EP0369906B1 - Oven with latch mechanism - Google Patents

Description

The present invention relates to ovens provided with an opening closable by a hinged door.

In known ovens, the door comprises a rigid frame articulated along one of its sides on the edge of the oven enclosure. A peripheral seal ensures the seal between the interior face of the door and the enclosure in the closed position. The door is generally retained by a hook mounted in the oven body and cooperating with a lug mounted in the door to retain the lug and the door in the locked position and release the lug and the door for opening the oven. The hook is generally rotatably mounted around a fixed axis of the furnace body, between an axial position in which it retains the lug and an exhaust position in which it releases the lug. The hook comprises a retaining housing in which the lug engages in the locked position when the hook is in the axial position. A retaining ramp limits the retaining housing and forms a bearing surface to retain the lug in the locked position and prevent the door from opening. An interlocking ramp can be provided on the front face of the hook to produce the pivoting and the escapement of the hook away from its axial position when the lug for door closing is introduced.

In known oven closings, the door can therefore accept two positions: an open position, in which it is not retained by the hook, and a locking position in which it is firmly held in the hook and cannot be opened only by maneuvering the hook itself. As a result, when the hook is operated to unlock the door, it suddenly opens and suddenly lets out the gases and vapors contained in the oven enclosure.

Such a sudden escape of vapors and gases when the door is opened is a major drawback in modern ovens, and in particular in steam ovens comprising an internal steam generator for cooking food.

Another drawback of known ovens is that their closing, to reach the locking position, is achieved in a short stroke corresponding to the sliding of the door lug on the hook engagement ramp. Such a short run makes it difficult to watertight closure that should be sought in steam ovens.

The documents US-A-4 163 443, US-A-4 554 907 and US-A-3 831 580 describe hanging structures for oven doors in which the lug integral with the oven door is hooked by the less a hook capable of moving, during the closing or opening movements of the door, in an oblique direction, the hook being guided by guide ramps. For each longitudinal position of the hook, the latter can admit one and only one transverse position, throughout its journey between an open position in which the lug escapes the hook, and a closed position in which the lug is inserted in the hook . These improved closing structures make it possible to increase the travel between the closed position and the open position, but do not make it possible to solve the problem of the sudden escape of the gases and vapors contained in the oven enclosure at the time of the opening.

The object of the present invention is in particular to avoid the drawbacks of known closing devices, by proposing a new attachment structure defining three distinct positions, namely an open door position in which the door is not retained by the means of latching, a latching position in which the door is simply retained and braked by the latching means, the door can then be opened by simple pull, and a locking position in which the door is firmly retained by the latching means 'hooking and can only be opened by actuation of said hooking means; in the locked position, the door is hermetically closed, and when the hooking means are unlocked, the door is partially released and ends up in the hooked position in which it is retained. Thus, the opening and closing are carried out in two stages, by obligatory passage in the intermediate hooking position.

According to another object of the invention, the passage from the open position to the locked position is effected by simple pushing of the door, first to make it pass from the open position to the position of latching, then to move it from the latching position to the locking position which occurs automatically. Likewise, the door is opened in two stages, firstly by actuating the locking means to bring the door in the hanging position, then pulling the door to bring it into the open position.

Another object of the invention is to promote the operation of steam ovens, on the one hand by providing a possibility of release of internal gases and vapors when the door is in the hanging position, on the other hand by braking and delaying the closing of the door by the obligatory passage in the hanging position.

• un crochet monté à coulissement longitudinal selon un axe longitudinal sur des moyens de guidage du corps de four, entre une position reculée de verrouillage dans laquelle les moyens de guidage interdisent le pivotement du crochet et une position avancée d'accrochage dans laquelle les moyens de guidage autorisent le pivotement du crochet autour d'un axe fixe, à l'écart de sa position axiale ;
• des premiers moyens élastiques sollicitent le crochet pour le rappeler en pivotement autour de son axe fixe vers sa position axiale ;
• une butée mobile de verrouillage, sollicitée par des organes d'actionnement, retient le crochet en position reculée de verrouillage et le libère sous l'action des organes d'actionnement. Ainsi, en position de verrouillage, le crochet retient fermement la porte qui ne peut être ouverte qu'en actionnant les organes d'actionnement de butée mobile de verrouillage. Par cet actionnement, la porte et le crochet viennent en position d'accrochage. A partir de cette position, la porte peut être ouverte en sollicitant le crochet par simple rotation autour de son axe fixe.

To achieve these and other objects, an oven according to the invention is provided with a closure comprising:

• a hook mounted to slide longitudinally along a longitudinal axis on means for guiding the oven body, between a retracted locking position in which the guide means prohibit pivoting of the hook and an advanced hooking position in which the guide means allow the hook to pivot about a fixed axis, away from its axial position;
• first elastic means urge the hook to pivot it around its fixed axis towards its axial position;
• a movable locking stop, urged by actuating members, retains the hook in the retracted locking position and releases it under the action of the actuating members. Thus, in the locked position, the hook firmly retains the door which can only be opened by actuating the movable locking stop actuating members. By this actuation, the door and the hook come into the hooking position. From this position, the door can be opened by requesting the hook by simple rotation around its fixed axis.

According to one possibility, the hook retaining ramp is inclined, so that, in the hanging position, the door can be opened by a traction exerted on its handle and making it possible to overcome the retaining force exerted by the hook and its elastic means on the lug according to the retaining ramp.

Similarly, an oblique hook engagement ramp can be provided; such a ramp, associated with second elastic means with longitudinal actuation of the hook, urging the hook in the direction of its advanced hooking position, makes it possible to remove the hook urged by the second elastic means with longitudinal actuation by pressing the lug on the interlocking ramp oblique, for the passage from the open door position to the hanging position by simple door push.

According to a particular embodiment, the door closure according to the invention comprises two identical hooks arranged in symmetrical opposition relative to the longitudinal plane, the hooks being guided by the same guide means, urged by the same locking means and by symmetrical elastic means, and cooperating with the same door lug which they hold on either side in the locked position and in the hooked position.

According to an advantageous embodiment, an oven provided with a closure according to the present invention comprises a double door, with an outer wall with a rigid frame articulated along one of its sides on the edge of the enclosure; the door further comprises an inner plate, shaped to adapt to the opening of the enclosure and to close it in the closed position; the inner plate is mounted on the outer door wall opposite its inner face, to which it is connected by connecting means allowing the relative movement of the inner plate relative to the outer wall parallel to the movement of the door around its joints; the connecting means comprise elastic means urging the inner plate away from the door. In this way, when the door is closed, the hook in the hooking position produces braking of the door and slows down the application of the inner plate on the opening of the enclosure. Such a slowdown is favorable to allow the seal to be positioned correctly relative to the walls of the oven enclosure, thus ensuring improved sealing.

Preferably the stroke of the hook between its locking position and its hooking position is slightly greater than the stroke of the inner plate relative to the outer door wall. Thus, during unlocking, the door is brought into the hooking position in which the inner plate slightly deviates from the oven body and releases the gases and vapors contained inside the enclosure.

• la figure 1 représente en vue de côté les organes fonctionnels d'une fermeture de four selon la présente invention, en position d'accrochage;
• la figure 2 représente une vue de côté de fermeture selon un second mode de réalisation de la présente invention, en position d'accrochage ;
• la figure 3 représente une vue de côté de la fermeture de la figure 2 en position de verrouillage ;
• la figure 4 est une vue partielle des organes de fermeture de la figure 2 en position intermédiaire entre la position d'ouverture et la position d'accrochage ; et
• la figure 5 est une vue de dessus en coupe partielle d'un four muni d'un dispositif de fermeture selon la présente invention.

Other objects, characteristics and advantages of the present invention will emerge from the following description of particular embodiments, made in relation to the attached figures, among which:

• Figure 1 shows a side view of the functional members of an oven closure according to the present invention, in the hanging position;
• FIG. 2 represents a side view of closure according to a second embodiment of the present invention, in the hooking position;
• Figure 3 shows a side view of the closure of Figure 2 in the locked position;
• Figure 4 is a partial view of the closure members of Figure 2 in the intermediate position between the open position and the hooking position; and
• Figure 5 is a top view in partial section of an oven provided with a closing device according to the present invention.

In the embodiment shown in FIG. 1, the oven body 1 can be closed off by an articulated door 2, which door 2 is retained in the locked position and in the hooked position by a closure assembly 3 secured to the oven body. 1. The closure assembly 3 comprises a fixed plate 4 provided with two transverse guide rods 5 and 6 perpendicular to the plate 4 and parallel to each other, spaced longitudinally along the longitudinal axis II of the device. A hook 7 is formed by a flat body 8 provided with an oblong posterior lumen 9 and an anterior lumen 10. The rod 5 slides with little play in the posterior lumen 9, while the rod 6 slides with little play in the anterior lumen 10. The oblong posterior lumen 9 is arranged along the longitudinal axis II of the device. The anterior lumen 10 is L-shaped, with a longitudinal branch 11 and a perpendicular L-shaped branch 12 connecting to the rear part of the longitudinal branch 11. The front end of the flat hook body 8 protrudes outside the body oven 1, as shown in the figure, and comprises a retaining housing 13 open upwards in which engages a lug 14 secured to the door 2, when the door is in the locking position and when the hook is in the position axial. The retaining ramp 15 limits the retaining housing 13 and forms a bearing surface for retaining the lug 14 in the locked position. A latching ramp 16 is provided on the front face of the hook to cooperate with the lug 14 when the door 2 is pushed towards the latching position.

The perpendicular branch 12 of the anterior lumen 10 develops in the opening direction of the hook retaining housing 13. Thus, the hook 7 can slide longitudinally along the longitudinal axis II between a first position, or hooking position, shown in FIG. 1, in which the rods 5 and 6 bear against the rear ends of the rear lights 9 and anterior 10, and a second position or locking position in which the rods 5 and 6 are in abutment against the anterior ends of the openings 9 and 10. In the attachment position shown in FIG. 1, the branch 12 authorizes the pivoting of the hook 7 around the rod 5 according to a limited angular movement: in the position shown in FIG. 1, the lug 14 is housed in the retaining housing 13. When the hook 7 pivots, the rod 6 coming into the bottom of the perpendicular branch 12, the hook releases the lug 14 which can then move along the longitudinal axis II, no longer being retained by the retaining ramp 15.

The hook 7 is biased obliquely forward and upward by a tension spring 17, one end of which is fixed to the flat hook body 8 and the other end of which is fixed to the plate 4. Thus, the spring 17 tends to return the hook 7 to its axial position, along the longitudinal axis II when the latter has been moved laterally for the passage of the lug 14. The spring 17 also biases the hook 7 towards its anterior position d 'hooking shown in Figure 1, when it has been moved rearward in the locked position.

The front part of the hook 7 comes out of the oven body 1 through a hole 18 formed in the wall of the oven body. To close this light 18 when the door is open or in the hanging position, the hook 7 comprises two protrusions 19 and 20, on either side of the hook 7, coming to bear against the front wall of the oven body 1 and thus closing the light 18 in the hooking position.

The oven door 2 is provided with a push plate 21 which, when the door is brought from the hooking position towards the locking position, bears on the anterior end of the hook 7 to push the hook back to the locked position.

The rear part of the flat hook body 8 7 includes an upper shoulder 22 intended to cooperate with a lower tooth 23 forming a movable stop and carried by a lever 24 rotating about a fixed axis 25 of the plate 4. The lever 24 is biased by an actuating rod 26 whose end comprises a core 27 of electromagnet 28 and a handle 29 for maneuvering. The electromagnet 28 is electrically connected in series on a power source 30 with a first switch 31 actuated by a door opening button 32 accessible by the user, and with a second switch 33 actuated by a ramp 34 of the hook 7. The second switch 33 is closed when the hook is in the locking position or back position, and is open when the hook is in all the other positions, and in particular in the hooking position shown in FIG. 1 .

The operation of the device is as follows: in the open position, the hook 7 is in the position shown in Figure 1, in which it is brought by the spring 17, parallel to the longitudinal axis I-I. When the door 2 is pushed towards the furnace body 1, the lug 14 comes to bear on the interlocking ramp 16, and tends to move aside laterally the hook 7 retained longitudinally by the thrust exerted by the spring 17, allowing the passage of the lug 14 and its insertion into the retaining housing 13. The device is then in the hooking position, shown in FIG. 1. If the pushing of door 2 is continued, the pushing plate 21 pushes the hook 7 backwards, against the spring retaining force 17, and brings it into the locking position in which the rods 5 and 6 are in abutment in the front bottom of the slots 9 and 10. In this position, the lever 24 is lowered under the effect of gravity, and the tooth 23 comes to bear in front of the shoulder 22 and retains the hook 7. In this position, the rod 6 is inserted in the part narrow of the anterior lumen 10, namely its longitudinal branch 11, and prohibits t out lateral pivoting of the hook 7. The device is then in the locked position, preventing the escape of the lug 14 and the opening of the door 2.

From the locked position, opening the door requires actuating the first switch 31, which powers the electromagnet 28 and lifts the lever 24 via the rod 26. The tooth 23 then leaves escape the shoulder 22, and the hook 7 returns to the hooking position under the action of the spring 17. The door 2 is then retained in this hooking position shown in Figure 1, position in which the lug 14 is engaged in the retaining housing 13. The complete opening of the door 2 requires pulling the door, to move the lug 14 longitudinally which is then in abutment against the retaining ramp 15, the movement of the lug 14 causing the hook 7 to pivot against the retaining force exerted by the spring 17. The hook 7 then returns to the latching position.

When one is in the locked position, and in the event of a power failure, it is no longer possible to actuate the electromagnet 28. It is then possible to unlock the door by manual actuation of the handle operating 29, the door opening process then being the same, that is to say comprising the intermediate hooking phase.

It has been observed that the oven doors tend in the long run to move slightly relative to the oven body. This then results in a misalignment between the lug 14 and the hook 7, which produces a variation in the force necessary for the passage of the lug in and out of the retaining housing 13.

To avoid such a variation, and to significantly increase the passage effort, and therefore the braking effort exerted by the closing means on the door in the hanging position, an embodiment shown in FIGS. 2 can be used. to 4, in which the closure device comprises two identical hooks 7 and 107, arranged in symmetrical opposition relative to the longitudinal axis II, as shown in the figures. The two hooks 7 and 107 are guided by the same rods 5 and 6, retained by the same locking means such as the lever 24, and cooperate with the same lug 14 which they hold on either side in the locking position. shown in Figure 3 and in the hooking position shown in Figure 2. The hook 7 is biased by its spring 17 in an oblique position, while the hook 107 is biased by the spring 117 disposed in an oblique position symmetrically relative to the spring 17. The operation of the two hooks 7 and 107 is symmetrical with respect to the axis II.

FIG. 2 shows the position of the device with two hooks when the door is in the hanging position. Either hook can pivot around the rod 5 to engaging or disengaging the lug 14.

In FIG. 3, in the locked position, the two hooks are moved back and retained by the lever 24. In this position, the pivoting of the hooks is made impossible by the rod 6 engaged in the anterior part of the corresponding anterior lumens 10 and 100.

In Figure 4, there is shown the relative position of the hooks 7 and 107 during the passage of the lug 14 between the open position and the hooking position, the hooks 7 and 107 being spaced apart on either side of the longitudinal plane II, by rotation around the rod 5.

5 shows, in top view in partial section, an oven provided with a closing device according to the present invention. In this embodiment, the oven body 1 has an opening 40 closed by the door 2. The door 2 comprises an outer wall 41 limited by a rigid frame 42 articulated on the oven body 1 along a vertical edge 43. The device closure 3 is arranged opposite the vertical articulation edge 43, and there are the hooks 7 and 107 cooperating with the lug 14 secured to a vertical upright of the frame 42.

The door further comprises an inner plate 44, shaped to fit onto the opening 40 of the enclosure and close it in the closed position. The inner plate 44 is mounted on the outer wall 41 of the door, opposite its inner face 45, to which it is connected by connecting means allowing the relative movement of the inner plate 44 relative to the outer wall 41 of door parallel to the movement of said door around its articulations 43. The connection is ensured by guide rods such as rods 46 and 47, and compression springs pushing the inner plate 44 away from the outer wall 41, to bring it into abutment on rod stops 46 and 47 not shown.

When the door is closed, the hooks 7 and 107 and the springs 17 and 117 which are associated with them produce the braking of the door 2 and slow down the application of the internal plate 44 against the opening 40 of the enclosure of the oven.

Preferably, the stroke of the hooks 7 and 107 between their locking position and their hooking position is slightly greater than the stroke of the inner plate 44 relative to the outer wall 41. In this way, when unlocking, the door East brought into the hooking position in which the inner plate 44 slightly deviates from the body 1 of the oven and releases the gases and vapors contained inside the enclosure.

Claims (10)

1. An oven with a latch mechanism comprising a hook (7) mounted in the oven body (1) and operating in conjunction with a pin (14) mounted in the door (2) in order to retain the pin and the door in the locked position, and in order to free the pin and the door in order to open the oven, the hook (7) comprising a retaining seat (13) in which the pin (14) engages in the locked position when the hook is in the axial position, a retaining ramp (15) limiting the retaining seat (13) and forming a support surface in order to retain the pin (14) in the locked position, an engagement ramp (16) being provided on the frontal face of the hook (7) in order to produce pivoting and escape of the hook away from its axial position when the pin (14) is introduced in order to close the door,
characterised in that:

- the hook (7) is mounted to slide longitudinally along a longitudinal axis (I-I) on guiding means (5, 6) of the oven body, between a retracted locked position in which the guiding means (5, 6) prevent the pivoting movement of the hook (7), and an advanced latched position in which the guiding means (5, 6) allow pivoting of the hook (7) about a fixed axis (5), away from its axial position,

- first resilient means (17) urge the hook to return pivotally about its fixed axis (5) towards its axial position,

- a mobile locking stop (24), urged by actuating members (26, 28, 31, 32) retains the hook (7) in a retracted locked position, and frees it under the action of actuating members,

so that, in the locked position, the hook (7) firmly retains the door (2), which may only be opened by actuation of the mobile locking stop actuating members (32), and so that, in the latched position, the door may be opened by urging the hook (7) to rotate about its fixed axis (5).

2. An oven according to Claim 1, characterised in that the hook retaining ramp (15) is inclined so that, in the latched position, the door may be opened by a tractional force enabling the retaining force exerted by the hook and its resilient means (17) on the pin (14) along the retaining ramp (15) to be overcome.

3. An oven according to one of Claims 1 or 2, characterised in that:

- the hook locking ramp (16) is oblique,

- second resilient means (17), actuated longitudinally, are provided in order to urge the hook (7) in the direction of its advanced latched position,

so that, when the door is closed in order to bring it into the latched position, the pin (14) supported against the oblique engagement ramp (16) pushes away laterally the hook (7) retained longitudinally by the second resilient means actuated longitudinally (17), and is introduced into the retaining seat (13).

4. An oven according to Claim 3, characterised in that the first and second resilient means are constituted by a single spring (17) disposed obliquely and providing a tractive force containing simultaneously a longitudinal component for returning the hook into the advanced latched position, and a perpendicular component for returning the hook into its axial position.

5. An oven according to any one of Claims 1 to 4, characterised in that:

- the hook (7) comprises a posterior oblong aperture (9) with a longitudinal axis (I-I) in which there slides a first transverse stem (5) of the oven body (1), forming an axis of rotation for the hook,

- the hook comprises an anterior aperture (10) in an L configuration, with a longitudinal branch of the L (11) and a perpendicular branch of the L (12) which connect at the posterior part of the longitudinal branch (11) diverging in the direction of opening of the retaining seat (13) of the hook, a second transverse stem (6) of the oven body being mounted to slide in the anterior aperture (10),

- the transverse stems (5, 6) and the apertures (9, 10) constituting the guiding means for the hook between the locked position and the latched position.

6. An oven according to any one of Claims 1 to 5, characterised in that the mobile locking stop is a lever (24) rotatable about a fixed axis (25) of the oven body and operating by means of a lower tooth (23) in conjunction with an upper shoulder (22) of the hook, and urged by an actuating stem (26) whose end comprises the core (27) of an electromagnet (28) and an operating handle (29), the mobile stop tooth (23) engaging on the shoulder (22) of the hook under gravitational force when the hook is pushed back into the locked position.

7. An oven according to Claim 6, characterised in that the electromagnet (28) is electrically connected in series with a first switch (31) actuated by a door-opening button (32) accessible to the user, and with a second switch (33) actuated by a ramp (34) of the hook (7), the said second switch (33) being closed when the hook is in the locked position, and open when the hook is in the other positions.

8. An oven according to any one of Claims 1 to 7, characterised in that it comprises two identical hooks (7, 107) symmetrically disposed opposite one another relative to the longitudinal axis (I-I), guided by the same guiding means (5, 6), urged by the same locking means (24) and by symmetrical resilient means (17, 117), and operating in conjunction with the same door pin (14), which they retain on either side in the locked position and in the latched position.

9. An oven according to any one of Claims 1 to 8, characterised in that:

- the door (2) comprises a rigid frame (42) hinged at one of its sides (43) to one edge of the enclosure of the oven, and defining an external wall (41),

- the door (2) further comprises an internal panel (44) configured to fit on to the opening (40) of the enclosure and to shut it off in the closed position,

- the internal panel (44) is mounted on the external wall (41) facing its internal face (45), to which it is connected by connecting means (46, 47) enabling relative displacement of the internal panel (44) with respect to the door, parallel to the displacement of said door around its hinges,

- the connecting means comprise resilient means urging the internal panel (44) away from the external wall (41),

so that, upon closing the door, the hook (7), in the latched position, produces a braking effect on the door, and slows the application of the internal panel (44) against the opening (40) in the enclosure.

10. An oven according to Claim 9, characterised in that the travel of the hook (7) between its locked position and its latched position is slightly greater than the travel of the internal panel (44) relative to the external door wall (41), so that, upon unlocking, the door is brought into the latched position in which the internal panel (44) moves slightly away from the oven body (1) and liberates the gases and vapours contained within the oven.

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