The utility model discloses a novel transmission box which comprises a box body, the box body is further provided with a transmission cavity, the transmission cavity is provided with an arc-shaped main transmission
stroke, the box body in the transmission cavity is in
pivot joint with a
handle, the
handle is connected with a first transmission piece, the first transmission piece is movably connected with the main transmission
stroke, and the transmission cavity is provided with a second transmission piece movably connected with the first transmission piece. And the
handle rotates to drive the first transmission part to move along the arc-shaped main transmission
stroke so as to drive the second transmission part to move, so that the door and window lock is opened or closed. The arc-shaped transmission stroke and the two movable connection transmission pieces are used for achieving the transmission process that rotation of a gear-free rack is changed into linear movement, the transmission stroke is increased, meanwhile, the transmission structure of the transmission box is simplified, the precision requirement of transmission parts of the transmission box is lowered, the transmission box is easier to install and maintain, and cost is saved.