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(11) | EP 0 625 607 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Device for the safe opening control of the loading port in washing-machines and the like |
| (57) A device is described for controlling the opening of the loading port in washing-machines
and the like comprising a pushbutton panel (1) provided with a pushbutton for opening
the port (4) and a pushbutton for interrupting the mains electrical supply (6). An
electromechanical device (60, 21, 27), selected from a plurality of thermoelectric
devices functionally similar but constructionally different, is mechanically fastened
to the pushbutton panel (1). Mechanical means (7, 40, 39) for coupling with said pushbutton
for opening the port co-operate with movable mechanical elements (11, 13; 22; 28,
29) of said electromechanical device (60, 21, 27) with the object of preventing the
operation of the port opening pushbutton (4) when, although the general electrical
mains switch is open, the washing-machine is in a particular operating condition,
for example, in the centrifuge condition. |
[0001] The present invention relates to a device for the safe opening control of the loading port in washing-machines and the like.
[0002] According to current safety regulations for washing-machines, it must not be possible to close the general electrical mains switch (and thus to start the machine) when the loading basket access door or port is open. Always according to the same regulations, after the unit has been started by closing the abovementioned general switch, it must not be possible, by pressing the port opening pushbutton, to open the port itself, it being compulsorily provided to this end that the general switch be reopened beforehand.
[0003] Solutions are known for this purpose wherein the port's locking bolt is mechanically connected to the general switch, and the latter's position determines or otherwise the possibility of opening the port.
[0004] Alternative solutions exist wherein the port's locking bolt is not connected mechanically to the general switch: it is possible, for instance, to provide for an opening handle located directly on the port. Obviously in this case the opening movement is deliberately made more difficult so as to prevent any specifically unwanted openings. But in order to ensure a sufficient degree of safety in use and to avert accidents, a microswitch is also associated with the port's locking bolt that ensures the opening of the machine's electrical power supply circuit when the port is open.
[0005] A further safety regulation also imposes that the immediate opening of the port after reopening the general electrical mains switch be prevented, while the washing-machine is in the centrifuge phase. Such a regulation provides that, under these conditions, the opening of the port be permitted only after a suitable delay time interval has elapsed, starting from the opening of the general switch, useful to ensure that the basket's rotational energy is by now almost completely exhausted.
[0006] The devices capable of ensuring the abovementioned delay are generally of the electromechanical type, comprising electrically activated bimetallic strips to operate the intervention of mechanical elements suitable for inhibiting the opening of the port, and they can be located in the proximity of the bolt of the port itself.
[0007] In such a case, however, it is necessary to make an electrical connection between the general switch, usually inserted in a pushbutton panel housed in the upper part of the machine's chassis, and the electromechanical device mounted on the port's closing device.
[0008] In the Italian patent application No. MI92A00753 dated 27 March 1992 there is in turn described a port locking device of a washing-machine constituted by a pushbutton panel with a bimetallic strip integrated in it that, by operating a mechanical element, locks the port's opening pushbutton and prevents its operation in the centrifuge condition.
[0009] This solution, while it does not require any electrical connection between the general switch and the port' bolt, involves the provision of a specific pushbutton panel that is not readily available on the market.
[0010] The object of the present invention is to provide a device for controlling and locking the opening of the port according to the abovementioned safety regulations, that is not affected by the specified problems and that, by making it possible to use widely-available components, has a low cost.
[0011] According to the present invention such object is attained thanks to a device for controlling the opening of the port in washing-machines and the like, comprising a pushbutton panel wherein there is a pushbutton for interrupting the mains electrical supply and a pushbutton for opening the port kinematically connected to a locking bolt of the port, and an electromechanical device provided with mechanical elements movable under the action of electrically-activated elements sensitive to predetermined operating conditions of the machine, characterized in that said electromechanical device is mechanically fastened to said pushbutton panel, and said pushbutton for opening the port is provided with mechanical coupling means that can be engaged by said movable mechanical elements to prevent the opening of the port itself in said predetermined operating conditions of the washing-machine.
[0012] Thanks to the present invention it is possible to provide devices for controlling the opening of ports using components that are functionally similar but that have different embodiments as they are produced by supplier firms that compete one with the other; to establish the connection between the pushbutton panel and the electromechanical device it will in fact be sufficient to provide for the accomplishment of suitably conformed mechanical coupling means, so that they can be adapted both to said port opening pushbutton and to said movable mechanical elements of the electromechanical device.
[0013] All this translates into a substantial reduction in the costs of mass-produced washing-machines and the like.
[0014] These and other features and advantages of the present invention will be made more evident by the following detailed description of some embodiments thereof, illustrated as non-limiting examples in the enclosed drawings, wherein:
Fig. 1 shows, in a plan view and partially sectioned, a pushbutton panel on which, according to the invention, a first type of electromechanical device is fastened;
Fig. 2 shows a view similar to Fig. 1, but with said pushbutton panel in the condition wherein the port is open;
Fig. 3 shows, in a cross-sectional view taken along the line III-III of Fig. 1, said pushbutton panel complete with a front panel for holding pushbuttons;
Fig. 4 shows a view similar to that of Fig. 3, but there is represented in it the condition wherein the machine is started up;
Fig. 5 shows,in a cross-sectional view taken along the line V-V of Fig. 2, said pushbutton panel complete with said panel for holding pushbuttons;
Fig. 6 is a cross-sectional view taken along the line VI-VI of Fig. 1 of the abovementioned electromechanical device;
Fig. 7 is a cross-sectional view taken along the line VII-VII of Fig. 6 of said electromechanical device;
Fig. 8 shows a partially-sectioned plan view of a part of the pushbutton panel of Fig. 1 on which there is fastened a second type of electromechanical device;
Fig. 9 is a cross-sectional view taken along the line IX-IX of Fig. 8 of the abovementioned second type of electromechanical device;
Fig. 10 shows a cross-sectional view of a detail of the pushbutton panel of Fig. 8 in the condition wherein the port is open;
Fig. 11 shows a partially-sectioned plan view of a part of the pushbutton panel of Fig. 1 on which there is fastened a third type of electromechanical device;
Fig. 12 is a cross-sectional view taken along the line XII-XII of Fig. 11 of the said third type of electromechanical device;
Fig. 13 shows a cross-sectional view of a detail of the pushbutton panel of Fig. 11 in the condition wherein the port is open.
[0015] With reference to Figs. 1-5, there is shown a pushbutton panel 1 comprising a sliding support 2 for housing a cursor 3 driven by a respective port opening pushbutton 4 (Fig. 5), a cursor 5 driven by a respective pushbutton 6 for interrupting the general electrical mains (Figs. 3 and 4), and other similar cursors 70, each driven by a respective pushbutton not visible in the drawings.
[0016] The pushbutton panel 1 is mounted in the front on the chassis 50 of a washing-machine, and it is provided with a pushbutton-holding panel 51 (Fig.s 3, 4 and 5) on which the pushbutton 4 for opening the port, that of the general electrical mains switch 6 and all the other pushbuttons for the operaton of the machine are mounted.
[0017] On the rear wall 72 of the sliding support 2 there is a first type of electromechanical device 60. On the cursor 3 there is also mounted a first type of rod 7 with a square cross-section. A tang 8, sliding on the sliding support 2 in a direction transversal to the cursors 3 and 5, is driven by the cursor 5 itself, when the corresponding general electrical mains pushbutton 6 is pressed, into a notch 9 with which the cursor 3 is provided, so as to prevent the sliding movement of the cursor 3 itself. The rod 7 ends at the rear with an oblique wall 10.
[0018] As shown in Figs. 3-5, a port opening control bracket 35 is mounted on a support 52 sliding vertically along a vertical guide provided in the chassis 50; said support 52 is provided in the upper part with a tooth 36, located at the port opening pushbutton 4, and with a striker 53, aligned with the general electrical mains pushbutton 6, suitable for preventing the operation of the pushbutton 6 itself when the bracket 35 is in the position of the bottom of its stroke, corresponding to the position wherein the port is open (Fig. 3).
[0019] The electromechanical device 60 comprises an arm 11 sliding transversally with respect to the cursor 3 in a fixed guide 12. To the arm 11, at the rear end of the rod 7, there is connected a square member 13 drilled so as to allow the terminal part of the rod 7 itself to slide inside it (Fig. 6). In the proximity of the square member 13 the arm 11 has an oblique wall 14 complementary with the oblique wall 10 of the rod 7 (Figs. 1 and 2).
[0020] At the opposite end of the arm 11 with respect to the rod 7 a spring 15, reacting against the container 80 of the electromechanical device 60, thrusts the arm 11 up against the rod 7 itself, so that the oblique walls 10 of the rod 7 and 14 of the arm 11 match.
[0021] The electromechanical device 60 also comprises a bimetallic strip 16, superimposed over a thermistor 17 suitable for heating the bimetallic strip 16 itself; the latter is fastened at one end to the container of the electromechanical device 60 and, at the opposite end, it is inserted in a slit 18 of a C-shaped locking cursor 19 (Fig. 7) that slides transversally to the arm 11 under the action of the bimetallic strip 16 itself. The arm 11 is provided in its part with a matching notch 20 (Figs. 6 and 7) suitable for the insertion of a terminal wing of the locking cursor 19 when the latter is in the end-stroke position corresponding to the displacement of the bimetallic strip 16 in the position illustrated with a dashed and dotted line in Fig. 6.
[0022] As shown in Fig. 8, to the rear wall 72 of the sliding support 2 of the pushbutton panel 1 it is possible to apply a second type of electromechanical device 21. This is provided with a circular through hole 37 (Fig. 9) partially closed by a pin 22 hinged at an axis perpendicular to the plane of Fig. 8 and rotating round it. One end of the pin 22, with a C-shaped cross-section, is inserted in a groove 23 of a rod 40 mounted on the cursor 3 of the pushbutton panel 1, having a circular cross-section with a diameter suitable for passing inside the through hole 37. The pin 22 is held in the at rest position by a spring 81, visible in Fig. 9.
[0023] A bimetallic strip 24, heated by a respective thermistor (not shown in the drawings), is fastened at one end to the container 82 of the electromechanical device 21 and is inserted at the opposite end in a locking cursor 26, sliding in a direction parallel to the axis of rotation of the pin 22 under the action of the bimetallic strip 24.
[0024] In Fig. 11 there is shown a third type of electromechanical device 27 that can be applied to the rear wall 72 of the sliding support 2 of the pushbutton panel 1. It comprises a through hole 38 partially closed by a device 28 integral with a striking lever 29, which can rotate round an axis perpendicular to the plane of Fig. 12 and is held in the at rest position by a pressure spring 30 (Fig. 12). The device 28 is inserted in the groove 23 of a rod 39 similar to the rod 40, mounted on the cursor 3 and sliding inside said through hole 38.
[0025] Once again, a bimetallic strip 31, always fastened at one end to the container 83 of the electromechanical device 27 and heated by a thermistor 73, is inserted at the other end in a slit 32 with which a locking cursor 33 sliding in a direction parallel to the rod 39 under the action of the bimetallic strip 31 is provided. Said locking cursor 33 has a central groove suitable for receiving a tang 34 with which the striker lever 29 is provided.
[0026] For all the types of devices described above, when the port (not shown in the drawings) is open, the port opening control bracket 35, by virtue of its very weight, is in the position at the bottom of its stroke and the striker 53 prevents the general electrical mains pushbutton 6 from being pressed (Fig. 3). In this way the start-up of the washing-machine is prevented when the port of the loading basket is open, according to the current safety regulations.
[0027] When the port is closed, the control rod 35 is thrust upwards by a closing bolt of the port itself (not shown in the drawings) and, by moving the striker 53, it allows the general electrical mains pushbutton 6 to be closed. The washing-machine can thus be activated by pressing the pushbutton 6 itself (Fig. 4).
[0028] The operation of the pushbutton 6, as well as closing the general machine start-up switch, causes the displacement of the tang 8 inside the notch 9 of the cursor 3, thus preventing it from sliding and as a consequence preventing the operation of the pushbutton for opening the port 4. In this way, always according to safety regulations, the opening of the port when the machine is in operation is prevented.
[0029] The function of the electromechanical devices 60, 21 and 27 is that of providing a further impediment to the operation of the opening pushbutton 4 of the port in the particular centrifuge condition. If in fact in such a condition, by pressing the general electrical mains pushbutton 6, the electrical power supply to the washing-machine were to be interrupted, the machine's basket would continue to rotate due to inertia. But since the operation of the pushbutton 6 removes the locking effect offered by the tang 9 to the sliding movement of the cursor 3 connected to the port opening pushbutton 4, it would be possible to open the port itself in the condition wherein the basket is in motion, something not permitted by the abovementioned safety regulations.
[0031] In the case of the first type 60 of such electromechanical devices, when the washing-machine is in the centrifuge phase an electrical current flows through the thermistor 17 and heats it up; the consequent heating up of the bimetallic strip 16 causes its deflection to the position illustrated with a dash and dotted line in Fig. 6, and the locking cursor 19 is thus displaced to the position where it prevents the sliding movement of the arm 11. This prevents the sliding movement of the rod 7 connected to the cursor 3, thus preventing the operation of the port opening pushbutton 4.
[0032] This condition persists for a certain time interval even after the general electrical mains switch has been pressed, because it is necessary to wait for the bimetallic strip 16 to cool down and to subsewuently return to the at rest position so that the locking cursor 19, coming out of the striker notch 20 of the arm 11, makes it possible for the arm 11 itself to slide freely. Such time interval must be sufficient to ensure that the machine's basket has come to a stop.
[0033] After such time interval the port can be opened by pressing the pushbutton 4. This operation causes the downward sliding movement of the tooth 36 of the control rod 35, that allows the disengagement of the locking bolt of the port itself.
[0034] In the case of the second type of electromechanical device 21, when the washing-machine is on and it is in the centrifuge phase an electrical current flows through the thermistor that causes it to heat up and as a consequence the bimetallic strip 24 is also heated up. The latter, deflecting, moves to the position indicated with a dashed and dotted line in Fig. 9, and as a consequence it displaces the locking cursor 26 to a position such as to prevent the rotation of the pin 22. This prevents the sliding movement of the rod 40 connected to the cursor 3 of the port opening pushbutton 4, and as a consequence the opening of the port. When the general electrical mains switch is opened the electrical current no longer flows through the thermistor; when, after the prescribed time interval, the bimetallic strip 24 has cooled down, it returns to the at rest position and the locking cursor 26 no longer opposes the rotation of the pin 22. This allows the rod 40 to slide freely and as a consequence the port may be opened with the same methods described in the previous case.
[0035] Lastly, in the case of the third type of electromechanical device 27, the centrifuge condition involves the passage of an electrical current in the thermistor 27 to heat the bimetallic strip 31. The latter, deflecting, comes to the position indicated with a dashed and dotted line in Fig. 11 and brings the locking cursor 33 to the position where it prevents the rotation of the striker lever 29. As a consequence the device 28 obstructs the through hole 38 and prevents the sliding movement of the rod 39 connected to the port opening pushbutton. The latter may be opened only when, after opening the general electrical mains switch, the bimetallic strip 31 will have cooled down and will have returned the locking cursor 33 to the at rest position. The device 28 will no longer oppose the sliding movement of the rod 39, and as a consequence the port may now be opened.
1. Device for controlling the opening of the loading port in washing-machines and the
like, comprising a pushbutton panel (1) wherein there is a pushbutton for interrupting
the mains electrical supply (6) and a pushbutton for opening the port (4) kinematically
connected to a locking bolt of the port, and an electromechanical device (60, 21,
27) provided with mechanical elements (11, 13; 22; 28, 29) movable under the action
of electrically-activated elements (16, 24, 31) sensitive to predetermined operating
conditions of the machine, characterized in that said electromechanical device (60,
21, 27) is mechanically fastened to said pushbutton panel (1), and said pushbutton
for opening the port (4) is provided with mechanical coupling means (7, 40, 39) that
can be engaged by said movable mechanical elements (11, 13; 22; 28, 29) to prevent
the opening of the port itself in said predetermined operating conditions of the washing-machine.
2. Device according to claim 1, characterized in that said mechanical coupling means
(7, 40, 39) with which the pushbutton (4) for opening the port is provided are represented
by a sliding rod having a conformation suitable for co-operating with said movable
mechanical elements (11, 13; 22; 28, 29) to lock and release the movement of the rod
itself.
3. Device according to claim 1 or 2, characterized in that said electrically-activated
elements (16, 24, 31) are represented by a bimetallic strip, movable by deflection
between two extreme positions, operating on a respective locking element (19, 26,
33) suitable for preventing the movement of said movable mechanical elements (11,
13; 22; 28, 29).
4. Device according to claim 2, characterized in that said movable mechanical elements
(11, 13; 22; 28, 29) are represented by a sliding arm (11), provided with a terminal
square member (13) and with an oblique wall (14).
5. Device according to claim 4, characterized in that said sliding rod (7) is provided
with an oblique wall (10) complementary with the oblique wall (14) of said sliding
arm (11).
6. Device according to claim 2, characterized in that said movable mechanical elements
(11, 13; 22; 28, 29) are represented by a rotating pin (22).
7. Device according to claim 6, characterized in that said sliding rod (40) is provided
with a groove (23) that can be engaged by said rotating pin (22).
8. Device according to claim 2, characterized in that said movable mechanical elements
(11, 13; 22; 28, 29) are represented by a device (28) integral with a rotating lever
(29).
9. Device according to claim 8, characterized in that said sliding rod (39) is provided
with a groove (25) that can be engaged by said device (28).