U.S. patent application number 16/002314 was filed with the patent office on 2018-10-04 for movable low temperature workbench.
This patent application is currently assigned to JCR PHARMACEUTICALS CO., LTD.. The applicant listed for this patent is JCR PHARMACEUTICALS CO., LTD.. Invention is credited to Minoru FUJII.
Application Number | 20180283762 16/002314 |
Document ID | / |
Family ID | 59013265 |
Filed Date | 2018-10-04 |
United States Patent
Application |
20180283762 |
Kind Code |
A1 |
FUJII; Minoru |
October 4, 2018 |
MOVABLE LOW TEMPERATURE WORKBENCH
Abstract
A movable workbench for performing work under low temperature,
such as -80.degree. C. or below. The movable workbench includes: a
worktable including a workspace forming member for providing a
workspace for work at low temperature and a refrigerant-reservoir
for containing a refrigerant, and disposed on a base with a moving
member; the workspace forming member including side and bottom
walls providing a workspace with an upper surface opening; the
upper surface of the workspace being open on the upper side of the
worktable; the refrigerant-reservoir accommodating the bottom wall
of the workspace forming member so that a gas phase in the
workspace is cooled when the refrigerant is provided in the
refrigerant-reservoir and the bottom wall of the workspace forming
member is subsequently cooled; and the moving member disposed on a
bottom surface of the base so that the worktable is movable with
the refrigerant-reservoir filled with the refrigerant.
Inventors: |
FUJII; Minoru; (Kobe-shi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
JCR PHARMACEUTICALS CO., LTD. |
Ashiya-shi |
|
JP |
|
|
Assignee: |
JCR PHARMACEUTICALS CO.,
LTD.
Ashiya-shi
JP
|
Family ID: |
59013265 |
Appl. No.: |
16/002314 |
Filed: |
June 7, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/JP2016/086319 |
Dec 7, 2016 |
|
|
|
16002314 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F25D 23/065 20130101;
F25D 3/105 20130101; F25D 3/10 20130101; F25D 2700/12 20130101;
B25H 1/20 20130101; F25D 2400/38 20130101; F25D 11/00 20130101;
B25H 1/16 20130101 |
International
Class: |
F25D 3/10 20060101
F25D003/10; F25D 11/00 20060101 F25D011/00; F25D 23/06 20060101
F25D023/06 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 10, 2015 |
JP |
2015-241544 |
Jun 27, 2016 |
JP |
2016-126597 |
Claims
1. A movable workbench comprising: a worktable comprising a
workspace forming member configured for providing a workspace for
work at low temperature and a refrigerant-reservoir configured for
containing a refrigerant, wherein the worktable is disposed on a
base equipped with a moving member, wherein: the workspace forming
member comprises a side wall and a bottom wall configured to
provide a workspace with an upper surface opening, the upper
surface of the workspace is open on the upper side of the
worktable, the refrigerant-reservoir is configured to accommodate
the bottom wall of the workspace forming member so that a gas phase
in the workspace is cooled when the refrigerant is provided in the
refrigerant-reservoir and the bottom wall of the workspace forming
member is cooled, and the moving member is disposed on a bottom
surface of the base so that the worktable is movable with the
refrigerant-reservoir filled with the refrigerant.
2. The movable workbench according to claim 1, further comprising:
a temperature measuring member in the workspace, configured so that
the temperature of the workspace can be sensed during work under
low temperature, and a temperature display member configured to
display the temperature measured by the temperature measuring
member.
3. The movable workbench according to claim 2, further comprising:
a temperature recording member configured to record the temperature
measured by the temperature measuring member.
4. The movable workbench according to claim 1, wherein a side wall
and a bottom wall of the refrigerant-reservoir are heat-insulated
from the outside world by a heat insulating member.
5. The movable workbench according to claim 1, wherein the
refrigerant-reservoir is configured to contain liquid nitrogen.
6. The movable workbench according to claim 1, further comprising a
lid configured for closing an open upper surface of the
workspace.
7. The movable workbench according to claim 1, further comprising a
stopper configured for fixing the moving member so as to prevent
movement of the base.
8. The movable workbench according to claim 7, further comprising a
fastener interlocked with the stopper, wherein the fastener is
configured to lock the lid to the worktable in a state that the
open upper surface of the workspace is closed by the lid when the
fixation of the moving member by the stopper is released, and the
lock is configured to be released when the moving member is fixed
by the stopper.
9. The movable workbench according to claim 1, further comprising a
handle configured to be gripped by a worker.
10. The movable workbench according to claim 9, wherein handles are
provided on both a rear side and a front side of the workbench.
11. The movable workbench according to claim 2, further comprising
a warning generating member that is configured to issue a warning
when the temperature measured by the temperature measuring member
is out of a preset temperature.
12. The movable workbench according to claim 1, wherein the moving
member is a caster.
Description
TECHNICAL FIELD
[0001] The present invention relates to a movable workbench that
provides a workspace for work at a low temperature, more
specifically, relates to a movable workbench, wherein a worktable
having a workspace forming member for providing a workspace for
work under a low temperature and a refrigerant-reservoir for
containing a refrigerant is placed on a base equipped with moving
member, and wherein the workspace forming member has a side wall
and a bottom wall to provide a workspace with an open upper
surface, the upper surface of the workspace is opened on the upper
side of the worktable, the refrigerant-reservoir is inside the
worktable so as to receive the bottom wall of the workspace forming
member from the lower side and let the gas phase in the workspace
be cooled when the refrigerant is provided in the
refrigerant-reservoir, and the base is provided with a moving
member at the lower part so that the worktable can be moved with
the refrigerant-reservoir filled with the refrigerant.
BACKGROUND ART
[0002] Work at low temperature is generally carried out in a cold
room. In the case of work that does not require a large space, a
cold insulation box containing a refrigerant, ice, dry ice, or the
like is prepared to perform the work in this cold insulation
box.
[0003] A low temperature chamber has an advantage, making it
possible to secure a sufficient workspace and to perform work under
sufficient temperature control when performing the work at a low
temperature.
[0004] However, the installation of the low temperature chamber
accompanies a large economic burden, and the temperature in the low
temperature chamber is limited to greater than about -50.degree. C.
during the work, if the worker's safety is taken into account.
Therefore it is difficult to operate the work in the low
temperature chamber, for example, at -80.degree. C. or below.
[0005] Although the cold insulation box has an advantage that the
work place can be relocated when performing the work at a low
temperature, making it difficult to work under sufficient
temperature control and limiting the workspace.
[0006] Even if dry ice is used as a refrigerant, it is difficult to
work at a low temperature such as -80.degree. C. or below using the
cold insulation box because the sublimation temperature of dry ice
is -79.degree. C.
[0007] A low temperature workbench for processing food at a low
temperature, which is kept at a low temperature by the cold air
ventilated from the cooling device on the workbench, has been known
(Patent Document 1).
[0008] This workbench is a fixed type, therefore the work place
can't be changed. And it is not applicable to the work to be
operated at low temperature such as -80.degree. C. or below.
PRIOR ART DOCUMENTS
Patent Documents
[0009] [Patent Document 1] Japanese Patent Application Publication
No. H11-235150
SUMMARY OF INVENTION
Problem to be Solved by Invention
[0010] The objective of the present invention is to provide a
movable workbench making it possible to perform work under low
temperature, for example, such as -80.degree. C. or below, with the
work place changed.
Means to Solve the Problem
[0011] As a result of intense studies addressed to the above
objective, the present inventors succeeded in developing a movable
workbench having a structure in which a worktable having a
workspace forming member for providing a workspace with an open
upper surface, and a refrigerant-reservoir placed to cool the
workspace from the bottom side are placed on a base equipped with
moving member to make it possible to carry out work while the work
place is changed. Thus the present invention includes the
following:
[0012] 1. A movable workbench comprising: [0013] a worktable
comprising a workspace forming member for providing a workspace for
work at low temperature and a refrigerant-reservoir for containing
a refrigerant, and disposed on a base equipped with a moving
member, [0014] the workspace forming member comprising a side wall
and a bottom wall so as to provide a workspace with an upper
surface opening, [0015] the upper surface of the workspace being
open on the upper side of the worktable, [0016] the
refrigerant-reservoir accommodating the bottom wall of the
workspace forming member so that a gas phase in the workspace is
cooled when the refrigerant is provided in the
refrigerant-reservoir and the bottom wall of the workspace forming
member is cooled, and [0017] the moving member disposed on a bottom
surface of the base so that the worktable is movable with the
refrigerant-reservoir filled with the refrigerant.
[0018] 2. The movable workbench according to 1 above further
comprising: [0019] a temperature measuring member in the workspace
so that the temperature of the workspace can be sensed during the
work under low temperature, and [0020] a temperature display member
to display the temperature measured by the temperature measuring
member.
[0021] 3. The movable workbench according to 1 or 2 above, further
comprising: [0022] a temperature recording member functioning to
record the temperature measured by the temperature measuring
member.
[0023] 4. The movable workbench according to any one of 1 to 3
above, wherein a side wall and a bottom wall of the
refrigerant-reservoir is heat-insulated from the outside world by a
heat insulating member.
[0024] 5. The movable workbench according to any one of 1 to 4
above, wherein the refrigerant contained in the
refrigerant-reservoir is liquid nitrogen.
[0025] 6. The movable workbench according to any one of 1 to 5
above, wherein a lid is further provided for closing an open upper
surface of the workspace.
[0026] 7. The movable workbench according to any one of 1 to 6
above, wherein a stopper is provided for fixing the moving member
so as to prevent movement of the base.
[0027] 8. The movable workbench according to 7 above further
comprising a fastener interlocked with the stopper, [0028] wherein
the fastener is capable of locking the lid to the worktable in a
state that the open upper surface of the workspace is closed by the
lid when the fixation of the moving member by the stopper is
released, and the lock is to be released when the moving member is
fixed by the stopper.
[0029] 9. The movable workbench according to any one of 1 to 8
above, wherein a handle to be gripped by a worker is further
provided.
[0030] 10. The movable workbench according to 9 above, wherein
handles are provided on both a rear side and a front side
thereof.
[0031] 11. The movable workbench according to any one of 1 to 10
above, wherein a warning generating member is further provided so
that the warning generating member is capable of issuing a warning
when the temperature measured by the temperature measuring member
is out of a preset temperature.
[0032] 12. The movable workbench according to any one of 1 to 11
above, wherein the moving member is a caster.
[0033] 13. A movable workbench comprising: [0034] a worktable 2
comprising a workspace forming member 4 for providing a workspace 5
for work at low temperature and a refrigerant-reservoir 6 for
containing a refrigerant, and disposed on a base 3 equipped with a
moving member 15, [0035] the workspace forming member 4 comprising
a side wall and a bottom wall so as to provide a workspace 5 with
an upper surface opening, [0036] the upper surface of the workspace
5 being open on upper side of the worktable 2 [0037] the
refrigerant-reservoir 6 accommodating the bottom wall of the
workspace forming member 4 so that a gas phase in the workspace 5
is cooled when the refrigerant is provided in the
refrigerant-reservoir 6 and the bottom wall of the workspace
forming member 4 is subsequently cooled, and [0038] the moving
member 15 disposed on a bottom surface of the base 3 so that the
worktable 2 is movable with the refrigerant-reservoir 3 filled with
the refrigerant.
Effect of Invention
[0039] The present invention enables to carry out work under low
temperature, for example, at -80.degree. C. or below with the work
place changed.
BRIEF DESCRIPTION OF DRAWINGS
[0040] FIG. 1 illustrates an external side view of a movable
workbench of example 1.
[0041] FIG. 2 illustrates an external front view of a movable
workbench of example 1.
[0042] FIG. 3 illustrates an external top view of a movable
workbench of example 1.
[0043] FIG. 4 illustrates a partial cross-sectional view of a
movable workbench of example 1 in a plane perpendicular to the
longitudinal centerline, in a state that a workspace is closed by a
lid. In the figure, casing 7, workspace 5, liquid nitrogen 10, and
gap 11 are shown as cross-sectional views, except lid 12, workspace
forming member 4, refrigerant-reservoir 6, heat insulating member
8, duct 9, and legs 7c.
[0044] FIG. 5 illustrates a partial cross-sectional view of a
movable workbench of example 1 in a plane perpendicular to the
lateral centerline, in a state that a workspace is closed by a lid.
In the figure, casing 7, workspace 5, liquid nitrogen 10, and gap
11 are shown as cross-sectional views, except lid 12, workspace
forming member 4, refrigerant-reservoir 6, heat insulating member
8, duct 9, and legs 7c.
MODE FOR CARRYING OUT THE INVENTION
[0045] In the present invention, the term "a workspace for work at
a low temperature" means a space filled with a gas phase lower than
the outside air to carry out work in a low temperature environment
cooler than the outside air. In most cases, the gas phase is air,
or a mixture of air and a vaporized refrigerant contained in a
refrigerant-reservoir. In the present invention, the term "low
temperature" means a temperature of approximately -51.degree. C. or
below, and in the case of using liquid nitrogen (boiling point:
196.degree. C.) as a refrigerant, means a temperature of roughly
-100.degree. C. or below, for example, -120.degree. C. or below,
-130.degree. C. or below. The temperature range is adjusted
depending on the nature of the work, for example, at -51 to
-200.degree. C., at -80 to -200.degree. C., at -100.degree. C. to
-180.degree. C., at -120.degree. C. to -180.degree. C., at
-130.degree. C. to -180.degree. C., at -130.degree. C. to
-185.degree. C., or the like as desired.
[0046] The workspace is provided on the upper side of a worktable
as a concave space whose upper surface is open so that workers can
easily work. As the specific gravity of a gas phase cooled to a
temperature lower than outside air becomes greater than that of the
outside air, the cooled gas phase remains in this concave space,
resulting in the workspace kept at a low temperature. The workspace
is substantially a rectangular space delimited by a workspace
forming member having a side wall and a bottom wall and an open
upper surface. The workspace forming member is preferably formed
using a material that maintains its strength even at a low
temperature lower than -100.degree. C., for example, a stainless
steel material, a titanium alloy, or the like. The stainless steel
material and the titanium alloy are also suitable as materials for
preventing rust due to dew condensation caused by temperature
change. Materials whose surfaces are rustproofed by fluorine
processing or the like are also suitable as a material for forming
the workspace forming member.
[0047] A refrigerant-reservoir is provided below the bottom wall of
the workspace forming member so as to receive the bottom wall from
the lower side. The refrigerant-reservoir is disposed such that
when the refrigerant is provided therein, the bottom wall and the
side wall of the workspace forming member are cooled so that the
gas phase (air) in the workspace is to be cooled to a desired low
temperature. The refrigerant-reservoir may be substantially formed
by a side wall and a bottom wall, and the upper side may be opened.
In the same way as the workspace forming member, the
refrigerant-reservoir is preferably formed using a material that
maintains strength even at a low temperature close to -100.degree.
C. and does not rust.
[0048] As the refrigerant-reservoir is disposed below the bottom
wall of the workspace forming member so as to substantially receive
the bottom wall from the lower side, a gap is generated between the
surface of the refrigerant and the bottom wall of the workspace
forming member. When the refrigerant is provided in the
refrigerant-reservoir, the bottom wall and the side wall of the
workspace forming member are cooled by the refrigerant. In
addition, since the gap is filled with the vaporized refrigerant,
the bottom wall and the side wall of the workspace forming member
are also cooled by this evaporated refrigerant. By cooling the
workspace forming member, the air in the workspace is also cooled.
By immersing the bottom wall (and additionally the side wall) of
the workspace forming member in the refrigerant, it is possible to
cool the gas phase (air) in the workspace more efficiently. As the
cooled gas phase (air) has a higher specific gravity than that of
the outside air, it is kept in the concave workspace, and as a
result, the air in the workspace is cooled more and more.
[0049] A ventilation hole may be provided in the side wall and/or
the bottom wall of the workspace forming member so that a low
temperature gas phase accumulated in the gap between the surface of
the refrigerant and the workspace forming member can flow into the
workspace through the ventilation hole. By influx of the low
temperature gas phase from the ventilation hole, the gas phase in
the workspace may be efficiently cooled.
[0050] Though there is no particular limitation as to the
refrigerant provided in the refrigerant-reservoir, examples include
liquid nitrogen, and ethanol to which dry ice is added. When liquid
nitrogen is provided as a refrigerant, the temperature in the
workspace can be cooled down at -160.degree. C. or below, for
example, -180.degree. C. or below, which make it possible to carry
out work continuously for a long time at low temperatures such as
-130.degree. C. or below, -160.degree. C. or below, or the
like.
[0051] An inlet for injecting a refrigerant is provided in the
refrigerant-reservoir. There are no particular limitations as to
the shape, position, or the like of the inlet as long as the
refrigerant can be injected into the refrigerant-reservoir. The
open upper side of the refrigerant-reservoir may be used as the
inlet. A duct that leads into the refrigerant-reservoir and
penetrates to the outside of the worktable may be provided and the
outside opening of this duct may be used as the inlet for the
refrigerant. In the case where the opening on the outside of the
duct is used as the inlet, this inlet can serve as an outlet for
the vaporized refrigerant. Further, an openable and closable lid
may be provided at the inlet to prevent evaporation of the
refrigerant from the inlet by closing the lid except for the
operation time to inject the refrigerant.
[0052] When liquid nitrogen is provided in the
refrigerant-reservoir as a refrigerant, the liquid nitrogen is
warmed by the outside air and vaporized. When the amount of liquid
nitrogen decreases to a certain amount or less due to vaporization,
it becomes difficult to keep the gas phase (air) in the workspace
at low temperature. Therefore, in order to keep the gas phase (air)
in the workspace at a low temperature for a long time, it is
preferable to insulate the refrigerant-reservoir from the outside.
At this time, it is preferable that the workspace forming member is
simultaneously insulated from the outside.
[0053] The insulation of the refrigerant-reservoir and the
workspace forming member from the outside is achieved by disposing
a heat insulating material between the outside of the worktable,
and the side and bottom walls of the refrigerant-reservoir and the
side wall of the workspace forming member. There are no particular
limitations as to the heat insulating materials applicable as the
material of the heat insulating member, but foamed plastic such as
polystyrene foam is preferably used as a heat insulating
member.
[0054] The heat insulating member is disposed, for example, so as
to fill a gap formed by the refrigerant-reservoir and the casing
when the refrigerant-reservoir is housed in the casing. In this
case, it is preferable that the heat insulating member is fixed to
the refrigerant-reservoir so as to cover the outside of the side
wall and the bottom wall of the refrigerant-reservoir, or fixed to
the casing so as to cover the inside wall surface of the casing
accommodating the refrigerant-reservoir. Though, the heat
insulating member may not be fixed to any of them. In addition, it
is possible to provide the casing with a function as a heat
insulating member by forming a casing with a member having a cavity
and made of stainless steel, titanium, or the like, and
accommodating a heat insulating material in this cavity. Likewise,
the refrigerant-reservoir may be provided with a function as a heat
insulating member.
[0055] The heat insulating member may be made of stainless steel,
titanium, or the like, and have a cavity filled with air or
depressurized to near vacuum. Here, a gas in the cavity or a cavity
itself acts as a heat insulating member. In this case, it is
possible to provide the casing with a function as a heat insulating
member by forming a casing with a member having a cavity filled
with air or depressurized to near vacuum, and made of stainless
steel, titanium, or the like. Likewise, the refrigerant-reservoir
may have a function as a heat insulating member. A stainless steel
member having a cavity depressurized to near vacuum is particularly
suitable as a heat insulating member for insulating the
refrigerant-reservoir from the outside. In the present invention,
the term "heat insulation" means a reduction in heat transfer or
thermal conduction by the physical and chemical properties of the
heat insulating material.
[0056] In the present invention, the workspace forming member and
the refrigerant-reservoir, integrated together to form a worktable,
are mounted on a base having a moving member, so as to be movable
in a state that the refrigerant-reservoir is filled with a
refrigerant. A caster can may preferably used as the moving
member.
[0057] The workspace forming member and the refrigerant-reservoir
are, for example, mounted on a base having a moving member and
accommodated in the casing, integrated together to form a
worktable, so that the refrigerant-reservoir substantially receives
the workspace forming member from the bottom. When a duct is
installed, this duct penetrates the heat insulating member and the
casing (or the casing integrated with the heat insulating member)
and connects the outside of the worktable and the
refrigerant-reservoir.
[0058] When mounting the worktable on the base having the moving
member, the worktable is fixed to the base with a fastener to
prevent it from falling from the base. However, the base and the
worktable may be integrally formed. For example, the casing of the
worktable may be formed integrally with the base, and the workspace
forming member and the refrigerant-reservoir may be accommodated in
the casing. Even when the base and the casing are integrally formed
as such, by regarding the casing integrated with the base as a part
of the worktable, that may be considered as a movable workbench as
a whole, wherein the worktable is mounted on the base having a
moving member.
[0059] The movable workbench of the present invention is the
workbench for work at a low temperature. Therefore, it is
preferable that it can be confirmed that the workspace is kept at
low temperature while working at low temperature. For this reason
it is preferable to dispose a temperature measuring member in the
workspace so that the temperature of the workspace can be sensed.
By displaying the temperature measured by the temperature measuring
member on the temperature display member, a worker can perform work
while checking the temperature displayed on the temperature display
member. In order to manage the working process, it may be required
to record the temperature measured by the temperature measuring
member. Therefore, a temperature recording member incorporating a
memory for recording the temperature measured by the temperature
measuring member may be provided. By providing the temperature
recording member, the measured temperature can be recorded over
time.
[0060] On the movable workbench, a warning generating member may be
further provided so as to be capable of issuing a warning when a
temperature measured by the temperature measuring member rises
above a preset temperature so that the work can reliably be
performed at a low temperature. For example, in the case that work
to be operated at -130.degree. C. or below is performed, if the
warning generating member is set so as to give a warning when the
temperature exceeds -135.degree. C., the warned worker can suspend
the work and wait until the temperature of the workspace
sufficiently declines. In this way, it is possible to avoid
performing work at the temperature not lower than the preset
temperature. In the case that the movable workbench has a lid, by
closing the lid during the suspension of the work, it is possible
to reliably suppress the temperature of the workspace from
exceeding the set temperature and to efficiently cool the
workspace. The warning can be performed by means such as a visual
display, a light emission signal, and/or a sound output, but a
buzzer sound is effective.
[0061] The movable workbench of the present invention is intended
to be used by accommodating an extremely low temperature
refrigerant such as liquid nitrogen. Therefore, it is preferable to
dispose a member for securing worker's safety on the movable
workbench. As a member for ensuring such safety, for example, a
stopper capable of fixing the moving member may be provided so as
to prevent unintended movement of the movable workbench during the
worker is working. Such a stopper is preferably the kind that is
easy for a worker to operate. When the moving member is a caster, a
preferable example is a foot brake. In addition, in the case that
the movable workbench has a handle for a worker to grasp, a grip
portion for operating the stopper may be provided on the handle so
that the stopper can be operated by hand. The grip portion is
interlocked with the stopper by a wire, and when the wire is pulled
upward by grasping the grip portion, the stopper is moved to a
position where the stopper can fix the caster. The grip portion is
locked by a fastener at a position where the wire is kept to be
pulled upward, and the work is performed in this state. When moving
the movable workbench, by releasing this lock and returning the
grip portion to the original position, the stopper moves to a
position where the stopper releases the caster.
[0062] A lid for closing an open upper surface of the workspace may
be provided on the movable workbench so that the temperature of the
gas phase in the workspace is kept low on the move. As it is
possible that the gas phase and the outside air in the workspace
have been mixed resulting in a rise of temperature in the workspace
upon moving the movable workbench, by closing the upper surface of
the workspace with the lid, such a rise of temperature in the
workspace can be prevented. In addition, when the work is
temporarily interrupted during the work, it is possible to reliably
keep the workspace at the low temperature by closing the lid and
efficiently cool the temperature in the workspace that has been
raised during the work.
[0063] In the case where a lid is provided on the movable
workbench, it is possible to prevent the worker from operating the
work while forgetting to fix the moving member by employing a
configuration in which the lid can be opened only when the moving
member is fixed by the stopper, thus safety of the movable
workbench is further improved. For example, a fastener for a lid is
provided on a worktable or a base so that the lid is locked to the
worktable by this fastener not to be opened and closed when the
stopper is in a position to release the moving member, and the lid
is unlocked to the worktable to be opened and closed when the
stopper is in a position to fix the moving member.
[0064] The movable workbench of the present invention may be
provided with a handle to be gripped by the worker as described
above. When one handle is provided on the movable workbench, the
movable workbench has a shape resembling a handcart. At this time,
the side provided with the handle is referred to as the rear side,
and the opposite side as the front side. The handles may be
provided on both sides of the movable workbench. In this case, the
rear side and the front side are not distinguishable of the movable
workbench, but for convenience it is possible to distinguish
between the rear side and the front side. As the worker can grip
the handle and push the movable workbench by hands so that the
movable workbench can be moved to the place where the work is
carried out, the efficiency of the work increases.
[0065] A function to adjust the height of the worktable may be
added to the movable workbench according to the physique of the
worker, the type of work, or the like. Such a function is realized
by, for example, providing a leg-attached platform capable of
extending and contracting a leg on the upper side of the base,
mounting a worktable on the leg-attached platform, and placing a
jack in a gap between the lower surface of a base part of the
leg-attached platform and the base so that the jack supports the
lower surface of the base part of the leg-attached platform. By
manipulating the jack in the upward direction, the base part of the
leg-attached platform is pushed upward and moves, and the legs of
the leg-attached platform are extended, and accordingly the
worktable moves upward. When the jack is operated in the downward
direction, the base part of the leg-attached platform moves
downward due to the weight of the worktable and the legs of the
leg-attached platform contract, and accordingly the worktable moves
downward. By operating the jack in this way, the height of the
worktable can be adjusted by the worker as desired.
EXAMPLES
[0066] Although a movable workbench of the present invention is
described in further detail below with reference to examples, it is
not intended that the present invention be limited to those
examples.
Example 1
[0067] As shown in FIGS. 1 to 5, the movable workbench 1 of the
present embodiment is that in which the worktable 2 is mounted on
the base 3. The worktable 2 includes the workspace forming member 4
forming the workspace 5, a refrigerant-reservoir 6 containing a
refrigerant, and a casing 7 accommodating the workspace 5 and the
refrigerant-reservoir 6. The inside of the casing forms a
substantially rectangular parallelepiped space, and the inside of
the side wall and bottom wall of the casing 7 is covered with the
heat insulating member 8 made of foamed plastic. The upper side of
the casing 7 is open. In the casing 7, a refrigerant-reservoir 6 is
installed. The refrigerant-reservoir 6 has a substantially
rectangular parallelepiped shape and its upper side is open so that
the side wall and the bottom wall thereof are surrounded by the
heat insulating member 8 in close proximity, and a substantially
rectangular parallelepiped space for containing a refrigerant is
inside of it. In the casing 7, the workspace forming member 4 is
further installed. The workspace forming member 4 forms inside a
substantially rectangular parallelepiped space by the side wall and
the bottom wall whose upper surface is open. This space serves as
the workspace 5 for performing work at a low temperature. A flange
4a extends outward from the upper end of the side wall of the
workspace forming member 4. The flange 4a rests on the step 7a
provided on the inner side of the upper end of the side wall of the
casing and the end of the flange 4a is in contact with the side
wall of the casing 7. By this flange 4a, the workspace forming
member 4 is prevented from moving in the lateral direction in the
casing 7, and is supported to form a space between the bottom wall
of the workspace forming member 4 and the bottom wall of the
refrigerant-reservoir 6. The refrigerant is contained in this
space.
[0068] The duct 9 is installed so as to penetrate the casing 7, the
heat insulating member 8, and the refrigerant-reservoir 6. The duct
9 has openings at the outside of the casing 7 and the inside of the
refrigerant-reservoir 6. The opening of the duct provided 9 on the
outside of the casing 7 serves as an inlet for injecting the
refrigerant into the refrigerant-reservoir 6. The opening on the
outside of the casing 7 is placed at the position above the opening
of the inside of the refrigerant-reservoir 6 so that the
refrigerant flows into the refrigerant-reservoir 6 when the
refrigerant has been injected. When the liquid nitrogen is provided
in the refrigerant-reservoir 6 as the refrigerant, this duct also
functions as an outlet for vaporized liquid nitrogen.
[0069] FIGS. 4 and 5 show a state in which the liquid nitrogen 10
is contained as a refrigerant in the refrigerant-reservoir 6. The
liquid nitrogen 10 contained in the refrigerant-reservoir 6 cools
the bottom wall and the side wall of the workspace forming member 4
above the liquid surface. Further, the gap 11 between the
refrigerant-reservoir 6 and the workspace forming member 4 is
filled with the nitrogen gas vaporized from the liquid nitrogen.
Since nitrogen is vaporized at about -195.degree. C. under
atmospheric pressure, the bottom wall and the side wall of the
workspace forming member 4 are also cooled by this vaporized
nitrogen.
[0070] In FIGS. 1 to 5, the open upper surface of the workspace 5
is closed by the lid 12. In this state, the lower surface of the
edge of the lid 12 rests on the step 7a provided on the inner side
of the upper end of the side wall of the casing, and the end of the
lid 12 is in contact with the side wall of the casing 7, resulting
in that the lid 12 is prevented from moving in the horizontal
direction, and the workspace is shut off from the outside air. The
handle 12a is provided on the lid 12. The lid 12 is generally
closed when the movable workbench 1 is moved, because the gas phase
and the outside air in the workspace 5 possibly may mix and the
temperature in the workspace 5 may rise. When working in the
workspace 5, the worker grips the handle 12a and removes the lid 12
to open the upper surface of the workspace 5. When the temperature
in the workspace 5 rises above a predetermined temperature during
the work, the worker temporarily stops the work and closes the lid
12, then after confirming that the temperature of the inside of the
workspace 5 becomes lower than the predetermined temperature, the
lid 12 is removed and the work is resumed.
[0071] The legs 7c are disposed at the four corners of the bottom
plate 7b of the casing 7. in the present embodiment, the legs 7c
are regarded as a part of the casing 7. The legs 7c are fixed at
the lower end of them to the upper surface of the base 3 with
fasteners and the worktable 2 as a whole is fixed to the base 3
with these fasteners. The base 3 is a member having a substantially
rectangular shape, when watching from upper side. On the upper
surface of one side of the base, the vertical rods 13 extending
upwardly from the base in a substantially vertical direction are
provided near both ends thereof, and the horizontal bar 14 is
passed between the vertical bars 13. This horizontal bar is used as
a handle when a worker pushes and moves the movable workbench 1 by
hand. For convenience, the side on which the handle is provided is
referred to as the rear side of the movable workbench 1, and the
opposite side as the front side.
[0072] The caster 15 is provided as a moving member at the four
corners of the lower surface of the base 3. On the rear caster, the
foot brake 16 is provided as a stopper so that the caster can be
fixed. While working in the workspace 5 or the injecting
refrigerant into the refrigerant-reservoir 6, the caster 15 is
fixed by the foot brake 16 so that the movable workbench 1 does not
move unintentionally while working, resulting in the improvement of
the safety of the work.
[0073] The temperature measuring member 17 is provided in the
workspace 5, and the temperature measured by the temperature
measuring member is displayed on a liquid crystal screen of the
temperature display member 18 attached to the horizontal bar 14 of
the handle. In the temperature recording member 20, a memory
capable of recording the temperature measured by the temperature
measuring member 17 is incorporated. The recorded temperature can
be read out. Consequently, as it can be verified later on that the
performed work was carried out at the low temperature, the movable
workbench 1 is particularly suitable for work requiring process
control.
[0074] In addition, the warning generating member 19 that issues a
buzzer sound when the temperature measured by the temperature
measurement member 17 exceeds a predetermined temperature is
provided adjacent to the temperature display member 18.
[0075] Hereinafter, as an example of the work using the movable
workbench 1, work for handling frozen cells is presented. This
working step is a step for transferring frozen cells for medical
use stored in a freezing bag from a storeroom to a transport
vehicle.
[0076] At first, liquid nitrogen as a refrigerant is injected from
the opening of the movable workbench 1 into the
refrigerant-reservoir 6 while the lid 12 closed. In order to
prevent the movable workbench 1 from moving while liquid nitrogen
is injected, the caster 15 is fixed by the foot brake 16. After
completion of the injection of the liquid nitrogen, the foot brake
16 is released, and the movable workbench 1 is moved to the
vicinity of a cell storage container containing frozen cells with
the handle 14 grasped.
[0077] The caster 15 is fixed by the foot brake 16, and it is
confirmed whether the temperature displayed on the temperature
display member 18 is lower than a predetermined temperature or not.
After confirming that the displayed temperature is equal to or
lower than the predetermined temperature, the warning generating
member 19 is activated so that a buzzer sound is emitted when a
temperature equal to or higher than the predetermined temperature
is sensed by the temperature measuring member 17. Further, the
temperature recording member 20 is activated so that the
temperature during the work is recorded.
[0078] The lid 12 is removed, and the frozen cells contained in the
freezing bag are taken out from the cell storage container and
transferred to the workspace 5. After confirming the lot of frozen
cells and that the freezing bag is not broken in the workspace 5,
the lid 12 is closed. Then the foot brake 16 is released, the
movable workbench 1 is moved by pushing with the handle 14 grasped,
and brought alongside a carrier of a transport vehicle for
transporting frozen cells. The caster 15 is fixed by the foot brake
16, and the lid 12 is removed. The frozen cells are taken out from
the workspace 5, and the cells are transferred to a container for
transporting cells which has been cooled to a predetermined
temperature in advance.
[0079] If a buzzer sound is issued from the warning generating
member 19 during the work, the work is immediately interrupted and
the lid 12 is closed. And then the work is resumed when the
temperature in the workspace 5 becomes lower than the predetermined
temperature. After finishing the work, the temperature recorded in
the temperature recording member 20 is retrieved, and the record is
checked to confirm whether the work has been performed at the
predetermined temperature or below, and saved for management.
INDUSTRIAL APPLICABILITY
[0080] According to the present invention, a workbench can be
provided that makes it possible to accomplish work to be carried
out at a low temperature, for example, at -130.degree. C. or below,
while changing the work place. Work that needs such low
temperatures includes, for example, work to handle frozen cells for
medical use.
REFERENCE SIGNS LIST
[0081] 1 movable workbench [0082] 2 worktable [0083] 3 base [0084]
4 workspace forming member [0085] 4a flange [0086] 5 workspace
[0087] 6 refrigerant-reservoir [0088] 7 casing [0089] 7a step
[0090] 7b bottom plate [0091] 7c leg [0092] 8 heat insulating
member [0093] 9 duct [0094] 10 liquid nitrogen [0095] 11 gap [0096]
12 lid [0097] 12a handle [0098] 13 vertical bar [0099] 14
horizontal bar (handle) [0100] 15 moving member (caster) [0101] 16
foot brake [0102] 17 temperature measuring member [0103] 18
temperature display member [0104] 19 warning generating member
[0105] 20 temperature recording member
* * * * *