U.S. patent number 3,814,297 [Application Number 05/306,950] was granted by the patent office on 1974-06-04 for inhalation actuated aerosol device for dispensing a metered quantity of fluid.
This patent grant is currently assigned to Bespak Industries Limited. Invention is credited to William Edward Warren.
United States Patent |
3,814,297 |
Warren |
June 4, 1974 |
INHALATION ACTUATED AEROSOL DEVICE FOR DISPENSING A METERED
QUANTITY OF FLUID
Abstract
A device for dispensing fluid from an aerosol container of the
kind having a spray stem or spray head which, when actuated,
dispenses fluid from the container, the device comprising a duct
having an inlet and an outlet, means to receive the aerosol
container with the outlet of the spray stem or head communicating
with the duct, a strut engageable with the stem or head so that
relative movement of the strut towards the container will press the
stem or head inwardly of the aerosol container, and means for
disengaging the strut to release the stem or head when the air
pressure at the outlet of the duct falls below the air pressure at
the inlet of the duct.
Inventors: |
Warren; William Edward
(Cuffley, EN) |
Assignee: |
Bespak Industries Limited
(Cheshunt, Waltham Cross, EN)
|
Family
ID: |
10472257 |
Appl.
No.: |
05/306,950 |
Filed: |
November 15, 1972 |
Foreign Application Priority Data
|
|
|
|
|
Nov 25, 1971 [GB] |
|
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54852/71 |
|
Current U.S.
Class: |
222/402.13;
128/200.23; 222/402.2 |
Current CPC
Class: |
A61M
15/0091 (20130101); A61M 15/009 (20130101) |
Current International
Class: |
A61M
15/00 (20060101); B65d 083/14 () |
Field of
Search: |
;222/402.13,402.2,402.11,3,402.15 ;128/208,203,211,173R |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Tollberg; Stanley H.
Assistant Examiner: Slattery; James M.
Attorney, Agent or Firm: Browne, Beveridge, DeGrandi &
Kline
Claims
I claim:
1. An aerosol device comprising an aerosol container of the type
which has a tubular valve stem and which on depression of the stem
measures out a metered quantity of fluid ready for discharge
through the stem when the stem is released, a duct which is in
fluid connection with the tubular valve stem and has one end open
to atmosphere and the other end arranged for insertion into the
mouth of a user, a two-part strut having a first part to engage the
stem and a second part which is manually engageable to move the
strut between an inoperative position in which the stem is released
and an operative position in which the stem is depressed, a flow
sensor in the duct, and means to move the first part of the strut
out of engagement with the stem to release the stem when the flow
sensor detects a flow of air in the duct when a user inhales
through the duct, the arrangement being such that release of manual
pressure from the second part of the strut will also release the
stem.
2. A device as claimed in claim 1 in which the flow sensor
comprises a vane in the duct sensitive to a pressure differential
between the outlet and the inlet of the duct.
3. A device as claimed in claim 1 in which the first part of the
strut carries a projection which is engageable by the vane to move
the said first part out of engagement with the stem.
4. A device as claimed in claim 1 in which the parts of the strut
are pivotally connected together.
5. A device as claimed in claim 4 in which the two parts of the
strut are spring biased into the position where the first part is
engageable with the stem.
6. A device as claimed in claim 4 in which the two parts of the
strut are integrally formed from plastics material.
Description
BACKGROUND TO THE INVENTION
The invention relates to aerosol containers, and more particularly
to devices for dispensing fluid from aerosol containers of the kind
having a spray stem or spray head which, when actuated, dispenses
fluid from the container. Such aerosol containers will be referred
to hereinafter as aerosol containers of the kind described.
With aerosol containers of the kind described known as
inward-charging, outward-discharging containers pressing the stem
or head inwardly of the container charges a metering chamber in the
container and when released the stem or head returns under spring
pressure, dispensing a metered dose of fluid
With aerosol containers of the kind described known as
outward-charging, inwardly discharging containers pressing the stem
or head inwardly releases a previously metered dose, and release of
the stem or head causes the next dose to be metered and stored.
With aerosol containers of the kind described known as continuous
spray containers pressing the stem or head inwardly causes
continuous emission of fluid until the stem or head is
released.
DESCRIPTION OF THE PRIOR ART
The use of aerosols for the relief of ailments such as asthma and
bronchitis has been known for many years, and dispensing devices
have been proposed for use with such aerosols which devices seek to
ensure that the user receives a dose of a drug at the commencement
of inhalation at a mouthpiece.
However such devices are specifically for use with one type of
aerosol, generally the outward-charging inwardly discharging
type.
Apparatus has been devised in which the user must suck at a
mouthpiece and then actuate the aerosol, the user not being able to
draw any breath until the aerosol is actuated. This is undesirable
as many users have difficulty drawing breath even under normal
circumstances.
In other known devices the user first cocks a spring on the device
and then draws a breath through the device. The spring is triggered
by a breath controlled valve and the energy stored in the spring is
utilised to actuate the aerosol. In other devices a toggle
arrangement prevents actuation of the aerosol until suction applied
by the user breaks the toggle. However these devices are
complicated in construction and therefore expensive. Furthermore as
considerable force is required to actuate the outward-charging,
inwardly discharging aerosol the dose is not always released right
at the start of drawing breath.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a device for dispensing
fluid from an aerosol container which device is of very simple and
inexpensive construction, being composed of only a small number of
moving parts.
It is a further object of the invention to provide such a device in
which a dose of fluid may readily be provided when suction is
applied to the device.
In general terms these objects are achieved by utilising the fact
that inward-charging outward-discharging containers require a very
low force to maintain the spray head or stem in the inward position
after charging, and hence a very low force to release the dose.
This permits the use of a very simple release mechanism.
Accordingly the invention provides a device for dispensing fluid
from an aerosol container of the kind described, the device
comprising a duct having an inlet and an outlet, means to receive
the aerosol container with the outlet of the spray stem or head
communicating with the duct, a strut engageable with the stem or
head and manually operable to press the stem or head inwardly of
the aerosol container, and means for disengaging the strut to
release the stem or head when the air pressure at the outlet of the
duct falls below the air pressure at the inlet of the duct.
The device according to the invention is very suitable for use with
an aerosol container containing medicament for asthma sufferers. If
the user manually moves the container and the strut toward one
another and then sucks at the duct outlet he will receive
medicament at or immediately after commencement of sucking.
The device is particularly suitable for use with an
inward-charging, outward-discharging container, as mentioned above,
since the force required to hold the head or stem in the inward
position, and hence the force required to disengage the strut, is
relatively small. It is however a significant advantage of the
device that it may be arranged for use with outward-charging,
inward-discharging or continuous spray containers while still
utilising a very simple construction of few parts. In order to
ensure that a single discrete dose is emitted at or immediately
after commencement of sucking, the strut, or means associated
therewith, may be arranged to seal the outlet of the stem or head
while the strut is in the engaged position.
The air pressure difference whereby the strut is disengaged may be
detected by a pressure responsive device, which may be a vane in
the duct. Alternatively, the pressure difference may be detected by
a device responsive to air flow in the duct resulting from said
pressure difference. Such a flow responsive device may comprise a
hot-wire anemometer.
DESCRIPTION OF A SPECIFIC EMBODIMENT
One specific example of the invention will now be described with
reference to the accompanying drawing which shows a device for
dispensing asthma medicament from an aerosol.
Referring to the drawing, a plastics casing 51 has an outlet
orifice 52 suitable for placing in the mouth of a user. The casing
51 defines a recess 53 in which there is placed an aerosol type
medicament dispenser 54. The dispenser 54 has a stem or spray head
55 with an outlet orifice 56 in one side. Pressing stem 55 inwardly
of the aerosol container causes a metering chamber (not shown) to
be primed, and release of the stem allows a metered dose of
medicament to issue from orifice 56.
In the device shown in the drawing, a press button 57 has a strut
58 integral therewith but pivotable about a flexible hinge. The
strut engages the end of the stem 55, so that when the press button
is pushed inward then the stem is pressed into the dispenser 54 and
the metering chamber is filled with medicament. Attached to the
strut 58 is a lever arm 59, and this in turn is engaged by a vane
61 pivoted to the body of the device at a hinge 62. The vane 61 in
its normal position as shown in the drawing blocks a duct within
the casing 51 and extending between an air inlet 63 and the outlet
orifice 52. However, when suction is applied at the outlet orifice
52 then the difference in air pressure across the vane 61 causes it
to move in an anti-clockwise direction thereby opening the passage
between the air inlet 63 and the outlet 52, and at the same time
striking the lever arm 59 and causing both the lever arm and also
the strut 58 to rotate in a clockwise direction about the hinge
joint between the strut and the press button 57. It will be clear
that, if before this occurs the press button 57 has been pressed
inwardly to hold the stem 55 into the dispenser 54, then the
above-described sequence of events will release the stem and spray
head 55 so that it will move downwardly and the dose of medicament
stored within the valve will be dispensed into the air stream
flowing out of the orifice 52. It will be appreciated that in use
of the device the asthma sufferer presses the push-button 57
upwardly and holds it and then draws breath through the outlet
orifice 52; the arrangement ensures that the medicament is
dispensed at the beginning of the inhalation thereby assuring
maximum effect.
So as to ensure that the device resets itself after use, the strut
58 is provided with an extension 64 engageable with a spring loaded
pin 65. When the device is operated the rotation of the lever arm
59 and the strut 58 by the vane 61 depresses the pin 65, but when
the press button 57 is thereafter released the pin tilts the strut
back towards the stem 55 to engage it.
The embodiment described is suitable for use with any reservoir of
the appropriate size and having a metering valve which is primed on
the inward stroke of the stem and dispenses medicament on the
outward stroke. One particular form of such a metering valve
utilizes a hollow stem as the receptacle, and is charged by
pressing the stem and spray head 55 inwardly past a stem seal until
the orifice 56 is within the reservoir, whereupon medicament under
pressure enters the hollow stem through the orifice, and subsequent
release of the stem and spray head 55 dispenses the medicament.
This is, however, only one of several possible valve constructions.
In some constructions the outlet orifice 56 is in the end of the
stem, not the side. The device of this example may be adapted for
use with an outward-charging, inward-discharging container, or a
continuous spray container, by providing means which seal the
outlet orifice when the strut is in the engaged position shown.
Thus pressing the strut inwardly will cause a dose of medicament to
be stored in the spray stem, removal of the strut allowing the dose
to escape through the outlet orifice of the stem.
Other modifications and improvements may be made without departing
from the invention, as will be appreciated by those skilled in the
art.
The sealing means may for example comprise a sealing pad on the
strut, or a piston carrying a sealing pad and interposed between
the strut and the spray stem.
If desired button 57 may be dispensed with, the relative movement
of the strut towards the container being brought about by manual
downward movement of the container.
* * * * *