Damping ring - for drain manhole cover made of specified grade of polyethylene having raised edge and specific shore hardness and modulus of elasticity

摘要

A drain manhole cover (4) rests on a damping ring (2), fitted to a recess in the manhole frame (3). The ring has a raised edge (1) and is made of polyethylene, esp. the grade LOTRENE (RTM). This material should have a hardness on the shore D scale of 55 and a modulus of elasticity of 220 MPa. ADVANTAGE - Rapid wear, caused by rattle due to passing traffic is prevented.