US3210781A - Mattress - Google Patents

Description

Oct. 12, 1965 H. v. B. POLLOCK 3,210,781

MATTRESS Filed Jan. 50, 1962 2 Sheets-Sheet 1 FIG. 2 FIG. 3

23 22 INVENTOR.

HAROLD VAN B. POLLOCK ATTORNEY Oct. 12, 1965 H. v. B. POLLOCK 3,210,781

MATTRESS Filed Jan. 30, 1962 2 Sheets-Sheet 2 INVENTOR. HAROLD VAN B. POLLOCK ATTORNEY United States Patent 3,210,781 MATTRESS Harold Van B. Pollock, 1422 W. 28th St., Minneapolis 8, Minn. Filed Jan. 30, 1962, Ser. No. 169,755 1 Claim. (Cl. -351) This invention relates to a mattress constructed of foamed elastomeric materials with end portions of the mattress being composed of material having a different composition or density than the middle portion of the mattress. The utilization of a combination of foamed elastomeric materials provides an article which has optimum resiliency and durability for use as a mattress.

It has previously been known to provide foamed elastomeric material such as foamed rubber or foamed synthetic resin in a mattress; however, it has not previously been known to combine uniformly thick sections of such material in a mattress to provide progressive resiliency from the end extremities of the mattress toward the center to accommodate in optimum manner the distribution of weight of a person lying on the mattress. The greatest loading on a mattress occurs in the center portion, whether by a person lying on the mattress or by a person entering or leaving the bed or sitting on the edge of the bed. It is preferred, therefore, to provide a tough, durable and firmly resilient material in the middle portion of a mattress and a less costly, less dense material in the end portions of the mattress where use is less severe.

When sections of uniform thickness are integrally bonded, there is provided a mattress of simple construction and excellent functionality.

It is an object of this invention to provide a mattress having progressively increasing firmness, resilience and durability from the head and foot portions of the mattress toward the middle of the mattress.

It is another object of this invention to provide a mattress of foamed resilient resinous material wherein the middle portion of the mattress comprises a material of dilferent density of composition than that of the end portions.

It is another object of this invention to provide a mattress of optimum durability at low cost.

Other objects will become apparent from the drawings and from the following detailed description in which it is intended to illustrate the applicability of the invention without thereby limiting its scope to less than that of all equivalents which will be apparent to one skilled in the art. In the drawings like reference numerals refer to like parts and:

FIGURE 1 is a perspective view of a mattress of this invention;

FIGURE 2 is a cross-sectional elevation of a portion of the mattress of FIGURE 1;

FIGURE 3 is a cross-sectional elevation of a portion of another embodiment of a mattress of this invention;

FIGURE 4 is a cross-sectional elevation of a portion of another embodiment of the mattress of this invention;

FIGURE 5 is a cross-sectional elevation of a portion of another embodiment of this invention;

FIGURE 6 is a cross-sectional elevation of a portion of another embodiment of this invention;

FIGURE 7 is a perspective view in cut-away of another embodiment of this invention.

In FIGURES 1 and 2 is shown mattress 10 of convention dimensions comprising center portion 11 and end portions 12 and 13 of uniform thickness and width adhered together by means of a conventional adhesive. In a preferred embodiment center portion 11 comprises foamed natural or synthetic rubber and end portions 12 and 13 comprise foamed resin such as polyurethane resin. Foamed rubber, either natural or synthetic, is known for 3,210,781 Patented Oct. 12, 1965 use in resilient elastomeric articles such as cushions and the like. Such material is of cellular construction with air cells within the rubber matrix either being connected by capillaries, or being discrete without capillary intercommunication. Foamed resilient resins such as polyurethane, vinyl, and polyethylene resins are also well known for use in flexible cushion articles or mattresses. Polyurethane comprises the products obtained by reacting an isocyanate with a polyfunctional polyester, glycol, polyether, castor oil, or other polyfunctional material. Foamed polyurethanes are obtained by adding water to the reactants. By varying the degree of branching in the polyfunctional material, foams of varying flexibility can be prepared. The diisocyanate reacts with the polyesters, converting a low molecular weight liquid polymer into a high molecular weight elastomer or plastomer. At the same time the diisocyanate reacts with water to generate carbon dioxide, which foams the resin. The density of the foam is controlled by the ratio of water to diisocyanate used. The preparation of flexible foam requires from 25 to 50 parts diisocyanate to each parts of polyester. Lighter foams are produced by increasing the ratio of isocyanate to water.

Flexible polyurethane foams which have a predominantly open cell structure are available is a density range of from 2 to 6 pounds per cubic foot. Mechanical properties are such that a 2.5 pounds per cubic foot urethane foam is superior to medium density rubber latex foam in load carrying characteristics and in tensile strength. Thus, for 2.5 pounds per cubic foot flexible urethane foam, indentation to 25% of the thickness of the foam material requires from 40 to 60 pounds loading per 50 square inches. The tensile strength of the same foam is from 17 to 25 pounds per square inch and the tear strength is from 3 to 6 pounds per inch. The elongation of the foam is from to 230%.

The combination of properties possessed by flexible polyurethane foam make it excellent for cushioning use. The flame resistant characteristic and the high tensile strength and tear resistance of the material make it especially attractive for use in mattresses.

Other foams may be provided by means other than by chemical reaction such as by mechanical mixing of air, carbon dioxide or another gas is whipped into the plastic at the right viscosity to produce a frothing or a foam, as in the production of some types of vinyl foams or rubber foam. Volatile solvents or liquids may also be used such as methylene dichloride or Freon (registered trademark) for foaming plastics, or flowing agents which thermally decompose may be used. Such materials are well known for use in foaming plastics such as vinyls, polyethylene polyesters, polyethers and other similar resilient materials as are usable herein.

Rubber foams comprise natural rubber or synthetic rubber such as neoprene or butadiene-acrylonitrile. The rubber foams range in density from about 10 to 25 or 30 pounds per cubic foot. The tensile strength of foamed natural rubber is from 15 to 30 pounds per square inch; of neoprene, from 20 to 100 pounds per square inch; and of butadiene-acrylonitrile, approximately 40 pounds per square inch. These rubbers are non-combustible and are safe for use in a mattress. The greater density of rubber foams in comparison to urethane foams, for example, provide articles having greater durability than articles made with foam resins of lesser density. It is preferred herein to provide rubber foam of approximately 15 pounds per cubic foot density in from 40% to 70% of the volume of the mattress. The combination of rubber and a light weight synthetic resin foam such as polyurethane in a mattress provides variability of resiliency from the ends of the mattress toward the center, and also provides an article having different resiliency than that which would obtain if either material alone were used in the mattress. Thus, a mattress is provided with progressive firmness from the ends of the mattress toward the center which corresponds approximately to the progressive loading to which the mattress is subjected in normal use. A combination of properties of resiliency and firmness is provided which is unavailable in a mattress of a single composition.

In FIGURE 3 is shown another embodiment of the invention wherein head and foot portions 12 and 13 of mattress 10' are secured to middle portion 11' by means of adhesive 14 coated on the faces of the rabbet joint shown. The greater length of such a joint in comparison to the butt joint shown in FIGURE 2 provides a correspondingly greater surface area for an adhesive bond between mattress sections and is desirable for providing a progressive change in the resiliency of the mattress from that of the foamed resin material in sections 12' and 13' to that of the foamed rubber material in middle portion 11' of the mattress.

In FIGURE 4 is shown another embodiment of a joint of a mattress of this invention, wherein foot portion 12" and middle portion 11" of mattress 10" are joined by a tongue and groove joint with adhesive 14" provided on the facing surfaces thereof. The tongue and groove joint provides the same advantages as the rabbet joint of FIG- URE 3, and is a preferred construction of a mattress of this invention.

In FIGURE is shown another embodiment of a mattress of this invention wherein foot portion 12" and middle portion 11 of mattress are joined by a vertical butt joint as shown in FIGURE 1 with adhesive 14 provided on the facing surfaces thereof and with a plurality of straps 15 embedded in both portions 12" and 11" of the mattress. Straps 15 preferably comprise twisted paper, natural or synthetic resin fiber such as jute, hemp, rayon, polyethylene or other spun or monofilamentary material for strengthening the joint between adjacent sections of the mattress. Straps 15 may be coated with adhesive and placed within slits in preformed mattress portions 12 and 11", or may be placed in a mold so that the resin and rubber upon being foamed in the mold envelop straps 15 and are bonded directly to the straps.

In FIGURE 6 is shown another embodiment of this invention comprising a modification of the embodiment of FIGURE 1 wherein three densities of composition are provided in mattress 20. Two endmost portions 21 of one composition and density are provided in combination with two intermediate portions 23 of a second composition and density and a centermost portion 22 of a third density. Endmost portions 21 may comprise four pounds per cubic foot foamed polyurethane resin while intermediate portions 23 comprise 10 pounds per cubic foot foamed butadiene-acrylonitrile synthetic rubber and centermost portion 22 comprises pounds per cubic foot foamed butadiene-acrylonitrile synthetic rubber.

As will be apparent a greater number of compositions or varying densities of a single composition may be provided in a mattress so that a greater or lesser number of distinct portions comprise the mattress.

A large variety of resilient elastomeric resins and rubbers may be used to provide a mattress of this invention; however, small cell foamed synthetic rubber and foamed polyurethane are preferred materials for use herein because of the resiliency, durability and low costs of such materials enable a utilitarian article to be manufactured inexpensively. It is necessary to provide sections of full mattress thickness to achieve the optimum economy and toughness in the mattress. Thus, in all embodiments of this invention, a mattress of uniform thickness from end to end and of uniform composition from top to bottom at any particular section is provided for securing the most desirable combination of properties in the article.

The embodiments of the invention as above described are intended to be used in conjunction with bed springs such as a box spring. The mattress may have springs incorporated thereinto, however, in the manner of an innerspring mattress. To provide such an embodiment it is necessary to pro-place the springs to be incorporated into the mattress into a mold and foam the resin and rubber in the mold subsequently. The foamed in place construction which results provides an innerspring mattress of very low cost. If preferred, pre-foamed material such as rubber can be cast into a mold independent of the time of placing of the spring in the mold and be subsequently vulcanized to provide an integral bond with the spring.

In FIGURE 7 is shown a portion of an embodiment of this invention provided with an integral spring. Mattress 30 comprises conventional box spring 31 integrally bonded to foamed in place synthetic resin and portions 32 and foamed rubber center portion 33. The spring is disposed in the lower portion of the mattress so as to provide a resilient cushion of foamed material between the upper mattress surface and the spring. Mattress 30 functions in the manner of a conventional innerspring mattress. Foamed synthetic resin end portions 32 of mattress 30 are integrally connected by side portions 34 and are adhesively attached to center portion 33 to provide a unitary structure.

While certain modifications and embodiments of the invention have been described, it is of course to be understood that there are a great number of variations which will suggest themselves to anyone familiar with the subject matter thereof and it is to be distinctly understood that this invention should not be limited except by such limitations as are clearly imposed in the appended claim.

I claim:

In a mattress comprising foamed elastomeric material of two different densities and helical springs embedded in said foamed material, the combination of a head portion, a foot portion, and two side portions, said portions surrounding a center portion, each of said portions being attached to said center portion, said head and foot portions being connected by said side portions, said head, foot and side portions being integral parts of a single member and having the same height, resiliency and density, said center portion being of a higher density and being stiffer than said side, foot and head portions, said springs being embedded only in said center portion.

References Cited by the Examiner UNITED STATES PATENTS 2,061,664 11/36 Lincoln 5-345 2,878,153 3/59 Hacklander 5-361 X 3,049,730 8/62 Wall et a1 5--351 3,069,701 12/62 McInerney 5-351 FOREIGN PATENTS 557,004 5/57 Belgium.

FRANK B. SHERRY, Primary Examiner.

GEORGE L. BREHM, Examiner.

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