[0001] This invention is concerned with a push-button device for opening the port-hole shaped
door in domestic washing machines.
[0002] Several means are already known for opening the port-hole door of domestic washing
machines, mainly lever shaped, but also by means of a sliding member.
[0003] These approaches my be relatively cost-effective but the aesthetic appearance on
the machine doesn't certainly meet one's expectancy, in particular considering the
present marketplace requirements.
[0004] Port-hole door opening devices have already been provided using a push-button located
on the machine control panel. This approach is certainly an improvement concerning
the aesthetic appearance, but it requires a moving slider adapted to connect the push-button
device to the latching members, and this largely complicates the construction of the
machine, with associated cost drawbacks, besides having a negative influence on the
safety required against accidental openings of the port-hole door.
[0005] It is an object of this invention to provide a device which, by overcoming known
drawbacks of the opening means already known, has all the desired advantages of cost-effectiveness
and aesthetic appearance, of course Without compromising the required safety levels.
[0006] The device according to this invention is characterized by a push-button device,
built into the port-hole door latching assembly, and mounted on the front wall of
the machine, close to said port-hole, and provided towards the inside with a movable
body having a sloping flat surface adapted to engage a corresponding surface of a
movable slider which normally retains the port-hole door closing latch, in order to
free said latch for opening said port-hole door.
[0007] The subject of this invention will become apparent from the following detailed description
of a preferred embodiment thereof, given herein for exemplary but non limiting purposes,
reference being made to the attached drawings, wherein:
Figure 1 shows a schematic front view of a domestic washing machine, including the
inventive device;
Figure 2 shows a cross sectional view along line II-II of Figure 1; and
Figure 3 shows a view corresponding to that of Figure 2, but with the port-hole door
open.
[0008] Referring now to the drawings, push button 1 according to this invention is mounted
in a built-in arrangement on the latching assembly of port-hole door 5, as it is shown
in Figures 2 and 3, in order to be actuated from outside on the machine front wall
7, in a position close to said port-hole 5. As it is shown in Figure 1, the general
arrangement obtained is simple and straightforward, as it is presently required in
modern machines, where as far as possible an attempt is made to render as unconspicuous
as possible the front panel controls, even reducing the number thereof.
[0009] As it is already known, port-hole door 5 of a washing machine is kept locked in a
closed position, with peripheral rubber ring 9 acting as a seal, through engagement
of a latch 4, hinged at one end, onto the metal ring 5a which surrounds port-hole
5. Engagement takes place with a corresponding stop portion in an area 2 of door-latching
and -locking, located near port-hole door 5 on the inner side of wall 7. Push button
1 is then located immediately between said latching and locking area 2 and a part
3 including the door-locking electrical components.
[0010] It should also be noted, as it is already known in the art, that latch 4 is pushed
into engagement with portion 2 by a slider 6 normally kept in a closed position by
a pawl (not shown), which is actuated when the machine is switched on. In fact, as
it is presently provided in general for washing machines, when port-hole door 5 is
closed, and as soon as the machine actuating switch is pressed, thereby starting the
washing sycle, the components of door lock 3 are supplied with an electrical voltage
and one among them, i.e. a thermistor, rapidly reaches its thermal stabilization temperature
thereby heating the bi-metallic couple it is lying upon and whose mechanical distortion
causes the electrical closure of a microswitch which in turn supplies power to the
electro-mechanical components of the machine. In this way, a mechanical locking of
port-hole door 5 is obtained by means of said pawl which stops slider 6. Only after
said locking operation has taken place can the washing machine start on its washing
program at the end of which, a certain time interval will have to elapse, as determined
by the thermal inertia of the bimetal, before the pawl can unlock the slider allowing
it to move, for instance in a lever like fashion, in order to free latch 4 and to
open the locking arrangement. It should be noted that the same degree of safety concerning
the port-hole door locking is obtained also in case of a possible power failure in
that thermal inertia keeps the port-hole door safely closed until the washing machine
moving members have come to a stop.
[0011] According to this invention, once slider 6 has been unlocked by the fact that the
washing cycle termination safety members end their function, it is just necessary
to press push-button device 1 all the way inwards, to its position shown in full lines
in Figure 3. It carries on its body a sloping flat surface 11 adapted to react against
a corresponding sloping surface 11a on slider 6, in order to move the latter towards
the unlocking position of latch 4, which gets free from engagement with stop 2, thereby
allowing port-hole door 5 to open completely as started and made easier by the spring
recovery of seal ring 9 which had been kept compressed while the machine was closed.
Meanwhile, push button 1 goes back to its starting position, shown in broken lines
in Figure 3, under the biasing action of a quick-return spring 8 provided between
the body and the seat of push button 1. It should be noted that a possible actuation
of push-button device 1 while the machine is operating, i.e. when the locking microswitch
is subjected to a voltage, would not result in any opening effect in that slider 6
would be unable to unlock latch 4, because the former is kept in a closing position
by the locking pawl.
1. An opening device for port-hole door (5) of a domestic washing machine which includes
a front wall (7) as well as the following members mounted therewithin, close to port-hole
(5): a portion (2) for latching and locking a latch member (4) hingedly mounted on
peripheral ring (5a) of said port-hole (5); a movable slider (6) for locking said
latch (4) on said member (2), and in addition an assembly (3) of door-locking electrical
components, characterized by including a push-button device (1) built into said front
wall (7) between said latching and locking member (2) and said electric assembly (3),
having towards the inside a movable body provided with a sloping flat surface (11)
adapted to come into engagement with a corresponding surface (11a) of said moving
slider (6) in order to free latch (4) for opening port-hole door (5).
2. The device of claim 1, characterized in that said push-button device (1) is provided
with a quick return spring (8) in order to be brought back to the starting position
after each operation.
