DOOR LOCK SYSTEM FOR AN APPLIANCE

The present invention relates to a door lock system for an ap pliance. In particular, the present invention relates to a door lock system for a domestic appliance. Preferably, the present invention relates to a door lock system for a cooking oven. Fur ther, the present invention relates to an appliance with a door lock system.

The door of an appliance, in particular of a cooking oven, is often closed by the closing force of door hinges. Said closing force pushes the door towards a front frame and compresses a gasket. On the one hand, the closing force generated by the door hinges is strong enough to overcome the internal pressure of a cavity, e.g. of an oven cavity during a cooking process. On the other hand, said closing force should be sufficiently weak in order to obtain an achievable opening force for the user.

Further, there are lock mechanisms for oven doors, which avoid an opening of the oven door during specific functions, e.g. dur ing a pyrolytic self-cleaning function, or by unauthorised per sons, e.g. children. These lock mechanisms are mechanical or electromechanical devices with a hook element or the like.

It is an object of the present invention to provide a door lock system that increase the closing force of the door, wherein the door lock system allows the use of door hinges generating low opening forces.

The object is achieved by the door lock system according to claim 1. According to the present invention a door lock system for an ap pliance, in particular for a domestic appliance, preferably for a cooking oven is provided, wherein the door lock system com prises :

a hook element pivotable around a pivot axis between an un locked released state and a locked released state and mova ble along a main axis perpendicular to said pivot axis be tween the locked released state and a locked pulled state, a first sliding member movable along the main axis and pro vided for pivoting the hook element to the locked released state, and

at least one further sliding member movable along the main axis and provided for pulling the hook element to the locked pulled state.

The core of the present invention is that the hook element is pivotable between the unlocked released state and the locked re leased state on the one hand and movable between the locked re leased state and the locked pulled state on the other hand, wherein said hook element is driven by the sliding members being movable along the main axis.

Preferably, in the unlocked released state, wherein the system is not interacting with the door, the user is allowed to open and close the door without any deviation from what is the normal functioning of an oven. Particularly, in the locked released state, wherein the system is locking the door without applying a pulling force, the device is locking the door without pulling it in order to avoid an opening of the door itself during specific functions or for safety reasons in order to prevent the opening of the door by not allowed persons, e.g. children. In other words, the device in this position can cover also the function of a so-called standard pyro latch. Preferably, in the unlocked pulled state, wherein the system is pulling the door without locking the door itself, the system pulls the door against the front frame through the gasket without locking it. In this posi tion, if the user tries to open the door, then he is able to open said door like a standard oven, wherein however a greater force is needed to open the door. The force for pulling is big ger, since it is necessary to overcome the force given by a spring element. For example, pulling the door forces an upper arm to slide, while a lower arm maintains the same position. In this condition the hook is disengaged and can rotate upwards al lowing the opening of the door. Optionally, there is also a fourth state, namely a locked pulled state, wherein the system is pulling the door and locking said door itself. In this state, the device avoids the manual opening of the door during the pulling function and the opening of the door itself during spe cific functions or for safety reason to prevent the opening of the door by not allowed persons, e.g. children.

Preferably, the door lock system comprises at least one motor for driving the sliding members.

In particular, the door lock system comprises at least one cam driven or drivable by the motor and provided for driving the sliding members, wherein preferably the cam includes at least two eccentric disks provided for driving the first sliding mem ber and the further sliding member, respectively.

Further, the door lock system may comprise at least one detect ing element for detecting the presence and/or proximity of a counterpart engageable with the hook element, wherein preferably the detecting element is movable along the main axis.

Additionally, the door lock system may comprise at least one first switch element switchable by the detecting element. In particular, the door lock system comprises at least one base part formed as a casing and/or a frame, wherein the hook ele ment, the sliding members, the cam and/or the detecting element are arranged within or at said base part.

Preferably, the door lock system comprises a second sliding mem ber and a third sliding member movable along the main axis and provided for pulling the hook element to the locked pulled state .

In the preferred embodiment, the second sliding member and the third sliding member are arranged in series, wherein said series is arranged parallel to the first sliding member.

Additionally, the door lock system may comprise a first spring element between the first sliding member and the base part, a second spring element between the second sliding member and the base part, a third spring element between the third sliding mem ber and the second sliding member and/or a fourth spring element between the detecting element and the base part.

Further, the door lock system may comprise a second switch ele ment responding to the locked released state, wherein preferably the second switch element is switchable by the first sliding member .

Moreover, the door lock system comprises a third switch element responding to the locked pulled state, wherein preferably the third switch element is switchable by the second sliding member.

In particular, the door lock system comprises a push element for holding the hook element in the unlocked state, wherein prefera bly a fifth spring element is arranged between said push element and the base part. Additionally, the door lock system may comprise a fixation ele ment for attaching the door lock system to a carrier, wherein preferably a sixth spring element is arranged between said fixa tion element and the base part in order to compensate a devia tion from the intended position of the counterpart engageable with the hook element along an axis perpendicular to the main axis and the pivoting axis.

For example, the third spring element between the third sliding member and the second sliding member provides a compensation of a deviation from the intended position of the counterpart en gageable with the hook element along the main axis.

Further, the present invention relates to an appliance, in par ticular a domestic appliance, preferably a cooking oven, wherein the appliance comprises at least one door lock system mentioned above .

Novel and inventive features of the present invention are set forth in the appended claims.

The present invention will be described in further detail with reference to the drawing, in which

FIG 1 illustrates a schematic exploded perspective view of a door lock system according to a preferred embodiment of the present invention,

FIG 2 illustrates a schematic perspective view of the door lock system according to the preferred embodiment of the pre sent invention, FIG 3 illustrates a schematic sectional side view of the door lock system according to the preferred embodiment of the present invention,

FIG 4 illustrates a schematic top view of the door lock system according to the preferred embodiment of the present in vention,

FIG 5 illustrates a schematic detailed sectional side view of a hook element in an unlocked released state of the door lock system according to the preferred embodiment of the present invention,

FIG 6 illustrates a schematic detailed sectional side view of the hook element in a locked released state of the door lock system according to the preferred embodiment of the present invention,

FIG 7 illustrates a schematic detailed sectional side view of the hook element in a locked pulled state of the door lock system according to the preferred embodiment of the present invention,

FIG 8 illustrates a schematic detailed perspective view of the hook element in the unlocked released state of the door lock system according to the preferred embodiment of the present invention,

FIG 9 illustrates a schematic detailed perspective view of the hook element in the locked released state of the door lock system according to the preferred embodiment of the present invention, and FIG 10 illustrates a schematic sectional perspective view of the door lock system according to the preferred embodiment of the present invention attached at an appliance.

FIG 1 illustrates a schematic exploded perspective view of a door lock system 10 according to a preferred embodiment of the present invention.

The door lock system 10 comprises a base part 12, a hook element 14 and a pivot 16. For example, the base part 12 is formed as a casing or a frame. The hook element 14 is attached by the pivot 16 within the base part 12, wherein the hook element 14 par tially sticks out of said base part 12. The hook element 14 is slidable along its longitudinal axis and pivotable around the axis of the pivot 16. The hook element 14 includes a hook en- gageable with a counterpart. The sliding movement of the hook element 14 is performed by sliding the pivot 16 perpendicular to the axis of said pivot 16. In this example, the pivot 16 is slidable between two guiding rails of the base part 12. Prefera bly, the pivot 16 is formed as a metal pin.

Further, the door lock system 10 comprises a first sliding mem ber 18, a second sliding member 20 and a third sliding member 22. The sliding members 18, 20 and 22 are movable within the base part 12 along a main axis perpendicular to the axis of the pivot 16. The second sliding member 20 and the third sliding member 22 are arranged in series. The first sliding member 18 is arranged parallel to the series of the second sliding member 20 and third sliding member 22.

Additionally, the door lock system 10 comprises a first spring element 24, a second spring element 26 and a third spring ele ment 28 corresponding with the first sliding member 18, the sec- ond sliding member 20 and the third sliding member 22, respec tively. The first spring element 24 acts between the first slid ing member 18 and the base part 12. The second spring element 26 acts between the second sliding member 20 and the base part 12. The third spring element 28 acts between the second sliding mem ber 20 and the third sliding member 22.

Furthermore, the door lock system 10 comprises a motor 36 and a cam 38. The motor 36 is provided for driving the cam 38. In this example, the cam 38 is a single-piece part and includes two ec centric disks 40 and 42 having a common axis. The first eccen tric disk 40 acts on the first sliding member 18, so that a ro tation of the motor 36 and the cam 38 results in a movement of the first sliding member 18. The second disk 42 acts on the sec ond sliding member 20, so that the rotation of the motor 36 and the cam 38 results in a movement of the second sliding member 20.

Additionally, the door lock system 10 comprises a detecting ele ment 44 and a fourth spring element 46. The detecting element 44 is arranged partially within the base part 12 and partially sticks out of said base part 12. The detecting element 44 is movable along the main axis. The detecting element 44 is ar ranged beside the hook element 14. The fourth spring element 46 acts between the detecting element 44 and the base part 12.

Further, the door lock system 10 comprises a push element 48, a fifth spring element 50, a fixation element 52 and a sixth spring element 54. The fifth spring element 50 acts between the push element 48 and the base part 12. The push element 48 is provided for pushing the hook element 14 into an unlocked posi tion. The sixth spring element 54 acts between the fixation ele- ment 52 and the base part 12. The fixation element 52 is pro vided for fixing the base part 12 on a carrier of the appliance or a door 60.

Moreover, the door lock system 10 comprises a first switch ele ment 30, a second switch element 32 and a third switch element 34. The first switch element 30 responds to the presence or proximity of the door 60, if the detecting element 44 is moved against the first switch element 30 by said door 60. Alterna tively, the first switch element 30 responds to the presence or proximity of a front frame of the appliance, if the door lock system 10 is attached at the door 60. The second switch element 32 responds to a locked position of the hook element 14. The third switch element 34 responds to a pulled position of the hook element 14.

The door lock system 10 is either in an unlocked released state, a locked released state or a locked pulled state. In the un locked released state of the door lock system 10, the hook of the hook element 14 is not engaged with the counterpart. In the locked released state of the door lock system 10, the hook of the hook element 14 engages with the counterpart. In the locked pulled state of the door lock system 10, the hook of the hook element 14 pulls the counterpart towards said door lock system 10. For example, the counterpart is a recess in the door 60 or in the front frame, respectively.

The first sliding member 18 is provided for pivoting the hook element 14 by a movement along the main axis. In the preferred embodiment, the hook of the hook element 14 is engaged or en- gageable with the counterpart, when the first sliding member 18 is pushed towards the hook element 14. In this example, the hook element 14 is formed as a two-armed lever, wherein the one lever-arm includes the hook, while the other lever-arm is pushed or pushable by the first sliding member 18. The movement of the first sliding member 18 towards the hook element 14 effects the transition from the unlocked released state to the locked re leased state of the door lock system 10. The first sliding mem ber 18 is driven by the motor 36 via the first eccentric disk 40 of the cam 38.

The second sliding member 20 and the third sliding member 22 are provided for the pulling the hook element 14 into its pulled po sition. In this example, a hook of the third sliding member 22 engages with an edge of the hook element 14.

FIG 2 illustrates a schematic perspective view of the door lock system 10 according to the preferred embodiment of the present invention .

The components of the door lock system 10 are substantially ar ranged within the base part 12. In FIG 2, the door lock system 10 is in the unlocked released state. FIG 2 clarifies, that the hook element 14 and the detecting element 44 are arranged side by side.

FIG 3 illustrates a schematic sectional side view of the door lock system 10 according to the preferred embodiment of the pre sent invention.

In FIG 3, the door lock system 10 is in the unlocked released state. The first sliding member 18 is in contact with the hook element 14. A movement of said first sliding member 18 towards the hook element 14 would effect that the hook element 14 pivots form the unlocked position to the locked position. The hook ele ment 14 is kept in the unlocked position by the push element 48. FIG 4 illustrates a schematic top view of the door lock system 10 according to the preferred embodiment of the present inven tion. FIG 4 clarifies the arrangement of the components of the door lock system 10.

FIG 5 illustrates a schematic detailed sectional side view of the hook element 14 in the unlocked released state of the door lock system 10 according to the preferred embodiment of the pre sent invention.

When the door 60 is open, the door lock system 10 is in the un locked released state. When the door 60 is manually closed, then the detecting element 44 is moved towards the first switch ele ment 30 by the door 60. Then, the first switch element 30 sends a signal to a control device, so that the motor 36 can be acti vated manually by the user or automatically by the control de vice, when the motor 36 is activated it turns and drives the cam 38. In turn, the first eccentric disk 40 of the cam 38 drives the first sliding member 18, which is shown in FIG 6.

FIG 6 illustrates a schematic detailed sectional side view of the hook element 14 in the locked released state of the door lock system 10 according to the preferred embodiment of the pre sent invention.

The first sliding member 18 has pushed the hook element 14 in the locked position, wherein the hook element 14 has been piv oted around the pivot 16. The movement of the first sliding mem ber 18 is stopped by deactivating the motor 36, after the second switch element 32 has detected the locked position of the hook element 14 and has sent a corresponding signal to the control device. The locked released state of the door lock system 10 is reached, when the movement of the first sliding member 18 has been stopped. In this example, the clearance between the hook of the hook ele ment 14 and the counterpart at the door 60 is about 4 mm.

In the locked released state of the door lock system 10 the door 60 is locked, but not pulled against the front frame. This avoids that the door 60 may be opened by any specific function. Further, there are safety reasons that the door 60 cannot be opened by unauthorised persons, e.g. children.

FIG 7 illustrates a schematic detailed sectional side view of the hook element 14 in a locked pulled state of the door lock system 10 according to the preferred embodiment of the present invention. In FIG 7, the door 60 is pulled towards the front frame of the appliance, wherein said door 60 engages with the hook element 14.

A pulling function may be requested manually by the user or au tomatically by the control device. If the pulling function is requested, then the signal from the second switch element 32 in dicating the locked position does not stop the motor 36 via the control device. The further rotation of the motor 36 and the cam 38 effect a movement of the first sliding member 18, the second sliding member 20 and the third sliding member 22 with the hook element 14. The simultaneous movement of the first sliding mem ber 18, the second sliding member 20 and the third sliding mem ber 22 pulls the hook element 14 with the door 60 and so pulls the door 60 to the front frame without pivoting said hook ele ment 14. This is enabled by the guiding rails of the base part 12, in which the pivot 16 is slidable.

The simultaneous movement of the first sliding member 18, the second sliding member 20 and the third sliding member 22 is stopped, when the second sliding member 20 reaches the third switch element 34. The third switch element 34 sends a signal to the control device, so that the motor 36 and the cam 38 are stopped. After the simultaneous movement of the first sliding member 18, the second sliding member 20 and the third sliding member 22 has been stopped, the door lock system 10 is in the locked pulled state.

In the locked pulled state of the door lock system 10 the user is able to open the door 60. However, a bigger force is required for opening said door 60 as in a conventional appliance. When the door 60 is pulled by the user, then the third sliding member 22 is moved along the main axis, while the first sliding member 18 and the second sliding member 20 remain in its position. This is possible, since the second sliding member 20 and the third sliding member 22 are coupled by a sliding system allowing a relative movement between the two parts. The third spring ele ment 28 gives the resistance force, which needs to be overcome in order to create said relative movement, and which is trans lated in a bigger force to be applied to the handle. In this condition, the hook element 14 is pivotable and the door 60 can be opened.

Once the door 60 is opened, the first switch element 30 sends a signal to the control device. Then, the motor 36 is activated again in order to obtain the unlocked released state of the door lock system 10. This avoids issues linked to a further closing of the door 60. When the door 60 is closed again by the user, the door lock system 10 reaches the locked pulled state.

The end of the locked pulled state the door lock system 10 is requested manually by the user or automatically by the control device. When the end of the locked pulled state the door lock system 10 is requested, then the motor 36 and the cam 38 are ac tivated again and start to rotate. The first sliding member 18, the second sliding member 20 and the third sliding member 22 are simultaneously moved towards the hook element 14, so that the door lock system 10 reaches the locked released state. Then, a signal from the second switch element 32 is sent to the control device without deactivating the motor 36. Said signal is only a stroke check. The motor 36 and the cam 38 rotate further, so that the first sliding member 18 is moved away and disengaged from the hook element 14. Then, the hook element 14 is pivoted to the unlocked position by the push element 48 due to force of the fifth spring element 50. After that, the rotation of the mo tor 36 and the movement of the first sliding member 18 are stopped by a time control. For example, the rotation of the mo tor 36 and the movement of the first sliding member 18 are stopped a certain time after the first sliding member 18 has been disengaged from the hook element 14. When the movement of the first sliding member 18 has been finished, then the door lock system 10 is in the unlocked released state shown in FIG 5.

In this example, the pulling stroke is about 6 mm, wherein the clearance between the hook of the hook element 14 and the coun terpart at the door 60 of about 4 mm has to be overcome, while the door 60 is pulled over a distance of about 2 mm.

FIG 8 illustrates a schematic detailed perspective view of the hook element 14 in the unlocked released state of the door lock system 10 according to the preferred embodiment of the present invention .

Optionally, the hook element 14 includes at least one lateral appendix 56, while the base part 12 includes a corresponding slotted guide system 58. In this example, the hook element 14 includes two lateral appendices 56 and the base part 12 includes two slotted guide systems 58. The lateral appendices 56 and the slotted guide systems 58 provide mechanical constraints for the movement and the pivoting the hook element 14. In this example, the slotted guide system 58 has the shape of the numeral "1".

The slotted guide systems 58 guarantee that the pivoting of the hook element 14 is allowed in one position only. In this exam ple, the pivoting of the hook element 14 is allowed only in the outermost position of the linear route of said hook element 14. In FIG 8 the positions of the lateral appendices 56 in view of the slotted guide systems 58 are shown for the unlocked released state of the door lock system 10.

FIG 9 illustrates a schematic detailed perspective view of the hook element 14 in the locked released state of the door lock system 10 according to the preferred embodiment of the present invention .

In FIG 9 the positions of the lateral appendices 56 in view of the slotted guide systems 58 are shown for the locked released state of the door lock system 10.

FIG 10 illustrates a schematic sectional perspective view of the door lock system 10 according to the preferred embodiment of the present invention attached at an appliance.

The door lock system 10 is attached at a chassis of the appli ance, wherein the hook element 14 and the detecting element 44 penetrate the front frame of said appliance.

The door lock system 10 includes tolerance compensation along the direction perpendicular to the main axis of said door lock system 10 and to the pivoting axis of the hook element 14. The door lock system 10 is fixed to the chassis by a locating sys tem, two pins and a single fixation screw. Said two pins are ar ranged at the end portion close to the hook element 14, while the locating system is arranged at the opposite end portion of the door lock system 10. The fixation screw connects the fixa tion element 52 to the chassis, wherein the sixth spring element 54 is arranged between the fixation element 52 and the base part 12. The sixth spring element 54 allows a movement of the base part 12 relative to the fixation element 52. This allows a com pensation of a deviation from the intended position of the door 60. For example, if the door 60 is higher than intended, then the position of door lock system 10 is adapted during the hook element 14 reaches the locked position. Thus, the sixth spring element 54 compensates the deviation from the intended position of the door 60.

Further, the door lock system 10 includes tolerance compensation along the main axis of said door lock system 10. The third spring element 28 between the second sliding member 20 and the third sliding member 22 allows relative movements of between said second sliding member 20 and third sliding member 22. The third spring element 28 maintains the intended distance between the second sliding member 20 and the third sliding member 22 and their intended positions to the hook element 14. If the door 60 is not in the intended position along the main axis, when the pulling function is activated, then the third spring element 28 compensates this deviation. In this example, the third spring element 28 is a compression spring.

The door lock system 10 according to the present invention may adopt three states, i.e. the unlocked released state, the locked released state and the locked pulled state. A transition from the unlocked released state to the locked released state is pos sible. Inversely, a transition from the locked released state to the unlocked released state is also possible. Further, a transi tion from the locked released state to the locked pulled state is possible, while the inverse transition from the locked pulled state to the locked released state is also possible. However, a transition from the unlocked released state to the locked pulled state and the inverse transition from the locked pulled state to the unlocked released are not allowed.

Although an illustrative embodiment of the present invention has been described herein with reference to the accompanying draw ings, it is to be understood that the present invention is not limited to that precise embodiment, and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the in vention. All such changes and modifications are intended to be included within the scope of the invention as defined by the ap pended claims.

List of reference numerals

10 door lock system

12 base part

14 hook element

16 pivot

18 first sliding member

20 second sliding member 22 third sliding member

24 first spring element

26 second spring element 28 third spring element

30 first switch element

32 second switch element 34 third switch element

36 motor

38 cam

40 first eccentric disk

42 second eccentric disk 44 detecting element

46 fourth spring element 48 push element

50 fifth spring element

52 fixation element

54 sixth spring element

56 lateral appendix

58 slotted guide system

60 door, oven door