[0001] The present invention refers to a tank-basket group for a washing machine, dryer
or washer dryer.
[0002] Known washing machines comprise an outer housing, a washing tank arranged inside
the outer housing and suitable for containing the lye, as well as a perforated clothes
basket, arranged rotatably inside the washing tank and defining inside a space for
containing the clothes to be washed. In front-loading washing machines and washes
dryers, the clothes basket is usually made up of a back wall through which the basket
is rotatably fixed inside the tank, a front wall defining a loading opening through
which it is possible to access the inside of the basket and a side wall that is perforated
so as to allow the exchange of lye between the washing rank and the inside of the
basket.
[0003] In top-loading washing machines, the clothes basket is usually made up of a back
wall and a front wall, through which the basket is rotatably fixed inside the tank,
as well as a generally cylindrical and perforated side wall to allow the exchange
of lye between the washing tank and the inside of the basket, in which the side wall
defines a loading opening through which it is possible to access the inside of the
basket.
[0004] In order to make the basket rotate inside the washing tank, known washing machines
comprise a motor and a belt drive that transmits the rotary motion of the motor to
a pulley arranged outside the washing tank and that is connected so as to rotate as
a unit with the clothes basket.
[0005] Thanks to the rotational movement of the basket, the clothes are agitated and rolled
around in the lye and the lye itself is pulled upwards in rotation by the basket from
which it falls on the clothes which are completely soaked and softened, so as to transfer
the impurities to the washing and rinsing lye.
[0006] However, in known washing machines and washer dryers, the rotary support of the clothes
basket in the back wall of the washing tank, which must withstand high mechanical
1 stresses in particular during the centrifuging of the clothes, and the positioning
and connection of the pulley in the same position are very bulky so that a part of
the depth of the outer housing cannot be exploited to contain clothes to be washed
and/or dried.
[0007] The purpose of the present invention is therefore that of proposing a tank-basket
group for washing machines, washer dryers or dryers having characteristics such as
to reduce the bulk that cannot be used for containing clothes.
[0008] Within the main purpose, a particular purpose of the invention is that of proposing
a tank-basket group having an overall depth that is smaller for the same depth of
the clothes basket.
[0009] These and other purposes are achieved with a tank-basket group for washing machines,
washer dryers or dryers, the tank - basket group comprising:
- a washing tank suitable for containing the lye and having a support wall,
- a clothes basket arranged inside the washing tank, the clothes basket having a back
wall that is rotatably connected to the support wall of the washing tank,
- a driving pulley arranged outside the washing tank and connected so as to rotate together
with the back wall of the clothes basket,
- a shaft projecting along a rotation axis from the back wall of the basket and rotatably
received in a support seat formed in the support wall of the tank, said shaft having
a back end facing outwards from the tank,
in which
- the pulley comprises a male fixing portion projecting along a rotation axis towards
the tank,
- the back end of the shaft forms a tubular wall with an outer surface that forms a
first bearing housing that receives a first bearing and an inner surface defining
a female pulley seat that receives the male fixing portion of the pulley axially in
the thickness of the support wall of the tank.
[0010] Thanks to the housing of the male fixing portion of the pulley in the thickness of
the support wall of the tank, axial space is saved making it possible to increase
the axial depth of the basket and therefore to increase the load of clothes for the
same outer dimensions of the household appliance.
[0011] In order to better understand the invention and to appreciate its advantages, hereafter,
we shall describe some embodiments given as an example and not for limiting purposes,
with reference to the attached figures, in which:
[0012] figure 1 is a schematic view, in vertical section, of a washing machine according
to an embodiment of the invention;
[0013] figure 2 is a schematic view, in vertical section, of a detail of a tank-basket group
of the washing machine in figure 1;
[0014] figure 3 is a longitudinal section view of a portion of a support shaft of the tank-basket
group according to an embodiment;
[0015] figure 4 is a front view of the support shaft in figure 3;
[0016] figure 5 is a longitudinal section view of a connection portion of a pulley of the
tank-basket group according to an embodiment;
[0017] figure 6 is a front view of the connection portion in figure 5.
[0018] With reference to the figures, a washing machine, washer dryer or dryer is wholly
indicated with reference numeral The machine 1 comprises an outer housing 2, a washing
tank 3 arranged inside the outer housing 2 and suitable for containing the lye, as
well as a perforated clothes basket 4, arranged inside the washing tank 3 in a rotatable
manner around a rotation axis R and defining a space 5, on the inside, for containing
the clothes to be washed and/or dried. The clothes basket 4 can be made up of a back
wall 6 through which the basket 4 is rotatably fixed to a support wall 12 of the tank
3, a front wall 7 defining a loading opening 9 through which it is possible to access
the inside of the basket 4 and a side wall 8 that is perforated so as to allow the
exchange of lye between the washing tank 3 and the inside of the basket 4 (Figure
1).
[0019] Alternatively, in top-loading washing machines, the clothes basket 4 is usually made
up of a back wall 6 and a front wall 7, through which the basket is rotatably fixed
to opposite support walls 12 of the tank 3, as well as a side wall 8 generally cylindrical
and perforated so as to allow the exchange of lye between the washing tank and the
inside of the basket, in which the side wall defines a loading opening (not illustrated)
through which it is possible to access the inside of the basket.
[0020] In order to make the basket 4 rotate inside the washing tank 3, the machine 1 comprises
a motor 10 and a drive 11, for example a belt drive, which transmits the rotary motion
of the motor 10 to a pulley 13 arranged outside the washing tank 3 and connected so
as to rotate as a unit with the clothes basket 4.
[0021] The tank 3 - basket 4 group also comprises a support shaft 14 that extends parallel
to the rotation axis R and projects from the back wall 6 of the basket 4 towards the
outside of the basket. The shaft 14 is rotatably received, through at least a first
bearing 16, in a support seat 15 formed in the support wall 12 of the tank 3, and
comprises a back end 17 facing outwards from the tank 3.
[0022] The pulley 13 comprises a male fixing portion 18 extending parallel to the rotation
axis R and projecting towards the tank 3 or, in other words, from outside of the tank
towards the inside. The back end 17 of the shaft 14 forms a tubular wall 19 with a
radially outer surface 20 (with reference to the rotation axis R) that forms a first
bearing housing 21 that receives the first bearing and a radially inner surface 22
that defines a female pulley seat 23 formed inside the back end 17 of the shaft 14.
[0023] The female pulley seat 23 receives the male fixing portion 18 of the pulley 13 axially
in the thickness of the support wall 12 of the tank 3 (Figure 2).
[0024] Thanks to the housing of the male fixing portion of the pulley in the thickness of
the support will of the tank, axial space is saved allowing the axial depth of the
basket to be increased and therefore the clothes load is increased for the same outer
dimensions of the household appliance.
[0025] In accordance with an embodiment, the male fixing portion 18 of the pulley 13 extends
axially in the area of the first bearing 16.
[0026] The inner surface 22 of the pulley seat 23 can be profiled, for example notched through
a plurality of longitudinal grooves 25 and even the male fixing portion 18 of the
pulley 13 can form an outer surface 24 with a matching shape, for example notched
and suitable for engaging the inner surface 22 through a shape coupling rotating as
a unit around the rotation axis R.
[0027] In accordance with an embodiment, the profiling, for example notching 25 of the pulley
seat 23 extends axially completely inside the axial extension of the first bearing
16.
[0028] This advantageously makes it possible to use the same axial space both for the rotatable
connection and the vertical support of the basket to the tank, as well as for the
connection of the pulley so as to rotate as a unit with the clothes basket.
[0029] The male fixing portion 18 can also comprise an axial hole, preferably central, that
receives a locking screw 27 and that opens into a back surface 28 opposite the tank
3, in a back cavity 29 having an axial with and depth such as to at least partially
receive a nut or a head 30 of the locking screw 27.
[0030] In accordance with an embodiment, the back cavity 29 has an axial depth greater than
2/3 of the axial height of the head 30 or of the nut of the locking screw 27.
[0031] Preferably, the back cavity 29 completely receives the head 30 or the nut of the
locking screw 27, so that the screw does not project axially out from the back cavity
29.
[0032] Thanks to this configuration, the locking screw remains completely inside the axial
bulk of the pulley and makes it possible to bring the tank-basket group, with the
pulley, closer to the outer housing 2 of the washing machine 1.
[0033] The locking screw 27 can be screwed in an internally threaded locking hole 31, formed
in a bottom 32 of the pulley seat 23.
[0034] In accordance with an embodiment, it is foreseen for there to be a second bearing
33 fitted onto an annular surface 34 of the shaft 14 between the first bearing 16
and the back wall 6 of the basket 4 and, similarly to the first bearing 16, the second
bearing 33 is also received in the support seat 15 of the tank 3, through an outer
ring. Advantageously, the locking hole 31 extends axially up to inside the area of
the second bearing 33.
[0035] The shaft 14 can also comprise an outer shoulder 35 facing outwards from the tank
3 and preferably configured as a circumferential step that axially defines the first
bearing housing 21 on a front side. On the other side, the pulley 13 forms a clamping
surface 36 that is preferably annular and substantially perpendicular to the rotation
axis R, said clamping surface 36 facing towards the tank 3 and being suitable for
engaging a back surface 37 of the first bearing 16 to clamp the first bearing 16 axially
against the outer shoulder 36 of the shaft 14, when the male fixing portion 18 is
locked in the female pulley seat 23.
[0036] In order to obtain a single support between the clamping surface 36 and the first
bearing 16 and in order to reduce the axial bulk of the pulley-shaft connection, the
first bearing 16 projects axially beyond the back end 17 of the shaft 14.
[0037] The second bearing 33 preferably has an inner diameter that is greater with respect
to the internal diameter of the first bearing 16, so that the outer shoulder 35 can
be obtained through just the processing of the first bearing housing and without further
reduction of diameter of the shaft at the annular surface 34. This configuration also
makes it possible to have an easy assembly of the tank-basket group through the insertion
of the shaft 14 from inside of the tank into the support seat 15 with the bearings
16, 33 already mounted.
[0038] In accordance with a preferred embodiment, the axial depth D38 of the pulley seat
23 is greater than half of the axial distance D40 between a back edge 39 of the pulley
13 (meant as the furthest back surface or portion of the pulley) and its clamping
surface 36 in contact with the first bearing 16.
[0039] Even more preferably, the ratio between the axial depth D38 of the pulley seat and
the aforementioned axial distance D40 is of between D38 / D40 = 0.75 to 1.25, obtaining
an optimal exploitation of the available axial space, taking into account the vertical
support requirements, the moments of cantilevered support of the basket, stress due
to the centrifugal forces and the twisting coupling between the pulley and the basket.
[0040] A frontal end 41 of the shaft 14 is anchored to the back wall 6 of the basket 4 so
that the shaft 14 rotates with the basket 4. In accordance with an embodiment, the
front end 41 can comprise circumferential anti-extraction grooves 42 engaged by corresponding
circumferential protuberances 43 of the back wall 6 and/or longitudinal anti-rotation
grooves 44 engaged by corresponding longitudinal protuberances 45 of the back wall
6. For such a purpose, the back wall 6 of the basket can comprise an anchoring body
46 and the front end 41 of the shaft is embedded in the anchoring body 46 during its
formation through moulding.
[0041] Further variants and/or additions are well within the capabilities of the man skilled
in the art, without for this reason departing from the scope of protection defined
in the attached claims.
1. A tank-basket group (3, 4, 13, 14) for a washing machine (1), washer dryer or dryer,
the tank - basket group comprising:
- a washing tank (3) suitable for containing the lye and having a support wall (12),
- a clothes basket (4) arranged inside the washing tank (3), the clothes basket (4)
having a back wall (6) that is rotatably connected to the support wall (12) of the
washing tank (3),
- a driving pulley (13) arranged outside the washing tank (3) and connected in a way
such as to rotate with the back wall (6) of the clothes basket (4),
- a shaft (14) parallel to the rotation axis (R) projecting from the back wall (6)
of the basket (3) and rotatably received in a support seat (15) formed in the support
wall (12) of the tank (3), said shaft (14) having a back end (17) facing outwards
from the tank (3),
characterised in that
- the pulley (13) comprises a male fixing portion (18) extending parallel to the rotation
axis (R) and projecting towards the tank (3),
- the back end (17) of the shaft (14) forms a tubular wall (19) with an outer surface
(20) that forms a first bearing housing (21) that receives a first bearing (16) and
an inner surface (22) defining a female pulley seat (23) that receives the male fixing
portion (18) of the pulley (13) axially in the thickness of the support wall (12)
of the tank (3).
2. Tank-basket group according to claim 1, wherein the male fixing portion (18) of the
pulley (13) extends axially in the area of the first bearing (16).
3. Tank-basket group according to any one of the previous claims, wherein the inner surface
(22) of the pulley seat (23) is notched and the male fixing portion (18) forms an
outer surface (24) that is notched and is suitable for engaging with the inner surface
(22) through shape coupling rotating as a unit.
4. Tank-basket group according to any one of the previous claims, wherein the notching
(25) of the pulley seat (23) extends axially completely inside the axial extension
of the first bearing (16).
5. Tank-basket group according to any one of the previous claims, wherein the male fixing
portion (18) comprises a hole (26) that receives a locking screw (27) and the pulley
(13) forms, in a back surface (28) opposite the tank (3), a back cavity (29) for receiving
a nut or a head (30) of the locking screw (27).
6. Tank-basket group according to claim 5, wherein the back cavity (29) has an axial
depth greater than 2/3 of the axial height of the head (30) or of the nut of the locking
screw (27).
7. Tank-basket group according to claim 5, wherein the back cavity (29) completely receives
the head (30) or the nut of the locking screw (27), so that it does not axially protrude
outside from the back cavity (29).
8. Tank-basket group according to any one of the previous claims, wherein the shaft (14)
comprises an internally threaded locking hole (31), said locking hole (31) being formed
in a bottom (32) of the pulley seat (23) and being suitable for receiving a locking
screw (27).
9. Tank-basket group according to claim 8, comprising: a second bearing (33) fitted onto
an annular surface (34) of the shaft between said first bearing (16) and the back
wall (6) of the basket, wherein said locking hole (31) extends axially up to inside
the area of the second bearing (33).
10. Tank-basket group according to any one of the previous claims, wherein said shaft
(14) comprises an outer shoulder (35) facing outwards from the tank (3) and axially
defining the first bearing housing (21), wherein the pulley (13) forms an annular
clamping surface (36) substantially perpendicular to the rotation axis (R) and facing
towards the tank (3), said clamping surface (36) being suitable for engaging with
a back surface (37) of the first bearing (16) to lock the first bearing (16) axially
against the outer shoulder (35) of the shaft, when the male fixing portion (18) is
locked in the female pulley seat (23).
11. Tank-basket group according to any one of the previous claims, wherein said first
bearing (16) projects axially beyond the back end (17) of the shaft (14).
12. Tank-basket group according to any one of the previous claims, comprising a second
bearing (33) fitted onto an annular surface (34) of the shaft (15) between said first
bearing (16) and the back wall (6) of the basket (4), wherein said second bearing
(33) has an internal diameter that is greater than the internal diameter of the first
bearing (16).
13. Tank-basket group according to any one of the previous claims, wherein an axial depth
(D38) of the pulley seat (23) is greater than half of the axial distance (D40) between
a back edge (39) of the pulley and its clamping surface (36) in contact with the first
bearing (16), preferably the ratio (D38/D40) between the axial depth (D38) and the
axial distance (D40) is of between 0.75 to 1.25.
14. Tank-basket group according to any one of the previous claims, wherein said shaft
(14) comprises a front end (41) anchored to the back wall (6) of the basket (4) so
that the shaft rotates with the basket, said front end (41) comprising:
- anti-extraction circumferential grooves (42) engaged by corresponding circumferential
protuberances (43) of the back wall,
- longitudinal anti-rotation grooves (44) engaged by corresponding longitudinal protuberances
(45) of the back wall.
15. Washing machine (1), washer dryer or dryer, comprising a tank basket group according
to any one of the previous claims.