| 摘要 |
<p>The invention concerns a tensioning device (7) for at least one torsion spring (2) fitted round a shaft (1) which is operatively linked to a door leaf with which it moves, executing a rotary motion as it moves. One end of the torsion spring (2) is fixed to a tensioning ring which can be rotated about the shaft (1) and, following tensioning of the spring by rotation of the tensioning ring (5), can be locked to the shaft (1) so that it can no longer rotate. The spring (2) can be tensioned manually, without the need for any great force and without danger for the fitter, by virtue of the fact that the tensioning ring (5) is fitted coaxially to the power-output element (9) of a high-ratio gear (8) whose power-input element (10) is operatively connected to the power-output element (9), and hence to the spring, by mounting the power-input element (10) in a housing (11) fitted to the shaft (1) or to the tensioning ring (5), the power-input element (10) being designed so that it can be connected to an ordinary hand-held rotary power tool.</p> |
