EP1544558B1

EP1544558B1 - Chest Freezer

Info

Publication number: EP1544558B1
Application number: EP04106513.7A
Authority: EP
Inventors: Gaetano Patent Dep Whirlpool Europe s.r.l. Cascini; Marco Patent Dep Whirlpool Europe s.r.l. Cambi; Angelo Patent Dep Whirlpool Europe s.r.l Braccagni; Giuliano Patent Dep Whirlpool Europe s.r.l. Rosi
Original assignee: Whirlpool Corp
Current assignee: Whirlpool Corp
Priority date: 2003-12-18
Filing date: 2004-12-13
Publication date: 2018-05-30
Anticipated expiration: 2024-12-13
Also published as: BRPI0405608A; EP1544558A3; EP1544558A2; ITVA20030050A1

Description

The present invention concerns a chest freezer of the type which includes a hollow body defined by a flat edge onto which a door closes.
The problem of frost formation on the internal surfaces of the cavity is known in the domestic freezer sector. This problem is particularly noticeable in relation to the peripheral edge of the cavity where the moist air from the exterior seeps through the peripheral seal owing to the reduced pressure created inside the freezer by both cooling of air (with consequent reduction in volume) and condensation of moisture. The build-up of frost on this peripheral zone may be alarming to the user, who may think the freezer is faulty, and may also prevent the baskets supported by the edges of the cavity from sliding easily and the door from closing properly, with a consequent increase in the energy consumption of the appliance. The normal temperature cycle inside the freezer, due to the normal on-off setting of the compressor associated with the refrigerant circuit, is a further cause of ingress of air owing to the continual variations in pressure inside the cavity. One solution to this type of problem is illustrated in EP-A-494587 , where an attempt was made to resolve the above-mentioned problem by using a diaphragm external to the cavity but in communication with it. This solution is, however, complicated and costly, although it considerably reduces the problem of frost formation within the cavity. US 2420240 A discloses an up-right refrigerator with an air channel surrounding the door and separated from the cavity by means of two annular gaskets in which upper and lower vents are present for putting the channel into communication with the cavity. EP 0879999 A2 discloses an anti-frost device for refrigerator in which heating means are present. GB 721035 A discloses a cabinet of a refrigerator with a recessed door to provide an air space for allowing convention air flow for transferring moisture from the freezer door to a lower compartment.
The object of the present invention is to provide a chest freezer which does not exhibit the disadvantages described above and for which production does not involve increased costs.
This object is achieved by means of the characteristics listed in the appended claims. All the essential features of a chest freezer according to the present invention are disclosed in the independent claim 1. Investigations and tests carried out by the Applicant have shown that, with the stratification of the air flows entering via the seal, the effect of a "channel" of variable section is to prevent frost formation on the frame of the cavity since the moisture is directed toward the interior of the cavity where frost formation (for example, on frozen products) is less problematic. This effect is due to the fact that, since the incoming moist air is warmer, it tends to rise, and suitable channels can therefore be used to guide this flow.
Said channels are preferably made on an internal surface of the door. This avoids costly modifications to the structure of the cavity, since only the mould used to make the internal door surface, commonly called the "inner door", is modified. The channels are substantially straight with a section which increases from the end zones toward the centre line zones on each side of the chest freezer, where the section of these channels is greatest. The channels preferably have three inclinations. Considering a vertical section, longitudinal to the channel, there is an inclination of the upper surface (with reference to the configuration when the door is closed) so as to increase the section from the ends toward a central zone.
Considering a horizontal section, longitudinal to the channel, there is an inclination toward the interior of the cabinet. Finally, considering a vertical section, transverse to the channel, there is an inclination (although slight) toward the interior of the cabinet.
Further advantages and characteristics of a freezer according to the present invention may be seen from the detailed description given below, which is given purely for illustration and is not limiting, with reference to the accompanying drawings in which:

Fig. 1 is a perspective view of a known type of a chest freezer with the door shown open;
Fig. 2 is a similar view to that in Fig. 1 and illustrates a chest freezer according to the invention;
Fig. 3 is a plan view of the internal surface of the door on the chest freezer in Fig. 2;
Fig. 4 is a sectional view according to the line IV-IV in Fig. 3;
Fig. 5 is a sectional view according to the line V-V in Fig. 3; and
Fig. 6 is a sectional view according to the line VI-VI in Fig. 3.

Referring to Fig. 1, 10 designates a chest freezer with a cabinet 12 on which a door 14 is hinged. The cabinet 12 has a cavity 12a for food preservation, accessible via its aperture A. This aperture is defined by an internal rim K on which unwanted frost deposits occur. The door 14 has a raised central portion 14a which penetrates the interior of the cavity 12a to improve thermal insulation. Around the rim K, the cabinet 12 has a flat frame 16 on which there rests a peripheral seal 18 which fits into a corresponding groove 20 in the door.
According to the invention, and referring to Fig. 2 and those following (in which like parts will be indicated using like reference symbols to those in the known freezer in Fig. 1), the door 14, at the side of the central portion of greater thickness 14a, has channels 22 of variable section, which, when the door 14 is closed, are positioned facing the frame 16.
Each channel 22 exhibits a form which is substantially straight with a U-shaped cross-section increasing from ends H (placed close to the vertical edges V of the cabinet 12 when the door is closed) toward a centre line zone M.
This variation in section is obtained by forming an internal edge 22a in each channel so that it is defined by two straight portions with an angle between them converging toward the centre line zone M. In this way the form of each channel 22 is substantially an isosceles triangle of which the base is parallel to the edge of the door and the two sides (which define the internal edge 22a of the channel) converge toward an apex at the centre line M so as to intersect an edge of the zone of greater thickness 14a of the door 14. A further variation in the section of the channels 22 is due to the variation in depth of the channels from the end zones H to the centre line M, this variation in depth being very clear in Fig. 4.
The bottom wall of each channel 22 preferably has a second inclination across its direction, such that its section also increases from the exterior toward the cavity 12a. It is therefore possible to identify, for the bottom wall of each channel 22, a double inclination in relation to the horizontal plane of the door: a first inclination, from the end zones H toward the centre line M, due to the variation in depth of the channel; and a second inclination in the transverse plane of the channel which facilitates the conduction of the incoming moist air toward zones away from the rim K. The side walls of each channel 22 are angled in relation to the vertical to facilitate removal from the mould.
In order further to facilitate the conduction of the moist air toward the cavity, each channel 22 has, on its edge 22a turned toward the interior of the cavity 12a and on the centre line M, a notch 26, trapezoidal in shape in the example illustrated, which penetrates the zone of greater thickness 14a of the door 14. This notch 26, when the door is closed, extends beyond the rim K ensuring that the moist air is rapidly carried away, owing to stratification of the flows, toward the cavity 12a.
Since the internal surface of the door 14 is usually obtained from a sheet of polymeric material (liner) by thermoforming, formation of the channels 22 involves only a modification to the thermoforming mould compared to known solutions. Another example, which is not part of the present invention, also functions if the channels are shaped in the opposite way, namely with the various inclinations running from the centre line M to the ends H. Obviously this involves placing the small trapezoidal "holes" in the corners instead of on the centre lines. However this example has disadvantages in respect to the stated invention, because the seal is less tight in the corners, so a hole which is on the centre line will provide greater thermal dispersion.

Claims

Chest freezer of the type comprising a hollow body (12)) in the form of a parallelepiped is comprising a flat edge (16) onto which a door (14) closes, characterised in that between this edge (16) and the door (14) are defined channels (22, 26) of variable section, said channels (22) being substantially straight with a section which increases from the ends (H), said ends (H) being placed close to the vertical edges (V) of the cabinet (12) when the door is closed, toward the centre line zones (M) where said section is greatest.
Chest freezer according to claim 1, characterised in that said channels (22) are made in an internal surface of the door (14).
Chest freezer according to claim 2, characterised in that the internal surface of the door (14) has, close to the edges, channels (22) each having one side substantially parallel to the edge of the door and two opposing sides (22a) inclined and converging toward said centre line zones (M).
Chest freezer according to claim 3, characterised in that the bottom surface of each channel (22) exhibits a first inclination in relation to the horizontal due to a difference in depth between the centre line (M) and the ends (H).
Chest freezer according to claim 4, characterised in that the bottom surface of each channel (22) exhibits a second inclination in relation to the horizontal due to an increase in depth toward the internal edge (22a) of the channel (22).