Japan

Device to Prevent Doors from being Left Unlocked

Description of Invention

Using this device, users can notice that a door is left unlocked. Mounted on the inside of the entrance door, the device can be activated and stopped only by locking and unlocking the door. When the key is opened, the G clef starts swinging like a pendulum and the alarm starts to sound. As time passes, the alarm sound changes. When the key is locked again, the sound stops. Because the volume of the alarm is adjusted so that users can hear the sound from outside the entrance, this system prevents users from leaving the front door unlocked.

Inventor(s)