EP2898810A1

EP2898810A1 - Revolving sprinkling assembly for dishwasher

Info

Publication number: EP2898810A1
Application number: EP14425005.7A
Authority: EP
Inventors: Andrea Ambrosi; Boris Milani
Original assignee: Bonferraro SpA
Current assignee: Bonferraro SpA
Priority date: 2014-01-28
Filing date: 2014-01-28
Publication date: 2015-07-29

Abstract

A revolving sprinkling assembly for dishwasher comprises a sprinkler (1) mounted on a socket (2), arranged at the outlet of a water supply duct, through an eccentric connector (4) having a water inlet (5a) that is out of axis with respect to a water outlet (6a), the sprinkler (1) being rotatably mounted on the eccentric connector (4) so as to rotate around an axis (X) coaxial with the water outlet (6a) and the eccentric connector (4) being in turn rotatably mounted on the socket (2) so as to rotate around an axis (Y) coaxial with the water inlet (5a), a gear (7) coaxial with the rotation axis (X) of the sprinkler being driven into rotation by the latter and engaging a fixed toothed crown (8) coaxial with the socket (2). In this way, the sprinkler (1) performs a planetary motion for an effective washing of the dishes with a reduction in cost, bulkiness, noise and water and power consumption with respect to a prior art planetary sprinkling assembly.

Description

The present invention relates to revolving sprinkling assemblies for dishwashers, and in particular to a sprinkling assembly including a device to provide the sprinkler with a planetary motion. This expression refers to a motion in which the sprinkler not only rotates around its own axis of rotation but also follows a circular path around a second axis of rotation, similarly to Earth that in addition to the daily rotation motion also performs the annual revolution motion around the Sun (although the latter motion is elliptical).
It is known that conventional revolving sprinkling assemblies essentially consist of a horizontal sprinkler provided with at least one propulsion nozzle at one end, as well as with wash nozzles arranged along the sprinkler to sprinkle the dishes contained in the dishwasher rack, and centrally pivoted on a vertical axis hollow socket arranged at the outlet of a water supply duct. Since the rotation axis of the sprinkler is fixed, the resulting paths followed by the nozzles consist of circumferences centered on said axis whereby the above-mentioned assembly directly sprinkles always and only the surfaces of the dishes which are along said circular paths, with a limited washing effectiveness.
IT 1263057 discloses a revolving sprinkling assembly of planetary type capable of directly sprinkling a much greater surface of the dishes thanks to the combination of the motion of a lower rotating sprinkler with that of at least another upper revolving sprinkler mounted in an eccentric position on the lower one, the sprinkling assembly yet retaining the same horizontal overall dimension of a conventional sprinkling assembly.
In practice, an upper revolving sprinkler of reduced size is eccentrically mounted on a conventional lower rotating sprinkler so that the motion of the upper sprinkler is the combination of two rotational motions and its nozzles follow complex trajectories. In this way the dishes are reached by the jets of water, coming from different points with different angles, emitted by the two sprinklers whereby the washing is more accurate and effective.
However this know sprinkling assembly, though effective, has at least two drawbacks due to its structure with two stacked sprinklers. A first drawback lies in its greater vertical dimension, which makes it difficult to use this configuration for the sprinkling assembly of the upper rack of a dishwasher with stacked racks. In fact, such a sprinkling assembly is placed on the ceiling of the wash tank or under the upper rack, and in both cases its greater vertical dimension reduces the space available for placing the dishes in the upper or lower rack respectively.
A second drawback of the two-sprinkler structure results from the higher water flow rate required to simultaneously feed the two sprinklers, each of which has a plurality of wash nozzles and at least one end propulsion nozzle. This results in a greater consumption of water, a higher noise level for the larger amount of water that falls on the bottom of the wash tank and the need for a larger wash pump, which costs more and uses more current.
Therefore, the object of the present invention is to provide a revolving sprinkling assembly which overcomes the above-mentioned limitations of prior art planetary sprinkling assemblies. This object is achieved by means of a sprinkling assembly in which the sprinkler is mounted on an end socket of the supply duct through an eccentric connector while a gear coaxial with the sprinkler and driven into rotation by the latter engages a fixed toothed crown coaxial with said socket. Other advantageous features are disclosed in the dependent claims.
The main advantages of the sprinkling assembly according to the present invention are the reduction in cost, size, noise and consumption of water and power with respect to a prior art planetary sprinkling assembly. In fact the present sprinkling assembly includes a single sprinkler, therefore the assembly is small enough to be used also for the upper rack and requires less water that can be supplied by a smaller pump, which is cheaper both in manufacturing and in use.
These and other advantages and characteristics of the sprinkling assembly according to the present invention will be clear to those skilled in the art from the following detailed description of three embodiments thereof, with reference to the annexed drawings wherein:

Fig.1 is an exploded side view showing a first embodiment of a sprinkling assembly according to the invention, in particular a sprinkling assembly to be mounted on the bottom of the wash tank below the lower rack of the dishwasher;
Fig.2 is a top perspective view of the sprinkling assembly of Fig. 1;
Fig. 3 is top perspective view of the sprinkling assembly in the assembled state;
Fig.4 is a longitudinal sectional view along the vertical midplane of the sprinkling assembly of Fig.1;
Fig.5 is top perspective view of a second embodiment of a sprinkling assembly according to the invention, in particular a sprinkling assembly to be mounted under the upper rack of the dishwasher;
Fig.6 is a longitudinal sectional view along the vertical midplane of the central portion of the sprinkling assembly of Fig.5;
Fig. 7 is a sectional view along line VII-VII of Fig.6; and
Fig. 8 is an exploded top perspective view of a third embodiment of a sprinkling assembly according to the invention, which is a variant of the second embodiment of Figs.5-7.

With reference to figures 1 to 4, there is seen that a revolving sprinkling assembly for dishwasher according to the invention includes a conventional sprinkler 1 provided with a plurality of wash nozzles 1a and at least one end propulsion nozzle 1b. A supply duct (not shown) ending with a socket 2 supplies water to sprinkler 1, which is usually mounted in a rotatable manner directly on said socket 2 through a short central hollow shaft 3 provided with resilient hooks 3a that engage a corresponding peripheral rib 2a formed close to the top of socket 2.
A first novel aspect of the present sprinkling assembly is given by the presence of an eccentric connector 4, interposed between socket 2 and shaft 3, that has a bottom portion 5 with a water inlet 5a that is out of axis with respect to a water outlet 6a formed in a top portion 6. Said eccentric connector 4 is further provided with coupling means that substantially reproduce the coupling means usually employed to couple members 2 and 3 between which it is arranged. More specifically, the bottom portion 5 is provided with resilient hooks 5b similar to the resilient hooks 3 a and suitable to engage rib 2a, and by the same token the top portion 6 is provided with a peripheral rib 6b similar to rib 2a and suitable to be engaged by hooks 3a.
In practice, therefore, sprinkler 1 is rotatably mounted on the top portion 6 of connector 4 so as to rotate with respect thereto around a first vertical axis X coaxial with the water outlet 6a, and connector 4 is in turn rotatably mounted on socket 2 of the supply duct so as to rotate with respect thereto around a second vertical axis Y coaxial with said socket 2 and with the water inlet 5a.
A second novel aspect of the present sprinkling assembly resides in the fact that sprinkler 1 is provided with a coaxial gear 7 that engages a toothed crown 8 fixed on the supporting structure of the sprinkling assembly. More specifically, gear 7 is preferably secured at the bottom end of a vertical rod 9, aligned with the rotation axis X, which passes through connector 4 and is made integral with sprinkler 1 through a coupling head 10 that engages a pin 1c formed inside sprinkler 1. The toothed crown 8 is preferably formed along the internal perimeter of a ring 11 arranged coaxial with socket 2 and secured through legs 12 to a flat filter 13 integral with socket 2.
The simple and effective operation of the sprinkling assembly according to the present invention is readily understood from the description above.
Sprinkler 1 is supplied with water coming from the wash pump through a supply duct ending with socket 2, said water passing in the hollow body of the eccentric connector 4 through inlet 5a and outlet 6a prior to reaching shaft 3. The water jets emitted by the sprinkler nozzles, in particular by the propulsion nozzle 1b, cause the rotation around axis X of sprinkler 1 and therefore also of rod 9 integral therewith, which rod 9 carries gear 7 which engages the toothed crown 8 secured on filter 13.
Thanks to this kinematic chain, the rotation of sprinkler 1 will cause therefore also the advancing of gear 7 along the toothed crown 8 and, as a consequence, the rotation around axis Y of the eccentric connector 4 driven by rod 9.
In this way, due to the distance d between the two axes of rotation X and Y, the rotation of the single sprinkler 1 results in a planetary motion in which the combination of the two rotational motions leads nozzles 1a, 1b to follow complex paths that cover a wide surface of the dishes to be sprinkled.
With reference now to figures 5 to 7, there is illustrated a second embodiment of a sprinkling assembly according to the invention to be mounted under the upper rack of a dishwasher with stacked racks. In these figures, the elements that are structurally and/or functionally equivalent to the above-described elements of the first embodiment are indicated by the same reference numerals with a prime.
In order to limit the vertical size of the sprinkling assembly, as clearly shown in the sectional view of Fig.6, in this embodiment the eccentric connector 4' rotatably mounted on the socket 2' of the supply duct 14, which is provided with a hook 14a for the coupling to the rack, has a double elbow shape that is more compact in the vertical direction. Furthermore, the eccentric connector 4' is mounted on socket 2', so as to rotate around a vertical axis Y', through a ring nut 15 that is provided with an external ring 15a having a toothed crown 8' formed along its internal perimeter. This ring nut 15 combines therefore the functions of the peripheral rib 2a and of ring 11 of the first embodiment.
Similarly, the hollow central shaft 3' of sprinkler 1' is shorter and rotatably mounted on the eccentric connector 4', so as to rotate around a vertical axis X', through a lock ring 16. More specifically, shaft 3' has internal radial projections 3a' that engage the horizontal arm of an inverted-T joint 10', in the vertical leg of said joint 10' there being secured a vertical rod 9' that passes through connector 4' and carries at the top a gear 7' which engages the toothed crown 8'. Moreover, in order to facilitate the rotation of sprinkler 1', a ring 17 of low-friction material is preferably interposed between the lock ring 16 and a top peripheral flange 3b' of shaft 3'.
By the same token, the operation of the second embodiment of the sprinkling assembly according to the present invention is substantially the same as the above-described operation of the first embodiment.
Sprinkler 1' is supplied with water coming from the wash pump through the supply duct 14 ending with socket 2', said water passing in the hollow body of the eccentric connector 4' through inlet 5a' and outlet 6a' prior to reaching shaft 3'. The water jets emitted by nozzles 1a' and 1b' cause the rotation around axis X' of sprinkler 1' and therefore also of rod 9' due to the drawing of joint 10' performed by the radial projections 3a', which rod 9' carries gear 7' that engages the toothed crown 8' secured on socket 2'.
Thanks to this kinematic chain, the rotation of sprinkler 1' will cause therefore also the advancing of gear 7' along the toothed crown 8' and, as a consequence, the rotation around axis Y' of the eccentric connector 4' driven by rod 9'. In this way, due to the distance d' between the two axes of rotation X' and Y', the rotation of the single sprinkler 1' results in a planetary motion in which the combination of the two rotational motions leads nozzles 1a', 1b' to follow complex paths that cover a wide surface of the dishes contained in the upper rack.
The third embodiment illustrated in Fig.8 is a variant of the second embodiment from which it differs in the type of mounting of the eccentric connector 4' on socket 2', which in this case is not achieved through an external ring nut 15 but through a hollow shaft 19 provided with side openings 19a and a closed bottom 19b. More specifically, shaft 19 is inserted through connector 4' so that its top projects from the water inlet 5a' in order to internally engage socket 2', while the side openings 19a allow the passage of water and the closed bottom 19b abuts on connector 4' thus closing the hole through which shaft 19 is inserted.
It should be noted that the toothed crown 8' is formed on the internal perimeter of a ring 18 preferably formed in a single piece with socket 2' and the supply duct 14, while the rest of the structure of the sprinkling assembly is unchanged with respect to the second embodiment. In fact, sprinkler 1' is still mounted on connector 4' through ring 16, and gear 7' is moved by the kinematic chain made up of rod 9' mounted on joint 10' which is driven into rotation by projections 3a' of shaft 3' that is integral with sprinkler 1'.
It is clear that the above-described and illustrated embodiments of the sprinkling assembly according to the invention are just examples susceptible of various modifications. In particular, the transmission ratio 10:1 illustrated in the figures (gear 7, 7' with four teeth and toothed crown 8, 8' with forty teeth) can be freely changed according to the desired rotational speed of sprinkler 1, 1' around axis Y, Y', for example in a range from 5:1 to 20:1. Moreover, the toothed crown 8, 8' could be formed on the external perimeter of ring 11 or 15a/18 respectively.
Similarly, the exact shape and arrangement of the members can change according to specific manufacturing needs as long as their functional relationship is maintained, and some members could be integrated into a single piece. For example, shaft 3, 3' could be formed directly on sprinkler 1, 1' or gear 7, 7' and rod 9, 9' could be obtained as a single monolithic body. Furthermore, the rotation axes X, X' and Y, Y' could be not exactly parallel as long as the alignment is maintained between axis X, X' and rod 9, 9' and the latter is perpendicular to the plane of the toothed crown 8, 8'.

Claims

Revolving sprinkling assembly for dishwasher comprising a rotating sprinkler (1; 1'), provided with wash and/or propulsion nozzles (1a, 1b; 1a' 1b'), which is mounted on a socket (2; 2') arranged at the outlet of a water supply duct, characterized in that said sprinkler (1; 1') is mounted on said socket (2; 2') through an eccentric connector (4; 4') having a water inlet (5a; 5a') that is out of axis with respect to a water outlet (6a; 6a'), the sprinkler (1; 1') being rotatably mounted on said eccentric connector (4; 4') so as to rotate around an axis (X; X') coaxial with said water outlet (6a; 6a') and the eccentric connector (4; 4') being in turn rotatably mounted on the socket (2; 2') so as to rotate around an axis (Y; Y') coaxial with said water inlet (5a; 5a'), and further characterized in that it includes a gear (7; 7') coaxial with the rotation axis (X; X') of the sprinkler and driven into rotation by the latter, said gear (7; 7') engaging a fixed toothed crown (8; 8') coaxial with said socket (2; 2').
Sprinkling assembly according to claim 1, characterized in that the coaxial gear (7) is secured at the bottom end of a vertical rod (9), aligned with the rotation axis (X) of the sprinkler (1), which passes through the eccentric connector (4).
Sprinkling assembly according to claim 2, characterized in that the toothed crown (8) is formed along the internal perimeter of a ring (11) arranged coaxial with the socket (2) and secured through legs (12).
Sprinkling assembly according to any of the preceding claims, characterized in that the eccentric connector (4) is provided in a bottom portion (5) thereof with resilient hooks (5b) suitable to engage a peripheral rib (2a) formed close to the top of the socket (2), and is provided in a top portion (6) thereof with a peripheral rib (6b) similar to said peripheral rib (2a).
Sprinkling assembly according to claim 1, characterized in that the coaxial gear (7') is secured at the top end of a vertical rod (9'), aligned with the rotation axis (X') of the sprinkler (1'), which passes through the eccentric connector (4').
Sprinkling assembly according to claim 5, characterized in that the toothed crown (8') is formed along the internal perimeter of an external ring (15a) of a ring nut (15) used for mounting the eccentric connector (4') on the socket (2').
Sprinkling assembly according to claim 5, characterized in that the eccentric connector (4') is mounted on the socket (2') through a hollow shaft (19) provided with side openings (19a) and a closed bottom (19b), said hollow shaft (19) being inserted through the eccentric connector (4') so that its top projects from the water inlet (5a') in order to internally engage the socket (2') while said closed bottom (19b) abuts on the eccentric connector (4').
Sprinkling assembly according to claim 7, characterized in that the toothed crown (8') is formed along the internal perimeter of a ring (18) formed in a single piece with the socket (2').
Sprinkling assembly according to any of claims 5 to 8, characterized in that the vertical rod (9') is inserted in the vertical leg of an inverted-T joint (10') that is driven into rotation by the sprinkler (1') through projections (3a') that engage the horizontal arm of said joint (10').
Sprinkling assembly according to any of the preceding claims, characterized in that the transmission ratio between the gear (7; 7') and the toothed crown (8; 8') is comprised in a range from 5:1 to 20:1, being preferably 10:1.