000001
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`BEDGEAR 1010
`IPR of U.S. Pat. No. 8,402,580
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`

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`U.S. Patent
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`Jul. 10, 2007
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`Sheet 1 of2
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`US 7,240,383 B2
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`FIG. 2
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`FIG. 4
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`U.S. Patent
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`Jul. 10, 2007
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`Sheet 2 of2
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`US 7,240,383 B2
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`iUS'I240383 B2
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`1
`WOVEN BED SHEET WITH ELASTOMERIC
`KNITTED CORNERS
`
`FIELD OF THE INVENTION
`
`The present invention relates to bedding and, more par-
`ticularly, to contoured or fitted bed sheets.
`
`DESCRIPTION OF RELATED ART
`
`Historically, contoured or fitted bed sheets have been
`fabricated using either woven or knitted fabrics. Woven
`sheets are typically fabricated with an elastic strip around
`the bottom edge of the sheet
`to assist
`the product
`in
`remaining secured to the mattress. This is necessary because
`the woven fabric has no ability to grab. However, in com-
`mercial laundry environments, the elastic has a much shorter
`life than the woven fabric, thereby limiting the service life
`of the product. Further, the utility of any woven contoured
`bed sheet is dependent upon the sidewall depth or height,
`specifically for the corners. In other words, if a contour sheet
`is fabricated with a sidewall height of eight inches, it will
`accommodate only mattresses with a thickness of slightly
`less than eight inches. Given that mattresses are manufac-
`tured in multiple thickness, and most heath care facilities
`and hospitality properties have mattresses of varying thick-
`nesses in service at any given time, this presents both service
`and functionality problems.
`Knitted contoured bed sheets offer the versatility inherent
`in knitted fabrics and are better suited for accommodation of
`
`varying mattress dimensions. Also, the stretch and recovery
`aspect of a knit material allows these sheets to be commonly
`made without elastic. However, knit fabrics are known to be
`less durable than woven alternatives and can be more
`
`complicated and costly to process in a commercial laundry.
`Knitted sheets present difficulties in being effectively pro-
`cessed through ordinary flat work ironers or folding machin-
`ery that are employed in many industrial processing facili-
`ties. Thus, while knitted bed sheets have gained large-scale
`market acceptance in the health care market, the processing,
`handling, and finished product appearance issues associated
`with them have caused the hospitality industry to largely
`continue the use of woven products.
`
`SUMMARY OF THE INVENTION
`
`The present invention provides a bed sheet that serves as
`a contoured bed sheet having certain advantages of both
`woven and knitted bed sheets, but without some of the
`respective drawbacks thereof. To that end, and in accordance
`with the principles of the present invention, a contoured bed
`sheet is provided by a woven sheet with knitted comer
`inserts having both non-elastomeric synthetic yarns and
`elastomeric synthetic yarns, with the elastomeric yarns
`being present in a range of between about 5% and about 25%
`by weight of the corner insert. The resulting sheet can be
`used as a contoured bed sheet like a knit sheet, but without
`a separate elastic strip, yet can be easily processed through
`conventional commercial laundry and folding machinery.
`Further, the product, when in use, appears to be a typical
`woven contoured bed sheet.
`
`there is thus provided a
`By virtue of the foregoing,
`contoured bed sheet with advantages of both woven and
`knitted bed sheets, but without some of the respective
`drawbacks thereof. These and other objects and advantages
`of the present invention shall be made apparent from the
`accompanying drawings and the description thereof.
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`BRIEF DESCRIPTION OF THE DRAWINGS
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`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.
`FIG. 1 is a perspective view of an exemplary woven base
`sheet for use in making a contoured bed sheet in accordance
`with the principles of the present invention;
`FIG. 1A is a top plan view taken at encircled area 1A of
`FIG. 1;
`FIG. 2 is a plan view of an exemplary knitted comer insert
`for use with the woven sheet of FIG. 1 to make a contoured
`
`bed sheet in accordance with the principles of the present
`invention;
`FIG. 3 is a perspective, partially cut away view of a
`contoured bed sheet according to the present invention made
`up from the woven sheet of FIG. 1 and a plurality of knitted
`corner inserts of FIG. 2; and
`FIG. 4 is an enlarged plan view taken at encircled area 4
`of FIG. 2.
`
`DETAILED DESCRIPTION
`
`With reference to FIG. 1, a rectangular woven base sheet
`10 has a field portion 12, with opposite lengthwise top and
`bottom segments 14, 16, and opposite left and right width-
`wise side segments 18, 20 as indicated by dashed lines. Each
`pair of adjacent segments (such as segments 14 and 18 by
`way of example) overlap in a comer area 22. A comer
`section 24 (shown in phantom in FIG. 1) of one or more
`(advantageously all four) comer areas 22 of the woven sheet
`10 is removed leaving a generally arcuate upper edge 26
`extending between points 28 along the periphery of the
`respective adjacent segments, such that each segment may
`now be seen as constituting a lengthwise or widthwise panel.
`Comer section 24 may be cut such that edge 26 has a pair
`of inwardly extending, generally straight, edge portions 26a,
`26b, that adjoin at rounded apex 26c as seen inf FIG. 1A.
`Sheet 10 can be of any woven fabric typically used in
`bedding such as cotton, polyester, or combinations thereof.
`Typically, a standard weave is employed.
`A contoured bed sheet 30 (FIG. 3) is formed by attaching
`to at least one, if not to a pair, or to all four, corner sections
`24 between respective pairs of adjacent segments or panels
`(14, 20; 20, 16; 16, 18; and/or 10, 14) a knitted comer insert
`40 (FIG. 2) which may, in the embodiment shown herein, be
`of generally triangular shaped having outer side edges 42, 44
`extending from bottom side edge 46 and adjoining at
`rounded apex 48. The comer insert 40 is attached, such as by
`stitching of the edges 42, 44 and apex 48 to upper edge 26
`of a comer section 24 of sheet 10. A safety stitch seam as at
`50 may be used. As a consequence, each comer insert 40
`joins together an adjacent pair ofpanels (14, 20; 20, 16; 16,
`18; and/or 10, 14) to thus define stretchable comers 52 so as
`to function as a contoured bed sheet and receive respective
`corners of a mattress 54.
`
`Comer inserts 40 are advantageously made from a stretch-
`able material which is knitted, either by warp or circular
`knitting. In order to give the advantageous results desired by
`the present invention, with reference to FIG. 4, corners 40
`are formed by knitting together a plurality of non-elasto-
`meric yarns 60 and a plurality of elastomeric yarns 62 (only
`one shown in FIG. 4), the latter advantageously making up
`about 5% to about 25% by weight of a comer insert 40,
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`although making up by weight within a narrow range of
`about 10% to about 25% may be further advantageous. In
`one embodiment, a weight of elastomeric yarns 62 of corner
`insert 40 is about 17%. Such amounts are believed to
`
`provide for sufficient expansion, at the same time ensuring
`that the corners 52 adequately grab the mattress 54.
`The elastomeric yarns 62 may be of any stretchable
`material, although an elastomeric segmented polyurethane,
`such as Spandex (which may be at
`least about 85% of
`segmented polyurethane), may be advantageous. The non-
`elastomeric yarns 60 may be any yarn that can be knitted to
`form the fabric comers 40, with one possibly advantageous
`non-elastomeric yarn being comprised of polyester. The
`overall weight per yard of a comer insert 40 is advanta-
`geously limited to be between about 50% and about 150%
`of the weight per yard of the base sheet 10. Further, corner
`inserts 40 are advantageously of substantially the same color
`as base sheet 10.
`To form the bed sheet 30, corner sections 24 of an
`appropriate size are removed from base sheeting 10. As an
`example, each comer section 24 of base sheet 10 may be cut
`between points 28 that are each about 22.5 inches (plus or
`minus about a half inch) from the apex 70 at each corner area
`22 to define upper edge 26 subtending a distance of about 32
`inches between adjacent pairs of points 28. The maximum
`distance between edge apex 26c and apex 70 may be about
`19.25 inches. The comer insert 40 side edges 42, 44, in turn,
`will each be about 15.25 inches long, with bottom edge 46
`being about 13 inches long. The distance from the bottom
`edge 46 to the apex 48 may be about 14 inches.
`The corners 40 are attached to the base sheeting 10 by
`stitching, such as safety stitching 50. Comers 40 may be
`attached at the rounded apex 48 to the apex 26c of upper
`edge 26, and subsequently stitched along sides 42 and 44
`and respective edge portions 26a and 26b. The bottom
`peripheral edge 80, optionally including bottom edge(s) 46,
`of the entire sheet 30 may be seamed to provide a finished
`sheet. Because of the difference in size between cut out
`corner sections 24 and comer inserts 40, the comer inserts
`are slightly stretched when sewn into base sheet 10 to form
`contoured bed sheet 30.
`
`The above bed sheet 30 provides the feel, appearance, and
`durability of a woven sheet. It can be processed using
`standard commercial laundry facilities. However, it fits on a
`mattress like a knitted sheet.
`It can also accommodate
`
`mattresses of varying thicknesses.
`By virtue of the foregoing,
`there is thus provided a
`contoured bed sheet with advantages of both woven and
`knitted bed sheets, but without some of the respective
`drawbacks thereof.
`
`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.
`The invention in its broader aspects is, therefore, not limited
`to the specific details, representative apparatus and method,
`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.
`What is claimed is:
`
`1. A bed sheet comprising:
`a woven fabric sheet including four corners and opposite
`lengthwise and widthwise side panels
`extending
`between respective pairs of said four comers; and
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`4
`a knit comer insert associated with at least one of the
`
`corners and having a plurality of non-elastomeric syn-
`thetic polyester yarns and a plurality of elastomeric
`synthetic yarns, the elastomeric synthetic yarns being
`present in a range of between about 5% and about 25%
`by weight of the knit comer insert.
`2. The sheet claimed in claim 1 further comprising
`four of the knit corner inserts each associated with a
`
`respective one of the four corners.
`3. The sheet claimed in claim 1 wherein the elastomeric
`
`synthetic yarns include at least about 85% segmented poly-
`urethane.
`
`4. The sheet claimed in claim 3 wherein the polyester
`yarns comprise about 83% by weight and the polyurethane
`yarns comprise about 17% by weight of the knit comer
`insert.
`5. The sheet claimed in claim 3 wherein the elastomeric
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`10
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`15
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`synthetic yarns comprise between about 10% and about 20%
`by weight of the knit comer insert.
`6. The sheet claimed in claim 1 wherein the elastomeric
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`20
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`synthetic yarns comprise between about 10% and about 20%
`by weight of the knit comer insert.
`7. The sheet claimed in claim 1, said knit comer insert
`being warp knitted.
`8. The sheet claimed in claim 1 further comprising a pair
`of the knit comer inserts each associated with a respective
`one of at least two of the corners.
`
`9. A method of making a bed sheet, comprising:
`obtaining a length of woven fabric including four corners
`and opposite lengthwise and widthwise edges extend-
`ing between respective pairs of the four corners;
`removing a comer from the length of woven fabric;
`obtaining a knit corner insert including a plurality of
`non-elastomeric synthetic polyester yarns and a plural-
`ity of elastomeric synthetic yarns, the elastomeric syn-
`thetic yarns being present in a range of between about
`5% and about 25% by weight of the knit comer insert;
`and
`
`attaching the knit comer insert between adjacent edges in
`place of the removed comer.
`10. The method of claim 9 wherein two of said comers are
`removed from the woven fabric, and knit corner inserts are
`attached to said woven fabric by
`attaching a respective one of two of said knit comer
`inserts between adjacent edges in place of each respec-
`tive one of the two removed comers.
`11. The method of claim 9 wherein the elastomeric
`
`synthetic yarns include at least about 85% segmented poly-
`urethane.
`
`12. The method of claim 11 wherein the polyester yarns
`comprise about 83% by weight and the polyurethane yarns
`comprise about 17% by weight of the knit panel comer
`insert.
`13. The method of claim 11 wherein the elastomeric
`
`synthetic yarns comprise between about 10% and about 20%
`by weight of the knit comer insert.
`14. The method of claim 9 wherein the elastomeric
`
`synthetic yarns comprise between about 10% and about 20%
`by weight of the knit comer insert.
`15. The method of claim 9 wherein each of said four
`corners is removed from the woven fabric, and knit comer
`inserts are attached to said woven fabric by attaching a
`respective one of four of said knit corner inserts between
`adjacent edges in place of each respective one of the
`removed four corners.
`16. The method of claim 15 wherein the elastomeric
`
`synthetic yarns are polyurethane and comprise 17% by
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`weight of the knit panel corner insert, and the non-elasto-
`meric synthetic polyester yarns comprise about 83% by
`weight of the knit corner insert.
`17. A bed sheet comprising:
`a woven fabric sheet including four corners and opposite
`lengthwise and widthwise side panels
`extending
`between respective pairs of said four corners, at least
`one of the comers including a stitching edge having a
`length measured between two opposing endpoints at a
`periphery of adjacent lengthwise and widthwise side
`panels longer than a straight line between the end-
`points; and
`a knit comer insert associated with at least one of the
`
`corners along the stitching edge and having a plurality
`of non-elastomeric synthetic yarns and a plurality of
`elastomeric synthetic yams, the elastomeric synthetic
`yarns being present in a range of between about 5% and
`about 25% by weight of the knit comer insert.
`18. The sheet claimed in claim 17 wherein the elastomeric
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`20
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`synthetic yarns include at least about 85% segmented poly-
`urethane.
`19. The sheet claimed in claim 18 wherein the elastomeric
`
`synthetic yarns comprise between about 10% and about 20%
`by weight of the knit corner insert.
`20. The sheet claimed in claim 18 wherein the non-
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`elastomeric synthetic yarns are polyester.
`21. The sheet claimed in claim 20 wherein the polyester
`yarns comprise about 83% by weight and the polyurethane
`yarns comprise about 17% by weight of the knit comer
`insert.
`22. The sheet claimed in claim 17 wherein the non-
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`elastomeric synthetic yarns are polyester.
`23. The sheet claimed in claim 17 wherein the elastomeric
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`synthetic yarns comprise between about 10% and about 20%
`by weight of the knit corner insert.
`24. The sheet claimed in claim 17, said knit corner insert
`being warp knitted.
`25. The sheet claimed in claim 17 wherein at least a
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`second comer includes a stitching edge having a length
`measured between two opposing endpoints of the second
`corner at a periphery of adjacent lengthwise and widthwise
`side panels longer than a straight line between the endpoints,
`with a second of the knit comer inserts attached to the
`
`stitching edge of the second comer.
`26. The sheet claimed in claim 17 wherein each of the four
`
`corners includes a stitching edge having a length measured
`between two opposing endpoints of the respective comer at
`a periphery of adjacent lengthwise and widthwise panels
`longer than a straight line between the endpoints thereof,
`with one each of four of the knit corner inserts attached to
`
`a respective one of the stitching edges.
`27. The sheet claimed in claim 17 wherein the stitching
`edge is generally arcuate between the endpoints.
`28. The sheet claimed in claim 17 wherein the stitching
`edge includes a pair of stitching edges portions, each extend-
`ing inwardly from respective ones of the endpoints toward
`an apex therebetween.
`29. The sheet claimed in claim 28 wherein the stitching
`edge portions adjoin at the apex.
`30. A method of making a bed sheet, comprising:
`obtaining a length of woven fabric including four comers
`and opposite lengthwise and widthwise edges extend-
`ing between respective pairs of the four comers;
`defining a stitching edge at a comer of the woven fabric
`having a length measured between two opposing end-
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`points at a periphery of adjacent lengthwise and width-
`wise side panels longer than a straight line between the
`endpoints;
`obtaining a knit corner insert including a plurality of
`non-elastomeric synthetic yarns and a plurality of elas-
`tomeric synthetic yams, the elastomeric synthetic yams
`being present in a range of between about 5% and about
`25% by weight of the knit comer insert; and
`attaching the knit comer insert along the stitching edge
`between adjacent lengthwise and widthwise edges at
`the corner.
`31. The method of claim 30 wherein the elastomeric
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`synthetic yarns include at least about 85% segmented poly-
`urethane.
`32. The method of claim 31 wherein the elastomeric
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`15
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`synthetic yarns comprise between about 10% and about 20%
`by weight of the knit comer insert.
`33. The method of claim 31 wherein the non-elastomeric
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`synthetic yarns are polyester.
`34. The method of claim 33 wherein the polyester yarns
`comprise about 83% by weight and the polyurethane yarns
`comprise about 17% by weight of the knit panel comer
`insert.
`35. The method of claim 30 wherein the non-elastomeric
`
`synthetic yarns are polyester.
`36. The method of claim 30 wherein the elastomeric
`
`synthetic yarns comprise between about 10% and about 20%
`by weight of the knit comer insert.
`37. The method of claim 34 wherein stitching edges are
`defined at two comers of the woven fabric and two of the
`
`knit comer inserts are attached to said woven fabric by
`attaching a respective one of the knit comer inserts along
`respective ones of the stitching edges between adjacent
`lengthwise and widthwise edges of the two comers.
`38. The method of claim 30 wherein stitching edges are
`defined at each of said four corners of the woven fabric and
`four of the knit comer inserts are attached to said woven
`
`fabric by attaching a respective one of each of the knit comer
`inserts along a respective one of the stitching edges between
`adjacent lengthwise and widthwise edges in of the four
`corners.
`39. The method of claim 38 wherein the elastomeric
`
`synthetic yarns are polyurethane and comprise 17% by
`weight of the knit panel corner insert, and the non-elasto-
`meric synthetic yarns are polyester and comprise about 83%
`by weight of the knit comer insert.
`40. The method of claim 30 wherein the stitching edge is
`generally arcuate between the endpoints.
`41. The method of claim 30 wherein the stitching edge
`includes a pair of stitching edges portions, each extending
`inwardly from respective ones of the endpoints toward an
`apex therebetween.
`42. The method of claim 30 wherein the comer is removed
`
`to define the stitching edge.
`43. A bed sheet comprising:
`a woven fabric sheet including four corners and opposite
`lengthwise and widthwise side panels
`extending
`between respective pairs of said four corners, at least
`one corner consisting essentially of a one-piece knit
`corner insert having a plurality of non-elastomeric
`synthetic yarns and a plurality of elastomeric synthetic
`yarns, the elastomeric synthetic yams being present in
`a range of between about 5% and about 25% by weight
`of the knit comer insert.
`44. The sheet claimed in claim 43 wherein the elastomeric
`
`synthetic yarns include at least about 85% segmented poly-
`urethane.
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`45. The sheet claimed in claim 44 wherein the elastomeric
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`55. The method of claim 54 wherein the elastomeric
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`iUS'I240383 B2
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`synthetic yarns comprise between about 10% and about 20%
`by weight of the knit corner insert.
`46. The sheet claimed in claim 44 wherein the non-
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`elastomeric synthetic yarns are polyester.
`47. The sheet claimed in claim 46 wherein the polyester
`yarns comprise about 83% by weight and the polyurethane
`yarns comprise about 17% by weight of the knit comer
`insert.
`48. The sheet claimed in claim 43 wherein the non-
`
`elastomeric synthetic yarns are polyester.
`49. The sheet claimed in claim 43 wherein the elastomeric
`
`synthetic yarns comprise between about 10% and about 20%
`by weight of the knit corner insert.
`50. The sheet claimed in claim 43, said knit corner insert
`being warp knitted.
`51. The sheet claimed in claim 43 wherein at least two of
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`the comers each consist essentially of said one-piece knit
`corner inserts.
`52. The sheet claimed in claim 43 wherein each of the four
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`corners consist essentially of said one-piece knit corner
`inserts.
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`53. A method of making a bed sheet, comprising:
`obtaining a length of woven fabric including four comers
`and opposite lengthwise and widthwise edges extend-
`ing between respective pairs of the four comers;
`removing a comer from the length of woven fabric;
`obtaining a knit corner insert including a plurality of
`non-elastomeric synthetic yarns and a plurality of elas-
`tomeric synthetic yarns, the elastomeric synthetic yams
`being present in a range of between about 5% and about
`25% by weight of the knit comer insert; and
`attaching between adjacent edges in place of the removed
`corner essentially only the one-piece knit corner insert
`such that the corner of the bed sheet consists essentially
`of the one-piece knit comer insert.
`54. The method of claim 53 wherein the elastomeric
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`synthetic yarns include at least about 85% segmented poly-
`urethane.
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`synthetic yarns comprise between about 10% and about 20%
`by weight of the knit comer insert.
`56. The method of claim 54 wherein the non-elastomeric
`
`synthetic yarns are polyester.
`57. The method of claim 56 wherein the polyester yarns
`comprise about 83% by weight and the polyurethane yarns
`comprise about 17% by weight of the knit panel comer
`insert.
`58. The method of claim 53 wherein the non-elastomeric
`
`synthetic yarns are polyester.
`59. The method of claim 53 wherein the elastomeric
`
`synthetic yarns comprise between about 10% and about 20%
`by weight of the knit comer insert.
`60. The method of claim 53 further comprising removing
`a second of the comers from the woven fabric, obtaining a
`second of the knit comer inserts, and attaching between
`adjacent edges in place of the removed second comer
`essentially only the second one-piece knit comer insert such
`that the second corner of the bed sheet consists essentially of
`the second one-piece knit corner insert.
`61. The method of claim 53 further comprising removing
`each of said four corners from the woven fabric, obtaining
`four of said one-piece knit comer inserts, and attaching
`between adjacent edges in place of each respective one of
`the removed four comers essentially only a respective one of
`four knit comer inserts such that the four corners of the bed
`
`sheet each consists essentially of one-piece knit comer
`inserts.
`62. The method of claim 61 wherein the elastomeric
`
`synthetic yarns are polyurethane and comprise 17% by
`weight of the knit panel corner insert, and the non-elasto-
`meric synthetic yarns are polyester and comprise about 83%
`by weight of the knit comer insert.
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`UNITED STATES PATENT AND TRADEMARK OFFICE
`
`CERTIFICATE OF CORRECTION
`
`PATENT NO.
`APPLICATION NO.
`
`: 7,240,383 B2
`: 11/162504
`
`DATED
`INVENTOR(S)
`
`: July 10, 2007
`: Richard Stewart
`
`Page 1 of 1
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`It is certified that error appears in the above—identified patent and that said Letters Patent is
`hereby corrected as shown below:
`
`Column 1
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`Line 25, “...in multiple thickness...” should be --
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`multiple thicknesses... --
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`Column 2
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`Line 41, “...as seen inf FIG. 1A.” should be -- as seen in FIG. 1A. --
`
`Line 50, “...of generally triangular shaped having...” should be -- ...of generally
`triangular shape having... --
`
`Claim 28
`
`Column 5, Line 55, “...a pair of stitching edges portions...” should be -- a pair of
`stitching edge portions --
`
`Claim 37
`
`Column 6, line 29, “The method of claim 34 wherein ” should be -- “The
`method of claim 30 wherein... --
`
`Claim 38
`
`Column 6, line 40, “...edges in of the four corners.” should be -- ...edges in one
`of the four corners. --
`
`Claim 41
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`Column 6, line 50, “...a pair of stitching edges portions...” should be -- a pair of
`stitching edge portions... --
`
`Signed and Sealed this
`
`Eleventh Day of March, 2008
`
`M WQIAM
`
`JON W. DUDAS
`Director ofthe United States Patent and Trademark Oflice
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