Note: Descriptions are shown in the official language in which they were submitted.
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PRODUCT-DISPENSING METHOD AND APPARATUS
Field of the Invention
This invention relates broadly to methods and apparatus
for dispensing flowable products, and particularly to such methods
and apparatus in which the product is dispensed from a container
as a spray and the opacity of the container prevents ready
observation of the quantity of the product remaining in the
container at any given time. The invention is particularly
applicable to aerosol dispensers of pharmaceuticals such as
nitr~glycerin, with respect to which it is particularly important
that the user be able to determine easily at any time how much of
the pharmaceutical remains in the container.
Backqround of the Invention
.
There are a variety of applications in which it is
important for a user to be able to determine readily the amount of
a product which remains in a dispensing container, As an example,
with respect to which the invention will be specifically described
hereinafter, it is known to package nitroglycerin in a metering
aerosol-type dispenser so that when a dose is to be administered
it can be sprayed directly into the mouth of the user, Typically
the spray device is arranged so that a full single dose is
administered by one depression of an axially reciprocable button
at the top of the container. Such pharmaceutical material is
indicated for use in many cases of angina,
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Since the container of the nitroglycerin is generally of
high opacity, either due to the optical nature of its walls or to
the application of opaque labels to the walls, the user cannot at
all times see how much of the nitroglycerin remains in the
container. This can be highly disadvantageous, particularly if
the user is planning to be away from other sources of supply of
nitroglycerin for a substantial period of time, and cannot tell
how much of the nitroglycerin remains in his dispenser. In such
event it is possible that he will run out of nitroglycerin when he
needs it badly, and when an alternate source is not readily
available to him.
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One method by which an approximation of the amount of
; flowable material remaining in the dispenser can be obtained is to
place the container in water, for example in a bowl or sink of
water. In one example of such use, a full canister containing ap-
proximately 200 doses will sink in the water; if the canister is
3/4 full, it will float with approximately a ~ of its volume pro-
truding above the top of the water, and if about half full it will
float with about more of its volume above the water surface. When
`~ it becomes depleted to the extent that it is only about ~ full, or
- when it is empty, it tends to float at a variably oblique angle
~- about half out of the water.
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Such a method of indication of the quantity of product
remaining in the container is obviously quite inaccurate. For
example, typically it may ~e difficult to tell whether the
canister is empty or has up to as much as SQ doses in it,
Knowledge of the quantity of product remaining in an
aerosol dispenser, or in other types of dispensers, is obviously
desirable in many other applications, whet~ler in connection with
pharmaceuticals or entirely different types of products.
Accordingly, it is an object of l:he invention to provide
a new and useful method and apparatus for storing and dispensing
flowable product from a container, and for indicating the quantity
of such product which remains in the container at any given time.
Another object is to provide such method and apparatus
in which the indications of remaining product quantity are suf-
ficiently accurate ~or practical purposes.
.
A further object is to provide such method and apparatus
which are very easy to use, and inexpensive to provide.
'
SummarY of the Invention
These and other objects of the invention are attained by
the provision of product-dispensing apparatus which comprises a
product-dispensing container for storing and dispensing a flowable
product and which is floatable in water when filled with a
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quantity of product within a predetermined range. Associated with
the container are flotation stabilizing means for stabilizing the
angular orientation of the container when it is floating in water;
also provided are scale means associated with the container, for
indicating the position of the surface of the water with respect
to the scale means while the container is floating on the water
and when the amount of the product which it contains is within the
above-mentioned predetermined range.
The more product the container has within it, the deeper
it sinks into the water. Since the depth of submersion is a
direct indication of the weight o the entiré assembly of
container and stabilizing means, and since the only variable
factor is the amount of product within the container, khe position
of the surface of the water as read from the scale means is a
direct indication of the quantity of product in the container the
scale may be marked to indicate directly the remaining number of
doses, for example, in the case of a pharmaceutical product such
as nitroglycerin.
,
In the preferred embodiment the flotation stabilizing
means comprises a vial, such as an opened-top cylinder
appropriately weighted at or toward its lower end so that it will
float in a stable vertical position when the container is placed
within it. The scale means is preferably provided in the form of
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graduations on the exterior of the vial, and one need then only
read the position of the surface of the water on the scale means
to obtain an indication of the ~uantity of product remaining in
the container.
In another embodiment of the invention the flotation
stabilizing means may be in the form of a weighting device secured
to the bottom of the container, and the container and weighting
device may be floated directly in the water, without using the
vial. The quantity of product in the container is then determined
by observing the position of the surface of the water with respect
to a scale on the container itself
In still another embodiment a removable cap, such as is
commonly used with aerosol dispensers, may be employed which is
weighted heavily at its upper end so that when the container with
cap is placed ln water, the combination floats with the cap facing
downwardly, in a stabilized vertical position: in this case the
scale means may be applied to an integral axial extension of the
cap extending along a side surface of the container itself.
`::
In both of the latter cases, as well as in the preferred
embodiment previously described, the weighting device may be
integral with the object to which it is secured; that is, in the
case of the weighted vial the lower end of the vial may be solid
and thick walled, and the material may be impregnated with special
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high-density material, to obtain the desired preferential
weighting of the bottom of the vial Similar arrangements for
accomplishing integral weighting of the bottom of the container or
the top of the cap may be employed if desired.
In this manner there is provided a particularly simple,
inexpensive and accurate method and apparatus for providing
indications of the amount of product remaining in a dispensing
container.
Brief Description of the Figures : ..
,
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These and other objects and features of:the invention
will be more readily understood from a considération:of the
following detailed description, taken in connection with the ac-
companying drawings, in which: .
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Figure 1 i8 a perspective view, with parts broken away,
of the preferred embodiment of the invention;
Figure lA is an enlarged fragmentary side view of a
portion of the side used in the embodiment of Figure l;
,
Figure 2 is a vertical sectional view of an alternate
embodiment of the invention, with parts shown in full;
Figure 3 is a similar view of still a third embodiment
of the invention; and
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Figure 3A is a side view of the inventive device of
Figure 3 shown in a position rotated by 90 about the vertical
axis from its position in Fig, 3, and inverted.
Detailed Description of Specific Embodiments
Referring now to the preferred embodiment of the
invention illustrated in Figs, 1 and lA, there is shown a standard
commercial metered-dose aerosol dispenser 10 such as is used for
spray-dispensing of nitroglycerin into the oral cavity,
Dispensing is accomplished by pressing downwardly the top button
12, to cause a spray o aerosol gas and fluid product to be
emitted from spray opening 14. It will be assumed in this example
that the product is nitroglycerin suitable for oral administration
in spray form for the relief of angina,
The container 10 conventionally has a main storage
portion 16 which comprise a hollow cyliadrical body of a rigid
material impervious to gas flow, such as p].astic coated aluminum,
having a closed bottom and a top which is closed by the cap-
receiving fitting 20. It will be understood that the cap (not
shown in Fig. 1) is normally sold with the container and snaps
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downwardly over the button and around the cap-receiving fitting
for easy removal and replacement. Since the dispensing container
in this embodiment may be entirely conventional, it is not shown
or described in further detail.
In accordance with the invention there is provided a
generally cylindrical vial 24 into which the dispenser lO can be
readily placed, and which typically has a flat bottom so that the
dispensing container lO will sit coaxially within it. The vial
can be of any suitable thin-walled plastic material, but in
accordance with the invention it is heavily weighted at its lower
end by the wéighting device 26 secured to the bottom thereof.
Weighting device 26 may be a disc of a dense metal such as lead,
cemented to or snapped into the inside of the bottom of the vial.
The weight of the weighting device is less than that which would
create a danger that the top of the vial r with the container
within it, might sin~ below the level of the water.
.
Indicia in the form of graduations 30 are spaced from
each other axially along the outer surface of the vial 24. In
this case eleven such graduations are shown, deining lO equal
intervals and it will be assumed as an example that 200 doses of
nitroglycerin are in the container when it is full. This means
that a space between successive graduation represents a change in
content by an amount equal to 20 doses.
The graduations are so located that, when the,container
is full, the vial will float in the water 31 contained in the
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ordinary glass or tumbler 33 with the uppermost graduation marked
200 at the surface of the water, and when the vial is empty the
lowermost graduation marked 0 will be aligned with the top of
water. If, for example, the level of the water is aligned with
the graduation marked 140, there will be 140 doses left in the
container.
It will be understood that the geometry and density of
the container and the weighting device, as ~ell as the positions
and spacings of the graduations, will be selected in such manner
that the container will be stabilized in the vertical position
shown, when floating in the water, by means of the vertical
floating vial in which it is contained, and so that the
graduations will provide the desired accurate indications of the
quantity of material remaining in the container. The effect of
the weighting device 26 is to stabilize the elevation angle, i.e.
the angle of tilt, of the vial, so that it remains substantially
;vertical while floating.
According to the method of the invention as represented
in Fig. 1 then, the user need merely remove the cap from the
container, place the container in the vial, and place the vial
bottom downward into the liquid so that it floats vertically as
shown, after which he observes that graduation which is aligned
with the top level of the water and, by counting the number of
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graduations below that level, he can ascertain the remaining
dosage. Alternatively, and preferably, numerals such as 0, 10,
20, 40 etc. are placed adjacent the corresponding graduations so
that the user can directly read the number of remaining-doses.
Figure 2 shows another embodiment, in which the vial is
not used. Instead, the weighting device 32 is secured directly to
the bottom of the container 34, which may be like the container 10
in Figure 1. However, in this case the graduations 36 are placed
directly on the outside wall of the container, rather than on a
vial. The weighting device at the bottom may be a disc of a dense
material such as lead, cemente~ to the bottom of the container
itself Again, the geometry, density and size of the container
and the weighting device, as well as the positions and spacings of
the graduations, are appropriately selected with respect to the
weight of the product in the container when filled and empty so as
to assure that the desired indications will be produced over the
appropriate range of container contents. As is true also in the
case of Figure 1, it is not always necessary to indicate the
quantity o product over the full range from full to empty, since
it is more critical to display the remaining amount as the empty
condition is approached: accordingly, one may, if desired, provide
only indicia at the low end of the range of amount, adjacent the
zero-fill condition.
Figures 3 and 3A illustrate still another embodiment in
which a special cap 40 is provided to replace the conventional
aerosol container cap. It is preferably adapted to fit and snap
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onto the top of the container in the conventional manner, and is
provided at its upper end with a weighting device 44 in the form
of a dense disc of metal, as an example; a scale 46 extends
integrally therefrom along the side of the adjacent container. In
Figure 3 the assembly is shown inverted, since this is the way the
assembly will float when placed into the water, due to the action
of gravity on the heavy top end of the cap. It is noted that the
special scale 46 need not be employed, but instead the graduations
of the scale may be marked directly on the sidewall of the
canister 10 as in the embodiment of Fig. 2. Alternatively, the
cap can be extended downwardly and completely around the outside
of the canister to form a skirt on the exterior of which the scale
graduations can be formed.
.
The operation is directly analogous to the other
embodiments shown in that the container, with the cap in place, is
placed gently into the water with the cap downward so that the
assembly floats vertically as shown in Fig. 3, and the position of
the water level with respect to the graduations is read. Again,
one can note or count the graduations remaining below the water
level, or, conveniently, the graduations can be numbered to
indicate directly the number of doses remaining in the container.
In all the foregoing embodiments, the weighting device
may be integral wlth its adjacent member; that is, in Figure 1 a
thick dense material may be formed integrally at the bottom of the
vial and in Figure 2 the same technique can be used at the bottom
of the container. In Figure 3, the desired weighting can be
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accomplished by using a disc of material which is similar in
appearance to that of the remainder of the cap but which is
impregnated with dense materials; in such case, the remainder of
the cap may preferably be made lightweight by forming it of a
basketweave configuration of plastic strips.
The invention has been described with respect par-
ticularly to the dispensing of nitroglycerin or other similar
pharmaceuticals, but it can be utilized to provide indications of
the amount of flowable product remaining in a dispensing container
where the container and/or the product differ markedly from those
specifically shown and described.
Accordingly, while the invention has been described and
shown with particular reference to specific embodiments in the
interest of complete definiteness, it wlll be understood that it
may be embodied in a variety of forms diverse from those
specifically shown and described, without departing from the
spirit and scope of the invention as defined by the appended
claims.
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