|국가/구분||United States(US) Patent 등록|
|미국특허분류(USC)||404/26 ; 52/21|
|발명자 / 주소|
|출원인 / 주소|
|인용정보||피인용 횟수 : 39 인용 특허 : 0|
A stackable height adjustment ring for supporting a manhole cover frame upon a concrete manhole shaft liner has a ring body that is formed from plastic resin, e.g., scrap plastic. The ring includes inner and outer radially spaced apart side walls and optionally a top wall. Brace arms which are integral with the walls preferably extend radially between the walls for holding them together. The rings have alignment members, e.g., an inner wall of the ring can have an upwardly facing shoulder upon its upper edge and the outer wall, a downwardly facing should...
A stackable height adjustment ring for supporting a manhole cover frame comprising, a ring body formed from polymeric material, said ring body including concentric inner and outer radially spaced apart upright side walls, the outer side wall defines an outside peripheral edge of the ring and the inner side wall comprises an inside edge of the ring surrounding a central opening, said inner and outer side walls having an annular passage therebetween extending from a top portion of the ring body to a bottom portion of the ring body, at least one vertically ...