INSPECTION PIT CAP Russian patent published in 2000 - IPC

FIELD: highway engineering. SUBSTANCE: inspection pit cap includes reinforced concrete plate with central conical through hole widening downward and having shoulder for supporting the cover. Novelty consists in that plate thickness is reducing towards periphery with flat lower surface and upper surface is inclined, at least, on one part of its length. Generating line of surface of central through hole forms angle of 1-6 deg with respect to vertical. Plate upper part has cast iron circular member embedded in body and having over its perimeter protrusion forming cap hole. Circular member protrudes above plate upper surface for height equalling 0.2-0.3 of plate maximum height. In this case, length of projection of generating line of surface of cast iron member onto vertical plane amounts to 0.45-0.5 of plate maximum height, and protrusion of cast iron member forms shoulder for supporting of cover. EFFECT: simplified manufacture of inspection pit cap, higher degree of factory readiness and quality of mounting, improved mechanical and physical characteristics and prolonged service life of inspection pit cap. 4 cl, 2 dwg