, 1987, entitled FLASHLIGHT, issued as U.S. Pat. No. 4,327,401, may be used. Also, tailcaps not having the lanyard ring holder feature and not having the charger feature may be used. Such tailcaps would have a smooth, contoured external appearance, as shown in FIGS. 7 and 10 of the drawings. Furthermore, a tailcap having a lanyard ring feature as well as a charging feature may be used with the flashlights of the present invention, although a tailcap not having a lanyard ring is preferred when using the charging feature.  
           [0021]    The charger for the flashlights of the present invention includes a housing, a circuit adapted to receive electrical power within a certain voltage range and to provide constant current at a predetermined rate to the batteries, and positive and negative contacts for contacting with positive and negative charging regions on the tailcap, which in turn and together with the electrical circuit of the flashlight provide for a charging circuit to the batteries. The charger may be adapted to convert AC to DC, and may be adapted to provide for various charging rates. The charger and the tailcap also contain a blocking diode to prevent a reverse charging condition to occur.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]    [0022]FIG. 1 is a partially foreshortened cross-sectional view of the head assembly and front battery of a preferred embodiment of the miniature flashlight of the present invention;  
         [0023]    [0023]FIG. 2 is a partial cross-sectional view of a forward end of the miniature flashlight, illustrating, in ghost image, a translation of the forward end of the flashlight;  
         [0024]    [0024]FIG. 3 is a partial cross-sectional view of a lamp bulb holder assembly used in accordance with the present invention, taken along the plane indicated by  3 - 3  of FIG. 2;  
         [0025]    [0025]FIG. 4 is an exploded perspective view illustrating the assembly of the lamp bulb holder assembly with respect to a barrel of the miniature flashlight;  
         [0026]    [0026]FIG. 5 is an isolated partial perspective view illustrating the electromechanical interface between electrical terminals of the lamp bulb and electrical conductors within the lamp bulb holder;  
         [0027]    [0027]FIG. 6 presents a perspective view of a rearward surface of the lamp bulb holder of FIG. 4, illustrating a battery electrode contact terminal;  
         [0028]    [0028]FIG. 7 is a partial cross-sectional view of a preferred embodiment of the present invention, showing the three battery construction and details of the tailcap used with the battery charging unit;  
         [0029]    [0029]FIG. 8 is a perspective view of the FIG. 7 flashlight within the battery charger housing of the present invention;  
         [0030]    [0030]FIG. 9 is a schematic diagram of the circuit for the FIG. 8 battery charger of the present invention;  
         [0031]    [0031]FIG. 10 is an enlarged cross-sectional view the tailcap of the FIG. 7 flashlight;  
         [0032]    [0032]FIG. 11 is a plan view taken along line  11 - 11  of the FIG. 10 tailcap;  
         [0033]    [0033]FIG. 12 is a plan view of switch knob  67 ; and  
         [0034]    [0034]FIG. 13 is a partial top view of the charger of FIG. 8. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0035]    Referring to FIGS.  1 - 8  and  10 - 13 , a miniature flashlight  20  in accordance with the present invention is illustrated. The miniature flashlight  20  is comprised of a generally right circular cylinder, or barrel  21 , enclosed at a first end by a tailcap/switch assembly  94  and having a head assembly  23  enclosing a second end thereof. The head assembly comprises a head  24  to which is affixed a face cap  25  which retains a lens  26 . The head assembly  23  has a diameter greater than that of the barrel  21  and is adapted to pass externally over the exterior of the barrel  21 . The barrel  21  may provide a machined handle surface  27  along its axial extent. The tailcap  94  may be configured to include provision for attaching a handling lanyard through a hole in a tab formed therein.  
         [0036]    Referring to FIG. 7, barrel  21  is seen to have an extent sufficient to enclose three miniature dry cell batteries  31  disposed in a series arrangement and suitable for recharging. As shown in FIG. 1, the center electrode  38  of the forward battery is urged into contact with a first conductor  39  mounted within a lower insulator receptacle  41 . The lower insulator receptacle  41  also has affixed therein a side contact conductor  42 . Both the center conductor  39  and the side contact conductor  42  pass through holes formed in the lower insulator receptacle in an axial direction, and both are adapted to frictionally receive and retain the terminal electrodes  43  and  44  of a miniature bi-pin lamp bulb  45  suitable for use with rechargeable batteries and a charger, preferably a high pressure, xenon gas filled type of lamp. Absent further assembly, the lower insulator receptacle is urged in the direction indicated by the arrow  36 , by the action of the spring  73 , to move until it comes into contact with a lip  46  formed on the end of the barrel  21 . At that point electrical contact is made between the side contact conductor  42  and the lip  46  of the barrel  21 .  
         [0037]    An upper insulator receptacle  47  is disposed external to the end of the barrel  21  whereat the lower insulator receptacle  41  is installed. The upper insulator receptacle  47  has extensions that are configured to mate with the lower insulator receptacle  41  to maintain an appropriate spacing between opposing surfaces of the upper insulator receptacle  47  and the lower insulator receptacle  41 . The lamp electrodes  43  and  44  of the lamp bulb  45  pass through the upper insulator receptacle  47  and into electrical contact with the center conductor  39  and the side contact conductor  42 , respectively, while the casing of the lamp bulb  45  rests against an outer surface of the upper insulator receptacle  47 .  
         [0038]    The head assembly  23  is installed external to the barrel  21  by engaging threads  48  formed on an interior surface of the head  24  engaging with matching threads formed on the exterior surface of the barrel  21 . A sealing O-ring  49  is installed around the circumference of the barrel  21  adjacent the threads to provide a water-tight seal between the head assembly  23  and the barrel  21 . A substantially parabolic reflector  51  is configured to be disposed within the outermost end of the head  24 , whereat it is rigidly held in place by the lens  26  which is in turn retained by the face cap  25  which is threadably engaged with threads  52  formed on the forward portion of the outer diameter of the head  24 . O-rings  53  and  53 A may be incorporated at the interface between the face cap  25  and the head  24  and between face cap  25  and lens  26 , respectively, to provide a water-tight seal.  
         [0039]    When the head  24  is fully screwed onto the barrel  21  by means of the threads  48 , the central portion of the reflector  51  surrounding a hole formed therein for passage of the lamp bulb  45 , is forced against the outermost surface of the upper insulator receptacle  47 , urging it in a direction counter to that indicated by the arrow  36 . The upper insulator receptacle  47  then pushes the lower insulator receptacle  41  in the same direction, thereby providing a space between the forwardmost surface of the lower insulator receptacle  41  and the lip  46  on the forward end of the barrel  21 . The side contact conductor  42  is thus separated from contact with the lip  46  on the barrel  21  as is shown in FIG. 2.  
         [0040]    Referring next to FIG. 2, appropriate rotation of the head  24  about the axis of the barrel  21  causes the head assembly  23  to move in the direction indicated by the arrow  36  through the engagement of the threads  48 . Upon reaching the relative positions indicated in FIG. 2 by the solid lines, the head assembly  23  has progressed a sufficient distance in the direction of the arrow  36  such that the reflector  51  has also moved a like distance, enabling the upper insulator receptacle  47  and the lower insulator receptacle  41  to be moved, by the urging of the spring  73  (FIG. 7) translating the batteries  31  in the direction of the arrow  36 , to the illustrated position. In this position, the side contact conductor  42  has been brought into contact with the lip  46  on the forward end of the barrel  21 , which closes the electrical circuit.  
         [0041]    Further rotation of the head assembly  23  so as to cause further translation of the head assembly  23  in the direction indicated by the arrow  36  will result in the head assembly  23  reaching a position indicated by the ghost image of FIG. 2, placing the face cap at the position  25 ′ and the lens at the position indicated by  26 ′, which in turn carries the reflector  51  to a position  51 ′. During this operation, the upper insulator receptacle  47  remains in a fixed position relative to the barrel  21 . Thus the lamp bulb  45  also remains in a fixed position. The shifting of the reflector  51  relative to the lamp bulb  45  during this additional rotation of the head assembly  23  produces a relative shift in the position of the filament of the lamp bulb  45  with respect to the parabola of the reflector  51 , thereby varying the dispersion of the light beam emanating from the lamp bulb  45  through the lens  26 .  
         [0042]    Referring next to FIG. 3, a partial cross-sectional view illustrates the interface between the lower insulator receptacle  41  and the upper insulator receptacle  47 . The lower insulator receptacle  41  has a pair of parallel slots  54  formed therethrough which are enlarged in their center portion to receive the center conductor  39  and the side contact conductor  42 , respectively. A pair of arcuate recesses  55  are formed in the lower insulator receptacle  41  and receive matching arcuate extensions of the upper insulator receptacle  47 . The lower insulator receptacle  41  is movably contained within the inner diameter of the barrel  21  which is in turn, at the location of the illustrated cross-section, enclosed within the head  24 .  
         [0043]    Referring next to FIGS. 4 through 6, a preferred procedure for the assembly of the lower insulator receptacle  41 , the center conductor  39 , the side contact conductor  42 , the upper insulator receptacle  47  and the miniature lamp bulb  45  may be described.  
         [0044]    Placing the lower insulator receptacle  41  in a position such that the arcuate recesses  55  are directionally oriented towards the forward end of the barrel  21  and the lip  46 , the center conductor  39  is inserted through one of the slots  54  such that a substantially circular end section  56  extends outwardly from the rear surface of the lower insulator receptacle  41 . The circular end section  56  is then bent, as shown in FIG. 7, to be parallel with the rearmost surface of the lower insulator receptacle  41  in a position centered to match the center electrode of the forwardmost one of the batteries  31  of FIG. 1. Insulator  41  has a cup-shaped recess  93  in its center sized to accommodate the center electrode of a battery and provide contact at end section  56 , as shown in FIGS. 2, 3 and  7 . If the batteries are inserted backwards so that the center battery electrode is facing toward the tailcap, there will be no possibility of a completed electrical circuit. This feature provides for additional protection during charging, there being the possibility of damage resulting if the batteries are placed in backwards and charging attempted. The side contact conductor  42  is then inserted into the other slot  54  such that a radial projection  57  extends outwardly from the axial center of the lower insulator receptacle  41 . It is to be noted that the radial projection  57  aligns with a web  58  between the two arcuate recesses  55 .  
         [0045]    The lower insulator receptacle  41 , with its assembled conductors, is then inserted in the rearward end of the barrel  21  and is slidably translated to a forward position immediately adjacent the lip  46 . After inserting the upper insulator receptacle  47  the lamp electrodes  43  and  44  are then passed through a pair of holes  59  formed through the forward surface of the upper insulator receptacle  47  so that they project outwardly from the rear surface thereof as illustrated in FIG. 6. The upper insulator receptacle  47 , containing the lamp bulb  45 , is then translated such that the lamp electrodes  43  and  44  align with receiving portions of the side contact conductor  42  and the center conductor  39 , respectively. A pair of notches  61 , formed in the upper insulator receptacle  47 , are thus aligned with the webs  58  of the lower insulator receptacle  41 . The upper insulator receptacle  47  is then inserted into the arcuate recesses  55  in the lower insulator receptacle  41  through the forward end of the barrel  21 .  
         [0046]    Referring again to FIGS. 1, 2 and  10 , the electrical circuit of the miniature flashlight in accordance with the present invention will now be described.  
         [0047]    Electrical energy is conducted from the rearmost battery  31  through its center contact  37  which is in contact with the case electrode of the forward battery  31 . Electrical energy is then conducted from the forward battery  31  through its center electrode  38  to the center contact  39  which is coupled to the lamp electrode  44 . After passing through the lamp bulb  45 , the electrical energy emerges through the lamp electrode  43  which is coupled to the side contact conductor  42 . When the head assembly  23  has been rotated about the threads  48  to the position illustrated in FIG. 1, the side contact conductor  42  does not contact the lip  46  of the barrel  21 , thereby resulting in an open electrical circuit. However, when the head assembly  23  has been rotated about the threads  48  to the position illustrated by the solid lines of FIG. 2, the side contact conductor  42  is pressed against the lip  46  by the lower insulator receptacle  41  being urged in the direction of the arrow  36  by the spring  73  of FIG. 10. In this configuration, electrical energy may then flow from the side contact conductor  42  into the lip  46 , through the barrel  21  and into the tailcap/switch assembly  94  of FIG. 7. The spring  73  electrically couples the tailcap/switch assembly  94  to the case electrode of the rearmost battery  31 . By rotating the head assembly  23  about the threads  48  such that the head assembly  23  moves in a direction counter to that indicated by the arrow  36 , the head assembly  23  may be restored to the position illustrated in FIG. 2, thereby opening the electrical circuit and turning off the flashlight.  
         [0048]    In a preferred embodiment, the barrel  21 , the tailcap/switch assembly  94 , the head  24 , and the face cap  25 , forming all of the exterior metal surfaces of the miniature flashlight  20  are manufactured from aircraft quality, heat-treated aluminum, which is anodized for corrosion resistance. The sealing O-rings  33 ,  49 ,  53  and  53 A provide atmospheric sealing of the interior of the miniature flashlight. All interior electrical contact surfaces are appropriately machined to provide efficient electrical conduction. The reflector  51  is a computer generated parabola which is vacuum aluminum metallized to ensure high precision optics. The threads  48  between the head  24  and the barrel  21  are machined such that revolution of the head assembly will open and close the electrical circuit as well as provide for focusing. A spare lamp bulb  68  may be provided in a cavity machined in the tailcap/switch assembly  94 .  
         [0049]    By reference to FIGS.  7 - 13  other features of the recharging feature of the preferred embodiments will be described. FIG. 7 shows a partial cross-sectional view of a flashlight having three dry cell batteries and a tailcap/switch assembly  94  especially adapted to be used in conjunction with a battery charger. The battery charger housing  62  is shown in FIG. 8 and a schematic diagram of the circuit for the charger is shown in FIG. 9.  
         [0050]    As shown in more detail in FIG. 10, the tailcap/switch assembly  94  includes negative charge ring  63 , diode  64 , diode spring  65 , ball  66 , switch knob  67 , a spare lamp  68 , insulator  69 , positive charge region or ring  70 , switch contact  71 , ground contact  72  and battery spring  73 . The spring  65  and ball being a ball detent in the radial cavity containing the diode  64 .  
         [0051]    When the flashlight is not in a battery charging mode, the tailcap may be used as an alternate flashlight switch to turn the flashlight on or off while maintaining a certain, predetermined focus for the light beam. As Shown in greater detail in FIG. 10, the tailcap/switch assembly  94  is in the “charge” position for charging and in the “off” position for normal flashlight operation. In the tailcap position shown, with the head of the flashlight rotated to be in the “on” position as described previously, the circuit is broken between switch contact  71  and ground contact  72  at the region of scallop  74 . In this position the forward ends of the switch contact  71  extend up through the scallop holes  74  cut in the ground contact  72 , but do not touch any part of ground contact  72 . The scallops are also shown in FIG. 11.  
         [0052]    Thus, the circuit from the barrel to ground contact  72  is broken at  74 . As shown, the remainder of the circuit after the break is from switch contact  71  to battery spring  73  to the electrode of the rearmost battery and thereafter to and through the head assembly as previously described.  
         [0053]    When the switch knob  67  is rotated in a counterclockwise direction 30 degrees, encased switch contact  71  also rotates 30 degrees, and the forward extensions of switch contact  71  come in contact with ground contact  72  at the scallops  74 . As shown in FIGS. 10 and 12 pin  91  is positioned within the positive contact region  70  of the tailcap and extends into slot  92  of switch knob  67  to provide a stop for the switch knob  67 . The pin  91  and slot  92  provide for a 30 degree rotation of the knob  67  to place the switch contact  71  into contact with ground switch  72 . In this position, as shown in phantom in FIG. 11, during normal flashlight operation with the head rotated so that the flashlight is “on” the current flowpath in the tailcap region is from the barrel to the ground contact  72  to switch contact  71  where they touch at  74 , then to battery spring  73  to the rearmost battery electrode.  
         [0054]    The forward end of the main barrel portion of switch contact  71  contains tabs  75 , also shown in FIG. 11, which are bent inward to form a shoulder against which the battery spring  73  rests as shown in FIGS. 10 and 11.  
         [0055]    The switch contact  71  and negative charge ring  63  are preferably made of machined aluminum or other suitable conductive material. The switch knob  67  and insulator  69  are preferably made of plastic or other suitable insulative material. The ball  66  is made of brass, bronze or other suitable conductive material. The springs  73  and  65  are preferably made of metal or alloy which has good spring as well as good electrical conductivity properties, such as beryllium copper. The contacts  71  and  72  are also preferably made of conductive metal, such as beryllium copper.  
         [0056]    When the flashlight is in the charging mode negative charge ring  63  is in contact with the negative contact of the charger housing, as shown in FIGS. 8 and 13. The positive charge region  70  of the tailcap/switch assembly  94  is in contact of the charger housing, as shown in FIGS. 8 and 13. The aluminum portion of tailcap/switch assembly  94  is anodized except for the positive charge region  70 , which has either not been anodized or which has had the anodized surface removed, as for example, by machining. An O-ring  76  is placed in the step  77  of the tailcap/switch assembly  94  to provide a water-tight seal, as at other locations described previously.  
         [0057]    For charging, the flashlight is placed into the charger housing  62 , as shown in FIGS. 8 and 13. The housing is made of a plastic, non-conductive material and includes front tongs  77 , rear tongs  78  and foot  79 . As shown in FIG. 13, negative housing contact  80  and positive housing contact  81  are positioned on the surface of the housing such that upon insertion of the flashlight into the tongs and placement so that the tailcap is resting against foot  79 , the housing contacts  80 ,  81  match up to and establish contact with negative charge ring  63  and positive charge region  70 , respectively.  
         [0058]    The circuit, as schematically shown in FIG. 9, is built into the charger housing  62  and receives its power from an external source, not shown. The circuit may be a potted module or printed circuit board. As shown, the circuit is for a 12 volt DC power supply, such as from a car battery or its equivalent. The charger housing may be fitted with a cord and plug for connecting to the external power source, or, optionally, may have a suitable plug built into the charger housing  62 .  
         [0059]    As shown in FIG. 9 the circuit has a housing  82 , and a positive input line which contains blocking diode  83 . Diode  83 , preferably a If 1.0 amp, E, 50 volt diode, permits current to flow only from left to right, in order to protect the circuit, flashlight and batteries. In the preferred embodiment the circuit is designed for DC input of 6-28 volts, with a voltage regulator  84  used to provide constant current to the batteries being charged. The voltage regulator  84  is preferably a standard integrated circuit voltage regulator having overload and temperature protection features. A 12.5 ohm resistor  85  and adjustment leg  86  complete the positive line input circuitry to the positive contact  81  of the battery charger housing  62 .  
         [0060]    In the negative, output line, of the charger circuit, diode  87  and 9 ohm resistor  88  are placed in parallel with LED  89  to develop a voltage of about 1.8 volts for energizing and lighting LED  89  when the batteries are being charged.  
         [0061]    Optionally, as shown in phantom lines in FIG. 9 is an AC converter, e.g., — 120 VAC: 12.6 VDC, or DC power source which may be included with the charger or provided as an optional component so that the battery charger may be charged from a standard wall outlet.  
         [0062]    As is shown in FIG. 9 the circuit provides for constant current supply to the batteries when charging. A typical charging rate would provide for a full charge to a completely dead battery in about  5  hours. By varying the values of resistors  85  and  88 , the battery design and power supply the charging rate may be increased or decreased as desired.  
         [0063]    When the flashlight is being charged, the tailcap  94  is rotated to be in the position shown in FIGS. 7 and 10. In that position and while charging, the current flowpath is from the external power source through the positive input line of the circuit shown in FIG. 9, to positive contact  81  of the charger housing, to positive charge region  70  of the tailcap and then to the barrel of the flashlight, the switch contact  71  and ground contact  72  not touching at scallops  74 . The current flow is then up to and through the components of the head assembly, as described previously. It should be noted, however, that the flashlights of the construction of the preferred embodiments must have the head rotated to the on position in order for charging to take place, that is, the circuit must be closed at conductor  42  and the lip  46  of barrel  21 . With charging current then flowing down through the batteries to spring  73 , as shown in FIG. 12, charging current re-enters the tailcap. From spring  73  current passes to switch contact  71 , to ball  66 , and then to diode  64 , which also as a safety feature, provides for only one-way current flow, and then to negative charge ring  63 , which is in contact with the negative charging contact  80  of the housing, as shown in FIG. 13.  
         [0064]    A battery charging system of the present invention may be adapted for use with flashlights having one or more batteries, and with M, or smaller sized rechargeable batteries, for example Ni-Cad batteries.  
         [0065]    While we have described a preferred embodiment of the herein invention, numerous modifications, alterations, alternate embodiments, and alternate materials may be contemplated by those skilled in the art and may be utilized in accomplishing the present invention. It is envisioned that all such alternate embodiments are considered to be within the scope of the present invention as defined by the appended claims.