EP3021730B1

EP3021730B1 - Combined washing and rinsing device and dishwashing machine provided therewith

Info

Publication number: EP3021730B1
Application number: EP14747776.4A
Authority: EP
Inventors: Luca Montagnana; Norberto CEVOLONI; Riccardo ORLANDI
Original assignee: Premark FEG LLC
Current assignee: Premark FEG LLC
Priority date: 2013-07-19
Filing date: 2014-07-17
Publication date: 2017-09-06
Anticipated expiration: 2034-07-17
Also published as: ES2647453T3; EP3021730A1; ITTO20130614A1; WO2015009916A1

Description

The present invention relates to a low-cost, small-sized combined washing and rinsing device. The invention further relates to a dishwashing machine including such a device.
Dishwashing machines, in particular those for professional use (in communities, hotels, restaurants etc.), are usually provided with a washing tank provided with a pair of coaxial rotating arms, a first one for dispensing the washing liquid (water and detergent) and the second for dispensing the rinsing liquid (water). Such a solution is illustrated in figure 1, in which reference numeral 1 is a washing tank of a dishwashing machine 1b (illustrated only in part for the sake of simplicity); the washing tank 1 is provided with filters 2, a washing arm 3 and a rinsing arm 4, mounted coaxial and overlapping each other over two coaxial dispensing pipes 5,6, which lead into the chamber 1.
As immediately apparent, such an arrangement, even if satisfactory, has a large size, in particular in the direction of a rotation axis A of the arms. Furthermore, it has relatively high construction and assembly costs.
In order to further reduce dimensions, it has been attempted to make a combined washing and rinsing device based on a single arm, which however, in actual fact, consisted of two arms arranged side-by-side (instead of overlapped) and joined to each other, provided with a common hub intended to couple to the two dispensing pipes. However, such a solution has proved to be complex and costly to make, and in all cases, is large-sized, in particular at the hub. Devices according to EP2522268 , JP2000157478 and WO2001/132358 do not solve these drawbacks.
It is the object of the invention to supply a combined washing and rinsing device which is free from the described drawbacks, and which is, in particular, easy and cost-effective to make, very efficient, reliable and small-sized.
According to the invention, a combined washing and rinsing device is thus supplied, as defined in claim 1.
In particular, the combined washing and rinsing device comprises: a single arm, delimited on the outside by a first face equipped with a plurality of first, washing nozzles and with a plurality of second, rinsing nozzles, which are arranged aligned with each other, the first nozzles to form at least a first row in a longitudinal direction of extension of the arm and the second nozzles to form at least a second row in said longitudinal direction; a hub carried by a second face of the arm opposite to the first, and arranged substantially on the center-line of the arm, which rotates, in use, on the hub, about a symmetry axis of the hub; and a double hydraulic delivery circuit defined by the arm for separately supplying the first and the second nozzles.
According to one of the main features of the invention, the arm is defined by an internally hollow body formed by a first and by a second half shell coupled to overlap each other at the part of the respective concavities thereof, the first half shell delimiting the first face on the part opposite to the concavity thereof, and the second half shell delimiting the second face, on the part opposite to the concavity thereof; while the double hydraulic delivery circuit is obtained inside the second half shell by means of a longitudinal rib which overhangs inside the concavity of the second half shell and which couples in a fluid sealing manner with the first half shell to form, inside the arm, a first and a second chamber, which are separate from each other, into which the first and the second nozzles lead, respectively.
The two half shells are fixed to each other in a fluid sealing manner. Preferably, the half shells are obtained by molding of a synthetic plastic material and fixed to each other by vibration welding.
In this manner, a small-sized integrated device, formed by a very limited number elements (two), which is easy to manufacture, is made.
The nozzles are arranged preferably inclined with respect to a plane perpendicular to the symmetry axis of the hub and to the rotation axis of the single arm.
The invention finally relates to a dishwashing machine provided with the aforesaid combined washing and rinsing device.
Further objects and advantages of the invention will be apparent from the description that follows of a non-limitative embodiment thereof, given only by way of example, set forth with reference to the accompanying drawings, in which:

figure 1 shows a washing and rinsing device for a dishwashing machine according to the prior art;
figure 2 shows a perspective, exploded view of a combined washing and rinsing device for a dishwashing machine according to the present invention;
figure 3 shows a plan view from the top on a slightly enlarged scale of the combined washing and rinsing device in figure 2;
figures 4, 5 and 6 show respective sectional views, figures 5 and 6 on enlarged scale, of the combined washing and rinsing device in figure 3, taken along plotting planes IV-IV, V-V and VI-VI, respectively; and
figure 7 shows, again on an enlarged scale, a perspective, three-quarters view from the bottom and sectioned as in figure 5 of the combined washing and rinsing device according to the invention, with parts removed for the sake of clarity.

With reference to figures from 2 to 7, reference number 10 indicates as a whole a combined washing and rinsing device for a dishwashing machine, such as the known professional dishwashing machine 1b in figure 1; in particular, the device 10 can be mounted in use on the dispensing pipes 5,6, as explained below, to replace the two arms 3 and 4.
According to the main aspect of the invention, the device 10 comprises a single arm 11, shown in exploded configuration in figure 2, delimited on the outside by a first face 12 provided with a plurality (a first group) of first washing nozzles 13 and a plurality (a second group) of rinsing nozzles 14; a hub 15 carried by a second face 16 of the arm 11 opposite to first face 12, and arranged substantially on the center-line of the arm 11; and a double hydraulic circuit 17 (figure 2) for dispensing operative fluids of the dishwasher 1b, defined by the arm 11 and by the hub 15, and adapted to separately supply the group of nozzles 13 and the group of nozzles 14, respectively.
The arm 11 rotates in use on the hub 15, about a symmetry axis A of the hub, as described more in detail below.
The nozzles 13 and 14 of each group are generally arranged aligned with one another. In the illustrated example, the first nozzles 13 are aligned to form, in a longitudinal direction of extension of the arm 11 (figure 3), at least a first row F1 of nozzles 13, while the second nozzles 14 are aligned to form in the same longitudinal direction D at least a second row F2 of nozzles 14.
According to a first aspect of the invention, the arm 11 is defined by a flat, internally hollow "biscuit-shaped" body, formed by a first half shell 18 and by a second half shell 19 coupled to each other to overlap at the side of their respective concavities 20 and 21, respectively.
The first half shell 18 delimits the first face 12 on the part opposite to its concavity 20 and the second half shell 19 delimits the second face 16 on the part opposite to concavity 21.
In combination with this conformation of the single arm 11, the double hydraulic circuit 17 is obtained within the second half shell 19 by means of a longitudinal rib 22 which overhangs inside the concavity 21 of the half shell 19 and which couples in a fluid sealing manner with the half shell 18 to form inside the arm 11 a first chamber 23 and a second chamber 24, reciprocally separate, to which the first nozzles 13 (in chamber 23) and the second nozzles 14 (in chamber 24) are lead.
Furthermore, the half shells 18,19 are fixed integrally to each other in a fluid sealing manner. In the illustrated example, the half shells 18 and 19 are obtained by molding of synthetic plastic material, are mechanically coupled by means of teeth 25 and are reciprocally welded in a fluid sealing manner along respective edges 26 and 27 delimiting the concavity 20 and 21 for the entire extension thereof and along the entire rib 22, which is coupled to a ridge 28 inside the half shell 18, which longitudinally extends for the entire length of the half shell 18. The integral, fluid sealing union per welding is obtained in any appropriate known manner adapted for synthetic plastic material, e.g. by ultrasound welding or preferably by vibration welding.
According to a further aspect of the invention, the hub 15 is obtained solely and integrally in one piece with the second half shell 19 and is formed (figure 7) by a first sleeve 29 and by a second sleeve 30 arranged coaxial with respect to axis A and having a different axial extension with respect to each other on the side of second face 16. In particular, the sleeve 29 is arranged radially outside and has, on the side of the face 16, an axial extension, which is greater than that, on the same part, of the sleeve 30, which is arranged instead radially on the inside, partially within the sleeve 29. Furthermore, the two coaxial sleeves 29 and 30 are shaped (by appropriately selecting their diameters, axial lengths and reciprocal positions) so as to be adapted in use to couple in idle, substantially fluid sealed manner with the traditional dispensing pipes 5 and 6 of a known dishwashing machine 1b, like the one in figure 1, so that the single arm 11 may be easily mounted in use, in rotating manner, on the pipes 5 and 6, instead of the two traditional arms 3 and 4.
The fact that the entire hub 15, i.e. both its sleeves 29 and 30, are obtained entirely integral in one piece with the half shell 19 allows to ensure the dimensional constancy and accuracy necessary to allow, in use, the later coupling with the two pipes 5 and 6, and to avoid the formation of undercuts, so that the half shell 19 may be molded in one step, without using molds with moveable parts, which considerably reduces the cost.
The sleeve 29 is not only arranged radially outside the sleeve 30, but it also integrally supports the sleeve 30 by means of one pair of diametrically opposite spokes 31 (figures 4 and 7), which delimit between the sleeves 29 and 30 and through the second half shell 19, in an empty radial space delimited between the sleeves 29 and 30, a pair of circumferentially extending axial through access apertures 32 to chamber 23.
According to the non-limiting, preferred illustrated embodiment, the arm 11 has, in the longitudinal direction D, a central section or part 33 provided with the hub 15 and, in a plan view, namely on a plane perpendicular to the symmetry axis A of the hub 15, is S-shaped (in a plan view from the bottom, i.e. on the side of face 16), in other words is shaped as an upside down S (in a plan view from the top, i.e. on the side of face 12).
Furthermore, the arm 11 has, again in the longitudinal direction D, a first section or peripheral part 34 and a second section or peripheral part 35 opposite to section 34, which sections 34 and 35 radially overhangingly protrude from the central section 33 in eccentric and diametrically opposite positions with respect to the symmetry axis of the hub 15.
The two peripheral sections 34 and 35 are provided with nozzles 13 and 14, while the central section 33 is nozzle-free and operates as supporting part to allow, as explained below, the hydraulic connection between the chambers 23,24 and the hub 15.
In particular, because of the S-shape of the central section or part 33, the chamber 23, despite extending for the entire length of the arm 11 in direction D and through the hub 15, is divided by the hub 15 and the rib 22 into two sections 23b and 23c (figure 2), opposite to each other and radially staggered but communicating, the chamber section 23b extending along the first section 34 of the arm 11 and the chamber section 23c extending along the second peripheral section 35 of the arm 11, respectively; the two chamber sections 23b and 23c are accessible through the hub 15, in particular through the respective axial through apertures 32 delimited between the sleeves 29 and 30, and in the case in point through the second half shell 19 at respective curvilinear stretches 36 of the central section 33.
Vice versa, the chamber 24 is a rectilinear chamber which extends through the hub 15, in particular, as explained below, through the sleeve 30, for the entire length of the arm 11 and along the two peripheral sections 34 and 35, parallel to and by the side of the sections 23b and 23c of the chamber 23.
Consequently, in the illustrated arm 11, the nozzles 14 are aligned along a same row F2 which extends on both the peripheral sections 34 and 35, while the nozzles 13 are aligned along the row F1, which extends only along the first section 34 and along a third row F3 which extends only along the second peripheral section 35 and which is parallel but unaligned with respect to row F1.
The spokes 31 are internally hollow and hydraulically connect, from opposite sides, the chamber 24 to the inside of the sleeve 30, through respective radial through apertures 37 obtained through the sleeve 30 at the spokes 31.
The chamber 24 is consequently delimited between the sleeve 29, the longitudinal rib 22 and at least one side wall of the half shell 19, in the case in point between a portion of a side wall 38 of the half shell 19, alongside section 34 and a portion of a side wall 39 of the half shell 19, opposite to wall 38, alongside section 35. The chamber 23 is instead delimited between the sleeve 29, the rib 22, the curvilinear stretches 36 of the central section 33 and respective portions of the side walls 38 and 39, section 35 alongside wall 38 and section 34 alongside wall 39, respectively.
According to a further aspect of the invention, the nozzles 13 and 14 are obtained integral in one piece with the first half shell 18, which is formed by molding, so as not to define any undercuts in axial direction i.e. a direction parallel to axis A. Furthermore, the nozzles 13 and 14 are arranged oblique with respect to a plane perpendicular to the symmetry axis A of the hub 15 and rotation axis in use of the single arm 11, so as to determine, in use, a propulsive impulse which determines the rotation of the single arm on the hub by virtue of the dispensing of a service washing fluid from the nozzles 13 and of the dispensing of a service rinsing fluid from the nozzles 14. In particular, the nozzles 13 are inclined with respect to the perpendicular P to the plane perpendicular to the axis A by an angle α1, while the nozzles 14 are inclined with respect to the perpendicular P to the plane perpendicular to the axis A by an angle α2 which is different from the previous angle, so as to compensate for the different flow rates which may be emitted by the nozzles 14 with respect to the nozzles 13 and vice versa.
Finally, according to the description above, it is apparent that the invention also relates to a professional dishwashing machine, like the dishwashing machine 1b in figure 1 but comprising a combined washing and rinsing device 10 as described above, in particular formed by a single "mixed" arm 11 which replaces and substitutes the traditional separate arms 3 and 4, in which the hub 15 is formed by the sleeves 29 and 30 arranged coaxial and having a mutually different extension, the sleeve 29 being coupled in a fluid sealing manner to the pipe 5 and the sleeve 30 being coupled in a fluid sealing manner to the washing and rinsing operative fluid feeding pipe 6, respectively, also arranged coaxial to each other, so as to support the single arm 11 in idle manner on at least of one (or both) of the pipes 5 and 6.
By virtue of the invention, the single arm 11 may also be adapted to existing dishwashing machines and, in all cases, an extremely compact combined washing and rinsing system is obtained, which is easy and cost-effective to make and mount, is completely reliable and which does not even need the propulsive nozzles usually present on the traditional arms.
All the objects of the invention are thus reached.

Claims

A combined washing and rinsing device (10) for a dishwashing machine (1b), in particular for a professional dishwashing machine, comprising a single arm (11) delimited on the outside by a first face (12) equipped with a plurality of first, washing, nozzles (13), and with a plurality of second, rinsing, nozzles (14), which are arranged at least partly aligned with each other, the first nozzles (13) to form at least a first row (F1) in a longitudinal direction (D) of extension of the arm (11) and the second nozzles (14) to form at least a second row (F2) in said longitudinal direction (D); a hub (15) carried by a second face (16) of the arm opposite to the first, and arranged substantially on the center-line of the arm (11), which is, in use, rotating on the hub (15), about a symmetry axis (A) of the hub; and a double hydraulic delivery circuit (17) defined by the arm (11) for separately supplying the first and the second nozzles; wherein:
i) - the arm (11) consists of an internally hollow body formed by a first (18) and by a second (19) half shell coupled to overlap each over at the part of the respective concavities (20, 21) thereof, the first half shell (18) delimiting, on the part opposite to the concavity (20) thereof, the first face (12) and the second half shell (19) delimiting, on the part opposite to the concavity (21) thereof, the second face (16);

ii) - the double hydraulic delivery circuit (17) is obtained inside the second half shell (19) by means of a longitudinal rib (22) which overhangs inside the concavity (21) of the second half shell (19) and which couples in a fluid sealing manner with the first half shell (18) to form, inside the arm (11), a first (23) and a second (24) chamber, which are separate from each other, into which the first (13) and the second (14) nozzles, respectively, are lead;

iii) - the first and second half shell (18, 19) are integrally fastened to each other in a fluid sealing manner; and wherein the hub (15) is obtained only and completely integral in one piece with the second half shell (19) and is formed by a first (29) and a second (30) sleeve, which are arranged coaxial and having, at the part of the second face (16), an axial extension which is different with respect to each other; characterized in that
the first sleeve (29) is arranged radially on the outside of the second sleeve (30) and integrally supports the second sleeve (30) by means of at least one pair of diametrically opposite spokes (31), which delimit, between the first and the second sleeve (29, 30), in the second half shell (19), a pair of circumferentially extending axial through apertures (32), for access to the first chamber (23).
A device according to claim 1, characterized in that said spokes (31) are internally hollow and hydraulically connect, on opposite sides, the second chamber (24) with the inside of the second sleeve (30), by means of respective radially through apertures (37) obtained through the second sleeve (30), at the spokes (31); the second chamber (24) being delimited between the first sleeve (29), said longitudinal rib (22) and at least one outer lateral wall (38; 39) of the second half shell (19).
A device according to any one of the preceding claims, characterized in that the hollow body defining the arm (11) has: an S-shaped central section (33) in plan, that is in a plan perpendicular to the symmetry axis (A) of the hub, and provided with said hub (15); and a first (34) and a second (35) peripheral section, which radially protrude overhangingly from the central section (33) in eccentric and diametrically opposite positions with respect to the symmetry axis (A) of the hub, the peripheral sections (34, 35) being equipped with said first and second nozzles (13, 14).
A device according to claim 3, characterized in that the second nozzles (14) are all aligned along a same second row (F2) which extends on both peripheral sections (34, 35), while the first nozzles (13) are aligned along a first row (F1) which extends on the first (34) of the peripheral sections and along a third row (F3) which extends on the second (35) of the peripheral sections and which is unaligned with respect to the first row (F1).
A device according to claim 3 or 4, characterized in that the first chamber (23) is divided, by the hub (15), into two sections (23b, 23c) which are opposite to each other and radially staggered and extend along the first (34) and the second (35) of the peripheral sections, respectively, and which are accessible through respective axial through apertures (32) made through the second half shell (19) at respective curvilinear stretches (36) of the central section (33).
A device according to any one of the preceding claims, characterized in that the first and second nozzles (13, 14) are obtained integral in one piece with the first half shell (18), which has been formed by moulding, so as to not define any undercut in axial direction.
A device according to any one of the preceding claims, characterized in that the said first and second nozzles (13, 14) are arranged oblique with respect to a plane perpendicular to the symmetry axis (A) of the hub and axis of rotation of the only arm (11), so as to determine, in use, a propulsive impulse which determines the rotation of the only arm (11) on the hub (15).
A professional dishwashing machine (1b), characterized in that it comprises a combined washing and rinsing device (10) according to any one of the preceding claims wherein the hub (15) is formed by a first and a second sleeve (29, 30) arranged coaxial and having a different axial extension with respect to each other, which are coupled in a fluid sealing manner to a first (5) and second (6) pipe for feeding washing and rinsing operating fluid, respectively, also arranged coaxial to each other, so as to idly support the only arm (11) on at least one of said pipes (5, 6).