US1454387A - Process of alloy knife hardening or tempering - Google Patents

Description

May 8, 1923. 1,4545%? T. B. LASHAR PROCESS OF ALLOY KNIFE HARDENING OR TEMPERING Filed Feb. 18, 1919 W lllmw WIHIIHHITI'"" Smoamfoz Thm as Lashar 45 require little if any N t T E s rar s.

metres 13. mm, or nnmenro'n'r, connnc'rroo'r, mission. we assocra'rm SILVER comrm, or cnrcnco, ILLINOIS, A conrone'rron or rnnmom PROCESS OF ALLOY KNIlIIE HARDENING- E Tml EPERIHGQ I Application filed February 1 To all whom it may concern:

Be it known that I, THOMAS B. LASHAR, of Bridgeport, in the county of Fairfield and State of Connecticut, haveinvented certain new and useful Improvements in a Process of Alloy Knife Hardening or Ten pering, of which the following 1s a specification.

The present invention relates to a process of hardening or temperin alloy table knife blades, while the bla es are at a natural temperature. 7 V

It is common practice, in the rocess of manufacturing cutlery to app 3 successive blows to the metal used to produce the blades of table knives,,these blows shaping to some extent the blades and imparting thereto approximately the required cross-section. These many blows have a tendency to raise the temperature" ofv the,

alloy and anneal the blade rendering it. so soft as to require subsequent treatment, such 7 as to harden or temper and sharpenit.

Such processes are expensive, re uirin considerable time, labor and the'pro 'onge use of machinery.

One of the principal objects of the present I invention is "to simultaneously-form. and harden or'temper the cutting edge'portion of the alloy blade of table knives by strik-' in the blade, without pre-heating it, and w ile the constituents of the. allo are in homo eneous mass, but not fu lycondensed, between surfaces so shaped and dissed as to simultaneously compress the al-' 0y at the marginal portion of the blade and impart the desired cross-section thereto, thus giving the blade a hardened or tem-. pered cutting edge which may or may not re uire sha ening in order torender it usefu as a cuttmg element.

Other objects of the invention are to-provide blades of'table .or carving'kn'ives of alloy, which are inexpensive, urable and after the stnln'ng of the blades in carrying. out the process, thus avoiding the annealing' action,- whichtakes place when the cutting'end portions must be ground to the desired contour- .50 andto so form the cutting edge portion 0% "alloy table knife their respective confronting faces, in plan 8, 1919. Serial No. 277,820.

- the alloy blade that a is of uniform texture and density.

Referring to theattached drawings'forming a part of this specification, showing the unfinis ed article and ap aratus by which 5 the process may be carried out:

F1 re 1 is an elevation of an unfinished theblade of which is to be acted upon.

Figure 2 is a cross-sectional view on the lines 2-2-of Figure 1, the dots indicatini its porosity.

igure 3 is a fragmentary sectional view on an enlarged scale 'transvers'all through complementary dies 'forshaping, ardening and sharpening the allo blade,the dies being separated and the lade therebetween. Fi re 4 is a view similar to Figure 3, with the dies together, showing the blade compressed. I

Figure 5 is a plan viewof one ofthe dies. .7 In carrying out the process, the alloy blade 6 which may be composed, as by way of example, of copper 50%; zinc 25%; and mckel 25% or other'niekel silver or German silver coin sition; is primarily sha ed or formed to en 'stantially the shapein plan of the. finished product as shown in Figure 1 of the drawing, byway 'of example, but thicker with the alloynotfully condensed, or'in other words of a slightly porous texture as indicated in. Fi re 2. The blade thus shaped or forme is subjected to a striking blow confining the slightly porous alloy in a cavity in cross section substantially that of the desired "cross section of. the finished blade, .Thismay be accom--' phshed by the use-of complemental dies 7 and Swhich have depressions 9 and 10in corresponding to the plan of the finished blade-"and tapering or varying in depth as indicated at 11 from one} longitudinal man-'- I gin toward the other longitudinal margin and also at the rounded end portion as mdi'cated at '12, so that when'the slightlyporous alloy, which may be of substantially uniform cross section, is struck betweenthe dies it will be compressed in general, but

that portion which provides the cutting edge will not only be shaped but also hardened,='rendered more dense; lit is to be understood that I do not confine myself to the strikin of the allo j forming the entire blade since that portion to provide the cuttin edge may alone be struck between hard sur aces, the confronting faces of which are so formed as to compress the alloy renderin it dense and shapely.

the term natural temperature I re- :ter to thattemperature which may exist without pre-heating the material. This may vary according to the temperature of the room or place where the process is carried out in contra-distinction to subjecting the material to artificial heat.

An alloy using copper as a basic element with a proportion of zinc not exceeding or does not have much eflect upon its malleability. 1 In fact the'zinc gives it fluidity and also acts as an excellent deoxidizing agent for the copper. Hence my process is well adapted to table and carver knife blades made'of alloy which has some fluidity so as to fill any minute voids, when com ressed, and adapts itself to dies or other orming means. The presence of nickel in the alloy assists greatly in the hardening thereof under the blow. The nickel is usually in a comminuted state when repared with the zinc and copper for mixing in the crucible and its tenacious quality assists in holding to ether the mass when flexed.

yexperiment it has been found that a single blow or striking of theallo will in most instances give the required s ape, angle, hardness and density to the portion of the blade providing the knife edge and rarely are more than three blows necessary. Any flash or bur which. may exist after the theater striking of the alloy, may be removed as by the use of carborundum without materially heating the alloy or annealing it.

I claim; 1. That process of shaping and hardening nickel silver alloy knife blades which consi'sts in subjecting the alloy while at a natural temperature to a striklng blow and confining the alloy in a cavity of a cross section substantially that desired for the finished blade. v

2. That process of shaping and hardening nickel silveralloy knife blades which consists in first shaping the alloy in a slightly porous state to the desired plan of'the finished blade and subsequently while at a nattural temperature subjecting the same to a striking blow and confining the alloy in a cavity of a cross section substantially that.

ural temperature between complemental .dies providing a cavity of substantially the shape desired for the finished blade.

5. That process of sharpening and hardening nickel silver alloy knife blades which consists in striking the alloy while at a mattural temperature by a die which is tapered to give the edge the desired an 1e.

- THUMAS B. SHAR.

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