U.S. patent application number 09/852631 was filed with the patent office on 2001-09-13 for liquid discharge regulator and liquid feeder equipped with the same.
Invention is credited to Higashi, Tatsuji, Inoue, Mitsuyoshi, Nakazawa, Hajime, Yamada, Keiichi, Yamamoto, Atsushi.
Application Number | 20010021830 09/852631 |
Document ID | / |
Family ID | 27326116 |
Filed Date | 2001-09-13 |
United States Patent
Application |
20010021830 |
Kind Code |
A1 |
Yamada, Keiichi ; et
al. |
September 13, 2001 |
Liquid discharge regulator and liquid feeder equipped with the
same
Abstract
A compact liquid discharge regulator is provided at low cost by
arranging a channel spirally formed in the surface of a passage
forming member. The surface of the passage forming member is
brought into close contact with the inner surface of a housing
part, and the channel functions as a liquid passage. In this
construction, the sectional form and length of the channel can be
formed at high precision in accordance with the design. Therefore,
a desired pipe loss is obtainable only by designing in advance the
sectional form and length of the channel so as to correspond to the
pipe loss. Particularly, with injection molding, mass production of
a passage forming member of identical pipe loss can be effected
merely by preparing a mold corresponding to the pipe loss, thus
leading to a considerable reduction in the manufacturing cost of
the discharge regulator.
Inventors: |
Yamada, Keiichi;
(Kaizuka-shi, JP) ; Inoue, Mitsuyoshi;
(Kashiba-shi, JP) ; Nakazawa, Hajime; (Osaka-shi,
JP) ; Yamamoto, Atsushi; (Osaka-shi, JP) ;
Higashi, Tatsuji; (Izumisano-shi, JP) |
Correspondence
Address: |
SMITH PATENT OFFICE
1901 PENNSYLVANIA AVENUE N W
SUITE 200
WASHINGTON
DC
20006
|
Family ID: |
27326116 |
Appl. No.: |
09/852631 |
Filed: |
May 11, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09852631 |
May 11, 2001 |
|
|
|
09296536 |
Apr 22, 1999 |
|
|
|
Current U.S.
Class: |
604/249 |
Current CPC
Class: |
A61M 5/16877 20130101;
A61M 5/141 20130101; Y10T 137/2559 20150401; Y10T 137/7839
20150401 |
Class at
Publication: |
604/249 |
International
Class: |
A61M 005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 3, 1998 |
JP |
10-188965 |
Jul 3, 1998 |
JP |
10-188966 |
Jul 3, 1998 |
JP |
10-188967 |
Claims
What is claimed is:
1. A liquid feeder comprising: a main body including; an outlet
part in one end of the main body, the outlet part having an outlet
for discharging a liquid stored in the main body, and a discharge
regulation section provided in the outlet part of the main body for
introducing the liquid from the main body to the outlet to regulate
the discharge of the liquid.
2. A liquid feeder according to claim 1, wherein the discharge
regulation section includes a discharge regulator comprising: a
casing having a liquid inlet part and a liquid outlet part; and a
passage forming member formed with a channel in a surface thereof,
the surface of the passage forming member coming into contact with
an inner surface of the casing to define a passage for introducing
a liquid from the inlet part to the outlet part and regulate the
discharge of the liquid from the outlet part.
3. A liquid feeder according to claim 2, wherein the channel is
formed windingly to have a length sufficiently longer than the
overall length of the passage forming member.
4. A liquid feeder according to claim 2, wherein the passage
forming member is of a columnar shape and the channel is spirally
formed in a peripheral surface thereof.
5. A liquid feeder according to claim 2, wherein a plurality of
housing parts for housing the passage forming member are disposed
in the casing and a plurality of passage forming members of
different pipe losses are housed in their respective housing parts
to obtain the plurality of liquid passages, the liquid discharge
regulator further comprising: a passage switcher for switching the
liquid passages such that the discharge of the liquid flowing
through the outlet part is regulated by selectively switching the
passage switcher.
6. A liquid feeder according to claim 5, wherein the channel is
formed windingly to have a length sufficiently longer than an
overall length of the passage forming member.
7. A liquid feeder according to claim 5, wherein the passage
forming member is of a columnar shape and the channel is spirally
formed in a peripheral surface thereof.
8. A liquid feeder according to claim 5, wherein the diameter of a
liquid passage from the inlet part to the channel becomes smaller
when approaching from the inlet part of the channel.
9. A liquid feeder according to claim 5, wherein the passage
forming member is formed of a plastic by infection molding.
10. A liquid feeder according to claim 5, wherein the passage
switcher is disposed between the housing part and the inlet or the
outlet part.
11. A liquid feeder according to claim 2, further comprising: a
bypass passage disposed in the casing for providing communication
between the inlet part and the outlet part; and a bypass passage
switcher for controlling switching of the bypass passage such that
when the bypass passage is opened, a liquid is allowed to discharge
through the outlet part in an amount sufficiently greater than the
flow rate of the passage formed by the passage forming member.
12. A liquid feeder according to claim 2, wherein the passage
forming member is movable relative to the casing, and, by a
relative movement of the passage forming member, a position of the
channel opposite to one of the inlet and outlet parts is changed
for correction of the length of the channel from one position to
another.
13. A liquid feeder according to claim 12, wherein the casing has a
cylindrical chamber, and the passage forming member has the form of
a cylinder and is movable along an axis direction of the
cylindrical chamber, further comprises: a controller rotatably
mounted in the casing but being unmovable with respect to the axial
direction, the controller being operatively engaged with the
passage forming member; and a movement conversion mechanism for
converting a rotational movement of the controller into an axial
movement of the passage forming member relative to the casing to
change the position of the channel opposite to one of the inlet and
outlet parts for the correction.
14. A liquid feeder according to claim 13, wherein the movement
conversion mechanism includes: a force transmission means for
transmitting the rotational force of the controller to the passage
forming member; and a retaining means for keeping the passage
forming member from being rotated by the rotational force of the
controller.
15. A liquid feeder according to claim 12, further comprising a
bypass passage disposed in the casing for providing communication
between the inlet part and the outlet part, the bypass passage
being subjected to switching control in response to the position of
the passage forming member relative to the casing, such that when
the bypass passage is opened, a liquid is allowed to discharge
through the outlet part in an amount sufficiently greater than the
flow rate of the passage formed by the passage forming member.
16. A liquid feeder according to claim 15, wherein the passage
forming member is of a hollow cylinder, having the channel spirally
formed in a peripheral surface thereof and a hollow region
functioning as the bypass passage.
17. A liquid feeder according to claim 12, further comprising a
regulation region located in a portion of the passage forming
member, the regulation region closing one of the inlet and outlet
parts to regulate liquid communication from the inlet part to the
outlet part.
18. A liquid feeder according to claim 2, wherein the diameter of a
liquid passage from the inlet part to the channel becomes smaller
as approaching from the inlet part to the channel.
19. A liquid feeder according to claim 2, wherein the passage
forming member is formed of a plastic by injection molding.
Description
[0001] This application is a continuation application of U.S.
patent application No. 09/296,536 filed on Apr. 22, 1999, currently
pending, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to liquid discharge regulators and
liquid feeders for use in the medical field and the like.
[0004] 2. Description of the Related Art
[0005] Presently, a combination of a liquid feeder and a discharge
regulator is employed to inject chemical liquids, such as
antibiotics and anti-cancer drugs, into the patient's body in
portions, e.g., several cubic centimeters per hour, over a long
period of time. Examples of the liquid feeder are power syringe
pumps, balloon infusers, and an apparatus described in the
International Publication No. WO95/28977. One of the examples of
the discharge regulator is described in Japanese Unexamined Patent
Publication No. 9-225028 (1997). In this discharge regulator, an
inlet part and an outlet part project from a casing. The inlet part
is connected to a liquid feeder through a tube, and the outlet part
is connected to a body connecting tube. With this construction, the
liquid stored in the liquid feeder is controlled as to discharge by
the discharge regulator while being injected into the body over a
long period of time.
[0006] In the casing of the discharge regulator there are provided
two tubes of fine (small) diameter with the same diameter and
different lengths which are made of polyvinyl chloride or the like.
One end of each tube is connected to the inlet part via a passage
branching part, and the other end is connected to the outlet part.
Thereby each tube functions as a liquid passage from the inlet part
to the outlet part. A control stopper is attached to the passage
branching part and it is arranged such that the liquid that has
reached via the inlet part can selectively flow through a plurality
of tubes of fine diameter by operating the control stopper.
Therefore, the plural tubes thus arranged have different pipe
losses and, by selectively changing the liquid passage with the
control stopper, the discharge of the liquid flowing through the
outlet part can be switched to the following three stages:
[0007] i) a first discharge obtained by injecting a liquid only
through one of the tubes of fine diameter (the discharge in
accordance with the pipe loss of one said tube);
[0008] ii) a second discharge obtained by injecting a liquid only
though the other tube (the discharge in accordance with the pipe
loss of the other said tube); and
[0009] iii) a third discharge obtained by injecting a liquid
through both tubes (the sum of the first and second
discharges).
[0010] Here, the pipe loss of a passage is determined by inside
diameter and length. In the above discharge regulator, the tubes of
fine diameter form a passage and their lengths are adjusted to set
the pipe losses at a suitable value so as to control the discharge.
Unfortunately, the inside diameter of tubes of fine diameter is
subject to a certain degree of variation. Therefore, if a tube of
fine diameter with a length corresponding to a predetermined pipe
loss is used as it is, the desired pipe loss may not be always
obtained. To this end, the following operations are performed to
set a desired pipe loss. Firstly, a tube of fine diameter having a
length corresponding to the pipe loss is prepared and a liquid is
actually allowed to flow to measure its pipe loss (flow rate),
thereby inspecting whether it is a predetermined value or not. As a
result, when the obtained value deviates from the predetermined
value, the length of the tube is altered and its pipe loss is
measured to check whether it is the predetermined value or not. It
is necessary to repeat these operations with respect to each
passage. This results in one of the factors which can increase the
cost of manufacture.
[0011] There is an idea of suppressing the variation in the inside
diameters of tubes of fine diameter by relatively increasing the
inside diameter. In this case, to obtain a predetermined pipe loss,
it is necessary to increase the length of a tube of fine diameter
as its inside diameter increases. This increases the size of
discharge regulators. In addition, when a tube of fine diameter is
housed in a casing, the tube might get bent to cause poor or no
flow of liquid.
[0012] The above discharge regulator provides a three-stage
switching of discharge. It is, however, desired a continuous
discharge regulation to effect fine adjustment in response to the
change of patient's condition and the efficacy of chemical liquids.
Unfortunately, the continuous discharge cannot be effected by the
conventional discharge regulators.
[0013] Although the conventional discharge regulators cannot
perform continuous discharge regulation, it is possible to approach
this regulation by arranging such that the discharge is switched to
more stages by having more tubes of fine diameter of different pipe
losses. However, in the conventional discharge regulators which
require a great number of tubes of fine diameter with an attempt to
the continuous discharge regulation, the cost of device increases
as the number of tubes of fine diameter increases. In addition, an
increase in the number of tubes increases the size of device.
[0014] Further, in the prior art, a liquid feeder and a discharge
regulator are separately and independently provided, and connected
by a tube. Therefore, to inject a liquid in portions into the
patient's body over a long period of time, a great number of
component parts are needed, which results in one of the factors
increasing the cost of liquid injection. In addition, it is
necessary to prepare a liquid feeder and a discharge regulator and
then connect them by a tube each time a liquid injection is made.
This lowers the operating performance of liquid injection.
SUMMARY OF THE INVENTION
[0015] It is an object of the present invention to provide a liquid
discharge regulator and a liquid feeder which have overcome the
above problems residing in the prior art.
[0016] According to an aspect of the invention, a liquid discharge
regulator comprises: a casing having a liquid inlet part and a
liquid outlet part; and a passage forming member formed with a
channel in a surface thereof, the surface of the passage forming
member coming into contact with an inner surface of the casing to
define a passage for introducing a liquid from the inlet part to
the outlet part and to regulate the discharge of the liquid from
the outlet part.
[0017] According to another aspect of the invention, a liquid
feeder comprises: a main body including an outlet part in one end
of the main body, the outlet part having an outlet for discharging
a liquid stored in the main body, and a discharge regulation
section provided in the outlet part for introducing the liquid from
the main body to the outlet to regulate the discharge of the
liquid.
[0018] These and other objects, features and advantages of the
present invention will become more apparent upon reading of the
following detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIGS. 1A to 1C are diagrams of a liquid discharge regulator
according to a first preferred embodiment of the invention;
[0020] FIG. 2 is a diagram showing a situation where the above
discharge regulator is put into service;
[0021] FIG. 3 is a disassembled perspective view of a modification
of the discharge regulator of FIGS. 1A to 1C;
[0022] FIG. 4 is a disassembled perspective view of another
modification of the discharge regulator of FIGS. 1A to 1C;
[0023] FIGS. 5A and 5B are diagrams of a liquid discharge regulator
according to a second preferred embodiment of the invention;
[0024] FIGS. 6A to 6C are cross sections of the above discharge
regulator;
[0025] FIG. 7 is a schematic view illustrating the relationship
between a passage branching part and a passage in the above
discharge regulator;
[0026] FIG. 8 is a diagram illustrating the relationship between
the rotating amount of a control stopper and the discharge;
[0027] FIGS. 9A and 9B are diagrams of a liquid discharge regulator
according to a third preferred embodiment of the invention;
[0028] FIGS. 10A and 10B are diagrams of a liquid discharge
regulator according to a fourth preferred embodiment of the
invention;
[0029] FIG. 11 is a cross section of the discharge regulator taken
along the line 11-11 of FIG. 10B;
[0030] FIG. 12 is a diagram showing a situation where the discharge
regulator of FIGS. 10A and 10B is put into service;
[0031] FIG. 13 is a perspective view, partially broken away, of a
passage forming member;
[0032] FIGS. 14A to 14C are diagrams showing discharge regulating
operation in the discharge regulator of FIGS. 10A and 10B;
[0033] FIG. 15 is a cross section of one preferred embodiment of a
liquid feeder according to the invention;
[0034] FIG. 16 is a cross section illustrating a state before a
cylinder is attached to a casing;
[0035] FIG. 17 is an enlarged view of a discharge regulation
section incorporated in the liquid feeder of FIG. 15; and
[0036] FIG. 18 is a diagram showing operation of the liquid feeder
of FIG. 15.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] The invention relates to a liquid discharge regulator and a
liquid feeder incorporating a discharge regulator which are used in
the medical field and the like. A description of preferred
embodiments of the liquid discharge regulator will be presented
prior to the description of preferred embodiment of the liquid
feeder.
Liquid Discharge Regulators
[0038] A. First Preferred Embodiment
[0039] FIGS. 1A to 1C are diagrams of a first preferred embodiment
of a liquid discharge regulator according to the invention. FIG. 2
is a situation where the discharge regulator of FIGS. 1A to 1C is
placed in service. A discharge regulator 1 is used in combination
with a liquid feeder 2. That is, a tube 3 extending from the liquid
feeder 2 is connected to an inlet part of the discharge regulator
1, and another tube (not shown) to be connected to the body is
connected to an outlet part 12. It is therefore possible to inject
a liquid in portions into the body over a long period of time.
[0040] Referring to FIG. 1B, in the discharge regulator 1, a
housing part 14 is disposed almost centrally of a casing 13 to
define a columnar housing space. A columnar passage forming member
15 is brought into engagement with the housing space of the housing
part 14 from one end of the casing 13 (the lower side as seen in
FIG. 1B), and the distal end of the member 15 is engaged to a step
portion 141 of the housing part 14. Thus, with the passage forming
member 15 housed in the housing part 14, an inlet part 11 is
inserted into one said end of the casing 13, so that the rear end
of the passage forming member 15 is engaged to the distal end of
the inlet part 11. Thereby, the passage forming member 15 is housed
and secured to the housing part 14 of the casing 13.
[0041] The passage forming member 15 is made of a resin material,
e.g., plastic. As shown in FIG. 1C, a channel 151 having a
rectangular, triangular or semicircular sectional form is spirally
provided in the surface of the passage forming member 15. The
outside diameter of the member 15 is the same or slightly larger
than the inside diameter of the housing part 14. When the passage
forming member 15 engages the housing part 14 in the above manner,
its surface is brought into close contact with the inner surface of
the casing 13 (the housing part 14). Thus, a liquid runs in the
housing part 14 via the inlet part 11 and then goes to the other
end (the upper side as seen in FIG. 1C) of the casing 13 through
the channel 151, which functions as a liquid passage.
[0042] Disposed at the other end of the casing 13 is an outlet part
12 integrally formed with the casing 13. The liquid that has
reached through the channel 15 flows through the outlet part 12. In
FIGS. 1A and 1B, reference numeral 10 designates a lock part by
which a body connecting tube (not shown) attached to the outlet
part 12 is fastened and locked against the outlet part 12.
[0043] As stated above, in the discharge regulator 11 according to
this embodiment, the channel 151 provided spirally in the surface
of the passage forming member 15 functions as a liquid passage,
thus producing the following effects. Specifically, a well known
manner, e.g., injection molding, can be used in manufacturing the
passage forming member 15 of plastic which has a channel 151 in its
surface, and the sectional form and length of the channel 151 can
be formed at high precision in accordance with the design. Hence, a
desired pipe loss is obtained at a time by designing in advance the
sectional form and length of the channel 151 so as to accord the
pipe loss. Particularly, with injection molding, mass production of
the passage forming member 15 of the same pipe loss can be effected
only by preparing a mold according to the pipe loss. This leads to
a considerable reduction in the manufacturing cost of the discharge
regulator 1.
[0044] In addition, the channel 151 serving as a passage is
spirally provided in the surface of the passage forming member 15
such that the channel 151 is sufficiently longer than the whole
length L of the passage forming member 15 (see FIG. 1B). Therefore,
the sectional area of the channel 151 can be increased by an amount
to ensure sufficient length. This results in the effect that the
passage (the channel 151) hardly becomes clogged. Also, a greater
sectional area of the channel 151 further facilitates the molding
of the channel forming member 15 and further improves the
precision.
[0045] Since the channel 151 functions as a passage, passages can
be concentrated at a narrow region. This leads to a compact device,
as compared to the prior art employing a tube of fine diameter as a
passage.
[0046] Although in the first preferred embodiment, the passage
forming member 15 is made of a resin material, e.g., plastic, it
may be formed by machining other material, e.g., glass or metals.
The molding method is not limited to injection mold and various
well-known molding methods can be employed. This is true for the
following preferred embodiments as well.
[0047] Although in the first preferred embodiment, the channel 151
is provided in the surface of the passage forming member 15 of a
columnar shape, the passage forming member 15 may have an arbitrary
sectional form. For example, solid or hollow columnar ones having
columnar, multi-prismatic or cylindrical shape can be adopted,
provided only that the surface of the passage forming member 15 is
brought into close contact with the inner surface of the casing 13
(the housing part 14) to introduce a liquid toward the outlet part
12 along the channel 151. This is true for the following preferred
embodiments as well.
[0048] Although in the first preferred embodiment, the channel 151
is spirally provided in the surface of the passage forming member
15, the channel 151 is merely required to be formed windingly such
as to have a length sufficiently longer than the whole length L of
the passage forming member 15, and it may be wound in random
fashion. Accordingly, the liquid discharge regulator may be
arranged as shown in FIG. 3 or 4.
[0049] FIG. 3 is a disassembled perspective view showing a
modification of the discharge regulator of FIGS. 1A to 1C. In a
discharge regulator 1, an inlet part 11 and an outlet part 12
project in directly opposite direction from the side surface of a
disk-like base part 161. A circular recess 162 is disposed
centrally of the upper surface of the base part 161, and the recess
162 is arranged to allow for the engagement of a disk-like passage
forming member 17. A cover part 163 is press-inserted into the
recess 162 to cover the discharge forming member 17 from its top
surface, so that the top surface of the discharge forming member 17
is brought into close contact with the surface of the cover part
163. Thus, in this embodiment, a casing 16 includes the base part
161 and the cover part 163, and a housing space for housing the
discharge forming member 17 is formed by the base part 161 and the
cover pat 163. That is, the recess 162 functions as a housing part,
in this embodiment.
[0050] A spiral channel 171 is formed in the top surface of the
discharge forming member 17. With the member 17 housed in the
recess (housing part) 162, a peripheral end 171a of the recess 171
is opposed to the inlet part 11 and, as shown by arrow FL1 in FIG.
3, when a liquid runs to the discharge forming member 17 via the
inlet part 11, the liquid is introduced to almost centrally of the
surface of the discharge forming member 17 along the channel 171.
An end 171b disposed centrally of the channel 171 is in
communication with a communication channel 164 disposed in the top
surface of the base part 161 via a through-hole (not shown) passing
through vertically of the discharge forming member 17. As shown by
arrow FL2 in FIG. 3, the liquid that has reached the end 171b along
the channel 171 serving as a passage, runs in the communication
channel 164 via the through-hole, goes to the outlet part 12 along
the communication channel 164, and then flows out through the
outlet part 12.
[0051] FIG. 4 is a disassembled perspective view showing another
modification of the discharge regulator of FIGS. 1A to 1C. This
discharge regulator distinctly differs from the previous one in
that a passage forming member 18 includes a rectangular flat plate
and its top surface is formed with a snaky (winding) channel 181,
and that both ends 181a and 181b of the channel 181 are directly
connected to an inlet part 11 and an outlet part 12, respectively,
which project from the side surface of a base part 191 constituting
a casing 19. Other constructions are substantially the same.
Therefore, as shown by arrow FL3 in FIG. 4, when a liquid runs in
the discharge forming member 18 via the inlet part 11, the liquid
reaches the end 181b along the channel 181 serving as a passage
and, as shown by arrow FL4 in FIG. 4, reaches the outlet part 12
and then flows out through the outlet part 12. In FIG. 4, reference
numerals 192 and 193 designate components corresponding to the
recess 162 and the cover part 163 of the device of FIG. 3.
[0052] As stated above, the liquid discharge regulators according
to the above modifications employ, as a liquid passage, the
channels 171 and 181 sufficiently longer than the whole length of
the passage forming members 17 and 18, which are formed in the
surface of the members 17 and 18, respectively, as does the case
with the device of FIGS. 1A to 1C. This enables the invention to
provide a compact device at a low cost.
[0053] B. Second Preferred Embodiment
[0054] FIGS. 5A and 5B are diagrams of a liquid discharge regulator
according to a second preferred embodiment of the invention. FIGS.
6A to 6C are cross sections of the discharge regulator of FIGS. 5A
and 5B. FIG. 6A is a cross section taken along the line 6A-6A of
FIG. 5B; FIG. 6B is a cross section taken along the line 6B-6B of
FIG. 5A; and FIG. 6C is a cross section taken along the line 6C-6C
of FIG. 5A.
[0055] Referring to FIGS. 6A to 6C, in a discharge regulator 1, two
housing parts 14A and 14B are provided in a casing 13 to define two
independent cylindrical housing spaces. Discharge forming members
15A and 15B are housed in the housing members 14A and 14B,
respectively. When comparing the discharge forming member 15A with
15B, it is common that channels 151 of the same sectional form are
formed in their respective surfaces and the surfaces are rendered
into close contact with the inner surface of the housing members
14A and 14B. Thereby, the channel 151 functions as a liquid
passage, similar to the first preferred embodiment. On the other
hand, the channel 151 is spirally formed in a relatively wider
pitch in the surface of the passage forming member 15A, whereas the
channel 151 is spirally formed in a relatively narrower pitch in
the surface of the passage forming member 15B. As a result, in this
embodiment, the pipe loss of the passage forming member 15A is
smaller than that of the member 15B, and the discharge RA of liquid
flowing through a passage A on the side of the passage forming
member 15A (see FIG. 7) is different from the discharge RB of
liquid flowing through a passage B on the side of the passage
forming member 15B (see FIG. 7). Other structural features of the
passage forming members 15A and 15B are the same as those of the
passage forming member 15 in the first preferred embodiment.
[0056] As shown in FIG. 6A, the housing members 14A and 14B are in
communication with the inlet part 11 via a passage branching part 5
on the side of the inlet part 11, while they are in directly
communication with the outlet part 12 on the side of the outlet
part 12. A control stopper 51 is rotatably engaged in the interior
of the passage branching part 5. FIGS. 7 and 8 illustrate
schematically a passage branching part 5 and a control stopper 51.
The passage branching part 5 is formed with three valve holes 52,
53 and 54 which have an open angle of 90 in three directions,
respectively, on a plane orthogonal to the axis of rotation of the
control stopper 51. The valve hole 53 is connected to the inlet
part 11 and the valve holes 52 and 54 provided in the sides are
connected to the housing members 14A and 14B, respectively. A
T-shaped communication path 56 is formed in the control stopper 51,
and a switching valve part is constructed by allowing each opening
of the communication path 56 to match or mismatch the respective
valve holes 52, 53 and 54.
[0057] As shown in FIGS. 5A, 5B and FIGS. 6A to 6C, one end of the
control stopper 51 passes through the casing 13 for exposure to the
outside, and the exposed part is defined as an operation input part
57. The operation input part 57 is shaped to a hexagon nut and free
to rotate by an engagement with an operation tool in the form of a
closed wrench (not shown). Disposed in the periphery of the
operation input part 57 is an indicator 58 which facilitates an
understanding of the direction of the control stopper 51 (the
communication path 56). Disposed in the casing 13 is a scale which
indicates the selection situation (the flow rate) of the passages A
and B in response to the indicator 58.
[0058] Referring now to FIG. 8, a description is now given on the
relationship between the rotating amount of the control stopper 51
and the discharge of liquid flowing through the outlet part 12. As
to "rotation angle" in FIG. 8, assuming it is "0.degree." when the
control stopper 51 is not operated, the respective rotation angles
are indicated when the control stopper 51 is rotated in a clockwise
direction as seen in FIGS. 6A to 6C, from the connecting status at
0.degree.. The connecting status at the respective rotation angles
are schematically shown in the column of "connected state," and the
respective discharges of liquid through the outlet part 12 are
indicated in the column of "discharge."
[0059] When the control stopper 51 is not operated, the valve hole
53 on the side of the inlet part 11 has no communication with the
valve hole 52 or 54, and thus both passages A and B are closed.
[0060] When the control stopper 51 is rotated 90.degree. clockwise
from the state indicated uppermost of the "connected state" column,
only the valve holes 53 and 54 are brought into communication.
Thereby the passage B alone is selected for fluid communication. As
a result, a liquid is discharged from the outlet part 12 at a
discharge RB according to the pipe loss of the passage B.
[0061] When the control stopper 51 is rotated 180.degree., the
valve holes 52, 53 and 54 are all brought into communication,
thereby both passages A and B are selected for fluid communication.
As a result, a liquid is discharged from the outlet part 12 at the
total discharges (RA+RB) according to the respective pipe losses of
the passages A and B.
[0062] When the control stopper 51 is rotated 270.degree., only the
valve holes 52 and 53 are brought into communication. Thereby the
passage A alone is selected for fluid communication. As a result, a
liquid is discharged from the outlet part 12 at a discharge RA
according to the pipe loss of the passage A.
[0063] As stated above, in the second preferred embodiment, the two
housing parts 14A and 14B are disposed in the casing 13 and the
passage forming members 15A and 15B having different pipe losses
are housed in their respective housing parts 14A and 14B to obtain
liquid passages A and B which are arranged such that they are
selectively switched by operation of the control stopper 51. This
permits a three-stage regulation of the discharge of liquid through
the outlet part 12. That is, the passage branching part 5 and the
control stopper 51 function as passage switching means.
[0064] Since the spiral channel 151 in the surfaces of the passage
forming members 15A and 15B is arranged to function as liquid
passages A and B, the same effect as the first preferred embodiment
is obtained in addition to the above-mentioned effects.
[0065] Although in the second preferred embodiment, the passage
forming members 15A and 15B are provided with the channels 151
having the same shape and different lengths such that the passages
A and B differ from each other in pipe loss, the channels 151 may
have the same length and different sectional areas or may have
different sectional areas and lengths such that the passages A and
B have different pipe losses.
[0066] Although in the second preferred embodiment, the two
passages A and B are formed and switching of discharge is
controlled by rotating the control stopper 51 of the passage
branching part 5 serving as passage switching means, three or more
passages may be provided to switch the discharge. Specifically,
three or more housing parts are disposed in the casing 13 and
passage forming members having different pipe losses are housed in
the respective housing parts, such that selective switching of
passage is effected by passage switching means.
[0067] Although in the second preferred embodiment, the passage
branching part 5 serving as passage switching means is provided on
the side of the inlet part 11, it may be positioned anywhere
between the inlet part 11 and the outlet part 12, for example,
between the outlet part 12 and the housing part 14A or 14B.
[0068] Although in the second preferred embodiment, a spiral
channel is provided as a passage forming member in a cylindrical
member, as in the case with the first preferred embodiment, any
modifications described in the first preferred embodiment may be
made in shape, material, and winding form.
[0069] C. Third Preferred Embodiment
[0070] FIGS. 9A and 9B are diagrams showing a liquid discharge
regulator according to a third preferred embodiment of the
invention. This discharge regulator is distinctly different from
that of the second preferred embodiment in that a bypass passage C
is substituted for the passage B which is formed by disposing the
passage forming member 15B in the housing part 14B, and that a
bypass passage switching part 6 for switching the bypass passage is
substituted for the passage branching part. Other basic
constitutions are the same. Therefore, a description is made in
detail on the differences. Similar reference numerals have been
used to denote similar parts and therefore its description is
omitted.
[0071] In a discharge regulator 1, a bypass pipe 7 which includes
serially-connected two pipes 71 and 72 parallel to a housing part
14A, is disposed between an inlet part 11 and an outlet part 12 to
define a bypass passage C. The pipes 71 and 72 may have an
arbitrary sectional form which is much greater than that of a
channel 151. This enables the invention to provide liquid
communication with the outlet part 12 via the bypass passage C in a
sufficiently larger amount than the flow rate of a passage A formed
by a passage forming member 15A.
[0072] A bypass passage switching part 6 for switching the bypass
passage C is provided in the junction between the pipes 71 and 72.
As shown in FIG. 9B, an opening 61 is disposed in the junction
between the pipes 71 and 72, and a liquid flows from the pipe 71 to
the pipe 72 via the opening 61. An operating rod 62 is slidably
mounted in the opening 61. A distal end 621 of the operating rod 62
is located in a casing 13 while a rear end 622 projects outwardly
of the casing 13. When the rear end 622 is pushed against the side
of the casing 13, the distal end 621 of the operating rod 62 closes
the opening 61 to close the bypass passage C, as shown in FIG. 9B.
When the rear end 622 is drawn out of the casing 13, the distal end
621 is withdrawn from the opening 61 to open the bypass passage C.
Thus, the bypass passage switching part 6 is composed of the
opening 61 and operating rod 62 in this embodiment.
[0073] In the liquid discharge regulator 1 so constructed, when the
operator pushes the operating rod 62 against the casing 13 to close
the bypass passage C, only the passage A which is constructed in
the same manner as in the first preferred embodiment is brought
into fluid communication, and a liquid is discharged from the
outlet part 12 at the discharge corresponding to the pipe loss of
the passage A. This produces the same effect as the first preferred
embodiment.
[0074] If it is desired to sharply increase the discharge of liquid
in response to the change of patient's condition and the efficacy
of chemical liquid, the discharge regulator 1 of this embodiment is
suitably applicable to such a case. That is, when the operator
draws the operating rod 62 from the casing 13 to open the bypass
passage C, both passages A and C are brought into fluid
communication. Then it is possible to discharge liquid through the
outlet part 12 in a sufficiently larger amount than the flow rate
of the passage A because the pipes 71 and 72 have the cross
sections considerably greater than that of the channel 151 as
stated earlier.
[0075] Although in the third preferred embodiment, the bypass
passage C is switched by closing/opening the opening 61 with the
operating rod 62, the bypass passage switching part 6 is not
limited to this arrangement. For example, it may be constructed by
the control stopper as used in the second preferred embodiment.
[0076] Although in the third preferred embodiment, the bypass
passage C is added to a discharge regulator of the type in which
only the passage A is provided for fine adjustment of liquid
discharge (the first preferred embodiment), the present invention
is applicable to discharge regulators of the type which have a
plurality of passages as in the second preferred embodiment.
[0077] D. Fourth Preferred Embodiment
[0078] FIGS. 10A and 10B are diagrams showing a liquid discharge
regulator according to a fourth preferred embodiment of the
invention. FIG. 11 is a cross section taken along the line 11-11 of
the FIG. 10B. FIG. 12 is a diagram illustrating a situation where
the discharge regulator of FIGS. 10A and 10B is placed in
service.
[0079] Referring to FIG. 12, a discharge regulator 1 is used in
combination with a liquid feeder 2. That is, a tube 3 extending
from the liquid feeder 2 is connected to an inlet part 11 of the
discharge regulator 1, and another tube (not shown) to be connected
to the body is connected to an outlet part 12. It is therefore
possible to inject a liquid in portions into the body over a long
period of time. Reference numeral 10 designates a lock part, by
which the tube connected to the body (not shown) attached to the
outlet part 12 is fastened and locked to the outlet part 12.
[0080] Referring to FIG. 11, in the discharge regulator 1, the
inlet part and the outlet part 12 are attached to the side surface
of a casing 13 in directly opposite direction. A housing part 14 is
disposed in the casing 13 such as to lie in line with the outlet
part 12. A housing space 14a is defined by the housing part 14 and
it is arranged such that the liquid supplied to the inlet part 11
runs into the housing space 14a from the side surface of the
housing part 14 by a connecting member 11a. From one end side of
the casing 13 (the right side as viewed in FIG. 11), a passage
forming member 15 is engaged to the housing space 14a of the
housing part 14.
[0081] FIG. 13 is a perspective view, partially broken away, of a
passage forming member 15. The member 15 is made of a resin
material, e.g., plastic, in a hollow cylindrical shape, and its
outside diameter is approximately the same as the inside diameter
of the housing part 14. The discharge forming member 15 is free to
move in the longitudinal direction of the housing space 14a while
being brought into close contact with the inner surface of the
housing part 14. A channel 151 is spirally formed in the surface of
the passage forming member 15, and it has a sectional form of
rectangle, triangle or semicircle, for a given distance D from the
other end (the lower left-hand as seen in FIG. 13). As a result,
the liquid that has reached the housing space 14a from the side
surface of the housing part 14 via the connecting member 11a can be
introduced along the spiral channel 151. Thereby, the channel 151
functions as a liquid passage.
[0082] A rectangular channel 152 is provided on one side (the upper
right-hand as seen in FIG. 13) of the channel 151 and an O ring 153
is embedded within the rectangular channel 152, so as to regulate a
liquid which flows via the O ring 153 from one to the other side or
in reverse direction, along the surface of the passage forming
member 15. A region 153R corresponding to the O ring 153 functions
as a regulation region.
[0083] In a peripheral region 154R extending from one end to the
other end of the O ring 153 on the surface of the passage forming
member 15, there is a bypass part 154 whose outside diameter is
smaller than that of the region 151R where the channel 151 is
formed. The bypass part 154 functions to introduce the liquid that
has reached via the input part 11 into a bypass passage, as is
described below.
[0084] One side of the hollow region of the passage forming member
15 is a cylindrical hollow region 155 and the other side thereof is
a prismatic hollow region 157. An internal thread 156 is screwed
into the internal peripheral surface of the hollow region 155.
[0085] A hollow cylindrical member 81 is arranged such as to fit
into the cylindrical hollow region 155. An external thread 82
corresponding to the internal thread 156 is screwed into the outer
peripheral surface of the cylindrical member 81 for engagement with
the internal thread 156, as shown in FIG. 11. A control knob 83 is
fixedly attached to one end of the cylindrical member 81 (the end
on the right-hand as viewed in FIG. 11) and the control knob 83 is
rotatable relative to the casing 13 and the housing part 14, with
its distal end projecting from the casing 13 (see FIG. 11). In
FIGS. 11 and 13, reference numeral 81a designates through-holes to
allow communication between the peripheral part of the cylindrical
member 81 and the hollow region 81b. Four through-holes 81a are
disposed equidistantly around the peripheral surface of the
cylindrical member 81.
[0086] Disposed in the prismatic hollow region 157 is a hollow
prismatic member 84 which projects from the other end of the
housing part 14 to the side of the passage forming member 15. The
widthwise inside diameter of the prismatic member 84 is the same or
slightly smaller than the inside diameter of the hollow region 157
such that a side part 84a of the prismatic member 84 (see FIG. 13)
is brought into contact with the hollow region 157. On the other
hand, the heightwise diameter of the prismatic member 84 is smaller
than the inside diameter of the hollow region 157, thereby
producing a heightwise space SP1.
[0087] As stated above, in this embodiment it is arranged such that
one end of the passage forming member 15 is subjected to the torque
of the control knob 83 and the other is brought into contact with
the side part 84a of the prismatic member 84. Therefore, the
passage forming member 15 is guided by the prismatic member 84 to
reciprocate within the housing part 14 according to the rotating
amount of the control knob 83. By operating the control knob 83,
position P of the channel 151 opposite the inlet part 11 via the
connecting member 11a is changed to correct the length of the
channel 151 from the position P to the outlet part 12; the inlet
part 11 and the O ring 153 (the regulation region 153R) are
oppositely disposed via the connecting member 11a to regulate the
flow of liquid into the side of the outlet part 12; or the inlet
part 11 is oppositely disposed with the bypass part 154 having a
smaller outside diameter than that of the region 151R formed with
the channel 151.
[0088] Referring to FIGS. 14A to 14C, description will now be made
on liquid discharge changes when the passage forming member 15 is
set at various positions by the control knob 83. In the figures,
solid arrows designate the flow of liquid which has been forced to
the housing space 14a via the inlet part 11 and the connecting
member 11a.
[0089] As shown in FIG. 14A, when the control knob 83 is operated
such that position P1 closely adjacent an O ring 153 in a region
151R formed with a channel 151 is located opposite the inlet part
11 via the connecting part 11a, the liquid forced to the housing
part 14 via the inlet part 11 and the connecting member 11a runs to
the side of the outlet part 12 along the channel 151, passes the
space SP1 between the hollow region 157 of the passage forming
member 15 and the prismatic member 84, goes through the hollow
region 84b of the prismatic member 84, and reaches the outlet part
12. At this time, since the liquid passes through the almost entire
length of the channel 151, the pipe loss of the passage formed by
the channel 151 is relatively high and thus the discharge R1 of the
liquid flowing through the outlet part 12 becomes relatively
low.
[0090] As the control knob 83 is operated to move the passage
forming member 15 to the side of the control knob 83, the position
opposite the inlet part 11 via the connecting member 11a is
gradually moved to the side of the outlet part 12. Thus, in
response to the rotation of the control knob 83, the length of the
channel 151 from the above-mentioned position to the outlet part 12
becomes gradually shorter and the pipe loss also becomes smaller.
As a result, the liquid is introduced into the outlet part 12
through the same path as shown in FIG. 14A, and the discharge of
the liquid flowing through the outlet part 12 is gradually
increased. Then, as shown in FIG. 14B, when one end of the passage
forming member 15 is engaged in the control knob 83, the length of
the channel 151 from position P2 opposite the inlet part 11 via the
connecting member 11a to the outlet part 12 becomes the shortest
and the pipe loss becomes the smallest, so that the discharge of
the liquid flowing through the outlet pat 12 results in
R2(>R1).
[0091] Subsequently, when the control knob 83 is rotated in reverse
direction to move the passage forming member 15 away from the
control knob 83, in just the reverse fashion to the above, the
length of the channel 151 from the position opposite the inlet part
11 via the connecting member 11a to the outlet part 12 becomes
gradually longer and the pipe loss also becomes gradually larger,
thereby reducing the discharge of the liquid flowing through the
outlet part 12. Then, if returned to the state shown in FIG. 14A,
the discharge of the liquid flowing through the outlet part 12
results in the minimum value R1. When the control knob 83 is
further rotated in the same direction, the inlet part 11 is located
opposite the O ring 153 (the regulation region 153R) via the
connecting member 11a, so that the inlet part 11 is substantially
closed by the O ring 153. As a result, the flow of liquid toward
the inlet part 12 is regulated and the discharge from the outlet
part 12 falls to zero.
[0092] In this regulated state, when the control knob 83 is further
rotated in the same direction, the inlet part 11 is located
opposite the bypass part 154 via the connecting member 11a, and the
liquid is introduced into the outlet part 12 via a bypass passage
which comprises the following in the order named: the space SP2
between the housing part 14 and the cylindrical member 81; the
through-hole 81a; the hollow region 81b of the cylindrical member
81; the housing space 14a; and the hollow region 84b of the
prismatic member 84. This bypass passage has a sectional area that
is much greater than that of the channel 151 throughout its whole
length, and the liquid is introduced into the outlet part 12 via
the bypass passage in a sufficiently greater amount (discharge
R3>>R1, R2) than the flow rate of the passage formed by the
passage forming member 15.
[0093] As stated above, in the liquid discharge regulator of this
embodiment, the control knob 83 is operated to change the length of
the channel 151 from the position of the channel 151 (e.g., the
position P, P1, or P2) opposite the inlet part 11 via the
connecting member 11a to the side of the outlet part 12, and the
pipe loss of the channel 151 located at that position is
continuously corrected, so that the discharge of liquid flowing
through the outlet part 12 is continuously regulated. This permits
a fine regulation of liquid discharge in response to the change of
patient's condition and the efficacy of chemical liquids.
[0094] This also leads to a compact device because unlike the prior
art, it is unnecessary to form in advance a plurality of passages
of different pipe losses by disposing a plurality of tubes of fine
diameter.
[0095] If desired to sharply increase a liquid discharge in
response to the change of patient's condition and the efficacy of
chemical liquids, a desired discharge is obtained by operating the
control knob 83 such that the bypass part 154 is located opposite
the inlet part 11 via the connecting member 11a.
[0096] In the liquid discharge regulator 1 of this embodiment, the
channel 151 formed spirally in the surface of the passage forming
member 15 is used as a liquid passage, resulting in the same effect
as in the first to third preferred embodiments.
[0097] Although in the fourth preferred embodiment the passage
forming member 15 is moved by the control knob 83, the housing part
14 may be moved instead of the passage forming member 15, or both
may be moved to change the position P of the channel 151 opposite
the inlet part 11 via the connecting member 11a. That is, with the
arrangement to permit the relative movement of the passage forming
member 15 with respect to the inlet part 11, the discharge of the
liquid flowing through the outlet part 12 is regulatable over a
wide range by changing the length of the channel 151 from the
position P opposite the inlet part 11 to the outlet part 12, or by
locating the inlet part 11 opposite the bypass part 154.
[0098] Although in the fourth preferred embodiment the passage
forming member 15 is moved relative to the inlet part 11, it may be
moved relative to the outlet part 12 such as to change the length
of the channel 151 from the position opposite the outlet part 12 to
the outlet part 12. With this arrangement, the same effect as in
the foregoing embodiments is obtained.
[0099] E. Others
[0100] As shown in FIG. 1C, in the above discharge regulator 1, it
is arranged such that the diameter of the passage forming member
15, 15A, 15B is reduced gradually as it advances along the channel
151 on the side of the inlet part 11. This produces the following
effect. Specifically, some of liquids which are subjected to
discharge regulation (e.g., physiological salt solution) is
partially crystallized at discontinuous portions due to a sharp
reduction in passage diameter. If such a crystallization occurs
within the passage, its crystalline might clog the passage. In this
invention, however, liquid crystallization is reliably prohibited
to prevent a clogging of the passage, by virtue of gradual
reduction in passage diameter as stated earlier.
Liquid Feeders
[0101] FIG. 15 is a cross section showing one preferred embodiment
of a liquid feeder according to the invention. This liquid feeder
includes a casing (a device body) 213 capable of storing a liquid
therein; a cylinder 221 with which the liquid stored inside of the
casing 213 is forced to an outlet part 216 disposed at the distal
end side (the upper side as viewed in FIG. 15) of the casing 213;
and a discharge regulation section 300, disposed in the outlet part
216 of the casing 213, for introducing the liquid fed by the
cylinder 221 into an outlet 216a and regulating the discharge of
the liquid flowing through the outlet 216a.
[0102] FIG. 16 is a cross section illustrating a state before a
cylinder is attached to a casing. A casing 213 is shaped into a
cylinder, the distal end of which (the upper end as seen in FIGS.
15 and 16) is closed by a bottom wall 213b, and the rear end (the
lower end as seen in FIGS. 15 and 16) is opened. An injection part
215 and an outlet part 216 extend upwardly from the bottom wall
213b. The injection part 215 has an inlet 215a for injecting a
liquid into the casing 213, and a check valve (a valve gear) 217 is
disposed therein. A cap 215A which is removable from the distal end
of the inlet 215a is attached to the side wall of the injection
part 215 via a connecting string 215B.
[0103] The outlet part 216 has an outlet 216a for discharging a
liquid externally of the feeder, and a discharge regulation section
300 is disposed in the interior of the outlet part 216. The
discharge regulation section 300 will be described later in
detail.
[0104] As to the casing 213 and a cylinder 221 as described later,
if at least the casing 213 is made of a transparent or translucent
synthetic resin, the casing 213 may carry a scale for accurate
measurement of the liquid to be filled and stored in a storage
chamber 212.
[0105] The other end opening of a side wall 213a of the casing 213
is formed with a slightly outwardly flared part 251, an internal
thread 252 is formed in the inner surface of the flared part 251,
and a small hole 253 connecting the interior of the casing 213 with
atmosphere is formed in the vicinity of the flared part 251. The
small hole 253 places the space of the rear surface side (the lower
side as seen in FIGS. 15 and 16) of a movable body 214 in the
casing 213 into communication with the atmosphere, in order to
allow for axial movement of the movable body 214. The small hole
253A is closed by a filter (not shown) which permits communication
of atmosphere but blocks intrusion of bacteria. Therefore, when the
liquid feeder is continuously used, for example, when a liquid is
injected into the body while being fed through the inlet 215a, the
above filter blocks intrusion of bacteria into the liquid, thereby
avoiding human infection.
[0106] In order to form the storage chamber 212 for storing the
liquid running through the inlet 215a on one end side (the upper
side as seen in FIGS. 15 and 16) in the casing 213, the movable
body 214 is inserted in the casing 213 such that it is in
fluid-tight and movable in an axial direction. As shown in FIG. 15,
similar to the bottom wall 213b of the casing 213, the movable body
214 is shaped into a disk whose central part has a slightly
expanded tapered surface. A fit 255 for securing a connecting rod
254 is disposed centrally of the rear side of the movable body 214,
and an annular groove 257 for confining a seal ring 256 is disposed
about the periphery of the movable body 214.
[0107] The connecting rod 254 functioning as an interlocking means
225 is a straight rod extending from the movable body 214 to the
other direction axially of the casing 213. With one end of the
connecting rod 254 fitted in the fit 255, it is secured centrally
of the movable body 214. A piston 222 is centrally secured to the
other end of the connecting rod 254. Thereby, the piston 222 is
coaxially linked and connected to the movable body 214. The piston
222 is shaped into a disk. A fit 258 for identifying the connecting
rod 254 is disposed centrally of the rear side of the piston 222,
and an annular groove 260 for confining a seal ring 259 is disposed
about the periphery of the piston 222.
[0108] Both seal rings 256 and 259 are composed of a rubber packing
having an approximately V-formed section. As shown in FIG. 15, the
seal ring 256 confined in the annular groove 257 of the movable
body 214 is oriented such that its acting portion (the side to
which the V-formed section opens) faces the storage chamber 212.
This reliably prevents liquid leakage from the storage chamber 212.
The seal ring 259 confined in the annular groove 260 of the piston
222 is oriented such that its acting portion faces the other end
side (the side exposed to atmospheric pressure) of the cylinder
221. This reliably prevents the air from invading into a vacuum
cylinder chamber 223.
[0109] The cylinder 221 is constructed by integrally closing one
end side of a cylindrical peripheral wall 221a with a bottom 221b
having a centrally located boss 261. A dome cover 263 having a
centrally located vent 262 is secured to the opening on the other
end of the peripheral wall 221a.
[0110] A rubber seal ring 264 is provided in the boss 261 of the
bottom 221b. With the connecting rod 254 inserted into the boss
261, one end of the interior of the cylinder 221 is subject to
airtight closure. A sealing 264 disposed in the boss 261 is
composed of an approximately V-formed packing, as is the seal ring
256 of the movable body 214 and the seal ring 259 of the piston
222, and it is arranged such that its acting portion faces the
casing 213 (the upper side as seen in FIG. 15). By virtue of the
vent 262 of the cover 263, the other end side of the piston 222 is
in communication with atmosphere.
[0111] Thus, with the other end of the cylinder 221 communicated to
the atmosphere, the connecting rod 254 is inserted air-tight into
the bottom 221b of the cylinder 221, and the piston 222 is inserted
air-tight into the cylinder 221 for movement in an axial
direction.
[0112] An external thread 265 projects from one end of the cylinder
221 and it is arranged such that when the external thread 265 is
screwed into an internal thread formed in the opening on the other
end of the casing 213, the cylinder 221 is coaxially connected to
the casing 213. The external thread 265 and the internal thread 252
constitute a connecting means 266 between the cylinder 221 and the
casing 213.
[0113] The connecting rod 254 is, as shown in FIG. 15, made
slightly longer than the length in the axial direction of the
casing 213, in order to locate the piston 222 outwardly axially
(the lower side as seen in FIGS. 15 and 16) from the other end of
the casing 213 when the movable body 214 is brought into engagement
with the bottom wall 213b of the casing 213.
[0114] Therefore, when the external thread 265 of the cylinder 221
is screwed into the internal thread 252, with the movable body 214
located at the rearmost on the other side of the casing 213, a
cylinder chamber 223 which has been maintained under vacuum between
the bottom 221b of the cylinder 221 and the piston 222 is to be
formed in the cylinder 221.
[0115] Referring now to FIG. 17, a discharge regulation section 300
will be described in detail. In the interior of an outlet part 216
where a discharge regulation section 300 will be arranged, a
housing part 216b is disposed to define a cylindrical housing
space. A cylindrical passage forming member 315 engages in the
housing space of the housing part 216b. With the passage forming
member 315 housed in the housing part 216b, its distal end is
engaged to a step portion 216c. The housing part 216b has a fixing
member (not shown) for engagement with the rear end of the passage
forming member 315. Thus, the passage forming member 315 is housed
and secured to the housing part 216b.
[0116] The passage forming member 315 is made of a resin material,
e.g., plastic, by means of injection molding. A channel 315a having
a sectional form, e.g., rectangle, triangle or semicircle, is
spirally formed in the surface of the passage forming member 315.
The outside diameter of the discharge forming member 315 is the
same or slightly larger than the inside diameter of the housing
part 216b. When the passage forming member 315 engages the housing
part 216b in the above manner, its surface is brought into close
contact with the inner surface of the outlet part 216 (the housing
part 216b). Accordingly, a liquid flows through the storage chamber
212 to the housing part 216b and reaches one end side (the upper
side as seen in FIG. 17) through the spiral channel 315a which
functions as a liquid passage.
[0117] Operation of the liquid feeder so constructed will be
described hereafter. As shown in FIG. 16, with the outlet 216a
opened, the movable body 214 is pushed up from the opening on the
other end of the casing 213 until it reaches the bottom wall 213b.
Then, as shown in FIG. 15, the internal thread 265 of the cylinder
221 engages in the external thread 252 of the casing 213, and the
cylinder 221 is axially rotated relative to the casing 213 in the
direction for screwing. Thereby, the cylinder 221 is screwed and
connected to the other end of the casing 213.
[0118] At this time, since the connecting rod 254 is made slightly
longer than the casing 213, the piston 222 moves away from the
bottom 221b of the cylinder 221 upon completion of engagement with
the casing 213 of the cylinder 221. As a result, a flat vacuum
cylinder chamber 223, as defined by the bottom 221b and the piston
222, is formed on one end side in the cylinder 221.
[0119] Then, with the outlet 216a closed, as a liquid is forced
through the inlet 215a by a syringe or the like, the movable body
214 moves to the other end side (downward) of the casing 213 to
increase the volume of the storage chamber 212 to be formed in
front of the movable body 214. At the same time, the piston 222
also moves to the other end side of the cylinder 221, so that the
volume of the above-mentioned vacuum cylinder chamber 223 is
gradually increased. Then, as shown in FIG. 18, preparation for
injection is completed when the piston 222 reaches the vicinity of
the cover 263. In FIG. 18, reference numeral 211 designates the
liquid thus stored in the storage chamber 212.
[0120] Thereafter, when the inlet 215a is covered with the cap 215A
and the outlet 216a is opened, the liquid 211 stored in the storage
chamber 212 is introduced into the outlet 216a via the channel 315a
functioning as a passage. The sectional form and length of the
channel 315a are determined in advance at the time of designing the
liquid feeder. Since the pipe loss of a passage formed by the
channel 315a has a predetermined value corresponding to the
sectional area and length, the liquid flows through the outlet 216a
at a discharge according to the pipe loss. The liquid discharged
through the outlet 216a is then injected into the patient's body
via a tube (not shown) connected to the outlet 216a.
[0121] As stated above, in the liquid feeder according to this
preferred embodiment, it is arranged such that the discharge
regulation section 300 is incorporated in the outlet part 216 of
the casing (the device body) 213 and the discharge of liquid
flowing through the outlet 216a is always regulated at a
predetermined value. Therefore, compared to the conventional cases
where a liquid feeder and a discharge regulator are provided
separately and independently and both are connected together by a
tube, this liquid feeder enables a simplified arrangement for
liquid injection to the patient and also lowers the cost. In
addition, this liquid feeder eliminates the need for work which has
been essential for liquid injection, namely the work of connecting
a liquid feeder and a discharge regulator by using a tube or the
like, thus improving the operating performance of liquid
injection.
[0122] Although in this embodiment, the discharge regulation
section 300 is incorporated in the liquid feeder constructed in
combination with the casing 213 and the cylinder 221, this
invention is applicable to any well-known liquid feeders, such as
power syringe pumps and balloon infusers. That is, the same effect
as the foregoing preferred embodiments is obtained by incorporating
the discharge regulation section 300 in the outlet part of the
liquid feeder.
[0123] Although in this embodiment, the passage forming member 315
constituting the discharge regulation section 300 is made of a
resin material, e.g., plastic, it may be made by machining other
material, e.g., glass or metals. The molding method is not limited
to injection molding and any other known molding methods may be
employed. The channel 315a is provided in the surface of the
columnar passage forming member 315, the channel forming member 315
may have an arbitrary sectional form. For instance, solid or hollow
columnar ones having a columnar, multi-prismatic or cylindrical
shape can be adopted, provided that the surface of the passage
forming member 315 is brought into close contact with the inner
surface of the casing 213 (the outlet part 216) to introduce a
liquid toward the outlet 216a along the channel 315a.
[0124] Although in this embodiment, the spiral channel 315a is
provided in the surface of the channel forming member 315, the
channel 315 is merely required to wind such as to have a length
sufficiently longer than the whole length L (see FIG. 17) of the
passage forming member 315, and it may be formed windingly in
random fashion.
[0125] Although in this embodiment, the discharge regulation
section 300 is constructed by the discharge regulator substantially
according to the first preferred embodiment (FIG. 1), it may be
constructed by any one of the discharge feeders according to the
second to fourth preferred embodiments.
[0126] Although in this embodiment, the discharge regulation
section 300 is attained by using, as a liquid passage, the channel
315a provided spirally in the surface of the channel forming member
315, and setting the pipe loss of this passage in advance, the
arrangement of the discharge regulation section is not limited
thereto. For example, discharge regulation can be effected by
using, as a passage, a glass tube of fine diameter or a tube of
fine diameter made of polyvinyl chloride, disposing it in the
outlet part 216, and suitably setting the pipe loss of the passage.
However, compared to the case using the glass tube or tube of fine
diameter as a passage, when the channel 315a is used as a passage,
as is the above embodiment, the following advantages are
obtained.
[0127] Description will now be given of the case where the passage
of a discharge regulation section is formed by a tube of fine
diameter. The pipe loss of the passage is determined by inside
diameter and length. Therefore, to control the flow rate, in
general, the pipe loss of the tube of fine diameter is suitably set
by adjusting its length. In this case, however, if a tube of fine
diameter having a length corresponding to a predetermined pipe loss
is used as it is, the desired pipe loss may not be always obtained
because a certain variation may occur in the inside diameter of
tubes of fine diameter. To this end, the following operations are
performed to set a pipe loss. Firstly, a tube of fine diameter with
a length corresponding to a pipe loss is prepared, and a liquid is
actually used to measure its pipe loss (flow rate), thereby
inspecting whether it is a predetermined pipe loss or not. As a
result, when the obtained value deviates from the predetermined
value, the length of the tube is altered and its pipe loss is
measured to check whether it is the predetermined value or not. It
is necessary to repeat these operations with respect to each
passage. This results in one of the factors which can increase the
cost of manufacture.
[0128] Alternatively, it is conceived to suppress the variation in
the inside diameters of tubes of fine diameter by relatively
increasing the inside diameter. In this case, to obtain a
predetermined pipe loss, it is necessary to increase the length of
a tube of fine diameter as its inside diameter increases. This
increases the size of discharge regulators. In addition, when a
tube of fine diameter is housed in a casing, the tube may get bent
to cause poor or no flow of liquid, making it difficult to perform
discharge regulation.
[0129] On the other hand, in the case where the channel 315a
provided spirally in the surface of the passage forming member 315
functions as a liquid passage, the following effect is obtained.
Specifically, the well-known methods, e.g., injection molding, can
be used in manufacturing the passage forming member 315 of plastic
which has the channel 315a on its surface, and the sectional form
and length of the channel 315a can be formed at high precision in
accordance with the design. Hence, a desired pipe loss is obtained
at a time by designing in advance the sectional form and length of
the channel 315a so as to correspond to the pipe loss.
Particularly, with injection molding, mass production of the
passage forming member 315 of identical pipe loss can be effected
only by preparing a mold corresponding to the pipe loss, thereby
leading to a considerable reduction in manufacturing cost.
[0130] In addition, the channel 315a serving as a passage is
spirally provided in the surface of the passage forming member 315
such that the channel 315a is sufficiently longer than the whole
length L of the passage forming member 315 (see FIG. 17).
Therefore, the sectional area of the channel 315a can be increased
by the amount of the ensured sufficient length, and the passage
(the channel 315a) hardly becomes clogged. Also, a greater
sectional area of the channel 315a further facilitates molding of
the channel forming member 315 and further improves the
precision.
[0131] Since the channel 315a is arranged to function as a passage,
passages can be concentrated at a narrow region and thus leads to a
compact device, as compared to the prior art employing a tube of
fine diameter as a passage.
[0132] As described above, a liquid discharge regulator includes
one or more passage forming members housed in a casing having
liquid inlet and outlet parts. A liquid is introduced from the
inlet part to the outlet part via a passage formed by the casing
and the passage forming member, thereby regulating the discharge of
the liquid flowing through the outlet part. The surface of the
passage forming member is formed with a channel, which functions as
a liquid passage. The channel can be readily formed with high
precision in accordance with the design by the recent machining
technique. Accurate setting of the pipe loss to be formed by the
channel is attainable only by designing its sectional form and
length appropriately. Hence, the passage of a desired pipe loss can
be obtained without repeating a sequence of steps of: measurement;
inspection; and then correction, in order to set a pipe loss as has
been conventional.
[0133] The channel may be formed windingly to have a length
sufficiently longer than the whole length of the passage forming
member. This permits a longer channel and ensures a pipe loss
suitable for liquid discharge regulation.
[0134] The passage forming member may be of a columnar shape, and
its peripheral surface may have a channel in spiral form.
[0135] There may be provided a plurality of liquid passages by
disposing a plurality of housing parts to house a passage forming
member in the casing and housing a plurality of liquid forming
members of different pipe losses in their respective housing parts,
as well as a passage switching means to control switching of the
liquid passages, such that the discharge of liquid flowing through
the outlet part is regulatable by selectively switching the liquid
passages with the passage switching means.
[0136] A plural-stage regulation of the discharge of liquid flowing
through the outlet part is attained by virtue of the plurality of
liquid passages which are obtained by disposing the plurality of
housing parts to house the passage forming member in the casing and
confining the plurality of passage forming members of different
pipe losses in their respective housing parts, as well as the
passage switching means to control switching of the passages.
[0137] The passage switching means may be disposed, for example,
between the housing part and the inlet part or the outlet part.
[0138] There may be disposed a bypass passage which provides
communication between the inlet part and the outlet part in the
casing, and a bypass passage switching means to control switching
of the bypass passage, such that when the bypass passage is opened,
a liquid flows through the outlet part in an amount sufficiently
greater than the flow rate of the passage formed by the passage
forming member.
[0139] Thanks to the bypass passage providing communication between
the inlet and outlet parts in the casing and the bypass passage
switching means to control switching of the bypass passage, when
the bypass passage is opened, a liquid flows through the outlet
part in an amount sufficiently greater than the flow rate of the
passage formed by the passage forming member. This permits a sharp
increase in the liquid discharge in response to the change of the
patient's condition and the efficacy of chemical liquids.
[0140] The passage forming member may be constructed such that it
is movable relative to the housing part and the position of the
channel opposite one of the inlet and outlet parts can be changed
by relative movement of the passage forming member. With this
construction, the pipe loss of the passage can be changed by
correcting the length of the channel from the aforesaid opposite
position to the other, namely the length of the passage. The
discharge of liquid flowing through the outlet part can be changed
continuously by virtue of the arrangement that the position of the
channel opposite one of the inlet and outlet parts is changed by a
relative movement of the passage forming member with respect to the
housing part, and the pipe loss of the passage is changed by
correction of the length of the channel from the opposed position
to the other, namely the length of the passage.
[0141] The bypass passage providing communication between the inlet
and outlet part is disposed in the casing and the bypass passage is
subjected to switching control according to the relative position
of the passage forming member to the housing member, whereby, when
the bypass passage is opened, a liquid flows through the outlet
part in an amount sufficiently greater than the flow rate of the
passage formed by the passage forming member.
[0142] Thanks to the arrangement that the bypass passage providing
communication between the inlet and outlet parts is disposed in the
casing and the bypass passage is subjected to switching control
according to the relative position of the passage forming member to
the housing member, when the bypass passage is opened, a liquid
flows from the outlet part in an amount sufficiently greater than
the flow rate of the passage formed by the passage forming member.
This permits a sharp increase in the liquid discharge in response
to the change of the patient's condition and the efficacy of
chemical liquids.
[0143] The passage forming member may be of a hollow columnar
shape, and a hollow region may serve as a bypass passage.
[0144] There may be provided, in the passage forming member, a
regulation region which closes one of the inlet and outlet parts to
regulate liquid communication from the inlet part to the outlet
part. In this construction, the outflow of liquid can be stopped by
the regulation region.
[0145] The diameter of the liquid passage from the inlet part to
the channel may become smaller as approaching from the inlet part
to the channel. When a liquid, e.g., physiological salt solution,
is allowed to flow, a sharp reduction in passage diameter might
cause the problem that part of the liquid is liable to crystallize
at discontinuous portions of the passage diameter and the passage
becomes clogged by crystalline. It is, however, possible to prevent
such a crystallization by gradually reducing the diameter of a
passage according to the invention.
[0146] The feature that the diameter of the liquid passage from the
inlet part to the channel becomes smaller as it approaches from the
inlet part to the channel is effective in preventing a portion of
liquid from being crystallized, thus free from a clogging of the
passage.
[0147] The passage forming member may be made of plastic, and its
manufacture by means of injection molding facilitates accurate
formation of the sectional form and length of the channel.
[0148] A liquid feeder with which liquid stored in a main body of
the feeder is delivered outside through an outlet of an output part
disposed on the distal end of the main body, incorporates, in the
outlet part, a discharge regulation section which introduces a
liquid from the interior of the main body to the outlet and
regulates the discharge of the liquid flowing to the outlet.
[0149] The discharge regulation section disposed in the outlet part
of the liquid feeder introduces a liquid from the interior of the
feeder to the outlet and also regulates the discharge of the liquid
flowing through the outlet. Thus, compared to the conventional
cases where a liquid feeder and a discharge regulator are provided
separately and independently and both are connected together by a
tube, the liquid feeder has a simplified arrangement for liquid
injection to the patient and also lowers the cost of manufacture.
In addition, the liquid feeder eliminates the need for work which
has been essential for liquid injection, namely the work of
connecting a liquid feeder and a discharge regulator by using a
tube or the like, thus increasing the operating performance of
liquid injection.
[0150] The above discharge regulation section may be constituted by
any one of liquid discharge regulators as set forth above.
Accordingly, the effect obtained by the discharge regulator is
attained in addition to the effect obtained by the liquid
feeder.
[0151] Although the present invention has been fully described by
way of example with reference to the accompanying drawings, it is
to be understood that various changes and modifications will be
apparent to those skilled in the art. Therefore, unless otherwise
such changes and modifications depart from the scope of the present
invention, they should be construed as being included therein.
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