Abstract:
A retractable, automatic, on/off flashlight system includes a retriever having a retriever spring and a line to be retracted by the retriever spring into the retriever in a retraction direction. A flashlight has a light source, a power source and a switch connected in a circuit. The switch has an actuator connected to the line. The actuator closes the switch and turns on the light source upon pulling the flashlight and the line away from the retriever in an extension direction.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to a retractable, automatic, on/off flashlight system. Such a system is to be used wherever a flashlight is needed to be illuminated for a brief period of time, with a minimum amount of effort by the user and where conditions do not permit the user to look for the flashlight or a switch. For example, police and fire rescue personnel may enter a dark room, construction workers or janitors may need to look into a dark space and bar tenders must shine a light into a dark region under a bar. In each case, a particular dark space must be illuminated for viewing an area or finding an object without searching for a flashlight or a switch. After a relatively short period of time, the light needs to be turned off and the hands of the user need to be free again. 
   2. Description of the Related Art 
   U.S. Pat. Nos. 2,762,037 and 2,114,266 merely show key chains at the end of a flashlight, with no interaction between the two. 
   U.S. Pat. Nos. 6,296,371 B1 and 5,008,784 show flashlights wherein a key ring is attached to a button, which is pushed or turned to turn on the flashlight. Similarly, U.S. Pat. No. 2,249,689 has a key ring on a plug, which is turned to switch on the light. Finally, U.S. Pat. No. 2,180,228 has a screw, which is rotated to move to a battery to turn the light on and off. A key chain is connected to the screw. 
   U.S. Pat. No. 2,715,676 shows a key retainer, which turns on a flashlight when it is moved. U.S. Pat. No. 4,819,140 has a key ring holder, but the light is turned on by pressing a case. U.S. Pat. No. 2,737,574 has a key holder, but the light is turned on by pressing a plunger. 
   U.S. Pat. No. 6,601,967 B1 shows a housing of a flashlight having a switch control for momentarily or stably turning on a light. 
   In each of the prior art devices, the flashlight must be found and then a switch must be located and actuated by the user. 
   A system in which the flashlight is easy to find and the switch is automatically operated for turning the light on and off, would be an advance in the art. 
   SUMMARY OF THE INVENTION 
   It is accordingly an object of the invention to provide a retractable, automatic, on/off flashlight system, which overcomes the herein fore-mentioned disadvantages of the heretofore-known devices of this general type, in which the flashlight can be easily located and in which the light source can be turned on and off without manually actuating a switch. 
   With the foregoing and other objects in view there is provided, in accordance with the invention, a retractable, automatic, on/off flashlight system. The system comprises a retriever having a retriever spring and a line to be retracted by the retriever spring into the retriever in a retraction direction. A flashlight has a light source, a power source and a switch connected in a circuit. The switch has an actuator connected to the line. The actuator closes the switch and turns on the light source upon pulling the flashlight and the line away from the retriever in an extension direction. The actuator opens the switch and turns off the light source upon allowing the flashlight and the line to be retracted in the retraction direction. The flashlight is always located at the retriever and thus is easy to find and the mere pulling and releasing of the flashlight have the effect of turning the light source on and off. Of course, the line may be a chain, etc. 
   In accordance with another feature of the invention, there is provided a switch spring biasing the actuator to open the switch. The retriever spring has a greater spring constant than the switch spring. In this way, it is assured that pulling the flashlight will always be sufficient to move the actuator and turn on the light. 
   In accordance with a further feature of the invention, the circuit includes two leads, and the actuator is a plunger having a crosspiece for interconnecting the leads. The crosspiece is moved toward the leads by the retriever spring and away from the leads by the switch spring. A washer is fixed on the plunger and biased by the switch spring for moving the plunger. These features provide a simple and reliable mechanism for spring-loaded operation of the switch. 
   In accordance with an added feature of the invention, the circuit includes two leads. An inflexible stop is disposed in the retriever and connected to one of the leads. The switch spring is a resilient finger disposed in the retriever and connected to the other of the leads. The actuator is a washer fixed to the line. The resilient finger is biased away from the inflexible stop, and the retriever spring causes the washer to move the resilient finger toward the inflexible stop. This extremely simple switch is disposed in the retriever and therefore the flashlight need not have any switch. The leads may follow the line from the retriever to the flashlight or the line may contain or be the leads. 
   In accordance with an additional feature of the invention, the switch is a pull switch disposed in the flashlight and having the switch spring, and the actuator is a pull line of the pull switch. This embodiment is very cost-effective since a standard ceiling fan or ceiling light pull switch may be used. 
   In accordance with yet another feature of the invention, the switch is a cable-actuated position sensor disposed at the flashlight. The sensor has a switch spring and a cable connected between the switch spring and the line for turning on the light source when the cable is extended by a certain distance. Such sensors are standard, self-contained devices having a built-in spring, reel, cable and electrical leads for connection to a circuit. 
   With the objects of the invention in view, there is also provided a retractable, automatic, on/off flashlight system, comprising a fastener, and a flashlight having a light source, a power source and a cable-actuated position sensor connected in a circuit. The position sensor has a spring-loaded cable connected to the fastener for turning on the light source when the cable is extended by pulling the flashlight a certain distance away from the fastener. Since the sensor has a cable spring-loaded on a reel, there is no need for a retriever with a spring and a spool. 
   With the objects of the invention in view, there is additionally provided a retractable, automatic, on/off flashlight system, comprising a retriever having a retriever spring and a line to be retracted by the retriever spring into the retriever. A flashlight is connected to the line and has a light source, a power source and a switch connected in a circuit. The switch is a capacitive proximity switch for turning on the light source when the flashlight is touched by a user. Such switches are commonly used for activating valves, for example. 
   With the objects of the invention in view, there is furthermore provided a retractable, automatic, on/off flashlight system, comprising a retriever having a retriever spring and a line to be retracted by the retriever spring into the retriever. A flashlight is connected to the line and has a light source, a power source and a switch connected in a circuit. The switch includes a pair of elements communicating with each other. One of the elements is disposed at the flashlight and the other of the elements is disposed at the retriever, for turning on the light source when the elements are spaced a certain distance apart. The elements may communicate through radio waves, acoustic waves or microwaves, for example. Many types of elements may be used in this embodiment, which only requires that the approach or separation of the elements be sensed. 
   Other features which are considered as characteristic for the invention are set forth in the appended claims. 
   Although the invention is illustrated and described herein as embodied in a retractable, automatic, on/off flashlight system, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. 
   The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWING 
       FIG. 1  is a diagrammatic, perspective view of a first embodiment of a retractable, automatic, on/off flashlight system according to the invention; 
       FIG. 2  is an enlarged, partly broken-away, side-elevational view of a flashlight of the first embodiment of the system of the invention; 
       FIG. 3  is a top-plan view of a retriever of a second embodiment of the system of the invention; 
       FIGS. 3   a  and  3   b  are enlarged, fragmentary, top-plan views of a portion of the retriever respectively showing a resilient finger pushed against and released from an inflexible stop; 
       FIG. 4  is a partly broken-away, perspective view of a third embodiment of the system of the invention; 
       FIG. 5  is a perspective view of a fourth embodiment of the system of the invention; and 
       FIG. 6  is a perspective view of a fifth embodiment of the system of the invention. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring now to the figures of the drawings in detail and first, particularly, to  FIG. 1  thereof, there is seen a retriever  1  having a cover  2  attached to a cup-shaped base  3  by a screw  4 . The screw  4  not only holds the cover  2  to the base  3 , but also connects a belt clip  5  to the cover. The belt clip  5  has a hole  10  formed in a shorter leg  6  thereof through which the screw  4  may be tightened and a smaller, non-illustrated hole in a longer leg  7  through which the screw holds the belt clip to the cover  2 . A chain which is not illustrated in  FIG. 1 , but will be described in more detail below, is spring-loaded in the retriever  1  and ends at a ring  8  which is retracted against a ferrule  9 . Such a retriever is available from The Hillman Group of Cincinnati, Ohio as Model #701290 under the designation Key Retriever. 
   According to the invention, a flashlight  30  is connected to the ring  8  by another chain  31 . As is seen in  FIG. 2 , the flashlight  30  has a front cap  32  and a rear cap  33 , which are screwed onto a hollow body  34 . The body  34  contains a light source, such as a bulb  35  having a side terminal screwed or otherwise engaged in a socket  36  which is in turn connected to a reflector  37 . However, one or more LEDs may be used instead of the bulb. Batteries  40  are biased against one another and against a base terminal of the bulb  35  by a spring  41 . A first lead  42  is electrically connected to the socket  36  and extends toward the rear cap  33  and a second lead  43  is electrically connected to the spring  41  and extends toward the rear cap  33 . Both leads  42 ,  43  are L-shaped in the vicinity of the end cap  33  and terminate with a gap there between. A switch  51  includes an actuator in the form of a plunger  45  which protrudes through the end cap  33  and through the gap  44  and terminates in a conductive crosspiece  46 . A non-conductive washer  47  of the switch  51  is fixedly disposed on the plunger  45 . A spring  48  normally biases the washer  47  against the L-shaped end of the leads  42 ,  43 . However, if the plunger  45  is pulled to the right in  FIG. 2  against the force of the spring  48 , the conductive crosspiece  46  electrically interconnects the leads  42 ,  43  and closes the circuit containing the batteries and the bulb, so that the bulb is turned on. If the plunger  45  is no longer pulled to the right in  FIG. 2 , the spring  48  moves the washer  47  and with it the plunger and the crosspiece to the left in  FIG. 2  and the bulb is turned off. A hole  49  in the end of the plunger is connected to the chain  31  by a ring  50  shown in  FIG. 1 . 
   Since the stiffness or spring constant k of the retriever spring is greater than the stiffness or constant k of the switch spring  48 , every time the flashlight  30  is extended from the retriever in an extension direction E, the plunger will be pulled and the bulb will turn on. Every time the flashlight is retracted in a retraction direction R, the plunger will be returned to its normal rest position and the bulb will be turned off. It should also be noted that any attachment device could be used in place of a belt clip to attach the retriever to a stationary object, such a piece of furniture or a counter, where the flashlight is to be used. 
   In the second embodiment of the invention illustrated in  FIG. 3 , the retriever  1  is once again shown, but with the cover  2  removed. It can be seen that the cup-shaped base  3  has a threaded socket  11  for receiving the screw  4 . A spool  13  has a base portion  14  rotating on the base  3  and a cylindrical portion  15  perpendicular to the base portion  14 . The cylindrical portion  15  has an opening  16  and a slot  17 . The socket  11  has a slot  18  for receiving one end of a spring  19 . The other end of the spring  19  passes through the opening  16  and is locked in place by passing through the slot  17 . A chain  20  is wound around the spool  13  between the base portion  14  and the cylindrical portion  15  and has a non-illustrated end connected to the spool  13 . A portion of the chain  20  below the base portion  14  near the point of connection to the spool  13  is shown in a broken-away portion of the base portion  14 . The chain  20  passes through the ferrule  9  which is disposed in a recess in the base  3 . All of the features of the retriever  1  described above are present in the Hillman Key Retriever mentioned above. 
   According to the invention, a switch  21  has an L-shaped, inflexible, electrically-conductive stop  22  fixedly mounted to the side of the cup-shaped base  3 . The switch  21  also has a switch spring in the from of a resilient, L-shaped, electrically-conductive finger  23  fixedly mounted to the side of the cup-shaped base  3 . An actuator in the form of a washer  24  is fixedly connected to the chain  20 . In the extended position of the chain  20  shown in  FIG. 3   a , the washer  24  has pushed the tip of the resilient finger  23  against and in electrical contact with the inflexible stop  22 . However, when the chain is retracted into the retriever, to the left in  FIG. 3 , the washer is lifted off the resilient finger  23  as shown in  FIG. 3   b  and passes under the base portion  14 . Therefore, the resilient finger  23  bounces back to its unbiased condition in which the tip of the finger  23  is moved away from the stop  22 . 
   Two electrical leads  25  are strung along the chain  20  from a non-illustrated flashlight into the retriever  1 . The electrical leads  25  protrude beyond the end of the chain at the point of connection to the spool  13 . One end of one of the electrical leads  25  is connected to the stop  22  and one end of the other of the electrical leads  25  is connected to the finger  23 . The other end of one of the electrical leads  25  is connected to the lead  42  and the other end of the other of the electrical leads  25  is connected to the lead  43  in the flashlight. In contrast to the first embodiment shown in  FIG. 2 , the flashlight of the second embodiment has no switch integral therewith, but instead the switch  21  will turn on the bulb  35  when the chain  20  is pulled and shut off the bulb  35  when the chain is retracted by the spring  19 . The distance by which the chain must be pulled to turn on the bulb is adjustable by suitable placement of the washer  24  along the chain  20 . 
   In the third embodiment of the invention illustrated in  FIG. 4 , a standard pull switch  60 , such as is used for a ceiling fan or a ceiling light, is disposed in the flashlight  30 . An actuator in the form of a chain  61  of the pull switch is connected between a non-illustrated switch spring in the pull switch  60  and the chain  31  leading to the retriever  1 , so that when the flashlight is pulled, the switch  60  will turn on the bulb. When the flashlight is pulled again, after the chain has been retracted by the retriever  1 , the bulb will turn off. 
   In the fourth embodiment of the invention illustrated in  FIG. 5 , an element, such as a capacitive proximity switch  70 , is disposed in or on the flashlight  30 . When a user approaches or grasps the flashlight, the proximity switch turns on the bulb. When the user releases the flashlight for retraction toward the retriever  1 , the bulb turns off. In this case, the proximity switch acts as the switch and the actuator. Alternatively, an element  71  could be placed in or on the retriever  1 , forming a transmitting pair with the element  70 . Elements  70  and  71  would communicate through radio waves, acoustic waves or microwaves, for instance, so that when the flashlight with the element  70  has been extended a certain distance from the element  71 , the bulb would turn on. Element  70  is both the switch and the actuator. 
   In the fifth embodiment of the invention illustrated in  FIG. 6 , a cable-actuated position sensor  80  is disposed in the flashlight  30 . The sensor  80  has a cable  81  wound on a reel  82  against the force of a spring  83 . The cable  81  is connected to the chain  31 . When the cable  81  is extended by a certain distance, the sensor  80  turns on the bulb. When the cable is retracted, the sensor  80  turns off the bulb. In this embodiment, a belt clip or other fastener may be used instead of the retriever, in which case the cable  81  is directly connected to the ring  8  which is fixed in place at the fastener. 
   In all of the embodiments described above, it is not necessary to use a chain  31  between the retriever  1  and the flashlight  30 . Instead, any type of cord, line or cable which is capable of winding on the spool  13  may be used. In the second embodiment of  FIG. 3 , the leads  25  themselves may replace the chain  31 . The use of the generic word “line” in the claims includes all of the possibilities mentioned above.