| 摘要 |
The actuator comprises a casing (1) and a spindle (6) coupled together by means of a threaded sleeve (10). An axial displacement of the sleeve along the spindle produces the desired relative rotation between the two main parts (1, 6). The displacement occurs in response to the supply of a fluid to a chamber (11) between one end (5) of the casing and a piston (12) which is displaceable along the spindle, and which in turn presses on the sleeve (10). The outflow of fluid through an aperture (13) is throttled at one or more predetermined points of the rotation by means of a spring loaded shoe (16). During the rotation the shoe overlaps the aperture (13) whereby a desired retardation of the rotation is obtained. Undesired throttling of the inflow of fluid, when the shoe overlaps the aperture et the opposite direction of rotation, is avoided due to the face that the pressure of the fluid overcomes the spring load. |
