US2062486A

US2062486A - Method of making pyrophoric flints

Info

Publication number: US2062486A
Application number: US722692A
Authority: US
Inventors: Jr Charles H Van Dusen; Edwin C Dietrich
Original assignee: COOPER SPARKELITE Ltd
Current assignee: COOPER SPARKELITE Ltd
Priority date: 1934-04-27
Filing date: 1934-04-27
Publication date: 1936-12-01
Anticipated expiration: 1953-12-01

Description

I De@ L 1936 C. H. VAN DusEN. JR., Er AL 2,062,486

METHOD OF MAKING PYROPHORIC FLINTS Filed April 27, 1934 Hfs. Z

Patented Dec. 1, 1936 f UNITED STATES METHOD F MAKING PYBOPHORIC FLINTS Charles H. Van Dusen, Jr., Cleveland Heights, and

Edwin C. Dietrich, East Cleveland, Ohio, as-

signors, by mesne assignments, to Cooper Sparkelite, Ltd., Dover, Del., a corporation of Delaware Application April 27, 1934, Serial No. 722,692

8 Claims.

The present invention relates to the fabricating or Working of pyrophoric alloys suchas4V cerium and mischmetal alloys, and more particularly to composite ilints made of these alloys, 6 and a method of manufacturing the same.

-In the familiar cigar and cigarette lighters. of commerce, small pieces of pyrophorio alloys,` commercially known as ints, are struck by suitably constructed toothed wheels or sharp rods, and give off sparks which usually ignite a suitably placed impregnated wick. 'I'hese iiints are usually rods-or sticks of very small cross section and comparatively short length, and since the pyrophoric materials used are hard and brittle, it is impossible to convert them to the desired shape by the usual means of cold working such as hammering, rolling, drawing or swaging, etc. On the other-hand, hot working is likewise impossible because of the great chemical activity of the material.

An object of the present invention is the provision of a novel commercial method of manufacturing, fabricating, or working pyrophoric alloys into useful shapes. l

Another object of the invention is the lprovision 'of a novel commercial method of manu, facturing ints of pyrophoric material which consists in working pyrophoric alloys within a protective metallic sheath to a desired shape and 30 subsequently removing a' portion of thek protective metallic sheath to expose the pyrophoric alloy.

Further objects and advantages of the invention will be apparent to those skilled in the art to which it pertains from the following description of the preferred embodiment of the invention described withreference to the accompanying drawing, of which l Fig. 1 is an elevation of an ingot comprising apyrophoric material enclosed in a protective sheath, with a portion ofthe sheath broken away to show the pyrophoric material;

Fig. 2 is a section of composite rod produced by the reduction of the ingot shown in Fig. 1:

Fig. 3 is aperspective of a composite iiint embodylng the present invention; and

Fig. 4 is a perspective of a lighter embodying the present invention. e

According to the present invention, pyrophoric material, such as alloys. of ceriumor mischmetal, with iron, copper, nickel, zinc, or magnesium, etc.is enclosed in a protective metallic sheath and worked, 'usually by a plurality of successive steps, 'to the desired shape, after which the protective materialis removed to expose the pyrophorlc material. We have found that pyrophorlc material lends itself readily to working and change of shape when it is properly supported 6 on all sides, as is the present instance. Thisv is especially true when the composite article ils worked at moderate temperatures or periodically annealed during the process of reduction. .In addition to confining the metal so that it cannot separate while being worked, the protective metal sheath prevents the same from burning, and chemical reaction.

While individual articles of any size or'shape may be made it has been found advantageous to make a rod of considerable length and subsequently cut the same to desired lengths. Preferably the pyrophoric alloy is first cast in rods of comparatively large cross section and suitable length, and slipped into a snugly tting metallic tube, slightly longer than the rod, after which the ends of the tube are closed in any suitable manner, as by burnishing, spinning, swaging or hammering, etc., to form a composite rod or ingot. The composite rod or ingot is then rolled, drawn, swaged, or hammered etc., to form a rod of the desired cross-section or shape. The ingot or rod may be Worked at a moderate temperature or may be annealed between passes or operations. The amount of work, that is, the percentage of reduction of cross section that is done at each pass through the hammer, rolls, swager, dies, or the like, Iis about the same as that with iron, copper or any ordinarily malleable metal. 'Ihe protective sheath is then =removed from the reduced composite rod to expose the pyrophoric material, `by grinding, milling or planing. etc., after which the bar is cut to the desired lengths.

Referring to the drawing, Fig. 1 illustrates a composite rod or ingot formed of a round cast rod l0 of pyrophoric material, such as ferrocerium or ferro-mischmetal, enclosed in a snugly tting tube or sheath Il made of copper or other suitable metal, the ends I2 and I3 of which have been tightly closed in some convenient manner. The rod I0 illustrated ois about one-half inch in diameter and ten or twelve inches long, and the copper tube or sheath Il has a wall thickness of about one-sixteenth or three-thirty-seconds of an inch. The composite rod or ingot .is reduced to the desired cross section or shape which in the present instance is illustrated in Fig. 2 as square, either by cold working, such as drawing, rolling etc., including inter-pass or inter-operationV annealing, or by hot working at a temperature not to exceed 500 C. or a dull red heat. In the latter instance, as the cross-sectional area of the rod is decreased the working temperature may be rapidly reduced, and inter-pass or inter-operation anneals' substituted for hot working. As the rod approaches the finished size the last few passes may be made without annealing which usually 55 also increases the strength of the enclosing or supporting sheath.

After a composite rod of the desired cross section has been. formed, which in the present instance is about one-eighth or five thirty-seconds 60 of an inch square, the enclosing sheath Il is removed f rom one side thereof by passing the bar under a grinding wheel, etc., to expose the pyro.

n superiority of pyrophoric properties over those ,of the prior art, and are more resistant to deterioration due to oxidation, etc., caused by exposure to air, moisture, carbon dioxide, etc., because a greater part oi the surface is protected by a tightly adheringprotective sheath. The stream of sparks which are struck from the pyrophoric material, in operation, consists of small particles of metal which are torn off by the striker bar or toothed wheel. These small particles of metal are heated by the friction incident to the striking or scratching and burn as they ily into the air. The superiority of the pyrophoricproperties of the present flint may be caused by the fact that apparently Vthe working of the alloy produces a granular structure from which particles may be readily torn o by the striker bar.

While the specicembodiment ofrthe invention illustrated shows copper as the supporting material, it is to be understood that metals such as iron, nickel, aluminum, tin, silver, or any other metal or alloy having suiiicient strength and vductility, and a high enough melting point, may

be substituted for the copper shown. It.is also to be understood that while the copper sides are Shown as being ush with the exposed surface of the pyrophoricmaterial, they may project above the exposed surface or any conguration of surface may be exposed.

Fig. i illustrates the flint shown in Fig. 3 embodied in acigar or cigarette lighter B of the scratch pin type and conventional construction. 'I'he int A is embedded in the body of the lighter in any well known manner. As the exposed surface of the pyrophoric material wearsvdown, the copper walls on the two sides act as guides for the striker or scratch pin and insure proper and successful action at each stroke. With the contact of the striker against the pyrophoric matel rial insured, a smaller or'narrower 'surface of Ipyrophoric material is required, with consequent economy in the amount of material used. It will be obvious that the cross section of the nished ilint may be round as well as rectangular. In the manufacture of ilints for use with toothed wheels it may be unnecessary to remove the protective covering as a separate operation since the pyrophoric material will be exposed at the ends upon the cutting of the reduced bar into the desired lengths. A

From the foregoing description of the invention, it will be apparent that a novel flint has beenproduced, together with a novel lighter and a novel method of working pyrophoric materialand man--4 ufacturing fiints therefrom. It is not intended to be limited to the particular construction or method illustrated vand described, as various changes therein may be made within the scope of the invention, but it is'the intention to cover any and all variations, adaptations or uses thereof as come within the knowledge or customary practice in the art to which this invention belongs, and we particularly point out and claim as our invention the following:

We claim:

1. The method of making a composite article of pyrophoric material and a. protective metal covering a portion thereof, which comprises enclosing a pyrophoric alloy in a metallic sheath to form a composite ingot, reducing said ingot to the desired shape. and subsequently exposing a prtion of the pyrophoric alloy.

2. The method of making a composite int of pyrophoric material and a metallic protective coating, which comprises enclosing the Dyrogphoric material in a metallic sheath, working the article thus formed to a desired shape, and subsequently removing a portion of the protective coating to expose the pyrophoric material.

`3. The method of making a composite iiint of pyrophoric material and a metallic covering which comprises, enclosing the pyrophoric material in a metallic sheath to form an ingot, reducing said ingot by a hot metal working process to form a rod of desired shape, and subsequently removing a portion of the enclosing sheath from the rod to expose the pyrophoric material.

4. The method of making a composite flint of pyrophoric material and a metallic protective covering which comprises enclosing the pyrophoric material in a metallic sheath to form an ingot, reducing said ingot by a metal drawing process to form a rod of desired shape, and subsequently removing a portion of the protective coating to expose the pyrophoric material.

5. The method of making a. composite int of a pyrophoric alloy and a metallic covering which comprises casting the pyrophoric alloy into the form of a rod, enclosing the cast rod in a snugly tting metallic sheath to fo'rm a composite ingot. reducing the composite ingot to a desired shape, and subsequently removing a portion of /the enclosing sheath to expose the pyrophoric material.

6. 'I'he method of making a composite int of a pyrophoric alloy and a protective covering which comprises casting the pyrophoric alloy into the form of a rod, enclosing the cast rod in a snugly tting metallic sheath to form a composite ingot, working the composite ingot to a desired shape by a cold working process, and cutting the rod to desired lengths.

'1. The method of making a composite ilint of a pyrophoric alloy and a protective covering which comprises casting the pyrophoric alloy into the form of a rod, enclosing the cast rodv in a snugly iitting metallic sheath to form a composite ingot, reducing the composite ingot to form a rod of desired shape by hot working followed by cold working, removing a portion of the enclosing v sheath from the rod to expose the pyrophoric alrolling, and removing a portion ofthe enclosing sheath to expose the pyrophoric alloy.

CHARLES H. VAN DUBEN, JR. EDWIN' C. DIETRICH.