EP3703548A1

EP3703548A1 - A spray arm

Info

Publication number: EP3703548A1
Application number: EP18789135.3A
Authority: EP
Inventors: Yusuf Koc; Mert PATKAVAK; Emine Birci
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2017-10-31
Filing date: 2018-10-18
Publication date: 2020-09-09
Also published as: TR201716903A2; WO2019086255A1

Abstract

The present invention relates to a spray arm used particularly in dishwashers, in which the spray arm body (2) can be rotated in varying directions.

Description

A SPRAY ARM

Technical Field
The present invention relates to a spray arm used particularly in dishwashers.
Prior Art
In the dishwashers used nowadays, a washing cycle generally comprises the steps of cold washing, main washing, rinsing and drying.
The washing group, one of the main parts of a dishwasher, is the section where washing is performed, comprising lower and upper basket components in which the items to be washed are placed, a cutlery basket, spray arms and filters. The upper spray arm joined to the basket and the lower spray arm joined to the lower region of the tub, enable transmitting water into the dishwasher by means of the orifices provided thereon. The position and the geometry of these orifices are designed so as to enable the water jet to scan a larger area inside the washing unit and to thereby reach all surfaces of the dishes.
In the dishwasher, the spray arm rotates as a result of the angular momentum generated by the water jet ejecting through the orifices provided thereon. Generally, the orifices generating said momentum are positioned towards the end portions of a spray arm. The jet ejecting through the orifices are involved in removing dirt from surfaces by flushing the dirty dishes.
In a dishwasher, upon activation of a circulation pump, water with detergent is transmitted to the pipes and therefrom to a spray arm. Water advances to both ends of the spray arm and reaches the dishes by passing through the orifices. The water jet ejecting during the washing step through the orifices forcibly impacts the dishes. Dirt is removed from the surfaces of the dishes as a consequence of said impact. However, when the spray arm rotates in a single direction, the water jet ejecting through the orifices cannot scan the entire area in the washing unit, failing to reach all surfaces of the dishes. Thus, dirt is not completely removed from the dishes, leading to a low washing performance.
State of the art European patent document no. EP2601878 mentions a spray arm capable of bi-directional rotation, in which the flow direction of water can be changed by means of a ball placed therein.
State of the art Chinese patent document no. CN102858222 discloses a spray arm having two washing ducts, in which water is directed to one of the ducts by means of a valve.
State of the art Chinese patent document no. CN203369879 discloses a spray arm capable of bi-directional rotation. An additional engine is used to bi-directionally rotate said spray arm.
None of the state of the art documents include a solution as in the present invention, in which a spray arm is capable of bi-directional rotation.
Brief Description of the Invention
The aim of the present invention is to realize a spray arm enabling differing water ejection characteristics required in different washing steps.
Another aim of the present invention is to realize a spray arm rotatable in both clockwise and counter-clockwise directions.
Detailed Description of the Invention
The spray arm for achieving the aim of the present invention is illustrated in the accompanying drawing, wherein:
Figure1: is a sectional view of the spray arm.
The elements in the figures are numbered individually and the correspondence of these numbers are given hereinafter.

Spray arm
Spray arm body
Washing nozzle
Rotation nozzle
Counter-rotation nozzle
Duct
Duckbill

In its most basic form, the spray arm (1) used particularly in dishwashers comprises

at least one spray arm body (2) with a preferably elongated structure like an airplane propeller, capable of rotating about an axis passing almost through its center, and having at least one water inlet disposed almost on its rotational axis,
at least one washing nozzle (3) enabling forcibly spraying on the dishes the water received through a water inlet and thereby cleaning the dirt on the dishes,
at least one rotation nozzle (4) positioned towards an end of the spray arm body (2), enabling the water received through the water inlet to be sprayed so as to create an angular momentum capable of rotating the spray arm body (2),
at least one counter-rotation nozzle (5) positioned towards the end of the spray arm body (2) where the rotation nozzle (4) is not positioned, enabling the water received through the water inlet to be sprayed so as to create an angular momentum capable of rotating the spray arm body (2) in the opposite direction with respect to the rotating direction of the rotation nozzle (4),
at least one duct (6) preferably extending from an end of the spray arm body (2) to the other end, enabling transmitting the water from the water inlet to the washing nozzle (3), rotation nozzle (4) and the counter-rotation nozzle (5), and
at least one duckbill (7) provided at the side of the duct (6) extending towards the counter-rotation nozzle (5), allowing or blocking water flow to the counter-rotation nozzle (5).

The spray arm (1) comprises at least one spray arm body (2) with a preferably elongated structure like an airplane propeller, capable of rotating about an axis passing almost through its center. The spray arm body (2) preferably comprises two spray arm blades but it is also possible for the spray arm body (2) to have more than two spray arm blades. A spray arm blade can also be produced as a single piece. The spray arm body (2) has a structure capable of rotating with ease about an axis preferably passing through its center of gravity. The rotation of spray arm blades is similar to the rotation of the spray arms of the state of the art dishwashers. Water is introduced to the spray arm body (2) by means of at least one water inlet provided almost on its rotational axis. Said water inlet is also similar to those of the spray arms of the state of the art dishwashers. At least one washing nozzle (3) is provided on the spray arm body (2), enabling forcibly spraying the water received through the water inlet on the dishes and thereby cleaning the dirt on the dishes. The washing nozzle (3) has a small cross-sectional area in order to be able to pressurize water, because decreasing the cross-sectional area of the washing nozzle (3), increases the pressure of the water ejecting therefrom.
At least one rotation nozzle (4) is provided on the spray arm body (2), enabling the water received through the water inlet to be sprayed so as to create an angular momentum capable of rotating the spray arm body (2). Said rotation nozzle (4) is preferably placed towards an end of the spray arm blade in order to create a higher angular momentum. The rotation nozzle (4) is placed angularly so as to be able to rotate the spray arm blades by creating an angular momentum on the blades by means of water. At the end of the spray arm body (2) where the rotation nozzle (4) is not positioned, at least one counter-rotation nozzle (5) is positioned, enabling the water received through the water inlet to be sprayed so as to create an angular momentum capable of rotating the spray arm body (2) in the opposite direction with respect to the rotating direction of the rotation nozzle (4). Water received through the water inlet is transmitted to the washing nozzle (3), rotation nozzle (4) and the counter-rotation nozzle (5) by means of the duct (6). The duct (6) preferably extends from an end of the spray arm body (2) to the other end. Said duct (6) may also be a space provided within the spray arm body (2).
At least one duckbill (7) is provided at the side of the duct (6) extending to the counter-rotation nozzle (5), allowing or blocking water flow to the counter-rotation nozzle (5) according to the water pressure. Said duckbill (7) allows water to pass if the water pressure is higher than a given value, thereby enabling water to reach the counter-rotation nozzle (5). The duckbill (7) does not allow water to pass if the water pressure is lower than a given value, and thus water cannot reach the counter-rotation nozzle (5). Said duckbill (7) preferably completely covers a section of the duct (6) like a plug, thereby not allowing water to leak. Water passage is thus only possible if the duckbill (7) opens.
In water pressures enabling water to reach the rotation nozzle (4) and the counter-rotation nozzle (5), the angular momentum which the counter-rotation nozzle (5) creates on the spray arm body (2) is higher than and in opposite direction to the angular momentum created by the rotation nozzle (4). Thus, the spray arm body (2) rotates in one direction when the water reaches only to the rotation nozzle (4), and the spray arm body (2) rotates in the other direction when the water reaches both to the rotation nozzle (4) and the counter-rotation nozzle (5). The angular momentum created by the rotation nozzle (4) and the counter-rotation nozzle (5) can be adjusted by varying one of, a plurality of or all of the parameters including, but not limited to their position on the spray arm body (2), water spraying angles, water spraying pressures, and the like.
In the preferred embodiment of the invention, the duckbill (7) is made of an elastomeric material. Hence the name, the duckbill (7) is preferably duck-bill shaped. One might imagine that the bill is closed when the water pressure is low, and that the bill opens when the water pressure is higher than a given value. Water passage is thus controlled without using an additional element. The water pressure enabling the bill to open can be adjusted by changing the elastic properties of the duckbill (7). The elastic properties can be changed by varying one of, a plurality of or all of the parameters, such as varying the materials used in producing the duckbill (7), varying the mixture ratio of the materials if more than one material is used, or changing the physical form of the duckbill (7) (e.g. giving it in an undulated structure). But the variable parameters are not limited to those.
The water pressure required by the spray arm (1) of the invention is provided by means of a water pump. Water pressure is varied by means of said water pump, enabling changing the rotational direction of the spray arm body (2).
The water flow orientation can be changed thanks to the spray arm body (2) being capable of rotating in varying directions. In the dishwasher using said spray arm (1), the portions where water fails to reach are reduced, thereby improving washing efficiency.

Claims

A spray arm (1) used particularly in dishwashers, comprising

- at least one spray arm body (2) with an elongated structure like an airplane propeller, capable of rotating about an axis passing almost through its center, and having at least one water inlet disposed almost on its rotational axis,

- at least one washing nozzle (3) enabling forcibly spraying the water received through the water inlet on the dishes and thereby cleaning the dirt on the dishes,

- at least one rotation nozzle (4) positioned towards an end of the spray arm body (2), enabling the water received through the water inlet to be sprayed so as to create an angular momentum capable of rotating the spray arm body (2), characterized by

- at least one counter-rotation nozzle (5) positioned towards the end of the spray arm body (2) where the rotation nozzle (4) is not positioned, enabling the water received through the water inlet to be sprayed so as to create a higher angular momentum compared to the rotation nozzle (4), capable of rotating the spray arm body (2) in the opposite direction with respect to the rotating direction of the rotation nozzle (4),

- at least one duct (6) preferably extending from an end of the spray arm body (2) to the other end, enabling transmitting the water from the water inlet to the washing nozzle (3), rotation nozzle (4) and the counter-rotation nozzle (5), and by

- at least one duckbill (7) provided at the side of the duct (6) extending towards the counter-rotation nozzle (5), allowing or blocking water flow to the counter-rotation nozzle (5).
A spray arm (1) according to claim 1, comprising a duckbill (7) allowing water to pass if the water pressure is higher than a given value, and not allowing water to pass if the water pressure is lower than a given value.
A spray arm (1) according to any one of the preceding claims, comprising the rotation nozzle (4) and the counter-rotation nozzle (5), wherein the angular momentums created by them are adjusted by varying one of, a plurality of or all of the parameters including, but not limited to their positions on the spray arm body (2), water spraying angles, and water spraying pressures.
A spray arm (1) according to any one of the preceding claims, comprising the duckbill (7), wherein its elastic properties can be changed by varying one of, a plurality of or all of the parameters, including but not limited to varying the materials used in producing thereof, varying the mixture ratio of the materials if more than one material is used, or changing its physical form.
A dishwasher using a spray arm (1) according to any one of the preceding claims.