US 2779035 A
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Jan. 29, 1957 A. A. MCMURRY DRAWSHEET Filed March 22, 1950 Zsnventor Ari/z u T'A Mc/Vurrg K. HM;
Gttorneg United States Patent DRAWSHEET Arthur A. McMurry, Butler, Pa., assignor to Special Textiles, Inc., Butler, Pa., a corporation of Pennsylvama Application March 22, 1950, Serial No. 151,233
1 Claim. (Ci. -354 This invention relates to drawsheets for beds, and more particularly refers to Waterproof laminated or composite drawshects.
Rubber sheeting or sheeting of other waterproof material is commonly used in hospitals and similar institutions to protect mattresses from wetting and staining by water, blood, urine, liquid medicaments, etc. This waterproof sheeting is effective in protecting the surface of the mattress but does not contribute to the patients comfort since its surface is essentially impervious to moisture and not adapted to facilitate ventilation. Rubber and other elastomers tend to cling to the body of the patient and so promote chafing. It is therefore common practice to cover the waterproof sheet with an ordinary bed sheet of textile fabric which considerably increases the comfort of the occupant of the bed. The provision of a waterproof sheet and a covering textile sheet is relatively expensive, increase the volume of supplies which a hospital must carry, and considerably increases the labor of bed-making. Furthermore, although the waterproof sheet protects the mattress, it itself becomes stained and discolored and must be periodically cleaned or replaced. Finally, sheeting of rubber and other elastomers tends, in use, to crack at creases or folds, and such cracks allow moisture to pass through.
My invention has as an object the provision of a laminated or composite drawsheet which takes the place of both the protective waterproof sheet and the textile covering sheet now generally used. It is a further object of my invention to provide such a composite sheet which may be washed or laundered as freely as an ordinary textile bed sheet. Another object of my invention is to provide a composite sheet, the waterproof layer of which will not readily crack or otherwise deteriorate in use. Yet another object of my invention is to provide such a sheet with edge regions of frictional or non-slip character so that such edges will stay in place when tucked under a mattress and so prevent the sheet from shifting or wrinkling.
My invention comprises a sheet of a suitable textile fabric of conventional dimensions having a center panel of the dimensions of the mattress surface composed of flexible waterproof material bonded to the fabric and covered with a second textile fabric panel which is also bonded to the flexible waterproof material. The con struction of this product may be understood by reference to the accompanying drawings of a present preferred embodiment of my invention, in which:
Figure 1 is a plan view of my drawsheet;
Figure 2 is a cross-section, to a greatly enlarged vertical. scale, through the drawsheet of Figure 1 on the plane lI-ll;
Figure 3 is a partial cross-section through an outer edge of the drawsheet in the plane lllill; and
Figure 4 is a partial cross-section taken at the boundary of the composite center panel section on the plane IVIV.
It will be understood that the drawsheet of my invention is conveniently manufactured in the form of a con- "ice tioned, their width is that of the mattress to be covered plus a margin suflicient to extend over the mattress sides. The remaining portions of the drawsheet on each side of this center panel are tucked around under the mattress and so do not need to be waterproof. I preferably provide, however, narrow panels 4 of flexible frictional material bonded to the textile base 1 along its edges to improve the adherence of these edges to the mattress when tucked into place. These panels 4 of frictional material are bonded to the reverse side of the textile base 1 so that they will engage the mattress undersurface when the drawsheet is wrapped around the mattress.
The textile fabric base of my drawsheet may be sheeting of the conventional type-that is, muslin of about 128 to thread count, or percale of about to 210 thread count. The covering panel may be of this same material or may be of other materials if desired. I find that a covering panel of about twoto six-ounce flannel, or of Canton flannel with the nap exposed, provides a very comfortable upper surface for my drawsheet.
The flexible waterproofing panel is preferably rubber or a rubber-like elastorner such as plasticized vinyl chloride polymers, known commercially as Koroseal, or chloroprene, known commercially as Neoprene. Other similar flexible waterproof products which are suitable for the purpose of my invention will doubtless suggest themselves to those skilled in the art and may be considered equivalents for my purpose. I encompass these in the term elastomers as used herein. The flexible frictional panels bonded to the back edges of my drawsheet may, for the sake of convenience, be of the same material as the central flexible waterproofing panel, as the materials above mentioned, which I prefer to use for this panel, possess the desired frictional properties. However, other materials could be used for this purpose since it is not necessary that these marginal panels be waterproof.
The material forming the flexible waterproofing panel may be applied to the textile fabric base as a solid film, a solution such as a latex, or a paste of the elastomer in a solvent. I prefer to apply this material in an uncured form, cover it with the covering textile fabric panel, calendar the composite product and then cure the elastomer at the appropriate temperature. By this method of manufacture the base and covering fabrics are bonded to the flexible waterproof panel as the latter is formed. It will be understood that the material of the waterproof panel impregnates both the base fabric and the covering fabric panel to a considerable degree, and the manufacture of my product is so controlled that the outer surfaces of the fabric base and the covering panel are not completely impregnated so as to lose their characteristic textile fabric appearance and feel. The flexible frictional material applied to form the marginal panels, however, may be applied to impregnate the base material completely if desired since the edges of the sheet do not come in contact with the bed patient.
It will be appreciated that bed sheets, particularly hospital bed sheets, must Withstand temperatures of boiling Water or steam in laundering. Such temperatures and the mechanical agitation of washing tend to disintegrate impreguated fabrics and wash out the impregnating material. Because of the textile fabric covering panels on both sides, however, the composite drawsheet of my insynapse v'enti'o'n withstands a considerably greater number of launderings than ordinary impregnated fabrics. This construction also retards the tendency of the flexible Waterproofing layer to crack after repeated foldings or creasing'an undesirable characteristic of conventional rubber or rubber-like sheets or fabric impregnated with rubber or rubber-like compounds. The presence of the textile fabric layer on each side of the flexible waterproofing layer causes the latter to bend, when folded or creased, on a greater radius than would be found if the textile were not doubled over between the folds of the waterproof layer. The provision of the frictional margins also retards the cracking of the Waterproof layer of my drawsheet, as the increased grip of sheet upon mattress so made possible reduces the tendency of the drawsheet to fold or Wrinkle under the movements of the patients body. The patients comfort is also thereby increased.
As the rubber or other elastorner is firmly bonded both to the base fabric and the covering fabric panel, the drawsheet of my invention withstands use and laundering without tending to pull apart or separate. If desired, however, it may be further strengthened against separating by stitching along each edge of the covering panel. Although I have described and illustrated the present preferred embodiment of my invention, it Will be under- 4. stood that the invention is not limited thereto but may be otherwise embodied or practiced Within the scope of my claim.
A washable drawsheet for covering a mattress comprising a. laminated central section consisting of upper and lower textile panels and an intermediate panel of flexible waterproofing material impregnating the under side of the upper textile panel and the upper side of the lower textile panel so as to bond the central section together, said section being of a Width at least equal to that or" the mattress, textile side panels adapted to tuck under a mattress, and marginal panels of flexible, frictional material bonded to the textile side panels so as to engage the underside of a mattress and hold the raves-heat in place.
References Cited in the file of this patent UNITED STATES PATENTS 690,772 Revalk I an. 7, 1902 2,222,782 Moses NOV. 26, 1940 2,507,107 Strauss Oct. 24, 1950 FOREIGN PATENTS 418,482 Great Britain Oct. 25, 1934