MANHOLE HATCH (VERSIONS) Russian patent published in 2016 - IPC E02D29/12 E03F5/02 

FIELD: manufacturing technology.

SUBSTANCE: in two versions of design of manhole hatch it comprises frame 1 with support ledge 2 arranged along inner contour of frame 1 and cover 3 with supporting surface 4 along its contour, which is in contact with support ledge 2 of frame 1. Frame 1 and cover 3 are made of plastic material (for example, from thermoplastic polymer compositions, polymer-sand compositions, composite materials, etc.) by casting or pressing in moulds. Frame and cover 3 can have in plane both round 5 and rectangular 6 shapes. At that, cover 3 can be installed either in frame 1 or free, or by means of hinge 7. In any version, in support ledge 2 of frame 1 there are cavities 8 for installation into them, at least of one support rod 9, whereon cover 3 rests. To increase carrying capacity of hatch it can be equipped with support elements 18, which should be performed in form of one or several support rings connected with support rods 9. First version of hatch design is characterised by that inner surface of cover 3 is smooth and directly rests on support rods 9 and support elements 18. Second version of design is characterised by that on inner surface of cover 3 there are stiffening ribs 19 in contact with support rods 9 and support elements 18.

EFFECT: invention solves task of improving strength properties of hatch at closed cover, which enables its use on roadway of roads; besides, task of improving security of service of manhole at open hatch cover solves simultaneously by same tools, which prevents people and animals falling into well.

30 cl, 26 dwg