Manual liquid dispenser

A manual liquid dispenser comprising:

• a mounting member mounted on an outer peripheral wall of a neck portion of a container and having an engaging cylinder extending upwardly therefrom:
• a large-diameter cylinder extending into the container, said large-diameter cylinder having a diameter in a lower half part thereof larger than a diameter in an upper half part thereof;
• a suction valve internally mounted in an opened bottom of said large-diameter cylinder;
• a sucking tube communicating with said suction valve and extending to the bottom of the container;
• a small-diameter cylinder inserted into and extending from the interior of said mounting member and integrally formed with a body having a liquid spraying section including a dispensing outlet;
• said small-diameter cylinder being slidably moved by the operation of the body;
• a rod member internally mounted in said small-diameter cylinder;
• said rod member having formed at the lower part thereof a piston expanded in diameter in a skirt shape;
• a flexible seal formed at the lower end of said piston and slidably contacted with the lower inner peripheral surface of said large-diameter cylinder;
• a spring arranged between the interior of said piston and the bottom of said large diameter cylinder for always urging said rod member upward;
• an outer cylinder formed at a lower end of said smalldiameter cylinder and slidably contacted at a lower end thereof with said upper half part of said large-diameter cylinder to form a first pressure chamber beneath said outer cylinder and inside said upper half part of said large diameter cylinder;
• a cylindrical member engaged with the outer periphery of said rod member, contacted at the upper end thereof with said outer cylinder and disposed at the lower end thereof at a radial communication hole formed in said rod member;
• a notch, communicating the first pressure chamber and the interior of said small-diameter cylinder, formed on the upper end surface of said cylindrical member;
• a flexible member formed at the lower end of said cylindrical member adjacent said radial communication hole, to externally expand when a second pressure chamber within said piston reaches a predetermined pressure;
• wherein a third pressure chamber is formed between said piston and the peripheral wall of said large-diameter cylinder when said piston is depressed downwardly;
• wherein, a downward force on said small-diameter cylinder forces liquid from said second pressure chamber through said radial communication hole, into said first and third pressure chambers, through said notch and into said liquid spraying section;
• and wherein release of said downward force allows said spring to return said piston upward thereby recharging said second pressure chamber through said suction valve, and forcing liquid from said third pressure chamber into said first pressure chamber, through said notch and into said liquid spraying section.