Abstract:
A portable light having a light head with a plurality of light elements and a rotatable diffuser to selectively diffuse the light produced by the light elements. The diffuser is operable by an actuator. The actuator further includes a switch for controlling the dimming level of the light elements. A separate switch controls whether the light is “on” or “off”.

Description:
PRIORITY CLAIM 
     This application claims priority to U.S. Provisional Patent Application No. 61/815,561 filed Apr. 24, 2013. The entire disclosure of the foregoing application is hereby incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to the field of portable lights and in particular to battery powered portable lights, such as flashlights and lanterns. 
     BACKGROUND OF THE INVENTION 
     Portable lights, such as flashlights and lanterns are regularly used by law enforcement, fire, rescue and other emergency personnel. Although numerous lights have been created for various emergency situations, there exists a need for a high-powered light that is durable, provides flexible lighting and is easy to use. 
     SUMMARY OF THE INVENTION 
     In light of the foregoing, according to one aspect, Applicant&#39;s invention provides a portable light having a housing and a light head connected with the housing. The light head comprises a plurality of light elements spaced apart from one another and a reflector comprising a plurality of concave reflective surfaces, wherein each light element is disposed within one of the concave reflective surfaces so that the reflective surfaces focus the light from the light element disposed within the respective reflective surface. A displaceable diffuser selectively diffuses the light from the light elements, wherein the diffuser comprises a plurality of first areas having a first dispersal pattern and a plurality of second areas having a second dispersal pattern different from the first pattern. The first and second areas are spaced about the diffuser so that in a first position the first areas of the diffuser overlie the reflectors so that the light from the light elements projects through the first areas, and wherein when the diffuser is in a second position, the second areas of the diffuser overlie the reflectors so that the light from the light elements projects through the second areas. The light further comprises a controller operable to control the light levels of the light elements so that in a first position the light elements provide a full light level and in a second position the light elements provide a dim light level that is less than the light provided by the full light level. An actuator is operable to displace the diffuser from the first position to the second position. The actuator comprises a switch actuable by the actuator, wherein the controller controls the light between the full light level and the dim light level in response to actuation of the switch. 
     According to another aspect, the present invention provides a portable light, comprising a housing having a compartment for receiving a battery and a light head. The light head comprises a light element, a heat sink and a connector for connecting the light head with the housing. The heat sink comprises a plurality of spaced apart fins for transferring heat from the heat sink and a bridge spanning two of the fins to provide a mounting surface. The connector is connected to the mounting surface bridging the two fins. According to one aspect the connector is pivotable relative to the light head or the housing so that the heat sink is pivotable relative to the housing. 
     According to yet another aspect, the present invention provides a portable light comprising a housing and an LED. The LED is operable in an “on” condition to provide a first illumination level and a “dim” condition to provide a second illumination level that is dimmer than the first illumination level. A battery within the housing provides power for the light element. The light further comprises a controller for controlling the light element between the “on” condition and the “dim” condition, wherein the controller comprises an LED driver operable to provide a first current to the LED in the “on” condition and a second current to the LED in the “dim” condition. The LED diver also comprises a feedback input connected with the LED and the controller selectively provides a voltage offset so that the current received by the LED driver is the same when the LED is in the “dim” condition as when the LED is in the “on” condition. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing summary and the following detailed description of the preferred embodiments of the present invention will be best understood when read in conjunction with the appended drawings, in which: 
         FIG. 1  is a perspective view of a portable light; 
         FIG. 2  is an exploded perspective view of a head of the portable light illustrated in  FIG. 1 ; 
         FIG. 3  is an enlarged perspective view of the light head illustrated in  FIG. 2 ; 
         FIG. 4  is an enlarged perspective view of the light head illustrated in  FIG. 2 , shown from a reverse angle; 
         FIG. 5  is an enlarged cross-sectional view of the light head illustrated in  FIG. 2 ; 
         FIG. 6  is an exploded perspective view of a lens assembly of the light head illustrated in  FIG. 2 ; 
         FIG. 7  is an exploded perspective view of a controller assembly for the light head illustrated in  FIG. 2 ; 
         FIG. 8  is a cross-sectional view of the controller assembly illustrated in  FIG. 7 ; 
         FIG. 9  is a perspective view of the controller assembly illustrated in  FIG. 8 ; 
         FIG. 10  is an enlarged fragmentary cross-sectional view of the light head illustrated in  FIG. 2 ; 
         FIG. 11  is an enlarged side view of a diffuser of the light head illustrated in  FIG. 2 ; and 
         FIG. 12  is a schematic drawing of a control circuit of the light illustrated in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the figures in general, wherein like elements are numbered alike throughout, a portable light is designated generally  10 . Referring to  FIGS. 1-2 , the light  10  may be any of a variety of battery powered light, such as a flashlight or lantern. In the present instance, the light  10  is a lantern. A lamp head  20  connected to the housing  12  has one or more light elements  110 . In the present instance, the lamp head  20  includes a diffuser  40  for selectively diffusing the light element(s) so that the operator can switch the light between a focused beam and a diffuse light source. 
     Referring to  FIG. 1 , the lantern includes a housing  12  having a hollow interior compartment for housing a power source, such as a battery that may be disposable or rechargeable. The housing may be configured in a variety of shapes, such as a cylindrical housing. However in the present instance the housing comprises a body that is shaped similar to a rectangular prism and has a handle  16  connected to and spaced apart from the body. A pair of strap loops may also be provided for attaching a strap to the housing so that the operator can carry the light  10  by the strap. Although the light  10  may be controlled by any of a number of switches or actuators, in the present instance, the light  10  includes a switch  14 , such as a toggle switch for turning the light on and off. 
     Referring to  FIGS. 1-5 , the lamp head  20  may be rigidly connected to the housing  12 , however, in the present instance, the lamp head  20  is pivotably connected with the housing. Specifically, a bracket  130  provides a pivotable connection between the lamp head  20  and the housing  12 . Referring to  FIGS. 2 and 4 , the mounting bracket  130  is rigidly connected to a heat sink  120  so that the heat sink does not move relative to the bracket. The mounting bracket  130  comprises a yoke  132  formed by parallel arms that project away from the rearward end of the heat sink  120 . The yoke  132  comprise a pair of axially aligned apertures so that a pivot pin can pass through the holes and form a pivot axis for the head, so that the head is pivotably connected with the housing. 
     As shown in  FIGS. 2 and 4 , the light  10  comprises a heat sink  120  having a plurality of elongated fins  122  extending away from a generally planar base  121 . The fins are vertically oriented and substantially parallel so that slots are formed between adjacent fins. As shown in  FIG. 4 , fins  123  are the longest and deepest fins. Moving toward the outer edges, the fins get progressively shorter and shallower so that the fins  125  adjacent the outer edge project outwardly from the base  121  less than half as far as the fins  123  near the middle of the heat sink. 
     In the present instance, the heat sink is formed so that a plurality of the fins are interconnected by bridges  124  that span two or more fins. Specifically, the outer end (i.e. the end remote from the base  121 ) of two adjacent fins  123  near the middle of the heat sink are connected by bridge  124   a  that spans between the two fins along the length of the fins. Similarly, a second pair of fins are interconnected or capped by a second bridge  124   b  that spans between the outer edges of the fins similar to bridge  124   a.    
     As shown in  FIG. 4 , the mounting bracket  130  is connected directly to the bridge  124   a  and  124   b . Specifically, the mounting bracket spans between bridge  124   a  and bridge  124   b  and is fixed to the bridges. In the present instance, the bracket is connected directly to the bridges by a mechanical fastener, such as a screw, bolt or other know fastener. 
     As shown in  FIG. 4 , if the lamp head  20  is pivotably connected with housing  12 , it may be desirable to include a cushion or elastomeric pad to cushion and contact between the head and the housing. In the present instance, an elastomeric bumper  128  is connected to the rearward end of the heat sink. More specifically, the bumper is connected to the bridges  124   a ,  124   b  by a mechanical fastener such as a screw, bolt or other known fastener. 
     Referring now to  FIG. 2 , the lamp head  20  comprises a face plate  22  a lens/reflector subassembly  30  a PC board  100  and a heat sink  120 . The PC board  100  is nested within the lens/reflector subassembly  30 , which in turn in nested within the facecap  22 . The facecap  22 , lens subassembly  30  and PCB  100  are then mounted onto the heatsink  100 . 
     As shown in  FIG. 5 , the facecap  22  comprises a generally hollow ring shape having an opening sized to receive the lens subassembly  30 . The inner diameter of the face cap  22  comprises a pair of counterbores that form shoulder against which the lens assembly abuts. A compartment  24  is formed in the upper end of the face cap. The compartment  24  is configured to provide a junction box for an electrical connection between the housing  12  and the lamp head  20 . As shown in  FIGS. 2 &amp; 5 , electrical leads  102  connected with the PCB  100  extend into the compartment  24 . A cover  26  closes the opening to the compartment and a seal  27  provides a fluid tight fit. An aperture extends through the cover to provide access for an electrical connection from the housing. Additionally a sealing element provides a fluid-tight seal between the compartment and the housing electrical connection. For instance, a compression nut may provide a fluid-tight seal between the chamber  24  and electrical leads from the housing. 
     Referring now to  FIG. 6 , the details of the lens/reflector subassembly will be described in greater detail. The lens subassembly comprises a lens  35 , a diffuser  40 , a reflector and an actuator  60 . The lens may be formed of a variety of transparent or translucent materials such as glass or plastic. However, in the present instance, the lens  35  is formed of high impact clear plastic. The lens  35  comprises a circumferential flange that extends outwardly away from the body of the lens to provide a flange to attach the lens to the heat sink  120 . The lens  35  has a central opening  36  configured to receive the actuator knob  60  used to operate the diffuser and control the dimming of the light. An annular shoulder is formed around the central opening in the lens and a plurality of locating elements, such as recesses or notches  37  are formed in the shoulder adjacent the central opening. In the present instance, the locating elements comprise a plurality of recesses  37  circumferentially spaced about the central opening in the lens  35 . 
     The diffuser  40  also may be formed of a variety of transparent or translucent materials. In the present instance, the diffuser comprises a translucent plastic disc. A circumferential flange extends inwardly around the disc thereby forming a lip  48  (shown in  FIG. 5 ). The diffuser comprises an aperture forming a central opening  46 . One or more locating features to locate the diffusion disc are formed at or adjacent the central opening  46 . For instance, in the present instance, locating notches  4  or recesses  47  extend outwardly from the central opening. The notches cooperate with actuator  60  to locate the diffusion disc relative to the actuator. 
     Referring to  FIG. 11 , the diffusion disc comprises a plurality of diffusion areas  42  and a plurality of non-diffusion areas  44 . The diffusion and non-diffusion areas  42 ,  44  are spaced around the circumference of the disc. More specifically, the diffusion areas are spaced apart from one another and are equally spaced around the diffuser. The non-diffusion areas  47  are also spaced apart from one another and are equally spaced around the diffuser. Additionally, in the present instance, the non-diffusion areas are interposed between the diffusion areas so that the areas alternate between diffusing areas and non-diffusing areas. 
     Referring to  FIG. 11 , diffusing areas  42  and non-diffusing areas  44  are formed from different patterns that diffuse the light differently. Although the areas may be formed in a variety of patterns, in the present instance, each non-diffusing area  44  is a generally clear circular area substantially free from distortion. In particular, each non-diffusing area  44  is substantially similar. Although the diffusing areas  42  may be formed in a variety of patterns, in the present instance, the diffusion areas are circular areas with a contoured pattern, such as a honeycomb pattern formed in the surface of the diffuser. The honeycomb pattern creates surfaces that tend to scatter or diffuse the light. As with the non-diffusing areas, in the present instance, each diffusing area is substantially similar. 
     Referring to  FIGS. 5-6 , the reflector  50  comprises one or more concave reflective surfaces  52  for focusing the light from the light elements  110 . In the present instance, the lamp head  20  comprises a plurality of light elements, so the reflector comprises a plurality of concave reflective surfaces spaced around the lamp head. Specifically, the reflector comprises a plurality of reflective surfaces spaced around the circumference of the reflector  50 . Although the shape of the reflectors may vary, in the present instance, each reflective surface is a substantially similarly shaped parabolic concave surface. The base of each reflective surface forms an opening and one of the light elements  110  projects toward or into the opening. As shown in  FIG. 6 , the reflector  50  further comprises a circumferential flange  54  extending radially outwardly. The reflector further comprises a circumferential groove or recess  56  extending around the upper surface of the reflector. The reflector  50  includes a central opening that aligns with the central openings in the diffuser  40  and lens  30  so that the reflector  50 , diffuser  40 , and end cap  40  can be axially aligned. 
     The lens subassembly  30  further comprises the actuator  60  that is operable to actuate the dimming function and to actuate the diffusion for the light. Referring to  FIGS. 7-9 , the details of the actuator subassembly  60  will be described in greater detail. As shown in  FIG. 7 , the actuator  60  comprises a rotatable knob  62  and a pushbutton dimmer actuator  75  nested within the rotatable knob. 
     The knob  62  comprises a generally cylindrical stem  64  projecting from an enlarged head  67 . The enlarged head  67  is a generally circular hub with a plurality of eccentric lobes  68  projecting away from the circular hub. A bore  65  extends through the enlarged head  67  and the stem  64 . Additionally, a counterbore  66  in the enlarged head intersects with and is coaxial with the bore  65 . Furthermore, the counterbore  66  opens into an enlarged recess formed in the top of the enlarged head. 
     The stem  64  includes an enlarged diameter cylindrical portion configured to mate with the mounting apertures  36 ,  46  in the lens  35  and the diffuser  40 . A circumferential groove around the stem forms a seat for a sealing element that maintains the fluid-tight seal between the actuator  60  and the lens  30 . In the present instance, the sealing element is an o-ring  86 . Additionally, a pair of grooves, such as snap ring grooves  72  are formed around the stem  64  for connecting the stem with the lens  35 , diffuser  40  and reflector  50  as discussed further below. 
     Referring to  FIG. 9 , the knob comprises a plurality of locating elements configured to cooperate with the lens  35  and diffuser  40 . Specifically, the underside of the enlarged head  67  comprises a pair of elongated ridges or ribs  70  that extend along the lobes  68 . The ridges  70  are configured to mate with the recesses  37  formed around the opening in the lens  35 . Specifically, the ridges  70  are configured so that the ridges can be aligned with and seated in the notches  37  in the lens. In this way, the cooperating ridges and recesses will impede movement of the actuator  60  relative to the lens. 
     The knob  62  also includes locating tabs  71  formed on the stem  64 . The locating tabs are configured to mate with the locating notches  47  formed in the central aperture of the diffuser  40 . In this way, the locating tabs  71  key into the diffuser notches  47 . The cooperating locating tabs  71  and notches  47  impede rotational movement of the actuator relative to the diffuser  40 . 
     The rotatable knob  62  houses the dimmer actuator  75  that is actuable to dim the light level for the LEDs in the light. The dimmer actuator  75  comprises an elongated stem  78  and an enlarged head  76 . The stem  78  is configured to slide within the central bore  65  of the knob  62 . Specifically, in the present instance, the dimmer actuator is inserted into the bore  65  of the actuator knob so that the stem of the dimmer actuator is coaxial with the stem  64  of the knob. A biasing element, such as a coil spring  84  is seated within the counterbore  66  in the knob so that the biasing element biases against the head of the dimmer actuator  75 . A flexible dome, such as a rubber boot  80  covers the enlarged recess  69  in the knob  62  and retains the dimmer actuator within the knob as shown in  FIG. 8 . A retaining ring  81  is fixed to the walls of the enlarged recess  69  in the knob  62  to fix the dome in place over the dimmer actuator  75 . 
     Referring again to  FIG. 6 , the actuator  60  is connected to the lens  35 , diffuser  40  and reflector  50  as follows. The stem  64  of knob  62  is inserted through the central apertures  36 ,  46  of the lens  35  and diffuser  40 . The knob  62  is then fixed to the diffuser  40  by a connector. For instance, a washer shaped like the profile of the stem  64  is mounted onto the end of the stem and a retaining ring such as an e-ring  82  is snapped into the snap ring groove  72  farthest from the end of the stem. The e-ring  82  locks the actuator  60 , lens  35  and diffuser  40  together by substantially limiting axial displacement of the lens relative to the knob  62  and the diffuser  40 . 
     After connecting the knob  62  with the lens  35  and diffuser  40 , the stem  64  of the knob is inserted into the central opening in the reflector  50 . A second retaining ring, such as an e-ring  82 , is snapped into the snap-ring groove  72  near the end of the stem  64 . In this way, the outer surface of the stem  64  mates with the inner surface of the openings in the lens  35 , diffuser  40  and reflector  50  to axially align the lens, diffuser and reflector with one another. 
     Referring again to  FIG. 2 , the PCB  100  may be fixedly connected to the heat sink  120  by any of a variety of connections, such as mechanical connectors or chemical connectors, such as epoxy. However, in the present instance, the heat sink  120  comprises elements for mechanically aligning and connecting the PCB  100  to the heat sink. Specifically, the heat sink  120  includes a plurality of spaced apart threaded sockets in the base  121  of the heat sink. A plurality of holes are formed in the PCB that align with the threaded sockets in the base of the heat sink  120 . Once aligned, the PCB  100  is connected to the heat sink with a plurality of connectors such as screws. 
     The heat sink  120  further comprises a plurality of threaded sockets for aligning the lens subassembly  30  with the PCB  100 . After the PCB is aligned with and fixed to the heat sink as discussed above, the lens assembly  30  is fixed to the heat sink, thereby aligning the lens assembly with the PCB  100 , which in turn aligns each of the light elements  110  with the corresponding parabolic reflective surfaces  52  of the reflector  50 . Specifically, the facecap  22  is aligned with the lens assembly  30  and connected to the heat sink with a plurality of connectors, such as screws. The screws extend through the facecap, through holes in the flange of the lens assembly and into the threaded sockets in the heat sink. 
     In addition to aligning the reflector with the light elements  110  on the PCB  100 , connecting the elements as described above also aligns the actuator  60  with a switch  112  on the PCB used to control the dimming of the light. Specifically, the dimmer actuator  75  is aligned with the switch  112  so that pressing the dimmer actuator actuates the switch. As described further below, the switch  112  is connected with a controller  220  that controls the operation of the light. The controller  220  dims the light in response to actuation of the switch  112 . 
     As shown in  FIG. 5 , when the lens assembly  30  is mounted to the heat sink, it may be desirable to seat a sealing element  90  between the lens assembly and the heat sink to provide a fluid-tight seal between the lens assembly and the heat sink. In the present instance, the sealing element is an o-ring  90  extending around the circumference of the flange on the lens. 
     Configured as described above, the actuator  60  is operable to control the diffuser  40  and the dimmer switch. More specifically, the diffuser is operable to vary how the light from the light elements is diffused. In a first position, the diffusion surfaces  42  are aligned with the light elements so that the diffusion surfaces overlie the parabolic reflective surfaces  52 . In this position, the light from the light elements  110  projects through the first diffusion surfaces  42  so that the light is diffused. If the operator desires to have a more focused or coherent beam of light, the operator moves the diffuser to a second position in which the non-diffusing surfaces are aligned with the light elements. 
     To move the diffuser to the second position, the operator pulls on the enlarged head  67  of the actuator to displace the actuator axially outwardly away from the lens  35 . As shown in  FIG. 5 , a gap separates the diffuser  40  from the inner wall of the lens  35  so that the actuator can be pulled outwardly to unseat the ridge  70  of the actuator from the notches  37  in the lens. The operator then rotates the actuator  60  to rotate the diffuser  40  to the second position. The locating tabs  71  on the actuator cooperate with the notches  47  in the diffuser so that rotating the actuator rotates the diffuser. The ridges in the enlarged heard seat into the next set of notches in the lens to ensure that the diffuser is aligned with the second position in which the non-diffusing surfaces are aligned with the parabolic reflective surfaces. 
     In addition to controlling the diffuser, the actuator  60  is operable to control the dimming by pressing the dimmer actuator  75 . Specifically, when the operator presses the flexible dome  80 , the operator drives the dimmer actuator downwardly against the bias of spring  84 . The stem  78  of the dimmer actuator  75  actuates switch  112  (shown in  FIG. 2 ), thereby dimming the light. In the present instance, the light is configured so that repeatedly pressing the dimming actuator  75  cycles the light through a series of dim level. For instance, the first actuation dims the light to 75% illumination, the second actuation within a predetermined time frame dims the light to 50% illumination and a third actuation within a predetermined time frame dims the light to 25% illumination. It should be understood that this is simply an example of how multiple dim levels can be actuated. The light can be configured to have as few as one dim level actuated by the dimmer switch or the light can have more than 3 dim levels. 
     The operation of the light may be controlled by any of a number of control circuits. However, in the present instance, an electronic controller  200  controls the operation of the light in response to signals received from the toggle switch  14  and the dimmer actuator  75 . Referring to  FIG. 12  the details of the controller will be described in greater detail. 
     As described above, the light  10  includes a lamp head  20  fixedly connected to the battery housing  112 . However, it may be desirable to releasably connect the lamp head  20  with the housing  12  so that the lamp head can be extended away from the battery housing. In such a configuration, the light includes an elongated power cord extending between the lamp head and the battery.  FIG. 12  illustrates that the light can be configured with a lamp head fixedly connected with the battery housing or releasably connected with the battery housing. Specifically, in  FIG. 12 , power source  210   a  reflects a configuration in which the light is powered by a battery housed within the housing adjacent the lamp head  20 . Power source  210   b  reflects a configuration in which the light is powered by a battery connected with the lamp head by an elongated coil so that the lamp head is not adjacent the casing in which the battery is housed. 
     As noted above, in the present instance, the light is controlled by a controller  220  such as a microprocessor or microcontroller. For example, as shown in  FIG. 12 , the controller  220  is a microcontroller such as a 20-pin CMOS microcontroller. The controller  220  receives signals from the toggle switch  14  and the dimmer switch  112  and controls the power to the light head in response to the signals received from the switch. For instance, dimmer switch  112  is designated switch S 1  in  FIG. 12  is in circuit with the controller. When the controller receives a signal indicating that S 1  is closed, the controller controls the dimming of the light. 
     The controller  220  may control the dimming in one of a variety of known mechanisms for dimming LEDs. For instance, the light  10  may include one or more LED drivers. In the present instance, the light includes a pair of LED regulators designated  230  in  FIG. 12 . The regulators may be any of a variety of regulators, however, in the present instance, the regulators  230  are 850 step-down DC-DC buck current regulators. The regulators are designed to operate as a constant current source, so the lights may be dimmed by pulsing the lights on and off. In this way, the level of dimming is determined by the percentage of pulses that the light is on versus off. 
     Alternatively, in the present instance, the system uses analog dimming, such as by controlling the current to the LEDs. Specifically, the controller controls the dimming by reducing the current to the LEDs. However, the system provides a closed loop feedback to ensure that the regulators  230  detect a constant current at the FB input. In particular, to dim the LEDs, the controller reduces the current to the LEDs. At the same time the controller increases the voltage of the pulse train from pins  5 ,  14  as the dimming increases. As a result, the system provides a DC voltage offset so that FB of the regulator  230  receives a 100 mV signal regardless of the reduced current at the LEDs. More specifically, the voltage across R 10  and R 11  sum at FB so at a 50% dim level, 50 mV cross R 10  and 50 mV cross R 11  so that FB sees 100 mV. 
     It will be recognized by those skilled in the art that changes or modifications may be made to the above-described embodiments without departing from the broad inventive concepts of the invention. It should therefore be understood that this invention is not limited to the particular embodiments described herein, but is intended to include all changes and modifications that are within the scope and spirit of the invention as set forth in the claims.