| 摘要 |
The mechanism for preventing theft of manhole covers includes two screws (3) which are pulled through the openings (1.1) formed on the central axis (1.2.) of the cover (1) for the manhole (2). The springs (4) are pulled over on the screws (3) in such a way that they are pressed between the head (3.1) of the screw and the butterfly (5) which are screwed on the screws (3) and are secured by nuts (6). Butterflies (5) cheers on the screws (3) while they are compressing springs (4) until the butterfly (5) do not reach the height of the position of the channel (2.1) which is arranged below the frame (8). Butterflies (5) have a border screws (7). A lid (1) is placed on the frame (8) of the manhole (2) so that the butterfly (5) enter into the channels (2.1) below the frame (8). Excenter key (9) is inserted into the hole (3.2, 3.3) of the head (3.1) of the screw (3) and rotate so that the butterfly (5) reclines with the border screw (7) on the frame (8). After that, butterflies (5) are moving upward by exerting pressure within the channel (2.1) until the spring (4) does not provide a sufficient force of pressure and attract the cover (1) on the frame (8). |
