Note: Descriptions are shown in the official language in which they were submitted.
CA 02462373 2004-03-09
SPRAY DISPENSER
The invention relates to a spray dispenser for delivering a
substance from a spray nozzle. The substance may be
delivered in the form of a fine mist, but also in form of
an atomized stream with larger drops. In all cases, such
spray dispensers include a filling substance reservoir
which receives the filling substance, and also a valve unit
that is connected to the filling substance reservoir, with
a spray head which in turn is furnished with a spray
nozzle.
There are several possibilities for expelling the filling
substance from the filling substance reservoir, and these
are realized in various spray dispenser constructions. For
example, expulsion of the filling substance by means of a
gas propellant is known. This principle is the worst,
because the gas propellant is known to be highly harmful to
the environment. In particular, because the gas propellant
has strong dependency on its temperature, the function of
the spray system is only possible within a narrowly defined
temperature range.
Another possibility is to expel the filling substance from
the filling substance reservoir by manual pressure on a
displacement piston. However, this principle does not meet
the requirement of convenience. According to this method,
the spray nozzle should be generally oriented in a certain
direction; when hand pressure is applied, the nozzle
frequently deviates from this direction.
A further known construction uses a receptacle made from
an elastomer material as a filling substance reservoir.
This material is capable of expansion. When the filling
substance is introduced ("charging"), the reservoir
expands. Due to its intrinsic elastic force it exerts a
pressure filling substance. When the valve is opened by
CA 02462373 2004-03-09
- 2 -
light pressure on the spray head, the reservoir ejects a
quantity of the filling substance through the spray nozzle
because of the reservoir's own elastic force indicated
above.
This principle has one disadvantage. This is that the
elastic force is constantly weakened over the course of
time as the filling substance reservoir becomes
progressively emptier. This means that the spray pressure
and thus also the volume of the spray jet expelled through
the spray nozzle diminishes over time. The resulting effort
thus changes over the lifetime of a spray dispenser, which
is undesirable. Moreover, towards the end of the spray
dispenser's lifetime, that is when the spray pressure on
the filling substance is very small, a certain quantity
remains in the reservoir. This remainder in the reservoir
can no longer be expelled because the elastic force has
become negligible.
The object underlying the invention is to design a spray
dispenser having a filling substance reservoir made from
elastic material such that the elastic force of the
reservoir remains at least approximately constant for the
majority of the spray dispenser's lifetime, and also
particularly in the last phase, that is when only a little
filling substance remains in the reservoir, it is still
sufficient to be able to expel the last remainder, or at
least the majority thereof, from the reservoir. In
addition, the residual quantity in the reservoir should be
as small as possible and the spray system's should be
barely dependent on temperature.
This object is solved by the features of claim 1.
The inventors have taken a new direction. They have
introduced an expansion body into the filling substance
reservoir, which reservoir is made from elastic material,
CA 02462373 2004-03-09
- 3 -
for example rubber. Thereby, before the two components are
assembled, the internal diameter of the reservoir is
smaller than the external diameter of the expansion body.
The expansion body therefore widens the reservoir during
introduction. The reservoir thus tightly encompasses the
expansion body and thus places it under a certain tension.
The inventors realized that the stress-strain curve of the
elastic material of the filling substance reservoir - with
selection of an optimum elastic material-remains at least
approximately constant, so that the reservoir's intrinsic
elastic force consequently remains unchanged regardless of
its expanded condition, and indeed over a relatively large
expansion range. This has two advantages: the quality of
the spray jet with respect to pressure and volume is
largely preserved for the lifetime of the spray dispenser.
In addition, towards end of the spray dispenser's life,
that is when only a small quantity of filling substance is
contained in the reservoir, the material of the reservoir
retains sufficient force so that even a residual quantity
may be expelled from the reservoir, in large part if not
completely.
There are many ways to implement the invention. This begins
with the assembly of the expansion body and the filling
substance reservoir. The expansion body may be shaped like
a projectile and consequently may have a cylindrical form
for most of its surface. The contour of the reservoir's
inner wall may have the same shape. In any case, the
expansion body may be inserted forcefully into the
reservoir, with the result that the reservoir is expanded.
The effect in this case is to draw the reservoir over the
expansion body.
A further possibility consists in expanding the reservoir
by means other than with the aid of the expansion body
itself. Thus, for example, it is conceivable to introduce
CA 02462373 2004-03-09
multiple rods into the reservoir, which extend parallel to
the longitudinal axis of the reservoir and are displaced
radially, thereby expanding the reservoir. Thereupon the
expansion body may be easily introduced with the reservoir
in the expanded condition.
Yet another possibility is to apply a vacuum to the outer
surface of the reservoir in order to achieve an expansion,
then to introduce the expansion body into the reservoir,
and finally to remove the vacuum again.
All spray nozzles of whatever kind must of course have an
opening for introduction of the filling substance, and also
an opening for its expulsion. The valve indicated in the
aforegoing is located in the apening for expulsion. This is
opened by pressure on the spray head - generally with the
forefinger.
Thereby, the design may be configured such that only one
valve is present. This serves both for filling the
reservoir and also to release the filling substance for the
purpose of spraying. In such a case, the valve is a clack
valve, which allows the filling substance - without
pressure being exerted on the spray head - to pass through
in one direction only, that is the filling direction.
An especially interesting embodiment consists in providing
the expansion body with a channel that extends through the
expansion body. The channel may pass through the expansion
body in the axial direction over its entire length. If the
shape of the reservoir is imagined as that of a sack, the
channel in the expansion body would open in the area of the
bottom of the sack. However, it is also conceivable to
provide the channel with lateral outflows, so that several
partial channels have their openings on the inner wall of
the filling substance reservoir. It is also advantageous to
provide channels in the longitudinal direction of the
CA 02462373 2004-03-09
- 5 -
expansion body for purposes of assembling the expansion
body, and thus create optimal conditions for the subsequent
filling process.
There is a wide range of design possibilities for the
individual elements of the spray dispenser according to the
invention. A selection of such possibilities is listed in
the following:
~ The reservoir is constructed from two or more layers.
The outer layer is made from chemically cross-linked
elastomer or from natural rubber or synthetic rubber, or
from mixtures of the two.
~ The inner layer may be made from an inert material that
does not react with the filling substance and does not
impair the quality thereof. Here, silicone or silicone
rubber for example are possible materials. One or more
layers may also consist of thermoplastic elastomer
(TPE) .
A barrier layer may also be provided between an inner
and an outer layer, preventing the filling substance or
components of the filling substance from diffusing
through the reservoir.
~ The outer layer only has to partially enclose the inner
layer or layers.
~ The partially closed layer may have the form of a cage
made from rings or of longitudinal bracing members or of
spirals or mesh.
~ Several expansion bodies may be provided instead of a
single expansion body. These may be combined for form a
single expansion body, which for example has the shape
of a projectile. It is also conceivable to use several
CA 02462373 2004-03-09
- 6 -
expansion bodies having different external dimensions.
Thus the expansion body may be furnished with ribs that
extend circumferentially and prevent flat contact with
the interior surface of the filling substance reservoir.
The expansion body may be equipped with extensions at
one or both ends, for example in the manner of a
manifold, with which the expansion body is retained in
the reservoir.
There are several possibilities for ensuring expansion of
the reservoir. As indicated in the aforegoing, this may be
effected by passing the reservoir forcibly over the
expansion body. Pincer-type rods are also possible, which
are inserted into the reservoir so as to expand it, and
then to allow introduction of the expansion body. In
addition, it is possible to introduce the expansion body
into the reservoir, wherein the expansion body initially is
not larger than the reservoir, but subsequently to increase
the dimensions of the expansion body by other means, for
example by heating or foam expansion or - if a hollow
expansion body is used - by inflating it with a liquid or
gaseous medium. Another possibility consists in inserting
an expansion body into the reservoir that is not larger
than the reservoir and then causing it to swell using
components added to or contained in the filling substance,
thus causing the dimensions thereof to increase and
creating the necessary state of stress.
The invention will be explained in more detail with
reference to the drawings. The drawings show in detail:
Figure 1 a diagrammatic lengthwise section of the
essential parts of a spray dispenser.
Figure 2 a second embodiment of a spray dispenser in a
view similar to that of figure 1.
CA 02462373 2004-03-09
_ 7 -
Figure 3 illustrates the stress-strain behaviour of the
elastic material from which a filling substance
reservoir according to the invention is
constructed.
The spray dispenser shown in figure 1 includes a filling
substance reservoir 1. In the present case this is double
walled. Specifically, it consists of a combination of an
external container 1.2 and an internal container 1.1.
Internal container 1.1 is made from a material that is
inert with respect to the filling substance in question.
External container 1.2 is made from an elastic material,
which forms the energy storage medium. The two containers
are arranged so that their corresponding surfaces are
directly adjacent one another. They retain this contact
even under any operating state. The internal container thus
follows movement of the external container as it expands or
contracts.
External container 1.2 is enlarged in its upper area to
form a flange 1.2.1. The flange is cylindrical.
A pot-shaped mounting body 2 is also shown. This tightly
encloses flange 1.2.1. Mounting body 2 has a cylindrical
peripheral wall 2.1, a circular plate 2.2 and a collar 2.3.
Mounting body 2 is itself enclosed by an accommodating
hollow body 3, specifically by throat 3.1 thereof. Mounting
body 2 is thus secured against axial displacement.
Flange 1.2.1 of external container 1.2 encloses a valve 4.
To this is connected a filling and emptying connector 5.
Filling substance is introduced through filling and
emptying connector 5 and through valve 4 for the purpose of
filling, and when the spray dispenser is used, is also
CA 02462373 2004-03-09
ejected therethrough in the opposite direction. This
process will be explained in detail below.
The most important element according to the invention is an
expansion body 6. This is enclosed by internal container
1.1. It is furnished with a plurality of grooves equally
distributed over its perimeter, so that a corresponding
number of longitudinal channels 6.1 is formed. Longitudinal
channels 6.1 extend practically the entire length of
expansion body 6. Thus, a conduit connection is created
between valve 4 and the lower area of filling substance
reservoir 1.
The external diameter of reservoir 1 is larger than the
internal diameter of expansion body 6 in the unassembled
condition. This means that when reservoir 1 is mounted -
pulled on - over expansion body 6 it is expanded and thus
encloses the latter under stress.
For the purpose of filling, the filling substance is
introduced under pressure through filling and emptying
connector 5 and further through valve 4 into the upper area
of reservoir 1. It then flows downwards through channels
6.1 of expansion body 6. Since the filling takes place
under pressure, reservoir 1 is expanded so that it is
lifted away from expansion body 6. An annular space is thus
created over the entire length of the filling substance
reservoir, which is filled with the filling substance.
During this expansion, the filling pressure of the filling
substance operates against the elastic force that is
intrinsic to the reservoir. The expansion of reservoir 1
may be continued until the outer surface of external
container 1.2 is largely flush against the inner surface
3.1 of the receiving hollow body. Valve 4 may be
constructed as a clack valve 4 so that it initially allows
only an inflow of the fill substance, but not a backflow.
Valve 4 is further constructed in such manner that the
CA 02462373 2004-03-09
_ g -
check or blocking function of valve 4 may be prevented, for
example by pressing a finger on a plunger - not shown here
- which may be a component of filling and emptying
connector 5.
Mounting body 2 may be moulded or injected onto reservoir
1, or may be placed thereon as a separate part. It may be
made from plastic, metal or a combination thereof.
In very general terms, the connection between mounting body
2 of reservoir 1 and the enclosed hollow body 3 may have
the form of a snap-locking connection. Thereby, a hook may
be conformed on one of these two fixtures, and
corresponding recesses or other mating elements may be
conformed on the other. Mounting body 2 may also be made
from fibre glass reinforced plastic, for example from fibre
glass reinforced polyamide or polyester.
Filling substance reservoir 1 may also be produced in
different ways. Accordingly, it may have a varying profile
over its length. Hollow body 3 for mounting may be made
from metal or plastic or any other material, for example
even from cardboard.
One interesting variation consists in that mounting body 2
is adhesively affixed to reservoir 1 during injection
moulding. Thereby, an insert may also be attached between
these components. The insert may contain the valve and be
permanently affixed thereto.
The spray dispenser shown in figure 2 differs from the one
shown in figure 1 as follows:
Filling substance reservoir 1 is only single-walled, not
double-walled.
An elastomer end plate 7 is provided.
CA 02462373 2004-03-09
- 1~ -
A positive fitting connection is created between elastomer
end plate 7 and the bottom end of reservoir 1, because the
bottom end of reservoir 1 is furnished with a flange 1.2.2
that cooperates with a corresponding collar 7.1 of end
plate 7. As may be seen, the bottom end of reservoir 1 is
open in the unassembled condition - unlike the embodiment
according to figure 1.
The neck of filling substance reservoir 1 has a bulge
1.2.3, which snaps into a corresponding annular groove in
mounting hollow body 3. Bulge 1.2.3 and the associated
annular groove extend concentrically with the longitudinal
axis of the spray dispenser.
In addition, end plate 7 is provided with a ring 7.2 that
may lie flush with internal surface 3.1 of hollow body 3,
thus performing a further fixing function.
Longitudinal channels 6.1 of expansion body 6 may - as seen
in cross-section - be distributed evenly over the perimeter
of expansion body 6. However, it is also sufficient to
provide a single such longitudinal channel. Also, in
addition to or instead of any longitudinal channels 6.1 on
the periphery, a central aperture may be provided that
penetrates the expansion body 6 for the entire length
thereof. In such a case, the filling substance is
introduced into the central channel through valve 4 from
above during filling, and exits there from at the lower
end. During expulsion, in the case of figure 1 it is forced
against the inner surface of internal container 1.1, and in
the case of figure 2 against surface 7.4 of end plate 7.
However, it is also possible to provide no longitudinal
channels at all, and consequently neither the channels 6.1
shown, which are in the peripheral area of expansion body
6, nor the described central channel. In such a case, the
filling substance is again introduced under pressure
CA 02462373 2004-03-09
- 11 -
through filling and emptying connector 5 and through valve
4. It then makes its way between the outer surface of
expansion body 6 and the inner surface of reservoir 1,
which causes these two surfaces to become separated and
reservoir 1 expands until it finally forms a annular space
of corresponding thickness and is filled at the same time.
The advantages of the invention are evident upon
consideration of the diagram in accordance with figure 3.
This shows the stress-strain behavior of the material from
which reservoir 1 is made - in the case of figure 1 of the
material of at least one of the container components, i.e.
of internal container 1.1 and/or of external container 1.2.
As may be seen from the diagram, there is a range in which
the stress-strain behavior is represented by an almost
horizontal line.
The corresponding parameters are chosen such that the
material of reservoir 1 is already subjected to an initial
stress I in the assembled but unfilled condition, and
subjected to a final stress II in the filled condition.
This means that the spray dispenser - or more precisely the
filling substance reservoir 1 - operates in the
approximately horizontal range indicated. Even if only a
small amount of filling substance remains between expansion
body 6 and reservoir 1, the material of the reservoir 1
still retains a certain elastic strength, which is
sufficient to generate a corresponding spray pressure when
the spray dispenser is used. This also serves to ensure
that no undesirable residue of the filling substance is
left behind in reservoir 1.
