United States Patent [19]
`Valence et al.
`
`[54] ULTRA LOW TEMPERATURE SPLIT DOOR
`FREEZER
`
`[75]
`
`Inventors: John H. Valence, Williamstown; Keith
`L. Wharton, Parkersburg, both of W.
`Va.
`
`[73] Assignee: Forma Scientific, Inc., Marietta, Ohio
`
`[21] Appl. No.: 445,040
`
`[22] Filed:
`
`May 19, 1995
`
`[51]
`
`Int. Cl.6
`
`............................ F25D 11100; F25D 21/06;
`A47B 96/04
`[52] U.S. Cl . .............................. 62/440; 62/275; 312/401;
`312/405
`[58] Field of Search .............................. 62/440, 452, 272,
`62/275, 443, 441; 312/401-404, 405
`
`[56]
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`Re. 20,402
`1,630,160
`1,953,836
`2,044,011
`2,051,733
`2,495,626
`2,987,601
`3,042,780
`3,052,508
`3,495,416
`3,633,374
`3,724,129
`3,726,578
`3,869,873
`3,939,666
`4,192,149
`
`6/1937 Misner ........................................ 62/99
`5/1927 Bayless ..................................... 62/440
`4/1934 Stevens et al ............................ 62/441
`6/1936 Nones ....................................... 62/441
`8/1936 Moore et al .............................. 62/441
`111950 Booth ........................................ 62/443
`6/1961 Levin ........................................ 219/19
`7/1962 Gursahaney .............................. 219/19
`9/1962 Fink ........................................ 312/404
`2/1970 Morrissey, Jr. et al ................... 62/155
`1/1972 Canter ....................................... 62/156
`4/1973 Stomquist ................................... 49/70
`4/1973 Armstrong .............................. 312/214
`3/1975 Thomas ..................................... 62/275
`2/1976 Bashark .................................... 62/150
`3/1980 Webb ........................................ 62/151
`
`111111111111111111111111111111111111111111111111111111111111111111111111111
`US005600966A
`[11] Patent Number:
`[45] Date of Patent:
`
`5,600,966
`Feb. 11, 1997
`
`4,288,135
`4,317,607
`4,332,142
`4,548,049
`5,027,615
`5,048,306
`5,056,332
`5,189,888
`5,349,832
`
`9/1981 Buchser et al .......................... 312/296
`3/1982 Gomolka ................................. 312/236
`6/1982 Prada ........................................ 62/152
`10/1985 Rajgopal ................................... 62/275
`7/1991 Wakatsuki et al ........................ 62/419
`9/1991 Wakatsuki et al ........................ 62/419
`10/1991 Tajirna et al .............................. 62/252
`3/1993 Anderson et al. . ....................... 62/248
`9/1994 Johnson et al. ........................... 62/447
`
`FOREIGN PATENT DOCUMENTS
`
`763775 12/1956 United Kingdom ..................... 62/440
`
`Primary Examiner-William Doerrler
`Attorney, Agent, or Firm-Pennie & Edmonds
`
`[57]
`
`ABSTRACT
`
`An upright split door, ultra low temperature freezer which
`includes a single chamber cooled by a cold wall refrigeration
`system and accessible by separate upper and lower doors.
`The refrigeration system maintains the chamber at a sub(cid:173)
`stantially constant, ultra low temperature, such as within the
`range of about -50° C. to -90° C. Short term items may be
`stored in and accessed from an upper portion of the chamber
`by the upper door without causing the very cold air in the
`freezer chamber from spilling out the lower portion of the
`chamber. Long term items may be stored in the lower
`portion of the chamber and accessed by the lower door. A
`horizontal mullion is mounted to the freezer side walls and
`extends between the two doors to provide a seal for respec(cid:173)
`tive lower and upper edges of the two doors. A self(cid:173)
`regulating heater strip is disposed within the mullion
`between upper and lower resilient sealing bulbs extending
`horizontally to prevent condensation build up in the mullion
`area.
`
`9 Claims, 2 Drawing Sheets
`
`Hamilton Ex. 1016
`Page 1
`
`

`

`U.S. Patent
`
`Feb. 11, 1997
`
`Sheet 1 of 2
`
`5,600,966
`
`FIG. I
`
`Hamilton Ex. 1016
`Page 2
`
`

`

`U.S. Patent
`
`Feb. 11, 1997
`
`Sheet 2 of 2
`
`5,600,966
`
`FIG. 2
`
`II
`
`IWU~j~ ~- 4il~
`1 1 r r,~~/.StJ
`/jp
`lv .... ~,~·~ "'~~-~-':~;:;~~:~~;'~·~:;:~-~~::;-::~:.::'·"~.-~ Ja
`~
`~
`' 'v
`~5~ .. ;,_· ........ ;.-·.·:··•·:.-· ... ,.,J-...)
`,
`~:4--~"Tn..-,NoC.to-.11--o
`
`l:
`~
`i
`
`/
`
`•• • ••• ••·•• ...... ~··· ...... •
`
`FIG. 3
`
`Hamilton Ex. 1016
`Page 3
`
`

`

`2
`closed to prevent the spillage of cold air until long term
`items disposed in the bottom of the chamber must be
`accessed. A horizontal mullion is mounted to the freezer side
`walls and extends between the two doors to provide a seal
`for respective lower and upper edges of the two doors. A
`self-regulating heater strip is disposed within the mullion
`between upper and lower resilient sealing bulbs extending
`horizontally. This heater strip will raise the temperature of
`the mullion area above the dew point to prevent condensa-
`tion from building up in this area. The heater strip is
`self-regulating in that its temperature will increase as ambi(cid:173)
`ent temperature decreases and vice versa.
`The ultra low temperature upright freezer of this invention
`will therefore have two front access openings to the same
`15 chamber which is cooled to a substantially uniform ultra low
`temperature. The ultra low temperature upright freezer of
`this invention will be used by storing short term, often(cid:173)
`accessed items in the upper portion of the freezer chamber
`which may be accessed by the upper door and storing long
`term items in the lower portion of the chamber which may
`be accessed by the lower door. The upper door may be
`repeatedly opened and closed to access the short term items
`therein without having the significant amount of cold air
`"spilling" from the bottom of the freezer, as in the conven-
`tiona! upright freezer, because the lower door will remain
`closed. The lower door, of course, may also be opened and
`closed to access the long term items within the lower portion
`of the chamber. However, as these are "long term" items and
`are not often accessed, the load on the refrigeration unit will
`30 not be taxed nearly as often as with conventional single door
`upright, ultra low temperature freezers. As a result of the
`present invention, the upright, ultra low temperature freezer
`will require less energy to run, will require less maintenance
`and may operate over a longer useful life than conventional
`35 upright, ultra low temperature freezers.
`These and other objectives and advantages of the present
`invention will become more readily apparent to those of
`ordinary skill in the art upon further review of the following
`detailed description of the preferred embodiment taken in
`conjunction with the accompanying drawings.
`
`20
`
`25
`
`5,600,966
`
`1
`ULTRA LOW TEMPERATURE SPLIT DOOR
`FREEZER
`
`FIELD OF THE INVENTION
`
`The present invention generally relates to ultra low tem-
`perature upright freezers which are particularly useful in
`laboratories and other scientific environments.
`
`BACKGROUND OF THE INVENTION
`
`5
`
`10
`
`Several types of upright, ultra low temperature freezers
`are available, for example, for cooling various scientific
`products to very low temperatures. One such upright freezer
`has been available since prior to this invention from Forma
`Scientific, Inc., located in Marietta, Ohio, under their "8Saa"
`and "9aa" series of freezers. These upright freezers use
`various controls but each traditionally included a single
`inner chamber cooled by a surrounding "cold wall" type
`refrigeration system operated by an ultra low temperature
`refrigeration unit disposed in the base of the freezer. Evapo(cid:173)
`ration or cooling coils run up and down the side walls and
`back wall of the freezer as well as through the top and
`bottom walls. No fans are used for cooling the freezer
`chamber. Cooling is only accomplished by conduction and
`convection from the freezer walls into the chamber. A single
`full length upright door is mounted by hinges in a conven(cid:173)
`tional fashion to the front of the freezer to provide access to
`the chamber. This particular freezer is capable of cooling the
`chamber to temperatures within the range of about -sao C.
`to -86° C.
`A problem which has arisen with such ultra low tempera(cid:173)
`ture freezers is that when the front door is opened, the
`extremely cold and heavy air within the chamber tends to
`spill out of the bottom of the chamber through the front
`opening of the freezer. Often, these freezers are used for both
`"long term" and "short term" items which must both be
`maintained at the same low temperature. Often, short term
`items must be accessed in a repeated fashion throughout the
`day and therefore the extremely cold and relatively heavy
`air, when compared to ambient air, sinks to the bottom of the 40
`freezer and spills or falls out the bottom of the front door
`opening resulting in a substantial loss of cold air every time
`the door is opened. This not only undesirably increases the
`temperature of the freezer chamber and its contents, but
`places increased loads on the refrigeration unit as it must 45
`operate on a more continuous basis to account for all of the
`lost cold air from within the chamber.
`It would therefore be desirable to provide an ultra low
`temperature freezer which allows ready access to both long
`term and short term items maintained therein at the same
`temperature but which prevents spillage of cold air from the
`bottom of the chamber when short term items are repeatedly
`accessed.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a perspective view of an upright, ultra low
`temperature freezer constructed in accordance with the
`present invention;
`FIG. 1A is a schematic cross-sectional view generally
`taken along line 1A-1AofFIG. 1 but showing the doors of
`the freezer in closed positions;
`FIG. 2 is a cross-sectional view of the mullion taken along
`line 2-2 of FIG. 1; and,
`FIG. 3 is an enlarged front view of the mullion and
`peripheral gasket area taken from encircled portion 3 of FIG.
`1·
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENT
`
`Referring first to FIGS. 1 and 1 A, an upright, ultra low
`temperature freezer 10 is shown and is generally formed by
`an insulated upper wall 12, an insulated bottom wall 14, a
`pair of insulated side walls 16, 18 and an insulated rear wall
`20. Upper and lower insulated freezer doors 22, 24 are
`hingedly mounted to side wall 18 and seal against front
`edges of top wall 12, bottom wall 14, side walls 16, 18 and
`a mullion 26, as will be described. As shown in FIG. 1,
`mullion 16 is mounted between side walls 16, 18 and
`
`50
`
`SUMMARY OF THE INVENTION
`
`55
`
`It has therefore been an object of the present invention to
`provide an upright split door, ultra low temperature freezer
`which includes a single chamber cooled by a cold wall
`refrigeration system. The refrigeration system maintains the 60
`chamber at a uniform or substantially uniform, ultra low
`temperature, such as within the range of about -sao C. to
`-9ao C. In accordance with the invention, the uniformly
`cooled chamber is accessed by separate upper and lower
`doors such that the upper door may be repeatedly opened for 65
`exposing an upper portion of the chamber and accessing
`short term items and the lower door may be maintained
`
`Hamilton Ex. 1016
`Page 4
`
`

`

`5,600,966
`
`3
`extending horizontally between upper and lower doors 22,
`24. Walls, 12, 14, 16, 18 and 20 as well as doors 22, 24
`preferably have four inch thick polyurethane foam insulation
`27 while mullion 26 preferably has two inch thick polyure(cid:173)
`thane foam insulation 29 (FIG. 2). Doors, 22, 24 have 5
`conventional latching handles 23, 25.
`Still referring to Figs. I and 2, an inner chamber or freezer
`compartment 28 is formed by the various walls 12, 14, 16,
`18, 20 of freezer 10 and may be accessed and sealed by
`doors 22, 24 closing against top wall 12, bottom wall 14, 10
`side walls 16, 18 and central mullion 26. A plurality of
`shelves 30 are preferably provided within an upper portion
`28a of freezer chamber or compartment 28 for holding
`various short term items and a shelf or shelves 31 may be
`provided in a lower portion 28b of freezer chamber or
`compartment 28 for holding various long term storage items. 15
`As further shown in FIG. 1, upper and lower portions 28a
`and 28b of freezer chamber or compartment 28 may be
`partitioned off by doors 33.
`As shown in FIG. 1 A, upright, ultra low temperature
`freezer 10 further includes a base 32 holding a refrigeration 20
`unit 34 which may be comprised of conventional low
`temperature refrigeration components, such as a compressor,
`condenser, expansion device, and evaporator unit. In a
`known manner, refrigeration unit 34 does not rely on fans to
`cool freezer chamber or compartment 28 but instead relies 25
`on evaporator coils 36, which may comprise copper tubing,
`extending from refrigeration unit 34 within base 32 into the
`various walls of freezer 10. Preferably, coils 36 extend
`within each of the top, bottom, side and rear walls 12, 14, 16,
`18, 20 of freezer 10 and thereby serve to efficiently and 30
`uniformly cool chamber or compartment 28 by conduction
`and convection only. The refrigeration unit and coil con(cid:173)
`figuration may be the same as used in the above-mentioned
`"8500" and "900" series of upright freezers available from
`Forma Scientific, Inc., located in Marietta, Ohio.
`Referring now to FIGS. 2 and 3, central mullion 26
`includes a pair of upper and lower two-bulb gaskets 38, 40
`which provide a seal against the respective inner surfaces 42,
`44 of upper and lower doors 22, 24. Central mullion 26
`further includes a self-regulating heating strip 46 extending 40
`horizontally and generally along an outer surface thereof
`between the upper and lower pairs of two-bulb gaskets 38,
`40 for preventing condensation build-up in the mullion area,
`Heater strip 46 includes a resistance-type heating element 48
`which is regulated such that the wattage supplied thereto and 45
`therefore the heat which it supplies to the mullion area is
`increased as ambient temperature decreases and vice versa.
`The preferred heater strip 46 may be obtained from Ray(cid:173)
`chem Company under Part No. H611050 for the 115 V
`version and under Part No. H621050 for the 220 V version. 50
`FIG. 3 iiiustrates the junction between mullion 26 and
`side wall16. In this regard, resilient bulbs 50, 52 of two-bulb
`gasket 38 align with resilient bulbs 54, 56 of three-bulb
`gasket 57 extending along the front edge of side wall 16.
`Likewise, bulbs 58, 60 of two-bulb gasket 40 align with 55
`respective inner bulbs 62, 64 of three-bulb gasket 65 also
`extending along the front edge of side wall 16. Respective
`third outside bulbs 66, 68 of three-bulb gaskets 57, 65 align
`as shown to complete the three-bulb seal at the junction of
`side wall 16 and mullion 26. It wiii be appreciated that a 60
`three-bulb seal is provided around the entire front periphery
`of freezer 10 as shown in FIG. 1. Also, as the junction
`between mullion 26 and side wall 18 is the same as the
`corresponding junction shown in FIG. 3, description thereof
`is not necessary.
`From the foregoing description, it wiii be appreciated that
`upright freezer 10 may be used to efficiently cool scientific
`
`35
`
`65
`
`4
`or other products down to temperatures in the range of -50°
`C. to -90° C. in a substantially uniformly cooled freezer
`chamber or compartment, and access may be made to the
`upper portion of this compartment without causing the
`substantial loss of this extremely cold air from the bottom of
`the compartment as would normally be the case with a
`conventional upright, ultra low temperature freezer. Further(cid:173)
`more, the present invention achieves this objective while
`still inhibiting the undesirable build-up of condensation.
`While a preferred embodiment of this invention has been
`detailed herein, it wiii be appreciated that further modifica(cid:173)
`tions and substitutions of these details may be made without
`departing from the spirit and scope of the invention. There(cid:173)
`fore, Applicants do not intend to be bound to the disclosed
`details, but only by the scope of the appended claims.
`What is claimed is:
`1. An upright freezer comprising:
`a freezer chamber contained by insulated peripheral walls
`including a pair of side walls, a top wall, a bottom wall
`and a rear wall;
`an insulated mullion extending across a front opening of
`said chamber and mounted between said pair of side
`walls;
`an upper insulated door and a lower insulated door
`hingedly secured to one of said side walls and, in closed
`positions, said upper door sealing against upper front
`edge portions of said pair of side walls and front edge
`portions of said top wall and said mullion, said lower
`door sealing against lower front edge portions of said
`pair of side walls and front edge portions of said bottom
`wall and said mullion; and,
`a refrigeration unit connected to said freezer which cools
`said chamber to a substantially uniform temperature
`below about -50° C.
`2. The upright freezer of claim I wherein said freezer is a
`cold wall type freezer having evaporator coils of said
`refrigeration unit contained within peripheral walls of said
`chamber.
`3. An upright freezer comprising:
`a freezer chamber contained by insulated peripheral walls
`including a pair of side walls, a top wall, a bottom wall
`and a rear wall, the front edges of said top wall, bottom
`wall and side walls including resilient three-bulb gas(cid:173)
`kets;
`an insulated mullion extending across a front opening of
`said chamber and mounted between said pair of side
`walls, said mullion including a pair of upper and lower
`two-bulb gaskets attached on an outside surface
`thereof;
`a self-regulating heating strip extending generally along
`an outside surface of said mullion between said pair of
`upper and lower two-bulb gaskets;
`an upper insulated door and a lower insulated door
`hingedly secured to one of said side walls and, in closed
`positions, said upper door sealing against the three-bulb
`gaskets of said pair of side walls and said top wall and
`against the upper two-bulb gasket of said mullion, said
`lower door sealing against the three-bulb gaskets of
`said pair of side walls and said bottom wall and against
`the lower two-bulb gasket of said mullion; and
`a refrigeration unit connected to said freezer which cools
`said chamber to a substantially uniform temperature.
`4. The upright freezer of claim 3 wherein the two bulbs of
`each of said upper and lower two-bulb gasket respectively
`
`Hamilton Ex. 1016
`Page 5
`
`

`

`5,600,966
`
`5
`meet and align with two inner bulbs of the three-bulb gaskets
`on the front edges of said side walls.
`5. An upright, ultra low temperature freezer comprising:
`a freezer chamber contained by insulated peripheral walls
`including a pair of side walls, a top wall, a bottom wall 5
`and a rear wall;
`a mullion extending horizontally across a front opening of
`said chamber and mounted between said pair of side
`walls;
`an upper door and a lower door hingedly secured to one
`of said side walls and having respective lower and
`upper edges thereof sealing against said mullion when
`in closed positions; and,
`a refrigeration unit connected to said freezer and includ(cid:173)
`ing evaporator coils contained within peripheral walls
`of said chamber which cool said chamber to a substan(cid:173)
`tially uniform temperature below about -50° C. to -90°
`c.
`
`6
`6. The upright freezer of claim 5 wherein said mullion
`includes a self-regulating heating strip extending generally
`along an outside surface thereof.
`7. The upright freezer of claim 6 wherein said heating
`strip is disposed between a pair of upper and lower two-bulb
`gaskets attached on an outside surface of said mullion and
`which respectively seal against lower and upper inner sur(cid:173)
`faces of said upper and lower doors.
`8. The upright freezer of claim 7 wherein the front edges
`of said top wall, bottom wall and side walls include resilient
`three-bulb resilient gaskets for sealing against said upper
`and lower doors.
`9. The upright freezer of claim 8 wherein the two bulbs of
`15 each of said upper and lower two-bulb gasket respectively
`meet and align with two inner bulbs of the three-bulb gaskets
`on the front edges of said side walls.
`
`10
`
`* * * * *
`
`Hamilton Ex. 1016
`Page 6
`
`