What function do elevator buffers serve?

Elevator buffers play a crucial role in safety and performance within an elevator system. They are designed specifically to absorb the impact when the elevator cab reaches the end of its travel, whether at the top or bottom of the shaft. This impact absorption is vital because it helps to reduce the potential for damage to both the elevator cab and the elevator shaft, as well as minimize the risk of injury to passengers.

When the elevator cab reaches its maximum travel distance, if the movement is not controlled properly, the buffers compress and provide a cushioning effect. This ensures a smoother stop, mitigating the forces that would be felt if the cab simply came to a sudden halt. The buffers thus act as a safety mechanism to protect both the equipment and those utilizing it.

This function is fundamentally different from the roles described in other options, which suggest functions that are not associated with the design or purpose of buffers. For instance, increasing the speed of the cab, stabilizing it during ascent, or providing emergency power supply are not the main purposes of buffers and do not align with their function within the elevator system.