DESCRIPTION
FLUORESCENTLAMPWITHPLURALENCLOSURESANDCONNECTORS
II. TECHNICAL FIELD
This invention relates to an improvement for fluores¬ cent lamps capable of enlarging its useful life by incor¬ porating a plurality of hermetically sealed enclosures acting as independent lamps.
III. BACKGROUND ART
In preparing fluorescent lamp tubes, it is the practice to coat the filament of the electrodes with a suspension of strontium and barium carbonates and zirconia or powdered zirconium in which suspension the coils are dipped and when the coils are heated to activate them in service, the carbon¬ ates are decomposed to form a coating consisting of a mix¬ ture of barium and strontium oxides, or a mixture of barium and strontium oxides and zirconia or zirconium. There is also enclosed in the tubes a small amount of mercury and an inert gas, such as argon, krypton, or a mixture of argon and krypton, and when an electric current is passed between the electrodes, ultra-violet radiations, are produced which are transformed by the fluorescent material into visible light.
The complete failure of gas-filled tubes, unless de¬ fects are present in their mechanical parts, is generally due to the sputtering off of all of the coating upon the filaments of the electrodes. However, it is well known that
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gas-filled tubes of the fluorescent type gradually blacken in service even when the coating of the oxides upon the filaments is -still intact.- The blackening of the tubes is pronounced at the end portions of the tubes in proximity to the electrodes although more of less blackening of the tubes occurs throughout the entire length of the tubes. This blackening is caused by a film comprising mercury which is deposited upon the interior surface of the tube during ser¬ vice in which the mercury may be entrained with or combined with other elements or compounds on the interior surface of the tube.
Several attemps have been made in the past to recondi¬ tion gas filled lamps, and more particularly, fluorescent lamps. One of these attemps is described and claimed by Louis C. Stringer in U. S. Letters Patent No. 2,304,714. However, even though the gas inside the lamp is changed like in the present invention, it is done by breaking the glass tube and fusing the edges together afterwards. This method is costly, time consuming and impractical.
Another method and apparatus of interest is described in U. S. Letters Patent No. 2,884,298, issued to Thomas T. Bryen. This method of apparatus involves the use of heat to get rid of the blackening of the tubes. Again, this method and apparatus is very cumbersome and impractical.
Still another approach is described in U. S. Letters No. 2,733,973 issued to Wallace Shaffer. Here, a high vol¬ tage is applied, between 5,000 and 12,000 volts, with a load current between 1 and 12 milliamperes, in order to
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"rejuvenate" the lamp tube. This invention requires the use of a high voltage generator and its operation may be quite dangerous. Furthermore, it is not effective in all cases as the inventor himself admits in said patent speci¬ fication that it is not known with certainty what transpires in the tubes when a high voltage is applied to it.
None of these patents, however, provide for any easy solution to the user. Most of the prior art requires the use of complicated rejuvenating equipment. The user, on the other hand, wants a fast solution and it is that .what the present invention gives him. The user can easily rotate the end cap on each end of the tube and the problem is fixed.
Other related inventions have been studied as part of the prior art. None of these inventions anticipate the novel features of the present invention.
IV. DISCLOSURE OF THE INVENTION
It is the object of the present invention to provide a fluorescent lamp capable of housing a plurality of indepenn dent lamp assemblies so that when one of them burns out, another lamp may be readily activated.
It is another object of the present invention to enlarge the useful life of the fluorescent lamp.
The invention also comprises such other objects, ad¬ vantages and capabilities as will later more fully appear and which are inherently possessed by the invention.
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V. BRIEF DESCRIPTION OF THE DRAWINGS
The advantages and novel features of the present in¬ vention will become apparent from the following detailed description of preferred embodiments of the invention illustrated in the accompanying drawings where:
Figure I shows the dual fluorescent lamp subjeet of the present application, with the right end cap sep¬ arated from the tube.
Figure 2 is a partial cross-section of the tube in Figure I along line 2-2.
Figure 2A is an exploded partial cross-sectional view of the connector and cap.
Figure 3 is a partial view in perspective of the end of the lamp tube, with the end cap separated.
Figure 4 shows the interconnections inside the end cap as seen from line 4-4.
Figure 5 is similar to Figure 1 with the only difference being that the end cap connector has only one contact, as is the case with some commercially available lamps.
Figure 6 is a partial cross-section of the tube illustrated in Figure 5 along line 6-6.
Figure 7 is a partial view in perspective of the end of the lamp tube, with the end cap connector separated.
Figure 8 shows the interconnection inside the end cap connector as seen from line 8-8.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to Figure 1, where a dual fluorescent lamp is shown with one of its end cap connectors 2 separated, it can be readily seen that the present invention may be embodied in standard commercially available fluorescent lamps.
In Figure 2 a cross-section of one end of dual lamp 1 is shown illustrating the preferred embodiment for the present invention as it is incorporated in a standard two pin lamp. The method of operation for fluorescent lamp is old. A voltage is applied to the two contact pins 11 which are connected through conductors 15 to contacts 8. Contacts 8 engage with electrode terminals 6 which in turn are con¬ nected through electrode wires 7 to filament 4. The glass envelope 13, hermetically sealed, contains a rarified at¬ mosphere that is ionized when filament 4 is heated. The filament 4 and electrode wires 7 are referred to, collectively as an electrode assembly 20. The ions are electrostatically accelerated inside the glass envelope 13. The inside wall of glass envelope 13 is covered with fluorescent material that is activated when the ions strike said inside wall.
The embodiment disclosed uses four electrode assemblies 20 and two independent'-glass envelopes which we refer to as lamp enclosure A 16 and lamp enclosure B 17. It is possible to have more than two independent lamp enclosures incorporated in the present invention with the consequent extension of the lamp's life. The electrode terminals 6 are fixed to the
outside part of end cap 3 which is similar to an end cap used in a common fluorescent lamp. The end cap 3 is attached to the glass envelope 13 by epoxy 21 or other similar composition. The only difference between end cap 3 and other commercially available lamp caps being the number and arrangement of these electrode terminals 6 and contacts 8. In order to harmonize this difference with commercially available socket's for fluorescent lamps, the end cap con¬ nector 2 provides means for connecting with these readily available sockets while making contact with one of the sets of electrode terminals 6, and consequently, one of the lamp enclosures 16 or 17 will be activated. . The end cap con¬ nector 3 has a guide 10 that receives key 9 on end cap 3, thereby insuring a good fast contact. Lamp enclosure A 16 is separated from lamp enclosure B 17 by divider 14 which is shown to be made out of glass in the preferred embodiment but other suitable materials may be used. Longitudinal divider 14 may be formed in a similar fashion as glass grown base 5 is formed. The shape of divider 14 will depend upon the number of enclosures formed. For instance, if there are three enclosures the divider's cross-section will have a Y-^shape, if there are four enclosures it would have an X-shape etc. The. preferred embodiment shows a cylindrical envelope but it is likely that the present invention will be produced as a superimposition of two cylindrical tubes, forming an 8-shaped cross-section. But the idea is the same and the shape of the tube will respond to usual production line
capabilities. Each one of the enclosures, 16 and 17, will be an independent fluorescent lamp.
The user will have to rotate end cap connector 2, on each end of the dual lamp 1, whenever he decides to change from one lamp enclosure to the other one. The enclosure to be activated will always end up situated so that it gives out the maximum amount of light, i.e. downwardly, if the area to be illuminated is below. This may also be accomplish if more than two enclosures 16 and 17, are used. The glass envelope 13 rotates but the connector 2 position relative to the commercially available socket to which it is connected is fixed for the lamps having more than one pin 11. Lamps with only one pin 11 will obviously present no problem since they can be readily rotated.
Figure 4 shows the inner part of the end cap connector 2 where the end of conact pins 11 are riveted at 12 and con¬ nected through conductor 15 to contacts 8. The outer wall 22- of connector 2 looks like any commercially available lamp and* it is capable of being inserted in any standard socket. Guides 10 and keys 9 insure a proper connection, improve mechanical stability of the assembly and impede rotation of the end cap connector 2.
Figure 2 also shows a peripheral groove 19 formed be¬ tween end cap 3 and glass envelope 13. This peripheral groove 19 receives rim 18 formed on the inner wall 23 of end cap connector 2, thereby providing a quick-connect snap action connection. Groove 19 may also be formed on the peripheral side wall of end cap 3.
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Another commercially available type of fluorescent lamp using only one contact pin is illustrated in Figure 5 through 8, showing how the present invention can be incorpora¬ ted, in a similar fashion as with the standard two pin type.
From Figure 6, it can be observed that- pin 11 is connected via conductor 15 to contact 8 which is in receivable alignment with electrode terminals 6. Electrode terminals 6 are connected to electrode wires 7 and the circuit is com¬ pleted with filament 4. Connector 2 receives end cap 3 connecting terminals 6 with contacts 8.
The user will have to turn each connector 2 on each end one-half turn in order to activate the other enclosure.
It is believed the foregoing description conveys the best understanding of the objects and advantages of the present invention. Different embodiments may be made of the invention herein'-described without departing from the in¬ ventive concept of the present invention. It is to be under¬ stood that all matter disclosed herein is to be interpreted merely as illustrative, and not in a limiting sense, except as set forth in the following appended claims.
VII. INDUSTRIAL APPLICABILITY
It is apparent from the previous paragraphs than an improvement of this type for fluorescent lamps is quite de¬ sirable since it lengthens the life of the device. The user only needs to rotate the lamp and use another lamp compart¬ ment in the same envelope. This not only reduces the cost per functional lamp but also reduces storage and inventory requirements, especially in large buildings. The introduction
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of these features of the invention is therefore a valuable improvement in this technology.
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