Household Appliance

Abstract

A household appliance including a housing that has an opening; a door rotatable about a first rotation axis between a closed position in which the opening is closed by the door and an open position in which the opening is opened; a first door-opening unit to generate a first opening force to the door at least when the door is in the closed position; and a second door-opening unit to generate a second opening force to the door at least when the door is in the closed position. The second door-opening unit is arranged closer to the first rotation axis than the first door-opening unit.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to a household appliance, in particular a refrigerator, more particularly, to a household appliance including a housing having an opening and a door rotatable about a rotation axis for selectively opening or closing the opening.

BACKGROUND OF THE INVENTION

[0002] Arrangements of the above type are known from the prior art. A damper is normally used to prevent sharp movement of the door, in particular, when the door is opened and closed with rotation movement about a horizontal axis where gravity of the door could make the door fall down sharply.

[0003] In a side-by-side refrigerator like that as disclosed in US 2004/0178710 A1, a mini-door attached to a main door for a refrigerating compartment is provided with a damper for damping the rotation movement of the mini-door. The damper includes a case filled with oil and a rotation shaft rotatably mounted in the case. The damper is arranged to the opposite sides of the mini-door and the rotation shaft of the damper is connected to a hinge shaft of the mini-door which projects from a side surface of the mini-door, whereby the rotation movement of the mini-door when it is opened is supposed to be damped by a friction force or a hydraulic force generated between the rotation shaft and the oil.

[0004] To mount the damper to the refrigerator, additional space located between a side edge of the opening and a corresponding outer wall of the housing in the longitudinal direction, should be reserved for mounting the damper when the damper is mounted at the same lever as the hinge shaft in the prior art. When the damper has a relatively large length in the transversal direction, such required space limits the dimension of the opening and the mini-door. This drawback is more obvious when a larger damper is employed to damp a mini-door having larger weight. Another possible way to increase the damping force would be use of dampers with more-viscous fluid. These possible solutions would lead to another problem: for doors with different characteristics, the manufacturers have to use dampers with different sizes and/or types.

[0005] In addition, it is known in the prior art to use a push-push type door-opening unit to lock the mini-door in a close position and to release the mini-door from the lock state and generate an opening force to push the mini-door away from the close position such that the mini-door can start to rotate before the gravity of the mini-door makes it rotate downwardly. Such door-opening unit is arranged in association with an upper portion of the mini-door. For mini-doors with different characteristics, it is found that the opening force generated by such door-opening unit sometimes is not sufficient enough to pre-open the mini-doors, in particular when a sealing gasket is provided between the mini-door and the main door.

SUMMARY OF THE INVENTION

[0006] It is accordingly an object of the invention to overcome at least one of the problems as set forth above, and to provide a household appliance, in particular a refrigerator, in which sufficient opening force for the door can be automatically generated to open the door.

[0007] An aspect of the present invention relates a household appliance in particular, a refrigerator, comprising a housing having an opening; a door rotatable about a first rotation axis between a close position in which the opening is closed by the door, and an open position in which the opening is opened; and a first door-opening unit which is configured to generate a first opening force to the door at least when the door is in the close position; characterized by comprising a second door-opening unit to generate a second opening force to the door at least when the door is in the close position, wherein the second door-opening unit is arranged closer to the first rotation axis than the first door-opening unit.

[0008] In such a way, it is possible to generate sufficient opening force to the door at different areas of the door. The door's being reliably and smoothly opened can be expected accordingly.

[0009] Other features which are apart or in combination with other features considered as characteristic for the invention are set forth in the depended claims.

[0010] According to a preferred embodiment of the invention, the door is attached to the housing by a hinge shaft which defines the first rotation axis, and the second opening force is acted to the hinge shaft, which is particularly advantageous and convenient to arrange the second door-opening unit.

[0011] According to a preferred embodiment of the invention, the second door-opening unit is arranged at least adjacent to the first rotation axis.

[0012] According to a preferred embodiment of the invention, the second door-opening unit comprises a spring. Preferably, the spring is torsion spring.

[0013] According to a preferred embodiment of the invention, the spring has an axis at least substantially parallel to the first rotation axis when the spring is under a free state.

[0014] According to a preferred embodiment of the invention, the first door-opening unit is arranged in association with an upper edge portion of the door.

[0015] According to a preferred embodiment of the invention, wherein the first door-opening unit comprises a latching member for locking the door in the close position.

[0016] According to a preferred embodiment of the invention, the household appliance comprises a braking system for damping the rotation movement of the door when the door rotates between the close and open positions.

[0017] According to a preferred embodiment of the invention, the second door-opening unit is coupled to the braking systems.

[0018] According to a preferred embodiment of the invention, the braking system comprises a damper and a transmission unit coupled between the door and the damper for transmitting the movement of the door to the damper.

[0019] According to a preferred embodiment of the invention, the damper comprises a rotatable element configured to rotate about a second rotation axis which is distanced from the first rotation axis.

[0020] According to a preferred embodiment of the invention, the transmission unit comprises a gear rotatable about the first rotation axis, and the second door-opening unit is coupled to the gear.

[0021] According to a preferred embodiment of the invention, the housing comprises a storage compartment and a main door for selectively opening or closing the storage compartment, and wherein the opening is formed through the main door and the door is attached to the main door.

[0022] According to a preferred embodiment of the invention, the main door has a longitudinal side wall and a side portion positioned between the side wall and a longitudinal edge of the opening adjacent to the side wall, and wherein the second door-opening unit is located in the side portion.

[0023] According to a preferred embodiment of the invention, the main door has a thermal insulation space filled with thermal insulation material therein, and the second door-opening unit is enclosed in a receiving chamber which is disposed the thermal insulation space and isolated from the thermal insulation material.

[0024] According to a preferred embodiment of the invention, the receiving chamber is defined by a casing, and the casing is attached to a frame mounted around the opening.

[0025] Another aspect of the present invention relates to a household appliance, in particular a refrigerator, comprising a housing having an opening; a door rotatable about a first rotation axis between a close position in which the opening is closed by the door, and an open position in which the opening is opened; a braking system for damping the rotation movement of the door when the door rotates between the open and close positions; and a door-opening unit to generate an opening force to the door at least when the door is in the close position; wherein the door-opening unit is coupled to the braking system.

[0026] According to a preferred embodiment of the invention, the braking system comprises a damper and a transmission unit coupled between the door and the damper.

[0027] According to a preferred embodiment of the invention, the door-opening unit is coupled to the transmission unit.

[0028] According to a preferred embodiment of the invention, the transmission unit comprises a gear rotatable about the first rotation axis, wherein the door-opening unit is coupled to the gear.

[0029] According to a preferred embodiment of the invention, the household appliance comprises a receiving chamber for enclosing the braking system and the door-opening unit.

[0030] According to a preferred embodiment of the invention, the housing has an thermal insulation space filled with thermal insulation material, the receiving chamber is disposed in the thermal insulation space and isolated from the thermal insulation material.

[0031] According to a preferred embodiment of the invention, the door-opening unit comprises a torsion spring.

[0032] The construction of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

[0034] In the drawings:

[0035] FIG. 1 is a schematic front view of a refrigerator according to a preferred embodiment of the present invention.

[0036] FIG. 2 is a schematic perspective view of a refrigerating compartment door according to a preferred embodiment of the present invention.

[0037] FIG. 3 is an enlarged sectional view of the section I-I in FIG. 1 according to a preferred embodiment of the present invention.

[0038] FIG. 4 is a schematic perspective view showing a door coupled to a braking system according to a preferred embodiment of the present invention.

[0039] FIG. 5 is a schematic exploded view of a transmission unit according to a preferred embodiment of the present invention.

[0040] FIG. 6 is a side view of a transmission unit with a cover member being removed according to a preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0041] In the following detailed description of the preferred embodiments, identical or similar features have the same reference signs.

[0042] Referring now to the figures of the drawing in detail and first, particularly, to FIGS. 1, and 2 thereof. The refrigerator 1 includes a housing 2 defining a refrigerating storage compartment (not shown) which has a frontal opening selectively closed and opened by a refrigerating compartment door 24. The refrigerating compartment door 24 is rotatable about a longitudinal axis.

[0043] In this embodiment, a freezer storage compartment (not shown) is arranged side by side to the refrigerating storage compartment and is selectively closed or opened by a freezer compartment door 48. The refrigerating and freezer compartment doors 24, 48 define the front surface of the refrigerator 1.

[0044] It should be understood that though the preferred embodiment as illustrated is a side by side refrigerator, the present invention should not be limited thereto.

[0045] The freezer compartment door 48 and the refrigerating compartment door 24 each has a handle 60 which facilitates users to open or close the freezer compartment door 48 and the refrigerating compartment door 24.

[0046] The refrigerating compartment door 24 comprises a front wall 40 defines a front surface of the refrigerating compartment door 24, a rear wall 42 which is faced to the refrigerating storage compartment when the refrigerator compartment door 24 is in the close position. The rear wall 42 is distanced from the front wall 40 and an thermal insulation space (not shown) is formed therebetween to receive thermal insulation material. The thermal insulation space is closed by upper and lower walls 37, and left and right side walls 39 of the refrigerating compartment door 24.

[0047] When the refrigerating compartment door 24 is opened, ambient air enters into the refrigerating storage compartment. The ambient air usually has a temperature higher than a preset temperature set by a user or manufacturer. In some area, the ambient air contains high humidity. Accordingly, a cooling circuit of the refrigerator 1 has to work to reduce the temperature and/or the humidity within the compartment, which increases the energy consumption of the refrigerator 1. To reduce the energy consumption caused by opening the refrigerating compartment door 24, an opening 4 is formed through the refrigerating compartment door 24 and is normally closed by a door 6.

[0048] Through this opening 4, the user can access, without opening the refrigerating compartment door 24, to the refrigerating storage compartment and/or a storage space on the rear side of the refrigerating compartment door 24, thereby reducing heat exchange between the refrigerating storage compartment 26 and the ambient.

[0049] The opening 4 has a rectangular shape and comprises a lower edge 4a, an upper edge 4b and side edges 4c, 4d. The lower and upper edges 4a, 4b extend transversely in horizontal direction, and the side edges 4c, 4d extend in longitudinal direction.

[0050] The side edges 4c, 4d are distanced from a respective side wall 39 of the main door 24. The main door 24 has side portions 25 each of which is located between a respective side edge 4c, 4d of the opening 4 and a respective side wall 39 of the main door 24.

[0051] The refrigerating compartment door 24 has a frame 38 mounted along the opening 4. The frame 38 has a first side which is exposed to the opening 4 and a second side which is faced to the space and therefore exposed the thermal insulation material in the space.

[0052] The opening 4 is selectively closed or opened by the door 6. For refrigerators, the refrigerating compartment door 24 with a door 6 thereon can be also called as a main door, and the door 6 can be called as a mini-door or a home-bar door.

[0053] Referring to FIGS. 1 to 5, the door 6 is attached to the refrigerating compartment door 24 by a hinge shaft 8. The hinge shaft 8 extends in a horizontal direction and has an end received in a bottom portion of the door 6 and another end extending beyond the door 6.

[0054] The hinge shaft 8 defines a first rotation axis A. The first rotation axis A is parallel to a horizontal plane and is adjacent to the lower edge 4a of the opening 4. The door 6 is rotatable about the first rotation axis A between an open position in which the door 6 is opened and thus the opening 4 is accessible, and a close position in which the opening 4 is closed by the door 6. Preferably, the door 6 is substantially parallel to the horizontal plane when it is in the open position.

[0055] The refrigerator 1 preferably has a first door-opening unit 43 to lock the door 6 in the close position and to release the door 6 from the locked state and generate a first opening force to push the door 6 away from the close position.

[0056] The first door-opening unit 43 may have typical push-push structure. By pushing the door 6, the door 6 is locked in the close position by a latch member 44 of the first door-opening unit 43 such that the downward movement of the door 6 is prevented, and by pushing again the door 6, the door 6 is released from the locked state and the first opening force is generated, for instance by a spring of the first door-opening unit 43, to push the door 6 away from the close position.

[0057] The first door-opening unit 43 is preferably arranged in association with an upper portion of the door 6, such that the door 6 can be locked easily and the door 6 can start to rotate with a relatively small opening force.

[0058] When the door 6 rotates to said predetermined angle after which the gravity of the door 6 is able to drive the door 6 to rotate downwardly, the door 6 would rotate sharply because of the gravity without any damping means.

[0059] In order to avoid sharp fall of the door 6, the refrigerator 1 comprises a braking system 5 to damp the downward rotation movement of the door 6. The damping force generated by the braking system 5 decreases the rotation speed of the door 6 when the door 6 is opened.

[0060] The braking system 5 coupled to the door 6 is preferably positioned between the front wall 40 and the rear wall 42 of the refrigerating compartment door 24. In this embodiment, each lower corner of the opening 4 is provided with one braking system 5. In the description below, the braking system 5 positioned at the right lower corner of the opening 4 will be described. However, it should be noted that it is also possible that only one side of the door 6 is provided with the braking system 5.

[0061] The braking system 5 comprises a damper 10 to generate the damping force. In this embodiment, the damper 10 is arranged below and distanced from the lower edge 4a of the opening 4. The damper 10 is also positioned below and at a distance from the door 6 in a longitudinal direction.

[0062] As shown in FIG. 3, the damper 10 has a chamber 22 and a rotatable element 20 inside of the chamber 22. The rotatable element 20 is configured to rotate about a second rotation axis B. The second rotation axis B is distanced from the first rotation axis A and parallel to the latter.

[0063] The chamber 22 is filled with viscous fluid (such as oil) which is in contact with the rotatable element 20, whereby when the rotatable element 20 rotates friction force is generated between the rotatable element 20 and the viscous fluid.

[0064] Referring to FIGS. 3 to 6 in combination with FIG. 1, the braking system 5 comprises a transmission unit 12. The transmission unit 12 is coupled between the door 6 and the damper 10. In particular, the input end of the transmission unit 12 is coupled to the hinge shaft 8, and the output end thereof is coupled to the rotatable element 20 of the damper 10.

[0065] When the door 6 is opened, the movement of the door 6 is transmitted to the transmission unit 12 by the hinge shaft 8. The transmission unit 12 then drives the rotatable element 20 to rotate. Meanwhile, the friction force is generated against the rotation movement of the rotation element 20 and is transmitted to the door 6 by the transmission unit 12. In such a way, the downward rotation movement of the door 6 is damped and sharp fall of the door 6 can be prevented. Hereinafter, the transmission unit 12 will be illuminated in more details.

[0066] The transmission unit 12, arranged between the front wall 40 and the rear wall 42 of the refrigerating compartment door 24, is located beside the opening 4, in the side portion 25 of the refrigerating compartment door 24. The output end of the transmission unit 12 extends downwardly beyond the lower edge 4a of the opening 4 to couple with the damper 10.

[0067] In this embodiment, the transmission unit 12 utilizes a gear transmission. The transmission unit 12 comprises a first gear 14 coupled to the hinge shaft 8. The first gear 14 has a gear shaft 14a with a bore (not shown) into which the hinge shaft 8 is inserted. When the hinge shaft 8 rotates, the first gear 14 is driven by the hinge shaft 8 to rotate about the first rotation axis A.

[0068] The transmission unit 12 further includes a second gear 18 coupled to the damper 10 to drive the rotatable element 20 of the damper 10. The second gear 18 is a cylinder gear in this embodiment, and rotatable about the second rotation axis B. The second gear 18 is located below the first gear 14.

[0069] In this embodiment, the transmission unit 12 further includes two transmission gears 15, 16 coupled in series between the first and second gears 14, 18. The transmission gear 15 coupled to the first gear 14 has a rotation axis that is parallel to the first rotation axis A. The transmission gear 15 is closer to the rear wall 42 than the first gear 14.

[0070] The rotation axis of the transmission gear 16 which is coupled between the transmission gear 15 and the second gear 18 is located lower than the first gear 14 and the transmission gear 15. The rotation axis of the transmission gear 16 is distanced from both of the first rotation axis A, the second rotation axis B as well as the rotation axis of the transmission gear 15 in the front-rear direction. As shown in FIG. 6, each of the rotation axes of the transmission gears 15, 16 is distanced from a plane defined by the first rotation axis A and the second rotation axis B.

[0071] The first gear 14 has a diameter less than the second gear 18. The transmission unit 12 has a transmission ratio less than 1 from the door 6 to the damper 10. In such a way, the damper 10 can be kept at a lower speed which is particularly advantageous when the damper 10 employs viscous fluid. Meanwhile, the damping force from the damper 10 can be amplified with such arrangement.

[0072] The braking system 5 includes a mounting base 50 for mounting the transmission unit 12. The mounting base 50 comprises a base plate 58 and a plurality of protrusions 54a, 54b, 54c, 54d projecting from the base plate 58. The gears 14, 15, 16, 18 are attached to the protrusions 54a, 54b, 54c, 54d by their gear shafts, respectively. The protrusions 54a, 54b, 54c, 54d each has an axis which is the same to the rotation axis of the gears 14, 15, 16, 18, respectively.

[0073] A cylindrical bore 55 is formed in the protrusion 54a and penetrating the base plate 58 to receive the hinge shaft 8. The hinge shaft 8 is then inserted into the bore of the gear shaft 14a of the first gear 14 for coupling with the first gear 14.

[0074] The mounting base 50 is preferably an integral member, for instance it can be made by insert molding process, which is particularly advantageous to control the distance between the protrusions 54a, 54b, 54c, 54d and accordingly the distance between the gears 14, 15, 16, 18 can be controlled more accurately.

[0075] The braking system has a cover 52 attached to the mounting base 50. The cover 52 has a cover plate 53 which is substantially parallel to the base plate 58.

[0076] The mounting base 50 comprises a plurality of connection portions 56 dependent from the base plate 58 and extending towards the cover 52. The connection portions 56 each has a bore with thread therein. The connection portions 56 extend in a direction parallel to the first rotation axis A. The cover 52 has a plurality of holes 57 formed through a cover plate 53 of the cover 52. Fixing means (not shown) for example screws are inserted through the holes 57 and into the bore of the connection portions 56, respectively, to fix the cover 52 to the mounting base 50. The gears 14, 15, 16, 18 are accordingly received between the base plate 58 and the cover plate 53.

[0077] To ensure the door 6 is able to reliably rotate to said predetermined angle after which the gravity of the door 6 is able to make the door 6 rotate downwardly when the door 6 is opened, a second door-opening unit 46 is preferably provided, in addition to the first door-opening unit 43, to generate a second opening force to the door 6 when the door 6 is in the close position. In such a way, when the door 6 is released from the locked state, the first and second opening force make the door 6 rotate at least to the predetermined angle after which the door 6 rotates because of the gravity thereof.

[0078] The second door-opening unit 46 is located lower than first door-opening unit 43 in a longitudinal direction when the door 6 is in the closed position. While the first door-opening unit 43 is located in association with the upper portion of the door 6, the second door-opening unit 46 is arranged closer to the first rotation axis than the first door-opening unit 43.

[0079] The second door-opening unit 46 is coupled to the hinge shaft 8, the second opening force accordingly acts on the hinge shaft 8 directly. In this embodiment, the second door-opening unit 46 includes a torsion spring 48. The torsion spring 48 may have an axis which is at least substantially parallel to the first rotation axis A when the torsion spring 48 is under a free state.

[0080] The cover 52 comprises a cavity 49 in which a cylinder 51 is extending towards the mounting base 50 along the first rotation axis A. The torsion spring 48 is attached to the cylinder 51 and a first end of the torsion spring 48 is coupled fixedly to the cover 52. The second end of the torsion spring 48 is coupled to the gear shaft 14a of the first gear 14.

[0081] In particular, the cavity 49 is opened at a side closer to the mounting base 50 to receive the hinge shaft 14a. The cylinder 51 has a front portion that is inserted into the bore of the hinge shaft 14a. The gear shaft 14a has a mounting projection 47 protruding from its outer surface. The mounting projection 47 has a receiving bore therein extending in a direction parallel to the first rotation axis A. The second end of the torsion spring 48 is received in the receiving bore of the mounting projection 47. In such a way, the second door-opening unit 46 is coupled to the first gear 14, the hinge shaft 8 and the braking system 5.

[0082] When the door 6 is maintained in the close position, the torsion spring 48 is twisted and thus has a potential energy because of torque. When the door 6 is released from the locked state by pushing the first door-opening unit 43, the torque of the torsion spring 48 and the first opening force generated by the first door-opening unit 43 drive the hinge shaft 8 to rotate, which makes the door 6 rotate outwardly.

[0083] In this embodiment, the potential energy of the torsion spring 48 is consumed when the door 6 reach its open position, i.e. the torsion spring 48 is under the free state when the door 6 is in the open position. Accordingly the second opening force is continuously acted on the door 6 when the door 6 rotates from the close position to the open position. However, the second opening force is decreased when the door 6 rotates from the close position to the open position, and the influence on rotation speed of the door 6 after the door 6 rotates because of its gravity can be ignored, because the second opening force is significantly smaller than the damping force generated by the braking system 5 and the gravity of the door 6.

[0084] As set forth above, the braking system 5 is arranged between the front and rear walls 40, 42 of the refrigerating compartment door 24. To prevent the thermal insulation material being contact with the transmission unit 12 and the damper 10, the transmission unit 12 and the damper 10 is enclosed in a casing 28 which insulates the braking system 5 from the thermal insulation material, as shown in FIG. 3.

[0085] Preferably, the casing 28 has a body 30 defining a receiving chamber 32 for receiving the transmission unit 12 and the damper 10. The receiving chamber 32 is disposed in the thermal insulation space of the refrigerating compartment door 24. The receiving chamber 32 is opened at one end thereof for allowing insertion of the transmission unit 12 and the damper 10. After the transmission unit 12 and the damper 10 are received in the receiving chamber 32, lids 34, 36 are attached to the body 30 to close the receiving chamber 32 such that the receiving chamber 32 is isolated from the thermal insulation material in the thermal insulation space.

[0086] The casing 28 is attached to the frame 38. This is advantageous to position the casing 28 when foaming the main door 24. The frame 38 has a first side exposed to the opening 4 and an opposite second side faced to the thermal insulation space. The casing 28 is attached to the frame 38 at the second side. The body 30 of the casing 28 is preferably made as an integral part of the frame 38 for instance by an insert molding process.

[0087] In particular, the casing 28 is positioned at a lower corner of the frame 38, with the receiving chamber 32 extending along the lower edge 4a and the side edge 4c.

[0088] In the embodiment as illustrated above, the braking system 5 is configured to damp the movement of the door 6 in the refrigerating compartment door (main door). However, the present invention should not be limited thereto. For instance, the present invention is also suitable for household appliance having a single door, such as dishwashers and ovens etc. The single door for such household appliance can also be damped according to the present invention, in particular when the door is rotatable about a horizontal axis.

Claims

1-24. (canceled)

25. A household appliance, comprising: a housing having an opening; a door rotatable about a first rotation axis between a closed position in which the opening is closed by the door and an open position in which the opening is opened; a first door-opening unit configured to generate a first opening force to the door at least when the door is in the closed position; and a second door-opening unit to generate a second opening force to the door at least when the door is in the closed position, wherein the second door-opening unit is arranged closer to the first rotation axis than the first door-opening unit.

26. The household appliance of claim 25, wherein the household appliance is a refrigerator.

27. The household appliance of claim 25, wherein the door is attached to the housing by a hinge shaft that defines the first rotation axis, and wherein the second opening force acts on the hinge shaft.

28. The household appliance of claim 27, wherein the second door-opening unit is arranged at least adjacent to the first rotation axis.

29. The household appliance of claim 25, wherein the second door-opening unit comprises a spring.

30. The household appliance of claim 29, wherein the spring is a torsion spring.

31. The household appliance of claim 29, wherein the spring has an axis at least substantially parallel to the first rotation axis when the spring is in a free state.

32. The household appliance of claim 25, wherein the first door-opening unit is arranged in association with an upper edge portion of the door.

33. The household appliance of claim 25, wherein the first door-opening unit comprises a latching member to lock the door in the closed position.

34. The household appliance of claim 25, further comprising a braking system to dampen a rotation movement of the door when the door rotates between the closed and open positions.

35. The household appliance of claim 34, wherein the second door-opening unit is coupled to the braking system.

36. The household appliance of claim 34, wherein the braking system comprises a damper and a transmission unit coupled between the door and the damper to transmit a movement of the door to the damper.

37. The household appliance of claim 36, wherein the damper comprises a rotatable element configured to rotate about a second rotation axis which is distanced from the first rotation axis.

38. The household appliance of claim 36, wherein the transmission unit comprises a gear rotatable about the first rotation axis, and wherein the second door-opening unit is coupled to the gear.

39. The household appliance of claim 25, wherein the housing comprises a storage compartment and a main door to selectively open or close the storage compartment; wherein the opening is formed through the main door; and wherein the door is attached to the main door.

40. The household appliance of claim 39, wherein the main door has a longitudinal side wall and a side portion positioned between the side wall and a longitudinal edge of the opening adjacent to the side wall, and wherein the second door-opening unit is located in the side portion.

41. The household appliance of claim 39, wherein the main door has a thermal insulation space filled with thermal insulation material, and wherein the second door-opening unit is enclosed in a receiving chamber which is disposed in the thermal insulation space and isolated from the thermal insulation material.

42. The household appliance of claim 41, wherein the receiving chamber is defined by a casing, and wherein the casing is attached to a frame mounted around the opening.

43. A household appliance, comprising: a housing having an opening; a door rotatable about a first rotation axis between a closed position in which the opening is closed by the door and an open position in which the opening is opened; a braking system to dampen a rotation movement of the door when the door rotates between the open and closed positions; and a door-opening unit to generate an opening force to the door at least when the door is in the closed position, wherein the door-opening unit is coupled to the braking system.

44. The household appliance of claim 43, wherein the household appliance is a refrigerator.

45. The household appliance of claim 43, wherein the braking system comprises a damper and a transmission unit coupled between the door and the damper.

46. The household appliance of claim 45, wherein the door-opening unit is coupled to the transmission unit.

47. The household appliance of claim 45, wherein the transmission unit comprises a gear rotatable about the first rotation axis, and wherein the door-opening unit is coupled to the gear.

48. The household appliance of claim 43, further comprising a receiving chamber to enclose the braking system and the door-opening unit.

49. The household appliance of claim 48, wherein the housing has a thermal insulation space filled with thermal insulation material, and wherein the receiving chamber is disposed in the thermal insulation space and isolated from the thermal insulation material.

50. The household appliance of claim 43, wherein the door-opening unit comprises a torsion spring.