EP2846099B1

EP2846099B1 - Retaining and locking device for a door of an electric household appliance, in particular an oven

Info

Publication number: EP2846099B1
Application number: EP14183934.0A
Authority: EP
Inventors: Fabrizio Promutico
Original assignee: Bitron SpA
Current assignee: Bitron SpA
Priority date: 2013-09-09
Filing date: 2014-09-08
Publication date: 2018-09-19
Anticipated expiration: 2034-09-08
Also published as: EP2846099A1; ITTO20130724A1; PL2846099T3; TR201819330T4

Description

The present invention relates to a retaining and locking device for a door of an electric household appliance of the kind defined in the preamble of claim 1.
A retaining and locking device of that kind is disclosed in WO 2010/041210 A1 .
One object of the present invention is to provide a retaining and locking device of an improved type, having a mechanical structure which is relatively simple, inexpensive and reliable in operation.
This and other objects are achieved according to the invention with a retaining and locking device having the features defined in claim 1.
In a currently preferred embodiment, the slider is mounted translatably in said support structure, in a predetermined direction which is operationally horizontal.
Additionally, the aforesaid lever is conveniently made in the form of a rocker lever, and it also has an actuating arm essentially opposite the retaining arm with respect to the axis of oscillation, the actuating arm being capable of interacting with the operating formation of the slider.
The retaining arm of this rocker lever is conveniently designed to grip and retain an interacting formation of the door of the household appliance when this door is closed.
Further characteristics and advantages of the invention will be made clear by the following detailed description, provided purely by way of non-limiting example, with reference to the appended drawings, in which:

Figure 1 is a perspective view of a retaining and locking device according to the present invention;
Figure 2 is an exploded perspective view of the device shown in Figure 1;
Figure 3 is a partial perspective view of the device according to the preceding figures, shown in the condition assumed when the associated door of the household appliance is open;
Figure 4 is a partially sectional view, taken essentially along the line IV-IV of Figure 3;
Figure 5 is a perspective showing part of the device according to the preceding figures, in the configuration assumed when the associated door of the household appliance is closed;
Figure 6 is a partial sectional view taken essentially along the line VI-VI of Figure 5;
Figure 7 is a perspective view similar to that of Figure 6, showing the device in the condition in which the door is locked in the closed position;
Figure 8 is a partial perspective view of the retaining and locking device according to the preceding figures;
Figure 9 is a perspective view showing two components of the retaining and locking device according to the preceding figures;
Figure 10 is a partial perspective view showing the interaction of the slider of the retaining and locking device with a switch for signalling the open or closed condition of the door;
Figure 11 is a perspective view, partially in section, showing some details of Figure 10 from another viewpoint;
Figure 12 is a view similar to that presented in Figure 10, and shows the condition in which the slider of the retaining and locking device causes the opening of the associated switch device; and
Figure 13 is a view, partially in section, showing some details of the device in the condition of Figure 12.

In the drawings, the number 1 indicates the whole of a retaining and locking device for a door (not shown) of an electric household appliance, in particular an oven.
In the embodiment shown by way of example, the device 1 comprises a support structure or casing 2, comprising a lower container or shell 3 of elongate shape, partially closed by an upper cover 4.
A control module, indicated as a whole by 5, having a respective casing 6, is inserted and retained adjacently to the cover 4, in the lower container or shell 3.
In a known way, the support structure 2 of the device 1 is intended to be fixed to a household appliance, at the opening of which is coupled the door with which the retaining and locking device 1 is associated.
With particular reference to Figure 2 and the following figures, a slider indicated as a whole by 7 is mounted in a longitudinally translatable way between the container or shell 3 and the cover 4.
The slider 7 has a horizontal, transversely projecting, appendage 7a. A spring 8, which is of the coil type in the illustrated embodiment, is interposed between this appendage 7a of the slider 7 and a stop 3a (see Figure 8 in particular) provided in the lower container or shell 3.
At one end, the slider 7 has a further, essentially vertical, transverse appendage 7b. This appendage extends out of the support shell 2 through an opening 3b formed in the base wall of the container or shell 3 (Figure 2).
The arrangement is such that the spring 8 tends to push the slider 7 into the longitudinal rest position shown in Figures 1, 3 and 4 and to keep it there, this position, as will be more apparent from the following text, being the position assumed by this slider 7 in use when the associated door of the household appliance is open.
A formation F (Figures 3, 5 and 7), intended to be gripped and retained by a retaining member of the device 1, is conveniently fixed to said door of the household appliance, in order to keep said door in the closed position of the household appliance.
In the illustrated embodiment, the formation F has a transverse groove 50 formed by two facing walls 51 and 52. This configuration of the formation F is shown purely by way of example. In simplified embodiments, this formation could even comprise only the portion or wall indicated by 51 in the drawings.
The groove 50 and the walls 51 and 52 of the formation F extend in a transverse direction with respect to the longitudinal direction of movement of the slider 7 relative to the support structure or casing 2 of the device 1.
In particular, the slider 7 can be engaged by the formation F of the associated door of the household appliance when this door is being closed, and can consequently be moved from the rest position shown in Figures 1, 3 and 4 to a working position shown in Figures 5 - 7, 12 and 13.
As will be more apparent from the following text, when the slider 7 is in the working position its end 7c, opposite the appendage 7b, interacts by means of an inclined plane with a movable member 9 (see Figure 10, for example) of the control module 5, which in this condition then causes the opening of a switch 10 inside said module. This switch 10 comprises a fixed conductive strip 11 and a movable conductive strip 12 with which said member 9 interacts.
In use, the switch 10 acts as an electrical sensor, to signal that the door of the household appliance with which the retaining and locking device 1 is associated has been closed.
The retaining and locking device 1 further comprises a rocker lever 13 mounted oscillatably about a pivot 14 carried in a preferably fixed position by the lower container or shell 3, under the slider 7.
The axis of the pivot 14 is substantially orthogonal to the trajectory of the slider 7, and is preferably horizontal.
The rocker lever 13 is of elongate shape, and extends essentially in the longitudinal direction of the slider 7. It has a retaining arm 13a, intended to interact with the formation F to retain the door in the closed position, and an actuating arm 13b essentially opposite the arm 13a with respect to the pivot 14.
In the embodiment illustrated in a simplified form, the rocker lever 13 has a generally curved shape, with its convexity on the side opposite the pivot 14. Its arms 13a and 13b are correspondingly curved downwards.
The rocker lever 13 has a central downwardly projecting appendage 13c, in which an opening 13d is formed for the passage of the pivot 14 (see Figure 2 in particular).
The central part of the rocker lever 13, including the appendage 13c, extends through a longitudinal slot 7d in the slider 7 (see Figures 2 to 5, for example).
Preferably, the centre of mass of the rocker lever 13 is located between the axis of the pivot 14 and the end of the forward arm 13a.
With reference to Figures 4, 6 and 7 in particular, the slider 7 in the longitudinally intermediate part has an operating formation 15 intended to interact, in the way described below, with the rear arm 13b of the rocker lever 13.
The formation 15 closes the rear of the slot 7d in which the rocker lever 13 extends, and has an inclined plane 15a on the side opposite the appendage 7b.
With reference to Figures 4, 6 and 7, for example, the lower profile of the forward arm 13a of the rocker lever 13 forms two recesses 13e and 13f, spaced apart longitudinally, the first of which is closer to the end of the arm 13a, while the second is closer to the pivot 14.
The slot 7d in the slider 7 in which the rocker lever 13 is mounted oscillatably is delimited at the front by a cross-piece indicated by 16 in Figures 2, 4, 6 and 7.
When the door of the household appliance is open, the slider 7 is kept in the rest position of Figures 3, 4 and 10 by the action of the spring 8 exerted on its transverse appendage 7a. In this condition, the forward arm 13a of the rocker lever 13 bears on the cross-piece 16 at the recess 13e, as can be seen, in particular, in Figure 4.
When the door of the household appliance is closed and its formation F engages the appendage 7b of the slider 7, the latter is translated longitudinally towards the control module 5, against the action of the spring 8, which is compressed.
As a result of this translation, the cross-piece 16 of the slider 7 is moved relative to the rocker lever 13, being brought into the recess 13f of its forward arm 13a. The operating formation 15 of the slider 7 is also caused to engage, with its own inclined plane 15a, the end of the rear arm 13b of said rocker lever 13, until this end is positioned on a top plane of said formation 15, as shown in Figures 6 and 7.
The change of configuration of the rocker lever 13 is also partially due to the force of gravity.
In this condition, the rocker lever 13 bears with its forward arm 13a on the cross-piece 16, in the recess 13f of this arm.
The closing of the door of the household appliance as a result of the actuation of the slider 7 causes the opening of the switch 10 and the signalling of the fact that the door has been closed.
Additionally, as a result of the closing of the door, the rocker lever 13 passes from the inactive disengagement position assumed with the door open, shown in Figures 1, 3 and 4, to the active engagement position shown in Figures 5 to 7, in which the distal end of its forward arm 13a is introduced into the groove 50 of the formation F connected to the door of the household appliance.
In this condition, the rocker lever 13 retains the door in the closed position.
In a known way, a locking member indicated by 20 in Figures 7 to 9 is mounted movably in the control module 5, the position of this member being controlled in a known way by an actuator within the module 5.
In particular, when the household appliance is activated after the closing of the door, the control module 5 causes the locking member 20 to emerge from its support casing 6 and to be introduced into a corresponding opening or seat 21 provided in the slider 7.
In the illustrated embodiment, the movement of the member 20 towards the locking position of the slider 7 is essentially vertical.
The locking member 20 inserted into the seat 21 of the slider 7 retains the latter securely in the working position, in which the rocker lever 13 keeps the door of the household appliance in the closed position.
In this condition, the door of the household appliance is closed and locked.
The door of the household appliance can be unlocked at the end of an operating cycle by means of a command imparted to the module 5 to cause the locking member to be retracted from the seat 21 of the slider 7.
When the member 20 has been retracted, the door of the household appliance is still closed, but is no longer locked, and the user can therefore open it simply by pulling.
If the power supply to the appliance, and to the control module 5 in particular, fails when the door is in the closed and locked condition, the user can still unlock the door of the appliance, by inserting a tool such as a screwdriver through a terminal opening in the support container or shell 3, indicated by 3c in Figures 1, 2 and 8.
When this tool, or any generally stick-like object, is inserted into the opening 3c, it can be used to push a sliding piece 22 (Figures 8 and 9) which carries a formation 22a having a terminal inclined plane 22b adapted to engage the distal end of the locking member 20 so as to cause this member 20 to be disengaged from the associated seat 21 of the slider 7. When the slider 7 has been unlocked in this way, the door of the household appliance can be opened without difficulty.
In the illustrated embodiment, the sliding piece 22 is associated with a return spring 22c, conveniently made in one piece with the sliding piece, for example by moulding from plastic material.
As shown more fully in Figure 9, in the illustrated embodiment the spring 22c has an essentially zigzag configuration, with one end 22d integral with and forming part of the sliding piece 22, while its other end 22e is free, and can react against a shoulder 3d of the support container or shell 3 (Figure 8).

Claims

Retaining and locking device (1) for a door of an electric household appliance, in particular an oven, comprising
a support structure (2) adapted to be fixed to the household appliance at an opening thereof with which said door is associated,
a slider (7) mounted in said support structure (2) movably along a predetermined operational trajectory, from a rest position to a working position, against the action of return means (8); said slider (7) being adapted to be displaced by the door along said trajectory, from the rest position to the working position when the door is being closed, for activating an electric sensor device (10) such as a switch (11, 12), which indicates that the door has been closed;
a lever (13) mounted oscillatably in said support structure (2) about a fixed axis (14) which is substantially orthogonal to the trajectory of the slider (7) and preferably horizontal, the lever (13) having a retaining arm (13a) for interaction with the door; the slider (7) having a control formation (15) adapted, when the slider passes from the rest position to the working position, to cause the lever (13) to pass from an inactive disengagement position to an active engagement position in which its retaining arm (13a) is capable of retaining the door in the closed position, and a retaining formation (16) which is spaced apart longitudinally from said control formation (15) and is capable of retaining said lever (13) in the inactive disengagement position when said slider (7) is in the rest position; and locking means (5, 20, 21) that can be activated to lock the slider (7) in the working position and, consequently, lock the lever (13) in the active engagement position;
wherein said lever (13) has a centre of mass between said axis (14) and the distal end of the retaining arm (13a) of said lever (13),
the device being characterized in that said retaining formation (16) of the slider (7) is movable between said fixed axis (14) and the distal end of the retaining arm (13a) of said lever (13).
Device according to Claim 1, wherein the retaining arm (13a) of said lever (13) has a profile which defines two longitudinally spaced recesses (13e, 13f), a first one (13e) of which is closer to the distal end of said arm (13a) and the second one (13f) of which is closer to said axis (14); the arrangement being such that when the slider (7) passes from the rest position to the working position the aforesaid retaining formation (16) of said slider (7) passes from the first recess (13e) to the second recess (13f) of the retaining arm (13a) of said lever (13).
Device according to any of the preceding claims, wherein the slider (7) is translatable relative to said support structure (2) along a predetermined direction.
Device according to any of the preceding claims, wherein said lever (13) is a rocker lever and has a actuating arm (13b) essentially opposite the retaining arm (13a) with respect to said axis (14), the actuating arm (13b) being capable of interacting with said operating formation (15) of the slider (7).
Device according to any of the preceding claims, wherein said locking means (5, 20, 21) are associated with unlocking means (22), which can be actuated manually from outside the support structure (2).
Device according to Claim 5, wherein said unlocking means comprise a sliding member (22) movable in said support structure (2) against the action of associated opposing means (22c) and provided with a pushing member (22a, 22b) capable of disengaging from the slider (7) a movable locking member (20) which is adapted to retain said slider (7) in the working position.
Device according to Claim 6, wherein said opposing means comprise a resilient member (22) made in one piece with said sliding member (22).