US20080263768A1

US20080263768A1 - Bias cut fitted sheets

Info

Publication number: US20080263768A1
Application number: US11/742,284
Authority: US
Inventors: Sri Hari Prasadh Balasundharam
Original assignee: Sharadha Terry Products Ltd
Current assignee: Sharadha Terry Products Ltd
Priority date: 2007-04-30
Filing date: 2007-04-30
Publication date: 2008-10-30

Abstract

A fitted sheet that fits on mattresses of various thicknesses by having a construction that is elastic along the side edges of the sheet. The sheet includes an insert extending from one side portion of the sheet to another. The insert is placed such that the side edge of the fitted sheet is formed by the insert. This allows the fitted sheet to fit more elastically over the corner of a mattress.

Description

FIELD OF THE INVENTION

The invention relates to bed linens, and more particularly to fitted bed sheets configured to accommodate mattresses of varying thicknesses.

BACKGROUND OF THE INVENTION

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 FIGS. 1 a and 1 b. Sheet 100 is made of a single piece of textile material. The piece of textile material is formed from a rectangular piece with four identical sections cutout from each corner, as shown in FIG. 1 a. The resultant shape includes a central section which serves as the top panel 102 of the fitted sheet 100. The top panel 102 is surrounded by four extensions which serve as side panels 104 of the sheet 100. Each side panel has two ends 106 and one bottom edge 107. Fitted sheet 100 is constructed by attaching end 106 to an adjacent end 106 using a hem 108. Thus, a corner fold is formed where the ends meet. The hem 108 is usually very strong, such as a 5-thread over-lock stitch, so that the hem will not fail quickly. A result of the described construction is a fitted sheet 100 with the form of a box having an open side defined by the four bottom edges 107. The constructed sheet is shown in FIG. 1 b. Frequently elastic is included along the bottom edges 107.
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.

SUMMARY OF THE INVENTION

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.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and features of the invention will become more apparent by referring to the drawings, in which:

FIG. 1 a illustrates the material construction of a prior art fitted sheet;

FIG. 1 b shows an enlarged corner fold construction of the sheet of FIG. 1 a;

FIG. 2 is a perspective view of part of the fitted sheet of the invention including an insert;

FIG. 3 illustrates a bias direction within a textile material;

FIG. 4 illustrates a possible orientation of the bias direction within the insert shown in FIG. 2;

FIG. 5 is a perspective view of the invention including an alternative insert;

FIG. 6 is a perspective view of the invention including another alternative insert;

FIG. 7 a is a plan view of the material construction of a fitted sheet in accordance with the present invention; and

FIG. 7 b shows the contrast between the bias directions of a body of the sheet and an insert.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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 FIG. 2. The fitted sheet 1 includes a top panel 10 and four side panels 12 attached thereto. Four edges 14 of the top panel are included at the locations where the top panel 10 meets the side panels 12. Four corner folds 16 are also included along the corners of the sheet. Sheet corners 18 are formed at the junction where the top panel 10 and the corner folds 16 meet. This construction forms a box shape that is open at the bottom. The bottom edge 15 may include elastic thereon.
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. FIG. 2 shows a fitted sheet 1 of the invention with a triangular insert 60 included at the corner fold 16 of the fitted sheet 1. FIG. 2 only shows a single insert 50 included in the fitted sheet 1. However, for simplicity, the fitted sheet 1 shown in FIG. 2 will be described in the following as including four triangular inserts 60. A complete plan view of sheet 1 including all four triangular inserts 60 is shown in FIG. 7 a. Further, a bias direction of the material in both the body 30 and the inserts 50 is shown in FIG. 7 b. The term “triangular” has its ordinary meaning which includes shapes that are of, or related to, a triangle, e.g. a boomerang has a triangular shape, without being a triangle.
Sheet 1, shown in FIG. 2 is formed of a body 30 and four inserts 50, specifically triangular inserts 60. The body 30 includes a top panel 32 and four side panels 34. In the described embodiment the side panels 34 are integrally formed with the top panel 32. However, they may be formed as separate pieces. Each side panel 34 includes a panel bottom 39 and two panel ends 37. If sheet 1 is rectangular, the body 30 may include two opposite long side panels 36. Triangular inserts 60 may be attached between the ends 37 of adjacent side panels 34. Each insert side edge 52 of the triangular insert 60 can be stitched to a panel end 37. The stitching forms a hem 80 at each intersection of the side panels 34 and the insert section 50. Preferably, the triangular insert 60 is shaped and disposed between the side panels 34 such that the insert bottom edge 54 is flush with the panel bottom 39. Accordingly, a continuous bottom opening 15 is formed around the fitted sheet 1. An apex 64 of the triangular insert 60 may be positioned to correlate with the top corner 18 of fitted sheet 1.
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 FIG. 3. The angle is typically approximately 45 degrees. In the bias direction, the textile material may stretch about 20% its normal size.
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 FIG. 4, the material within the insert 50 may be oriented such that the bias direction 55 is substantially aligned with the corner fold 16 of the sheet 1. For maximum stretch along the corner fold 16, the bias direction 55 of the material may be parallel, or almost parallel, to the corner fold 16. Alternatively, a large quantity of stretch can be achieved within a 5 degree angle of the corner fold. Additionally, a less strict alignment of the bias direction 55, say within a 30 degree or greater angle, of the corner fold 16 will result in less stretch.
Another embodiment of the fitted sheet of the invention is shown in FIG. 5. The illustrated fitted sheet 1 includes an insert 50 that is an elongated insert 70. The elongate insert extends from one side of the fitted sheet to a second side and continues to a third side. Thus, the elongate insert 70 shown makes up one entire side 12 of the fitted sheet 1 and includes two of the corner folds 16. One embodiment may include two elongate inserts 70 at opposite ends of the fitted sheet. In this embodiment, the body 30 of the fitted sheet 1 only includes two opposite side panels 34. Each insert side edge 52 is stitched to an end 37 of a side panel 34 with a hem 80. Additionally, the insert top edge 72 is stitched directly to the top panel 32 of the body 30 along an edge 14 of the fitted sheet 1.
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 FIGS. 2, 4 and 5 have the insert side edge 52 angled with respect to the corner fold 16 of the fitted sheet. This provides an advantage that the hem 80 formed along the interconnection between the insert 50 and the body 30 is not aligned with the desired stretching direction of the fitted sheet 1. For example, since it is desirable to stretch fitted sheet 1 lengthwise along corner fold 16, angling insert side edges 52 with respect to side edge 16 lessens any impact hem 80 has on the stretching direction, if any. The hem used to attach the insert 50 to the base section 30 may be a bias hem. Although the angled insert side edges 52 are advantageous, the invention may be formed with an insert of any shape, such as that shown in FIG. 6.
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.

Claims

1. A fitted sheet made of at least one textile material comprising:

a body having a concave shape and including:

a top panel with four edges, and four side panels with at least two ends, wherein a respective side panel is adjacent one of the four edges; and

at least one triangular insert including two insert side edges and a bottom edge, wherein each of the insert side edges is attached to a respective end of two adjacent side panels;

wherein a corner fold of the fitted sheet extends from the insert bottom edge to a point on the body.

2. The fitted sheet of claim 1, wherein the at least one triangular insert is four triangular inserts.

3. The fitted sheet of claim 1, wherein the body includes side folds where the top panel meets the side panels, and

an apex of the triangular insert is positioned where the corner fold meets the side folds.

4. The fitted sheet of claim 1, wherein the sheet is elongated, the top panel is rectangular and two of the side panels are short, the short side panels being opposite one another.

5. The fitted sheet of claim 4, wherein the at least one triangular insert is two triangular inserts, the two triangular inserts each being attached to an end of one of the short side panels.

6. The fitted sheet of claim 1, wherein the textile material of the at least one triangular insert includes a bias direction angled with respect to both the direction of the warp and the direction of the weft of the textile material.

7. The fitted sheet of claim 6, wherein the bias direction of the at least one triangular insert is substantially aligned with the corner fold that extends from the bottom edge of the triangular insert to the point on the body.

8. The fitted sheet of claim 6, wherein the bias direction of the at least one triangular insert is within 30 degrees of the corner fold that extends from the bottom edge of the triangular insert to the point on the body.

9. A fitted sheet made of a textile material comprising:

a body having a concave shape and including:

a top panel with four edges, and at least one side panel having at least two ends, wherein the side panel is adjacent at least one of the four edges; and

at least one insert including two insert side edges and a bottom edge, wherein a first one of the insert side edges is connected to one of side panel ends and a second one of the insert side edges is connected to an other of the side panel ends;

wherein a corner fold of the fitted sheet extends from the bottom edge to a point on the body of the fitted sheet, and the insert is made of a textile material having a weft and a warp that are orientated at an angle with respect to the corner fold.

10. The fitted sheet of claim 9 wherein the at least one insert is two inserts,

the at least one side panel is two side panels,

each insert is connected to both of the side panels along its respective insert side edges, and

two corner folds of the fitted sheet extend from the bottom edge of each insert to separate points on the body of the fitted sheet.

11. The fitted sheet of claim 9 wherein each insert includes a top edge adjacent the top panel of the body.

12. The fitted sheet of claim 10 wherein the two side panels are longer than the two inserts.

13. The fitted sheet of claim 9 wherein the textile material of the insert section includes a bias direction angled between the direction of the warp and the direction of the weft of the textile material.

14. The fitted sheet of claim 13 wherein the bias direction of the insert section is substantially aligned with the corner fold.

15. The fitted sheet of claim 13 wherein the bias direction of the insert section is within 30 degrees of the corner fold that extends from the bottom to the body of the fitted sheet.