| 摘要 |
In a device for making an opening in a concrete-cast wall or ceiling in connection with a shuttering, a conical shaped body (14) is provided, at its centre, with a screw thread (17) or similar wedge face and with a shank (18) which is rotatable therein, is likewise provided with a screw thread (19) or similar wedge face, is supported on the shuttering (15) during its rotation and lifts the body from the shuttering or out of the concrete (10). <IMAGE>
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