Patent Publication Number: US-2017356633-A1

Title: Lamp with proximity sensing

Description:
PRIORITY 
     This application is a continuation of application Ser. No. 15/180,008 filed on Jun. 11, 2016, the contents of which are incorporated herein by reference. 
    
    
     FIELD OF DISCLOSURE 
     The present disclosure relates to light fixtures, such as those light fixtures generally referred to as lamps. 
     BACKGROUND 
     Proper workstation lighting is critical to the effectiveness of office workers. Many workstations are illuminated with overhead lighting. Use of overhead lighting alone requires an overabundance of light across an over inclusive area. The result is significant energy consumption. Use of task lighting in addition to overhead lighting reduces the lighting levels required from the overhead lights, greatly reducing overall energy use. Further, today&#39;s office tasks heavily involve reading from backlit screens. Task lighting allows for the generation of focused light when the task requires, such as reading a hard copy page, while helping to reduce eye strain and improve computer-based reading comfort. 
     Use of task lighting dates back to the candle and kerosene lamp. Today&#39;s task lights, however, seek ever increasing energy efficiency with the use of light emitting diode technology, dimming capability and sensor based control. There is also an ever present desire to improve the mechanical and electrical systems of light fixtures to maintain structural and lighting performance while facilitating the manufacture of lamps with simple, elegant, and clean-lined industrial design. 
     SUMMARY 
     In one embodiment, the present disclosure describes a lamp having a head with a light source and at least one support arm supporting the head at a joint. The joint allows relative motion between the at least one support arm and the head. The joint includes a sliding electrical contact and a torque insert. The at least one support arm is electrically conductive, and a ground wire is grounded to the support arm, the support arm being in electrical contact with the torque insert. 
     In another embodiment, the present disclosure includes a lamp comprising a head having a primary light source. The head is connected to a support. The support includes a first support portion at least partially comprising an electrically conductive material, a second support portion at least partially comprising an electrically conductive material, and a first joint connecting the first support portion to the second support portion to allow relative movement between the first support portion and the second support portion. The first joint has a torque insert formed with a conductive exterior housing. The first joint provides two current conducting paths from the first support portion to the second support portion. A first current conducting path comprises electrically charging the first support portion, and contact conduction from the electrically conductive material of the first support portion to the electrically conductive material of the second support portion through the exterior housing of the torque insert. A second current conducting path comprises a sliding electrical contact electrically isolated from the conductive material of the first support portion, the conductive material of the second support portion, and the torque insert. 
     These and other aspects of the present invention will become apparent to those skilled in the art after a reading of the following description of the preferred embodiments, when considered in conjunction with the drawings. It should be understood that both the foregoing general description and the following detailed description are explanatory only and are not restrictive of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top perspective of a lamp according to embodiments of the present disclosure. 
         FIG. 2  is a bottom perspective of the lamp of  FIG. 1 . 
         FIG. 3  is a cross sectional view of the lower arm of the lamp of  FIG. 1  taken along the length of a lower arm. 
         FIG. 4  is a side view of the lower arm of the lamp of  FIG. 1  with a cover sheet omitted. 
         FIG. 5  is a detailed side view of an intermediate joint with the cover sheets omitted from each of the lower and upper arms. 
         FIG. 6  is an exploded view of the components of the intermediate joint shown in  FIG. 5 . 
         FIG. 7  is a perspective cross section of the spacer of the intermediate joint. 
         FIG. 8  is a cross section taken at plane VIII-VIII of  FIG. 5 . 
         FIG. 9  is a detailed side view of an upper joint with the cover sheet omitted from the upper arm. 
         FIG. 10  is an exploded view of the components of the upper joint shown in  FIG. 9 . 
         FIG. 11  is a detailed view of the spacer of the upper joint. 
         FIG. 12  is a cross section of the upper joint taken at plane XII-XII of  FIG. 9 . 
         FIG. 13  is a cross section of the head of the lamp taken at plane XIII-XIII of  FIG. 1 . 
         FIG. 14  is a bottom view of the head of the lamp with the cover removed. 
         FIG. 15  is a top view of the head of the lamp with the cover sheet omitted, and the housing shown in phantom lines. 
     
    
    
     DETAILED DESCRIPTION 
     Exemplary embodiments of this disclosure are described below and illustrated in the accompanying figures, in which like numerals refer to like parts throughout the several views. The embodiments described provide examples and should not be interpreted as limiting the scope of the invention. Other embodiments, and modifications and improvements of the described embodiments, will occur to those skilled in the art and all such other embodiments, modifications and improvements are within the scope of the present invention. Features from one embodiment or aspect may be combined with features from any other embodiment or aspect in any appropriate combination. For example, any individual or collective features of method aspects or embodiments may be applied to apparatus, product or component aspects or embodiments and vice versa. 
     Turning to  FIGS. 1 and 2 , a lamp  20  is shown according to one embodiment. The lamp  20  is shown with a base  22 . The base  22  may be configured to rest on a support surface such as a desktop or the floor. The illustrated embodiment may be commonly referred to as a task light by one of ordinary skill. In other embodiments, the base  22  may be configured for mounting to a wall or a vertical panel, or may comprise a clamp or other more permanent mounting fastener. In other words, the base  22  may take a large variety of known configurations. As such, one or more of the novel features of the present disclosure may be applied to task lights, floor lights, reading lights, etc. 
     The illustrated embodiment of the lamp  20  includes a base stem  24  having a projection  26 . The base stem  24  may be configured to rotate relative to the base  22 . In the illustrated embodiment, the base stem  24  is configured to rotate about an axis perpendicular to the support surface on which the base  22  is configured to rest. 
     Staying with  FIGS. 1 and 2 , a lower arm  28  is attached to the base stem  24  at a lower joint  30 . The lower joint  30  is shown as a pivot connection between the lower arm  28  and the base stem  24 . The pivot axis of the lower joint  30  is shown as generally perpendicular to the axis of rotation of the base stem  24 , such that the lower arm  28  has a substantial ability to move relative to the base  22 . 
     The lamp  20  as shown in  FIGS. 1 and 2  also includes an upper arm  32 . The upper arm  32  is joined to the lower arm  28  at an intermediate joint  34 . The intermediate joint  34  is configured to allow relative motion between the lower arm  28  and the upper arm  32  with respect to one or more reference axes. As discussed further below, the intermediate joint  34  is also configured to allow for the passage of electrical current from a location upstream (i.e., toward the base  22 ) of the intermediate joint  34  to a location downstream (i.e., toward a head  36 ). While the lamp  20  in the illustrated embodiment includes an upper arm  32  and a lower arm  28 , additional arms, and respective joints, are also contemplated. Alternatively, embodiments of the lamp  20  may only comprise a single arm. 
     The upper arm  32  supports the head  36  of the lamp  20 . The head  36  may be attached to the upper arm  32  by an upper joint  38 . The upper joint  38  may be configured to allow relative movement between the head  36  and the upper arm  32  with respect to one or more reference axes. As discussed further below, the upper joint  38  is also configured to allow for the passage of electrical current from a location upstream (i.e., toward the base  22 ) of the upper joint  38  to a location downstream passed the upper joint  38  and into the head  36  for powering a primary light source  40  located within the head. 
     Again, the lamp  20  according to the present disclosure is defined by the claims and not by the illustrated embodiment shown in  FIGS. 1 and 2 . The lamp  20  may be a task light as illustrated, may be a floor lamp with even longer arms, may include only one arm, or no arms at all. The lamp  20  may rest on a horizontal surface, be fixed to a vertical surface, or otherwise attach to a reference point. In its simplest form of a first embodiment, the lamp  20  includes a head  36  with a primary light source  40 . The head  36  is attached to a support  41  that comprises at least one joint, the upper joint  38  for example. The lamp  20  is wired so that current passes upstream and downstream of the joint at least when the primary light source  40  is activated. In its simplest form of a second embodiment, the head  36  itself incorporates unique function and structure as discussed below, and the at least one joint may be optional. 
     Turning to  FIG. 3 , the lower arm  28  is shown in cross section along the length of the lower arm. The lower arm  28  is formed primarily of an electrically conductive material, such as metal. Example materials include aluminum, steel, copper or conductive carbon or nanocarbon composite material. In one embodiment, the lower arm  28  is manufactured by casting or additive manufacturing (3-D printing) to allow the lower arm to be formed with an inner cavity  42  and side openings  44 . Wiring channels  46 , see  FIG. 4 , are formed along an exterior side of the lower arm  28 . The casting method allows for the lower arm  28  to be formed with an elongated shape without having a constant profile along its length, and without significant additional machining steps during manufacturing. Forming the lower arm  28  by extrusion is also possible, but requires significant additional machining because the extrusion process would generate a conduit of constant profile, as known in the art. Forming the lower arm  28  with one or more side openings  44  eases assembly of the lamp  20  by allowing access to components from the side of the lower arm  28  instead of only having access from the ends of an extruded arm. 
     As seen in  FIG. 3 , the lower arm  28  at least partially houses a spring counterbalance system  48 . The spring counterbalance system  48  assists with a smooth feel as the user moves the head  36  and arms  28 ,  32  relative to the base  22 , thereby assisting the user to oppose the force of gravity. The spring counterbalance system  48  includes a lower spring  50  to assist motion at the lower joint  30 , and an upper spring  52  to assist motion at the intermediate joint  34 . The lower spring  50  may be fixed at an upper end thereof within the lower arm  28 . A first cable  54  may be attached to a lower end of the lower spring  50 . The first cable  54  may exit the lower arm  28  and be fixed to the projection  26 . Thus, the lower spring  50  may be biased toward a contracted position that occurs when the lower arm  28  is lifted to be closer to the tip of the projection  26 . 
     Similarly, the lower end of the upper spring  52  may be fixed within the lower arm  28 . A second cable  56  may be relatively fixed to the upper arm  32  and pass into the lower arm  28  for attachment to the upper spring  52 . The upper spring  52  is biased toward a contracted position that occurs when the upper arm  32  is lifted to be closer to parallel with the lower arm  28 . While one embodiment of the spring counterbalance system  48  has been shown and described, other spring counterbalance systems are well-known in the art for assisting with motion of lamp components. One skilled in the art will appreciate that other spring counterbalance systems or even other counterbalance systems without springs may be suitable for use with lamps  20  as described herein. 
     The upper arm  32  may also be formed from a cast metal material to provide electrical conductivity along the upper arm. The upper arm  32  may also include side openings  44  and at least one wiring channel  46 , as shown in  FIG. 5 , to facilitate assembly and wiring of the lamp  20 . 
     As seen in  FIGS. 1 and 2 , cover sheets  58  may be attached to the sides of the lower arm  28  and the upper arm  32  to hide the sides of each arm and provide a clean finished appearance to the lamp  20 . The cover sheets  58  may be attached by any known method, including adhesive, friction fit, fasteners, etc. The combination of the construction of the arms  28 ,  32 , the internal components of the intermediate and upper joints  34 ,  38  as discussed below, and the cover sheets  58  provide the lamp  20  with its clean appearance with substantially hidden joints. The cover sheets  58  may be colored to provide a desired overall color scheme, to match other cover sheets placed atop other lamp elements, such as the base  22  or the head  36 . 
     Turning to  FIGS. 5-8 , the intermediate joint  34  is shown in more detail. The lower arm  28  includes a first bore  60  passing through the lower arm near an upper end thereof. The upper end of the lower arm  28  may have a U-shape configured to straddle a portion of a first spacer  62 . The first spacer  62  may be fixed to and extend from the upper arm  32 . As seen in  FIGS. 6 and 7 , the first spacer  62  includes a first aperture  64  configured to align with the first bore  60  of the lower arm  28 . In one embodiment, a torque insert  66  passes through the first bore  60  and the first aperture  64  to act as a pin connecting the lower arm  28  to the upper arm  32 . The torque insert  66  allows relative rotation between the arms  28 ,  32  but includes an internal resistance for prevent unwanted rotation. As known in the art, torque inserts are designed to produce a predetermined resistance to rotation. The mechanics that allow torque inserts to provide resistance are known in the art. Example torque inserts are able from Leeco of Taiwan or from Reell of St. Paul, Minn. The torque inserts  66  used in the lamp  20  are configured to allow relative rotation between the arms  28 ,  32  when manipulated by the user, but are simultaneously configured to provide sufficient resistant that rotation at the intermediate joint  34  is not caused by gravity alone. Unwanted movement may be referred to in the industry as droop. In another embodiment a hinge (not shown) can be used that does or does not provide integrated torque resistance. The use of a hinge (defined herein to mean any component that permits with or without torque at least some rotational movement between rigid structures such as arms  28 ,  32 ), would permit manipulation by a user. Electrical conductive elements of the hinge could provide the electrical conductive paths as described herein. Further, the ability of the arms  28 ,  32  to remain in a selected orientation can be provided by using the counterbalance system  48 , or components such as those known in the art including without limitation a friction hinge such as those available from GEM Products, Inc., of Orange Park, Fla., a constant torque hinge, a position hinge, a clutch, a torque hinge, a detent hinge, or set screws or adjustable protrusions adjacent the hinge to provide friction retention between arms  28 ,  32 . 
     The torque insert  66  is press-fit into a friction fit within the first bore  60  and the first aperture  64  as may be best understood from  FIG. 8 . The circumference of the first bore  60  and the circumference of the first aperture  64  may be keyed or otherwise deviate from a circular shape to match the outer periphery of the torque insert  66 . The keyed shape helps to minimize slip between the torque insert  66  and either the lower arm  28  or the upper arm  32 . While not shown, a torque insert  66  may also be used at the lower joint  30  to selectively allow pivotal motion between the base stem  24  and the lower arm  28 , while providing resistance to avoid droop. 
     The exterior housing  68  of the torque insert  66  is made from metal or another electrically conductive material, as seen in  FIG. 6 . The press-fit between the torque insert  66  and at least a portion of the first bore  60  through the conductive lower arm  28  provides a continuation of a first conductive path from the lower arm into the exterior housing  68  of the torque insert. The first conductive path continues from the torque insert  66  into the first spacer  62  due to the press-fit between the torque insert and the first aperture  64 . The first conductive path is able to continue because at least a portion of the first spacer  62  extending from the first aperture  64  is formed from a conductive material, such as steel or aluminum in one embodiment. 
     The first conductive path continues further from the first spacer  62  to the upper arm  32 . As seen in  FIG. 5 , metal screws  70  simultaneously join the first spacer  62  with the upper arm  32  and provide contact to continue the conductive path from the first spacer  62  into the upper arm  32 . The first spacer  62  may be joined to the upper arm  32  with other fasteners. Alternatively, the first spacer  62  may be integrated with the upper arm  32  in such a manner that contact between electrically conductive materials continues. 
     To summarize, the first conductive path proceeds from the lower arm  28  to the upper arm  32  by way of the first spacer  62  and the torque insert  66 . The first conductive path may be characterized by the use of the upper and lower arms  28 ,  32  themselves as part of the first conductive path. The first path does not require, in this embodiment, a wire running from within the lower arm  28  to within the upper arm  32 . 
     A second conductive path extends through the intermediate joint  34  with the use of a first sliding electrical contact  80 . Therefore, the second conductive path, in this embodiment, is also formed without the need for a wire running from within the lower arm  28  to within the upper arm  32 . The first sliding electrical contact  80  may be best seen in  FIG. 6 . The first sliding electrical contact includes a lower arm lead  82  and a first spacer lead  84 . The lower arm lead  82  may reside within a first lead groove  86  formed in the lower arm  28 . The first lead groove  86  may include the first bore  60  as a portion thereof. The lower arm lead  82  may be held in position within the first lead groove  86  by an electrically insulating first cap  88 . The lower arm lead  82  may include a first terminal  90  and a first wave washer  92 . The first wave washer  92  is configured to axially align with the first bore  60  and the first aperture  64 . An inner radius of the first wave washer  92 , however, is sufficient to avoid contact with the torque insert  66 . As seen in  FIG. 8 , a portion of the first cap  88  may extend radially between the torque insert  66  and the first wave washer  92  in order to electrically isolate the first wave washer from the torque insert. 
     Maintaining electrical isolation between the first conductive path and the second conductive path is important to avoid shorting the circuit created by the lamp  20 . As the current and voltage increase, the potential for arcing of current from one path to the other increases. To avoid arcing, the separation distance and/or the robustness of the insulator between the first and second conductive paths would need to increase. In one embodiment, the risk of arcing is low through the lamp  20  because the lamp may operate with low amperage. 
     As seen in  FIG. 7 , the first spacer lead  84  may be incorporated with the first spacer  62  as a module. To maintain electrical separation between the first conductive path, which passes through a body  94  of the first spacer  62 , and the second conductive path, which passes through the first spacer lead  84 , an insulating sheath  96  may be provided. The insulating sheath  96  is disposed between the body  94  of the first spacer  62  and the first spacer lead  84 . The first spacer lead  84  may include a first annular contact  98  and a second terminal  100 . The first annular contact  98  is configured to be axially aligned with the first bore  60  and the first aperture  64 . The first annular contact  98  continues the second electrical path by contacting at least a portion of the first wave washer  92  of the lower arm lead  82 . The first annular contact  98  also has an inner radius of sufficient size to avoid contact with the torque insert  66 , and may be separated from the torque insert by a portion of the first cap  88 . One of ordinary skill in the art will appreciate that while the illustrated embodiment has the first wave washer  92  associated with the lower arm lead  82 , the wave washer could instead be associated with the first spacer lead  84  in place of the first annular contact  98 . Alternatively still, the first sliding electrical contact may have two flat annular contacts and not a portion with a wave configuration. 
     The assembly of the intermediate joint  34  of the illustrated embodiment is completed by attaching a fastener  102  to the torque insert  66  as seen in  FIG. 8 , which in turn presses the first cap  88  toward the first spacer  62  to help ensure a sufficient pressing contact between the first wave washer  92  and the first annular contact  98  to extend the second conductive path from the first terminal  90  located upstream of the pivot point of the intermediate joint  34  to the second terminal  100  located downstream of the pivot point. One skilled in the art will appreciate that as the lower arm  28  is rotated relative to the upper arm  32 , the first wave washer  92  will rotate with respect to the first annular contact  98  while maintaining at least one point of contact therewith. 
     By designing the intermediate joint  34  to provide the first and second conductive paths through distinct types of electrical relay as discussed above, the packaging space and the size of the torque insert  66  are reduced, allowing for more slender arms  28 ,  32  and a joint whose components are capable of being packaged within the width of the respective arm. Alternative constructions that use a pair of sliding electrical contacts in a single joint, or a bifurcated arm to conduct both paths therethrough, have been found to require a greater structure that can degrade the appealing and elegant nature of the design. 
     Turning to  FIGS. 9-12 , the upper joint  38  is shown in more detail. The features of the upper joint  38  are similar in many ways to the intermediate joint  34 . A second bore  110  passes through an upper end of the upper arm  32 . At least a portion of the upper arm  32  comprises an electrically conductive material extending continuously from the first spacer  62  to the second bore  110  such that the first conductive path extends substantially the entire length of the upper arm  32 , and includes the conductive material of the upper arm itself. A torque insert  66  having a metal exterior housing  68  is press-fit into the second bore  110  to continue the first conductive path in a similar fashion as described with respect to the intermediate joint  34 . 
     A second spacer  112 , at least partially comprising an electrically conductive material, is used to connect the upper arm  32  to the head  36  at the upper joint  38 . The second spacer  112  is shown in detail in  FIG. 11 . The second spacer  112  has a second aperture  114  to axially align with the second bore  110 . The second spacer  112  is attached to the upper arm  32  by the torque insert  66 , which also provides the continuation of the first conductive path from the exterior housing  68  into the second spacer  112 . 
     A second sliding electrical contact  120  is provided for forming a portion of the second electrical path through the upper joint  38 . Like the first sliding electrical contact  80 , the second sliding electrical contact  120  is at least partially positioned by a second cap  122  inserted into the second bore  110  and a second lead groove  124  of the upper arm  32 . The second cap  122  positions and electrically isolates an upper arm lead  126  of the second sliding electrical contact  120  from the upper arm  32 . The upper arm lead  126  comprises a third terminal  128  and a second wave washer  130  similar to the lower arm lead  82  described above. 
     As seen in  FIG. 11 , the second spacer  112  includes a spacer lead  132  electrically isolated from the electrically conductive spacer body  134  of the second spacer by an insulation layer  136 . The spacer lead  132  may include a second annular contact  138  to align with and contact the second wave washer  130 . The spacer lead  132  also includes a fourth terminal (not shown). In the illustrated embodiment, the second spacer  112  is configured as a conduit with a passage  140  running longitudinally therein. The spacer lead  132  is configured such that the fourth terminal resides at least partially within the passage  140 , and is electrically isolated from the conductive material of the spacer body  134  of the second spacer  112 . 
     The assembly of the upper joint  38  of the illustrated embodiment is completed by attaching a fastener  102  to the torque insert  66  as seen in  FIG. 12 , which in turn presses the second cap  122  toward the second spacer  112  to help ensure a sufficient pressing contact between the second wave washer  130  and the second annular contact  138  to extend the second conductive path from the third terminal  128  located upstream of the pivot point of the upper joint  38  to the fourth terminal located downstream of the pivot point within a passage  140  of the second spacer  112 . 
     As seen in  FIG. 11 , the second spacer  112  also includes a sleeve  142  at least partially surrounding a portion of the second spacer. The sleeve  142  is formed from an electrical insulator to prevent the continuation of the first conductive path directly from the spacer body  134  of the second spacer  112  to the head  36 . Isolating the head  36  from the charged spacer body  134  helps prevent interference with the electronics within the head  36 . 
     Having described the mechanical structure of the support  41  of the lamp  20 , use of that structure to provide current to the head  36  can now be more readily understood. The lamp  20  of the illustrated embodiment is configured to receive power in the form of AC current commonly available from wall sockets as known in the art. The lamp  20  has a power cord  150  that terminates at one end with a two-pronged plug as known in the art. The power cord  150  includes a first hot wire  152  (also known as a positive current wire) and a first neutral wire  154  (as known as a ground wire or negative current wire). As seen in  FIG. 1 , the power cord  150  may pass into the lower arm  28  through a cord opening  156 . The power cord  150  may then immediately exit the side of the lower arm  28  through a side opening  44  and run along the wiring channel  46  as shown in  FIG. 4 . 
     Prior to reaching the upper end of the lower arm  28 , the wiring channel  46  may split, and the first hot wire  152  is separated from the first neutral wire  154 . In the illustrated example, the first neutral wire  154  is then connected into the first conductive path. For example, the first neutral wire  154  may be stripped and soldered to a crimp terminal  158  which is in electrical contact with the electrically conductive material of the lower arm  28 . The lower arm  28  is then electrically charged when the plug is engaged with a source of current. The first hot wire  152 , on the other hand, is feed into connection with the second conductive path by joining the first hot wire with the first terminal  90  of the first sliding electrical contact  80 . While there may be some advantages to connecting the first neutral wire  154  to the first conductive path, the lamp  20  may operate sufficiently if the first hot wire  152  were connected to the first conductive path and the first neutral wire was then connected to the second conductive path. 
     Continuing on, the first conductive path passes the intermediate joint  34  as discussed above, without requiring a wire passing through the intermediate joint. After passing the intermediate joint  34 , the first conductive path continues on to the upper joint  38  by way of the conductive material of the upper arm  32  itself. 
     The second conductive path passes the intermediate joint  34  through the first sliding electrical contact  80  as discussed above, without requiring a wire passing though the intermediate joint. The second conductive path then comprises a second hot wire  160  run along the upper arm  32  and connected between the second terminal  100  of the first sliding electrical contact  80  and the third terminal  128  of the second sliding electrical contact  120 . 
     Upon arriving at the upper joint  38 , the first conductive path continues from the upper arm  32  to the second spacer  112  via the exterior housing  68  of the torque insert  66  as discussed above. The second electrical path passes through the upper joint  38  by way of the second sliding electrical contact  120  as discussed above. 
     Then, in order to accommodate the input requirements of the electronics within the head  36 , the first and second conductive paths should be recaptured within a second neutral wire  162  and a third hot wire  164  respectively. In the illustrated embodiment, the third hot wire  164  connects to the fourth terminal of the second sliding electrical contact  120  and runs through the passage  140  of the second spacer  112  into the head  36 . Similarly, an additional terminal  166  receives the first conductive path from the conductive material of the spacer body  134  and transfers the first conductive path to the second neutral wire  162 , which may also be feed through the passage  140  and into the head  36 . 
     Turning to  FIGS. 13-15 , the head  36  is shown in more detail. The head  36  comprises a housing  200 . The housing  200  at least partially provides an enclosure and acts as a heat sink for the primary light source  40 . Thus, the housing  200  is preferably made from a thermally conductive material, such as cast aluminum. The primary light source  40  may include one or more light emitting diodes mounted to a circuit board  202  within the housing  200 . The primary light source  40  and the circuit board  202  are then arranged relative to the housing  200  such that the housing  200  accepts and dissipates the heat generated by the primary light source. As known in the art, proper heat sinking of mid and high power light emitting diodes can increase their usable life. 
     The primary light source  40  may also include a reflector  204  and a lens  206  configured to distribute light from the one or more light emitting diodes into a desired pattern. Light emitted from the primary light source  40  is generally directed in a first direction relative to the housing  200 . The first direction is often downward onto a support surface for the lamp  20 . 
     One or more indicator light sources  208 , such as light emitting diodes, may also be provided within the head  36 . In the illustrated embodiment, the indicator light sources  208  are mounted to the circuit board  202  to emit light in a second direction, substantially opposite the first direction. The housing  200  may include one or more openings  210  aligned with the indicator light sources  208  to allow light emitted from the indicator light sources to pass through the housing. An applique  212  may be applied to the housing  200  over the openings  210  to hide the presence of the openings when light is not being emitted from the indicator light sources. 
     A cover  214  may be attached to the housing  200  to complete the enclosure of the circuit board  202  and other driving components within the head  36 . 
     The electronics associated with the head  36  of the lamp  20  may optionally include several commonly used elements individually or in combinations, such as a driver, AC/DC converter, microprocessor, firmware, etc., as known in the art. The electronics may also include one or more sensors to facilitate one or more functions of the lamp. A first sensor may include a proximity sensor  220 . The proximity sensor  220  may operate using capacitive sensing technology or other close range proximity sensor technology. The proximity sensor  220  may be mounted to the circuit board  202 . In one embodiment, where the proximity sensor  220  is a capacitive sensor, the circuit board  202  is electrically connected to the housing  200  such that the proximity sensor  220  is electrically connected to the housing  200 . When a charge is applied to the housing  200 , substantially the entire housing  200  acts as part of the proximity sensor  220  to detect an approaching object, such as a user&#39;s hand, as is known in the art. 
     As is known in capacitance sensing, the user&#39;s hand forms the second half of a capacitor. As the distance between the hand and the housing  200  decreases, small changes in capacitance occur and can be monitored by firmware logic or a microprocessor. The proximity sensor  220  is preferably configured to detect when the user&#39;s hand, or other body part, is approaching the head  36  of the lamp  20 , without requiring contact. In certain embodiments, the proximity sensor  220  is a capacitance sensor configured to detect approaching objections within a distance of 12 inches or less, 6 inches or less, 4 inches or less, or 3 inches or less from the housing  200  without requiring physical contact between the user and the housing  200 . The sensitivity of the proximity sensor  220  will vary depending on whether the user approaches the housing  200  with their entire palm versus the tip of a finger. In other embodiments, it is possible that the proximity sensor  220  only detects actual contact between the user and the housing  200 . 
     The proximity sensor  220  may employ dynamic sensing to avoid false positives. Specifically, the proximity sensor  220  is monitored for a change in capacitance, for example, as opposed to a predetermined threshold capacitance. If monitored for a predetermined capacitance threshold, other objects in the vicinity of the head  36  could produce noise that are picked up as half of the monitored capacitor. For example, a computer display monitor near the head  36  may create a false positive. To compensate, the proximity sensor  220  is monitored for a change. Thus the capacitance level occurring with the computer monitor nearby is factored out and set as the initial capacitance. Introduction of the user&#39;s hand into range of the proximity sensor  220  than causes a change in capacitance allowing the lamp  20  to react as discussed below. 
     In one embodiment, the proximity sensor  220  is operably connected to the indicator light sources  208 . Applicant has found that the indicator light sources  208  should principally remain off when the lamp  20  is not in-use, as well as when the primary light source  40  is illuminated. Having the indicator light sources  208  continuously illuminated while the primary light source  40  is on may be distracting to a user. Thus, when the proximity sensor  220  detects an approaching object, one or more of the indicator light sources  208  may be triggered to illuminate. The indicator light sources  208  would extinguish when the user&#39;s hand is withdrawn or after a predetermined period of time, such as five seconds. 
     The indicator light sources  208  may serve several purposes. First, illumination of the indicator light sources  208  provides visibility of their location through the applique  212 . The indicator light sources  208  may act as a location indicator of a user interface  222  of the lamp  20 . The number or pattern of the indicator light sources illuminated may provide the user with an indicator of the operational mode of the lamp  20 . Operational modes may include, “on”, “off”, various brightnesses, “night mode” to provide a very dim light only, “demo” mode, or to enable or disable certain functions of the lamp  20 . 
     In one embodiment, the primary light source  40  is controlled through the user interface  222 . The user interface  222  may allow the user to provide commands that turn the primary light source  40  on and off. The user interface  222  may also accept commands to adjust the intensity of the primary light source  40 , such as 100%, 50% and a very dim night mode. In an embodiment, the user interface  222  includes the plurality of indicator light sources  208 . The indicator light sources  208  may be arranged in a linear array as shown in  FIG. 15 . The indicator light sources  208  may be driven such that all of the indicator light sources illuminate when the primary light source  40  is at full brightness, and successively fewer of the indicator light sources illuminate as the primary light source is dimmed. 
     The user interface  222  may also include a track pad  224 , exposed through a slot  226  in the housing  200 . The track pad  224  may also be described as a touch surface or a slider. The track pad  224  may be part of a capacitance sensor  228  configured to detect the proximity or contact with a user, and translate the actions of the user into operational signals for driving the primary light source  40 . Capacitance sensor technology is generally known in the art and commonly found in user interfaces outside of the lighting industry, such as touch screen computer displays. As such, one of ordinary skill in the art will understand that various gestures on or near the track pad  224  can result in adjustment in the operation of the primary light source  40 . For example, the primary light source  40  may turn on and off in response to a tap upon the track pad  224 . The primary light source  40  may be controlled to automatically return to the previous brightness setting. If the user slides their finger along the track pad  224 , the primary light source  40  may increase or decrease intensity based on the direction of sliding. A touch of the track pad  224  may also set the brightness based on the location along the track pad being touched. A double tap may jump to maximum brightness. In an embodiment, the capacitance sensor  228  is configured to detect the user&#39;s hand or finger generally when there is contact with the track pad  224  or at least the portion of the applique  212  directly above the slot  226 . 
     In addition to the user controlled functions of the lamp  20  discussed above, the head  36  may include a third sensor, such as a passive infrared sensor  230  configured to automatically control one or more operations of the lamp  20 . In one example, the infrared sensor  230  is positioned behind a protective cover  232  and is provided with a wide field of vision. The infrared sensor  230  acts as a motion detector using infrared beam technology to detect motion of warm objects, such as humans, based on whether or not the object has crossed the beams being emitted. In practice, the infrared sensor  230  is operable to sensor the presence of a user at their workstation. If the primary light source  40  is illuminated, and the passive infrared sensor  230  has failed to detect motion for a predetermined period of time (e.g. 15 minutes), the electronics within the head  36  may trigger the primary light source  40  to extinguish. This feature prevents unnecessary or undesired use of energy. In some embodiments, the primary light source  40  may be triggered to illuminate, returning to the most recent illumination mode, when motion is detected by the infrared sensor  230  once again. When motion returns, the indicator light sources  208  may also temporarily illuminate to indicator to the user what the most recent illumination mode was. The user may have the option to disable and re-enable the infrared sensor  230 , for example, by touching and holding at a portion of the track pad  224 . A pattern of the indicator light sources  208  may flash to indicator when the operation mode (enabled versus disabled) of the infrared sensor has occurred. In other embodiments, the infrared sensor  230  may be disabled in the night mode of the lamp  20 , so that the lamp remains on as a nightlight even after motion in the vicinity has stopped. Night mode may be achieved by holding the lowest position of the track pad  224 . Again, night mode may be indicated by its own unique pattern of illuminated indicator light sources  208 . In night mode, the intensity of the indicator light sources  208  may be dimmed, and the primary light source  40  set to its lowest intensity. The night mode may be highly applicable to use of the lamp  20  within the hospitality industry. The lamp may also have a demo mode, in which the infrared sensor  230  is adjusted to extinguish the primary light source  40  after only a few seconds of inactivity, instead of several minutes. 
     The present disclosure illustrates and discusses several embodiments for a lamp  20  with a support  41  having joints  34 ,  38  that facilitate transmittal of current in a clean and compact form factor that avoids exposed wires adjacent to the joints and hides the appearance of a pivot pin. One of ordinary skill in the art that the current transmitting joints (e.g. intermediate joint  34  and upper joint  38 ) may be used as part of a mounting or supporting apparatus for other electronic devices besides lamps. For example, a support  41  according to the present disclosure may be used to provide current up to a display or computer monitor. In another embodiment, instead of task lighting, the head  36  may be designed as a vanity mirror with illumination. 
     The lamp  20  with one or more joints as discussed above may be summarized in terms of the following paragraphs: 
     Paragraph A: A lamp, comprising: 
     a head having a light source; and 
     at least one support arm supporting the head at a joint, the joint configured to allow relative motion between the at least one support arm and the head, 
     wherein the joint comprises a sliding electrical contact and a torque insert, and 
     wherein the at least one support arm is electrically conductive, and a ground wire is grounded to the support arm, which is in electrical contact with the torque insert. 
     Paragraph B: A lamp, comprising: 
     a head having a primary light source, the head connected to a support, the support comprising:
         a first support portion at least partially comprising an electrically conductive material;   a second support portion at least partially comprising an electrically conductive material;   a first joint comprising a torque insert formed with a conductive exterior housing, the first joint connecting the first support portion to the second support portion to allow relative movement between the first support portion and the second support portion;       

     wherein the first joint provides two current conducting paths from the first support portion to the second support portion, 
     wherein the first current conducting path comprises electrically charging the first support portion, and contact conduction from the electrically conductive material of the first support portion to the electrically conductive material of the second support portion through the exterior housing of the torque insert, and 
     wherein the second current conducting path comprises a sliding electrical contact electrically isolated from the conductive material of the first support portion, the conductive material of the second support portion, and the torque insert. 
     A lamp  20  with one or more unique sensor-based functions as discussed above may be summarized in terms of the following paragraphs: 
     Paragraph C: A lamp, comprising: 
     a housing made at least partially from an electrically and thermally conductive material; 
     a primary light source positioned within the housing such that the housing dissipates heat generated by the primary light source, the primary light source configured to emit light in a first direction relative to the housing; 
     at least one indicator light source positioned relative to the housing to emit light in a second direction relative to the housing, the second direction being substantially opposite the first direction; and 
     a first sensor electrically connected to the housing, wherein the first sensor is a capacitive proximity sensor that triggers illumination of the at least one indicator light source when a user&#39;s hand approaches the housing. 
     Paragraph D: The lamp according to Paragraph C, wherein the capacitive proximity sensor uses dynamic sensing to monitor for a change of capacitance as an object approaches the housing. 
     Paragraph E: The lamp according to Paragraph C, further comprising a second sensor, the second sensor being a capacitive sensor with a track pad, the track pad arranged adjacent to the at least one indicator light source and configured to receive commands to alter operation of the primary light source. 
     Paragraph F: The lamp according to Paragraph E, further comprising a third sensor, the third sensor being a motion sensor, the motion sensor configured to extinguish the primary light source when no motion has been detected for a predetermined amount of time. 
     The lamp  20  may be manufactured with a wiring method described by the following paragraphs as supported by the discussion above. 
     Paragraph G: A method of wiring a lamp, the lamp comprising a head having a light source and a first support portion, made from electrically conductive material, movable with respect to a second support portion made from electrically conductive material, the method comprising: 
     feeding a cord into the first support portion, the cord comprising a first wire and a second wire; 
     electrically connecting the first wire to the first support portion, 
     electrically connecting the first support portion to the second support portion, 
     electrically connecting a third wire from the second support portion to the light source, 
     electrically connecting the second wire to a sliding electrical contact that is electrically isolated from the conductive material of the first support portion and the electrically conductive material of the second support; and 
     electrically connecting a fourth wire from the sliding electrical contact to the light source. 
     Paragraph H: The method of Paragraph G, wherein the lamp further comprises a third support portion disposed between the first support portion and the second support portion, and the sliding electrical contact comprises a first sliding electrical contact and a second sliding electrical contact; 
     wherein electrically connecting the first support portion to the second support portion comprises:
         electrically connecting the first support portion to the third support portion, and   electrically connecting the third support portion to the second support portion;       

     wherein, electrically connecting the second wire to the sliding electrical contact comprises connecting the second wire to the first sliding electrical contact; 
     wherein, electrically connecting the fourth wire comprises electrically connecting the fourth wire to the second sliding electrical contact; and 
     the method further comprises electrically connecting a fifth wire between the first sliding electrical contact and the second sliding electrical contact. 
     The lamp  20  may be manufactured with a method described by the following paragraph as supported by the discussion above. 
     Paragraph I: A method of making a support for a lamp, comprising: 
     casting at least one support arm from an electrically conductive material, the at least one support arm being cast such that the at least one support arm does not have a constant profile along a length thereof; 
     inserting a wire into an inner cavity of the at least one support arm; 
     running a portion of the wire along an exterior of the at least one support arm; 
     attaching a cover sheet to the at least one support arm to hide the portion of the wire. 
     The lamp  20  may be described by the following paragraphs in means-plus-function format as supported by the discussion above. 
     Paragraph J: A lamp comprising: 
     a head having a light source; and 
     at least one support arm supporting the head at a joint, the joint configured to allow relative motion between the at least one support arm and the head, the joint comprising:
         conductive means for providing a pair of electrically separate current paths through the joint.       

     Paragraph K: The lamp of paragraph J, further comprising an indicator light source; and sensor means for triggering activation of the indicator light source. 
     Although the above disclosure has been presented in the context of exemplary embodiments, it is to be understood that modifications and variations may be utilized without departing from the spirit and scope of the invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the appended claims and their equivalents.