Canadian Patents Database / Patent 1090748 Summary
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|(12) Patent:||(11) CA 1090748|
|(21) Application Number:||330255|
|(54) English Title:||FOAM-GENERATING DEVICE FOR A PUMP SPRAYER|
|(54) French Title:||DISPOSITIF MOUSSEUR POUR ATOMISSEUR A POMPE|
- Bibliographic Data
- Representative Drawing
- Admin Status
- Owners on Record
|(52) Canadian Patent Classification (CPC):||
|(51) International Patent Classification (IPC):||
|(72) Inventors :||
|(73) Owners :||
|(71) Applicants :|
|(74) Agent:||SMART & BIGGAR|
|(22) Filed Date:||1979-06-21|
|(30) Availability of licence:||N/A|
|(30) Language of filing:||English|
|(30) Application Priority Data:|
A foam generating device for a manually
operated dispensing pump capable of dispensing
a foamable liquid from a container and ejecting
it into the atmosphere through an atomizing noz-
zle, the foam-forming device comprises an air
inlet and a screen retained in the path of the
spray. The screen can be retained in a foam-
-forming position by suitable means such as a
housing operatively associated with the dis-
pensing pump. Substantially all the spray passes
through the foam-forming device without contact
except by the screen, thereby generating foam with
little modification of the spray pattern.
THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A foam generating device for a hand-
-held, foam-spraying apparatus comprising
a manually operated dispensing pump,
including an atomizing nozzle, for drawing a
foamable liquid from a container and ejecting it
as a spray into the atmosphere through the atom-
said foam generating device being oper-
atively associated with the dispensing pump for
producing foam from the spray without substantially
modifying the predetermined spray pattern and com-
prising a screen retained in the path of the spray,
and means for introducing air into the spray so that
the spray is permitted to foam upon contact with
the screen; said foam generating device permitting
the passage of substantially all the spray there-
through without contact except by the screen.
2. The device according to Claim 1
including means for connecting said device to the
dispensing pump for movement between first position
for producing foam and a second position for per-
mitting spray to be ejected without producing foam,
and means for selectively securing the device in the first and second
3. The device according to Claim 1 or 2, wherein the screen has a size
in the range of from 60 to 200 mesh.
4. The device according to Claim 1 or 2, wherein the screen has a size
in the range of from 100 to 180 mesh.
5. The device according to Claim 1 or 2 wherein the screen is spaced
at a distance of from 0.8 to 4 mm from the atomizing nozzle.
6. The device according to Claim 1 or 2 wherein the screen is spaced
at a distance of from 2 to 3 mm from the atomizing nozzle.
7. The device according to Claim 1 or 2 wherein the screen has a
size in the range of from 60 to 200 mesh, and the screen is spaced at a
distance of 0.8 to 4 mm from the atomizing nozzle.
8. The device according to Claim 1 or 2 wherein the screen has a
size in the range of from 100 to 180 mesh, and the screen is spaced at a
distance of from 2 to 3 mm from the atomizing nozzle.
A FOAM-GENERATING DEVICE FOR A
The present invention resides in a foam
generating and dispensing device and, more par-
ticularly, to a foam generating device for a manu-
ally operated atomizing dispenser having the capacity
to spray a foamable liquid as a foam.
,Foam generating and dispensing devices
are wll known in the art. The demand for these
devices has heretofore been satisfied almost
exclusively by the disposable, self-contained
aerosol dispensers, due to their convenience and
adaptability to a wide variety of products and
,15 foaming conditions. However, the continued use of
such self-contained aerosol dispensers is presently
being re-evaluated, due in part to recently espoused
environmental concerns over the effects of some of
the chemical propellants used therein and in part
to changing economic conditions. Accordingly,
workers in the art have embarked upon a search for
,an acceptable replacement for the aerosol foam
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Generally, those replacement deviceswhich have been proposed are of the type which
include a collapsible bottle and a foam-forming
cap assembly. The foam-forming cap assembly
typically includes a homogenizing element of
sponge-like material providing minute tortuous
passages in which a flow of foamable liquid and
air from the container is mixed to provide foam.
Exemplary devices of this type are described in
US Patent No. 3,985,271; US Patent No. 3,973,701;
US Patent No. 3,937,364; and US Patent No. 3,572,590.
In such devices, the mixture of air and liquid loses
considerable velocity as it passes through the homo-
genizing element. Consequently, such devices unde-
sirably have only limited "reach", i.e., theyrequire the use to dispense the foam in near proximity
to the surface upon which the foam will be deposited.
Furthermore, because the user must apply his efforts
to expel both liquid and air simultaneously, appreci-
able energy is wasted in forming and dispensing
; the foam. Still further, such devices are unecono-
mical inasmuch as they require that the bottle be
-~ only partially filled with a foamable liquid so
that the necessary internal air supply is avail-
able for foam formation.
Consequently, attempts have been made
to convert a conventional manually-operated
atomizing dispenser (or "pump sprayer" as they
are often called) to a foam-forming device, thereby
~0 overcoming some of the disadvantages of the "col-
lapsible bottle" foamers. Specifically, it has
been appreciated that (a) a pump sprayer is highly
efficient, i.e., the user's efforts are directed
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to expelling only liquid, thereby minimizing the
labor involved in its operation, and (b) it has
considerable "reach", i.e., the liquid can be pro-
jected over a considerable distance. Nevertheless,
it is believed that foam-generating pump sprayers
have heretofore not met with success. For what-
ever reason, it would appear that pump sprayers
(which have replaced the aerosol dispenser in
numerous other applications) have not been made
adaptable to the generation and dispensation of
a foam of commercially acceptable quality.
Accordingly, it is an object of the pre-
sent invention to provide a foam generating and
dispensing device for a hand-held, manually operated
dispenser which requires only minimal effort to
operate which has considerable reach, which can
spray a foam of commercially acceptable quality,
and which can be economically produced by con-
ventional fabrication techniques. It is also an
object of this invention to provide a pump sprayer
or manually operated atomizing dispenser having
the capacity to spray a foamable liquid as a foam.
The present invention provides a foam
generating device for a hand-held, foam-spraying
apparatus comprising a manually operated dispen-
sing pump, including an atomizing nozzle, for
drawing a foamable liquid from a container and
ejecting it as a spray into the atmosphere through
the atomizing nozzle, said foam generating device
being operatively associated with the dispensing
pump for producing foam from the spray without
substantially modifying the predetermined spray
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pattern and comprising a screen retained in the
path of the spray, and means for introducing air
into the spray so that the spray is permitted to
foam upon contact with the screen, said foam gen-
erating device permitting substantially all thespray to pass therethrough without contact except
by the screen.
The device generates foam on the surface
of the screen using air external to the dispensing
pump. Consequently, the user's labor is miminized
since the amount of liquid expelled in the form of
a foam is directly proportional to the effort con-
tributed, there being no wasted energy due to the
compression of air as in the "collapsible bottle"
; Additionally, minimal velocity is lost
by the spray as it is converted to foam in the
device since substantially all the spray passes
through the foam generating device without con-
tact except by the surface of the screen. Accord-
ingly, the reach of the spraying apparatus utilizing
the present foam generating device is considerably
increased compared to the "collapsible bottle"
Furthermore, the foam generating device
of the present invention provides a foam of com-
mercially acceptable quality, i.e., it is relatively
dry and stable and has little tendency to drip when
deposited on a vertical surface. Consequently,
the device is eminently suited for spray-foaming
household cleaners and the like.
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Still further, the foam generator of the
present invention is very economical to produce
; since, in some instances, it can be readily con-
structed with only minimal modification for use on
a pre-existing pump sprayer.
Fig. 1 is a side elevation view, showing
the foam generating device in cross-section attached
to a conventional manually operated foam-spraying
Fig. 2 is a front elevation view of the
foam generating device of Fig. 1.
~ ig. 3 is a cross-sectional side elevation
view of another embodiment of a foam generating
Fig. 4 is a side elevation view, par-
tially in cross-section, of another embodiment of
a foam generating device attached to a conventional
^ hand-held dispensing pump.
Fig. 5 is a front elevation view of the
foam generating device of Fig. 4.
`~ Referring to Figs. 1 and 2, a manually
operated dispensing pump 10 is detachably con-
nected by a conventional threaded coupling 11 to
a container 12 for receiving a foamable liquid
therein. It is not a requirement of this inven-
~ tion that the dispensing pump be connected to
- the container, though such is desirable to enhance
l mobility. Generally, a conventional hand-held
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dispensing pump/containter combination, such as
is currently marketed for household use, is pre-
ferred. Regardless of the particular form chosen,
it is understood that fluid communication will be
provided between the dispensing pump and the foam-
able liquid, e.g., through a dip tube 13 (shown
in phantom), so that the dispensing pump is able
to draw liquid from the container.
As used herein, the term "foamable liquid"
is meant to include any liquid having the capacity
to form a foam when dispensed by the foam-spraying
apparatus of the present invention. Generally,
such liquids will exhibit the following properties:
surface tension in the range of 20 to 45 dyne/cm,
preferably 25 to 35 dyne/cm; density in the range
of 0.8 to 1.2 g/cc, preferably 0.98 to 1.05 g/cc;
and viscosity in the range of 0.9 to 1.7 centi-
- stokes, preferably 1.1 to 1.4 centistokes.
The dispensing pump may generally be of
any conventional construction, so long as it in-
cludes an atomizing nozzle 14. The term "atomi-
zing nozzle" as used herein is intended to be
generic to a mechanism for providing a fine spray
of liquid through a single or a plurality of orifices.
Such dispensing pumps are generally provided with
a compression mechanism, e.g., a piston 15 and an
actuator 16, to force the liquid from the container
through the atomizing nozzle with sufficient velocity
to form the spray. Suitable dispensing pumps will
preferably provide a spray having a velocity in the
range of 15 to 21 meters/sec. through an orifice
having a diamenter in the the range of from 0.3 to
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0.65 mm and a land length in the range of from
0.25 to 0.6 mm. Exemplary dispensing pumps
which may be used in the present invention include
the AFA 7510 sprayer manufactured by the AFA Corpo-
ration and the Canyon CS sprayer manufactured by theCanyon Corporation.
The foam dispensing device of the pre-
sent invention includes a bell-shaped housing 20
which is provided with a screen 21. The housing
is operatively attached to the dispensing pump
by a suitable mechanism such as a snap-fit mech-
anism which consists of a peripheral projection
22 which extends from the atomizing nozzle and a
complimentary annular groove 23 defined by the
inner surface of the housing 20. The housing 20
functions to retain the screen 21 in the path of
the spray at a predetermined distance d from the
- atomizing nozzle, i.e., the distance from the point
at which the spray is ejected from the dispensing
pump into the atmosphere (which point will typically
coincide with the location of the nozzle face 24).
~ In order to generate a high quality foam, dista@ce
; d will generally be in the range of from 0.8 to
4 mm, preferably in the range of from 2 to 3 mm.
Furthermore, the screen size will generally be in
the range of from 60 to 200 mesh (U.S. Sieve Series),
preferably in the range of from 100 to 180 mesh.
; Screens having a smaller mesh size than that indi- ~-
cated will severely reduce spray velocity and cause
~0 excessive dribbling, whereas screens having a
larger mesh size will permit spray to pass there-
through without sufficient foaming. The screen
can be made of any material which is inert to the
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foamable liquid which will be dispensed. Because
of their low cost and characteristically flat
surface conformations, plastic screens, such as
those made from polyethylene or polypropylene,
are preferred. Furthermore, such plastic screens
are eminently suited for sonic or electronic
welding, thus providing a convenient method of
attaching the screen to housing 20, should the
housing be constructed of a similar plastic
material. Other methods of attachment, such as
by a suitable adhesive or press-fit mechanism,
can also be used.
The foam generating dèvice also includes
means for introducing air into the spray so that
the spray is permitted to foam upon contact with
the screen. One method of accomplishing this is
to construct housing 20 so that the diameter of
the opening therein is larger than the diameter
i of the spray pattern at the point which it inter-
;~ 20 cepts the screen, whereby air is permitted to
enter the foam generating device from the front.
This will be better understood by referring to
Fig. 2, which shows the screen diameter s of the
spray pattern as it intercepts the screen 21
(depicted by shading) and the diameter o of the
opening of housing 20. Another method is exempli-
fied by Fig. 3, wherein housing 20' defines pass-
ageways 25 which permit air to flow into the
spray through the wall of the foam-forming means.
Either of these methods, or a combination thereof,
may be used. In either method, however, the foam
generating device should be constructed so as to
provide the proper amount of air for good foam
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formation. Specifically, if too little air is avail-
able, some of the spray will pass through the screen
without foaming, thereby resulting in an undesirably
wet foam being ejected from the foam-spraying appara-
It is a requirement of the foam generating
device of the present invention that substantially
all the spray pass therethrough without contacting
any surface except the surface of the screen.
Mechanical breakup of the spray, such as by im-
pinging upon the walls of housing 20, should be
minimized, since such will cause the reduction of
spray velocity and result in undesirable dribbling
from the foam-spraying apparatus.
It will be appreciated that the foam
generating device of the present invention is cap-
able of numerous embodiments. For example, it may
be constructed so as to be detachable from the -
dispensing pump, as exemplified by Figs. 1 to 3, or
it may be permanently integrated with the dispens-
ing pump, as exemplified by Figs 4 and 5. In Fig. 4,
the foam generating device comprises an integral
box-like member 30, which protrudes outwardly from
a dispensing pump 10' adjacent to the atomizing
nozzle. The box-like member includes a flap 31,
retaining a screen 21, and defines suitable air
passages 35 at a position rearward of the flap. -
Flap 31 is connected to the box-like member by a
hinge 32 so that the flap can be pivoted 270 from
a foam generating position, wherein the screen is
retained in the path of the spray, to a position
where no foam is generated (shown in phantom).
Suitable locking pins 33 and 34 snap-fit into mating
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recaptacles defined by the box-like member 30 and
the upper surface of the dispensing pump 10', re-
spectively, to enable the user to lock flap 31 in
the desired operating position.
, 5 The type of dispensing pump to be used
in the present foam-spraying apparatus is not crit-
; ical. For example, the dispensing pump can be a
finger-actuated, vertically-oriented mechanism as
` well as the hand-actuated, horizontally-oriented mech-
; 10 anism like that shown in Figs. 1 and 4. Addition-
, ally, the form of the screen can be varied within
the scope of the functional requirements suggested
earlier. For example, the screen may be arcuate
in cross-section, e.g., protruding away from the
atomizing nozzle, and the openings of the screen
can be of any desired configuration, i.e., the
~- openings need not be s~uare.
In order to demonstrate the effective-
~'~ 20 ness of the foam-forming apparatus of the present
invention, experiments were performed by testing
~ two commercially available dispensing pumps, i.e.,
';f1 the AFA 7510 sprayer and the Canyon CS sprayer,
;~ with and without the foam generating device de-
picted in Figs. 1 and 2. The foam generating device
included a 100 mesh (U.S. Sieve Series) nylon screen
' spaced a distance d of 3 to 4 mm from the atomi-
zing nozzle and had an opening o of about 10 mm.
For comparison, an AFA 5910 sprayer was
tested with and without an AFA 5912BA foaming
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A foamable liquid cleaner having a sur-
face tension of 31.2 dyne/cm, a density of 1.02
g/cc, and a viscosity of 1.37 centistokes was used
in all tests.
The results of these experiments are
shown in Table 1. It can be seen that the AFA
5912BA foaming attachment severely modified the
predetermined spray pattern and rendered the dis-
pensing pump relatively hard to operate.
In contrast, the foam generating device ;
of the present invention did not substantially
modify the predetermined spray pattern nor did it
substantially affect the amount of effort required ~-
to operate the dispensing pump. In addition, the
present foam generating device was able to produce
a very good quality foam - much like that produced
by a typical aerosol dispenser.
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Sorry, the representative drawing for patent document number 1090748 was not found.
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|Forecasted Issue Date||1980-12-02|
|Fee Type||Anniversary Year||Due Date||Amount Paid||Paid Date|
|Current Owners on Record|
|THE DOW CHEMICAL COMPANY|
|Past Owners on Record|