Abstract:
An assembly of components for modifying a battery compartment to allow the use of batteries of a size other than originally designed. The assembly includes a hollow, electrically conductive, cylindrical adaptor, a first end of which is internally threaded for attachment to the existing battery compartment and a second end of which is externally threaded for acceptance of the existing battery compartment cap. The assembly further includes a hollow, electrically insulative, cylindrical insert. The adaptor and insert each include conductive electrical elements to connect a new configuration battery positioned within the insert to the existing battery compartment and compartment cap contacts. The adaptor and insert are coaxially aligned and loosely attached together in a manner that allows free rotational movement between them about a common central axis while retaining the adaptor and insert in close association.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates generally to battery compartment enclosures for electronic devices and the like. The present invention relates more specifically to a battery compartment modification to permit the use of an alternative type of battery in the compartment. Even more specifically the present invention relates to a retrofit, removable, adaptor assembly that extends and modifies the battery compartment of a night vision goggles device, and permits the continued use of the original battery compartment cap assembly.  
         [0003]     2. Background of the Invention  
         [0004]     Battery compartments for housing and connecting batteries used in powering various electronic devices such as night vision goggles, flash lights, camera light meters, etc., are well known in the art. Such battery compartment designs often include removable battery compartment caps which enable the battery or batteries contained within the compartment to be removed and replaced with new or recharged batteries.  
         [0005]     One specific night vision device that incorporates a battery compartment that lends itself to modification to receive a preferred battery type is the AN/PVS-7B/7D night vision goggle manufactured by ITT Industries. Referring to  FIG. 1A  (prior art), there is shown a AN/PVS-7B/7D night vision goggle device  10  (illustrated in dotted outline form) which includes a horizontally oriented battery compartment  12 , closed and covered by a removable (internally threaded) battery compartment cap  14 . The battery compartment cap  14  is tethered to the night vision goggle device  10  by way of retainer strap  16 . The battery compartment  12  is typically loaded with either lithium sulfur dioxide BA-5567/U batteries or two (2) AA batteries.  
         [0006]      FIG. 1B  shows in cross-section detail the typical configuration of battery compartment  12  enclosing a BA-5567/U battery  18  with battery compartment cap  14  secured in place. Electrical conductor  20  connects flat spring contact  22  (which contacts battery  18 ) with the electronics of the night vision goggle device  10 . Tether  16  is attached to battery compartment cap  14  in such a manner as to permit easy rotation of the cap to thread onto the opening of battery compartment  12 .  
         [0007]     Efforts have been made in the past to improve the functionality of the battery compartment cap  14  but have generally not addressed modification of the battery compartment to accommodate alternate battery selections. U.S. Pat. No. 6,194,097 issued to Nelson et al. on Feb. 27, 2001 entitled Battery Compartment Cap Having an Improved Contact, assigned to ITT Manufacturing Enterprises, Inc. (the disclosure of which is incorporated herein by reference) describes an effort to improve the battery compartment cap for the night vision goggle device that is the subject of the present invention as well. Although the modification described improves the ability of the cap to maintain electrical contact with the batteries there is nothing disclosed that is directed to accommodating alternate battery choices for the device.  
         [0008]     Although the battery compartment  12  (as shown in prior art  FIGS. 1A and 1B ) functions in a generally satisfactory manner, there exist certain disadvantages which reduce its utility. Battery selection is limited to two choices, either a single lithium sulfur dioxide BA-5567/U battery or two (2) AA batteries. The physical dimensions of the battery compartment were built around these two battery choices. An inability to procure either of these two battery choices, the BA-5567/U or the two AA batteries, could render the night vision goggle device inoperable or place it out of service.  
         [0009]     Other problems with the existing design for the battery compartment and cap include concerns about misalignment of the electrical contacts when loading certain types of batteries and the excessive weight of certain types of batteries that the night vision goggle device is designed to be used with. A lithium battery, for example, will generally weigh less than the equivalent alkaline cell. The BA-5567/U batteries have a nominal weight of 16 g while the AA batteries have weights of 22 g-23 g each for a total battery weight of 44 g-46 g. The newer and now readily available CR123A battery, on the other hand, as an example of an alternate battery capable of providing the same voltage and a greater power output, has a nominal weight of 16 g-17 g.  
         [0010]     Still another problem with the existing design concerns the expected capacity of the lithium sulfur dioxide BA-5567/U batteries or two (2) AA batteries. The BA-5567/U batteries have a nominal capacity of 0.86 AH while the AA batteries have capacities of 1.8 AH to 2.6 AH. By addressing the physical constraints of the original design, a different and more desirable battery, for example the CR123A, could be used. The CR123A has nominal 1.3 AH capacity which would extend use beyond the capacity of the BA-5567/U battery of the original design and yet would provide a much lighter weight battery at 16 g-17 g total than the AA batteries at 44 g-46 g total.  
         [0011]     A further consideration in choosing a battery for the night vision device involves the frequent necessity of carrying spare batteries for the night vision device and the various other battery powered devices that may typically be carried. More of the various other battery powered devices (lights, electronic sights, etc.) are using the CR123A type batteries, making it desirable for the night vision device to likewise be capable of using such batteries. It would therefore be desirable if the user could either use such batteries directly within the night vision device or carry a lightweight adaptor that permitted such use. The result would be the need to carry spares of only a single type of battery rather than multiple sets of spares. As a further advantage to this approach, the user could transfer batteries from one device to another if spares were not available and the ongoing use of a particular device became urgent.  
         [0012]     It is, therefore, a primary objective of the present invention to provide the ability to select a different battery combination to address the power output and weight issues and substantially overcome the disadvantages associated with the battery design selection and alignment of the prior art. The objective is to provide the ability to chose a more desirable “standard sized” battery for the AN/PVS-7B/7D night vision goggle system and at the same time, teach similar configurations for modifying and retrofitting other battery compartments for similar battery exchanges.  
         [0013]     It is a further objective of the present invention to provide an apparatus for allowing the use of a more desirable battery, while at the same time not requiring permanent alteration of the base night vision goggle system. It would be worthwhile to have a modification structure that could be easily removed so as to allow the system to return to its previous use of battery choices.  
         [0014]     It is a further objective that the above described modification structure would require a minimal number of components such that its use and/or its removal could be accomplished in the field without the need for tools to assemble or disassemble the night vision goggle system.  
         [0015]     In particular, it is an object of the present invention to provide an adaptor assembly for the use of an alternate battery in the battery compartment of a night vision goggle system, that maintains the use of the existing battery compartment cap and cap tether. It is an object to permit placement of the adaptor assembly by opening the battery compartment (unscrewing the cap), removing the existing batteries from the night vision goggle system, replacing the existing batteries with the new battery/adaptor assembly, and then re-securing the threaded cap.  
         [0016]     It is an object of the present invention to provide an adaptor assembly for allowing the use of an alternate battery in a night vision goggle system that is cost effective in providing a more efficient power source for the system without an excessive increase in the cost of the night vision goggle system itself.  
       SUMMARY OF THE INVENTION  
       [0017]     In fulfillment of the above objectives, the present invention provides an apparatus for modifying a battery compartment to allow the use of batteries of a size other than the original design consideration. The apparatus is comprised of two primary components, the first of which is a hollow, electrically conductive, cylindrical adaptor, a first end of which is internally threaded for attachment to the existing battery compartment and a second end of which is externally threaded for acceptance of the existing battery compartment cap. This first component provides a first electrically conductive path (the negative contact, for example) to the new battery positioned within the assembly. The second primary component of the apparatus is an electrically insulative, cylindrical insert for positioning at least one battery within the existing battery compartment. This second component provides a second electrically conductive path (the positive contact, for example) through a contact element positioned at one end of the component to the new battery positioned within the assembly. The second component is coaxially aligned with and centered partially inside the first component. An attachment ring holds the hollow cylindrical adaptor of the first component in loose (rotationally free) attachment to the cylindrical insert of the second component. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]     For a detailed understanding of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings wherein:  
         [0019]      FIG. 1A  (prior art) is a perspective view of an exemplary night vision device shown in dotted outline format, disclosing the position of the placement of the present invention;  
         [0020]      FIG. 1B  (prior art) is a cross-sectional view of a prior art battery compartment cap in the closed position on the battery compartment;  
         [0021]      FIG. 2  is an exploded perspective view of the various components and elements of the present invention;  
         [0022]      FIG. 3  is a cross-sectional view of a first preferred embodiment of the present invention positioned in place in the battery compartment of the night vision device shown in  FIG. 1A ; and  
         [0023]      FIG. 4  is a cross-sectional view of a second preferred embodiment of the present invention positioned in place in the battery compartment of the night vision device shown in  FIG. 1A . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]     Referring again to  FIG. 1A  (prior art), a AN/PVS-7B/7B night vision goggle device  10  (illustrated in dotted outline form) is shown to include a horizontally oriented battery compartment  12 , closed and covered by a removable (internally threaded) battery compartment cap  14 . The battery compartment cap  14  is tethered to the night vision goggle device  10  by way of retainer strap  16 .  FIG. 1B  (prior art) shows in cross-sectional detail the typical configuration of battery compartment  12  enclosing a BA-5567/U battery  18  with battery compartment cap  14  secured in place. Electrical conductor  20  connects flat spring contact  22  (which contacts battery  18 ) with the electronics of the night vision goggle device  10 . Tether  16  is attached to battery compartment cap  14  in such a manner as to permit easy rotation of the cap to thread onto the opening of battery compartment  12 .  
         [0025]     The structure and design of the present invention is directed towards; (1) configuring the geometry of the battery compartment to appropriately enclose and hold the alternate desired battery shape and size, and (2) extending the electrical contact(s) required to connect the new battery to the electrical circuitry (wiring) of the existing battery compartment. The battery adaptor of present invention provides an “adaptor” component and an “insert” component to achieve these requirements.  FIGS. 2 and 3  disclose a preferred embodiment of the present invention while  FIG. 4  discloses an alternate embodiment of the invention.  
         [0026]     Referring to  FIG. 2 , there is shown an exploded perspective view of the preferred embodiment of a removable battery adaptor assembly made in accordance with the objectives of the present invention. The battery adaptor assembly generally comprises a hollow cylindrical adaptor element  24 , a hollow cylindrical insert  26 , an O-ring  32 , and a contact assembly  28 . The components of the battery adapter assembly may be manufactured from any well known conventional materials which, as described in more detail below, provide the necessary rigidity and electrical characteristics (conductive or non-conductive). For example, adaptor element  24  may be constructed from any suitable electrically conductive material such as aluminum. The cylindrical insert  26  may be manufactured from any suitable insulating material, such as high density plastic. The contact assembly  28  may be constructed from any suitable electrically conductive and physically resilient material, such as beryllium copper or stainless steel.  
         [0027]     Adaptor element  24  is designed to attach to the existing battery compartment opening (not shown in  FIG. 2 ) and to receive the attachment of the existing battery compartment cap (also not shown). As a result, adaptor element  24  defines a central circular opening  40  through which the existing battery contact inside the cap makes contact with the new battery inserted into the assembly of the present invention. Internal edge  34  defines this circular opening and, as described in more detail below, provides an electrical contact surface to connect with the conductive elements present in the existing battery compartment cap.  
         [0028]     The remaining structure of adaptor element  24  comprises two sections; the externally threaded cap connector section  36  and the internally threaded battery compartment connector section  38 . This combination of internally and externally threaded cylindrical sections effectively extends the battery compartment longitudinally (along the axis shown in dashed line in  FIG. 2 ) to accommodate the new battery geometry. A new O-ring  32  is used (and positioned as shown in  FIG. 3 ) to form a seal between the adaptor element  24  and the existing battery compartment (not shown) just as an existing O-ring in the existing battery compartment cap (not shown) accomplishes between the existing cap and the top of adaptor element  24 . The section of adaptor element  24  that includes the internally threaded battery compartment connector includes gripping slots  39  to facilitate attachment and removal of the adaptor element  24  to the battery compartment housing. These gripping slots are similar to those typically positioned on the existing battery compartment cap which now (with the use of the present invention) facilitate attachment and removal of the cap to the adaptor element  24 .  
         [0029]     Cylindrical insert  26 , in contrast to adaptor element  24 , is preferably made of non-conductive material and serves primarily to modify the geometry of the battery chamber to accommodate the desired alternate battery size and shape. In  FIG. 2 , cylindrical insert  26  is shown to be a cylindrical sleeve with internal opening  48  sized to accommodate the new battery (not shown). The outward or open end of cylindrical insert  26  is configured to engage (in a manner shown in more detail below with  FIG. 3 ) adaptor element  24 . The engagement between cylindrical insert  26  and adaptor element  24  involves snapping the semi-flexible tabs  46  (formed at the upper end of insert  26  by the placement of slots  42  radially through the wall of the cylinder) into the inside of adaptor element  26 . In the preferred embodiment shown, six radially arrayed slots  42  divide the upper end of the insert into six semi-flexible tabs  46  that bend slightly to allow engagement of this end of the insert  26  with an internal circular attachment ring (not shown in this view) on adaptor element  24 . This internal circular attachment ring formed on the inside of adaptor element  24  engages the external circumferential slot  44  formed in cylindrical insert  26  as shown. The manner of this engagement is explained in greater detail in the cross-sectional view of  FIG. 3  discussed below.  
         [0030]     Finally in  FIG. 2 , the elements of the contact assembly  28  are shown positioned below the lower end of cylindrical insert  26 . Contact disc  29  is held in place in the lower end of cylindrical insert  26  by retaining ring  31 , which in the preferred embodiment is an inside snap ring as shown. Contact disc  29  provides the electrical connection between one of the two battery contacts (the positive contact, for example) and the appropriate circuitry (wiring) in the existing battery compartment. The manner of positioning and securing contact disc  29  into cylindrical insert  26  is described in more detail below.  
         [0031]     Reference is now made to  FIG. 3  for a description of the internal structures of the various components of the present invention, as seen in cross-sectional detail. In  FIG. 3 , the cross-sectional structure of cylindrical adaptor  24  is similar in some respects to the prior art battery compartment cap structures disclosed generally in  FIGS. 1A and 1B . Cylindrical adaptor  24  therefore includes a circular opening  40  defined by the cylindrical wall of the adaptor  24 . This cylindrical wall is slightly offset midway along its height such that the internal diameter of the lower section is approximately equal to the external diameter of the upper section. This is to simultaneously accommodate the connections to the existing cap (internally threaded) at the upper section and the existing battery compartment opening (externally threaded) at the lower section, where previously the existing cap directly connected to the existing battery compartment opening.  
         [0032]     Interrupting the internal face of this cylindrical wall of adaptor  24  at approximately the aforementioned wall offset, is attachment ring  35  which, as described above, serves to connect adaptor  24  to insert  26  in a manner that allows them to freely rotate with respect to one another around the central axis shown in dashed line form in  FIG. 3 . As briefly described above, attachment ring  35  snaps into circumferential slot  44  formed at the open end of insert  26 . This assembly process is made possible by the placement of radial slots  42  (dashed outline) in the open end of insert  26  to form tabs  46  which bend slightly to allow attachment ring  35  to slide into engagement with circumferential slot  44 . The loose engagement between adaptor  24  and insert  26  allows the battery positioned in the present invention to be held in place between the spring-loaded electrical contact of the existing battery compartment cap (see  FIG. 1B ) and the contact assembly  28  positioned at the base of insert  26 . The absence of rigid engagement between adaptor  24  and insert  26  allows for adaptor  24  to be screwed onto the battery compartment without rotating insert  26  and to additionally tighten when the existing battery cap is screwed onto the adaptor  24 . The engagement of adaptor  24  and insert  26  also facilitates the retention of the components of the present invention together as an assembly, reducing the chance of losing one or more of the components of the assembly during battery replacement.  
         [0033]     Positioned on an interior perimeter of the lower section of adaptor  24  is a circumferential lip configured to receive and retain O-ring  32  that seals the battery compartment adaptor  24  to the associated battery compartment  12 . It should be understood, however, that other techniques for sealing the adaptor  24  to the battery compartment  12  can be used. For example, if the adaptor is manufactured from a molded plastic material (as described in more detail below) the O-ring  32  can be replaced with one or more unitarily formed sealing ribs to further reduce the assembly costs of the battery compartment enclosure.  
         [0034]     Still referring to  FIG. 3 , the circumferential lip  34  positioned on adaptor  24  operates to define an electrical contact for the cylindrical adaptor  24  to complete the electrical circuit with the battery compartment contact ring  30  which, in the preferred embodiment, constitutes the negative contact conductor of the power supply for the night vision goggle. From the battery contact positioned in the existing battery compartment cap (not shown in  FIG. 3 ) current flows into the conductive adaptor  24  by way of contact surface  34 . Current from the battery then flows through adaptor  24  to contact ring  30  which is electrically connected (in a manner omitted for clarity) to the balance of the circuitry within the night vision goggle device. The positive contact, in the preferred embodiment, comprises contact assembly  28  made up of the combination of contact disc  29  and retaining ring  31 . These conductors come into contact with battery compartment electrical contact  56  which extends up from within the compartment as shown and described above with respect to prior art  FIG. 1B . This allows new (alternate) battery  60  to be positioned as shown within the confines of insert  26 , pressed between the contact assembly  28  and the spring loaded contact in the existing battery compartment cap (not shown).  
         [0035]     As indicated above, the second main component of the assembly of the present invention is the electrically insulated cylindrical insert  26  shown positioned within the existing battery compartment  12  in  FIG. 3 . The general structure of the cylindrical insert  26  is open at one end (sufficient for insertion of battery  60 ) and closed at the other. The closed end retains the battery  60  and in the preferred embodiment provides the electrical connection for the positive electrode of the battery to the copper contact post  56  of the night vision goggle. As described above, contact disc  29  is held in position by the insertion of retaining ring  31  snapped into place in a groove on the internal periphery of the closed end of the cylindrical insert  26 . Contact disc  29  rests on a circular shelf formed in the structure of insert  26  on the internal edge of the base thereof, adjacent the above described groove into which retaining ring  31  is placed. In this manner, contact assembly  28  closes the base of insert  26  so as to enclose battery  60 .  
         [0036]      FIG. 4  provides an alternate embodiment of the assembly of the present invention wherein each of the components is modified slightly to accommodate a different assembly process. The configuration of the open and closed ends of insert  27  is distinct from insert  26  shown in  FIGS. 2 and 3 . Adaptor  25  in  FIG. 4  is likewise modified from adaptor  24  shown in  FIGS. 2 and 3  to accommodate the modification of the open end of insert  27 . In this embodiment, insert  27  is constructed with a closed base through which a narrow aperture is formed to receive a conductive screw/bolt assembly  62 . Contact washer  58 , which is also electrically conductive, carries current from the battery through screw/bolt assembly  62  to existing battery compartment contact post  56 .  
         [0037]     The open end of insert  27  provides a somewhat simpler means for connecting insert  27  to adaptor  25 . Rather than structuring slots and tabs in the open end of insert  27 , an external snap set ring  47  is simply positioned in a narrow slot on the peripheral wall  45  of this open end of the insert  27 . A circular shelf is provided in adaptor  25  to receive and center the snap set ring  47 . The same loose engagement between insert  27  and adaptor  25  is achieved by way of these structures which permit insert  27  to freely rotate with respect to adaptor  25  about the centerline axis shown in  FIG. 4 . The remaining features of the assembly of the present invention shown in  FIG. 4  remain generally the same as those disclosed in  FIGS. 2 and 3 .  
         [0038]     Reference is again made to  FIGS. 2 and 3  for a description of an alternate embodiment of the adaptor component of the present invention. As mentioned above, it is possible for adaptor  24  to be manufactured of a molded plastic material and for the conductive path required to be provided by a conductive element integrated into or positioned on adaptor  24 . One such manner of achieving a conductive path through adaptor  24  would be to mold a conductor into the material of adaptor  24  by positioning a contact ring (not shown) at contact surface  34  that, by way of an internally positioned (molded) wire connects to a similarly molded contact ring (not shown) positioned above the point of contact with contact ring  30 . A similar structure could be established on the exterior surface of adaptor  24  by adhering such contact rings at the positions indicated and adhering a conductive path between them down the interior wall surface of the adaptor  24 . These contact rings could be replaced by one or more discrete contact pads in further embodiments of this alternate approach to establishing the conductive path between the existing cap and the balance of the existing battery compartment.  
         [0039]     Although the battery compartment adaptor assembly of the present invention is especially suited for use with the battery compartment of a AN/PVS-7B/7D night vision goggle device as shown and described herein, the basic structures and concepts implemented can be easily modified in size and/or shape to fit in many other applications where it is desired to utilize a more efficient or cost effective battery as a power source. It should be understood therefore that the embodiments described herein are merely exemplary and that a person skilled in the art may make many variations and modifications to the embodiments utilizing functionally equivalent elements to those described herein. Any and all such variations or modifications as well as others which may become apparent to those skilled in the art, are intended to be included within the scope of the invention as defined by the appended claims. The present invention finds specific industrial applicability in support of battery operated devices.