US1614562A - Apparatus and method of wire drawing and alloy wires used for radiotubes and other purposes - Google Patents

Description

1 1927. 1,614,562 Jan c. A. LAISE APPARATUS AND METHOD OF WIRE DRAWING AND ALLOY WIRES USED FOR RADIOTUBES AND OTHER PURPOSES Filed Sept. 5, 1925 .:NHPMHN A. :"MHPJHHM?"- Q WIT N E s 5 INVENTOR Patented Jan. 18, 1927.

CLEMENS A. LAISE, OF HAWORTH, NEW JERSEY.

APPARATUS AND METHOD or WIRE DRAWING AND ALLOY wmns USED ron RADIO- TUBES AND OTHER runrosns. I

Application filed September 5, 1925. Serial No. 54,628.

My invention relates generally to an apparatus and process of manufacturing very fine wires of various metals or alloys of metals, and itis particularly adapted for the 5 manufactureof very fine nickel-chromium alloy wires or tungsten alloy wires or molybdenum alloy wires particularly adapted for use as-resistance wire, and in radiotubes, and other purposes.

It is well known in the art that very fine wires of certain metals or alloys cannot be drawn down by the ordinary processes of wire drawing after they reach a certain cross section because they lack suflicient tensile strength. It is also well known that tungsten and molybdenum wires when alloyed to a substantial degree with other metals or mixed with rare earths in a substantial amount cannot be mechanically worked and drawn down to very fine size by the prior well known means and methods of the art and because also of a loss in the necessary tensile strength, and because alsoof the difticulty of obtaining suitable wire drawing dies, which have the required fineness and which will retain their diameters during the drawing operation. The addition of a very small proportion of the rare earthsto tungsten or molybdenum necessary to permit the use of the resulting wires as filaments for incandescent lamps when operated on alternating current does not weaken the wire sufiiciently'to prevent wire drawing down to a small'diameter by the processes of the prior art, but when these additions or alloys are made to the greater degree which is required for use in,radio tubes, then the product is so changed in its structure that it is weakened to such a degree that it does not have sufficient tensile strength in relation to its coefiicient of friction to permit of its reduction in drawing by the mechanical working and the wire drawing of the ordinary workin and wire drawing processes now known in the art. 1

The apparatus and process developed by me and which will be hereinafter described enables one to reduce the cross section of wires substantially uniformly throughout their length after they have reached a size when their tensile strength .no longer permits them to be drawn through dies by the well known processes of theprior art. In order to accomplish this important and necessary result, resort is had 'to electro-chemical means and in that, fundamentally, my inventlon consists. Through the combined action, therefore, of electrolysis and chemical solution upon the material of the wire when the wire is passing through a suitable bath of electrolyte one is enabled to uniformly reduce the cross section of a metal wire which could not be drawn further down by the ordinary processes of wire drawing and thus the wire products are made suitable for uses in the art to which they could not have heretofore been put because of the. fact that the art had not disclosed a method to accomplish those ends.

It .is well known, of course, that a chemical solution has heretofore been resorted to and electro-chemical processes have been resorted to for the purpose of cleaning and pointing wires or sharpening instruments, but 1 believe that I am the first to utilize these agents for the actual i'nanufacture of very line wires for useful and particularly for commercial purposes. fine wires having roughened surfaces which I have found to be much superior for radio tube filament to wires of the same size having a smooth surface as a wire having a smooth surface does not give as high an clectron emission as does the same size wire having a roughened surface. Since, therefore, by my process of reducing the dian'ieter of the wire by electro-chemical means produces a wire with aroughened surface, 1 thereby produce a superior wire of higher electron emission than any heretofore pro-.

duced.

By the term roughened surface, I mean a surface which is not polished which is the inevitable result of the ordinary method of wire drawing now known in the art.

In the manufacture of Wires for radio tubes capable of'high electron emission it is customary to use as an ingredient of these wires the metals tungsten, molybdenum, platinum, and so forth. It is necessary however to activate these metals by the'addi- -tion thereto or the alloying therewith of substantial amounts of either thorium, yttrium, vanadium, strontium, barium compounds,

.etc. As soon, however, as the above elements in the substantial amounts required for radio work have been added to or alloyed with, the pureinetals of tungsten, molybdenum or platinum, itis difficult, as has been said above, if not actually impossible, to pro- I thus produce very ducethe resultant composite wire having a suiiicient fineness of cross section by the ordinary metal working processes of whatelevation and partly in cross section of 'a pass.

wire reducing plant by means of which my process for reducing the cross section of wires and providing them with a roughened surface may be carried out.

Fig. 2 is a plan view thereof. K

Fig. 3 is a section on line 3-3of Fig. 2.

Fig. 4 is a section on line 44 of Fig. 2.

Referrin to the drawings, W is a composite or al oy wire of. the material above described reduced to a comparatively large cross section by'any known wire working process. 10 is a spool of wire which has reached the limit of its tensile strength by the ordinary wi're drawing processes, which spool is placed on a spool holder 12 and so mounted that a suitable tension may be imparted t0 the wire by various well known means, such as the small weight 14 secured by means of a strap 16 to the holder at 18, A

said strap passing around a small brake or friction pu ley 20. The wire W then passes entirely around a wheel 22 in the direction of the arrow so that the lengths of wire measured by the circumference of the disc or' wheel 22 will be recorded when the striker arm 24 engages the arm 26 of a counter mechanism 28 suitably placed upon the pedestal 30.

Supported. on legs 34 and 36 is a hard rubber receptacle 40, the cavity of which is filled with a suitable electrolyte 42 and which is provided at each end with slots'44 and 46 for the reception of the wire W. The mercury contacts consisting ofcylindrical cells 50 and 52 are provided at each end of the hard rubber receptacle 40, the upper parts of the cells 1 being slotted as at. 54 and 56 within which the wire also is enabled to pass. As shown. each of these cells is filled with Hg and through each of which the wire is caused to The slots in the cells and in the hard rubber receptacle above referred to while of suflicient width to receive the wire are yet so small that the mercury cannot ooze therefrom, the mercury thus forming a wall against or through which the electrolyte cannot pass. 60 is a copper plate secured at the bottom of the receptacle 40 by means of. a

binding post 62, .which late 60 forms the cathode terminal in the e ect-rolyte, the wire as above explained. Adjacent the electro-- lytic bath is a cleaning tank supported upon suitable supports 37 and 39, as shown, .which consists of a copper tube or box 41 being also provided at each end with mercury contacts 61 and 63, slotted as above described at 66 and 68, the slots being of sufiicient width to permit the passage of the wire yet prevent the assage therethrough of the mercury.

ounted on a support 70 is a pair of spring pressed fingers 72 and 74 pivoted at '76 around which is a s ring 78 operating to hold the fingers toget er. At the end of the fingers are pads 80 and 82 of felt or the like between which the wire passes to clean or dry it. From't-he cleaning fingers the wire passes to a receiving spool 84 mounted upon a driven shaft 86 journaled on a sup-- port 75, to which is also secured-a pulley 88 which is driven by means of a motor M through a drive belt 90. Any suitable well known means such as cams for impartin lateral motion to the s 01 84 (not shown? are provided to cause t e wire to be-smoothly and properly wound thereupon.

As will be clear] ratus justdescribe is suitable for the operation of my processes and the production of the new products desired. To briefly recapitu'late, a spool of wire which -has' reached the limit of its tensile strength by Inn understood, the appathe ordinary wire drawing processes is,

placed upon a spool holder and the .wire then passes through a suitable electrolyte in the electrolytic cell which latter is provided with the mercury contacts as described acting as one terminal, and with a copper contact acting as-the other terminal. The wire is subjected to an electrolysis in this cell and being the anode is thus reduced diameter and is provided with a roughened surface.

The wire then passes to a second receptacle filled with water to wash ofi any chemicals that may have adhered to the wire, and" from there passes to the cleaning instrument, as described, and is wound upon the receiving spool by means of the motor, as clearly shown and described. The process is repeated again and again. until the wire reaches the desired cross section.

I am enabled to reduce the diameter of the wire bya small and uniform amount during each passage'of the wire through the electrolyte by causing the wire to pass through the electrolyte at a continuous and uniform speed and regulating the stren h of the current in the manner above escribed.

. cyanide.

When tungsten or molybdenum alloys or mixtures are to be acted upon the electrolyte which I have found referable for use, and which produces excel ent results, is prepared by adding to a liter of distilled water 400 guns. to 500 gms. of caustic soda and 200 guns. to 250 gms. of potassium ferro-- Although this electrolyte produces excellent results, it is, of course, ob-

vious that any suitable electrolyte may be used in carrying out my process.

When wires of other metals are to be reduced in cross section,-I use the standard acid or alkali solutionswhich are used-for the electrolysisof the particular metal under treatment, all of which are well known in the electro-chemical art.

Having thus described my invention what I claim as new and desire to'secure by Let ters Patent is: 1

1. The process of producing finemetallic or alloy wires by electro-chemical action which consists in repeatedly passing the wire through an electrolytic bath when immersed in the electrolyte thereof.

2. The rocess of producing metallic wires whic COIlSlStS 1n gradually reducing the cross section of said wires by repeatedly drawing the same through the electrolyte in an electrolytic cell.:

The process of producing wires of fine cross section and of high electron emission by electro-chemical action" by repeatedly drawing the wire through the electrolyte of an electrolytic cell.

4. The process of producing wires of fine comprises, a receptacle, mercury pockets in opposing walls of said receptacle, said walls being provided with passageways therethrough into said receptacle to permit the movement of a wire into said receptacle, an

electrolyte in said receptacle, the passageways being sufliciently narrow to prevent the escape of mercur from said pockets, the mercury in said poc ets forming a seal for the electrolyte, an electric terminal in the receptacle and. an electric circuit connection between the mercury and the said terminal.

8. Apparatus of the type described which comprises, a receptacle adapted to hold a liquid, mercury pockets in op esite walls of said receptacle the walls 0 said pockets having'passa' s therethrou'gh leadinginto and from sai receptacle to permit the free movement of a wire through said passages into and from said receptacle, said passages being sufliciently narrow to prevent the escape of mercury from said pockets, the mercury forming seals for the liquid in the re:

ceptacle.

' CLEMENS A.. LAISE.

7 Apparatus of the type described which

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