| 摘要 |
<p>A well expander comprises an adapter (18) for its connection to a drive, a hollow casing (1) with a central channel (2) and with radial openings (3) in its lateral wall, sliding cutters (6) provided with clamping blocks (4) and secured in the radial openings (3) of the casing (1), and a mechanism for sliding out the cutters (6), consisting of a piston (15) and a holder (17) of the cutters (6). The piston (15) is connected to the casing (1) in a manner providing for the possibility of their common rotation and is rigidly connected with the adapter (16). The wall of the piston (15) is provided with radial channels (20) connecting its central channel (16) with an annular cavity (21) formed by the walls of the piston (15) and of the casing (1). The holders (17) of the cutters (6) is mounted with a gap in the central channels (16, 2) of the piston (15) and of the casing (1) and has an annular protrusion (24). In the central channel (16) of the piston (15) is mounted a saddle (26) capable of co-operating with the annular protrusion (24) of the holder (17).</p> |
