Valve having suck-back feature
AssigneeLoctite Corporation
InventorJames H. Taylor, Jr.
Life of this patent
Estimating the term…
Abstract
A valve assembly has a spring-biased discharge valve seated for closing the discharge whereafter product is sucked back from a discharge nozzle during a continued movement of the valve in the direction of closing. Parts of the valve may be relatively adjusted for regulating the amount of suck-back flow of product from the nozzle.
Claims8
In a valve assembly comprising a housing containing a liquid discharge passage, a discharge nozzle extending from said passage, a discharge valve in said passage for closing the flow of liquid therethrough upon engagement with a valve seat, and said passage downstream of said valve defining a variable volume chamber in communication with said nozzle for creating a suck-back flow of liquid from said nozzle upon an increase in volume of said chamber, the improvement wherein said valve is spring-biased into a closing position and is moved into an open position in response to a predetermined level of liquid pressure in said passage upstream thereof, said valve having a portion engaging said valve seat in said closing position, said valve seat being defined by the wall of said discharge passage upstream of said variable volume chamber, and said valve having a stop shoulder thereon axially spaced from said valve portion, the wall of the variable volume chamber adjacent to said valve seat defining an abutment, said stop shoulder and said valve portion being disposed in said chamber adjacent said abutment, said stop shoulder and said valve portion being disposed in said chamber when said discharge valve is in said open position, whereby upon a decrease of said liquid pressure below said predetermined level said valve moves into said closing position and thereafter continues movement upstream into said passage until said stop shoulder and said abutment interengage the volume of said chamber thereby expanding to effect said suck-back flow of liquid from said nozzle.
In a valve assembly of the type having a discharge valve for closing a liquid discharge passage from which a discharge nozzle extends, a chamber in communication with said nozzle, means for expanding the volume of said chamber for effecting a suck-back flow of liquid from said nozzle after a closing of said valve, the improvement wherein said valve is moved into closed and open positions respectively by a return spring acting on a downstream end thereof and by pressurized liquid acting on the opposite end thereof sufficient to overcome the spring force, a portion at said opposite end of said valve engaging the wall of said passage upstream of said chamber in said closed position, said wall terminating in an abutment forming a wall of said chamber, and said valve having a stop shoulder spaced from said valve portion, whereby said valve comprises said volume expanding means upon continued movement thereof into said passage after reaching said closed position until said abutment and said shoulder interengage.
Dependencies are inferred from the claim text.