US 3258791 A
Description (OCR text may contain errors)
July 5, 1966 5. J. Kl -\PLAN 3,258,791
MATTRESS PAD Filed April 6, 1964 United States Patent 3,258,791 MATTRESS PAD Sidney J. Kaplan, 1616 W. Grand Ave., Waukegan, Ill. Filed Apr. 6, 1964, Ser. No. 357,488 4- Claims. (Cl. -347) This invention relates to a novel cushion pad and, more particularly, to a spongifoam cushion for use as a mattress pad or the like wherein a great amount of air circulation is desired. It is to be understood that the term mattress pad as used herein includes a mattress per se or a mattress overlay.
A mattress pad which allows the air to circulate freely has much utility in hospitals where it has formerly been necessary to change the mattress pads on each bed three or four times a year due to the absorbance of perspiration from the patients lying thereon.
The typical fiat foam rubber pad has not been found to be effective in hospitals due to the lack of proper air circulation thereby making the patient uncomfortable and causing excessive perspiration. Mattresses consisting of a foam material have been considerd hot and hence unpleasant by many persons. In addition, some persons find polyurethane spongifoam material too rigid a substance for proper resting comfort. This material tends to resist initial deformation under light load although it may yield satisfactorily under heavy loads. The employment of a grooved spongifoam surface in order to achieve a softness and air circulation is known, but only a minimum amount of circulation has resulted.
A particular configuration has been discovered which effectively and economically achieves the softness desired by most persons and provides good air circulation.
In the present invention a cellular spongifoam material is employed to form a mattress pad having a novel configuration. The instrumental surface of the pad, that is, the surface upon which the person lies, contains a plurality of upwardly extending protuberances which are adapted to support an outer sheet. The novel construction of the pad allows air to be trapped under the sheet and movement by the person on the sheet causes a bellows action which results in a great amount of air circulation. In addition to the circulatory properties of the pad, its softness with respect to initial deformation is outstanding and the invention provides a pad with numerous features not heretofore known in economical cushion construction.
A more detailed explanation of the invention is provided in the following description and claims and is illustrated in the accompanying drawing which discloses fully the principles of the invention.
In the drawings:
FIGURE 1 is a fragmentary view in perspective of the mattress pad of the present invention combined with a mattress and outer sheet;
FIGURE 2 is a plan view in schematic form of the mattress pad of the instant invention wherein the crosses indicate a protuberance peak and the dots indicate a cavity nadir;
FIGURE 3 is a sectional view of the mattress pad taken along the line 33 of FIGURE 2;
FIGURE 4 is a sectional elevation of the mattress pad taken along the line 44 of FIGURE 2; and
FIGURE 5 is an enlarged fragmentary perspective view of the mattress pad.
Referring to FIGURE 1, a mattress is illustrated with the mattress pad 12 of the present invention nested thereon, and a sheet 14 is shown supported by the mattress and pad. The mattress pad 12 is formed of a cellular spongifoam material such as polyurethane foam.
The use of such a foam having a substantially uniform 3,258,791 Patented July 5, 1966 cellular count and an open-cell construction helps to provide the necessary softness and compressibility in addition to its self-ventilating properties due to its inherent porosity. Furthermore, open celled polyurethane foam is light in weight, relatively economical and washable. The advantages of such mattress pads for hospital use are readily apparent. As a specific example, polyurethane having a density between about 2 pounds per cubic foot and about 8 pounds per cubic foot has been found suitable. A preferable range of densities is from about 3 to about 6 pounds per cubic foot.
As seen most clearly in FIGURES 25 the instrumental surface 15 of the mattress pad 12 includes a plurality of upwardly extending undulating protuberances 16 which are respectively separated by a plurality of undulating cavities 18. The walls defining the cavities are substantially the shape of the protuberances and the cavities 18 are interconnected by ridges 20 which also serve to bridge the protuberances. The apexes 22 of the ridges are approximately one half the distance between the peaks 24 of the protuberances and the nadirs 26 of the cavities 18.
When a sheet is supported by the instrumental surface of the pad it is apparent that a large amount of air is effectively trapped within the cavity formation and only a minor portion of the sheet is in contact with solid material. When a downward force is exerted against the protuberances by a person lying upon the sheet, the protuberances are easily compressed downwardly to the level of ridge 20, thereby providing a soft, resilient and comfortable cushion.
The undulating protuberances obviate the initial rigidity which has been found undesirable in prior art cushions. Furthermore, only the instrumental surface of the pad generally conforms to the body contours and hence the overall pad provides effective support.
Since the upper portion of the protuberances form only a minor portion of the instrumental surface, it is observed that the weight of the body will not cause a general deformation of a large portion of the pad surface; in effect only the immediate area in contact with the body hecomes deformed. The protuberances act individually under pressure and do not substantially affect any of the non-contacted protuberances.
The ridge formation does not allow the contacted protuberances to be totally compressed under ordinary weight, and therefore a certain amount of cavitation remains. A downward compression of the protuberances 16 to the level of ridges 20 results in an instrumental surface area which comprises one half air space and one half spongifoam material. A sheet on top of the pad will effectively trap air within the remaining cavitation, thereby achieving greater air circulation. Any movement by the person lying upon the sheet will additionally cause a bellows action which is aided by the inherent circulatory properties of the open-celled material. The novel combination resulting from the co-action of the sheet with the mattress pad provides a highly effective cushion, not heretofore known in the prior art. The novel construction further provides generous resilience but no permanent distortion.
In a specific example, a suitable overall height for the mattress pad was 2 /2 inches and the nadirs of the cavities were approximately inch from the base. The ridge apexes 22 were about inch above the cavity nadirs. A suitable and effective construction comprises protuberances of uniform height which are laterally spaced (measuring across the cavities) approximately two inches apart, peak-to-peak. The configuration is achieved using a conventional hot wire method which is well known in the art. In this method, a single block of foam is cut by an undulating hot wire to produce two substantially identical surfaces, with the protuberances of one corresponding to the cavities of the other.
A pad containing between about and 150 protuberances per square foot has been found suitable. In a preferred embodiment, a mattress pad with about seventy-two protuberances per square foot can be used successfully.
The invention has been described as applied to a preferred embodiment and it will be understood that various substitutions and changes may be effected by those skilled in the art without departing from the spirit and scope of the novel concepts and principles of this invention. Al though a bed mattress pad has been shown and described it is to be understood that no limitation is intended With respect to the use of the pad of the present invention and the particular embodiment shown in FIGURE 1 is for illustrative purposes only.
What is claimed is:
1. A mattress pad comprising a cellular spongifoam material having an instrumental surface containing from about 20 to about 150 undulating protuberances per square foot of substantially uniform height separated respectively by respective undulating cavities of substantially uniform depth, the walls defining said undulating cavities having substantially the shape of said undulating protuberances, said undulating protuberances being adapted to support an outer sheet thereon, a plurality of ridges interconnecting said cavities, said protuberances being bridged by said ridges, the apexes of said ridges being substantially one half the distance between the peaks of said protuberances and the nadirs of said cavities whereby said ridges provide a resistance against excessive compression and said pad retains at least partial cavitation under ordinary Weight.
2. A mattress pad comprising a polyurethane spongifoam material having a density between about 3 pounds per cubic foot and about 6 pounds per cubic foot and having an instrumental surface containing between about 20 and about 150 protuberances per square foot separated re spectively by a plurality of undulating cavities, the Walls defining said cavities having substantially the shape of said protuberances, the upper surfaces of said protuberances forming only a minor portion of said instrumental surface and supporting an outer sheet thereon, a plurality of ridges interconnecting said cavities, said protuberances being bridged by said ridges, the apexes of said ridges being substantially one half the distance between the peaks of said protuberances and the nadirs of said cavities whereby the instrumental surface area comprises about one half air space and about one half polyurethane material thereby retaining said cavitation upon compression of said protuberances to substantially the height of said ridge apexes.
3. A mattress pad comprising a polyurethane spongifoam material having a density between about 3 pounds per cubic foot and about 6 pounds per cubic foot and having an instrumental surface containing between about 20 and about protuberances per square foot separated respectively by a plurality of undulating cavities, the nadirs of said cavities being about /8 inch from the base of said pad, the Walls defining said cavities having substantially the shape of said protuberances, the upper surfaces of said protuberances forming only a minor portion of said instrumental surface and supporting an outer sheet thereon, a plurality of ridges interconnecting said cavities, said protuberances being bridged by said ridges, the apexes of said ridges being substantially one half the distance between the peaks of said protuberances and the nadirs of said cavities whereby the instrumental surface area comprises about one half air space and about one half polyurethane material thereby retaining said cavitation upon compression of said protuberances to substantially the height of said ridge apexes.
4. A mattress pad as defined by claim 1 in combination with a mattress having one surface thereof juxtaposed with the surface of said mattress pad opposite said instrumental surface, and a sheet supported by said mattress pad and resting upon said peaks of said protuberances.
References Cited by the Examiner UNITED STATES PATENTS 2,897,741 8/1959 Mauch 5-347 X 3,205,515 9/1965 Unger 5345 X FOREIGN PATENTS 1,244,182 9/1960 France.
904,25 3 8/ 1962 Great Britain.
FRANK B. SHERRY, Primary Examiner.
CASMIR A. NUNBERG, Examiner.
A. M. CALVERT, Assistant Examiner.