摘要 |
A single acting semi-rotating spring returned pneumatic actuator has a plurality of springs (10) in a circular array, for effecting return movement of two pistons (5) slidable in a bore in the body (1) and each having a rack portion (6) meshing with a pinion (7) on an output shaft (8) extending perpendicularly of the axis of the bore. The springs (10) are each arranged in individual seatings and are maintained in position by means of a suitable flanged spring guide (12) carrying an end cap (18) in such a way as to facilitate access to and replacement of the springs (10). In particular, the end cap (18) is held on to the spring guide (12) by means of a screw (20) with an internal threaded through hole (20 min ) which is of a length sufficient to guarantee that upon release of the screw (20) to effect removal of the end cap (18) the springs (10) are completely relaxed. |