a. Field of Invention
The invention relates generally to improvements in pump dispensers, and more particularly to such pump dispensers having an improved spout valve assembly including an elastomeric one-way valve forming an air tight spout capable of quick shut-off of the discharge channel to prevent drying of product within the discharge channel.
b. Description of Related Art
The known manually actuated pump dispensers especially those designed for the dispensing of personal care products which may be in the form of pastes or gels, typically have both inlet and outlet check valves for respectively controlling the flow of liquid product into the pump chamber during each piston suction stroke and for controlling the outflow of the liquid product from the pump chamber during each piston compression stroke.
Such pump dispensers are advantageous in that they permit dispensing of products in a metered quantity over an extended period of use. However, extended use of many available pump dispensers often resulted in accumulation and drying of product at the dispenser head outlet or in the channel leading up to the outlet, which must be avoided from both an operational as well as hygienic point of view.
In order to address the drawbacks of product accumulation and drying with conventional pump dispensers, several valve designs have been proposed for sealing the channel leading up to the dispenser head outlet. U.S. Pat. No. 5,186,368 (hereinafter “the '368 Patent”) and U.S. Pat. No. 5,447,258 (hereinafter “the '258 Patent”) are exemplary of such a known pump dispensers. While the valve designs of the '368 and '258 Patents have improved upon conventional pump dispenser valve designs, as discussed below, these designs are nevertheless problematic in their own respect.
Specifically, referring to FIGS. 4 and 6 of the '368 Patent, the elastomer valve, referred to as a shutter 1, is mounted by telescoping it over a nipple (see FIG. 6) formed at the front end of pump head 2. Shutter 1 sealingly engages the nipple along the forward peripheral edge thereof as well as along the side periphery. Head 2 is disposed in sealed contact with side wall 11 of the shutter over a first surface which extends only over the inside of side wall 11, and the head is further disposed in sealed contact with the inside surface 210i of end wall 10. These assembly requirements enable shutter 1 to be sealingly engaged with the nipple.
As readily evident from the description of the '368 Patent valve design, the valve assembly is disadvantageous in that shutter 1 can easily dislodge over repeated use because of the ineffective mounting thereof on the nipple of pump head 2. This tendency to dislodge is especially of concern when the shutter is subjected to pasty product under high pressure during pumping. Further, the shutter cannot otherwise be strengthened for enhancing its mounting with the head since it is of a one-piece construction, and the shutter can only be rigidified to a certain degree since sufficient elasticity is needed for opening and closing the slit.
Turning now to the valve design of the '258 Patent, referring to FIG. 1 of the '258 Patent, the valve assembly includes first and second valve bodies 7, 11 partially retained within the dispenser head by stopper 22. Valve body 11 is specifically retained within the dispenser head by engaging part 8 disposed in contact with projection 3a on one side of part 8 and stopper surface 22b on the other side thereof. Valves 7 and 11 operate by means of their engagement at location 10 (denoted opening part 10), where valve body 11 is disposed in sealing engagement with shaft 6 of valve 7. Thus, during downward pressing of head 20, product enters from pipe 2 into the space between valve 11 and shaft 6. When sufficient pressure is created, valve 11 expands radially to break the contact between end opening part 10 and shaft 6, and allow product to exit. Upon release of pressure on head 20, opening part 10 of valve 11 resumes contact with shaft 6 to seal the exit.
As readily evident from the description of the '258 Patent valve design, the valve assembly of the '258 Patent is disadvantageous in that it includes at least three components, namely valve bodies 7 and 11, and stopper 22 for effective sealing of the exit channel. Further, valve bodies 7 and 11, and stopper 22 are of relatively complicated designs. From a manufacturing point of view, for pump dispensers often made by the hundreds-of-thousands, the addition of a single component, as well as the preparation required for a relatively complicated mold can add significantly to the overall cost of the finished product. Further, as readily evident from the discussion above, while the valve assembly of the '258 Patent may provide adequate sealing of the outlet channel at early stages of dispenser operation, extended use of the '258 Patent pump dispenser invariably results in accumulation and drying of product at the dispenser head outlet due to product accumulation between opening part 10 and shaft 6.
In a similar manner as the '368 and '258 Patents, the spout valve designs of U.S. Pat. Nos. 6,497,346, 6,065,642 and 5,377,877 are problematic due to their complicated operation and assembly, and further due to the inadequate mounting thereof to the dispenser head.
It would therefore be of benefit to provide a pump dispenser having an improved elastomeric spout valve which both facilitates easier and more economical manufacture and assembly of the pump dispenser, which securely remains mounted to the dispenser head over the life of the pump dispenser for reducing or virtually eliminating the odds of the valve being dislodged from the dispenser head, regardless of pressures required for opening the valve slit, and which is robust in design and efficient in operation. It would also be of benefit to provide a spout valve which will quickly respond for sealing the discharge flow path during each piston suction stroke irrespective of the viscosity of the product being dispensed.
The invention solves the problems and overcomes the drawbacks and deficiencies of prior art pump dispenser designs by providing in combination an improved deformable spout valve which both facilitates manufacture and assembly of the pump dispenser, which securely remains mounted to the dispenser head over the life of the pump dispenser, regardless of pressures required for opening the spout valve slit, and which provides repeatability in the cross-sectional quality of the discharged product over the life of the pump dispenser.
The present invention thus provides a manual pump dispenser including a discharge head reciprocable between pressure and return strokes. The pump dispenser may include a spout valve assembly located within an opening in the discharge head. The spout valve assembly permits outletting of liquid product through a passage in fluid communication with the discharge head opening during each of the pressure strokes, and includes a spout valve retained substantially within the discharge head opening by a retainer. The spout valve may be disposed within an opening in the retainer, and include a slit at a first end thereof and an orifice at a second opposite end thereof. The slit may include slit lips directly engageable with each other to define a slit closed configuration and disengageable from each other to define a slit opened configuration. The spout valve may be made of a material for permitting predetermined opening of the slit under pressure from the liquid product during each of the pressure strokes for thereby allowing the liquid product to be discharged out through the slit when in the slit opened configuration, and for otherwise permitting rapid closing of the slit to prevent the liquid product from being discharged through the slit when in the slit closed configuration.
For the pump dispenser described above, the slitted first end of the spout valve may protrude out through the retainer opening beyond an outer surface profile of the discharge head to prevent liquid product from accumulating within the retainer opening. The retainer may fixedly retain the spout valve within the discharge head opening by the provision of an annular rib disposed within an annular groove for providing a snap-fit engagement between the retainer and the discharge head. The retainer may include a flange at an inner end thereof engageable with a complementary flange provided adjacent the second opposite end of the spout valve for fixedly retaining the spout valve within the discharge head opening. The spout valve may include a section tapered toward the slit. The retainer opening may include a complementary taper as the spout valve tapered section to securely retain the spout valve within the retainer opening. The spout valve may be formed of a silicone and/or a thermoplastic elastomer.
The present invention further provides a spout valve assembly for a manual pump dispenser including a discharge head reciprocable between pressure and return strokes. The spout valve assembly may be located within an opening in the discharge head. The spout valve assembly permits outletting of liquid product through a passage in fluid communication with the discharge head opening during each of the pressure strokes, and includes a spout valve retained substantially within the discharge head opening by a retainer. The spout valve may be disposed within an opening in the retainer, and include a slit at a first end thereof and an orifice at a second opposite end thereof. The slit may include slit lips directly engageable with each other to define a slit closed configuration and disengageable from each other to define a slit opened configuration. The spout valve may be made of a material for permitting predetermined opening of the slit under pressure from the liquid product during each of the pressure strokes for thereby allowing the liquid product to be discharged out through the slit when in the slit opened configuration, and for otherwise permitting rapid closing of the slit to prevent the liquid product from being discharged through the slit when in the slit closed configuration.
For the spout valve assembly described above, the slitted first end of the spout valve may protrude out through the retainer opening beyond an outer surface profile of the discharge head to prevent liquid product from accumulating within the retainer opening. The retainer may fixedly retain the spout valve within the discharge head opening by the provision of an annular rib disposed within an annular groove for providing a snap-fit engagement between the retainer and the discharge head. The retainer may include a flange at an inner end thereof engageable with a complementary flange provided adjacent the second opposite end of the spout valve for fixedly retaining the spout valve within the discharge head opening. The spout valve may include a section tapered toward the slit. The retainer opening may include a complementary taper as the spout valve tapered section to securely retain the spout valve within the retainer opening. The spout valve may be formed of a silicone and/or a thermoplastic elastomer.
The present invention yet further provides a spout valve assembly for a pump dispenser including a discharge head. The spout valve assembly may be located within an opening in the discharge head. The spout valve assembly permits outletting of liquid product through a passage in fluid communication with the discharge head opening, and includes a spout valve retained substantially within the discharge head opening by a retainer. The spout valve may be disposed within an opening in the retainer, and include a slit at a first end thereof and an orifice at a second opposite end thereof. The slit may include slit lips directly engageable with each other to define a slit closed configuration and disengageable from each other to define a slit opened configuration. The spout valve may be made of a material for permitting predetermined opening of the slit under pressure from the liquid product for thereby allowing the liquid product to be discharged out through the slit when in the slit opened configuration, and for otherwise permitting rapid closing of the slit to prevent the liquid product from being discharged through the slit when in the slit closed configuration.
For the spout valve assembly described above, the slitted first end of the spout valve may protrude out through the retainer opening beyond an outer surface profile of the discharge head to prevent liquid product from accumulating within the retainer opening. The retainer may fixedly retain the spout valve within the discharge head opening by the provision of an annular rib disposed within an annular groove for providing a snap-fit engagement between the retainer and the discharge head. The retainer may include a flange at an inner end thereof engageable with a complementary flange provided adjacent the second opposite end of the spout valve for fixedly retaining the spout valve within the discharge head opening. The spout valve may include a section tapered toward the slit. The retainer opening may include a complementary taper as the spout valve tapered section to securely retain the spout valve within the retainer opening. The spout valve may be formed of a silicone and/or a thermoplastic elastomer.
Additional features, advantages, and embodiments of the invention may be set forth or apparent from consideration of the following detailed description, drawings, and claims. Moreover, it is to be understood that both the foregoing summary of the invention and the following detailed description are exemplary and intended to provide further explanation without limiting the scope of the invention as claimed.
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate preferred embodiments of the invention and together with the detail description serve to explain the principles of the invention. In the drawings:
Turning now to the drawings wherein like reference characters refer to like and corresponding parts throughout the several views, a discharge head is generally designated 10 in
Briefly, the dispenser of the '258 Patent includes a pump housing which defines a pump cylinder having a pump piston disposed for reciprocation therein. The housing, which is open at its upper end is supported by a conventional container closure in the form of an internally threaded cap, which is adapted to support the pump housing within the interior of a container to dispense the liquid product from the container as desired. Supported at the upper end of the pump piston is a discharge head (designated pressure base 20), similar to discharge head 10 according to the present invention.
Turning now to
As shown in
As illustrated in
Referring to
With retainer 26 and valve 22 thus assembled as shown in
Those skilled in the art would appreciate that the reverse taper of surfaces 36, 47 of valve 22 and retainer 26 may be provided and functions equally well in all these type of dispensers to retain the valve positively in place without dislodgement even under extreme and repeated high pressures of the dispensed fluids.
The operation of discharge head 10 will now be described in detail with reference to
Specifically, once the pump for discharge head 10 is primed and the pump chamber is partially filled with the liquid product to be dispensed, together with a residual amount of air and/or liquid vapor, downward finger pressure on head 10 will initiate downward movement of the pump piston on its operative stroke. Throughout the initial portion of the stroke, the main discharge valve (not shown) will be retained in a closed position by upward pressure of the pump spring. As such downward movement continues, however, the main discharge valve will open such that liquid product is discharged through hollow piston rod 19, through passages 14, 16, and out thorough slit 38.
Thereafter, when finger pressure on head 10 is released, the piston commences its upward stroke, by energy stored in the pump spring. Upward movement of the piston produces a pressure drop in the pump chamber, causing liquid to be sucked into the pump chamber via a dip tube, in readiness for a further downward stroke. During the upward stroke, slit 38 remains in a closed configuration.
The assembly of discharge head 10 will now be described with reference to
Specifically, in order to assemble discharge head 10, spout valve 22 may be disposed within opening 24 within head 10, and thereafter, retainer 26 may be snap-fitted within opening 24 with valve 22 already in place. Alternatively, as shown in
The spout valve assembly according to the present invention thus provides several benefits over those of the prior art. For example, spout valve assembly 18 including spout valve 22 and retainer 26 facilitates assembly of the pump dispenser, and is further securely disposed at an end of the discharge head nozzle for reducing or virtually eliminating the odds of valve 22 being dislodged from discharge head 10. During shipment and periods of non-use, slit 38 effectively seals passage 14 from atmosphere, thus preventing leakage of product from passage 14 and further preventing drying of product within passage 14. The spout valve assembly according to the present invention also avoids the need for any means acting between spout valve 22 and discharge head 10 for retaining the valve in place, as evident with conventional valve assemblies, as such retention means are often inadequate for preventing dislodgement of the spout valve from the pump head. Yet further, contrary to conventional valve assemblies, the valve assembly of the present invention does not require any specific portion of the elastomeric valve to be sealed with the discharge head, but simply provides the required sealing upon the snap-fit engagement of retainer 26. Moreover, valve assembly 18 includes only two components, i.e. valve 22 and retainer 26, which from a manufacturing point of view provide an extremely cost-effective pump dispenser design.
As discussed above, various modifications may be made to the spout valve assembly without departing from the scope of the present invention. For example, although a single outlet slit 38 is illustrated in
Although particular embodiments of the invention have been described in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those particular embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.