Note: Descriptions are shown in the official language in which they were submitted.
20~3669
,:-
DPV 56 28th August 1991
GK/B
DEUTSCHE PRA2ISIONS-VENTIL GMBH
Flow regulating valve
The invention relates to a flow regulating valve for a container
containing a product which is capable of flow and which is exposed to a
gas pressure and a delivery valve in a delivery duct so that the
product issues through the delivery duct when the delivery valve is
opened, wherein the flow regulating valve has in the delivery duct a
valve seat of hard material and a rubber-elastic regulating member
which when the delivery duct is opened is urged against the valve seat
by the internal pressure of the container and which constricts the
through-flow cross-section of the delivery duct in the region of at
least one throttle duct forming a portion of the delivery duct less and
less with decreasing internal pressure, in order to keep the through
flow substantially constant.
In a known flow regulating valve of that kind (EP 234 797 Bl),
the regulating member is in the form of a rubber disc with an axial
central bore forming the throttle duct and a recess on the side which
is towards the valve seat. When there is a high internal pressure in
the container, the rubber disc is radially compressed so that the
through-flow cross-section of the bore is narrowed down. With
decreasing internal pressure, the narrowing of the bore is
correspondingly less and thus the through-flow cross-section is
greater. As the through flow is a function of the internal pressure
and the through-flow cross-section, it remains substantially constant
independently of the internal pressure. However rubber-elastic
material has the property that it swells when it comes into contact
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with certain fluids, for example grease-bearing or oily fluids, as are
frequently contained in such containers such as aerosol or spray cans.
In addition the nomina] dimensions of rubber-elastic components cannot
be maintained with close tolerances in manufacture, quite apart from
the fact that they are temperature-dependent and change in the course
of time due to ageing phenomena. As however the endeavour is to keep
the through-flow cross-section very small, for example about 0.2 nm ,
in order to avoid unnecessary consumption of the product contained in
the container, the through flow is dependent to a considerable extent
on the nominal dimensions of the regulating member being accurately
maintained.
The invention is based on the problem of providing a flow
regulating valve of the general kind set forth, in which the through
flow is maintained with a higher degree of accuracy.
lS In accordance with the invention that problem is solved in that
the throttle duct is delimited by a groove in the valve seat and the
regulating member.
In that solution, the throttle duct is delimited for the
predominant part by the groove and only for a small part by the rubber-
elastic regulating n~mber. As the groove is provided in a hard
material which can be made with narrower dimensional tolerances than a
rubber-elastic member and from a material which on the one hand does
not swell and which on the other hand is subject to minor ageing
phenomena, overall the through-flow cross-section of the throttle duct
can be made and maintained more accurately than that of a bore in a
rubber-elastic material. In a corresponding fashion the through flow
can also be very accurately set and maintained so that it is possible
to consume the product contained in the container as sparingly as
possible, substantially independently of fluctuations in the internal
pressure in the container, the rubber-elastic regulating member being
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pressed into the groove to a greater or lesser extent in dependence on
the internal pressure and in that way keeping the flow constant.
It is preferably provided that the valve seat is formed by a
shoulder surface in a connecting portion for a dip tube, the connecting
portion being provided on the housing of the delivery valve. That
configuration requires only minor modification to conventional delivery
valves of spray cans.
Alternatively it is possible for the valve seat to be formed by a
shoulder surface in a part of the delivery duct which passes through an
actuating fitment of the delivery valve for the container. In that
arrangement the conventional delivery valve does not have to be changed
at all while in the case of the conventional actuating fitment, only a
minor alteration is required.
Preferably the valve seat is formed by a substantially conical
shoulder surface. That automatically provides for centering of a
regulating member of corresponding shape.
mus the surface of the regulating member which co-operates with
the valve seat can be formed by at least a part of a spherical or a
conical surface. A spherical surface has the advantage that the
contact surface area between the valve seat and the regulating member
is correspondingly small and accordingly the pressure required to
achieve deformation of the regulating member, for determining the
through-flow cross-section of the throttle duct, can also be
correspondingly low. In contrast the conical surface has the advantage
that it is simpler to produce.
It can then be provided that the spherical surface is formed by a
part of the surface of a spherical zone, the flat surfaces of which
each form a respective one of the base surfaces of a cylinder, the
outside diameter of which is somewhat smaller than the inside diameter
of a portion of the delivery duct, which is disposed around the
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respective cylinder. In that way the cylinders additionally provide
for guidance of the regulating member in the delivery duct without
impeding the through flow.
The base surface of the cone can also at the same time form the
base surface of a cylinder, the outside diameter of which is somewhat
smaller than the inside diameter of a portion of the delivery duct,
which is disposed around the cylinder. In that configuration the
cylinder also provides for an additional guidance effect without
impeding the through flow.
It can then be provided that at least one narrow by-pass duct
communicates the region, which contains the compressed gas, of the
container upstream of the regulating member, through the housing of the
delivery valve, to the delivery duct. That narrow by-pass duct permits
mixing of the compressed gas contained in the container with the
issuing product when the delivery valve is opened so that on the one
hand the arrangement provides that the product is consumed even more
sparingly when the delivery valve is opened while on the other hand
providing finer distribution of the product in the form of particles on
issuing from the spray head of the container.
If the by-pass duct ends eccentrically in a swirl chamber through
which the delivery duct passes, that provides for still better mixing
of product and compressed gas,
The invention and developments thereof are described in greater
detail hereinafter with reference to the drawings of preferred
embodiments in which:
Figure 1 is a view in axial section through a delivery valve with
a flow regulating valve according to the invention in a valve carrier
of a spray container (not shown), the regulating valve being in the
form of a spherical zone with axial extensions in the form of
cylinders,
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Figure 2 is a view from below of the housing of the delivery
valve shown in Figure 1,
Figure 3 is a view in axial section of the housing of the
delivery valve shown in Figures 1 and 2 with a regulating member in the
form of a ball,
Figure 4 is a view in axial section of the housing of the
delivery valve shown in Figures 1 and 2 with a regulating member in the
form of a cone and a cylinder formed at the base surface thereof,
Figure 5 shows a modified flow regulating valve as shown in
Figure 1, in accordance with the invention, having an insert with a
swirl chamber,
Figure 6 is a view from below of the insert shown in Figure 5,
Figure 7 shows a modification of the valve housing shown in
Figure 1,
Figure 8 is a view from below of the valve housing shown in
Figure 7,
Figure 9 is a modification of the valve housing shown in Figure
7,
Figure lO is a view from below of the valve housing shown in
Figure 9,
Figure 11 shows a further embodiment of the invention in which
the regul.ating valve is inserted in the actuating fitment of a delivery
valve,
Figure 12 is a view fram below of the actuating fitment shown in
Figure 11,
Figure 13 shows a modification of the actuating fitment shown in
Figure 11,
Figure 14 is a view from below of the actuating fitment shown in
F'igure 13, and
Figure 15 is a modification of the actuating fitment shown in
FiguL^e 13.
As shown in Figures 1 and 2, the housing 1 of a delivery valve is
fixedly inserted in a valve carrier 2. The valve carrier 2 forms the
upper part of a top of a container containing a product which is
capable of flow and which exposed to a gas pressure. The seal between
the top and the valve carrier 2 is made by means of a rubber seal 3.
The valve housing 1 is fixed in the valve carrier 2 by a radially
inward peripheral wall 4 of the valve carrier 2 being provided at a
plurality of peripheral locations with inwardly impressed bulge
portions 5 which engage under a flange 6 of the valve housing 1. By
virtue of that arrangemRnt, a clamping edge 7 which is provided at the
top side of the valve housing 1 presses a rubber-elastic sealing disc 8
against an end wall 9 of the valve carrier 2. A hollow valve shank lO
engages through a central hole in the sealing disc 8. The edge of the
hole bears against a constriction 12 in the valve shank lO, in which
there are transverse holes 13 which com~unicate with the internal
cavity in the valve shank lO. A valve actuating fitment with spray
nozzle or the like can be fitted onto the valve shank lO in the usual
way. The valve shank lO is urged upwardly by a spring 14. The cavity
15 which accommodates the spring 14 is communicated with the interior
of the container by way of a duct 16 which extends through a connecting
portion 17 for fitting a dip tube 18 thereon. When the valve shank lO
is depressed by means of the actuating fitment, the edge of the hole in
the sealing disc 8 is bent downwardly by the constriction 12. As a
result the transverse holes 13 are exposed and a delivery duct is
opened, which leads from the interior of the container outwardly
through the connection 17, the cavity 15, the transverse holes 19 and
the cavity in the valve shank lO.
Between the peripheral wall 4 of the valve carrier 2 and the
peripheral wall of the valve housing 1, there remain an annular
deflection space 19 for the material of the sealing disc 8 and filling
ducts 1~ which join thereto and which communicate the deflection space
20 with the interior of the container outside the housing 1. A central
hole is provided in the end wall 9 so that there is an annular filling
opening 21 around the valve shank 10.
In the filling operation, care is taken to provide that the fluid
to be introduced passes not only through the cavity in the shank 10
into the interior of the container but also through the filling opening
21. When that happens the filling pressure axially compresses the
sealing disc 8 in the clamping region and presses it into the
deflection space 19. Consequently a gap is exposed between the sealing
disc 8 on the one hand and the end wall 9 and the peripheral wall 4 on
the other hand, and the fluid to be introduced can flow through that
gap into the container. In addition the fluid to be introduced can
also be introduced by way of the delivery duct when the delivery valve
is open.
15A flow regulating valve is also provided in the duct 16 of the
connection 17. It has a valve seat 22 in the form of a conical
shoulder surface in the connecting portion 17. Provided in the valve
seat 22 is a groove 23 which extends in the flow direction and which,
; together with a regulating member 24 of rubber-elastic material,
delimits a throttle duct. The surface of the regulating member 24,
- which co-operates with the valve seat, is formed by a part of the
surface of a spherical zone, the flat surfaces of which each form one
of the base surfaces of a cylinder 25 and 26 respectively. The outside
diameters of the cylinders 25 and 26 are somewhat smaller than the
inside diameter of the portion of the delivery duct, which is disposed
around the respective cylinder 25 or 26. When the regulating member 24
is introduced into the connection 17 it is pressed beyond radially
inwardly projecting bevelled securing projeceions 27 which are formed on
the inside of axial bar portions 28. The bar portions 28 are separated
from each other by slots 29.
The regulating member 24 is omitted from the view from below in
Figure 2, for the sake of simplification of the drawing.
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20 with the interior of the container outside the housing 1. A central
hole is provided in the end wall 9 so that there is an annular filling
opening 21 around the valve shank 10.
In the filling operation, care is taken to provide that the fluid
to be introduced passes not only through the cavity in the shank 10
into the interior of the container but also through the filling opening
21. When that happens the filling pressure axially compresses the
sealing disc 8 in the clamping region and presses it into the
deflection space 19. Consequently a gap is exposed between the sealing
disc 8 on the one hand and the end wall 9 and the peripheral wall 4 on
the other hand, and the fluid to be introduced can flow through that
gap into the container. In addition the fluid to be introduced can
also be introduced by way of the delivery duct when the delivery valve
is open.
A flow regulating valve is also provided in the duct 16 of the
connection 17. It has a valve seat 22 in the form of a conical
shoulder surface in the connecting portion 17. Provided in the valve
seat 22 is a groove 23 which extends in the flow direction and which,
together with a regulating member 24 of rubber-elastic material,
delimits a throttle duct. The surface of the regulating member 24,
which co-operates with the valve seat, is formed by a part of the
surface of a spherical zone, the flat surfaces of which each form one
of the base surfaces of a cylinder 25 and 26 respectively. The outside
diameters of the cylinders 25 and 26 are somewhat smaller than the
inside diameter of the portion of the delivery duct, which is disposed
around the respective cylinder 25 or 26. When the regulating member 24
is introduced into the connection 17 it is pressed beyond radially
inwardly projecting bevelled securing projections which are formed on
the inside of axial bar portions 28. The bar portions 28 are separated
from each other by slots 29.
The regulating member 24 is omitted from the view from below in
Figure 2, for the sake of simplification of the drawing.
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When the delivery valve is opened by the valve shank lO being
depressed, the regulating member 24 is immediately pressed against the
valve seat 22 by the product or fluid which flows out under the gas
pressure obtaining in the container, as shown in Figure 1, so that the
flow of product through the throttle duct which is delimited by the
groove 23 and the regulating member 24 is throttled. At the beginning
of the emptying operation, when the container is still full, a high gas
pressure still obtains in the container. That causes the rubber-
elastic material of the regulating member 24 to be partially pressed
into the groove 23 and substantially constrict the throttle duct, at
the point of contact between the valve seat 22 and the regulating
member 24, so that a correspondingly smaller amount of product issues.
If on the other hand the gas pressure decreases in the course of
emptying of the container, the pressure applied to the regulating
member 24 also decreases so that it penetrates into the groove 23 to a
lesser depth and the through-flow cross-section of the throttle duct is
somewhat increased. In that way the arrangement ensures that,
irrespective of the internal pressure in the container, the through
flow of product through the throttle duct remains substantially
constant and econonomical consumption of the product is guaranteed.
The housing 1 comprises a material, for example plastics material
or metal, which is comparatively hard in comparison with the rubber-
elastic material of the regulating member 24. The groove 23 can
therefore be produced with comparatively close dimensional tolerances.
Its dimensions are then less dependent on temperature or ageing.
Admittedly the dimensions of the rubber-elastic regulating member 24
can only be maintained with greater tolerances and are to a higher
degree dependent on temperature and subjected to changes caused by
ageing. As however only a small part of the surface of the regulating
member 24 delimits the throttle duct, the dimensions of the throttle
duct can nonetheless be maintained more accurately overall and are less
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temperature-dependent and less subject to changes caused by ageing,
than a throttle duct which is delimited over its entire periphery by a
rubber-elastic material. The conical surface of the valve seat 22, in
conjunction with the spherical surface of the regulating member 24,
which bears thereagainst, provides for centering of the regulating
member 24 in the valve seat 22 so that the regulating ~2mber 24 bears
sealingly against the valve seat over the entire periphery of its
spherical portion, except for the groove 23, while the cylinders 25 and
26 serve for guiding the regulating member 24 in the delivery duct and
the annular space surrounding them allows the product to pass through
unimpededly.
As soon as the delivery val~e is no longer actuated, that is to
say the val~,e shank lO is no longer being pressed down, the spring 14
urges the valve shank lO back into the illustrated position in which
the delivery valve is closed and then the regulating member 24 drops
down again under its own weight until it bears against the securing
projections 27.
Figure 3 shows a modification of the flow regulating valve
illustrated in Figure 1, in which there is a regulating member 24a in
the form of a ball, in place of the regulating member 24. All other
details are identical to the embodiment shown in Figure 1, for which
reason Figure 3 only shows the housing 1 with the flow regulating
valve. The mode of operation of the flow regulating valve illustrated
in Figure 3 also corresponds to that of the flow regulating valve shown
in Figure 1.
The modification illustrated in Figure 4 also differs from the
embodiment shown in Figure 1 only by the regulating member 24b which
has a cone 30. The base surface of the cone 30 at the same time forms
the base surface of the cylinder 26, the outside diameter of which is
smaller than the portion of the delivery duct, which is disposed around
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the cylinder 26. The mode of operation of that flow regulating valve
also corresponds to that of the flow regulating valve illustrated in
Figure 1~
The modification shown in Figures 5 and 6 only differs from that
shown in Figure 1 in that a housing portion la which extends the
housing 1 is fitted with a press fit onto the connecting portion 17 of
the housing 1, and in turn has a connecting portion 17a into which the-
dip tube 18 is fitted with a press fit. The housing portion la then
has an intermediate wall 31 with a bore 32 therethrough, and a
substantially cup-shaped insert 33 is inserted between the lower end of
the connecting portion 17 and the intermediate wall 31. In its
underside the insert 33 has a swirl chamber 34 which communicates by
way of narrow grooves 35 opening tangentially into the swirl chamber
34, with an annular space 36 which in turn communicates by way of a
slot 37 in the peripheral wall of the housing portion la with the
region of the interior of the container, which is filled with
compressed gas. A coaxial bore 39 also extends through the bottom 38
of the insert 33 and is aligned with the swirl chamber 34 and the bore
32. The grooves 35 on the underside of the insert 33 are closed
downwardly by the intermediate wall 31. With the annular space 36 and
the slot 37 they form a narrow by-pass passage through which the
compressed gas can pass into the swirl chamber 34, flows tangentially
thereinto and is mixed with the product wh ch issues through the bore
32 upon actuation of the delivery valve, with the product being divided
into fine particles. In that way there is an additional throttle
action in the delivery duct, which ensures still more economical
consumption of the product.
The embodiment shown in Figures 7 and 8 only differs from that
shown in Fig~re 1 in that upstream of the flow regulating valve, in its
side wall, the housing 1 has fine bores 40 which extend radially
through the side wall to the delivery duct and which also form a narrow
by-pass duct for the discharge of compressed gas and mixing thereof
with the product upstream of the throttle duct.
The embodiment shown in Figures 9 and lO only differs from that
shown in Figures 7 and 8 in that the shoulder of the housing 1, which
adjoins the connecting portion 17, has radial grooves 41 and the
outside of the connecting portlon 17 has narrow axial grooves 42 which
are aligned with the radial grooves 41 and which are closed by the dip
tube 18 except for their ends and in that way form an equally narrow
~microfine) by-pass duct as the bores 40.
The embodiment shown in Figures 11 and 12 essentially only
differs from that shown in Figures 5 and 6, in the following respect.
The housing lb is of a one-part configuration and does not contain the
flow regulating valve. On the contrary the flow regulating valve is
contained in a cap-like actuating fitment 43 for actuation of the
lS delivery valve, more specifically in a connecting Fortion 45 which is
formed on the end portion 44 of the actuating fitment 43 which is also
made from hard plastics material or metal, the upper end portion of the
valve shank lO being inserted with a press fit in the connecting
portion 45. Provided in the conical valve seat 22 in the connecting
portion 45 are a plurality of grooves 23 which, together with t'ne
regulating member 24, form the regulatable throttle duct. A plurality
of axial grooves 46 are also provided in the cylinder 26 of the
regulating member 24, being arranged in a distributed array over the
periphery thereof. Downstream of the flow regulating valve, a radial
bore 47 joins the portion of the delivery duct which is delimited by
the connectir.g portion 45. The radial bore 47 terminates in an annular
groove 48. A substantially cup-shaped nozzle insert 49 is a snug fit
in the annular groove 48. On the radially inward side of its end
portion, the nozzle insert 49 also has a swirl chamber 50 which is
communicated with the bore 47 by way of tangential ducts and bores
leading to the annular space 51. Also provided in the bottom of the
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chamber 50 is a coaxial bore 52 forming -the discharge nozzle. The mode
of operation is the same as that of the embodiment illustrated in
Figures 5 and 6.
The embodiment shown in Figures 13 and 14 only differs from that
illustrated iul Figures 11 and 12 in that, instead of the regulating
member 24, it has the regulating member 24b and only one groove 23.
The nozzle insert 49 which is fitted in the annular groove 48 is
omitted from Figure 13 for the sake of simplicity of the drawing.
The embodiment shown in Figure 15 only differs from that shown in
Figures 13 and 14 in that it has the regulating member 24a instead of
the regulating member 24b.
