Quick coupler

A quick coupler comprising:

• a male part including a male part main body internally defining a first passage having a male valve core and a first spring disposed therein;
• the male valve core being located in a front end of the male part main body and the first spring being located between and having two ends elastically pressed against the male valve core and a rear inner end of the male part main body;
• the male part main body being externally provided with a radially outward protruded portion, which has a slanted pushing surface and a chamfered locating surface facing forward and rearward, respectively, relative to the male part main body;
• and
• a female part including a front female case, a rear female case, and an outer sliding sleeve;
• the front female case being provided with a plurality of first through holes and a plurality of second through holes, which are circumferentially alternated and axially staggered on a front circumferential surface of the front female case for receiving first steel balls and second steel balls therein, respectively, such that the first steel balls are located axially in front of the second steel balls;
• and the front female case further having a second spring externally fitted around it;
• the front and the rear female case being connected together to internally define a second passage communicable with the first and second through holes;
• the second passage having a movable valve core, a fixed core shaft, and a third spring disposed therein;
• the fixed core shaft being connected to the rear female case, the movable valve core being movably fitted around an outer side of the fixed core shaft, and the third spring being fitted between and having two ends elastically pressed against the movable valve core and a bottom of the fixed core shaft;
• and the outer sliding sleeve being slidably fitted on an outer side of the front female case and the second spring;
• and wherein when the male part is connected to the female part, the slanted pushing surface of the radially protruded portion on the male part main body pushes against the first steel balls and the second steel balls on the female part sequentially to thereby drive the outer sliding sleeve toward the rear female case by a first stroke and a second stroke in sequence;
• and when the second steel balls are pushed by the slanted pushing surface to move across the protruded portion to abut on the chamfered locating surface, the outer sliding sleeve is elastically pushed by the second spring to an original position for pressing the second steel balls down to a locked position, such that the male and the female part are connected together and the first passage is communicable with the second passage.