BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
[0001] The invention relates to a nozzle cap rotatably mounted at the end of the injection
cylinder for a trigger type liquid dispenser.
PRIOR ART
[0002] A trigger type liquid dispenser operates, as simply shown by an example in Fig. 11,
to actuate a piston 2 several times with a trigger 1 to suck liquid from a container,
to pull the trigger 1 in this state to press the piston 2 into a pumping chamber to
pressurize the interior in the pumping chamber, and to open an exhaust valve by the
high pressure liquid to inject the liquid through an injection cylinder 4 and the
nozzle port of a cap 5.
[0003] The nozzle cap 5 has, as known per se, a liquid guide engaged fixedly with the end
of the injection cylinder 4, and a nozzle body rotatably engaged with the end of the
liquid guide and opened with a nozzle port at the center therof. The nozzle body can
be selected to three types of states of "foam", "direct" and "closure", i.e., injecting
the liquid content in a foaming state, injecting the liquid content in a water column
state as it is or closing to stop injecting the liquid content, according to the rotating
position of the nozzle body.
[0004] Heretofore, foaming means has a foaming cylinder arranged on the front face of the
nozzle port of the nozzle body. The foaming cylinder is of a mere cylinder which lacks
variable reflection of injecting liquid and can not foam the liquid efficiently.
SUMMARY OF THE INVENTION
[0005] It is, therefore, a principle object of the present invention to provide a nozzle
cap having a foaming cylinder capable of efficiently foaming liquid.
[0006] In order to achieve the above and other objects, there is provided according to the
present invention 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.
[0007] The foaming cylinder 7 collides to reflect injected liquid onto the inner peripheral
wall to thus involve air in the liquid to foam the liquid. Thus, 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 as compared with the cylindrical foaming cylinder of merely smooth inner
peripheral surface to thus effeciently foam the liquid.
[0008] These and other objects and features will become more apparent from the following
description of the preferred embodiments of the present invention when read in connection
with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009]
Figs. 1 (A) and 1 (B) are longitudinal sectional view of an embodiment of a nozzle
cap according to the present invention;
Figs. 2 to 7 are longitudinal sectional views of the essential portions of different
embodiments having various peripheral uneven portions;
Fig. 8 is a sectional view of the essential portion of the embodiment in which the
inner peripheral uneven portion is formed shortly in an axial direction and the inner
diameter of the portion not formed with the uneven portion of the foaming cylinder
is 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 longitudinal sectional view of the other embodiment in which a foaming
cylinder 7 and a nozzle body 5a are integrally formed; and
Fig. 11 is a schematic view of a conventional trigger type liquid dispenser.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0010] Embodiments of the present invention will now be described in detail with reference
to the accompanying drawings. First embodiment of a nozzle cap for a trigger type
liquid dispenser according to the present invention will be described by referring
to Figs. 1 (A) and1 (B). A nozzle cap 5 comprises a nozzle body 5a an a lituid guide
5b. The liquid guide 5b is engaged fixedly with the end of a liquid injection cylinder
4. The nozzle body 5a has substantially triangular shape in the front shape. A nozzle
port 6 is perforated at the center on the front face of the nozzle body 5a. The nozzle
body 5a is rotatably engaged through a short cylindrical portion 5c with a plug 9
at the end of the liquid guide 5b.
[0011] Figs. 1 (A) and 1 (B) show "foaming" position of the nozzle cap. Shallow grooves
10 are formed at a plurality of peripheral positions on the peripheral surface of
the end of the plug 9 of the liquid guide 5b in a longutudinal direction from the
front end face over a predetermined zone. Liquid passages 11 are formed at a plurality
of peripheral positions on the inner periphery of an end cylindrical portion 5c in
longitudinal line direction from the rear end face over a predetermined zone. A spin
groove 12 is disposed at the rear side face of the nozzle port 6. At the "foaming"
position, the shallow grooves 10, 10 communicate between the liquid passage 11, 11
and the spin groove 12 to thus inject high pressure liquid through the spin groove
12 and the nozzle port 6 in an atomized state to collide the atomized liquid to the
inner peripheral wall of the foaming cylinder 7 to foam the liquid.
[0012] When the nozzle body 5a is rotated to the "direct" position, deep groove of different
direction, not shown in the Fig. 1, of the plug 9 communicates the liquid passages
11, 11 directly with the nozzle port 6 to thus inject the high pressure nozzle directly
in a water column state without spin from the nozzle port 6. When the nozzle body
5a is rotated to the "closure" position, the portion not formed with the shallow grooves
10, 10 and the deep groove of the plug 9 is disposed to interrupt between the liquid
passages 11, 11, the nozzle port 6 and the spin groove 12 to shut off the communication
thereamong.
[0013] The foaming cylinder 7 is integrally formed as an outer periphery thereof with a
large-diameter mounting cylinder 13. The mounting cylinder 13 is engaged fixedly within
a peripheral wall 14 projected toward the front face side so that the foaming cylinder
7 is arranged at an air gap 13A of suitable distance on the front face of the nozzle
port 6 of the nozzle body 5a. The foaming cylinder 7 and the mounting cylinder 13
are integrated by a front end plate. Air intake openings 15 are perforated peripherally
at the end plate and communicate with the air gap 13A. The foaming cylinder 7 also
has an engaging projecting circumferential strip 16 formed on the outer peripheral
surface of the mounting cylinder 13 to be engaged with an engaging inner circumferential
groove 17 formed on the inner peripheral surface of the peripheral wall 14.
[0014] The inner peripheral uneven portion 8 on the inner peripheral wall of the foaming
cylinder 7 is formed substantially by half near the nozzle port 6 for colliding injecting
liquid from the nozzle port 6 and the projecting strip is spirally projected on the
inner wall to be formed in the uneven state.
[0015] The inner peripheral uneven portion 8 of the foaming cylinder 7 may be formed in
an uneven state on the inner wall of the foaming cylinder 7, and is not limited to
the embodiment in Fig. 1.
[0016] Fig. 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 state 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 state 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 state in the inner peripheral
wall. In the example of Fig. 5, a plurality of projections 8C are projected on the
inner peripheral wall of the foaming cylinder 7 to form an uneven state on the inner
peripheral wall. In the example of Fig. 6, a plurality of pores 8D are 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. 7, small projections 8E of triangular
projecting shape on a plane are formed at a predetermined circumferential interval
on the inner peripheral wall of the foaming cylinder 7 to form an uneven state on
the inner peripheral wall.
[0017] When the nozzle body 5a is set to the "foaming" position, an angle for diffusing
liquid (atomized state) injected from the nozzle port 6 depends differently upon the
viscosity of the liquid to be injected. Therefore, the formation of the uneven portion
8 is preferably devised on the basis of the viscosity of the liquid to be injected.
[0018] In case of low viscosity liquid, the liquid is injected to be disperesed in a wide
angel from the nozzle port 6. Thus, the injected liquid (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, a range that the low viscosity liquid is contacted with
the uneven portion 8 becomes a peripheral surface near the nozzle port 6 on the inner
peripheral wall of the foaming cylinder 7 as compared with that of the high 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.
[0019] On the other hand, in case of high viscosity liquid, the liquid 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.
[0020] Further, in order to reduce the resistance of the foaming cylinder 7 against the
injected liquid in case of low 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 increased
larger than the maximum inner diameter of the uneven portion 8. Thus, such configuration
eliminates to increase the resistance of the inner wall portion 7a of the foaming
cylinder 7 not formed with the uneven portion 8 so that the injecting pressure of
the liquid from the injection port 18 increses. Also, the atomizing pattern can be
varied.
[0021] In 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 formed smaller
than the minimum inner diameter of the uneven portion 8. However, when the inner diameter
of the portion 7a is excessively reduced, the resistance increases excessively to
cause the injecting pressure of the liquid to reduce, thereby permitting the liquid
to leak and drop from the injection port.
[0022] 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 preferable 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 to reduce
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.
[0023] In the embodiments described above, the foaming cylinder 7 is formed independently
from the nozzle body 5a. However, the foaming cylinder 7 may be formed integrally
with the nozzle body 5a. Fig. 10 shows the example of this case. A 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 face 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.
[0024] The respective portions are molded of synthetic resin material.
[0025] 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 complicatedly reflected by the uneven portion 8. Therefore,
the nozzle cap having high foaming efficiency can be provided.
1. A nozzle cap having a foaming cylinder (7) arranged on the front face of a nozzle
port (6) of a nozzle body (5a), characterising in that an inner peripheral uneven
portion (8) is formed on the inner peripheral wall of the foaming cylinder (7).
2. The nozzle cap according to claim 1, wherein said uneven portion (8) is formed
by spirally projecting a projecting strip on the inner peripheral wall of said foaming
cylinder (7).
3. The nozzle cap according to claim 1, wherein said uneven portion (8) is formed
by spirally recessing groove on the inner peripheral wall of said foaming cylinder
(7).
4. The nozzle cap according to claim 1, wherein said uneven portion (8) is formed
by peripherally projecting a plurality of ring-like projecting strips (8A) on the
inner peripheral wall of said foaming cylinder (7).
5. The nozzle cap according to claim 1, wherein said uneven portion (8) is formed
by peripherally recessing a plurality of ring-like grooves (8B) on the inner peripheral
wall of said foaming cylinder (7).
6. The nozzle cap according to claim 1, wherein said uneven portion (8) is formed
by projecting a plurality of projections (8C) on the inner peripheral wall of said
foaming cylinder (7).
7. The nozzle cap according to claim 1, wherein said uneven portion (8) is formed
by recessing a plurality of pores (8D) on the inner peripheral wall of said foaming
cylinder (7).
8. The nozzle cap according to claim 1, wherein said uneven portion (8) is formed
by forming small projections (8E) of triangular projecting shape in plane at a predetermined
peripheral interval on the inner peripheral wall of said foaming cylinder (7).
9. The nozzle cap according to claim 1, wherein when low viscosity liquid is injected,
said uneven portion (8) is formed in a short range near the nozzle port (6) in an
axial direction of said foaming cylinder(7).
10. The nozzle cap according to claim 1, wherein when low viscosity liquid is injected,
the inner diameter of a portion (7a) not formed with the uneven portion (8) of said
foaming cylinder (7) is larger than the maximum inner diameter of the uneven portion
(8).
11. The nozzle cap according to claim 1, wherein when low viscosity liquid is injected,
the uneven portion (8) is formed in a long range of a direction farther from the nozzle
port (6) in an axial direction of said foaming cylinder(7).
12. The nozzle cap according to claim 1, wherein said nozzle body (5a) and foaming
cylinder (7) are integrally formed.