发明名称 Manhole cover lifting apparatus
摘要 A manhole cover is seated on a flange in a frame from which depends a skirt forming an access opening to a cavity. A cover lifting mechanism external the access opening includes an arm secured to the cover and a tubular cylinder fixed to the skirt, the cylinder including internal aligned journal bushings. A tubular shaft depends from the arm into the journal and axially displaces and rotates about the journal axis. The shaft has an axially extending central bore with a threaded portion. A threaded rod in the central bore rotates about the shaft axis and is captured to a bearing secured to the cylinder lower end. The rod upper end is squared to receive a socket wrench for manually turning the rod with a mechanical advantage which lifts the shaft, the arm and thus the cover out of its seat. Once lifted, the cover is readily rotated away from the access opening by rotating the shaft in the journal while the threads remain engaged.
申请公布号 US5531541(A) 申请公布日期 1996.07.02
申请号 US19950408075 申请日期 1995.03.22
申请人 FAIRFIELD INDUSTRIES 发明人 CLOVER, DANIEL S.;SISCO, MARK S.
分类号 E02D29/14;(IPC1-7):E02D29/14 主分类号 E02D29/14
代理机构 代理人
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