US2069720A - Composite flooring material - Google Patents

Description

Feb. 2, 1937.

COMPOS ITE FLOORING MATERIAL Filed June 24, 1935 w ITN ESS INVENTOR film M ATTORNEYS H. c. HARVEY 2,069,720

Patented Feb. 2, 1937 UNITED STATES PATEN' orr cs COMPOSITE FLOORING MATERIAL Application June 24, 1935, Serial No. 28,113

4 Claims. (Cl. 154-49) My invention relates to a composite flooring material and provides for an aggregate, in the form of a unit sheet, of a substantially rigid baseboard of a fibrous material, having resiliency, and comparatively high heat and sound insulating characteristics, the baseboard being impregnated,

with respect to at least one lateral surface thereof but preferably throughout all of its surfaces, with a waterproofing and hardening material, for instance, an oxidized drying oil, the baseboard having superimposed upon a so impregnated lateral surface a comparatively thin sheet of an impervious covering material such as rubber, the baseboard and covering sheet being joined by a suitable cementitious material.

The fibrous material constituting the rigid base of my composite flooring material is of the type known in the art as pulp board. Such pulp board is usually made by running paper pulp, wood 20 pulp or the like into a mold and by means of pressure or otherwise, removing the majority of the water (see, for instance, United States Letters Patent No. 971,936, dated October 4, 1910, and No. 1,272,566, dated July 16, 1918) and subsequently 25 drying out the remainder of the water by the application of heat, preferably in a suitably constructed dryer.

When pulp board has been produced in this manner it is a commercial article (except, possibly, for subsequent shaping operations or subseduent surfacing operations) such ashas been known in the market for many years.

This board, in contradistinction to a board of this general type which has been subjected to heat and heavy pressure after it has been dried to fuse its binder and to compact it into a hard board, is characterized by softness of texture, substantial porosity, and a comparative structural weakness, but a high degree of resiliency. It is to this type 40 of board I refer in my claims as porous pulp board.

In order to attain one of the objects of my invention, i. e. to impregnate the baseboard constituting the backing to which the impervious covering material is to be applied, with a waterproof and hardened material, I dip the porous pulp board into a suitable oxidizing oil, or a mixture of such oils, for instance, a mixture (preferably hot) of linseed and China-wood oils, for only such length of time as is necessary to impregnate the surfaces of the board to the desired extent.

The oxidizing oil or mixture of oxidizing oils used in carrying out this impregnation process is preferably maintained at a temperature of 200 F. during the dipping operation.

The thus impregnated pulp board is then baked so as to cause oxidation of the oils and a consequent hardening of the impregnated surfaces.

The oil treatment of the baseboard by complete dipping, with subsequent oxidation, as just described, is effective also to protect the composite flooring material from the influence of varying atmospheric conditions, thereby reducing difliculties due to expansion or contraction induced by varying atmospheric conditions at the place of use of the flooring material.

As examples of oxidizing oils other than linseed oil and China-wood oil, the following may be mentioned; perilla oil, blown rapeseed'oil, sesame oil, and rosin oil. These oils are all drying oils, but it is within the contemplation of my invention to use what may be characterized as semidrying oils, such as soy bean oil. Fish oils likewise may be used, but for the fact that they possess a disagreeable odor.

The depth to which the surfaces are impregnated depends upon the thickness and porosity of the board, and the highest average weight to which the board is to be subjected in use. The depth is to be great enough to enablev the board to resist deformation to the desired degree, but not so great as to destroy, or app eciably to decrease, the resiliency of thebaseboard. If these two ends cannot be obtained with a board of a certain thickness, then, other things being equal,

a thicker board will have to be used. I prefer to use a board impregnated with a paraflin wax emulsion, produced in the manner disclosed in United States Patent to Hubert L. Becher, 'No. 1,939,616, dated December 12, 1933. Witha board so produced, and having a density of 25 pounds per cubic foot, a surface impregnation having a depth of one thirty-second 2) inch is suitable, under conditions of ordinary household use, for a board one-half /2) inch thick. I

While it is easier to impregnate a board by dipping, thus impregnating both sides thereof, and a board so produced has the advantage of resisting absorption of moisture from below, it is obvi-. ous that my invention may be practiced with the use of a board impregnated on one side only.

The impervious covering material to be applied to the baseboard hereinabove described in attaining the objects of my invention, is preferably a sheet of rubber, thin as compared to the thickness of the baseboard, the thickness of the two elements being preferably, but not necessarily, in the ratio of 8 to 1, so that, for instance, if the baseboard is half an inch thick, the sheet of rubber secured thereto is one-sixteenth of an inch thick. This ratio of rubber to fibre board which may, of course, be varied within wide limits and is herein given by way of illustration rather than by way of limitation, serves not only to reduce the weight of the composite flooring material but also to effect a substantial saving in the cost of manufacture thereof, the usual rubber flooring material being of substantially greater thickness than the rubber portion of my composite material, for instance, one-quarter of an inch.

In the accompanying drawing, in which is illustrated by way of example an embodiment of my novel composite flooring material, Fig, 1 is a perspective view of a large unit sheet of such material; Fig. 2 is a vertical section on an enlarged scale through such unit sheet; and Fig. 3 is a vertical section through a sheet of the composite flooring material in which the rubber covering is of the flat surface type as distinguished from the ribbed surface of the form shown in Figs. 1 and 2.

Referring to Figs. 1 and 2, in such drawing, A is the substantially rigid baseboard of fibrous material constituting the porous pulp board hereinabove described, and B is the comparatively thin sheet of rubber of the same lateral dimensions as the baseboard, which is secured by a suitable cementitious compound C to the baseboard. D

represents the portions of the baseboard impregnated with the oxidized drying oil or oils.

The impervious covering used in my composite flooring material is preferably rubber which has been previously vulcanized and which, as shown in Figs. 1 and 2 of the drawing, may be provided with a serrated or ribbed surface E.. One of the objects of the use of such ribbed surface is to eliminate any tendency of the flooring to squeak when walked upon or when furniture is moved thereover.

In Fig. 3, in which I have illustrated, in section, a composite flooring material having a smoothsurfaced covering sheet, F is the substantially rigid baseboard similar to the baseboard A of Figs. 1 and 2, G is the thin sheet of rubber superimposed thereon and secured thereto by a cementitious compound H, and I represents the portions of the baseboard impregnated with the oxidized drying oil or oils.

An additional function, and a feature of paramount importance as demonstrated by actual tests, of forming the covering material of a sheeting of ribbed rubber is that the serrated or ribbed surface assists in a great measure in preventing deformation of the base. While I do not, at this time, desire to be restricted to any definite theory with respect to the operation of such ribbed surface in the prevention of deformation of the base material, I believe that the results obtained are due to the effect of thickening the covering material and correspondingly protecting the base due in part to the spreading out of the end and side portions of the apex portions of the ribs, whereby they are depressed into the spaces ordinarily occupying the grooves on each side of the rib. Thus, when a castor or dome",- for instance, supporting the leg of a piece of furniture, rests upon the apexes of the ribs supporting the load, it deforms the ribs by spreading them out, thereby resulting in an increase in the thickness of the covering sheet. Only the ribs supporting the load are substantially deformed and such deformation is not communicated to the adjacent portions of the covering, the'ribs being capable of spreading laterally by themselves and therefore not affecting the remaining portions of the covering. When, therefore, the load is removed, the deformation, having been substantially localized, has not been transmitted to other portions of the surface; hence it is not necessary for such other portions to take part in the recovery after removal of stress. In a smooth-surfaced covering, no substantial localization of the deformation is possible as any deformation is necessarily transmitted to portions contiguous the point of application of the stress where no room or space is provided for lateral expansion. It would be necessary for a large area to take part in the recovery from the deformation, and as this cannot be done, substantially permanent deformation results. being of a more yielding character than a smooth surfaced covering sheet, they are more resilient and since space is afforded by the ribbed or serrated surface into which the upper and side portions of the ribs may flow, the covering material has a markedly increased resiliency and therefore the capacity of correspondingly increasing the protection afforded the base material.

I have carried out a series of tests of my novel composite flooring material to determine the extent of indentation under a specific load and-the amount of indentation remaining immediately after the removal of the load, and therefore the recovery of the composite flooring material after removal of such load. Such tests, which The apexes of the ribs\ may be appropriately called "hardness tests" were made to compare the degree of indentation, during load and immediately after removal of the load, as between a baseboard without impregnation with the oxidizing drying oil, a baseboard the surfaces of which had been impregnated with the oxidized drying oil, an unimpregnated board with a sheet of rubber having a smooth surface, an impregnated board covered with a sheet of rubber having a smooth surface, an unimpregnated board having a covering of serrated or ribbed rubber and. an impregnated board covered with serrated or ribber rubber.

The tests were carried out using a threequarter inch steel ball pressed upon the material under pressure of 100 pounds, for half a minute, the indentation, during load, and after removal of the load being given in mils. The baseboard subjected to the tests was one having a thickness of finds of an inch. The results were as follows:

Covered with Covered Board only smooth tub with nerber rated rubber A B A B A B I Unimprcgnated base inch 86 46 102.5 41 112.5 33 Impregnated base 64 22.5 78.5 25 18 material provided with the smooth rubber surface. The deeper indentation made under load in the completed boards, covered respectively with smooth rubber and serrated rubber, being measured with respect to the flooring as a whole, is to be attributed to the fact that the rubber yields more than does the impregnated baseboard, and that the serrated rubber, the upper portion of which is composed only of separated strips of rubber, of triangular cross-section, would obviously yield more than would a solid body of rubber. On the other hand, the serrated rubber, or at least the ribbed portion thereof, would recover practically completely. The fact that in the samples tested there is a greater absolute recovery when the impregnated base is not covered than when it is covered with smooth rubber, indicates that the base only has a higher percentage of recovery than has the aggregate of base and smooth rubber, and the smooth rubber does not recover therefore as well as does the base.

It will be noted that my novel composite flooring material is constituted of a base having a resilient core and a. resilient surface sheet. The combined efiect of such structure is to yield a high degree of resiliency and sound insulating characteristics not obtainable in flooring material in which only one of the elements is constituted of a resilient material. Walking on my composite flooring material is therefore less tiring and substantially noiseless, particularly if the surface of the covering material is ribbed, as shown in the drawing.

The fibre board which may be used as a base for my composite flooring material may be of the usual type hereinabove described, or may be a pulp board which has been treated, either during or after manufacture, so as to render the finished board fire resistant. One type of such fire resistant pulp board is disclosed in United States Letters Patent to Hubert L. Becher, No. 1,907,711, dated May 9, 1933, but, of course, any other similarly treated pulp board or fibre board may be used in carrying out my invention.

The cementitious material that may be used for attaching the sheet of rubber to the sheet of rigid baseboard to obtain my novel composite flooring material may be any well-known cementing composition or mastic.

The unit sheets of composite flooring material constituting the structure made in accordance with my invention, may be provided with any desired decorative surfacing, for instance, colored designs or so-called repeat patterning.

I make no claim herein broadly to a fibrous base material to which has been applied a decorative surface sheet such as linoleum or rubber, as such aggregate is no part of my invention, being shown to be old in the patent literature.

While I have described my novel composite flooring material as comprising an aggregate of a substantially rigid baseboard of fibrous, porous material and a comparatively thin sheet of rubber, it is obvious that there may be substituted for the fibrous material any other suitable resilient porous product, and for the thin sheet of rubber any other suitable decorative material such as linoleum, so long as the objects of my invention are obtained and the flooring material thus constituted falls within the ambit of the appended claims.

I claim:

1. A composite flooring material comprising a large unit sheet of porous pulp board as hereinbefore defined, such board being of substantial thickness and constituting a baseboard and being impregnated throughout at least a portion thereof contiguous to one of its lateral surfaces with an oxidized drying oil, and a comparatively thin sheet of impervious covering material of greater resiliency than said baseboard secured to the lateral surface contiguous to such impregnated portion, the resulting aggregate being adapted to constitute a substantially elastic floor body.

2. A composite flooring material as claimed in claim 1, in which the impervious covering material consists of rubber.

3. A composite flooring material as claimed in claim 1, in which the impervious covering materialconsists of ribbed rubber.

4. A composite flooring material as claimed in claim 1, in which the impervious covering material consists of linoleum.

HAROLD c. HARVEY.

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