US1743800A - Expanded-metal lath - Google Patents

Description

Jam.v 1'4, 1930.

1 J. w. PEARCE EXPANDED METAL LATH Filed Jan. 5', 1929 Mfg@ Q y FAU,

Patented. Jan. 14, 1,930

UNITED STATES vPATENT OFFICE JAMES W. PEABCE, OF PHILADELPHIA, `ZEIENNSYLVAIN'IZA, ASSIGNOR T0 NORTE WEST- EBN EXPANDED METAL COMPANY, F GHICAGD,A ILLINOIS, A CORPORATION OF ILLINOIS EXPANDED-HETAL LATE Application med January 5, 1928. Serial No. 330,519.

Theinvention relates to improvements in expanded metal lath and method of maln'ng the'same and it consists in the matters hereinafter described and more particularly pointed p .5 out in the appended claims.

. The expanded metal lath with which my 1nventionis articularly concerned isof that type formecPl by.v operating upon a previously slitted sheetto bend or deiiect the strands toproduce the" open diamond mesh, the bent strands extending diagonally of the sheet in opposite directions and being connected at their'intersections b bonds or bridges disposed in rows extending transversely of the Sheet.

' ln this type of lath the strands are not placed under'tension by stretching as in diamond mesh lath made by simultaneously slitting and stretching. the strands so that it may 2o be readily and advantageouslymade from very light auge sheet metal. Lath of this kind heretdore generally accepted by the trade for the support of mortar and plaster coats in walls and ceilings, measures about 24 wide 25 and 96 long and the slitted sheet from which it is produced measures 8" wide by about 108 long. Such lath is furnished in diierent standard gauges and'weights` namely 24,. 25, 2 6 and 27 gauge, which weighs about 3.4, 3.0,

- 2.5 and 2.2 pounds per square yard respectively, the most popular' being the lightest gauge andweight, because greatervyarda e issecured for the same weight and purc ase price. Such sheets were slitted previous to expansion to provide about one hundred and thirty strands extending transversely of the sheet. Said bonds are about. twelve hundredths of an. inch wide and the strands are about six hundredths of an inch wide. The bonds are spaced about seven eights of an inch` apart longitudinally of the sheet so that there are about one hundred and twenty four rows -of such bonds and strands.

As such sheets are expanded to about twenty four inches wide which is about 'three times the original width, the transverse ing of the bonds inreach row will be a y ut three eighths inches apart. The above mentioned-lath represents the best form of open diamoild mesh lath which the manufacturers have heretofore` made and which the trade has customarily accepted as the mortar and plaster support in walls and ceilings.

As a result of my study and research in this art,' I have discovered that the lath above mentioned has a number' of inherent objections. For example, with such lath it has been necessary for the plasterer to use a relatively dry mortar for the first coat. This requires the use of more mortar to properly cover the lath than is'necessary with a mortar of a more fluid 0r mushy consistency. Such relatively dry mortar is also more diicult to apply so that the area of lath covered in a predetermined period of time is reduced. The natural inclination of the plasterer is to increase the fluidity of the mortar so thatit may be more` Veasily applied. Such practice howeverI embodies other and probably more objectionable features. That is to say when this more fluid mortar is used a very considerable portion thereof will pass through the mesh under trowelling and form large keys or gobs at the Arear of the lath, which slough of under their own weight. This not only results in a waste of mortar but brings forth another objectionable condition. It will vbe' understood o v course that it is desired ,to obtain a at surface `to provide a lath of this'kind which will have better mortar retaining ualities in that the metal ofthe lath is distri uted in a` different open diamond mesh as well as the strands andrbonds are materially increased.

Still another Objectof the invention is to im.v

provide a lath of this kind which is practical to make from a previously slitted sheet, upon -machines at present'in use without cha the sheet rectangular.

Fig.-.3 is a view in elevatlon on a full size scale of one corner fragment of the sheet shown in Fi 1 with the correct proportion of 'the slits t ereinto define the vstrands and and 6 6 respectively of F' bonds.

Fig. 4 is a view of the fragment shown in Fi 3 after the same has been expanded.

igs. 5 and 6 are detail sectional views on an enlarged scale as taken on the lines 5-5 In the present invention Igprovide a blank sheet o f metal 1 of the desired gauge, weight and dimensions as heretofore employed which blank' approximates eight inches in width and one hundred and eight inches in length.

I operate upon said sheet in any-convenient lmanner to produce therein transverse rows of slits 2 2 extending lengthwise of the sheet. These rows of slits are so arranged Y that those in one row overlap and are disposed between those of adjacent rows to form" transverse rows of bonds or bridges 3 and 4 respectively the endmost bonds in each alternate row being integralwith the selvage portions 5 5 of the sheet.

The areas between the overlaplping slits f define the strands 6-6 which in t e finished sheet extend diagonally of the sheet and are f connected at their intersections by the integral bonds 3 and 4 respectively, the strands and bonds being disposed 'edgewise at an angle to the plane of the sheet.

In my improved lath the overlapping slits 1n one row are purposely spaced closer t0- gether than heretofore, thus making the .strands 6-6 about five-hundredths of an inch in width instead of about'six-hundredths as fore mentioned. This produces about one hundred and ift -siX strands in each transverse row instea o f one hundred and thutyas before mentioned. It is' apparent that 1n a .sheet of the same unit area there is thus providedin each transverse row an increased number of strands amounting to about one-fifth more strands than in a slitted sheet whereinthe strands are six-hundredths of an inch wide.

I purposely arrange the bonds closer to-` gether so that the length of the strands are reduced in proportion to that extent whereby the number of rows of slits lerngthwisel vin the sheet is increased in number to about one hundred and forty-four. This represents an increase of about one sixth more rows than heretofore employed. By increasing fth and increasing the number of rows of strands about one-slxth an increase in strands and bonds is afforded in the sheet of the same unit area amounting to about one-third more than the number heretofore formed in such a sheet.

Such a slitted sheet is then expanded in the usualmanner, as b the expanding machines now in usc and w ich can be employed for this purpose without change exceptreadjustment changes, Whensuch a sheet is expanded and trimmed in the usual manner it will have the same unit area as before mentioned and approximating twenty-four inches by ninety-six inches.

It is pointedoutthat in the finished ex-V panded sheet as shown in Figs. 4, 5 and 6 the bonds in each alternate tgansvers'e row 'extend edgewise and perpendicularly to the plane of the sheet while the bonds 1n each intermediate roware inclined and extend edgewise at an'angle of about 60 to the plane of the sheet. This peculiar difference 1n angularity is due to certain characteristics 1n the sheet itself after bein slit as Ifor instance with a particular type o slitting?. mechanismwhich forms no part of the present invention.

` As .is well known in sheet lath of this kind, the stiffness of the sheet as represented by the tendency to flexcunder its own weight 1n applyingit in place upon the usual furringv strips as well as its action in remaining flat when so applied, is-due tothe number of bonds provided and the relative angularlty of such bondsto the .plane of the sheet.

With my improved lath, with the same weight per unit area of sheet, the metal 1s distributed in amanner different from that heretofore' recognized as the only possible way.- Therefore, .a greater number of bonds is provided in my improved sheet wlth the bonds .in one-half of the rows disposed edge- Wise and perpendicularly to the plane of the sheet and with the other'half disposed edgewise at the sixty degree angle before menthe mmiber of strands in each row about 011etioned so that the stiffness of the sheet is increased. .SuchA a sheet of course handles `aresmaller in area but greater in number anda greater` number of mortar retardingV elements as defined by the strands and bonds are presented. Such a lath better receives the mortar which may be used in that mushy .consistency desired by the plasterers so that the same is better adapted for faster application and of a less depth or thickness than heretofore possible.

Again with an increased number of smaller mesh, together with an increased number of retarding elements less motar is consumed `in forming tlie'keys in the rear side of the lath and the keys are smaller and lighter in weight so that they do not slough off. Thus waste is reduced to a minimum as well as the objectionable pulling action on those portions the length of a stranden two sides of the diamond mesh being approximately threefourths lof an inch, alternate bonds being a plane at right angles to the plane of the vlath while the other alternate bonds are at an acute angle to said plane.

In testimony whereof, I set my hand, this Srdday of J an., 1929.

r JAMES'W. PEARCE.

of the mortar line with the mesh or openings.

The thin coat of mortarmade practical by my improvedlath is indeed desired by the plasterers because it is more economical and easier applied and it dries or seasons quicker sothat less shifting of scaffolding between coats is necessary. Actual tests disclose the mortar and plaster saving qualities of my improved lath.

It is pointed sions of the strands and bonds as well as the extent, the number thereofis increased about athird which indeed more than compensates for the reduction mentioned so far as stiffness of the finished lath is concerned.

With the increased number of strands `and bonds the lath is better distributed in the wall material which it more effectively retains and reinforces.

' While in describing the invention Iv have referred in detail to certain dimensions, details of construction as well as form andarout that although the dimen- 'open diamond mesh is reduced to a certain rangement of the parts thereof, the same is to be considered purely as illustrative so that I do not wish to be limited theretoexcept as may be pointed out specifically inthe appended claims.

I claim as my invention: 1. A n improved mortar receivin and holding, expanded sheet metal diamon mesh lath, the strands of which are approximately .05 inches in width and anu'mber of strands in each vlongitudinal row of meshes being vapproximately 144 in a'lath v96 inches along@ after the metal has been expanded. 1

2. Anim rovedmortarreceiving andhold- A Y' ing, expan ed sheet""meta1 diamond shape strands, the strands'ofwhich are -a lath expanded transversel p three to one', having bon connecting the mately five-hundredths inches in wi and -the len h of a strand on'twosides of the mesh being from center to centerdiamon of the bondsapproximately` three fourths ofanmch.

at the rate Of roxi- 3. An improved mortar receiving and Y holding, expanded sheet metal diamond shape three to one, having vbon rox- {ive-hundredths inches in wi have hereunto

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