Portable light

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.

Claims

1. A portable light, comprising: a housing having a compartment for receiving a battery; a light head comprising: a light element; a heat sink; and a connector for connecting the light head with the housing, wherein the heat sink comprises: a plurality of spaced apart fins for transferring heat from the heat sink, wherein each fin has a first side and a second side; a generally planar base attached to a plurality of the fins along the first side of each fin; and a bridge spanning two of the fins and interconnecting the two fins to provide a mounting surface along the second side of the two fins, wherein the connector is connected to the mounting surface bridging the two fins.

2. The portable light of claim 1 wherein the connector is pivotable relative to the light head or the housing so that the heat sink is pivotable relative to the housing.

3. The portable light of claim 2 wherein a plurality of heat sink fins are spaced apart from the bridges.

4. The portable light of claim 3 wherein the plurality of heat sink fins spaced apart from the bridges have a width that is substantially narrower than the fins connected by the bridges.

5. The portable light of claim 1 wherein the fins have a width and a length that is substantially longer than the width, wherein the bridge interconnects the two fins along a substantial portion of the length of the fins.

6. A portable light, comprising: a housing having a compartment for receiving a battery; a first connector connected with the housing; a light head comprising: a light element; a heat sink; and a second connector for pivotably connecting the light head with the first connector, wherein the heat sink comprises: a plurality of spaced apart longitudinally elongated fins for transferring heat from the heat sink, wherein each fin has a longitudinally elongated outer edge, wherein a gap is formed between a first of the elongated fins and a second of the elongated fins; and a bridge spanning the gap between the first fin and the second fin, wherein the bridge interconnect the longitudinally elongated outer edge of the first fin with the longitudinally elongated outer edge of the second fin to provide a mounting surface, wherein the second connector is connected to the mounting surface bridging the two fins.

7. The light of claim 6 wherein the bridge extends along a majority of the elongated length of the first and second fin.

8. The light of claim 6 wherein the heat sink comprises a second gap formed between a third of the elongated fins and a fourth of the elongated fins and a second bridge spans the second gap between the third and fourth fins, the second bridge interconnects the third and fourth fins, wherein the second connector is connected to the second bridge.

9. The light of claim 6 wherein the bridge forms a generally planar surface.

10. The light of claim 6 wherein each of the fins has an inner edge connected to a body of the heat sink, wherein the outer edge of each fin is remote from the inner edge of each fin.

11. The light of claim 6 wherein the bridge directly connects the outer edge of the first fin with the outer edge of the second fin.

12. The light of claim 6 wherein the second connector is directly connected to the bridge.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) 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:

(2) FIG. 1 is a perspective view of a portable light;

(3) FIG. 2 is an exploded perspective view of a head of the portable light illustrated in FIG. 1;

(4) FIG. 3 is an enlarged perspective view of the light head illustrated in FIG. 2;

(5) FIG. 4 is an enlarged perspective view of the light head illustrated in FIG. 2, shown from a reverse angle;

(6) FIG. 5 is an enlarged cross-sectional view of the light head illustrated in FIG. 2;

(7) FIG. 6 is an exploded perspective view of a lens assembly of the light head illustrated in FIG. 2;

(8) FIG. 7 is an exploded perspective view of a controller assembly for the light head illustrated in FIG. 2;

(9) FIG. 8 is a cross-sectional view of the controller assembly illustrated in FIG. 7;

(10) FIG. 9 is a perspective view of the controller assembly illustrated in FIG. 8;

(11) FIG. 10 is an enlarged fragmentary cross-sectional view of the light head illustrated in FIG. 2;

(12) FIG. 11 is an enlarged side view of a diffuser of the light head illustrated in FIG. 2; and

(13) FIG. 12 is a schematic drawing of a control circuit of the light illustrated in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

(14) 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.

(15) 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.

(16) 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.

(17) 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.

(18) 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 124a 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 124b that spans between the outer edges of the fins similar to bridge 124a.

(19) As shown in FIG. 4, the mounting bracket 130 is connected directly to the bridge 124a and 124b. Specifically, the mounting bracket spans between bridge 124a and bridge 124b 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.

(20) 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 124a, 124b by a mechanical fastener such as a screw, bolt or other known fastener.

(21) 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.

(22) 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 & 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.

(23) 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.

(24) 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 4or recesses 47 extend outwardly from the central opening. The notches cooperate with actuator 60 to locate the diffusion disc relative to the actuator.

(25) 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.

(26) 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.

(27) 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.

(28) 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.

(29) 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.

(30) 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.

(31) 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.

(32) 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.

(33) 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.

(34) 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.

(35) 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.

(36) 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.

(37) 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.

(38) 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.

(39) 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.

(40) 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.

(41) 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.

(42) 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.

(43) 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.

(44) 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 210a reflects a configuration in which the light is powered by a battery housed within the housing adjacent the lamp head 20. Power source 210b 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.

(45) 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 51 in FIG. 12 is in circuit with the controller. When the controller receives a signal indicating that 51 is closed, the controller controls the dimming of the light.

(46) 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.

(47) 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 R10 and R11 sum at FB so at a 50% dim level, 50 mV cross R10 and 50 mV cross R11 so that FB sees 100 mV.

(48) 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.