REVERSE GEAR DRIVE ALARM LOCK

The utility model discloses a reverse gear driven alarm lock, relating to the field of non-hanging locks. The utility model provides with a reverse lock room at the outer side of a positive lock room and two lock heads are driven by two gears. The lower end of the positive lock head is provided with a section of rack which is engaged with an active tooth bar and an active gear is engaged with a passive tooth bar while a passive gear is engaged with the rack on the inverse lock head. When the positive lock head is forward, the active tooth bar and the active gear are pushed to drive the passive tooth bar and the passive gear and then the reverse lock head is pushed reversely forward. A sliding block and a positioning rotary board are arranged between two lock rooms and the tail of the reverse lock head is connected with a contacting device and then an alarm.