In common refrigerators shelves in refrigerators are movable within the tracks provided in the body horizontally parallel to each other. In case a shelf is to be repositioned into another track, all of the items must be removed from the shelf before the shelf can be removed from its track.

In the state of the art, for instance in US Patent No. 5913584 and 5199778 rack gear mechanisms are defined to provide vertical movement of the shelves within the compartment. However, this kind of additional mechanisms are costly.

In Swiss Patent 688246, a mechanism to move the shelves vertically by means of a drive device is defined.

The object of this invention is to provide a household appliance with shelf tracks within the body to facilitate vertical or horizontal movement of the shelves.

The household appliance realized to attain the objects of this invention is shown in the attached drawings, in which Figure 1 is the perspective view of the household appliance comprising a shelf track to accommodate a single shelf slot.

Figure 2 is the perspective view of the household appliance comprising a shelf track to accommodate multiple shelf slots.

Figure 3 is the exploded view of a shelf and multiple castors.

Figure 4 is the schematic view of of a shelf track including front sloped crossing tracks in which a shelf can be moved downwardly or upwardly from the junction points.

Figure 5 is the schematic view of a shelf track including rear sloped crossing tracks in which a shelf can be moved either downwardly or upwardly from the junction points.

Figure 6 is the schematic view of a shelf track including concave curved crossing tracks.

Figure 7 is the schematic view of a shelf track including convex curved crossing tracks.

Figure 8 is the schematic view of a shelf track including"S"formed crossing tracks.

Parts shown in the figures are numbered as follows : 1. Household appliance 2. Shelf 3. Shelf track 4. Horizontal tracks 5. Crossing tracks 6. Shelf slots 7. Junction point 8. Protrusion 9. Castors The household appliance (1), preferably a refrigerator, according to this invention comprises one or more shelves (2) on which articles are placed and one or more shelf tracks (3) to support and keep the shelves (2) in which the shelves (2) can move.

The shelf track (3) comprises one or more horizontal tracks (4), one or more crossing tracks (5) to adjust the shelf (2) downwardly or upwardly and move between the horizontal tracks (4), one or more junction points (7) at which the

horizontal tracks (4) and crossing tracks (5) are met and shelf slots (6) to enable the complete removal or placement of a shelf (2).

The shelf (2) comprises one or more protrusions (8) at the edges that contact the shelf tracks (3) to provide movement inside the shelf track (3).

Shelf (2) is placed within the household appliance by pushing forward after the protrusions are inserted into the shelf slots (6).

In order to move to an upper position, the shelf (2) is pulled out until it reaches the junction points (7) and then pressed upwardly. As the horizontal track (4) is guided into the intersecting upper crossing track (5) and mounted into the next upper track (4), the shelf is pushed inside the appliance to be fully placed into the horizontal track (4).

Whereas, in order to move to a lower position, the shelf is pulled out until it reaches the junction points (7) then its is guided towards the crossing track (5) intersecting the lower horizontal track (4). As it is inserted into the lower track, the shelf (2) is pushed inside the appliance (1) to be fully placed into the horizontal track (4).

In an embodiment of this invention, the shelf track (3) comprises junction points (7) to guide the shelves (2) to the upper or lower horizontal tracks (4). (Figure 4).

In another embodiment of this invention, the shelf track (3) comprises junction points (7) to guide the shelves (2) to either upper or lower horizontal tracks (4).

(Figure 5).

In another embodiment of this invention, the shelf track (3) comprises a single shelf slot (6) to provide the removal of the shelf (2) out only at a predetermined level. (Figure 1)

In another embodiment of this invention, the shelf track (3) comprises several shelf slots (6) to enable the shelf (2) to be completely pulled out from each horizontal track (4). (Figure 2) In another embodiment of this invention, the crossing tracks (5) are sloped frontally or rearwardly to facilitate the vertical or horizontal movement of the shelves (2) without having to remove the items placed onto the shelves (2).

(Figure 4 and 5) In another embodiment of this invention, the crossing tracks (5) are preferably convex or concave curved to provide smooth movement and to facilitate the vertical or horizontal movement of the shelves (2) without having to remove the items placed onto the shelves (2). (Figure 6 and 7) In another embodiment of this invention, the crossing tracks (5) are formed like the letter"S"to allow stepwise adjustment while the shelves (2) are moved between the horizontal tracks (4). (Figure 8) In a preferred embodiment, the shelf (2) comprises one or more castors (9) to facilitate the movement of the shelf (2) within the shelf track (3).

In the preferred embodiment, the castors (9) are secured to the protrusions (8).

As no additional mechanism is used to adjust vertical movement of the shelves (2) according to this invention, it is inexpensive to produce.

Thus the structure of the crossing tracks (5), the user is not affected by the weight of the shelves on which storage items are placed while adjusting the height of the shelves (2). As the shelf tracks (3) enables the repositioning of the shelves (2) without pulling the shelves completely out of the appliance, it provides an advantage in use wherein the door of the appliance cannot be fully open due to limited area of use.