US1626658A - Manufacture of incandescent lamps - Google Patents

Description

H. (:7.v ANDERSON IANUFAGTURE 0F. INQANDESCENT LAMPS Filed April 29. 1922 FIGQ "INVENTOR HOMER G. ANDERSQ-N ATTORNEY Patented May 3, 1927.

'E Q ATENTN M CE HOMER GEORGE ANDERSON, OF EAST o ANGE, NEW EEsEv, AssmNo To wEs'rING- HOUSE LAMP COMPANY, A coEro'EA'rIoN or rEN sYLvANIA,

MANUFACTURE OF INCANIDESCENT LAMPS. I

Application filed April 29, 1922. j Serial No. 557,371.

r This invention relates to the manufacture of incandescent lamps and has special refer ence to a device for applying and indicating the tension on a lamp filament which is being formed.

7 An ob 'ect of my invention is to provide a device for indicating, at all times,- the tension on a filament being threaded to afila' ment-forming machine. Another object of my invention is to provide an'indicator whereby thetension on a filament being fed into a forming machine can be determined, so that a substantially uniform tension may be applied thereto, whereby more desirable results will be secured in the manufacture of filaments which are bent into zigzag form. y I 'A further object, of my invention is to provide a device for indicating filamenttension in a filament-forming machine and a tensioning device to provide for accurately adjusting such tension so that filaments of different gauge may be formed. a

A still further object of my invention is the manufacture of filaments bent into zigzag form, while maintaining uniform the.

cross-section thereof. p

, Other objects and advantages of the invention will be apparent as the description proceeds.

- In bending filaments preparatory to winding the same upon spiders for incandescent lamps, it has been customary to feed the filament into the machine under a tension more'or less indefinite and with no provision for indicating under what tension the fil'a-r ment is formed. It is found that unsatis-' factory results, such as non-uniform cross section and short burn-out life of the formed filament, have been due to the non-uniform tension to'which the filament has been subjected while being bent into shape and heated in an atmosphere of forming gas. According to my invention, I propose to form the filament while subjected to asubst antially uniform tension, which is' adjustable according to the size of and properties desired for the filament and which is indicated preferably by the movement of a pointer over a graduated scale.

It has been found that the homogeneity, amount of stretching, molecular structure and the burn-out life of a filament are dependent on the forming tension, that is, the higher the forming tension, the shorter the tachment and tensioning devicefor' a fila ture. The controlling tension appears to be the maximum tension to whichlthe particular section of filament considered, is subected while being formed.',fA.filament subjected to a uniform tension according to my 'invention,m'ay be formed at a higher tension than the average tension on a filament viously "used, for thesamereduction in burn-out life;v By accurately controlling the "tension at which a filament 'is formed, I can therefore control theproperties thereof, such as' the burn-out life, molecular structure, 'homogenelty and amount ment-bending or formingmachine; Q

Fig. 2 1s a side 'view of 'the dev ce shown inFlg. 1, the filament and tensloning device therefor being omitted for clearness; I

Fig. 3is'a section on the line IIIIIi of life, which depends on the molecular strucformed under 'a' varying tension as 'pre Fig. 1 looking in the direction of the arrows, the set screw being omitted for clearness;

and,

Fig. 4: is a side view of a filament-forming machine illustrating an application of my invention thereto.

My invention may be employed in connection with an apparatus for bending' filamentssuch'as is described and claimedin J the application of Anton Lederer, Serial Number 879,761, filedDeceinber 30, 1914,

now Patent #1,4t19,153, June 13, 1922,'and assigned to the ,l/Vestinghouse Lamp Com pany, or it may be usedon the modification thereof shown in Fig. 4.

In said figure, a frame 1 in the form of a table carries the various parts of themachine, Beneath the top' of this frame may be mounted a drivingmechanism including a driving shaft 2 connected through gearing 3 to the lower end of avcounter shaft 4 mounted in a standard 5 on the top of the frame. The counter shaft 4 may be geared at its upper, end to a horizontal shaft6 suitably journaled on the standard 5 andcarry an adjustable drum 7 over which the" filament 8 to'be formed is wound by the movement of-the drum. The filament wireis 'given a sinuous or zigzagform by being wound back and forth on suitable forming the collar 35' supporting the spring, reduces the-lever arm -of thefilament passin'giover the pulley 32 and thereby provides, in effect,

a. stiffer spring for being stressed I by the I filament. f

When aspring is desired that lessstifi', I one of the other studs, for instance 'stu d' l5,

is used, as shown in 1, thereby increasing the lever arm of the filament for lndicating a weaker tension for the same displace- .ment of the spring. In this way, therange of tensions indicated on the scale maybe varied to suit the filament being formed.

The fiat leaf spring may be calibrated by detaching the arm'lO from the machine and supporting it in horizontal position. The

spring is then loaded by means of a thread or wire passing thereover and placed under 1, the dot-dash position of the pointer shows a position thereof when the filament is under tension.

By my invention, I have provided means whereby the filament tension may be accurately controlled and measured. The provision of the tensioning device for a separate drum instead ofdirectly for the filament spool, as heretofore, eliminates the former objectionable features of eccentric spools,

spools of various diameters and in various stages of being unwound and non-uniform axle-spoo1 spring-grips. These former objectionable features made it lmposslble to keep the filament under a uniform tension.

fill By eliminating the noted former defects, I Y

can wind the filament on a continuous forming machine under. a uniform tension, which may be accurately adjusted to any deslred degree by my external tension control and shown by my indicator and thereby produce a homogeneous filament of unvarying crosssection, stretched in the forming machine according to the tension applied thereto, be cause it .is heated in the forming machine while under a uniform tension. The forming of the filament under a uniform tension, makes it possible to form filaments of much smaller cross-sections than heretofore, because breakage due to fluctuations in tension is eliminated. J

lVhile I havev illustrated what I now consider to be a preferred embodiment of my invention, it is to be understood that many changes may be effected therein and I wish to be limited only by the scope of the appended claims.

What is claimed is:

1. In a filament-bending machine, a filament-threading arm, a scale attached thereto, a resilient plate attached to said arm, said plate 1 means "for guiding the, filament' and a po nter'movable along'the scale to indicate the tension on the"filament."

2.,In a filamentebending machinefla filamentthreading' 'arm,i a graduatedscale I atl tached thereto, a resilient plate attached to a collar adjustable on said arm, said plate carrying means for guiding the filament and v a pointer-f movable along'the 'scalei'to indicate'the tension on'the'filament. I

. 3. A forming machine comprising a filament-threading rm, means for indicating the tension on thefilam'ent bein'g formed comprising a gi aduat'ed scale attached to the filament threadingarm, a flat spring carrying a pulley for guiding-the filament and a pointer adapted to move over the scale.

4. In a'filament-bending machineyan arm holding 'me'ans" for guidinga filament and movable for the purpose of bending the filament, means for indicating the tension on the filament being bent comprising a resilient member, a pulley carried on sald member over which the filament passes and a pointer adapted to indicate filament tension.

5. In a filament-forming machine, a filament threading arm, a graduated scale attached thereto, means for indicating filament tension comprising a spring member adjustably held on said arm and holding a pulley u over which the filament passes and a pointer attached to said spring and indicating the tension on the filament, by its position with respect to the scale.

' 6. In a filament-forming machine, an'arm for guiding the filament, a graduated scale attached thereto, a collar clamped on said arm and holding a resilient member and a bushing for modifying the effective stiffness of the resilient member comprising a hollow cylindrical member on said arm provided with studs of various lengths adapted to engage the resilient member, said resilient member supporting means for guiding the p filament and a pointer moving over the graduated scale. v V

7. Means .for indicating the tension on a filament being Woundupon a filament-forming machine comprising a threading arm, a scale and a spring 011 said arm, said spring carrying a filament guiding pulley and a pointer movable over said scale.

8. Means for indicatlng the tension on a filament being wound upon a filament-forming machine comprising a threading arm, ,a scale and a spring on said arm, said spring carrying a filament guiding pulley and a pointer movable over said scale, a bushing adjustably held on said arm and provided with studs projecting various distances from r the same and each adapted to engage the spring according to the positionof the bush- 9. Means for indicating the tension on a filament belng wound upona filament-form- ,ing machine comprising atthreading arm, ,a

;.graduated scale supported near the free end of saidcarm, a clamping member adjustably holding aspring on said arm, said spring ea rrying :a filament guiding pulley and a pointer movable over said scale, a bushing adjustably held on said arm and provided .WithYStlIdS projecting various distances from c the same andeach adapted tolbe engaged with the spring according to, the position of the bushing. I

- 1 0. A filament-bendingmachine comprising ,a forming drum, a cylinder, a filament 7 cylinder, a resilient member having a pulley over which the filament passes and means associated with said member for indlcating subscribed my the tension .on the filament as the filament passes onto the forming drum. I

11. lnafi-lamentbending machine, a spool from which the filament is unwound, an accurately formed, and centered drum around which the filament, is drawn without sliping, a braking device on the drum, adjustable so that any desired tension may be applied to the filament, a resilient member holding an idler over which the filament passes in such a way that bending occurs if the filament tension varies and 'means for indicating the tension on the filament as it is about to ,be bent.

In testimony whereof, I have hereunto HOMER GEORGE ANDERSON.

name this 28th day of April,

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