referring now in more detail to the exemplary drawings for purposes of illustrating embodiments of the invention , wherein like reference numerals designate corresponding or like elements among the several views , referring first to fig2 and 4 , the personal water filtration cup apparatus of the present invention includes , generally , a pair of inner and outer containers 21 and 23 forming , respectively , a cup device and a fluid receptacle 21 and 23 . the cup device 21 includes in its lower extremity a through filter device , generally designated 25 , for flow of liquid upwardly through a grill 27 to lift a flapper 29 of an isolation device , generally designated 31 , off the grill for flow of liquid into the upper cup 33 to provide filtered water . when pressurization of the filter device is diminished , the flapper 31 will lay down over the grill 27 as shown in fig3 to prevent backflow of liquid into the filter device . the receptacle 23 is conveniently constructed of readily available plastic material and is formed in its lower portion with a peripheral rib 41 ( fig4 ) to elevate the bottom wall 43 slightly . the bottom wall 43 is formed with a through - port 45 which receives the stem 47 of a poppet valve , generally designated 49 , that serves to vent air into the receptacle when the plunger - type cup apparatus is elevated . the upper portion of the receptacle 23 is formed with an upwardly and readily outwardly tapered flange 52 configured for convenient receipt of a turnback engagement flange 53 formed in the upper extremity of the cup apparatus . the cup apparatus 21 is configured in its lower portion with an integral transverse wall defining the grill 27 ( fig1 ) to form a plurality of through - ports 49 arrayed thereabout and covering the majority of the transverse cross - section of the cup 33 to thereby provide for a high - volume combined flow area to provide minimal resistance to flow of fluid . the grill 27 may take numerous different forms , and in the preferred embodiment provides a combined flow area of at least 50 % of the overall cross - sectional area of the cup and preferably approximately 60 % of the overall flow area to thereby provide for the desired structural integrity while still minimizing the resistance to fluid flow upon pressurization of the filter device . with continued reference to fig1 , the grill 27 is spaced a distance upwardly about one - fifth the length of the overall cup apparatus from the bottom end 51 thereof , and is formed in its upper extremity with coarse internal female threads 53 . an upwardly opening filter cup , generally designated 57 , is received in the lower extremity of the cup apparatus and is formed with a cylindrical wall configured in its upper extremity with male threads 61 for meeting with the lower extremity of the filter cup is configured with a radially outwardly projecting rib 65 to complement a fit within a cross section of the receptacle . the filter cup 57 is formed with a lower wall defining a grill generally designated 67 . also configured throughout the majority of its transverse area with a plurality of flow ports 69 which provide a combined flow area in excess of 25 % of the overall transverse cross section of the cup apparatus and in the preferred embodiment provide a combined cross - sectional flow in excess of 50 % of the overall transverse cross - section of the cup apparatus . the grill 27 is formed centrally with an enlarged bore 60 which receives a downwardly projecting compressible stem 62 of the isolation device 31 . the stem 62 is formed on its lower extremity within an enlarged cross - section stop 64 to cooperate in securing the isolation device to the grill . the filter apparatus includes a cylindrical filter 71 which may be constructed of any desirable commercially available filter media for filtration of water such as conventional charcoal filter . the filter 71 is sandwiched between a pair of felt retainer disks 73 and 75 to provide for containment against any possibly dislodged particles , but to allow for free flow of fluid as introduced from the lower grill 67 and to pass through the upper grill 27 . the interior wall of the cup above the grill 27 is preferably formed with a cylindrical peripheral retainer rib 40 configured to cooperate with the peripheral edge of the flapper to provide for protection of the thin peripheral edges thereof . the flapper itself is in the form of a circular plate and is configured to taper radially outwardly from a thick central section to a thin peripheral edges to thereby , in the manner dictated by well - known plate stress formulas , provide for a memory tending to maintain the flexible flapper 29 by its downwardly into contacting relationship over the pores 49 of the grill 27 to provide for sealing engagement therewith , but , to , upon application of pressure from the filter chamber on the order of 15 psi or so , provide for bending of the flapper to allow the peripheral edges to be raised for high volume flow therepast to provide for rapid flow of the newly filtered liquid . the isolation device is selected and configured to provide for effective sealing thereof as described above while providing for ready flexing under upward acting pressure to thereby provide for efficient flow . as will be appreciated by those skilled in the art , the flapper is to be constructed of material which is relatively tough and resistant to high temperatures on the order of 450 degrees fahrenheit and more , as would be consistent with washing in a dishwasher or the like and to yet provide for the operation dictated by the disciplines of the present invention . a material found successful for this operation is floor silicone material , but may be one of several food - safe elastomeric materials known to those skilled in the art . it will be appreciated by those skilled in the art the outer receptacle and cup apparatus may be molded of pc material and the filter cup 57 of an abs or abs blend material . in manufacture , these components may be molded separately and available for ready assembly . in one preferred embodiment , a pouring closure in the form of a cap device , generally designed 81 ( fig1 - 14 ) may be provided for snap fit onto the personal filter body assembly of the present invention as shown in fig1 . the cap device 81 is formed with a domed closure 83 configured in its lower peripheral wall with a gland 85 configured to be friction - fit over the exterior of the lip to set on the top of the combined apparatus . the cap assembly 83 may be constructed of , for instance , abs , and will be formed with an upwardly open stub drinking tube 87 covered by a friction fit plug 89 carried from a strap 90 hinged at a pivot pin 91 of an upstanding stem 93 for convenient opening and closure of the tube 87 . in manufacture , it will be appreciated that there are a minimum number of assembly steps . as an example , referring fig3 , the disk 75 may be nested down into the filter cup 57 overlying the grill 67 , the filter stacked up thereon and the disk 73 placed thereover , and the combination then fitted up into the bottom end of the cup apparatus and the filter cup 57 rotated to engage the respective threads 61 and 53 to tighten the assembly in position to slightly compress the filter media to maintain a slight pressure thereon and maintain some force on the engaged threads to facilitate closure of the filter cup into the cup apparatus . an o - ring 99 will be fitted down over the filter cup 57 to nest on the peripheral rib 65 . the umbrella isolation device 31 may be then introduced to the cup assembly from the top end thereof and the stem 62 inserted through the bore 60 to drive the conical holer 64 downwardly through such bore to compress the sides thereof , and , upon clearing the lower edge of the lower surface of the grill 27 , expand and maintain the isolation device in place . it will be appreciated that a relief bore 98 is formed in a center top of the filter to provide clearance for the fastener 64 . it will be appreciated that the diameter of the cup apparatus is of a size sufficiently smaller than the inside diameter of the receptacle such that the cup apparatus will telescope efficiently into the receptacle without binding , it being further appreciated that the o - ring 99 will provide a dynamic seal with the wall thereof . thus , the components may be easily separated and the receptacle 23 filled with , for instance , tap water , and the cup apparatus 21 introduced thereinto as guided by the flare of the bell section so as to slide conveniently downwardly in plunger fashion to contact the lower extremity thereof with the water in the receptacle as shown in fig9 and 10 . as the cup apparatus is plunged downwardly , the o - ring will prevent escape therepast of water . thus , as the apparatus is forced downwardly , causing the water to flow upwardly through the opening 69 in the grill 67 and into and through the filter device 71 to flow upwardly through the top felt discs 73 and through the ports 49 to apply a pressure underneath the reduced in thickness peripheral portions of the flap 29 , thereby applying a bending force to the diametrically outer portions thereof to thus bend the flapper and raise the edges thereof a shown in fig1 to permit a high volume flow of water as depicted by the directional arrows 101 upwardly into the cup 33 . as the full volume of water is passed upwardly through the filter device 71 , as for instance 16 ounces thereof , while the cup device is pressed downwardly through its full stroke , the cup 33 will be filled with filtered water ready for consumption . as the end of the downward stroke is reached , the other portion of the lip 51 will flex and snap over the upper edge of the bell section 51 to draw the cup apparatus into place within the receptacle for a secure joinder . the filtered water is then available for ready consumption , and , if desirable , the cap 81 ( fig1 and 14 ) may be snapped down into place over the lip 53 to close the top of the cup portion while making the filtered water available for consumption by merely lifting the lever 91 to unplug the stub tube 87 for ready access to the water . in the meantime , it will be appreciated that when the pressure in the filter chamber has been reduced , the memory of the material in the flapper will cause it to return to its horizontal position shown in fig4 to be disposed in overlying sealing relationship over the ports 49 to thus act somewhat as a check valve to prevent flow of water back downwardly and to the filter compartment . thus , in those many instances where users add energy or flavoring substances to the filtered water , the filter will be isolated from those substances to thus prevent contamination and clogging of the filter and protect the long life thereof . if desirable , the cup apparatus may be removed from the exterior receptacle and will be available for transporting the filtered water about as desired by the user . it should also be noted that , when the cup apparatus is retained in the receptacle 23 as shown in fig4 , once the filtered water has been consumed , the cup assembly 21 may be rapidly withdrawn by the user grasping the overhang of the rib 53 to draw it vertically upwardly as the wall of the cup defining the bell mouth 51 is flexed inwardly to allow for release , thereby freeing the cup assembly to be lifted relative to the receptacle . it will be appreciated that this action will cause a partial vacuum to be generated beneath the lower grill 67 , thereby applying a pressure differential across the poppet valve 49 , causing such poppet valve to be raised off its seat for introduction of atmospheric air to thereby break the partial vacuum and free the cup assembly to be drawn quickly and rapidly upwardly to be removed from the receptacle for refill of the receptacle itself . when the apparatus is emptied and it is desired to wash the cup apparatus , it can be placed directly in an automatic dishwasher or the like and tests have proven that the isolation device , filter and components will accommodate the heat and environment of such a dishwasher and will be available for subsequent . from the foregoing it will be appreciated that the self - filtering portable bottle apparatus of the present is economical to manufacture , efficient to use and offers the flexibility of allowing the user to supplement his or her drink with additives and supplements without concern for clogging the filter to thereby provide for a long and trouble free life . the invention may be embodied in other forms without departure from the spirit and essential characteristics thereof . the embodiments described therefore are to be considered in all respects as illustrative and not restrictive . although the present invention has been described in terms of certain preferred embodiments , other embodiments that are apparent to those of ordinary skill in the art are also within the scope of the invention . accordingly , the scope of the invention is intended to be defined only by reference to the appended claims .
inner and outer containers , telescoped together so the outer container can receive unfiltered liquid to be forced through a filter in the inner container , the inner container including an isolation flapper to permit flow from the filter but block flow back to the filter .