| 摘要 |
A valve actuator with an arcuate piston (30) disposed within a housing (10) including a side wall (12) having a partition (18) and two end plates (14, 16) whereby when joined, the housing forms a first and a second compartment (20, 22). An arcuate piston (30) travels between the compartments via an opening (24) in the partition in an oscillating manner. A removable piston assembly enables (24) removing the arcuate piston (30), output shaft (32) and lever arms (34a, 34b) supporting the piston in order to remove the output shaft (32) or to engage a spiral (68) connecting the output shaft (32) with the housing. The spiral spring (68) may be pretensioned by winding before inserting the piston assembly into the housing. Fluid pressure applied to either compartment (20, 22) urges movement of the arcuate piston into the opposite compartment. |
