The present invention relates to a door, especially for a household appliance which is fitted with a heat-insulating glazing.
A refrigerator with an insulated glazed door is known, for example, from U.S. Pat. No. 5,622,414. The door of this refrigerator is substantially constructed of two glass panels held at a fixed distance from one another by two spacers, of which the outer panel projects by a small distance over the inner panel in an edge zone in order to provide a working surface for a hinge for pivoting the door. In this edge zone the spacer is also lengthened beyond the edge of the inner panel in order to form a contact surface to which a plate of the hinge can be screwed. Since the hinge plate and the spacer must generally be made of metal for reasons of mechanical stability, a poor thermal insulation action of the door is obtained in this edge zone. There is thus a risk that condensation will deposit externally on this poorly insulated area of the door which, if not removed, can result in damage.
The formation of condensation could certainly be avoided by electrical heating using heating wires attached to the surface of the outer glass panel but this type of heating increases both the manufacturing costs of the appliance and also, as a result of intensified heat input exactly at a weak point of the thermal insulation, the power consumption of the appliance during operation and thus its operating costs.
A heat-insulating door for a household appliance having the features of the preamble of claim 1 is known from U.S. Pat. No. 5,588,421. This door comprises a frame made of sheet metal which ends on an outer side flush with a front glass plate and in which an opening is cut wherein a smaller inner plate is affixed. This door is primarily described as a door for a baking oven but should also be suitable for refrigerators. However, if such a door were in fact to be used in a refrigerator, the problem would also arise here that the heat conduction of the frame adjacent to the cool zone of the refrigerator would result in the formation of condensation on the exposed outer surfaces of the frame. The poor thermal insulation effect of the frame would also result in a high energy consumption of the refrigerator.
It is thus the object of the present invention to provide a door for a household appliance having large-area insulating glazing which exhibits good thermal insulation effect and is especially suitable for use in refrigerators.
The object is solved by a door having the features of claim 1. By dividing the frame into an outer frame part which bears the outer pane, an inner frame part which, when the door is mounted in a household appliance, closes its interior together with an inner pane, and an interposed thermal insulation element, the insulating capacity of the frame is decisively improved and the formation of condensation is prevented.
As a result of a preferred embodiment, the frame does not extend over the edge of the outer pane so that it is not visible for an observer looking at the door from the front and gives the impression that the door is formed substantially by the outer pane.
The frame is preferably connected to the outer frame by gluing. In order to conceal this type of gluing or other means for fixing the outer pane on the frame, the outer pane is provided with opaque decoration at least in its edge area. In order to protect it from damage, the decoration is preferably attached to the surface of the outer pane facing the inner pane.
In order to prevent air from the interior of the household appliance being able to reach the outer pane, a gap between the inner pane and the frame is preferably filled by a compressible sealing strip. Appropriately, this sealing strip is attached between the inner pane and the inner frame part.
The thermal insulation element is preferably a plastic profile element which engages in positive contact in grooves at least in the outer frame part. In order to effect a reliable coherence between the frame part and the insulation element, the grooves are at least locally undercut.
A particularly high insulation effect can be achieved with a thermal insulation element embodied as a hollow profile.
A flexible sealing profile which is provided to abut in an airtight fashion against the body of the household appliance when a door mounted on a household appliance is closed and thus to seal its interior, is preferably retained in a groove of the frame which is bounded at least by the inner frame part and the thermal insulation element.
A good insulation effect with a small thickness of the door at the same time can be achieved if the inner frame part, the thermal insulation element and the outer frame part are adjacent to one another from inside to outside not or not only in the thickness direction of the door but primarily transverse thereto, in a plane parallel to the inner pane of the door.
Further features and advantages of the invention are obtained from the following description of exemplary embodiments with reference to the appended figures. In the figures:
The outside of the door is formed by a glass panel 3 which is glued at its back to a frame 4 made of metal. Acting on the frame 4 are two hinge supports 5 fixedly connected to the body 1 of which only the upper one can be seen in the figure. An inner glass panel 6 (see
A handle 10 attached to the outer glass panel 3 is screwed in the frame 4 through two holes in the glass panel 3.
Formed on a side of the outer frame part 12 facing away from the cover profile 14 are two laterally undercut grooves 17 in which respectively one plastic web 18 engages in a form- and force-locking fashion. The two webs 18 produce a rigid connection to an inner frame part 19 which is likewise provided with grooves 17 in which the webs 18 engage. The inner glass panel 6 is connected at its edges to the inner frame part 19 by means of an adhesive layer 21. The inner glass panel 6 is thus connected rigidly to the outer glass panel 3 by means of the frame parts 12, 19 and the webs 3 and the layer of air enclosed in the gap 22 located therebetween form an effective insulation over a large part of the surface of the door 2. In the edge region of the door 2 the webs 18 are substantially responsible for the thermal insulation effect which, on the one hand as a result of their small cross-sectional area and on the other hand, as a result of the fact that they consist of a poorly heat-conducting plastic, present a considerable heat transfer resistance. A further contribution to the insulation effect comes about because the inner frame part 19 and the outer frame part 12 are hollow profile elements in which heat transport is substantially only possible along the walls.
Direct contact of cold air from the interior of the store cupboard with the webs 18 is prevented by a flexible seal 23 which engages in a gap 24 defined by the webs 18 between the frame parts 12, 19 and is anchored therein, and which is filled with ferromagnetic material in a fashion known per se on a side facing away from the anchoring on an opposing side so that it nestles tightly against the front of the body 1 as a result of magnetic force when the door is closed. The inner frame part 19 shields the seal 23 from the interior of the refrigerator so that cold air can only penetrate from there in a narrow intermediate space 25 between the seal 23 and the inner frame part 19 to a small extent.
The inner glass panel 3 is connected to the outer glass panel 3 by means of a spacer element 26, which can comprise an aluminium profile for example, as is known from window construction for buildings, and which interconnects the two glass panels 3, 6 hermetically by means of gluing or putty. The two glass panels 3, 6 and the spacer element 26 can be pre-assembled using technique known from insulated glass window construction and the intermediate space between the glass panels 3, 6 can be filled with a known gas having a better insulation capacity than air.
Before joining together the two glass panels 3, 6, an opaque decoration 27 is applied to the back of the outer glass panel 3 in an edge region, e.g. by screen printing, which decoration extends from the edge of the pane 3 inwards as far as over the spacer element 26 to conceal this and the frame 4 on the ready-mounted door.
As in the embodiment in
Here, the inner frame part 19 is separated from the inner glass panel 6 by a gap which is filled with a circumferential foam strand 29. At its side facing the glass panel 6, the foam strand 29 has a plurality of easily deformable ribs 30 which nestle closely against the glass panel 6. On the opposing side the strand 29 is anchored on the inner frame part 19 by a projection 31 which engages in positive contact into an undercut groove of the frame part 19.
A magnetic seal 23 which provides for an airtight connection of the door 2 to the front of the body 1 is anchored in a groove 32 which is formed on the one hand by the inner frame part 19 and on the other hand by a rib 33 which is thickened at the end and protrudes from the hollow profile 28 towards the body 1.
The magnetic seal 23 has a flexible tongue 34 which, when the door 2 is closed, nestles against its back over the entire length of the outer frame part 12 and thus closes a cavity 35 between the rib 33 and the outer frame part 12 in an airtight fashion and thereby contributes additionally to the thermal insulating effect of the door in the area of the seal 23.
Since, in this embodiment, the inner frame part 19 has no supporting function and is exposed to no strong mechanical loadings, it can be executed as very thin walled which likewise improves its insulating effect or, instead of metal, it can be made of a comparatively better-insulating plastic material. Another possible modification is to construct the inner frame part 19 in one part with the plastic hollow profile 28.
Number | Date | Country | Kind |
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103 24 854.4 | Jun 2003 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP04/05943 | 6/2/2004 | WO | 7/24/2006 |