Nozzle adapter for Presta valve

A nozzle adapter for an inflation valve comprising:

• a connection seat including an imaginary axis line defined on a center of the connection seat, an inlet defined on a first end of the imaginary axis line, an outlet formed on a second end of the imaginary axis line, an air stop ring received in the outlet, a conduit defined between the inlet and the outlet, an engagement position defined in the conduit, a coupling defined as part of the connection seat, and a stopping means formed outside the coupling, the coupling having at least one controlling trench defined outside the conduit, wherein the at least one controlling trench extends to the engagement position via the inlet, and a respective controlling trench has a trench portion extending toward the outlet adjacent to the air stop ring;
• at least one control element accommodated in the at least one controlling trench, wherein a respective control element has a fixing shaft extending on a first end thereof and connected with the trench portion, such that the at least one control element swings along the fixing shaft arcuately, the respective control element has an engaging portion extending from a second end thereof and has a controlled portion, wherein the engaging portion is toothed and extends out of the engagement position;
• at least one returning element arranged on the at least one control element so that the engaging portion is pushed into the engagement position;
• a seal cover positioned outside the coupling of the connection seat and having a cylindrical actuation portion positioned within the conduit, wherein when the seal cover is longitudinally moved the cylindrical actuation portion engages the at least one control element which moves the engaging portion in and out of the engagement position;
• and
• an airtight space being defined in the coupling by mating the seal cover with the stopping means.