| 摘要 |
The invention relates to the field of inspection hatches or manholes consisting of a support-frame and of a cover. A cover 11 of a manhole or of an inspection hatch is provided with at least one lifting hole 10 in which a key or other suitable tool may be inserted so as to lift the cover 11 off its support-frame, either by means of a direct force or by means of a lever arm. The lifting hole 10 contains two portions 16, 17 of space of various depth forming a step or level, and a crosspiece 15 formed in the orifice of the cavity at a place situated above the edge of the step or level. The invention may be used to facilitate the operation consisting in lifting, either directly or by means of a lever arm, the cover of an inspection hatch or of a manhole. <IMAGE>
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