Spring Device Torque Return Clutch for Timepiece Duration

The patent applies dynamics by making the connection state between the mainspring and barrel dynamic rather than static. The torque transfer clutch unit automatically engages or disengages the wheel train connection based on the winding state of the mainspring. When the mainspring is sufficiently wound, the clutch engages to enable torque return and rewinding. When the mainspring unwinds below a reference level, the clutch disengages to prevent power consumption and ensure sufficient output torque for driving the timepiece. This dynamic adaptation resolves the contradiction between extending duration time and maintaining adequate power output.

The patent applies partial action by having the torque return unit operate only during specific conditions - when the mainspring is sufficiently wound and the clutch is engaged. During this partial operation period, excess torque is used to rewind the spring, extending duration time. When the clutch disengages, all torque is directed to driving the timepiece without being consumed by rewinding. This partial operation allows the system to achieve extended duration without requiring increased maximum output torque or larger barrel volume.

The patent applies self-service by enabling the mainspring to rewind itself using its own output torque when sufficiently wound. The torque return unit transfers part of the output torque back to the mainspring through the wheel train, allowing the spring to service its own rewinding needs. This self-service mechanism extends duration time without requiring external power input. The system automatically manages this self-service through the clutch unit, which ensures that rewinding only occurs when excess torque is available, preventing torque deficiency for driving the driven object.