WO2010041210A1

WO2010041210A1 - Locking device for the door of an electric household appliance, in particular the door of a pyrolytic oven

Info

Publication number: WO2010041210A1
Application number: PCT/IB2009/054414
Authority: WO
Inventors: Dino Chirumbolo
Original assignee: Itw Industrial Components S.R.L. Con Unico Socio
Priority date: 2008-10-09
Filing date: 2009-10-08
Publication date: 2010-04-15
Also published as: ITTO20080739A1; EP2344712A1; IT1392241B1

Abstract

A door locking device (1) including a support (5), a retaining hook (6) for the door (3), rotationally carried by the support about an axis (A) between a working position, in which it locks the door, and a rest position, and actuating means (10) of the retaining hook including an abutting element (11) for the door, movably carried by the support, a slide (12) sliding on the support perpendicularly to the axis and against the bias of elastic means (14), operatively associated to the abutting element to be displaced thereby; first and second inclined plane means (20,21), operatively associated to each other and carried by the slide (12) and by a stem (31) of the retaining hook, respectively, the latter facing the opposite side of the door, to rotate the retaining hook (6) between the rest and working positions upon displacement of the slide; and a safety device (22) carried by the support facing the slide, and including a pawl (25) movable between an extracted position and a retracted position in which, with the slide in the working position, it engages/does not engage a through perforation (27) of the slide.

Description

Title of Invention: LOCKING DEVICE FOR THE DOOR OF AN ELECTRIC HOUSEHOLD APPLIANCE, IN PARTICULAR THE

DOOR OF A PYROLYTIC OVEN

TECHNICAL FIELD

[1] The present invention relates to a door locking device for a electric household appliance, particularly adapted to lock the door of a pyrolytic oven in a closing position. BACKGROUND ART

[2] For safety reasons, it is known that in many types of household appliances, e.g. washing machines, dishwashers and pyrolytic ovens, the door of the electric household appliance must be locked in the closing position during the operation of the electric household appliance itself, in order to prevent the user from accidentally opening the door. In particular, pyrolytic ovens are ovens capable of running a self-cleaning cycle in addition to the normal cooking cycles, in which the oven reaches much higher temperatures than during normal operation (thus potentially dangerous for the user) in order to eliminate, by pyrolysis indeed, particles of dirt (e.g. grease) present on the walls of the oven. At least when running such a self-cleaning cycle, the oven door must thus be locked in an absolutely reliable manner.

[3] The known door locking devices for pyrolytic ovens are usually actuated by servo motors, thus being very costly, and more in general are large in size and complex in structure. DISCLOSURE OF INVENTION

[4] It is an object of the present invention to obviate the described drawbacks by providing a door locking device of low cost, small dimensions and high structural and operational simplicity, so as to be absolutely reliable. In particular, it is a further object of the invention to provide a door locking device of the aforesaid type which, by virtue of its features of simplicity and cost-effectiveness, is adapted to be applied on pyrolytic ovens but at the same time may conceptually be applied even to other types of electric household appliances, and above all which may use already existing components of washing machine and dishwasher door locking devices, so as to allow considerable scale economies.

[5] The present invention thus relates to a door locking device for an electric household appliance, in particular a pyrolytic oven, as defined in claim 1.

[6] In particular, the device according to the invention comprises a support fixable to a carcass of an electric household appliance by the side of a door thereof, retaining means for the door, rotationally carried by the support between a working position, in which they lock the door when the latter is closed, e.g. by engaging into a specific side seat of the door, and a rest position, in which they are rotated apart from the door, and actuating means of the retaining means comprising at least one abutting element for the door, movably carried by the support.

[7] According to an aspect of the invention, the device further comprises: a slide slidingly carried by the support in a direction perpendicular to the rotation axis of the retaining means and against the bias of first elastic means, operatively associated to the abutting element to be displaced thereby, upon the closing of the door, from a rest position, in which it is normally kept by the elastic means, towards a working position; first and second inclined plane means carried by the slide and the retaining means, respectively, and operatively associated to each other to rotate the retaining means between the rest and working positions, and vice versa, upon displacement of the slide between the respective rest and working positions, and vice versa; and a safety device integrally carried by the support, in a position facing the slide, and comprising a pawl movable between an extracted position and a retracted position, in which it is adapted, when the slide is in the working position, to engage/not engage a perforation of the slide to lock the sliding thereof on the support.

[8] In particular, the retaining means may consist in a retaining hook rotatably carried by the support and able to directly engage the door or in a rotating element carried by the support and operatively associated with a retaining pin coupled in an articulated manner and with play with a fork-shaped portion of the rotating element and slidingly guided in a through seat of the support facing in use the door.

[9] In both cases, the second inclined plane means are defined by the free, wedge-shaped end of a stem of the retaining hook or the rotating element, radially and overhangingly protruding with respect to the rotation axis of the same from a fork-shaped body of the retaining hook or rotating element, while the first inclined plane means consist in at least a beveled front edge of a first recess made through the slide, which beveled edge is arranged transversally to the sliding direction of the slide and in a position closest to the door, and in a prismatic embossment integrally obtained with the slide and arranged over the first recess, covering the same, having an opening facing the beveled edge and throughly engaged, in use, by the stem of the retaining hook or rotating element.

[10] When the retaining means consist on the rotating element associated with the retaining pin, the stem may be provided with a shallow recess delimited along the sliding direction of the slide by opposite oblique surfaces converging toward the slide; in this case the first inclined plane means also comprise a beveled tooth provided on an internal inclined surface of the embossment facing the recess in the slide and op- eratively associated with the wedge shaped stem and the shallow recess thereof to rotate the rotating element of the retaining means upon a movement of said slide along said sliding direction so as to extract or retract the retaining pin from/in the through seat in the support to engage/disengage it with/from the door.

[11] The safety device is an electromagnetic device provided with a parallelepiped-shaped casing from a face of which the pawl overhangingly protrudes, in the extracted position, and is snappingly and integrally carried by the support with the aforesaid face being parallel to and facing the slide above the same.

[12] Thereby, a highly simple and functional door locking device is obtained, in which the retaining means may be free from return spring, because they are guided towards both the working and rest positions by the first and second inclined plane means, which thus determine the movement in both directions about the rotation axis. Furthermore, the locking during the pyrolysis function may be performed very easily, using a common electromagnetic safety device of the type used in washing machines, with consequent high constructional economies. Finally, but not less importantly, if the user tried to force the door opening when the door is closed and locked (e.g. during the pyrolysis function), the mechanical stresses transmitted by the door to the retaining means are completely relieved on the first and second inclined plane means, thus producing at most a stress on the slide directed perpendicularly to its laying plane, i.e. perpendicularly to the sliding direction thereof. Therefore, the pawl of the safety device is not substantially concerned by any stress, thus ensuring a long life and a high reliability of the door locking device as a whole. A further improvement is also reached when the retaining means consist in a rotating element associated with a sliding retaining pin; in this case, in fact all the stresses are taken by the pin and then transmitted directly to the support through the guiding seat of the pin, so that the rotating axis of the retaining means is not interested by any stress. BRIEF DESCRIPTION OF THE DRAWINGS

[13] Further features and advantages of the present invention will be apparent from the following description of two preferred embodiments thereof, merely provided by way of non-limitative example and with reference to the accompanying drawings, in which:

[14] - figure 1 shows a three-quarter axonometric view from the top of a door locking device according to the invention;

[15] - figure 2 shows an exploded axonometric view of the door locking device in figure l;

[16] - figure 3 shows a three-quarter axonometric view on enlarged scale and from the top of a component of the device in figures 1 and 2; [17] - figures 4 and 5 show an axonometric view on enlarged scale of a second component of the device in figures 1 and 2 and a partial section view of an assembly detail of the components in figures 3 and 4, respectively;

[18] - figures 6 and 7 diagrammatically show an orthogonal three-quarter elevation view of the device in figure 1, in cross section taken along a plotting plane V-V, in two different operating positions of the same; and

[19] - figures 8 and 9 show in an enlarged scale a three-quarter axonometric view from the top of a detail of a different embodiment of the door locking device according to the invention, represented in the same two different operating positions of figures 6 and 7. BEST MODE FOR CARRYING OUT THE INVENTION

[20] With reference to figures from 1 to 6, numeral 1 indicates as a whole a door locking device for an electric household appliance, in particular a pyrolytic oven, of which only part of a carcass or body 2 thereof is shown for simplicity (figures 5 and 6), delimiting a service compartment (non shown) closed in use by a pivoting door 3 which, under certain conditions, must be locked to prevent its manual opening.

[21] For this purpose, the door locking device 1 comprises: a support 5 fixable in a known manner to the carcass or body 2 by the side of the door 3; retaining means 6 consisting in a retaining hook for the door 3, rotationally carried by the support 5 about an axis A (figure 5) between a working position (figure 7), in which the retaining hook locks the door 3 when the door 3 itself is closed, e.g. by inserting itself into a specific side seat 7 of the door 3, and a rest position (figure 6), in which it is rotated apart from the door3, in a direction opposite to the same; and actuating means 10 of the retaining hook 6.

[22] The actuating means comprise, in turn, an abutting element 11 for the door 3, movably carried by the support 5; and a slide 12 slidingly carried by the support 5 against the bias of first elastic means 14 in a direction D (indicated by the arrow in figure 7) perpendicular to a rotation axis A of the retaining hook 6 and operatively associated to the abutting element 11 to be displaced thereby, upon of the closing of the door, from a rest position (shown in figure 6) towards a working position (shown in figure 7). The slide 12 is normally kept by the elastic means 14 in the rest position in figure 6, due to the force F exerted by the elastic means 14 on the slide 12, and which, as we will see, must be exceeded by the user during the step of closing the door3 in order to complete the closing itself. The elastic means 14, preferably defined by a helical spring arranged with the axis being parallel to the direction D, as well as their assembly arrangement on the support 5, are only diagrammatically shown in figures 2, 6 and 7, being obvious for a person skilled in the art; for example, the helical spring 14 may be inserted into a seat 15 of the support 5, with an end secured to an overhang 16 and the opposite end secured to the slide 12, inside a longitudinal slot 18 made through the latter and which slidingly engages the overhang 16 to at least partially act as a guide for the slide 12 (figure X).

[23] Furthermore, according to an aspect of the invention, the actuating means 10 comprise first inclined plane means 20 and second inclined plane means 21 carried by the slide 12 and the retaining hook 6, respectively, and operatively associated to each other to rotate the retaining hook 6 between the rest position (figure 6) and the working position (figure 7) and vice versa, upon displacement of the slide 12 between the respective rest and working positions, and vice versa; and a safety device 22 integrally carried by the support5, in a position facing the slide 12, and according to the invention identical to the safety devices used to lock washing machine doors.

[24] In particular, the device 22 is an electromagnetic device of the known type enclosed in a substantially parallelepiped-shaped casing 24 and comprises a pawl 25, movable by means of electromagnetic means 26 of known type, between an extracted position (figure 7) from the casing 25 and a retracted position in the casing 25 (figure 6), in which it is adapted, when the slide 12 is in the working position, to engage/not engage a perforation 27 of the slide 12 to lock/not lock its sliding on the support 5.

[25] In the example shown, the safety device 22 is snappingly and integrally mounted to the support 5, slightly spaced apart therefrom, e.g. by means of snap-locking means 23 of known type, in a position parallel to and overlapping the slide 12 and the pawl 25 overhangingly protruding, in the extracted position, from a face 28 of the casing 24 arranged facing the slide 12, which thus slides sandwiched between the support 5 and the casing 24 integral thereto.

[26] The second inclined plane means 21 are carried by a free end 30 of a stem 31 of the retaining hook 6, stem 31 facing in use the side opposite to the door 3 and towards the slide 12, radially and overhangingly protruding with respect to the rotation axis A of the retaining hook 6.

[27] In particular, the retaining hook 6 comprises a curved hooking portion 33, facing the door 3 in use, a fork-shaped body 34 provided with respective side pins 35 defining the rotation axis A, snappingly engaged in use in respective side seats 36 of the support 5, and the stem 31, which overhangingly protrudes from the fork-shaped body 34, from the side opposite to the hooking portion 33, substantially from the middle line of the body 34.

[28] The free end 30 of the stem 31, which is prismatic, is wedge-shaped and delimited, towards the slide 12, by a pair of oblique surfaces 38 (figure 4) reciprocally converging towards the side of the slide 12 and jointed to each other by a rounded portion 39 and, towards the fork-shaped body 34 and on the side or face of the stem 31 facing the slide 12 in use, by an oblique step 37. The latter and the surfaces 38 with the joining portion

39 form the inclined plane means 21.

[29] On the other hand, the first inclined plane means 20 consist in a beveled front edge

40 (figure 3) of a first recess 41 made through the slide 12, which beveled edge 40 is arranged transversally to the sliding direction D of the slide 12 and in a position closest to the door 3, and in a prismatic embossment 42 integrally obtained with the slide 12 and arranged over the recess 41, covering the same, having an opening 43 facing the beveled edge 40 and throughly engaged, in use, by the stem 31 of the retaining hook 6.

[30] In particular, the slide 12 is shaped as a flat plate and the perforation 27 is a through perforation obtained perpendicularly to the laying plane of the slide 12, so as to face the pawl 25 only when the slide 12 is in the working position; in turn, the pawl 25 of the safety device 22 is movable between the extracted and retracted positions, perpendicularly to the laying plane of the slide 12 and therefore, in the extracted position, protrudes from the face 28 perpendicularly to the same.

[31] The abutting element 11 for the door 3 consists of an L-shaped appendix integrally obtained with a front edge 50 (figure 3) of the slide 12, facing the door 3 in use, and the support 5 is provided with a seat 52 (figures 6, 7) for receiving the abutting element 11 when the slide 12 is in the working position (figure 7); instead, in the rest position of the slide 12, the abutting element 11 is in a position extracted from the seat 52, e.g. protruding within one frame-like end 55 of the support 7, intended in use to receive part of the side edge of the door 3 (figures 6,7).

[32] According to the preferred embodiment, the door locking device 1 according to the invention further comprises an emergency releasing device 60 consisting in an L- shaped plug 61 slidingly carried by the slide 12 against the bias of second elastic means 63 and in the same sliding direction D as the slide 12, and in a housing and guiding seat 65 (with a substantially T-shaped cross section) for the plug 61, obtained in the slide 12 itself in a position immediately adjacent to, and communicating with, the perforation 27 for receiving the pawl 25.

[33] The plug 61 is provided, on the side opposite to the door 3, with a slanting surface appendix 66 arranged so as to be adapted to be inserted, by the side and against the bias of the second elastic means 63, into the perforation27 in order to push the pawl 25 towards the retracted position so as to release the slide 12; the elastic means 63, again defined by a helical spring arranged with the axis parallel to the direction D, are normally housed in the same seat 65 of the slide 12 or laterally thereto, in a recess 70 of the slide 12.

[34] The device 1 further comprises a microswitch 80 integrally carried by the support 5, by the side of the same, and an actuating appendix 81 for the microswitch 80, integrally carried by the slide 12, laterally thereto, on the same side engaged by the microswitch 80 on the support 5.

[35] In use, the force F exerted by the spring 14 holds the slidel2 in the position in figure

6, with the L-shaped element 11 being extracted with respect to the seat 52; in this position, the inclined plane means 20 and 21 cooperate in contact for keeping the retaining hook 6 on the side opposite to the door 3, so as to keep it out from the frame- like end 55.

[36] When the door 3 is gradually taken to the closing position, it makes its edge partially engage the frame-like end 55 and intercepts the abutting element 11 overhangingly protruding therein, thus causing a thrust thereon which is transmitted to the slide 12, making it slide in the direction D against the bias of the force F of spring 14, which is overcome by the thrust exerted by the user when he/she closes the door 3 (possibly with the aid of a closing spring of the door 3, known and not shown). Therefore, the element 11 retracts within the seat 52, the spring 14 is compressed and the stem 31 gradually protrudes from the interior of the embossment 42, because the retaining hook 6 is secured to the support 5 and therefore it may not follow the slide 12 in its sliding motion.

[37] The wedge-shaped end 30 consequently comes in contact with the beveled edge 40, first with the oblique step 37 and then with one of the surfaces 38 (the one facing the opposite side of the embossment 42), which causes a sliding interference between the slide 12 and the hook 6 which applies a torque on the latter, thus causing the counter clockwise rotation thereof (in the direction of arrow R, figure 7) with the consequent insertion of the hooking portion 33 into the frame-like end 55 and the engagement of the door 3 by insertion of the hooking portion 33 into the seat 7; the size of the latter and the hooking portion 33 are chosen, according to the invention, so as to ensure the engagement of the portion33 in the seat 7 with a predetermined clearance G. The door 3 is thus locked although not in a definitive manner.

[38] The described movement makes appendix 81 activate the microswitch 80 and furthermore makes the perforation 27, which in the starting position of figure 6 was misaligned with respect to the pawl 25, face the latter (figure 7); an activation of the electromagnetic means 26 (e.g. caused by selecting the pyrolysis function and/or by the signal output by the microswitch 80) consequently takes the pawl 25 to the extracted position and inserts it into the perforation27. In this configuration (figure 7), the door 3 is definitively locked because the spring 14 may not take back the slide 12 (locked by the pawl 25) to the starting position, even if the closing stress on the door 3 should cease.

[39] However, according to an aspect to the invention, even if the user exerted an opening stress on the door 3, in the direction of the arrow S (figure 7), such a stress may not especially cause the sliding of the slide 12 in any case, and especially does not stress the sliding of the slide 12, because in this configuration (working position, figure 7) the hook 6 rotated, with respect to the starting position (rest position), to such an extent as to arrange with the stem 31 substantially parallel to slide 12 and support 5; all the stresses transmitted by the door 3 to the hook 6 are then released onto the support 5 through the pins 35, without stressing the pawl 25. [40] When the door 3 needs to be opened, the pawl 25 is released from the perforation 27; now, the thrust F of the spring 14, no longer opposed either by the closing stress exerted on the door 3, or by the pawl 25, pushes the slide 12 towards the door 3; therefore, when the user applies an opening stress S on the door, the door 3 may retract at least by an amount equal to clearance G, thus allowing the slide 12, which cooperates against the door 3 pushed by the spring 14 and through the abutting element 11, to advance towards the door 3 by an equal amount G; such a movement makes the stem 31 gradually insert itself in the opening 43, taking the surface 38 opposite to the slide 12 to a contact position with the embossment42, in particular with an inclined plane 100 defined therein (figure 7); the sliding contact between the inclined planes 100 and 28 produces the application of a torque on the stem 31 so as to make the hook 6 rotate clockwise, thus producing the extraction of the portion 33 from the seat 7 and freeing the door 3, which may be opened, while the slide 12, under the bias of the spring 14, and the hook 6 under the combined action of the inclined plane means 20 and 21 (in this case the inclined planes 100 and 38), return to the rest position in figure 6.

[41] If, due to a failure, the pawl 25 remains in the extracted position, it is however possible for a maintenance technician to open the door 3, by acting on the plug 61, by means of a wrench or pin inserted into the carcass 2 (known and not shown); indeed, by pushing the plug 61 against the bias of the spring 63, the plug itself is slid with respect to the slide 12, making the inclined plane appendix 66 laterally insert itself into the perforation 27 so as to act on the pawl25 in order to push it towards the retracted position, thus freeing the slide 12; by applying an opening stress on the door 3, the door itself may thus be opened, as previously described.

[42] With reference now to Figures 8 and 9, it is shown a possible, further improved variation of the door locking device of the invention. The details similar or identical to those already described are indicated by the same reference numbers.

[43] The embodiment of figures 8 and 9 of the door locking device of the invention is indicated overall by the reference number 100 and it is identical to the device 1 already described in all details except the retaining means 6 for the door, which are replaced by retaining means600. In practice, the retaining means 6 consisting in a single element embodied by the retaining rotating hook 6 are replaced by retaining means 600 consisting of two elements, in particular consisting in a rotating element 601 and in an associated pin 602 carried in an articulated manner by the rotating element 601 and slidingly guided in a through seat 500 of the support 5 in use facing the door 3 and provided perpendicular to the slide 12.

[44] The rotating element 601 is identical to the retaining hook 6 except that the curved hooking portion 33 is replaced by a fork shaped portion 603, facing the door 3 in use and engaged with play by a head 604 of the pin 602. Accordingly, rotating element 601 comprises the fork shaped portion 603, a fork-shaped body 34 provided with corresponding side pins 35 (only one of which is shown in figure 9) defining the rotation axis A, snappingly engaged in use in corresponding side seats 36 of the support 5; and a stem 31, which overhangingly protrudes from the fork-shaped body 34, from the side opposite to the fork-shaped portion 603 carrying the pin 602.

[45] The free end 30 of the stem 31 is wedge-shaped and the stem 31 is provided, towards the fork-shaped body 34 and on the side of the stem facing opposite to the slide 12, with a shallow recess 605 delimited along the sliding direction D of the slide 12 by opposite oblique surfaces 606, 607 converging toward the slide 12.

[46] All together, the recess 605 with the surfaces 606, 607, and the wedge-shaped end 30 of the stem 31, which is prismatic and delimited, towards the slide 12, by at least one oblique surface 38 form inclined plane means 210 provided on the rotating element 601, which replace the inclined plane means 21 of the retaining hook 6; in particular, the second oblique surface 38 and the oblique step 37 of the inclined plane means 21 are replaced by the recess 605 ensuring a smoother rotation of element 601 with respect to hook 6.

[47] Also the first inclined plane means 20 of the device 1 are replaced in device 100 by inclined plane means 200 consisting: in a beveled front edge 40 (figure 8) of a first recess 41 made through the slide 12, which beveled edge 40 is arranged transversally to the sliding direction D of the slide and in a position closest to the door 3; in a prismatic embossment 42 integrally obtained with the slide 12 and arranged over the first recess 41, covering the same, having an opening 43 (figure 9) facing the beveled edge and throughly engaged, in use, by the stem 31 (figure 8); and, in addition to the components of inclined plane means 20, in a beveled tooth 201 provided on an internal inclined surface 202 of the embossment 42 facing the recess 41 in the slide 12 and op- eratively associated with the wedge shaped stem 31 and the shallow recess 605 thereof to rotate the rotating element 601 of the retaining means 600 upon a movement of the slide 12 along the sliding direction D, indicated in figures 8 and 9 by the arrows.

[48] Accordingly, the actuating means consisting in first inclined plane means 200 and second inclined plane means 210 carried by the slide 12 and the rotating element 601 of the retaining means 600, respectively, are operatively associated to each other to rotate the element 601 between the rest position (figure 8) and the working position (figure 9) and vice versa, upon displacement of the slide 12 between the respective rest and working positions, and vice versa, in order to retract or extract, respectively, the retaining pin 602 in/from the through seat 500 in the support 5 to disengage/engage it from/with the door 3 in place of the curved hooking portion 33 of device 1.

[49] The variant 100 described has, over the device 1, the advantage that all the stresses transmitted by the door 3 to the pin 602 which replaces hook 6 are then released directly onto the support 5 through the pin 602 and the walls of seat 500, so without not only stressing the pawl 25, but also the pins 35; in such a manner no stresses are transmitted to the rotating axis A ensuring a longer life to the device and a smoother operation thereof. For the rest the operation of device 100 is identical to that of device 1 already described.

Claims

[Claim 1] A door locking device (l;100) for an electric household appliance, including a support (5) fixable to an electric household appliance carcass (2) by the side of a door (3) of the same, retaining means (6; 600) for the door, rotationally carried by the support between a working position, in which they lock the door when the door is closed, and a rest position, and actuating means (10) of the retaining means comprising an abutting element (11) for the door, movably carried by the support; characterized in that it further comprises: a slide (12) slidingly carried by the support in a direction (D) perpendicular to a rotation axis (A) of the retaining means (6) and against the bias of first elastic means (14), the slide being operatively associated to the abutting element (11) to be displaced thereby, upon closing the door, from a rest position, in which it is normally maintained by the elastic means (14), towards a working position; first (20;200) and second (21;210) inclined plane means carried by the slide (12) and by the retaining means (6;600), respectively, and operatively associated to each other to rotate the retaining means (6;600) between the rest and the working positions, and vice versa, upon displacement of the slide (12) between the corresponding rest and working positions, and vice versa; and a safety device (22) integrally carried by the support (5), in a position facing the slide, and including a pawl (25) movable between an extracted position and a retracted position, in which it is adapted, when the slide is in the working position, to engage/not engage a perforation (27) of the slide to block the sliding thereof on the support (5).

[Claim 2] A door locking device according to claim 1, characterized in that said second inclined plane means (21;210) are carried by a free end (30) of a stem (31) of the retaining means (6;600) facing the side opposite to the door and towards the slide (12), radially and overhangingly protruding with respect to the rotation axis (A) of the retaining means.

[Claim 3] A door locking device according to claim 2, characterized in that said retaining means (6) consist in a retaining hook (6) comprising a curved hooking portion (33), facing the door in use, a fork-shaped body (34) and provided with corresponding side pins (35) defining the rotation axis (A), snappingly engaged in use in corresponding side seats (36) of the support; and said stem (31), which overhangingly protrudes from the fork-shaped body (34), from the side opposite to the hooking portion (33); the free end (30) of the stem being wedge-shaped and being delimited, towards the fork-shaped body and on the side of the stem facing the slide, by an oblique step (37).

[Claim 4] A door locking device according to claim 3, characterized in that said first inclined plane means (20) consist in a beveled front edge (40) of a first recess (41) made through the slide (12), which beveled edge (40) is arranged transversally to the sliding direction (D) of the slide and in a position closest to the door, and in a prismatic embossment (42) integrally obtained with the slide and arranged over the first recess (41), covering the same, having an opening (43) facing the beveled edge and throughly engaged, in use, by said stem (31) of the retaining hook.

[Claim 5] A door locking device according to claim 2, characterized in that said retaining means (600) consist in a rotating element (601) and in an associated pin (602) carried in an articulated manner by the rotating element (601) and slidingly guided in a through seat (500) of the support (5) in use facing the door and provided perpendicular to the slide (12); said rotating element (601) comprising a fork shaped portion (603), facing the door in use and engaged with play by a head (604) of said pin (602), a fork-shaped body (34) provided with corresponding side pins (35) defining the rotation axis (A), snappingly engaged in use in corresponding side seats (36) of the support; and said stem (31), which overhangingly protrudes from the fork-shaped body (34), from the side opposite to the fork-shaped portion (603) carrying the pin (602); the free end (30) of the stem being wedge-shaped and the stem (31) being provided, towards the fork-shaped body and on the side of the stem facing opposite to the slide, with a shallow recess (605) delimited along the sliding direction (D) of the slide by opposite oblique surfaces (606,607) converging toward the slide.

[Claim 6] A door locking device according to claim 5, characterized in that said first inclined plane means (200) consist: in a beveled front edge (40) of a first recess (41) made through the slide (12), which beveled edge (40) is arranged transversally to the sliding direction (D) of the slide and in a position closest to the door; in a prismatic embossment (42) integrally obtained with the slide and arranged over the first recess (41), covering the same, having an opening (43) facing the beveled edge and throughly engaged, in use, by said stem (31) of said rotating element (601); and in a beveled tooth (201) provided on an internal inclined surface (202) of the embossment facing the recess in the slide (12) and operatively associated with said wedge shaped stem (31) and the shallow recess (605) thereof to rotate said rotating element (601) of the retaining means (600) upon a movement of said slide (12) along said sliding direction (D).

[Claim 7] A door looking device according to anyone of the preceding claims, characterized in that said slide (12) is shaped as a flat plate; said perforation (27) of the slide being a through perforation obtained perpendicularly to the laying plane of the slide so as to face said pawl (25) only when the slide is in the working position; said pawl (25) of the safety device (22) being movable between said extracted and retracted positions, perpendicularly to the laying plane of the slide (12).

[Claim 8] A door locking device according to anyone of the preceding claims, characterized in that said abutting element (11) for the door consists of an L-shaped appendix integrally obtained with a front edge (50) of the slide, facing the door in use; said support (5) being provided with a seat (52) for receiving the abutting element (11) when the slide is in the working position; while in the rest position of the slide, the abutting element (11) is in a position extracted from said seat (52) therefor.

[Claim 9] A door locking device according to anyone of the preceding claims, characterized in that said safety device (22) is an electromagnetic device enclosed in an essentially parallelepiped-shaped casing (24), snappingly and integrally mounted to the support, in a position parallel to and superimposing the slide (12); said pawl (25) overhangingly protruding, in the extracted position, from a face (28) of the casing arranged facing the slide (12).

[Claim 10] A door locking device according to anyone of the preceding claims, characterized in that it further comprises an emergency releasing device (60) consisting in an L-shaped plug (61) slidingly carried by the slide (12) against the bias of second elastic means (63) and in the same sliding direction (D) as the slide (12), and in a housing and guiding seat (65) for the plug, obtained in the slide (12) itself in a position immediately adjacent to, and communicating with, the perforation (27) of the slide for receiving the pawl of the safety device; the plug (61) being provided, on the side opposite to the door, with a slanting surface appendix (66) arranged so as to be adapted to be inserted, by the side and against the bias of the second elastic means (63), into the perforation (27) of the slide in order to push the pawl (25) towards the retracted position to the extent for releasing the slide (12). [Claim 11] A door locking device according to anyone of the preceding claims, characterized in that it further comprises a microswitch (80) integrally carried by the support (5), by the side of the same, and an actuating appendix (81) for the microswitch, integrally carried by the slide (12), laterally to the same, on the same side engaged by the microswitch (80) on the support (5).