Mechanical switch of photoelectrical type and a key assembly of a keyboard

A mechanical keyboard key assembly of photoelectrical type, comprising:

• mechanical switches of the photoelectrical type and a printed circuit board (PCB), characterized in that:
• each mechanical switch of the mechanical switches of the photoelectrical type comprises:
• an upper cover, a lower cover, a press shaft and a primary spring, the upper cover and the lower cover matching to form into a hollow holding cavity, in which the press shaft and the primary spring are positioned, the holding cavity is further provided with a sound optical path mechanism abutting against the primary spring, the sound optical path mechanism comprising a secondary spring, a ram, a ram stop guiding groove, and a guiding bracket, the guiding bracket is coupled with the press shaft, moves up and down as the press shaft moving up and down;
• and a chute is provided on the guiding bracket;
• an upper end of the ram is provided with a protruding strip, which is arranged in the chute and can freely move along the chute;
• when the guiding bracket moves up and down, the protruding strip is restricted by the chute and drives the ram to rotate by itself;
• the secondary spring is mounted on the ram above the protruding strip and stops at a top of the guiding bracket;
• a lower end of the ram is arranged in the ram stop guiding groove, on which a slot is provided for the protruding strip to slide;
• the lower end of the ram is provided with an optical path structure;
• there is provided a photoelectrical circuit on the PCB, which is consisted of a light transmitter infrared (IR) and a light receiver phototransistor (PT);
• said each mechanical switch of the mechanical switches of the photoelectrical type is mounted on the PCB, the optical path structure provided on the lower end of the ram forms into a working relationship with the photoelectrical circuit on the PCB corresponding to said each mechanical switch of the mechanical switches of the photoelectrical type, and an up and down motion and rotation of the ram can shut or turn on the photoelectrical circuit which is consisted of the light transmitter IR and the light receiver PT.