This invention relates in general to lighting fixtures and more specifically to an adjustable lamp socket and mounting assembly, and using the mounting assembly for the rotational alignment of a lamp and socket within a luminaire.
High intensity discharge (HID) lighting is prevalent in our society. It is used for both interior and exterior applications where improved visibility is required. For interior applications, HID luminaries can be found in sports arenas, warehouses, industrial plants, office and other commercial lighting situations. For exterior applications, HID luminaries are used to illuminate roadways, parking areas, sports fields, signs, buildings, and the like. Often, a luminaire containing a HID lamp is placed several meters off the ground, and access for installation and maintenance purposes is via an overhead lift or bucket truck.
HID lamps and luminaries are manufactured according to IESNA (Illuminating Engineering Society of North America) and ANSI standards which define their photometric characteristics. To meet these standards, the lamps and fixtures are tested under laboratory conditions, and the results are reported as a manufacturer's rated values for lamp lumens, wattage, luminance and luminance performance. However, when comparing laboratory test results with actual field measurements, the results can differ. Such differences can be due to several variables such as manufacturing variations, arc tube alignment, lamp position, and field installation conditions, to name a few.
Manufacturing variations can directly affect the light output of the lamp. While each manufacturer develops their own set of tolerances that meet the IESNA and ANSI standards, the specifications themselves permit a certain amount of tolerance which leads to variations in light output and light distribution. Other problems may arise during luminaire assembly. For example, the lateral position of the lamp within the luminaire housing can vary, so that it is not centered within the optical system of the luminaire. Furthermore, the vertical position of the lamp is also critical, and lamps with different physical characteristics (i.e. size, dimension and shape of bulb), and ratings (i.e. wattage), require different vertical positions within the luminaire housing. To address the lateral and/or vertical positioning problem, most of the many different luminaire manufacturers employ some type of support mechanism to effect various lateral and/or vertical adjustment capabilities and methodologies.
Another factor affecting the photometric output of the lamp, is the number of arc tubes within the glass envelope. Typically, HID lamps have either one or two arc tubes. Lamps with a single arc tube, called ‘single-arc’ lamps, are the most prevalent. The major components of a single-arc lamp include a hermetically single alumina arc tube, a steel frame and its associated dome mount support which fixes the arc tube within a weather resistant glass envelope, a residue gas getter for collecting discharged gases within the vacuum tube; and the brass recording base for inserting the lamp into a socket. In general, single-arc lamps have a lifespan of approximately 20,000 hours of use before they need to be replaced.
Lamps having two arc tubes, referred to as ‘dual-arc’ lamps, are also available. A dual-arc lamp has the same components as a single-arc lamp with the exception that it contains two arc tubes are rather than one. For example,
While the dual-arc lamp clearly has its advantages, it also has disadvantages. One disadvantage with the dual-arc lamp is related to its photometric distribution of the light. The single-arc lamp can be inserted (i.e. twisted, screwed or seated) into a socket with little concern regarding the final axial orientation of the arc tube. That is to say, the lamp can be axially rotated to any position within the socket, and the same lumen output pattern will result. In a dual-arc lamp, however, the final orientation of the two arc tubes when seated in a socket is very important.
A dual-arc lamp functions by cycling on and off between the two arc tubes; when one tube is on, the other is off. To ensure the resultant distribution pattern of the light from a dual-arc lamp is even regardless of which arc is on or off during operation, the two arc tubes are manufactured so that each arc tube is situated parallel to each other and are aligned in the same horizontal plane within the glass envelope. After installation into the socket, the axial orientation of the two arc tubes within the luminaire is crucial. When a dual-arc lamp is inserted into a socket it is important that both the arc tubes remain horizontally aligned, and as parallel to or co-planar as possible to the luminaire lens. When there is deviation from this alignment and orientation constraint, the resulting light distribution pattern will likely have undesirable directional effects or other optical aberrations (e.g. shadows) which negatively affects the overall lumen output.
Unfortunately, the adjustment of either the lamp or the lamp and socket together in combination is not easily facilitated. At present, the typical process is to manually align the dual-arc tubes by partially unseating, i.e., unscrewing the lamp from the corresponding socket. This approach, however, can be problematic as the electrical connection between the lamp or lamp base and socket may not be properly maintained which can create premature failures. While lateral and/or vertical adjustment mechanisms exist, practitioners have not successfully addressed the problem of the rotational or axial alignment or positioning of the lamp within the luminaire housing. Furthermore, it is a significant challenge to design a mechanism for axial adjustment which will interface with and/or couple to the plethora of available support brackets. Thus, while the extended life-span of the dual-arc lamp makes it attractive from a long term maintenance perspective, the alignment and adjustment considerations have hindered widespread adoption.
The accompanying figures where like reference numerals refer to identical or functionally similar elements throughout the separate views and which together with the detailed description below are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention.
In overview, the present disclosure concerns mounting assemblies that are adjustable and configured to allow or provide for lamp alignment, e.g., angular or rotational alignment for a lamp socket and associated lamp or the like. More specifically various inventive techniques and apparatus for securing and adjusting or rotationally aligning or realigning lamps that are arranged and constructed for use in various environments, including severe outdoor environments will be discussed and disclosed.
The lamps that are of particular interest may vary widely but include dual arc HID (High Intensity Discharge) lamps. Dual arc HID lamps can be subject to extreme environments, including outdoor environments, over long periods of time and necessitate relatively exacting adjustments relative to an associated luminaire assembly in order to operate properly. In order to obtain the relatively long life expectancies that such lamps are capable of, these adjustments must be maintained over these life expectancies without otherwise adding new or contributing to existing failure modes. Thus, in systems, equipment and devices that employ dual arc HID lamps for illumination of large areas, e.g., street lighting systems, parking lot lighting systems, or indoor lighting systems, where the dual arc HID lamps must be properly rotationally or angularly aligned, the present apparatus and methods can be particularly advantageously utilized, provided they are practiced in accordance with the inventive concepts and principles as taught herein.
The instant disclosure is provided to further explain in an enabling fashion the best modes, at the time of the application, of making and using various embodiments in accordance with the present invention. The disclosure is further offered to enhance an understanding and appreciation for the inventive principles and advantages thereof, rather than to limit in any manner the invention. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.
It is further understood that the use of relational terms, if any, such as first and second, top and bottom, and the like are used solely to distinguish one from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.
Much of the inventive functionality and many of the inventive principles are best implemented with mechanical components that may be fashioned using various fabrication technologies, e.g., metal stamping, forming, or various other metal working techniques. It is expected that one of ordinary skill, notwithstanding possibly significant effort and many design choices motivated by, for example, available time, current technology, and economic considerations, when guided by the concepts and principles disclosed herein will be readily capable of selecting appropriate fabrication technologies and generating or otherwise providing appropriate tooling to generate such components. Therefore, in the interest of brevity and minimization of any risk of obscuring the principles and concepts according to the present invention, further discussion of fabrication of such components, if any, will be limited to the essentials with respect to the principles and concepts of the various embodiments.
Referring to
The lamp socket is a standard generally known lamp socket which is adapted to secure, via a threaded interface 106 (threads on base of lamp mate with threads in the lamp socket), a lamp 109, e.g., dual arc HID lamp as shown. Note that in
Typically the bracket 101 will be secured or attached to a mounting arrangement (not specifically shown) (e.g., one or more metal elements) that provides a mechanical interface (direct or indirect) to a luminaire assembly. Ordinarily the lamp 109 will be adjusted vertically (higher or lower) or longitudinally (forward or backward) with respect to the reflector of the luminaire assembly. For example in various embodiments, the mounting arrangement (not specifically shown) is attached to the luminaire and includes some elements (not specifically shown) that are arranged for disposal adjacent to attachment members 111. These elements can have slotted openings that allow for longitudinal adjustment and some vertical adjustment via screws (not shown) that are secured to the attachment members 111 at holes 113. After appropriate adjustment, the bracket 101 and mounting arrangement are secured together by tightening the screws. The mounting arrangements and reflectors are generally known but vary widely with varying luminaire assemblies as provided by different manufacturers of such assemblies. Accordingly, it is expected that the attachment members 111 of the bracket 101 will also vary in form according to the luminaire assembly.
The mounting plate 103 in one or more embodiments is generally circular as shown with a first flange 123 and a second flange 125 and is further configured to rotate (relative to the bracket) together with the lamp socket 105 and lamp 109 about an axis 126. The mounting plate 103 in one or more embodiments, includes one or more socket tabs 115 that are configured to be coupled or attached to the lamp socket 105 using, e.g., threaded screws 117 that pass through openings 119 (e.g., 0.22″ diameter openings with centers spaced at 1.38″) in the socket tabs 115 and which are engaged or secured via threaded openings 201 (see
The bracket 101 further comprises a locking member 127 and the mounting plate 103 further comprises a complementary locking member 129, where the locking member 127 and complementary locking member 129 are configured to engage the mounting plate 103 and the bracket 101 at one of a multiplicity of angular rotations or positions when the bracket is disposed adjacent to the mounting plate, i.e., when the rear surface 203 is adjacent to a bracket surface 131, e.g., a front surface 131 of the bracket 101.
In some embodiments, the locking member 127 comprises a multiplicity of cavities (pockets, dimples, or the like) 133 disposed in the bracket 101 and the complementary locking member 129 further comprises one or more projecting members (bumps in the rear surface not specifically shown) that are configured for disposal in one or more of the multiplicity of cavities 133 to thereby engage the mounting plate 103 and the bracket 101. In other embodiments, the locking member 127 comprises a multiplicity of perforations (openings, apertures) 205 in or through the bracket 101 and the complementary locking member 129 further comprises a projecting member 207 that is configured for disposal within or through one of the multiplicity of perforations 205 to engage the mounting plate 103 and the bracket 101. It is noted that the pockets or perforations could be disposed in the mounting plate 103 with the complementary features (bumps, pins, etc.) disposed in the bracket 101. The multiplicity of perforations 205 in or through the bracket 101 in some embodiments further comprise a multiplicity of circular perforations (e.g., 0.175″ diameter circular openings) in the bracket and the projecting member 207 is a pin, e.g., circular or other cross sectional shaped pin, projecting from the mounting plate or rear surface 203 of the plate and configured for disposal within any one of the multiplicity of circular perforations 205. Note that the pin may be fashioned from separate stock of appropriate dimensions and the pin body can then be brazed or riveted or press fit to the mounting plate 101. The pin also may be formed from the same sheet stock that is used for the mounting plate by cutting out an appropriately located tab and then bending this tab to project from the rear surface 203 in one or more metal stamping operations. The pin formed by stamping operations is likely to have a rectangular cross section and in this case the multiplicity of perforations 205 would not necessarily need to be circular in form, although various practicalities may suggest a circular perforation.
The multiplicity of cavities 133 or perforations 205 in the bracket 101 can be disposed in at least a portion of a arc 209 (e.g., circular arc with a 1.0″ radius each angularly spaced at nominally 12.8 degrees from adjacent perforations) as shown. The portion of the arc 209 generally needs to encompass a sufficient portion to account for the range of angular rotations or rotational positions that may be required in order to properly orient a dual arc lamp. In the embodiment depicted, this portion of an arc comprises a substantially full circle although other embodiments utilize substantially a half circle or slightly more than a half circle (see
Referring additionally to
In the embodiment depicted, the axial body 211 is a circular body with an opening along an axis 126, where the inner surface of the opening is threaded. The axial body 211 can be separately formed with the appropriate opening machined and threaded with the resultant axial body brazed, press fit, or riveted to the mounting plate 103. A screw 137 is then disposed through a washer 139 and secured to the axial body 211 with the bracket and then the spring disposed about the axial body and secured between the mounting plate and the washer and screw. Thus as shown in
Thus as described and configured, the mounting assembly 100 (lamp relative to the bracket) can be rotationally adjusted since the mounting plate 103 and engaging structure 301, while mechanically coupled to the bracket 101, are configured to disengage the mounting plate 103 and the bracket 101 by applying sufficient pressure to the resilient member 135 (spring) so that the projecting member (pin) 207 is no longer disposed in one of the multiplicity of perforations 205. Then by merely rotating the mounting plate 103 (with lamp socket 105 and lamp 109) to another of the multiplicity of angular rotations, i.e., where the projecting member (pin) 207 is aligned with another perforation, and engaging the mounting plate 103 and bracket 101 at the other of the multiplicity of angular rotations by releasing the pressure on the projecting member (pin) 207, the pin is thus disposed in the other perforation (re-engage the locking member 127 and complementary locking member 129). This will be further described below with reference to
The discussions above, with reference to
The means for holding the mounting plate 103 and the bracket 101 can be described alternatively as comprising an annular body, e.g., the axial body 211, and a spring 135 or other resilient structure, disposed about the axis 126 and configured to urge the mounting plate toward the bracket, i.e., such that the mounting plate 103 and bracket 101 are disposed adjacent to one another as in
The bracket in various embodiments further comprises a multiplicity of openings or perforations 205 disposed in a generally circular arc about the axis and the mounting plate further comprises a projecting member 207, pin or the like projecting from the mounting plate and configured to be disposed in one of the multiplicity of openings or perforations 205 (see
Referring to
Beginning with
Thus a method of aligning (e.g., rotationally or angularly positioning) a lamp to a desired rotational position with respect to a luminaire, includes and begins with disengaging as depicted in
After disengaging the mounting plate 103 and bracket 101, the method of aligning includes rotating, as reflected in
After properly orienting, i.e., rotating the lamp, and as reflected in
Referring to
The locking and complementary locking members 805, 807 are similarly configured in varying embodiments and similarly operate as described with reference to
The mounting plate further comprises an integral first flange 813 and a second flange 815 that in one or more embodiments are disposed in a plane generally defined by the mounting plate. The bracket further comprises a limiting member 817 that is disposed and configured to interfere with the first flange 813, specifically at the outer portions of edges 818, and thus limit the mounting plate to rotational positions within defined limits. The limiting member 817 can be a tab that is formed and folded via metal stamping techniques so as to extend or project away from the bracket 801 and toward the mounting plate 803. In various embodiments at least a portion of the first flange 813 is formed with an outer edge having a larger radius than an outer edge of the second flange 815. With this arrangement and with the selection of proper dimensions and locations, the second flange 815 will clear the limiting member 817 during rotations of the mounting bracket about axis 819 while the first flange 813 (at least the outer portions of the edges 818 of the first flange 813) will interfere with the limiting member, i.e., tab, 817 and thus limit rotational positions about axis 819 of the mounting plate relative to the bracket to predetermined or defined limits, e.g., 180 degrees or other appropriate limitations.
In one exemplary embodiment the diameter of the first flange is 2.7″ while the second flange has an outer edge with a diameter of 2.25.″ In this instance the location of the limiting member 217 is nominally 1.14″ from the axis 819 and this member or tab is approximately 0.5″ in width. In one embodiment, the number of perforations is selected as 15 and these are angularly spaced at 12.857 degrees with a first perforation center on a horizontal line through the axis. With this arrangement a lamp can be oriented within +/−6.5 degrees of an optimum setting. If needed slight further angular adjustment of the lamp can be performed by adjusting the torque used to seat the lamp in the lamp socket.
Referring to
The mounting assemblies, mounting systems and methods, discussed above, and the inventive principles thereof are intended to and can alleviate various problems associated with the deployment of a luminaire that are inherent in prior art techniques. This is particularly so for a luminaire that utilizes a dual arc HID lamp or the like, where angular or rotational positioning is important for proper illumination. By providing a bracket that is suitable for mounting to a luminaire assembly and a separate mounting plate that is rotationally adjustable with respect to the bracket and thus luminaire, a lamp can be appropriately adjusted without running the risk of a lower quality higher maintenance electrical connection between the lamp and the lamp socket that may result when the lamp is backed out of the lamp socket. Thus it is expected that the convenient methods of adjusting the angular position of a dual arc HID lamp or the like as discussed and described herein will result in broader acceptance of such lamps as well as higher quality installations of these lamps with lower failure rates and more uniform illumination characteristics. These improvements should result in longer life expectancy and lower maintenance costs (lower overall costs) for many illumination systems.
This disclosure is intended to explain how to fashion and use various embodiments in accordance with the invention rather than to limit the true, intended, and fair scope and spirit thereof. The foregoing description is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications or variations are possible in light of the above teachings. The embodiment(s) was chosen and described to provide the best illustration of the principles of the invention and its practical application, and to enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims, as may be amended during the pendency of this application for patent, and all equivalents thereof, when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.
Number | Date | Country | |
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60703838 | Jul 2005 | US |