[0001] The present invention relates to a washing machine comprising a cabinet into which
a tub is mounted containing a rotatable drum, between the cabinet and the tub being
installed a deformable tubular device for allowing the load and unload of clothes
through aligned apertures in the cabinet, in the tub and in the drum and for preventing
water spillage outside the tub.
[0002] In the known washing machines the above deformable tubular device is a rubber bellow
which performs the above functions.
[0003] Unbalance load causes the wash unit, i.e. the assembly of the tub and drum, to move
inside the cabinet, transmitting forces and vibrations through dampers, springs and
bellow to the cabinet and therefore to the floor as well.
[0004] Despite the flexibility of the known rubber bellows, the material and geometric stiffness
thereof causes the transmission of relevant forces between the wash unit and the cabinet,
particularly tangential forces. This high loads do create high reaction forces which
require a design utilizing space which would be better used by using a bigger wash
unit.
[0005] An object of the present invention is to provide a washing machine of the type specified
at the beginning of the description which does not present the above technical problems,
without increasing the overall cost of the machine.
[0006] The above object is reached thanks to the features listed in the appended claims.
[0007] The basic idea underlying the present invention is to replace the traditional rubber
bellow with a component made of a textile or fabric with very low stiffness between
the wash unit and the cabinet for sealing purposes. With the term "fabric" we mean
any kind of woven, knitted or felted material. The advantage compared to existing
solutions, i.e. rubber bellows, is mainly the high flexibility and independence of
geometric "decoupling" features of the fabric compared to the material and geometric
stiffness of current rubber seals. Fabric will not buckle under tangential load, hence
not creating high reaction forces. This may allow for a design utilizing less space
for mechanical structure. As a consequence, noise and vibrations are reduced to a
surprising and unexpected extent if compared to machines using the traditional rubber
bellows. The lower level of forces and vibrations between the washing unit and the
cabinet allows a higher spinning speed and, at the same time, increases the life of
the appliance. According to a preferred embodiment of the present invention, with
the aim of having homogeneous properties of the fabric component, this latter may
be produced by using continuous tube knitting or seamless knitting in order to avoid
any change of thickness throughout the entire surface of the tubular device made of
fabric. The two ends of the tubular device may use sewing to enclose attachment elements
(for instance rubber O-rings or toroidal metal or polymeric springs) for fixing the
device to the tub, on one side, and to the cabinet, on the other side.
[0008] Further advantages and features according to the present invention will be clear
by the following detailed description, with reference to the attached drawing which
shows the application of a fabric sealing within a state of the art top loading washing
machine.
[0009] Even if the present description of one possible execution of the invention is focused
on a top loading washing machine, it is clear that the solution of the present invention
can be used also on front loading washing machines as well.
[0010] With reference to the drawing, a bellow 10 made of fabric is interposed between a
tub 1 containing the rotating drum 2 and a top frame 3 or inner frame 4 of the washing
machine cabinet which is the aperture for loading and unlading clothes to or from
the drum 2. A lid 5 that closes the top frame 3 requires an additional seal (not shown)
which is not a function of the fabric sealing.
[0011] The fastening of the fabric bellow 10 to the tub 1 is achieved by coating the contact
surface of the fabric bellow end 10a with rubber and by using an annular spring (not
shown) in an annular groove 12 to apply pressure against the tub 2. The fastening
to the top frame 3 is achieved in the same way. The interface for the water inlet
(not shown) is done by using an O-ring that is fit between the pipe and the fabric
and then clamped.
[0012] The fabric component 10 must fulfill the technical requirements of the operating
environment which are resistance (shrinkage, swelling, fatigue, etc.) to contact with
water and detergent solution with temperatures ranging from 10°C to 95°C as well as
vapor of detergent solutions, of chemical solutions (including ozone) as can be found
in a washing machine as well as steam, self contact due to folding at frequencies
up to 250Hz and occasional contact to adjacent components at lower frequencies, contact
(tearing) with sharp objects of laundry (i.e. zipper) during loading and unloading,
contact with laundry items at high speeds (only for front loaders), and decolorization
due the above.
[0013] The fabric must be attached and form a sealing interface (>100mm water column) with
the wash unit (i.e. tub 1), the entrance (i.e. inner frame or front panel 3) as well
as inlet systems for water, steam, detergent or lighting. This can be done directly
or by using attachment elements like springs, wires or clamps. The fastening area
of the fabric bellow 10 may be treated or modified to achieve better fit (i.e. over
molded or coated with rubber, plastic, metal or rubber parts sewn into the fabric).
[0014] The fabric used for bellow 10, which for top loaders has a roughly square pattern
and for front loaders has a circular cylindrical shape, can be chosen among synthetic
textiles with waterproof properties. For instance, the textiles made by polyester
fibers, aramid fibers, polyamides as nylon, polyurethane and polyolefines. The above
textiles can be dyed, and treated in order to obtain water resistance. Metallic nanoparticles
for making textiles more resistant to water and pathogens such as bacteria and fungi
can be used as well.
1. Washing machine comprising a cabinet (3, 4) into which a tub (1) is mounted containing
a rotatable drum (2), between the cabinet and the tub being installed a deformable
tubular device (10) for allowing the load and unload of clothes through aligned apertures
in the cabinet, in the tub and in the drum and for preventing water spillage outside
the tub, characterized in that said tubular device (10) is made of fabric.
2. Washing machine according to claim 1, wherein the tubular device (10) is seamless.
3. Washing machine according to claim 1 or 2, wherein fastening means are used for fixing
ends (10a) of the tubular device (10) to the tub (1) and to the cabinet (3, 4) respectively.
4. Washing machine according to claim 3, wherein the ends (10a) of the tubular device
(10) have a coating of rubber material or the like for assuring a waterproof connection
with the tub (1) and the cabinet (3, 4).
5. Washing machine according to claim 3 or 4, wherein said fastening means are annular
springs or O-rings.
6. Washing machine according to any of the preceding claims, wherein the fabric is chosen
in the group consisting of polyester textiles, aramid textiles, polyamide textiles,
polyurethane textiles, polyolefines textiles and combination thereof.