The device used on public toilet door locks which replacing the traditional ones. The user can leave the toilet without touching the lock or the handle. Operated by foot and the ratchet on the lock, people can prevent the bacterial infection from hands touching.

The design of the ratchet check mechanism can utilize a pull rod to pull the ratchet wheel on the triangular door bolt and maintain the counterclockwise rotation, and connect the tail of the pull rod to the pedal at the bottom of the door panel. When the user picks up the pedal, the power is transmitted by the pedal. The ratchet lever and the ratchet rotate.

門鎖及腳踏機構等技術。