Patent ID: 8956039
Filing Date: 2015-02-17
Classification: B01F

Abstract:
1. A safety protection device for a speed changing device of a mixer being disposed in the mixer and interconnected to a gear shift fork, the safety protection device comprising: an operating rod assembly with an operating section, a driven section, and a drive section; a control unit formed on the operating rod assembly; a device panel fixed on the mixer and including an display surface and a back surface, in the device panel being formed a through hole, and the driven section of the operating assembly being pivoted in the through hole of the device panel; a tact switch connected to one end of a trigger arm, and another end of the trigger arm being provided with a trigger roller, the tact switch being fixed on the display surface of the device panel, and the trigger roller of the tact switch being aligned with the control unit; a motor controller electrically connected to the tact switch, when the trigger roller is disengaged from the tact switch, power of the motor controller will be turned off; and an eccentric drive shaft including a connecting section and an eccentric driven section eccentrically formed on the connecting section, the connecting section being formed with an axial hole for insertion of the drive section of the operating rod assembly, and the eccentric driven section of the eccentric drive shaft being interconnected to and driving the gear shift fork to perform gear shift.