Note: Descriptions are shown in the official language in which they were submitted.
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The invention relates to a nozzle cap rotatably mounted
at the end of the injection cylindex for a trigger type
liquid dispenser.
Aspects of the prior art and preferred embodiments of
the invention will be described with reference to the
accompanying drawings, in which:
Figs. l(A) and l(B) are respectively a longitudinal
sectional view and end view of one embodiment of a nozzle cap
according to the present invention;
Figs. 2 to 7 are longitudinal sectional views of : ~
essential portions of different embodiments having various -
peripheral uneven portions; -
Fig. 8 is a sectional view of the essential portion of
the emboaiment in which the inner peripheral uneven portion
is formed~shortly in an axial direction and the inner
diameter of the portion is not formed with the uneven portion
of the foaming cylinder lS larger than the maximum inner
diameter of the uneven portion; - ~ :
Fig. 9 is a sectional view of the essential portion of
still another embodiment in which the inner diameter of the
portion not formed with the uneven portion of the foaming
cylinder is smaller than the minimum inner diameter of the
uneven portion;
Fig. 10 is a longitudinàl sectional view of the other
embodiment in which a foaming cylinder 7 and a nozzle body 5a
are integrally formed; and
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Fig. 11 is a schematic view of a conventional trigger
type liquid dispenser.
Referring now to Fig. 11, a prior art, trigger type
liquid dispenser is operated by actuating a piston 2 several
times with a trigger 1 to suck liquid from a container.
Pulling the trigger in this state urges the piston 2 into a
pumping chamber to pressurize the interior thereof and open
an exhaust valve. The high pressure liquid is injected
through an injection cylinder 4 and the nozzle port of a cap --~
5.
The nozzle cap 5 has, a liquid guide fixedly mounted on
one end of the injection cylinder 4 and the nozzle body ~ ~
rotatably engaging the end of the liquid guide. The nozzle ~ -
body has a nozzle port at the center thereof. The nozzle
body can be set to three states, namely "foam", "direct" and
"close", i.e., for injecting the liquid in a foamed state,
for injecting the liquid in a normal liquid state, for
preventing flow of the liquid, depending on the angular
position of the nozzle body.
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The foaming means is in the form of a foaming cylinder
arranged on the front face of the nozzle port of the nozzle
body. The foaming cylinder is a simple cylinder which does
not foam the liquid efficiently.
According to one aspect of the present invention, there
is provided: a nozzle cap comprising a nozzle body having a
divergent nozzle port and a foaming cylinder attached to a
nozzle body to be axially aligned and forward of said
divergent nozzle port, said foaming cylinder further `
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comprising an inner peripheral uneven portion formed on an
inner peripheral wall of said foaming cylinder having a
substantially uniform cross-sectional opening and an inner
peripheral even portion defined by said inner peripheral wall
of said foaming cylinder having a substantially uniform
cross-sectional opening, said inner peripheral uneven portion
of said foaming cylinder is adjacent to said divergent nozzle
port so that liquid injected from the divergent nozzle port
is dispersed outwardly and directly impinges on the adjacent
uneven portion.
One aspect of the invention provides a nozzle cap
comprising a foaming cylinder 7 arranged on the front face of
the nozzle port 6 of a nozzle body 5a, wherein an inner
peripheral uneven portion 8 is formed on the inner peripheral
wall of the foaming cylinder 7.
The foaming cylinder 7 causes in~ected liquid to be
reflected onto the inner peripheral wall and thus air in the
liquid to foam the liquid. The inner peripheral uneven
portion 8 is formed on the inner peripheral wall of the
foaming cylinder 7 to reflect the injected liquid from the ;-~
nozzle port 6 by the inner peripheral uneven portion 8.
Unlike the prior art cylindrical foaming cylinder, which has
smooth inner peripheral surface, this results in a more
efficient foaming of the liquid.
In preferred embodiments of this aspect, the invention
provides~
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The above nozzle cap, wherein said uneven portion is
formed by spirally projecting a projecting strip on the inner
peripheral wall of said foaming cylinder.
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The above nozzle cap, wherein said uneven portion is
formed by spirally recessing a groove on the inner peripheral
wall of said foaming cylinder.
The above nozzle cap, wherein said uneven portion is -~
formed by peripherally projecting a plurality of ring-like ~ -
projecting strips on the inner peripheral wall of said
foaming cylinder.
The above nozzle cap, wherein said uneven portion is
formed by peripherally recessing a plurality of ring-like
grooves on the inner peripheral wall of said foaming
cylinder. `
The above nozzle cap, wherein said uneven portion is
formed by projecting a plurality of projections on the inner
peripheral wall of said foaming cylinder.
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The above nozzle cap, wherein said uneven portion is ~ -
formed by a plurality of recesses on the inner peripheral
wall of said foaming cylinder.
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The above nozzle cap, wherein said uneven portion is
formed by forming small projections of a triangular
projecting shape at predetermined peripheral intervals on a
circumferential plane of the inner peripheral wall of said
foaming cylinder~ ~`
The above nozzle cap, wherein when low viscosity liquid
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is injected, said uneven portion is formed on the inner wall
nearest said divergent the nozzle port in an axial direction
of said foaming cylinder and the length of said uneven
portion is less than half the length of said ~oaming
cylinder.
The above nozzle cap, wherein ~hen a low viscosity
liquid is the material to be foamed, the inner cross- -
sectional opening of said even portion of said foaming
cylinder is larger than the maximum inner cross-sectional
opening of said uneven portion.
The above nozzle cap, wherein when high viscosity liquid
is injected, the uneven portion is formed over a substantial
portion of the length of said foaming cylinder in an axial
direction of said foaming cylinder~
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The above nozzle cap, wherein said nozzle body and said
foaming cylinder are formed as one integrated part.
The above nozzle cap, wherein a high viscosity liquid is
the material to be foamed, the inner cross-sectional opening
of said even portion of said foaming cylinder is smaller than
the minimum inner cross-sectional opening of said uneven
portion.
Embodiments of the present invention will now be
described in detail with reference to Figs. 1 to 10 of the s;~
accompanying drawings.
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Referring now to Figs. l(A) and l(B), a first
embodiment of a nozzle cap for a trigger type liquid
dispenser according to the present invention which show, a
nozzle cap ~ comprises a nozzle body 5a and a liquid guide
5b. The liquid guide 5b is engaged fixedly with the end of a
liquid injection cylinder 4. The nozzle body 5a has a
- substantially triangular shape when reviewed from the front.
A nozzle port 6 is provided in the center of the front face
of the nozzle body 5a. The nozzle body 5a is rotatably
engaged via a short cylindrical portion 5c with a plug 9 at
the end of the liquid quide 5b.
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Figs. l(A) and l(B) show the "foaming" position of the
nozzle cap. Shallow longitudinal grooves 10 are formed at a
plurality of peripheral positions on the front of the plug 9
of the liquid guide 5b. Longitudinal liquid passages 11 are
formed at a plurality of peripheral positions on the inner
periphery of an end cylindrical portion 5c and extends from
the rear end face thereof. A spin groove 12 is disposed on
the rear side face of the nozzle port 6. In the "foaming"
position, the shallow grooves 10 establish communication
between the liquid passages 11 and the spin groove 12 so as
to inject high pressure liquid through the spin groove 12 and
the nozzle port 6 in an atomized state such that it collides
against the inner peripheral wall of the foaming cylinder 7,
thereby causing the liquid to foam. -
When the nozzle body 5a is rotated to the direct
position, a deep groove, not shown in the Fig. 1, of the plug
9 establishes communication between the liquid passages 11
directly with the nozzle port 6 so as to inject liquid into
the high pressure nozzle directly in a normal liquid state
without spin imparted from the nozzle port 6. When the
nozzle body 5a is rotated to the "closed" position, the ;
portion not formed with the shallow grooves 10 and the deep
groove of the plug 9 is disposed so as to break communication
between the liquid passages 11, the nozzle port 6 and the
spin groove 12.
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The foaming cylinder 7 is integrally formed with a
large-diameter mounting cylinder 13. The mounting cylinder
13 is engaged fixedly within a peripheral wall 14 projecting
toward the front face such that the forming cylinder 7 forms
an air gap 13A on the front face of the nozzle port 6 of the
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nozzle body 5a. The foaming cylinder 7 and the mounting
cylinder 13 are integrally mounted by a front end plate. Air
intake openings 15 are peripherally disposed in the end plate
and communicate with the air gap 13A. The foaming cylinder 7
also has a projecting circumferential strip 16 formed on the
outer peripheral surface of the mounting cylinder 13,
engagably with an engaging inner circumferential groove 17
formed on the inner peripheral surface of the peripheral wall
14.
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An inner peripheral uneven portion 8 extends on the
inner peripheral wall of the foaming cylinder 7. Liquid from
the nozzle port 6 and the projecting strip is spirally
projected onto this uneven portion of the inner wall.
The inner peripheral uneven portion 8 of the foaming
cylinder 7 may be formed as an uneven portion on the inner
wall of the foaming cylinder 7, and is not limited to the
embodiment shown in Fig. 1.
Figs~ 2 to 7 show different examples of inner peripheral
uneven portions 8 of the foaming cylinder 7. In the example
of Fig. 2, grooves are spirally recessed on the inner
peripheral wall of the foaming cylinder 7 to form an uneven
portion on the inner peripheral wall. In the example of Fig.
3, a plurality of ring-like projecting strips 8A are
peripherally projected on the inner peripheral wall of the
foaming cylinder 7 to form an uneven portion on the inner
peripheral wall. In the example of Fig. 4, a plurality of
ring-like peripheral grooves 8B are peripherally recessed on
the inner peripheral wall of the foaming cylinder 7 to form
an uneven portion in the inner peripheral wall. In the
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example of Fig 5, a plurality of projections 8C are
pro~ected on the inner peripheral wall of the foaming
cylinder 7 to form an uneven portion on the inner peripheral
wall. In the example of Fig. 6, a plurality of pores 8D are
recessed on the inner peripheral wa:Ll of the foaming cylinder
7 to form an uneven portion on the :inner peripheral wall. In
the example of Fig. 7, small projections 8E of triangular
shape are formed at predetermined c:ircumferential intervals
on the inner peripheral wall of the foaming cylinder 7 to
~0 form an uneven portion on the inner perîpheral wall.
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When the nozzle body 5a is set to the "foaming" ~- - -
position, an angle for diffusing liquid in the atomized state
injected from the nozzle port 6 depends on the viscosity of
the liquid to be injected. Therefore, the formation of the
uneven portion 8 is preferably determined by the viscosity of
the liquid to be injected.
In case of low viscosity liquid, the liquid is dispersed
over a wide angle from the nozzle port 6. Thus, the injected
liquid in the atomized state is diffused at the position near
the nozzle port 6 axially as compared with the case of high
viscosity liquid. Accordingly, when the foaming cylinders,
which have the uneven portions of the same shape, are
employed, the low viscosity liquid that contacts the uneven
portion 8 tends to form a peripheral layer near the nozzle
port 6 on the inner peripheral wall of the foaming cylinder 7
as compared with that of the high
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viscosity liquid. Thus, in the case of low viscosity liquid,
as shown in Fig. 8, it is desirable to form the uneven
portion 8 shorter and nearer to the nozzle port 6 axially as
compared with the case of high viscosity liquid. When the
uneven portion 8 is formed too long in the axial direction in ~ -
the foaming cylinder 7, the resistance of the uneven portion
8 against the liquid injected from the nozzle port 6 is -
increased so that the injecting pressure of the liquid
injected from an injection port 18 decreases. For example,
as shown in Fig. 8, the uneven portion 8 is formed on the
portion near the side of the nozzle port 6 from the center of `~ -~
the inner peripheral wall of the foaming cylinder 7. When
the foamability is good and the viscosity of the liquid is
low, foaming is performed efficiently even if the uneven
portion 8 is formed shorter in the axial direction of the
foaming cylinder 7.
- On the other hand, in case of high viscosity liquid, theliquid is diffused and injected in a relatively narrow angle
from the nozzle port 6 as compared with the case of low
viscosity liquid. Thus, it is preferable to form the uneven
portion 8 longer in the axial direction farther from the
nozzle port 6.
Further, in order to reduce the resistance of the
foaming cylinder 7 against the injected liquid in case of low
25~ viscosity liquid, as shown in Fig. 8, the inner diameter of
the portion 7a formed with no uneven portion 8 of the forming
cylinder 7 may be made larger than the maximum inner diameter
of the uneven portion 8. Thus, such a configuration prevents
the resistance of the inner wall portion 7a of the foaming
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cylinder 7 not formed with the uneven portion 8 from
increasing so that the injecting pressure of the liquid from
the injection port 18 increases. Also, the atomizing pattern
can be varied.
In the case of high viscosity liquid, as shown in Fig.
9, the inner diameter of the portion 7a not formed with the
uneven portion 8 of the foaming cylinder 7 may be made
smaller than the minimum inner diam,eter of the uneven portion
8. However, when the inner diameter of the portion 7a is -~-~S
excessively reduced, the resistance increases excessively to
cause the injecting pressure of the liquid to decrease,
thereby permitting the liquid to leak and drop from the
injection port.
The uneven portion 8 of the inner peripheral wall of the
foaming cylinder 7 is formed mainly on the rear half portion
near the nozzle port 6 on the inner peripheral wall of the
foaming cylinder 7, and it is pxeferable not to form the
uneven portion 8 on the entire inner peripheral wall of the
foaming cylinder 7. If the uneven portion 8 is formed on the
entire inner peripheral wall of the foaming cylinder 7, the
resistance against the injected liquid by the uneven portion
8 is excessively increased, resulting in a reduction of the
injection pressure of the liquid. The axial length of the
uneven portion 8 on the inner peripheral surface depends upon
the viscosity of the liquid.
In the embodiments described above, the foaming cylinder
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7 is formed independently from the nozzle body 5a. However,
the foaming cylinder 7 may be formed integrally with the ;
nozzle body Sa. Fig. 10 shows the example of this case. A
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foaming cylinder 7 is projected integrally from the front
wall of the outer periphery of the nozzle port. When the
foaming cylinder 7 is integrally formed with the nozzle body
5a, if an air intake port 15 is formed on the front ace of ~ ,
the nozzle cap, it cannot be removed from a mold after ''
molding it in a casting mold. Therefore, in the embodiment
of Fig. 10, an air intake port 15 is formed on the side of ~ ~
the nozzle cap. "
The respective portions are molded of synthetic resin
material. '
According to,the present invention as described above,
the uneven portion 8 is formed on the inner peripheral wall ~'~
of the foaming cylinder 7 so that the injecting liquid from '
the nozzle port 6 is multiply reflected by the uneven portion
8, resulting in a nozzle cap having a high foaming
; effi~iency.
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