Note: Descriptions are shown in the official language in which they were submitted.
CA 02294856 1999-12-29
WO 99/61367 PCT/US98/10810
AEROSOL SPRAY DISPENSER WITH SWINGING DOWNTUBE
Meld of the Invention
This invention relates to an aerosol spray dispenser for dispensing fluids, in
particular aerosol spray cans for dispensing liquids. Further, the present
invention is
directed to aerosol spray container configurations and constructions, in
particular to the
configuration and construction of the lower portion or bottom of aerosol spray
dispensers.
Background of the Invention
In the past decade, the manufacture and use of aerosol cans in the United
States
has decreased in favor of spray bottle type dispensers. This trend has
developed for a
variety of reasons, including:
i) eliminate the release of gas or liquid propellants, in particular
hydrocarbon
propellant such as propane and butane;
ii) eliminate the cost associated in charging an aerosol can with a gas or
liquid
propellant;
CA 02294856 1999-12-29
WO 99/61367 ' PCT/US98/10810
-2-
iii) eliminate misuse of aerosol products by consumers (e.g., lighting
aerosols
on fire, sniffing propellants);
iv) eliminate the ever increasing significant risk to manufacturers and
bottlers
of aerosol from resulting misuse;
v) eliminate aerosols that contain a significant amount of hydrocarbons, which
can act essentially as bombs; and
vi) eliminate the large disposal of chemical propellants left in aerosols when
discarded by consumers when the aerosol is essentially empty of liquid.
This partial list of significant factors for eliminating aerosols would make
one
wonder why aerosols have not been completely eliminated at this point in time.
The
reason for the existence of aerosols today is the significant cost savings to
bottlers, since
aerosols cost a fraction of the cost as the same size spray pump dispenser.
Thus, a
bottler can sell the same amount of product for significantly less cost and
receive the
same or greater selling price to the consumer versus product sold in spray
pump
dispensers.
CA 02294856 1999-12-29
WO 99/613b7 PCT/US98/10810
-3-
There exists a tremendous economic advantage to bottlers to continue using
aerosol, especially if the above problems can be overcome and eliminated by an
improvement in technology.
Aerosols are currently significantly overfilled with propellant, in particular
liquid
hydrocarbon propellant to ensure the product is fully dispensed from the can
prior to the
propellant running out. The amount of overfilling percentage wise must be
increased if
the aerosol is used in such a manner that at some orientations of the aerosol,
a significant
amount of propellant is released instead of product. Specifically, when an
aerosol is
highly tilted with a low product level, excessive propellant can be released.
With
oriented type downtubes, this problem can be significant even with higher
products level
if it so happens that the aerosol is oriented with the pickup end of the
downtube out of
the product.
It is highly desirable if an aerosol can be developed that eliminates this
effect
based on the orientation of the aerosol so that little or no excessive
propellant is released
during the life cycle of the aerosol. If this can be achieved, then
significantly less
overfilling of propellent is required in order to ensure substantially
complete evacuation
of product from the aerosol. Such an improved aerosol would leave less
propellant in
the aerosol when the product is used up, significantly reducing the amount of
chemical
propellant currently being disposed in landfills.
CA 02294856 1999-12-29
WO 99/61367 PCT/US98/10810
-4-
Further, misuse of aerosols can be substantially reduced or eliminated by
designing or configuring an aerosol that does not allow the release of
excessive propellant
without product release, no matter what orientation the aerosol is placed.
This
improvement would save or improve many lives, and significantly reduce the
danger
associated with current aerosol use. Further, this will greatly decrease the
exposure of
manufacturers and bottlers to potential liability suits resulting from misuse.
There exists many liquid dispensers having weighted pickup tubes for
maintaining
the pickup end of the downtube in the liquid being dispensed at various
orientation.
Typically, the pickup tube (e. g. , plastic pickup tubes) are weighted by
adding a separate
weight to the pickup tube. However, there exist some liquid dispensers that
use
materials such as metal tubing, which are significantly more dense than the
liquid
product being dispensed. In these applications, the metal tube acts as a
weight even
when fully submerged in liquid product due to its significantly greater
density than the
surrounding liquid (i. e. , there is little relative buoyancy).
Conventional aerosols typically use plastic pickup tubes made of, for example,
polypropylene and polybutane due to their inexpensive cost. The upper ends of
the
pickup tubes are rigidly connected to the valve body of the aerosol during
assembly.
Thus, no weight is required since the downtube is fixed in a downward
orientation by
the valve body, and cannot essentially move at all inside the aerosol. The
prior art is
CA 02294856 1999-12-29
WO 99/61367 PCT/US98/10810
-5-
void of any teaching of using unweighted plastic downtubes that are flexibly
connected
to the valve body or other dispensing device. Further, the prior art does not
teach a rigid
or semirigid downtube that is flexibly connected to the dispensing device so
as to swing
and extend to a lower portion of the container.
There exist many examples of highly flexible weighted downtubes for use in
liquid dispensing for containers. However, highly flexible weighted downtubes
are
unsuitable for high speed manufacturing of aerosol dispensers, particularly
aerosol cans,
due to their difficult handing properties, especially those relating to
structural instability.
Specifically, it is nearly impossible to load an aerosol an with a highly
flexible weighted
downtube due to the high rotational forces exerted on the highly flexible
downtube that
tend to cause the weight to move radically outwardly causing significant
misalignment
with the aerosol can opening during loading. Further, highly flexible weighed
downtubes
become tangled together during bulk storage and shipping, making loading onto
automatic
equipment difficult or impossible.
Containers having a variety of different bottom configurations are used for
consumer and industrial products. In particular, aerosol containers ("cans")
produced
in the billions in the United States have convex shaped bottom configurations
when
viewing the bottom from inside the can. This type of configuration can sustain
substantial pressures up to and exceeding 160 pounds-per-square-inch ("psi")
while
CA 02294856 1999-12-29
WO 99/61367 PCT/US98/10810
-6-
providing a bottom that allows the can to stand upright on a horizontal flat
surface such
as counter top or table. Specifically, a conventional aerosol an is
constructed of a metal
cylinder having a top and bottom portion.
A conventional aerosol can having sheet metal construction (e. g. , steel)
includes
a cylindrical body made by bending sheet metal into a cylinder and butt
welding the
vertical ends together to form a vertical welded seam; a stamped sheet metal
top having
a concave configuration when viewing the top from inside the can; and a
stamped sheet
metal bottom having a convex configuration when viewing the bottom from inside
the
can. The perimeter of the stamped sheet metal top and bottom are attached to
the top
perimeter and bottom perimeter, respectively, of the sheet metal cylindrical
body.
Specifically, the perimeter edge of the stamped sheet metal top and the
stamped sheet
metal bottom are configured to provide a peripheral receiving groove for
receiving the
top and bottom perimeter edge, respectively, of the sheet metal cylindrical
body. The
perimeter edge of the stamped sheet metal top and the stamped sheet metal
bottom are
crimped over the respective perimeter edges of the sheet cylindrical body to
form
hermetically sealed perimeter connections between the stamped sheet metal top
and
bottom and the sheet metal cylindrical body.
The conventional aerosol can includes a valve unit made of stamped sheet metal
in combination with additional components for providing the functioning of the
valve.
CA 02294856 1999-12-29
WO 99/61367 PCT/US98/10810
_7_
A substantially rigid downtube is connected to the valve body, and extends to
a perimeter
position at the bottom of the can. The conventional convex shape of the can
provides
a perimeter well or drain in which the pickup end of the downtube is placed.
From 1989 to 1992 many patents were applied for and issued concerning gas
aerosol, pressurized dispensers. The primary focus of these inventions and the
ultimate
reason for them were at least two-fold.
1. The current use of liquified gas propellant, i. e. , propane, butane,
pentane,
etc. have been found to pollute the atmosphere and are known as VOC's. These
products also are under the right conditions explosive and extremely
flammable. With
the current propellants used there is also a very high amount of VOC release
during the
filling and pressurization phase of production. California and New Yark have
already
begun restricting the VOC content on products and the current environmental
move is
to clearly remove or highly regulate VOC's within the decade "1990's". VOC's
will
soon be joining CFC's as hazardous, undesirable and dangerous products. Some
have
even been referred to as carcinogenic. Now, as previously mentioned factory
VOC
output is of immediate concern, but so is household pollution. With the
tighter more
efficient, less ventilated new buildings and homes - VOC concentrations are
becoming
extremely important as they tend to collect and create much worse health risks
within our
workplaces, home, etc. With the full negative impact of concentrated exposure
still
CA 02294856 1999-12-29
WO 99/61367 PCT/US98/10810
_g_
unclear, the majority of atmospheric experts are warning as more unfavorable
data
appears disastrous repercussions for all persons, along with the environment
as a whole.
2. The price of the current liquid propellants is more expensive than gas
propellants, per unit.
As stated, the industry has for years searched for a suitable solution, during
this
period the aerosol market has begun to shrink being replaced by trigger pump
sprayers,
etc. Since the downturn in aerosol production two primary units have emerged
as
possible replacements.
1. A separate balloon or bag was added into the aerosol containers which
would contain the product. This idea allowed for the aerosol unit to be
operated from
any altitude or angle during the entire spraying process, ensuring that the
product would
always expel and that the gas propellant would be used efficiently, i. e. ,
never expel
simply gas. These containers have been in use to expel many food products.
They
effectively keep products separated like cheese, etc. An attempt to convert
these food
expelling aerosols to operate as a replacement for conventional aerosols have
left a lot
to be desired. U.S. Patent 5,211,316 (Adalberto et al.) is a good
demonstration of this
idea in the prior art. Problems concerning these bag "aerosols" are product
compatibility
with the bag, a constant flow (i. e. , consistent amount) of product,
production in speed,
CA 02294856 1999-12-29
WO 99/61367 PCT/US98/10810
-9-
bag breakage, and spray dispersion (low pressure). As is demonstrated in the
Adalberto
et al. , patent, the aerosol package is complicated which increases the
possibility that
complications are more likely which could result in minute defects which could
result in
product failure of a tremendous magnitude involving millions of units. Because
these
defects may easily be overlooked at the factory, product failure could well
happen during
the worst possible circumstances. In short, the more integral parts
functioning in these
designs the more chances of unacceptable high number of failures will elude
quality
inspections at the factories. If a reliable inspection process could be
initiated to increase
the possibilities of mistake detection the cost would be prohibited, and as
stated
previously the cost is already too high except for those limited uses where it
is being
employed.
2. An aerosol which utilizes a gas propellant and maintains the basic parts
with a "vapor tap" system or "control device" which regulates the gas to
liquid ration
that will best utilize the pressure changes associated with gas propellants.
The problem
with gas charged aerosols is that while the product level drops so does the
gas P.S.I. the
normal head space P.S.I. for a liquid gas propellant was between 35-55 P.S.I.
The
pressure is automatically maintained because once some of the head pressure is
used the
liquified gas would turn to gas and replace it. U.S. Patent 5,125,546 (Dunne
et al.)
discloses one of each of the gas aerosol products, bag & pressure regulation.
U.S.
Patent 5,143,288 (Kohler et al. ) shows the benefits of using vapor tap holes
to regulate
CA 02294856 1999-12-29
WO 99/61367 PCT/US98/10810
-10-
pressure which left "enough" pressure left over to cover misuse so that can
contents
would be certain to empty. The amount was 4015 P.S.I. U.S. Patent 4,940,171
(Gilroy)
discloses small vapor tap holes in the valve body which would regulate the gas
even more
efficiently, resulting in impressive aerosol spraying with lower initial
pressure.
A few gas aerosol inventions employed "gas revisions" to maintain a constant
pressure. As an idea, too much cost and complicity dooms this concept (see
U.S. Patent
4,995,533 to Vanoninck). So to summarize the current aerosol packaging market
problem, is the use of environmentally safe gases is desired in such a way
that the
aerosol spray characteristics do not suffer and the production price,
dependability of
product are maintained in or near the current industry standards. The impact
of our
invention on these desired characteristics will become evident.
As previously noted, the most promising aerosol package (#2) involves
environmentally friendly gases in a current aerosol package employing a "vapor
tap(s)"
means to control and enhance spraying characteristics. "Vapor tap" technology
is well-
known such as a valve disclosed in U.S. Patent 3,575,320, issued April 20,
1971 to
Jimmie Mason. The problems associated with these "vapor tap" inventions are
not
identified but are clear to any person familiar in the art. Tests conducted by
different
inventors confirm the viability, reliability of such devices.
CA 02294856 1999-12-29
WO 99/61367 PCT/US98/10810
-11-
The problem which our invention solves in a very inexpensive way is referred
to
in the industry as "misuse". Misuse is when the aerosol being used is
inappropriately
tiled which allows propellant gas to escape without the product. This occurs
when the
can is tilted in such a way that leaves the product entry point exposed to
only gas. When
the valve is opened, gas escapes which is not replenishable, as when liquified
gases were
employed. The amount of gas released is affected by the gas pressure. Tests
show that
a ten second spray of an aqueous solution containing a head space gas pressure
of 95 PSI
the pressure will drop to approximately 87 PSI with a release of approximately
2.0 grams
per second of product. The same test performed when only gas is released for
only five
seconds demonstrated a pressure drop to 55 PSI or a loss of 40/SS within half
the time.
The amount of gas released during misuse was varied with the same product
contained,
90 % of a 16 % contained produce slightly less amounts as the head pressure
was
reduced, at 55 PSI, five seconds of gas release dropped the pressure to 20
PSI, beginning
pressure of 40 PSI was reduced after the gas release 15 PSI, etc. The tests
were also
conducted where less product was available. All of these test met with similar
greatly
reduced head pressure. Therefore, the possible loss of gas pressure from
simple misuse
would ultimately leave the leftover gas insufficient to not only empty the
container but
a substantial amount. The industry has experimented with all types of flexible
downtubes, but have found all unacceptable. The industry does, however, have a
dispensing valve which will prevent gas loss from the inventors position. Our
invention
CA 02294856 1999-12-29
WO 99/61367 PCT/US98/10810
-12-
is industry friendly and eliminated the unwanted loss of gas. These properties
are shown
in the diagrams.
It is our invention's intention to produce a cost-efficient, simple industrial
modification which shall be incorporated into a single, reliable and workable
aerosol.
Summary of the Invention
An object of the present invention is to provide an improved aerosol
dispenser.
Another object of the present invention is to provide an improved aerosol
dispenser having a swinging downtube.
A further object of the present invention is to provide an improved aerosol
dispenser having a concave can bottom.
Brief Description of the Drawings
Figure 1 is a cross-sectional view of a preferred aerosol can dispenser
according to the present invention having a swinging downtube.
CA 02294856 1999-12-29
WO 99/61367 PCT/US98/10810
-13-
Figure 2 is a detailed cross-sectional view of a preferred flexible connector
according to the present invention.
Figure 3 is another preferred connector according to the present invention.
Figure 4 is a further preferred flexible connector according to the present
invention.
Figure 5 is a preferred connector according to the present invention having a
"tube-inside-tube" construction.
Figure 6 is a cutaway portion of a one-piece downtube having a flexible joint
defined by a contracted portion having reduced wall thickness.
Figure 7 is another preferred embodiment of one-piece downtube having a
flexible joint with a continuous diameter with other portions of the downtube,
however, having wall portions of reduced thickness to provide flexibility.
Figure 8 is a further preferred embodiment of a one-piece downtube according
to the present invention having a flexible joint with an increased diameter
relative to
CA 02294856 1999-12-29
WO 99/61367 PCT/US98/10810
-14-
the remaining portions of the downtube with reduced wall thickness to provide
flexibility.
Figures 9-12 show various orientations of an aerosol dispenser according to
the
present invention revealing the pickup end or connector end, either of which
can
pickup fluid emersed in the liquid contents of the container no matter what
orientation.
Figure 13 is another preferred embodiment of the downtube according to the
present invention made of a synthetic polymer, which is initially rigid during
insertion
into the aerosol dispenser, however, softens due to contact with one or more
chemicals so as to become significantly flexible to allow the pickup end of
the
downtube to swing inside the container.
Figure 14 is another preferred embodiment of the down tube according to the
present invention constructed by coating a flexible tube with a rigid or semi-
rigid
outer coating providing a flexible joint at an upper portion thereof.
CA 02294856 1999-12-29
WO 99/61367 PCT/US98/10810
-15-
Detailed Description of Preferred Embodiments
Definitions: The term "aerosol dispenser" referred to herein is defined by a
dispenser for dispensing a fluid (e. g. , gas, liquid, emulsion, gas/liquid
mixture and
other materials having fluid like properties such as powders, and mixtures
thereof),
and containing a propellant (e. g. , gas and/or liquid converting to gas). A
typical
aerosol dispenser includes a container, a selective release valve, typically
actuated by
finger manipulation, a downtube extending from the selective valve, product
contents,
and a propellant. The term "aerosol dispenser" is particularly directed
towards
aerosol canned type spray dispensers having a fabricated sheet metal can
having a
concave shaped can bottom and a convex shaped can top, a valve unit connected
to
the can top, a finger actuated nozzle connected to the valve unit that is
actuated by
pressing down on the top of the nozzle, a downtube extending from the valve
unit to a
parameter position where the can bottom is joined with the cylindrical side
wall of the
can, product contents, and a propellant.
An aerosol can 10 according to the present invention is shown in Figure 1.
The aerosol can includes a can container 12 comprising a cylindrical body
portion 14,
a concave shaped can bottom 16 when viewing the bottom from inside the can, a
concave shaped can top 18, a valve unit 20, a finger actuated nozzle 22, and a
downtube 24 connected to the valve unit 20 by a flexible connector 26 to allow
the
CA 02294856 1999-12-29
WO 99/61367 PCT/US98/10810
- 16-
downtube 24 to swing so that the pickup end 28 moves in close proximity to the
concave shaped can bottom 16. The aerosol can 10 is charged with various
product
contents, for example, liquid L, and a pressurized gas G, acting as a
propellant.
Alternatively, the gas propellant can be replaced with a liquid that converts
to gas
during the use and consumption of the gas from the aerosol container, and
other
combinations of mixtures of product and gas can also be substituted.
The concave shaped can bottom 16 is designed to have a low spot 30 at or
near the center thereof to act as a drain for liquid when the aerosol can 10
is in a
vertical orientation. Thus, even with a rigid or semi-rigid downtube that is
not
flexibly connected to the valve unit 20, but instead is rigidly connected to
the valve
unit 20, this provides a configuration that substantially evacuates the
contents of the
aerosol dispenser. In the preferred embodiment, the pickup end 28 of the
downtube
24 moves in close proximity to the concave shaped can bottom 16 at various
tilted
orientations of the aerosol can. Thus, the pickup end 28 is substantially
maintained in
the fluid throughout the operational life of the product.
The aerosol dispensers according to the present invention include swinging
downtubes. The swinging downtubes can be constructed to have multiple piece
constructions or single-piece constructions.
CA 02294856 1999-12-29
WO 99/61367 PCT/US98/10810
-17-
A variety of multiple piece construction downtubes are shown in Figures 1-5.
Figure 1, a flexible connector 26 is shown. The flexible connector 26 has a
continuous thickness wall, as is made from a plastic or other synthetic
polymer,
and/or rubber type products. The material for making the flexible connector
must be
selected to withstand the operating conditions within the aerosol container,
particularly
the chemical resistivity of the product contained therein. Further, the
flexible
connector must remain sufficiently flexible throughout its life to insure
proper
swinging operation of the downtube.
In Figure 2, a flexible connector 32 is shown having a peripheral groove 34,
which reduces the thickness at that location of the tube, and provides
additional
flexibility.
In Figure 3, a flexible connector 36 is shown having a zone 38 of thinner wall
thickness to enhance the flexibility of this connector.
In Figure 4, a flexible connector 40 is shown having a thicker portion 42 and
a
thinner portion 44 providing additional flexibility.
CA 02294856 1999-12-29
WO 99/61367 PCT/US98/10810
-18-
In Figure 5, a flexible joint hereinafter referred to as a "tube-within-a-
tube"
construction is shown. Specifically, a substantially flexible tube 46 having
an outer
diameter approximately equal to the inner diameter of the pickup tube 24' and
attachment portion of the valve unit 20' flexibly connects the downtube 24' to
the
valve unit 20'. The ends of the tube 46 can be interference fit, adhered,
and/or
mechanically fastened in some manner inside the downtube 24' and valve unit
20' .
For example, heated pins can be pressed into the downtube 24' and valve unit
20' to
provide mechanical fasteners.
A variety of single-piece construction type downtubes are shown in Figures 6-
8.
In Figure 6, a single-piece downtube 24" is shown having a flexible joint 48
defined by a constriction having thinner wall thickness.
In Figure 7, another one piece downtube 24" is shown having a flexible joint
50 having a uniform interdiameter with the downtube, however, having thinner
wall
thickness at the joint. The embodiments shown in Figures 6 and 7 can be made
by
locally stretching the downtube to thin the wall thickness to provide a
flexible joint.
CA 02294856 1999-12-29
WO 99/61367 PCTIUS98/10810
-19-
In Figure 8, a downtube 24" is shown having a flexible joint 52 defined as an
expanded portion having thinner wall thickness to provide flexibility. This
embodiment can be formed by locally heating the tube and pressurizing the
inside of
the tube to cause the expanded portion.
The operation of an aerosol dispenser according to the present invention as
shown in Figures 9-12.
In Figure 9, the aerosol can 10 is in a vertical orientation. The pickup end
28
of the downtube 24 is clearly emersed in the Liquid. Even with very low liquid
levels, the pickup end 28 will still remain substantially emersed in the
liquid.
In Figure 10, the aerosol can 10 is shown at approximately a 45 degree angle.
The pickup end 28 of the downtube 24 swings to the lowest position in the
aerosol
can 10. Even with very low liquid levels in this orientation, the pickup end
28 will
remain emersed in the liquid.
In Figure 11, the aerosol can 10 is at approximately a 90 degree originetation
with the pickup end 28 positioned at a lowest position inside the aerosol can
10 thus,
even with very low liquid levels the pickup end 28 will remain in the liquid.
CA 02294856 1999-12-29
WO 99/61367 PCTNS98/10810
-20-
In Figure 12, the aerosol can 10 is at an orientation of approximately 135
degrees with the pickup end 28 extending out of the fluid. In this particular
embodiment, the connector end 54 is provided with an alterative means for
picking up
fluid such as a ballcheck valve and/or very small holes 56 in the connector
end 54 of
the pickup tube 24. Alternatively, bodies of swinging downtubes according to
the
present invention are shown in Figures 13-14.
In Figure 13, a downtube 58 is shown that is initially rigid or semi-rigid
prior
to being loaded into the aerosol can. Once inside the aerosol can, the
downtube 58
chemically reacts with the liquid product so as to soften and become somewhat
flexible. However, the tube remains still sufficiently flexible with
sufficient structural
stability so as not to fold onto itself when the aerosol can is in an upside
down
position. Thus, the pickup end is held at or near the bottom of the aerosol
can.
In Figure 14, a downtube 60 is shown constructed of a flexible tube 62 having
a rigid or semi-rigid coating 64 provided thereon. The coating 64 can be
applied by a
dipping process andlor spray material onto the flexible tube 62-.
