Pump maintaining container internal pressure

Patent metadata

Field	Value
Publication number	US-9731890-B2
Application number	US-201514684234-A
Country	US
Kind code	B2
Filing date	Apr 10, 2015
Priority date	Apr 11, 2014
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

A piston pump for dispensing fluid from a closed container in which during the cycle of operation to dispense fluid, atmospheric air is discharged into the reservoir towards reducing a vacuum that might otherwise be created within the container.

First claim

We claim:

1. A dispenser for dispensing fluid from a container comprising:
a container having a container outlet opening, the container closed other than the container outlet opening,
a fluid in the container,
a pump mechanism including a fluid pump and a replenishing air pump,
the fluid pump in communication with fluid in the container through the container outlet opening, the fluid pump receiving the fluid from the container and discharging the fluid from the container out a discharge outlet,
the fluid pump comprising a piston pump with a fluid piston and a fluid chamber casing forming a fluid chamber within which the fluid piston is reciprocally slidable relative the fluid chamber casing along a fluid axis in a cycle of operation to draw the fluid from the container and discharge the fluid out the discharge outlet,
the fluid pump in communication with fluid in the container through the container outlet opening, the fluid pump receiving the fluid from the container and discharging the fluid from the container out the discharge outlet,
the replenishing air pump comprising a piston pump with a replenishing air piston and a replenishing air chamber casing forming a replenishing air chamber within which the replenishing air piston is reciprocally slidable along a replenishing air axis in the cycle of operation to draw air from the atmosphere and discharge the air into the container via the outlet opening,
the fluid axis and the replenishing air axis are parallel,
the replenishing air piston is fixed to the fluid piston for movement in unison together,
the replenishing air chamber casing is fixed to the fluid chamber casing for movement in unison together.

2. A dispenser as claimed in claim 1 wherein the dispenser dispenses the fluid onto a person's hand.

3. A dispenser as claimed in claim 2 wherein the fluid is selected from the group consisting of cleaning fluids, disinfecting fluids, and hand creams.

4. A dispenser as claimed in claim 1 wherein, in the cycle of operation, the fluid pump draws a volume of fluid from the container and the replenishing air pump discharges into the container a volume of air approximately equal to the volume of fluid such that a sum of a volume of the fluid within the container and a volume of air in the container after successive of the cycle of operation is maintained relatively constant.

5. A dispenser as claimed in claim 1 wherein, in the cycle of operation of the pump mechanism, the replenishing air pump discharges into the container a volume of air and the fluid pump draws a volume of fluid from the container less than the volume of air such that a sum of a volume of the fluid within the container and a volume of air in the container after successive of the cycle of operation is a raised pressure above atmospheric pressure, and
the dispenser includes a pressure relief arrangement to prevent the pressure in the container from increasing above the raised pressure.

6. A dispenser as claimed in claim 1 wherein, in the cycle of operation, the replenishing air pump discharges into the container a volume of air and the fluid pump draws a volume of fluid from the container greater than the volume of air such that a sum of a volume of the fluid within the container and a volume of air in the container after successive of the cycle of operation is a vacuum below atmospheric pressure, the dispenser including a vacuum relief arrangement to prevent the vacuum in the container from increasing above a maximum vacuum threshold.

7. A dispenser as claimed in claim 1 wherein, in the cycle of operation, when the pressure within the container is less than a threshold pressure above atmosphere, the replenishing air pump discharges into the container a volume of air greater than the volume of fluid and when the pressure within the container is equal to or greater than the threshold pressure above atmosphere, the replenishing air pump does not discharge air into the container.

8. A dispenser as claimed in claim 7 including at least one of (a) a pressure relief arrangement to prevent the pressure in the container from increasing above a safety pressure threshold above atmospheric pressure, and (b) a vacuum relief arrangement to prevent the pressure in the container from decreasing to below a vacuum safety threshold below atmospheric pressure.

9. A dispenser as claimed in claim 1 wherein:
the cycle of operation consists of a first stroke and an opposite second stroke,
A. the replenishing air pump discharges the air into the container via the outlet opening in the first stroke during which first stroke the fluid pump discharges the fluid from the discharge outlet, and
B. the replenishing air pump draws in the air in the second stroke during which second stroke the fluid pump draws the fluid from the container.

10. A dispenser as claimed in claim 9 wherein the first stroke is a retraction stroke and the second stroke is a withdrawal stroke.

11. A dispenser as claimed in claim 10 wherein:
the fluid pump includes a one-way fluid inlet valve and a one-way fluid outlet valve, and
the replenishing air pump includes a one-way replenishing air inlet valve and a one-way replenishing air outlet valve.

12. A dispenser as claimed in claim 10 wherein the replenishing air chamber is a stepped chamber having a replenishing air inner chamber portion coaxial with a replenishing air outer chamber portion, the replenishing air inner chamber portion having a diameter different than a diameter of the replenishing air outer chamber portion.

13. A dispenser as claimed in claim 1 wherein the pump mechanism further includes a discharge air pump,
the discharge air pump comprising a piston pump with a discharge air piston and a discharge air chamber casing forming a discharge air chamber within which the discharge air piston is reciprocally slidable along a discharge air axis in the cycle of operation to draw air from the atmosphere and discharge the air out the discharge outlet,
the fluid axis and the discharge air axis are parallel,
the discharge air piston is fixed to the fluid piston for movement in unison together,
the discharge air chamber casing is fixed to the fluid chamber casing for movement in unison together.

14. A dispenser as claimed in claim 13 wherein the fluid is a liquid capable of foaming and the air discharged from the discharge air pump and the fluid from the fluid pump are simultaneously passed through a foam generator to produce foam.

15. A dispenser as claimed in claim 14 wherein:
A. the replenishing air pump discharges the air into the container via the outlet opening while the fluid pump discharges the liquid from the discharge outlet, and
B. the replenishing air pump draws in the air while the fluid pump draws the liquid from the container.

16. A dispenser as claimed in claim 1 wherein:
the pump mechanism further includes a discharge air pump,
the discharge air pump comprising a piston pump with a discharge air piston and a discharge air chamber casing forming a discharge air chamber within which the discharge air piston is reciprocally slidable along a discharge air axis in the cycle of operation to draw air from the atmosphere and discharge the air out the discharge outlet,
the fluid axis and the discharge air axis are parallel,
the discharge air piston is fixed to the fluid piston for movement in unison together,
the discharge air chamber casing is fixed to the fluid chamber casing for movement in unison together,
the cycle of operation consists of a retraction stroke and an opposite withdrawal stroke,
A. the discharge air pump discharges

Assignees

• Op Hygiene Ip Gmbh

Inventors

• Ophardt Heiner
• Jones Andrew

Classifications

• B05B11/1087

  Combination of liquid and air pumps · CPC title

• B05B11/3087

  Operations & Transport · mapped topic

• A47K5/14

  Foam or lather making devices · CPC title

• B65D83/14 Primary

  Containers for dispensing liquid or semi-liquid contents by internal gaseous pressure, i.e. aerosol containers comprising propellant · CPC title

• A47K5/1207 Primary

  Dispensing from the bottom of the dispenser with a vertical piston · CPC title