Abstract:
The present invention provides a unique dual mode, inline switch mechanism that is fully integrated into the rear cap of a flashlight assembly to provide a completely self contained and waterproof switching mechanism. The switch assembly further provides dual mode functionality including an ON position and a momentary ON position while also including a reliable OFF position that prevents the accidental activation of the light when the user desires that it remain off. The entire mechanism resides in the end cap of the flashlight assembly and includes an end cap structure that is designed to be rotatably attached to the end of a flashlight housing, a tactile ratchet lock assembly similar to a ballpoint pen, a plunger and an elastomeric cover. The switch mechanism is fully integrated on the interior of the flashlight providing the highly desirable, fully contained, in line functionality.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is a continuation-in-part of U.S. patent application Ser. No. 10/378,538, filed Mar. 3, 2003, now U.S. Pat. No. ______, which claims priority from earlier filed provisional patent application No. 60/373,464, filed Apr. 18, 2002. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    The present invention relates generally to a dual mode switch for improved functioning in flashlight devices. More specifically, the present invention relates to an improved pushbutton switching mechanism for flashlights that provides a momentary and constant ON feature as well as a positive, reliable OFF position.  
           [0003]    Flashlights of varying sizes and shapes are generally well known in the art. A number of such designs are known that utilize two or more batteries as their source for electrical energy. Typically, these batteries are carried in series in a tubular body, where the tubular body also serves as a handle for the flashlight. In order to operate the flashlight, an electrical circuit is established from one terminal of the battery, through a conductor to an external switch located in an opening in the side of the tubular body and then through another conductor to one contact of a bulb. After passing through the filament of the bulb, the electrical circuit emerges through a second contact of the bulb in electrical contact with a conductor, which in turn is in electrical contact with the flashlight housing. Finally, the flashlight housing provides an electrically conductive path to the other terminal at the rear of the battery. Actuation of the external switch completes the electrical circuit selectively enabling electrical current to pass through the filament of the bulb, thereby generating light that is then typically focused by a reflector to form a beam of light.  
           [0004]    In general, the above described flashlight switch mechanisms operate in two basic manners. The first method of operation is a pushbutton type switch on the side or bottom of the light. The user depresses the switch, which has an internal mechanism that locks in the engaged position, turning the flashlight on. To turn the light off, the user again depresses the switch, unlocking it and turning the light off. This design has several drawbacks. One drawback is that the increased number of parts creates additional assembly steps and increases the difficulty of assembly process. Another drawback is that when a flashlight of this type is stored in luggage, it is susceptible to being compressed by items that may shift during transit, thereby activating the flashlight and draining the battery. A further drawback associated with this possibility of accidental activation is evident in high intensity flashlights that generate a great deal of heat during operation. If a flashlight of this type is tightly packed in luggage and accidentally activated, it may cause a fire.  
           [0005]    In an attempt to resolve the drawbacks noted above, with respect to the push-button type switches, a second type of rotatable switch was developed for in-line use in flashlights. In one design, an end cap is rotatably secured to the flashlight body. To establish the required electrical contact, the end cap is rotated making contact between the rear contact of the batteries and the housing of the flashlight thereby energizing the circuit and illuminating the lamp bulb. A number of such prior art designs feature rotatable end caps which are rotated to move the batteries longitudinally within the flashlight body towards the lamp bulb, thereby causing contact between the battery contact and the base contact of the lamp bulb. In the open position, the battery is typically spring biased away from the base contact of the bulb. In other designs, miniature flashlights have been designed where the rotatable switch is located in the reflector end of the flashlight body. The lamp bulb is located within an insulated receptacle at the reflector end of the flashlight with one or more conductive pins being rotatably aligned by movement of the switch portion of the device to establish electrical contact. While these switch mechanisms are internal to the device and thus less subject to damage, they are overly complicated in design thereby requiring higher assembly tolerances, which result in making them more costly to manufacture.  
           [0006]    There is therefore a need for a unique flashlight switching design that provides dual mode functionality with a reliable OFF position that has improved functionality over the designs of the prior art. There is a further need for a flashlight switch device that requires a reduced number of parts thereby simplifying assembly and manufacture while providing the necessary dual mode functionality described above.  
         BRIEF SUMMARY OF THE INVENTION  
         [0007]    In this regard, and in furtherance of the above stated objectives, the present invention provides a unique dual mode, inline switch mechanism that is fully integrated into the rear cap of a flashlight assembly to provide a completely self contained and waterproof switching mechanism. The switch assembly further provides a reliable OFF position that prevents the accidental activation of the light when the user desires that it remain off.  
           [0008]    The flashlight of the present invention is constructed of primarily three sub assemblies including a flashlight head, a housing and an end cap. The entire basic structure of the switch of the present invention resides in the end cap of the flashlight assembly and includes an end cap structure that is designed to be rotatably attached to the end of a flashlight housing, a contact plate, a plunger and an elastomeric cover. Only the contact plate in the assembly in the preferred embodiment of the present invention is required to be conductive. The end cap structure may be conductive so that its material is consistent with the material used in the outer housing of the flashlight however this is not required. The remaining components however are all electrically insulative and designed to properly isolate the conductive components to insure proper operation of the switch assembly. The plunger and contact plate are assembled and supported in an opening centrally located in the end cap. This provides for the plunger and contact plate to be located in a position at the rear of the flashlight where its motion is limited to a controlled and predictable linear travel. As can be seen, in this manner a switch assembly that operates in an in-line fashion is provided.  
           [0009]    By limiting the travel of the plunger and contact plate to a predictable distance, the present invention can achieve the desired multifunctionality, namely, a momentary ON function, a full ON function and a verifiable OFF function. Each one of the functions is selected by rotating the end cap assembly including the switch of the present invention. As the end cap of the assembly is rotated, its linear spacing relative to the flashlight housing is increased or decreased thereby altering the mode of switch operation. In this manner an economical flashlight assembly is provided that has a reduced number of operational parts as compared to the prior art thereby producing a more reliable product.  
           [0010]    The switch in the end cap further operates in conjunction with the spring element located in the head of the flashlight to further insure retention of the batteries and a positive electrical contact between the batteries and the head assembly. Further, the spring bias caused by the spring assembly in the head of the flashlight causes the batteries to be pressed rearwardly, which in turn causes the contact plate and plunger to be urged rearwardly creating the normally open bias for the switch assembly.  
           [0011]    In an alternate embodiment, the switching function related to the momentary ON position and the constant ON position are accomplished within the structure of the end cap using a ratcheting cam lock mechanism. In this embodiment, the contact plate remains in full contact with the end of the housing and the battery. A combination of contacts within the structure of the cap are then operable to active the light using the pushbutton. The constant OFF position is achieved by slightly unthreading the end cap from the flashlight housing until the contact plate is moved out of contact with the housing thereby breaking the path of the circuit and preventing the light from being energized.  
           [0012]    Accordingly, one of the objects of the present invention is the provision of a low cost flashlight having a superior dual mode switching mechanism. Another object of the present invention is the provision of a flashlight having a dual mode switching mechanism that includes a momentary ON, a full ON and a verifiable OFF position. A further object of the present invention is the provision of a flashlight having a dual mode switch that includes a reduced number of moving components thereby reducing manufacturing and assembly costs while improving the reliability of the assembly. Yet a further object of the present invention is the provision of a flashlight assembly having a dual mode switch that is integrated in an inline fashion and is waterproof.  
           [0013]    Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    In the drawings which illustrate the best mode presently contemplated for carrying out the present invention:  
         [0015]    [0015]FIG. 1 is an exploded perspective view of a flashlight employing the dual mode switch assembly of the present invention;  
         [0016]    [0016]FIG. 2 is a cross-sectional view thereof taken along Line  2 - 2  of FIG. 1;  
         [0017]    [0017]FIG. 3 is an exploded view of the end cap assembly thereof;  
         [0018]    [0018]FIG. 4 is a cross-sectional view thereof taken along Line  4 - 4  of FIG. 3;  
         [0019]    [0019]FIG. 5 is an exploded view of the head assembly thereof;  
         [0020]    [0020]FIG. 6 is a cross-sectional view thereof taken along Line  6 - 6  of FIG. 5;  
         [0021]    [0021]FIG. 7 a  is an enlarged cross-sectional view thereof in the ON position;  
         [0022]    [0022]FIG. 7 b  is an enlarged cross-sectional view thereof in the momentary ON position;  
         [0023]    [0023]FIG. 7 c  is a cross-sectional view thereof in the OFF position;  
         [0024]    [0024]FIG. 8 is an exploded view of an alternate embodiment of the end cap assembly of the present invention; and  
         [0025]    [0025]FIG. 9 is a cross-sectional view of the alternate embodiment end cap taken along the line  9 - 9  of FIG. 8. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0026]    Referring now to the drawings, a flashlight assembly including an end cap with the dual mode switch of the present invention is illustrated and generally indicated at  10  in FIGS.  1 - 7 . In accordance with the present invention, an in-line flashlight  10  is provided having a momentary ON, full ON and confirmable OFF position. The flashlight  10  has three major components including an end cap  12 , an outer housing  14  and a head assembly  16 . When fully assembled the components interface with one another for form a novel and useful flashlight  10  that has previously been unknown in the art.  
         [0027]    Turning to FIGS. 1 and 2 as a general overview, the flashlight  10  of the present invention has an outer housing  14  that is preferably electrically conductive, however, a circuit trace or contact wire may be installed in the outer housing  14  to serve as a path of conductivity in lieu of the outer housing  14 . The head assembly  16  is press fit into one end of the housing  14  and the end cap  12  is threadedly received onto the other end of the outer housing  14  opposite the head assembly  16 . The head assembly  16  further includes a spring  18  and plunger  20  that extends into the outer housing  14  and is in electrical communication with one contact of a lighting element  22  located within the head assembly  16 . The second contact of the lighting element  22  is in electrical communication with the head assembly casing  24  and in turn with the wall of the outer housing  14 . Batteries  28  are inserted into the outer housing  14  so that one end of the lower battery  28  is in electrical communication with the spring  18 . The end cap  12  is threaded onto the outer housing  14  to retain the batteries  28 . As can be seen, once the flashlight  10  is fully assembled, the batteries  28  are spring biased in a direction that exerts a force against the end cap  12 .  
         [0028]    Turning now to FIGS. 3 and 4, detailed views of the several components of the end cap  12  are shown. The end cap  12  contains the operational elements of the switch assembly of the present invention and is threadedly received onto the end of the outer housing  14 . The end cap  12  has a casing  30  that may or may not be constructed of electrically conductive material and includes an axial bore  32  through the center thereof. A plunger  34  is slideably received through the axial bore  32  in the casing  30  of the end cap  12 . The plunger  34  is preferably a nonconductive material such as a molded plastic that has resilient material properties while serving to prevent any conduction of electricity through the plunger  34  and into the end cap  12  casing  30 . Further, the plunger  34  has fingers  36  that contract allowing it to be inserted into the bore  32  within the cap  12  with clips on the end of the fingers  36  so that it remains in its assembled position when the flashlight  10  is disassembled for servicing the batteries  28 . A switch plate  38  is installed on the bottom of the plunger  34 . The switch plate  38  is a conductive metallic plate that is connected to the bottom surface of the plunger  34  either through the use of a fastener, an adhesive or through hot melting plastic pins  40  that integrally formed with and extend from the plunger  34  through openings in the switch plate  38 . When fully assembled, the end cap  12  allows the switch plate  38  and plunger  44  to be slideably movable within the axial bore  32 . However, the fingers  36  on the upper end of the plunger  34  serve to retain the plunger  34  within the bore  32 , preventing it from falling out in addition to limiting the overall axial travel of the plunger  34 . Once assembled, it can be seen that the travel of the switch assembly is limited to the distance “d” between the clips on the end of the fingers  36  on the plunger  34  and the sidewalls of the bore  32  in the end cap  12 . The end cap  12  is then threaded onto the end of the outer housing  14  wherein the threaded portion engages the threaded end of the outer housing  14 . An elastomeric cover  42  may be seated in the end of the cap  12  covering the switch plunger  34  and waterproofing the end cap  12  assembly. A retaining ring  44  is pressed into the end cap  12  after the elastomeric cover  42  is installed, retaining the elastomeric cover  42  in place. The elastomeric cover  42  may also include a tab  46  on the interior side that engages the fingers  36  of the plunger  34  preventing the fingers  36  from collapsing toward one another further retaining the plunger  34  in the endcap  12 .  
         [0029]    As is shown in FIGS. 5 and 6, the head assembly  16  of the flashlight  10  includes a lighting element  22  that is generally a mounting board  48  with light generating elements  50  mounted thereon. Preferably, the mounting board  48  is a circuit board having circuit traces and control electronics mounted thereto (not shown). Electrical connections with the light generating  50  elements are achieved as follows. First, a circuit trace is provided on the front surface of the board  48  that contacts the center of the flashlight head assembly  16 . The head assembly  16  is conductive and is in turn in contact with the outer housing  14  providing a path for the positive DC current to flow. The negative DC pole of the battery  28  is in contact with a cap  20  that retains spring  18  when the batteries  28  are removed from the outer housing  14 . The current is conducted along spring  18  to a circuit trace on the back of the board  48  thus providing the second point of electrical contact. The lighting assembly  22  is maintained in contact in its correct assembled position within the head  51  portion of the head assembly  16  with a long screw  52  that holds the board  48  in contact with the head  51 . Further, screw  52  has a non-conductive sleeve  54  that acts as a guide for maintaining spring  18  in the proper operational position. An opening  56  is provided in the circuit board  48  to facilitate the injection of a sealing material between the circuit board  48  and the head  51  to form a water proof seal around all of the lighting elements  50  thereby preventing infiltration of water or other contaminants into the body of the flashlight  10 . The sealing material may be any appropriate material such as an epoxy potting compound or a silicone sealant.  
         [0030]    Turning to FIGS. 7 a - 7   c , the operational relationship between all of the fully assembled components is shown. In FIG. 7 a , it can be seen that the batteries  28  are spring biased in a direction towards the rear of the outer housing  14  and towards the end cap  14 . The second contact of the batteries  28  is in constant contact with the center of the switch plate  38 . When the cap  12  is threaded onto the flashlight  10 , it begins to press the batteries  28  downwardly into the outer housing  14 . The batteries  28  further press upwardly causing the switch plate  38  to move into contact with the underside of the end cap casing  30 . If the cap  12  is fully threaded onto the outer housing  14 , the switch plate  38  comes into rigid contact with the end of the outer housing  14  energizing the flashlight circuit in a full “on” function. With the cap  12  only partially threaded onto the outer housing  14 , as is shown in FIG. 7 c , it can be seen that if the allowed travel distance (T) between the electrically conductive outer housing  14  and the switch plate  38  is greater than the maximum operable distance (d) of the switch assembly, the flashlight  10  remains “off” and cannot be energized by pressing the plunger  34  because the gap is too great to be overcome by the travel of the plunger  34 . The limited travel of the switch is important in defining the function of the switch. In this position, the flashlight  10  is in a confirmed “off” position. When the cap  12  is further threaded onto the outer housing  14  as shown in FIG. 7 b  and the travel distance (T) between the switch plate  38  and the outer housing  14  is no longer greater than the operable limit (d) of the switch components, the switch can be depressed, pushing the batteries  28  downwardly, allowing the switch plate  38  to come into momentary contact with the outer housing  14  and momentarily energize the flashlight  10 . If released, the batteries  28  push the switch back breaking the contact, thus providing a momentary “on” function.  
         [0031]    The present invention also anticipates that the push button switch may be employed as one component in the switching and function selection on a flashlight  10 . For example, in addition to using the switch of the present invention, a flashlight may also incorporate electronics and a selector switch to further selectively energize the flashlight in a strobe or signal code manner. This also allows the end cap  12  to be threaded on tightly under most operational circumstances. The end cap  12  would then be unthreaded slightly to produce the momentary “on” function. Further, the switch of the present invention may be incorporated in parallel or series with other switching mechanism as have been described.  
         [0032]    Turning to FIGS. 8 and 9 illustrate an alternate embodiment end cap  100  construction that allows the end cap to be fully threaded onto the outer housing for all operations except the confirmed OFF position. The exterior appearance and manner in which the end cap interfaces with the exterior housing of the flashlight remains the same. The end cap includes an end cap casing  30  with an elastomeric actuator member  42  in the end thereof and a retainer ring  44  to hold the elastomeric member  42  in place. In this embodiment the operational components of the switch mechanism including the configuration used as a contact plate and plunger have been changed using a ratchet lock type pushbutton as is commonly found in ballpoint pens. The plunger assembly includes a plunger guide  102  that is received into a bore in the end cap casing  30 . The plunger guide serves to support the operable members of the switch assembly and insulate them from the end cap casing  30 . A plunger element  104  is inserted within the plunger guide  102 . The plunger element  104  has a contact end that has an inner contact surface  106  and an outer contact surface  108 . When the end cap assembly  100  is fully threaded onto the outer housing  14  of the flashlight the outer contact  108  is in full contact with the outer housing  14  and the inner contact is in electrical communication with one contact of the battery  28 . It can be appreciated that to achieve a constant and confirmed OFF position in this embodiment, the end cap  100  need only be slightly loosened to break the contact between the outer contact surface  108  and the flashlight housing  14  thereby interrupting the circuit.  
         [0033]    The operable elements of the switch include a tension spring  110 , a contact cup  112  and a contact spring  114 . The tension spring  110  is disposed between the outer contact  108  and the contact cup  112  and in addition to exerting a rearward force on the contact cup  112  the tension spring  110  also provides an electrically conductive path between the outer contact  108  and the contact cup  112 . The contact spring  114  is in electrical communication with the inner contact  106 . In the normal, off position, as can be seen in FIG. 9, the contact spring  114  is not in contact with the contact cup  112 . Disposed to the rear of the contact cup  112  are the two operable inner  116  and outer  118  elements of the ballpoint pen style ratchet lock. As can be seen pressure on the elastomeric cover  42  depresses the ratchet lock elements  116 ,  118  and in turn the contact cup  112 . When the assembly is depressed slightly to a depth less than the depth required to allow the inner element  116  of the ratchet lock to rotate the contact cup makes electrical contact with the contact spring  114  providing a momnetary ON feature. If the user releases the switch assembly, since the ratchet lock elements  116 ,  118  were not engaged, the light returns to the off position. Further, if the user depresses the switch to a depth that allows the inner element  116  of the ratchet lock to rotate, the switch remains in the engaged, constant ON position. To return the light to the off position, the user must again depress the switch to a sufficient depth to allow the ratchet to rotate again thereby disengaging the lock and allowing the tension spring  110  to push the contact cup  112  out of contact with the contact spring  114 . In this manner, the operation of this switch embodiment allows tactile and audible feedback when the switch is operated.  
         [0034]    It can therefore be seen that the present invention provides a novel integrated in line dual mode switch assembly that enhances the function of a flashlight device. The switch assembly provides an the desirable ON, momentary ON and confirmable OFF features in a flashlight having a reduced number of operational parts, thereby enhancing the reliability of the flashlight while reducing the manufacturing costs associated therewith. Further, the present invention can be modified to accommodate a number of different flashlight configurations to create a highly useful and versatile switch assembly. For these reasons, the instant invention is believed to represent a significant advancement in the art, which has substantial commercial merit.  
         [0035]    While there is shown and described herein certain specific structure embodying the invention, it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited to the particular forms herein shown and described except insofar as indicated by the scope of the appended claims.