US3167931A

US3167931A - Cabinet construction

Info

Publication number: US3167931A
Application number: US303811A
Authority: US
Inventors: James G Bryson
Original assignee: Carrier Corp
Current assignee: Carrier Corp
Priority date: 1963-08-22
Filing date: 1963-08-22
Publication date: 1965-02-02
Anticipated expiration: 1982-02-02

Description

Feb. 2, 1965 J. G. BRYSQN 3,167,931

CABINET EONSTRUCEION Filed Aug. 22, 1963 2 Sheets-Sheet 1 IZiIIZ FIG. :3

vINVENTOR.

JAMES 6. BRYSQN.

ATTORNEY.

J. G. BRYSON CABINET CONSTRUCTION Feb. 2, 1965 2 Sheets-Sheet 2 Filed Aug. 22, 1963 INVENTOR. JAMES G. BRYSON.

FIG. 6

loam ATTORNEY.

United States PatentfOiliCe 3,157,931 Patented F 2, 1965 3,167,931 CABINET CGNSTRUCTION JamesG. BrysonTyler, Tex.,-assignor to Carrier Corporation,- Syraeuse, N.Y.,-a corporation of Delaware FiledAug. 22, 19:53am No. 303,811 6 Claims. (Cl. 62-373) This invention relates-to cabinets, and, more particularly,- it relatesto facilitating the opening of the acwss door to a cabinet such as a refrigerated cabinet.

Refrigerated-cabinets generally comprise a-box section having .anaccess-opening covered by a hing'edly mounted access door. his frequent practice to provide an airtight seal between the access door and the box section by means of asuitable gasket which is often of the magnetic type. Such gaskets usually have a firsted'ge portion fixedly secured to one ofthe members such as the access door, a second edge .portion :which carries one or more magnets designed to temporarily sealingly'en'gage the second edge portion to a metal flange on the box section, and an extensible web portion between the first and second edge portions of the gasket. The extensible web portion allows the gasket to accommodate itself to the shape of the access opening ofrthe refrigerator box and to the clearance which exists. between'the' box and the access'door sections. The extensible Web portion of the gasket is also desirable because the portioniof the access door closest to 'the hinges may approach the access opening of the "box section more closely than the portion of the door remote from the hinges. This type of construction'has found Wide application in household refrigerators; including food freezers and frozen food storage cabinets. Refrigerators of this type are usually also provided with a'rigid handle on the access door which the user-pulls to break the adhesion between the magnetic portion of the gasket andthe box section in order to gain access to the refrigerator.

Even though the force exerted by the magnetic gasket tending to maintain the refrigerator door closed is relativelysm-a-ll, users often complain that an excessive pull is-required in order to open the access door. This prob lem is particularly acute with low temperature refrigerators such as food freezers and arises for-two reasons. First, when the refrigerator door is opened and then closed, ambienta-ir at room temperature escapes into the interior of-the box-section. This relatively warm air is rapidly cooled'in the interior of the refrigerator after the door is closed. As the air inside the refrigerator is cooled, it is reduced in volume giving rise to a materially lower pressure inside the refrigerator than that of the ambient air on the exterior of the door. This difference in pressure across the access door result in a force tending to keep the door closed, which must be overcome in order topull the door open. It'has been found'that for a typical household freezer, having an interior temperature of about F., the difference inpressure across the access door due to the cooling of warm air admitted into the box section may be on the order of about two inches of water. I Such a refrigerator typically has a door area of about thirteen square feet and, consequently, this difference in pressure may result in a force of about three hundred pounds tending to keep the door closed. This force, tending to oppose opening of the door, Will exist until the pressures are equalized by leakage of ambient air into the refrigerator, which may take several minutes or longer. The user may find, -therefore, that it is exceedingly dithcult or impossible to reopen the door for a period of time after it has been closed. Second, as the user initially pulls on the door handle to open the door, the expansibleWebporti-onof the'gas'ket extends sufficiently to slightly increase the internal volume of the refrigerator. Even though the pressures across the door are equal, thi increase in internal volume of the refrigerator results in a specification and attached drawings, wherein:

the magnetic pull exe'rted by the gasketwhich' is relatively nominal, but must also overcome the force tending to keep the door closed by reason of the pressure difference across the door due to the'diiference in'i-ntern'al and external'pressures acting on the door.

'Itis therefore the principal object of this invention to facilitate the opening ofa cabinet door.

It is a further object of this inventionto' pnovide a means and method for reducing the difference in pressure across a cabinet door so as to facilitate opening thereof.

It is a further object of this invention to provide a means'for admitting ambient air into the interior of a refrigerated enclosure upon the occurrence of an excessively great pressure difference tending to resist opening of its accessd-o'or.

It is a still further object of this invention-to provide an improved cabinet construction.

These and other objects of this invention are achieved in the illustrated preferred embodiments thereof by providingta refrigerator'cabinet, such'as a frozen food-storage" compartment, having valve means responsive to a predetermined pressure difference between the interior and the exterior of'lthe cabinet. The valve means serves to admit ambient air into the interior of the cabinet to prevent an excessive pressure difference from occurring across'the access door.

'In one embodiment of this invention the valve isdisposed inthe access door section of' the ref-rigeratedenclosure and is'disposed on the outer Wall thereof'so that the valve is warmed by. ambient air to prevent the accumulation offrostthereon which might-cause malfunction in the operation of the-valve. In another embodimentof this invention the valve is located inthe cabinet section of the refrigerated enclosure and-means may be provided to supply'heat-to the valve from the hot gas-line of the refrigeration system to maintain th'e temperature of the valve sufficiently high to prevent moisture fromfreezing thereon. I n

The Iforegoingand other objects of this invention will become more apparent by. reference to the following FIGURE -1 is a fragmentary cross-sectional view through a lpohtion of'ref'rigera'ted cabinet embodying the instant invention;

FIGURE 2 is 'a cross-sectional view through the valve shown inFIGURE 1;

FIGURE 3 is a planvi'ew'looking downwardly onthe valve slr wn'inFIGURE 1;

FIGURE '4 is a fragmentary view, partly broken away and in cross-section, of a refrigerated enclosure utilizing another embodiment of applicants invention;

FIGURE Sisa fragmentary cross-sectional view showingthe'detail orthevie'w illustrated in'FIGURE 4; and

FIGURE'6 is a plan'view of the valve Shown in FIG- URE 5.

'outer'wall-including a metal flangediportion 12 defining v an accessopening to the interior of the cabinet.

floor to support the refrigerator. Suitable inner wall members 14 andil cooperate with outer wall 121to form a double wall construction for the reception-of insulation 16. A refrigerator shelf 17 is provided in the interior of box section 11 and may be cooled by tubes 18 which form part of the evaporator of a conven A gasket or sealing means 25 is provided to make a Box: section 11 is provided with a base 13 which rests on-the 29.. When this difference in pressure-exceeds the pressure at which check valve 32 opens, additionalambient air is automatically admitted into the interior of the refrigerator through check valve 32 and

vent passages

33, 34, so as to increase the"pressure,,-in the interior of box 11. By designing check valve 32 to open at a suitably low pressure dilference,.t he corresponding difference in internal and external pressures across door2tl may be reduced to an extent that only a small force is necessary to open the door. Likewise as the user begins to open door 20 and the pressure inbox 10 is reduced by expansion of gasket 25,.check valve 32 admits additional amsubstantially'airtight seal between access door section 2-0 and box section 11 when the door is in a closed position. Gasket suitably comprises a first edge portion'zd which is fixedly secured to outer wall 23 of access door section 29 by one or more sheet metal screws 27. Gasket 25 hasa second edge portion 28 carrying magnetic means 29 such as a magnet which is ,attractedto metal flange 12.

to make temporary relatively airtight engagement with box section 11. An extensible imperviousweb portion 30 extends between first edge portion 26 and second edge portion 28 of gasket 25. Extensible portion 30 compensates for any non-uniformity in the distance between access door 26 and box 11 and permits the gasket to adapt itself to'the shape of the cabinet with which it is used. a

This cyclic fluctuation may produce a pressure difference In accordance with this invention a check valve 32 extends through. outer wall 23 of one of the members such .as access door 20. A suitablevent passage 33 is provided through insulation 24. One or more suitable vent passages 34 are provided through inner wall 22 of access door 20.

Ventpassage 34 is preferably provided at a location on door 29 that is of relatively high temperature, above the dew point of the ambient air, andis desirably at a location which is above 32 R, if possible, so that the vent passage will not become clogged by ice formation due to condensation of moisture from the air in contact therewith.

It will be appreciated that in the location shown valve 32 is in heat exchange relation with, and receives heat from the relatively warm ambient'air to assist in pre venting frost formation thereon. Other means, such as those to be subsequently described may be .used to supply heat to valve 32, if desired.

by heat sealing or riveting at 38. to base member 35.

Diaphragm member 37 may be provided with a slightly 'bossed peripheral edge portion 39 to make sealing .en-,

gagement about the contacting edge of base member 35. It has been found that for the purposes of thisinvention diaphragm member 37 may suitably have suificient flexi- A flexible plastic bient air'into the interior of the'box to facilitate the open ing of the door. Using the example previously discussed, valve 32 may open at a pressure difference of about /2 lb. per square foot thereby limiting the force due to the pressure difference across a thirteen square foot door to only about 6 /2 lbs. Consequently, the force required to open the door is limited to only 6 /2 lbs. morethan that normally required toovercomethe force of attraction of the magnetic gasket.

It will be appreciated that a permanently open vent passage could be employed to-equalize the pressures between the interior and exterior of the cabinet. This solution, however, is not satisfactory because in the case of a refrigerated enclosure there is a measurable pres sure fluctuation due to cycling of the refrigeration equipment from an operating to a non-operating condition.

across the door on the order of +.O2 to '.05 inch of water. If a permanently open vent passage were provided from the exterior into the interior. of box 10, a considerable amount of cooled air would escape from the box when'the refrigeration equipment cycled on and a considerable amount of warm air wouldbe admited to the box each time the refrigeration equipment cycled on. This loss of refrigerated air and intake'of warm air would undesirably require providing increased cooling capacity and would result in poor control of temperatures in the refrigerated enclosure. To prevent this, applicants valve is arranged so that a minimum pressure difference greater than that normally experienced due to cycling of the refrigeration equipmentis necessary before'checkvalve 32 opens.

Referring now particularly to FIGURE 4, there is shown another. embodiment of applicants invention as applied to a typical household refrigerator, suchas afrozen food bility so that a pressure difference of approximately A0 inch of water, which is equivalent to about /2 lb. "per square foot pressure, acting on the underside thereof,

'as shown in FIGURE 2, is sufficient to open the-valve.

Preferably, valve 32 is located on theunderside of I the exterior surface of door 20 so that it is concealed from view but is exposed to the heat of theambientajr therer r storage compartment or freezer. In this embodiment, refrigerator 45 is provided with a box section 46. having an access'opening therein which isv closed by an access door section 47' and gasket 48, similar to that described with reference to the preceding embodiment of this. invention. A suitable rigid handle 49 is provided to open door .47. A compressor: 59 having a hot gas line 51 leading to a condenser 52 ismountedon the exte ior of box section .46 as'shown in'the drawing. Evaporator tubes 53 of the refrigeration system aredisposed beneath shelf 54' to cool the interior of the refrigerator. Box section 46 has an inner wall 669 and an outer'wall 61 between which is disposed insulation 62. p

An opening 65, which may have a suitable grommet about it, is formed in inner wall so of box section 46 and connects witha vent passage 63 through insulation 62. In order to prevent the entrance of moisture'into insulation'material 62 a wax or other coating 64 is preferably applied about the periphery of vent passage 63. A valve assembly 66 is secured by fastening means 7% about a suitable opening formed in outer wall 61 connecting with vent passage 63. p

Valve assembly 66 comprises a base'member 67 which may be of metal or other material having one or more ports 71 formed therein. A flexible diaphragm 68, which may be formed of plastic'or metal, is secured by suitable means 69 to base member 67. As in the preceding embodiment, valve 66 is preferably designed to operate at F '3 a suitably low. pressure difference such as /2 lb. per square foot difference in pressure so as to facilitate opening of door 47- by admitting ambient air into the interior of box 46. On the other hand, valve 66 is also designed as in the preceding embodiment so that it will not normally be openedby the differences in pressure encountered by cycling of the refrigeration system, so as to prevent unwarrantedreductionin control andelfective capacity of the refrigeration system. It will also be apparent that valve 66, like valve 32 previously described, is a check valve which operates in only one directionso that air may be admitted into box 46. but is 'not permitted to escape from the box to the exterior.

Means are provided to supply heat to valve 66' in order to prevent malfunction of the valve due to ice formation about it. As shown in FIGURE 5, the means to heat valve 66 may comprise hot gas line 51 leading from compressor 50 to condenser 52 placed in heat exchange relation with the valve. In effect, heat absorbed by evaporator coil 53 from the box is rejected from 'hotgas line 51 to supply the heat required to keep valve 66 above the freezing point or at least above the dew point of both ambient air and the air contained in box 46. This effectively prevents the condensation of moisture on valve 66 and eliminates ice formation thereon which might otherwise prevent proper operation of the valve. Y

Other methods of heating valve 66may be employed, if desired, and as illustrated in FIGURE 4, the valve may be placed'in heat exchange relation with the relatively warm compressor 50 or condenser, 52,'as well as hot gas line 51 in order to' achieve the desiredheating. It will be appreciated that in a particular situation, any one of these means of supplying heat to valve 66 or any combination of them may be employed thereby enabling considerable flexibility in the location of the valve. In many situations the heat of the ambient air alone may be sufficient to maintain the valve above the desired temperature so that additional heating means is not required.

Many modifications and embodiments of this invention will be readily perceived from the foregoing description. For example, the valve member employed may be of the ball and seat variety rather than being of the flapper valve type as shown in the drawings. The entire valve may, if desired, be made of plastic or other material and may be located at any suitable point on either the box or door section. In addition, while the invention has been de scribed with reference to a refrigerated enclosure, other applications can be envisioned to reduce the force required to open the access door, an enclosure or other device whether or not a gasket of the type herein described is employed. It is preferred, however, to use a valve which senses a pressure difference between the exterior and interior of the cabinet with which it is employed, and automatically opens to admit ambient air therein upon the occurrence of a pressure exceeding a predetermined maximum desired pressure which is below that which gives rise to an inconveniently high force necessary to open the door.

Accordingly, other embodiments, modifications and applications of this invention within the scope of the following claims will become apparent to those skilled in the art.

I claim:

1. A refrigerated cabinet comprising:

a box section having means defining an access opening therein,

an access door section adapted to substantially close said access opening,

said cabinet including sealing means providing a seal between said access door and said box section to substantially prevent the passage of air between the interior and exterior of said box section when said access door is closed, said sealing means comprising a gasket secured to one of said sections, said 6 gasket having magnetic means associated therewith to retain it in sealed. engagement with the other of said sections, said gasket including an expansible web portion tending to initially increase the internal volume of said cabinet upon attempting. to open said access door, a refrigerationsystem associated with said cabinet to refrigerate the interior thereof, and a pressure operated check valve associatedwith said cabinet, said' check valve,

being disposed at a location on said cabinet such that it normally receives sufficient heat to inhibit the accumulation offrost thereon, so that the operationof said valve is not normally. impaired by frost, and

being constructed so as to automatically open in response to a predetermined differencein pressure between the interior and the exterior of said cabinet, thereby facilitating the opening of said access door by, admitting ambient air into said cabinet to prevent a pressure difference from existing'across saiddoor in' excess of said predetermined difference caused by an initial increase in volume of said cabinet due. to expansion of said gasket'uponattemptin'g to open said door.

2. A refrigerated'cabinet as defined in claim 1 wherein said check valve is designed to open at a pressure greater than the differences in pressure across said door due to cycling of the refrigeration system andless than a predetermined maximum pressure across said door which would give rise to an excessively high force opposing opening of said door.

3. A refrigerated'cabinet comprising:

a box section having means defining an accessv opening therein, an access door section adapted to substantially clos said access opening,

said cabinet including means providing a seal between said access door and said box section to substantially prevent the passage of air between the interior and exterior of said box section when said access door is closed, and

a pressure operated check valve associated with one of said sections, said valve comprising:

a ported base member disposed between the interior and exterior of said cabinet,

a diaphragm member secured to said base and covering the port in said base member on the side of said base member adjacent the interior of said cabinet, said diaphragm being flexible and arranged to flex away from said base to uncover said port and to admit air automatically into said cabinet upon the occurrence of a predetermined difference in pressure between the exterior and the interior of said cabinet, so as to facilitate opening of said access door.

4. A refrigerated cabinet comprising:

a box section having an access opening therein;

an access door section adapted to close said access opensaid cabinet including means adapted to provide an air seal between said access opening and said access door;

cooling means including a refrigeration system disposed so as to cool air in said cabinet;

valve means automatically operable upon the existence of a pressure difference in excess of a maximum desired difference in pressure between the interior and the exterior of said cabinet, for admitting air into said cabinet to reduce the pressure difference to a pressure not exceeding said maximum desired pressure difference;

means to supply heat from a portion of said refrigeration system to the region of the location of said valve means to reduce impairment of the operation of said valve by inhibiting the accumulation of frost thereon;

and i said means to supply heat from said refrigeration system to the region of the location of said valve means comprising a compressor of said refrigeration system disposed in heat'exchange relation with said valve means. 5. A refrigerated cabinet comp'ring: I a box section having an access opening therein; an access door section adapted to close said access opens; said cabinetincluding means adapted to provide an air seal between said access openingand said access door; cooling means including a refrigeration system disposed so as to cool air in said cabinet; valve means automatically operable upon the existence of a pressure difference in excess of a maximum desired difference in'pressure between the interior and the exterior of said cabinet, for admitting air into said cabinet to reduce the pressure difference to a pressure not exceeding said maximum desired pres sure difference; I means to supply heat from a portion of said refrigeration system to the region of the location of said valve means to reduce impairment of the operation of said valve by inhibiting the accumulation of frost thereon; and said means to supply heat from said refrigeration system to the region of the location of said valve means comprising a condenser of said refrigeration system disposed in heat exchange relation with said valve 7 means. I 6. A refrigerated cabinet comprising: a box section having an access opening therein;

an access door section adapted to close said access opens; 7 said cabinet includingmeansadapted to provide'an air seal between said accessopening andsaid access door; cooling means including a refrigeration system disposed so as to cool air in said'cabinet; i V v e i valve means automatically operable upon theexistence of a pressure difference in excess of a maximum desired difference in pressure between the interior and 10 the exterior of said. cabinet for admitting air into said cabinet to reduce the pressure difference to a pressure not exceeding saidmaximum desired pressure difference; 7 means to supply heat from a portion of said refrigeration system to the region of the location of said valve means to reduce impairment of'the operation of said valve by inhibiting the accumulation of frost thereon; and a r said means adapted to provide an. air seal comprising a gasket secured to one of said sections, said gasket having magnetic means associated therewith to retain it in sealedengagement with the other'of said sections, said gasket'including'an expansible web portion tendingto initially increase the internal volumeof said cabinet upon opening of said access door.

References, Cited by-theExaminer UNITED STATES PATENTS 2,135,091 11/38- Newill O 62-275 0 2,774,116 12/56 Vv'olverton 9887 1/58 'Hobbs a 9887 RGBERT A..OLEARY,' Primary Examiner. V

WILLIAM J. WYE, Examiner.

Claims

3. A REFRIGERATED CABINET COMPRISING: A BOX SECTION HAVING MEANS DEFINING AN ACCESS OPENING THEREIN, AN ACCESS DOOR SECTION ADAPTED TO SUBSTANTIALLY CLOSE SAID ACCESS OPENING, SAID CABINET INCLUDING MEANS PROVIDING A SEAL BETWEEN SAID ACCESS DOOR AND SAID BOX SECTION TO SUBSTANTIALLY PREVENT THE PASSAGE OF AIR BETWEEN THE INTERIOR AND EXTERIOR OF SAID BOX SECTION WHEN SAID ACCESS DOOR IS CLOSED, AND A PRESSURE OPERATED CHECK VALVE ASSOCIATED WITH ONE OF SAID SECTIONS, SAID VALVE COMPRISING: A PORTED BASE MEMBER DISPOSED BETWEEN THE INTERIOR AND EXTERIOR OF SAID CABINET, A DIAPHRAGM MEMBER SECURED TO SAID BASE AND COVERING THE PORT IN SAID BASE MEMBER ON THE SIDE OF SAID BASE MEMBER ADJACENT THE INTERIOR OF SAID CABINET, SAID DIAPHRAGM BEING FLEXIBLE AND ARRANGED TO FLEX AWAY FROM SAID BASE TO UNCOVER SAID PORT AND TO ADMIT AIR AUTOMATICALLY INTO SAID CABINET UPON THE OCCURRENCE OF A PREDETERMINED DIFFERENCE IN PRESSURE BETWEEN THE EXTERIOR AND THE INTERIOR OF SAID CABINET, SO AS TO FACILITATE OPENING OF SAID ACCESS DOOR.