|국가/구분||United States(US) Patent 등록|
|미국특허분류(USC)||404/26 ; 404/25 ; 52/20|
|발명자 / 주소|
|출원인 / 주소|
|인용정보||피인용 횟수 : 27 인용 특허 : 1|
A hollow, flexible, bendable, cylindrical-shaped, hat-like sleeve is water-tightly joined with the upper end of the riser section of a manhole structure. The free end of the sleeve is trimmed so that its upper edge fits beneath the shoulder of the frame supporting the manhole cover to prevent subsurface water from entering into the manhole interior through the regions between the manhole cover supporting frame and the top of the riser section, which is usually fitted with adjustment rings to bring the manhole cover frame up to grade. The sleeve is easily...
Apparatus for providing a water-tight seal in the region above the riser section of a manhole structure comprising: resilient, compressible, bendable sleeve means having an outwardly extending integral projection cast into the top portion of said riser section, the portion of the sleeve means adjacent said projection extending into and being adjacent to the interior surface of the riser section adjacent the top end thereof, the outer diameter of the riser section at the top end being greater than the outer diameter of the projection; a manhole cover supp...