IT202100031358A1 - HINGE FOR HOUSEHOLD APPLIANCE COVERS - Google Patents

Description

Patent application for industrial invention entitled:

HINGE FOR HOUSEHOLD APPLIANCE COVERS

DESCRIPTION

The present invention concerns a hinge for household appliance lids.

In particular, the present invention relates to a hinge for the lids of top-loading household appliances or hob lids.

Purely by way of example and without limitation, in the remainder of this discussion we will describe the present invention with reference to a top-opening household appliance such as for example a washing machine.

To attach the lids of top-loading washing machines to the respective frame? known to use horizontal hinges with cylindrical cams which, thanks to their inclined profile, allow a certain balancing force to be transferred to the lid during closing.

This balancing force? generated by the elastic resistance of a spring placed in axis with the aforementioned cylindrical cams and deformed by them in compression.

The transformation of the elastic reaction force into a balancing torque of the lid falling? caused precisely by the inclined profile of the cylindrical cam.

Thanks to this inclination, in fact, the elastic reaction force that is transmitted between the inclined surfaces of the cams is actually a cam and a follower, has a transversal component which by virtue? of the distance of its point of application from the rotation axis of the hinge, determines a twisting moment acting on the part of the hinge integral with the lid. ? It is precisely this torque that causes the lid to balance when closing.

Once the lid has closed, the spring is compressed and, when the lid is opened again, the elastic release of the spring generates a torque which favors the opening of the lid, making it easier for the user to lift.

Known hinges of the type described are not free from drawbacks.

A first inconvenience? given by the extreme complexity? constructive.

Purpose of the present invention? therefore, that of providing a hinge for the lids of household appliances capable of overcoming the drawbacks of the known art and which is at the same time simple and economical to manufacture and practical to use.

Further purpose of the present invention? is to provide a hinge for household appliance lids that is structurally simple and has a limited number of components.

Yet another purpose of the present invention? is to provide a hinge for household appliance covers that provides an effective motion damping effect. According to the invention, these purposes and others are achieved by a door hinge comprising the technical characteristics described in the attached claims.

The technical characteristics of the invention, according to the aforementioned purposes, are clearly described in the attached claims and its advantages are evident from the detailed description that follows, with reference to the attached drawings which illustrate exemplary and non-limiting embodiments, in which: - the figure 1 illustrates, in a schematic perspective view, an embodiment of a hinge for household appliance lids according to the present invention;

- figure 2 represents an exploded view of the hinge of figure 1;

- figures 3 to 5 illustrate, in respective schematic perspective views with transparent parts to better highlight others, the hinge of figure 1 in three different configurations of use;

- figures 3a, 4a and 5a are three sectional views of the hinge of figure 1 in the respective configurations referred to in figures 3 to 5;

- figure 6 illustrates a detail of the hinge referred to in the previous figures.

As illustrated in figure 1, with reference number 1 ? indicated as a whole is an embodiment of the hinge for household appliance covers according to the present invention.

Preferably but not limitedly, throughout this discussion the term household appliance is intended to refer to a hob or a top-loading washing machine.

Hinge 1? intended to be mounted, in pairs, on a household appliance such as a hob or a top-loading washing machine, to connect the frame to its cover so that the latter is movable with respect to the frame itself and, in in other words, making the cover movable with respect to the frame between a closed and an open position and vice versa.

A portion of cover C, for example of a hob, is represented purely by way of example in figures 3a, 4a and 5a.

The hinge 1 includes a fixed body 2, which can be connected integrally to a frame, not shown, of the household appliance, and a mobile element 3, visible in figures 3a, 4a, 5a and, transparently, in figures 3, 4 and 5, connected to a cover C of the same appliance.

Hinge 1? suitable to make the cited and only partially illustrated cover C mobile with respect to the cited and not illustrated frame, between a closed position and an open position and vice versa.

With reference to figures 1 and 2, the hinge 1 includes a control shaft 4, stably connected to the fixed body 2.

What will it be like? better described below, the mobile element 3 is adapted to rotate with respect to the fixed body 2 and the control shaft 4 around a respective axis R of rotation.

A screw element 5 ensures stable fixing of the control shaft 4 to the fixed body 2.

The control shaft 4 develops longitudinally parallel to the aforementioned rotation axis R.

The control shaft 4 has a polygonal cross section.

Advantageously, the drive shaft 4 has a hexagonal cross section.

As illustrated in figures 1 and 2, the hinge 1 includes a first helical spring 6 fitted on the control shaft 4.

The first helical spring 6 defines, for the hinge 1, a first elastic member capable of generating an elastic force to balance the weight of the aforementioned lid C during its opening and closing.

As illustrated in the attached figures, the hinge 1 includes a first screw 7 having a cavity 7th central housing of the control shaft 4.

The cavity? 7th center of the first screw 7 ? counter-shaped with respect to the control shaft 4.

The coupling between the cavity The central 7a of the first screw 7 and the control shaft 4 defines a form coupling suitable for transmitting a torque between these two components.

The hinge 1 also includes a first internally threaded sheath 8.

The first internally threaded sheath 8? suitable to be connected to the aforementioned mobile element 3 of the hinge so that the twisting moment is transmitted between these two components but at the same time mutual sliding in the direction of the R axis of rotation is allowed, as represented schematically in figures 3 to 5. In other words, the first sheath 8? connectable to the mobile element 3 to rotate integrally with it, although they are free to slide reciprocally in the longitudinal direction.

The first sheath 8 is internally threaded, in the following for brevity? also indicated only as the first sheath 8, it has a substantially cylindrical size.

The first internally threaded sheath 8 engages in screwing/unscrewing with the aforementioned first screw 7 so that its rotation around its rotation axis R simultaneously determines its translation along the same rotation axis R.

The first screw 7 and the first internally threaded sheath 8 together define a first operational screw-nut assembly 9.

The first sheath 8 clearly defines the nut of the first operational screw-nut group 9.

As illustrated in the attached figures, the first helical spring 6 and the first sheath 8 are arranged in succession along the rotation axis R.

As illustrated in figure 1, with the first helical spring 6 fitted on the control shaft 4, it has its own end coils 6a, 6b. one in contrast with the first sheath 8 and the other, through the interposition of a washer 10, in contrast with the fixed body 2.

According to the configuration of the hinge 1 just indicated, the above-described translation of the first sheath 8 along the rotation axis R determines a variation in the axial development of the first helical spring 6.

In particular, what will it be like? described in detail below, with reference to the drawings of the attached figures, a translation of the first sheath 8 from left to right determines a compression of the first helical spring 6, as specifically shown in figures 4 and 5.

The aforementioned first screw-nut operating group 9 defines, for the hinge 1, respective actuation means of the first elastic member 6 to determine the deformation of the same first elastic member 6 and transmit to the mobile element 3, to which the first sheath 8 is? rotatably integral, the relative elastic balancing force of the aforementioned and not illustrated lid. As illustrated in figures 1 and 2, the hinge 1 includes a second helical spring 16 fitted on the control shaft 4 similarly to the first spring 6.

As illustrated in the attached figures, the hinge 1 includes a second screw 17 having a cavity central, not visible in the attached figures, housing the control shaft 4.

The aforementioned and not illustrated cavity? central of the second screw 17, in analogy with the first screw 7, ? counter-shaped with respect to the control shaft 4.

The coupling between the cavity central part of the second screw 17 and the control shaft 4 defines a form coupling suitable for the transmission of a twisting moment between these two components.

Advantageously, as illustrated in figure 1, the first and second screws 7, 17 are made in a single body, and arranged adjacent in succession in a direction parallel to the aforementioned rotation axis R and their respective cavities. central units define, as a whole, a single cavity? passing inside the assembly defined by the two first and second screws 7, 17.

The hinge 1 also includes a second internally threaded sheath 18.

The second internally threaded sheath 8? suitable to be connected to the aforementioned mobile element 3 of the hinge so that the twisting moment is transmitted between these two components at least for a portion of the angular movement of the lid 3 but at the same time mutual sliding in the direction of the rotation axis R is allowed, as represented schematically in figures 3, 4, 5.

The second sheath 18 is internally threaded, in the following for brevity? also indicated only as the second sheath 18, it has a substantially cylindrical size.

The second internally threaded sheath 18 engages in screwing/unscrewing with the aforementioned second screw 17 so that its rotation around its rotation axis R simultaneously determines its translation along the same rotation axis R.

The second screw 17 and the second internally threaded sheath 18 together define a second operational screw-nut assembly 19.

The second sheath 18 clearly defines the nut of the second screw-nut operating group 19.

As illustrated in the attached figures, the second helical spring 16 and the second sheath 18 are arranged in succession along the rotation axis R. The second helical spring 16 defines, for the hinge 1, a second elastic member capable of generating an elastic force to reset the second sheath 18.

As illustrated in figure 1, with the second helical spring 16 fitted on the control shaft 4, it has its own end coils 16a, 16b. one contrasting with the second sheath 18 and the other contrasting with a stop pin 11 stably inserted at one end. longitudinal of the control shaft 4.

The first screw 7 and the second screw 17 have respective threads in opposite directions, so as to give the first sheath 8 and the second sheath 18 respective opposite translation directions in correspondence with the same rotation of the mobile element 3 around the axis R of rotation.

According to the configuration of the hinge 1 just indicated, the above-described translation of the second sheath 18 along the rotation axis R determines a variation in the axial development of the second helical spring 16.

In particular, what will it be like? described in detail below, with reference to the drawings of the attached figures, a translation of the second internally threaded sheath 18 from right to left determines a compression of the second helical spring 16, as specifically shown in figure 5. The aforementioned second screw-nut operating group 19 defines, for the hinge 1, respective actuation means of the second elastic member 16 to determine the deformation of the second elastic member 16 itself.

Both the first screw 7 and the second screw 17 have a plurality? of principle, as advantageously happens in the maneuvering screws.

The screws at more? principles have the aim of achieving high pitches without excessively lightening the core of the screw, a circumstance which would compromise the mechanical resistance of the screw itself.

According to the embodiment illustrated in the attached figures, the first screw 7 and the second screw 17 have six principles, so as to substantially conform to the number of faces of the control shaft 4, thus simplifying assembling the hinge 1.

In general terms, the first screw 7 and the second screw 17 advantageously have respective threads having a number of leads equal to the number of sides of the polygon defining the cross-section of the control shaft 4.

Advantageously, the hinge 1 according to the invention features high viscosity damping grease. distributed interposed between the second screw 17 and the second sheath 18, to exert a dampening action on their mutual screwing/unscrewing movement. High viscosity damping grease, known as damping grease, is a very viscous grease which, when placed between two mutually moving parts, exerts a damping action during their movement, like a shock absorber element.

In essence, these are greases formulated with high molecular weight synthetic oils and available in a wide range of viscosities. depending on the type of movement you want to obtain.

Depending on specific needs, these greases are able to offer a wide variety? of resistant couples.

Furthermore, since? the moving parts are separated by a tenacious and adhesive film of grease, in addition to the elimination of the play between the parts themselves, the development of noise and wear are also significantly reduced.

The aforementioned second screw-nut operating group, together with the high viscosity damping grease? distributed interposed between the respective second screw 17 and second sheath 18 defines, for the hinge 1, respective damping means 20 configured to exert a damping action on the movement of the mobile element 3.

Advantageously, the threads of the first screw 7 and the second screw 17 have a triangular profile.

This circumstance, i.e. the adoption of a thread with a triangular profile, although normally avoided in maneuvering screws in favor of rectangular threads (which generate less friction), is in reality? useful in the hinge 1 according to the invention as it increases the friction between the screw and the nut, just as sought for the purposes of damping the mutual motion between the screws 7, 17 and the relative sheaths 8, 18.

The internal thread of the first sheath 8? clearly homologous to that of the first screw 7.

The internal thread of the second sheath 18 ? clearly homologous to that of the second screw 17.

As mentioned above, thanks to the adoption of a multiple-start thread, the sheaths 8, 18 first and second are ? allowed to achieve a high axial translation in the face of limited rotations around the R axis.

Advantageously, the first screw 7 has a pitch between 25 and 35 mm.

Experimentally, yes? found that, in the intended use for balancing the lids of household appliances and with springs and diameters of the type normally used in known type hinges, an optimal value of the pitch of the first screw 7? equal to approximately 33 mm.

With this pitch, and the diameter normally used in known type hinges, at a rotation of approximately 110? sexagesimals, equal to the normal opening/closing angle, for example, of the lid of a washing machine, a translation of the first screw of approximately 10 mm and a corresponding and equivalent compression of the spring is obtained, which is therefore capable of carrying out the correct elastic reaction force suitable for balancing the aforementioned lid.

Advantageously, both the first screw 7 and the first internally threaded sheath 8 are made of plastic material.

Similarly, the second screw 17 and the second internally threaded sheath 8 are also advantageously made of plastic material.

For the purposes of practical production, for example by moulding, both the first sheath 8 and the second sheath 18 can be made in two halves. In figure 6? illustrated as an example one of the two halves? through which? the second sheath 18 has been assembled.

As illustrated in figures 3, 4 and 5, the mobile element 3 has a hole 3a for housing both the first sheath 8 and the second sheath 18.

Obtained in an internal cylindrical wall of the hole 3a, the mobile element 3 has a slot 12.

The first sheath 8 has a projection 8a, emerging from a substantially cylindrical surface of the first sheath 8 itself and counter-shaped with respect to the aforementioned slot 12 to slide into the same slot 12 of the mobile element 3 to define a sort of key suitable for transmission of the torque, precisely between the mobile element 3 and the first sheath 8.

Thanks to this key? defined the above described shaft-hub coupling between the mobile element 3 and the first sheath 8.

The second sheath 18 also has a respective projection 18a, emerging from its substantially cylindrical surface and shaped to slide into the same slot 12 of the mobile element 3 but also to allow a relative rotation around the axis R between mobile element 3 and second sheath 18.

In essence, as illustrated in figures 3a, 4a and 5a, the slot 12 has an angular extension ? greater than the angular extension ? of the projection 18a, so as to determine the transmission of motion between the mobile element 3 and the second sheath 18 only for an angularly determined portion of the movement of the mobile element 3.

In other words, even in the case of the shaft-hub coupling between the second sheath 18 and the mobile element 3, the projection 18a of the second sheath 18 defines a sort of key but with the difference that the twisting moment between these components is ? transmitted only for a portion of the rotation of the mobile element 3.

In use, with reference to figure 3a, starting from an open configuration of the cover C and for a first anti-clockwise rotation of the mobile element 3 according to the direction of the arrow depicted, the projection 18a of the second sheath 18 does not engage with the walls of extremity? of the slot 12, therefore remaining stationary with respect to the rotation axis R.

A closing rotation of the cover C therefore occurs without there being any rotation of the second sheath 18 (with respect to the second screw 17) and therefore no damping action exerted by the damping means 20.

Upon reaching an intermediate configuration close to closing, for example around 30? sexagesimal (in the sense that 30? remain at the closure), as illustrated in figure 4a, the projection 18a of the second sheath 18 engages with the one end wall? of quarry 12 and ? therefore dragged into rotation by the mobile element 3.

In other words, starting from the intermediate configuration of figure 4a and until the closing condition of the cover C illustrated in figure 5a is reached, the second mobile element 3 drags the second sheath 18 into rotation and, consequently, the action of damping caused by high viscosity grease? placed between the second screw 17 and the second sheath 18.

As illustrated in figure 3 which shows a configuration of the hinge 1 corresponding to a condition of maximum opening of the lid C of the appliance with an angle greater than 90? (normally 110?), the first sheath 8 is substantially completely screwed onto the first screw 7 and, consequently, the helical spring 6 assumes its position of maximum extension. Similarly, the second sheath 18 is also substantially entirely screwed onto the second screw 17.

Starting from the maximum opening condition described and illustrated above, a closing movement of the lid C of the appliance causes a simultaneous rotation of the mobile element 3 to which the lid itself is located. constrained and, consequently, a partial unscrewing of the first sheath 8 from the respective first screw 7, and of the second sheath 18 from the second screw 17, as clearly illustrated in figures 4 and 5.

Unscrewing the first sheath 8 from the first screw 7 also determines a translation of the first sheath 8 itself as it approaches the fixed body 2 and, consequently, a compression of the first helical spring 6.

This compression, or rather the reaction of the first spring 6 to this compression, constitutes a force that opposes the closing of the cover C, thus balancing its weight force and, in practice, slowing down its descent. The unscrewing of the second sheath 18 from the second screw 17 also determines a translation of the second sheath 18 itself towards the stop pin 11 and, consequently, a compression of the second helical spring 16.

This compression, or rather the reaction of the second spring 16 to this compression, constitutes a resetting force of the second sheath 18 which will return at the end of its damping action. to resume its initial angular position.

In other words, the second helical spring 16 is operationally active on the aforementioned second lead screw group 19 and configured to give the second sheath 18 a roto-translation suitable for bringing the projection 18a back into an operational condition of engagement with the aforementioned slot 12.

To the balancing action of the helical spring 6 is therefore added, starting from a certain angular position, the damping action operated by the grease (damping grease) placed between the second screw 17 and the second sheath 8 which, as mentioned, it contributes both to slowing down and smoothing the mutual movement of the components involved and, consequently, also of the cover C.

The effect of the damping grease on the operation of hinge 1 is ? therefore completely comparable to that of a shock-absorbing element, for example of the type with a fluid piston.

As illustrated in figure 2, the second sheath 18 has a cavity? 21 end ring finger? designed to house excess damping grease. Thanks to the cavity? 21, any damping grease deposited in excess between the second screw 17 and the second sheath 18? accumulated and preserved like this? to remain available in any case.

Advantageously according to the hinge 1 of the invention? can it be adapted easily? the entity of the desired damping effect (both as a function of the weight of the cover C but also in light of the specific needs of the household appliance manufacturer) even just by varying the length of the second operational screw-nut group 19 or even just by varying the length of the second sheath 18 alone In fact, by decreasing the surface exposed to sliding with high viscosity grease? the damping action exerted is reduced and, vice versa, it can be increase by increasing this surface (i.e. with a second longer screw 17 and/or second sheath 18).

The hinge 1 for household appliance lids according to the invention achieves the intended purposes and achieves important advantages.

A first advantage? given by the fact that through the hinge 1 according to the invention, advantageously it is possible to obtain an effective damping action without the need? to introduce cumbersome piston damping devices.

Further advantages, connected to the introduction of a screw damping device with high viscosity grease? are found in the particularly simple assembly of the hinge.

An additional advantage? connected to the use of damping grease, which in fact allows a damping effect to be obtained without the introduction of further specific components such as piston shock absorbers, therefore contributing to reducing the overall number of elements that make up the hinge.

Yet another considerable advantage? given by simplicity? of regulation of the entity? of the damping action that in the hinge according to the invention? easily obtainable even just by varying the length of the second screw and/or even just the second sheath, without it also being a new design of the damper device is required.

Yet another advantage? given by the possibility? to easily vary the starting point (and therefore the operating range) of the damping action, simply by modifying the screwing of the second sheath on the second screw, even just by interposing appropriate spacer elements.

Claims (11)

1. Hinge for household appliance lids, including: - a fixed body (2), which can be connected integrally to a frame of the household appliance; - a movable element (3), which can be connected integrally to a cover of the household appliance, capable of rotating with respect to said fixed body (2) around a respective axis (R) of rotation to make said cover movable with respect to the frame of the household appliance between a closed position and an open position; - a control shaft (4), developing longitudinally parallel to said rotation axis (R) and stably connected to one of said fixed body (2) and mobile element (3); - a first elastic member (6) capable of generating an elastic force to balance the weight of said lid; - actuation means of said first elastic member (6) to determine its deformation and transmit said elastic balancing force to said mobile element (3), said actuation means comprising a first operating group (9) lead screw, said first group (9 ) operational by presenting a first screw (7) and a first internally threaded sheath (8), said first screw (7) and first threaded sheath (8) engaging in screwing/unscrewing so that the rotation of said mobile element (3) determines at the same time a reciprocal translation between said first screw (7) and first internally threaded sheath (8) along the same rotation axis (R) and the deformation of said first elastic member (6); - damping means (20) configured to exert a damping action on the movement of said mobile element (3), said hinge being characterized by the fact that said damping means (20) comprise a second operational screw-nut group (19) presenting a second screw (17) and a second internally threaded sheath (18), said second sheath (18) being operationally connectable to said mobile element (3) and capable of engaging with said second screw (17) in screwing/unscrewing, grease of high viscosity damping? being distributed interposed between said second screw (17) and said second sheath (18), to exert a damping action on their mutual screwing/unscrewing movement. 2. Hinge according to claim 1, in which said mobile element (3) has a hole (3a) for housing and engaging said second sheath (18), characterized by the fact that said mobile element (3) has a slot (12) obtained in the wall of said hole (3), and by the fact that said second sheath (18) has a projection (18a) capable of slidingly engaging inside said cavity (12), said second sheath (18) and mobile element ( 3) defining a sliding shaft-hub coupling in which said second sheath (18) defines a shaft and said mobile element (3) defines a hub, said slot (12) presenting an angular extension (?) greater than the angular extension (?) of said projection (18a) so as to determine the transmission of motion between said mobile element (3) and said second sheath (18) only for an angularly determined portion of the movement of said mobile element (3). 3. Hinge according to claim 2, characterized by the fact that said damping means comprise a second elastic member (16) for resetting said second sheath (18), operatively active on said second screw-nut group (19) and configured to impart to said second sheath (18) a roto-translation suitable to bring said projection (18a) back into an operational condition of engagement with said slot (12). 4. Hinge according to any of the previous claims, characterized in that said first screw (7) and second screw (17) have respective threads in opposite directions, so as to give said first sheath (8) and second sheath (18) opposite translation directions. 5. Hinge according to any of the previous claims, characterized in that said first and second screws (7, 17) are made in a single body, and arranged adjacent in succession according to said axis (R) of rotation. 6. Hinge according to claim 5, characterized in that said first and second screws (7, 17) are made of plastic material. 7. Hinge according to any of the previous claims, wherein said control shaft (4) has a polygonal cross section defined by a polygon having a determined number of sides, characterized by the fact that said first screw (7) and second screw (17 ) have respective threads having a number of leads equal to said determined number of sides of said polygon. 8. Hinge according to claim 7, wherein said drive shaft (4) has a hexagonal cross section and said first screw (7) and second screw (17) have a six-point thread. 9. Hinge according to any of the previous claims, characterized in that said second sheath (18) has at least one cavity? (21) end ring finger? designed to house damping grease. 10. Hinge according to any of the previous claims, characterized in that said first screw (7) and said second screw (17) have respective cavities? (7a) central housings for said control shaft (4), said control shaft (4) being rotatably integral with said first screw (7), with said second screw (17) and with said fixed body (2). 11. Hinge according to any one of the previous claims, characterized in that said thread of said first screw (7) has a thread pitch between 25 and 35 mm.