US3314134A - Ignition spark wheels - Google Patents

Description

April 18, 1967 G. BIESENBACH 3,314,134

IGNITION S PARK WHEELS Original Filed Oct. 28, 1964 2 Sheets-Sheet 1 INVENTOR.

Y GINN BIESENBACIH 2 Sheets-Sheet 2 Original Filed Oct. 28, 1,964

Pierce Pierce Bldnk Form 4 5 W Q I a) ,h' mm I all FIIIL mm m .m ,3 Y H m F e a W. m

INVENTOR GINN BIESE BACH A TTORNEY United States Patent Office 3,314,134 IGNITION SPARK WHEELS Ginu Biesenbach, 120 Madison Ave.,

Reading, Pa. 19607 Original application Oct. 28, 1964, Ser. No. 407,035, new

Patent No. 3,262,289, dated July 26, 1966. Divided and this application Apr. 1, 1966, Ser. No. 539,503

6 Claims. (Cl. 29-159) This invention relates to mechanical igniting means, generally referred to as cigar or cigarette lighters, and it particularly relates to lighters of this type equipped with a novel type of spark wheel.

This is a division of applicants copending application Ser. No. 407,035, filed Oct. 28, 1964, now Patent No. 3,262,289.

Igniting means of the so-called cigarette lighter type generally include either the type utilizing a wick having one end immersed in a liquid fuel or abutting a cotton wad or the like soaked in liquid fuel while the other end is positioned adjacent a so-called spark wheel, or the type utilizing butane or a similar igniting type gas, issuing from a nozzle adjacent the spark wheel. The spark wheel is adapted to be rotated, either manually or by a ratchet mechanism or the like, against a flint, whereby a spark is formed. This spark ignites the flame producer comprising either the fuel-fed wick or the jet of gas which then provides a flame.

The spark wheel is generally constructed of a hard, metallic, abrasive substance which is adapted to strike a spark from frictional contact with the flint. However, because it is necessary to form the spark wheel with very fine tolerances so that it may be of a standard, replaceable size and shape, it has always, heretofore, been necessary to construct the wheel of material which is suificiently soft to permit cutting and machining. Consequently, the durability of the wheel, under conditions of use, has been of an undesirably short duration. Furthermore, the cost of labor and tools involved in the cutting and machining processes has been a primary factor in the total cost of production of the wheel. In addition, it has, heretofore, been advisable to construct the wheel of solid stock in order to provide sufficient strength and rigidity to withstand the pressures and shocks of the cutting and machining processes. It was also necessary to use excess stock to permit cutting and shaping.

It is one object of the present invention to overcome many of the aforementioned difiiculties by providing a spark wheel for ignition mechanisms which is of much greater strength and hardness and which is, nevertheless, less costly to produce than spark wheels of the same type heretofore available.

Another object of the present invention is to provide a spark wheel which is far more durable under conditions of use than those previously available.

Another object of the present invention is to provide a process for making spark wheels which substantially reduces waste of materials and substantially reduces the amount of labor required.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following description when read in conjunction with the accompanying drawings wherein:

FIG. 1 is a perspective view of a cigarette lighter equipped with a spark wheel embodying the present invention.

FIG. 2 is an enlarged, exploded view of the spark wheel shown in FIG. 1.

FIG. 3 is a perspective view showing the wheel of FIG. 2 in assembled condition.

3,314,134 Patented Apr. 18, 1967 FIG. 4 is an exploded view, similar to FIG. 3, but showing a spark wheel, embodying the present invention, for use in so-called automatic type lighters.

FIG. 5 is a perspective view showing the parts of FIG. 4 in assembled condition.

FIG. 6 is a diagrammatic, flow-sheet view showing the parts in their successive stages of manufacture.

Referring now in greater detail to the various figures of the drawings wherein similar reference characters refer to similar parts, there is shown in FIG. 1 a cigarette lighter, generally designated 16. The cigarette lighter here illustrated is of the manual type wherein the spark wheel 12 is manually rotated against a flint (not shown) to strike a spark which ignites a wick 14 positioned within the confines of a tri-walled wind-screen 16. The lower end of the wick is in contact with a cotton pad or the like, soaked in lighter fluid, in a chamber within the body of the lighter 10. l

The spark wheel 12 is constructed of two sections, an outer, hollow section 18 and an inner section 20. The outer section 18 is constructed by punching a centrallyapertured blank from strip steel, press-forming the blank into hollow cup shape, milling or otherwise cutting teeth or knurling on the outer surface of the peripheral wall, and then nitriding the cup-shaped part to provide it with an extremely high surface hardness.

This process of forming the section 18 is illustrated at the left-hand side of FIG. 6 where the strip steel 22 is indicated as being simultaneously pierced with a small aperture 24, to form an opening for a supporting shaft, at one area, while at an adjacent area, a previously-pierced portion is being punched out to form the blank 26. The blank 26 is then pressed into the hollow, cup-shaped body 28. It is then usually necessary to trim away any excess or wrinkled-up material produced during the forming step. The teeth 36 on the outer surface of the peripheral wall are then either milled, machined or cold-chiseled by either one or a combination of two or more series of cuts at different angles. The milling process is preferred and is illustrated in the flow diagram of FIG. 6.

All of the cutting, machining, etc., up to this point, takes place while the steel, which is of the so-ca-lled nitriding type is in a relatively soft or unhardened condition. At this point, the part is nitrided or case hardened to form the finished section 18.

Nitriding is the method of case hardening certain steel alloys by heating in an atmosphere containing active nitrogen at a temperature of about 925 -1100 F. for periods ranging from a few minutes to about hours. or more, depending on the type of alloy being treated and the desired depth of the case to be produced. The steel must contain elements in solid solution that are capable of forming nitrides. These elements include aluminum, chromium, molybdenum, vanadium and tungsten. The hardest cases are obtained with aluminum bearing steels.

The most common source of nitrogen for the nitriding process is ammonia. At elevated temperatures, ammonia decomposes at the surface of the steel to form atomic nitrogen and atomic hydrogen. Both of these atomic forms are unstable and rapidly pass to the molecular form, but during the transition period, while the nitrogen is atomic, it is susceptible to being absorbed by the steel. To provide an adequate supply of atomic nitrogen, fresh ammonia is continuously passed into the atmosphere. The nitrogen diffusing into the steel reacts with the aluminum, etc. to form very hard reaction products.

There is practically no warpage or distortion in the nitriding process because it takes place at relatively low temperatures. Preferably, however, the alloy should possess a sorbitic structure prior to nitriding, which is produced by heating to the austenitizing temperature, quenching and tempering at the proper temperature and then removing the outer or white layer to eliminate all traces of decarburization to prevent embrittlement at the surface by the nitriding process. This is usually accomplished by the steel producer prior to delivery, but if not, it is done before the blanks are sheared out. It is sometimes also desirable, if there is a rough machining and then a final machining of the parts, to reheat the parts after the rough machining to between about 1l00 to 1300 F. in order to remove stresses produced during this rough machining.

In the present instance, it has been found preferable to start with strip steel, having a thickness of about 0.024 0.050 inch, of the so-called Nitralloy 135 modified (type G) having a content of:

Component-- Percent by wt. Carbon O.30.4 Manganese 0.4-0.7 Chromium 0.91.4 Molybdenum O.150.25 Aluminum 0.81.2 Iron Balance However, the particular composition of the nitriding steel alloy may be varied in accordance with desired results or with the materials available from various producers.

The inner section 20 may also be formed of nitrided steel but is preferably not so constructed because this section is not subject to the wear and stresses of the outer section 18, the knurled peripheral wall of which acts as the spark-striking means. This section 29 is preferably constructed from free machining steel or brass and may be machined either from strip stock and formed into hollow cup shape, as illustrated, or from bar stock, in which event it would be a solid plug insertable into the outer section 18.

The right-hand side of FIG. 6 illustrates the production of the inner section 20 whereby a steel strip 40 is simultaneously pierced and punched to form an aperture 42 and blank 44, similarly to the process for forming the blank for the outer section 18. The blank is then, similarly, press-formed into the cup-shaped body 46.

In the form of the invention illustrated in FIGS. 1, 2 and 3, where a manually-operated spark wheel is used, the cup-shaped body 46 constitutes the inner section 20 and is ready for assembly with the outer section 18, unless it is desired to construct the section 20 of the same nitrided steel as section 18, in which case, the strip 40 is made of the same nitriding type steel and the body 46 is nitrided prior to assembly.

If the spark wheel is to be used in a so-called automatic lighter device, the inner section is provided with ratchet teeth on its radial face. These ratchet teeth are successively engageable by an actuating finger, indicated at 48 in FIG. 5, which serves to engage a ratchet tooth to rotate the spark wheel one or more steps each time the lid on the lighter is opened. This type of automatic lighter is a standard, commercially-available type and, in itself, froms no part of the present invention. It has, therefore, not been here illustrated. However, a spark wheel utilizable for such automatic lighter device is illustrated in FIGS. 4 and 5 where the spark wheel, generally designated 59, comprises an outer section 52, identical with the section 18 of spark wheel 12, and an inner section 54, substantially similar to the section 20 except that it is provided with an annular series of ratchet teeth 56 on the radial face thereof.

Although the section 54 may also be constructed of free machining steel or brass, similarly to the section 20, it is sometimes preferable to construct it of the same nitriding steel as the outer section because of the added strength thereby afforded to the ratchet teeth 56. In either case, however, when the body 46 (shown in FIG. 6) is punched into shape, the same punch die is preferably provided with ratchet-tooth forming portions that form the ratchet teeth simultaneous.y with the formation of the body 46 itself. If the part is to be nitrided, this nitriding process takes place in the succeeding step to produce the finished section, this finished section being either section 20, if not provided with ratchet teeth, or section 54, if it is provided with such teeth.

In the flow diagram of FIG. 6, the resultant assembled roduct is illustrated as being the spark wheel 12 which includes an inner section 20 that has been neither provided with ratchet teeth nor nitrided, both these optional steps being omitted. Furthermore, the assembled wheel has been constructed with a frictional force-fit between the inner and outer sections. However, it may sometimes be preferable, especially where the ratcheted form is used, to insure against slippage by providing additional interlocking means such as one or more detents or fingers on one section engageable in corresponding apertures in the other section. Or the outer surface of the peripheral wall of the inner section may be knurled to increase the frictional engagement of the force-fitted parts. Any other feasible and desirable interlocking means may also be used within the scope of the present invention.

As indicated previously, the inner section may be conr structed from bar stock rather than from strip stock as illustrated. In such case, the press-forming step is eliminated, since the punched-out blank constitutes a solid plug immediately insertable into the outer section. Such solid plug may, sometimes, be preferred, especially when using softer, un-nitrided steel, bras-s, or similar material, since the solidity provides increased strength.

It is also within the scope of the present invention to construct the spark wheel of only one section corresponding to the outer section 18. In such case, the spark wheel itself would be of hollow construction. However, since the sparking function is provided entirely by the outer peripheral surface of this outer section, such wheel would be operative for the desired purpose. Although such wheel would have less strength and durability than the two-part type described above, the nitriding would provide effective hardness and sufiicient durability for many purposes, whereas the total cost of the wheel would be much less than that of the two-part type because of the saving in labor and materials. On the other hand, it may be desirable to construct this single section as a solid disc punched out from bar stock in the manner indicated above with regard to the inner section. In that case, the solid disc, after being nitrided, would have all the strength and durability of the ordinary solid disc type of wheel plus the added hardness provided by the nitriding.

It is, further, within the scope of the present invention to make the outer section 18 rotatable relative to the inner section 2%, whereby the inner section acts as a stationary hub for the rotatable outer section.

The punch process of the present invention provides a far simpler and less costly method of producing a more durable and better spark wheel than previously available. This punch process is made feasible when used in conjunction with the nitriding process because there is no preceptible warpage or distortion during the nitriding process. This permits the greatest accuracy in the final product because such final product will correspond exactly to the form of the die in the punching process.

C bviously, many modifications of the present invention are possible in the light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

The invention claimed is:

1. A method of making spark wheels for ignition devices which comprises punching a circular blank from a stri of steel, pressing said blank into a hollow, cupshaped body having a radial wall bounded by a peripheral wall, and then forming an abrasive surface on said peripheral wall, said blank being punched from a strip of a nitriding steel alloy and said body being nitrided to form an outer section, then forming a second circular blank to constitute an inner section, and thereafter inserting said inner section within the hollow of said outer section in such a manner that the peripheral Wall of the outer section encompasses the periphery of the inner section.

2. The method of claim 1 wherein said inner and outer sections are secured together.

3. The method of claim 1 including the step of forming ratchet teeth on said second blank.

4. The method of claim 1 wherein said second blank is punched from strip stock and is then formed into a hollow cup-shaped body.

5. The method of claim 1 wherein said second blank is punched from bar stock to form a solid plug.

6. The method of claim 1 wherein said inner section 15 is constructed of a nitriding steel alloy and is nitrided after being formed.

References Cited by the Examiner UNITED STATES PATENTS 518,908 4/1894 Ackerman 148-12.1 1,728,033 9/1929 Blake et a1. 72-348 1,974,981 9/1934 Carvalho 72-348 2,390,417 12/1945 Bramberry 14812.1

10 3,010,856 11/1961 Seelig et al. 14814 X DAVID L. RECK, Primary Examiner CHARLES N. LOVELL, Examiner.

Claims (1)

1. A METHOD OF MAKING SPARK WHEELS FOR IGNITION DEVICES WHICH COMPRISES PUNCHING A CIRCULAR BLANK FROM A STRIP OF STEEL, PRESSING SAID BLANK INTO A HOLLOW, CUPSHAPED BODY HAVING A RADIAL WALL BOUNDED BY A PERIPHERAL WALL, AND THEN FORMING AN ABRASIVE SURFACE ON SAID PERIPHERAL WALL, SAID BLANK BEING PUNCHED FROM A STRIP OF A NITRIDING STEEL ALLOY AND SAID BODY BEING NITRIDED TO FORM AN OUTER SECTION, THEN FORMING A SECOND CIRCULAR BLANK TO CONSTITUTE AN INNER SECTION, AND THEREAFTER INSERTING SAID INNER SECTION WITHIN THE HOLLOW OF SAID OUTER SECTION IN

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