EP1907225A1

EP1907225A1 - Adjustable wheels

Info

Publication number: EP1907225A1
Application number: EP06805631A
Authority: EP
Inventors: Fredrik Adamsson
Original assignee: Electrolux Home Products Corp NV
Current assignee: Electrolux Home Products Corp NV
Priority date: 2005-07-15
Filing date: 2006-07-07
Publication date: 2008-04-09
Also published as: WO2007009614A1; NO20080806L; SE0501685L

Abstract

A wheeled levelling device (1) arranged to level and move refrigerators or freezers (2). The wheeled levelling device is adjustable from the front of the refrigerator/freezer through turning an adjusting rod (4). The wheeled levelling device is inserted in a rectangular hole of the bottom plate (5) of the refrigerator/freezer, preferably one in each corner, and interacts with two opposite sides of the rectangular hole. A wheel assembly (10) of the wheeled levelling device pivots around one of the sides of the rectangular hole during its operation as a convex ridge (40,41) of the wheel assembly interacts with a transversal wall (18) facing the wheel assembly.

Description

The present invention relates to a wheeled levelling device for households appliances such as refrigerators or freezers, more particular to the kind of wheeled levelling devices being operational from the front side of the refrigerator or freezer even if one of the wheeled levelling device is positioned at the rear of the refrigerator/freezer.

BACKGROUND OF THE INVENTION

For household products such as refrigerators or freezers it is an advantage if their installation can be done quickly and easily. One aspects of the installation process is to move the cabinet of the refrigerator/freezer in place and it is not uncommon that the cabinet is to be inserted in a narrow area squeezed between shelves and other cabinets in a kitchen. In order to facilitate the insertion refrigerators are generally equipped with roller assemblies or wheels allowing a back and forward motion of the cabinet. The use of roller assemblies also reduces the risk of undesirable scratch marks on the floors. Another desirable feature is the option of levelling the cabinet compensating for variations in the floor surface. It is naturally unsatisfactory if the cabinet stands unstable and even more the cabinet might twist when not supported on supports. The twisting of the cabinet may damage the function of the refrigerator preventing the doors from proper sealing leading to inefficient and power consuming operation. The aesthetic implications of a twisting or tilting refrigerator may also be perceived as unpleasant for the consumer. Furthermore the function of the refrigerator/freezer might be hampered if not levelled properly, for instance water in a defrosting system may flow in wrong directions.

One option for levelling refrigerators is providing adjustable legs as for example, in US 5 967 472 but most system uses different kinds of levelling systems comprising rollers or wheels.

US 3 534430 describe another levelling system having retractable front rollers and height adjustable front feet. The rear of the cabinet has non-adjustable wheels. US 5 971 408 describe a levelling system using height adjustable wheels positioned in the front part of the cabinet and the rear of the cabinet having non-adjustable wheels. Further levelling systems having adjustable front wheels and non-adjustable rear wheels are described in US 6 601 806 and US 4 783 879. US 4 748 715 describes a further roller assembly of adjustable front wheels. US 6 594 856 describes another pivotal roller mechanism.

In many cases it is not enough to merely adjust the front wheels and a problem with many levelling systems is to adjust the rear support of cabinet. Often it is impossible to directly access the rear part of the cabinet of a household appliance such as a refrigerator - commonly fitted in a narrow area against a wall. It is therefore an advantage if the rear supports can be height adjusted from the front of the cabinet. US 6 871 379 shows a stove using wheeled levelling devices in the rear of the stove. The wheeled levelling devices being adjustable by tightening an adjustment bolt using a socket wrench. US 4 789 121 shows a wheeled levelling device being accessible from the front by a threaded rod. US 4 955 569 describe a refrigerator levelling system. The levelling system comprising a front and a back set of rollers and adjustable legs mounted in the front of the refrigerator. The back rollers being height adjustable from the front side of the refrigerator through a connecting rod. US 5 749 550 also shows a wheeled levelling device for the rear of a cabinet adjustable from the front of the cabinet.

It is of course important to keep the production time and costs of the levelling system as low as possible. Thus a levelling device being simple to assemble and to install in the refrigerator cabinets is desirable and further that the components of the levelling device are not too complicated to manufacture. Moreover the levelling devices must be constructed to withstand substantial pressure since a cabinet in itself has a substantial weight and when filled even heavier. Another aspect is size restrictions. A refrigerator or a freezer comprises many parts each part competing for space, thus it is desirable that each part take up as little space as possible.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a wheeled levelling device that eliminates or at least minimizes some of the disadvantages mentioned above, this is achieved by presenting a wheeled levelling device for a cabinet, preferably a refrigerator or a freezer, the wheeled levelling device comprising; a holder having a transversal holder wall, a wheel assembly with a roller and a transversal roller case wall having two opposite roller case sidewalls between which said roller is rotatably secured, and an adjusting rod that passes through a roller case hole in the wheel assembly and through a holder hole in the holder, the holder and the wheel assembly arranged to pivot in relation to each other around a pivot point, where the wheeled levelling device is mounted in a rectangular hole in a bottom plate of said cabinet, and where each side wall has a convex ridge opposite to the transversal roller case wall and where the convex ridges are arranged to interact with the transversal holder wall as the wheel assembly pivots around the pivot point.

According to further aspects of the invention:

- the pivot point is situated at the lower end of the transversal roller case wall where the lower end of the transversal roller case wall is engaged to the bottom plate.

- the wheeled levelling device is accessible from the front of the cabinet through the threaded rod and that the height of wheeled levelling device can be adjusted by rotating the threaded rod.

- a spring is arranged around the threaded rod between the holder hole and the roller case hole pressing the upper part of the transversal roller case wall and the upper part of the transversal holder wall apart, where preferably the roller case hole is in the upper part of the transversal roller case wall and preferably the holder hole is in the upper part of the transversal holder wall.

- a nut is mounted on the threaded rod at the outer side of the roller case hole, which nut has an elongated body extending in a transversal direction of the threaded rod and which nut is prevented from following a rotational movement of the threaded rod by a stop member of the wheel assembly, the stop member being in the form of a flange fixed at the upper end of the transversal roller case wall and being arranged to extend above said nut.

- the threaded rod has an operative area between a first stop and a second stop enclosing the upper part of the transversal roller case wall and the upper part of the transversal holder wall and their operative components.

- the wheeled levelling device is inserted in a hole, preferably a rectangular hole, in the bottom plate of the cabinet wherein the wheeled levelling device is retained by holder retaining means arranged in the lower part of the holder and by roller case retaining means arranged in the lower part of the wheel assembly where preferably the holder retaining means is in the form of a folded tab protruding from the lower end of the transversal holder wall and where preferably the roller case retaining means is in the form of a folded tab protruding from the lower end of the transversal roller case wall. - the holder comprises two opposite roller case side walls and that two joining tabs protrudes from the lower ends of the holder sidewalls opposite to the transversal holder wall, where the joining tabs are folded inwards clasping the transversal roller case wall from each side.

- the pivot point is at the connection between a lower roller case tab and a bottom plate.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a perspective view of the preferred embodiment of the wheeled levelling device according to the present invention, and

Figure 2 shows the wheeled levelling device positioned in the rear part of a refrigerator/freezer and,

Figure 3 is an exploded perspective view of the preferred embodiment of the wheeled levelling device according to the present invention, and

Figure 4 is a top view of the preferred embodiment of the wheeled levelling device according to the present invention, and

Figure 5a is a cross sectional side view along the line I - 1 of figure 4 of the wheeled levelling device in its lowest position, and

Figure 5b is a cross sectional side view along the line I - 1 of figure 4 of the wheeled levelling device in a heightened position.

DETAILED DESCRIPTION OF THE INVENTION

In the following the present invention according to the preferred embodiment will be described. The invention is not intended to be limited to the preferred embodiment. Modifications and alternatives within the spirit and scope of the invention are also intended to be covered.

Figure 2 shows the wheeled levelling device 1 installed in the rear part of a refrigerator/freezer 2 arranged in a rectangular hole in the bottom plate 5 of the refrigerator/freezer 2. The wheeled levelling device 1 comprises a threaded rod 4 extending to the exterior of the front side of the refrigerator/freezer 2. By rotating the threaded rod 4 using a screwing arrangement 6 at the end of the threaded rod 4 accessible from the front of the refrigerator/freezer 2 a roller 10a of the wheeled levelling device 1 will be pushed down or up depending of the rotational direction thereby increasing or decreasing the height distance between the floor and the bottom plate 5. In the figure the front part is shown with an ordinary foot 8. Of course the wheeled levelling device 1 may also be used in the front of the refrigerator/freezer 2 as well as other levelling devices with or without rollers. By adjusting the supports 1, 8 - normally one in each corner of the bottom plate 5 - the refrigerator/freezer 2 can be levelled properly.

Figure 3 shows an exploded perspective view of the preferred embodiment of the wheeled levelling device 1, figure 1 shows the wheeled levelling device 1 assembled and figure 4 shows the wheeled levelling device from above. The wheeled levelling device 1 comprises a holder 9 mating a wheel assembly 10. The wheel assembly 10 comprising a roller case 10b, a roller axle 10c and a roller 10a. The roller 10a is rotatably secured in the roller case 10b by the roller axle 10c. The roller case 10b comprises two opposite roller case sidewalls 13, 14 (roller case side wall 14 hidden in figure 1 and 3) enclosing the roller axle 12 and the roller 10a and a transversal roller case wall 15. The roller case side walls 13, 14 are substantially triangular shaped - a first side of the triangle following the transversal roller case wall 15, a second side protruding from left to right (direction according to figure 3) at an obtuse angle α from the lower end of the transversal roller case wall 15 and a convex third side closing the triangle from the top of the transversal roller case wall 15 till the right end of the second side. The triangle intersection point between the second and the third side has a bevelling 35, 36 (bevelling 36 seen in figure 5b). The convex third side has a recess 44, 45 (recess 44 seen in figure 5b) in its middle part and a convex ridge 40, 41 between the recess 44, 45 and the bevelling 35, 36. The holder 9 comprises two opposite holder side walls 16, 17 and a transversal holder wall 18. The holder side walls 16, 17 have a right-angled triangular shape - the first leg along the transversal holder wall 18 and the second leg protruding from right to left (direction according to figure 3) at an right angle from the end of the transversal holder wall 18 and the hypotenuse closing the triangle substantially from the top of the transversal holder wall 18 till the left end of the second leg. Each roller case sidewall 13, 14 has a corresponding side hole 19, 20 (side hole 20 not seen in the figures) in their lower parts wherein the roller axle 10c is inserted. The roller axle 10c is cross riveted in each end at the side holes 19, 20. The roller case sidewalls 13, 14 comprises indentations 21, 22 (indentation 22 not seen in the figures) around the side holes 19, 20 preventing the ends of the riveted roller axle 12 protruding out from the side walls 13, 14. A threaded rod 4 having a first stop 23 preventing a cylindrical nut 24 arranged on the threaded rod 4 to be further screwed. The threaded rod 4 comprising the cylindrical nut 24 being inserted in a roller case hole 25 in the upper part of the transversal roller case wall 15. A spring 26 is thereafter applied around the threaded rod 4 - the threaded rod 4 thereafter being inserted in a holder hole 27 at the upper part of the transversal holder wall 18. Finally a protective washer 28 is applied on the threaded rod 4 and a second stop 29 is created by flat pressing the end of the threaded rod 4. The holder 9 and the wheel assembly 10 are thus joined in their upper parts through the threaded rod 4 - the spring 26 pressing them apart against the cylindrical nut 24 and the protective washer 28 at the second stop 29 respectively. The holder 9 and the wheel assembly 10 are facing each other at their open ends with the holder sidewalls 16, 17 enclosing the roller case sidewalls 13, 14. The lower parts of the holder 9 and the mating wheel assembly 10 are joined by two joining tabs 30, 31 - at each triangle point at the lower part of the holder side walls 16, 17 - clasping the transversal roller case wall 15. The lower end of the transversal roller case wall 15 comprises a lower roller case tab 32 protruding backwards preventing the joining tabs 30, 31 from sliding off the transversal roller case wall 15. An upper roller case tab 33 protruding backwards at the upper end of the transversal roller case wall 15 prevents the cylindrical nut 24 from rotating as the threaded rod 4 is operated. The upper roller tab 32 is folded from backwards the transversal roller case wall 15 and also strengthens the transversal roller case wall 15 in the transversal direction. The other end of the threaded rod 4 preferably has a screwing arrangement 6 comprising a third stop 6c preventing a hexagonal nut 6b to be further screwed and a cross-headed end surface 6a of the threaded rod 4. The cross- headed end surface 6a is also tooled to prevent the hexagonal nut 6b to be screwed off. Of course the invention is by no way limited to the actual embodiment of the screwing arrangement 6.

Figure 5a shows the wheeled levelling device 1 in its lowest position having a height h = HO between the ground 37 and bottom plate 5 of the refrigerator/freezer 2. The wheeled levelling device 1 is inserted in a rectangular hole in the bottom plate 5. The bottom plate hangs on the lower roller case tab 32 and a lower holder tab 38 protruding backwards from the lower part of the transversal holder wall 18. The wheel assembly 10 will pivot around a pivot point 7 - at the connection between the lower roller case tab 32 and the bottom plate 5 - as the cylindrical nut 24 moves back and forward along the threaded rod 4, the pivoting movement determined by the convex ridge 40, 41 at the roller case sides 13, 14 interacting with the transversal holder wall 18. The convex ridge 40, 41 meets the lower part of transversal holder wall 18. The curvature of the convex ridge 40, 41 determined by the length of the rectangular hole in the bottom plate 5, i.e. in order to maintain the distance between lower ends of the transversal roller case wall 15 and the transversal holder wall 18 thereby preventing the bottom plate 5 from coming off the lower holder tab 38 or the lower roller case tab 32 and also preventing the pivoting movement to get stuck. The pivoting movement causes the height h to change from a first height HO (figure 5a) to a second height Hl (figure 5b). When the threaded rod 4 is screwed clockwise the cylindrical nut 24 will move backwards along the threaded rod 4 lowering the height h and vice versa when screwed anti-clockwise. The cylindrical nut 24 is prevented by the upper roller case tab 33 to fully revolve and the cylindrical nut 24 will therefore screw along the threaded rod 4 as the threaded rod 4 is revolving. The direction of the movement of the cylindrical nut 24 is determined by the revolving direction of the threaded rod 4 and by the thread direction. The right angled distance between the roller cylindrical nut 24 and the pivot point 7 works a first lever arm and the right angle distance between the roller axle 12 and the pivot point 7 works a second lever arm. Having the first lever arm longer than the second lever arm reduces the force needed to adjust the height h. The obtuse angle α of the roller case side walls 13, 14 prolongs the operative distance of the cylindrical nut 24 compared to for instance if it was right angled. The spring 26 doesn't have any practical function during normal operation, i.e. when the wheeled levelling system 1 is subjected for a weight from a refrigerator/freezer 2, but when it is not subjected from any weight, for example if the refrigerator is tilted on its side, the spring 26 holds the holder 9 and the wheel assembly 10 apart keeping the wheeled levelling system 1 contained in the rectangular hole of the bottom plate 5. The recesses 44, 45 in the roller sidewalls 13, 14 (see figure 3 and 5b) are for installation purposes. During installation of the wheeled levelling system 1 the upper parts of the holder 9 and the roller case 10b is compressed, e.g. by hand, till the recesses 44, 45 meets the opposite side reducing the bottom area of the wheeled levelling device 1 which can then be inserted in the rectangular hole of the bottom plate where after the hand pressure is released the spring 26 yields back. An upper holder tab 46 protrudes at the upper part of the transversal holder wall 18 and is U-shaped in order to strengthen the transversal holder wall 18 in its transversal direction; of course this part is not essential for the function of the wheeled levelling device 1. The roller case hole 25 is preferably oblong in the vertical direction since the roller case hole 25 will follow a convex path as the wheel assembly 10 pivots around the pivot point 7, in so the threaded rod can stay horizontal during the pivot operation without wobbling up or down. The holder 9 and the roller case 10b are preferably cut and/or punched from a metal plate and thereafter folded to the desired shape. The lower roller case tab 32 will be exposed for more pressure than the lower holder tab 38 during operation and therefore the material thickness of the roller case 10b preferably can be larger than the material thickness of the holder 9. The side walls of the holder 9 and the roller case 10b is of course not limited to a triangular shape even though it is preferred. Furthermore it is obvious that the upper roller case tab 33 could be any stopping member preventing the cylindrical nut 24 from following the rotational movement of the threaded rod 4, for instance by folded parts protruding from the side walls 13, 14. The holder 9 could also be integrated in the bottom plate 5, for instance by punching three sides in the bottom plate 5 and folding the forth side upwards as the holder 9. The cylindrical nut 24 could of course have other forms for example such as an elongated rectangular nut, but also other forms are possible as long as the stopping member 33 prevents the nut 24 from following the rotation of the threaded rod. Moreover the pivot point 7 at the connection between the bottom plate 5 and the lower roller case tab 32 may move slightly in the connection area during the levelling operation due to the interaction at the connection and the interaction between the convex ridges 40, 41 with the transversal holder wall 18.

Thus it can be seen that the wheeled levelling device 1 can easily be installed and operated. It can further be seen that the installation of the wheeled levelling device can be accomplished simply by inserting the wheel assembly 10 and the holder 9 in a rectangular hole from above leading to a quick and safe installation process. A cabinet 2 is easy and quickly levelled by employing a plurality of wheeled levelling devices 1 at its bottom plate 5.

Whereas the invention has been shown and described in connection with the preferred embodiment thereof it will be understood that many modifications, substitutions, and additions may be made which are within the intended broad scope of the following claims. From the foregoing, it can be seen that the present invention accomplishes at least one of the stated objectives,

Claims

1. Wheeled levelling device (1) for a cabinet (2), preferably a refrigerator or a freezer, the wheeled levelling device (1) comprising; a holder (9) having a transversal holder wall (18), a wheel assembly (10) with a roller (10a) and a transversal roller case wall (15) having two opposite roller case sidewalls (13, 14) between which said roller is rotatably secured, and an adjusting rod (4) that passes through a roller case hole (25) in the wheel assembly (10) and through a holder hole (27) in the holder (9), the holder (9) and the wheel assembly (10) arranged to pivot in relation to each other around a pivot point (7) characterised in that the wheeled levelling device is mounted in a rectangular hole in a bottom plate (5) of said cabinet (2), in that each side wall (13, 14) has a convex ridge (40, 41) opposite to the transversal roller case wall (15) and in that the convex ridges (40, 41) are arranged to interact with the transversal holder wall (18) as the wheel assembly (10) pivots around the pivot point (7).

2. Wheeled levelling device (1) according to claim 1 characterised in that the pivot point (7) is situated at the lower end of the transversal roller case wall (15) where the lower end of the transversal roller case wall (15) is engaged to the bottom plate (5).

3. Wheeled levelling device (1) according to any preceding claims characterised in that the wheeled levelling device (1) is accessible from the front of the cabinet (2) through the threaded rod (4) and that the height of wheeled levelling device (1) can be adjusted by rotating the threaded rod (4).

4. Wheeled levelling device (1) according to any preceding claims characterised in that a spring (26) is arranged around the threaded rod (4) between the holder hole (27) and the roller case hole (25) pressing the upper part of the transversal roller case wall (15) and the upper part of the transversal holder wall (18) apart, where preferably the roller case hole (25) is in the upper part of the transversal roller case wall (15) and preferably the holder hole is in the upper part of the transversal holder wall (18).

5. Wheeled levelling device (1) according to any preceding claims characterised in that a nut (24) is mounted on the threaded rod (4) at the outer side of the roller case hole (25), which nut (24)has an elongated body extending in a transversal direction of the threaded rod (4) and which nut (24) is prevented from following a rotational movement of the threaded rod (4) by a stop member (33) of the wheel assembly (10), the stop member (33) being in the form of a flange fixed at the upper end of the transversal roller case wall (15) and being arranged to extend above said nut (24).

6. Wheeled levelling device (1) according to any preceding claims characterised in that the threaded rod (4) has an operative area between a first stop (23) and a second stop (29) enclosing the upper part of the transversal roller case wall (15) and the upper part of the transversal holder wall (18) and their operative components (24, 26, 28).

7. Wheeled levelling device (1) according to any preceding claims characterised in that the wheeled levelling device (1) is inserted in a hole, preferably a rectangular hole, in the bottom plate (5) of the cabinet (2) wherein the wheeled levelling device (1) is retained by holder retaining means (38) arranged in the lower part of the holder (9) and by roller case retaining means (32) arranged in the lower part of the wheel assembly (10) where preferably the holder retaining means (38) is in the form of a folded tab protruding from the lower end of the transversal holder wall (18) and where preferably the roller case retaining means (32) is in the form of a folded tab protruding from the lower end of the transversal roller case wall (15).

8. Wheeled levelling device (1) according to any preceding claims characterised in that the holder comprises two opposite roller case side walls (13, 14) and that two joining tabs (30, 31) protrudes from the lower ends of the holder sidewalls (16, 17) opposite to the transversal holder wall (18), where the joining tabs (30, 31) are folded inwards clasping the transversal roller case wall (15) from each side.

9. Wheeled levelling device (1) according to any preceding claims characterised in that the pivot point (7) is at the connection between a lower roller case tab (32) and a bottom plate (5).