Patent Abstract:
An example apparatus embodiment includes a flashlight operable from a primary electric storage battery and from another battery having an external casing that has a different outer diameter and possibly a different overall length than the primary battery. In some embodiments, a battery adapter extends a battery compartment to hold a longer substitute battery. In other embodiments a batter adapter holds a battery with a dimension, for example a diameter of the battery case, that is too large to allow the battery to slide into the battery compartment. Another example embodiment includes a battery adapter without a flashlight.

Full Description:
FIELD OF THE INVENTION 
     Embodiments are related to handheld flashlights powered from one or more electric storage batteries held in a battery compartment within the flashlight. 
     BACKGROUND 
     A handheld flashlight may be powered by one or more electric storage batteries enclosed in a battery compartment inside the body of the flashlight. When the flashlight is turned on, electrical energy stored in the batteries is converted to light energy by a light emitter such as an incandescent bulb, light emitting diode (LED), or fluorescent bulb. The batteries, light emitter, and an electrical switch may be connected in a series electrical circuit. Some flashlights include an electrical circuit for dimming the light output from the flashlight or causing light to be emitted in a flashing pattern. 
     Some flashlights use high-capacity batteries such as lithium batteries, nickel metal hydride batteries, or other high-capacity battery technologies. High-capacity batteries may use a different battery casing to distinguish the batteries from zinc-carbon, alkaline, and rechargeable batteries. 
     A flashlight adapted to hold a lithium battery or other high-capacity battery may have a battery compartment that is the wrong internal diameter and possibly the wrong internal length for accepting another type of battery. If a battery of the correct size and shape is not available when the high-capacity battery needs to be replaced, the flashlight may be incapable of producing a useful amount of light until the correct replacement battery is located. It may be more difficult to obtain new high capacity batteries than carbon-zinc or alkaline batteries in remote areas, after normal business hours, or during an emergency. 
     SUMMARY 
     An example embodiment includes a flashlight body. The flashlight body includes a light emitter coupled to the flashlight body and a battery compartment formed as an internal cavity of the flashlight body. The battery compartment may be formed with an internal diameter sized for acceptance of a primary battery. A first contact surface may be formed at an end of the battery compartment. 
     The example embodiment further includes a battery adapter. The battery adapter includes a first end having a second contact surface coupled to the first contact surface of the battery compartment; a second end opposite the first end, the second end of the battery adapter formed with a third contact surface sized for coupling to the second contact surface; and an aperture passing through the first end and the second end of the battery adapter, the aperture formed with a diameter sized for a sliding fit of a substitute battery. The example embodiment further includes an an end cap coupled to the second end of the battery adapter. 
     Another example embodiment includes a battery adapter for a flashlight body. The example battery adapter includes a first contact surface near a first end of the battery adapter, the first contact surface adapted for securely coupling to a corresponding contact surface on a flashlight body; a second contact surface at an end opposite the first end, the second contact surface adapted for securely coupling to the first contact surface on another of the battery adapter; and an aperture passing through the first end and the second end of said battery adapter. The aperture may be sized for a sliding fit of a substitute battery. 
     In some embodiments, the primary battery has a battery case with a larger diameter and/or a shorter length than the battery case of the substitute battery. In other embodiments, the primary battery has a smaller diameter and/or a longer length thn the battery case of the substitute battery. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a side view of an example apparatus embodiment including a flashlight with a removable battery adapter interposed between the flashlight body and the endcap. 
         FIG. 2  shows a view toward a first end of the example flashlight of  FIG. 1 . 
         FIG. 3  shows a view toward a second end of the example flashlight of  FIG. 1 . 
         FIG. 4  shows a side view of the example embodiment of  FIG. 1  with the example battery adapter removed. 
         FIG. 5  is a side view of an example battery adapter. 
         FIG. 6  is an end view of the example battery adapter of  FIG. 5 . 
         FIG. 7  is a cross-sectional view A-A of the example flashlight embodiment with the battery adapter interposed between the flashlight body back segment and the endcap, and further showing an example of a substitute battery in the battery compartment and battery adapter. 
         FIG. 8  is an alternative cross-sectional view A′-A′ with the battery adapter removed and an example of a primary high-capacity battery enclosed within the battery compartment. 
         FIG. 9A  is a cross-sectional view B-B of an example battery adapter having threaded contact surfaces. 
         FIG. 9B  is an alternative cross-sectional view B′-B′ of an example battery adapter having contact surfaces sized for a close fit to corresponding contact surfaces on a flashlight body or on another battery adapter. 
         FIG. 10  is a side view of two example electric storage batteries compatible with the example embodiment of  FIG. 1  (Prior Art). 
         FIG. 11  is an end view of the two example batteries of  FIG. 10 , further illustrating an example internal diameter of the flashlight body in an example embodiment. 
         FIG. 12  is another alternative cross-sectional view A″-A″ of an example flashlight embodiment with more than one battery adapter interposed between the flashlight body and the end cap and more than one substitute battery. 
         FIG. 13  is another alternative cross-sectional view A′″-A′″ showing a battery adapter coupled to an outer surface of the flashlight body and an example primary battery that is longer and smaller diameter than the substitute battery held by the battery adapter. 
     
    
    
     DESCRIPTION 
     Some example embodiments include a flashlight operable from a primary battery retained with a battery compartment formed in the flashlight body and from a substitute battery retained in the battery compartment and slidably engaging with a battery adapter attached to an end of the flashlight body. Other example embodiments include a battery adapter having an aperture sized for a sliding fit of a substitute battery. Embodiments are advantageous for replacement of a primary battery with a substitute battery having a different diameter than the primary battery and possibly a different length than the primary battery. 
     A primary battery may be a high-capacity electric storage battery such as, but not limited to, a lithium battery, a nickel metal hydride battery, and a high capacity alkaline battery. Examples of a substitute battery include, but are not limited to, a zinc carbon battery, an alkaline battery, and a rechargeable battery. A new high-capacity battery stores more ampere-hours of electrical energy than a new zinc-carbon battery of comparable size. 
       FIG. 1  shows a side view of an example handheld flashlight embodiment. The example embodiment  100  includes a flashlight  102  having a body  104  coupled to an optional battery adapter  112  and an end cap  106 . When the flashlight is turned on, possibly by operation of a power switch  130 , light shines out of a first end  136  of the flashlight. In some embodiments, the flashlight may be turned on by rotation of a front segment  104 A of the flashlight body relative to a back segment  104 B. In some embodiments the front segment  104 A is separable from the back segment  104 B. The front segment  104 A and back segment  104 B may alternatively be formed as an integral unit. 
     Batteries are retained inside the battery compartment by the end cap  106  at a second end  138  of the body  104 . When the flashlight is to be operated with a substitute battery, the battery adapter  112  is attached to the flashlight between the second end  138  of the body  104  and the end cap  106 . The battery adapter may optionally have an outer dimension  148  that matches an outer dimension  146  of the body  104 . In some embodiments, the battery adapter holds a substitute battery that has a larger diameter than the diameter of the primary battery and is therefore larger than the outer dimension of the flashlight body. When the body  104  is formed as a cylinder, the outer dimension  146  is a diameter of the cylinder. The body may alternatively be formed with a polygonal surface, for example one or more flat surfaces to prevent the flashlight from rolling when placed on another surface. 
       FIG. 2  shows an example view toward the first end  136 . A light emitter  110  is visible behind an optional transparent window  108 .  FIG. 3  shows a view toward the end cap  106  at the second end  138  of the flashlight  102 . In the example of  FIG. 1 , the end cap, battery adapter, and flashlight body couple to one another by the engagement of threaded contact surfaces. The contact surfaces may alternatively be adapted for a close sliding fit or a snap fit. 
       FIG. 4  shows an example embodiment  100  arranged for operation with a primary battery. When the primary battery is being used to power the flashlight, the end cap  106  is attached directly to the body  104 , and the battery adapter is omitted. 
       FIG. 5  shows a side view of an example battery adapter  112  having an outer housing  113 . In the example embodiment of  FIG. 5 , a first end of the battery adapter is formed with an external thread  115  selected to engage with a corresponding internal thread on the flashlight body and with the internal thread  116  on another battery adapter  112 . An internal thread  116  is formed near the second end opposite the externally threaded end. An aperture passes through the battery adapter from the first end to the second end. In some embodiments, an optional hollow sleeve  114  has an inner diameter  124  that is slightly larger than the external diameter of a substitute battery, giving a sliding fit of the substitute battery. The hollow sleeve  114  may have an outer diameter  123  matching an inner diameter  150  of the battery compartment in the body  104  of the flashlight  102 .  FIG. 6  shows a view toward the internally threaded end of the battery adapter example of  FIG. 5 . 
       FIG. 7  is a cross section A-A representing an example of a substitute battery  132  in the battery compartment  142  of the flashlight body  104 . The substitute battery  132  may slidably engage the hollow sleeve  114  in the battery adapter  112 . The battery adapter holds the battery in position for a terminal  140  on the battery to make electrical contact with a battery contact terminal  126  in the body  104 . The substitute battery  132  may be too long to be contained within the battery compartment  142 . The battery adapter may extend the length of the battery compartment  142 , with the substitute battery passing through the battery adapter to contact a battery terminal contact spring  128  attached to the end cap  106 . 
       FIG. 8  shows an alternative cross sectional view A′-A′ of the example flashlight embodiment  102 . In the example of  FIG. 8 , a primary battery  134  slides into the battery compartment  142  with the terminal  140  on the battery in contact with the terminal  126  in the body  104 . The end cap  106  is directly engaged with the body  104 , the battery adapter having been omitted from the flashlight body. 
       FIG. 9A  shows a cross-sectional view B-B of the example battery adapter  112  of  FIG. 5  and  FIG. 6 . The internal diameter  124  of the hollow sleeve  114  fits closely into an aperture formed in the battery adapter  112 . In some embodiments the sleeve is formed as an integral part of the battery adapter. The sleeve may alternatively be omitted and the internal aperture in the battery adapter formed with an aperture having a diameter  124  corresponding to the outer diameter of a substitute battery. An exterior contact surface  150  is adapted to couple to a corresponding interior contact surface  152  on another battery adapter or on a flashlight body. 
       FIG. 9B  shows an alternative cross-sectional view B′-B- having an exterior contact surface  150  and an interior contact surface  152  adapted for securely coupling with corresponding surfaces on another battery adapter or on a flashlight body. The secure coupling may be implemented as a close sliding fit between the surfaces or by a snap fit between joined parts. 
       FIG. 10  shows an example of a comparison between a length  122  of a battery casing for a primary battery  134  and a length  118  of a battery casing for a substitute battery  132 .  FIG. 11  shows an example of a comparison between the diameter  120  of a battery casing for a primary battery and the diameter  124  of a battery casing for a substitute battery. The diameter  120  of the primary battery further represents a minimum inner diameter  144  of the battery compartment  142 . In an example embodiment, the primary battery  134  has a casing size corresponding to a CR123 lithium battery and the substitute battery  132  has a casing size corresponding to an AA alkaline, zinc carbon, or rechargeable battery. In another example embodiment, the primary battery is a D size battery and the substitute battery is a C size battery. In another example embodiment, the primary battery size is CR123 and the substitute battery size is AAA. It will be appreciated that many other size combinations are within the scope of the disclosed embodiments, with the primary battery  134  generally having a different length and/or diameter than the substitute battery  132 . 
       FIG. 12  shows another alternative cross-sectional view A″-A″ in which more than one battery adapter  112  has been interposed between the body  104  and end cap  106 . More than one battery adapter  112  may be used when more than one substitute battery  132  has been used to replace a primary battery. 
       FIG. 13  shows another alternative cross-sectional view A′″-A′″ in which the primary battery  134  has a smaller diameter and a greater length than the substitute battery  132 . The battery adapter may be arranged to couple to an exterior surface of the flashlight body as shown in the figure. 
     Unless expressly stated otherwise herein, ordinary terms have their corresponding ordinary meanings within the respective contexts of their presentations, and ordinary terms of art have their corresponding regular meanings.

Technology Classification (CPC): 5