None.
In general, the present invention relates to a pump used in a soap dispenser. More particularly, the present invention relates to a diaphragm pump having a flexible dome that is depressed to pump soap from the dispenser. Most particularly, the present invention relates to a diaphragm pump having a dome that includes a fold line that reduces pumping force and provides for more complete discharge of fluid from the pump. The present invention further relates to a dome having an inwardly extending flap that acts as an inlet value.
Dispensers are widely available for dispensing a variety of flowable materials including creams, lotions, soaps and pastes, all of which will be generally referred to as “soap.” These dispensers incorporate a variety of pumps including diaphragm pumps. In most cases, the diaphragm pump includes a base to which a flexible dome is attached to define a pumping chamber therebetween. The flexible dome component is used to create pressure to open an outlet valve and release product from the dispenser and also create a vacuum that opens an inlet valve to bring product back into the pump chamber.
Existing domes, generally have a continuous surface and are typically hemispherical in shape. As a result, the existing domes do not collapse in a repeatable consistent fashion. For example, sometimes, one side of the dome will collapse to a greater extent than another side upon application of the same force at the same location. These inconsistencies affect pump performance by creating dead spaces, where fluid is trapped behind the collapsed portion of the dome and cannot escape through the outlet. As a result, less than a complete charge of fluid is dispensed from the pumping chamber.
In similar fashion, existing domes require a relatively large amount of force to collapse the dome. When larger and smaller pump output is desired, the size of the dome must be increased to keep optimum pump efficiency constant as measured by compression ratio and the ratio of dead space to the dome internal volume. This is of particular concern, when a customer requests a different output because the ancillary pump components must also change size in order to accommodate the larger dome. Most times, however, compromises in performance are accepted over changing these components.
To account for the relatively large force needed to compress the domes, most dispensers incorporate a lever that provides a mechanical advantage to allow the user to pump soap from the dome. In hands free dispensers, larger or more batteries must be supplied to provide sufficient power with a minimally acceptable battery life.
As a result, there is a need for a diaphragm pump that requires relatively less force to dispense soap than existing dome pumps. There is a further need for a dome pump that collapses in a repeatable consistent fashion.
Further considering the issue of pump efficiency, another source of inefficiency is the currently used “floating” ball inlet check valve. The floating ball inlet check valve is provided at the inlet to prevent fluid from going back into the bottle when the dome is depressed. The floating ball rests in an open position allowing soap to fill the chamber beneath the dome, and closes in response to the pressure applied to the dome. As the ball floats toward the closed position, some soap leaks back through the inlet into the bottle. As a result, less than a complete charge of fluid is pumped from the chamber. Therefore, a better valve at the inlet would be desirable.
The floating ball design has additional disadvantages in that since it rests in an open position, the floating ball is prone to sticking after it rests for a period of time. Moreover, in terms of manufacture the floating ball design adds complexity to the pump assembly in terms of adding a component, namely the ball, providing inlet geometry that holds the ball in place, and, in assembly by adding the step of inserting the ball within the inlet. Consequently, a pump assembly that eliminates the floating ball inlet valve is desirable.
In light of the foregoing, it is an object of the present invention to provide an improved dome pump.
It is a further object of the present invention to provide a dome pump that requires less force to compress the dome than existing pumps.
It is still a further object of the present invention to provide a dome pump that collapses in a repeatable fashion.
It is yet another object of the present invention to provide a dome pump having a flap valve extending inward from the dome.
In view of at least one of the foregoing objects, the present invention generally provides a pump for dispensing soap from a container in a dispenser, the pump including a base, a flexible dome attached to the base defining a chamber therebetween, an inlet and an outlet formed in the base and opening into the chamber, the inlet being in fluid communication with the container, and wherein the dome has a fold line.
The present invention further provides a pump for dispensing soap from a container housed within a dispenser, the pump including a base, and, a flexible dome attached to the base defining a chamber therebetween, the dome having a first tier extending axially outward and radially inward from the base toward an annular shoulder that extends radially inward from an axial extremity of the first tier, and a second tier extending axially outward and radially inward from the annular shoulder defining a fold line between the first and second tiers, and an inlet and outlet formed in the base and opening into the chamber, where the inlet is in fluid communication with the container.
The present invention further provides a pump for dispensing soap from a container housed within a dispenser, the pump including a base, a flexible dome attached to the base defining a chamber therebetween, an inlet and an outlet formed in the base and opening into the chamber, the inlet being in fluid communication with the container, and a flexible flap extending inwardly from the dome into the chamber, the flap being adapted to selectively close the inlet.
For a complete understanding of the objects, techniques and structure of the invention, reference should be made to the following detailed description and accompanying drawings wherein:
A dispenser having a pump assembly according to the concepts of the present invention is depicted in
With continued reference to
The pump assembly 20 is a diaphragm pump and includes a base 21 and a flexible dome 22. With reference to
To discharge soap from the chamber 23, base 21 further includes an outlet 30 defined therein, the outlet 30 may communicate with an outlet passage 31 extending behind the base 21 and downwardly toward a nozzle 33, where fluid is ultimately dispensed at 35. As shown, the nozzle 33 may snap onto the outlet passage 31. Nozzle 33 may include a radially extending flange 36, best shown in
As will be appreciated, soap residue may cling to the outlet passageway 31 and over time drip from the nozzle 33. To prevent such dripping, a valve 26 may be provided downstream of outlet 30. The valve 26 may be of any type including a ball check valve or the like. In the example shown, a septum-type valve 26 is provided at the tip of the nozzle 33. As best shown in
In accordance with one aspect of the invention, the flexible dome 22 is adapted to collapse in a consistent fashion. To that end, the dome 22 may be provided with a fold line, generally indicated by the numeral 40. A “fold line” is a structure formed integrally in the dome 22 to control or facilitate the collapse thereof. For example, the fold line 40 may include a positive or negative structure within the dome 22, such as a reinforced area that resists buckling causing a relatively weaker area to buckle, or a weakened area created by removing material. The fold line 40 may also be a pre-stressed area that changes the moment of inertia of the dome to increase the likelihood of buckling in a defined area. In the example shown, fold line 40 includes a crease formed between first and second tiers 41, 42 in the dome 22. The crease outlines the second tier 47 increasing its propensity to collapse, as described more completely below. As best shown in
As best shown in
In accordance with another aspect of the present invention, the dome 22 may include an attachment portion, generally indicated by the numeral 50, generally at its perimeter 51. This assembly may be used to attach the dome 22 to the base 21 without a snap ring, as commonly done in the art. As best shown in
Since the dome 22 and accordingly the flange 52 are made of a flexible material, the flange 52 may be compressed to fit within the channel and expand upon release to securely attach the dome 22 to the base 21 in a sealing arrangement.
In accordance with yet another aspect of the present invention the dome 22 may be provided with a radially inwardly extending flap 65 that may be used as an inlet valve to prevent soap from returning to the container 25 during the pumping stroke. The flap 65 may be formed integrally with dome 22 ie. as a single unit. In general, flap 65 covers inlet 24 to prevent soap from reentering the container 25 from chamber 23. As shown, the flap 65 may rest in a closed position (
As shown in
As is further shown, inlet 24 may be located radially outward of outlet 30, such that the radial inward extension of a flap 65 that extends about the entire circumference of dome 22 does not cover the outlet 30. By using a flap 65 that extends about the entire circumference of dome 22, assembly of the dome 22 and base 21 may be made without having to circumferentially align the flap 65 and inlet 24.
It will be appreciated that the flap 65 may, however, be formed to extend along only a portion of the dome's circumference necessary to cover the inlet 24 and avoid interference with the outlet 30. For example, if the inlet 24 is located at an upper portion of the chamber 23 and the outlet 30 is located at a lower portion of the chamber 23, the flap may extend inwardly from only the upper portion of the dome 22 leaving the outlet 30 open. As discussed previously, the outlet 30 may be provided with its own check valve to prevent soap from leaking from the chamber 23, when the pump is not in use.
In light of the foregoing, it should thus be evident that a dome pump for dispensing soap, according to the concepts of the present invention, substantially improves the art. While, in accordance with the patent statutes, only the preferred embodiment of the present invention has been described in detail hereinabove, the present invention is not to be limited thereto or thereby. It will be appreciated that various modifications may be made to the above-described embodiment without departing from the invention. Therefore, to appreciate the scope of the invention, reference should be made to the following claims.
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