[0001] The present invention relates to a laundry washing machine of the top-charging type,
particularly for domestic use, provided with a counterweight for the dynamic equilibration
of the tub-drum assembly of the machine.
[0002] As generally known, laundry washing machines of the top-charging type are at present
being constructed to have the smallest possible dimensions so as to permit them to
be installed in limited spaces.
[0003] The efficient dynamic equilibration of the tub-drum assembly of laundry washing machines
of this type requires the employ of at least one counterweight formed of a material
having a high specific weight. This material may be contained in a suitably formed
container or may itself be formed to a compact block. The counterweight is generally
attached to the outer periphery of the tub at a lower or lateral portion thereof.
This manner of mounting the counterweight requires it to be considerably heavy and
thus to have relatively great dimensions, so that the accommodation of the counterwieght
in a washing machine of reduced dimensions offers considerable difficulties.
[0004] It is therefore an object of the present invention to eliminate this disadvantage
by providing a counterweight of the described type which is mounted on the top portion
of the tub of the machine adjacent the access opening thereof.
[0005] The location of the counterweight in this position results in an upwards displacement
of the center of gravity of the tub-drum assembly, whereby the lever arm of the center
of gravity with respect to the suspension points of the tub-drum assembly within the
frame of the machine is correspondingly shortened.
[0006] This permits a counterweight of reduced weight and dimensions as compared to hitherto
employed counterweights to be employed for ensuring an efficient dynamic equilibration
of the tub-drum assembly.
[0007] As a result, there is considerably more space available in the washing machine for
mounting the counterweight itself or for installing the various electrical and mechanical
components of the machine.
[0008] In addition,the formation of the counterweight requires a smaller amount of material,
with the attendant economical advantages.
[0009] These and other objects are attained according to the invention by a laundry washing
machine of the top-charging type, particularly for domestic use, comprising a tub
suspended in a frame of the machine, a drum rotatably mounted in said tub and provided
with two spring-biased peripheral doors adapted to partially overlap one another in
the closed position, and at least one counterweight of a material having a high specific
weight for the dynamic equilibration of the tub-drum assembly, said tub being provided
with a top opening giving access to said drum.
[0010] In accordance with the invention, a laundry washing machine of the above specified
type is characterized in that said counterweight is formed with at least one central
through-opening and is mounted on the top portion of said tub, so that said through-opening
coincides with said access opening and with a charging port formed in the frame of
the machine, flexible means being provided for connection to the respective peripheral
borders of said counterweight and said charging port.
[0011] The characteristics of the invention will become more evident from the following
description, given by way of a nonlimiting example with reference to the accompanying
drawings, wherein:
fig. 1 shows a partially sectioned elevational view of a top portion of a laundry
washing machine of the top-charging type provided with a counterweight according to
the invention, and
fig. 2 shows a perspective view of the counterweight according to the invention as
applied to the tub-drum assembly of a laundry washing machine of the top-charging
type.
[0012] Shown in figs. 1 and 2 of the drawings is a laundry washing machine of the top-charging
type, comprising a washing tub 3 suspended within an outer frame 4 by means of a not
shown system of upper springs and lower shock absorbers, and a drum 5 rotatably mounted
within tub 3 and provided with a peripheral opening 6 adapted to be closed by spring-biased
door flaps 7, only one of which is shown in fig. 1, adapted to overlap one another
in the closed position.
[0013] Formed in the upper portion of tub 3 is a through-opening 8 giving access to drum
5 for introducing and discharging the laundry into and out of drum 5, respectively.
[0014] For ensuring an efficient dynamic equilibration of the tub-drum assembly 3-5, there
is in addition provided a counterweight 9 formed of a material having a high specific
weight, such as cement, baryte or the like, which may be contained within a suitably
shaped container or be formed as a compact block of the selected material.
[0015] Counterweight 9 is formed with at least one central through-opening 10 and with a
channel-shaped outer peripheral rim 11 for purposes to be described later.
[0016] For mounting counterweight 9 in the laundry washing machine, it is located on the
top portion of tub 3 in such a position that its through-opening 10 coincides with
a charging port 12 formed in the frame of the machine thereabove, and with.the access
opening 8 of the tub. In this position the counterweight is subsequently affixed to
the tub of the machine by means of bolts 13 and nuts 14 or equivalent fastener elements.
[0017] Charging port 12 is surrounded by a frame structure 15 acting as a charging funnel
and having a free edge 16 partially projecting into the interior of the machine.
[0018] Connected between the free edge portion 16 of frame structure 15 and channel-shaped
outer peripheral rim 11 of counterweight 9 is a bellows-shaped flexible element 17
for permitting the laundry to be safely introduced into and withdrawn from drum 5.
For connecting flexible element 17 to frame structure 15, the free egde portions 16
and 18, respectively, cf the frame structure and the flexible element brought into
contact with each other, whereupon a profiled rigid clamping element 19 is slipped
onto the contacting edge portions.
[0019] The other free edge portion 20 of flexible element 17 is introduced into the channel-shaped
edge 11 of counterweight 9 and retained therein by means of an expansible annular
member 21.
[0020] The flexible element 17 may have a different shape and be connected between the charging
port and the counterweight in a different manner without thereby leaving the scope
of the invention.
[0021] As shown particularly in fig. 1, counterweight 9 is formed with to opposing lateral
edge portions 22 partially projecting into opening 10 for being engaged by a hooks
23 provided on the door flaps of the drum, should the latter be rotated with its door
flaps accidentally open.
[0022] The described location of the counterweight on top of the tub of the washing machine
results in an upwards displacement of the center of gravity of the tub-drum assembly
and thus in a shorter lever arm of the center of gravity with respect to the suspension
points of the assembly within the frame of the machine.
[0023] As a result, the dynamic equilibration of the said assembly is achieved by employign
a counterweight of the same Material as abobe specified, although of reduced weight,
so that the counterweight may be designed with reduced dimensions and formed of a
reduced amount of material.
[0024] As the dimensions of the counterweight are thus reduced, its accommodation within
the frame of the machine as well as that of the other components thereof is greatly
facilitated.
1. A laundry washing machine of the top-charging type, particularly for domestic use,
comprising a tub suspended in the frame of the machine, a drum rotatably mounted in
said tub and provided with two spring-biased peripheral doors adapted to be partially
superimposed on one another in the closed position, and at least one counterweight
of a material having a high specific weight for ensuring the dynamic equilibration
of the tub-drum assembly, said tub being provided with a top opening giving access
to said drum, characterized in that said counterweight (9) is formed with at least
one central through-opening (10) and is mounted on the top portion of said tub (3)
so that said through-opening (10) coincides with said access opening (8) and with
a charging port (12) formed in the frame of the machine, flexible means (17) being provided for connection to the respective peripheral borders of said counterweight
(9) and said charging port (12).
2. A laundry washing machine according to claim 1, characterized in that said counterweight
(9) is formed with at least two opposing lateral edge portions (22) partially projecting
into said access opening (10) an cooperating with corresponding hooks (23) affixed
to said doors of said drum.