TECHNICAL FIELD
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This application relates generally to freezer units and, more specifically, to a freezer unit with a door assembly adapted to limit vacuum induced door opening issues.
BACKGROUND
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Freezer units are commonly used in both commercial and residential environments. Such freezer units are accessible by a door that is pivotable between open and closed positions relative to an opening into the cooled compartment. The door commonly carries a perimeter gasket to seal against the face of the cabinet, in the regions surrounding the opening, when the door is moved to the closed position.
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In practice, the freezer door is hard to open if an attempt to open the door is made shortly after closing of the door. More specifically, when the freezer door is opened, the cold interior air leaving/exiting the freezer cabinet compartment, and is replaced by warm, lower density outside/ambient air. After the door is closed, the warm air inside of the freezer compartment rapidly cools, reducing its volume which creates a low-pressure condition (vacuum) inside the cabinet compartment. The force of the vacuum inside the compartment pulls the door against the cabinet and compresses the gasket, reducing the gap distance between the door and face of the cabinet. As a result, to open the door shortly after closing, a higher-than-normal force is required to overcome and break the vacuum. The low-pressure condition dissipates over time because the cabinet compartment is not perfectly sealed from the ambient environment.
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When opening the door shortly after closing, the process of opening includes pulling the door (e.g., using a handle), increasing the gap distance between the door and the face of the cabinet as the gasket expands from its vacuum compressed condition and overcoming the force induced by the low-pressure condition in the compartment, up to the point when gasket stretches/expands enough to break contact with the face of the freezer cabinet. Once the gasket breaks contact with the face of the freezer cabinet, ambient air, which begins entering the cabinet compartment, equalizes the pressure inside and outside of the freezer cabinet, and results in easy and rapid opening of the door.
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The opening force required for opening the door gradually increases from initial movement of the door to the point that the gasket breaks contact with the freezer face. During this process, the user is pulling the door and expanding the condensed air inside of the freezer compartment by an amount based upon the pressure differential between the compartment and ambient, the gasket compression distance that must be overcome and the inner door surface area subjected to the low-pressure condition. The higher-than-normal force required to open the freezer door under these conditions is undesirable.
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It would be beneficial to provide a freezer unit with a door assembly that is configured to limit the above-noted problem.
SUMMARY
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In one aspect, a method for enhancing door openability when the door is in the closed position and a low-pressure condition exists within the internal compartment of a freezer unit is provided, where the freezer unit includes a cabinet defining an internal compartment with an access opening, a cooling system for cooling the internal compartment, and a door movable between a closed position covering the access opening and an open condition uncovering the access opening, wherein the door carries a perimeter gasket engageable with a face of the cabinet, in regions surrounding the access opening, when the door is in the closed position. The method involves utilizing a door to cabinet gap limiter to limit compression of the gasket between the door and the cabinet when the door is in the closed position and the low-pressure condition exists. The method may further involve adjusting the door to cabinet to gap limiter to vary and set a desired or suitable lower limit of the dimension of a gap between an inner face of the door and the face of the cabinet, when the door is in the closed position.
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In another aspect, a freezer unit includes cabinet defining an internal compartment with an access opening, a cooling system for cooling the compartment to a set point temperature and a door movable between a closed position covering the access opening and an open condition uncovering the access opening. The door carries a perimeter gasket engageable with a face of the cabinet, in regions surrounding the access opening, when the door is in the closed position. A door closure limit device is configured and positioned for limiting compression of the gasket between the door and the cabinet when the door is in the closed position.
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The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
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- Fig. 1 is a perspective view of a freezer unit;
- Fig. 2 is a front elevation of the freezer unit;
- Fig. 3 is a perspective view of a door to cabinet gap limiter on the freezer unit;
- Fig. 4 is a top down view of the door to cabinet gap limiter;
- Fig. 5 shows a door gasket without compression;
- Fig. 6 shows a door gasket compressed;
- Figs. 7-10 show alternative embodiments of door to cabinet gap limiters.
DETAILED DESCRIPTION
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Referring to Figs. 1-4, a freezer unit 10 is shown and includes a cabinet 12 (e.g., formed by a frame structure with internal and external skins between which insulation is provided) an internal compartment 14 that is cooled by a refrigeration system 16 atop the unit (e.g., cooled air is circulated into the internal compartment by the refrigeration system). In embodiments, the refrigeration system may include an evaporator and associated fan, a compressor, a condenser and associated fan and an expansion device, all located along a path of refrigerant medium. A cabinet temperature sensor can be installed inside the compartment 14, or in a return air duct that circulates past the evaporator, or in any location within the cooled space that will serve as the basis for controlling the refrigeration system to cool the compartment 14 to a set point temperature (e.g., a freezing temperature).
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The freezer unit 10 includes a door 20 that is movable (e.g., pivotable via hinges 22) between the illustrated closed position and an open position relative to an opening 18 that is used to access the compartment 14. Here, the door 20 includes a door handle 24 that, in implementations, is a simple pull handle and, in other implementations, may operate a latching/unlatching function of the door. The door 20 carries a perimeter gasket 26 that faces toward the cabinet and engages with a face 12a of the cabinet, in regions surrounding the access opening 18, when the door is in the closed position. In embodiments, the gasket may carry an internal magnet 27 near its distal face to help seal and hold the door in the closed condition against the face of a freezer cabinet.
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The typical gasket 26 includes a normal, uncompressed condition in which a seal face 26a of the gasket is spaced from an inner face 20a of the door by a distance X1, per Fig. 5, and the gasket is configured to permit compression in a direction toward the inner face 20a that places the seal face 26a of the gasket at a distance X2 from the inner face 20a, per Fig, 6, wherein distance X2 is smaller than distance X1. Some very slight gasket compression from state shown in Fig. 5 when the freezer door 20 is in the closed position and the pressure of the internal compartment 14 is equalized to the external ambient pressure. However, such compression tends to be fairly limited. However, under the above-described low-pressure condition occurring immediately after door closure, the gasket can compress markedly toward the condition shown in Fig. 6.
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To address this issue, the freezer unit 10 includes one or more door to cabinet gap limiters 30 to limit compression of the gasket 26 between the door and the cabinet when the door is in the closed position and the low-pressure condition exists inside the compartment 14. The door to cabinet gap limiter is a door closure limit device that includes a component 32 carried by the door 20, wherein the component engages with a structure on the cabinet 12 to define a lower limit of a dimension of a gap G between the inner face 20a of the door and the face 12a of the cabinet 12, when the door is in the closed position. The lower limit of the dimension of the gap G is the smallest gap dimension obtainable under normal use (e.g., under normal door closure conditions, including when a low-pressure condition exists in the compartment 14). The component 32 carried by the door includes a stop 32a (e.g., of hard rubber) located along a perimeter edge 20b of the door and a stop mount arrangement 32b configured to enable adjustment of a position of the stop so as to adjust (decrease or increase) the lower limit of the dimension of the gap G. Here, the stop mount arrangement is an angle bracket 34 to which the stop 30 is fixed, and the angle bracket is secured to the door edge 20b by one or more threaded fasteners 36 passing through slots 38 of the bracket 34 and into tapped holes in the door. The slots 38 are oriented such that, when the fasteners 36 are loosened, sliding the bracket relative to the fasteners 36, via the slots 38, enables the distance D between the distal end of the stop 32a and the inner face 20a of the door to be varied, and the fasteners 36 can be tightened when the desired distance is achieved. Because the contact between the distal end of the stop 32a and the face 12a of the cabinet sets the lower limit of the dimension of the gap G, this adjustment enables the adjustment of the gap as needed to achieve desired sealing when the door is in the closed position, while preventing undesired gasket compression, and corresponding reduction of the gap, when the low-pressure condition exists in the internal compartment 14.
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Positioning the one or more door to cabinet gap limiters 30 opposite the pivot hinges of the door can be advantageous. In embodiments, it is desirable to position at least one door to cabinet gap limiter in a position spaced from the door pivot axis defined by the hinges 22 (e.g., positioning at least one door to cabinet gap limiter 30 closer to the side of the door that is opposite the side of the door at which the hinges are located).
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Other door to cabinet gap limiter configurations are possible.
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For example, Fig. 7 shows an embodiment in which the stop 32a is fixed to the face 12a of the cabinet, and the bracket (adjustable as above) engages the outwardly extending free end of the stop 32a to define the gap. In this embodiment, the bracket 34 moves away from the stop 32a when the door 20 is opened.
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Per Fig. 8, in another embodiment, the door to cabinet gap limiter may be more integrated into the door, such as door 20 including an integrated peripheral extension 20c that incorporates with an end stop 32a, and with an adjuster 32c internally of the door.
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Per Fig. 9, in another embodiment the door to cabinet gap limiter may be in the form of a stop 42a that is located at an exterior edge 26b of the gasket 26 and/or a stop 42b that is located at an interior edge 26c of the gasket 26. In one implementation, the stop(s) 42a, 42b could be threadedly engaged in openings of the inner face 12a of the door to provide for adjustment. In other implementations, the stop(s) 42a, 42b could be formed integral with the gasket 26 (e.g., molded as part of the gasket or adhered to the gasket).
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Per Fig. 10. in another embodiment, the door to cabinet gap limiter includes a structural component 44 internal of the gasket 26. The structural component 44 is of a material (e.g., sufficiently hard) and/or configuration (e.g., sufficiently stable) such that the component 44 is not compressed by the low-pressure condition in the internal compartment, and thus limits gasket compression and sets the lower limit of the gap.
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The above-described embodiment(s) provide a method for enhancing door openability when the door is in the closed position and a low-pressure condition exists within the internal compartment of a freezer unit that includes a cabinet defining an internal compartment with an access opening, a cooling system for cooling the internal compartment, and a door movable between a closed position covering the access opening and an open condition uncovering the access opening, wherein the door carries a perimeter gasket engageable with a face of the cabinet, in regions surrounding the access opening, when the door is in the closed position. The method involves utilizing a door to cabinet gap limiter to limit compression of the gasket between the door and the cabinet when the door is in the closed position and the low-pressure condition exists.
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Notably, during set-up of a given freezer unit, the door to cabinet to gap limiter may be adjusted to define a lower limit of a dimension of a gap between an inner face of the door and the face of the cabinet, when the door is in the closed position, so as to achieve both acceptable door closure and gasket sealing as well as suitable limiting of gasket compression under the low-pressure condition within the freezer compartment.
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By implementing the above-described door to cabinet gap and gap compression limiter(s), the situation in which the gasket compresses materially due to a low-pressure condition in the internal compartment of the freezer unit is reduced, along with the corresponding increased difficulty of opening the freezer door under such condition.
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It is to be clearly understood that the above description is intended by way of illustration and example only, is not intended to be taken by way of limitation, and that other changes and modifications are possible.