BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to a low-temperature storage according to the preamble
of independent claim 1.
Description of the Related Art
[0002] Such a low-temperature storage is known from
JP 2010 025471 A considered as the closest prior art for the present invention.
[0003] In a low-temperature storage to be used for storage of frozen goods, etc., or cold
preservation of biological tissues and specimens, etc., air inside the storage is
cooled, thereby occasionally bringing about a negative pressure state where atmospheric
pressure inside the storage is lower than the atmospheric pressure outside the storage.
Since the negative pressure state inside the storage makes it difficult to open a
door of the low-temperature storage, the low-temperature storage is generally provided
with a pressure adjusting device to resolve the negative pressure state inside the
storage (e.g.,
JP 2010 025471 A).
[0004] In
JP 2010 025471 A, a user removes a plug for closing a port for in flow of the air outside the low-temperature
storage into the storage, thereby resolving the negative pressure state inside the
storage. The user occasionally drops the plug, when removing the plug for closing
the port. In such a case, depending on the installing location, structure, etc., of
the low-temperature storage, it occasionally becomes burdensome for the user to pick
up the dropped plug and close the port with the plug again.
[0005] Moreover,
US 4 986 502 A describes a drain plug with a threaded shank to be screwed into a threaded hole of
a pressurized vessel. A groove or recess is formed on the outer periphery of threaded
shank and extends generally, axially along and parallel to central axis of the shank.
Upon partial unscrewing of the plug from within the hole, the pressurized gas or fluid
will flow outwardly through the groove or recess, thereby alerting the operator of
the residual pressure within the pressurized system.
SUMMARY OF THE INVENTION
[0006] A low-temperature storage according to the present invention comprises: a heat-insulating
housing including an opening face; a heat-insulating door configured to open or close
the opening face; a cooling device configured to cool an article stored inside the
heat-insulating housing; and a through-hole passing through a heat-insulating wall
included in the heat-insulating housing from an outer side of the storage to an inner
side thereof and having an internal thread formed on an inner periphery thereof. A
plug member is configured to open or close an opening portion of the through-hole
on the outer side of the storage, and includes an external thread configured to be
threadedly engaged with the internal thread and a flange member configured to abut
onto a face having the opening portion formed therein, by threaded engagement between
the external thread and the internal thread, the external thread having a plurality
of cuts formed in a portion of an outer periphery thereof, the cuts being equal in
shape and provided at regular intervals in the outer periphery of the external thread,
and being configured to open a part of the opening portion in a state where the flange
member does not abut on the face having the opening portion formed therein, while
the external thread is threadedly engaged with the internal thread.
[0007] Other features of the present invention will become apparent from descriptions of
this specification and of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] For more thorough understanding of the present invention and advantages thereof,
the following description should be read in conjunction with the accompanying drawings,
in which:
Fig. 1 is a perspective view illustrating a low-temperature storage 10 according to
one embodiment of the present invention;
Fig. 2 is a perspective view illustrating a low-temperature storage 10 in a state
where heat-insulating doors 21 and 22 are open;
Fig. 3 is a plan view illustrating a low-temperature storage 10;
Fig. 4 is a diagram illustrating an exploded pressure adjusting device 30 and a portion
of a heat-insulating wall of a heat-insulating housing 20;
Fig. 5 is a diagram illustrating a state where members 60 and 61 are actually mounted
onto a heat-insulating wall of a heat-insulating housing 20;
Fig. 6 is a perspective view illustrating a plug member 62;
Fig. 7 is a side view illustrating a plug member 62;
Fig. 8 is a cross-sectional illustrating a pressure adjusting device 30 in a state
where a through-hole 80 is closed; and
Fig. 9 is a cross-sectional view illustrating a pressure adjusting device 30 in a
state where a through-hole 80 is open.
DETAILED DESCRIPTION OF THE INVENTION
[0009] At least the following details will become apparent from descriptions of this specification
and of the accompanying drawings.
[0010] An outline will now be described of a low-temperature storage 10 according to one
embodiment of the present invention with reference to Figs. 1 and 2. Fig. 1 is a perspective
view illustrating the low-temperature storage 10 in a state where a heat-insulating
door 21 is closed, and Fig. 2 is a perspective view illustrating the low-temperature
storage 10 in a state where heat-insulating doors 21 and 22 are open. Here, it is
assumed that an X-axis direction is a side-to-side direction relative to the low-temperature
storage 10, a Y-axis direction is an up- and-down direction relative to the low-temperature
storage 10, and a Z-axis direction is a fore-and-aft direction relative to the low-temperature
storage 10.
[0011] The low-temperature storage 10 is configured to store frozen goods, etc., or preserve
biological tissues, etc., in an ultralow temperature range lower than or equal to
-85°C, for example, and includes a heat-insulating housing 20 including an opening
face at the front thereof (+Z side).
[0012] The heat-insulating doors 21 and 22 configured to open or close the opening face
at the front are provided on the opening face at the front of the heat-insulating
housing 20, and a cooling device 23 configured to cool an inside of the storage is
provided on the lower side (-Y side) of the heat-insulating housing 20. A pressure
adjusting device 30 configured to resolve a negative pressure state inside the storage
is provided on a side surface on the left-hand side (-X side) of the heat-insulating
housing 20.
[0013] The heat-insulating door 21 is a so-called outer door and is provided with a control
panel 31 that is configured to perform setting of the temperature inside the storage,
and the like. A handle 32 configured to open and close the heat-insulating door 21
is provided at the left edge of the heat-insulating door 21. A lock member 33, which
is configured to fix the heat-insulating door 21 together with the handle 32 when
the heat-insulating door 21 is closed, is provided on the side surface on the left-hand
side of the heat-insulating housing 20. The heat-insulating door 22, which is configured
to enhance the heat-insulating properties inside the storage, is provided inside the
heat-insulating door 21 as an inner door.
[0014] Fig. 3 is a plan view illustrating the low-temperature storage 10. The heat-insulating
housing 20 includes a metallic inner case 40, a metallic outer case 41 provided such
that the inner case 40 is covered, and a heat-insulating material 42 filled between
the inner case 40 and the outer case 41 so as to enhance the heat-insulating properties,
for example. The inner case 40 and the outer case 41 have an opening face, at the
front, so that the frozen goods, etc are taken out and put in.
[0015] The heat-insulating door 21 is a metallic door whose inside is filled with a heat-insulating
material 45. Packing 46, which is configured to enhance airtightness inside the storage
when the heat-insulating door 21 is closed, is provided at the inner periphery of
the heat-insulating door 21. The low-temperature storage 10 becomes in a hermetically-sealed
state when there is no air to enter and exit in the pressure adjusting device 30 while
the heat-insulating doors 21 and 22 are closed.
[0016] The pressure adjusting device 30 will be described in detail with reference to Fig.
4. Fig. 4 is a perspective view illustrating the exploded pressure adjusting device
30 and a portion of a heat-insulating wall of the heat-insulating housing 20 on which
the pressure adjusting device 30 is mounted.
[0017] A through-hole 50, which passes through the heat-insulating wall from the outside
of the storage to the inside thereof, is formed in the heat-insulating wall of the
heat-insulating housing 20 on which the pressure adjusting device 30 is mounted. The
pressure adjusting device 30 is inserted into the through-hole 50 and includes members
60 and 61 configured to form a path for the air outside the storage to flow into the
storage, and a plug member 62 configured to open or close the path for inflow of the
air.
[0018] The member 60 is a flanged tubular member to be inserted into the through-hole 50
from the inside of the storage, and includes a cylindrical member 70 with an external
thread formed on the outer periphery thereof and a flange member 71 that is integrally
formed on one end of the cylindrical member 70.
[0019] The member 61 is a flanged tubular member to be inserted into the through-hole 50
from the outside of the storage, and includes a cylindrical member 72 and a flange
member 73 that is integrally formed on one end of the cylindrical member 72. On the
inner periphery of the cylindrical member 72, such an internal thread is formed as
to be threadedly engaged with the external thread formed on the cylindrical member
70.
[0020] Fig. 5 is a diagram illustrating a state where the members 60 and 61 are actually
mounted onto the heat-insulating wall of the heat-insulating housing 20. By threaded
engagement between the external thread of the cylindrical member 70 and the internal
thread of the cylindrical member 72, the flange member 71 abuts onto the wall surface
of the inner case 40 from the inner side of the storage, and the flange member 73
abuts onto the wall surface of the outer case 41 from the outer side of the storage.
Thus, the flange members 71 and 73 are joined to each other in such a manner as to
press the heat-insulating wall of the heat-insulating housing 20 from both the inner
side and the outer side of the storage. A through-hole 80, which is configured to
pass through between the inner side of the storage and the outer side thereof, is
formed inside the cylindrical members 70 and 72 as the path for inflow of the air.
[0021] The plug member 62 is a member configured to open or close an opening portion 81
of the through-hole 80 on the outer side of the storage, and includes an external
thread 75, a knob 76, and packing 77 as shown in Fig. 6. The knob 76 and the packing
77 correspond to a flange member. Fig. 6 is a perspective view illustrating the plug
member 62 and Fig. 7 is a side view illustrating the plug member 62.
[0022] As shown in Fig. 4, the external thread 75 is a column thread configured to be threadedly
engaged with the internal thread of the cylindrical member 72. On the outer periphery
of the external thread 75, a plurality of cuts 100a to 100d are formed along the direction
of the threaded engagement of the external thread 75. A length of the cuts 100a to
100d is substantially equal to a length d of the external thread 75 shown in Fig.
7. Therefore, the cuts 100a to 100d are formed over the entire length of the external
thread 75 in the threaded engagement direction. In an embodiment of the present invention,
the external thread 75 is formed such that the cuts 100a to 100d, which are equal
in shape, are provided at regular intervals in the outer periphery of the external
thread 75.
[0023] The knob 76 is formed at one end of the external thread 75 integrally therewith,
and is in a columnar shape with a diameter greater than that of the external thread
75, for example. The packing 77 is pasted to a face of the knob 76 on the external
thread 75 side, along the outer circumference of the external thread 75.
[0024] With the external thread 75 being threadedly-engaged with and screwed into the internal
thread of the cylindrical member 72, the packing 77 abuts onto a face around an opening
of the flange member 73 (the face having the opening portion 81 formed therein). Therefore,
as shown in Fig. 8, the plug member 62 securely closes the through-hole 80, which
prevents the cool air from leaking from the inside of the storage to the outside thereof.
Fig. 8 is a cross-sectional view illustrating the pressure adjusting device 30 in
a state where the through-hole 80 is closed (cross-sectional view of the cross section
along a line A-B of Fig. 3, when viewed in the -Z direction). Herein, only the cut
100a out of the cuts 100a to 100d in the external thread 75 is illustrated for easy
understanding of cross-sectional structure of the pressure adjusting device 30.
[0025] Fig. 9 is a cross-sectional view of the pressure adjusting device 30 in a state where
the through-hole 80 is open. Fig. 9, similarly to Fig. 8, is a cross-sectional view
of the cross section along the line A-B of Fig. 3, when viewed in the -Z direction.
When the plug member 62 is rotated to loosen the external thread 75, the packing 77
is brought to a state where it does not abut on the face around the opening of the
flange member 73. In a state where the external thread 75 is loosened, a part of the
external thread 75 is threadedly engaged with the internal thread of the cylindrical
member 72. In such a state, there is nothing blocking a space between the cut 100a
and a part of the opening portion 81, for example. Thus, for example, when the inside
of the storage is in a negative pressure state, loosening of the external thread 75
enables an inflow of the air outside the storage into the storage. That is to say,
the negative pressure state can be resolved by loosening the external thread 75.
[0026] Hereinabove, a description has been given of the low-temperature storage 10 according
to an embodiment of the present invention. Since the external thread 75 of the plug
member 62 has the cuts 100a to 100d formed therein, the negative pressure state inside
the storage is resolved without the plug member 62 being removed, in an embodiment
of the present invention. As a result, the possibility is decreased that the plug
member 62 is dropped when the negative pressure state is to be resolved, thereby being
able to reduce the burden of the user. Furthermore, for example, in a case where the
user has the low-temperature storage capable of resolving the negative pressure using
the plug member without cuts, if only the plug member 62 with the cuts is newly provided,
a similar effect to that in an embodiment of the present invention can be achieved
without any special work, etc.
[0027] For example, in place of the external thread 75, an external thread with the cuts
provided in a cylindrical member can also be used. The external thread with the cuts
provided in a cylindrical member, however, might have component strength, as the external
thread, lowered since the inside of the cylindrical member is hollow. In a case of
the external thread 75, the column member is used instead of the cylindrical member,
thereby being able to enhance the component strength of the external thread 75.
[0028] For example, even if the cuts in the external thread 75 are formed only in a portion
of the external thread 75, the similar effect can be achieved to that in an embodiment
of the present invention. However, in a case where the cuts are each formed only in
a part from a tip edge of the external thread 75 (the edge on the side opposite to
that of the knob 76), for example, there is a possibility that the user may turn the
knob 76 too much, in order to get communication between the inside and the outside
of the storage, thereby removing the plug member 62. In the case of the external thread
75, the cut 100a is formed over the entire length of the external thread 75 in the
direction of the threaded engagement. This enables the user to securely resolve the
negative pressure state simply by turning the knob 76 slightly to loosen the external
thread 75.
[0029] The external thread 75 has four cuts 100a to 100d formed therein. Thus, the negative
pressure state can speedily be resolved as compared with a case of the external thread
having only one cut, for example.
[0030] For example, the through-hole configured to communicate between the inside and the
outside of the storage can be formed in the heat-insulating door 21 at the front of
the low-temperature storage 10. The heat-insulating door of a common low-temperature
storage, however, is of a dual structure (structure including the inner and outer
doors) similarly to that in an embodiment of the present invention. This makes the
structure of the low-temperature storage complicated when the through-hole is formed
at the front. In the low-temperature storage 10, the through-hole 80 is formed in
the heat-insulating wall on a side surface of the heat-insulating housing 20, thereby
being able to make the structure of the low-temperature storage 10 a simple structure
with the convenience for the user being secured.
[0031] The above embodiments of the present invention are simply for facilitating the understanding
of the present invention and are not in any way to be construed as limiting the present
invention, the scope of which is defined by the claims.
1. Tieftemperatur-Lagerungseinrichtung (10), die umfasst:
ein wärmeisolierendes Gehäuse (20), das eine Öffnungsfläche enthält;
eine wärmeisolierende Tür (21, 22), die zum Öffnen oder Schließen der Öffnungsfläche
eingerichtet ist;
eine Kühlvorrichtung (23), die zum Kühlen eines im Inneren des wärmeisolierenden Gehäuses
(20) gelagerten Gegenstandes eingerichtet ist;
ein Durchgangsloch (80), das durch eine in dem wärmeisolierenden Gehäuse (20) enthaltene
wärmeisolierende Wand von einer Außenseite der Lagerungseinrichtung (10) zu einer
Innenseite derselben hindurch verläuft und ein an einem Innenumfang desselben ausgebildetes
Innengewinde aufweist; sowie
ein Stopfen-Element (62), das zum Öffnen oder Schließen eines Öffnungsabschnitts (81)
des Durchgangslochs (80) an der Außenseite der Lagerungseinrichtung (10) eingerichtet
ist und ein Außengewinde (75), das so eingerichtet ist, dass es mit dem Innengewinde
in Gewindeeingriff gebracht wird, sowie ein Flanschelement (76, 77) einschließt, das
so eingerichtet ist, dass es durch Gewindeeingriff zwischen dem Außengewinde (75)
und dem Innengewinde an einer Fläche anliegt, in der der Öffnungsabschnitt (81) ausgebildet
ist,
dadurch gekennzeichnet, dass
das Außengewinde (75) eine Vielzahl von Einschnitten (100a, 100b, 100c, 100d) aufweist,
die in einem Abschnitt seines Außenumfangs ausgebildet sind, wobei die Einschnitte
(100a, 100b, 100c, 100d) gleiche Form haben und in regelmäßigen Abständen in dem Außenumfang
des Außengewindes (75) vorhanden sind, und so eingerichtet sind, dass sie einen Teil
des Öffnungsabschnitts (81) in einem Zustand öffnen, in dem das Flanschelement (76,
77) nicht an der Fläche mit dem darin ausgebildeten Öffnungsabschnitt (81) anliegt
und dabei das Außengewinde (75) in Gewindeeingriff mit dem Innengewinde ist.
2. Tieftemperatur-Lagerungseinrichtung (10) nach Anspruch 1,
wobei das Durchgangsloch (80) an der wärmeisolierenden Wand an einer Seitenfläche
des wärmeisolierenden Gehäuses (20) ausgebildet ist.