US2667594A

US2667594A - Electric incandescent lamp

Info

Publication number: US2667594A
Application number: US203837A
Authority: US
Inventors: Herman E Hermanson; Fredrick S Lamb
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1951-01-02
Filing date: 1951-01-02
Publication date: 1954-01-26
Anticipated expiration: 1971-01-26

Description

Jan. 26, 1954 H. E. HERMANSON ET AL 2,667,594

ELECTRIC INCANDESCENT LAMP Filed Jan. 2, 1951 Invervtors Hevman E. Hermansoh, Fredrick S.Lamb, y K-7-- Theh- A htornea.

Patented Jan. 26, 1954 2,667,594 ELECTRIC IN CANDESCENT LAMP Herman E. Hermanson,

Fredrick S.

Lamb, Cle

assignors to General El poration of New York Application January 2, 1951,

East Cleveland, and

veland Heights, Ohio, ectric Company, a. cor- Serial N 0. 203,837

6 Claims. (Cl. 313274) Our invention relates to electric incandescent lamps and similar devices, and more particularly to a mount structure therefor. The invention is of particular utility in connection with electric incandescent lamps of the double-ended tubular type having a base at each end and a filament extending longitudinally of the lamp, such as shown and described in U. S. Patent 2,032,791, Cartun, and 2,158,949, Blake, assigned to the assignee of the present invention.

Lamps of the above-mentioned double-ended tubular type are in general use at present and comprise a tubular glass envelope having metal end caps or bases sealed to the opposite ends thereof and an elongated mount supported within the envelope between the metal end caps. The mount comprises an elongated filament extending longitudinally of the envelope and supported at a plurality of spaced points along its length by a number of anchor wires insulatively fastened, by means of glass beads, to an elongated stay member which is resiliently compressible longitudinally between and supported in place by the end caps of the envelope. The stay mem ber comprises a main or center section preferably formed of a metal channel so as to possess adequate rigidity and provided at itsopposite ends with terminal wires or end conductors which are electrically connected to the ends of the filament and which bear against the end caps to make electrical connection therewith.

Heretofore, the glass support beads for the filament anchor wires of such lamp mounts have been attached or fastened in place on the metal channel by means of a fused seal therebetween, the glass beads being securely held in place by the bond between the glass and the metal of which the channel is formed. Such a fused seal type of attachment of the glass beads to the metal channel requires the use of a suitable metal for the channel which will readily wet and adhere to the glass of which the support beads are made. Up to the present the metal most suitable and preferably employed for this purpose has been a special high-chrome iron alloy of the so-called stainlesssteel type. Such a material, however, is quite expensive, thus adding materially to the cost of the finished lamp.

It is an object of our invention, therefore, to provide an electric incandescent lamp of the above-mentioned general type having a mount structure of simple and relatively inexpensive construction and easy to fabricate.

Another object of our invention is to provide an electric incandescentlamp of the above-mentioned general type having a lamp mount in which the glass beads which support the filament anchor wires are fastened to the stay member of the mount by means of a mechanical interlock therebetween.

According to the invention, the opposite side walls of the channel-shaped stay member of the lamp mount are deformed laterally of the channel at corresponding opposite points spaced therealong, as by inward or outward indentations therein, to form locking shoulders thereon which are at least partially embedded in the glass support beads for the anchor wires to thereby key and mechanically lock the glass beads in place on the channel.

Further objects and advantages of our invention will appear from the following description of a species thereof and from the accompanying drawing.

In the drawing, Fig. l is a longitudinal sectional view, partly in elevation, of an electric incandescent lamp according to the invention; Fig. 2 is an enlarged fragmentary perspective view of the mount structure of the lamp shown in Fig. 1; Fig. 3 is an enlarged transverse section of the mount structure taken on the line 33 of Fig. 2; and Fig. 4 is a sectional view ilthe method of forming the glass beads and attaching them to the channel member of the mount structure.

Referring to the drawing, the lamp there shown is of the double-ended tubular type shown in the above-mentioned U. S. Patents 2,032 791 an aperture 7 at the center of the end cap 3, the said aperture being sealed by a mass of glass tipped-01f residue of a 8 which constitutes the glass exhaust tube and.

ll, channel member ['3 at a slight angle relative free or outer'ends are bent to extend transversely of extent longitudinally thereof.

small glass support beads 3 which is sheltered within the cavity formed by the boss 5.

Mounted within and extending longitudinally of the envelope I is an elongated lamp mount 9 according to the invention comprising a filament support structure Ill and an elongated filament ll supported thereby. The filament support structure H! comprises a stay member 1200mposed of an elongated straight center section 13 extending longitudinally the wall thereof and provided at its opposite ends with terminal wire or conductor extensions l4, l5. The center section 13 of stay member I2 is preferably in the form of an approximately V- shaped channel member to one end of whichthe terminal wire 44 is electrically connected as by welding. The other terminal wire i5 is insulatively secured to the other end of the channel member l3 by a short length of glass rod IS in which the respective ends of the channel member l3 and wire it are embedded.

As shown, the terminal wires or end conductors l5 extend from the opposite ends of the thereto, and their the channel member 13 and-are formed into loops ll which encircle the bosses 5, 6 on the respectively adjacentend caps to thereby position the lamp mount 9 within the envelope i with the filament ll extending more or less axially of the said envelope. The loop IT on one or both terminal wires Ill, i5 is initially formed with a slight pitch or spiral shape, i. e., it is formed as a coil of less than one full turn, for the purpose of making the stay member l2 resiliently compress ble to a slight During the manufacture of the lamp, the spiral-shaped loop or loops 11 more or less flatten out as the stay mom-- *ber I2 is compressed between the opposite end the loops il thus resiliently bearing against the concave inner side of the end caps and'so making good electrical contact therewith.

The filament H is in the form of a coiled caps 3, 4,

tungsten wire which extends substantiallythc entire'length and axially of the is stretched out and clamped envelope i and or otherwise electrically connected at its ends to short spur wires 48, i9 welded to the terminal wires id, id, re-

filament ii is additionally supspectively. The ported at intermediate points along its length by one or more support or anchor wires 23 extending from the channel member it at spaced points therealong, the said support wires being provided at one end with filament supporting loops 2| and being secured at their other ends and insulated from the channel member by means of 22 in which thesupport wires 20 are embedded.

In accordance with the invention, the glass beads 22, in place of being fastened to and held in place on the channel member 53 by means of a fused glass-to-metal seal as has heretofore been the practice, are mechanically anchored to the channel member instead. For such purpose, the channel member 13 is formed, at spaced points along its length corresponding to the location of the glass beads thereon, with locking shoulders provided, in this instance, by small lateral deformations or both of the side walls 2d of the channel member l3, preferably at their upper or free edges 25, as shown. The said indentations 23 are preferably provided in both of the side walls 24 of the channel at corresponding opposite points of the tube 2 adjacent or indentations S in one and be locked in place bead to the channel member.

spaced along its length. The glass beads 22 engage and are immovably held in place on the channel member I 3 by the said locking shoulders, the glass beads substantially filling the interior cross-sectional space of the channel at the respective indentations 23 (Fig. 3) so as to engage on the channel member 13 by the indentations. As shown in Fig. 3, the glass of the beads 22 preferably extends over the free longitudinal edges 25 of the channel member l3 and down around the outer sides thereof, as indicated at 26, so as to actually embed the indentededge portions 23 of the channel member. The result, therefore, is a secure and strong clamping mechanical interlock of the glass bead to-t-hechannel such as effectively holds the bead immovably in place on the channel.

As shown in Fig. 4, the glass beads 22 are each formed from a short length of relatively small diameter glass rod or a pressed powdered glass pellet 27. The glass rod 2? is suitably heated at one end to a plastic condition and the said heated end then pressed down into the channel member it (which is also preferably heated to a slight degree) at the region of the respective group of indentations therein so as to cause the softened glass to substantially fill the interior cross-sectional space of the channel at said point (Fig. 3) and also flow down over the outside surfaces of the side walls 24 of the channel member, as shown at 26 in Fig. 3, thus embedding the indented edge portions 23 of the channel member in the glass and thereby securely locking the glass After the attachment of the glass rods 21 to the channel member i3, the upper ends of the rods 21 are heated to a plastic condition and fused down, whereupon the support wires 20 are inserted endwise into and embedded in the glass to complete the support wire mounting.

Inasmuch as the attachment of the glass beads fected by automatic means such as causes the location of the glass beads lengthwise of the channel member l3' to vary within small limits, it is preferable that a series or group (e. g., two or three) of contiguous identations 23 be provided in the channel member i3 at the approximate location of each bead 22 so as to allow for any such slight variation in bead location and assure that the glassbead'will engage or embed at least a part of one or more of the indentations 23 of its respective group and become locked to the channel. The mechanical fastening of the glass beads 22 to the channel member l3 in accordance with the invention therefore permits the use of an ordinary and much less expensive metal for the channel member than the high chrome-iron alloy heretofore employed for such purpose. Thus the channel member l3 may be formed of ordinary rolled iron or steel, for instance, as a result of which the cost of the lamp mount 9 and of the finished lamp is considerably reduced.

Although a preferred embodiment of our invention has been disclosed, it will be apparent that the invention is not tobe limited to the specific construction and arrangement of parts shown but that they may be widely modified within the spirit and scope of our invention as defined by the appended claims.

What we claim as new and desire to secure by Letters Patent of the United States is:

1.- An electric lamp comprising a glassenvelope. a mount within said envelope comprisingan elongated filament and an elongated metallic stay member extending longitudinally of the filament and carrying support wires engaging and supporting the filament at spaced points therealong, said stay member comprising a metal channel provided at spaced points therealong with lateral deformations in at least one of its side Walls, and glass beads insulatively fastening said support wires to said channel, said channel being of a metal incapable of readily forming an adherent bond with the glass of said beads, and said glass beads being shaped in situ in engaging and interlocking relation with the said deformations to mechanically hold the beads immovably in place on said channel against movement longitudinally as well as laterally thereof.

2. An electric lamp comprising a glass envelope, a mount within said envelope comprising an elongated filament and an elongated metallic stay member extending longitudinally of the filament and carrying support wires engaging and supporting the filament at spaced points therealong, said stay member comprising a metal channel provided with longitudinally spaced indentations in at least one of its side walls, and glass beads insulatively fastening said support wires to said channel, said channel being of a metal incapable of readily forming an adherent bond with the glass of said beads, and said glass beads substantially filling the interior cross-sectional space of said channel at the region of respective ones of said indentations and being shaped in situ in engaging and interlocking relation with the said indentations to mechanically hold the beads immovably in place on said channel against movement longitudinally as well as laterally thereof.

3. An electric lamp comprising a glass envelope, a mount within said envelope comprising an elongated filament and an elongated metallic stay member extending longitudinally of the filament and carrying support wires engaging and supporting the filament at spaced points therealong, said stay member comprising a metal channel having the free edge portion of at least one of its side walls inwardly indented at spaced points therealong to provide locking indentations, and glass beads insulatively fastening said support wires to said channel, said channel being of a metal incapable of readily forming an adherent bond with the glass of said beads, and said glass beads substantially filling the interior cross-sectional space of said channel at the region of respective ones of said indentations and being shaped in situ into at least partially embedding relation with the indented free edge portions of said channel to mechanically lock the beads to the channel and hold them immovably in place thereon against movement longitudinally as well as laterally thereof.

4. An electric lamp comprising a glass envelope, a mount Within said envelope comprising an elongated filament and an elongated metallic stay member extending longitudinally of the filament and carrying support wires en aging and supporting the filament at spaced points therealong, said stay member comprising a metal channel having the free edge portions of both its side walls indented to provide opposed sets of indentations spaced apart longitudinally of the channel, and glass beads insulatively fastening said support wires to said channel, said channel being of a metal incapable of readily forming an adherent bond with the glass of said beads, and said glass beads substantially filling the interior cross-sectional space of said channel at the region of respective sets of said indentations and being shaped in situ into at least partially embedding relation with the latter to mechanically lock the beads to the channel and hold them immovably in place thereon against movement longitudinally as Well as laterally thereof.

5. An electric lamp comprising a glass envelope, a mount Within said envelope comprising an elongated filament and an elongated metallic stay member extending longitudinally of the filament and carrying support wires engaging and supporting the filament at spaced points therealong, said stay member comprising a metal channel having the free edge portions of both its side walls indented to provide longitudinally spaced groups of contiguous opposed sets of indentations, and glass beads insulatively fastening said support wires to said channel, said channel being of a metal incapable of readily forming an adherent shaped in situ into at least partially embedding relation with the indentations of at least one of the said opposed sets thereof in its respective group to mechanically lock the beads to the channel and hold them immovably in place thereon against movement longitudinally as well as laterally thereof.

6. A lamp mount comprising an elongated stay member, an elongated filament extending longitudinally of said stay member and supported therefrom, a plurality of support wires carried by said stay member and engaging and supporting the filament at spaced points therealong, said stay member comprising a metal channel having the free edge portion of at least one of its side walls inwardly indented at spaced points therealong to provide locking indentations, and glass beads insulatively fastening said support wires to said channel, said channel being of a HERMAN E. HERMANSON.

FREDRICK S. LAM References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,306,912 Keyes June 17, 1919 1,607,515 Duncan Nov. 16, 1926 1,649,907 Mayer Nov. 22, 1927 1,662.032 Mullaney Mar. 6, 1928 1,884,957 Adams Oct. 25, 1932 2,082,616 Cartun June 1, 1937 2,425,865 Cartun Aug. 19, 1947 2,434,779 Willis Jan. 20, 1948