EP1039012A1

EP1039012A1 - Safety door lock system for use in particular on washing machines with an electronic system on board

Info

Publication number: EP1039012A1
Application number: EP99830159A
Authority: EP
Inventors: Giuseppe Bussini
Original assignee: Siber BV
Current assignee: Siber BV
Priority date: 1999-03-22
Filing date: 1999-03-22
Publication date: 2000-09-27

Abstract

Safety door lock system for washing and drying machines, with electronic system on board, made up of a housing or body (2) containing an electromechanical device with at least one power micro-switch (5) for starting the machine and an electromagnet (6) connected to a slide system for locking and releasing the door of the machine, said slide system made up of at least a first sliding member (7) moved by the closing of the door and at least a second sliding member (9) moved by the electromagnet (6) characterised by the fact that it includes a means of selection (10) both to allow the movement of the second sliding organ (9) from a first position to a second position only after the movement, in opposition to an elastic means (11), of first sliding member (7) from a first position to a second locking position of the door and also to hold the first sliding member (7) in the second position when the second sliding member (9) is in the second position.

Description

The present invention regards a safety door lock system for use in particular on washing machines with an electronic system on board.
As is well known washing machines with rotating drums must be provided with a means which allows the door or port hole to open only when the machine is disconnected or when the drum has stopped or has almost stopped turning.
For this purpose several devices have been made which take advantage of the expansion of bodies or substances with a high dilatation coefficient housed in telescopic cells.
Other devices, on the other hand, make use of a magnetic field generated by powered coils, which move part of the magnetic circuit, and are used to immediately lock the catch and consequently the door of the washing machine.
Also well known are those devices whereby delayed opening of the door is achieved by taking advantage of a slow and controlled return to the rest position of a bellows, similar to a pneumatic organ, which is rapidly compressible during starting the slow expansion of which is controlled by the bleed or eddying speed of the air.
It is also well known that at present the more sophisticated washing machines have an electronic system which governs the working of the machine and therefore, among other things, also the locking and release of the door itself.
The devices available on the market present drawbacks which are more or less important due to the fact that their operation is always a compromise between the locking times of the door, which must be very rapid, and the releasing times of the same which must be delayed by a pre-set time in order to allow for the total stopping of the moving parts of the machine.
These drawbacks are even more pronounced if the devices are applied to "wash and dry" type washing machines.
In fact, in this type of machine the temperature at the end of the operating cycle is extremely high and therefore has a strong influence over, for example, the release devices of the door catch which make use of the dilation of bodies or the expansion of substances with a high expansion coefficient.
Furthermore, the known devices, as seen, are always activated by the electronic system on board the machine so, in the case of a breakdown in the electronic system, this will automatically result in a breakdown in the safety door locking system.
For example unwanted excitation of the electromagnet could take place with resulting automatic release of the door even in dangerous conditions.
The aim of the present invention is to eliminate the above listed drawbacks by achieving a safety door lock system, in particular for washing machines with an electronic system on board, which allows the machine to start immediately, as soon as the door is closed, and with no delay at the end of the cycle when the drum has stopped.
An important aim of the invention, within the sphere of this objective, is to design, in particular, a safety door lock system for washing machines with an electronic system on board, which permits the machine to start immediately the door is closed, both during the drying phase and during the checking for dryness of clothes phase, even if the machine cycle has not finished.
Another aim of the invention is to achieve, in particular, a safety door lock system for washing machines with an electronic system on board which, besides being able to apply it indifferently to any model of washing machine, immediately locks the door catch once this is closed, and keeps it locked for all the programmed operations such as, the number of drum turns, the water level, the water temperature, etc..
This aim, together with other objectives, are achieved in a safety door lock system for washing and drying machines, with electronic systems on board, which include a housing or body containing an electromechanical device having at least one power micro-switch for starting the machine and an electromagnet connected to a slide system for locking and releasing the door of said machine. Said slide system must include at least one slide element activated by the dosing of said door and at least one further slide element activated by said electromagnet, characterised by the fact that it includes a means of selection both to enable the movement of said latter element from a first position to a second position only following the shifting of position of said former slide element from a first to a second locking position of said door, opposed by an elastic means, and for the retaining of said first slide element in said second position when said second slide element is in said second position.
Greater details of the invention are anyway evident from the following detailed description of a door lock system, made with reference to the attached indicative and non-limiting drawings, in which:

figure 1 is a plan view of the door lock system in the open position of the door in accordance with the invention; and
figure 2 is a plan view of the door lock system in the closed position of the door in accordance with the invention.

With reference to the above described figures, the door lock system, in accordance with the invention, indicated as a whole by the reference number 1, includes a housing or body, as a whole indicated by 2, which is attached to the bodywork or frame of the washing machine by means of the two holes 4.
The body 2 contains an electromechanical device with at least one power micro-switch 5 to start the washing machine and an electromagnet 6 connected to a slide system for locking and releasing the door of the machine, not shown in the drawings.
The slide system includes at least one primary sliding member 7 which is moved by the door being closed, and in particular by the introduction of its connecting section into the opening 8, and at least one second sliding member 9 which is moved by the electromagnet 6.
To improve its operating capacity the door lock includes a means of selection, indicated by the number 10, which allows the changing of position of the second sliding member from an initial position to a second locking position of said door only after the change of position of the first sliding member 7 has taken place on closing the door.
In particular when the door closes the first sliding member 7 moves from an initial position to a second position, in opposition to an elastic means in the form of a spring 11.
Once the second sliding member 9 has been moved into the second position by the electromagnet 6, the first sliding member 7 will also be held by the selection means in the second position thus locking the door.
Special safety measures are included in order to hold the second sliding member in the second door lock position.
The safety measures include a labyrinth type member 12, sliding in a seating 13 in the body 2, with which it engages by means of a pin 14, the core 15 of the electromagnet.
Thanks to the particular shape of the seat 16 present on the labyrinth type member it is possible to hold the second sliding member 9 in the second position for at least two or more excitations of the electromagnet.
The safety measures also include at least one electromechanical semiconductor 18 so as to limit the feed current to the electromagnet 6 in the case of an operating fault in the electronic system on board the machine.
This solution prevents, for example, the unwanted opening of the door should an element short circuit resulting in continuous feed of the electromagnet with consequent opening of the door of the machine.
In this case the labyrinth type member 12 locks the movement of the second sliding member 9 in the first opening position of the door even if the electromagnet has been energised and the electromechanical semiconductor 18, on interrupting the feed to the electromagnet, prevents the latter from being successively energised to return the second sliding member to the release position of the door after a further "n" number of impulses.
More precisely the selection means 10 includes at least one catch 20 the end section of which protrudes from a opening 21 obtained in the housing 2.
The catch 20 turns in relation with the first sliding member 7 so as to protrude from the opening 21 when the first sliding member is in the initial position so as to prevent the movement of the second sliding member 9 in the second position.
Furthermore the catch 20 is made to re-enter the opening 21 when the first sliding member is in the second position so as to enable also the movement of the second sliding member in the second position.
The second sliding member has a catch restraining face 22 in opening 21 when it is in the second position so as to prevent the return, caused by the action of the spring 11, of the first sliding member to the first position.
To facilitate the rotation of the catch 20, opening 21 has at least one lead-in delimited on one side by a sloping edge 23 and on the opposite side by a rounded edge 24.
Furthermore, the second sliding member 9 has control means, delimited by a tailpiece 25 of the power micro-switch 5.
The power micro-switch 5 includes a first part fulcrum element 40 of a movable contact 41 and a second fulcrum element 42 of a spring 43.
The spring 43 engages a pin placed at one end of a rod which limits the movable contact whereas the opposite end of the same is rounded and engages the first fulcrum element 40.
In this way the movable contact 41 is moved from a first position into a second position and vice versa at a speed which does not depend on the speed of the movement of the tailpiece of the second sliding member.
This solution favourably enables the closing and opening of the electric contacts avoiding rubbing between the movable contact and the catch and consequently eliminating friction and wear.
Besides, the contact is snapped closed thus limiting the formation of micro-welding between the movable and fixed contacts 50.
The operation of the door lock system in accordance with the invention is evident from what has already been described and illustrated.
In particular and referring to the illustrated drawings the operation can be briefly divided into three phases.
In the first phase where the door is open the power micro-switch is open and the first sliding member 7 and the second sliding member 9 are in the released position.
In this status the power micro-switch 5 will not enable the machine to start.
In phase 2 the door is closed and the catch is inserted into opening 8.
In this phase the door catch presses against the sloping face 30 of the first sliding member 7 causing it to move into the second position.
The movement loads the spring 11 and causes the catch 20 to retract into the opening 21 allowing the electromagnet to move the second sliding member 9.
In this status, besides the lock of the door, we have the switchover of the micro-switch from normally open to normally closed thus allowing the machine to start.
In the third release phase of the door the electromagnet 6 is powered.
When the electromagnet is powered it energises generating a magnetic field which attracts its integral core 15 to the second sliding member 9 which, by means of pin 14 moves the labyrinth unit 12 one or more positions depending on the number of excitations of the electromagnet.
When the pin 14 reaches the section of the housing 16 which allows the second sliding member to move into the initial position, the first sliding member moves into the first position and the door is released while at the same time the power micro-switch 5 changes from the contact closed position to the contact open position.
In practice it can be seen how the door lock in accordance with the invention is particularly advantageous in allowing the machine to start immediately as soon as the door is closed and no delay occurs at the end of the cycle when the drum is stopped. Stopping may also take place during any drying phase to check if clothes are dry, where complete safety is guaranteed on opening the door both when the complete cycle of the machine is not completed and in the case of an operating fault in the electronic system on board the machine.
In the case of a loss of power the door can be opened using a pull rod attached to the end of member 9.
The door is released by pulling the rod twice or "N" times where the same operating conditions exist as when there is power.
The conceived invention may be subject to numerous changes and variations all of which fall within the context of the concept of the invention; furthermore all the details can be replaced by technically equivalent elements.
In practice the materials used plus the dimensions could vary according to the requirements and status of the technology.

Claims

Safety door lock system for washing and drying machines with electronic system on board made up of a housing or body containing an electromechanical device with at least one power micro-switch for starting the machine and an electromagnet connected to a slide system for locking and releasing the door of said machine, said slide system made up of at least a first sliding member moved by the closing of said door and at least a second sliding member moved by said electromagnet characterised by the fact that it includes a means of selection both to allow the movement of said second sliding organ from a first position to a second position only after the movement, in opposition to an elastic means, of said first sliding member from a first position to a second locking position of said door and also to hold said first sliding member in said second position when said second sliding member is in said second position.
System in accordance with claim 1, characterised by the fact that it includes safety measures for holding said second sliding member in said second position
System in accordance with one or more of the previous claims characterised by the fact that said safety measures include a labyrinth type system which engages the core of said electromagnet, said labyrinth type system locking said second sliding member in said second position for at least two excitations of said electromagnet.
System in accordance with one or more of the previous claims characterised by the fact that said labyrinth type system moves in a housing of said body and engages said core by means of a pin.
System in accordance with one or more of the previous claims characterised by the fact that said safety measures include at least one electromechanical semiconductor the function of which is to limit the feed current to said electromagnet should there be an operating fault in said electronic system on board.
System in accordance with one or more of the previous claims characterised by the fact that said selection means includes at least one catch one end of which exits from an opening in said body, the movement of said catch being synchronised with the movement of said first sliding member which enables it to protrude from said opening when said sliding member is in said first position thus preventing the said second sliding member to move into the said second position and to retract into said opening when said first sliding member is in said second position thus allowing said second sliding member to move into said second position.
System in accordance with one or more of the previous claims characterised by the fact that said second sliding member has a restraining face of said catch in said opening when said second sliding member is in said second position so as to prevent the return of said first sliding member to said first position because of the action of said elastic means, maintaining the door locked.
System in accordance with one or more of the previous claims characterised by the fact that said opening has at least one lead in for the rotation of said catch.
System in accordance with one or more of the previous claims characterised by the fact that said second sliding member has a means of control over said power micro-switch.
System in accordance with one or more of the previous claims characterised by the fact that at least one micro-switch includes a first fulcrum element of a movable contact and a second fulcrum element of a spring, one end of which is engaged with said movable contact in opposition with said first fulcrum element in order to move said movable contact from a first to a second position and vice versa at a speed which does not depend on the speed of the movement of the second sliding member.