The invention relates to bed linens, and more particularly to fitted bed sheets configured to accommodate mattresses of varying thicknesses.
Fitted sheets are advantageous for the bottom sheet of a set because they hold themselves on the mattress. A fitted sheet is less likely to separate from the mattress than a flat sheet that is merely tucked under the edges of the mattress. Accordingly, the fitted sheet is less likely to leave a user lying directly on the mattress after a restless night's sleep. The advantage of a fitted sheet comes from its shape, which is convex and corresponds to the mattress it is designed to cover. Unlike a flat sheet, a fitted sheet is shaped like an open ended box. It has a top portion and four side portions that are each connected to the top portion and two neighboring side portions. Four corners are formed at each of the junctions where the top portion and two side portions meet. Advantageously, the sides fit snugly around the sides of the mattress.
To further secure the fitted sheet to the mattress, many fitted sheets include elastic around at least a part of the opening. The elastic assures that the opening of the fitted sheet is smaller than the mattress when in a relaxed state. Thus, the sides of the fitted sheet wrap around and slightly under the mattress. This construction provides pockets in the ends of the fitted sheet which encircle the ends of the mattress. The elastic must be stretched to remove the sheet from the mattress.
A typical construction of a fitted sheet is shown in
The pockets formed in the ends of the fitted sheet should fit snugly around the mattress; superfluous fabric is considered unattractive. However, mattresses come in a variety of thicknesses and therefore a fitted sheet that can adapt to fit mattresses of various thicknesses is desirable. Accordingly, even if the fitted sheet is marketed for a mattress of a specific thickness, it is desirable for the fitted sheet to be flexible to adjust for thick mattress pads, feather beds or other accessories. If the fitted sheet is too tight it is difficult to put on the mattress. Pulling the corner folds of the fitted sheet around the corners of the mattress can be very difficult. Further, if the sheet fits too tightly it is more likely to pop off the mattress at the corners, leaving the user lying directly on the mattress. Thus, it is advantageous for a fitted sheet to be elastic, especially at the corners, such that it can adapt to mattresses of various thickness.
Many textile materials are somewhat elastic, and articles made from textile materials have a certain degree of elasticity. This is advantageous for fitting the sheet onto the mattress. However, the prior art construction has limitations and the elasticity of the material is not fully utilized. The strength of hem 108 along the corner folds at ends 106 prevents the corner fold from having any degree of elasticity. In order to fit over the corners of the mattress, elasticity is most important along the corner fold of the sheet. Thus, the prior art construction of fitted sheets produces sheets that lack elasticity in the area where it is needed most.
Thus, a fitted sheet without a hem located along the corner fold of the sheet is desirable. Further, a fitted sheet which has increased elasticity along the corner folds of the sheet is also desirable.
In one aspect of the invention, a fitted sheet is configured to fit snugly over mattresses of various thicknesses by having a construction that is elastic along the corner folds of the sheet. The sheet includes a triangular insert extending from one side panel of the sheet to another. The triangular insert includes two insert side edges and a bottom edge. The triangular insert is disposed between two adjacent side panels by attaching each insert side edge to an end of the side panel. The insert is placed such that the corner fold of the fitted sheet extends from the bottom edge of the insert to a point on the body of the sheet. Accordingly, the fitted sheet does not include an inelastic hem along each corner fold. Thus, the fitted sheet fits more elastically over the corners of a mattress by utilizing the elastic properties of the fabric insert.
In another exemplary construction, the fitted sheet may include a body having a top panel that serves as a top portion of the sheet and four side panels extending downward therefrom. Four triangular inserts can be included, each attached between a neighboring pair of side panels. The apex of the triangular insert is positioned next a point on the body of the fitted sheet, optionally where the top panel and the side panels all meet each other. It is not a requirement of the invention that the fitted sheet include four triangular inserts. A single insert can be used to provide one flexible corner fold. Such a configuration is still an advantage over the prior art because the flexible corner fold can be placed over the mattress after the other corner folds.
Another construction of the fitted sheet may include a body of the sheet with a top panel and two side panels. The two side panels are directly opposite one another. An elongated insert may be included extending from one side panel of the sheet to the opposite side panel. This elongated insert extends over an entire side of the sheet and includes two corner folds. If the sheet is rectangular, the elongated inserts may be included along the short sides of the sheet. One elongated insert may be used by itself, if desired.
The fitted sheet is made of a textile material which may be woven or knit fabric. The textile material includes some natural flexibility and may be flexible along both the weft and the warp. A bias direction of the material is at an angle between the direction of the weft and the warp. Specifically, the bias direction may be at 45 degrees between the weft and the warp. The elasticity of the textile material is greatest along the bias direction. To utilize this elasticity, the textile material may be oriented within the insert to take advantage of the elasticity of the bias direction. To provide maximum elasticity, the bias direction may be aligned or substantially aligned with the corner folds of the sheet, for example, within 5 degrees. Alternatively, the bias direction may be less strictly aligned with the corner fold, such as within 30 degrees.
These and other objects and features of the invention will become more apparent by referring to the drawings, in which:
a illustrates the material construction of a prior art fitted sheet;
b shows an enlarged corner fold construction of the sheet of
a is a plan view of the material construction of a fitted sheet in accordance with the present invention; and
b shows the contrast between the bias directions of a body of the sheet and an insert.
The fitted sheet embodying the present invention includes several geometric features that are consistent throughout the different embodiments of the invention. These features are labeled in
The fitted sheet 1 may be rectangular in shape. Accordingly, sheet 1 can include two long sides 22 and two short sides 24. Likewise, the top panel 10 of sheet 1 can include two long edges 26 and two short edges 28.
Sheet 1 includes at least one insert 50. A corner fold 16 extends from a bottom edge 54 of the insert 50 to the body 30 of the sheet.
Sheet 1, shown in
Fitted sheet 1 is made of a textile material which may be woven or knit fabric. The insert 50 and the body 30 may be formed of the same textile material or of different textile materials. The textile material can have a first elasticity in the direction of the warp and a second elasticity in the direction of the weft. However, the maximum elasticity of the material is along the bias direction 55 which is at an angle between the directions of the warp and the weft. The bias direction is illustrated in
To utilize the elasticity of the textile material or fabric in the bias direction 55, the material can be oriented within the insert 50 to take advantage of the stretch of the bias direction. As shown in
Another embodiment of the fitted sheet of the invention is shown in
If the fitted sheet 1 is rectangular, the elongate inserts 70 may be disposed either along the long side 22 or the short side 24. In the illustrated embodiment, the elongate insert 70 is disposed along the short side 24. Accordingly, the insert top 72 is attached to body 30 along the short top edge 28.
The embodiments shown in
Thus, while there have been shown, described, and pointed out fundamental novel features of the invention as applied to several embodiments, it will be understood that various omissions, substitutions, and changes in the form and details of the illustrated embodiments, and in their operation, may be made by those skilled in the art without departing from the spirit and scope of the invention. Substitutions of elements from one embodiment to another are also fully intended and contemplated. The invention is defined solely with regard to the claims appended hereto, and equivalents of the recitations therein.