[0001] The present invention relates to a hinge for the door of electrical household appliances,
particularly for hinging the door of dishwashers.
[0002] As is known, the doors of electrical household appliances, such as traditional ovens,
microwave ovens or dishwashers, are connected to the body of the appliance by means
of a pair of coaxial hinges, which allow the door to rotate with respect to the body
of the appliance in order to open or close it.
[0003] Several types of hinges for the door of electrical household appliances are known
depending on the type of appliance in which they are to be installed and depending
on the requirements to be met.
[0004] In particular, in the field of dishwashers, hinges are known which are designed to
be used in pairs so as to allow the rotation of the door of the dishwasher with respect
to the body of the appliance about a horizontal axis that is proximate to the lower
side of the door. Such hinges are composed of a coupling element, to be fixed to the
body of the appliance, and a supporting element, to be fixed to the door, which are
mutually hinged about a main axis, which constitutes the axis about which the door
is rotated with respect to the body of the appliance in order to open or close it.
In these types of hinges, an effect of compensation of the weight of the door is generally
required which can vary from appliance to appliance and depending on the covering
panel, if any, that is applied to the outer side of the door, such as for example
in the case of fitted appliances. Such compensation effect is obtained generally by
means of a spring, which is connected to the supporting element by means of a connecting
element, which is hinged to a portion of the supporting element about a second axis
which is parallel to, and spaced from, the main axis so that the elastic reaction
of the spring generates a torque, about the main axis, that contrasts the torque generated
by the weight of the door, which increases as the extent of the opening of the door
increases. The function of the connecting element is to vary adequately the arm of
the elastic reaction generated by the spring, with respect to the main axis, in order
to counterbalance in the best possible manner the weight of the door both during opening
and during closure.
[0005] In the field of dishwashers, the need is felt to be able to keep the door open in
any position despite the two contrasting forces, the weight of the door and the elastic
reaction of the spring, which are unlikely to be perfectly balanced in any position.
[0006] In order to meet this requirement, several hinges have been devised which however
are structurally complicated and/or expensive.
[0007] The aim of the present invention is to meet the requirement described above by providing
a hinge for the door of electrical household appliances, particularly for hinging
the door of dishwashers, which is structurally simple.
[0008] Within this aim, an object of the invention is to provide a hinge that is composed
of a limited number of components that are simple to manufacture and assemble.
[0009] Another object of the invention is to provide a hinge that can be manufactured with
competitive costs.
[0010] This aim, as well as these and other objects that will become better apparent hereinafter,
are achieved by a hinge for the door of electrical household appliances, particularly
for hinging the door of dishwashers, comprising a coupling element, which can be fixed
to the body of the appliance, and a supporting element, which can be fixed to the
door and is hinged to said coupling element about a main axis, an element being provided
for connecting said supporting element to elastic means that contrast the rotation
of said supporting element with respect to said coupling element in the direction
of rotation that corresponds to the opening rotation of the door with respect to the
appliance, friction means being also provided which are interposed between said connecting
element and said coupling element in order to slow the rotation of said supporting
element with respect to said coupling element about said main axis,
characterized in that said friction means are connected to said coupling element and engage against two
opposite faces of said connecting element.
[0011] With reference to the figures, the hinge according to the invention, generally designated
by the reference numeral 1, comprises a coupling element 2, which can be fixed to
the body of the appliance, and a supporting element 3, which can be fixed to the door
and is hinged to the coupling element 2 about a main axis 4.
[0012] The coupling element 2 and the supporting element 3 can be made, in a per se known
manner, of blanked and folded metal plate and be fixed respectively to the body of
the appliance and to the door, which are not illustrated for the sake of simplicity,
by way of connecting means of a known type, such as for example screws, bolts, rivets
or other technically equivalent connecting means.
[0013] The hinge according to the invention also comprises an element 5 for connecting the
supporting element 3 to elastic means 6, which contrast the rotation of the supporting
element 3 with respect to the coupling element 2 in the direction of rotation that
corresponds to the opening rotation of the door with respect to the appliance.
[0014] The hinge according to the invention further comprises friction means 7, which are
interposed between the connecting element 5 and the coupling element 2 in order to
slow the rotation of the supporting element 3 with respect to the coupling element
2 about the main axis 4.
[0015] According to the invention, the friction means 7 are connected to the coupling element
2 and engage against two opposite faces of the connecting element 5.
[0016] The connecting element 5 has a substantially plate-like shape and the friction means
7 engage the two opposite larger faces of the connecting element 5.
[0017] The connecting element 5 is hinged, proximate to one of its ends, to the supporting
element 3 about a second axis 8, which is parallel and spaced with respect to the
main axis 4, and to the coupling element 2 about a third axis 9, which is parallel
and spaced with respect to the main axis 4 and the second axis 8. The connecting element
5 is connected to the elastic means 6 with a portion thereof that is arranged opposite
the second axis 8 with respect to the third axis 9, and the connecting element 5 can
slide, on a plane which is perpendicular to the main axis 4, with respect to the coupling
element 2.
[0018] More particularly, the third axis 9 is formed by a pivot 10, which is fixed to the
coupling element 2, and the coupling element 5 mates with such pivot 10 by means of
an elongated slot 11, so that the connecting element 5 can rotate, in its plane of
arrangement, with respect to the coupling element 2 about the third axis 9, i.e.,
with respect to the axis of the pivot 10, and can also perform a translational motion,
in its plane of arrangement, with respect to the pivot 10.
[0019] Conveniently, a resting element 12 is provided, which is connected to the coupling
element 2 laterally to the connecting element 5. Such resting element 12 defines,
in cooperation with the pivot 10, a guiding passage 13 for a portion of the connecting
element 5 that is arranged between the slot 11 and a side of the connecting element
5 that faces the resting element 12.
[0020] The resting element 12 is preferably constituted by a roller 14 or a pulley, which
is pivoted to the coupling element 2 about a fourth axis 15, which is parallel to
the main axis 4.
[0021] The elastic means 6 are constituted by a helical spring 16, which is connected, with
one of its ends, to the coupling element 2 and, with its opposite end, to the portion
of the connecting element 5 that is arranged opposite the second axis 8 with respect
to the third axis 9.
[0022] The friction means 7 comprise a pair of plates 17a, 17b, preferably made of synthetic
material, which are fitted on the pivot 10 with the connecting element 5 interposed
so as to engage the two opposite larger faces of the connecting element 5.
[0023] Advantageously, pushing means 18 are provided for pushing the plates 17a, 17b against
the two opposite faces of the connecting element 5.
[0024] Conveniently, the pusher means 18 comprise at least one spring 19, which is constituted
preferably by a conical helical spring which is fitted around the pivot 10 and is
interposed between a shoulder 10a of the pivot 10 and one of the two plates 17a, 17b
so as to pack together the plates 17a, 17b and the connecting element 5.
[0025] In practice, one of the two plates 17a, 17b, constituted by the plate 17a, is interposed
between the connecting element 5 and the coupling element 2, while the other plate
17b is interposed between the connecting element 5 and one end of the spring 19, which
engages, with its opposite end, against the shoulder 10a that is formed at one end
of the pivot 10.
[0026] Operation of the hinge according to the invention is as follows.
[0027] In order to hinge a door to the body of an electrical household appliance, two hinges
according to the invention are used which are fixed by means of the coupling element
2 to the body of the appliance and by means of the supporting element 3 to the door
so that the main axes of the two hinges coincide, generally horizontally, so as to
define the axis about which the door is rotated in order to open and close the appliance.
[0028] If the appliance is constituted by a dishwasher, the two hinges are arranged proximate
to the lower side of the door, so that the rotation axis of the door is proximate
and parallel to the lower side.
[0029] Starting from the fully closed position of the door, shown in Figure 1, a rotation
of the door in the opening direction and therefore a rotation of the supporting element
3 about the main axis 4 with respect to the body of the appliance, i.e., with respect
to the coupling element 2, produces a partial rotation of the connecting element 5
about the third axis 9 and a sliding of the connecting element 5 with respect to the
pivot 10, between said pivot 10 and the roller 14, as shown in Figures 2 and 3. This
sliding of the connecting element 5 causes an elongation of the spring 16, which produces
an elastic reaction that generates a torque which contrasts the opening rotation of
the supporting element 3 about the main axis 4 with respect to the coupling element
2.
[0030] The opening rotation of the supporting element 3 with respect to the coupling element
2 about the main axis 4 can continue until the door is completely open and is reached
when the slot 11 stops with one of its ends against the pivot 10, as shown in Figure
3.
[0031] Starting from this fully open position of the door, a rotation of the door in the
closing direction and therefore a rotation of the supporting element 3 about the main
axis 4 with respect to the body of the appliance, i.e., with respect to the coupling
element 2, causes the sliding of the connecting element 5 with respect to the coupling
element 2 between the pivot 10 and the roller 14. This sliding is assisted by the
elastic reaction of the spring 16.
[0032] Both during the opening rotation and during the closing rotation of the supporting
element 3 with respect to the coupling element 2 about the main axis 4, the sliding
of the connecting element 5 with respect to the coupling element 2 is slowed by the
friction of the plates 17a, 17b against the two opposite faces of the connecting element
5.
[0033] This slowing effect of the plates 17a, 17b allows to stop the door in any position
between the fully open position and the fully closed position, simply by releasing
the door. In this case, the fraction of the weight of the door or of the elastic reaction
of the spring that is in excess is in fact contrasted effectively by the friction
generated by the plates 17a, 17b against the two opposite faces of the connecting
element 5.
[0034] The spring 19 of the pusher means 18 has the effect of increasing the friction between
the plates 17a, 17b and the connecting element 5 and to recover any plays arising
from the machining tolerances of the plates 17a, 17b of the coupling element 2, of
the pivot 10 and of the connecting element 5, and of compensating for the wear of
the plates 17a, 17b.
[0035] In practice it has been found that the hinge according to the invention fully achieves
the intended aim, since it allows to stop the opening of the door in any position
despite a structure that is extremely simple and composed of a limited number of elements
that are simple to manufacture and assemble.
[0036] The hinge thus conceived is susceptible of numerous modifications and variations,
all of which are within the scope of the appended claims; all the details may further
be replaced with other technically equivalent elements.
[0037] In practice, the materials used, as well as the dimensions, may be any according
to requirements and to the state of the art.
[0038] The disclosures in Italian Patent Application No.
MI2009A001321 from which this application claims priority are incorporated herein by reference.
[0039] Where technical features mentioned in any claim are followed by reference signs,
those reference signs have been included for the sole purpose of increasing the intelligibility
of the claims and accordingly, such reference signs do not have any limiting effect
on the interpretation of each element identified by way of example by such reference
signs.
1. A hinge (1) for the door of electrical household appliances, particularly for hinging
the door of dishwashers, comprising a coupling element (2), which can be fixed to
the body of the appliance, and a supporting element (3), which can be fixed to the
door and is hinged to said coupling element (2) about a main axis (4), an element
(5) being provided for connecting said supporting element (3) to elastic means (6)
that contrast the rotation of said supporting element (3) with respect to said coupling
element (2) in the direction of rotation that corresponds to the opening rotation
of the door with respect to the appliance, friction means (7) being also provided
which are interposed between said connecting element (5) and said coupling element
(2) in order to slow the rotation of said supporting element (3) with respect to said
coupling element (2) about said main axis (4), characterized in that said friction means (7) are connected to said coupling element (2) and engage against
two opposite faces of said connecting element (5).
2. The hinge according to claim 1, characterized in that said connecting element (5) has a substantially plate-like shape, said friction means
(7) engaging the two opposite larger faces of said connecting element (5).
3. The hinge according to claims 1 and 2, characterized in that said connecting element (5) is hinged, proximate to one of its ends, to said supporting
element (3) about a second axis (8), which is parallel and spaced with respect to
said main axis (4), and to said coupling element (2) about a third axis (9), which
is parallel and spaced with respect to said main axis (4) and said second axis (8);
said connecting element (5) being connected to said elastic means (6) with a portion
thereof that is arranged opposite said second axis (8) with respect to said third
axis (9) and said connecting element (5) being able to slide, on a plane which is
perpendicular to said main axis (4), with respect to said coupling element (2).
4. The hinge according to one or more of the preceding claims, characterized in that said third axis (9) is formed by a pivot (10), which is connected to said coupling
element (2), said connecting element (5) mating with said pivot (10) by means of an
elongated slot (11) for the rotation of said connecting element (5) with respect to
said coupling element (2) about said third axis (9) and for the sliding of said connecting
element (5) on its plane of arrangement with respect to said pivot (10).
5. The hinge according to one or more of the preceding claims, characterized in that said elastic means (6) comprising a helical spring (16), which is connected, by means
of one of its ends, to said coupling element (2) and, by means of its opposite end,
to said portion of the connecting element (5) that lies opposite said second axis
(8) with respect to said third axis (9).
6. The hinge according to one or more of the preceding claims, characterized in that it comprises a resting element (12), which is connected to said coupling element
(2) laterally to said connecting element (5), said resting element (12) defining,
in cooperation with said pivot (10), a guiding passage (13) for a portion of said
connecting element (5) that is arranged between said slot (11) and a side of said
connecting element (5) that faces said resting element (12).
7. The hinge according to one or more of the preceding claims, characterized in that said resting element (12) is constituted by a roller (14) pivoted to said coupling
element (2) about a fourth axis (15), which is parallel to said main axis (4).
8. The hinge according to one or more of the preceding claims, characterized in that said friction means (7) comprise a pair of plates (17a, 17b) which are fitted around
said pivot (10) with said connecting element (5) interposed so as to engage the two
opposite larger faces of said connecting element (5).
9. The hinge according to one or more of the preceding claims, characterized in that it comprises pushing means (18) for pushing said plates (17a, 17b) against the two
opposite faces of said connecting element (5).
10. The hinge according to one or more of the preceding claims, characterized in that said pusher means (18) comprise at least one spring (19), which is fitted around
said pivot (10) and is interposed between a shoulder (10a) of said pivot (10) and
one of said two plates (17a, 17b) in order to pack together said plates (17a, 17b)
and said connecting element (5).
11. The hinge according to one or more of the preceding claims, characterized in that said spring (19) is constituted by a conical helical spring.