contacts stops 26 and 28 torsion spring 15 enables output shaft 34 of actuator assembly 14 to continue rotating even though disc 18 and valve shaft 20 are stopped from further rotation this helps prevent actuator 32 from failing due to overheating output shaft 24 is able to continue rotating because torsion spring 15 provides a compliant interface between valve shaft 20 and output shaft 34 such that output shaft 34 may rotate without requiring valve shaft 20 to rotate in contrast in existing valve assemblies a valve shaft is rigidly connected to an actuator output shaft such that the output shaft may only rotate if the valve shaft is able to rotate torsion spring 15 may be any suitable torsion spring known in the art factors in determining the suitable design e g geometry and material attributes of torsion spring 15 for a particular assembly include the operational valve shaft 20 loads torsional output levels of actuator assembly 14 and the degree of pretwist or u201c flex u201d or u201c wind up u201d required from torsion spring 15 in the first embodiment illustrated in fig1 a and 1b torsion spring 15 is formed of a spring steel and has a rectangular cross section a torsion spring having a round wire cross section may also be used in accordance with the present invention as illustrated in fig2 a which is a partial perspective cross sectional view.