U.S. patent application number 13/700614 was filed with the patent office on 2013-05-30 for cartridge-type dispenser.
This patent application is currently assigned to YOSHINO KOGYOSHO CO., LTD.. The applicant listed for this patent is Taizo Nakao, Eiichi Terakawa, Toru Toma. Invention is credited to Taizo Nakao, Eiichi Terakawa, Toru Toma.
Application Number | 20130134188 13/700614 |
Document ID | / |
Family ID | 45003565 |
Filed Date | 2013-05-30 |
United States Patent
Application |
20130134188 |
Kind Code |
A1 |
Terakawa; Eiichi ; et
al. |
May 30, 2013 |
CARTRIDGE-TYPE DISPENSER
Abstract
A cartridge-type dispenser has a cartridge main body with a
filling space, an extrusion nozzle on the front, and a piston
slidably disposed in the filling space. The piston extrudes
contents of the filling space from the extrusion nozzle by applying
a push-in force. The piston includes a trunk portion having an
outer circumferential wall running along an inner wall of the main
body with a gap therebetween, a front wall on one end of the trunk
portion directly contacting the contents of the filling space, and
a rear wall on the other end whereon a rod of a push-in tool
applies the push-in force on the piston. On the outer
circumferential wall of the trunk portion, protrusions are
provided, which contact the inner circumferential wall of the main
body. The points of contact form sliding parts of the piston but do
not seal the main body interior.
Inventors: |
Terakawa; Eiichi;
(Kurashiki-shi, JP) ; Nakao; Taizo;
(Kurashiki-shi, JP) ; Toma; Toru; (Koto-ku,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Terakawa; Eiichi
Nakao; Taizo
Toma; Toru |
Kurashiki-shi
Kurashiki-shi
Koto-ku |
|
JP
JP
JP |
|
|
Assignee: |
YOSHINO KOGYOSHO CO., LTD.
Tokyo
JP
KURARAY NORITAKE DENTAL INC.
Kurashiki-shi, Okayama
JP
|
Family ID: |
45003565 |
Appl. No.: |
13/700614 |
Filed: |
April 21, 2011 |
PCT Filed: |
April 21, 2011 |
PCT NO: |
PCT/JP2011/002342 |
371 Date: |
January 30, 2013 |
Current U.S.
Class: |
222/386 |
Current CPC
Class: |
A61C 5/62 20170201; B05C
17/00576 20130101; B65D 83/0005 20130101 |
Class at
Publication: |
222/386 |
International
Class: |
B65D 83/00 20060101
B65D083/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 28, 2010 |
JP |
2010-122721 |
Claims
1. A cartridge-type dispenser comprising: a cartridge main body
defining a filling space for contents and provided with an
extrusion nozzle at a front end portion of the cartridge main body;
and a piston slidably arranged in the filling space of the
cartridge main body and configured to cause the contents of the
filling space to be extruded from an end of the extrusion nozzle in
response to application of a push-in force, wherein: the piston
includes (i) a trunk portion having an outer circumferential wall
arranged opposite to an inner circumferential wall of the cartridge
main body so as to define a gap therebetween, (ii) a front end wall
portion provided at one end portion of the trunk portion in direct
contact with the contents of the filling space, and (iii) a rear
end wall portion provided at another end portion of the trunk
portion to be pressed with a rod of a push-in tool for application
of the push-in force to the piston; and the outer circumferential
wall of the trunk portion is provided with a protrusion, which is
in contact with the inner circumferential wall of the cartridge
main body to form a sliding part of the piston without sealing off
an interior of the cartridge main body.
2. The cartridge-type dispenser of claim 1, wherein the trunk
portion of the piston has an hourglass shape having a reduced
diameter at a middle portion thereof in a push-in direction of the
piston.
3. The cartridge-type dispenser of claim 1, which satisfies the
following conditions: X-D.sub.1.ltoreq.1 mm; and X-D.sub.2.ltoreq.1
mm wherein D.sub.1 and D.sub.2 represent, respectively, dimensions
at one end portion and the other end portion of the trunk portion
of the piston, and X represents an inner dimension of the cartridge
main body.
4. The cartridge-type dispenser of claim 1, which satisfies the
following conditions: D.sub.3-X.gtoreq.0.01 mm; and
D.sub.4-X.gtoreq.0.01 mm wherein D.sub.3 and D.sub.4 represent,
respectively, dimensions at one end portion and the other end
portion of the trunk portion of the piston, inclusive of the
protrusion, and X represents an inner dimension of the cartridge
main body.
5. The cartridge-type dispenser of claim 1, which satisfies the
following conditions: X-D.sub.1.ltoreq.1 mm; X-D.sub.2.ltoreq.1 mm;
D.sub.3-X.gtoreq.0.01 mm; and D.sub.4-X.gtoreq.0.01 mm, wherein
D.sub.1 and D.sub.2 represent, respectively, dimensions at one end
portion and the other end portion of the trunk portion of the
piston; D.sub.3 and D.sub.4 represent, respectively, dimensions at
one end portion and the other end portion of the trunk portion of
the piston, inclusive of the protrusion; and X represents an inner
dimension of the cartridge main body.
Description
TECHNICAL FIELD
[0001] The present invention relates to a cartridge-type dispenser
suitable for extruding viscous materials such as composite resin
used for dental treatment or the like, wherein a contents-extruding
piston does not fall easily out of a dispenser main body and yet is
capable of extruding the contents with a smooth action.
BACKGROUND ART
[0002] Paste materials with high viscosity, such as composite resin
and adhesive agent, are often used in dental treatment or the like
and generally extruded from a syringe-type dispenser or a
cartridge-type dispenser. In the syringe-type dispenser, contents
are extruded from a nozzle by applying a push-in force to a plunger
fitted in a syringe main body to slide the plunger in the syringe
main body. On the other hand, in the cartridge-type dispenser
wherein a piston is arranged in a cartridge main body (referred to
below simply as a "main body"), the contents are extruded by
fitting the main body to a separately prepared push-in tool
(trigger-type push-in tool) and pushing in the piston. (Refer,
e.g., to Patent Document 1 identified below.)
[0003] In particular, in the cartridge-type dispenser, the contents
filled in the main body are disposed once used in a single
treatment, and from perspectives of quality assurance and hygiene,
a dispenser of this type is frequently used in recent years.
However, since there is a variation and the like in molding
accuracy of the piston and the main body which constitute the
dispenser, in case where a diameter size of the piston is small,
the piston can be easily disengaged from the main body. On the
other hand, in case where the diameter size of the piston is large,
although this case has an advantage of improved airtightness, the
piston can be disengaged from the main body due to an increase in
an inner pressure when the piston is installed after the contents
have been filled in, and as a result, assembly becomes laborious,
and moreover, an operation of extruding the contents can be slowed
down, which sometimes causes malfunction in which the contents
cannot be smoothly extruded.
(Patent Document)
[0004] Patent Document 1: JP 2001-057987A
DISCLOSURE OF THE INVENTION
Technical Problem
[0005] It is an objective of the present invention to provide a
cartridge-type dispenser suitable for extruding viscous materials,
wherein a piston does not easily fall out and yet is capable of
extruding contents with a smooth action.
Solution to Problem
[0006] The present invention provides a cartridge-type dispenser
comprising: a cartridge main body defining a filling space for
contents and provided with an extrusion nozzle at a front end
portion of the cartridge main body; and a piston slidably arranged
in the filling space of the cartridge main body and configured to
cause the contents of the filling space to be extruded from an end
of the extrusion nozzle in response to application of a push-in
force. The piston includes: a trunk portion having an outer
circumferential wall arranged opposite to an inner circumferential
wall of the cartridge main body so as to define a gap therebetween;
a front end wall portion provided at one end portion of the trunk
portion in direct contact with the contents of the filling space;
and a rear end wall portion provided at another end portion of the
trunk portion to be pressed with a rod of a push-in tool for the
application of the push-in force to the piston itself. The outer
circumferential wall of the trunk portion is provided with a
protrusion, which is in contact with the inner circumferential wall
of the cartridge main body to form a sliding part of the piston
without sealing off an interior of the cartridge main body.
Advantageous Effects of the Invention
[0007] Provision of a protrusion on the trunk portion of the
piston, as a sliding part of the piston, makes it possible to
reduce the contact area between the piston and the inner
circumferential wall of the main body. Accordingly, even when the
piston is firmly fitted to the main body at the sliding part to
prevent the piston from being easily disengaged from the main body,
the piston is able to slide smoothly, thereby improving
operability. Furthermore, a tiny gap is formed between the piston
and the main body in a part of the piston other than the sliding
part. As a result, when the piston is assembled after the contents
are filled in, air remaining in the main body is discharged to the
outside through the gap, and the inner pressure is not
increased.
[0008] With an hourglass shape of the trunk portion of the piston
having the reduced diameter at the middle portion in the push-in
direction of the piston, it is possible to further reduce the
contact area between the piston and the inner circumferential wall
of the main body.
[0009] Furthermore, when the sizes of the one end portion and the
other end portion of the trunk portion of the piston are D.sub.1
and D.sub.2 (where D.sub.1 is closer to a front end portion, and
D.sub.2 is closer to a rear end portion), and the size of the
interior of the main body is X, it is preferable that a difference
between the sizes D.sub.1, D.sub.2 and X, i.e. the gap formed
between the main body and the trunk portion of the piston,
satisfies the conditions X-D.sub.1.ltoreq.1 mm and
X-D.sub.2.ltoreq.1 mm, because in this case the contents are in a
good state of preservation for a longer period of time. Here, from
the perspective of securing the gap, it is preferable that 0.01
mm.ltoreq.X-D.sub.1.ltoreq.1 mm and 0.01
mm.ltoreq.X-D.sub.2.ltoreq.1 mm. It is further preferable that 0.02
mm.ltoreq.X-D.sub.1.ltoreq.0.5 mm and 0.02
mm.ltoreq.X-D.sub.2.ltoreq.0.5 mm. It is most preferable that 0.04
mm.ltoreq.X-D.sub.1.ltoreq.0.2 mm and 0.04
mm.ltoreq.X-D.sub.2.ltoreq.0.2 mm.
[0010] Moreover, when the sizes of the one end portion and the
other end portion of the trunk portion of the piston, inclusive of
the protrusion, are D.sub.3 and D.sub.4 (where D.sub.3 is closer to
the front end portion, and D.sub.4 is closer to the rear end
portion), it is preferable that a difference between the sizes
D.sub.3, D.sub.4 and X, i.e. the size when the protrusion is fitted
to the main body, satisfies D.sub.3-X.gtoreq.0.01 mm and
D.sub.4-X.gtoreq.0.01 mm, because in this case the piston is
further prevented from disengagement. Here, from the perspective of
achieving a smooth sliding movement, it is preferable that 0.5
mm.gtoreq.D.sub.3-X.gtoreq.0.01 mm and 0.5
mm.gtoreq.D.sub.4-X.gtoreq.0.01 mm. It is further preferable that
0.3 mm.gtoreq.D.sub.3-X.gtoreq.0.05 mm and 0.3
mm.gtoreq.D.sub.4-X.gtoreq.0.05 mm. It is most preferable that 0.26
mm.gtoreq.D.sub.3-X.gtoreq.0.10 mm and 0.26
mm.gtoreq.D.sub.4-X.gtoreq.0.10 mm. On the other hand, when a total
length of the piston in the push-in direction is D.sub.5, the
length D.sub.5 needs to be determined as appropriate, because an
appropriate length of D.sub.5 depends on a length of the interior
of the main body in the push-in direction, as well as a stroke of
the push-in tool.
BRIEF DESCRIPTION OF DRAWINGS
[0011] FIG. 1A shows a general embodiment of a dispenser according
to the present invention in a cross sectional lateral view, and
FIG. 1B shows the general embodiment of the dispenser according to
the present invention when the dispenser shown in FIG. 1A is viewed
from a rear end wall thereof.
[0012] FIG. 2 is a perspective appearance view of a piston arranged
in the dispenser shown in FIGS. 1A and 1B, with three protrusions
provided on a cylindrical trunk portion thereof.
[0013] FIG. 3 shows another example of the piston favorably
applicable to the present invention in which middle sections of the
protrusions provided in the piston are removed to divide the ribs
into upper and lower end sections so as to further reduce the
contact area between the piston and the main body.
[0014] FIG. 4 shows another example of the piston favorably
applicable to the present invention in which the protrusions are
provided in a portion of the piston other than the end portions
thereof with respect to FIG. 3.
[0015] FIG. 5 shows another example of the piston favorably
applicable to the present invention in which a single protrusion is
helically formed.
[0016] FIG. 6 shows another example of the piston favorably
applicable to the present invention in which the trunk portion of
the piston is depressed so that the piston does not make contact
with the main body even when the piston itself is deformed.
[0017] FIG. 7 shows another example of the piston favorably
applicable to the present invention in which the protrusions
provided in the upper and lower end portions of the piston shown in
FIG. 6 are joined.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0018] The present invention will be described below in further
detail, with reference to the accompanying drawings.
[0019] FIGS. 1A and 1B show a general structure of a dispenser
according to the present invention in a cross sectional view, and
FIG. 2 is a perspective appearance view of a piston arranged in the
dispenser shown in FIG. 1A and FIG. 1B.
[0020] Reference numeral 1 in the drawings denotes a main body
defining a filling space M for contents. The main body 1 can be
made of high-density polyethylene (HDPE), low-density polyethylene
(LDPE), polypropylene (PP), acryl, polyethylene terephthalate
(PET), polyoxy-methylene (POM), polybutylene terephthalate (PBT),
and the like. The main body 1 includes at a front end portion
thereof an integrally formed extrusion nozzle 1a and also includes
around an outer circumferential wall of a rear end opening 1b
thereof a flange 1c for linkage to a separately prepared push-in
tool (not shown). The main body 1 is preferably made of PBT, in
particular.
[0021] Reference numeral 2 denotes the piston arranged in the main
body 1. The piston 2 has a trunk portion 2a having an outer
circumferential wall arranged opposite to an inner circumferential
wall of the main body 1 so as to define a gap therebetween, a front
end wall portion 2b provided at one end portion of the trunk
portion 2a in direct contact with the contents of the filling space
M, and a rear end wall portion 2c provided at another end portion
of the trunk portion 2a to be pressed with a rod (not shown) of a
push-in tool for application of a push-in force to the piston 2
itself. As the trunk portion 2a of the piston 2, a cylinder having
sizes (diameters) D.sub.1 and D.sub.2 at the one end portion and
the other end portion (where D.sub.1 is closer to the front end
wall portion 2b, and D.sub.2 is closer to the rear end wall portion
2c) and a size D in the middle portion of the trunk portion 2a in a
push-in direction is used, where D.sub.1, D.sub.2, and D are
equal.
[0022] Reference numeral 3 denotes longitudinal ribbed protrusions
integrally formed on the trunk portion 2a of the piston 2. The
protrusions 3 are provided at three positions on the outer
circumferential wall at regular intervals such that an end of each
protrusion 3 contacts the inner circumferential wall of the main
body 1 for sliding in the main body 1 in conjunction with a
movement of the piston 2. Furthermore, sizes D.sub.3 and D.sub.4 of
the piston 2 at the one end portion and the other end portion
(where D.sub.3 is closer to the front end wall portion 2b, and
D.sub.4 is closer to the rear end wall portion 2c), inclusive of
the protrusions 3, are larger than an inner diameter X of the main
body 1. The material for the piston 2 may comprise elastomer,
rubber, LDPE (such as linear low density polyethylene (LLDPE)),
HDPE, PP, acryl, and the like. Among others, LDPE is preferably
used.
[0023] Reference numeral 4 denotes a nozzle cap mounted on the
extrusion nozzle 1a to close off an extrusion orifice of the
extrusion nozzle 1a. In the embodiments illustrated in the drawings
the nozzle cap 4 is linked by engagement means, such as undercuts.
Alternatively, however, the nozzle cap 4 may be screwed by a
thread. A fitting effect provided by the above engagement means or
screw structure allows positioning of the cap, to thereby
facilitate the assembling and prevent disengagement of the cap when
the cap is loosely mounted and also prevent damage to the cap when
the cap is tightly or deeply mounted.
[0024] In case where the nozzle cap 4 is provided with the fitting
effect, it is preferable to employ a hardly deformable nozzle cap
4. The reason is that, although an easily deformable nozzle cap 4
has an advantage that it can be mounted even when the size is not
precisely set, such an easily deformable cap tends to be disengaged
or to be damaged. In order to restrict deformation of the nozzle
cap 4 and provide the nozzle cap 4 with the fitting effect with the
extrusion nozzle 1a, HDPE, LDPE, PP, acryl, and the like can be
used as the material of the nozzle cap 4, and in particular, HDPE
is preferably used.
[0025] An outer diameter of the extrusion nozzle 1a is preferably
as small as possible in the dental treatment, and therefore the
inner diameter D.sub.6 is necessarily small. As for the inner
diameter D.sub.6 of the extrusion nozzle 1a, it is preferable that
0.01.ltoreq.D.sub.6/X.ltoreq.0.60, and it is further preferable
that 0.25.ltoreq.D.sub.6/X.ltoreq.0.55.
[0026] In the dispenser with the above structure, when the piston 2
is fitted to the main body 1, a contact part between the piston 2
and the main body 1 is formed only by the protrusions 3.
Accordingly, the piston 2 is able to slide smoothly even in a
fitting state (i.e. the state in which the piston 2 cannot undergo
disengagement) where the protrusions 3 are in a tight contact with
the inner circumferential wall of the main body 1.
[0027] A tiny gap P is formed between the piston 2 and the main
body 1 in a region where the protrusions 3 are not provided (refer
to FIG. 1A). When the piston 2 is gradually pushed in to be fitted
to the main body 1 after the contents have been filled in, air
remaining in the main body 1 is discharged through the gap into the
outside, and an inner pressure is not increased. As a result, the
piston 2 is prevented from being disengaged from the main body 1
due to an increase in the inner pressure.
[0028] FIGS. 3 to 7 show different embodiments of the piston
favorably applicable to the cartridge-type dispenser according to
the present invention.
[0029] FIG. 3 shows the piston 2 in which the protrusions 3 are
provided at the end portions of the trunk portion 2a of the piston
2 while a shape of the trunk portion 2a remains cylindrical. In
this case, contact of the piston 2 with the main body 1 is made at
the protrusions 3 provided at a front end portion and a rear end
portion of the piston 2. Accordingly, a contact area is further
reduced, and operability is further improved.
[0030] FIG. 4 shows the piston 2 in which the protrusions 3 are
provided in a portion of the trunk portion 2a other than the end
portions thereof while the shape of the trunk portion 2a remains
cylindrical. In this case, as in FIG. 3, the contact area is
further reduced, and operability is further improved.
[0031] FIG. 5 shows the piston 2 in which the single protrusion 3
is helically formed while the shape of the trunk portion 2a remains
cylindrical, which shows an example of the smallest number of the
protrusion still satisfying demand characteristics of the present
invention.
[0032] FIGS. 6 and 7 show the pistons 2 in each of which the size
(diameter) D in the middle portion of the trunk portion 2a in a
longitudinal direction thereof is minimized with respect to the
sizes (diameters) D.sub.I, D.sub.2 (D.sub.1=D.sub.2) at the end
portions of the trunk portion 2a, so that the trunk portion 2a has
an hourglass-shaped cross section tapering from the end portions
toward the middle portion in the longitudinal direction.
[0033] In each of the pistons 2 shown in FIGS. 6 and 7 with the
hourglass-shaped trunk portion 2, as in FIG. 3, the contact of the
piston 2 with the main body 1 is made at the protrusions 3 provided
at the front end portion and the rear end portion of the piston 2.
Accordingly, the contact area is further reduced, and operability
is further improved.
[0034] The protrusions 3 may be provided only at the end portions
of the trunk portion 2a, over an entire length of the trunk portion
2a, or even alternately provided at the front end portion and the
rear end portion of the trunk portion 2a of the piston 2.
Particularly, when the protrusions 3 are provided alternately at
the front end portion and the rear end portion of the trunk portion
2a of the piston 2, intrusion of light through the gaps is better
prevented, and therefore quality of the contents is maintained in a
more stable manner.
[0035] In addition, although the drawings show the examples of one,
three, and six protrusions 3 provided along a circumference of the
trunk portion 2a, the number of the protrusions is not specifically
limited.
Examples
[0036] The following describes examples of the present invention.
However, the present invention is not limited to the examples
described below.
[0037] As the cartridge-type dispensers, the bodies made of PBT and
the pistons made of the materials described below were prepared,
and a vibration test, a depressurization test, a loading test, and
a curing test were conducted to evaluate performance of each
dispenser.
[0038] Vibration Test
[0039] The main body fitted with a piston was laid on a pan secured
to a vibration machine (TUBE MIXER TRIO HM-2F manufactured by As
One Corporation) and vibrated for one minute at a dial reading of
10, and presence of disengagement of the piston from the main body
was checked.
[0040] Depressurization Test
[0041] An extrusion nozzle was filled with CLEARFIL.TM. PHOTO CORE
(manufactured by Kuraray Medical Inc.) and irradiated with light
for twenty seconds with JET-LITE 3000 (manufactured by Morita
Corporation) to be cured, and thus the extrusion nozzle was closed
off. Subsequently, the piston was fitted to the main body and laid
for three minutes at 70 Torr, and the presence of disengagement of
the piston from the main body was checked.
[0042] Loading Test
[0043] A piston was fitted to the main body and pushed in at a
cross-head speed of 100 mm/min with AUTOGRAPH (AGS-G 500N
manufactured by Shimazu Corporation), and a maximum load value
measured before the front end wall portion 2b of the piston comes
into contact with the inner circumferential wall of the main body
was measured as a force required for pushing in the piston.
[0044] Curing Test
[0045] The main body was filled with CLEARFIL PHOTO CORE and fitted
with the piston and then irradiated from the direction of the
piston with light for one minute with JET-LITE 3000, and presence
of curing of the filler was checked.
Inventive Example 1
[0046] The main body with X=4.42 mm, and the piston made of acryl
and having a shape as shown in FIG. 3 with D.sub.1 (=D.sub.2)=4.30
mm, D.sub.3 (=D.sub.4)=4.60 mm, and D.sub.5=6.80 mm were molded.
Table 1 shows the results of evaluation.
Inventive Example 2
[0047] The main body with X=4.42 mm, and the piston made of LDPE
and having a shape as shown in FIG. 7 with D.sub.1 (=D.sub.2)=4.30
mm, D.sub.3 (=D.sub.4)=4.60 mm, and D.sub.5=6.80 mm were molded.
Table 1 shows the results of evaluation.
Comparative Example 1
[0048] The main body with X=4.42 mm, and the piston made of LDPE
without the protrusion and with D.sub.1 (=D.sub.2)=4.30 mm and
D.sub.5=6.80 mm were molded. Table 1 shows the results of
evaluation.
Comparative Example 2
[0049] The main body with X=4.42 mm, and the piston made of LDPE
without the protrusion and with D.sub.1 (=D.sub.2)=4.54 mm and
D.sub.5 3.40 mm were molded. Table 1 shows the results of
evaluation.
TABLE-US-00001 TABLE 1 Inventive Comparative Examples Examples 1 2
1 2 Material of main body PBT Inner diameter size (X) of main 4.42
body (mm) Material of piston Acryl LDPE Shape of piston FIG. 3 FIG.
7 Without protrusion Diameter (D.sub.1) of trunk portion 4.30 4.30
4.30 4.54 of piston (mm) Diameter (D.sub.3) of trunk portion 4.60
4.60 N/A N/A of piston, inclusive of protrusion (mm) X - D.sub.1
(mm) 0.12 0.12 0.12 -0.12 D.sub.3 - X (mm) 0.18 0.18 N/A N/A Piston
total length (D.sub.5) 6.80 6.80 6.80 3.40 in push-in direction
(mm) Vibration test No No Yes No (piston disengagement from main
body) Depressurization test No No No Yes (piston disengagement from
main body) Loading test (N) 16 14 0 106 Curing test No No No No
(occurrence of curing of filler)
[0050] It will be appreciated from Table 1 that, in the
cartridge-type dispenser in which the piston is not provided with
the protrusion on an outer surface thereof and the piston has a
diameter smaller than the inner diameter of the main body, the
piston easily underwent disengagement in response to the vibration.
Furthermore, in the cartridge-type dispenser in which the piston is
not provided with the protrusion on the outer surface thereof and
the piston has a diameter larger than the inner diameter of the
main body, although the piston was not disengaged in response to
the vibration, the piston inevitably underwent disengagement when
the inner pressure increased, and moreover, the load measured at
the time of pushing in the piston was remarkably large. On the
other hand, in the cartridge-type dispenser according to the
present invention, the piston did not undergo disengagement even
when the vibration was applied and when the inner pressure was
increased, and the load measured at the time of pushing in the
piston was confirmed to be small.
INDUSTRIAL APPLICABILITY
[0051] The present invention provides a cartridge-type dispenser
suitable for extruding viscous materials that is capable of
ensuring a smooth operation of extruding contents while preventing
a piston from being easily disengaged from a main body.
REFERENCE NUMERALS
[0052] 1 Main body [0053] 1a Extrusion nozzle [0054] 1b Rear end
opening [0055] 1c Flange [0056] 2 Piston [0057] 2a Trunk portion
[0058] 2b Front end wall portion [0059] 2c Rear end wall portion
[0060] 3 Protrusion [0061] 4 Nozzle cap [0062] M Filling space
[0063] P Gap formed by piston and main body
* * * * *