Dishwasher with moving water nozzles

Abstract

 A dishwasher with at least a rotating spray arm having water nozzles presents one of such nozzles which is moving while the spray arm is rotating in order to improve the efficiency of washing, particularly in the corner area of the washing chamber.

Description

[0001] The present invention relates to a dishwasher having at least a rotating spray arm with spray nozzles.

[0002] It is well known in the art of dishwashing machine to provide in the washing chamber of the dishwasher one or more spray arms fed by water manifolds and driven into rotation by the force exerted by water jets projected by certain nozzles properly disposed on the spray arms.

[0003] It also known the problem of reaching with water jets all the zone of the washing machine chamber, particularly when such chamber has a rectangular place. In this case the coverage of the corner areas is difficult to obtain in an efficient way. A first known way is to provide the nozzles at the distal ends of the spray arms with a certain inclination in order to assure the corner zones are covered. With this solution when the nozzles are near the vertical wall of the chamber the inclined water jets impinge the walls of the chambers with a poor cleaning result. Another solution is to provide further spray arms rotating on the end of the main spray arm. With this so called orbital spray arms a better coverage of the corner area is reached but the overall complexity and vertical dimension of the spray arm is increased.

[0004] It is an object of the present invention to provide a dishwashing machine which solves the above problem in a very efficient and economical way.

[0005] According to the invention, the above object is reached thanks to the features as listed in the appended claims.

[0006] The gist of the present invention is to arrange at least certain nozzles, and preferably the nozzles placed at the distal ends of the spray arm, so that they can move and preferably rotate according to a certain pattern in order to change the inclination of the water spray along the rotation of the spray arm. By means of a back and forth predetermined rocking movement, each nozzle can direct the water jet according to a vertical direction (near the side wall of the washing chamber) or to an inclined direction (when the ends of the spray arm are far from the side walls of the washing chamber, i.e. in the corner areas of such chamber). Further advantages and features of a dishwasher according to the present invention will be clear from the following detailed description, provided as non limiting example, with reference to the attached drawings in which:

• figure 1 is a perspective view of a spray arm of a dishwasher according to the invention;
• figure 2 is an exploded view of the spray arm of figure 1;
• figure 3 is a longitudinal cross section of the spray arm of figure 1;
• figure 4 is an enlarged view of a detail of figure 3; and
• figure 5 is an enlarged view of a detail of figure 3.

[0007] With reference to the drawings, with 10 is indicated a spray arm of a dishwashing machine having a washing chamber and racks for containing crockery (not shown). The spray arm 10 is fed through a water manifold 12 having cylindrical water tight coupling 12a well known in the art.

[0008] The spray arm 10 has a plurality of nozzles 14 formed by shaped holes provided in the upper half 10a of the arm, and two rotating nozzles 16 placed at the ends of the spray arm 10. In figure 1 only the nozzles on one part of the spray arm are shown. Each rotating nozzle 16 comprises a semi cylindrical element 18 having coupling pins 18a rotating in corresponding shaped openings 19 of the spray arm 10 and a slot 18b forming the aperture for the water jet.

[0009] In the coupling 12a of the spray arm 10 there is provided a fixed central pin 20 extending with a certain play within the spray arm 10 and provided with a plate portion 20a having a cam groove 22. The cam groove 22 is adapted to cooperate with a feeler pin 24 of an elongated follower 26 slidably mounted in the spray arm 10. Each end of the elongated follower 26 is provided with an opening 26a adapted to cooperate with a peg 18c stemming out from the semi cylindrical element 18 perpendicularly to the rotation axis of the element 18, shown in figure 5 with reference X-X. The follower 26 is centrally provided with auxiliary opening 26b which are used either for assuring the water flow coming from the manifold 12 or for guiding the follower along a longitudinal direction, by cooperating with corresponding longitudinal rims (not shown) provided in the lower half 10b of the spray arm 10.

[0010] During the working of the dishwasher, the spray arm 10 rotates according to the direction indicated by arrow A in figure 1. Such movement is driven by certain nozzles 14 having a predetermined direction. During such movement, the feeler pin 24 of the follower 26 slides in the cam groove 22 of the fixed pin 20, driving a back and forth movement of the follower 26. Such movement on its turn drives an oscillating rotation of the spray nozzle 16, particularly of the semi cylindrical element 18 assuring therefore a desired change of the water jet direction during rotation of the spray arm. The feeler pin 24 and the groove 22 are shaped in order to guarantee that the position of the slots 18b of the rotating nozzle 16 are substantially vertical when the ends of the spray nozzles are near the side walls of the washing chamber (direction B shown in figure 1), and inclined towards the tips of the spray arm (direction C in figure 1) when the ends of this latter are in the corner zones of the washing chamber.

[0011] All the components of the spray arm according to the present invention are advantageously made in polymeric material; particularly the rotating spray arms 16 present the coupling pins 18a of each rotating element 18 snap-engaged in corresponding seats of the spray arm 10. The shape of the openings 19 in the spray arm 10 correspond to the shape of the element 18 for assuring a smooth and water-tight rotation. The shown cam system for driving the rotation of the rotating nozzles 16 is only one example on how it is possible to obtain such rotation. Other systems may be used as well, for instance based on levers or on different cam systems.

Claims

1. Dishwasher, having at least a rotating spray arm (10) with water nozzles (14, 16), characterized in that at least one of the water nozzle (16) is moving while the spray arm is rotating.

2. Dishwasher according to claim 1, wherein the moving water nozzle (16) is rotating along an axis (XX) substantially perpendicular to the axis of the spray arm (10).

3. Dishwasher according to claim 2, wherein the rotation of the water nozzle (16) is a back and forth rotation.

4. Dishwasher according to any of the preceding claims, wherein the moving water nozzles (16) are placed at distal ends of the spray arm (10).

5. Dishwasher according to any of the preceding claims, wherein each moving nozzle (16) comprises a rotating element (18) with a water opening (18b) and rotatably mounted in a corresponding opening (19) of the spray arm (10).

6. Dishwasher according to claim 5, wherein each spray arm (10) comprises a cam device (20, 22) fixed to a manifold (12, 12a) for feeding water to the spray arm (10) and extending through such manifold, and a follower (24, 26) placed inside the spray arm (10) and cooperating with said cam device in order to drive the rotation of the element (18) according to a predetermined pattern.

7. Dishwasher according to claim 6, wherein each rotating element (18) is rotatably mounted in an upper half (10a) of the spray arm (10) and presents an integral peg (18c) cooperating with a corresponding opening (26a) of the follower (26).

Drawing