A surgical stapling apparatus (50) comprises a handle assembly (52), an actuation shaft (8) having a connector (12), and a retraction mechanism (2) positioned within the handle assembly. The retraction mechanism includes a motor (5) coupled to a transmission shaft (17), a first gear (18) rotatably mounted on the transmission shaft, the first gear configured to engage a second gear (25), a clutch (23) operatively attached to the second gear, a main shaft (20) rotatably connected to the clutch, and a pulley (21) coupled to the main shaft, the pulley being operatively attached to the connector. The connector and the pulley may be attached via a cable (14). The retraction mechanism may include a spring motor (19) for maintaining the cable in tension. The spring motor may have a spring element (35) wrapped around and interconnecting at least two arbors (36,37).
