Patent Grant
8456088
This invention relates to electric lamps and more particularly to reflector lamps. While the invention has applicability to lamps generally, including arc discharge lamps, it has specific application to tungsten halogen (T-H) parabolic reflector lamps (PAR lamps).
In tungsten-halogen lamps, the deposition of evaporated tungsten deposits on the envelope wall is reduced or retarded by the regenerative action of the halogen cycle, which operates by virtue of the temperature gradient between the filament and the bulb. As a general concept:
PAR lamps typically comprise a light source such, for example, as a tungsten halogen capsule comprised of quartz or a hard glass, mounted in a pressed borosilicate glass body having a reflective coating applied to the inner surface of the body. A pressed glass lens usually covers the front aperture of the body and may contain optical elements to give a desired beam shape, for example, a spot or flood configuration. General service PAR lamps typically have a medium screw base attached to the body for electrical connection to 100V to 240V circuits. In many T-H PAR lamps the hard glass capsule contains stiff electrical lead-ins that connect to the relatively deformable inner leads of the light source and that are themselves pressed into the seal area of the capsule. Such capsules are shown in U.S. Pat. No. 5,660,462, Bockley, et al., and U.S. Published Patent Applications 2005/0212396 A1, Oetken, et al. and 2006/0043890 A1, Kling (all of which are assigned to the assignee of the instant invention). Often, in such lamps the capsule is supported by crimping the leads into metal eyelets that are formed in the base of the envelope body.
Problems arise in the sealing of the heavy metal lead-ins into the glass. The differences in thermal expansion of the heavy metal lead-ins and the glass eventually causes cracking problems that shorten the life of the lamps. While numerous metal alloys have been developed to attempt to match, within a critical range, the thermal expansion of the glass, these alloys themselves are expensive and, sometimes, difficult to work with.
Another technique that has been employed utilizes additional parts such as a metal disc that fastens to the capsule and centers it in the neck of the envelope body. Such a technique is shown in U.S. Pat. No. 5,751,095, Zalar, which also employs multiple glass or ceramic insulators to guide the lead-ins to the screw base.
It would be an advance in the art to provide a simple and inexpensive way to mount a single ended hard glass capsule with deformable, flexible lead-ins into a hard glass reflector.
It is, therefore, an object of the invention to obviate the disadvantages of the prior art.
It is another object of the invention to enhance electric lamps.
Yet another object of the invention is the improvement of electric lamps, in particular, T-H lamps.
These objects are accomplished, in one aspect of the invention, by the provision of a light source capsule having a capsule envelope with a wall defining an enclosed volume, and having a sealed portion. A light source, such for example, as an incandescent filament operating on the above-described halogen cycle, is positioned in the enclosed volume and has deformable electrical leads-ins extending through the sealed portion of the capsule envelope. Stiff lead-in engagers are aligned with and overly the sealed portion of the capsule envelope and are electrically coupled, as by welding, to the electrical leads. The stiff lead-in engagers are electrically conductive.
In another aspect of the invention, the objects are accomplished by providing a lamp that contains a light source capsule as described above.
The stiff lead-in engagers eliminate the previous problems encountered with the prior art lamp capsules and provide a simple and economical expedient for mounting hard glass or quartz capsule with deformable leads into a hard glass reflector.
For a better understanding of the present invention, together with other and further objects, advantages and capabilities thereof, reference is made to the following disclosure and appended claims taken in conjunction with the above-described drawings.
Referring now to the drawings with greater particularity, there is shown in
A light source 26 is positioned within the enclosed volume 22 and has deformable electrical leads-ins 28, 30 extending through the sealed portion 24 of the capsule envelope 18 and exiting from end 51 of the sealed portion 24. The electrical lead-ins 28, 30 are formed of molybdenum wire having a diameter of 0.5 mm and are quite easily distorted during normal handling. Further, by themselves, they are not capable of supporting the weight of the light source capsule 16. A reflector coating 34, for example, aluminum, is applied to the interior surface of the envelope 12. Molybdenum (moly) foils 42, 44, are sealed within the seal 24 and also connect the inner ends 46, 48 of the deformable electrical lead-ins. The moly foils 42, 44 are most clearly illustrated in
Lead-in engagers 32 are aligned with and overlay the sealed portion 24 of the capsule envelope 18. In a preferred embodiment, one lead-in engager 32 lies on each side of the sealed portion 24, and is electrically coupled to the electrical leads 28, 30, for example, by welding. The lead-in engagers also are electrically conductive. The neck portion 36 of the lamp envelope 12 includes the base 14; and the base 14 includes receptacles 38, 40 formed to receive the two lead-in engagers 32. The receptacles 38, 40 as shown in
The sealed portion 24 of the light source capsule 16 can take any of several configurations and as shown in
In the embodiment shown in
To fix the light source capsule 16 into the lamp envelope 12 the distal portions 32c are fitted into grommets 53, 55 sealed into the base 14 where they can be staked or welded to fix the position. If desired, the grommets can be eliminated and the distal portions 32c fitted into cylindrical apertures formed in the press seal region, similar to the apertures 58, 59 shown in
An alternate embodiment of the invention is shown in
Additionally, the terminal portions 54c, 56c can be provided with compressible spring locks 62. When the terminal portions 54c, 56c are inserted into the apertures 58, 59, the spring locks 62 will compress while passing through the apertures and then expand on the underside of the base 14, thus maintaining the entire capsule 16 in position without the necessity of any other elements.
In either of the embodiment disclosed herein, the lamp 10 is completed by adding a screw base 64 and making the appropriate electrical connections 63, 65 to side 66 of the screw and insulated bottom 68, respectively, to provide the electrical connections to the lead-in 28, 30.
There is thus provided a simple and economical mount for light source containing lamp capsules.
While there have been shown and described what are at present considered to be the preferred embodiments of the invention, it will be apparent to those skilled in the art that various changes and modifications can be made herein without departing from the scope of the invention as defined by the appended claims.
| Number | Name | Date | Kind |
|---|---|---|---|
| 3323855 | Prijn | Jun 1967 | A |
| 3904909 | Vause | Sep 1975 | A |
| 4241391 | Pitkjaan et al. | Dec 1980 | A |
| 4608624 | Blaisdell et al. | Aug 1986 | A |
| 5660462 | Bockley | Aug 1997 | A |
| 5751095 | Zalar | May 1998 | A |
| 20050212396 | Oetken | Sep 2005 | A1 |
| 20060043890 | Kling | Mar 2006 | A1 |
| 20090033219 | Stark | Feb 2009 | A1 |
| Number | Date | Country |
|---|---|---|
| 1489413 | Mar 1969 | DE |
| 1632987 | Mar 2006 | EP |
| 2020677 | Feb 2009 | EP |
| 61 11204 | Jan 1986 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20110095681 A1 | Apr 2011 | US |
