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(11) | EP 1 433 535 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Fluid pump dispenser having product having retraction feature |
| (57) A fluid pump dispenser (10) of the loss motion piston type provides for maintaining
the discharge ports (33) open a slight interval at the commencement of each plunger
upstroke while the pump chamber (21) expands to retract productfrom the discharge
passage (13) into the chamber to thereby avoid the formation of product droplets at
the exit end of the discharge spout (12). Such is effected in accordance with one
embodiment by reducing the friction force acting between the piston (18) and the pump
cylinder (16) relative to the friction force acting between the piston (18) and the
stem (11). In another embodiment an inlet valve assembly has a portion lying in the
path of the piston which portion is connected by spring legs to a valve portion such
that the restoring force of the spring legs shifts the piston together with the stem
at the commencement of the plunger upstroke which maintains the discharge passage
in open communication with the chamber.
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