USRE5232E - New yokk - Google Patents

Description

Hard Rubber.

N9. 5,232. `Rissuedlan.14,18%.

'UNITED S'ra'rns PATENT OFFICE. A

AUsfriN o. nar, orvunw Youn, N. Y.

IMPROVEMENT IN HARDVRUBBER.

Specification forming 'part 0f Letters Patent No.` 21,122, dated August 10, 1358; reisue No. 6:20; dated November il, 1858; extended seven years; reissue No. 5,232, dated January 14, 1873.

Division C.

I hereby declare that the following is a 1" ull,

clear, and exact description thereof.

lhe nature of iny invention consists in heating sulphur and India rubber or caoutchouc, .or other equivalent or vulcanizable gunis'iin such a manner as to make a new special artiii cial productwhich shall possess hardness, and

`also the properties of indestructibility, ilexibility, and elasticity, thereby iitting it for vmany useful purposes in the arts to ,which no rubber, compounds which werev known previ- Y ous to my invention were adapted. .Y

It is well known that Charles Goodyear on the 15th of June, 18gt4, patented a process of vulcanizing rubber, so as to preserve-it soft and exiblc when exposed to the summers sun or winters cold, or to thev action ol' various solvents; and that NelsouGoodycar on the 6th of May, 1851, patented 'a process of manufacturing a hard-rubber compound, which he corrcctl y described in saidpatent as a hard and indexible substance hitherto unknown.7

The process of Charles Goodyear produced what is known in the arts as vulcanized soft.

` ruhberyand the process oi' Nelson. Goodyear,

byvhim upon the product made by him 5 and' -it consists of a compound which shali possess not only all the hardness oi the Nelson Geodyear product, but also, in addition, the indispensable properties of ilexibiiity and elasticity-qualities whichcan not beiniparted to it by Goodyeals process, but which are absolutely necessary to render it available for many purposes in the arts.

The process lby which I malte my new. special compound differs from the process by which the Nelson Goodyear product is made in nearly every one ot' the various elements of the treatment to which sulphur and India rubber, or other vnlcanizable gum -ninst be subjected to produce hard com pounds-that is to say, it dil'ers, irst, in the proportion of ingredients; second, in the degree of vnloaniz.

ing heat to which these ingredients are eze.

posed; and, linally, in the lnature and character ol' the resnltingproduct.

rlhe Nelson Goodyear proportions oingre dieuts are from foury to sixteen'ounces of suiphur to sixteen ounces of rubber; butthe 1851 patent states that a better resultwill be ob tained from eight ounces of sulphur and eight ounces of some earthy .base-magnesia, for exampleto sixteen ounces of rubber; my proportions are one part byweight oi' sulphur to twoparts by 'weight of rubber, or other vulcani'zable gum, and no earthy base whatever, for although an earthy base might be added, its addition will hot improve the product. Nelson Goodyears vulcanizing heat is prescribed in said patent as to counnence be low or at' about 260O and terminate at about 2750 Fahrenheit; my vulcauizing heat is couimenced-at 21750', and is always carried inany degrees beyond that point, frequently reaching to 25000, 3050, and 3100 Fahrenheit, and seinetime's higher, the length oi time the compound requircsto be treated depending greatly, as well known, upon the 'temperature,employed Moreover, Goodyea-ris process merely @einem plates subjecting hisnlixture of ingredients to the ,vnleaniziug .heatwehielnhglireiets for the length of time which he prescribes, "ith`7 out` any allusion whatever to the importance of what may be termed il heating intervalsllw or in other words, the exposure oi' the ingre dients tov one degree of temperature for a tain interval of time., then to a higher degree for a cert-ain other intervahand so oil until the operation is completed; Whereas li have foundit in ce1-tain cases to be well-nigh iurdispensable to the production of a desirable result to observe such heating intervals.

The mere statcnientoi these diiierences between luy method and tfliatovGoodyear may 'duced by theA two processes are compared.

rl.`hus, ifGoodyea-rs mixture be taken at sixteen ounces of sulphur to sixteeny ounces ot' rubber, it may be exposed to the temperature which he directs for any length of time, without producing anything but a soft, semi-hard, or leathery product, and, of course, therefore, such a mixture, so treated, is worthless for hard rubber purposes; or, if his preferred mixture-of eight ounces of sulphur and eight minces of earthy base to sixteen ounces of rubber-s-be adopted, and be `exposed to the temperature which he directs for thefthree (to six hours7 which 'he prescribes, the product will indeed be hard, butV it will also be brittle and utterly destitute of the indispensable qualities of flexibility' and elasticity, while it' it be heated longer than six hours v itwill be'still more brittle and comparatively worthless. Finally, ifto sixteen ounces ot'rubber any other proportioii's'of sulphur between the extremes which Goodyear gives ol' four to sixteen ounces be selected, the proportion of ounces of. earthy base 'to the rubber bein g in creased or diminished according' as such selected proportion of sulphur is diminished or increased, as is directed by his patent, the results will range according to the particular proportions chosen, between the soft or semihard productabove mentioned, and the britile and comparatively worthless compound rei'erre d to. Butiu my new compound the results of merely soft rubber On the one hand and ot' hard rubber;7 which is brittle and comparatively worthless on the other hand, are alike avoided, and a product is made which is characterized by the qualities of ivory-like hardness accompanied by the spring temper oi' steel, thereby furnishing precisely the proprrties'which are found to be essential in the arts, and which are absolutely unknown to the Goodyear coi'npound.' I My invention, in fact, is based upon the chemical discovery, which,`so far as I am aware, I was the first to announce, that when a mixture composed of about two parts'by weight of rubber or other vuleanizable gum, and one part of sulphur, is exposed to a vulcanizing heat commencin g at about 2750 Fahrenheit and carried to 3000 or upward, such a chemical change is produced in the compound that a hard ivorylike product will be formed which will be tough, indestructible, and highly ilexible and elastic. lIence, the special method or process of treating sulphur combined with rubberor other gum in such a manner as to produce these results, together with the special compoundor product possessing these properties when produced, constitute my invention, the said special process forming the subicct ofseparate Letters latent of even date herewith.

'Io enable others to put my iniprovcm'ent into use, l will describe the moet' iu which I have practiced it with success.

l` take :i riinvenient quantity of any suita ble 'crude rubber, preferably the rubber of Para, or other vulca-nizable gum, and combine sulphur with it, in the usual manner, in the proportion of about one part by weight of sulphur to two parts by weight of rubber or oth'- er gum, and after treating the compound in Fthe way well known to manufacturers for preparing rubber compounds for vulcanization, I place the article or articles to be vulcanized in a suitable heaterL-if preferred, one in which the temperature is equalized in the manner vhereinafter described-and I then let on the steam or other heat and run the temperature preferably directlyup to 27 50 Fahrenheit, and from that point carryv it to 3000, 3050, or 8100, or eveuhigher, according to eircumstances, the time during which the process is to be continued being easily determined by the operator, according to the mode adopted for applying the heat, and to the grade of result desired to be produced. I frequently make various changes in the length of tim'e and degree of heat employed at the dii'erent `steps of the process to adapt the temperature to di'erent kinds of stock or different degrees of vifilcanization as required for different articles of manufacture.

It has been found in the manufacture of hard rubber and other gum compounds, that if vulcanization is performed in large heaters, v

it is sometimes ditiicult to Vulcanize equally in every part of the heater. Articles in one portion of the apparatus may be done too much or burned'while those in another 'p'art may be slack. These imperfect-ions I am able to obviate, when lrequired, by establishing a circulation in the heater which equalizes the temperature in every part of it. This may be accomplished by means of a double-acting pump or a fan, or other equivalent device, which shall draw out the steam from one end of the cylinder andtransfer the same into the head of the opposite end, as seen in the drawing, where A represents the heating-cylinder supplied with steam for heating it up under pressure by the tube c.' rIhe articles to be vulcanized are placed within A. The circulation to equalize the tempe aturc in all parts ismade by working the pump B, or its equivalent, which draws the steam from the C-end of the heater through valve a and forces it through valve b, and thence through pipe D, whence it strikes against head F, and is distributed through the perforated plateE, and so through the body of the cylinder.

It is evident that a single-acting pump, or a double-acting pump, or'a rotary pump, or a forcing and exhausting fan may be used for this purpose. v

I do not make any claim to any special form of apparatus, for a variety of known apparatus might be used to accomplish the e'eet. Even a. current of steam forced in" at one end :md out at the other would also aid in keeping up the circulation, and tend to equalize the heat, but 'very' imperfectly.

. The novelty consists iu the making an artifcial circulation in a. vnlcnniziug apparatus irrespective of the special means employed for that purpose.

I do not claim, in the broad, a. hard compound formed by vulcauizing sulphur and rubber or other equivalent gums, irrespective of the special product made; but

What I claim as my invention, and desire to secure by Letters Patent, is-

The herein-described special] product formed by vu-lcanizin g in any suitable apparatus a mixture of two parts by weicht of' india rubber or other vulcanizable gum, and one part by weight of sulphur ata. temperature commenced at or about 2750 and carried to the degrees of temperature hereinabove mentioned, so that such product shall possess the properties of flexibility and elasticity2 substantially as de` scribed.

AUSTIN G. DAY.

Witnesses:

T. B. BEEGHER, l W. H. 'Wereuzrmm

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