Tool removed double triangular type manhole cover - requires two pincer levers engaging sockets in each leaf removal

摘要

The double triangular type forged steel manhole cover is designed to prevent unauthorized removal and requires two pincer action levers (19) each engaging two sockets (4, 5) in respective leaves (3a) to effect cover removal. The cover is of rectangular variety split diagonally into two; with the two halves being inter-hingeably connected, and the sockets locate at each extremity of opposed parallel outer edges. Considering a pair of sockets (4, 5) they have outer faces (6) inclining away from one another and into the cover body, and inner concave faces (7) at a lesser incline. Tool engagement is thus only possible using the lever specially provided, by virtue of its auto-locking leverage action. Preferably the tool is a cranked (8, 11) intermediary hinged (9) lever.