Draining device for air control equipment

A draining device for air control equipment comprising:

• a bottom shell having a draining hole formed through a bottom surface of the bottom shell;
• a top shell covered on a top of the bottom shell and having
• a sleeve part being hollow and communicating with the draining hole of the bottom shell;
• and
• two inclined recesses formed in the inside wall of the sleeve part;
• a knob mounted in the sleeve part and having
• a central hole communicating with the draining hole of the bottom shell;
• two sliding protrusions formed on and protruding transversely from an outside wall of the knob, and each sliding protrusion mounted slidably in one inclined recess of the top shell;
• and
• two tabs formed on a top surface of the knob, and each tab having an inner inclined side, and the inclined sides of the tabs facing to each other, wherein a bottom distance between bottom edges of the inner inclined sides of the tabs is smaller than a top distance between top edges of the inner inclined sides of the tabs;
• a switch mounted in the bottom shell and having a button;
• and
• a connecting device having
• a connecting tube mounted through the central hole of the knob and communicating with the draining hole of the bottom shell;
• a flange formed around the connecting tube and mounted across the inner inclined sides of the tabs of the knob;
• and
• an extension rod formed on and protruding out from the flange and having
• an end protrusion mounted through the top shell and the bottom shell and abutting the button of the switch.