U.S. patent application number 14/608332 was filed with the patent office on 2016-08-04 for dispenser head.
The applicant listed for this patent is TREMCO ILLBRUCK PRODUCTIE B.V.. Invention is credited to Stefan COPPUS, Theo OSTENDORF, Goslin VAN HERPEN.
Application Number | 20160221744 14/608332 |
Document ID | / |
Family ID | 56553843 |
Filed Date | 2016-08-04 |
United States Patent
Application |
20160221744 |
Kind Code |
A1 |
COPPUS; Stefan ; et
al. |
August 4, 2016 |
DISPENSER HEAD
Abstract
A dispenser unit comprising a dispenser can and a dispenser head
which is provided with a delivery tube. The delivery tube has a
longitudinal section with a lumen tapering in flow direction and a
tube-like extension having an approximately constant inner diameter
which corresponds to the smallest diameter of the adjacent section
with the tapering lumen. A plug whose cross-sectional dimensions
correspond to the lumen of the extension so that the discharge tube
can be sealed by receiving the plug in its discharge opening. The
length of the constant diameter extension is so chosen that in case
of clogging small sections of the extension can be cut off to
reopen the delivery opening of the delivery tube.
Inventors: |
COPPUS; Stefan; (Breda,
NL) ; VAN HERPEN; Goslin; (Hardinxveld-Giessendam,
NL) ; OSTENDORF; Theo; (Rosmalen, NL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TREMCO ILLBRUCK PRODUCTIE B.V. |
Arkel |
|
NL |
|
|
Family ID: |
56553843 |
Appl. No.: |
14/608332 |
Filed: |
January 29, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B65D 83/206 20130101;
B65D 83/224 20130101; B65D 83/303 20130101 |
International
Class: |
B65D 83/30 20060101
B65D083/30; B65D 83/20 20060101 B65D083/20; B65D 83/48 20060101
B65D083/48 |
Claims
1.-21. (canceled)
22. A dispenser head for opening a valve of a can containing a
fluid and dispensing the fluid from the can under pressure of a
propellant medium, the dispenser head comprising: a base for
mounting the dispenser head on the can, a valve seat adapted to fit
to the valve of the can in a fluid-tight manner, an orifice in
fluid connection with the valve seat, and a delivery tube to
dispense the fluid under pressure of the propellant medium when the
tube is arranged at the orifice of the dispenser head in a
fluid-tight manner, the delivery tube having a first end arranged
at the dispenser head orifice and a second opposite end of the tube
having a discharge opening from which the fluid is dispensable, the
delivery tube comprising: at least one longitudinal section between
the two ends of the tube, wherein the at least one longitudinal
section has a lumen which tapers toward the discharge opening and
which has a first inner diameter at a first end portion and a
second narrower inner diameter at a second end portion, wherein the
first end portion of the lumen is directed toward the dispenser
head orifice and the second end portion is directed toward the
discharge opening of the tube, and a tubular extension positioned
between the second end portion of the at least one longitudinal
section and the discharge opening, the discharge opening being
positioned at a free end of the tubular extension, the tubular
extension having an approximately constant inner diameter equal to
at least a smallest diameter of the tapering longitudinal section,
and a minimum length of the tubular extension being selected to
receive and hold a plug having a cross-sectional shape suitable to
completely fill the discharge opening such that the discharge
opening is effectively sealed.
23. The dispenser head according to claim 22, wherein the tapering
longitudinal section comprises at least first and second
sub-sections having different tapering angles, the tapering angle
of the first sub-section adjacent to the tubular extension being
smaller than the tapering angle of the second sub-section having a
tapering lumen.
24. The dispenser head according to claim 22, wherein the tubular
extension has a length that allows shortening of the tubular
extension without interfering with the at least one tapering
longitudinal section which is adjacent to the tubular
extension.
25. The dispenser head according to claim 22, wherein the tubular
extension has a length at least equal to a length of the plug.
26. The dispenser head according to claim 22, wherein the tubular
extension has a length of at least about 10 mm.
27. The dispenser head according to claim 22, wherein the tubular
extension has a maximum length of less than about 33% of a length
of the delivery tube.
28. The dispenser head according to claim 22, wherein the tubular
extension has a length essentially not adversely affecting a foam
volume of a predefined aliquot of the fluid under pressure, when
the fluid is dispensed from the can by the propellant medium.
29. The dispenser head according to claim 22, wherein the tubular
extension has a length about 2 to about 25 times an inner diameter
of the discharge opening.
30. The dispenser head according to claim 22, wherein the at least
one tapering longitudinal section arranged adjacent to the tubular
extension tapers over its length with an essentially constant
tapering angle.
31. The dispenser head according to claim 22, wherein the plug is
adapted to be arranged in frictional connection with the tubular
extension when in sealing engagement within the tubular
extension.
32. The dispenser head according to claim 22, wherein the plug is
fastened by a detachable, one-piece connection with the dispenser
head.
33. The dispenser head according to claim 22, wherein the plug has
an end portion tapered toward a free end of the plug for insertion
of the plug in the discharge opening.
34. The dispenser head according to claim 22, further comprising a
tamper evident device, wherein the tamper evident device is
provided with the plug adapted for insertion into the discharge
opening.
35. The dispenser head according to claim 22, further comprising a
manually operable actuator for actuating the valve of the can when
the dispenser head is mounted on the can, and a tamper evident
device positioned between the manually operable actuator and an
outer casing of the dispenser head, wherein the tamper evident
device is provided with the plug adapted for insertion into the
discharge opening.
36. The dispenser head according to claim 22, further comprising a
fastening device to fasten the delivery tube when not in use to
dispense fluid from the can, wherein the fastening device is
detachable from the dispenser head, and wherein the plug is
arranged at or adjacent to the fastening device.
37. The dispenser head according to claim 36, wherein the fastening
device has a projection whose cross-sectional shape is adapted to a
cross-sectional shape of a mounting section of the delivery tube to
mount the delivery tube to the dispenser head when the mounting
section is in engagement with the projection.
38. The dispenser head according to claim 22, further comprising a
manually actuated lever for actuating the valve of the can when the
dispenser head is mounted on the can, the dispenser head having a
tamper evident device positioned between the manually actuated
lever and an outer casing of the head, and the tamper evident
device having a projection whose cross-sectional shape is adapted
to a cross-sectional shape of a mounting section of the delivery
tube.
39. The dispenser head according to claim 22, wherein the delivery
tube comprises plastic.
40. The dispenser head according to claim 22, further comprising a
mount for mounting the delivery tube, the mount having a
circumferentially closed flange encircling a recess for receiving a
mounting section of the delivery tube.
41. A dispenser unit comprising a dispenser head according to claim
22 and a pressurized can, wherein the can comprises a valve for
dispensing fluid content of the can, the valve being adapted to
connect with the valve seat of the dispenser head in a fluid-tight
manner.
42. A delivery tube adapted for mounting at a dispenser head for
opening a valve of a can containing a fluid to dispense the fluid
under pressure of a propellant medium from the can and through the
delivery tube when the dispenser head is mounted on the can and is
tightly fitted to the valve by a valve seat so that an orifice of
the dispenser head is in fluid connection with the valve seat on
one side and with the delivery tube on another side, the delivery
tube having a first end adapted to be arranged at the orifice in a
fluid-tight manner and a second opposite end having a discharge
opening from which the fluid is dispensable, the delivery tube
comprising: at least one longitudinal section between the two ends
of the tube, wherein the at least one longitudinal section has a
lumen which tapers toward the discharge opening and which has a
first inner diameter at a first end portion and a second narrower
inner diameter at a second end portion, wherein the first end
portion of the lumen is directed toward the dispenser head orifice
and the second end portion is directed toward the discharge opening
of the tube, and a tubular extension positioned between the second
end portion of the at least one longitudinal section and the
discharge opening, the discharge opening being positioned at a free
end of the tubular extension, the tubular extension having an
approximately constant inner diameter equal to at least a smallest
diameter of the tapering longitudinal section, and a minimum length
of the tubular extension being selected to receive and hold a plug
having a cross-sectional shape suitable to completely fill the
discharge opening such that the discharge opening is effectively
sealed.
Description
[0001] The invention relates to a dispenser head for opening a
valve of a dispenser can and dispensing a fluid under pressure of a
propellant medium from the can, wherein the dispenser head is
provided with a base for mounting the dispenser head on the can,
the dispenser head being provided with a seat adapted to tightly
fit to the valve of the can and with an orifice being in fluid
connection with the valve seat, wherein the dispenser head
furthermore is provided with a delivery tube dispensing a fluid
under pressure of the propelling medium when the tube is connected
with the orifice of the dispenser head in fluid tight manner, said
delivery tube having a first end being arranged at the dispenser
head orifice and a second end comprising a discharge opening from
which the can content is dispensed, the tube comprising at least
one longitudinal section between both said ends with a lumen which
is tapering towards the discharge opening.
[0002] Canned fluids to be dispensed by the dispenser head--and
also covered by the present invention--especially are common in the
field of construction, for instance for sealing joints at the place
of construction, without being restricted thereto. For example,
such foam compositions may be polyurethane foams or latex foams or
the like.
[0003] WO 2005/120987 A1 discloses a delivery tube for such
dispensing head, the free cross-sectional area of this delivery
tube being progressively reduced, i.e. having a lumen tapering
towards the dispensing opening along the length of the delivery
tube thereby obtaining an increased foam volume.
[0004] It is quite common that a dispenser unit comprising head and
can is only partially emptied with the consequence that when taking
up the dispenser unit for the next use, which may be days later,
the discharge opening of the delivery tube is blocked by dried foam
or the dried composition from which the foam is generated. In this
context and in general according to the present invention, the
phrase "dried" foam or composition also covers "cured" foam or
composition. However, cutting off the clogged free end section of
the tube would shorten the length of the section of the delivery
tube having the tapering lumen with the consequence that the effect
of this design--increasing the foam volume--would be impaired.
Furthermore, cutting off the clogged free end section of the
delivery tube would result in a larger diameter of the
progressively tapering lumen at the discharge opening of the tube
so that the discharge opening cannot be closed and sealed by the
plug anymore to prevent further drying or curing of the foam
composition that is present in the tube. In fact, the said plug has
a given diameter to fit into the tube end in its initial shape so
that the said plug would have a too small diameter to close and
seal the tube having a cut-off end portion. The other way around, a
plug having a diameter to fit and seal the tube having a cut-off
end portion would be too large to fit into the discharge opening of
the originally provided tube. Accordingly, in case the tube is
clogged by dried foam, a new tube must be provided, which is
expensive and inconvenient.
[0005] The object to be achieved by the present invention is to
provide a delivery head with a delivery tube which avoids the
above-discussed drawbacks by employing means which are easy to
handle and do not or only by a negligible amount increase
production cost, and which still provides an increased volume of
dispensed foam due to the tapering lumen of the discharge tube.
[0006] The foregoing objects and improvements are attained by a
dispenser head comprising a delivery tube according to claim 1 or
by a respective delivery tube adapted to be mounted at a respective
dispenser head, the tube comprising at least one longitudinal
section with a lumen which is tapering towards the discharge
opening and which is provided with a large inner diameter at a
first end portion and a narrow inner diameter at a second end
portion, namely narrower than the large inner diameter, wherein the
first end portion of the lumen is directed towards the dispenser
head orifice and the second end portion is directed to the
discharge opening of the tube, and a tube-like extension positioned
between the second end of said at least one longitudinal section
and said discharge opening, wherein the discharge opening is
provided at the free end of the extension, the extension having an
approximately constant inner diameter equaling to at least the
smallest diameter of said longitudinal section, the minimum length
of said extension being chosen such that it can receive and hold a
plug having a cross-sectional shape suitable to completely fill the
discharge opening thereby effectively sealing said discharge
opening. Preferred embodiments are defined by the dependent
claims.
[0007] According to the invention, the extension of the delivery
tube may predominantly or only have the function to serve as seat
for the plug, so that the extension can be correspondingly short so
that the presence of the extension will have no or only a
negligible effect on the function of the progressively tapering
section of the delivering tube, namely to increase the foam volume.
Accordingly, the extension for instance may have a length of only a
few millimeters, especially lower than about 10 mm.
[0008] However, the extension may as well be dimensioned such that
in case the discharge opening of the delivering tube is clogged its
length provides the possibility to cut off at least one short
section of the extension thereby removing the clogged range while
still retaining a length of the extension long enough to provide a
proper seat for the plug. In such cases cutting off the free end of
the extension with the clogging substance is a solution being
highly preferred for practical reasons. Preferably, the extension
is dimensioned in length so that at least two or more sections of
the extension can be cut off while still retaining a length of the
extension long enough to provide a proper seat for the plug,
wherein each section may have a length of about .gtoreq.2.5 mm or
of about .gtoreq.5 mm, without being restricted thereto.
[0009] To make the above-said solution available means that the
extension has to be longer than would be necessary just for
receiving the plug. Tests have shown that calculating the length of
the extension such that it also considers the necessity to cut off
a short length of the free end section of the extension to re-open
the delivering tube would not result in relevant impairment of the
effect of the progressively tapering section on the volume of the
foam. Since re-use of an only partially emptied dispenser unit
often will not happen more than once or twice, the initial length
of the extension can be correspondingly calculated.
[0010] Preferably, the constant diameter extension has a length at
least equal to the length of the closure plug, so that even in case
one or more sections of the extension is cut off, plug can
cooperate with the extension over the entire length of the plug
without worsening the sealing properties of the plug.
[0011] Preferably, independent from or in combination with the
above captioned feature, the constant diameter extension has a
length of at least about 5 mm or at least about 10 mm or at least
about 15 mm, most preferred the length of the constant diameter
section preferably amounts up to about 40 mm or up to about 30 mm,
more preferably only up to about 20 mm or even only up to about 15
mm. This has been found to be a preferred cut-off-length in view of
the length of the foam composition that is cured or solidified in
the tube during the period of non-use when the can is used by
craftsmen in the field of construction.
[0012] In general according to the present invention, the term
"about" when referring to a measurable value such as an amount,
distance or volume, and the like, is meant to encompass variations
of .+-.20%, preferably .+-.10%, more preferably .+-.5%, even more
preferably .+-.1%, and yet even more preferably .+-.0.1% from the
specified value, as such variations are appropriate to perform the
disclosed methods.
[0013] Preferably the length of the extension having a constant
inner diameter is chosen such that it provides the possibility of
shortening the extension without interfering with the adjacent
section having a tapering lumen. Especially, the constant diameter
extension may have a length essentially not adversely affecting a
foam volume of a predefined aliquot of the pressurized can content,
when the can content is dispensed from the can by the propellant
medium. Accordingly, the length of the constant diameter section
preferably is adapted so that the foam volume is diminished by the
presence of the constant diameter section of not more than about 12
vol.-% or of not more than about 8 vol.-% or not more than about 6
vol.-% of the dispensed foam composition or even of not more than
about 4 vol.-% or of not more than about 2 vol.-% of the foam
volume, respectively, in relation to the foam volume achieved under
same dispensing conditions without the constant diameter section at
the tube.
[0014] It has been found in diligent studies that to keep
interference low or at least essentially negligible, preferably the
constant diameter extension has a maximum length of about
.ltoreq.33% or more preferably about .ltoreq.25% or .ltoreq.about
20% of the tube length, especially about .ltoreq.17% of the length
of the tube. Especially, the constant diameter extension may have a
maximum length of about .ltoreq.33% or more preferably about
.ltoreq.25% or about .ltoreq.20% of the length of the tapering
section of tube, especially about .ltoreq.17% of the length of the
tapering section. In diligent studies this has been shown to be
favorable especially when applying canned polyurethane foam
compositions or canned latex foam compositions as used in the field
of construction, though not being restricted thereto. The length of
the extension may be .gtoreq.about 2% or .gtoreq.about 4% of the
tube length, preferably or .gtoreq.about 6% or .gtoreq.about 8% or
more preferably .gtoreq.about 10% of the tube length, for instance
about 12% to 16% of the tube length. The "tube length" in this
respect is the entire tube length including the mounting section to
mount the delivery tube at the dispenser head. Especially, in a
more restrictive approach, the "tube length" in this respect may be
the length of the tube without the mounting section.
[0015] The mounting section is considered to be the section of the
tube which is overlapping with the corresponding mounting section
of the dispenser head when the tube is mounted at the head, e.g.
when the tube is threaded or pressed over or into a sleeve-like
mounting portion of the dispenser head.
[0016] Accordingly the length of the mounting section may be the
length of the tube being provided with a thread for mounting the
tube at the dispenser head.
[0017] Preferably the constant diameter extension has a length
being about 2-times to about 25-times the inner diameter of the
discharge opening, which has been found to be favorable to not
adversely affect the dispense of the foam, especially with respect
to dispensing velocity and foam volume.
[0018] Since the delivery tube including this extension is normally
made of plastic material like for instance LLDPE, cutting off a
longitudinal segment of the extension can be done by means of a
simple tool like pincers or pliers or even a knife.
[0019] The dispenser tube may have a total length from about 6 cm
to about 30 cm, more preferred from about 8 cm to about 25 cm or
from about 10 to about 20 cm, especially about 15 cm, so that the
tube length is adapted to most common applications of the canned
composition, especially with respect to seal a joint between two
constructional parts by dispensing the foam into the joint.
[0020] The tapering section of the dispenser tube is provided with
an end portion having a large inner diameter at a first end section
of said lumen and a narrower inner diameter at a second end section
of said lumen, wherein the first end section is arranged adjacent
to the dispenser head orifice and the second end portion more
distant from the dispenser head orifice and is attached to the
constant diameter extension. The lumen of the longitudinal tapering
section preferably is tapering continuously over its length, so
that each cross-section of the lumen being more close to the
delivery end of the tube than another cross-section is narrower
(smaller in its cross-section area) than the said other
cross-section. Preferably, the lumen is tapering without step-like
change of the cross-section diameter. Preferably, the tapering
section tapers continuously, i.e. there are no constant diameter
sections within the tapering section, which however might be
present in some instances.
[0021] The tapering section may taper in a uniform manner (constant
tapering angle over the length of the tapering section) or
non-uniform (with different tapering angles over the length of the
said section).
[0022] Especially, the tapering angle may be larger at the first
end of the lumen and may decrease in direction to the second end of
the lumen, for instance stepwise or with decreasing relative
amount.
[0023] Irrespective of the tapered design of the tapering section,
the ratio of the diameters of the lumen at its first end to that of
its second end may be .gtoreq.about 1.25 or .gtoreq.about 1.5,
preferably .gtoreq.about 2 or .gtoreq.about 2.5, especially about
3. Said ratio may be .ltoreq.about 6 or .ltoreq.about 5 or
preferably .ltoreq.about 4 or .ltoreq.about 3.5. This achieves
rapid dispense velocity in combination with high foam volume of the
dispensed can content.
[0024] According to the invention, in general, the "tapering" of
the tapering section is given with respect to the lumen of the
tapering section. Furthermore, in general the tapering angle is the
inclination angle of the inner wall of the tube defining the lumen
to the longitudinal axis of the tube.
[0025] The total length of the tapering section may be
.gtoreq.about 50% or .gtoreq.about 67% or preferably .gtoreq.about
75% of the total length of the tube, especially .gtoreq.about 80%
or .gtoreq.about 85% of the total length of the tube, without being
restricted thereto.
[0026] Preferably the length of the extension in addition to the
length of the total length of the tapering section is equal to the
total length of the tube, but there may be--though not
preferred--further tube sections, especially at the end portion of
the tube opposite to the extension, like for instance a
non-tapering mounting section of the tube or the like.
[0027] The tapering longitudinal section may comprises at least two
sub-sections with different tapering angles, the tapering angle of
the first sub-section adjacent to the extension being smaller than
the tapering angle of the other (second) sub-section with a
tapering lumen. The tapering angle of the first and the second
sub-section may be constant over its length respectively. The ratio
of the tapering angle of the first sub-section to that of the
second sub-section may be .gtoreq.about 1.5 or .gtoreq.about 2,
especially .gtoreq.about 3, said ratio may be .ltoreq.about 20 or
.ltoreq.about 10, for instance about 5-7. The ratio of the first to
the second sub-section may be about 10:1 to about 1.25:1 or about
6:1 to about 1.35:1, especially about 4:1 to about 1.5:1, for
instance about 2:1 (the length of the second sub-section is
measured without the tube section engaging the part of the
dispenser head for fastening the tube in its position to dispense
the can content). This has been found to be favorable to achieve a
large volume of dispensed foam, especially in connection with the
constant diameter section.
[0028] Preferably, the plug is adapted to be arranged in frictional
connection with the extension when being in sealing engagement
within the extension.
[0029] The plug may have an end portion which is tapered towards
the free end of the plug by way of which the plug is easier
inserted in the discharge opening of the tube.
[0030] Preferably, the plug is fastened by a detachable a
one-piece-connection with the dispenser head, so that that the plug
is secured at the dispenser head to avoid the loss of the plug. The
plug preferably is fastened at a tamper evident device of the
dispenser head but may be fastened at any other area or portion of
the head.
[0031] Preferably, the dispenser head may comprise a manually
operable actuation means, preferably designed as a lever, for
actuating the valve of a can when the dispenser head is mounted at
the can, wherein the head comprise a tamper evident device
positioned between the actuation device and an outer casing of the
head. The plug may be fastened at this tamper evident means.
[0032] A fastening device for fastening the tube at the head when
the tube is not in use may be provided. The fastening device may be
manually detachable from the head or may be integral with the
dispenser head. The tamper evident device can be formed with a
means for fastening the delivery tube when the tube is not arranged
at the dispenser head for dispensing the can content, e.g. during
transport of the head which may be mounted at the can, what also
improves easy handling and easy manufacture of the head. However,
the fastening device in principle may be provided at any other area
or portion of the head. The means for fastening the tube at the
head may be designed as a projection which is shaped that it can be
inserted in the end of the delivery tube with the larger inner
diameter or, vice versa, that this end can be slid over the second
projection. The second projection may separate from the first
projection. Alternatively the first and the second projection may
be attached to each other, for instance arranged adjacent to each
other, wherein the plug is designed as an extension of the
projection.
[0033] Most preferably, the plug for closing the tube is arranged
nearby or adjacent to the fastening device for the tube or even at
said fastening device. The plug for closing the discharge opening
can also be provided as part of a tamper evident device. The tamper
evident device may be formed with a projection being shaped and
dimensioned such that it constitutes a plug which can be inserted
in the lumen of the free end of the extension. This arrangement has
the advantage that the plug as part of the larger tamper evident
device is easier to handle than an item consisting of nothing but
the plug. The plug may be arranged at the fastening device, for
instance at the free end of the projection be designed as the
fastening device.
[0034] A plug as described above can be obtained by cutting off a
segment from an accordingly dimensioned and shaped--preferably
cylindrically--profile of plastic material.
[0035] The plug may be formed with an end portion which is tapered
towards the free end of the plug by way of which the plug is
inserted in the discharge opening.
[0036] Furthermore, the invention is related to a dispenser unit
comprising a head according to the present invention and a
pressurized can, wherein the can comprises a valve for dispensing
the can content and the can valve is adapted to be connected with
the valve seat of the dispenser head in an air tight manner.
[0037] The dispenser tube has been described in combination with
the dispenser head, but it is to be understood that the tube with
all features of it according to the present invention also is
disclosed independent from the head, though the tube is adapted to
be mounted at a related dispenser head.
[0038] The fluid of the can, which is dispensed thought the
dispenser head and through the delivery tube especially may be a
foam composition like a polyurethane foam or other polymer foam,
though not being restricted thereto.
[0039] In the following an exemplary embodiment of the invention
will be explained with reference to the enclosed drawings in
which:
[0040] FIG. 1 is a longitudinal section of a dispenser head;
[0041] FIG. 2 is a side view of a delivery tube;
[0042] FIG. 3 shows a section along line A-A in FIG. 2;
[0043] FIG. 4 is a view according to FIG. 1a of a modified
dispenser head;
[0044] FIG. 5 is a longitudinal section of a dispenser head
according to FIG. 1 schematically showing the mounted delivery
tube.
[0045] With reference to FIG. 1, a dispenser head 10 and a can 12
on which the head 10 is mounted form a dispenser unit for
generating foam from a fluid with which the can is partially
filled. The dispenser head is provided with a base 11 by means of
which the dispenser head is mounted on the can.
[0046] The can comprises a valve (not shown) which is operated by
means of an actuating device designed here for example as a lever
14 pivotably attached to the head. The actuating lever 14 is
provided with an adapter 16. A passage 17 extending through adapter
and lever constitutes a connection between the valve attached to
the can, comprising valve seat 17a to fluid tightly engage the can
valve 12a, and mounting means 17b to mount the dispenser tube. The
mounting means here for example are designed comprising an opening
28a in the actuating lever 14 for receiving the mounting section 20
of a delivery tube 22. The discharge tube at its free end is
provided with a discharge opening 23, such as shown in FIG. 2 and
FIG. 3. FIG. 5 schematically shows the disperser head according to
FIG. 1 and the delivery tube 22 according to the present invention
being mounted at the dispenser head. When the tube is mounted the
free end 22a of the tube 22 may abut against the base 28c of recess
28b, terminated by opening 28a (FIG. 1), to provide a tight and
defined mounting state of the tube. The delivery tube may be
designed according to FIGS. 2 and 3.
[0047] With further reference to FIGS. 2 and 3, the mounting
section 20 of the delivery tube to be connected with the dispenser
head 10 is provided with an internal thread 24 by means of which
the delivery tube may be attached to the adapter 16. For this
purpose the adapter 16 comprises an annular seat 26 for receiving
mounting section 20 which seat coaxially encircles passage 17 and
its orifice 18. A sleeve-like component 28 separating seat 26 from
passage 17 is provided with a thread 27 on its outer
circumferential surface 29 which thread--when the delivery tube is
attached to head 10--cooperates with the internal thread 24 of
mounting section 20 of the delivery tube thereby obtaining a
fluid-tight connection. The can content is passing orifice 18 of
the dispenser head to pass into the tube, wherein in this
embodiment the orifice 18 is provided at the free end of the sleeve
28 but may be provided in other suitable manner.
[0048] The mounting means 17b of the dispenser head 10 for mounting
the tube are provided with a circumferentially closed flange 17c
encircling the recess 28b receiving the mounting section 20 of the
tube. Especially, the flange 17c may be circumferentially closed,
i.e. without windows or through holes, to prevent the tube from
deforming cross-sectionally when positioned in its mounting
position, especially during dispense of the can content. The inner
surface of the flange 17c may abut against the outer surface of the
mounting section of the mounted tube to securely preserve its shape
and to avoid any can content leaks at the mounting means which
would hamper an exchange of the tube.
[0049] The delivery tube 22 comprises a tapering longitudinal
section 33 between both said ends 22a,22b of the tube, wherein the
tapering longitudinal section 33 is provided with a lumen 38 which
is tapering towards the discharge opening 23 and which is provided
with a first end portion 38a having a large inner diameter and a
narrow inner diameter at a second end portion 38b of said lumen,
wherein the first end portion 38a directed to the dispenser head
orifice for dispensing the can content, especially is arranged
adjacent to the dispenser head orifice 18, and the second end
portion 38b is directed to the discharge opening of the tube. A
tube-like extension 36 having a constant inner diameter is
positioned between the second end portion of the 38b of the lumen
38 and the tube end 22b. Especially, the tube discharge opening 23
is arranged at a free end of the extension 36. Evidently, the first
and second end portions 38a, 38b of the lumen are arranged at the
first and second end portions 33a, 33b of the longitudinal
section.
[0050] Accordingly, the delivery tube 22 with longitudinal axis 22'
comprises three sections, namely a first tapering section 30, a
second section 32 and a third section 36 (namely constant inner
diameter extension 36).
[0051] Furthermore, a mounting section 20 is provided, which also
may taper but which is not considered as part of first tapering
section 30 to the extent to which the mounting section is engaging
the outer surface of the annular seat 26.
[0052] The lumen 38 of the longitudinal section is tapering
continuously over its length. So the total lumen 38 provides lumens
39, 41 (sub-lumens) of the first and second sections 30, 32,
respectively, as discussed below.
[0053] The inner diameter of the lumen at its narrow end portion
38b is about 1/4 of the inner diameter of the lumen at its wide end
portion 38a.
[0054] First and second sections 30 and 32 have tapering lumens 39,
41, respectively, with different tapering angles as can be taken
from FIGS. 2 and 3 of the drawing. The lumen 39 of first tapering
section 30 has a tapering angle larger than the tapering angle of
lumen 41 of second tapering section 32 of the delivery tube, for
instance the angle ratio may be about 5. Third section having the
constant inner diameter extension 36 the free end 40 of which
defines the discharge opening 23, has a lumen which constitutes an
extension of the two sections 30 and 32 comprising a tapering lumen
has a more or less constant inner diameter along its length. The
diameter of the lumen of the extension is at least essentially
equal or equal to the diameter of the lumen of the second end
portion of the longitudinal tapering section, what might be given
in general in the present invention.
[0055] The wall thickness of the tapering section is at least
essentially constant over the length of the tapering section, so
that the outer surface of the tapering section is at least
essentially tapering as the inner surface of the tapering section
or as the lumen. The wall thickness of the extension may be
essentially constant over its length and may be essentially equal
to the wall thickness of the tapering section. This, respectively,
may be given in general with respect to the present invention.
[0056] According to the given embodiment, the total length of the
tube is about 15 cm, the length of the first tapering section 30 is
about 25% of the tube length, the length of the second tapering
section 32 is about 50% of the tube length. The length of the
extension or of the third section, respectively, is about 2 cm.
[0057] According to the given embodiment, the length of section 36
represents about 15% of the total length of delivery tube 22. In
the embodiment of the enclosed drawing that portion of mounting
section 20 which is positioned in seat 26 does not contribute to
the effect of the tapered portion(s) of the delivery tube when
delivery tube 22 is connected to head 10 since then the first
portion of the delivery tube is formed by cylindrical passage 17.
In this specific embodiment the length of the extension or third
section 36 is about 13% of the total length of the tube. Since the
length of the mounting section 22 of the tube is quite short, the
length of the extension or third section 36 is here is about 15.5%
of the total length of the tapering section of the tube without the
mounting section. The mounting section of the tube here is the
length of the tube being provided with thread 24 what is
essentially equal to the length of annular seat 26 which is
overlapping with the tube in its mounted state.
[0058] Section 36 is long enough to receive a closure member. The
closure member in the given embodiment is designed as a plug 47
which is adapted to be inserted into the lumen of the delivery
tube. The plug 47 has a diameter or cross section corresponding to
the diameter or cross-section of the lumen to seal the tube when
inserted in the lumen. Such plug is provided on a tamper evident
device 42 which is originally positioned between the casing 44 of
head 10 and actuating lever 14 as shown in FIG. 1. This device 42
made of a suitable plastic is formed in such a way that it
comprises a projection 46 which is so dimensioned and shaped that
it can be inserted through discharge opening 23 forming a plug 47
in the free end of section 36 having a corresponding inner
cross-section. The plug 47 also can be designed or arranged in
other form, for instance as a separate plug.
[0059] In addition the tamper evident device 42 can be provided
with a second stump-like projection 48 which can serve for holding
delivery tube 22 in which case the delivery tube is slid with its
mounting section 20 over projection 48 which may have a
correspondingly shaped cross-section, and held in this position by
adequate fixing means before first use. It is to be understood that
other fastening means to fasten the tube at the dispenser head can
be provided, though the shown embodiment is a preferred one.
[0060] The length of third section 36 having a constant diameter is
such that it provides the possibility of cutting off two or three
short portions in case discharge opening 23 is clogged by dried or
cured substance. In FIG. 3 reference number 50 indicates a possible
cutting line along which a short portion 52 may be cut from
extension 36 to free discharge opening from clogging material by
thereby creating a new discharge opening which is free. The length
of the extension or third section 36 in the embodiment of FIG. 3
provides the possibility to cut off more than one portion if this
became necessary.
[0061] In view of the fact that the delivery tube will be made from
elastic material like polyethylene some slight deviations from the
respective set value will be unavoidable.
[0062] Extensive tests have shown that a tapering delivery tube can
be provided with an additional extension section 36 having a
constant inner diameter without markedly impairing the effects of
the tapered length of the delivery tube on condition that the end
section does not exceed a certain length relatively to the tapered
section(s).
[0063] In the embodiment of FIG. 4, the dispenser head shows the
same construction and features as the head of FIG. 1, despite the
following features. Plug 54 for closing the discharge opening 23
and holder 56 for delivery tube 22 are provided on separate parts
which are attached to the lateral outer surface of dispenser head
10 by means of webs 58, 60, respectively, so that at least the plug
54 they may be removed for use by simply manually breaking web
58.
* * * * *