This is from the B737NG airplane manual. Boeing doesn't offer the technical drawings in the pilot manuals, one would have to have access to the maintenance manuals. Boeing is very sticky about their material being published on the internet.
Autopilot Flight Director System (AFDS)
The AFDS is a dual system
consisting of two individual flight control ...
On just about all airplanes the Stall Protection System disengages the autopilot automatically whenever a range of parameters is exceeded. One of them is approaching stall. Generally the Autopilot will be kicked off automatically just before stick shaker onset on a traditional non-FBW airplane, and it can't be reengaged until the parameters that were ...
In the AF447 accident, the autopilot disconnected because of inconsistent airspeed:
Temporary inconsistency between the airspeed measurements, likely following
the obstruction of the Pitot probes by ice crystals that, in particular, caused the
autopilot disconnection and the reconfiguration to alternate law;
(BEA - Final Report)
As long as the airspeed ...