US2862147A

US2862147A - Lamp with automatic filament shifting means

Info

Publication number: US2862147A
Application number: US541148A
Authority: US
Inventors: Conti Vincent
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-10-18
Filing date: 1955-10-18
Publication date: 1958-11-25
Anticipated expiration: 1975-11-25

Description

V. CONT] Nov. 25, 1958 LAMP WITH AUTOMATIC FILAMENT SHIFTING MEANS Filed Oct. 18, 1955 3 Sheets-Sheet 1 NOV. 25, 1958 v, co 2,862,147

LAMP WITH AUTOMATIC FILAMENT SHIFTING MEANS Filed Oct. 18, 1955 5 Sheets-Sheet 2 /7 TTOP/VE'Y)? LAMP WITH AUTOMATIC FILAMENT SHIFTING MEANS Filed Oct. 18, 1955 V. CONT] I Nov. 25, 1958 3 Sheets-Sheet 3 a w W v Z 3 Z 4 I 0 m w M 8 2 M 2 w nm n uw a 0 wan" m M, 5 N f 6 I E j w 0 j J 2 m x 4 2 a z w w mw m a 0 .2 a 8 0 w 6 2 I a HHW #w W HHHHI. m 0. 4/0 6 0 m fl H/ a 2 4 9 40 w j 2 f/// M 2 United States Patent "ice 1 LAMP WITH AUTOMATIC FILAMENT SHIFTING MEANS Vincent Conti, New York, N. Y.

Application October 18, 1955, Serial No. 541,148

18 Claims. (Cl. 315-65) The present invention relates to means, in a lamp having a plurality of filaments, for causing only one filament at a time to be energized and for automatically shifting electrical connection to a second filament in case the first filament should break.

The invention is here disclosed embodied in an incandescent bulb useable for illumination purposes, but it is applicable for use in other types of bulbs as well.

It is often desired that the failure of a filament should not result in complete failure of the bulb. Accordingly, a plurality of filaments may be incorporated into the bulb, only one of those filaments normally being energized, and means may be provided which, upon failure of the normally energized or primary filament, will automatically shift electrical connection to the normally unenergized or secondary filaments. Various arrangements have been proposed in the past to accomplish this end, but they are all fairly expensive and complicated, or else are not sulficiently reliable in operation.

In accordance with the present invention, an arrangement has been devised which is easily assembled, does not add appreciably to the cost of the bulb, and will perform the desired functions in a reliable and well nigh foolproof manner. The arrangements of the present invention are particularly well adapted for incorporation into bulbs which may be mounted either base-up or base-down, and will in most instances function effectively no'matter in which of these ways the bulbs are mounted.

Broadly described, the invention utilizes means for completing electrical connection to the secondary filament or filaments, which means is operatively associated with the primary filament and sensitive to the position thereof. If the primary filament should break for any reason the separated segments of that filament will fall, and the operative association between the means and the primary filament is such that when the latter falls the means will be modified to produce the desired result. In one form the means is mounted on and slidable along a lead connected to one terminal of the lamp and is supported by the primary filament. When the primary filament breaks the support will be destroyed, the means will move downwardly, and that downward movement will elfectuate the desired electrical connection to the secondary filament. This can be done either by having the means directly connected to and supporting one end of the secondary filament, so that when the means falls that filament end will move into electrical connection with the lead, or that filament end can be physically mounted on but insulated from the lead, the means itself being electrically connected to the lead and, when it falls, engaging and making electrical connection with the appropriate end of the secondary filament. According to another form an end of the primary filament is electrically connected to the lead and the means is electrically connected to the corresponding end of the secondary filament, the means normally being insulated from the lead but the movement of the primary filament attendant upon a break therein causing the primary filament to 2,862,147 Patented Nov. 25, 1958 engage the means and thus complete electrical connec-.

tion to the secondary filament.

While the present invention is here specifically disclosed as relying exclusively on the force of gravity for eflfecting the desired results, it will be appreciated that the use of auxiliary means such as springs to make the switching action even more positive is not necessarily precluded. However, the use of springs or other devices is not at all essential to the operation of the instant devices. l e f To the accomplishment of the above, and to such othe objects as may hereinafter appear, the present invention relates to lamp structure for effecting automatic switch-, ing from a primary to a secondary filament, as defined in the appended claims and as described in this specification, taken together with the accompanying drawings, in which:

Fig. l is a perspective view of a lamp having two filaments, one above the other, constructed according to the present invention, the lamp being shown with the primary filament active;

Fig. 2 is a fragmentary view similar to Fig. 1 but showing the position which the parts assume when the primary filament breaks;

Fig. 3 is a view similar to Fig. 1 but illustrating one manner in which the invention may be applied to a bulb having primary, secondary and tertiary filaments adapted to be sequentially energized, the primary filament being shown energized;

Fig. 4 is a fragmentary view similar to Fig. 3 but showing the positions which the parts assume when the primary filament breaks;

Fig. 5 discloses the invention embodied in a two-filament bulb of specifically different construction from that shown in Fig. 1;

Fig. 6 discloses a structure comparable to that of Fig. l but with a specifically difierent arrangement of parts;

Fig. 7 is similar to Fig. 6 but showing the position which the parts assume when the primary filament breaks;

Fig. 8 is a perspective view of a bulb constructed according to the present invention in which three filaments all positioned at the same level are embodied, the primary filament being shown energized;

Fig. 9 is a view similar to Fig. 8 but showing the position which the parts assume when the primary filament breaks; a

Fig. 10 is a perspective viewof .yet another two-filament bulb in which yet another embodiment of the present invention is disclosed, the primary filament being shown energized;

Fig. 11 is a view similar to Fig. 10 but showing the position which the parts assume when the primary filament breaks;

Fig. 12 is a side elevational view of yet another em bodiment of the present invention, the bulb being shown in a base-up position;

Fig. 13 is a cross sectional view on an enlarged scale of theoperative parts of the bulb of Fig. 12, the primary filament being shown broken; and v Fig. 14 illustrates the bulb of Fig. 12 in a base-down position. 7

In the embodiment of Figs. 1 and 2 the lamp comprises a base generally designated 2 and an evacuated bulb generally designated 4. The base 2 is provided, as is.

v are respectively electrically connected to the

terminals

6 and 8. The ends 20:: and 22a of the

filaments

20 and 22 3 respectively are physically and electrically connected to appropriate points on the lead 26. The ends b and 22b of the

filaments

20 and 22 respectively are physically connected to insulators 28 and on the lead 24.

The means for completing anelectrical circuit through one or the

other filaments

20 or 22 is generally designated 32. It comprises a conductive wire coiled about the vertical portion 24a of the lead 24 at 34 so as to make electrical connection therewith and be slidable therealong.

Arms

36 and 38 extend from the coiled portion 34 toward the

filaments

20 and 22 respectively, those arms terminating in loops and 42 respectively which surround the

filaments

20 and 22 respectively adjacent their

ends

20b and 22b respectively. 7

When the lamp of Figs. 1 and 2 is in its base-up position there shown, the filament 22 constitutes the primary filament and the filament 26 is the secondary filament. The loop 42 rests upon and is supported by the filament end- 225 and makes electrical connection therewith via the looped portion 34 and the arm 38. Thus the filament 22 is energized. The loop 40 is supported by the arm 36 out of engagement with the filament end 20b, and consequently the filament 20 is not energized. In order to prevent vibration from causing the loop 40 to intermittently engage the filament 20 and energize it, the sides of the loop 40 may be covered with insulating material 44, and insulating material 46 may correspondingly cover the sides of the loop 42.

'As shown in Fig. 2, if the filament 22 should break it would fall and consequently. would no longer support the loop 42 and the remainder of the means 32. Hence the coiled portion 34 will slide downwardly along the lead 24a until the loop 40 rests on the filament 20, at which time electrical connection will be made to the filament 20 and that filament will beenergized.

If the bulb of Figs. 1 and 2 should be inverted to a base-down position, the structure will operate in the same way, except that the filament 20 would become the primary filament and the filament 22 would become the secondary filament;

Figs. 3 and 4 disclose a structure essentially similar to that shown in Figs. 1 and 2, and similar reference numerals are applied to similar parts. However, the embodiment of Figs. 3 and 4 difiers from'that of Figs. 1 and 2 primarily in the following respects: In addition to the

filaments

20 and 22, a third filament 20 is employed.

The end 22b of the primary filament 22 is constituted by a short length of structurally strong material pivotally connected to the end of the lead portion 24a at 48, and the end 20b of the intermediate filament -20 is similarly constructed and pivotally connected at to the insulator 28. The switching means 32 comprises two coiled portions 34 and 34', the loop 42' at the end of the arm 38 depending from the coiled portion 34 being received around the part 22b. The loop 40 is not only connected to the coiled portion 34 by the arm 36, as before, but is also connected to the coiled portion 34 by the arm '38. A loop 40, which surrounds the third filament 20', is supported by arm 36 connected to coiled portion 34'. The loops 42', 40 and 40' are of gradually increasing size. T he'loop 40' is provided at its top and bottom with curved shields 49 aligned with the filament end 20b.

Inthis embodiment, the filament 22 constitutes the primary filament, the filament 20 constitutes the secondary filament, and the filament 20' constitutes the tertiary filament. When the filament 22 is intact the means 32 will be supported by the loop 42' so thatthe loop 40 is spaced from the filament 20 and the loop 40' is spaced from the'filament 20. V

-It will be noted that'electrical connection to the end 22b' of the filament 22 is eifectuated independently of the means 32, and hence it is not essential that the loop 42' make electrical connection with the filament end 22b. Since the filament ends 20b and 22b are formed of substantially rigid material, much stronger than the actually incandescent portion of the filament proper, the reliability of support of the means 32 is greatly enhanced. These modifications could, of course, be incorporated even into those embodiments where they are not specifically illustrated.

If the primary filament 22 should break the support which it afforded the means 32 will be destroyed and consequently the

coiled portions

34 and 34 will slide downwardly along the lead 24a until the loop 40 engages the filament end 26b. The means 32 will then be supported by the filament 20 and that filament will be energized. Since the loop 40' is larger than the loop 40, no energization of the tertiary filament 20' will take place. This position of the parts is illustrated in Fig. 4. It may be noted that an adidtional advantage of the use of the pivotally mounted substantially rigid portion 22b (or 20b) is that said portion, when it pivots downwardly, will because of its own weight and rigidity tend to pull the means 32 downwardly, and thus will more readily ensure that proper electrical connection with the next succeeding filament is efiectuated.

If the filament 20 of Fig. 4 should break the means 32 will then slide downwardly along the lead 24a an additional distance, until the loop 40 rests upon and makes electrical connection with the tertiary filament 20. It may be noted that when the loop 40' rests upon the filament 20' it will be supported by one of the shields 49 which extend along a substantial portion of the length of the filament 20' and consequently distribute the weight of the means 32, thus rendering it most unlikely that the weight of the means 32 will have any appreciable effect on the longevity of the filament 20'. It will be appreciated that the shields 49 could be employed in other embodiments of my invention for this purpose, even when they are not there specifically disclosed.

If the bulb of Figs. 3 and 4 should be inverted, it would function in substantially the same manner as just described, the filament 22 remaining the primary filament and the

filaments

20 and 20 remaining the secondary and tertiary filaments respectively.

It will be understood that while the embodiments of Figs. 3 and 4 shows three filaments, any number of filaments could be employed using-the principles there disclosed. 9

Fig. 5 illustrates my invention embodied in a lamp of specifically dilferent design. There the

ends

20a and 22a of the

filaments

20 and 22 respectively are physically and electrically connected to lead 26, as before. The filament ends 20b and 22b are physically connected to and supported by blind lead 52 by means of

insulators

28 and 30 respectively. The lead 24 which is electrically connected to the tip terminal 6 extends centrally of the bulb 4. The portion 34 ofthe means 32 iscoiled about and slidable along the live lead 24' and its

arms

36 and 38 carry at their

ends loops

40a and 42. The loop 42 may be in all respects similar to the loop 42 of Fig. l, but the loop 40:: as specifically disclosed in Fig. 5 is quite small and closely engages the filament end 20b, thus being similar to the loop 42' of Fig. 3. Because of the use of a small loop 49a, the filament 20 in the embodiment of Fig. 5 will be the primary filament whether the lamp is in the position shown or inverted.

If, in the embodiment of Fig. 5, the insulating material 44 is wholly or partially eliminated from the loop 42, the means 32 would function to achieve the desired results even if the bulb were mounted at a horizontal position. The primary filament 20 would support the means 32 against rotative sliding around the lead 24' with the sides of the loop 42 spaced from the end 22b of the filament 22. When the primary filament 20 breaks that support will be lost, the coiled portion 34 of the means 32 will rotatively slide over the lead 24, and consequently the hated side-of the loop 42 will engage the end 22b of the secondary filament 22, thus energizing the latter.

This same principle could, also, be employed in connection with other embodiments, such as the embodiments of Figs. 3-4, 6-7 and 8-9.

The embodiment of Figs. 6 and 7 is essentially similar to that of Figs. 1 and 2. However, the

ends

20b and 22b of the

filaments

20 and 22 are shown as formed of strong rigid elements similar to the similarly numbered parts in Fig. 3. In addition, the arm 38 of the means 32 does not carry a loop 42 but is instead directly physically secured to the filament end 22, as by's'older 54. Hence the operation of the embodiment of Figs. 6 and 7 will be essentially similar to that of Figs. 1 and 2 except that the filament 22 will remain the primary filament no matter in What position the lamp may be mounted. Moreover, in the embodiment of Figs. -6 and 7 the element 30' to which the filament end 22b is pivotally connected at 48 is shown as conductive, thus effectuating electrical connection to the filament 22 independently of the means 32. Hence it is immaterial whether the arm 38 be electrically connected to the lead 24a or to the filament end 22b. Alternatively, if electrical connection is ettectuated between the arm 38 and the filament end 22b and with the use of an element 30' which is conductive as shown, reliance need not be placed upon electrical connection between the coiled portion 34 and the lead 24, and hence the coiled portion 34 may be more loosely wound around the lead 24a than would otherwise be the case. It will be understood that these modifications could be carried over into the other embodiments even where not specifically illustrated.

The loop 40 of Figs. 6 and 7 may be provided at its top and bottom, as illustrated, with small permanent -magnets 56. When the primary filament 22 breaks, as

illustrated in Fig. 7, one or the other of these magnets 56, depending upon the position of the lamp, will engage with the filament 20 and will serve twofunctions. They distribute the weight of the means 32 along a substantial portion of the length of the filament 28, in this way paralleling the effects of the shields 49 on the loop 40 of Fig. 3, and in addition they serve to ensure adequate physical and electrical contact between the loop 48 and the filament 28 even when the lamp is subjected to vibration. Alternatively, the end 28b of the filament 20 could be permanently magnetized in place of or in addition to the use of the magnets 56 carried by the loop 40.

Figs. 8 and 9 disclose the invention as embodied in a lamp having a plurality of filaments disposed at the same level. In Figs. 8 and 9 the lead 24 is connected to the side terminal 8, while a plurality of leads 5%, 60 and 62 are all connected to the tip terminal 6. The

filaments

64, 66 and 68 are respectively the primary, secondary and tertiary filaments. Their ends 64a, 66a and 68a are connected electrically and physically to the leads 58, '60 and 62 respectively. Their other ends 64b, 66band 681) are physically connected to insulator 70 at the tip of the lead 24. The coiled portion 34 of the means 82 has three arms 72, 74 and 76 which carry

loops

78, 80 and 82 respectively, each of increasingly greater size, which surround the filament ends 64b, 66b and 68b re spectively. The size of the loop 78 is such that when the primary filament 64 is intact the

loops

80 and 82 will be held out of engagement with their respective filament ends 661) and 68b. .Thus only the primary filament 64 will be energized. When, as illustrated in Fig. 9, the primary filament 64, will slide downwardly along the lead 24 until it is supported by engagement between the loop 80 and the secondary filament 66, thus energizing that filament. The size of the loop 82 will ensure, however, that the tertiary filament will not be energized. If the secondary filament 66 should break then the means 32 will slide downwardly until the loop 76 rests on and energizes the tertiary filament 68. Although this particular construction is disclosed in a lamp having three filaments, it will be apparent that a similar construction could be employed in lamps having two filaments or more than three filaments.

In the embodiment of Figs. 10 and 11 the upper end of the lead 24a is provided with an insulating coating 84 above and below which wider

conductive elements

86 and 88 are positioned, those elements being electrically connected to the lead 24a. The end 22b of the filament 22 is provided with a loop 90 adapted to slide along the insulated portion 84 and to engage and make electrical connection with one or the other of the

conductive elements

86 or 88. The arm 36 of the means 32 is directly electrically and physically attached to the end 20b of the filament 20, and the arm 38 is directly physically secured to the end 22b of the filament 22 but is electrically insulated therefrom, as by the connecting means 92. In this embodiment, when the filament 22 is intact, the means 32 will maintain the filament end 22b in a position intermediate between the

conductive elements

86 and 88, thus preventing energization of the secondary filament 22. The primary filament 20 will be energized via the coiled portion 34 and the arm 36 of the means 32. (Alternatively, as in Fig. 6, the element 30 to which the filament end 20b is pivotally connected at 50 may be conductive, in which case there is no necessity for the means 32 to be electrically connected to the lead 24a, as will become apparent.) When the filament 20 breaks the means 32 is no longer supported thereby, and consequently the filament end 22b will be permitted tofall into engagement with the lowermost of the conductive el6-

ments

86 or 88 depending upon the position of the lamp, and the secondary filament 22 will then be energized.

In the embodiment of Figs. 12-14 the lead 24a is provided with

enlarged portions

94 and 96 conductively connected thereto. Two

composite elements

98 and 100 are slidably mounted on the lead 2401 between the

portions

94 and 96. The element 98 comprises

conductive parts

102 and 104 separated by insulation 106, the

conductive parts

102 and 104 being held out of conductive engagement with the lead 24a proper but the part 102 being engageable with the conductive portion 94 when the bulb is in the position shown in Figs. 12 and 13. The element 100 comprises

conductive parts

108 and 110 separated by insulation 112, the

parts

108 and 110 being held out of conductive engagement with the lead 24a proper but the part 108 being engageable with the conductive portion 96 when the bulb is positioned in base-down position as shown in Fig. 14. The filament end 2211' is physically and electrically connected to the part 102 and the filament end 20b is physically and electrically connected to the part 108. .The part 104 carries, by means of wire 114, a loop 116 which surrounds but is normally out of engagement with the filament end 22b. The part 110 carries, by means of wire 118, a loop 120 which surrounds but is normally out of engagement with the filament end 2%. A substantially rigid wire 122 connects part 102 with part 110, and a substantially rigid wire 124 connects part 104 with part 108, the

wires

122 and 124 maintaining the spacing between the

elements

98 and 100, that spacing, as shown, being somewhat less than the spacing between the

parts

94, 96.

When. the bulb is in base-up position, and when the filament 22 is intact, as shown in Fig. 12, the filament 22 will be energized by a circuit which may be traced through the lead 24a, portion 94, part 102, filament 22 and lead 26. The filament end 2% will not be electrically connected to lead 24a because the part 108 is separated from the portion 96 and because the loop 120 which is electrically connected to the part 102 is out of engagement with the filament end 20b. If now, as shown in Fig. 13, filament 22 should break, its end 22b would engage with loop 116, and consequently the end 20b of the filament 20 would be connected with lead 24a via part 108, wire 124, part 104, wire 114, loop 116, filament end 22!), part 102 and portion 94.

If the bulb should be in base-down position, as shown in Fig. 14, the same results will obtain, except that now part 108 will be in engagement with the portion 96, and the filament 20 will become the primary filament and the filament 22 will become the secondary filament.

It will be appreciated from the above discussion that in each case relative movement between the primary filament and the lead attendant upon the breaking of the primary filament will cause connection to be made to the secondary filament to energize the latter, and this by means of simple structure which may rely exclusively upon the force of gravity to accomplish the desired results. A number of embodiments of the invention have been here disclosed which illustrate but some of the ways in which the principle of my invention can be embodied. Of course, there are many types of lamp and bulb constructions, and I have illustrated my invention only in connection with a limited number of them, but the invention is clearly applicable to bulb constructions other than those here specifically disclosed and many variations may be made in the specific details of the structure, all within the spirit of the invention as defined in the following claims.

I claim:

1. An electric lamp comprising a bulb having terminals, primary and secondary filaments in said bulb, said secondary filament being adapted to light when said primary filament breaks, electrical connections between one end of each of said filaments and one of said terminals, an electrical connection between the other end of said primary filament and the other of said terminals, an elongated vertical lead electrically connected to said other terminal, and means for connecting the other end of said secondary filament to said other terminal when said primary filament breaks, said means being mounted on said lead, slidable therealong, and comprising a conductive structure physically connected to said primary filament and normally spaced at a given point from one of said lead and said secondary filament, said space defining an open circuit between said secondary filament and said lead, whereby relative movement between said primary filament and said lead attendant upon the breaking of said primary filament causes said means to slide along said lead'until said space disappears, thereby electrically connecting said other end of said secondary filament to said lead.

2. An electric lamp comprising a bulb having terminals, primary and secondary filaments in said bulb, said secondary filament being adapted to light when said primary filament breaks, electrical connections between one end of each of said filaments and one of said terminals, an electrical connection between the other end of said primary filament and the other of said terminals,'an elongated vertical lead electrically connected to said other terminal, and means for connecting the other end of said secondary filament to said other terminal when said primaryfilament breaks, said means being mounted on said lead to be slidable therealong and having a first portion normally engageable with and supported by said primary filament, and a second portion operatively engageable with said secondary filament and effective to cause relative motion between said lead and either one of said secondary filament and said second portion, thereby to complete electrical connection between said lead and said other end of said secondary filament, whenever said primary filament breaks and said means moves relative to said lead.

3. An electric lamp comprising a bulb having terminals, primary and secondary filaments in said bulb, said secondary filament being adapted to light when said primary filament breaks, electrical connections between one end of each of said filaments and one of said terminals, an electrical connection between theother end of said primary filament and the other of said terminals, an elongated vertical lead electrically connected to said other terminal, and means for connectingthe other endof said secondary filament to said other terminal when said primary filament breaks, said means being mounted on said lead, slidable therealong and electrically connected thereto, said means comprising a first portion normally engageable with and supported by said primary filament and a second portion normally spaced from said secondary filament but movable into engagement therewith to complete the electrical circuit thereto whenever said primary filament breaks and thus destroys the support for said means.

4. The lamp of claim 3, in which said second portion of said means comprises a member normally positioned above said secondary filament and movable downwardly to rest upon said secondary filament when said primary filament breaks.

5. The lamp of claim 3, in which one of said portions comprises a loop normally extending at least partially around the corresponding filament and movable downwardly to rest upon said filament.

6. The lamp of claim 3, in which the sides of said loop are covered with insulation but the upper and lower portions of said loop are exposed.

7. The lamp of claim 3, in which one of said portions comprises a member extending over and along the length of the corresponding filament for an appreciable distance, whereby the weight of said means is distributed over a substantial portion of the length of said filament when said means is supported thereby.

8. The lamp of claim 3, in which one of said portions comprises a permanent magnet engageable with the corresponding filament when said means is supported thereby,

thus ensuring engagement between said portion and said filament.

9. The lamp of claim 3, in which one of said filaments comprises a conductive portion of appreciable strength adjacent said lead, the corresponding portion of said means being engageable therewith when said means is supported thereby.

10. An electric lamp comprising a bulb having terminals, primary, secondary and tertiary filaments in said bulb, said secondary filament being adapted to light when said primary filament breaks and said tertiary filament being adapted to light when both said primary and secondary filaments break, electrical connections between one end of each of said filaments and one of said terminals, an electrical connection between the other end of said primary filament and the other of said terminals, an elongated vertical lead electrically connected to said other terminal, and means for sequentially connecting the other ends of said secondary and tertiary filaments respectively to said other terminal when said primary and secondary filaments respectively break, said means being conductive,

mounted on said lead so as to be slidable thereover, and having first, second and third portions, said first portion normally being engageable with and supported by said primary filament, said second and third portions being spaced from said secondary and tertiary filaments respectively by progressively increasing distances, breakage of said primary filament causing said means to slide over said lead until said second portion engages with and is supported by said secondary filament, thereby electrically connecting said other end ofsaid secondary filament to said lead, breaking of said secondary filament causing said means to slide over said lead until said third portion engages with and is supported by said tertiary filament, thereby electrically connecting said other end of said tertiary filament to said lead.

11. An electric lamp comprising a bulb having terminals, primary and secondary filaments in said bulb, said secondary filament being adapted to light when said primary filament breaks, electrical connections between one end of each of said filaments and one of said terminals, an electrical connection between the other end of said primary filament and the other of said terminals, a lead electrically connected to said other terminal and having a substantially vertical portion comprising an insulated part above a conductive part, and means for connecting the other end of said secondary filament to said other terminal when said primary filament breaks, said means comprising a structure operatively connected between said primary and secondary filaments, supported by said primary filament and in turn supporting said other end of said secondary filament adjacent the insulated part of said lead, breaking of said primary filament removing the support for said means and causing said other end of said secondary filament to fall to and engage the conductive part of said lead, thereby causing said secondary filament tolight.

12. The lamp of claim 11, in which said other end of said secondary filament is looped around the insulated part of said lead, the conductive part of said lead comprising a portion of increased diameter positioned below said other end of said secondary filament, said other end of said secondary filament falling to rest on said conductive portion of increased diameter when said primary filament breaks.

13. An electric lamp comprising a bulb having terminals, primary and secondary filaments in said bulb, said secondary filament being adapted to light when said primary filament breaks, electrical connections between one end of each of said filaments and one of said terminals, an electrical connection between the other end of said primary filament and the other of said terminals, an elongated vertical lead electrically connected to said other terminal, and means for connecting the other end of said secondary filament to said other terminal when said primary filament breaks, said means comprising a first portion mounted on said vertical lead so as to be slidable therealong, a second portion extending from said first portion and resting on said primary filament, and a third portion extending from said first portion and normally spaced from one of said lead and said secondary filament, said space defining an open circuit between said secondary filament and said lead, whereby relative movement between said primary filament and said lead attendant upon the breaking of said primary filament causes said means to slide along said lead until said space disappears, thereby electrically connecting said other end of said secondary filament to said lead.

14. An electric lamp comprising a bulb having terminals, primary and secondary filaments in said hub, said secondary filament being adapted to light when said primary filament breaks, electrical connections between one end of each of said filaments and one of said terminals, an electrical connection between the other end of said primary filament and the other of said terminals, an elongated vertical lead electrically connected to said other terminal, and means for connecting the other end of said secondary filament to said other terminal when said primary filament breaks, said means comprising a first portion mounted on said vertical lead so as to be slidable therealong, a second portion extending from said first portion and resting on said primary filament, and a third portion extending from said first portion and normally spaced from said secondary filament, said space defining an open circuit between said secondary filament and said lead, whereby relative movement between said primary filament and said lead attendant upon the breaking of said primary filament causes said means to slide along said lead until said space disappears, thereby electrically connecting said other end of said secondary filament to said lead.

15. An electric lamp comprising a bulb having terminals, primary and secondary filaments in said bulb, said secondary filament being adapted to light when said primary filament breaks, electrical connections between one end of each of said filaments and one of said terminals, an electrical connection between the other end of said primary filament and the other of said terminals, an elongated vertical lead electrically connected to said other terminal, and means for connecting the other end of said 10 secondary filament to said other terminal when said primary filament breaks, said means comprising a first portion mounted on said vertical lead so as to be slidable therealong, a second portion extending from said first portion and resting on said primary filament, and a third portion extending from said first portion and connected to said other end of said secondary filament, said other end of said secondary filament normally being spaced from said lead and movable relative thereto along with said third portion of said means, said space defining an open circuit between said secondary filament and said lead, whereby relative movement between said primary filament and said lead attendant upon the breaking of said primary filament causes said means to slide along said lead until said space disappears, thereby electrically connecting said other end of said secondary filament to said lead.

16. An electric lamp comprising a bulb having terminals, primary and secondary filaments in said bulb, said secondary filament being adapted to light when said primary filament breaks, electrical connections between one end of each of said filaments and one of said terminals, an electrical connection between the other end of said primary filament and the other of said terminals, an elongated vertical lead electrically connected to said other terminal, and means for connecting the other end of said secondary filament to said other terminal when said primary filament breaks, said means being conductive and comprising a first portion mounted on said vertical lead so as to engage and being electrically connected to the latter and so as to be slidable therealong, a second portion extending from said first portion and resting on said primary filament, and a third portion extending from said first portion and normally spaced from one of said lead and said secondary filament, said space defining an open circuit between said secondary filament and said lead, whereby relative movement between said primary filament and said lead attendant upon the breaking of said primary filament causes said means to slide along said lead until said space disappears, thereby electrically connecting said other end of said secondary filament to said lead.

17. An electric lamp comprising a bulb having terminals, primary and secondary filaments in said bulb, said secondary filament being adapted to light when said primary filament breaks, electrical connections between one end of each of said filaments and one of said terminals, an electrical connection between the other end of said primary filament and the other of said terminals, an elongated vertical lead electrically connected to said other terminal, and means for connecting the other end of said secondary filament to said other terminal when said primary filament breaks, said means being conductive and comprising a first portion mounted on said vertical lead so as to engage and being electrically connected to the latter and so as to be slidable therealong, a second portion extending from said first portion and resting on said primary filament, and a third portion extending from said first portion and normally spaced from said secondary filament, said space defining an open circuit between said secondary filament and said lead, whereby relative movement between said primary filament and said lead attendant upon the breaking of said primary filament causes said means to slide along said lead until said space disappears, thereby electrically connecting said other end of said secondary filament to said lead.

18. An electric lamp comprising a bulb having terminals, primary and secondary filaments in said bulb, said secondary filament being adapted to light when said primary filament breaks, electrical connections between one end of each of said filaments and one of said terminals,

11 terminal, and means for connecting the other end of said secondary filament to said other terminal when said primary filament breaks, said means being conductive and comprising a first portion mounted on said vertical lead so as to engage and being electrically connected to the latter and so as to be slidable therealong, a second portion extending from said first portion and resting on said primary filament, and a third portion extending from said first portion and connected to said other end of said secondary filament, said other end of said-secondary filament normally being spaced from said lead and movable relative thereto along with said third portion of said means, said space defining an open circuit between said secondary filament and said lead, whereby relative movement between said primary filament and said lead attendant upon the breaking of said primary filament causes said means to slide along said lead until said space disappears, thereby electrically connecting said other end of said secondary filament to said lead.

References Cited in the file of this patent UNITED STATES PATENTS v Jameson June 20, 1882