US2035884A - Composite flooring material - Google Patents

Description

March 31, 1936.

H.-c. HARVEY COMPOSITE FLOORING MATERIAL Filed Jan. 24, 1935 TlrTl.

Patented M 31, 1936 2,035,884 3 2,035,884 COMPOSITE FLOORING MATERIAL Harold 0. Harvey, Trenton, N. J., assignor tov The Agasote Millboard Company, Ewing Twn-' ,SUNITED STATES PATENT OFFICE ship, N. J., a. corporation of New Jersey Application January 24, 1935, Serial No. 3.263

2 Claims.

My invention relates to acomposite flooring material consisting of an aggregate of a substantially rigid base board of fibrous material, having resiliency and high heat and sound insulating characteristics, at least one face portion of which is impregnated with sulfur, upon which sulfurimpregnated face there is superimposed a compar'atively thin sheet of impervious covering material such as rubber, the base board and covering material being joined by a cementitious material.

One of the objects of my invention is to provide a sheet of a composite flooring material having strength and rigidity, while being at the same time elastic,-and one of the particular objects of my invention is to create a flooring adapted to support comparatively heavy furniture, such as desks or bureaus, without being permanently marked, at least to any substantial degree. When I refer to flooring material, I include in this term wall material as my composite flooring is suitable for use also as a wall board.

7 The fibrous material constituting the rigid base or base board 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 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 Patents No. 971,936, dated October 4, '1910, and No. 1,272,566, dated July 16, 1918), and subsequently drying out the remainder of the water 7 by the application of heat, preferablyin a suit- "ably constructed dryer.

When pulp boardhas been produced in this manner, it is a commercial article (except possibly for subsequentshaping operations or subsequent surfacing operations) such as has been known on the market for many years. The board may be of fireproof composition, for instance, as dis closed in United States patent to Hubert L.

Becher, No. 1,907,711, May 9, 1933. Such a board may be, and preferably is, provided with a suitable binder, for instance, by incorporating with the pulp in the beater a paraflln wax emulsion, such as disclosed in United States-Letters Patent to Hubert L. Becher, No. 1,939,616, December 12,

1933. The elasticityand extent of-porosity of the board will depend somewhat upon the extent to which the water has been removed therefrom by pressure, or. otherwise, prior to the drying opera- .tion, although for my purposes -a board from which as much water as has thus been removed by pressure is suitable, and is preferable as it ment of my invention. is a perspective view of a sheet of my composite involves the application of the least amount of heat for drying.

In accordance with my invention, this board,

after it has been dried, is impregnated with sulfur to a short distance from at least one face thereof, the depth of impregnation depending somewhat upon the use to which the flooring is to be put, and the density of the board. For a board manufactured as above described, when it has a thickness of slightly less than one-half 10 suitable material, preferably very thin as com- 20 pared to the thickness of the base board, the thickness of the two elements being preferably,

. but not necessarily, in the ratio of 8 to 1, so that, i

for instance, if the base board is one-half an inch thick, the sheet of rubber is one-sixteenth of 25 an inch thick. This ratio of rubber to flbre board may, of course, be varied within wide limits, and is herein given by way of illustration rather than by way of limitation, it being, however, one of the objects of my invention to produce a very inexpensive flooring material, and therefore to use a practical maximum cfv the less expensive material, namely the base board, and a minimum.

of the more expensive material, namely, the 3 rubber or other covering. In place of rubber, I may use, for instance, linoleum, but prefer to use a linoleum whose backing consists, not of burlap but of a felt-like fabric base such, for instance, as

disclosed in United States patent to Edwin L. 40

Blabon, No. 1,132,647, dated March 23, 1915.

In the accompanying drawing, Ishow by way of illustration, but not of limitation, an embodi- In such drawing, Fig. 1

material, and Fig. 2 is a vertical section on an enlarged scale through such sheet. In Fig. 1, which is drawn on a small scale, the showing of the sulfur-impregnated portion of the base board has been omitted, but such portion is clearly shown in Fig. 2.

In such drawing, A is the substantially rigid base board of fibrous material, constituting the pulp board hereinabove described. and B is a comparatively thin sheet of rubber'whichis se- 66 the base board. S, S represent sulfur-impregnated portions of the base board.

When a piece of base board is dipped in sulfur,

' of course, the edge portions will also be impregnated with sulfur. As, however, such base board is most economically manufactured in the form of sheets of very large size, for instance, 14 feet inlength, such sheets may for many purposes have to be trimmed to a definite size, and therefore the sulfur-impregnated edge portions may have to be trimmed off: I have therefore not shown them in the drawing. Obviously the flooring may be used either in the form of larger sheets or smaller sheets. My material, may, for instance, be cut into squares or other shapes, and provided with coverings of contrasting colors, and then laid in position to form an imitation of a. tessellated marble flooring.

The sulfur is preferably maintained at a temperature of from 280-300 F. during the impregnation process. The sulfur in the impregnated portion of the board will be in crystalline form; it should not be rendered amorphous.

Care must btaken not to impregnate the board too deeply, as the presence of sulfur in the board hardens the same and therefore destroys its in-' herent elasticity. It is not within the scope of my claims to employ a base board entirely impregnated with sulfur, or impregnated to such an extent as to deprive such board as a whole of its :latu'al elasticity which makes it agreeable to the rea .3

It is th primary. object of my invention to pre-'- vent, at least as far as possible, the permanent deformation of the base board by pressure brought to bear upon the flooring, so that when the pressure is released, the rubber or other covering which is cemented to the base board, will not show. a permanent marking. Such pressure is frequently, applied to a fioor either by a heavy object of furniture concentrating its pressure through four legs,,or by a chair tilted so as to rest upon two legs and concentrating all of the weight of the occupant upon two comparatively sharp edges. An elastic flooring material, such as rubber or linoleum, would, if left to itself, in nfost cases be automatically restored to an even surface, but if the base board to which it is cemented is distorted, for instance, by suffering an indentation, the surface material is not capable of overcoming the pull of the more substantial base board, and will not be able to compensate for the indentation. In-the preferred form of my invention, therefore, I refrain from impregnating the base board with sulfur to such an extent as to destroy its elasticity, and I use only enough sulfur to accomplish the object of my invention, which is primarily that of preventing, at least to a substantial extent, a deformation of the base board. The depth of impregnation will therefore depend upon-a number of factors, the most important beingthe pressure to which the finished flooring is to besubjected over alimited area. If the pressure is so great as to call for a comparatively deep impregnation, the elasticity factor will have to be preserved by using 'a. thicker base board. By

way .of practical example: If the base board is approximately a half inch in thickness, the depth of impregnation might be one-sixteenth of an inch, and the thickness of the rubber coating about one-sixteenth of an inch. Of course, the thicker, and therefore-the more expensive, the rubber coating, the less need be the depth of impregnation because the rubber coating itself they were felted in a moist condition, is to reand suffer an indentation, but the natural tendency of the fibres which have been dried after sume as far as possible their original shape and therefore to restorethe board as a whole to its original shape. While the original shape can perhaps never be fully restored, unless the pressure was extremely light, there is at least a partial restoration, and this is, of course, an important factor in an aggregate of base board and covering material cemented thereto. Itis one of the advantages of the use of sulfur, in the formation of a protective impregnated surface portion, that not only will such portion resist distortion but will be permitted to attain a partial restoration,.after pressure has been removed, of the originalshape of the board. At this time I am unable to account for this phenomenon, but 30 it is my theory, to which I do not desire to stand committed, that the sulfur, being in the form of v more or less discrete crystals, will not offer a great amount of resistance to at least partial restoration by re-alignment of the fibres. That- 35 theaddition of sulfur imparts hardness to paper material is apparently a well recognized fact.-

See, for instance, United tates pagnfi to Crehore'No. 74,996, March 3, 1868, and ay and even as a wall material, the sulfur-impregnated portion will be water-repellant and will be dis tasteful to such insects and other pests as have an aversion for sulfur, and thus serve to protect the board as a whole, at least to a certain extent, 55

,against the ravages thereof.

I claim: I 1. A composite flooring material comprising a sheet of substantially rigid base board of fibrous mateial, having a degree of resiliency, said base 6 board being of substantial thickness and being impregnated with respect to at least one surface portion thereof with crystalline sulfur, and an impervious covering material secured by a cementitious substance tothe impregnated sur-. face portion of such board, the depth of the impregnation being sufilcient to afford substantial resistance to deformation by pressure to which the flooring material is to be subjected, but not so deep as to destroy the essential resiliency of the base board.

2. A composite flooring material as described in claim 1 in which the impervious covering material HAROLD c. I 75

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