US3654512A - Lamp with support for filament to extend life of filament and envelope filled with krypton and/or xenon - Google Patents

Abstract

The specification discloses a lighting system which uses a low voltage lamp filament of a certain increased length to which a predetermined reduced voltage is applied, which is less than the rated voltage of the lamp. The lamp filaments are each supported at their ends on rods and a rod having an insulating grommet is supported between each pair of rods which support the ends of the filament to support the intermediate part of the filament. Thus the center rod support acts on the filament as a support for two parts of a cantilever beam.

Description

United States Patent Spiteri [54] LAMP WITH SUPPORT FOR F ILAMENT T O EXTEND LIFE OF FILAMENT AND ENVELOPE FILLED WITH KRYPTON AND/OR XENON [72] Inventor: Joseph Splteri, Erie, Pa.

[73] Assignee: Truck-Lite Company, Inc., Jamestown, NY

[22] Filed: May 14, 1970 [21] Appl.No.: 37,183

Related 0.8. Application Data [63] lCgginuation-in-part of Ser. No. 785,909, Dec. 23,

521 u.s.c| ..315/64,315/66,3l5/200, 315/241, 315/273 51 1m.c| ..I-I0lj7/44 5s FieldofSearch ..3l5/64,66,200,20l,205, 315/241, 272, 273, 65, 67, 68

[ 56] References Cited UNITED STATES PATENTS 3,416,028 12/1968 Levin ..315/64 X [451 Apr. 4, 1972 3,275,922 9/1966 Meyer et al. 1 5/200 X 2,306,559 12/1942 Pearson ..315/66 3,075,123 l/l963 Faulds ....3l5/200 X 3,215,891 11/1965 Fritz et al... ....315/200 X 2,082,326 l/l937 Dulberg ..315/66 2,896,125 7/1959 Morton ....3 1 5/200 X 2,981,866 4/1961 Tsien et a1. ..315/200 FOREIGN PATENTS OR APPLICATIONS 398,693 9/1933 Great Britain ..3 15/64 Primary ExaminerEli Lieberman Assistant Examiner-Saxfield Chatmon, Jr. Attorney-Charles L. Lovercheck [5 7] ABSTRACT The specification discloses a lighting system which uses a low voltage lamp filament of a certain increased length to which a predetermined reduced voltage is applied, which is less than the rated voltage of the lamp. The lamp filaments are each supported at their ends on rods and a rod having an insulating grommet is supported between each pair of rods which support the ends of the filament to support the intermediate part of the filament. Thus the center rod support acts on the filament as a support for two parts of a cantilever beam.

1 Claim, 9 Drawing Figures LAMP WITH SUPPORT FOR FILAMENT TO EXTEND LIFE OF FILAMENT AND ENVELOPE FILLED WITH KRYPT ON AND/OR XENON REFERENCE TO CO-PENDING APPLICATION This application is a continuation-in-part of patent application, Ser. No. 785,909, filed Dec. 23, 1968.

STATEMENT OF INVENTION This invention relates to lighting systems of the incandescent filament type and, more particularly, to lamps and the life of such lighting systems.

OBJECTS OF THE INVENTION It is an object of the invention to provide an improved filament support in an incandescent lamp.

Another object of the invention is to provide a filament support which will increase the life of the lamp.

Another object of the invention is to provide a filament support at a plurality of points.

Another object of the invention is to provide a lamp that will have a longer life with comparable candlepower output than an ordinary lamp of the same power consumption.

Another object of the invention is to provide a lamp wherein the lamp will operate at a lower temperature with comparable candlepower output than the ordinary lamp.

Another object of the invention is to provide a more rugged filament and filament support for a lamp adapted to be used in the automotive/truck industry.

Another object of the invention is to provide a lamp that offers a reduction in power consumption with comparable candlepower to a lamp of similar output.

Another object of the invention is to provide a lamp that is more economical to operate and more reliable than a lamp of comparable power consumption and light output.

DESCRIPTION OF THE DRAWINGS FIG. 1 shows a side elevational view of an incandescent lamp constructed in accordance with the present invention with parts broken away and shown in section.

FIG. 2 is a transverse sectional view taken substantially through a plane indicated by section line 22 of FIG. 1.

FIG. 3 is an enlarged detail view showing a portion of the filament assembly associated with the lamp of the present invention.

FIG. 4 is a simplified circuit diagram of a voltage reducing circuit associated with the invention.

FIG. 5 shows an enlarged partial view of the support taken at line 55 ofFlG. 2.

FIG. 6 shows the vibration pattern of a filament supported only at its ends.

FIG. 7 shows a filament supported at an intermediate point.

FIG. 8 shows the vibration pattern of a filament supported at two intermediate points.

FIG. 9 shows the vibration pattern of a filament support.

DETAILED DESCRIPTION OF THE DRAWINGS Now with more particular reference to the drawings, FIGS. 1 and 2 illustrate a typical incandescent lamp constructed in accordance with the present invention, generally referred to by a reference numeral 10. As in the case of most incandescent types of lamps, the lamp 10 includes an outer glass envelope 12 having an enlarged end chamber portion 14 within which a tungsten filament assembly 16 is mounted in spaced relation to the envelope base 18 to which the externally threaded connector 20 is secured by the nonconductive bonding material 22. A plurality of support rods 24 are embedded in the internal projection 26 of the base 18 for mounting the filament assembly 16 within the illumination chamber portion 14. Further, the envelope may be internally coated with a silica coating and filled with Krypton and/or Xenon gas after being evacuated.

As more clearly seen in FIGS. 2 and 3, the filament assembly includes a plurality of tungsten filaments 28 electrically interconnected in series and supported at their-junctures 30 by the upper ends 32 of the support rods 24. In the illustrated embodiment, five standard tungsten filaments are shown. The terminal ends 30 of the series connected filaments are connected to the support rods 24, constituting electrical conductors connecting the terminal ends of the filaments to the threaded connector 20 at 42 as shown in FIG. 1 and to a conductive terminal element 44 mounted on the nonconductive end closure 46. The voltage rating of the filaments, the number of such filaments and the voltage applied to the filaments is selected in accordance with certain critical parameters.

The rods 24 are supported between rods 24 on projection 26. The upper ends of rods 24' have eyelets 60 formed in them, which receive the wire making up rod 24. Three rods 28 may be provided as shown. The rod 24 supports the filament 28 at its intermediate part and prevents vibration of the filament between its ends.

The envelope may be filled with Krypton and/or Xenon gas which will have a tendency to inhibit oxidation of the filament.

FIG. 4 illustrates a typical voltage reducing circuit that may be utilized in order to control the reduced voltage applied to the series connected filaments in accordance with the present invention. Other voltage reducing circuit arrangements for this same purpose are disclosed in prior co-pending application, U.S. Ser. No. 676,799 entitled Incandescent Lamp Circuit," which was filed on Oct. 20, 1967.

FIG. 5 is a partial enlarged view of part of FIG. 3.

FIG. 6 is a schematic diagram of a filament supported by a center support.

FIG. 7 is a schematic view of a filament supported by two outside supports and an intermediate support.

FIG. 8 is a schematic view of a filament supported by two outside supports and two intermediate supports according to the invention.

In the embodiment of the invention shown in FIG. 9, a schematic view of a incandescent lamp is shown wherein the supports 124 support the filament made up of the filament elements 160 and 161. The supports 124 will be supported in a base similar to the manner in which the supports 24 are supported in the embodiment of FIG. 1. The elements 124 will be connected to terminals so that a voltage of say volts can be connected to the filament and a voltage of 12 volts can be connected to the terminals connected to filament 161.

The foregoing specification sets forth the invention in its preferred practical forms but the structure shown is capable of modification within a range of equivalents without departing from the invention which is to be understood is broadly novel as is commensurate with the appended claim.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In combination with a source of voltage of predetermined value adapted to be directly applied to a standard lamp filament producing illumination of a predetermined lumen output at rated voltage,

a long life lamp assembly comprising filament means having an equivalent length and diameter corresponding to a plurality of said standard lamp filaments enclosed in a single enclosing element, each supported at both of its ends and at an intermediate point and connected in series,

and voltage reducing means connecting said filament means to the source of voltage for applying a reduced voltage less than rated voltage,

the number of said lamp filaments and the reduced voltage being sufficient to produce a total illumination at least equal to said predetermined lumen output whereby the life of said filament means is an exponential function of the ratio of the rated voltage to the reduced voltage,

said voltage reducing means comprising a diode connected in series with said filament means across the voltage source, and a capacitor connected in parallel with the filament means.

Claims (1)

1. In combination with a source of voltage of predetermined value adapted to be directly applied to a standard lamp filament producing illumination of a predetermined lumen output at rated voltage, a long life lamp assembly comprising filament means having an equivalent length and diameter corresponding to a plurality of said standard lamp filaments enclosed in a single enclosing element, each supported at both of its ends and at an intermediate point and connected in series, and voltage reducing means connecting said filament means to the source of voltage for applying a reduced voltage less than rated voltage, the number of said lamp filaments and the reduced voltage being sufficient to produce a total illumination at least equal to said predetermined lumen output whereby the life of said filament means is an exponential function of the ratio of the rated voltage to the reduced voltage, said voltage reducing means comprising a diode connected in series with said filament means across the voltage source, and a capacitor connected in parallel with the filament means.

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