Abstract:
This invention relates to flat bedding top sheets having releasable corner fasteners adapted to releasably secure sheet to an underlying mattress by having male elements placed on one side panel brought into alignment and contact with female elements located on opposite corresponding side panels to form corners. Specifically, the bed sheet of the present invention is a fitted flat sheet having a cutout portions at both of its bottom corners that permit, with the aid of separable fasteners located at the cutout portions, to convert the sheet from a planar configuration to a configuration comprising two pockets adapted to retain the sheet on the mattress. The top sheets of the present invention do not require elastic strips around the corners of the sheets to secure the sheet to the mattress.

Description:
CLAIM OF PRIORITY 
       [0001]    The present invention claims the priority of the U.S. Provisional Patent Application 61/270,146, filed on Jul. 6, 2009. The contents of the aforementioned applications are fully incorporated herein by reference. 
     
    
     FIELD OF INVENTION 
       [0002]    This invention relates to bedding top sheets, and more particularly, to bedding top sheets having releasable fasteners. One aspect of the invention relates to flat fitted sheets having releasable corner fasteners to create pockets which fit around the corners of a mattress to fit snugly over mattresses of various thicknesses wherein the sheets do not have an elastic strip sewn around the bottom corners of the sheet. 
       BACKGROUND OF THE INVENTION 
       [0003]    Numerous problems have been encountered in both the manufacture and use of conventional fitted sheets. Conventional fitted sheets typically employ various combinations of seams and/or elastic bands at the corners. The contoured corners thus formed are intended to fit snugly over the corners of an underlying mattress whenever the sheet is in use. 
         [0004]    Bed linen manufacturers generally produce conventional fitted sheets having a single set of dimensions for each standard bed size, difficulties frequently arise when the sheets are used by the consumer. When the conventional fitted sheets are placed over a relatively thinner or smaller mattress, the corners may not fit snugly, causing the sheet to bunch or wrinkle across the bed surface, making the bed uncomfortable and unattractive. Conventional fitted sheets are used with relatively thicker or larger mattresses, it is often difficult to stretch the last corner over the mattress, and ripping or tearing of the corner construction may occur, particularly after repeated use and laundering. In addition, conventional fitted sheets require the end user to lift at least one corner of the mattress to place the fitted sheet on the mattress. 
         [0005]    Contoured or fitted sheets overcome some of the problems associated with flat bedsheets by sewing an elastic strip around the bottom corners of the sheet to create pockets which fit around the four corners of the mattress. The sheet is tucked under the mattress for three corners than on the forth corner, the mattress is lifted up to allow the pocket of the sheet to be slipped over the corner of the mattress. Principle disadvantages of conventional fitted sheets are they often wear out at the pockets, are bulky to store, wash, and handle and that the end user must lift up the mattress to allow the pocket of the sheet to be slipped over the corner of the mattress. 
         [0006]    U.S. Pat. No. 5,173,976 to Jubinville discloses a mattress cover/fitted bedding top sheet which consists of a substantially rectangular blank of textile material with opposed sides and opposed ends. A pair of generally triangular pieces are cut out of the opposed sides adjacent the ends. Each of the triangular cut outs has a pair of opposed sides, an apex directed inwardly on the textile material and a base coincident with one of the sides of the textile material. The sides of the triangular cut outs are joined to form a biased side seam such that, when placed on a mattress, textile material is drawn under the end of the mattress. 
         [0007]    U.S. Pat. No. 6,983,500 to Wootten discloses a fitted cornerless bedclothing item such as a sheet, mattress pad, anti-allergy cover, blanket or coverlet includes a top portion, side portions and end portions, and elastic segments stitched to edges of respective side and end portions. One or more elastic bindings are provided at lower edges of the side and end portions to cause the tops of the elastic segments to be positioned below the respective upper corners of the mattress on which the bedclothing item is mounted, such that no ears or pockets are formed when the bedclothing item is mounted on mattresses of at least two different sizes and/or thicknesses. The elastic segments are made of knitted or woven elastic filaments, such as SPANDEX® fabric, and can be shaped to have a straight lower edge and a curved upper edge, the curved upper edge advantageously approximating an end of an ellipse. 
         [0008]    U.S. Pat. No. 4,245,365 to Large, et al. discloses a fitted top contour sheet having an end pocket receiving the rear of a mattress and pairs of hooks and eyes to secure the bottom of the pocket to the mattress. 
         [0009]    U.S. Pat. No. 4,912,790 to Macdonald discloses a fitted bedding top sheet includes a substantially rectangular main body portion of substantially the same dimensions as a selected mattress. Side portions extend from the sides of the main body portion and terminate in longitudinal edges. End portions extend from the ends of the main body portion and terminate in end edges. Substantially vertical corner seams join the side portions to the adjacent end portions, each seam extending from an inner end at a corner of said main body portion to an outer end at the junction of a longitudinal edge and an end edge. The side edges and end edges are thereby joined together to define a perimeter. There is elastic in at least a portion of the perimeter, to permit the sheet to fit snuggly around a mattress. Macdonald discloses that the vertical corner seams are at least partly elasticized. 
         [0010]    U.S. Pat. No. 5,165,128 to Honig discloses a fitted bedding top sheet of a generally rectangular blank of fabric material having two bottom corners, each corner cut away by three curved lines to form a junction having an angle of substantially 90 degrees, to each of which a band of stretchable material is sewn, in stretched condition, to the outside edge of the cut corners and along the entire edge portion of the bottom of the blank, which cut corners are then joined by stitching at each corner and bottom edges thereof, thereby forming two expandable pockets for engaging the bottom corners and bottom portion of a mattress. 
         [0011]    Other patents disclosing fitted bedding top sheets, or variations thereof, include U.S. Pat. No. 2,598,141 to Simpson, U.S. Pat. No. 2,605,483 to Ridenhour, U.S. Pat. No. 3,013,283 to Steffinich, U.S. Pat. No. 3,638,252 to Palenske, U.S. Pat. No. 3,832,743 to Smith, U.S. Pat. No. 4,045,832 to DiForti, U.S. Pat. No. 4,095,300 to Ruben, U.S. Pat. No. 4,384,380 to Glaha, et al., U.S. Pat. No. 4,964,184 to Lewis, U.S. Pat. No. 5,029,353 to Kimball et al., U.S. Pat. No. 5,084,929 to Staudinger, U.S. Pat. No. 5,729,847 to Allardice, U.S. Pat. No. 6,041,456 to Pharr, U.S. Pat. No. 7,293,306 to Hermanczuk, U.S. Pat. No. 7,380,297 to Bauer, U.S. Patent Publication No. 2004/00255381 to Generalovich II, U.S. Patent Publication No. 2007/0151028 to Bauer, U.S. Patent Publication No. 2009/0044337 to McKee, and non-US Patent document GB2292075A to Wong. 
         [0012]    The use of stitched darts and/or elastic to form the fitted corners as disclosed in the foregoing patents requires the use of manufacturing procedures that are more complicated and expensive than would be needed if such stitching were not required. Furthermore, sheets made in such manner cannot be laid out flat, and are therefore more difficult to fold, package and store. 
         [0013]    The use of Velcro fasteners with sheets is also disclosed in U.S. Pat. Nos. 3,832,743 and 4,241,466. These patents disclose the use of releasable fasteners for separably fastening one edge of a bedding top sheet to a side or end panel of an underlying bottom sheet to prevent the bedding top sheet from coming loose or untucked during use. 
       SUMMARY OF THE INVENTION 
       [0014]    An object of the present invention is to provide a bed sheet comprising a flat one piece top sheet having a top panel, at least three side panels, and at least three bottom panels; the flat one piece top sheet having the two portions removed to eliminates the extra overage at the corner of the bed; a male element of a releasable corner fastener being placed on the edge of at least one side panel; a female element of a releasable corner fastener being placed on the edge of at least one side panel; the male element and female element forming a corner when the male element is placed on the edge of side panel which corresponds to the female element placed on a corresponding edge of a side panel are joined together; the at least three bottom panels having 90 degree edges. 
         [0015]    According to the present invention, bedding top sheets are provided that are adapted by means of adjustable, releasable fasteners to be quickly installed over or removed from mattresses without requiring the end user to lift up the mattress to allow the corners of the sheet to be placed over the mattress. The bedding top sheets of the invention are designed and constructed so as to be easily manufactured, folded and stored. 
         [0016]    According to one embodiment of the invention, a fitted flat sheet is provided having releasable corner fasteners which do not have an elastic strip sewn around the bottom corners of the sheet. 
         [0017]    According to another embodiment of the invention, a fitted sheet is provided that comprises corners formed by releasable corner fasteners placed on corresponding side and bottom panels of the sheet. 
         [0018]    According to a preferred embodiment of the present invention, the releasable corner fasteners have a male element and a corresponding female element. 
         [0019]    This invention relates to a fitted bedding top sheet that has cut out bottom portions each of which portions are oriented at 90 degree angles to be folded about the bottom corners of a mattress wherein the corners are formed by male elements of the releasable corner fastener placed on one side panel being in contact with female elements placed on an opposite corresponding side panel. 
         [0020]    It is an object of the present invention to provide for an improved fitted sheet. 
         [0021]    Another object is to provide for such a sheet which has bottom corner cutout portion with a male element of a releasable corner fastener place on one side panel which is aligned and connected with a female element of a releasable corner fastener placed on the corresponding opposite side panel permitting a sheet to be firmly secured to a corner of the mattress, whereby the sheet can be converted from a first planar configuration to a second, pocketed configuration. 
         [0022]    It is another object of the present invention to provide for an improved fitted sheet which can be easily and quickly secured to a corner of the mattress. 
         [0023]    It is another object of the present invention to provide for an improved fitted sheet which will be firmly secured to a corner of the mattress so it will not become dislodged during use. 
         [0024]    The present invention is a sheet construction that engages a mattress securely around the corners of a mattress without requiring elastic strips at the corners of the mattress. The sheet construction includes a main panel having mattress-encompassing side and bottom panels at corresponding ends. Corners are formed by two cooperating side panels that overlap and are detachably secured together via releaseable corner fasteners having corresponding male and female elements. 
         [0025]    It is an object of the present invention that the sheets have releaseable corner fasteners that include, but are not limited to, buttons, snaps, zippers, Velcro, hooks, magnetic snaps and oriental frogs, all having corresponding male and female elements. 
         [0026]    A further objective is to provide a sheet which is easy to wash, store, and handle. 
         [0027]    It is another object of the present invention to provide bedding top sheets which facilitate the covering of a mattress without the use of “Hospital style corners” or “Military style corners”. 
         [0028]    Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0029]      FIG. 1  is a top view of one embodiment of a bed sheet of the present invention having releasable corner fasteners in a flat position before it is folded about a mattress having 90 degree angles along the edges of the bottom panels of the sheet. 
           [0030]      FIG. 2  is a top view of an embodiment of a bed sheet as depicted in  FIG. 1  showing the direction in which the corresponding side panels will be folded to form a corner around the a mattress. 
           [0031]      FIG. 3  is a top view of one embodiment of a bed sheet of the present invention in a flat position before it is folded about a mattress having 45 degree angles along the edges of the bottom panels of the sheet. 
           [0032]      FIG. 4  is a top view of an embodiment of a bed sheet as depicted in  FIG. 3  showing the direction in which the corresponding side panels will be folded to form a corner around the a mattress. 
           [0033]      FIG. 5A  is a side view of one of the bottom corners of the sheet after it is folded about a mattress showing corresponding side panels secured by a releasable fastener in the form of a button. 
           [0034]      FIG. 5B  is a side view of one of the bottom corners of the sheet after it is folded about a mattress showing corresponding side panels secured by a releasable fastener in the form of a zipper. 
           [0035]      FIG. 5C  is a side view of one of the bottom corners of the sheet after it is folded about a mattress showing corresponding side panels secured by a releasable fastener in the form of a looped button. 
           [0036]      FIG. 5D  is a side view of one of the bottom corners of the sheet after it is folded about a mattress showing corresponding side panels secured by a releasable fastener in the form of conventional snaps. 
           [0037]      FIG. 5E  is a side view of one of the bottom corners of the sheet after it is folded about a mattress showing corresponding side panels secured by a releasable fastener in the form of oriental frogs. 
           [0038]      FIG. 5F  is a side view of one of the bottom corners of the sheet after it is folded about a mattress showing corresponding side panels secured by a releasable fastener in the form of a magnetic snaps. 
           [0039]      FIG. 5G  is a side view of one of the bottom corners of the sheet after it is folded about a mattress showing corresponding side panels secured by a releasable fastener in the form of a fabric ties. 
           [0040]      FIG. 5H  is a side view of one of the bottom corners of the sheet after it is folded about a mattress showing corresponding side panels secured by a releasable fastener in the form of a lacing/ribbon. 
           [0041]      FIG. 5I  is a side view of one of the bottom corners of the sheet after it is folded about a mattress showing corresponding side panels secured by a releasable fastener in the form of hooks. 
           [0042]      FIG. 5J  is a side view of one of the bottom corners of the sheet after it is folded about a mattress showing corresponding side panels secured by a releasable fastener in the form of a velcro. 
           [0043]      FIG. 6  is a side view of one of the bottom corners of the sheet after it is folded about a mattress showing corresponding side panels secured by a releasable fastener in the form of a button with an untucked bottom panel. 
       
    
    
       [0044]    Like numbers are used to designate like parts in all figures of the drawings. In  FIGS. 1-4 , the length direction of the sheet is designated with an arrow identified by the letter L and the width direction of the sheet is designated with an arrow identified by the letter W. The dashed lines shown in  FIGS. 1-4  are fold lines showing where the sheets of the invention would drape over the edges of an underlying mattress (not shown). In each of  FIGS. 1-4 , the length and width of the subject sheets as measured between the fold lines at the four corners should generally correspond to the dimensions of the top surface of the standard mattress size with which the sheet is to be used. The distance between the fold lines and the respective edges of the sheet should generally correspond to the thickness dimension of the mattress with which the sheet is to be used. 
       DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0045]    The invention is further described and explained in relation to  FIGS. 1-6  below. For the fitted sheets of the present invention, the releasable corner fasteners of the invention are desirably utilized on at least two corners, preferably the two bottom corners. It is desired to make a bedding top sheet that will remain untucked at the head of a bed but will fasten snugly over the bottom sheet and mattress at the foot of a bed, the releasable corner fasteners of the invention are desirably used on only the bottom corners. 
         [0046]    It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement of parts herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and drawings. 
         [0047]    For purposes of the present invention, the bed sheets disclosed herein are understood to be manufactured primarily from textile materials. The fitted bedding top sheet of the present invention may be formed of any conventional sheet fabric, woven or knitted. The sheets of the present invention made be constructed of cotton, polyester, linen, rayon, or a blend thereof. 
         [0048]    The bedding top sheet of the present invention pertains to all top sheets, including but not limited to blankets, coverlets, quilts, duvets, mattress pads, bed spreads and comforters. 
         [0049]    The bedding top sheets of the present invention facilitate the covering of a mattress without the use of “Hospital style corners” or “Military style corners”. 
         [0050]    As depicted in  FIGS. 1 and 2 , one embodiment of the bed sheet  10  of the present invention provides a flat one piece top sheet appears as two intersecting rectangular shapes comprising top panel  20 , side panels ( 30 ,  40 ,  70 ), bottom panels ( 50 ,  60 ,  80 ), where sections  90  and  100  are eliminated to eliminates the extra overage at the corner of the bed, giving it much neater lines and reduces chances of tripping when walking around the bed. As depicted in  FIG. 1 , a male element  110  of a releasable corner fastener is placed on the edge of side panel  30  which corresponds to female element  130  of a releasable corner fastener placed on the edge of side panel  70  which form a corner when male element  110  is joined to corresponding female element  130 . Similarly, as depicted in  FIG. 1 , a male element  120  of a releasable corner fastener is placed on the edge of side panel  40  which corresponds to female element  140  of a releasable corner fastener placed on the edge of side panel  70  which form a corner when male element  120  is joined to corresponding female element  140 . As seen in  FIGS. 1 and 2 , bottom panels  50 ,  60  and  80  have 90 degree edges. 
         [0051]    Male elements ( 110 , 120 ) and female elements ( 130 ,  140 ) of a releasable corner fastener may be of various types including, but not limited to, buttons, snaps, zippers, Velcro, hooks, magnetic snaps, and oriental frogs. 
         [0052]    The bottom panels of the bed sheets ( 50 ,  60 ,  80 ) extend past the depth of the mattress and may be either tucked in or left out to hang loosely like a bed skirt if desired. 
         [0053]    As depicted in  FIGS. 3 and 4 , another embodiment of the bed sheet  10  of the present invention provides a flat one piece sheet appears as two intersecting rectangular shapes comprising side panels ( 30 ,  40 ,  70 ), bottom panels ( 50 ,  60 ,  80 ), where sections  90  and  100  are eliminated to eliminates the extra overage at the corner of the bed, giving it much neater lines and reduces chances of tripping when walking around the bed. As depicted in  FIG. 1 , a male element  110  of a releasable corner fastener is placed on the edge of side panel  30  which corresponds to female element  130  of a releasable corner fastener placed on the edge of side panel  70  which form a corner when male element  110  is joined to corresponding female element  130 . Similarly, as depicted in  FIG. 1 , a male element  120  of a releasable corner fastener is placed on the edge of side panel  40  which corresponds to female element  140  of a releasable corner fastener placed on the edge of side panel  70  which form a corner when male element  120  is joined to corresponding female element  140 . As seen in  FIGS. 1 and 2 , bottom panels  50 ,  60  and  80  have 45 degree edges. As seen in  FIGS. 3 and 4 , the flat one piece sheet is cut on a 45 degree angles bilaterally on the sides and foot of the bed to reduce overlapping and bunching making it easier to make a bed. The top flat sheet appears as two intersecting rectangular shapes but angled  45  at the foot/side of the bed to reduce over lapping or bunching. 
         [0054]    Male elements ( 110 , 120 ) and female elements ( 130 ,  140 ) of a releasable corner fastener may be of various types including, but not limited to, buttons, snaps, zippers, Velcro, hooks, magnetic snaps, and oriental frogs. 
         [0055]    The bottom panels of the bed sheets ( 50 ,  60 ,  80 ) extend past the depth of the mattress and may be either tucked in or left out to hang loosely like a bed skirt if desired. 
         [0056]    The sheet  10  of the present invention has a top panel  20  and bottom panels  50 ,  60 , and  80  with side panels  30 ,  40 , and  70  extending between the top and the bottom of the sheet. Each sheet has a bottom panels  50 ,  60 , and  80  which will allow the sheet to be tucked under a mattress. At each of the bottom corners of the sheet  10 , cutout portions  90 ,  100  are provided. 
         [0057]    Side panels  30 ,  70  have complimentary fasteners  110 ,  130  disposed therealong. When the side panels  30 ,  70  are folded about the corner of the mattress, the fasteners  110 ,  130  will be secured together in order for the sheet to be secured to the mattress. It should be noted that while the fasteners  110 ,  130  are shown as buttons, any conventional fastener such as, but not limited to, hook and loop fasteners, snap fasteners, zipper, Velcro, magnetic snaps, oriental frogs could be used, as long as the fastener will securely hold the bottom portion of the sheet onto the bottom of the mattress. In addition, the number of fasteners on the side panels is not material. For example, three fasteners are shown in  FIG. 1-4  and five fasteners are shown in  FIGS. 5D and 5F . 
         [0058]    Side panels  40 ,  70  have complimentary fasteners  120 ,  140  disposed therealong. When the side panels  40 ,  70  are folded about the corner of the mattress, the fasteners  120 ,  140  will be secured together in order for the sheet to be secured to the mattress. It should be noted that while the fasteners  120 ,  140  are shown as buttons, any conventional fastener such as, but not limited to, hook and loop fasteners, snap fasteners, zipper, Velcro, magnetic snaps, oriental frogs could be used, as long as the fastener will securely hold the bottom portion of the sheet onto the bottom of the mattress. In addition, the number of fasteners on the side panels is not material. For example, three fasteners are shown in  FIG. 1-4  and five fasteners are shown in  FIGS. 5D and 5F . 
         [0059]      FIGS. 5A to 5J  and  FIG. 6  shows the sheet in its final folded position about the corner of the mattress. In  FIGS. 5A to 5J , bottom panels  50 ,  60 ,  80  have been folded under the mattress and extends between the mattress and the box spring. Panels  30 ,  40  and  70  have been folded onto the side of the mattress and the male elements of the releasable fasteners  110 ,  120  have been engaged with the female elements of the releasable fasteners  130 ,  140  thereby forming two pockets that retain the sheet on the mattress. 
         [0060]    Bottom panels  50 ,  60  and  80  may remain untucked if desired by the end user. 
         [0061]    In use, an end user would first place top panel  20  on the top side of a mattress. Panels  30 ,  40  and  70  would be folded down along the side of the mattress along fold lines  170 ,  190  and  210  as depicted in  FIG. 1 . Next, male elements of the releasable fasteners  110 ,  120  will be engaged with the female elements of the releasable fasteners  130 ,  140  thereby forming two pockets that retain the sheet on the mattress. Then the bottom panels  50 ,  60  and  80  would be folded under the mattress if desired. This same procedure would be performed on the opposite bottom corner and this would quickly and easily secure the bottom of the sheet to the bottom of the mattress. It is contemplated that bottom panels  50 ,  60  and  80  may remain untucked if desired by the end user. 
         [0062]      FIGS. 5A to 5J  relate to an embodiment of the invention employing various releasable corner fasteners. In  FIG. 1-4 , sheet  10  is shown in a flat position, as if extended outwardly past the top surface of an underlying mattress. Releasable fastener  110 / 130  and  120 / 140  are disposed perpendicularly to each other and in general alignment with fold lines  170 ,  190  and  210  as indicated by arrows  150  and  160  in  FIGS. 2 and 4  respectively. Releasable fastener  110  is secured to side panel  30  and releasable fastener  130  is secured to side panel  70  located toward the foot of sheet  10 . Male elements of the releasable fasteners ( 110 ,  120 ) which will be engaged with the female elements of the releasable fasteners ( 130 ,  140 ) are preferably made of Velcro, buttons, snaps, zippers, hooks, magnetic snaps, oriental frogs or some other similar releasable fastening material. 
         [0063]    Referring to  FIG. 1 , side panels  30 ,  40  and  70  of sheet  10  are draped downwardly from fold lines  170 ,  190  and  210  causing male elements of the releasable fasteners ( 110 ,  120 ) and female elements of the releasable fasteners ( 130 ,  140 ) to be brought into facing and contacting alignment with each other. 
         [0064]    Referring to  FIG. 1 , sheet  10  is shown in a substantially flat position, as if extended outwardly past the top surface of an underlying mattress. Bottom panels  50 ,  60  and  80  are defined by fold lines  180 ,  200  and  220 . Bottom panels  50 ,  60  and  80  may be tucked under a mattress along fold lines  180 ,  200  and  220 . In the alternative, the end user may choose to have bottom panels  50 ,  60  and/or  80  untucked. 
         [0065]    Referring to  FIG. 5A-5J , the corner of sheet  10  is fully formed and secured by male elements of the releasable fasteners ( 110 ,  120 ) located on side panels  30  and  40  respectively and female elements of the releasable fasteners ( 130 ,  140 ) located on side panel  70  brought into facing and contacting alignment with each other. 
         [0066]    Releasable corner fasteners  110 / 130  and  120 / 140  are adapted to removably connect side panel  30  to side panel  70 , as well as, side panel  40  to side panel  70  together to maintain the side panels in substantially fixed relationship to each other, whereby the sheet of material follows the natural contour of the mattress. 
         [0067]    Releasable corner fasteners  110 / 130  and  120 / 140  may be hook and loop type material, such as that available under the trademark VELCRO, as well as, any other fasteners, including but not limited to buttons, conventional snaps, looped buttons, oriental frogs, magnetic snaps, fabric ties, or zippers. 
         [0068]    With additional reference to  FIG. 1 , the top panel  20  is substantially-rectangular piece of fabric sized to fit a desired size of mattress, e.g. twin, full, queen, king or emperor. 
         [0069]    The bedding top sheets of the present invention come in lengths and widths that are fairly standard including, but not limited to, twin, full, queen, king, or emperor size. 
         [0070]    Female elements of the fastener ( 130 ,  140 ) are provided to extend in a transverse direction with respect to male elements of the fastener ( 110 , 150 ). 
         [0071]    The female elements of the fastener ( 130 ,  140 ) may be detached from male elements of the fastener ( 110 , 150 ) to allow the sheet  10  to become loose and unfolded and to allow for easy removal from the mattress. 
         [0072]      FIG. 1  illustrates the sheet  10  having a central rectangular top panel  20  of a size to cover the top of the mattress. Side panels  30 ,  40  and  70  are of sufficient length and width to cover the sides of the mattress. The edges of side panels  30 ,  40  and  70  are locked at each corner by the several methods illustrated in  FIGS. 5A to 5J . When the sheet  10  is placed on a mattress the top portion  20  will lie smoothly without wrinkling. The end portions of panels  30 ,  40  and  70  will fit smoothly around the corner of the mattress and can be locked to each other by a fastening mechanism, including but not limited to, buttons, zipper, looped buttons, conventional snaps, oriental frogs, magnetic snaps, fabric ties, lacing/ribbons, hooks, and Velcro, as illustrated in  FIGS. 5A to 5J . 
         [0073]    The sheet is removed by detaching the female elements of the fastener ( 130 ,  140 ) from male elements of the fastener ( 110 , 150 ). The sheet can be laundered and ironed. The sheet of the present invention is easy to lock into position and to remove. 
         [0074]    Panels  30  and  70  can be locked to each other at the corner. Similarly, panels  40  and  70  can be locked to each other at the corner. The locking mechanism can be used at either or both corners. 
         [0075]    Since the sheet is usually folded back at the head end of the bed, in a preferred embodiment, the releasable corner fasteners need only be secured to the two corners at the foot of the bed. 
         [0076]    The sheet of the present invention comprises a generally rectangular flat piece of woven material wherein a portion of material  90  and  100  has been removed from each corner located at the end portion of the sheet to form a 90 degree angle. 
         [0077]      FIGS. 5A to 5J  are side views of one corner of the flat sheet showing the association of the releasable fastening means for retaining the flat sheet about the mattress. 
         [0078]    The flat sheet of the invention comprises a generally flat quadrilateral panel of fabric, preferably woven, having a main or central area designated generally by the numeral  20  and defined at opposite ends by the fold lines  170 ,  190  and  210  which may be taken to be fold lines. On the lateral sides, the main area is defined by fodl lines  180 ,  200  and  220  which define the side panel  30 ,  40 , and  70 , as well as, bottom panels  50 ,  60  and  80 . The size of the mattress may be any of the known standard sizes, including but not limited to, twin size, queen size, and king size. 
         [0079]    As illustrated in  FIG. 1 , the flat sheet of the present invention is formed from a generally rectangular panel, the lower left and right corners of the bottom end of the sheet being cut at 90 degree angles as seen in  FIG. 1 . As indicated by broken lines, generally quadrilateral portions  90  and  100  are cut away at each corner so as to leave the end and side panels extending from the main area of the sheet, side panels being designated by the numerals  30 ,  40  and  70  and bottom panels being designated by the numeral  50 ,  60  and  80 . 
         [0080]    As seen in  FIG. 3 , another embodiment of the present invention comprises each outside corner of bottom panel having a triangular portion removed to result in a panels  50 ,  60  and  80  having 45 degree edges. 
         [0081]    As seen in  FIG. 1-4 , it will be noted that broken lines  170 ,  180 ,  190 ,  200 ,  210  and  220  have been illustrated in side and bottom panels  30 ,  40 ,  50 ,  60 ,  70  and  80 . These broken lines represent fold lines and are illustrated in drawing for purposes of illustration only and do not appear in the finished product. They are included herein to illustrate the top, side and bottom panels that lies between the broken lines and defining the main area and the fold lines of the side panels are equivalent to the thickness dimension of the mattress, while the fold lines of the bottom panel constitutes that portion of the bottom panel that is tucked under the mattress. 
         [0082]    The thickness or height of the mattress is encompassed by that portion of the side panel lying between the fold lines  170  and  180 ,  190  and  200 , as well as  210  and  220  respectively 
         [0083]    It is therefore apparent upon reading this disclosure in view of the accompanying drawings that the bedding top sheets disclosed herein offer significant advantages that have not previously been disclosed or appreciated. Other alterations and modifications of the invention may become apparent upon reviewing this disclosure, and it is intended to cover all such alterations and modifications as fall within the scope of the appended claim.