초록 ▼

The plunger may be locked down after a full depression stroke so that the overall height of the pump assembly and the container with which it is associated can be significantly reduced. A special valve component loosely encircling the plunger and slidable with friction along the interior surface of

The plunger may be locked down after a full depression stroke so that the overall height of the pump assembly and the container with which it is associated can be significantly reduced. A special valve component loosely encircling the plunger and slidable with friction along the interior surface of the barrel is initially positioned during factory assembly in a closed position covering vents in the sidewall of the barrel, thereby blocking the undesirable ingress of liquid into the barrel above the piston should the container be laid on its side during shipment or other handling. Upon the first unlocking upstroke of the plunger to its extended position, a shoulder on the plunger lifts the valve to an open position so the vents can function properly to introduce ambient air into the container replacing pumped-out product. The valve remains stored in its open position until such time as the plunger is once again locked down beyond the limit of its normal depression stroke, this action causing a second shoulder on the plunger to push the valve back down to its closed position.

대표청구항 ▼

In a dispensing pump having a tubular plunger that is reciprocable within a hollow barrel of the pump between extended and depressed positions for drawing liquid into the barrel during extension strokes and for discharging liquid from the barrel during depression strokes, the improvement comprising:

In a dispensing pump having a tubular plunger that is reciprocable within a hollow barrel of the pump between extended and depressed positions for drawing liquid into the barrel during extension strokes and for discharging liquid from the barrel during depression strokes, the improvement comprising: vent means associated with said barrel and adapted to communicate the interior of the latter with the interior of a container with which the pump is operably associated; lock means operably associated with said plunger for releasably holding the latter in a locked position inwardly beyond said depressed position when the plunger is selectively moved to said locked position; a valve operable within said barrel between an open position exposing said vent means and a closed position sealably covering said vent means and precluding liquid flow into the barrel; and structure operably associated with said plunger for opening said valve during reciprocation of the plunger between said depressed and extended positions, and for closing the valve during holding of the plunger at said locked position.