US3210587A

US3210587A - Lamp mount and component therefor

Info

Publication number: US3210587A
Application number: US230936A
Authority: US
Inventors: Robert L Vile
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1962-10-16
Filing date: 1962-10-16
Publication date: 1965-10-05
Anticipated expiration: 1982-10-05
Also published as: DE1489601A1; GB989147A

Description

Oct. 5, 1965 R. L. VlLE LAMP MOUNT AND COMPONENT THEREFOR Filed Oct. 16

FIG.3.

FIG. I.

FIG 4.

FIG. 5.

INVENTOR.

ROBERT Lv VlLE.

United States Patent 3,210,587 LAMP MOUNT AND COMPONENT THEREFOR Robert L. Vile, Perth Amboy, NJ, assignor to Westinghouse Electric Corporation, Pittsburgh, Pa, a corporation of Pennsylvania Filed Oct. 16, 1962, Ser. No. 230,936 Claims. (Cl. 313-271) This invention relates to electrical devices and has particular reference to a filament mount and a unitary filament-bridge assembly for an electric incandescent lamp.

In the manufacture of electric incandescent lamps the ends of the filament are supported by and connected directly to the lead-in conductors either by clamping or welding the members together. In the case of large lamps rated at 300 watts or above having coiled coils, the conductors are attached to the singly-coiled end sections of the filament and means must be provided to prevent them from becoming crushed or broken during the welding or clamping operation. This was accomplished in the prior art by fashioning so-called inserts consisting of short pieces of molybdenum wire or the like bent to very close tolerances so as to make a tight fit with the coiled end sections. These inserts were manually placed into the end sections before the latter were joined to the lead-in conductors and served as a sort of mandrel that prevented the coil turns from collapsing while being clamped or welded. The inserts had to be carefully formed and loaded into the coiled ends of the filament in order to lock them in place while the filament was being mounted on and fastened to the lead-in conductors.

When mounting such large coiled-coil filaments it is also necessary to provide some means of supporting the medial portion of the filament to prevent the latter from sagging excessively or breaking under shock or vibration conditions. This requirement was met in the prior art mount structures by bridging the lead-in conductors with wires joined by an insulator, and then anchoring an auxiliary support wire in the insulator. The use of such bridge assemblies and separate coil inserts was not only costly from a material standpoint but made the assembly of the mount a complicated operation that slowed down production and increased the manufacturing cost of the lamps.

It is, accordingly, the general object of the present invention to provide an improved mount structure for supporting an energizable component within an electrical device such as an electric lamp or the like.

Another object is the provision of a filament mount for an electric lamp that is rugged, simple to make and requires a minimum amount of material.

Still another object is the provision of a filamentbridge assembly that can be fabricated as a separate unit that is capable of being conveniently handled and attached directly to the lead-in conductors of a lamp stem.

The foregoing and other objects and advantages which will become obvious to those skilled in the art are achieved in accordance with the present invention by utilizing the end portions of the bridge wires as the coil inserts. This is accomplished by bending end segments of the bridge wires to form offset leg portions that are adapted to interlock with the coiled end sections of the filament in the same manner as the separate coil inserts used heretofore. The opposite ends of the bridge wires are embedded in a glass insulator together with an auxiliary support wire which is coupled to the central portion of the filament. When thus assembled, the aforesaid members form an integral filament-bridge assembly that can be conveniently handled and attached as a separate unit to the lead-in conductors of the lamp stem.

Thus, the bridge structure according to the present invention comprises a dual-purpose component that functions both as a coil insert and as an auxiliary support means for the filament.

A better understanding of the invention will be obtained from the accompanying drawing, wherein:

FIGURE 1 is a front elevational view of a lamp mount according to one embodiment of the invention;

FIG. 2 is a side elevational view of the upper portion of the mount as viewed along the reference line IIII of FIG. 1, in the direction of the arrows;

FIG. 3 is a front elevational view of the V-shaped coiled-coil filament shown in the preceding figures;

FIG. 4 is a perspective view of the bridge component used in the filament-bridge assembly shown in FIGS. 1 and 2;

FIG. 5 is a similar view of the completed filamentbridge assembly in the final stage of fabrication; and

FIGS. 6 to 8 are elevational and perspective views of other types of filament-bridge assemblies according to the invention.

Although the dual-purpose bridge structure and subassernbly technique of the present invention can be used with advantage in the manufacture of various types of electrical devices, it is especially adapted for use in mounting coiled-coil incandescent lamp filaments having a rating of 300 watts and above and has, accordingly, been so illustrated and will be so described.

EMBODIMENT I In FIGS. 1 and 2 there is shown one embodiment of a mount 10 for a 750 watt incandescent lamp according to the present invention. As illustrated in FIG. 1, the mount consists of the usual glass flare 12 having an axially extending exhaust tube 14 depending from one end and a press 15 at its opposite end that is hermetically sealed around and supports a pair of lead-in

conductors

16 and 18 in upstanding spacedapart relation. The ends of the conductors above the press are flared outwardly to provide a pair of

divergent end segments

17 and 19, respectively, which are fastened as by welding or the like to preselected portions of the unitary filament-bridge assembly 20 of the present invention.

According to the particular embodiment of the invention shown in FIGS. 1 and 2, the aforesaid unitary filament-bridge assembly consists of a V-shaped coiled-coil tungsten filament 22 having a centrally located open turn or bight 23 and axially extending singly'coiled

end sections

24 and 25 that are substantially straight and include a plurality of turns. The filament 22 is held in place on the mount 10 by a pair of L-

shaped bridge wires

26 and 28, the short segments whereof constitute what will be hereinafter called

offset leg portions

27 and 29, respectively. These leg portions extend into and are so dimensioned that they frictionally engage the substantially

straight end sections

24 and 25 of the filament 22 and thus eifect an interlocking juncture therewith.

The opposite ends of the

bridge wires

26 and 28 are embedded in an insulator 34 of suitable vitreous material, such as hard glass or the like. The bridge wires and filament are thus joined or tied together by the insulator and form a unitary filament-bridge assembly 20 that can be made and handled as a separate unit, and subsequently attached to the lead-in conductors. Also embedded in the insulator is an auxiliary support wire 30 which, as shown most clearly in FIG. 2, extends upwardly from the insulator 34 and to one side of the filament 22 and has a laterally extending arm 31 with a hook 32 formed at its end that is closed around the bight 23 of the filament.

As will be noted from FIG. 1, the L-shaped

bridge support wires

26 and 28 are so oriented that the ends thereof opposite the

offset leg portions

27 and 29 are located proximate and substantially perpendicular to one another. Thus, the filament 22 and bridge component (that .is,the

conjoined bridge wires

26 and 28, the support wire 30, and insulator 34 illustrated in FIG. 4) are so arranged that the filament-bridge assembly 20 comprises a generally rectangular structure in which the insulator is located diagonally opposite the bight portion 23 of the filament (see FIG. 1) and all the elements, except for the auxiliary support 30, lie in substantially the same plane (see FIG. 2).

The

bridge wires

26 and 28 and the auxiliary support wire 30 are, of course, fabricated from a suitable refractory metal such as molybdenum that will withstand the extreme temperatures that prevail within the lamp when the filament is energized.

As shown in FIGS. 1 and 2, the flared

end segments

17 and 19 of the lead-in conductors 16 and 1.8, respectively, extend across both legs of the

bridge wires

26 and 28 proximate the right angle bends therein and are fastened to the filament-bridge assembly 20 at the junctures between the

offset leg portions

27 and 29 and the

coil end sections

24,and 25. They may be fastened either by welding, as here shown, or by clamping so that the lead-in conductors are mechanically and electrically joined to both the bridge wires and the overlying turns of the filament. It has been found that a stronger mount can be obtained by welding or otherwise fastening the lead-in

conductors

16 and 18 to the

respective bridge wires

26 and 28 at their second point of intersection (

points

33 and 35 shown in FIG. 1) which is remote from the offset leg portions and located between these portions and the insulator 34-.

As shown in FIG. 3, the filament 22 as fabricated is V-shaped and dimensioned to nestingly interlock with the bridge component shown in FIG. 4. To mount the filament the

coiled end sections

24 and 25 are simply slipped over the

offset leg portions

27 and 29 so that the filament bight 23 lays in the support hook 32, as illustrated in FIG. 5, thereby forming the unitary filamentbridg-e assembly 20. The hook 32 is then closed (as indicated by the dotted portion of FIG. to lock the filament 22 in place and complete the fabrication of the assembly which can then be handled and fastened to the lead-in conductor-s as a separate subassembly without coming apart.

EMBODIMENT II In FIG. 6 there is shown another filament-bridge assembly 20a that is substantially the same as the one above described except that the offset leg portions 27a and 29:: are of arcuate configuration rather than straight. The curvature of the offset leg portions is such that they are slightly convex inwardly toward .the upstanding auxiliary support arm. Upon being forcibly slipped over the curved leg portions the end sections 24a and 25a of the coiled-coil filament 22a are displaced from their normally straight configuration. The resulting deformation of these coil end sections imparts a stress to the adjoining unsupported portions of the filament that causes the coil barrel to bow outwardly and assume an arched configuration, as illustrated in FIG. 6. The stressed filament is, accordingly, rigidified and made more resistant to sag. A detailed discussion of this phenomenon is set forth in US. Patent No. 2,924,735 of J. Martin, dated February 9, 1960 and owned by the assignee of the present invention.

The aforesaid prestressed filament-bridge assembly 20a is rigidly fastened to the lead-in conductors 16a and 18a, shown in dotted outline in FIG. 6, in the same manner as described previously.

EMBODIMENT III In FIG. 7 there is shown another embodiment of the present invention wherein a unitary filament-bridge assembly 20b is provided which is adapted to accommodate a coiled-coil filament 22b of linear configuration having a centrally located open turn 23b and substantially straight axially-extending singly-coiled end sections 24b and 25b. According to this embodiment, the bridge wires 26b and 231) are provided with two right angle bends that are so located that the offset leg portions 27b and 2% are substantially coaxial with the filament end sections and the opposite end portions of the wires parallel with filament and terminate at a point opposite the open turn 23b where they are joined by a glass insulator 34b. The auxiliary support wire 30]) in this case constitutes a straight piece of wire that is looped around the open turn 23b and extends laterally to the insulator.

The insulator, the bridge and support wires, and the filament thus all lie in approximately the same plane according .to this embodiment. The filament can be supported in the desired coaxial relationship with the stem by fastening the assembly 2017 at four points to suitably formed lead-in conductors 16b and 18b, such as those shown in dotted outline in FIG. 7.

EMBODIMENT IV In FIG. 8 there is shown another embodiment for axially mounting a coiled-coil filament 22c having coiled end sections 240 and 25c which extend transversely with respect to the coil body or filament axis. As there shown, the unitary filament-bridge assembly 200 is similar to the assembly shown in FIG. 7 except that the offset leg portions 270 and 29c are so formed that they extend laterally of the filament axis and are aligned with transversely extending coiled end sections of the filament. Thus, in this case, the insulator and the portions of the bridge wires which it joins lie in a plane that is generally perpendicular to the filament plane. However, by suitably bending and fastening the lead-in conductors 16c and (shown in dotted outline in FIG. 8) to the filament-bridge assembly 20c and using a diagonally oriented auxiliary support wire 300, this type of filament can also be very conveniently and securely supported in axially extending relationship with the stem and lamp.

Summary It will be apparent from the foregoing that employing a bridge structure that serves both as a coil insert and as an auxiliary filament-supporting means in accordance with the present invention reduces the number of parts and operations required to mount the filament and, thus, materially decreases the manufacturing cost of the lamp. In addition, the aforesaid dual-purpose bridge structure enables the filament to be assembled with the bridge in a separate operation to form a unitary filament-bridg assembly that can be readily handled and quickly attached to the ends of the lead-in conductors thereby improving the quality of the mounts and further facilitating their fabrication.

Since the lead-in conductors can very readily be welded rather than clamped to the filament-bridge assembly, the ends of the conductors do not have to be flattened and formed into clamps as was the case heretofore. The conductors can, accordingly, be made of harder material (nickel-plated iron, for example, instead of the soft nickel generally used) thus further improving the shock-resistant properties of the mounts.

While several embodiments have been illustrated and described, it will be obvious to those skilled in the art that various modifications in both the configuration and arrangement of parts can be made without departing from the spirit and scope of the invention.

I claim:

1. A mount for an electric lamp or the like comprising;

a coiled filament,

a pair of bridge wires each having an offset leg portion at one end at least a part of which extends into and engages the respective ends of said filament,

6 a vitreous insulator joining the opposite ends of said other of said leg portions at the point at which they bridge wires and thereby coupling said bridge wires intersect, and and filament together into a unitary assembly. a stem having a press that is hermetically sealed around a pair of lead-in conductors having end segments that said lead-in conductors and holds them in upstandare fastened to the offset leg portions of the respec- 5 ing position. tive bridge wires and to another portion of said wires 4. The incandescent lamp mount set forth in claim 3 remote from said leg portions and located between wherein; said leg portions and said insulator, and said filament is V-shaped, a vitreous stem sealed to said lead-in conductors and said bridge wires are arranged to form a generally recholding them in upstanding supporting relationship 10 tangular structure with said filament, and with said unitary assembly. said insulator is located diagonally opposite the apex 2. A mount for an electric lamp or the like as set forth of said filament. in claim 1 wherein said lead-in conductors are fastened 5. The incandescent lamp mount set forth in claim 3 to the parts of the respective offset leg portions of said wherein; 'bridge wires located within the filament and are also fassaid filament is of linear configuration and the singlytened to the overlying turns of said filament. coiled end sections thereof extend in a direction trans- 3. A mount for an electric incandescent lamp comverse to the filament axis, and prising; the leg portions of said bridge wires joined to said filaa coiled-coil filament of refractory Wire having a singlyment are offset and lie in a different plane than said coiled section at each end, insulator and the legs of said bridge wires which it a pair of L-shaped bridge wires each having one of its joins.

leg portions located within and frictionally interlocked with the respective singly-coiled end sections References Cited y the Examiner of said filament so as to form a juncture therewith, UNITED STATES PATENTS said bridge wires being so arranged that the ends thereof opposite the leg portions joined to said filament 2116384 5/38 Cal-mm 313 316 X 2,848,642 8/58 WlSCO et al 313-344 X lie proximate one another, 2 877 375 3/59 P 313 315 a glass insulator joining the proximate ends of said Carson Q 2,910,611 10/59 Jordan et a1 313--315 X bridge wires and tying said wires and filament into a 2,924,735 2/60 Martin 3133 15 X umtary filament bridge assembly. 3 007 074 10/61 S 1 3 2 a pair of spaced lead-in conductors having divergent wasey et a 31 79 end segments that extend across both of the leg FOREIGN PATENTS portions of the respective bridge wires proximate the bends therein and are welded to the end sections of said filament and to the leg portions located there- 35 in and thus support said filament-bridge assembly, DAVID GALVIN Prlmmy Exammer' each of said lead-in conductors being fastened to the JAMES KALLAM, Examiner- 7l4,761 9/54 Great Britain.

Claims

1. A MOUNT FOR AN ELECTRIC LAMP OR THE LIKE COMPRISING; A COILED FILAMENT, A PAIR OF BRIDGE WIRES EACH HAVING AN OFFSET LEG PORTION AT ONE END AT LEAST A PART OF WHICH EXTENDS INTO AND ENGAGES THE RESPECTIVE ENDS OF SAID FILAMENT, A VITREOUS INSULATOR JOINING THE OPPOSITE ENDS OF SAID BRIDGE WIRES AND THEREBY COUPLING SAID BRIDGE WIRES AND FILAMENT TOGETHER INTO A UNITARY ASSEMBLY, A PAIR OF LEAD-IN CONDUCTORS HAVING END SEGMENTS THAT ARE FASTENED TO THE OFFSET LEG PORTIONS OF THE RESPECTIVE BRIDGE WIRES AND TO ANOTHER PORTION OF SAID WIRES REMOTE FROM SAID LEG PORTIONS AND LOCATED BETWEEN SAID LEG PORTIONS AND SAID INSULATOR, AND