Abstract:
A bed sheet, comprising in combination, a top panel for covering a mattress top, a surrounding side panel adapted to surround the side edges of the mattress, the top panel removably attachable to the side panel to form a bed sheet for the mattress wherein in use, the top panel can be detached and removed from the side panel when the bed sheet is covering the mattress whereby the side panels are left in position on the side edges of the mattress.

Description:
FIELD OF INVENTION 
       [0001]    This invention relates to bedding and bed sheets and in particular but not exclusively to a bed sheet with a removable and replaceable panel. 
       BACKGROUND OF THE INVENTION 
       [0002]    Bedding and bed linen is known prior art. The changing of sheets is a routine and often time consuming task especially where there are several beds to be made. Where the bed has a heavy mattress under which bed sheets have to be tucked, the effort of lifting such mattresses can also require great physical effort. 
         [0003]    The process of placing a standard sheet on any mattress is a skilled task since the corners of the sheet have to be securely tucked under the four corners of the mattress. Access to the under side of the mattress is often restricted by the construction and design of the bed itself such as where there are bed ends, panels and rails. These structures are often coupled with the sheer weight of many prior art mattresses such as those of the latex type construction making the task ever more difficult. 
         [0004]    The typical and prior art method of changing a standard bed sheet set is to either lift or entirely remove the mattress from the bed and then to remove the sheets by pulling the sheet out from beneath the mattress. The process is then basically reversed to re-make the bed. 
         [0005]    Prior art in relation to standard bed sheets has mainly concentrated on simplifying the often cumbersome process of changing the sheets without a need to remove the mattress. Such prior art sheets commonly disclose the use of elastic around the peripheral edge of the sheet commonly referred to as a fitted sheet adapted to keep the bed sheet in place on the mattress. There is also prior art relating to standard sheets which disclose the use of a mattress protector and/or the use a waterproofing sheet underlying the fitted sheet. Such prior art includes U.S. Pat. No. 7,047,580 (Finn) which discloses a multi-layer mattress protector which utilises a least two moisture proof layers with the top moisture proof layer being releasably attached to and removable from the bottom moisture proof layer. The top moisture proof layer can also be removed from the mattress protector while someone is in the bed. 
         [0006]    Common disadvantages or limitations of the prior art include the problem where the depth of the elasticised sides of fitted sheets often do not extend far enough beneath the mattress to ensure that the sheet remains firmly in place. Prior art disclosing the use of mattress protectors beneath fitted sheets have the disadvantage that there is an extra cost as well as an increase in labour and time to remove the separate mattress protector beneath the sheets when they have to be washed. The same problems also apply to the use of waterproof sheets beneath fitted sheets which also require frequent washing. 
         [0007]    In the case of bedding used by infant occupants, there is also a problem wherein the arms and legs of the infant can become entangled especially where there is a gap between the top and bottom of the sheet. The problem with the use of mattress protectors and waterproof sheets underlying bed sheets is also more acute where used with young children or the infirm where the constant supply of mattress protectors and moisture proof sheeting is an important limitation especially in commercial and institutional application. 
         [0008]    In the case of infant use, safety is a priority and there have been numerous cases of injury and even death from suffocation and/or strangulation especially where sheets have become loose and the infant has become entangled in them. In the case of infant application, the process of placing a standard sheet on a cot or crib mattress is often made difficult because the corners of the sheet have to be tucked very securely under the four corners of the mattress. Access to the corners of a cot or crib mattress is often restricted by bars, panels, slats or rails which are inherent in the design of most prior art cots and cribs. Mattress access can be further restricted by the presence of bumpers which are often used to prevent the child from injuring itself. Current mattress designs, whether of inner spring or foam construction often have squared off corners which are designed to limit the ability of an infant to access areas between the mattress and the insides of the cot or crib. Such designs further impede the ease or speed with which a prior art cot or crib sheet can be changed. 
         [0009]    A typical method of changing a cot or crib sheet set is to remove the bumpers, if present, lift or entirely remove the mattress from the cot or crib and then remove the standard sheet by pulling the sheet from beneath the mattress. The process is reversed to remake the bedding of the cot or crib. 
         [0010]    Naturally, prior art inventions relating to cot or crib sheets have concentrated on simplifying the cumbersome process of changing the sheets without the need to remove the mattress or bumpers from the cot or crib. 
       OBJECT OF THE INVENTION 
       [0011]    It is therefore an object of the present invention to provide an improved bed sheet system which seeks to overcome or ameliorate the disadvantages or limitations of the prior art or to at least provide the public with a useful choice. 
       STATEMENT OF INVENTION 
       [0012]    Accordingly in one aspect therefore the invention resides in a bed sheet, comprising in combination, 
         [0000]    a top panel for covering a mattress top,
 
a surrounding side panel adapted to surround the side edges of the mattress,
 
the top panel removably attachable to the side panel to form a bed sheet for the mattress wherein in use,
 
the top panel can be detached and removed from the side panel when the bed sheet is covering the mattress whereby the side panels are left in position on the side edges of the mattress.
 
         [0013]    Preferably the top panel is removably attached to the side panel by fastening means in the form of a continuous zipper fastener. In the alternative the top panel can be removably attached to the side panel by means of hook and loop fasteners such as Velcro™. 
         [0014]    The top panel can also be removably attached to the side panel by means of press studs or other equivalent readily detachable fasteners. 
         [0015]    Preferably a flap of material can be used to hide or protect the fastening means from inadvertent release. 
         [0016]    Preferably the top panel incorporates a waterproof layer. 
         [0017]    More preferably the top panel is lined with a waterproof layer that is also hypoallergenic and has anti-fungal, anti-asthmatic and dust-mite inhibition properties. 
         [0018]    In a preferred example of the invention, for typically infant application, the invention resides in a bed sheet, comprising in combination. 
         [0000]    a mattress case adapted to fully enclose a mattress,
 
the case comprising top and bottom panels joined together to form the mattress case, the top panel of which is removable when the mattress case is covering the mattress whereby the bottom panel is left in position on the mattress.
 
         [0019]    Preferably in one version the top and bottom panels of the mattress case are joined together by a surrounding side panel to accommodate the thickness of the mattress. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0020]    In order for the invention to be better understood and put into practical effect, reference will now be made to the accompanying drawings wherein 
           [0021]      FIG. 1  shows a preferred embodiment of the invention according to Example 1, and 
           [0022]      FIG. 2  shows a preferred embodiment invention according to Example 2. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Example 1 
       [0023]    Referring now to the accompanying drawings an initially to  FIG. 1 , there is shown a preferred bed sheet system  10  according to Example 1. The sheet system includes a side panel  12  and a removable top panel  14  which are securely attached together by the use of a detachable fastener  16 , in this case, preferably by a continuous zipper fastener  16 . The sheet has no bottom panel shown by broken line  12   a  representing the edges of the side panel  12  underneath the mattress  18 . This system provides for the ease of changing the sheets by removing or attaching the top panel to the surrounding side panels while still covering the mattress  18 . The system in combination creates a safe sleeping environment for young children and the physically and mentally handicapped for whom the accidental removal of the top panel could cause a safety issue. The attachment means in the form of the continuous zipper fastener  16  is positioned in such a manner that it cannot be easily accessed by the infirm, child or adult occupant. Preferably while the fastener is a zipper fastener, other attaching and detaching means can also be utilised such as hook and eye fasteners, for example Velcro™, clasps, press studs, buttons and plurality of prior art snap fasteners. In this embodiment where the removable attachable means is a zipper, the slide of the zipper is preferably located on the base or side panel of the sheet system. The zipper can be made of any appropriate material but is preferably a continuous moulded plastic separating zipper. In addition, the zipper can be attached in such a way that the pull of the zipper can be hidden under the base of the zipper when the zipper is fully closed. The slide of the zipper preferably remains with the base or side of panel of the sheet system. The zipper is attached in such a way that the zipper pull can be completely hidden from view and is not accessible to the infirm, child and adult occupant when covered by a flap of material  14   a . The zipper  16  preferably surrounds the entire perimeter of the top surface of the mattress and extends where the base of the zipper or where the zipper is inserted is located. The teeth of the zipper preferable extend under the zipper insert and the zipper pull can be pushed under the insert. The side panel and removable top panel can be made of any material suitable for sheeting and bedding. A waterproof, hypo-allergenic, dust mite resistant, anti-asthmatic and mould resistant lining can be incorporated into the top panel to provide added protection to the mattress. In preferred embodiments the sheet system is made of polyester/-cotton fabrics. 
         [0024]    It is expected that the removable top panel and corresponding half of the zipper attachment means will be laundered much more frequently than the base or side panel. The preferred embodiment with the plastic moulded separating zipper has been shown to withstand a significant number of washing and tumble dryings without affecting the integrity and continuous function of the zipper and top panel. 
         [0025]    The side panel or base of the sheet system is substantially identical to the length of the mattress plus twice the depth of the mattress. Preferably a number of elasticised strips  20 ,  22  are placed on either side panel and end panel  23  or on each  26 ,  28 ,  30  end where on all four vertical corners or seams allow for improved adjustability of fit for a multitude of sizes of mattresses as well as to maintain the integrity of the removable top panel. Preferably the removable top panel of the preferred sheet system is substantially almost identical in dimension to the top surface of the mattress. The half of the moulded plastic zipper that does not contain the slide is attached to the removable top panel  14  in such a manner that a fabric flap  14   a  can be used to provide a cover for the zip when the top panel is attached to the side panel. A waterproof, hypo-allergenic, dust mite resistant, anti-asthmatic, mould resistant lining is incorporated into the removable top panel to prevent damage to the mattress in the event of an accident. This lining also aides in maintaining the integrity of the top panel through numerous washings and dryings. 
       Example 2 
       [0026]    Referring now to  FIG. 2 , there is shown a preferred embodiment of the invention according to Example 2. Example 2 shows a pediatric or infant application of the invention. As with Example 1, the paediatric or infant application uses a safety sheet system  40  which includes a bottom panel  42  and removable top panel  44  which are securely attached by means of a continuous zipper fastener  46 . The design of the preferred embodiment eliminates the possibility of an infant removing the sheet and wrapping or entangling itself in the fabric of the sheet. The top panel is completely removable and attachable to the bottom panel by use of the continuous zipper means. This system provides for the ease of changing of the sheets by using the zipper to either remove or attach a top panel to the bottom panel. This system also creates a safer sleeping environment for the infant as the preferred zipper fastener is positioned in such a manner that the infant or child cannot access it. While the preferred attachment means is a continuous zipper fastener, other attachment means such as hook and eye fasteners for example Velcro™, clasp, press studs, buttons and a plurality of snap fasteners can also be used. In a most preferred embodiment, the use of the zip provides a simple means of attaching the top panel  44  to the bottom panel  42  wherein the slide of the zipper can be located on the bottom panel of the sheet system. The zipper may be made out of any appropriate material but the preferred version is of a moulded plastic construction. In addition the zipper can be attached in such a way that the pull of the zipper can be hidden under the base of the zipper when the zipper is completely closed. The pull or slide of the zipper is also preferably located in an inaccessible portion of the sheet system. The removable top panel is designed in such a manner that the simple attaching means can be covered by a flap of material  44   a  that extends beyond the attaching site. The zipper in this embodiment is attached in such a way that the zipper pull or slide can be completely hidden from view and inaccessible from an infant occupant. The zipper surrounds the entire perimeter of the surface of the mattress  46  and extends to where the base of the zipper or a zipper insert is located. The teeth of the zipper extend under the zipper insert and the zipper pull can pushed under the insert out of view. The bottom panel and the removable top panel of the sheet system can be made of any material suitable for sheeting or bedding. A waterproof, hypo-allergenic, dust mite resistant, anti-asthmatic, mould resistant lining has been incorporated into the under-surface of the top panel to provide protection to the mattress. In preferred embodiments, the sheet system is preferably made from polyester/-cotton fabrics. 
         [0027]    It is expected that the removable top panel and the corresponding half of the zipper attachment means will be laundered much more frequently than the rest of the mattress case. The preferred embodiment with the moulded plastic zipper fastener has been shown to withstand a significant number of washings and tumble dryings yet still maintain its integrity and function as initially designed. 
         [0028]    The bottom portion or bottom panel  42  of the mattress case is almost identical in length to the length of the cot or crib mattress plus twice the thickness of the mattress  46  to allow for the base of the sheet system to completely cover the bottom and four sides of the cot or crib mattress. 
         [0029]    In the alternative, a side panel  48  equal in width to the thickness of the mattress may be used between the top and bottom panels. 
         [0030]    A number of strips  52 ,  54 ,  56 ,  58  or wide elastic have been strategically placed across the bottom panel and the sides  60 ,  62 ,  64  to allow for improved adjustability of fit to mattresses of different makes and sizes as well as to maintain the positional integrity of the removable top panel. The section of the moulded plastic zipper fastener that incorporates the zipper slide is attached to the bottom side of the sheet system with the slide at an inaccessible end of the bottom panel. 
         [0031]    The removable top panel of the sheet system is also almost identical in dimensions to the top surface of the mattress. The half of the moulded plastic zipper fastener that does not contain the slide is attached to the removable top panel in such a manner that a fabric flap can be used to cover zipper when it is attached to the bottom of the mattress case. A waterproof, hypo-allergenic, dust mite resistant, anti-asthmatic, mould resistant lining has also been incorporated into the removable top panel to prevent damage to the mattress in the event of an accident. The lining also aides in maintaining the integrity of top panel through numerous washing and dryings. 
       ADVANTAGES OF THE INVENTION 
       [0032]    The examples of the preferred embodiments hereinbefore described have several advantages over the prior art. In the case of the infant or paediatric application, safe sleeping recommendations with a simple bed sheet system are recommended and endorsed by various organisations concerned with sudden infant death syndrome and other child safety bodies. The sheet systems allow for the saving in time and physical effort required to change a prior art standard or cot or crib sheet set wherein only the top panel has to be removed as opposed to changing the complete sheet. 
         [0033]    In terms of cost savings, where only a removable top panel is required to be laundered there is both a financial as well as a resource saving of both water, electricity and laundry detergent. Furthermore as the top panels can include a mattress protection lining, there is no need to purchase a separate mattress protector. The removal of a top panel caters to tired or sleeping infants when having to change the sheets due to an accident. Importantly the ability to change simply the top panel of a sheet or mattress case without having to lift a mattress or bend over a cot or crib, bars, panels, slates or rails limits the potential for lower back or abdominal strain of the user. 
         [0034]    The present sheet system is also able to be utilised in any situation both on a private, commercial or institutional basis where numerous sheets have to be changed. 
       VARIATIONS 
       [0035]    It will of course be realised that while the foregoing has been given by way of illustrative example of this invention, all such and other modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as is herein set forth. 
         [0036]    Throughout the description and claims this specification the word “comprise” and variations of that word such as “comprises” and “comprising”, are not intended to exclude other additives, components, integers or steps.