Patent Application
20090193584
The present invention relates to bedding and, more particularly, to contoured or fitted bed sheets.
Contoured or fitted bed sheets are typically made from either woven fabric or knitted fabric. Contoured fitted sheets made from woven fabric generally have no inherent ability to stretch and grab around the mattress and so are often finished with an elastic binding around the bottom edge of the sheet to assist in holding the sheet to the mattress. The elastic binding presents problems, especially in the hospitality and healthcare markets where they are handled in commercial laundry environments. The harsh laundering processes involved tends to shorten the life of the elastic thereby limiting the service life of the sheet. Further, each sheet is typically fitted to a mattress having a thickness related to the sidewall depth or height of the sheet, especially at the corners. But, there is little uniformity to mattress thicknesses across styles or manufacturers creating particular problems in facilities that have a lot of beds, as typical of health care facilities and hospitality properties. Additionally, some beds, especially in the health care environment, are adjustable. Non-stretchable woven contoured sheets tend to slip off the corners of mattresses as the ends of such beds are raised and/or lowered.
Knitted contoured bed sheets avoid some of these problems as they inherently stretch to fit and hold better to various thicknesses and adjusted positions of mattresses, without the need for an elastic binding. But, knit fabrics are typically less durable and have a less desirable hand than woven fabrics. Moreover, knitted fabrics are more complicated and costly to process in commercial laundry as they are not easily handled with ordinary flat work ironers or folding machinery common in commercial laundry settings. As a result, knitted sheets tend to require more manual handling, and thus increase processing costs as compared to woven fabrics. Further, laundry efficiency is generally reduced by the need to handle both woven and knitted fabrics. Also, hybrid products combining both woven and knit fabrics have been introduced, but are not sufficient to meet the demands of the health care and hospitality markets.
The hospitality market tends to prefer woven fabrics and the healthcare market, while accepting of knitted fabrics, could also benefit from woven fabrics. To that end, attempts have been made to add stretch and recovery characteristics to woven fabric without requiring elastic binding around the edge. One proposal is to include spandex yarns or core-spun yarns along with the traditional, typically non-elastic yarns. But results have been considered unsatisfactory. For example, spandex based yarns tend to become discolored and degrade when exposed to chlorine and heat, both commonly encountered in commercial laundry settings. Core-spun yarns are undesirable because they lack durability in the institutional wash process and they limit the ability to control the elastomeric content in the fabric. Another proposal has been to induce a stretch characteristic into the sheet by treatments that affect the sinuosity and crimp of the yarns. However, the treatment process undesirably increases cost and often involves chemicals considered harmful to workers and the environment.
The present invention provides a woven bed sheet that serves as a contoured or fitted bed sheet but without the above-discussed drawbacks. To that end and in accordance with the principles of the present invention, the bed sheet is defined by a one-ply woven web of warp and fill yarns in which a plurality of either the fill yarns or the warp yarns (or both) are non-spandex, non-core spun elastomeric yarns. The elastomeric yarns allow the sheet to stretch along the warp or fill direction of those yarns, i.e., along the length and/or width of the sheet. That woven sheet can be used as a contoured bed sheet with the benefits of woven sheets, such as desirable durability and hand along with acceptable laundry processing behavior, and with the benefits of knitted sheets such as the ability to fit different sized mattresses and to stay bound to the corners of mattresses as they are raised and lowered on adjustable beds, but without the discoloration and/or chemistry drawbacks of prior proposals to render woven sheets suitably elastic.
By virtue of the foregoing, there is thus provided a woven bed sheet that serves as a contoured or fitted bed sheet but without the above-discussed drawbacks. These and other objects and advantages of the present invention shall be made apparent from the accompanying drawings and the description thereof.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and together with the general description of the invention given above and the detailed description of the embodiment given below, serve to explain the principles of the present invention.
With reference to
In one example, substantially all, or all, fill yarns 52 are non-spandex, non-corespun elastomeric yarns. Advantageously, such fills yarns 52 include an elastic multifilament yarn, such as a bi-component polyester textile fiber. In one example, the bi-component polyester textile fiber is elasterell-p. The remaining yarns, including warp yarns 50, provide yarns other than non-spandex, non-corespun elastomeric yarns. In one example, the warp yarns 50 may include all or substantially all non-elastomeric yarns such as natural fibers, e.g., cotton fibers, synthetic fibers, e.g., polyester fibers, or combinations, and/or blends thereof. This elastomeric yarn fill/non-elastomeric yarn warp configuration is preferred because in industrial weaving the yarns in the warp are under tension, which is difficult to control with elastomeric yarns.
The non-spandex, non-corespun elastomeric yarns are woven into the woven fabric 10 in quantities sufficient to allow the field portion 12 to stretch in the lengthwise direction 56 such that the top 18 edge and bottom 20 edge extend along the elastomeric fill yarns 52 toward dashed lines 58a and 58b, respectively. In one embodiment, the non-spandex, non-corespun elastomeric fill yarns 52 include between about 5% to about 70% by weight of the woven fabric 10. In another embodiment, the non-spandex, non-corespun elastomeric fill yarns 52 include between about 10% to about 50% by weight of the woven fabric 10. In yet another embodiment, the non-spandex, non-corespun elastomeric fill yarns 52 include between about 15% to about 30% by weight of the woven fabric 10.
The woven fabric 10, in one embodiment, is stretchable in the lengthwise direction 56 in a range of about 2% to about 50% of its unstretched length. In another embodiment, the woven fabric 10 is stretchable in the lengthwise direction 56 in a range of about 5% to about 25% of its unstretched length.
With reference to
The upper side panel 72 of contoured bed sheet 68 extends between upper left 86 and upper right 88 corner pockets. The upper 72 side panel of
The upper left 86 and upper right 88 corner pockets and lower left 90 and lower right 92 corner pockets of
The contoured bed sheet 68 is stretchable in the lengthwise direction 56 across the top and side panels as indicated by dashed lines 110a and 110b. This is advantageous because commercial folders for woven bed sheeting, generally receive bed sheets widthwise rather than lengthwise. Indeed, because the elastomeric yarns extend along the length of the bed sheet, widthwise insertion into commercial folders prevents needless and excessive lengthwise stretching of the elastomeric yarns thereby preserving its stretch. Although the embodiment illustrated in
With reference to
In one example, substantially all, or all, warp yarns 50′ are non-spandex, non-corespun elastomeric yarns, as defined above. Advantageously, such warp yarns 50′ include an elastic multifilament yarn, such as a bi-component polyester textile fiber. In one example, the bi-component polyester textile fiber is elasterell-p. The remaining yarns, including fill yarns 52′, provide yarns other than non-spandex, non-corespun elastomeric yarns. In one example, the fill yarns 52′ may include all or substantially all non-elastomeric yarns as described above.
The non-spandex, non-corespun elastomeric yarns are woven into the woven fabric 100 in quantities sufficient to allow the field portion 12 to stretch in the lengthwise direction 56 so that the top edge 18 and bottom edge 20 extend along the elastomeric warp yarns 50′ toward dashed lines 58a and 58b, respectively. In one embodiment, the non-spandex, non-corespun elastomeric warp yarns 50′ include between about 5% to about 70% by weight of the woven fabric 100. In another embodiment, the non-spandex, non-corespun elastomeric warp yarns 50′ include between about 10% to about 50% by weight of the woven fabric 100. In yet another embodiment, the non-spandex, non-corespun elastomeric warp yarns 50′ include between about 15% to about 30% by weight of the woven fabric 100.
The woven fabric 100, in one embodiment, is stretchable in the lengthwise direction 56 in a range of about 2% to about 50% of its unstretched length. In another embodiment, the woven fabric 100 is stretchable in the lengthwise direction 56 in a range of about 5% to about 25% of its unstretched length.
The woven fabric 100, may be used to form a contoured bed sheet similar in construction to contoured bed sheet 68 illustrated in
With reference to
In one example, substantially all, or all, warp yarns 50′ and fill yarns 52 are non-spandex, non-corespun elastomeric yarns as defined above. Advantageously, such warp yarns 50′ and fill yarns 52 include an elastic multifilament yarn, such as a bi-component polyester textile fiber. In one example, the bi-component polyester textile fiber is elasterell-p. The remaining yarns provide yarns other than non-spandex, non-corespun elastomeric yarns.
The non-spandex, non-corespun elastomeric yarns are woven into the woven fabric 200 in quantities sufficient to allow the field portion 12 to stretch in both the widthwise direction 54 and the lengthwise direction 56. The fabric 200 stretches in the widthwise direction so that the left 14 edge and right 16 edge extend along the elastomeric warp yarns 50′ toward dashed lines 58a′ and 58b′, respectively. The fabric 200 also stretches in the lengthwise direction 56 so that the top edge 18 and bottom edge 20 extend along the elastomeric fill yarns 52 toward dashed lines 58a and 58b, respectively. In one embodiment, the non-spandex, non-corespun elastomeric yarns include between about 1% to about 100% by weight of the woven fabric 200. In another embodiment, the non-spandex, non-corespun elastomeric yarns include between about 10% to about 80% by weight of the woven fabric 200. In yet another embodiment, the non-spandex, non-corespun elastomeric yarns include between about 15% to about 60% by weight of the woven fabric 200.
The woven fabric 200, in one embodiment, is stretchable in both the widthwise direction 54 and lengthwise direction 56 in a range of about 2% to about 50% of its unstretched length. In another embodiment, the woven fabric 200 is stretchable in both the widthwise direction 54 and lengthwise direction in a range of about 5% to about 25% of its unstretched length.
Additionally, the woven fabric 200 may be used to form a contoured bed sheet similar in construction to contoured bed sheet 68 illustrated in
While
The bed sheet 68 may have additional finishing alterations such as, for example, providing a hem or binding of various types around the outer edge.
In use, the woven fabrics 10, 100, 200 are formed into contoured bed sheet 68 to stretch along the top surface and over the sides of a mattress so as to grip the underside of the mattress without requiring elastic binding along the hem of the contoured bed sheet 68. The resulting contoured bed sheet 68 provides the benefits of woven sheets, such as desirable durability and hand along with acceptable laundry processing behavior and with the benefits of knitted sheets such as the ability to fit different sized mattresses and to stay bound to the corners of mattresses as they are raised and lowered on adjustable beds, but without the discoloration and/or chemistry drawbacks of prior proposals to render woven sheets stretchable.
By virtue of the foregoing, there is thus provided a contoured bed sheet with the advantages of both woven and knitted sheets, but without some of the drawbacks.
While the present invention has been illustrated by the description of an embodiment thereof, and while the embodiment has been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. An important aspect of the invention is that the woven fabrics and contoured bed sheet consist of a one-ply woven fabric, which does not include woven fabrics having additional plies. Further, it is understood that while the contoured bed sheet no longer requires the use of an elastic binding or hem to grip the underside of a mattress, an elastic binding or hem may be added to the contoured bed sheet of the invention. In addition, consisting essentially of, as used herein, is understood not to exclude additional handling or finishing treatments as may be desirable for the woven fabrics and or contoured bed sheets of the invention such as, for example, dying and bleaching treatments, or other treatments that may affect the appearance, stretch characteristics, durability, or hand of the woven fabrics and or contoured bed sheet. The invention in its broader aspects is, therefore, not limited to the specific detail, representative apparatus and methods and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the general inventive concept.
