Patent Publication Number: US-6222138-B1

Title: Battery operated appliance, flashlight and switching systems technical field

Description:
CROSS-REFERENCE 
     This is a division of Patent Application Serial No. 08/985,556, filed Dec. 5, 1997 by the subject inventors, issued Apr. 4, 2000 as U.S. Pat. No. 6,046,572, assigned to the herein assignee, and herewith incorporated by reference herein. 
    
    
     TECHNICAL FIELD 
     The subject invention relates to battery operated appliance, flashlight and switching systems. 
     BACKGROUND 
     Even though battery operated appliances and flashlights and electric switches go back to the nineteenth century, there is room for improvement, as this disclosure will show. 
     SUMMARY OF THE INVENTION 
     It is a general object of the invention to provide improved battery operated appliances. 
     It is a germane object of the invention to provide improved power supply systems for battery operated appliances. 
     It is a related object of the invention to provide improved flashlight systems. 
     It is also an object of the invention to provide improved electric switches. 
     Other objects of the invention become apparent in the further course of this disclosure. 
     The invention resides also in a method of operating an electrical ON-OFF switch having an ON-OFF position push-button switch actuator and a rotary switch actuator, and, more specifically, resides in the improvement comprising, in combination, effecting electrical ON and OFF switching with the rotary switch actuator, rotating that rotary switch actuator past an OFF switching rotary motion to a further OFF position, and releasably blocking the ON-OFF position push-button switch actuator in an OFF position with that rotary switch actuator in that further OFF position of that rotary switch actuator. 
     From a related aspect thereof, the invention resides in an electrical ON-OFF switch having an ON-OFF position push-button switch actuator and a rotary switch actuator, and, more specifically, resides in the improvement comprising a rotary motion-to-translatory motion translator in said rotary switch actuator, and a releasable specifically, resides in the improvement comprising a rotary motion-to-translatory motion translator in said rotary switch actuator, and a releasable ON position blocker extending from the rotary switch actuator to the ON-OFF position push-button switch actuator and blocking that push-button switch actuator in an OFF position with the rotary motion-to-translatory motion translator and including said rotary motion-to-translatory motion translator. 
     The invention resides also in a method of providing an electric light source having a housing including a tail end with a bistable OFF and ON switching function and with a momentary ON switching function for said electric light source, and, more specifically, resides in the improvement comprising, in combination, unifying the bistable OFF and ON switching function and the momentary ON switching function into one electric toggle switch having an external switch actuating lever having a stable first position in which the electric light source is OFF, a stable second position in which the electric light source is ON, and a momentary third position biased toward the first position so that the electric light source is momentarily ON only as long as the external switch actuating lever is manually held in the third position against the biasing toward the first position, forming in a side of the tail end a recess having a side wall for laterally protecting the external switch actuating lever against accidental interference, and mounting the electric toggle switch in the tail end inside that recess so that such side wall protects the actuating lever against accidental interference. 
     From a related aspect thereof, the invention resides in an electric light source having a housing including a tail end, and, more specifically, resides in the improvement comprising, in combination, a recess in a side of that tail end, and a toggle switch mounted in the tail end inside of that recess and having an external switch actuating lever in that recess having a stable first position in which the electric light source is OFF, a stable second position in which the electric light source is ON, and a momentary third position biased toward first position so that the electric light source is momentarily ON only as long as the external switch actuating lever is manually held in its third position against the bias toward its first position. 
     The invention resides also in various combinations of these aspects. By way of example, the invention resides also in a method of casting a light beam with a flashlight, comprising, in combination with other aspects of the invention herein disclosed, casting a first light beam with a first lamp and reflector assembly, removing that first lamp and reflector assembly and substituting therefor an alternative second lamp and reflector assembly, and alternatively casting a second light beam of a different configuration with that alternative second lamp and reflector assembly. 
     The invention similarly resides in a flashlight, comprising, in combination with other aspects of the invention herein disclosed, a first light-beam-casting lamp and reflector assembly, a different light-beam-casting second lamp and reflector assembly, and a common receptacle in the flashlight for the first light-beam-casting lamp and reflector assembly and alternatively for the second lamp and reflector assembly. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The subject invention and its various aspects and objects will become more readily apparent from the following detailed description of preferred embodiments thereof, illustrated by way of example in the accompanying drawings which also constitute a written description of the invention, wherein like reference numerals designate like or equivalent parts, and in which: 
     FIG. 1 is a longitudinal section through a flashlight according to an embodiment of the invention; 
     FIG. 2 is a transverse section taken on the line  2 — 2  in FIG. 
     FIG. 3 is a section similar to FIG. 2 but with different batteries according to an embodiment of the invention; 
     FIG. 4 is a view similar to FIG. 1 after a section taken on the line  4 — 4  in FIG. 3; 
     FIG. 5 is a perspective exploded view showing the flashlight of FIGS. 1 to  4  on a reduced scale in a battery loading and unloading condition according to an embodiment of the invention; 
     FIGS. 6 and 7 are front and rear views of a contact plate useful in the embodiments of FIGS. 1 to  5 ; 
     FIGS. 8,  9  and  10  are enlarged longitudinal views of a switch that may, for instance, be used in the flashlight of FIGS. 1 to  5 , and illustrate successive closed, unblocked open, and blocked open positions, respectively, according to an embodiment of the invention; 
     FIG. 11 is a view similar to FIG. 1, but showing a toggle-type tail end switch pursuant to an embodiment of the invention; 
     FIG. 12 is an end view of the tail end switch of FIG. 11; 
     FIG. 13 is a section taken on the line  13 — 13  in FIG. 12; and 
     FIG. 14 is a side view, partially in section, of an alternative flashlight head. 
    
    
     MODES OF CARRYING OUT THE INVENTION 
     The drawings show methods and apparatus according to embodiments of the invention. 
     From one aspect thereof, the drawings show a method of providing an electric appliance  10  with first and second electric power supplies  12  and  13 , such as seen in FIGS. 1 to  4 . 
     This method according to an embodiment of the invention arranges first batteries  14  of a first type in a first pattern  15  inside a space  16  in the appliance  10 , and establishes a first electric power supply  12  with such first batteries  14  arranged in their first pattern  15 . 
     The first batteries  14  may at any time be removed from the space  16  in the appliance  10 , and second batteries  20  of a different second type are arranged in a different second pattern  21  inside the space  16  in the appliance  10  and a different second electric power supply  22  is established with such second batteries  20  arranged in their second pattern  21  pursuant to the illustrated embodiment of the invention as seen in FIGS. 3 and 4 and as more fully disclosed below. 
     A standard dictionary definition of the term battery in electrical terminology is “(1) a group of two or more cells connected together to furnish electric current, (2) a single voltaic cell.” In the same manner, The New IEEE Standard Dictionary of Electrical and Electronics Terms, published by The Institute of Electrical and Electronics Engineers (Fifth Edition, 1993), provides the following definition: 
     “battery (primary or secondary). Two or more cells electrically connected for producing electric energy. 
     [Common usage permits this designation to be applied also to a single cell used independently. In this document, IEEE Std 100, unless otherwise specified, the term ‘battery’ will be used in this dual sense.]” 
     The subject disclosure and accompanying claims similarly use the term battery to refer not only in the ancient sense to a combination of two or more primary or secondary cells, but to refer alternatively to a single cell as well, such as any one cell or battery  14  and/or any one cell or battery  20 , herein simply called “battery,” whether it consists of one, two or more elements or cells. 
     Numerous variations are within the scope of the invention. According to one such variation, the second batteries  20  are selected and arranged in their second pattern  21  to provide the second electric power supply  13  with an output voltage substantially equal to an output voltage of the first electric power supply  12 , such as between main terminals  24  and  25  as more fully disclosed below. 
     For optimum design and utility, the second batteries  20  may be arranged so that their second pattern  21  has an overall length substantially equal to an overall length of the first pattern  15 , such as seen in FIGS. 1 and 4. 
     Such design may be further optimized and rendered more versatile by arranging the second batteries  20  in parallel groups of  27 ,  28  and  29  of which each is substantially equal in length to a length of the first pattern  15 . This is illustrated by way of example in FIGS. 3 and 4, showing a first group  27  composed of a first pair of batteries  20 , a second group  28  composed of a second pair of batteries  20 , and a third group  29  composed of a third pair of batteries  20 . In the section of FIG. 4, the second pair of batteries  20  of the second group  28  would look like the first or third pair of batteries  20  in the group  27  or  29 , although only one battery  20  of that second group is visible in the section of FIG.  3 . Such parallel groups  27 ,  28  and  29  of second batteries  20  may have an overall voltage substantially equal to an overall voltage of the first batteries  14  arranged in the first pattern  15 . 
     According to the embodiment shown in FIGS. 1 to  4 , the batteries  14  and  20  of different first and second types have different lengths. By way of example, the first batteries  14  are selected from a kind of battery having a length that is a fraction of a length of a battery of the second type. Preferably, a first number of the first batteries  14  in first pattern  15  is selected to be substantially equal to a denominator of such fraction, the second batteries  20  are arranged in parallel groups of  27 ,  28  and  29  of which each is substantially equal in length to a length of the first pattern  15 , and a second number of the second batteries  20  in each of such parallel groups  27 ,  28  and  29  is selected to be substantially equal to a numerator of said fraction. 
     The second batteries  20  preferably are selected to be substantially equal in number to the aforesaid first number multiplied by a ratio of an output voltage of each of the first batteries  14  to an output voltage of each of the second batteries  20 . 
     These embodiments will now be illustrated by a couple of practical examples. For instance, each first battery may be a kind of battery that has a length that is two-thirds the length of each second battery  20 . In the illustrated embodiment, the fraction therefore is ⅔, with “2” being the numerator and “3” being the denominator of that fraction. Accordingly, FIG. 1 shows three (3) batteries  14  of the first type, which is equal to the denominator of two-thirds, with the above mentioned first number thus being three. Conversely, the embodiment according to FIGS. 3 and 4 includes in each group  27 ,  28  and  29  of second batteries  20  two (2) of such second batteries of the second type, which is equal to the numerator of two-thirds, with the above mentioned second number thus being two. 
     Since three times two-thirds is equal to two, it follows that the second pattern  21  of batteries  20  as arranged according to FIG. 3 and 4 has an overall length substantially equal to an overall length of the first pattern  15  of first batteries  14 . In this embodiment, each pair of second batteries  20  in any group  27 ,  28  or  29  has essentially the same overall length as the three first batteries  14  in the first pattern  15  seen in FIGS. 1 and 4. In practice, this conveniently permits the second kind of batteries  20  to be readily substituted for the first kind of batteries  14 , and such first kind of batteries  14  to be readily substituted back for the second kind of batteries  20  without any lengthwise or other adjustment or rearrangement of the appliance  10 . 
     By way of example, each of the batteries  14  of the first type may have an output voltage of three volts, and each of the batteries  20  of the second type may have an output voltage of one and one-half volts. Such output voltage of one and one-half volts is the traditional single-cell voltage of carbon/zinc batteries and their modern successors, culminating in the alkaline battery. 
     An output voltage of three volts is easily realized by combining two such cells in series into one battery. However, modern lithium batteries have three-volt cells. Accordingly, either three-volt batteries of the traditional kind or three-volt lithium batteries may be employed at  14 . In this respect, lithium batteries are preferred at  14 , since they are readily available in their three-volt version. However, the alternative accommodation of one and one-half volt batteries such as at  20  in FIGS. 3 and 4, is equally advantageous in practice, since the supply of such traditional one and one-half volt batteries is much more prevalent than the supply of modern three-volt lithium batteries. Accordingly, if the user of the appliance  10  should be at an outpost or other remote location where lithium batteries are not available or have run out, he or she may nonetheless continue to operate the appliance with the more readily available one and one-half volt batteries  20 . 
     In that case, operation of the appliance  10  can continue without exchange or alteration of the load  31 , since the parallel groups  27 ,  28  and  29  of second batteries  20  preferably are arranged in the second pattern  21  to have an overall voltage substantially equal to an overall voltage of the first batteries  14 . In this respect, each pair of second batteries  20  in any group  27 ,  28  or  29  then has an overall voltage of two times one and one-half volts, being three volts, which is equal to the voltage of each first battery  14  in our current example. Accordingly, a series connection of the batteries  20  in the three groups  27 ,  28  and  29  provides an output voltage of nine volts for the second power supply  13 , which amounts to the same as the nine volt output voltage of the first power supply  12  when composed of the three series-connected first batteries  14 . 
     In this respect, the above mentioned first number of first batteries  14  is equal to three (3) and the output voltage of each such first battery  14  is three volts in our current example. The output voltage of each of the second batteries  20  is one and one-half volts, so that the ratio of the output voltage of each first battery  14  to the output voltage of each second battery is 3 to 1.5, being  2 . Multiplying the aforesaid first number of three (3) by that ratio of two (2) we obtain six (6) as the number of series-connected second batteries  20 . 
     Since modern lithium batteries are very powerful and therefore preferred, they can readily be substituted without lengthwise or similar adjustment of the appliance and without change of the load  31 , as soon as their supply resumes. 
     By way of example, the load  31  may be a flashlight bulb, such as a nine-volt lamp in our current example, but the invention is neither limited to lamps nor to flashlights, but has utility with other apparatus or appliances and loads. 
     By way of further example, two-volt batteries may be employed in the appliance  10 . Familiar two-volt batteries include lead-acid batteries, preferably of the maintenance free coiled or cylindrical type. For instance, if the first batteries  14  are two-volt lead-acid batteries, then the overall voltage of their first pattern  15  or power supply  12  at terminals  24  and  25  is six volts. In that case, a like voltage may be realized in the appliance  10  by two series-connected groups  27  and  28  of batteries  20 , with each of such groups comprising a pair of one and one-half volt batteries. Overall lengths are again the same, if the length of each lead-acid battery  14  is two-thirds of the length of each one and one-half volt battery  20 . 
     By way of further example,. if the length of each one and one-half volt second battery  20  is equal to three-quarters of the length of each first battery  14 , then a power supply voltage of six volts can be realized at equal lengths among patterns  15  and  21  with three batteries  14  of a two-volt type, and four batteries  20  of a one and one-half volt type. 
     Carbon-zinc, manganese, alkaline, and lithium batteries are known as primary batteries. Secondary batteries include the above mentioned lead-acid battery and nickel-cadmium and other rechargeable batteries, all of which may be employed in the practice of the subject invention. 
     In apparatus terms, FIGS. 1 to  4  show an example of an electric appliance  10  for operation with alternative first and second electric power supplies  12  and  13  comprised of first batteries  14  of a first type and second batteries  20  of a different second type, respectively. Such appliance has a first battery compartment  17  in the appliance adapted to accommodate the first batteries  14  in a first pattern  15  inside a space in that appliance. First circuitry, such as shown at  45 ,  46 ,  48 ,  53 ,  57  and  58  in FIGS. 6 and 7, is designed or adapted to interconnect the first batteries  14  as the first electric power supply  12 . A second battery compartment  16  in the space inside the appliance is designed or adapted to accommodate different second batteries  20  in a different second pattern  21  inside that space in appliance  10 . Second circuitry, such as shown at  51 ,  54 ,  56  and  59  in FIGS. 1 to  4  and as described below by reference to FIGS. 6 and 7, may be designed or adapted to interconnect the different second batteries  20  as a second electric power supply 
     According to a preferred embodiment of the invention, the first and second battery compartments  17  and  16  have substantially equal lengths, but preferably have different widths. 
     In the illustrated embodiment, the first batteries  14  are electrically connected in series for establishing the first electric power supply  12  in their first pattern  15 . Alternatively, the second batteries  20  may be electrically connected in series for establishing the second electric power supply  13  in their pattern  21 , especially if the overall or output voltage of the second power supply  13  is to be equal to that of the first power supply  12 . 
     Various switching devices and circuits are known for connecting batteries in series or for that matter in parallel or in any combination of series and parallel connection. FIGS. 1 to  7  show a device for effecting such alternative series connections. 
     In particular, a first contact plate  35  is shown in FIGS. 1, and  4  to  7  for connecting a first battery  14  of the series of first batteries  14  to the terminal  24  after such first batteries have been installed in the appliance. Such first contact plate  35  is also designed to connect second batteries  20  in series with each other and with the load  31  through the terminal  24 . A corresponding second contact plate  36  at the other end of the battery compartment  16  connects series-connected first batteries  14  to the switch terminal  25 , and alternatively connects second batteries  20  in series with each other and with the switch terminal  25 . 
     The first contact plate  35  may be moveable relative a remainder of the appliance  10 . By way of example, the first contact plate  35  may be located on a retainer  37  that releasably retains such contact plate at a housing  38  of the appliance. By way of example, the retainer  37  may comprise rod  39  which, in turn, may be axially moveable in a corresponding bore  41  at the space  16  in the housing  38  of the appliance  10 . 
     In this manner the contact plate  35  may be swung out of the way and batteries may be inserted into, and may be removed from, the space or battery compartment  16  through the top after temporary removal of the load or lamp assembly  42  therefrom. After completion of such an operation, the contact plate  35  may be swung back into position, such as shown in FIGS. 1 and 4. 
     FIGS. 6 and 7 show rear and front views of the contact plate  35 . A “front view” in this respect is the view as seen from the battery compartment  16 . A “rear view” is a view of the opposite side of the contact plate  35 , such as after removal of the insulating cover disc  43  therefrom. It may be noted that the orientation of the rear view of FIG. 7 agrees with the orientation of FIG. 3, but that front view of FIG. 6 has been swung around the vertical so as to show it in the drawings. 
     Electrically conducting bars  45  and  46  are arranged on the rear side  47  of the contact disc  35  in order to connect batteries  20  in series, for example. A central contact  48  extends from the front side  49  through the disc  35  and electrically conducting bar  45  to and through the rear side  47 . The other contact disc  36  may have a similar corresponding central contact  51 . 
     In the embodiment of FIGS. 1 and 2, batteries  14  extend in series between the corresponding central contacts  48  and  51  which, in turn, are contacted by contact springs or other main terminals  24  and  25 , respectively. Electrically conducting bars of the type shown in FIG. 6 at  45  and  46  are needed in other embodiments, such as shown in FIGS. 3 and 4, or in an embodiment that unifies the features of FIGS. 1 to  4 , for instance. 
     For example, considering an electric supply circuit from the point of view of main terminal  24 , it is seen that such circuit extends through central contact  48  and conducting bar  45  to a contact  53  that is connected to that bar  45  through disc  35 . Batteries  20  of the first group  27  are connected in series between that contact  53  and an opposite corresponding contact  54  on the opposite contact disc  36 , seen only in FIGS. 2 and 4. 
     An electrically conducting bar (not shown) similar to the contact bar  46  extends in second disc  36  between contact  54  and another contact  56  thereon, seen only in FIG. 2 because of the sectioning of FIG.  4 . Batteries  20  of the second group  28  are connected between that contact  56  and another contact  57  on the contact disc  35 . That contact  57 , in turn, is connected to one end of conducting bar  46  which, in turn, extends and has another end connected to a further contact  58  on the disc  35 . 
     Batteries  20  of the third battery group  29  are connected in series between that further contact  58  and an opposite contact  59  on second contact disc  36 . An electrically conducting bar (not shown) similar to bar  45  extends between that contact  59  and central contact  51  on contact disc  36 . 
     Batteries  20  thus are connected in series between opposite main terminals  24  and  25 . However, various other arrangements are within the scope of the invention. By way of example and not by way of limitation, batteries could be connected selectively in parallel and in series to provide different watt hours and different voltages for different needs. Alternatively or additionally, voltage regulating devices could be provided, such as in one of the contact discs  35  and  36 , for instance, especially if the batteries are of a nickel-cadmium or other type having varying voltage characteristics during discharge or otherwise. 
     Variations within the scope of the invention include first batteries  14  electrically connected in series, such as shown in FIGS. 1 and 2, for establishing a first electric power supply  12 , and second batteries  20  electrically connected in series, such as shown in FIGS. 3 and 4, for establishing a second electric power supply  13 . 
     However, at least some of the batteries in at least one of the first and second patterns  15  and  21  may be electrically connected in parallel to establish at least one of the first and second electric power supplies. 
     Also within the scope of the invention, batteries in one of the first and second patterns may be electrically connected in series to establish one of the first and second electric power supplies, and batteries in the other of the first and second patterns may be electrically connected in parallel to establish the other of the first and second electric power supplies. 
     By way of example, the three pairs  27 ,  28  and  29  of series-connected batteries  20  may be connected in parallel with each other, simply by making the discs  35  and  36  of electrically conductive material insulated from the body of the appliance  10 . 
     Further within the scope of the invention, the second batteries may be selected and arranged in the second pattern to provide the second electric power supply with an output voltage different from an output voltage of the first electric power supply. 
     Moreover, the second batteries may be selected and arranged in the second pattern to provide the second electric power supply with an electrical work output different from an electrical work output of the first electric power supply. 
     According to an embodiment of the invention, such as seen when comparing FIGS. 3 and 4 with FIGS. 1 and 2, the batteries of one of the first and second types  14  and  20  are laterally confined inside the space  16  in a narrower confinement than the other batteries  20  or  14  of the other of such first and second types. For instance, as seen in FIG. 2, the first batteries  14  are laterally confined in a narrower confinement than the second batteries  20  which occupy most of the space  16 , as in FIG.  3 . 
     Where the first batteries  14  have a first dimension, and the second batteries  20  have a different second dimension, such first batteries may be accommodated in a first region  17  of the space  16  corresponding to that first dimension, and the second batteries  20  may be accommodated in a second region of that space  16 . The region  17  may be a first battery compartment having a first dimension corresponding to the first dimension of the first batteries, and a second battery compartment may have a different second dimension at  16  corresponding to the second dimension of the second batteries. By way of example and not by way of limitation, the first region  17  may be the central region within which the first batteries  14  are accommodated such as seen in FIG. 2, and the second region may be the space  16  within which the second batteries  20  are accommodated such as seen in FIG.  3 . If the above mentioned first and second dimensions are different thicknesses or diameters of the first and second batteries  14  and  20 , then danger to the load  31  from erroneous insertion of batteries may automatically be prevented. For instance, if the first batteries  14  are thicker than the second batteries  20 , then each of the lobes  33  of the space  16  within which the second batteries  20  are accommodated may be made laterally too small for accommodation of the first batteries  14 . In this manner, the appliance  10  can be designed so that no user will accidentally load six lithium batteries into the appliance and thereby destroy the bulb or other load  31  with an eighteen-volt supply voltage. Conversely, a user who erroneously loads a pair of second batteries  20  into the central region of the space  16  will readily note such error from the feeble glow or other weak output of the bulb or load  31 , and can easily correct such error by loading the second batteries  20  correctly, such as shown in FIGS. 3 and 4. To mention but one of many possible examples, a lithium battery of the type DL123A has a diameter of more than 16 mm, but an alkaline battery Size AA or UM 3  has a diameter of not more than 14 mm, so that the two kinds of batteries  14  and  20  can easily be distinguished in their placement in the appliance  10 , such as pursuant to FIGS. 2 and 3, respectively. 
     The first and second regions or battery compartments  17  and  33  where the first and second batteries  14  and  20  are accommodated, respectively, may thus be interconnected through the space  16  inside the appliance  10  without danger to the load  31  through accidental overvoltage from erroneously inserted batteries. This sharing of battery accommodation regions or compartments  17  and  33  is an advantageous space confining feature of the illustrated embodiment of the invention. 
     FIGS. 1,  4 ,  8 ,  9  and  10  also show an electrical ON-OFF switch  60  for the appliance  10 . FIGS. 1,  4  and  8  show such switch in a closed or ON position. FIGS. 9 and 10 show such switch in an open or OFF position. The switch  60  has an ON-OFF position push-button switch actuator  61  and a rotary switch actuator  62 . The ON-OFF position push-button switch actuator may be biased to an OFF position, such as by the bias or terminal spring  25 . In the position shown in FIG. 9, the actuator  61  is manually actuable against the bias of the spring  25  to the electrical ON position shown in FIG.  8 . However, in the position shown in FIG. 10, the ON-OFF position push-button switch actuator  61  is releasably blocked in an OFF position with the rotary switch actuator  62  against actuation to the ON position shown in FIG. 8 
     In apparatus terms, the electrical ON-OFF switch  60 , having an ON-OFF position push-button switch actuator  61  and a rotary switch actuator  62 , includes a releasable ON position blocker  63  extending from that rotary switch actuator  62  to the actuator  61 . As shown by way of example in FIG. 10, the blocker  63  blocks the push-button switch  61  against movement to the ON position. In this or any other manner within the scope of the invention, the ON-OFF push-button switch is releasably blocked in an OFF position with the rotary switch actuator. By way of example and not by way of limitation, the illustrated embodiment of the invention shows the blocker  63  in the form of a coupling of two elements, comprising a first blocking element  64  connected to the rotary switch actuator  62  and a second blocking element  65  connected to the push-button switch actuator  61  or directly to the plunger  66  thereof. 
     In the embodiment shown in FIG. 10, the first blocking element  64  is in a position wherein it blocks the second blocking element  65  so that the push-button switch actuator  61  cannot move from its OFF position to its ON position. The blocker  63  accordingly is an ON position blocker; blocking the push-button type switch  61  against movement to its ON position. 
     In the embodiment shown in FIGS. 1,  4 ,  8 ,  9  and  10 , the actuator  61  is equipped with or has a spring-biased switch activating plunger  66  moveable between ON and OFF positions. The releasable ON position blocker  63  is coupled to that switch activating plunger  66 . Such plunger may be electrically conductive so as to complete an electric circuit therethrough in its ON position shown in FIGS. 1,  4  and  8 . However, this is not a requirement within the broad scope of the invention, since the plunger may otherwise actuate an electric circuit. 
     By way of example, such an operating plunger that does not conduct the switching current is shown at  127  in FIG. 2 of U.S. Pat. No. 5,590,951, by John W. Matthews, Ph.D., issued Jan. 7, 1997 to Laser Products Ltd., for “Switch-Less Flashlights,” hereby incorporated by reference herein. 
     In particular, that prior-art technology enables rear-end switching of flashlights and the like without an electrical rear-end switch. In that case, delivery of electric power from a battery to a lamp is concentrated at the lamp assembly area, and there need to be no electrical lead or connection from the tail end where the plunger  127  is located to the lamp assembly area. Accordingly, while FIGS. 1,  4 ,  8 ,  9  and  10  show switch contacts  67  at the plunger  66 , it should be understood that within the scope of the invention, such switch contacts may be separate or may even be remote from the plunger  66 , as in the above-referenced U.S. Pat. No. 5,590,951. 
     In either case, switch contacts are held normally open [“N.O.”] by the spring  25  such as in FIG. 9 or by another bias. 
     Such switch contacts are also locked in an open position by the manually releasable OFF position lock  63 , such as in FIG.  10 . 
     It may be said that the electrical ON-OFF switch  60  is equipped with switching contacts, such as  67 , having a normally open [“N.O.”] position, such as shown in FIG. 9, and that such switching contacts are releasably blocked in their open position, such as shown in FIG. 10 against actuation to their closed position such as illustrated in FIG.  8 . 
     In apparatus terms, the electrical ON-OFF switch  60  has switching contacts, such as contacts  67 , having a normally open [“N.O.”] position, such as shown in FIG. 9, and the releasable OFF position lock  63  is coupled to these switching contacts, such as shown in FIG.  10 . This is in addition to the alternative closed position, such as shown in FIG.  8 . 
     When locking of the switch actuator  61  or plunger  66  against actuation to the ON position is desired, then the blocker  63  is manually actuated, such as indicated by an arrow rear-end symbol  69  in FIG.  10 . The second blocking element  65  is then coupled to the manually actuated first blocking element  64 , with minimum, if any, play therebetween. 
     Conversely, there is play  71  between these blocking elements  64  and  65  not only in the ON position of the switch  60  such as shown in FIG. 8, but also in the unlocked OFF position such as shown in FIG.  9 . That play  71  in FIG. 9 is sufficiently large to permit actuation of the switch  60  from its unlocked OFF position such as shown in FIG. 9, to its ON position such as shown in FIG. 8 by actuation of the push button switch  61  through depression of the plunger  66 . There accordingly is more play between the blocking elements  64  and  65  in an ON position and in an unblocked OFF position of the electrical ON-OFF switch, than in an OFF position, such as shown in FIG. 10, blocked by the ON position blocker  63 . 
     In the embodiment illustrated in FIGS. 1,  4 ,  8 ,  9  and  10 , the first blocking element  64  is also a switch activator. It may be said in this respect that the rotary switch  62  has a switch activator integral or in one piece with the first blocking element  64 . In that case, the rotary switch may operate via the first blocking element  64  and plunger  66  to actuate the switch  60  to its ON position and to releasably retain it in that ON position, such as shown in FIG. 8, where the switch contacts  67  are closed, such as for energization and operation of a load  31  from a power supply  12  or  13 . 
     The switch actuator  61  may be coupled to the rotary switch actuator  62  via the blocker  63  or first and second blocking elements  64  and  65 . Such coupling is tight in the embodiment as illustrated in FIG. 8, being in effect a mechanical connection for releasably locking the contacts  67  in a closed position and thereby the switch  60  in its ON position. Such coupling in the embodiment as shown in FIG. 9, is sustained by the bias of the switch terminal spring  25  which in effect couples the actuator  61  or plunger  66  to the first blocking element  64 , thereby biasing of the contacts  67  to their normally open [“N.O.”] position and thereby of the switch  60  to its OFF position. Such coupling permits actuation of the contacts  67  to their closed position and thereby of the switch  60  to its ON position, such as by operation of the actuator  61  or plunger  66  against the bias of the switch terminal spring  25 . 
     In the embodiment of FIG. 10, the coupling of the plunger  66  to the first blocking element  64  is supplemented by the second or OFF position blocking element  65 , that restrains or in effect locks the actuator  61  or plunger  66  in the OFF position of the switch  60 . 
     In the illustrated embodiment of the invention, the electrical ON-OFF switch  60  has a base  73  and the rotary switch actuator  62  is mounted on that base and is connected to the ON position blocker. By way of example, the rotary switch actuator  62  may be integral with the first blocking element  64 . Such rotary switch actuator preferably extends over at least part of the base  73  and of the push-button actuator  61 , and over the releasable ON position blocker  63 . 
     The switch base  73  may have a cylindrical configuration and the rotary switch actuator  62  may be a manual actuation knob on that base. Such actuation knob or rotary switch actuator  62  may be threaded on the cylindrical switch base  73  by mating threads  75 . In this manner, the actuation knob or rotary switch actuator  62  may travel back and forth on the cylindrical base  73 , as such actuation knob or rotary switch actuator is manually rotated in the sense of rotation of the symbolically indicated arrow  69  and conversely in the opposite sense of rotation. In this or any other manner within the scope of the invention, manual rotary motion of the actuation knob or rotary switch actuator  62  is translated into translatory motion from the closed switch or ON position shown in FIG. 8 to the unblocked OFF position shown in FIG.  9  and hence to the blocked OFF position shown in FIG. 10, such as by rotation in the direction of arrow  69  past the unblocked OFF position switching rotary motion. As apparent from FIG. 9 to FIG. 10, this translates rotary motion of the rotary switch actuator  62  into translatory motion of that rotary switch actuator past the OFF switching rotary motion in the illustrated embodiment. Accordingly, there is a rotary motion-to-translatory motion translator at  75  in the rotary switch actuator  62 , and the releasable ON position blocker  63 , which extends from such rotary switch actuator to the ON-OFF position push-button switch actuator  61 , in effect includes such rotary motion-to-translatory motion translator. Contrariwise, a converse manual rotation of the actuation knob or rotary switch actuator  62  will translatorily move the assembly  61 ,  62 ,  63  from the blocked OFF position shown in FIG. 10 to the unlocked OFF position shown in FIG.  9  and hence to the closed switch or ON position shown in FIG. 8, as desired by the operator or user of the appliance. 
     It is thus seen that the switch  60  can be blocked against accidental activation by one to two extra turns of the actuation knob or rotary switch activator  62  past the unblocked OFF position shown in FIG. 9 to a further OFF position as shown in FIG.  10  and described above. 
     Such actuation knob or rotary switch activator  62  and its blocking element  64 , as well as the OFF position blocker  63 , may at least partly be of electrically insulating material so as to avoid electric current conduction from the spring-biased plunger  66  to the base  73  via the blocking elements  64  and  65 . However, where resistance against wear and tear is important, at least the actuation knob or rotary switch actuator  62  and the first blocking element  64  may be made of metal or of another strong, electrically conductive material. 
     In that case, an electrically insulating layer may be imposed or located between the mating threads  75 , such as indicated at  76  near the bottom of FIG.  10 . Various techniques, such as anodization in the case of aluminum parts, are available for that purpose. The second blocking element  65  is shown as being of electrically insulating material to prevent inadvertent ON switching of the load  31  in the blocked position of the switch  60 , such as shown in FIG.  10 . 
     The switch actuator  61  may include an elastomeric diaphragm  78  connected to the actuation knob or rotary switch actuator  62  and to the plunger  66 , and preferably covering the assembly  62 ,  63  and  64  on one side. 
     By way of example, the electric switch  60  may be a tail end switch assembly of a flashlight or other appliance  10 . In that case, the cylindrical base  73  and an end of the appliance  10  may have mating threads  79 . 
     The blocking feature such as illustrated in the drawings culminating in FIG. 10, is highly useful in practice. For instance, if the appliance  10  is a flashlight or other device stored and transported in knapsacks, duffelbags or other containers, then the blocking feature according to the invention prevents inadvertent closure of the switch  60  through contact of the push-button switch actuator  61  with the other objects in, or with parts of, the bag or other container. 
     Moreover, if the appliance is for use in deep-sea diving or in other environments where external pressure increases, the blocking feature of the invention prevents undesired actuation of the switch  60  through such increasing pressure. 
     In these cases, the currently disclosed aspect of the invention prevents useless consumption or discharge of the power source or supply  12  or  13 . 
     Such prevention of accidental energization of the load  31  may also safeguard the user against harm, such as in situations where accidental actuation of the lamp or other energy-emitting load  31  may attract predators or alert enemies. 
     At the same time, the appliance retains its utility for alternative switching through push-button  61  for momentary light emission or momentary actuation of the load for other purposes, or through rotary switch  62  for longer energizations; all at an instant and without need for extra blocking switches or external caps or other external blocking devices. 
     FIG. 11 is a view similar to FIG. 1, for instance, but with a different tail end switch. In a broader sense, however, FIG. 11 illustrates embodiments of an electric light source  100 , similar to the appliance  10  shown in FIG.  1  and described above, and of a method of providing an electric light source (a) having a housing  80  including a tail end  81  with (b) a bistable OFF and ON switching function and with a momentary ON switching function for that electric light source  100 . 
     This method according to the currently disclosed aspect of the invention unifies such bistable OFF and ON switching function and such momentary ON switching function into one electric toggle switch  82  having an external switch actuating lever  83  having a stable first position  84  in which the electric light source is OFF, a stable second position  85  in which that electric light source is ON, and a momentary third position  86  biased toward the first position  24  so that the electric light source  12  is momentarily ON only as long as the external switch actuating lever  83  is manually held in such third position  86  against its biasing toward the first position  84 . 
     The illustrated embodiment also forms in a side  88  of the tail end  81  a recess  90  having a side wall  91  for laterally protecting the external switch actuating lever  83  against accidental interference. 
     The currently disclosed embodiment mounts the electric toggle switch  82  in the tail end  81  inside recess  90  so that side wall  91  protects the actuating lever  83  against accidental interference. 
     As seen in FIG. 12, recess  90  may be formed with a second side wall  92  for further protecting the external switch actuating lever  83  against accidental interference. 
     As seen in FIGS. 11 and 12, recess  90  may be formed as a groove open at an end of tail end  81  and the external switch actuating lever  83  may be located in that groove. 
     While different arrangements of switch positions  84  to  86  are within the scope of the invention, the first position  84  preferably is located between second and third positions  85  and  86 , such as shown in FIG.  11 . 
     In the best mode currently contemplated, the second position  85 , being the stable ON position, is made to be closer to the light source  100  than the momentary third position  86 . 
     In the embodiment illustrated in FIGS. 11 and 12, the first, second and third positions  84 ,  85  and  86  advantageously are in a longitudinal plane through the housing  80 , such as represented by the plane of the paper on which FIG. 11 is drawn. 
     In apparatus terms, the currently disclosed aspect of the invention resides in an electric light source  100  having a housing  80  including a tail end  81  having a recess  90  in a side  88  of the tail end  81  and including a toggle switch  82  mounted in that tail end inside of recess  90  and having an external switch actuating lever  83  in that recess having a stable first position  84  in which the electric light source is OFF, a stable second position  85  in which the electric light source is ON, and a momentary third position  86  biased toward the first position  84  so that the electric light source is momentarily ON only as long as the external switch actuating lever  83  is manually held in such third position against its biasing toward the first position  84 . Recess  90  may have a side wall adjacent the external switch actuating lever  83 . Preferably, such external switch actuating lever  83  is located between side walls  91  and  92  of that recess, such as seen in FIG.  12 . 
     Embodiments of this invention have several advantages over the prior art. Unlike the suggestion by Adolph E. Goldfarb in his U.S. Pat. No. 4,504,889, issued Mar. 12, 1985, to fit a flashlight “with a toggle or slide switch in addition to the momentary switch,” the subject invention unifies the momentary switch function with the bistable ON-OFF function for an electric light source into one and the same toggle switch which, as such, may be of conventional design, such as sold for motor controls. Unification of the bistable and momentary switch functions into one 3-position toggle switch improves switchability and performance of the electric light source over prior-art alternatives where the momentary switch was separate from an ON-OFF switch . 
     Mounting the 3-position toggle switch into the tail end of the electric light source housing adds operational convenience and efficacy for many uses and situations which is lacking in prior-art proposals such as seen in U.S. Pat. No. 3,652,846 by Walter A. Starek, II, issued Mar. 28, 1972, 3,711,699 by Joseph G. Bacevius, issued Jan. 16, 1973, 4,000,403 by Marion D. Rice, issued Dec. 28, 1976, and 4,250,446 by Raymond Ponte, issued Feb. 10, 1981. 
     Unlike prior-art designs such as seen among the above mentioned patents and also in U.S. Pat. No. 5,299,375 by Thummel et al., issued Apr. 5, 1994, and 5,471,777 by Kenneth E. McDonald, issued Dec. 5, 1995, the subject invention as embodied in FIGS. 13 and 14 protects the 3-way toggle switch against accidental interference which includes a wide variety of accidental actuations of the electric light source from such sources as unintended manual actuation by the user, and interference from other objects, such as in a bag or other container in which the electric light source is packed, or interference from a bag or other enclosure itself, or interference from algae or other objects in underwater operations, to name a few examples. 
     Toggle switch  82  may be electrically connected to the remainder of the flashlight in any desired manner. By way of example, FIG. 11 shows a lead  93  connecting an input or common terminal of toggle switch  82  to the main terminal  25  of the battery power supply. Output terminals of toggle switch  82  for the stable ON position and for the momentary ON position may be “grounded” such as shown at  94  by connection to an electrically conducting tail end and flashlight body for connection to the load. 
     An embodiment of the currently disclosed aspect of the invention provides a further switching function or further switch  96  in addition to the toggle switch  82 . Such further switching function or switch may be in parallel to such electric toggle switch  82 . Such further switching function may be remotely operated. In other words, the further switch may be of a remotely operated kind. 
     By way of example, FIGS. 12 and 13 show part of a cable release switch  96  that may, for instance, be similar to a cable release for photographic cameras, in that a tip  97  of a release cable contacts a part  98  upon actuation of the cable release. In the case of the embodiment of FIGS. 11 to  13 , the part  98  may be a contact connected by the electric wire  93  to the main terminal  25  of the battery power supply. The cable tip  97 , on the other hand, may be an electric contact that “grounds” that part of the power supply for connection to the load. 
     In this manner, the user of the flashlight or light source  100  is provided with the convenient alternative of a proximately controlled switch  82  and a remotely controlled switch  96 . 
     A further aspect of the invention uses known flashlight head exchanging technology for providing different flashlight beams in combination with other aspects of the invention. In this respect, FIG. 1 shows the casting of a first light beam  58  with a first lamp and reflector assembly  42 . That first lamp and reflector assembly may be removed, such as shown in FIG. 5, illustrating removal of the first lamp and reflector assembly as a unit. An alternative second lamp and reflector assembly  142 , such as shown in FIG. 14, may then be substituted therefor, and a second light beam  68  of a different configuration may then be cast with that alternative second lamp and reflector assembly  142 . As seen from a comparison of FIGS. 1 and 14, the alternative second lamp and reflector assembly  142  shown in FIG. 14 is different from the first lamp and reflector assembly  42  shown in FIG.  1 . In apparatus terms, an illustrated embodiment of the invention comprises, in combination with other aspects of the invention, a first light-beam-casting lamp and reflector assembly  42 , a different light-beam-casting a second lamp and reflector assembly  142 , and a common receptacle  101  in the flashlight  10  for that first light-beam-casting lamp and reflector assembly and alternatively for that second lamp and reflector assembly. These different assemblies may have like threads  102  for alternatively fitting into a mating thread in the common receptacle  101 . 
     Desired configurations of light beams  58  and  68  may be realized by appropriate dimensioning and relative location of lamp and reflector in each assembly  42  and  142 , or by other conventional means. In this manner, a spread light beam  58  may, for example, be cast with the first lamp and reflector assembly  42 , and a narrow light beam  68  may alternatively be cast with the alternative second lamp and reflector assembly  142 . By way of example, FIG. 1 shows a first lamp housing  42  having a light beam spreading electric light source and reflector assembly for emitting a spread light beam  58 . FIG. 14, on the other hand, shows a second lamp housing  142  having a narrow light beam emitting electric light source and reflector assembly. In this respect, “spread” and “narrow” are relative terms, with the second light beam  68  being narrower than the first light beam  58 . The lamp housings  42  and  142  may have like spring terminals  24  for a supply of electric battery power to the light source. An additional spring  103  may be provided for shock absorbing purposes. Features of various aspects of the invention may advantageously be combined. For instance, the aspect of the invention disclosed with the aid of FIGS. 5 and 14 may be combined with any of the embodiments shown in the other drawings for such purposes as better selective beam casting and switching. 
     By way of example, casting of a first light beam, such as beam  58 , with a first lamp and reflector assembly  31  may be energized by electric power from one of the first and second electric power supplies  12  and  13 , and alternative casting of a second light beam, such as beam  68 , with an alternative second lamp and reflector assembly  142  may be energized by electric power from one of such first and second electric power supplies. 
     In this manner, different light beams may, for instance, may be energized from different electric power supplies, if desired, and different lamp and reflector assemblies may be provided and used for different electric power supplies. Different light-beam-casting lamp and reflector assemblies, such as  31  and  142 , may be combined with the above mentioned toggle switch system  88  for greater versatility. Another combination within the scope of the invention in a flashlight may comprise in combination a first light-beam-casting lamp and reflector assembly  31 , a different light-beam-casting second lamp and reflector assembly  142 , a common receptacle  101  for the first light-beam-casting lamp and reflector assembly and alternatively for the second lamp and reflector assembly, an electrical ON-OFF switch  60  for a lamp in either of such first and second lamp and reflector assemblies, an ON-OFF position push-button switch actuator  61  and a rotary switch actuator  62  in that electrical ON-OFF switch, and a releasable ON position blocker  63  extending from the rotary switch actuator to the ON-OFF position push-button switch actuator. Such electrical ON-OFF switch then is a switch for the lamp in either of the first and second lamp and reflector assemblies.