The present invention relates to systems and methods for mechanically supporting and electrically coupling arc tubes in high intensity discharge (“HID”) lamps such as metal halide lamps. More particularly, the invention relates to such systems and methods which provide mechanical support and electrical coupling of the arc tube in an HID lamp with few or no welds.
HID lamps such as metal halide lamps have found widespread acceptance in lighting large outdoor and indoor areas such as athletic stadiums, gymnasiums, warehouses, parking facilities, and the like, because of the relatively high efficiency, compact size, and low maintenance of HID lamps when compared to other lamp types. A typical HID lamp includes an arc tube which is mechanically supported within a light-transmissive outer lamp envelope. The arc tube includes two or more electrical leads which are each electrically coupled to a source of electrical power exterior of the outer lamp envelope.
In such a lamp, the mounting structure which provides mechanical support and electrical coupling for the arc tube within the outer lamp envelope includes one or more metal components which are welded for mechanical and electrical integrity. In the fabrication of such lamps, the practice of welding such components, unless automated, is labor intensive which adds expense to the fabrication process. Further, the welding of various lamp components requires numerous weld schedules for the components which may comprise different materials and geometries. Still further, the welding electrodes require a significant amount of maintenance to achieve an optimum weld. Thus the elimination of welds in the mounting structure for the arc tube is desirable to reduce the time and expense required to fabricate such lamps.
Another disadvantage of the typical HID lamp mounting structure having welds to maintain the mechanical and electrical integrity of the structure results from the susceptibility of the one or more welds in such lamps to mechanical failure during shipping of the lamps. The welds provide a relatively strong mechanical coupling of components when the weld is subjected to shear. However, the welds are relatively weak when subjected to a bending moment, which is the typical mode of mechanical failure in such lamps during shipping.
In the fabrication of HID lamps, it is important to properly position the arc tube within the outer lamp envelope so that the light center of the lamp is optimized. In the known methods of fabricating HID lamps, the various components of the arc tube mounting structure must be aligned manually by the production operator before being mechanically joined or fixtured with specialized tooling. Such an alignment process is time consuming if done manually and expensive if done using fixtures. Thus the elimination of the alignment process in the fabrication of HID lamps is desirable to reduce the time and expense required to fabricate such lamps.
Accordingly, it is an object of the present invention to provide a novel system and method for mechanically supporting and electrically coupling arc tubes in HID lamps which obviates the deficiencies of known systems and methods.
It is another object of the present invention to provide a novel system and method for mechanically supporting and electrically coupling arc tubes in HID lamps with few or no components which are welded for mechanical integrity.
It is yet another object of the present invention to provide a novel system and method for mechanically supporting and electrically coupling arc tubes in HID lamps with few or no components which are welded for electrical integrity.
It is still another object of the present invention to provide a novel system and method for mechanically supporting and electrically coupling arc tubes in HID lamps which is amenable to automation.
It is a further object of the present invention to provide a novel system and method for mechanically supporting and electrically coupling arc tubes in HID lamps which reduces mechanical failure during shipping of the lamp.
It is yet a further object of the present invention to provide a novel system and method for aligning the light center of an HID lamp.
These and many other objects and advantages of the present invention will be readily apparent to one skilled in the art to which the invention pertains from a perusal of the claims, the appended drawings, and the following detailed description of the preferred embodiments.
a is a schematic illustrating a front view of a prior art pinched body arc tube.
b is a schematic illustrating a front view of a prior art formed body arc tube.
a is a schematic illustrating a front view of a prior art mounting structure for a 400 watt metal halide lamp.
b is a bottom view of
a is a schematic illustrating a front view of a 350 watt open fixture metal halide lamp according to one aspect of the present invention.
b is a bottom view of
a is a schematic illustrating a front view of the mounting structure of the lamp illustrated in
b is a bottom view of
a is a schematic illustrating one embodiment of the frame suitable for the mounting structure illustrated in
b is a bottom view of
c is a section of
a is a schematic illustrating one embodiment of the stem clamp suitable for the mounting structure illustrated in
b is a bottom view of
a and 8b are schematics illustrating different embodiments of the arc tube retaining tabs suitable for the shroud cap illustrated in
a is a schematic illustrating a front view of the mounting structure illustrated in
b is a bottom view of
a is a schematic illustrating a front view of a 350 watt enclosed fixture metal halide lamp according to one aspect of the present invention.
b is a bottom view of
a is a schematic illustrating a front view of the mounting structure in the lamp illustrated in
b is a bottom view of
a is a schematic illustrating a front view of one embodiment of the frame suitable for the mounting structure illustrated in
b is a bottom view of
c is a section of
a is a schematic illustrating a front view one embodiment of a stem clamp suitable for the mounting structure illustrated in
b is a top view of
a is a schematic illustrating a front view of one embodiment of an arc tube clip suitable for the mounting structure illustrated in
b is a bottom view of
a is a schematic illustrating a side view one embodiment of a heat shield suitable for the mounting structure illustrated in
b is a bottom view of
a is a schematic illustrating a side view of one embodiment of the arc tube clip suitable for the mounting structure illustrated in
b is a bottom view of
While the present invention is suitable for mechanically supporting and electrically coupling arc tubes in any type of HID lamp, it may be easily understood in the embodiment suitable for metal halide lamps.
Metal halide lamps include light emitting chemicals which are hermetically sealed within an arc tube formed from light transmitting material such as quartz glass or ceramics. The arc tube may comprise a pinched body or a formed body as illustrated in
There are many sizes of metal halide lamps which range between about 32 watts and 2000 watts and generally include either a medium type base for lower wattage lamps (150 W or below) or a mogul type base for higher wattage lamps (175 W or greater).
a and 2b illustrate a typical prior art mounting structure for providing mechanical support and electrical coupling for a shrouded formed body arc tube in a 400 watt metal halide lamp having a mogul type base. With reference to
The frame 12 is mechanically supported at one end by the stem assembly 14. The integrity of the mechanical support of the frame 12 by the stem assembly 14 is maintained by one or more welds between the frame 12 and the spring clip 18.
The arc tube 22 is mechanically supported at one end by an arc tube retaining clip 28 and at the other end by a strap 30. The retaining clip 28 and strap 30 are each mechanically supported from the frame 12. The integrity of the mechanical support of the retaining clip 28 and strap 30 from the frame 12 is maintained by one or more welds.
The generally tubular shroud 24 surrounds the central portion of the arc tube 22 and is mechanically supported at each end by a shroud cap 26. Each of the shroud caps 26 is mechanically supported from the frame 12. The integrity of the mechanical support of the shroud caps 26 from the frame 12 is maintained by one or more welds.
The arc tube 22 includes an arc tube lead 32 at each end. Each arc tube lead 32 is electrically coupled to one of the stem leads 20. The integrity of the electrical coupling between the arc tube leads 32 and the stem leads 20 is maintained by one or more welds.
While of utility in HID lamps of any type and wattage, the present invention may be easily understood in the embodiments suitable for mechanically supporting and electrically coupling the arc tubes of metal halide lamps.
Open Fixture Lamps:
a and 3b illustrate a 350 watt open fixture metal halide lamp. With reference to
a and 4b illustrate the arc tube mounting structure for the lamp illustrated in
The frame 52 is mechanically supported at one end by the stem assembly 54. In one embodiment of the present invention, the integrity of the mechanical support of the frame 52 by the stem assembly 54 is maintained without a weld.
a and 5b illustrate one embodiment of the frame according to the present invention. With reference to
a and 6b illustrate one embodiment of the stem clamp according to the present invention. With reference to
The frame 52 may be mechanically supported by the stem assembly 54 by positioning each leg 64 through the apertures 70 formed by the upper tab 68 and the lower tab 69 of one of the pairs of retaining tabs 67. Each pair of retaining tabs 67 laterally constrains the leg 64 received therethrough. With further reference to
With further reference to
Each frame receiving tab 80 forms a slot 81 which is adapted to receive therein a swaged portion 66 of one of the legs 64 of the frame 52. The swaged portions 66 on each leg 64 are positioned so that when received in the frame receiving tabs 80 of the shroud cap 76, the shroud cap may be mechanically supported between the legs 64 at a substantially right angle thereto. The integrity of the mechanical support may be maintained by crimping the tabs 80 about the swaged portion 66 received therein. The integrity of the mechanical support is further maintained by the lateral constraint of the terminal ends of the legs 64 by the stem assembly 54. Thus the integrity of the mechanical support of one or both of the shroud caps 76 from the frame 52 may be maintained without a weld.
The shroud 44 is a generally tubular member formed from light transmitting material. The shroud may be mechanically supported at each end by positioning the shroud 44 between each shroud cap 76 so that the longitudinal axis of the shroud 44 is substantially parallel to each leg 64. The integrity of the mechanical support of the shroud 44 between each shroud cap 76 may be maintained by bending the shroud retaining tabs 78 to be in contact with the outer surface of the shroud 44 as illustrated in
The arc tube 42 includes a bulbous light emitting chamber 43 between two end portions 45. The arc tube 42 may be supported at each end portion 45 by the arc tube retaining tab 82 of one of the shroud caps 76. Each tab 82 forms an aperture 83 adapted to receive a portion of one end portion 45 of the arc tube 42 therethrough. The arc tube 42 is positioned between the tabs 82 of each shroud cap 76 so that the longitudinal axis of the arc tube 42 is substantially parallel to the legs 64 of the frame 52.
Each end portion 45 of the arc tube 42 includes an axial positioning portion 47 which is of larger cross-sectional dimension than the end portion 45. The cross-sectional dimension of the axial positioning portion 47 is large enough to prevent the passage of the axial positioning portion 47 through the aperture 83 of tab 82 of each shroud cap 76. The shroud caps 76 may thus be spaced apart a distance to prevent axial movement of the arc tube 42 supported therebetween.
The arc tube 42 forms the light emitting chamber of the lamp, and thus the axial positioning of the arc tube is critical in optimizing the light center of the lamp. Thus the light center of the lamp may be determined by positioning the swaged portions 66 of the legs 64 which thus determines the axial position of the shroud caps 76, which thus determines the axial position of the arc tube 42. This method of aligning the light center of the lamp eliminates the time consuming process of manually aligning the arc tube during fabrication of the lamp.
In some lamps, the radial position of the arc tube is critical to the operation of the lamp. In such lamps having formed body arc tube as illustrated in
Electrical Coupling:
In addition to providing mechanical support for the arc tube in HID lamps, the mounting structure provides electrical coupling of the arc tube to a source of electrical power for operating the lamp. The aspect of the present invention directed to the electrical coupling of the arc tube to a power source is suitable for any type HID lamp and may be easily understood in the embodiment for open fixture metal halide lamps.
a and 9b illustrate the embodiment of the present invention illustrated in
The arc tube 42 includes the arc tube lead 90 at one end and the arc tube lead 92 at the other end thereof. The connector 94 provides electrical coupling between the arc tube lead 90 and one of the stem leads 60. The connector 96 provides electrical coupling between the arc tube lead 92 and the other stem lead 60. In one embodiment of the present invention, the integrity of the electrical coupling between the arc tube leads 90,92 and the stem leads 60 may be maintained without welds.
The coil 102 is adapted to receive a portion adjacent the terminal end of the arc tube lead 90 therein so that the coil 102 extends axially around the portion of the arc tube lead 90 received therein. At least a portion of the coil 102 is crimped around the portion of the arc tube lead 90 received therein to establish and maintain the integrity of the electrical coupling between the connector 94 and the arc tube lead 90. Thus the integrity of the electrical coupling between the arc tube lead 90 and one of the stem leads 60 may be maintained without a weld.
With reference to
The coil 106 is adapted to receive a portion adjacent the terminal end of the arc tube lead 92 therein so that the coil 106 extends axially around the portion of the arc tube lead 92 received therein. At least a portion of the coil 106 is crimped around the portion of the arc tube lead 92 received therein to establish and maintain the integrity of the electrical coupling between the connector 96 and the arc tube lead 92. Thus the integrity of the electrical coupling between the arc tube lead 92 and one of the stem leads 60 may be maintained without a weld.
In the fabrication of lamps, the stem is susceptible to breakage due to its relative fragility. In the event that the stem must be replaced after the connectors 94,96 and the stem leads 60 have been electrically coupled, such electrical coupling must be suitable for uncoupling and recoupling the connectors with a new stem and stem leads.
Enclosed Fixture Lamps:
a and 13b illustrate a 350 watt enclosed fixture (i.e. unshrouded) metal halide lamp. With reference to
a and 14b illustrate the arc tube mounting structure for the lamp illustrated in
The frame 116 is mechanically supported at one end by the stem assembly 118. In one embodiment of the present invention, the integrity of the mechanical support of the frame 116 by the stem assembly 118 is maintained without a weld.
a and 15b illustrate one embodiment of the frame according to the present invention. With reference to
a and 16b illustrate one embodiment of the present invention suitable for mechanically supporting the frame in an enclosed fixture lamp. With reference to
The frame 116 may be mechanically supported by the stem assembly 118 by positioning the terminal end of the leg 128 through the aperture formed by the lower tab 136 and positioning the swaged portion 130 nearest the terminal end of the leg 128 into the slot 135 formed by the corresponding upper tab 134. The tabs 134,136 laterally constrain the terminal end of the leg 128. The integrity of the mechanical support may be maintained by crimping the upper tabs 134 about the portion of the leg 128 received therein.
With further reference to
With further reference to
a and 17b illustrate an arc tube clip of one embodiment of the present invention. With reference to
Each frame receiving tab 142 forms a slot 143 which is adapted to receive therein a swaged portion 130 of the leg 128 of the frame 116. The integrity of the mechanical support of the arc tube clips 140 may be maintained by crimping the tabs 142 about the swaged portion 130 received therein. Thus the integrity of the mechanical support of one or both of the arc tube clips 140 from the frame 116 may be maintained without a weld.
With further reference to
Each end portion 117 may include an axial positioning portion 119 which is of larger cross-sectional dimension than the end portion 117. The cross-sectional dimension of portions 119 is large enough the prevent the passage of portions 119 through the slots 145. Thus the arc tube clips 140 may be spaced apart a distance to prevent axial movement of the arc tube 112 supported therebetween.
The light center of the lamp 110 may be determined by positioning the swaged portions 130 along the length of the leg 128.
Metal halide lamps of lower wattage (i.e. about 150 W and below) typically include a medium type base.
a and 19b illustrate one embodiment of the heat shield according to the present invention. With reference to
Each of the slots 162 is adapted to receive one of the legs 166 therein at the portion of the leg 166 adjacent the terminal portion 168. Each of the gaps 161 is adapted to receive therein the terminal portion 168 of the leg 166 received in the adjacent slot 162. The tabs 160 may be crimped to retain the terminal portions 168 received in the gaps 161.
With further reference to
The present invention is suitable for supporting pinched body arc tube as well as formed body arc tubes.
The arc tube clip 184 further includes a pair of arc tube clamping portions 188 adapted to receive one pinched end of the arc tube 180 therebetween. The pinched end of the arc tube may be retained between the clamping portions 188 by compressing the clamping portions 188 around the pinched end of the arc tube and securing the tab 189 behind the frame received in the slots 187 formed by the frame retaining tabs 186.
In many HID lamps it is desirable to getter excess gasses such as hydrogen and oxygen from within the outer lamp envelope. Typically a getter material is mounted within the outer lamp envelope by welding a getter cap to the lamp mounting structure. In yet another aspect of the present invention, the getter cap may be supported within the outer lamp envelope with no welds between the getter cap and the mounting structure.
While preferred embodiments of the present invention have been described, it is to be understood that the embodiments described are illustrative only and the scope of the invention is to be defined solely by the appended claims when accorded a full range of equivalence, many variations and modifications naturally occurring to those of skill in the art from a perusal hereof.
This application claims the priority of U.S. Provisional Patent Application Ser. No. 60/125,999 filed Mar. 24, 1999.
Number | Date | Country | |
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60125999 | Mar 1999 | US |
Number | Date | Country | |
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Parent | 09534443 | Mar 2000 | US |
Child | 11081709 | Mar 2005 | US |