Description

Dishwasher

Technical Field

This invention relates to a dishwasher equipped with a rack designed to hold the objects to be washed.

Dishwashers are designed to wash objects such as dishes, cutlery and pans used to prepare and consume meals . Dishwashers are normally used both in the home and in commercial establishments such as restaurants.

Background Art

Dishwashers are known which comprise a lower drawer and an upper drawer that can be pulled out of a wash compartment . The compartment can be accessed by the user through an open/close door. Each drawer comprises a rack designed to hold the objects to be washed. The lower drawer is pulled out in two consecutive steps: a first step in which the drawer slides horizontally until it strikes a limit stop and a second step in which the drawer is lifted vertically away from the horizontal surface on which it rests. In this way, the user does not need to bend down repeatedly to place objects or remove them from the bottom rack of the dishwasher. Dishwashers of this kind are not free of disadvantages.

In particular, the horizontal movement of the drawer and the lifting of the rack are completely independent and require separate movement parts. This leads to greater structural complexity .

Disclosure of the invention

This invention has for an aim to overcome the above- mentioned disadvantages by providing a dishwasher having a simple structure . Another aim of the invention is to provide a dishwasher where the rack can be moved in a horizontal direction and in a vertical direction by applying a force in a single direction, said

force being applied directly by the user.

These aims and others, which are more apparent in the description which follows, are achieved, in accordance with the present invention, by a dishwasher with the structural and functional features described in the appended independent claims .

Further embodiments of the dishwasher are described in the dependent claims.

Brief Description of the Drawings The invention will now be described in more detail with reference to the accompanying drawings, which illustrate non- limiting preferred embodiments of it.

Figure 1 is a schematic side view of a dishwasher according to the invention with a drawer in two different positions. Figure 2 is a schematic side view of the dishwasher of Figure 1 with the drawer in yet another position.

Figures 3 and 4 are two enlarged views of a single detail from Figure 2.

Figures 5a to 5f show the steps of pulling out the drawer.

Detailed Description of the Preferred Embodiments of the Invention With reference to the accompanying drawings, the numeral 1 denotes a dishwasher.

The dishwasher 1 comprises an internal wash compartment 2 accessible by the user through a door 20 used to open and close it. The compartment 2 is normally defined by an upper surface, a lower surface, two side surfaces, a rear surface and a front surface. The door 20 is made in the front surface. When closed, the door 20 is usually in a vertical position and fits snugly against the other parts of the dishwasher 1 to create a watertight seal that prevents water from leaking out. When open, the door 20 is in a substantially horizontal position.

The dishwasher 1 also comprises a first drawer 3 which in turn comprises a corresponding rack 31 designed to hold the objects to be washed: dishes, cutlery and any other utensils used for cooking and consuming meals. In the configuration illustrated, the rack 31 comprises a support 310 that connects it to the other

parts of the drawer 3.

The dishwasher 1 also comprises a support 4 on which the drawer 3 moves from a first position where the rack 31 is inside the compartment 2 to a second position. Advantageously, the support 4 comprises a first portion 41 inside the wash compartment

2 and a second portion 42 made on a wall 21 of the door 20, facing upwards when the door 20 is in the substantially horizontal, fully open configuration.

The dashed lines in Figure 1 represent the first drawer 3 in the first position on the support 4, while Figure 2 shows the first drawer 3 in the second position. In the second position, the rack 31 is at least partly outside the compartment 2. Advantageously, in the second position, the rack 31 is higher up than it is when the drawer 3 is in the first position. Advantageously, in the second position, only a small end portion of the rack 31 is inside the wash compartment 2. Preferably, as illustrated in Figure 2, in the second position, the drawer 3 is completely outside the compartment 2. Passing from the first to the second position, the first drawer 3 moves out of the compartment 2 through the opening that can be closed by the door 20. In particular, in the second position, the drawer 3 is in a configuration of stable equilibrium. In this document, "configuration of stable equilibrium" means a position to which a system returns spontaneously when a disturbing force applied to it is removed.

The first drawer 3 comprises means 32 for lifting the rack 31 relative to the support 4. Advantageously, actuation of the lifting means 32 causes a simultaneous vertical and horizontal lifting movement of the rack 31. The lifting means 32 are operated by applying an external force.

In particular, the support 4 and the parts 10 of the drawer

3 that remain in contact with the support 4 for the entire duration of drawer 3 movement from the first to the second position define an instantaneous interface. Each position adopted by the geometric centre of gravity of this interface during the movement of the first drawer 3 from the first to the second position along the support 4 corresponds to a single and

predetermined vertical distance of the geometric centre of gravity of the rack 31 from a fixed reference point in space.

Vertical distance means the distance measured along a straight vertical line drawn between the orthogonal projections onto said line of the rack's geometric centre of gravity and of the fixed reference point in space. Figures 5b to 5f in particular show a variation in the height of the geometric centre of gravity of the rack 31 relative to the geometric centre of gravity of the interface. Preferably, the function that links the vertical position of the geometric centre of gravity of the rack 31 to the horizontal position of the geometric centre of gravity of the interface is not a monotonic function: thus, passing from the position of the rack 31 shown in Figure 5b to the position of the rack 31 shown in Figure 5e, the geometric centre of gravity of the rack 31 gradually rises with respect to the geometric centre of gravity of the interface, whereas passing from the position of the rack 31 shown in Figure 5e to the position of the rack 31 shown in Figure 5f, the geometric centre of gravity of the rack 31 is gradually lowered with respect to the geometric centre of gravity of the interface. There is therefore a precise correlation between the position of the drawer 3 /support 4 interface and the height of the rack 31. The application of a substantially horizontal pulling force on the first drawer 3 thus causes the rack 31 to move along a predetermined path. The movement of the first drawer 3 from the first to the second position is accompanied both by a horizontal and a vertical movement of the rack 31. Advantageously, the dishwasher 1 comprises elastic means to assist the user in pulling the first drawer 31 out of the wash compartment 2.

By applying a force in a constant direction, the user can therefore pull the rack 31 out completely in such a way as to place it at least partly outside the wash compartment 2 and in a raised position. This makes it easier to place objects to be washed in the rack 31 and to remove them after washing without having to bend down repeatedly. Furthermore, the extremely simple operation makes pulling out the rack 31 a direct and spontaneous action that does not require use of buttons or other controls, however intuitive, to operate the means for moving the first

drawer 3 or the rack 31.

With reference to Figure 1, when the first drawer 3 is in the first position, the geometric centre of gravity of the rack 31 is at a first predetermined vertical distance from a fixed reference point below it.

With reference to Figure 2 , when the first drawer 3 is in the second position, the geometric centre of gravity of the rack 31 is at a second predetermined vertical distance from the fixed reference point below it . The second predetermined vertical distance is greater than the first predetermined vertical distance, preferably by a quantity of between 60 mm and 160 mm.

With reference to Figures 5a to 5f, during the movement from the first to the second position, the drawer 3 passes through a third position (see Figure 5e) where the vertical distance of the geometric centre of gravity of the rack 31 from the reference point below is at its largest and corresponds to a third predetermined vertical distance. The movement of the drawer 3 from the first to the third position requires the application of an external force and once it has moved past the third position, the drawer 3 moves spontaneously towards the second position. As shown for example in the drawings, the geometric centre of gravity of the rack 31 in the second position (see Figure 5f) is lower than it is when the first drawer 3 is in the third position along the support 4 (see Figure 5e) . The difference between the third and the second predetermined vertical distance is 10% less than the difference between the third and the first predetermined vertical distance.

During the movement between the first and the second position, the first drawer 3 defines a path divided into a first and a second part, the action of the lifting means 32 being applied in the second part of the path.

In the first part of the path, on the other hand, the first drawer 3 moves in a direction parallel to the support 4 and maintains the configuration adopted in the first position. The distance and relative orientation of the components of the first drawer 3 thus remain the same as those adopted in the configuration associated with the first position of the first

drawer 3 on the support 4. In this document, the expression "configuration of the first drawer 3" means the relative orientation of the components of the first drawer 3 itself.

Advantageously, the slope of the path followed by the rack 31 changes at least at the passage between the first and the second part of the path. That is because during the passage between the first and the second part of the path the lifting means 32 are actuated.

Advantageously, a force applied to the first drawer 3 in a substantially horizontal direction allows the first drawer 3 to be moved in both the first and the second part of the path.

The force is preferably a manual force applied by a user. For this purpose, the first drawer 3 has a handgrip located in a position that can be easily accessed by the user. Advantageously, the dishwasher 1 comprises means 5 for stopping a protrusion 33 located on the first drawer 31. The protrusion 33 moves relative to the means 5 at least during the first part of the path. The lifting means 32 are activated when the protrusion 33 on the first drawer 3 strikes the stopping means 5.

Advantageously, the stopping means 5 are fixed in space. Preferably, the stopping means 5 are located inside the wash compartment 2.

As shown in the drawings by way of example, the stopping means 5 are the end portion of a guide 50 along which the protrusion 33 moves when the first drawer 3 moves along the first part of the path. Advantageously, the guide 50 extends horizontally. As shown in the drawings by way of example, the protrusion 33 is rototranslationally engaged with the guide 50. Advantageously, the lifting means 32 comprise an articulated arm 320 comprising at least one intermediate hinge 320a, the articulated arm 320 connecting the protrusion 33 to the rack 31. More specifically, the articulated arm 320 comprises a first and a second rod 320b, 320c connected to each other at one end by the intermediate hinge 320a. The other end of the first rod 320b is connected to the protrusion 33, while the other end of the second rod 320c is connected to the rack 31 by a hinge 32Of.

Advantageously, the dishwasher 1 comprises a second sliding drawer that can be pushed into and pulled out of the wash compartment 2. The second drawer comprises a respective rack for holding the objects to be washed. The second drawer and the respective rack are positioned above the first drawer 3 and the rack 31 at least when the first drawer 3 is in the first position on the support 4.

Advantageously, the dishwasher 1 comprises first retaining means for keeping the second drawer inside the compartment 2 when the first drawer 3 is at least partially outside the compartment 2. Preferably, the dishwasher 1 comprises second retaining means for keeping the second drawer inside the compartment 2 when the first drawer 3 is in the second position on the support 4.

Advantageously, in a front view not shown in the drawings, the dishwasher 1 has a vertical plane of symmetry passing through the middle of the internal wash compartment 2. The first drawer 3 is substantially symmetrical about this plane of symmetry.

The first drawer 3 advantageously comprises elements 34 to facilitate its movement on the support 4. The facilitated movement elements 34 comprise the parts 10 of the drawer that remain in contact with the support 4 for the entire duration of drawer 3 movement from the first to the second position. In the preferred embodiment illustrated in the drawings, the facilitated movement elements 34 comprise rolling bodies 34a, 34b that interact with the support 4, which acts as a rail for the rolling bodies 34a, 34b; the facilitated movement elements 34 may comprise bodies that slide on the support 4; in the latter case, sliding bodies and the support are made of a low-friction material .

As shown by way of example in Figures 5b to 5f, the movement of the lifting means 32 is accompanied by the advancing of the facilitated movement elements 34 of the first drawer 3 along the support 4.

Advantageously, the lifting means 32 comprise an articulated mechanism 321 which in turn comprises a first four-point linkage 322. The first four-point linkage 322 comprises a first member 323 in turn comprising two elements 34 for the facilitated movement of the drawer 3 along the support 4; the first four-point linkage 322

also comprises a second member 324 which remains parallel to the imaginary line joining the two facilitated movement elements 34. The second member 324 consists of a portion of the rack 31 between two hinges 324a, 324b forming part of the first four-point linkage 322 and connected to the rack 31. The second member 324 moves in a vertical plane parallel to the direction in which the rack 31 is pulled out of and pushed into the wash compartment 2.

Advantageously, the articulated mechanism 321 of the lifting means 32 comprises a twin four-point linkage 325 comprising a lower four-point linkage 326 and an upper four-point linkage 327. The lower and upper four-point linkages 326, 327 are separate from the first four-point linkage 322. A first member 328 of the twin four-point linkage 325 forms part of the lower four-point linkage 326 only and consists of the facilitated movement elements 34 of the drawer 3 which are in common with the first four-point linkage 322. A second member 329 of the twin four-point linkage 325 forms part of the upper four-point linkage 327 only and remains parallel to the first member 328. The second member 329 comprises a portion of the rack 31 between two hinges 329a, 329b forming part of the upper four-point linkage 327. The two hinges 329a, 329b are connected to the rack 31. The second member 329 moves in a vertical plane parallel to the direction in which the rack 31 is pulled out. A rod forming part of the upper four-point linkage 327 is the extension of the articulated arm 320. Advantageously, in the second position:

-the crank forming part of the first four-point linkage 322 and the crank forming part of the twin four-point linkage 325 hinged at the same point as the former together define a first concavity 330; -the cranks forming part the lower four-point linkage 326 and of upper four-point linkage 327, both hinged at the same point together define a second concavity 331; the first and the second concavities face at least one common point; this configuration making it possible to define a configuration of stable equilibrium. This configuration occurs when the first drawer 3 is in the second position on the support 4.

During the movement from the second to the first position,

the first drawer 3 follows the same path but in the opposite direction to that of the movement of the first drawer 3 from the first to the second position.

Preferably, the stopping means 5 comprise means for locking the drawer 3 which prevent the drawer 3 from moving from the second to the first position in the configuration adopted by the drawer 3 in the second position.

After passing the third position during its movement from the second to the first position, the first drawer 3 moves spontaneously towards a fourth position. The fourth position of the first drawer 3 on the support marks the passage from the first to the second part of the path.

In a first embodiment, the locking means can be released manually using a special control (not illustrated) to allow the first drawer 3 to be moved from the fourth position to the first position.

Alternatively, to allow the drawer 3 to move from the fourth to the first position, the locking means can be released by applying a force greater than the force required to move the first drawer 3 from the second to the fourth position.

Advantageously, the dishwasher 1 comprises braking means that slow the downward motion of the rack 31 during the movement of the first drawer 3 from the third to the fourth position. Especially when the rack 31 is fully loaded, this prevents undue stress and avoids the risk of damaging the first drawer 3 and the objects it holds.

In the example, non-limiting embodiment illustrated in the drawings, during use, a force applied by the user enables the first drawer 3 to be pulled out of the internal compartment 2 where it is located during a wash. This force is advantageously applied in a substantially horizontal direction. As it is pulled out, the first drawer 3 first moves in a direction parallel to a supporting surface 4 while maintaining the same configuration. The first drawer 3 comprises a protrusion 33 that is mobile in a guide 50 inside the wash compartment 2. The protrusion 33 is engaged by locking means made on the guide 50. These locking means hold back the protrusion 33 and oppose the movement of the first drawer 3 in

the pulling out direction. This activates the means 32 for lifting the rack 31 of the first drawer 3 and thus causes a change in the configuration of the first drawer 3. At this stage, the rack 31 of the first drawer 3 is lifted and advances in the pulling out direction. At the same time, the first drawer 3-support 4 interface advances in the pulling out direction. After passing the dead centre where the first drawer 3 is at the maximum height above the support 4, the first drawer 3 moves spontaneously towards a configuration of stable equilibrium. To push the first drawer 3 back into the wash compartment 2 , the user applies a force in the opposite direction to that applied to pull out the first drawer 3. The locking means oppose the movement of the protrusion 33 relative to the guide 50. As a result, the protrusion 33 remains locked in this position and the lifting means 32, acting in the opposite direction to that in which they act when pulling out, guide the rack 31 and lower it towards the guide 50. When the first drawer 3 is pushed into the wash compartment 2, the first rack 31 is first raised to a position of maximum height and after passing this dead centre, tends to move down again under its own weight. Next, by applying a horizontal force greater than the force required to pass the dead centre, the locking means are released. Alternatively, the locking means might be released by operating manually on a specific control . After disengaging the locking means from the protrusion 33, the first drawer 3 can move freely into the wash compartment 2.

The invention brings important advantages .

It advantageously enables the first drawer to be lifted to a raised position of stable equilibrium using even just one hand. Secondly, the system makes it possible to move the first drawer and at the same time lift the rack by applying a force in the same direction thus making it quicker and easier to pull out the first drawer itself.

Another important advantage is that the device is extremely simple and thus inexpensive.

A further and no less important advantage is that the device is extremely robust and reliable and requires little maintenance

since there are no electrical actuators.

Moreover, the pulling out device is intuitive, direct and very easy for anyone to use {including persons who have problems using a control panel to switch electrical actuators on and off) . The invention can be modified and adapted in several ways without thereby departing from the scope of the inventive concept.

Moreover, all details of the invention may be substituted by other technically equivalent elements .

In practice, the embodiments of the invention may be made from any material, and in any size, depending on requirements.