Patent Publication Number: US-7213961-B2

Title: Low voltage luminaire assembly

Description:
FIELD OF THE INVENTION 
   The present invention relates to a low voltage luminaire assembly. More particularly, the present invention relates to a low-voltage luminaire assembly having a quick-release transformer and at least one quick-release lamp holders that are mountable to a surface. Still more particularly, the present invention relates to a method of installing, removing and replacing components of a low voltage luminaire assembly. 
   BACKGROUND OF THE INVENTION 
   Light fixtures are used in homes and buildings to provide various forms of illumination. Some light fixtures serve both functional and aesthetic purposes, such as for illumination of work surfaces below cabinets and in cabinetry and furniture in constricted areas. 
   In one form, strings of low-voltage accent lights are provided as part of an under-cabinet installation kit to be used by builders or by after-market consumers. These under-cabinet lights are typically mounted to surfaces under kitchen cabinetry or recessed into shelf portions of cabinets to provide additional lighting for countertops. Such under-cabinet lights often use tracks or “raceways” that are used to mount individual lamp assemblies. Electrical wires are routed in the raceways. The lamp assemblies typically pierce the electrical wires when the lamp assemblies are mounted to the raceways. 
   Conventional under-cabinet lights suffer from various drawbacks. For instance, their raceways are usually made of a rigid material with a fixed orientation such as a straight line, which limits orientation of the under-cabinet lights. Since the raceways must be measured and cut to fit specific surfaces, installation of known under-cabinet lights can be time-consuming. Also, if a raceway is measured incorrectly, additional time and materials are wasted. Furthermore, if an electrical wire is pierced incorrectly when installing individual lamp assemblies on the raceway, the entire under-cabinet light may have to be replaced. Moreover, failure of a transformer supplied with some under-cabinet lights to convert 120 volts to 12 volts usually requires replacement of the entire under-cabinet light. 
   A modular, quick-release, under-cabinet luminaire assembly is desirable that is easily installed and serviced. 
   SUMMARY OF THE INVENTION 
   The present invention provides a low-voltage, under-cabinet lighting fixture or luminaire assembly for permanent or temporary and surface or recessed mounting. In general, the luminaire assembly is low-profile and modular with quick-release electrical connections to connect individual lamp assemblies and a transformer to objects quickly and easily. Further, the component parts of the modular luminaire assembly are simple, reliable, and economical to manufacture and use. 
   In one aspect of the invention, a luminaire assembly is provided with a transformer, a plurality of lamp holders, a plurality of input and output electrical wires, a rotary dimmer switch, and an electrical plug component. The transformer and the plurality of lamp holders have respective supply and output apertures with quick-release electrical connections for the electrical wires. The transformer and lamp holders are prearranged to evaluate functional and aesthetic requirements, for instance, in an under-cabinet area. Once these requirements are satisfied, the transformer and lamp holders are adhesively or mechanically attached to the under-cabinet area, and the electrical wires are tailored to the necessary installation dimensions. 
   In another aspect of the invention, a method is disclosed for installing a luminaire assembly similar to the foregoing embodiment. The method includes the steps of fitting the transformer and lamp holders to an area; tailoring the electrical wires to the dimensions of the area; attaching the transformer and lamp holders to the area; inserting the electrical wires in the transformer and lamp holders via quick-release connections; inserting a plurality of bulbs in the lamp holders; and connecting the luminaire assembly to a source of electrical power. 
   In a further aspect of the invention, a method is disclosed for selectively removing and replacing components of a luminaire assembly similar to the foregoing embodiment. The method includes the steps of disconnecting the luminaire assembly from a source of electrical power; releasing electrical wires from one of a transformer and a lamp holder via quick-release connections; removing one of the transformer and lamp holders from an installation area; attaching one of a new transformer and new lamp holders in the installation area; reinserting the electrical wires in one of the new transformer and lamp holders and reconnecting the luminaire assembly to the electrical power source. Further steps may include attaching additional lamp holders to the luminaire assembly; replacing the transformer with a higher rated transformer; adjusting positions of one of the transformer and lamp holders; and inserting a plurality of bulbs in the new lamp holders. 
   Other objects, advantages and salient features of the invention will become apparent from the following description, which, taken in conjunction with the annexed drawings, discloses preferred embodiments of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Referring now to the drawings that form a part of this original disclosure: 
       FIG. 1  is a top perspective view of a luminaire assembly in accordance with a first embodiment of the present invention; 
       FIG. 2  is a partial, top perspective, exploded view of the luminaire assembly of  FIG. 1 ; 
       FIG. 3  is a cross-sectional view of a lamp holder taken along line  3 — 3  of  FIG. 2 ; and 
       FIG. 4  is a perspective view of a lamp holder according to a second embodiment of the present invention. 
   

   The detailed description below uses numerical and letter designations to refer to features in the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar parts of the invention. 
   DETAILED DESCRIPTION OF THE INVENTION 
   Detailed reference will now be made to the drawings in which examples embodying the present invention are shown. The drawings and detailed description provide a full and detailed written description of the invention, and of the manner and process of making and using it, so as to enable one skilled in the pertinent art to make and use it, as well as the best mode of carrying out the invention. However, the embodiments set forth in the drawings and detailed description are provided by way of explanation of the invention only and are not meant as limitations of the invention. The present invention thus includes any modifications and variations of the following examples as come within the scope of the appended claims and their equivalents. 
   It is also to be understood that references herein to such terms as “top,” “bottom,” and “side” of objects or surfaces are intended solely for purposes of providing an enabling disclosure, and in no way suggest limitations regarding the operative orientation of the luminaire assembly  10  or any components thereof. 
   As broadly embodied in  FIGS. 1–4 , a low-voltage luminaire assembly is provided with a quick-release transformer and a plurality of quick-release lamp holders. The transformer and the plurality of lamp holders are temporarily or permanently mountable to a surface or recessed area, such as an under-cabinet kitchen area, during original construction or as an after-market installation. Embodiments of applications and operations of the transformer, the lamp holders, and their quick-connect/quick-release mechanisms are described below. 
   An under-cabinet lighting fixture or luminaire assembly  10 , according to a first embodiment of the present invention, is shown in  FIG. 1 . The luminaire assembly  10  has a transformer  12 , an electrical plug component  24 , a rotary dimmer switch  30 , and a plurality of lamp holders  34   a–d . The transformer  12  has a mounting side  14  that is attachable to a surface area (not shown). A double-sided adhesive tape  16  may be used to mount the transformer  12 , but the transformer may be mounted in any suitable manner. Similarly, the plurality of lamp holders  34   a–d  have respective mounting sides  40   a–d  attachable by double-sided adhesive tape  42   a–d . In this example, a wax-type paper (not shown) is peeled away from the mounting sides  14  and  40   a–d  to expose the respective adhesive tapes  16  and  42   a–d  for adherence to the surface area. However, any attachment mechanism may be substituted for the double-sided adhesive tape  16 ,  42   a–d , such as other forms of adhesive, screws, bolts, nails, nuts, rivets, pins, snap-fittings, press-fittings, and the like. Another suitable attachment mechanism is described below with respect to  FIG. 4 . 
   The transformer  12  shown in  FIG. 1  is an Underwriters Laboratories Inc. (U.L.) Listed Class 2 unit, which meets or exceeds requirements set forth in U.L. Standards 1585 for Class 2 Transformers. In general, a Class 2 unit is any portable power unit under 60 watts (W), which is usually evident from its electrical cord. The Class 2 unit is often used for incandescent and LED lamps, solenoid coil and bell ringing circuits, and may have a single or multiple output circuit with secondary circuit protection. The Class 2 unit is powered by alternating current voltages of 120VAC, 208/240VAC or 277/480VAC, and will output direct current voltages of 12VDC or 24VDC. 
   In the example shown in  FIG. 1 , the transformer  12  is a low voltage system, less than about 120 VDC. More particularly the transformer  12  is approximately between about 20W to about 60W maximum. The purpose of the transformer  12  is to “step down” typical household power of 120VAC for use by the plurality of lamp holders  34   a–d . For example, assuming 120VAC, 60 hertz (Hz), 0.5 ampere (A) input to the transformer  12 , a single circuit of about 11.5VAC, 60W is output from the transformer  12 . Moreover, the transformer  12  may have an electrical protection system (EPS) that limits it to 60W by a built-in circuit breaker. 
   The transformer  12  has a supply aperture/quick-release fitting  18  and an output aperture/quick-release fitting  20 , as shown in  FIGS. 1 and 2 . The transformer  12  is connected to the 120VAC electrical source via the quick-release fitting  18 , an electrical input wire  22 , and the electrical plug component  24 . Similarly, the quick-release fitting  20  connects the transformer  12  to at least one lamp holder  34   a . The quick-release fittings  18  and  20  are described in greater detail below. Although a variety of transformers may be used as the transformer  12 , a suitable transformer is available from Hatch Transformers, Inc. of Tampa, Fla. 
   Since transformer wattage is determined as a function of the number of lamp holders and electrical wire gauge, specific applications may require a transformer with a rating other than as described above. Accordingly, in another embodiment of the present invention, the component parts of the luminaire assembly  10  are provided separately, or as a “kit” tailored to specific requirements. For example, the luminaire assembly  10  described above is provided with up to six (6) lamp holders  34  having a total of twelve (12) bulbs  38  ( FIG. 2 ). If additional lamp holders or lamp holders with greater bulb capacities (e.g., above 5W) are contemplated, larger gauge wire and larger capacity transformers may be provided, although specific applications and local electric codes may require Class 1 hard wiring. 
   The lamp holder  34   a  is attached to the transformer  12  by an electrical lead wire  32 , as shown in  FIGS. 1 and 2 . Additional lamp holders  34   b–d  are linked to the lamp holder  34   a  and to each other by a plurality of lamp holder lead wires  52   a–c . Each of the wires  32  and  52   a–c  may be attached via quick-release fittings  44 , as described in detail below with respect to  FIG. 2 . Alternatively, one or more of the wires  32  and  52   a–c  may be provided as permanent parts of one or more of the lamp holders  34   a–d . For instance, lead wire  32  may be permanently attached at one end to the lamp holder  34   a  for subsequent insertion of its free end in the output aperture  20  of the transformer  12 . Alternatively, lead wire  32  may be provided as a stand-alone wire for later insertion in both the transformer  12  and the lamp holder  34   a . As shown in  FIG. 1 , the various electrical wires  22 ,  32  and  52   a–c  permit the transformer  12  and the plurality of lamp holders  34   a–d  to be oriented in straight or non-linear arrangements to accommodate irregular or tight spaces. As noted, it should be understood that although  FIG. 1  shows four lamp holders  34   a–d , fewer or additional lamp holders may be provided. 
   An exploded view of a portion of the luminaire assembly  10  of  FIG. 1  is shown in  FIG. 2 . As described above, both the supply aperture/quick-release fitting  18  and the output aperture/quick-release fitting  20  are quick-connect/quick-release push-in wiring terminals. Electrical wire  22  has an input end  22   a , as shown in  FIG. 2 . An outer insulation covering made, for instance, of plastic is stripped to expose a conductive metal lead on the input end  22   a , as is shown on the opposite end  22   b  of the electrical wire  22 . More specifically, the illustrated input wire  22  is approximately 8 inches long and rated as SPT-2#18AWGx2C (gauge), 105° C., for the 120VAC power supply. The input wire  22  is cut to any desired length and has solid or twisted-and-overtinned leads that are stripped ⅜ inch to be “stabbed” into and captured by the fitting  18 . Similarly, the lead wire  32  and wires  52   a–c  ( FIG. 1 ) are approximately 12 inches long and rated as #16 gauge, 105° C., to supply the 12VDC power from the transformer  12  to the lamp holders  34   a–d . In addition to stripped conductive leads, or alternatively, some or all of the wires  22 ,  32 ,  52   a–c  may terminate in male telephone-type plugs, jacks, pins or the like for respective insertion in the fittings  18 ,  20 , and  44 , as described below. 
   The quick-release fitting  20  may have a detent or connector spring that defines a spring constant, as shown in  FIG. 2 . A stripped end  32   a  of the lead wire  32  is stabbed into the quick-release fitting  20  and held by the spring constant. As described above, the fitting  18  receives the end  22   a  of the wire  22  in a similar push-pull or stab-fit manner. Thus, the wires  22  and  32  are captured by their respective fittings  18  and  20  and held by spring constants until quickly released. Although a detent is used as fittings  18  and  20  in this embodiment, any quick-release female mechanism, such as, but not limited to, a plurality of pressure plates, leaf springs, an aperture having a plurality of capture teeth disposed circumferentially about the aperture, or similar fittings and connectors may be used. The female fittings  18  and  20  and male wires  22  and  32  may be interchangeable. For example, the wires  22  and  32  may be provided with female terminals, and the fittings  18  and  20  may be provided with male leads for respective insertion in the female terminals. 
   To release the lead wire  32  from the quick-release fitting  20 , a quick-release button  21  is provided with the transformer  12 . By pressing the button  21 , the spring constant of the quick-release fitting  20  is temporarily neutralized to release the end  32   a  of the electrical wire  32 . A similar quick-release button (not shown) is provided on the transformer  12  to quickly release the electrical wire  22  from the quick-release fitting  18 . 
   As shown in  FIGS. 1 and 2 , the electrical plug  24  has a prong component  26  and a cable piercer component  28 . The electrical plug  24  and cable piercer component  28  are rated for 120VAC. As shown, once the end  22   b  of the wire  22  is positioned in the prong component  26 , the cable piercer component  28  slides or snaps on the prong component  26  to pierce the end  22   b  with metallic blades or teeth (not shown) located on an underside of the component  26  to establish an electrical circuit. 
   A rotary switch  30  is shown in  FIGS. 1 and 2 . The rotary switch  30 , for example, is U.L. Listed 6A-1025V with a built-in electrical cable piercer (not shown). The cable piercer of the rotary switch  30  operates in a manner similar to the cable piercer component  28  to establish an electrical connection with a portion of the wire  22 . In this embodiment, the rotary switch  30  functions as a rheostat. Once the rotary switch pierces the wire  22 , the rheostat function of the rotary switch  30  permits the luminaire assembly  10  to be selectively dimmed and brightened by adjusting resistance in the electrical circuit. As the resistance is increased, electrical current is decreased and likewise, power output (W) is decreased to dim a lamp or bulb  38 . It should be noted that the electrical plug  24 , the prong component  26  and the cable piercer component  28 , as well as the rotary dimmer switch  30 , may be provided as a unitary device, or as modular components as described above. 
   The lamp holder  34  is preferably made in part of Noryl® brand, SE-1 plastic (105° C. U.L. rating 28V, 37.5W), available from General Electric Company. The lamp holder  34  has the supply aperture  44  and an output aperture  46  for attachment of the electrical wires  32  and  52   a–d . A plurality of bulb receptacles  36  in the lamp holder receive a plurality of bulbs  38 . The receptacles  36  are provided with corrosion-resistant contacts, such as a retaining spring  37  for retention of the bulbs  38 . In this embodiment, the bulbs  38 , shown in phantom in  FIG. 3 , are releasably held by a spring constant of the retaining springs  37 . A preferred bulb  38  is a wedge-base xenon lamp, which is approximately about 2W to about 10W, more particularly about 5W maximum, which does not exceed the maximum wattage of the transformer  12 . Other types of bulb bases and retention mechanisms may be substituted for the foregoing example. For instance, incandescent, fluorescent, halogen, neon, and other similar lamps may be substituted for xenon. A cylindrically shaped, screw-in bulb base with a complementary receptacle may also be suitably substituted for the wedge-base. 
   As shown in  FIG. 3 , corrosion-resistant wire guides and retaining springs  48  are located near the supply aperture  44  and the output aperture  46  for releasable attachment of the electrical wires  32  and  52   a–c . Similar to the foregoing description regarding the input end  22   a  of the wire  22  and the quick-release fitting  18 , ends of the electrical wire  32  and  52   a–d  are respectively stabbed into the lamp holder  34  via the supply aperture  44  and the output aperture  46 , captured by the retaining springs  48  and held by a spring constant. Also similar to the description of button  21  above, by pressing quick-release buttons  50  (see  FIG. 2 ), the spring constant of retaining springs  48  may be temporarily overcome to release the electrical wires  32  and  52   a–c . Although two receptacles  36  positioned opposite one another are shown in  FIGS. 1–4 , other orientations and fewer or additional receptacles  36  may be provided in the lamp holders  34 . A suitable compact, low profile lamp holder for use as a lamp holder  34  is available from Hatch Transformers, Inc. of Tampa, Fla., although any suitable lamp holder may be used. 
   A lamp holder assembly  134  according to a second embodiment of the present invention includes a lamp holder  134   a  and a mounting assembly  140  for attaching the lamp holder assembly  134  to a surface area, as shown in  FIG. 4 . In this embodiment, the mounting assembly  140  defines a securement part  142  having an arcuate opening  156  therein that receives a screw, bolt, nail, rivet, pin and the like to secure the lamp holder assembly  134  to the surface area. A guide piece  154  is also provided to flush-mount the lamp holder assembly  134  in a surface area corner or along an edge of a wall. It is to be noted that various other shapes and orientations of the foregoing elements may be provided and such variations and modifications are within the scope of the invention. Also, similar securement parts and guide pieces may be provided to mount the transformer  12 . 
   The invention may be better understood with reference to the following embodiments of operations and methods of using the present invention. 
   In one embodiment of the invention, a method for installing the low-voltage luminaire assembly  10  is provided. With reference to  FIGS. 1–3 , the method includes the steps of providing a low-voltage luminaire assembly kit having a plurality of lamp holders  34   a–d  and a transformer  12 . At least two of the plurality of lamp holders  34   a–d  are linked via lead wires  52   a–c . The at least two lamp holders  34   a–d  are attached to an object or area (not shown). The transformer  12  is attached to the object or area, A lead wire  32  is connected from one of the lamp holders  34   a–d  to the transformer  12 . The transformer  12  is connected to a source of electrical power (not shown). 
   The method of this embodiment may include further steps, such as, but not limited to, the following steps. A length of lead wire  32  and  52   a–c  required between each lamp holder  34   a–d  is measured. A lead wire  32 , 52   a–c  is then cut to the required length. An electrical plug component  24  is attached to the transformer  12  to connect the transformer  12  to the electrical power source. A dimmer switch  30  may be attached proximate the electrical plug component  24 . The dimmer switch  30  may be configured to selectively adjust a resistance in an electrical circuit between the electrical plug component  24  and the transformer  12 . A lamp  38  is inserted in one of the lamp holders  34   a–d . The wire  32  and  52   a–c  may be routed in a non-linear orientation. Moreover, an aesthetic covering (not shown) of any color, shape or material can be provided to cover the wires  32  and  52   a–c.    
   In another embodiment of the invention, a method for servicing the luminaire assembly  10  is provided. In this embodiment, the steps include disconnecting the luminaire assembly  10  from a source of electrical power (not shown). The electrical wires  22 ,  32  and  52   a–c  are released from one of a transformer  12  and a lamp holder  34  via quick-release connections  18 ,  20  and  44 . One of the transformer  12  and lamp holders  34   a–d  is removed from an installation area (not shown). One of a new transformer (not shown but similar to 12) and a new lamp holder (not shown but similar to  34   a–d ) is attached in the installation area. The electrical wires are reinserted in one of the newly attached transformer and the new lamp holder. The luminaire assembly is then reconnected to the electrical power source. 
   The foregoing method may include additional steps such as, but not limited to, the following steps. Additional lamp holders (not shown but similar to  34   a–d ) are attached to the luminaire assembly  10 . The transformer  12  is replaced with a higher rated transformer (not shown but similar to 12). A position of one of the transformer and the lamp holders is adjusted. A plurality of bulbs  38  may be removed or inserted. In the event the original adhesive tape  16 ,  42   a–d  is unusable, the transformer and lamp holders may be repositioned using another adhesive, a screw, a bolt, a nut, a rivet, a nail, a pin, a snap-fitting, a press-fitting, or any other suitable fastening means. 
   While advantageous embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.