Abstract:
A portable lighting device includes a main front lamp directed in a first direction, an auxiliary lamp directed in a second direction different from the first direction and a controller connected to the auxiliary lamp so as to selectively illuminate the auxiliary lamp.

Description:
BACKGROUND 
       [0001]    The present disclosure relates generally to lighting systems and methods and, in particular, to a portable lighting device that may include motion, orientation and/or illumination intensity control and associated methods. 
         [0002]    Working in a dark and space restrictive environment may present a number of hazards and lighting challenges. As an example, a coal mine often includes miners sharing limited space with heavy equipment in a dark environment. As a result, a miner risks being struck by a piece of equipment if the operator of the equipment cannot see the miner. This is especially true if the miner is not facing the piece of equipment (so that the miners cap lamp shines in another direction) or the miner squats down or bends over or is working in a ditch so as to be further shielded from the equipment operator&#39;s field of view. 
         [0003]    Furthermore, while a miner&#39;s cap lamp provides the miner with illumination in the forward direction, the miner&#39;s peripheral views typically are not lit or are poorly lit by straying light from the cap lamp main front lamp. As a result, a miner may not see a piece of equipment approaching from, or moving on, the side and become injured due to unintentional contact with the equipment. Alternatively, the miner may not see a sidewall of the mine or other obstacle with his peripheral vision due to darkness and run into it. 
         [0004]    In addition, while cap lamps may provide good illumination as the miner looks into the distance, the bright light provided by the cap lamp may become blinding to the miner due to reflection if he is looking directly at a surface or an object up close. 
         [0005]    Other types of workers, including but not limited to rescue personnel such as firefighters, may face similar issues in dark, smoky and space restrictive environments such as burning structures. 
         [0006]    Accordingly, a need exists for a cap lamp, a cap lamp system and/or method that addresses at least some of the above issues. 
       SUMMARY 
       [0007]    A portable lighting device includes a main front lamp directed in a first direction, an auxiliary lamp directed in a second direction different from the first direction and a controller connected to the auxiliary lamp so as to selectively illuminate the auxiliary lamp. In an embodiment, the controller flashes the auxiliary lamp. 
         [0008]    In an embodiment the portable lighting device includes an orientation sensor connected to the controller, such that the controller activates the auxiliary lamp when the orientation sensor detects tilting or downward movement. The portable lighting device can also include, with or without the orientation sensor, an external motion detector connected to the controller, such that the controller illuminates the auxiliary lamp when movement is detected by the external motion detector. 
         [0009]    The auxiliary lamp can be a first side lamp and the device can include a second side lamp connected to the controller, a first external motion detector corresponding to the first side lamp and a second external motion detector corresponding to the second side lamp. In one arrangement, the first and second external motion detectors are connected to the controller and the controller illuminates the first side lamp when movement is detected by the first external motion detector and the controller illuminates the second side lamp when movement is detected by the second external motion detector. 
         [0010]    In an embodiment, the portable lighting device can include an illumination intensity sensor connected to the controller, such that the controller is configured to dim the main front lamp when a light intensity detected by the illumination intensity sensor rises above a predetermined level. 
         [0011]    The portable lighting device can be configured as a cap lamp. 
         [0012]    The device can further include a housing and a battery connected to the controller and the main front lamp and the auxiliary lamp. In such an arrangement, the battery, the controller, the main front lamp and the auxiliary lamp can be positioned within the housing. 
         [0013]    An embodiment of a portable lighting device for retrofitting a cap lamp system that includes a cap lamp adapted to attach to a helmet, a battery pack and a power cord supplying power from the battery pack to the cap lamp, includes a housing adapted to be attached to the helmet and an auxiliary lamp positioned in the housing. In one arrangement, the auxiliary lamp is adapted to be selectively illuminated by the battery pack. The auxiliary lamp can be configured to flash. 
         [0014]    The portable lighting device can further include a controller and an orientation sensor connected to the controller, such that the controller activates the auxiliary lamp when the orientation sensor detects tilting or downward movement. The portable lighting device can further include a switch for manually activating the auxiliary lamp. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a side perspective view of an embodiment of the portable lighting device of the invention; 
           [0016]      FIG. 2  is a schematic of the portable lighting device of  FIG. 1 ; 
           [0017]      FIG. 3  is a flow chart showing processing performed by the programmable logic controller of the portable lighting device of  FIGS. 1 and 2 ; 
           [0018]      FIG. 4  is a rear perspective view of an inline embodiment of the portable lighting device of the invention; 
           [0019]      FIG. 5  is an enlarged rear perspective view of the portable lighting device of  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    An embodiment of a portable lighting device is indicated in general at  10  in  FIG. 1 . While the description below is directed to an embodiment where the portable lighting device is a cap lamp as used in mines, the portable lighting device may alternatively be a cap lamp used in other environments, a hand held flashlight, a portable light that otherwise attaches to a user or any other type of portable light. 
         [0021]    As illustrated in  FIG. 1 , the cap lamp includes a housing  12 , a main front lamp  14 , a tail lamp  16  and side lamps  18   a  and  18   b  ( FIG. 2 ). Each lamp preferably is at least one light emitting diode (LED), but may be any other type of lamp known in the industry. 
         [0022]    While the main front lamp  14  is activated by a conventional switch ( 22  in  FIG. 1 ), as known in the art, the tail lamp  16  and side lamps  18   a  an  18   b  may be activated by an auxiliary lamp control switch, indicated at  24  in  FIG. 2 . Auxiliary lamp control switch  24  may be configured to manually turn the tail lamp  16  and side lamps  18   a  and  18   b  on individually or together. Auxiliary lamp control switch may also have a setting so that the cap lamp controller activates the tail lamp and side lamps in the manner described below. Of course control of the main front lamp  14  may alternatively be incorporated into switch  24  as well so that the separate, dedicated main front lamp control switch  22  is unnecessary. 
         [0023]    As illustrated in  FIG. 2 , the cap lamp includes a programmable logic controller  26  that communicates with auxiliary lamp switching module  32 . The lamp switching module  32  is electrically connected to a battery  34  and the tail lamp  16  and side lamps  18   a  and  18   b . The battery is connected to a transformer  36  so that the appropriate power is provided to the controller  26 . While the battery  34  is preferably a lithium-ion battery, any type of battery may be used. In addition, while  FIG. 2  shows the battery  34  positioned within the cap lamp housing  12 , the battery could instead be positioned in a separate battery pack that is worn on the user&#39;s waist and connected to the cap lamp housing via a cord (as known in the art and shown in  FIG. 4 ) and the components within the cap lamp housing. 
         [0024]    An orientation sensor or motion sensor  42  is also connected to the controller. The motion/orientation sensor sends a signal to the controller when the cap lamp  10  is either moved in the downward direction or tilted forward or backward. The controller uses this indication as will now be described with respect to  FIG. 3 . Suitable motion/orientation sensors are well known in the art and readily available. 
         [0025]    As indicated at  44  in  FIG. 3 , the cap lamp may be configured in either manual mode or automatic mode via a switch ( 24  in  FIG. 2 ). As a result, as noted previously, the tail and side lamps may be manually switched on, as indicated at  46  in  FIG. 3 . 
         [0026]    If the cap lamp auxiliary lighting switch is configured for an automatic mode of operation, as indicated at  48  of  FIG. 3 , the controller ( 26  of  FIG. 2 ) monitors the orientation/motion sensor  42  of  FIG. 2  for downward movement, forward or rearward tilting of the cap lamp or any other movement that would indicate that the worker has bent over or otherwise caused the cap lamp to traveled downwards. When the controller receives a signal from the orientation/movement sensor, it sends a signal to the lamp switching module  32  and tail lamp  16  and side lamps  18   a  and  18   b  are illuminated, as indicated at  52  in  FIG. 3 . This enables the miner to be better seen by nearby equipment operators so that pinning or crushing injuries are more likely to be avoided. 
         [0027]    The tail and side lamps may be configured to either be steadily illuminated or they may flash to further alert equipment operators of potential danger. 
         [0028]    As illustrated at  54  in  FIG. 3 , the tail and side lamps of the cap lamp remain off if the orientation/motion sensor does not detect downward movement, forward or rearward tilting of the cap lamp or any other movement that would indicate that the worker has bent over or otherwise caused the cap lamp to traveled downwards (and if they are not otherwise illuminated by other cap lamp functionality described below). 
         [0029]    As shown at  56  in  FIG. 3 , after the controller has activated the tail and side lamps of the cap lamp, it monitors the orientation/motion sensor to detect if the miner has stood up or otherwise moved to return to his original upright or elevated position. The controller will turn off the side and tail lamps once this occurs ( 58  in  FIG. 3 ) to save battery power. The tail and side lamps remain on if he has not done so ( 62  in  FIG. 3 ). 
         [0030]    As shown in  FIG. 2 , the cap lamp features external motion detectors  64   a  and  64   b  that monitor the side or peripheral areas of the miner through openings formed in the sides of the cap lamp housing. The external motion detectors  64   a  and  64   b  also are in communication with the cap lamp controller  26 . The controller is configured so that when motion, such as by moving machinery, is detected on either side of the cap lamp by the motion detectors, the corresponding side lamp  18   a  or  18   b  is illuminated. As a result, the cap lamp provides enhanced lighting to the appropriate side of the miner. If the side lamps are switched on manually so that they are constantly on/illuminated, the controller may be configured to increase the intensity of a side lamp when there is motion detected on the corresponding side of the cap lamp. Suitable motion detectors are well known in the art and readily available. 
         [0031]    When the miner is looking at surfaces that are close, the LED main lamp  14  can result in eye fatigue due to glare and high intensity light reflecting off of the surface. To address this issue, as illustrated in  FIG. 2 , a light intensity sensor  72  is provided. The light sensor  72  may be positioned on the cap lamp housing or within the housing adjacent to an opening that permits it to detect the level of light intensity in front of the cap lamp, and thus the miner. The light intensity sensor  72  communicates with the controller  26 . Based on the light intensity detected by sensor  72 , the controller adjusts the intensity of illumination provided by the main front lamp  14 . As a result, the cap lamp uses feedback to reduce the light output of the main lamp  14  when glare or increased intensity is detected by sensor  72 . Suitable light intensity sensors are well known in the art and readily available. 
         [0032]    As illustrated in  FIGS. 4 and 5 , an embodiment of the device may take the form of a cap lamp inline flasher module  82  that is positioned inline or in series circuit with the power cord  84  that provides power to the cap lamp  86  from the battery pack  88 . For increased safety (as explained below), the inline flasher  82  is placed at the back of a miners helmet  90  (or other type of headgear) using a fastener such as a clip, a hook and loop fastener; a magnetic fastener or any other type of fastener known in the art. 
         [0033]    As illustrated in  FIG. 5 , the flasher module  82  features a pair of LED lamps  92   a  and  92   b  (although any number may be used) that are powered by the battery pack  88  when activated by a push button  94 . The LED lamps  92   a  and  92   b  preferably flash when activated, but they may alternatively be configured to remain constantly illuminated (or the module may provide selection between the two). 
         [0034]    The flasher module  82  may house an orientation/motion sensor and controller (that is configured to control lamps  92   a  and  92   b ), as illustrated in  FIG. 2 , to provide the functionality illustrated in  FIG. 3 . As a result, an automatic mode of operation is provided where the controller monitors the orientation/motion sensor for downward movement, forward or rearward tilting of the module  82  or any other movement that would indicate that the miner has bent over or otherwise caused the module to travel downwards. When the controller receives such a signal from the orientation/movement sensor, it flashes or otherwise illuminates the pair of LED lamps  92   a  and  92   b . This allows operators of heavy equipment to better see miners in the vicinity so as to reduce injuries and deaths that are the result of a miner that was not seen being pinned or crushed by heavy equipment. 
         [0035]    The embodiment of  FIGS. 4 and 5  therefore provides a retrofit for existing cap lamp systems. 
         [0036]    In alternative embodiments, the lamps of the cap lamp or module could be controlled by a voice input in combination with, or in place of, the motion, gesture, and/or orientation control described above. 
         [0037]    It will be appreciated by those skilled in the art that the relative directional terms such as upper, lower, rearward, forward and the like are for explanatory purposes only and are not intended to limit the scope of the disclosure. 
         [0038]    All patents referred to herein, are hereby incorporated herein by reference, whether or not specifically done so within the text of this disclosure. 
         [0039]    In the present disclosure, the words “a” or “an” are to be taken to include both the singular and the plural. Conversely, any reference to plural items shall, where appropriate, include the singular. 
         [0040]    From the foregoing it will be observed that numerous modifications and variations can be effectuated without departing from the true spirit and scope of the novel concepts of the present disclosure. It is to be understood that no limitation with respect to the specific embodiments illustrated is intended or should be inferred. The disclosure is intended to cover all such modifications as fall within the scope of the claims.