U.S. patent number 3,661,189 [Application Number 05/049,070] was granted by the patent office on 1972-05-09 for liquid dispenser.
This patent grant is currently assigned to Owens-Illinois, Inc.. Invention is credited to Gary L. Bowser, Roger D. Lenhardt.
United States Patent |
3,661,189 |
Bowser , et al. |
May 9, 1972 |
**Please see images for:
( Certificate of Correction ) ** |
LIQUID DISPENSER
Abstract
Method and apparatus for dispensing a precise amount of liquid
from a sealed container into a syringe, open at one end, without
engaging the syringe plunger. A positive and negative pressure is
successively applied to the liquid in the sealed container forcing
it through a conduit into the syringe. The predetermined position
of the conduit in the syringe determines the level of the liquid in
the syringe.
Inventors: |
Bowser; Gary L. (Toledo,
OH), Lenhardt; Roger D. (Toledo, OH) |
Assignee: |
Owens-Illinois, Inc.
(N/A)
|
Family
ID: |
21957904 |
Appl.
No.: |
05/049,070 |
Filed: |
June 23, 1970 |
Current U.S.
Class: |
141/1; 141/116;
141/378; 604/186; 141/114; 141/329; 422/550 |
Current CPC
Class: |
A61M
5/1782 (20130101) |
Current International
Class: |
A61M
5/178 (20060101); B65b 003/14 () |
Field of
Search: |
;23/259
;128/215,218R,218C
;141/1,2,18,21,25-27,114-116,119,94,309,329,369,378
;222/401,402 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
taylor, D. G., Protective Coating Applicator, in IBM Technical
Disclosure Bulletin, 8(1), p. 86, June 1965, TK 7800 I13..
|
Primary Examiner: Earls; Edward J.
Claims
We claim:
1. Apparatus for controllably dispensing a precise amount of liquid
from a sealed container to an open-topped container,
comprising:
means for supporting said sealed container,
means connected to said sealed container for alternately
establishing a negative and positive pressure within the
container,
conduit means extending from the interior of said sealed container
to a preselected point in the interior of said open-topped
container and having its outside terminal portion extending in a
downwardly direction,
guide means connected to said support means for guiding and
aligning the open-topped container telescopingly over the terminal
end of said conduit, and,
means connected to said guide means for adjusting the vertical
position thereof.
2. The apparatus as claimed in claim 1 wherein said pressure
establishing means extends into the sealed container and above the
level of liquid in the container to establish a positive and
negative pressure upon the surface of the liquid in the
container.
3. The apparatus claimed in claim 1 wherein said conduit means
extends to a point within said sealed container which point is
below the liquid level in the sealed container.
4. The apparatus as claimed in claim 1 wherein the preselected
point in the interior of the open-topped container corresponds to
the desired level of liquid to be dispensed into said open-topped
container.
5. The apparatus as claimed in claim 1 including indicia means
adjacent to said guide means for indicating the volume of liquid to
be dispensed into said open-topped container.
6. Method for controllably dispensing a precise amount of liquid
from a sealed container to an open-ended container through a
conduit means, comprising the steps of:
supporting said sealed container,
positioning said open-ended container in an upright position,
positioning said conduit means between the interior of said sealed
container and the interior of said open-ended container so that the
outside terminal portion of said conduit means extends in a
downwardly direction within said open-ended container,
guiding and aligning said open-topped container telescopically over
the terminal end of said conduit means so that the terminal end of
said conduit means coincides with a predetermined point in the
interior of the open-ended container corresponding to a preselected
volume encompassed by the container volume below said point,
and
alternately applying a positive and negative pressure within the
sealed container to deliver an excess of the desired amount of
liquid through said conduit and into said open-ended containers and
to withdraw the excess.
7. Method for controllably dispensing a precise amount of liquid
from a sealed container to an open-ended container through a
conduit means, comprising the steps of:
supporting said sealed container,
positioning said open-ended container in an upright position,
positioning said conduit means between the interior of said sealed
container and the interior of said open-ended container so that the
outside terminal portion of said conduit means extends in a
downwardly direction within said open-ended container,
adjusting the relative position of said open-ended container and
the terminal end of said conduit means telescoped therein so that
the terminal end of said conduit means coincides with a
predetermined point in the interior of said container, and
applying a positive pressure within the sealed container to force a
quantity of liquid through said conduit and into said open-ended
containers to a depth greater than the position of the terminal
portion of said conduit, and then applying a negative pressure
within the sealed container to return that quantity of liquid from
the open-ended container that is above the terminal portion of the
conduit.
Description
THE INVENTION
This invention relates to a method and apparatus for dispensing
liquids. More particularly, the invention relates to a method and
apparatus for dispensing a precise volume of liquid into a syringe
without engaging the syringe plunger and without first attaching a
needle.
The present trend in the distribution of drugs on the hospital
level is to prepare and administer such drugs as a unit dose or a
single unit. Unit-dose drug distribution is a system of packaging
drugs in individual doses containing a predetermined amount of the
drug ready for direct administration to the patient. The drugs
packaged may include solid and liquid orals, injectables and
topicals; they may be prepared in the single-unit form either by
the drug manufacturer or by the hospital pharmacist. Under this
system, the pharmacist sends the exact or maximum useable quantity
of properly labeled drugs needed for a period of time (usually two
to four times per 24 hour period). Each medication unit is clearly
identified and sealed from the time of preparation by the
pharmacist until the time of administration at the patient's
bedside.
In the past, the hospital pharmacy would supply drugs in large
volume to the floor in a hospital where the drugs were used in
quantity. The nurse or person in charge of administering drugs on
that floor would draw medication when needed from the large supply
reservoir and would return the reservoir to a shelf or drug storage
area on that floor. This multiple-dose procedure has led, however,
to numerous errors either in administering the correct quantity of
medication since the drugs might be prepared by a large number of
persons working on the floor whose work load requires them to spend
less time in preparing medication. In order to minimize errors and
to increase overall efficiency, many hospitals are transferring to
the new unit-dose method of handling drugs.
Applicants' invention relates to a method and apparatus to
implement unit-dose packaging of liquid injectable drugs into a
syringe. Prior to this invention, syringes were filled to the
desired volume by inserting the needle of the syringe into a vial
containing the liquid and depressing and withdrawing the plunger in
the syringe to draw the liquid from the vial into the syringe. If
too much liquid was drawn into the syringe, it was ejected into a
waste receptacle by depressing the plunger. This method of
packaging did not lend itself to the unit-dose system since the now
unsterile needle must be transferred from the hospital pharmacy to
the patient and then be reused on the patient in an unsterile state
or after it has been cleaned with alcohol and cotton.
Applicants' invention minimizes the risk of contaminating the
syringe during filling and transportation by providing a method and
apparatus for dispensing a known volume of liquid into a syringe
through the "tip end" of the syringe without engaging the plunger
and without first attaching a needle to the syringe.
The other advantages of unit-dose system for injectables over the
previously used multiple-dose system is that the new system
decreases the probability of medication error both in the quality
and quantity of the drug administered; it decreases the risk of
pilferage since it places drug control with the hospital pharmacist
rather that the nursing unit; it provides for complete
identification of the drug, lot number, expiration date, etc., from
the time the drug leaves the hospital pharmacy up to the time of
administration to the patient. It can be seen that this system
places in the hands of the pharmacist the responsibility of drug
preparation, thereby relieving the nurse of one of the three stages
of medication distribution.
SUMMARY OF THE INVENTION
With these advantages of the unit-dose system over the
multiple-dose system, it is the object of this invention to provide
a method and apparatus for dispensing a known volume of fluid into
a syringe without engaging the plunger and without first attaching
a needle to the syringe.
It is another object of this invention to provide a method and
apparatus to dispense liquid into a syringe which is adaptable to
the unit-dose method of packaging.
It is an object of this invention to provide a method and apparatus
to dispense a known volume of liquid into syringes of various
volume capacities.
It is also an object of this invention to provide a method and
apparatus to dispense liquid into a syringe adaptable to the
unit-dose packaging process which decreases the risk of
contamination over the present method of dispensing using plunger
movement.
In order to implement these objectives, this invention provides a
method and apparatus for dispensing liquid into a needless syringe
by supporting the syringe in an inverted position with the tip end
extending upwardly and the plunger end extending downwardly;
inserting into the barrel of the syringe a liquid conduit means,
filling the syringe with liquid, withdrawing excess liquid from the
barrel of the syringe through the conduit means until the desired
volume fluid remains in the syringe.
The accompanying drawings illustrate the preferred embodiment of
the syringe filling apparatus of this invention.
IN THE DRAWINGS:
FIG. 1 is a perspective drawing of the dispensing apparatus which
is the subject of this invention.
FIG. 2 is a partial perspective sectional view of the dispensing
apparatus shown in FIG. 1 taken along line 2--2' wherein the
syringe is in a raised position.
FIG. 3 is a partial perspective sectional view of the dispensing
apparatus similar to that of FIG. 2, wherein the syringe is in a
lowered position.
DESCRIPTION OF THE APPARATUS
Referring now to FIG. 1, there is provided a dispensing apparatus
generally designated by the numeral 10. The dispensing apparatus
10, which may also be referred to as a ringstand, includes a flat
base 11 and a support rod 12 extending perpendicularly from the
base. Since it is desirable that the apparatus be easily cleaned,
it is preferred that it be made of a non-corroding metal such as
stainless steel or aluminum, or be chromium plated.
Support rod 12 is provided with a plurality of support clamps 23
and 33 which serve the function of holding vial 20 which is a
sealed container in an inverted position. Bottle hold down clamp 33
is slideably mounted on rod 12 and is held at the desired height by
mount 32, which is also slideably attached to rod 12. Clamp 33 is
free to rotate about rod 12 within slot 17 of mount 32.
Support clamp 23 is slideably mounted onto rod 12 and is
characterized by two pairs of bifurcated support members 27 and 28.
Within the lower support member 28 is provided a threaded thumb
screw 18.
As shown in FIG. 1, support clamps 23 and 33 coact to securely hold
a vial 20, placed therebetween, in a secure inverted position. Vial
20 is of the type commonly used to store liquid injectables. As
shown in FIG. 2, vial 20 contains a metal closure 22, open at the
center thereof with a resilient liner 26 (FIG. 2) covering the
center of the metal overcap, thereby permitting the perforation of
the liner with a needle without removing the closure. In this
invention, vial 20 may be considered a multi-dose package from
which liquids are drawn to fill many unit-dose packages.
A long air supply needle 25 is inserted through liner 26, shown in
FIG. 2, and extended into the inverted vial 20 until the tip of the
needle is above the level of liquid in the inverted vial. It will
become obvious from the remaining description that the tip of
supply needle 25 should always raise above the liquid in the
inverted vial. Hollow flexible tube 16 communicates between
resilient bulb 15 shown in FIG. 1 and air supply needle 25. Bulb 15
is supported above vial 20 by means of bulb support clamp 43 which,
like clamps 23 and 33, is slideably mounted to support rod 12.
Although FIG. 1 shows a bulb 15 as supplying air to vial 20, it
should be understood that any means may be provided supplying the
necessary positive and negative pressure upon the liquid in the
vial.
As shown in FIGS. 1 and 2, located below clamp 23 and slideably
mounted to support rod 12 is another clamp 13. This clamp has
located therein a vertical opening 41 used to guide a syringe 40
open at one end and placed therein into alignment with conduit 35.
Syringe support clamp 13 has also located therein opening 37 to
align that clamp with calibrated scale 30. Opening 37 is of a
larger diameter than scale 30 so that clamp 13 may be vertically
moved with respect to clamp 23.
Scale or indicia means 30 is a rod with a flat surface at its lower
end containing calibrations 31 thereon. The scale is inserted into
vial support clamp 23 and securely held in position in said clamp
by set screw 21. Scale 30 is so positioned into clamp 23 that it is
substantially parallel to rod 12. Thus, when knob 36 of clamp 13 is
rotated, clamp 13 is free to move in a vertical direction to align
with any of the calibrations 31 on the scale.
Dispensing conduit 35 is securely clamped into a vertical position
within bifurcated support member 28 by means of thumb screw 18.
Conduit 35 consists of two needles extending axially in opposite
directions. One needle is inserted into vial 20 through resilient
liner 26 so that it just pierces the liner and does not extend
appreciably beyond the liner; the other needle is inserted into the
tip end 44 of syringe 40 which syringe is held in position by guide
clamp 13.
OPERATION OF THE FILLING APPARATUS
The remaining description relates to the calibration and operation
of the dispensing apparatus 10 and shows how this invention lends
itself to the unit-dose method of drug distribution.
Although the calibration of the instrument shall be described
below, it is assumed for purposes of explaining the method of
operation that the apparatus has been properly calibrated for the
particular syringe being filled.
FIGS. 2 and 3 show syringe support clamp 13 in the extreme upper
and lower positions respectively with respect to calibrations 31.
It should be understood that clamp 13 may be adjusted to any
position by means of knob 36 so as to align with the desired
calibrations 31 on scale 30. The calibrations indicate the volume
of liquid which will be dispensed into the syringe 40 by
compressing and releasing resilient plunger 15, shown in FIG.
1.
Referring to FIGS. 1 and 2, in the operation of the apparatus,
clamp 13 is adjusted by means of knob 36 so that the top plane 14
of clamp 13 aligns with the desired scale reading on the
calibrations 31. This represents the volume of liquid to be
dispensed into the syringe. Then, a graduated syringe 40, having
graduations directly related to the calibrations 31 of scale 30, is
inserted tip end first through the opening 41 of guide clamp 13.
While the syringe is being inserted in clamp 13, the lower end of
conduit 35 is inserted into the tip end 44 of the syringe. When the
flange 46 of the syringe comes to rest against the bottom plane of
clamp 13, it is secured in place during the filling operation by
the operator who merely holds his finger against the flange.
After the syringe 40 is in the filling position about conduit 35
and clamp 13 has been aligned with the desired volume calibration
31 on scale 30, the operator depresses bulb 15, shown in FIG. 1.
Air is forced through tube 16 and through air supply needle 25,
causing a positive pressure upon the surface of the liquid in vial
20. This pressure forces the liquid from the vial through the upper
and lower needles of conduit 35 and into syringe 40. If the liquid
level in the syringe rises above the lowermost tip of conduit 35,
that liquid is drawn back into vial 20 when bulb 15 is released.
This is caused by the negative pressure in the bulb being
transmitted through tube 16 and air supply needle 25 to the surface
of the liquid in the vial. If the uppermost end of needle 25 is
below the level of the liquid in the vial, it can be seen that,
upon release of bulb 15, the liquid in the vial will be drawn
through needle 25, through line 16, and into bulb 15.
This drawback problem can be eliminated if the end of needle 25 is
always positioned above the level of the liquid in inverted vial
20. The vacuum or negative pressure on the surface of the liquid in
vial 20 caused by the release of bulb 15 draws back into vial 20
the liquid from syringe 40, which is above the terminal end of
conduit 35. When the liquid level in the syringe corresponds to
lowermost point of the conduit, no more liquid is drawn back into
vial 20. Rather, the vacuum above the liquid level in the vial and
in bulb 15 is released by the air which is drawn through tip end 44
and then through conduit 35. The liquid level in the syringe should
now coincide with the terminal end of conduit 35. Since the
operation of this dispensing apparatus always causes the terminal
end of conduit 35 to correspond to the level of liquid in the
syringe 40, the volume calibrations 31 can be easily placed on
scale 30 as hereinafter described.
CALIBRATION OF THE DISPENSING APPARATUS
It must first be pointed out in the description of the method of
calibrating this dispensing apparatus that the calibrations 31 are
made to coincide with the linear volume calibrations on the wall of
the particular syringe to be filled. If different syringes 40 are
used of varying internal diameters and volumes, it is obvious that
the linear scale on the wall of one syringe may not correspond to
the linear scale on the wall of another syringe of a different
internal diameter. Therefore, the calibrations 31 must be changed
each time a syringe is used which does not have the same internal
diameter, volume, or plunger location as does the calibrating
syringe.
For purposes of illustration, it is assumed that the syringes of
one manufacturer coincide with those of another so that the same
calibrations 31 may be used for all syringes. It is also assumed in
order to make this calibration that all syringes come with some
prepackaged plunger 47 or other means to hold liquid in the
syringe, which plunger is located at the same constant position
with respect to the uniform graduations on the wall of the syringe.
It is preferable for purposes of calibration and dispensing that
the prepackaged plunger 47 always be located at the largest number
calibration on the syringe, which, in the preferred embodiment, is
number 2 1/2.
Referring now to FIG. 3, conduit 35 is securely clamped into the
lower bifarcated member 28 or clamp 23 by means of thumb screw 18
so that the tip of the uppermost needle of conduit 35 just
perforates liner 26.
A syringe 40, containing uniform volume graduations beginning with
the number 0 and containing a plunger 47 pre-positioned at the
largest volume calibration on the syringe is inserted into support
clamp 13 until the flange 46 of the syringe 40 contacts the bottom
plane of the clamp 13. The syringe is held in place against the
clamp 13 by one finger of the operator. The clamp 13 and syringe 40
are adjusted by releasing knob 36 until the plane corresponding to
the 0 graduation on the wall of the syringe coincides with the
terminal end of conduit 35 as shown in FIG. 3. The point on scale
30 which is horizontally aligned with the top plane 14 of clamp 13
is scored with the number which corresponds to the largest number
on the graduation of the wall of the syringe, which in this
instance is the number 2 1/2. This represents a volume of 2 1/2
cc.
The clamp 13 and the syringe 40 are then raised as shown in FIG. 2
by releasing knob 36 until the terminal end of conduit 35 coincides
with the largest number graduation on the wall of the syringe,
which in the preferred embodiment is 2 1/2 . The point on scale 30,
which is horizontally aligned with the top plane 14 of clamp 13, is
scored with the number 0. This represents a volume of 0 cc. When
the needle is at the maximum number graduation on the wall of the
syringe, it is desirable that the plunger 47 be pre-aligned with
this graduation and that the needle contact the plunger. If the
plunger is not so aligned, a corrective factor equal to the volume
between the plunger and the largest number graduation must be added
to the volume indicated on the calibration scale 31.
After two lines have been scored on scale 30 representing the
minimum and maximum volume which can be accommodated by the
syringe, the remainder of the space between these two lines is
equally divided into the desired number of major and minor
graduations corresponding to the number of major and minor
graduations on the wall of the syringe.
When scale 30 has been calibrated for one syringe of a given
internal diameter and volume, it can be used for any other syringe
of the same internal diameter and volume provided that the flange
46 and the plunger 47 are in the same position within the syringe
as the syringe used for calibration.
It can be seen from this description of the method of calibration
that any commercial syringe can be used for unit-dose dispensing if
the dispensing apparatus has been calibrated for that particular
syringe as described above.
It can also be seen that the above-described syringe dispenser can
be easily adapted to the unit-dose distribution system, since a
pharmacist can fill a large number of syringes having the same
capacity, diameter, and plunger position to any desired volume
level in a short period of time by merely inserting the syringe
into the guide clamp, adjusting the guide to align with the desired
volume on the scale and depressing the bulb to force liquid both
into and out of the supply vial. A needle containing a protective
cover can be positioned over the tip end of the syringe immediately
after dispensing by this method. The syringe is now ready to be
used in the unit-dose distribution system.
This dispensing apparatus permits a large number of the same
syringes to be filled to a known volume without moving the plunger
and without first attaching a needle to the syringe, thereby
promoting efficiency and safety in the filling of syringes.
* * * * *