Which process creates a wedging effect on the drive sprocket when the drive chain breaks?

The process that creates a wedging effect on the drive sprocket when the drive chain breaks is pawling. In the context of escalator and lift systems, pawling refers to a mechanism where special pawls or latches engage with the sprocket teeth to provide a backup system when the drive chain is compromised. This action ensures that, even in the event of a chain failure, the engagement of the pawls creates a physical grip on the drive sprocket, preventing unexpected movements and maintaining safety.

This safety feature is crucial for the operation of escalators and other similar mechanisms. It ensures that a broken chain does not lead to a catastrophic failure that could endanger passengers. The instant engagement of the pawls upon chain failure allows the system to remain stable while maintenance or repairs can be carried out. Therefore, this mechanism's role in safety reinforces the importance of proper design in escalator systems.