US1028118A - Tubular incandescent lamp. - Google Patents

Description

E. R.' KNOWLES. TUBULAR INGANDESCENT LAMP. APPLICATION FILED .1.111.12, 1910.

'l 1,028,1 18 Patented June 4, 1912.

2 nvclll'o; MM( zwi @M4 EDWARD R. KNOWLES, 0F NEW YORK, N.

:TUBU'LAR INCANDESCENT LAMP.

spciaation f Letters raient.

Patented-.rune aiuta.

Application ined January 12, 1910. serial No. 537,708.

[o lall whom t may concern:

Be it known that I, EDWARD R. KNOWLES, a citizen of the United States, residing at thecity of New York, in the borough of Brooklyn and State of New York, have invented certain new -and' useful Improvements in Tubular Incandescent Lamps, of which the following is a full, clear, and exact description.

1 0 The present invention pertains' to that kind vof electric light wherein the body of the.

lamp consists of an exhausted glass tube in closing a filament which is disposed centrally in a single longitudinal line therein.v

In previous lamps of this ltype there has been great dificulty in so sealing the filament in the tube that it 'will be truly adjusted in the axis o-f lthe tube, securely held in position and kept uniformly straight under all thermal conditions. It has also been diiiicult to reduce the physical dimensions of vsuch lamps, andto make 'them in such man ner that any number 'of lamps can be made sensibly the same and so that the cost of manufacture will notbe prohibitive.

To obviate these and other defects in lamps of this type as heretofore made, one object of the invention is to provide a novel means of holding up the filament within V the tube whereby its accurate adjustment and safe anchorage are secured previously? to and without interference from the sealing of the tube, rendering these operations less difficult of accomplishment in the'manufacture of this class of lamps.

A second object of the invention is to' so anchor the lament as to keep it uniformly straight under every thermal or anti-thermal condition, thereby minimizingand preventing its vibration from any cause and further precluding its coming into contact with or getting dangerously near the walls of the surrounding tube, due to flexure, bowing or ment being of eater than ordinary length and corresponding tenuity.

A third object is to reduce to the smallest practicable dimensions the metallic contacts needed to place the lamp electrically in circuit and to so locate the same thatthe lam may be rotated axiallyto any position an so that one will see vnothing but the glass `tube and filament located therein, in whatever position the lamp is laced and when 'the lamp is lighted there w1l1be seen an unbroken line of light andA a' luminous sheath its mounting.

.attaching means being spaced apart a presagging and this notwithstanding the fila thereforshining brightly from end to'. end with no furnishings or appendages to break its continuity or impair its brilliancy.

A fourth object is to provide a ready and convenient means ofv attachment for the-` lamp whereby it can be suspended, framed or bracketed and held in any desired position in complete safety as regards itself and A fifth object is to insure the production of a filament of uniform length having attaching means thereon adapted for engagement with anchoring means in the tube, said determined distance, the lament and attaching' means constituting a unitary structure.

Referring to the drawings which forlm a part of these specifications and in which similar letters or figures are used to designate corresponding parts: Figure 1 is a side elevation'of the lamp showing the manner of supporting the filament by spring anchor supports sealed into but not through theso wall of the'glass tube and the manner of attaching the leading-in wires tothe spring anchor supports and of sealing them in the ends of the tube and attaching the metal Contact' pieces thereto. Figs. 2, 3, 4, 5 and- 85 6 show various ways in which the spring anchor supports can be sealed into but not through the wall of the glass tube and in which the leading-in wires may be attached thereto. 'Fig 7 is a perspective view showing the flattened spring form ofthe anchor support. Fig. 8 is a longitudinal section of the Alamp showing the filament supported by two spring anchor supports, sealed into the glass tube at points other than 1n the same 95 straight line. Fig. 9`is a longitudinal section of the lamp showing the filament sup-- ported by one spring anchor support', the other end having its `terminal sealed directly through the end of the tube. Fig. 1() 1s a longitudinal section. Fig. 11 is a transverse section of the lamp and its fixture contacts illustrating the manner of connecting it to the fixture; said section being taken on line VA-A of Fig. 10. Fig. 12 is an end view of the ber socket showing the connecting members therein. Fig. 13 is a view of a filament attaching piece before the samel has been rolled up and bent to form a hook thereupon. Fig. 14 is a view of the same' 110 i' to. The

isa view of the same showing the hooked end, and a filament cemented in position in the tubular portion thereof. Fig. 16, is a perspective `view of a modified form of a filament attaching piece. t

The body of the lamp and the filament thereof are respectively designated by the reference figures 1 and 2. The former consists of a transparent glass receptacle in the shape of a tube, usually straight and sealedl at both ends. The latter is a filament, p referably of carbon, similar to those `in use in the so called bulb type of lamps but run in a single straight line along the axis of its tubular envelop. however that my anchorages are adapted to support laments vof vother material than carbon.

In Figs. 1 and 8, V-shaped'anchor supports 3, 3 are provided at or neareach end of the tubular lamp body 1 for the purpose of sustainin the filament 2 in its correct .central position as shown in the various iigres of the drawings. These V-shaped anchor supports 3, 3, are each preferably made L platinumA .section 10 is attached. These spring anchor supports 3,3, are sealed inte- ,riorly at Dthe tip 5 of the V loop, one near each end of the tube and at a predetermined distance apart, into the w'all of the "glass tube,

. but not passing through it,l the tips 5, 5, be 40 ing entirely covered with the glass of the tube; or with glass or the like united therepoints of sealing of the tips 5, 5, into the wall of the tube 1 may be at any ypoints on the circumference of the tube l so long as they are the required distance apart and the h'ooked points 12, 12, are on the axis of the tube 1, thus obviating any necessity for getting them in the same straight line as .in lamps'heretofore made.

The upper ends 12,112, of these spring anchors 3, 3, are adjusted, during the process of sealing into the wall of the tube, so that they are exactly in line on the axis of the tube 1.

While the tube 1 isopen at vboth ends and after the spring anchors 3, 3,- are adjusted therein, the filament 2 is introduced into the tube 1 and securely attached at its end to the inturned ends 12, 12`of the spring anchors' by' a suitable cement joint 12 or in any other approved manner. My preferred form of attachin the filament will be hereinafter describe A After the filament is secured in position to the spring anchors one or both of the spring anchors are bent outwardly toward the open It may be h'ere noted' ends of the tube thus putting a tension on the .filament and holding it tense and straight in the axis of the tube. As the of the anchors will relax outwardly or en wardly in the inclosing'tube, it is evident that the lament will always be kept straight by and between them, the filament f acting when cold or contracted to keep the anchors under a greater or less tension and.

lwhen hot or expanded having itsslack taken mits the use of wire therefor of a fair degree,

of stiffness since the springs act in unison. The glass tube lis then sealed on the platinum sections 10, 10 ofthe leading-in wires, an exhausting tube being added at 7 for connection to the vacuum pumps and the lamp finally sealed up at 7, after exhaustion.

Figs. 2 to 6 inclusive show-various meth- "ods fof sealing the tip 5 of the V or Asubstantially V-shaped anchor support into the tube 1. In Fig. 2 the anchor support conf sists of a straight portion 3 towhich is at- 95 tached at a point above its terminal. 5 the'- leading-in wire 9, 10, the 'terminal 5 being sealed into but not through the .wall of the tube 1.

In Fig. 3 the anchor ysupports consist, of a straight portion 3 in which is va loop 4 through which is hooked the leading-in wire 9, which isi in turn secured' to connection 10.

In Fig. 4 the tip 5 of the V-shaped anchor is. first sealed into a glass bead X which in turn is attached torthe wall of the tube 1.

In Fig. 5 the V-shaped anchor may be made ofpany spring material, 'mechanically fastened at its tip to a platinum wire O which in turn is sealed at its tip 5 into but not through the wall of the tube 1.

In Fig. l6 a modicat-ion of the V-shapedl anchor 1s shown, .in which-a substantially flat bottom portion 5.is provided for the anchor. Inwardly bowed arms 4 upwardly extending from 5 are in turn united to the respective arms 3 and 4, the latter corresponding to arms 3 and 4 in the" several modifications above described. A :recess-5` is preferably "formed with 'under-cut walls whlch `may be pressed into the body of the tube on the inner side thereof,'by a suitable tool. The dat portion-5 ofthe anchor is then sprung into this recess and any suitable materlal may then be used to seal the anchor in place. A Asmall ring or oval 3 may 'be provided in connection with this form of device and is adapted to be sprung up over the shouldered portions of the arms4 to, engage the recesses thereabove when it isu deposed.

sired to place the arm 3 under tension. This form of construction may be of advantage at times, when it is desired to avoid the use of platinum, since a securing -material or cement may be selected which will have substantially the same coefficient of expansion as the material of which the wire forming the V-shaped anchor in this case is com- By this method of manufacture it will be seen that all of the work involved in securely anchoring and adjusting the filament can be accurately erformed before the tube needs to be close at either end and yet all of the advantages of an end seal of the leading-in wires is obtained whereby the lampcan be placed in any position and without there being any attachment on the lamp to interfere with or obscure the' light. 'By this method of manufacture it is also possible to place the spring anchors at the same distance apart in all lamps, to use the same length filaments in all lamps and to seal all lamps to precisely the same length.

To adapt the lamp for connection in an' electric circuit 'the ends 6, 6 are inclosed in metal caps 8, 8 which are cemented or fastened to the body of the lamp by the cement 11, 11 the leading-in Wires 10, 10 being soldered or fastened to the caps 8, 8,.

In Figs. 10 and 11 I have shown a form of connector forming part of a reflector or fixture' by means of which the lamp can be quickly introduced into or removed from the electric circuit and can be securely held in place when so introduced into the electric circuit. The small sections of ber tube 12 are .slotted partly through at one side, as at 13, said slot being s uiiciently wide to admit a cap S'therethrough. To the inside of these .tubes are secured spring clips 14 which may be formed simply of strips of wire, united to the said-ber tubes by screws 15. Tubular uprights 16 are screwed into each of said tubes, preferably for appearance, in the portion thereof adjacent to and in alinement with the slot therein, and conductive wires `extend upward through the-V uprights, .and in turn are secured to screws 15. 'I he outer ends ofthe fiber tubes may be plugged with small shves of cork 17. The above affords a very simple and inexpensive, but eicient means for making connection with and maintaining the lamps iii position. Uprights 16 are secured by soldering, or in any other suitable manner, to a hollow base .bar 18, which for ornamentalpurposes may be l of brass. Upon the side of this bar adjacent the lamp sockets is secured a reiiector 19. This may be of polished metal or may have secured to the inner sides thereof, strips of porcelain, glass or the like. If the transverseV section of the reiector be semi-circul'ar as shown, the lamp sockets should preferably be. placed well below the edges thereof. Ihave therefore shown a neat unitary structure for supporting the lamp, and one 1n which obviously the lamp may be inserted merely by snapping it `into position without regard to the particular disposition of any side thereof. An insulating thimble y20 is provided midway of the length of the base bar and conductive leads are inserted therethrough and respectively extend through the hollow base bar and unite or may be integral with the wires leading downwardly through the uprights at the ends of the reflector.

The preferred form of attaching the filament to the anchor devices hereinbefore i'efer'red toinvolves the use of small hooked members 21 preferably having a tubular filament-engaging portion 22. I prefer to construct these in the following manner. A short piece of wire is flattened or rolled down at vone end'23 as shown in Fig. 18. The fiattened wire is then drawn through a die to roll up the flattened portion'into tubular form as shown in Fig. 14; and finally the wire end is bent into the form of a hook or loop 24. The filament end is then introduced into `tubular portion 22, which is slightly pinched together thereupon and cement applied thereto, which makes a. iii-1n connection and affords excellent electrical contact. The loops 24 are slipped over hooks 12 of the anchors when assembling and cement 1-2 is applied to the jointure in they manner aforesaid. It is obvious that my filament may be joined to the anchor which may in such case have straight ends by merely cementing the respective ends of said filamentand anchor together without interosing the tubular connecting piece, and this form of construction has been indicated at 2 in Fig. 6. I may also make the attaching member simply by rolling wire into a'helical coil`as at 25 in Fig. 16 -andthen bending an end of said coil into a hook as at 26.

Having described my invention, what I claim is: l

1. In an, incandescent lamp,a filament ancher-forming a current conductor comprising twov members having free extremities,

the portion of the anchor adjacent the point.

ioe

member, and a: leading-in wire connected with the extremity of the other member.

2. In an incandescent-electric lamp, a filament anchor consisting `o'f a current conductor anchored at a point intermediate its ends onthe bulb .of the lamp to form a pair of free members, a lament connected with one member, and a leading in wire connected with the other member. 4

3. In an incandescent electric' lamp, a filament anchor consistin of a currentV conductor bent at a point intermediate its ends i in the 4form of a V and having its bend anchored on the wall of the bulb of the lamp,

y point of union between the members being anchored on the'bulb of the lamp, a lament connected with the free extremity of Vthe spring member and a leading-in Wire connected With the extremity of the other member.

5. In an incandescent electric lamp, a'lament anchor consisting .of a current conductor anchored at a point intermediate its ends on' the bulb of the lamp to form a pair of free members, one member thereof consti-l tuting a spring, a filament connected with the spring member and a leading-in Wire connected with the other member.

6. In an incandescent electric lamp, a ilai ment anchor consistin of 'a current conductor bent at a point lntermediate its ends inthe form of a V and having its bend anchored on the Wall of the bulb of the lamp,

one member of the anchor constituting a spring, a filament connected to the free ex tremity of the spring member of the anchor and extending in one direction and a leading-in Wire connected to the other free extremity of the anchor and extending oppof sitely to the filament.

7. In an incandescent electric lamp, a filament anchor consistin of a current conductor bent at a point intermediate its ends in the form of a V, and having its bend anchored onthe wall of the bulb of the lamp,

one member 'of the anchor constituting a spring, and provided with a hook at the extremity of thespring member, a ilamentv provided with an eye attached to each end of said filament, and attached to the free extremity of the free member of the'anchor and extending in one direction, and leading# in-Wires connected to the other free extremity of the anchor extending oppositely to the filament.A y

8. In an incandescent electric lamp, a fila'- ment anchor consisting of a current conductor'bent at a point intermediate its ends in the form of a V and having `its bend anchored on the Wall of the'bulb of the lamp,

one member of the anchor constituting a. spring, a filamentprovided with an eye attached to each end Aof said filament, and4 attached to the free extremity of the free member of the anchor and extending in one direct-ion, and leading-in-wires connected to4

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