COMMISSIONER'S DECISION
OBVIOUSNESS: Aerosol Dispensing Container
The application relates to an aerosol container for spraying antiperspirants
and other substances free of liquified propellant. It was refused for
failing to define a patentable advance in the art. The Board was not
persuaded that the invention claimed is taught by or is obvious from the
cited art.
Final Rejection: Reversed
This decision deals with a request for review by the Commissioner of
Patents of the Examiner's Final Action dated August 28, 1975, on appli-
cation 140,066 (Class 222-53). The application was filed on April 18,
1972, and is entitled "Aerosol Dispensing Device." The Patent Appeal
Board conducted a Hearing on November 10, 1976, at which Messrs. D.N.
Deeth and P.K. Holland represented the applicant. Also in attendance was
Dr. R.S. Tonge, a representative of Unilever Limited.
The application relates to an aerosol container for spraying antiperspirants
and other substances free of liquefied propellant. The presence of liquid
propellant in sprayed materials causes chilling and other undesirable eff-
ects for the user. The device comprises a main compartment provided with a
dispensing valve, and which contains the substance together with sufficient
pressurised propellant vapour to effect dispensation. At the bottom of
the container is a reservoir containing both liquefied propellant and
pressurised propellant vapour. A communicating valve is located between
the reservoir compartment and the main compartment. Figure 2 of the application
illustrates the device claimed.
(See formula 1)
In the Final Action the examiner refused the application for failing to de-
fine patentable subject matter over the following patents, common knowledge
and expected skill.
British 875,384 Aug. 16, 1961 Clark et al
United States 3,258,163 June 28, 1966 Brush
Clark discloses dispensing devices, and in particular devices for dispensing
flowable materials by the pressure of the vapour of a liquid propellant which
has a low boiling point. It is an object of the Clark invention "to provide
a novel and improved device for dispensing flowable materials by vapour
pressure in which contact between liquid propellant and flowable material is
reduced." Figure 1 of the patent illustrates his invention.
(See formula 1)
Brush discloses a dispensing container of the gas propelled type which operate
at low pressures. The drawing, below, illustrates the invention and shows a
pressure reducing valve 24 between a propellant charge 14 and a product con-
tainer 12.
(See formula 2)
In the Final Action the examiner stated (in part):
The British Patent and this application are quite similar in
purpose. However the British Patent does not provide a mechan-
ical pressure reducing valve. Orifices 9 and 10 do act to prevent
a liquid flow and because of their capillary nature do effect
some pressure reduction but nothing of any great value. However
to provide a pressure reducing valve between a high pressure pro-
pellant container and a lower pressure product container is held
obvious in view of Brush who does just that. To provide a dome
shaped top to the propellant container is held to be a mere matter
of choice and elementary design. To provide a fill valve at 19
is also held to be a mere matter of choice and elementary design.
Note element 62 of Brush in this regard.
...
It is here held that the alterations applicant has made to the
device of British Patent 875,384 are obvious in view of Brush and
common knowledge. In this respect applicants' attention is drawn
to British Patent 399,650 of October 12, 1933 which establishes
that a one way rubber sleeve valve as shown in Fig. 2 of the
instant application is common knowledge.
To employ it as applicant has done is but expected skill. Applicant's
attention is also drawn to British Patent 875,384, page 1 lines 53-
57 wherein is stated that "The aperture and the outlet aperture
may be in the form of valves but are preferably small seized
orifices" (emphasis added) Thus patentee envisaged valves
generally but chose a pin type.
In response to the Final Action the applicant argued that the application
is not open to objection on the ground stated by the examiner. He says that the
Clark invention possesses disadvantages that rule it out of consideration
for commercial use, and that the valve in Brush operates in an entirely
different manner from that in the present application. He also stated (in
part):
The British Patent also fails to disclose the use of a communicating
valve, which, as required by the claims in the present application
is constructed so that it is held closed except when opened by
a predetermined level of pressure difference between the product
compartment and the propellant reservoir to permit propellant
in the vapour phase to pass from the propellant reservoir to
the product compartment. It must be emphasized that the only means
shown in the British Patent 875,384 for limiting the mixing of
propellant product when in use is the provision of capillary openings 9
and 10. Note that mixing is limited and not prevented, as will be
appreciated from a careful study of the specification. Applicants
agree with the Examiner when he states that the capillary openings
9 and 10 permit gas to flow into the container 1 to effect product
discharge, but they cannot agree that these self same capillary
openings will act to prevent liquid flow. Certainly, liquefied
gas propellant cannot flow out of the tube 6 via tube 8 even if
the device is inverted, but what the Examiner has not appreciated
is that liquid product is not necessarily prevented from entering
the capillary opening 9, especially when the container is shaken
or inverted. There is clearly no mechanism whereby the propellant
pressure in the tube 6 can be maintained at a value in excess of
that within the headspace of the can: in fact the pressure inside
and outside tube 6 will normally be the same. Hence, at the moment
when product is dispensed, pressure within the headspace will drop,
liquefied propellant in tube 6 will boil-off causing more propellant
gas to enter the headspace. The consequence of this will be that
the temperature of the liquefied propellant will fall due to loss of
latent heat of evaporation, gas pressure within tube 6 will diminish
due to the temporary temperature reduction and product might at
this point be drawn into the propellant reservoir tube, especially
if the device is inverted.
...
Brush is clearly concerned with low pressure systems: a dispensing
pressure of 3-10 lbs per square inch is referred to at column 1,
line 23 and Brush makes particular reference to the use of a pressure
of 3 psi at column 4, line 9. This very low pressure clearly has a
profound effect on the nature of the product which is to be dispensed,
and also on the sensitivity of the valve inside the Brush device.
Brush states at column 4, line 23 that
"The container may be used to dispense air sensitive
liquids with a gentle controlled flow, and without
atomisation or foaming or spray effect associated
with the usual aerosol container." (emphasis added).
It can be concluded from this that the Brush device would be quite
ineffective for dispensing an atomised spray which it is noted is
a most important attribute of Applicants device.
In this connection, claim 1 of the present application requires
the presence of a liquefied gas propellant, while Brush discloses
only a compressed gas. Claim 2 requires that the second compart-
ment be adapted to contain a liquefied gas, and it is not clear
that the compartment 14 is adapted to withstand liquefied gas
pressure.
The question to be considered is whether or not the applicant has made a
patentable advance in the art. Claim 1 which is before us reads as
follows:
An aerosol dispensing device having a top outer wall, a bottom outer
wall, a substantially cylindrical side outer wall, and a bell-shaped
interior wall, consisting essentially of:
i) a first compartment within the device having as one of
its boundaries the bell-shaped interior wall, the first
compartment containing a substance to be dispensed and
a liquefiable gas propellant in vapour phase, the substance
when a liquid comprising also dissolved propellant gas
at the saturation concentration appropriate for the liquid
substance and the propellant gas;
ii) a dispensing valve extending through an outer wall inter
connecting the first compartment and the atmosphere;
iii) a second compartment within the device having as one of its
boundaries the bell-shaped interior wall, and having an
inlet through an exterior wall for introduction of a liquefied
gas propellant, the second compartment containing liquefied
gas propellant in liquid and vapour phase; the vapour pressure
in the second compartment being higher than the vapour
pressure in the first compartment; and
iv) a communicating valve extending through the interior wall inter-
connecting the first and second compartments, the communicating
valve permitting the passage of vapour phase propellant from the
second to the first compartment while preventing passage of liquid
phase propellant from the second to the first compartment; the
communicating valve comprising an open ended tube extending from
the interior bell-shaped wall part way into the second compartment
in such a manner that its open end remote from the interior bell-
shaped wall is always above the level of the liquefied gas
propellant whatever the position of the device; and the communicating
valve having a resilient member which holds the communicating valve
closed except when the gas pressure difference between the first
and the second compartments rises to a predetermined level
following dispensation of substance from the first compartment.
At the Hearing Mr. Deeth raised some interesting arguments which require
careful consideration. Dr. Tonge demonstrated the use of different dis-
pensers, and also assisted the Board with some relevant observations.
In order to determine whether or not an invention is present, it is necessary
to review the prior art and consider its cumulative effect (see DeFrees and
Betts Machine Co. D.A. Acc. Ltd.25 Fox Pat. C. 58 at 59).
The applicant is seeking with an improved device to avoid the disadvantage
of liquefied gas propellant being dispersed with the product, a disadvan-
tage common to the usual aerosol dispensers. Both for economy and for
ecological reasons it would be advantageous to reduce as far as possible
the amount of propellant distributed into the atmosphere when the product
is dispensed.
The primary reference (Clark) was discussed on page 3 of the present
disclosure in the following terms:
In British Patent Specification No. 875,384 there is described
and illustrated a dispensing device which makes use of a standard
can and differs from the conventional system, in which the product
to be dispensed is mixed with liquefied propellant, in that the
propellant is contained in a separate receptacle which is attached to the
dip-tube. In the assembly of the device the product to be dispensed
is filled into the can, the said receptacle is fitted to the dip-
tube which is in turn fitted to the dispensing valve. Propellant
cooled to well below its boiling point is then fed into the recept-
acle, the receptacle sealed with a plug having an opening for re-
leasing vapour, but not liquid propellant and the assembly disposed
within the can to which the valve is secured as quickly as possible.
Although this device requires the use of a reduced amount of propel-
lant compared with the case where the product to be dispensed and
propellant liquid are mixed, the device is essentially impractical in
commercial terms since it does not lend itself to a high speed filling
operation. Furthermore, because of the impossibility of preventing loss
of propellant during assembly operation, the product to propellant
ratio in the final device would be highly variable.
We note that the Clark patent is owned by the present applicant (Unilever Limited).
At the Hearing Mr. Deeth pointed out that the Clark device is so designed
that it could never lend itself to a high speed filling operation, which
"is a must in the manufacture of aerosol products." He also stated that it
was impossible to prevent the loss of propellant during the assembly operation.
The Clark patent does not disclose an inlet through an exterior wall through which
liquefied gas propellant can be introduced into the propellant reservoir. This
according to the applicant is a most important feature. The Clark patent
uses capillary openings for limiting the mixing of propellant and product. In
this application, the applicant uses a communicating one-way valve, which is
constructed so that it is closed except when opened at a predetermined pressure
differential between the product compartment and the propellant reservoir
to permit propellant in the vapour phase to pass from the propellant reservoir
to the product compartment. Clark did however, suggest that the "outlet
aperature may be in the form of valves, but are preferably small sized orifices...."
We note that the British "provisional specification" discussed the use of
valves, such as a Bunsen type valve. In the "complete specification" however,
all reference to the Bunsen type valve was deleted and emphasis was placed on
a "capillary tube arrangement," which is also the only arrangement shown in
the drawings. An explanation for the deletion was given by Dr. Tonge at
the Hearing. He stated that the co-inventor of the Clark patent told him
that they had thought of using valves, and did some experimenting with valves
of the Bunsen type. The valves they tested "did not operate satisfactorily;
they could not get them to work smoothly - they tended to clog."
The examiner also brought British Patent 399,650 into his final action to
show that a one-way rubber sleeve valve is old. It does not however show the
"septum tube 17" (see Figure 2 of the instant application supra). The septum
tube prevents the liquefied gas propellant from entering the product compart-
ment. In any event the applicant is not relying solely on the valve for
novelty, but on the combination of the dispenser as a whole.
The Brush patent is only concerned with low pressure has propellant systems;
a dispensing pressure of 3-10 pounds per square inch is used. This low pressure
has a direct effect on the nature of the product which is to be dispensed.
Brush states that his container is used "to dispense air sensitive liquids with
a gentle controlled flow, and without atomization or foaming or spray effect
associated with the usual aerosol container." It appears clear then that
Brush's device would be ineffective for dispensing an atomised spray, which is
one of the objectives of the present device.
The poppet valve used by Brush operates in a manner which is different from
valve 16 in the present application. The Brush device will operate with a
gas propellant, but it would not operate as intended with a liquefied gas
propellant. The propellant liquid would pass through the poppet valve if the
container was held in any position but upright. This would obviate the
advantages gained in separating product and liquefied propellant. The opening
and closing of the poppet valve in Brush is caused entirely by pressure
fluctuation in the upper (product) compartment, and is completely unaffected
by pressure changes in the lower propellant compartment.
The valve in the dispenser of this application remains closed except when
the gas pressure difference between the product compartment and the propell-
ant reservoir rises to a predetermined level. It is clear then that the
valve in Brush operates on a principle entirely different from the instant
valve.
The device as claimed in this application essentially consists of two compart-
ments separated by a bell-shaped interior wall. When held in the normally
upright position, an upper compartment is provided for filling with the
product to be dispensed. This is referred to as the first compartment. The
second compartment is used for charging with liquefied gas propellant. A
conventional dispensing valve is provided at the top of the container. A
second communicating one-way valve is fitted between the compartments. The
one-way valve includes an open-ended tube arranged to permit propellant gas
to pass from the propellant reservoir to the product compartment, but to
prevent passage of liquid gas propellant to the product compartment irrespective
of the position in which the dispensing device is held. The open tube ex-
tends from the interior bell-shaped wall part way into the second compartment
in such a manner that its open end remote from the interior bell-shaped wall
is always above the level of the liquefied gas propellant whatever the position
of the device. The communicating valve also prevents liquid product from
entering the reservoir compartment containing the liquefied gas propellant.
The applicant has made no attempt to claim the broad concept of keeping the
product separate from the propellant, but has claimed what he states is an improved
dispenser "which is both cheap and easy to construct and assemble, and which
functions to dispense the product in the substantial absence of liquefied gas
propellant."
It is of interest to note that the applicant has filed for patents in some
twenty countries, and has to date received 10 to 12 patents on his dispensing
device.
We have reviewed the prior art and have considered its cumulative effect
(see DeFrees v. D.A. Acc. Ltd., supra). We are not persuaded however, that
the invention claimed is taught by or is obvious from the prior art, common
knowledge or expected skill. The applicant has overcome different problems,
especially one of packaging, and has obtained a result in a more expeditious
manner than heretofor. For example, no step of refrigeration is required in
the instant packaging procedure, nor is there any loss of propellant. There
is, in our view, sufficient evidence of thought, design, ingenuity in the
invention and novelty in the combination (see Merco Nordstrom Valve Co. v
Corner (1942) Ex. C.R. 138 at 155).
We believe that the claims on file are directed to patentable subject matter,
and recommend that the Final Action be withdrawn, and the application returned
to the examiner for resumption of prosecution.
J.F. Hughes
Assistant Chairman
Patent Appeal Board, Canada
I have reviewed the prosecution of this application and the recommendations
of the Patent Appeal Board. In the circumstances I have decided to withdraw
the Final Action, and return the application to the examiner for allowance.
J.H.A. Gari‚py
Commissioner of Patents
Dated at Hull, Quebec
this 31st, day of December, 1976
Agent for Applicant
Ridout & Maybee
111 Richmond St. W.
Toronto, Ontario