A rotational device for wash jets in dishwashers and dishwashers equipped with said device

Abstract: A rotational device for washing jets in dishwasher and dishwasher equipped with said device, having rotatable arms (1,2) with a nozzles plurality (3,3') to spray the washing fluid toward the ware to wash and having means to allow teh rotation of said arms (1,2) during the washing operation, characterized in that at least a number of said washing jet nozzles are orientated/swinging in inclination direction of the respective jet to give themselves a rotational component to the arm in order to explicate the double function both of washing and of rotational propulsion.

Description: The present invention concerns a rotational device for washing jets in a dishwasher and a dishwasher equipped with said device. This solution is conveniently applicable in industrial dishwashers but can be used also in home dishwashers. In prior art, a rotative dishwasher jet device involves substantially two free rotatable horizontal arms supported on a central vertical axis, each arm having two opposed semiarms, each semiarm having a plurality of washing jets to hit the ware to be washed which has been disposed in the washing chamber of the dishwasher between said two arms. The rotational movement of the arms is obtained utilizing generally one or a couple of external jets for each arm, (one external motion jet for each semiarm placed at its extremity), tangentially oriented in opposition which have the specific function of rotation only (Eg. DE-A-1628547 and DE-A-142849). The drawback of these well known solutions (separate nozzles for arm-rotation) is a reduction of the washing flow, and the washing performance is reduced by up to 25%. The purpose of the present invention is to obviate said drawback. This and other purposes are reached with the present invention as claimed in claim 1 by means of a rotational device for washing jets in a dishwasher and a dishwasher equipped with said device, comprising jet rotatable arms with a plurality of jet nozzles to spray the washing fluid to the ware to be washed and having means to allow the rotation of said arms during the washing operation, wherein at least a number of said washing jet nozzles are inclined to give a rotational component to the arm in order for it to perform the double function both of washing and rotational propulsion, whereby said washing nozzles have a fissure shape and present a convex surface, the fissure being inclined in respect of a transverse plane of the arm with an angle f between 50° and 63° and all said fissures are parallel one to the other in both said arms. With this solution we obtain a total utilization of the water in the circle as a mechanical effect on the components being washed, avoiding that a part of it is used for rotation only. The rotatory motion of the washing arms with the invention, in fact, is not given by a specific pushing external nozzle, but by the sum of the push components of the washing jet nozzles, increasing by up to 25 % the wash efficiency. The invention is better understood with the enclosed description and drawings supplied for example only, in which: Figure 1 represents a side view of one washing arm according to this invention with a semiarm end partially axially sectioned according to the plane of Figure 2, for the visualization of the washing jets. Figure 2 represents a top view of the washing arm of Figure 1. Figure 3 represents a transverse sectional view on the plane B-B of Figure 2 of the washing arm in correspondence with a sprayer nozzle. The Figures disclose that the invention regards a rotational device for washing jets in a dishwasher and a dishwasher equipped with said devices, the device being a rotational arm, having a pair of semiarms (1, 2) with a plurality of nozzles (3, 3') to spray the washing fluid toward the ware to be washed and a means to allow the rotation of said arm (1, 2) during the washing operation, wherein at least a number of said washing jet nozzles are oriented to give themselves a rotational component in order to perform the double function both of washing and of rotational propulsion, characterised in that said washing nozzles (3, 3') have a fissure shape (g) and present a convex surface, and all said fissures (g) are parallel one to the other in both said arms. In particular it is disclosed that the jet pray nozzles are distributed in an equal manner and symmetrically along the respective semiarms (2) that extend from a rotational central body (1) in a misaligned manner (Figure 2) for a value of approximately 10 millimeters. There are four jets for each semiarm and all present a jet fissure nozzle (g) on a convex surface to give to a fan shape to the jet of spray. The fissures (g) are oriented, if compared to a transverse plane, with an angle f comprised between 50° and 63° and with a slope, if compared to the perpendicular µ angle, between 2° and 10° preferably 5°. The central jet axis of each nozzle is slightly inclined toward the exterior with an angle β between 7° and 13°, with the exception of the external nozzle 3' that is obtained on a tilted plane at the end of the semiarm with an angle ∂ between 7° and 13°, consequently this end nozzle (3') is more tilted toward the exterior if compared to the internal ones (∂) forming a total slope of β+∂ angle, namely between 14° and 26°. The Figures disclose furthermore that adjacent to the hub of the central portion of the arm (1) there is a central sprayer nozzle (4), slightly eccentric if compared to the rotation axis, the jet of which has the function to cover the central shadow zone that generally is scantily covered by the nozzles (3) of the semiarms. The washing water feeding is made under the hub 1 in the known manner. The solution in the Figures includes the realization of the rotary arm in a single piece in diecast plastic material, but it is evident that the same can be made even in other materials, and even made in more pieces and in particular three pieces: a central one as hub and two interchangeable bayonet-pluggable detachable semiarms. We point out furthermore that the hole (5) of the central hub (1) is endowed with two toothed wings (6) that lodge a blockage screw bolt (7) retained by this head. This bolt is used for securing the arm on the rotation axis support, and has substantially a knurled cylindric head (7) semicylindrically retained in a loose manner between said two wings (6) that prevents its axial extraction but does not prevent the screwing rotation or unscrewing rotation and this obviously allows the easy assembly and disassembly of the respective arms for the respective cleaning and maintenance, even manually and without the danger of losing the respective fixation bolt. In a more expensive variation the spraying nozzles (3, 3') can be obtained by means of a rotatable bush, in such a case rotating the bush that bears the respective jet fissures (g) we can even vary the orientation of the jet giving even a variable rotational force component. This allows adjustment of the rotation speed of the arm, said carvings (g) being tilted as described above.

Claims: A rotational device for washing jets in a dishwasher and a dishwasher equipped with said device, having rotatable arms (1,2) with a plurality of nozzles (3,3') to spray the washing fluid toward the ware to be washed and having means to allow the rotation of said arms (1,2) during the washing operation, wherein at least a number of said washing jet nozzles are inclined to give a rotational component to the arm in order to perform the double function both of washing and of rotational propulsion; whereby said washing nozzles (3, 3') have a fissure shape (g) and present a convex surface; characterized in that the fissure is inclined in respect of a transverse plane of the arm with an angle f between 50° and 63° and all said fissures (g) are parallel one to the other in both said arms (1-2). A rotational device for washing jets in a dishwasher and a dishwasher equipped with said device according to claim 1, characterized in that: said fissure (g) is tilted from a transverse plane of the arm with an horizontal angle f between 50° and 63°; the corresponding jet axis of said fissure is tilted from the vertical on the transverse plane of the arm with a vertical angle µ between 2° and 10°. A rotational device for washing jets in a dishwasher and a dishwasher equipped with said device according to claim 2, characterized in that: the jet axis of of the nozzles (3, 3') is slightly inclined in opposition, toward the external side with an angle (β, β+∂) between 7° and 26°. A rotational device for washing jets in a dishwasher and a dishwasher equipped with said device according to claim 2, characterized in that the jet axis of the nozzles (3) with the exception of the end one (3') is slightly inclined toward the external side with an angle (β) between 7° and 13° and the nozzle at the extremity is more tilted if compared to the previous ones. A rotational device for washing jets in a dishwasher and a dishwasher equipped with said device according to claim 4, characterized in that the nozzle at the extremity is more tilted in the same sense for a value angle (β+∂) between 14° and 26°. A rotational device for washing jets in a dishwasher and a dishwasher equipped with said device according to claim 1, characterized in that said nozzles are disposed on rotational bushes to be oriented to vary the slope of the respective jets for the respective rotational component. A rotational device for washing jets in a dishwasher and a dishwasher equipped with said device according to claim 1, characterized in that the fissures of said nozzles (3, 3') are substantially parallel to each other. A rotational device for washing jets in a dishwasher and a dishwasher equipped with said device according to claim 1, characterized in that in proximity to the hub (1) is found at least a further nozzle (4), placed slightly eccentrically if compared to the rotational axis. A rotational device for washing jets in a dishwasher and a dishwasher equipped with said device according to claim 1, characterized in that said arm: is made of a plastic material, presents an axial holing (5) for fixation with a screw bolt means (7) to a rotation axis, and over this axial holing (5) are two opposite arcuate resiliently yielding wings having internal teeth (6), that encapsulate and clamp and maintain in position the respective bolt head of said screw means (7), the clamping of said two toothed wings with opposite arch being realized in such a way as to prevent the free extraction of the screw but sufficiently loose to allow its rotation in the arm (1). A rotational device for washing jets in a dishwasher and a dishwasher equipped with said device according to claim 1, characterized in that said arm: is made of a plastic material, presents an axial holing (5) for the fixation with a screw bolt means (7) to a rotation axis and over the respective axial holing (5) protrudes upward two opposite clamping means (6) to clamp and maintain in position encapsulating the head of said bolt (7); said head bolt (7) being substantially knurled and cylindric; said two opposite wings are arcuate and have a respective toothing realized in such a way to prevent the free axial exit of said ring (7) but sufficiently loose to allow rotation of the screw in the arm (1 ).

Inventors: FAVARETTO MAURIZIO, TONON FERNANDO, FAVARETTO, MAURIZIO, TONON, FERNANDO
Applicants: WERY SPA, WERY S.P.A.
Application year: 1990
Main classification: A47L15
IPC codes: A47L15