U.S. patent application number 12/459782 was filed with the patent office on 2010-01-14 for convection barrier.
This patent application is currently assigned to F. HOFFMANN-LA ROCHE AG. Invention is credited to Christof Fattinger, Remo Anton Hochstrasser, Thomas Zumstein.
Application Number | 20100005826 12/459782 |
Document ID | / |
Family ID | 40100700 |
Filed Date | 2010-01-14 |
United States Patent
Application |
20100005826 |
Kind Code |
A1 |
Zumstein; Thomas ; et
al. |
January 14, 2010 |
Convection barrier
Abstract
A convection barrier for a freezer is disclosed. The convection
barrier may include a foil having at least one opening therein,
storage and transport means for storing and moving the foil so as
to transport the at least one opening to a desired position
allowing access through the at least one opening to the interior of
the freezer at the desired position and tensioning means for
continuously keeping the foil in a tensioned state.
Inventors: |
Zumstein; Thomas; (Therwil,
CH) ; Fattinger; Christof; (Blauen, CH) ;
Hochstrasser; Remo Anton; (Oberwil, CH) |
Correspondence
Address: |
MINTZ LEVIN COHN FERRIS GLOVSKY & POPEO
ONE FINANCIAL CENTER
BOSTON
MA
02111
US
|
Assignee: |
F. HOFFMANN-LA ROCHE AG
Basel
CH
|
Family ID: |
40100700 |
Appl. No.: |
12/459782 |
Filed: |
July 8, 2009 |
Current U.S.
Class: |
62/449 |
Current CPC
Class: |
F25D 23/025 20130101;
F25D 11/04 20130101; F25D 13/02 20130101; A01N 1/0242 20130101;
A01N 1/02 20130101 |
Class at
Publication: |
62/449 |
International
Class: |
F25D 23/02 20060101
F25D023/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 9, 2008 |
EP |
08160042.1 |
Claims
1. A convection barrier for a freezer, comprising: a foil having at
least one opening; storage and transport means for storing and
moving the foil to transport the at least one opening to a desired
position to allow access through the at least one opening to the
interior of the freezer at the desired position, and tensioning
means for continuously keeping the foil in a tensioned state.
2. The convection barrier according to claim 1, wherein the storage
and transport means further comprise two reels to which the ends of
the foil are mounted and between which the foil extends, as well as
a drive for rotating the reels so as to wind up or unwind the foil
to transport the at least one opening to the desired position.
3. The convection barrier according to claim 1, further comprising
a frame, the frame being insertable in the foil at a location
between the ends of the foil such that the at least one opening for
allowing access to the interior of the freezer can be transported
to the desired position.
4. The convection barrier according to claim 2, wherein the drive
has a motor connected to one of the two reels and the tensioning
means has a return spring connected to the other one of the two
reels for continuously keeping the foil in a tensioned state.
5. The convection barrier according to claim 4, wherein the drive
further comprises a belt engaging both of the two reels and the
return spring has a low spring rate.
6. The convection barrier according to claim 4, wherein the return
spring has a high spring rate.
7. The convection barrier according to claim 4, wherein the return
spring is a torsion spring.
8. The convection barrier according to claim 2, wherein the drive
and the tensioning means comprise two motors, one of the two motors
being connected to one of the two reels and the other motor being
connected to the other one of the two reels and a control unit for
operating the two motors in an asynchronous manner so as to
continuously keep the foil in a tensioned state.
9. The convection barrier according to claim 1, wherein the foil is
made from polytetrafluoroethylene.
10. A freezer comprising a housing and a door, the housing having
an opening allowing access to the interior of the freezer through
the opening when the door of the freezer is open, wherein the
convection barrier of claim 1 is arranged on the freezer such that
the opening allowing access to the interior of the freezer is
covered by the foil.
11. The freezer according to claim 10, wherein one or more motors
or a belt of the convection barrier are mounted to the freezer
outside its housing.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to European Patent
Application No. 08160042.1, filed Jul. 9, 2008, the entire contents
of which are herein incorporated by reference in their
entirety.
FIELD
[0002] Embodiments of a convection barrier are described herein. In
particular, embodiments of a convection barrier having a foil,
storage and transport means and tensioning means are provided. More
particularly, the convection barrier embodiments disclosed herein
may be used in connection with a freezer.
BACKGROUND
[0003] In clinical studies a wide variety of assays can be carried
out to answer questions related to diagnosis (e.g., biomarker),
treatment (e.g., efficacy of a drug) and prevention of
diseases.
[0004] Large sample collections of biological samples can be
established, e.g., within the context of clinical studies. Such
biological samples may include without limitation blood samples
(e.g., whole blood, plasma, serum), urine samples, tissue samples,
cells (e.g., cell lines, primary cell cultures), proteins, DNA, RNA
(e.g., RNAi, mRNA), or antibodies.
[0005] An automated facility for storing biological samples at
-80.degree. C. is used in the UK biobank and is described, for
example, in the article "Designing and implementing a large-scale
automated -80.degree. C. archive," by Justin M. Owen and Peter
Woods, published in the International Journal of Epidemiology 2008;
37: i56-i61 (doi: 10.1093/ije/dym293). The store described therein
comprises a system of drawers arranged in a manner so as to form a
shelf, which allows robotic access to the biological samples whilst
maintaining storage conditions. The drawers can be opened
individually by the robot pulling the respective drawer outwards so
as to allow access to the interior of the drawer where the
biological samples are stored.
[0006] However, this system has disadvantages. First, at its front
surface each drawer is provided with a block made of styrene in a
manner such that the styrene blocks of adjacently arranged drawers
abut against one another. Upon opening an individual drawer by
pulling the drawer outwardly, there is inherently the risk of an
adjacently arranged drawer also being pulled out, even though not
intended, thereby causing an unwanted temperature rise. Also, the
total leakage of cold air is comparatively high because the system
does not have a separate front door for closing the system.
[0007] Cooling of a complete humidity controlled room for storing
biological samples as described above to about -80.degree. C. is
generally feasible. However, standard handling devices, such as for
example robots, usually do not work properly at such temperatures.
Therefore, particularly for long-term storage of biological
samples, specific -80.degree. C. freezers are typically used.
[0008] These specific freezers for long-term storage usually have a
thermally insulating door which separates the environment outside
the freezer (e.g., a -20.degree. C. environment) from the
-80.degree. C. interior of the freezer. In a so-called "robotic
store," a plurality of such freezers is arranged as well as a robot
for taking the samples out of each freezer. As mentioned above, the
robot cannot be arranged in the -80.degree. C. environment.
Instead, the robot is arranged outside the freezers in the warmer
-20.degree. C. environment where it is capable of working properly.
However, particularly with conventional upright standing freezers
certain problems may arise in this configuration. First, upon
having opened the door in order to allow the robot to access the
interior of the freezer, the -80.degree. C. cooled air flows out of
the interior of the freezer while at the same time -20.degree. C.
air flows from the environment into the interior of the freezer,
leading to a rise in temperature and humidity within the interior
of the freezer. This is particularly the case because the door of
the freezer usually must remain open for a considerable period of
time until the desired one or more biological samples have been
removed. Secondly, the flow of -80.degree. C. air out of the
freezer and -20.degree. C. air into the freezer creates two
effects: (i) a negative pressure that makes the door extremely
difficult to open again until the negative pressure is equalized by
inflowing air through the sealing of the door of the freezer, which
usually takes a considerable period of time (e.g., up to 30
minutes); and (ii) the cooling down of the -20.degree. C. air which
is more humid than the -80.degree. C. air results in formation of
ice within the freezer, requiring defrosting of the freezer more
often.
[0009] It is therefore an object of the invention to overcome the
aforementioned disadvantages and to provide suitable measures to
avoid or at least greatly reduce the above-described scenarios.
Also, loss of energy should be reduced to a minimum while at the
same time frequent access to the stored biological samples should
be possible.
[0010] This object is achieved through the convection barrier
embodiments disclosed herein and through a freezer comprising such
convection barrier embodiments.
SUMMARY
[0011] Disclosed herein are embodiments of a convection barrier.
Some embodiments of the convection barrier are particularly
well-suited for use in a freezer. Exemplary embodiments of the
convection barrier may include a foil having at least one opening
therein, storage and transport means for storing and moving the
foil to transport the at least one opening to a desired position to
allow access through the at least one opening to the interior of
the freezer at the desired position and tensioning means for
continuously keeping the foil in a tensioned state.
[0012] In some embodiments, the foil may cover the opening to the
interior of the freezer so that no cold air (e.g., -80.degree. C.)
may flow out of the interior of the freezer or that only small
amounts of cold air may flow out of the freezer when the freezer
door is open. However, it must be possible to access a desired
sample or samples stored in the interior of the freezer. In some
embodiments, this can be achieved by allowing access (e.g., by a
robot) to a desired one or more samples through an opening or
openings provided in the foil. According to some embodiments,
because a sample may be stored at any location in the interior of
the freezer, the opening must be movable to the position where the
respective sample is located or stored. To move the one or
openings, some embodiments of the convection barrier may include
storage and transport means for storing and transporting the foil
so that the opening in the foil can be moved to the position and
stored in this position to allow access to a sample through the
opening. To avoid jamming of the foil and in order to keep the air
cold (e.g., -80.degree. C.) within the interior of the freezer,
tensioning means are provided for keeping the foil in a tensioned
state during storing and transporting. Thus, outflow of cold air
(e.g., -80.degree. C.) out of the interior of the freezer and
backflow of warmer air (e.g., -20.degree. C.) from the environment
into the interior of the freezer is prevented or at least greatly
reduced. Accordingly, the above-described disadvantages of
temperature rise in the interior of the freezer and negative
pressure making the door extremely difficult to open are prevented
or at least greatly reduced by the convection barrier embodiments
disclosed herein.
[0013] In some embodiments of the convection barrier, the storage
and transport means may comprise two reels to which the opposite
ends of the foil are mounted and between which the foil extends.
Some embodiments of the convection barrier may also include a drive
for rotating the reels so as to wind up or unwind the foil from the
respective reel to transport the at least one opening to the
desired position.
[0014] Some embodiments of the convection barrier may comprise a
frame having at least one opening, the frame being insertable into
the foil at a location between the ends of the foil such that the
at least one opening of the frame for allowing access to the
interior of the freezer can be transported to any desired position.
According to some embodiments, the frame may be rigid and stable to
reliably position the opening at a desired location so as to allow
access (e.g., by a robot) to the interior of the freezer through
the at least one opening.
[0015] In some embodiments of the convection barrier, the drive may
comprise a motor connected to one of the at least two reels, and
the tensioning means may comprise a return spring connected to the
other one of the at least two reels for continuously keeping the
foil in a tensioned state. In exemplary embodiments, that reel to
which the motor is connected may be driven by the motor while the
other reel is acted upon by the return spring so that the foil is
always kept in a tensioned state. This configuration is
advantageous because it allows various additional embodiments to be
conceived, as discussed below.
[0016] In some embodiments, the drive may further comprise a belt
engaging both of the two reels, and the return spring may be a
spring having a low spring rate. Since the belt already provides
for synchronization of the two reels, i.e., the reels are driven
with the same speed, the return spring must only have a low spring
rate in order to keep the foil in a tensioned state. While the
outer diameter of the respective reel with the foil wound around it
continuously changes during movement of the foil, the return spring
maintains the foil in a tensioned state.
[0017] In some embodiments, the return spring may be a spring
having a high spring rate. Particularly in the case where there is
no mechanical connection between the two reels (e.g., by means of
the aforementioned belt), it is advantageous that the spring has a
high spring rate in order to make sure that the foil is always kept
in a tensioned state.
[0018] One example of a return spring having a high spring rate
includes without limitation a torsion spring. In some embodiments,
the torsion spring can be arranged within a hollow reel to achieve
the advantages of the convection barrier according to some
embodiments of the invention.
[0019] In some embodiments of the convection barrier, the drive and
the tensioning means may comprise two motors. Some embodiments may
include one of the two motors being connected to one of the two
reels and the other motor being connected to the other one of the
at least two reels. The convection barrier may also, according to
some embodiments, comprise a control unit for operating the two
motors in an asynchronous manner so as to continuously keep the
foil in a tensioned state. In some embodiments, the control unit
may have two functions: First, it may control the speed of the
reels, depending on whether the reel is winding the foil up or
unwinding the foil, depending on how much of the foil is still
wound around the respective reel. The control unit may also
function, according to some embodiments, to drive the two motors in
an asynchronous manner so as to make sure that the foil is always
kept in a tensioned state. In this embodiment, one of the two
motors may act in a manner similar to the aforementioned mechanical
return spring, depending on the direction of movement of the
foil.
[0020] Possible materials for the foil may include without
limitation, polytetrafluoroethylene or a mesh, e.g., a glass mesh,
coated with polytetrafluoroethylene. Polytetrafluoroethylene is
readily available on the market and is capable of fulfilling the
requirements with regard to the operational demands, in particular
with respect to temperature, mechanical stress and durability.
[0021] As already mentioned above, embodiments of the convection
barrier may be used in connection with a freezer. In some
embodiments, the freezer may comprise a housing and a door. In some
embodiments, the housing may have an opening allowing access to the
interior of the freezer through the opening when the door of the
freezer is open. Embodiments of the freezer preferably further
comprise a convection barrier as described above. The convection
barrier may be arranged, according to some embodiments, such that
the opening allowing access to the interior of the freezer is
covered by the foil.
[0022] In one particularly advantageous embodiment of the freezer,
one or more motors, or a belt, of the convection barrier may be
mounted to the freezer outside its housing. This is advantageous
because the motor or motors work well in the environment outside
the freezer, e.g., in a -20.degree. C. environment, while this is
not the case in the environment in the interior of the freezer,
e.g., in a -80.degree. C. environment. Also, maintenance of these
components is possible in the environment outside the freezer
(e.g., -20.degree. C.).
BRIEF DESCRIPTION OF THE FIGURES
[0023] Further advantageous aspects of the invention will become
apparent from the following description of embodiments of the
convection barrier with the aid of the Figures 1-15.
[0024] FIG. 1 shows a cross-sectional side view of a freezer in
accordance with some embodiments of the invention with an
embodiment of the convection barrier according to the some
embodiments of invention mounted thereto.
[0025] FIG. 2 shows a front view of an embodiment of the convection
barrier according to the invention.
[0026] FIG. 3 shows the upper reel of the convection barrier to
which the foil is mounted according to some embodiments of the
invention.
[0027] FIG. 4 shows the lower reel of the convection barrier to
which the foil is mounted according to some embodiments of the
invention.
[0028] FIG. 5 shows a perspective view of an embodiment of the
freezer according to the invention with an embodiment of the
convection barrier according to the invention mounted thereto.
[0029] FIG. 6 shows the detail VI of FIG. 5 in an enlarged
view.
[0030] FIG. 7 shows the detail VII of FIG. 5 in an enlarged
view.
[0031] FIG. 8 shows the detail VIII of FIG. 5 in an enlarged view,
partially broken away.
[0032] FIG. 9 shows the detail IX of FIG. 5 in an enlarged view,
partially broken away.
[0033] FIG. 10 shows a perspective view of an embodiment of the
freezer according to the invention with an embodiment of the
convection barrier according to the invention mounted thereto.
[0034] FIG. 11 shows the detail XI of FIG. 10 in an enlarged
view.
[0035] FIG. 12 shows the detail XII of FIG. 10 in an enlarged
view.
[0036] FIG. 13 shows a perspective view of an embodiment of the
freezer according to the invention with an embodiment of the
convection barrier according to the invention mounted thereto.
[0037] FIG. 14 shows detail XIV of FIG. 13 in an enlarged view.
[0038] FIG. 15 show detail XV of FIG. 13 in an enlarged view.
DETAILED DESCRIPTION
[0039] FIG. 1 shows a cross-sectional side view of a freezer 1
according to the invention with a convection barrier 2 mounted
thereto, with the door of the freezer 1 not being shown in FIG. 1
for the sake of simplicity. Freezer 1 comprises a housing 10 having
an opening 11 at the front side of the freezer (in FIG. 1 on the
right hand side). A plurality of compartments 13 are arranged in
the interior 12 of freezer 1. In the third compartment from the
bottom, a drawer 3 is represented by way of example which carries a
plurality of trays 30 in which, e.g., microtubes (not shown), may
be arranged in which the samples are stored. Convection barrier 2
comprises a foil 20, the two opposite ends of which are mounted to
two elongate reels, an upper reel 21 and a lower reel 22, so that
the foil extends therebetween. Convection barrier 2 is mounted to
freezer 1 such that foil 20 of convection barrier 2 covers the
opening 11 of freezer 1 so that the flowing out of cold air (e.g.,
-80.degree. C. air) from the interior 12 of freezer 1 is prevented
or is at least greatly reduced. As can be seen in FIG. 1, in order
to get access to the respective drawer 3 carrying the tray 30 with
the desired sample, a frame 23 comprising one or more openings 230
(see FIG. 2) is inserted in the foil at a location between the two
ends of the foil 20 such, that the one or more openings 230 allow
access to drawer 3 carrying the tray 30 with the desired
sample.
[0040] One embodiment of convection barrier 2 according to the
instant invention is shown in FIG. 2. In the embodiment shown in
FIG. 2, outer frame 24, foil 20, and frame 23 carrying the one or
more openings 230 (e.g., four openings) can be seen. Accordingly,
columns (e.g., four) of drawers may be arranged in the interior of
freezer 1. In order to get access to the various compartments 13 in
the interior 12 of freezer 1 where the respective drawer 3 carrying
the tray 30 with the desired sample is arranged, frame 23 must be
movable up and down in order to get to the respective location, as
this is indicated by the arrows in FIG. 2. Frame 23 is preferably
made from metal, e.g., aluminium, so as to reliably and stably
position the openings 230 at the desired location in front of the
respective drawer 3. For proper functioning, foil 20 should be kept
in a tensioned state.
[0041] FIG. 3 shows the elongated upper reel 21 with the one end of
foil 20 mounted thereto in an enlarged view, while FIG. 4 shows the
lower reel 22 with the opposite end of foil 20 mounted thereto.
Through rotation of the upper and lower reels 21, 22 foil 20 can be
wound up or unwound from the respective reel. This can be achieved
in various ways, as explained in more detail below.
[0042] FIG. 5 shows a perspective view of an embodiment of a
freezer according to the instant invention comprising a specific
embodiment of a convection barrier according to the invention. In
this embodiment, like parts are assigned like reference signs but a
letter "a" is added. Accordingly, freezer la comprises a housing
10a and a door 100a which is shown in its open position. Convection
barrier 2a comprises an outer frame 24a, a foil 20a with a frame
23a carrying one or more openings 230a. Foil 20a extends between
the two ends thereof which are mounted to elongate upper reel 21a
and elongate lower reel 22a, respectively. A motor 25a drivingly
engages an axle 210a which itself is connected to elongate upper
reel 21a for rotatably driving upper reel 21a. A control unit 26a
is provided for operating motor 25a. Lower elongate reel 22a is
also connected to an axle 220a. Two belt pulleys 211a and 221a (see
also FIG. 6 and FIG. 7) are mounted to axles 210a and 220a,
respectively. An endless belt 27a is guided over belt pulleys 211a
and 221a and engages the pulleys 211a and 221a, thus mechanically
connecting axles 210a and 220a. Accordingly, as motor 25a rotatably
drives axle 210a (and upper reel 21a) pulley 211a is also rotated
and via belt 27a causes pulley 221a to rotate, thus rotating axle
220a (and lower reel 22a). Accordingly, upper and lower reels 21a,
22a essentially rotate with the same speed.
[0043] FIG. 6 shows detail VI of FIG. 5 in an enlarged view.
Although already shown in FIG. 5, FIG. 6 more clearly shows that
motor 25a and control unit 26a as well as drive pulley 211a and
belt 27a arranged on axle 210a are located outside the freezer,
e.g., in the above-mentioned -20.degree. C. environment where they
work properly and can be maintained. The same holds true for drive
pulley 221a arranged on axle 220a, as seen in greater detail in
FIG. 7.
[0044] In FIG. 8 the detail VIII of FIG. 5 is shown in an enlarged
view and partially broken away. It can be seen how foil 20a enters
beneath outer frame 24a and can be wound up or unwound from reel
21a. FIG. 9 shows the detail IX of FIG. 5, also partially broken
away. From FIG. 9 it can be seen that a torsion spring 28a arranged
in the interior of reel 22a, which in some embodiments may be
hollow. Torsion spring 28a is a weak spring which is always in a
tensioned state, even when frame 23a carrying the openings 230a is
in its lowermost position, so that foil 20a is always kept in a
tensioned state.
[0045] FIG. 10 shows a further embodiment of the freezer according
to the invention comprising a specific embodiment of a convection
barrier according to the invention. In this further embodiment,
like parts are again assigned like reference signs but a letter "b"
is added. Accordingly, freezer 1b comprises a housing 10b and a
door 100b which is shown in its open position. Convection barrier
2b comprises an outer frame 24b, a foil 20b with a frame 23b
carrying one or more openings 230b. Foil 20b extends between the
two ends thereof which are mounted to elongate upper reel 21b and
elongate lower reel 22b, respectively. A motor 25b drivingly
engages an axle 210b, as can be seen in FIG. 11 showing detail XI
of FIG. 10 in an enlarged view. Motor 25b is connected to elongate
upper reel 21b for rotatably driving upper reel 21b. A control unit
26b is provided for operating motor 25b. In the interior of lower
reel 22b which is embodied as a hollow reel, a torsion spring 28b
is arranged.
[0046] This can be seen more clearly in FIG. 12 showing detail XII
of FIG. 10, also partially broken away. From FIG. 12 it can be seen
that there is a torsion spring 28b arranged in the interior of reel
22b, which is embodied as a hollow reel. Torsion spring 28b is a
weak spring which is always in a tensioned state, even when frame
23b carrying the one or more openings 230b is in its lowermost
position, so that foil 20b is always kept in a tensioned state.
[0047] As to the operation, it is essentially referred to the
embodiment described above with respect to FIGS. 5-9, however,
since there is no mechanical connection between the two reels via a
belt, torsion spring 28b is a spring having a high spring rate.
[0048] FIG. 13 shows a perspective view of still a further
embodiment of a freezer according to the instant invention
comprising a specific embodiment of a convection barrier according
to the invention. In this embodiment like parts are assigned like
reference signs but a letter "c" is added. Accordingly, freezer 1c
comprises a housing 10c and a door 100c which is shown in its open
position. Convection barrier 2c comprises an outer frame 24c, a
foil 20c with a frame 23c carrying openings 230c. Foil 20c extends
between the two ends thereof which are mounted to elongate upper
reel 21c and elongate lower reel 22c, respectively. A motor 25c
drivingly engages an axle 210c, as can be seen in FIG. 14 showing
detail XIV of FIG. 13 in an enlarged view. Axle 210c is connected
to elongate upper reel 21c for rotatably driving upper reel 21c
with the aid of motor 25c. A control unit 26c is provided for
operating motor 25c. Lower elongate reel 22c is also connected to
an axle 220c. A further motor 28c drivingly engages an axle 220c,
as can be seen in FIG. 15 showing detail XV of FIG. 13 in an
enlarged view. Axle 220c is connected to lower reel 22c for
rotatably driving lower reel 22c with the aid of motor 28c. Also,
motor 28c is connected to control unit 26c (this connection not
being shown in FIGS. 13-15). Control unit 26c operates the two
motors 25c and 28c in an asynchronous manner. Depending on the
direction of winding foil 20c, one of the two motors 25c, 28c acts
as the driving motor while the other motor 28c, 25c acts in a
manner similar to the return spring. For example, as motor 25c acts
as the driving motor and foil 20c is wound up onto upper reel 21c,
then foil 20c is unwound from lower reel 22c and motor 28c acts as
the return spring, thus continuously keeping foil 20c in a
tensioned state. Or the other way round, as motor 28c acts as the
driving motor and foil 20c is wound up onto lower reel 22c, then
foil 20c is unwound from upper reel 21c and motor 25c acts as the
return spring, thus continuously keeping foil 20c in a tensioned
state.
[0049] Finally, it is to be noted that many alternatives are
conceivable, for example springs other than torsion springs can be
used and the openings for gaining access to the interior of the
freezer do not necessarily have to be provided in a frame. Also, it
is to be noted that the convection barrier is a separate unit which
can be adapted to the respective freezer to which it is to be
mounted. Accordingly, the scope of protection is not intended to be
limited by the described exemplary embodiments of the invention but
rather is defined by the appended claims.
* * * * *