for convenience and clarity in describing these embodiments , similar elements or components appearing in different figures will have the same reference numbers . the new mattress cover 10 shown in fig1 a has top wall 12 , bottom wall 13 , side walls 14 , 15 and openable end wall 16 with zipper 17 formed of zipper tracks 18 , 19 , extending along the length of end wall 16 and further extending partially around the corners 20 a , 20 b of the cover and along the side walls 14 , 15 respectively . fig1 b , 1c and 1d illustrate stages of zipper closure , where fig1 b shows the zipper 17 closed in the area 17 a and open in the area of 17 b all the way to the end 17 c . thus , zipper pull 21 , alternately called zipper tab , has closed area 17 a of the zipper upstream in the direction of arrow 17 d . at the open end 17 c zipper tracks 18 , 19 are slightly spaced apart . also in fig1 b the external barrier flap 23 is shown in its upward partially folded - down position with its bottom adhesive coated surface 23 a covered by a protective strip 24 . fig1 b and 1c show vinyl strips 26 , 27 fixed to cover 10 adjacent the end portions of zipper tracks 18 and 19 . a buckle closure is provided and has a first part 51 that is attached to the side wall 14 of the mattress cover and a second part 52 that is attached to the zipper pull 21 , whereby said first part and said second part are securely engaged by a user when said zipper is closed ( see fig1 c and 1d ). in the illustrated example , the first part 51 and second part 52 include the following components . the first part 51 includes a durable piece of fabric 51 a that is stitched or otherwise secured to the side wall 14 of the mattress cover . a first connection part 51 b is secured to the fabric 51 a at its free end . the first connection part 51 b includes two lateral prongs having a memory retaining quality and which spring back to their original orientation after being pressed inward . the second part 52 also includes a durable piece of fabric 52 a having a first end and a second end . the first end of the fabric 52 a is secured to the zipper pull 21 . a second connection part 52 b is secured to the second end of the fabric 52 a . the second connection part 52 b includes a cavity forming an opening at its distal end . the cavity is adapted to receive the two lateral prongs , which snap into position and lock the buckle closure together ( see fig1 c and 1d ). fig1 c and 1d illustrate completion of the zipper closure process of fig1 b , showing zipper pull 21 moved into its final closure position , drawing together zipper tracks 18 , 19 . the buckle closure is shown in its locked position , where connection parts 51 b and 52 b are joined together in a snap - fit relationship . the buckle closure will remain locked until a user manually squeezes together the two lateral prongs to allow the separation of the parts . reviewing the zipper closure stages , fig1 c and 3a show exterior barrier flap 23 in its partially folded - down position , and fig1 d and 3b show external barrier flap 23 in its fully folded - down and sealed position atop vinyl strips 26 , 27 and zipper tracks 18 , 19 . in this sealed or closed position adhesive surface 23 a of flap 23 tightly adheres to the outer surfaces of vinyl strips 26 , 27 and to exposed top surfaces of zipper tracks 18 , 19 , and to any exposed upper surface of zipper pull 21 , thus sealing off any opening that might have existed in the area of the terminal end zipper closure where pull 21 is positioned adjacent the terminal ends of zipper tracks 18 , 19 . fig1 c and 3a further illustrate peel - off strip 24 exposing adhesive surface 23 a of barrier flap 23 . as indicated , strip 24 is peeled off flap 23 just before flap 23 is fully folded down to engage vinyl strips 26 , 27 . it would be an optional alternative to have the adhesive surface and peel - off strip on vinyl strips 26 , 27 for subsequent adherence to flap 23 instead of peel - off strip and adhesive on flap 23 . in still further variations attachment strips 26 , 27 are not required to be vinyl , but could be any material , surface or coating to which external barrier flap can be securely adhered . in a still further alternative structure the adhesive surface would be replaced with velcro ® ( hook and loop ) or similar engageable layers on the flap and vinyl strips respectively . fig3 a and 3b illustrate a further feature and embodiment of the present invention , namely the above - disclosed structure with the further element of an internal barrier strip 40 which is an elongated strip extending the full or partial length of the zipper opening . strip 40 has opposite side edges 41 and 42 , with only one edge sewn to the cover 10 , and accordingly the remainder of internal flap 40 can hang down freely away from the zipper closure . in fig3 b internal barrier strip 40 is shown horizontally as it would appear if a mattress were inside the mattress cover , and the mattress was then pushing upward as indicated by arrows 44 against the bottom of internal barrier strip 40 . otherwise , the barrier strip 40 is free to hang as seen in dashed line representation 40 a in fig3 a . this strip 40 may be sewn at one or both of its ends which correspond to ends of the zipper tracks themselves . when employing both external barrier flap 20 and internal barrier strip 40 along with attachment strips 26 , 27 , all potential openings for bed bugs to exit a mattress cover are restricted , namely any path beneath and toward the zipper closure , the junction of the zipper pull with the ends of the zipper tracks , any path beyond the zipper pull . a second embodiment of the above - described invention is shown in fig4 where external barrier flap 30 is secured to cover 10 on one side of zipper track 19 , and adapted to fold transversely across and seal to both attachment strips . peel - off strip 32 exposes adhesive surface 31 . a third embodiment of the above - described invention is shown in fig5 , where the external barrier flap and attachment strips described above are not utilized or required . in this embodiment the buckle closure is secured between the side wall 14 and the zipper pull 21 as described above . the buckle closure ensures that the zipper remains closed when said zipper is in its closed state to prevent penetration or passage therethrough by bed bugs . the buckle closure should be attached at an appropriate location on the side wall 14 , such that the zipper pull 21 is unable to move after the snap fit closure of the buckle is made by the user . the new mattress cover is preferably constructed of polyester knit fabric and urethane laminate that is impervious to penetration or passage therethrough by bed bugs ; however other fabrics may be used if they are bed bug proof against bed bugs feeding through , biting through or traveling through the fabric . conventional zippers may be used , so long as they too are bed bug proof . the attachments strips are preferably vinyl sheet material , but other materials are acceptable they are suitable for releasable attachable to the external barrier flap . the external barrier flap is preferably a conventional fabric tape with an adhesive material or coating on one side and a peel - off protection sheet on the adhesive side . the above - described mattress cover structures provide apparatus embodiments of the present invention , which can also be defined as a method of achieving secure releasable closure against exit of bed bugs from within a mattress cover . such method , with a mattress cover having a zipper closed opening , comprises the steps : a . providing generally flat attachment strips on the outer surfaces of the mating zipper tracks near their closure end , b . providing an external barrier flap with a first part thereof fixed to said cover near said zipper closure end , with a main part thereof extending from said first part and situated in its open position spaced apart from said zipper closure end , where said main part has one adhesive surface covered by a peel - off protective sheet , c . closing said zipper , after inserting a mattress within said cover , by moving the zipper pull to the closure ends of said tracks , d . securing a buckle closure having a first part that is attached to the mattress cover , and a second part that is attached to the zipper pull , whereby said first part and said second part are securely engaged by a user when said zipper is closed , and e . removing said peel - off protective sheet and folding said main part adhesive surface down onto said attachment strips for sealing said zipper closure . while the invention has been described in conjunction with several embodiments , it is to be understood that many alternatives , modifications , and variations will be apparent to those skilled in the art in light of the foregoing description . accordingly , this invention is intended to embrace all such alternatives , modifications , and variations which fall within the spirit and scope of the appended claims .
a mattress cover and bed bug barrier combination formed of a fabric mattress cover having walls that define an enclosure with an elongated opening extending in at least one of said walls , a zipper attached to said cover for closing said elongated opening , said zipper having a proximal end portion , a distal end portion with a distal end , and a zipper pull movable to said distal portion for closing said zipper . a buckle closure is provided and has a first part that is attached to the mattress cover , and a second part that is attached to the zipper pull , whereby said first part and said second part are securely engaged by a user when said zipper is closed , for providing an additional locking feature to ensure that the zipper remains closed when said zipper is in its closed state .