대표
청구항
▼
1. A closure assembly for a containing structure, such as a milk tank, which containing structure defines a containing chamber for a liquid, and which has an opening, such as a manhole, defined by a ring structure, said assembly comprising: a. an outside cover member having an outer perimeter portion adapted to be positioned adjacent said ring structure, and also having a main inner portion extending across said perimeter portion, said inner portion having a first vent opening leading to ambient atmosphere; b. an inside venting closure member adapted...
1. A closure assembly for a containing structure, such as a milk tank, which containing structure defines a containing chamber for a liquid, and which has an opening, such as a manhole, defined by a ring structure, said assembly comprising: a. an outside cover member having an outer perimeter portion adapted to be positioned adjacent said ring structure, and also having a main inner portion extending across said perimeter portion, said inner portion having a first vent opening leading to ambient atmosphere; b. an inside venting closure member adapted to be positioned in an operating location adjacent said cover, said closure member having an inner portion that is located below the first vent opening and a perimeter portion surrounding said inner portion; c. said closure member being characterized in that it has a relaxed position where in its operating location and without external forces applied thereto, the inner portion is spaced downwardly from said first vent opening to permit air flow through said first vent opening, said closure member having an upwardly deflected position where, with an upper surge force exerted upon said closure member, the inner portion of the closure member is positioned against said first vent opening in closing relationship therewith; d. said closure member being further characterized in that in its operating location the closure member provides a second vent opening means spaced from said first vent opening and leading to said containing chamber to permit air flow to and from said containing chamber to an area between said cover member and said closure member; whereby with the venting closure member in its operating location and in its relaxed position, said containing chamber can be vented to ambient atmosphere, and with a surge force exerted against said closure member, said closure member moves to its upwardly deflected closure position to block possible flow of liquid outwardly through said first vent opening. 2. The assembly as recited in claim 1, wherein the inner portion of the closure member is contoured so that at least a portion of an upper surface thereof slopes downwardly toward said second vent opening, whereby liquid which may pass up through said second vent opening would flow by gravity back through said second vent opening. 3. The assembly as recited in claim 1, wherein said closure member has a peripheral flange portion which, with the closure member in its operating location, is positioned between the outer perimeter portion of the cover member and said ring structure so as to provide a seal between said cover and said ring structure. 4. The assembly as recited in claim 3, wherein said closure member has a passageway defining member defining a passageway that extends from said second vent opening means to a third vent opening which, with the closure member in its operating location, communicates with said containing chamber. 5. The assembly as recited in claim 4, wherein said passageway defining member is positioned adjacent the perimeter portion of the closure member and extends at least partly along a circumferential portion of said closure member. 6. The assembly as recited in claim 5, wherein said passageway defining member extends entirely around the circumference of the closure member. 7. The assembly as recited in claim 6, wherein said passageway defining member is a skirt member which extends downwardly and outwardly from the perimeter portion of the closure member, said skirt member having a lower edge portion which, with the closure member in its installed position, fits against the ring structure, to define with the ring structure said passageway. 8. The assembly as recited in claim 7, wherein said skirt member is formed with said third vent opening at a location spaced circumferentially from said second vent opening means. 9. The assembly as recited in claim 8, wherein said third vent opening is located diametrically opposite said second vent opening means. 10. The assembly as recited in claim 1, wherein said outside cover member has a downwardly extending peripheral flange surrounding said first vent opening, whereby, with the venting closure member in its upwardly deflected position, the inner portion of the closure member forms a closure with the flange of the cover member. 11. The assembly as recited in claim 1, wherein said closure member has a peripheral flange member which, with the closure member in its operating location, is positioned between the outer perimeter portion of the cover member and said ring structure so as to provide a seal between said cover and said ring structure, said closure member having at its perimeter portion a downwardly and outwardly extending moderately flexible skirt portion which, with the venting closure member in its operating location, is positioned against said ring structure, said skirt portion defining with said ring structure a circumferential venting passageway extending around said closure member. 12. The assembly as recited in claim 11, wherein there is a third vent opening formed in said skirt member, and said third vent opening is circumferentially spaced from said second vent opening means. 13. A venting closure member adapted to be used for a containing structure, such as a milk tank, which containing structure defines a containing chamber for a liquid, which has an opening, such as a manhole, defined by a ring structure, and which has an outside cover member having an outer perimeter portion adapted to be positioned adjacent said ring structure, and also having a main inner portion extending across said perimeter portion, said inner portion having a first vent opening leading to ambient atmosphere, said venting closure member adapted to be positioned in an operating location adjacent said cover, said closure member having an inner portion that is located below the first vent opening and a perimeter portion surrounding said inner portion, said closure member being characterized in that it has a relaxed position where in its operating location and without external forces applied thereto, the inner portion is spaced downwardly from said first vent opening of the cover member to permit air flow through said first vent opening, said closure member having an upwardly deflected position where, with an upper surge force exerted upon said closure member, the inner portion of the closure member is positioned against said first vent opening in closing relationship therewith, said closure member being further characterized in that in its operating location the closure member provides a second vent opening means spaced from said first vent opening and leading to said containing chamber to permit air flow to and from said containing chamber to an area between said cover member and said closure member; whereby with the venting closure member in its operating location and in its relaxed position, said containing chamber can be vented to ambient atmosphere, and with a surge force exerted against said closure member, said closure member moves to its upwardly deflected closure position to block possible flow of liquid outwardly through said first vent opening. 14. The venting closure member as recited in claim 13, wherein the inner portion of the closure member is contoured so that at least a portion of an upper surface thereof slopes downwardly toward said second vent opening, whereby liquid which may pass up through said second vent opening would flow by gravity back through said second vent opening. 15. The venting closure member as recited in claim 13, wherein said closure member has a peripheral flange portion which, with the closure member in its operating location, is positioned between the outer perimeter portion of the cover member and said ring structure so as to provide a seal between said cover and said ring structure. 16. The venting closure member as recited in claim 15, wherein said closure member has a passageway defining member defining a passageway that extends from said second vent opening means to a third vent opening which, with the closure member in its operating location, communicates with said containing chamber. 17. The venting closure member as recited in claim 16, wherein said passageway defining member is positioned adjacent the perimeter portion of the closure member and extends at least partly along a circumferential portion of said closure member. 18. The venting closure member as recited in claim 17, wherein said passageway defining member extends entirely around the circumference of the closure member. 19. The venting closure member as recited in claim 18, wherein said passageway defining member is a skirt member which extends downwardly and outwardly from the perimeter portion of the closure member, said skirt member having a lower edge portion which, with the closure member in its installed position, fits against the ring structure, to define with the ring structure said passageway. 20. The venting closure member as recited in claim 19, wherein said skirt member is formed with said third vent opening at a location spaced circumferentially from said second vent opening means. 21. The venting closure member as recited in claim 20, wherein said third vent opening is located diametrically opposite said second vent opening means. 22. The venting closure member as recited in claim 13, wherein said closure member has a peripheral flange member which, with the closure member in its operating location, is positioned between the outer perimeter portion of the cover member and said ring structure so as to provide a seal between said cover and said ring structure, said closure member having at its perimeter portion a downwardly and outwardly extending moderately flexible skirt portion which, with the venting closure member in its operating location, is positioned against said ring structure, said skirt portion defining with said ring structure a circumferential venting passageway extending around said closure member. 23. The venting closure member as recited in claim 22, wherein there is a third vent opening formed in said skirt member, and said third vent opening is circumferentially spaced from said second vent opening means.
