EP2348148A1

EP2348148A1 - Locking device with a sliding latch

Info

Publication number: EP2348148A1
Application number: EP10151662A
Authority: EP
Inventors: Dusan Heldak; Pavol Vasko; Manfred Haerer; David Machado Martins
Original assignee: Whirlpool Corp
Current assignee: Whirlpool Corp
Priority date: 2010-01-26
Filing date: 2010-01-26
Publication date: 2011-07-27
Anticipated expiration: 2030-01-26
Also published as: PL2348148T3; EP2348148B1; ES2404142T3

Abstract

A security latch (4) for preventing the unintentional release of drum access doors (100,200) of a top loading clothes washing machine drum provided with two door sections, one of the door sections carrying the catches, the other carrying the slots. The security latch is associated with a stop (T) against the rim (R) of the door containing the slots, when the doors are closed. The stop is positioned on the door carrying the catches and comprises a push button which is returnable towards the outside of a hollow socket by a spring (K). The stop (T) is the end of a member (S) which is slidable towards the drum interior according to a sliding direction (D) which forms a predetermined acute angle (α) with a tangential direction of the drum circumference at the intersection point (P) with the same circumference.

Description

The invention relates to a security latch for preventing the unintentional release of drum access doors of a top loading clothes washing machine drum provided with two doors sections, especially in the case when fabrics are trapped on the doors edges. The washing machine according to the invention is provided with two door sections: a first section carrying closing catches (at least one) and a second section presenting slots corresponding to said catches. Closing catches are engaged into corresponding slots when the doors are closed.
In particular the invention is related to a security latch for a washing machine drum, which is reliable and easy to handle in comparison with known latches.
From GB-A-1,161,218 it is known a washing-machine drum with two door-sections. The two door sections are fixed at either side of the drum opening by spring-loaded hinges. The free parts of the door sections are provided with a closing system which comprises catches, in particular hooks, on the first door section whose terminals are directed towards the outside of the drum, and with slots in the second door section. The springs of the hinges tend to cause the door sections to open towards the outside, so that when the elements of the closing system are in engagement with each other, the hooks are forced into the slots. In order to open the door, it is necessary to exert a pressure on the door sections which is directed towards the inside of the drum. Such a closing system is very reliable owing to the fact that when the closed doors are subjected to a pressure which is directed from the inside of the drum towards the outside (as during spin drying), the force which keeps the door sections engaged increases as the speed increases.
No security latch is disclosed together with this known solution so that when fabrics rest trapped between the drum access doors, they can cause the door to unintentionally open under the effect of the drum rotation, particularly during tumbling.
From EP 402252 it is known a security latch for preventing the doors to move towards the interior of the drum of a washing machine. The latch is associated with a stop against the opening of the door sections, when the doors are closed, and wherein catches are engaged into slots. One of the door sections presents a flat recess into which a security lock is fitted and secured, the latch consisting of a spring returned pusher that is movable in the direction opposite to the hooks, and which is provided with a flat base collar which limits the movement of the pusher. The latch acts as a stop against the rim of a door section, when the doors are closed, limiting the translational relative movement and play of the two door sections and so preventing the unintentional opening of two doors. The stop associated with the pusher is designed so as to move below the door, towards the drum interior, via pressing action on the spring control mechanism of the latch. The stop is returnable towards the outside of the hollow socket by a spring substantially along the radial direction of the drum. The pusher is moving perpendicularly to the tangential direction of the drum surface. This solution has the drawback that the dimension of the stop are quite large in order to properly contrast the door opening without breaking; it has to absorb dynamic impulsive forces generated by the rotating loaded drum and transmitted to the door section against which the stop acts. In addition, the pusher lays in a position above the drum circumference surface, which can interfere with other fixed parts of the drum, during rotation. Moreover, a relative high force pressure has to be exerted by the user on the pusher to move the stop below the door in order to unlatch the two doors for their disengagement. Finally, the closing system given by the hooks engaged into the slots intervenes after of the security latch (which is less robust than the same closing system) and which renders the closing system not solicited in case fabrics rest trapped between the two door sections. The above known latch is stressed as soon as clothes are trapped between the two door sections, therefore requiring a great stiffness for bearing high forces which, for the first degree of rotation, can be higher than 200N.
From DE 2237409 it is known a security lock for washing machine doors provided with a door latch consisting of a slider positioned on the on the external tangential surface of one door section which superposes and lock by interference the rim of another door section when the doors are closed, blocking the relative rotational and translational movements of the two doors and so preventing their opening towards the drum interior. User intervention is required to latch or unlatch the doors. Also for this solution the force against the doors opening is entirely absorbed by the slider rather than partially absorbed by closing system. Also this solution requires the slider being relatively robust and operable with a certain force for securely lock and unlock the second door.
The present invention overcomes the limitations presented by the above known solutions by providing a security device for a door of a drum which has a simplified construction, which requires a reduced force to unlatch the doors and which has a higher reliability.
By way of example, particular embodiments of the invention will now be described with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a first door section according to the invention;
Figures 2 and 2a show a perspective view of a preferred embodiment of the security latch and its longitudinal cross-section;
Figure 3 shows a detail of the slidable member of the latch of Fig. 2;
Figure 4 shows a cross-section of the two door portions in their closed position, latched with the latch of Fig. 2;
Figure 5 shows the same configuration of Fig. 4 with an alternative embodiment of the latch;
Figure 6 shows a cross-section of the two door sections according to the invention in their closed position wherein the security latch is in the unlatching position;
Figure 7 shows the configuration of Fig. 6 with the alternative embodiment of the latch shown in Fig. 5; and
Figure 8 show a cross-section of the door with two door flaps in closed position equipped with the security latch of Figure 3, when a force is applied on the door sections, towards the drum interior.

With reference to the above described drawings, the top load washing-machine drum according to the present invention is provided with an opening through which laundry is loaded by the user, and which is closable by a door constituted by a first and a second door sections 100 and 200 respectively, hingedly mounted at each side of the drum opening. Normally, hinges 210 and 110 are associated with springs exerting a force that drives and maintains the disengaged door sections towards an open position. The first door section 100 carries two catching elements 150, such as hooks, of a catch and slot closing system which further comprises slots 250 formed in the second door section 200. The first door section 100 further comprises a security latch L, which at least includes a sliding member S cooperating with a support body B. The support body B, which is preferably made of plastic material, advantageously comprises two halves that once connected together, house the sliding member S. The two halves can be connected together preferably by means of a snap connection and the assembled body B can be fixed to the first door section 100, preferably within a door recess. Rivets, screws or other known fixing means are also suitable to fix the support body B in the recess or alternatively, in any other portion of the first door section. The support body B presents guiding means GB cooperating with corresponding guiders GS of the sliding member, for guiding the sliding member S, preferably according to a linear sliding direction D. Guiding means and corresponding guiders are complementary elements and can be, for instance protruding means such as pins or bars, or groves or guides or recesses. Guiders GS or guiding means GB have also the function to not allow any rotational movement along the sliding direction D, and preferably also to limit the movement of the slider S in the locking position. This last function can be accomplished by additional limiting members (not shown).
The sliding member S is also preferably made of plastic and presents a shaped contact portion C that allows the user to move the element and, preferably formed with the same, a stop portion T. Preferably, the stop portion T presents a beak shaped end, for instance an almost triangular cross-section shape.
The sliding member S is movable towards the inside of the drum according to sliding direction D which forms an acute angle α with the tangential direction of the drum circumference, at an intersection point P. By exerting a pressing action on the contact portion C of the sliding member S, user causes the sliding member S to move into an unlatching position against the force of a spring K, in which the major portion of the sliding member lies below the drum circumference level.
Preferably the acute angle (α) is comprised in the range between 3° and 40° and more preferably between 5° and 30°.
Preferably, elastic means K urging against the body B and the slidable member S are applied to keep the slidable member S resting in a latching position.
The overall displacement of the slidable member S can be broken in two displacements, one tangential and the other radial. The displacement in the tangential direction is grater than the one in the radial direction so that compared to the latch disclosed in EP 402252 , a lower force pressure is requested to move the sliding member in the unlatching position, making the security latch more user friendly than known solutions.
When door is closed catches 150 engage corresponding slots 250 forming, together with hinges 110 and 210, the door closing system. Shape and dimensions of the catches and slots allow a relative translational and rotational movement of the ends of the door sections in their closed position, ensuring the proper engagement and disengagement of the two door sections and the right mechanical play of the same when in their closed configuration.
During closure operation, the beak shaped end of the stop portion T facilitates the latching of the two door sections 100 and 200 by the security latch L without requiring the intervention of the user on the same latch L. Automatic latching happens during door closure, whenever the sliding member S is forced towards the drum interior in the unlatching position by entering in contact with the rim R of the second door portion. When the two door portions 100 and 200 became engaged, the spring K returns and maintains the slidable member in the latching position, with effect of securing the closed door portions.
In the door closed position, the beak shaped end of stop portion of the security latch L overlaps the rim R of the second door portion 200, preventing from an unintentional release of the two door sections.
According to Figure 8, the latch according to the present invention allows the two door sections to move toward the drum interior, letting the hinges 110 and 210 of the two door sections to intervene to contrast the opening, prior than the intervention of the latch L, especially when fabrics rest trapped between the two door sections.
The present solution allows the construction of the stop member to be less robust and therefore cheaper, while keeping the latching system is highly reliable.
To unlatch the door, the end portion of the stop member end has to be moved by the user intervention on the slidable element S via a pressing action on its control portion C. Specifically, it has to be moved against the elastic force at least at the same height of the rim of the first door section and for which a gap required to disengage catches from the slots, is provided.
When unlatched, door sections open in a direction towards the outside of the drum by a pressure directed towards the inside D of the drum.
Said pressure is exerted on the first door section 100, which carries the catches 150. The movement of the two door sections towards the drum interior is limited by the hinges110 and 210.
Thanks to such configuration a security latch for preventing the doors of a washing drum, in particular a top loading drum, from opening especially during the tumbling spin cycle when fabrics are washed and can be trapped between the two doors.

Claims

Security latch (L) for preventing the unintentional release of closing catches (150) engaged into slots (250) of access doors (100,200) inside the drum of a clothes washing machine, one of the door carrying the catches, the other the slots, said security latch being associated with a stop portion (T) against the rim (R) of the door containing the slots when the doors are closed, said stop portion (T) being positioned on the door carrying the catches and comprising a push button which is returnable towards the outside of a hollow socket by a spring (K), characterized in that the stop portion (T) is the end of a member (S) slidable towards the drum interior according to a predetermined sliding direction (D) which forms a predetermined acute angle (α) with a tangential direction of the drum circumference, at an intersection point (P) thereof.
Security latch according to claim 1 wherein the slidable member (S) is movable in a predetermined unlatching position wherein the displacement measured along a tangential direction of the drum circumference at the intersection point (P) of the drum circumference is grater than the displacement measured in the radial direction of the drum circumference.
Security latch according to claims 1 or 2 wherein the sliding member (S) further comprises a beak shaped end and a contact portion (C).
Security latch according to any of the preceding claims claim wherein the predetermined acute angle (α) is comprised in the range between 3° and 40°.
Security latch according to claim 4 claim wherein the predetermined acute angle (α) is preferably comprised in the range between 5° and 30°.
Security latch according to any of the preceding claims comprising a body (B) provided with a guiding means (GB) into which the slidable member (S) is guided.
Security latch according to claim 6 further comprising corresponding guiders (GS).
Security latch according to claim 5 wherein the body (B) is snap fixed to the door.
Security latch according to any of the preceding claims wherein the latch (L) is made of plastic material.