Blast proof apparatus for the coin return cavity of a public phone

A blast proof apparatus for a coin return cavity of a public phone comprising:

• A pivot, formed and positioned inside the top of the coin return cavity;
• An inner cover, having a width greater than the coin return mouth together with a plurality of through holes formed on a surface thereof;
• An outer cover, having a width less than both the inner cover and the coin return mouth which bonds to the outer surface of the inner cover to form a coin return mouth cover, and then by said pivot to occlude the coin return mouth;
• and
• A spring element, positioned at the fixation point of said pivot, the elasticity force of the spring is to be applied to the outer cover, so the inner and outer covers are closely binds together to form a coin return mouth cover;
• under the normal situation, said cover allows only single direction--push inward to open the coin return mouth, once an explosion occurs within the coin return cavity, the high pressure formed will be released by pushing the outer cover outward through the through holes of the inner cover in order to avoid possible damage in the coin return apparatus.