US3352217A - Means for forming lines of weakness in cementitious floors, pavements and the like - Google Patents

Description

H- J. PETE 7 1 1 l 2 W 2 mm 5 s s 3 U t ,0 e 3 I e T h I T S N E 5 M E E Nov. 14, 1967 s ETAL MEANS FOR FORMING LINE OF WEAKNESS IN c FLOORS, PAV MENTS AND THE LIK Filed Dec 28 19 4 J4 a/ My INVENTORS Ear/0n JIfe/erd w Z272 W 7301077'14 3 ATTORNEY J. PETERS ET AL 3,352,217 NG LIN S OF WEAKNESS IN CEMENTITIOUS Nov. "14, 1967 MEANS FOR FORMI FLOORS PAVEMENTS AND THE LIKE Flled Dec. 28, 1964 3 Sheets-Sheet w m M ATTORNEY NOV. 14, 1967 H PETERS ET AL 3,352,217

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MEANS FOR FORMING LINES OF WEAKNESS IN CEMENTITI Filed Dec. 28, 1964 FLOORS PAVEMENTS AND THE LIKE 3 Sheets-Sheet 5 4 INVENTORS 1Z0 r/an J fe zens a L in W. 7301027119! ATTORNEY United States Patent 3,352,217 MEANS FOR FORMING LINES 0F WEAKNESS IN CEMENTITIOUS FLGORS, PAVEMENTS AND THE LIKE Harlan J. Peters, Anaheim, and Lin W. Bowling, Altadena, Calif. (both of 9616 E. Beverly Road, Pico Rivera, Calif. 90660) Filed Dec. 28, 1964, Ser. No. 421,558 3 Claims. (CI. 9418) This invention relates to means and method for forming divisions in the surface portions only of cementitious bodies such as floors, pavements and the like, to produce defined lines of weakness therein along which cleavage or fracture of the body due to shrinkage or settling thereof is more apt to occur than on either side of such lines.

A particular object of the invention is to provide a divider strip for the above purpose which may be readily directly applied to and imbedded edgewise in the surface portion of a body of soft freshly deposited cementitious material without the use of forms or molds and without interfering with subsequent leveling and troweling of such surface.

Another object is to provide in association with the divider strip a means for facilitating application of the strip whereby longitudinal alignment of the strip will be insured, whereby positioning of the strip in transverse perpendicular relation to the surface of the cementitious body in which it is imbedded may be readily effected, and whereby the upper margin of the imbedded strip will be uniformly spaced below the surface of the body such distance as to permit troweling and finishing of such surface above the strip without coming in contact therewith.

Another object is to provide a combined divider strip and a flange applicator in which the latter normally projects laterally from the upper margin of the strip in fixed right angular relation thereto throughout the length thereof so as to rigidly hold the strip against flexing, and which when serving to facilitate application of the strip will also serve as a stop to arrest or obstruct advance of the strip into the cementitious body and thereby determine the extent of submersion of the strip therein so as to uniformly space the upper margin of the strip beneath the surface of the body, wherein the applicator comprises a thin ribbon-like strip of hard sheet material capable of being flexed longitudinally and which is so attached to the divider strip that it may be stripped or torn therefrom by a forceful pull imposed on the applicator.

A further object is to provide a method of fabricating a cementitious floor or panel having top and bottom surfaces and embodying permanently imbedded division strips with upper and lower margins thereof spaced inwardly from said top and bottom surfaces whereby defined lines of weakness are formed in said floor or panel extending between the bottom surface thereof and the lower margins of said division strips.

Another object is to provide a separable connection uniting the strip and the applicator throughout their lengths which will permit ready detachment and removal of the flange application when the dividing strip is anchored in place in the cementitious body with the flange applicator countersunk in the surface of a body of cement.

Another object is to provide a cementitious body having a defined continuous bottom or base area with a superimposed surface area, wherein the surface area is divided into a multiple of areas by permanently imbedded divider strips having upper and lower margins spaced inwardly from the base and surface areas.

With the foregoing objects in view, the invention resides in the parts and in the combination, construction and arrangement of parts hereinafter described and claimed, and illustrated in the accompanying drawings.

The several views in the drawings are as follows:

FIG. 1 is an isometric view of a length of the dividing strip, and its separable flange applicator showing the preferred embodiment of the invention.

FIG. 2 is an enlarged cross section taken on the line 2-2 of FIG. 1 showing the strip and flange applicator as unitarily formed.

FIG. 3 is an exaggerated view of the sectional portion defined by the broken line rectangle 3 of FIG. 2 showing the fractionable line of weakness between the dividing strip and flange applicator.

FIG. 4 is a side detail of the structure shown in FIG. 3 With the separable flange applicator partly detached from its associated dividing strip.

FIG. 5 is an isometric and sectional view showing the dividing strip and flange applicator as initially applied to a cementitious body.

FIG. 6 is a view similar to FIG. 5 showing the manner of removing the separable flange applicator from the dividing strip and leaving the dividing strip imbedded in the cementitious body with its upper margin spaced beneath the surface thereof.

FIG. 7 is an isometric and sectional view similar to FIG. 6 depicting the mode of finishing the surface of the cementitious body and forming an open channel therein immediately following the operation shown in FIG. 6.

FIG. 8 is an enlarged detail in cross section of the portion defined by the broken line rectangle 8 in FIG. 7.

FIGS. 9, 10 and 11 are isometric sectional views depicting modifications of the invention.

FIG. 12 is an isometric view illustrating a manner of initially applying the dividing strip of FIG. 1 to the surface of a soft cementitious body, and

FIG. 13 is an enlarged view in cross section as seen on the line 14-14 of FIG. 12 depicting the manner in which the divider strip is implantedinto the cementitious body in perpendicular relation to the surface thereof.

In the drawings A indicates generally a dividing strip for positioning in a cementitious body B, such as a concrete floor, pavement, side-walk or the like. The strip A embodies a web 15 of uniform width and thickness and of any desired length as occasion may require.

A continuous anchoring element 16 is provided on the inner margin of the web 15, which element may be in the form of a bead integral with the web, as shown in FIGS. 1 and 2, or may comprise a separate length of suitable material of U-shaped cross section disposed astride the web in frictional or detachably adhered engagement therewith, as indicated at 16 in FIG. 11. The element 16 may be of any desired contour in cross section suitable for effecting anchorage engagement with a body of cementitious material in which the web and element are imbedded.

However the element 16 is preferably provided with a rounded or tapered outer margin a to facilitate its insertion edgewise into a penetratable body of unsolidified cement, and also provided with inner margins or shoulders bb projecting laterally from the opposite sides of the web 15 which effect anchorage engagement with the cementitious body in which the element is imbedded.

Extending longitudinally of the upper margin of the web 15 throughout the length thereof, in separable engagement therewith, is a flange applicator C embodying a thin laterally stiff ribbon 17, which ribbon is of uniform width throughout and here shown as attached intermediate its margins to the web 15 so as to project equidistant from the opposite sides thereof. The ribbon 16 forms oppositely extending marginal flanges dd projecting laterally from opposite sides of the web 15 in. perpendicular relation thereto.

The ribbon 17 of the flange applicator C serves in the application of the divider strip A as a stop for limiting the extent of submergence of the web 15 in the body B and to position the upper margin of the web 15 spaced below the adjacent surface of the body B in uniform and definite relation thereto, as will presently be described.

The ribbon 17 is preferably integral with the web 15 as shown in FIGS. 1 and 2.

Where the ribbon 17 is integral with the web 15 as shown in FIGS. 2-3, the web is formed at its juncture withthe ribbon with a line of weakness along which the ribbon may be stripped from the web by imposing an outward pull on the ribbon relative to the web. Such line of weakness is here shown as formed by providing a continuous channel h either on one or both of the sides of the web 15 adjacent the underside of the ribbon 17 whereby a thin fragile fracturable wall k is formed along the bottom of the channel h. The channel or channels h may be molded in the web 15 as indicated at h in FIG. but are preferably carved therein by means of a sharp blade which is applied to the surface of the web to form a thin line severing the surface of the web along and throughout its juncture with the ribbon 17 along which line the, wall k will fracture on an outward pull being imposed on the ribbon 17 as shown in FIG. 4.

Although the dividing strip A may be of any suitable dimensions it is preferably constructed to have an overall width and height of approximately one to one and onehalf inches; the several views in the drawings being exaggerated for the sake of clarity.-The.wall thickness of the web and ribbon 17 is preferably one-sixteenth of an inch or thereabouts, with the bead 16 having an overall thickness of five-thirty-seconds of an inch, yet the strip is quite rigid and resistant to bending by reason of its T- cross section, as in the case of T-iron, and accordingly the strips are produced in lengths and usually marketed in bundles.

This stilt unbendable character of the strip A renders it readily alignable in application and also in conjunction with the narrowness of the web 15 and bead 16 in being readily manually pressed into the soft cementitious body B which is accomplished as will now be described.

A body of soft fresh cementitious material comprising the usual mixture of cement, sand, gravel or crushed rock and water, is applied to a surface and leveled to form a panel B of desired thickness all in a conventional manner; the panel having flat top and bottom surfaces in and n, as shown in FIG. 13.

While the mass of the panel is soft and penetratable, a length of the strip A is imposed edgewise on the top surface In of the panel with the tapered lower edge a of the bead 16 lowermost and with the strip extended upright perpendicular to the panel surface m. This operation may be effected by grasping the applicator C of the strip between the fingers-and thumb of the hand, as shown in FIGS. 12 and 13,or it may begrasped inboth hands,

and where the strip A is of considerable length it may be grasped in the hands of two or more persons.

Downward pressure is then applied to the strip A through the flange applicator C either progressively or simultaneously at intervals along the length thereof so as to force the web 15 edgewise into the panel, the strip being thus advanced downward until the upper face of the applicator ribbon 17 extends flush with the surface of the panel as shown in FIG. 5. During this operation the material of the panel, being in a soft plastic state, the pressure of the ribbon 17 on the surface of the material. in advancing to its counter-sunk position in the panel will effect displacement of the material immediately therebeneath so as to cause a portion of the displaced material to be crowded over the shoulders bb of the anchoring bead 16.

When the cementitious mass of the panel B has set and hardened sufficiently around the head 16 to hold the web 15 against withdrawal, the separable applicator ribbon 17 is removed by grasping an end thereof and exerting an upward pull thereon so as to strip the ribbon from engagement with the web as indicated in FIGS. 4 and 6.

The ribbon 17 is sufficiently flexible to bend in the direction of its length and its underside is sufficiently smooth and close grained as not to adhere to the cement therebeneath so that the .ribbon will separate from the panel without an appreciable amount of cement clinging thereto.

In separating the ribbon 17 from the web 16 the fragile wall k of the web 15 will fracture and part along the channel It with a regular cleavage on a plane slightly below or approximately on the level of the bottom of the recess or channel r molded by the ribbon 17, and whereby the then upper margin s of the web 15 will extend on a plane below the top surface m of the body or panel B a distance slightly in excess of the depth of the recess r which equals the thickness of the ribbon 17 and which in the instance here set forth, is approximately one-sixteenth of an inch.

On removal of the applicator ribbon 17 and before the cementitious material has fully hardened and still moist, the recessor channel r is filled with cement either by adding cement to the channel, if need be, or by troweling cement from the surface of the panel in sufficient quantity to fill the shallow channel, only a very small volume of cement being needed in either event. The surface of the material placed in the channel is then troweled to bring the surface thereof on a level with the adjacent top surface m of the panel B.

The narrow upper margin s of the submerged web 15 will then be buried under a thin narrow layer of surface cement, which layer is then displaced while workable to provide an open channel I in the cementitious panel B extending immediately above and along the upper margin s of the web 15, the channel side walls leading from the opposite sides of the upper margin of the web 15 and being rounded outward into mergence with the adjacent surface of the panel, as shown in FIG. 7. The channel t is here shown as formed-by a hand tool D embodying a pair of spaced parallel transversely rounded flanges u-u on the adjacent margins of a. pair,

of side-by-side trowel blades v--v on a handle w, the flanges u-u being insertable through the thin layer of cement above the upper edge s of the web 15 and positionable astride such edge, whereby the tool D may be guided along the web '15 to form a narrow channel in the cement and at the same time mold the margins of the channel, the bottom of which will consist of the upper edge s of the web 15.

The divider strip A when thus applied extends transversely into the cementitious panel B from the outer surface m thereof usually only through a minor portion of the thickness of such panel whereby a portion ofthe panel lies between the inner margin of the strip and the inner side n of the panel as indicated at E in FIG. 13. The. portion E of the panel. underlying the web 15 of the strip A being of less thickness than the portion of the panel on opposite sides of the divider strip constitutes the line of weakness along which the panel is apt to crack or rupture on shrinking or setting of the panel.

While a specific embodiment of the invention has been above set forth, the strip A is subject to modification in details without departing from the essence of the invention or altering the principle of its operation. For example, in some instances, the flange applicator ribbon may be narrowed, as indicated at 17' in FIG. 9, and provided with beveled margins y-y, whereby, when the ribbon is stripped from the anchored web 15 the channel formed in the cement above the web will be sufficiently narrow that the sides thereof may be finished by a tool D without previously filling the channel with cement.

As before stated the fracturable wall portion k may be formed between molded grooves h as shown in FIG. 10 and the anchoring bead may be applied to the lower margin of the web 15 as indicated at 16' in FIG. 11.

The divider strip A and flange applicator C are preferably formed of a hard plastic capable of being fractured in effecting separation of the applicator C from the strip A, such for example as styrene.

We claim:

1. A divider strip for cementitious panels comprising an elongate web having an anchoring element extending along one margin thereof throughout its length, and a flange applicator ribbon separably connected to the other margin of said web projecting laterally therefrom throughout the length thereof; said flange applicator comprising a ribbon of hard thin, sheet material capable of being flexed longitudinally; said web and ribbon being unitary and the separable connection therebetween comprising a fragile Wall in said web adjacent said ribbon severable by an outward pull imposed on said ribbon, whereby said flange applicator may be stripped from said web.

2. The structure called for in claim 1 in which said web has a continuous channel extending longitudinally thereof adjacent said ribbon the bottom of which constitutes said fragile Wall.

3. In a divider strip for forming a line of weakness in a cementitious panel, the combination with an elongate web having inner and outer longitudinal margins and being resistant to bending in the direction of the width thereof and having an anchoring bead projecting laterally from the inner margin thereof; of a flange applicator detachably connected to the outer margin of said web extending coextensive therewith and projecting in lateral relation thereof for temporary imbedment in the surface of the cementitious panel to limit the extent of submergence of the web therein and to position the upper margin of the web in counter-sunk relation to the surface of the panel; said flange applicator comprising a thin ribbon of hard sheet material capable of being flexed longitudinally on being pulled lengthwise away from said web, said flange applicator being unitarily connected with the upper margin of said Web by a fragile wall capable of being fractured by an outward pull imposed on said flange applicator, whereby said flange applicator may be stripped from said web to there by leave the latter embedded in the cementitious body With its upper margin spaced below the normal surface of such body.

References Cited UNITED STATES PATENTS 1,731,335 10/1929 Fischer 9418 X 1,763,369 6/1930 Robertson 94-17 1,769,990 7/1930 Fischer 9418 2,016,968 10/1935 Marble 94-18 X 2,098,714 11/1937 Awbrey 94-17 2,167,550 7/1939 Jenkins 9418 X 2,629,143 2/ 1953 Spector 20-55 2,708,016 5/ 1955 Penton.

2,967,467 1/1961 Maude 94-18.2 3,038,395 6/1962 Middlestadt 9422 X 3,172,237 3/1965 Bradley 9418 X 3,234,860 2/1966 Lacy 9418 JACOB L. NACKENOFF, Primary Examiner.

Claims (1)

1. A DIVIDER STRIP FOR CEMENTITIOUS PANELS COMPRISING AN ELONGATE WEB HAVING AN ANCHORING ELEMENT EXTENDING ALONG ONE MARGIN THEREOF THROUGHOUT ITS LENGTH, AND A FLANGE APPLICATOR RIBBON SEPARABLY CONNECTED TO THE OTHER MARGIN OF SAID WEB PROJECTING LATERALLY THEREFROM THROUGHOUT THE LENGTH THEREOF; SAID FLANGE APPLICATOR COMPRISING A RIBBON OF HARD THIN, SHEET MATERIAL CAPABLE OF BEING FLEXED LONGITUDINALLY; SAID WEB AND RIBBON BEING UNITARY AND THE SEPARABLE CONNECTION THEREBETWEEN COMPRISING A FRAGILE WALL IN SAID WEB ADJACENT SAID RIBBON, SEVERABLE BY AN OUTWARD PULL IMPOSED ON SAID RIBBON, WHEREBY SAID FLANGE APPLICATOR MAY BE STRIPPED FROM SAID WEB.

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