U.S. patent application number 12/009518 was filed with the patent office on 2008-05-22 for valve for use in a container which employs pressure to dispense product.
Invention is credited to Christian T. Scheindel.
Application Number | 20080116231 12/009518 |
Document ID | / |
Family ID | 39415911 |
Filed Date | 2008-05-22 |
United States Patent
Application |
20080116231 |
Kind Code |
A1 |
Scheindel; Christian T. |
May 22, 2008 |
Valve for use in a container which employs pressure to dispense
product
Abstract
A pressurized dispensing container for dispensing fluid products
contains a valve stem which engages a resilient annular restoring
boot to assure that the valve is returned to its closed state once
manual force is removed from the valve. A valve stem shoulder
engages the upper end of the restoring boot. To avoid having the
boot snap around the shoulder and thus fail to restore the valve to
its closed state when required, the following design feature is
employed. The upper end of the annular boot has an inwardly facing
flange which engages an annular recess or groove in the valve stem
which recess is at a position directly below the valve shoulder.
Certain dimensional relationships are optimum to provide assurance
of full engagement between the inwardly facing boot flange and stem
recess.
Inventors: |
Scheindel; Christian T.;
(Randolph Center, VT) |
Correspondence
Address: |
Lloyd McAulay;Cowan, Liebowitz & Latman, P.C.
1133 Avenue Of The Americas
New York
NY
10036-6799
US
|
Family ID: |
39415911 |
Appl. No.: |
12/009518 |
Filed: |
January 18, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11842632 |
Aug 21, 2007 |
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12009518 |
Jan 18, 2008 |
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11334716 |
Jan 18, 2006 |
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11842632 |
Aug 21, 2007 |
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10882625 |
Jun 30, 2004 |
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11334716 |
Jan 18, 2006 |
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10816969 |
Apr 2, 2004 |
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10882625 |
Jun 30, 2004 |
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10285238 |
Oct 31, 2002 |
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10816969 |
Apr 2, 2004 |
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Current U.S.
Class: |
222/402.1 |
Current CPC
Class: |
B65D 83/48 20130101 |
Class at
Publication: |
222/402.1 |
International
Class: |
B65D 83/00 20060101
B65D083/00 |
Claims
1. In a vertically movable valve for use in a pressurized
dispensing container, the valve movable between an upper closed
state and a depressed dispensing state, the valve including a valve
stem with an axis, at least one dispensing opening at a lower zone
of the stem, the improvement in a resilient annular sealing grommet
around the stem, comprising: an upper boot portion of said grommet
having an upper edge, a shoulder on said valve stem, said shoulder
and said upper edge of said grommet engaging to provide a restoring
force when said valve is depressed, an inwardly extending annular
flange at said upper edge of said boot, an annular recess on said
stem, said recess being adjacent to and below said shoulder, said
boot flange and said stem recess engaging to provide full insertion
of said flange into said recess.
2. The improvement of claim 1 wherein: said stem recess has an
opening whose width is greater than the thickness of said boot
flange.
3. The improvement of claim 1 wherein: the inner diameter of said
boot below said flange has an interference fit relation to the
outer diameter of said stem below said recess.
4. The improvement of claim 2 wherein: the inner diameter of said
boot below said flange has an interference fit relation to the
outer diameter of said stem below said recess.
5. The improvement of claim 1 wherein said flange has a lower
surface and said boot has an inner wall further comprising: a
fillet at the juncture between said flange lower surface and said
boot inner wall.
6. The improvement of claim 2 wherein said flange has a lower
surface and said boot has an inner wall further comprising: a
fillet at the juncture between said flange lower surface and said
boot inner wall.
7. The improvement of claim 3 wherein said flange has a lower
surface and said boot has an inner wall further comprising: a
fillet at the juncture between said flange lower surface and said
boot inner wall.
8. The improvement of claim 4 wherein said flange has a lower
surface and said boot has an inner wall further comprising: a
fillet at the juncture between said flange lower surface and said
boot inner wall.
9. The improvement of claim 1 wherein: there is nominal clearance
between the inner end of the boot flange of the inner end of the
stem recess, said nominal clearance comprising at least one of a
diameter clearance and a thickness clearance.
10. The improvement of claim 2 wherein: there is nominal clearance
between the inner end of the boot flange of the inner end of the
stem recess, said nominal clearance comprising at least one of a
diameter clearance and a thickness clearance.
11. The improvement of claim 3 wherein: there is nominal clearance
between the inner end of the boot flange of the inner end of the
stem recess, said nominal clearance comprising at least one of a
diameter clearance and a thickness clearance.
12. The improvement of claim 5 wherein: there is nominal clearance
between the inner end of the boot flange of the inner end of the
stem recess, said nominal clearance comprising at least one of a
diameter clearance and a thickness clearance.
13. The improvement of claim 8 wherein: there is nominal clearance
between the inner end of the boot flange of the inner end of the
stem recess, said nominal clearance comprising at least one of a
diameter clearance and a thickness clearance.
14. The improvement of claim 1 wherein: the outer diameter of the
upper edge of said boot is at least equal to the outer diameter of
said shoulder.
15. The improvement of claim 2 wherein: the outer diameter of the
upper edge of said boot is at least equal to the outer diameter of
said shoulder.
16. The improvement of claim 4 wherein: the outer diameter of the
upper edge of said boot is at least equal to the outer diameter of
said shoulder.
17. The improvement of claim 13 wherein: the outer diameter of the
upper edge of said boot is at least equal to the outer diameter of
said shoulder.
18. The improvement of claim 3 wherein: said stem to boot
interference is approximately 11 mils on a diameter.
19. The improvement of claim 4 wherein: said stem to boot
interference is approximately 11 mils on a diameter.
20. The improvement of claim 17 wherein: said stem to boot
interference is approximately 11 mils on a diameter.
Description
REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of Ser. No.
11/842,632 filed 21 Aug. 2007 and Ser. No. 11/842,640 filed 21 Aug.
2007; which applications in turn are continuations-in-part of Ser.
No. 11/334,716 filed 18 Jan. 2006, which in turn is a
continuation-in-part of Ser. No. 10/882,625 filed 30 Jun. 2004,
which in turn is a continuation of Ser. No. 10/816,969 filed 2 Apr.
2004, now abandoned, and which in turn is a continuation of Ser.
No. 10/285,238 filed 31 Oct. 2002, now abandoned; the entire
disclosures of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] This invention relates to a valve for use in dispensing
product from a pressurized container and more particularly to a
valve with a design that minimizes the risk of a particular type of
valve failure.
[0003] The particular type of valve failure to which this invention
is addressed is one involving the relationship between the
resilient boot that restores a valve to the closed state when
pressure is removed and the valve stem which engages the boot. The
problem that arises is that, particularly in smaller valves, the
upper rim around the boot snaps over the stem shoulder against
which it abuts when the vertical pressure on the boot exceeds a
threshold peculiar to the boot.
[0004] The seriousness of this problem is inversely proportion to
the size of the valve and more directly proportional to the
pressure which has to be exerted to open the valve and to hold it
open.
[0005] Applicant's U.S. Pat. No. 5,785,301 and U.S. Pat. No.
6,425,503 and U.S. Pat. No. 6,340,103 are representative of prior
valve designs for use in hand held pressurized containers
dispensing a variety of products.
[0006] The valve designs to which this invention is addressed have
a sealing grommet which surrounds the valve stem. When the valve is
closed, the lower portion of the sealing grommet encases the
product openings in the valve stem and prevents product from being
dispensed. The upper portion of the grommet is a thin wall boot
portion whose upper edge engages a shoulder that extends out from
the stem. When the stem is depressed to open the valve, the
shoulder pushes down on the boot causing the boot to buckle. The
boot, being resilient, therefore exerts a restoring force on the
stem shoulder and thus on the stem to return the valve to its
closed state once actuating pressure is removed from the valve
stem.
[0007] There are times when the pressure exerted by the valve
shoulder on the resilient boot to open the valve causes the boot to
snap around the shoulder, thus losing the restoring force and
making the valve ineffective.
[0008] The major purpose of this invention is to provide a valve
design that minimizes the risk of this failure of engagement
between boot and valve stem shoulder.
[0009] It is a further and related purpose of this invention to
meet the above objective in a design which minimizes the additional
cost of fabricating the valve so as to make this improved valve
economically viable or attractive in a wide range of pressurized
dispensing containers.
[0010] It is a further related purpose of this invention to provide
such an improvement such that present manufacturing and assembly
processes can readily be adapted to assembling the valve.
BRIEF DESCRIPTION
[0011] This invention involves the provision of a radially inwardly
extending annular flange at the upper edge of the boot and a mating
annular recess on the stem. Since the upper edge of the boot abuts
the stem shoulder, this annular recess on the stem has to be
adjacent to and below the stem shoulder.
[0012] It is important that the edge flange on the grommet will be
fully inserted in the recess on stem wall. To assure this full
engagement, it is desirable that the inner diameter of the boot
below the flange essentially equal the outer diameter of the stem
below the recess. A slip fit relationship would be preferable in
most cases.
[0013] This valve has been designed and tested and is shown to
minimize or entirely avoid valve failure due to the boot snapping
over the shoulder.
[0014] It is believed that the key reason why the design is
effective is that the downwardly facing surface of the stem which
engages the upwardly facing surface of the boot is by this design
extended radially inward. Accordingly, the net force exerted on the
boot is brought radially inward. This relationship provides a
greater surface over which stem to boot contact is maintained and
appears to favorably affect the resolution of forces which
otherwise tend to pull the upper edge of the boot out and around
the engaging shoulder.
DEFINITIONS
Nominal Clearance
[0015] This term is used to refer to structural relations where the
design values or target values of engaging structures are selected
in part with an eye to the expected manufacturing tolerances and in
part to prevent bonding of the boot flange on the stem recess.
[0016] For example, the depth of the stem recess being slightly
greater than the length of the boot flange coupled with the
thickness of the inner end of the stem recess being slightly
greater than the thickness of the end of the boot flange. In one
embodiment, the stem recess design value is 15 mils and the boot
flange length design value is 14 mils. In that embodiment, the
design values are that at the innermost area of the stem recess.
The width is 24 mils and at the end of the boot flange, the
thickness is 20 mils.
[0017] These nominal clearance relations assure that, when
manufacturing tolerances are taken into account, there will be room
for the flange to fit fully within the recess in both closed and
open valve states.
[0018] The above examples are for a given embodiment. The amount of
the nominal clearances will be a function of experience with
particular materials, manufacturing machines and the size of the
valve.
Up and Down; Lower and Upper
[0019] The terms up and down as well as relational terms lower and
upper are used to refer to the relations when a container having a
valve is sitting on the shelf. In use, the container is usually
tilted or upside down when used. It should be understood that these
terms are used to provide easier description and refer to the valve
when on a container sitting on a shelf.
BRIEF DESCRIPTION OF THE FIGURES
[0020] FIG. 1 is a schematic view, in partial longitudinal
sectional view of the valve of this invention in a closed state.
FIG. 1 shows the stem shoulder 32 engaging the upper edge of the
boot 26 and also shows the boot flange and stem recess
engagement.
[0021] FIG. 2 is a schematic view, similar to that of FIG. 1,
except that it shows the valve in an open state, that is in a
product dispensing, state. FIG. 2A shows an alternate valve stem
opening 22a.
[0022] FIG. 3 is an elevational view of the movable valve element
which is also called the stem. It includes the button 18 and
shoulder 32. FIG. 3 shows the annular recess 38 below the shoulder,
which recess engages the boot flange 36.
[0023] FIG. 4 is a longitudinal sectional view of the grommet in
its relaxed state showing the inwardly facing annular boot flange
36 at the upper edge of the boot 26. This is the flange that
engages the annular recess 38 in the stem.
[0024] FIG. 5 is a larger scale view of the boot flange 36 and stem
recess 38. It is an exploded view to best show the relationship
between the flange and recess.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] The FIGs. illustrate a single embodiment. As shown in FIG.
1, the valve is a three piece valve assembly. It is constituted by
a mounting cup 10, a movable valve element 12 and a resilient
annular sealing grommet 14. The movable valve element 12 is also
referred to as a valve stem 12.
[0026] In FIGS. 1 and 2, a finger operated actuator 16 is used to
move the valve from a FIG. 1 closed state to its FIG. 2 open state.
In the open state, product is dispensed because of the pressure
within the container to which the valve is mounted.
[0027] A lower portion of stem 12 has a button 18 which fits into a
recess 20 in the grommet 14. The valve stem has two openings 22
(one of which is shown) through which product is dispensed when the
valve is open. When the valve is in the closed position shown in
FIG. 1, the button 18 abuts against a surface 24 of the grommet 14
thereby effectively sealing the contents of the container from
access to the valve openings 22. When the valve stem 12 is
depressed, as shown in FIG. 2, the button 18 moves down within the
recess 20. In that condition, edge recesses or openings 25 in the
button 18 permit communication from within the container through
these openings 25 to the valve stem openings 22 so that product can
be dispensed.
[0028] The upper portion of the grommet 14 is called a boot 26. A
center section 28 of this boot collapses under vertical pressure,
as shown in FIG. 2, so as to permit the valve stem 12 to move down
and place the valve stem openings 22 in communication, through the
button edge recesses 25, with the product to be dispensed.
[0029] This opening and closing of the valve involves an engagement
between the upper surface 30 of the boot 26 and a downwardly facing
surface 31 of a shoulder 32 in the valve stem 12. The shoulder 32
engages the boot 26 so that the boot section 28 buckles outwardly
when finger pressure is applied to force the stem 12 in a downward
direction. But the resilient nature of the boot 26 material pushes
the boot 26 up once finger pressure is removed thereby closing the
valve. The valve is held tightly closed by pressure underneath the
button 18 from the pressurized material in the container. The boot
26 material is selected to have a resilience appropriate to the
pressures required in a particular design.
[0030] When the valve is open, as shown in FIG. 2, the passage of
the Product P is through the edge recesses 25 (see FIG. 3) in the
button 18, then through the openings 22 in the valve stem, then up
the center passage 34 in the valve stem 12 and out through the
actuator 16.
[0031] The problem that occurs in connection with these vertically
actuated valve stem designs is that in certain circumstances the
pressure required to open the valve is sufficiently great so that
the upper end of the boot 26 can occasionally snap around the
shoulder 32 thereby essentially disabling the valve and holding it
open.
[0032] A design which overcomes this problem of loss of proper
engagement between boot 26 and shoulder 32 is one that includes an
inwardly facing annular flange 36 at the upper edge of the boot 26
and an engagement between this flange 36 and an annular recess 38
in the stem 12.
[0033] Because of the small sizes of the flange 36 and recess 38,
dictated by the small size of the entire valve structure, it is
important that various dimensional relationships be selected to
assure that the boot flange 36 is fully inserted into the stem
recess 38. In order to achieve this full insertion result and in
view of the inevitable variations due to tolerance and manufacture,
the following relationships have been found to be valuable and are
preferred.
[0034] It is important that the opening 40 to the annular recess 38
be greater than the thickness of the flange 36 so that the recess
opening 40 will not obstruct the full insertion of the flange. It
is the engagement between the upper surface 30 of the boot and the
lower surface 31 of the shoulder 32 that brings about opening and
closing. Thus a tight fit between flange 36 and recess 38 is of
little significance and could actually create resistance to the
full insertion of the flange 36 into the recess 38. As shown in
FIG. 5, this dimensional relationship is arranged by having a
sloping surface 42 for the lower surface of the recess 38.
[0035] A further feature that aids in assuring the full insertion
of the flange 36 into the recess 38 is to have an interference fit
relationship between the annular surface 44 of the boot immediately
below the flange 36 and the corresponding annular surface 46 of the
valve stem 12. This assures that no part of the flange 36 sits
outside of the recess 38.
[0036] It is also useful that the recess 38 extend inwardly
nominally more than the length of the flange 36 and that the inner
thickness of the recess 38 be at least nominally greater than the
thickness of the inner edge of the flange 36. These two clearance
relations work together to assure room for the flange 36 in the
recess 38 and thus removes the possibility that the flange will not
fully sit within the recess. These two clearances also provide room
to accommodate flange distortion under pressure when the valve is
opened.
[0037] The stem diameter just below the recess is greater than the
corresponding boot diameter. The design value in one embodiment are
that the stem diameter is 152 mils and the corresponding boot
diameter is 148 mils. This four mil diameter difference serves to
compensate sufficiently for manufacturing tolerances and to assure
that the entire flange will be inserted into the stem recess.
[0038] In large part for reasons of assembly of grommet and stem,
the diameter of the shoulder 32 cannot be as great as might be
desired for the purpose of assuring that the boot does not snap
over the shoulder. It becomes useful to make sure that the upper
surface 30 of the boot extends radially outward to at least the
outer end of the downwardly facing surface of the shoulder 32. This
provides as much of an engagement surface as possible thereby
minimizing unit pressure area and further helping to assure that
the forces between boot 26 and shoulder 32 are resolved to reduce
the tendency for the boot to snap over the shoulder.
[0039] A 45 degree fillet 48 at the corner of the flange 36 and
boot wall 44 serves to guide and keep the flange 36 in place. The
45 degree surface 42 at the recess opening provides room to
accommodate the fillet 48.
[0040] The valve stem opening 22 shown in FIG. 3 is deemed optimum
for use with a liquid flowable product such as a gel shave. By
contrast, when dispensing a product as a spray or mist or aerosol,
it has been found preferable to employ a more rectangular valve
stem opening such as shown in FIG. 3A.
[0041] The approximately triangular opening 22 of FIG. 3 permits
the user to meter out the amount of product being dispensed by the
extent to which the user depresses the valve stem. By contrast, for
spray products, a minimum volume of liquid is required in order to
effect an adequate spray from the spray head. If used for spray
dispensing, the triangular opening 22 of FIG. 3 tends to result in
a dribbling of product initially and at the end of the closing of
the valve. The FIG. 3A rectangular opening 22a minimizes this
problem.
[0042] In one product designed for a gel shave, the inverted
triangular opening 22 has the following dimensions: a 50 mil length
or height; a 42.5 mil upper edge and a 10 mil tip or lower
edge.
[0043] A typical valve stem opening 22a, such as is shown in FIG.
3A, for a product providing a spray or mist has a height of 50 mils
and a width of 20 mils.
An Example of the Embodiment
[0044] The following table presents an example of a single
embodiment of this invention in which the dimensional relationship
discussed above are represented by a specific set of dimensions.
The following provides an indication of the nominal nature of the
interference and clearances which assure the full insertion of the
flange 36 into the recess 38. TABLE-US-00001 MILS Stem Shoulder 32
Diameter 230 Stem Recess 38 Inner Diameter 122 Stem 46 Diameter
below Recess 152 Stem Recess 38 Width at Inner Diameter 24 Stem
Recess 38 Width at Recess Opening 32 Stem Recess 38 Depth 15 Boot
26 Upper Edge Diameter 230 Boot Flange 36 Inner Diameter 124 Boot
Flange 36 Thickness 20 Boot Inner Diameter 44 below Flange 148 Boot
Flange 36 Length 13 Interference between Boot 26 Diameter 4 And
Stem 46 Diameter below Recess (152-148) Clearance between Boot
Flange 36 4 Thickness and Stem Recess 38 Width at their Inner Ends
(24 minus 20) Clearance between Boot Flange 36 2 diameter and Stem
Recess 38 diameter (122 minus 124)
[0045] While the foregoing description and drawings represent the
presently preferred embodiments of the invention, it should be
understood that those skilled in the art will be able to make
changes and modifications to those embodiments without departing
from the teachings of the invention and the scope of the
claims.
* * * * *