Note: Descriptions are shown in the official language in which they were submitted.
BACKGROUND OF INVENTION
Field of the Invention
The present invention relates to an improved
droplet dispensing closure which is connectable to a
bottle neck opening and preferably, but not exclusively,
a bottle containing a medicinal liquid. The droplet
closure has a dispensing tube in which at least a
dispensing section thereof is of constant inner diameter
and wherein droplets can be dispensed, as soon as the
bottle is inclined above the horizontal, at a rate which
is slow enough to permit the counting of individual drops
emitting from the dispensing tube.
Description of Priox Art
Various closure members are known for
dispensing liquid from a bottle at a drip feedrate. A
product similar to that of the present invention is
described, for example, in German Patent DE 29 49 223
dated September 19, 1980. The present invention is an
improvement of such closure and wherein drops can be
dispensed as soon as the bottle is positioned at an angle
above horizontal, whereas in the reference, it is
necessary to place the bottle to a vertical position in
order for the closure to start dispensing. The inner
diameter of the drip tube is often tapered and the drops
are not of even size and air can infiltrate through the
drip tube.
Another disadvantage of the prior art closures
is that when the sealing cover is placed onto the
closure, it often damages the dispensing tube or the air
vent tube, thereby affecting the operation of the
dispensing closure. Also, the cover often touches the
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end of the dispensing tube and forces liquid back nto
the bottle. This could result in contamination as the
liquicl forced back in was exposed to outside air and
light. Still further, the prior art designs often admit
too much air into the bottle at an uneven rate, thereby
resulting ln an uneven dispensation rate.
It is desirable that the dispensing rate be
slow and constant whereby the drops can be easily counted
as they are dispensed. This is particularly important
when dispensing a medical product. It has also been
found that it is important to maintain, at least the
dispensing section of the dispenser tube of a constant
diameter, in order to achieve an accurate drop size in
dispensing the fluid.
SUMMARY OF INVENTION
It is a feature of the present invention to
provide an improved droplet dispensing closure for
connection to a bottle opening for dispensing liquid
therefrom at an even drop volume and slow enough to
permit the counting of individual droplets being
dispensed, and wherein such liquid can be dispensed by
inverting the bottle past the horizontal.
Another feature of the present invention is to
provide an improved droplet dispensing closure for
connection to a bottle opening and wherein the dispensing
closure is attachable in a cover which is securable over
a bottle neck opening to simultaneously attach the
dispensing closure in the bottle opening.
According to the above features, from a broad
aspect, the present invention provides a droplet
dispensing closure for connection to a bottle opening.
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The dispensing closure comprises a cup-shaped body having
outer circumferential retention means and sealing means
for retention and sealing engagement with the opening. A
drop dispensing tube extends from a bottom wall of the
body and has an outlet opening disposed above an outer
rim of the cup-shaped body. A dispensing hole is
provided in registry with the tube for admitting liquid
into the tube. An air vent tube, of predetermined
length, extends under the bottom wall to one side of the
dispensing hole. The air vent tube has a constant
diameter pasage to admit outside air into the air vent
tube. The dispensing tube has a constant inner diameter
dispensing section. The air vent tube admits air into
the bottle at an equal volume as liquid is forced through
the dispensing hole when the bottle is inverted at a
position past horizontal. The drip at the outlet of the
dispensing tube is slow enough to permit counting of
drops being dispensed.
BRIEF DESCRIPTION OF DRAWINGS
A preferred embodiment of the present invention
will now be described with reference to the examples
thereof as illustrated in the accompanying drawings in
which:
FIGURE 1 is an exploded view showing the
droplet dispensing closure of the present invention in
relation to a bottle containing d liquid therein and also
in relation with a cover;
FIG~RE 2 is an enlarged fragmented section view
showing the droplet dispensing closure construction and
its relationship with a bottle neck opening;
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FIGURE 3 is a section view showing the cover
design;
FIGURE 4 is a slde view illustrating the
operation of the droplet dispensing closure when
connected to a bottle containing a medicinal liquid
therein; and
FIGURE 5 is an exploded view of an improved
dispensing closure and bottle for dispensing accurate
single doses of a medicinal liquid.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings, and more
particularly to Figures 1 and 2, there is shown at 10,
the droplet dispensing closure of the present invention.
As herein shown, the dispensing closure is connectable in
the opening 11 of a bottle neck 12 so as to dispense the
liquid 13 contained in the bottle, in droplet form. The
bottle 14 can be of any shape or size and is preferably,
a bottle containing a medicinal liquid 13 therein. A
sealing cover 15 is placed in threaded engagement about
the bottle neck 12 by engaging 'he threads 16 thereon and
seals an air passage in the air vent tube 26 and isolates
the dispensing tube 18 formed with the dispensing closure
to prevent dispensing or expose the liquid to con-
taminants.
As better illustrated in Figure 2, the
dispensing closure 10 is molded from plastic material,
herein polyethylene, and defines an outer cylindrical
wall having a circumferential holding ring 17 and one or
more cylindrical sealing flanges 20 thereabout to
constitute a sealing means when the body 19 is press-
fitted into the bottle neck opening 11. The bottle neck
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also has a circumferential channel 17' therein for
receiving the ring 17 in snap-fit therein. The flanges
20 deform in the bottle neck opening 11 to constitute a
plurality of further spaced apart seals all around the
bottle neck opening to prevent the liquid 13 from seeping
out of the bottle. A cylindrical abutment rim 21 is also
provided about the cup-shaped body 19 and sits on the
outer ledge 22 of the bottle neck 12.
The droplet dispensing closure 10 is injection
molded as a single part with the drop dispensing tube 18
being disposed centrally of the cup-shaped body 19 and
extending from a bottom wall 23 of the cup-shaped body.
The dispensing tube defines an outlet opening 24 at its
free end which is located at a predetermined distance
above the abutment rim 21 of the cup-shaped body 19.
This permits the tube 18 to be directed closer to the
ear, nose, etc. of a patient for dispensing droplets, A
dispensing hole 25 is provided in the bottom wall and in
registry with the dispensing tube 18 for admitting liquid
into the tube.
An air vent tube 26 is also molded integrally
with the cup and extends downwardly from the bottom wall
23. The air vent tube 26 has a straight body which
extends a predetermined distance under the bottom wall 23
to a free end 27 which is disposed above the liquid level
13 contained in the bottle. An air admission hole 26' of
constant diameter is provided in the air vent tube to
admit outside air into the air vent tube and the bottle,
when inverted. The size of the air admission hole 26'
and the dispensing hole 25 are predetermined and have a
fixed ratio dependent on the viscosity of fluid to be
2 ~ 3 g
dispensed. Based on the relative viscosity of liquids,
the ratios of openings of the feed tube to the air intake
tube are:
Oil substances 1.666
Water 0.625
Alcohol mixtures 0.375
Alcohol 0.2876
This ratio achieves a constant drip volume when
dispensing liquid from the bottle through the dispensing
tube. It is pointed out that with the design of the
present invention, as soon as the bottle 14 is tipped
past the horizontal line 30, as shown in Figuré 4, the
droplet dispensing closure 10 will start dispensing drops
of even size, as shown at 31, and of a constant volume.
Simultaneously, the air vent will admit air bubbles 32
into the liquid 13 at an equal volume. In order for this
to be achieved, it is also important that the inner
diameter 24' of the tube 18 be of a constant size to
prevent air from seeping into the tube as liquid is
dispensed. A plurality of division walls 28 form pockets
about the inner circumferential top wall 42 of the
dispensing closure 10 to retain any fluid that may drip
along the dispensing tube 18. This fluid is minimal and
would not form droplets when the bottle is inverted. The
dispensing tube intake end extends flush with the top
edge of these division walls so as to receive thereon the
sealing end 38 of a sealing annular ring provided in the
cover 15 to seal the air vent hole 26'. The division
walls 28 also constitute strengthening ribs for the
cover.
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Referring now additionally to Figure 3, there
is shown the construction of the cover 15 which is
removably securable about the bottle neck 12. The cover
15 is provided with an inner cylindrical thread 35 for
engagement with the outer thread 16 of the bottle neck.
A locating annular sealing ring 37 also extends axially
and centrally from the innex top wall of the cover. The
inner surface 36 of the ring 37 is tapered to facilitate
locating the dispensing tube 18 therein and to fric-
tionally engage the tube 18. Accordingly, for automatic
assembly, the dispensing closure 10 is frictionally
retained in the cover 15 by frictional retention of the
dispensing tube 18 within the ring 37. The combination
is then disposed over the bottle neck and the closure 10
is pushed in the bottle opening. The holding ring 17
enters the channel 17' and the cap is released or rotated
about the bottle neck. Accordingly, the entire assembly
is connected to the bottle in one machine ste~. The
cover 15 is also provided with a protrusion section 36 so
as to form an elongate cavity 39' with the ring 37. The
cavity 39 has a taper and is largex a-t its inner open end
to facilitate locating the dispensing tube 18 therein.
When the cover 15 is threaded about the bottle neck, the
bottom end 38 of the sealing ring 37 will sit on the top
surface 42 of the ribs 28 and of the air vent tube 26.
Accordingly, air cannot be admitted in the bottle and no
li~uid will be dispensed through the tube 18 when the
bottle is inverted. The dispensing tube 18 is also
sealed by the tapered cavity 39 in the cover lS.
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Referring now to Figure 5, there is shown a
further embodiment of the droplet dispensing closure lO'
of the present invention as herein used with a single
dose dispensing bottle 50. In this embodiment, the
dispensing section 34' of the closure 10' is provided at
the end of the dispensing tube 18'. The cover 15' is of
different shape and is provided with a convex nipple 48
therein to abut against the dispensing opening 24'. As
herein shown, the air vent is provided as a constant
diameter vent tube and this droplet dispensing closure
was conceived to dispense drops at a much faster rate
than the closure illustrated in Figures 1 and 2. A
plunger element, in the form of a tapered nib 45, is
insertable into the outer end of the vent tube 26' to
seal the tube. This plunger element is connected to a
flexible strap 44 which is molded integral with the body
l9'. By applying downward pressure on the connected end
of the strap 44, as shown by arrow 43, the tapered nib 45
will be subjected to an outer pulling force, as indicated
by arrow 46 to dislodge the nib 45 from the openlng of
the vent hole to cause the dosage in the bottle 50 to
flow out when the bottle is inverted. In this particular
embodiment, the inner diameter of the vent tube and the
dispensing section of the dispensing tube are identical.
Accordingly, drops are dispensed at an even flow rate
when the bottle is inverted to any position past the
horizontal, as shown in Figure 4.
A dosage calibrating funnel element Sl is
removably positioned inside the bottle 50 to automati-
cally calibrate a predetermined quantity of liquid to be
dispensed through the dispensing tube 18'. The funnel
element 51 is comprised of an elongate, open-ended,
tubular portion 52 having a conical seating section 53.
Retention friction ribs 54 are provided about a base wall
of the seating section to hold the funnel element 51
firmly within the bottle 50. An opening 55 admits liquid
within the seating section 53 and tubular portion 52 when
the bottle is not inverted. An excess flow hole 56 is
provided for excess liquid to leak out of the funnel
element 51 when the bottle is inverted. Accordinqly, the
precise liquid dose is determined by the size of the
tubular portion from its free end 57 to the hole 56. One
or more of these holes can be positioned about the
tubular portion 52 at a predetermined location therealong
depending on the volume of the desired dosage. The free
end 57 of the tubular portion 52 is received in friction
fit within the flared bottom open end 58 of the
dispensing tube 18' so as to permit only the liquid
within the tube 52 to be dispensed.
It is within the ambit of the present invention
to cover any obvious modifications of the preferred
examples described herein, provided such modifications
fall within the scope of the appended claims.
