US 3027573 A
Description (OCR text may contain errors)
April 1962 J. E. BELL, JR 3,027,573
IMPROVED MATTRESS ASSEMBLY Filed May 27, 1959 INVENTOR JAMES EDMUND BELL, JR
ATTORNEY United States Patent U 3,027,573 IMPROVED MATTRESS ASSEMBLY James Edmund Bell, Jr., Greenville, Del., assignor to E. I. du Pont de Nemours and Company, Wilmington, Del, a corporation of Delaware Filed May 27, 1959, Ser. No. 816,192 2 Claims. (Cl. 5-355) Bed mattresses vary widely in their properties, construction, and the materials from which they are made. In general, they consist of a firm but resilient inner material encased in a substantial cloth ticking. Felts of cotton or of curled hair have been widely used in the core. Arrangements of coil springs generally covered with cotton felt are common. More recently, foam pads of elastomeric materials have been used as the resilient core material. The assembly of all of these types requires skill and specialized manufacturing equipment; and, therefore, mattresses are commonly offered to the public in the form of a complete unitary article. They are large and awkward in shape and too heavy to be handled easily. Although they are subject to soil from many sources, it is usually impractical to clean them or to make any repairs in them with home facilities. For cleaning, it is necessary to return the mattress to a specialized service for complete dismantling and reassembly. For this reason, many kinds of protective coverings have been proposed and are in general use.
The taste of the public also varies widely in the choice of both aesthetic and working qualities desired. To satisfy this need, many colors and designs in the covering fabrics are offered and the internal construction is varied to give hardness or softness, or any intermediate range of resilience. This means that many different models must be provided by the vendor and consequently, large inventories are required.
It is an object of this invention to provide a compound mattress which can be easily assembly from its elements. Another object is to provide a new type of mattress with a luxurious, enveloping and cushioning surface. It is a further object of this invention to provide a mattress having the firm supporting qualities of an elastic foam, but with damped recovery properties to avoid the quick bounce of such foam mattresses. A still further object of this invention is to provide a mattress assembled from a relatively small number of different elements to provide wide variations in color, pattern, hardness, and other qualities. A further object is to provide a mattress which may be easily disassembled into its elements for repair and cleaning and in which all of the elements are completely washable and sterilizable. Other objects will appear hereinafter.
These objects are achieved according to this invention by providing a compound mattress consisting of three primary elements, an upper envelope, a lower envelope, and a core. Each of these elements is constructed of materials best suited for its particular function, and the three are readily assembled without special skill or tools to form a luxurious and highly desirable, as well as durable, sleeping mattress.
The upper envelope comprises a quilted sleeping surface extending over the entire top surface of the mattress and attached thereto a fabric skirt to provide a portion of the side wall. The quilted surface is a batt of highly resilient crimped fibers of a synthetic, linear organic polymer quilted between a top sheet and a bottom sheet of fabric also composed of synthetic, linear organic polymeric fibers. The quilting stitching may be in any design desired, and preferably is at a sufiicient spacing so as not to inhibit the fluffiness of the covering envelope. The side-wall fabric is preferably the same as that used in the top surface, although it may have an 3,fi27,573 Patented Apr. 3, 1962 inner reinforcement, either of fabric or other stiffening a cut.
The crimped resilient synthetic fibers used in the batt permit laundering in the quilted condition without substantial loss of bulk and resilience and with little if any change in length and width. Acrylic fibers, such as polyacrylonitrile or copolymers containing at least acrylonitrile in the polymer, such as the copolymer of methyl acrylate, polyamide fibers, such as nylon, polyester fibers, and cellulose acetate fibers have all been found to give satisfactory behavior. It is preferred to use poly(ethylene terephthalate) fibers.
The batt, before covering, is preferably surfacebonded by applying a binder material to only the extreme upper surface of the batt to bind the protruding fiber ends together and prevent the leaking of fibers through the fabric covering the mattress. Such bonding is readily accomplished by spraying.
FIGURE 1 shows an elevated perspective view of the three components of this invention.
FIGURE 2 shows an open view of the top component.
In FIGURE 1, there is shown top covering envelope 1, foamed core 2, and bottom covering envelope 3. Side panels 4 are provided for both the top and bottom envelopes. Zipper tracks 5 and 6 are also provided to interlock the top and bottom envelopes in the composite assembly shown in FIGURE 2.
A three component mattress of this invention including an elastomeric core and a top and bottom covering envelope, is constructed. An elastomeric twin-sized mattress core, a slab of foamed polyether urethane, known under the trademark of NOPCO Foam, 6 inches thick is provided with a bottom covering envelope of cotton fabric and a top envelope of 70 denier nylon taffeta. The top envelope is a multi-ply assembly of two 70 denier nylon taffeta sheets covering a batt of poly(ethylene terephthalate) fibers (2 ounces per square foot), crimped in accordance with the teachings of U8. Patent 2,311,174 and having a staple length of 4 inches, the filament denier being 1.75. These two nylon sheets are quilted together to provide a bulky covering envelope. Prior to quilting the top envelope, the batt is sprayed lightly with an acrylic resin binder composition known under the trademark of Rhoplex D-lS. To provide additional support for the side panels of both envelopes, an 8 ounce cotton backing is provided for the side panels of the envelopes.
Sheets 7 and 8 of the top envelope cover a batt of synthetic crimped fibers 9 having a thin spray 10 of the acrylic resin known under the trademark Rhoplex 15, to hold the fiber ends in place. These sheets are quilted at 3-4 inch intervals in diamond shapes 11 by threads 12, to provide a bulky, resilient cover for the foamed core 2.
In order to realize the soft and luxuirous feel of the synthetic fiber batts, light-weight and relatively smooth fabrics are preferred for covering. Continuous filament fabrics have been found highly desirable in the top cover. However, spun yarns or textured continuous filament yarns may be used for all or a portion of the top covering fabric to alter the frictional qualities of the surface as desired. Desirable fabrics for the top cover range in weight from 2 ounces to 4.5 ounces per square yard. The fabrics used on the inner surface of the batt may, if desired, be lighter than those on the outer surface. Continuous filament nylon fabrics have been found especially desirable.
The lower envelope is similar in size and general form to the upper envelope except that the main surface is not quilted, but is made from a durable fabric. If desired, this may be a cotton fabric. A fabric skirt which forms the bottom portion of the side wall of the mattress is similar to the skirt portion of the upper envelope but does not extend as far on the side wall. The fabric used in this lower envelope skirt may be the same as that used in the upper envelope skirt, or it may be different in color, weight, and design as preferred. The two envelopes are identical in dimensions except for the longer extension of the upper envelope skirt.
The core of the mattress is preferably a shaped slab of a foamed elastomer which may or may not contain molded depressions or designs to vary its firmness and resilience. Its length and width dimensions are somewhat larger than those of the upper and lower envelopes so that when placed within and between the two envelopes the foam core is slightly compressed.
In assembly, the foamed elastomer core is placed inside one of the envelopes, the second envelope is drawn over the other side of the core, and the two envelopes fastened together along the edge of their skirt side wall portion. A connecting enclosure means for the two envelopes is provided in the form of a zipper fastener connecting the edges of the upper and lower skirts and extending at least around one side and one end of the mattress. In the preferred embodiment, this zipper closure extends completely around the side wall of the mattress, and is of the type commonly used in the fronts of jackets and which permits a complete separation of the two sides and easy reassembly.
The compound mattress described is found to have extremely pleasant enveloping and relaxing qualities. The highly resilient batt of crimped synthetic fibers permits easy compression under light loads but in further compression is restrained by the firmer qualities of the clastomer core. The fiber batt tends to recover from compression more slowly than does a foamed ela'stdrner -core, and it thereby provides a damping effect and greatly reduces the bounciness which is characteristic of foam rubber mattresses and which is considered objectionable by many.
The compound mattress is lighter and more easily handled than other mattresses of similar thickness and performance qualities. It may be disassembled easily by simply unfastening the zipper and removing the upper and lower envelopes. The envelopes may be laundered in any suitable manner including the use of home laundry machines. In most cases, the bulk and loftiness of the crimped synthetic fiber batts are improved by laundering and where this does not occur gentle manipulation of fiufiing by hand restores any loss in bulk. Such action is, of course, impossible with conventional mattresses. The lower envelope may be washed in a similar manner and the foamed elastomer core may be scrubbed without damage. The three primary elements of the compound mattress may also be sterilized separately if desired.
The amount of crimped synthetic filaments used in the batt of the upper envelope varies between about 1 ounce ounce and about 4 ounces per square foot, about 1.8 to about 3 ounces per square foot being preferred. Less than about 1 ounce fails to give the desired damping effect while an amount greater than about 4 ounces compacts the fibers so tightly that the covering envelope becomes as resilient as the formed elastome'ri'c core and consequently also fails to provide adequate damping. The thickness of the foamed elastorner core ranges from 3 inches to 6 inches depending on the degree of cushioning desired and economic factors.
It is critical that synthetic crimped fibers be utilized to provide the damping characteristic. Natural fibers have been found unsuitable in that such fibers have very little resilience as compared with the synthetic crimped fibers and tend to mat together after use to provide a very undesirable cover. I
Any washable binder composition which holds the fiber ends in place can be utilized, whether thermoplastic, thermosetting or elastomeric. Among these suitable binders, there are included washable synthetic rubber latex, poly(vinyl chloride), ether resins, and epoxy resins. In the rubber latex group, neoprene is preferred for its washability.
The compound features of the mattress of this invention are of great importance in providing a wide variety of combinations of hardness or softness, and color, design and other aesthetic features without maintaining a largeinventory of entirely complete mattresses. A few types of elastomer foam cores providing differences in hardness may be placed within envelopes of any chosen design to provide wide choice with a relatively small inventory.
Of great importance also are the outstanding comfort and supporting qualities of compound mattresses of this design and the capacity of each component to be subjected to washings Without deleterious effects.
The mattress assembly of this invention is highly desirable in that the quilted batting of synthetic crimped fibers is free to move verticallythus providing e'nveloping cushioning which is not obtained with normal quilted structures. For a given Weight of batting, the synthetic fibers will assume two to three times the thickness which would be experienced if natural fibers were used, but when compressed with normal body weight wouldactuab ly be approximately the same thickness as those battings of natural fibers which insulate without providing cushioning. The batting is preferably quilted with a pattern that leaves a minimum of about nine square inches between stitch lines. Such a batting is free from shifting or lumping during washings. A natural fiber batting must be stitched with a very close pattern to inhibit in part the movement of the fibers, but still such battings have been found to shift and lump during washings.
1. An improved separable compound mattress assembly characterized by a low resistance to low magnitude compressional deformations and disproportionately increased high resistance to higher magnitude compressional deformations, said assembly comprising a foamed polyether urethane elastomeric interior core unit of given resili'ence, and a launderable exterior unit surrounding said core, the said exterior unit comprising a top portion and a detachable bottom portion connected together, said top portion comprising a quilted layer comprising a top sheet ofsynthetic fabric, a bottom sheet of synthetic fabric, and a batt contained between the sheets and comprised of a. quantity 'of resilient crimped fibers of a solid synthetic linear organic polymer of ethylene terephthalate stitched in place between said sheets, said quantity of fibers ranging from about one and one-half to three ounces per square foot of batt and evenly distributed so that said batt possesses a resilience substantially different from said core and recovers from compression more slowly than said resilient core to provide a suitable damping action to eliminate oscillatory vibration effects, or bouncing, in said mattress assembly when the mattress assembly is subjected to compression loads in use.
2. The improved assembly of claim 1 in which the upper surface of the batt is coated with a binder material to secure the fibers of the batt in position.
References Cited in the file of this patent UNITED STATES PATENTS