US1201738A - Method and apparatus for shaping filaments. - Google Patents

Description

I. W. IANVIER.

METHOD AND APPARATUS FOR .SHAPING FILAMENTS.

APPLICATION FILED JAN. 27 I914.

Patented Oct. 1 7, 1916.

Fig. I.

Witnesses w. Aw b m m m a a A rmn M h o J 1 UNITE enn w. univvinn,

S PA

Ti FF or NEWARK, NEW JERSEY, ASSIGNOR TO eENEnAL'nLEc-rnm v COMPANY, A CORPORATION on NEW YORK. i

METHOD. AND APPARATUS FOR. SHAPING FILAMENTS.

Specification of Letters Patent.

PatentedOct. 17, 1916,

Application fi led January 27, 19151. Serial No. 814,616. Y

To all whom it may concern:

Be it'known' that I, J,OHN:W. .JANvrER, a citizen of the United States, residing at Newark, county of Essex, State of New Jersey Improyements in Methods and Apparatus for Shaping Filaments, of which the follow- -ing isa specification.

. My invention relates toa method of and apparatus for shaping and mounting metallic filaments, particularlyfilaments such as tungsten, which soften at operatingtemperatures, and are "mountedupon comparatively small and resilient supports in the lamp, and is especially applicable to metallic filament s made of comparatively heavy" or stiff ends. Serious wire.

Metallic are usually given a winding "the wire filaments in'a continuous piece looped or' zigaag form by back and forth over the supports on which 'it is carried in the lamp,

so that the shaping of the filament is an incident of the operation of placing it on the supports,

The filament maybe made of a Wire of suit-- able ductile material, such as tungsten, wound ,back and forth in'one continuous piece supported at suitable points intermediate its in winding the wire back and forth over its supports, and in making the loops uniform and properly mounted, particularly. Where the supports are comparatively small and resilient and the wireis heavy or stifi and hard to bend; 1 p

The object of my invention is to provide a method and apparatus for-producing in a simple and easy manner filaments which are.

accurately shaped into a definite and predetermined form, and-Which are ready to-be ther change in the form ofthe filament.

A further object is to enable the operator to makethe filament of the exact form and sizewhich it will be when mounted on its resilient or flexible. supports in the lamp.

"' A 'sti-ll'iuittherobject is to provide a 'method a'n'd means of making a sinuous'or zigzag filament in'which the loops are of luniformuand definite size, so that when'the filament'is mounted on the supports every loop engages its support with substantially the same tension as every other loop.

In carrying out my invention I bend the have invented certain 'new' and useful I while hot. j The loops of the filament may be elondifficulties are encounteredfilament into a loop' or loops of approximately the form which it will be when loop of a definite and predetermined length.

after which the shaped filament. may be placed on its supports with bending or shaping. I prefer to elongate the loops'while the wire is heated in some suitable manner, as by the passage of current through it. If the wire, as for example, 'dragvn tungstemgis quite resilient, the heating not'only vfacilitates the operation of elongating the loops, but the loops w 1ll set, and will retain when cool the shape lnto which they were drawn gated to the desired extent in various suit able ways, but I preferto provide an-apparatus upon which the filament can be easily and quickly wound into approximately-nits finished form, and by which the loops can then be elongated to whatever extentlmay be necessary to bring thefilament into its finished form. Preferably thisapparatus is so constructed that the operation of wind-J ing and, setting the filament can be accom- 1 plished very quickly and easily by' comparatively unskilled labor, and the lengtheof the stretched loops may be regu'lated :very' accurately'. The apparatus is preferablyso constructed that it can at will be 'placedinl a (su table atmosphere in which the filament may be heated to the desired extent without injury 1 U My invention will best be understoodin connection with the accompanying drawing, in which, merely for purposes ofillustration, ll-have shown some of the various-forms in which my invention may be embodied, and in which- 1 Figure 1 is aperspective view, with some parts in: section, of one formof device suitable for practising my invention Fig. 2. is

a view, at right angles to the plane of Fig. 1,

of-the lower part of the device shownin Fig. 1 and with a part in section; and Fig. .3 is a r view of a modified formof the upper end of the device shownin Fig. 1. r

t In the particular apparatus or filament shaper shown in the drawing, a suitableisupport, such as a rod '1', has heads 2 and 3 slidably or otherwise suitably mounted on it so as to be relatively movable toward and away i of the lower head 3.

in engagenent with the stops land 5.

from each other. A stop I limits the movement of the upper head 2 and if desired a stop. 5 may be used to limit the movement The relative movement of these heads may be produced in any suit able way. In the preferred construction the heads 2 and 3 are biased in any suitable manner so as to have a tendency to move away from each other and into normal position, where they are a definite distance apart and This tendency may be produced by the weight of the lower head 3, by a spring, or by any means which urges the heads away from each other. I prefer to use a spring, such as a spring 6, with one end rigidly supported, as for example, by an adjustable abutment 7, and the other end exerting upon the movable head 2 a thrust which tends to move this head away from the other one and -against the stop I.

I The wire of which the filament i's to be formed is secured to the mm'ableheads 2 and 3 111 any suitable manner, while those heads'are closer together than normal, after supports 10 mounted on and insulated from it and also provided with hooks 11. The wire of which the filament is to be formed is wound over the hooks 9 and 11 into approximately the form of the finished filament, but since the heads are closer together than normal the loops are more open and shorter than when the filament is finished. For purposes of illustration I have indicated a .wire 12 which has been mounted upon the hooks and is ready to bedrawn into the finished form by the movement of the heads 2 and 3 away from each other into normal relation. To facilitate ,tlie shaping of the filament I preferto heat 'the wire in some suitable way, preferably by passingcurrent through it., One way of attaining this result is shown in the drawing, in which binding posts 13 are provided, by means of which the ends of the wire may be firmly clamped to the head 3, and at the same time an electrical connectiongi s'established to conductors or bars 14:. t -which the binding posts 13are connected. rrent is supplied to these conductorsthrong suitable terminals 15, which may be connected in any suitable manner we source of cur rent. As the hooks 9 and 11 are-insulated, the application of voltage to the terminals I, with a convenient operating handle, for

moving the head 2 against the. thrust of the spring (3 a definite distance and to a sutlicient extent, as shown in Fig. 1, to facilitate easy winding of the wire 12 over the hooks 9 and 11. I also prefer to provide locking means, such as a set screw 17, by which the head 2 can be firmly fixed in any desired relation to the other head, regardless of the .thrust exerted b the spring 6. I also prefer to provide some suitable clamping means, such as the set screw 18, for at will holding the lower head 3 immovable.

The heads 2 and 3 may be biased to move away from each other by other means than the spring, as shown, in the modification illustrated in Fig. 3. In this particular arrangement the head 2 is urged. upward into normal position by the pull exerted upon it by a suitable weight 19 connected to the head by a cord or cable 20 running over suitable pulleys. lVhen the cam 16 is thrown back into the position shown in Fig. 1, the weight 19 will raise the head 2 the distance necessary to bring it against'the stop 4:.

The number of hooks on the heads may be varied as desired and the invention is equally useful in making filaments consisting of only one loop of heavy wire. In this case the two ends of the wire are secured ance witl my invention, the heads 2 and 3 are movel toward each otherto a suitable extent, eitherby hand or by the use of the. cam 16. In either case I prefer, in a device constructed in accordance with Fig. 1, to compressthe spring 6 so that the heads will have. a tendency to move away from-each other when released. Vhen the heads are properly positioned closer together than normally, they are temporarily fixed by being clamped to the support 1 by means of the set screws 17 and 18. One end of the wire of which the filament is to be made is then clamped under" one of the binding posts 13. The wire is then bent over one of the hooks 9,'carried back to the hook 11 adjacent to the binding post to which the end was secured, back to another hook 9, and. so

into normal relation. This may bedone by naom'ss '1, looped into-the approximate form of the finished filament, but the loops are considerably shorter and the bends are considerably more rounded than in the finished filament. The filament is then brought into its final form by moving the heads away from each other a suit'able distance to bring-them unclamping the head 2 from the support 1, whereupon the thrust of the spring 6 moves .the. head 2 upward funtil it strikes-the stop 4. The filament isnow the correctshape andthe loops are of an exact and uniform length so that they can be putupon the resilient supports very easily and quickly The filament is. of the exact size andshapethat it willbe when in the lamp so that-nofurther manipulation whatever is required:

. The operation of shaping the filament is greatly facilitated by heating it to a suitable temperature. In shaping tungsten filaments, for example, this heating-is carried out in an inert atmosphere, asfor example by inserting theshap'er with the wire upon it into a substantially vertical flaskorjar open at the lower end and keptfilled with a mixture of hydrogen and nitrogen, or other suitable ghs. The operator ean easily raise the shaper'into the'jar through the open lo'wer end, and then the wire is heated in any suitable manner,-preferably by supplying current to: the terminals 15, whereupon. sulficient current flows from one terminal through the wire to the other terminal to heat the wire and soften it so that the spring 6 moves theheadsaway from each other into normal-relation and the loops are stretched to the proper length. A' further advantage of heating the wire is that it is set and retains its shape when cool.- v By my invention a plurality of filaments of exactly the same dimensions and configuration Inay be obtained. It may be employed with special advantage when any part of the supporting means of the filament is too weak to stand the strain that would be imposed upon it if the filament were wound over the support. It is applicable inconneetion with the manufacture of filaments 'What I claim as new and desire to secure by Letters Patent ofthe United States, is

1. The method of. shaping a Wire into a I long filament having a plurality of loops of substantially equal and degnite length which consists, in bending the ire into loops of approximately the size ofthe corresponding loops of the finished filament, holding the ends of the wire and simultaneously moving the bends-of all-the loops into definite and predetermined positions While holding the ends of the wire immovable but permitting the intermediate portion to move lengthwise to equalize the loops.

2. Themethod of shaping a long looped filament of tungsten which consists in bend-- inga tungsten wire into a plurality of loops each shorter than the corresponding loop of the finished filame'nt,-heating the wire in an inert environment to render it pliable, and then stretching all the loops'to definite dimensions lengthwise while holding the ends of the bent wire immovable but leaving the intermediate part. free to mov'eilengthe wise to equalize the loops.-

' 3. Apparatus for shaping filaments comprising relatively movable members for engaging a loop of wire near the ends of said loop and at the bight, said-members being members to a definite and uniform distance,

and .means for keeping the wire hot while said members separate.

4. Apparatus for-shaping a looped ,filament comprising a member for engagingthebight of a loop of-wire, another member for firmly engaging the'sides of, the loop, said members being relatively movable at will toward each other from normal position to engage a loop shorter than that of the finished filament, means for stopping said members in normal position adefinite distance apart, and means for heating said wire to soften it and thereby permit the return of said members to normal position;

5. Apparatus for shaping a looped 'filament comprising a support, a member on said support for engaging a loop of wire near the ends of said loop, a second member on said support for engaging the bight of the loop, said members being normally a definite distance apart and being movable toward each other at will, means tending to maintain said members in normal relation and at, said distance apart, and means for heating the loop of wire while supported bysaid members.

6. Apparatus for shaping a looped-filament comprising a support, a member on said support for engaging a loop of wire near the ends of said loop, a second memnormal position a definite distance from her on said. suppdrtQfor-engaging the bi 'ht;

of the loop, said :inember s,.-I being n'orma 1y a definite distaneeiapar'it'fand"mounted to-be ing; two relatively movable insulazted supmovable toward. each. othely; a spring strainedby movement of saldlmemhersto ward each other, and electrical connections for passing current through the wire. bf the loopto heat it. I I

'7. Apparatus for shaping arl'oopedmetal lic filament comprising two relativelynmbm able members foriengaging-a wireloo'p-at the bight and at points on the sidesbf the loop, means to prevent relative movement Oi said wire and said supports; means for. heat ingthe wire on said supports,-"and,me'ans for moving said supports relatively to each other while the filament is heated to elongate the loop a definite amount,

8. Filament shaping apparatus comprismg two relatively movable heads normallya definite distance apart and biased when closer than normal to move away from each other into normal position, means for se-. curing a loop of wire shorter than the loop of the finished filament to said heads with the bight of the loop connected to one of said heads and the sides of the loop connected to the other head, and means for heating-said filament to a temperature which permits said heads to move away fromeach other automatically into normal position and thereby elongate the loop.to the size of the 1 finished filament. w

9. Apparatus for" shapinga looped filale ment comprising a central support-inggcrod', two heads slidably mounted onjsaidrfod; and. biased to move away from eaeh other. into each other, means on one ofr saidheads, -for engaging thebight ofaloop or wire, means on the" other of said."headsfor-rigidly attaching the ends of theloop thereto, and

means for supplyingcurrent to the filament on said heads to heat it and thereby permit said heads to move away; from each other" into normal position and .elongatethe loop to .a definite'lengt'h.

10 Filament shaping apparatus comprisports mounted to move relat1vely to each other, means for securing a' looped filament. onqsa d supports with} one of said su ppotgts' in engagementwit-h the bight ofthei a spring normally tending to move said-supports away from each other into normaL-positio'n, restraining means for holdinglone of said supports immovable against the. force exerted by saidspring while said filament 1s being placed in position and "for releasing,

saidsupport to permit said spring to move' it'to a definite point and'therebystretch the loop of the filament to a' definite length.-

. 11.. a device for shaping a loo'ped'fila' ment, the combination of a support, two

heads :slidably mounted on said sirppofrt -to move relatively to, each other; astopfior engaging'on e of said heads tos-limit-its move ment away from the other, aispring forno'rnally holding said head against is'aid'} stop,

, an insulated support J on one of'said heads for engaging the 'bight ,of'ag-loop oliwire,1 binding posts on'. the other head forllclamp ingfthe ends of said loop'to. said other head and supplying currentto the loop, and a manually controlled camforholding said firstmelitioned headjawayfirom the'stop to permiti'placing on 'said'heads a loop shorter than that oi the finished filament and for re- 'leags ing fsaidlhead}at will top'ermit said to theilength 'ofi a" loop. of the finishedfilameri v, v

In witness iwh'ereofgfl have hereunto set hand this 23d day ofi January, 1914.

S NJVHITEHEAD, J H. ELKINS. 7

spring toim'ove said head into engagement "with saids'topfand thereby stretch the loop

Images