Patent ID: 8439234
Filing Date: 2013-05-14
Classification: B05B

Abstract:
1. A non-dripping suck-back nozzle which is set onto a dispenser comprising: a press cover having a horizontal channel defined therein; a revolving cover, the press cover being movable relative to the revolving cover, the revolving cover screwed onto the dispenser; a cylinder being set into a top opening of the dispenser, the cylinder having a top shoulder formed around one end thereof, a bottom of the top shoulder abutting against the top opening of the dispenser, an upper chamber and a lower chamber both defined in the cylinder, at least one exhaust hole opened on the upper chamber of the cylinder; a bead, a spring, a needle valve, a second piston and a connecting bar being set into the cylinder, the connecting bar axially connected to the press cover, the connecting bar having a hollow channel, the hollow channel communicating with the horizontal channel of the press cover; the second piston having an inner round pole, an outer part and a connecting ring, the inner round pole being hollow, the outer part enclosing the inner round pole, the connecting ring formed between the inner round pole and the outer part, the connecting ring corresponding to a middle of the outer part, the inner round pole and the outer part and a top of the connecting ring defining a connecting ring-shaped groove, the connecting bar having a lower periphery defined at a lower end thereof, wherein when the lower periphery of the connecting bar is plugged into the connecting ring-shaped groove to abut against the connecting ring of the second piston, it is airtight between the second piston and the connecting bar; the connecting bar and the second piston both set in the upper chamber of the cylinder, the bead being set in the lower chamber of the cylinder; the needle valve having a round rod and a convex ring, the convex ring defined around the round rod, a top end of the round rod of the needle valve passing through the inner round pole of the second piston and the round rod inserted into the hollow channel of the connecting bar, the needle valve moved by the motion of the connecting bar which is axially moved by the press cover, a plurality of first sub channels defined between the connecting bar and the round rod so that a volume of fluid from the dispenser can flow into the horizontal channel of the press cover via the first sub channels, a plurality of second ribs which is extended upwardly from the convex ring being axially defined on the round rod, a plurality of second sub channels respectively defined by each two adjacent second ribs on the round rod and the inner round pole so that the fluid from the dispenser can flow into the first sub channel via the second sub channel; and an annular groove defined on the convex ring, one end of the spring abutting against a bottom of the lower chamber, another end of the spring enclosing the round rod and abutting against the convex ring of the needle valve; wherein the needle valve is moved toward the second piston by an elasticity of the spring until the annular groove of the needle valve abuts against the inner round pole of the second piston so that it is airtight between the second piston and the needle valve; wherein, when the lower periphery of the connecting bar is plugged into the connecting ring-shaped groove to abut against the connecting ring of the second piston, the annular groove of the needle valve departs from the inner round pole of the second piston; when the annular groove of the needle valve abuts against the inner round pole of the second piston so that it is airtight between the second piston and the needle valve, the lower periphery of the connecting bar departs from the connecting ring of the second piston; in addition, because the lower periphery departs from the connecting ring, a space between the connecting bar and the needle valve is enlarged.