Patent ID: 9694374
Date: 2017-07-04
CPC Classifications: B05B,B65D,F16K

Claim:
1. A suck-back valve selectively actuatable for dispensing liquid through a dispensing opening in an open condition of the valve, comprising: a spring member comprising a distal web that defines an exit orifice bounded by a shoulder wall, a proximal web, and a plurality of flexibly elastic bands helically connecting the distal web and proximal web for resiliently urging the distal web and the proximal web toward a predetermined spacing; and a pin comprising an elongated shaft having a proximal end and carrying a substantially hollow frustoconical cone at a distal end of the shaft, said cone having an outer valving surface and said shaft having a bore of predetermined cross-sectional extent defined longitudinally along and within the shaft to create a continuous fluid passageway through and along the pin; wherein the pin is coupled at the pin proximal end to the proximal web of the spring member and the cone valving surface abuts, in a closed condition of the valve, the distal web shoulder wall to capture the pin within the spring member for relative longitudinal displacement of the pin between a first position in which the valve is closed and a second position in which the valve is open for dispensing of liquid, so that a distally-directed actuating force selectively applied to the pin distally displaces the pin and the coupled proximal end of the proximal web against a compressive return urgency of the elastic bands to reduce the spacing between the distal web and the proximal web and to displace the valving surface distally from the valving surface abutment with the distal web shoulder to open the valve and enable a dispensing release of the liquid through the discharge opening of the open valve; wherein the distal web shoulder comprises a valve seat against which the valving surface abuts in the closed position of the valve, and wherein with said distal displacement of the pin the valving surface moves from abutment with the valve seat to define, between the valving surface and the valve seat, the dispensing opening as a spacing between the valving surface and the valve seat; and wherein the pin bore is predeterminately sized so that, when the distally-directed actuating force on the pin is at least reduced, the return urgency of the elastic bands proximally displaces the pin to close the dispensing opening between the valving surface and the valve seat and enable at least some dispensed liquid that remains proximate the dispensing opening to be sucked back through the pin bore as the valve is deactivated from the open condition to the closed condition.