US2290554A - Method of fabricating reinforced material - Google Patents

Description

July 21, 1942.

C. H. HACK METHOD 0F FABRICATING vREINFORGED MATERIAL Filed June 27, 1940 .BY ma'.

Patented 21,?1942,4`

, in nate; s

poration ofNew Jersey application June Y21;,1940, serai-N0, 342,743 n. Y i "'roiiig'f' i The present invention'i'relates tothe reinforcing of soft plastic materials, and particularlyto the reinforcingof softmetals, the ductility of whichx;

permit their cold.v rolling.' v

For'the sake of clarity my invention .will-Ehe described with respect to the strengthening or reinforcement of sheet lead :or alloys of lead.

Lead sheet is used for-many purposes.'V jSorne'ofV these uses arefor flashings, roofing; fand .various architectural purposes, `as well asfor-thelining of tanks and the like. Since lead issomewhat Weak as a structural material, attempts have been made to either alloy the rn'ate'riali'n'l order Lto strengthen it, orto attach, support, linevor. other.. wise mechanically stiften, themetalr inlsorn',l way or other. If the sheet iswhung vertically bysupporting -attahmentstit willoften fail by` creeping or buckiingpfdueto its owiiweig'ht'unlessthe de.

sign and, the nmnber.,ofattaehrnentserstnesses are carefully planned, solas "toi"relieveV theistrain on the lead sheet. Ro'ionng willA at timessagfand elongate under the,f orce Yoffits weightgfandithis property-ofthemetal is usua y' termed' crawlings The longtime negation Ork-'stretch ofthe .f-

metal under steady loads'is due fto the inherent plasticnature. ofthe 'metalg,Furthermore-lead Vhas a considerable eoefficientofj'expansii'n, and .when it is l subjected to.'r periodic vchanges o`f Ytemperature itl tends to fail by buckling and subsequent cracking.

one of the emette Qffu'ie ,prsent A invention is to provide a stronger sheet flead orvlead `alloy which will overcomefto a great ,degree the inherent tendencyoflead to elongate; creep.:buckle.v kand crack-. Other objects of 'my invention and novelfeatures of constructionwillbeconie apparent from thespecificationA when lconsidered together with the accompanying drawing,jin'which rial as iron, tinnedwiron, galvanized iron,l steel,

stainless' f steel, .moneL` inickel, ,.copper, brass, bronze-'or the"like,1whichissuitably embedded in the'sheet of lead', or, if desired, between two sheets offlead,it being understood that ,thislatter prod uct can be so fabricated as nottobe subsequently thicker than the `single lead-sheet with the reinforcing means embedded therein. The thickness of .thefabricated product will,`of course, 'be dependent upon the'us'efto'whichit is to be put.

Withfreference'nowto Figs.`1 and'2, in which similar numerals refer to similar parts, l representsl a .sheetk of lead'ofrany v desired thickness which i `s placed fiat on' the bed -'2"bffa rolling mill of the vtype used A,in rollin'glead. 0n top of this sheet of leadl is placed La-'wire-mesh screen 3.

304 With the passage space through thel rolls 4 being .v approximately the same ora little less than the "thickness of the sheet, the lead and the screen are simultaneously passed through the rolls. In order to insure the proper; embedding of the wire-mesh screen into the lead sheet,`my invention contem- `plates re-passingtheleadsheet through the rolls Fig. 1 is aperspectivefview `f a suitable rolling apparatus and of my novel product'before and after being-rolled;l1ig.2 is adetailed view in cross sectionof myfabricatedproduct; and Fig. 3 is a diagrammatic,representation"of the improved properties exhibited by my lnovel product.

As understood at thepresent time, stretchingHV of a metal under tension mayresult in sudden v failure in the space ofa fewminutesby reason of the imposition of a load too great forthv metal to bear,A but failure may also result by4 a'V very gradual process of elongation which can' only be noted .by careful measurements during thefcourse of weeks or months. vThe vi'lrst phenomenon is commonly vtested for and denoted by what is one or more times. However, in Viewv of the fact that the amount of reduction of thickness of the lead sheet should be carefully controlled, since it is'not desirable to f orce the wire to elongate, nor .to elongate the lead so much that the ends thereof willl lack the reinforcing properties of the wire screen, it is well to subject the lead sheet only to such a number of' rolling operations as may be -suicient properly to embed the wire mesh into the sheet. Generally speaking, twice passing. the

,amount of the-,clearance space between the. rolls .lead sheet through the rolls with a roll clearance space slightly smallerthan the thickness of the sheet to be Arolled is sufficient. Of course, the

" will depend upon the hardness of the alloy to be known as the ultimate tensile strength, while the: latter is called "creep." Lead sheet reinforced tion it is also desirable to have the lead 110W over rolled,` and the size of the wire mesh usedA as a reinforcingagent. `In the operation of vmy invenmesh being held in place regardless of the amount and degree of bending to which the reinforcedj sheet lead may be subjected, my invention. primarily contemplates sweating the ,wires in the lead following the rolling operation.. The procedure is as follows: 4

The reinforcing agent, for example, an iron wire screen, is first suitably coated with a-soft solder. The lead sheet andth'e coated wire mesh are then passed together through the rolls in a manner similar to that described above. After rolling, the top side of the rolled lead sheet into which the wire mesh is em bedded is `coated with a suitable flux of. zinc chloride, or the like, which mayffbe, applied by brushing, and placed in an oven for a short period of time, and heated at a `temperature of about 230 C. until the solder-coating on the wire mesh is melted and the wire thus sweated rmly into the lead sheet. The temperature and time of the sweating operation may vary between wide limits, depending upon the alloy or the solder used. Usually, ten minutes-are sum'- cient to accomplish the desired result. -After being removed from thev oven, the. reinforced sheet lead is washed so as to remove. the surplus zinc chloride therefrom.

The remarkably improved` properties of the 1 product reinforced according to my invention.

are vividly illustrated by the tables given. below. Table I shows the ultimate tensile strength to failure on specimens of pure commercial lead sheets and antimonial lead sheets.- 'I'hese specimens weregabout 0.04" thick, `and were pulled on the testing machine at a rate. of about 0.5" per minute on a 2.0"- test length. Table II illustrates the -vastly increased resistance tocreep imparted to sheets of lead and of anti-- monial lead when reinforced according tothe present invention.

TABLE I Ultimate tensile strength of sheet lead and amti-l monial lead reinforced withron wire mesh Y, Tensile Composition of sheet Reinforcementreinforced None 12 mesh x .011 diameter iron wire.

l4 mesh x .017 diameter iron wire.

12 mesh x .011 diameter iron wire (wire mesh soldered or sweated in the metal sheet).

14 mesh x .017 diameter iron wire (wire mesh soldered or sweated in the metal sheet).

None c 14 mesh x .015 diameter on wire.

14 mesh x .015 diameter iron wire (wire mesh soldered or sweated in the metal sheet).

ses sees 6% antimonia 1cm. 6%-antimonial lead. 6% antimonial lead.

este Tnu I1 Creep strength-percent elongation under load- Load Tlmerand percent creep pel| sq.

mh Zwecks iwceks B'wceks Specimen A Lead sheethavingnjnoverali ag. :mm-" thickness of .040"-not wo v 2:60- 1b 7 mm'd 800 Broke in one day Specimen B 1 und sneeinsvingsncvmu 1,250 0.00 o.0o 0.00 thicknessk ci .040" rein 1,3150 .00 .03 .03 forced with 14- mesh-wireol 2,250 .00 .'03 .07 .011" dinmetet.- 3.a!) .l0 .l1 .Zi

Specimen C Lead sheet having. an overall thickness of .046" ninfcrdwith 1'4 mesh wire of I, 250 0. 00 0; 00 0. 00 .017r diameter which has 1,750 .03 .07 been sweated or soldered irl` 2; 250' 00 00 03 Vthe leadlsheeL-.. 3,00) .03 .07 .l0

Specimen D y --1% antimonia lendsheet ig 0% e havingIan-overallthlelrncss 800. sa 1b; I 2L@ of'ow not ramr0rd"" l 1,000 1 11.7 v Brokc'inlldays Specimen E i (W1, antimonial-lead having Il {,250', 0.00 0.00 0.00

an-overallthicknessci" 12.750 .00 .00 y.00` reinforced with 14 mesh 2,250 .10' .10 .17 wire of .05" diameter 3,000 .13 .20 .V30

Specimen F 6%.antimcnin11eno having time i."

. re orce w1 rneshwireof..U l5diamete-r 1% o'gg which has been sweate'd or 2*, 250 '03 '07 soldered inthe antimonial 3; 000, "10. 23. 37

'Ifo` more clearly illustrate t data embodiedin Tablev II, referenceis. made toliig.` III, which graphically sets forth the contents of this' table. graphic illustration' is' self-explanatory, and no furtherselabo-rati'omis necessary.`

It is tov be underswod. thatv the foregoing description; of my inventionihas been given merely for illustrative purposes, andi no undue limita-- tions should `be deduced. therefrom. Thus, it is' to be understood that the? scope of my' invention is: sufiiciently; broad toA embrace4 the' reinforcing of lead or lead alloy sheets with` wire mesh on both top and bottomy sides'. Furthermore', the reinforcement may be accomplished by placing wire mesh between two leador lead alloy sheets, and then rolling the same, as hereinabovev described.

Also', it is to be' understood that the reinforcement of the sheet may bey accomplished by'means other than. rolling, such. its",y for' instance, placing the. lead sheet, together with the wire mesh, in a press or-by extruding.l lead ribbon together with the wire mesh in. aimannersimilar to the method of extruding cable sheathing. around cable.

I claim:

A process for making a reinforced leadl or lead alloy sheet which: comprises-- coating a wire

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