Cyclic pressing-down gear arrangement

A cyclic pressing-down gear arrangement, comprising:

• a hollow first housing, which has an end adapted to communicate with an outside environment, the first housing comprising a stop mounted therein at a predetermined position, the end of the first housing that communicates with the outside environment comprising a fitting opening formed therein, adapted to receive a spray can having a top to which a spraying head is mounted to fit therein;
• a press bar, which is rotatably mounted in the first housing and comprises a protrusion and an elastic element, the protrusion being located above the spraying head, the elastic element having an end supported on the stop;
• a circuit control unit, which is electrically connected with a power supply, a motor, and a switching element, the motor comprising a rotation spindle, the rotation spindle extending into the first housing, the rotation spindle comprising a first gear mounted thereto, the switching element being set at a predetermined location with respect to the press bar, the circuit control unit being provided with at least a first activation time point and at least a second activation time point so that the circuit control unit is operable to activate the motor at the first activation time point;
• and
• a second gear, which is rotatably mounted in the first housing and is operatively coupled to the first gear, the second gear comprising at least one cam mounted thereto to be in contact engagement with the press bar, whereby when the motor is activated, the first gear drives the second gear to cause the cam to drive the press bar down so that the protrusion presses the spraying head to make the spray can spray and when the cam is rotated to contact and trigger the switching element, the motor is shut down and a restoration spring force of the elastic element drives the press bar to return.