Compact multipurpose dustproof mask

A compact multipurpose dustproof mask comprising:

• a body pipe having an outlet hole formed at one end and a mouth contact hole formed at the other end thereof, and the end where the mouth contact hole is formed is held in the mouth or nose;
• a backward flow preventing ball installed to be capable of moving back and forth and biased by a magnetic force in a direction to block a narrow hole formed inside the body pipe so that the body pipe can be open/shut according to pressure of internal air;
• and
• a branch pipe formed between the mouth contact hole of the body pipe and the backward flow preventing ball, the branch pipe having an inlet hole having a shape corresponding to a filter formed at one end thereof so that the filter is connected.

A compact multipurpose dustproof mask comprising:

• a body pipe having an outlet hole formed at one end and a mouth contact hole formed at the other end thereof, and the end where the mouth contact hole is formed is held in the mouth or nose;
• a backward flow preventing ball installed to be capable of moving back and forth and biased by at least one spring in a direction to block a narrow hole formed inside the body pipe so that the body pipe can be open/shut according to pressure of internal air;
• and
• a branch pipe formed between the mouth contact hole of the body pipe and the backward flow preventing ball, the branch pipe having an inlet hole having a shape corresponding to a filter formed at one end thereof so that the filter is connected.