Abstract: The present invention discloses an electromagnetic air pump including an air chamber operable to be compressed or expanded. The air chamber is defined by a platform surface and a rubber cap operable to be pressed downward. The rubber cap includes a support and a cover. During the operation of the electromagnetic air pump, the cover is configured to bear against the support with the platform surface when the cover is pressed downward. When the air chamber is compressed or expanded, each pair of geometrically symmetrical parts of the cover corresponds to a pair of displacement changes relative to the platform surface, wherein a difference between the pair of displacement changes is not greater than 5%. Thus, the rubber cap is provided with an effect of a substantially uniform stress.

Abstract: A refillable ink box proofed against the formation of airlocks during filling includes an ink storage chamber, a seat, and an insertion tube. The box includes a bottom plate, and first and second side walls. The bottom plate and first and second side walls form the ink storage chamber. The seat protrudes to the exterior and carries insertion tube, ink outlet, and air guiding port. The insertion tube defines the ink inlet and also an air vent. The ink inlet communicates with the ink outlet port, the ink outlet communicates with the ink storage chamber. The air guiding port equalizes gas pressure with outside atmosphere and is positioned above the ink outlet.

Abstract: A refillable ink box proofed against the formation of airlocks during filling includes an ink storage chamber, a seat, and an insertion tube. The box includes a bottom plate, and first and second side walls. The bottom plate and first and second side walls form the ink storage chamber. The seat protrudes to the exterior and carries insertion tube, ink outlet, and air guiding port. The insertion tube defines the ink inlet and also an air vent. The ink inlet communicates with the ink outlet port, the ink outlet communicates with the ink storage chamber. The air guiding port equalizes gas pressure with outside atmosphere and is positioned above the ink outlet.

Abstract: A switching apparatus for a driving system includes a motor, a first function unit, a second function unit and a power switching unit. The power switching unit includes a planetary gear set connected to the motor and driven by the motor and a swinging mechanism connected to the planetary gear set and driven by the planetary gear set. The power switching unit is switchable between a first position, where the power switching unit is drivingly connected to the first function unit, and a second position, where the power switching unit is drivingly connected to the second function unit.

Abstract: A breaking switch for ink feeding channel and a printing device using the breaking switch prevents leakage of ink when a printing device is not level or not well placed. The printing device includes a case, an ink box, an ink feeding channel from the ink box, and a breaking switch for ink feeding channel. The breaking switch clamps or releases the ink feeding channel and includes a supporting base and a pressing plate. The pressing plate is rotatable between open and closed positions. When on a level working surface, the supporting leg lifts the pressing plate away from the supporting portion. When the supporting leg is free and suspended the pressing plate presses on the supporting portion and closes off the ink supply.

Abstract: A switching apparatus for a driving system includes a motor, a first function unit, a second function unit and a power switching unit. The power switching unit includes a planetary gear set connected to the motor and driven by the motor and a swinging mechanism connected to the planetary gear set and driven by the planetary gear set. The power switching unit is switchable between a first position, where the power switching unit is drivingly connected to the first function unit, and a second position, where the power switching unit is drivingly connected to the second function unit.