Device to open the lid of a washing-up machine such as a dish-washer, a pan-washer or similar

Abstract: Device (10) to open the lid (11) of a washing-up machine (12), such as a dish-washer, a pan-washer or similar, wherein said lid (11) is movable vertically from a closed position to an open position and vice versa, by means of gripper means (14) which can be activated manually and are connected to the movable element (24) of a fluido-dynamic actuator (25), elastic return means (30) being associated with the movable element (24) of said fluido-dynamic actuator (25) to take it automatically to an inactive position when said lid (11) is in the open position.

Description: FIELD OF THE INVENTION This invention concerns a device able to open and close the lid of a washing-up machine, such as a dish-washer, a pan-washer or similar. BACKGROUND OF THE INVENTION The state of the art includes washing-up machines comprising a base frame, which houses the functional equipment of the machine, closed at the upper part by a lid defining with the base frame the washing compartment of the machine. The base lid is normally parallelepiped in shape and is able to be moved vertically, from a lowered, closed position to a raised, open position, by means of a handle hinged on the base frame. State-of-the-art washing-up machines, as known for example from EP-A-0,629,375, are provided with a device able to facilitate the raising of the lid, normally comprising a hydraulic piston associated with the lid handle, which is also connected to compensation springs. Activating the piston does facilitate the raising of the lid, but at the same time makes it difficult for the operator to lower the lid since, in order to close the lid manually, he is obliged to overcome the resistance of the fluid which feeds the piston itself. The present Applicant has devised and embodied this invention to overcome this shortcoming and to obtain further advantages. SUMMARY OF THE INVENTION The invention is set forth and characterized in the main claim, while the dependent claims describe other characteristics of the invention. The purpose of the invention is to achieve a device which will allow an easy and practical manual movement of the lid of washing-up machines, reducing to a minimum the effort required by those working said machines. To be more exact, the invention proposes to make the operation easier for the operator when he has to manually lower the lid of the washing-up machine which is provided with a fluido-dynamic piston able to raise said lid. The device according to the invention comprises further elastic return means connected with the movable element of the fluid-dynamic actuator in order to automatically take said outwater to the inactive position when the lid is in the open position. In the inactive position, the fluid feeding the fluid-dynamic piston is completely discharged therefrom, so that when the lid is manually lowered the operator has to overcome only the resistance of said elastic means and not that of the fluid in the piston. It is therefore extremely easy and practical to lower the lid, and requires a minimum effort from the operator who has to carry it out. Moreover, should there be any malfunctioning of the fluid-dynamic piston, or a failure of the electric energy or a lack of feeding fluid, and therefore should it not be possible to automatically raise the lid, the lifting operation can be carried out in a completely manual fashion, with minimum effort on the part of the operator. BRIEF DESCRIPTION OF THE DRAWINGS These and other characteristics of the invention will become clear from the following description of a preferential form of embodiment, given as a non-restrictive example, with reference to the attached drawings wherein: Fig. 1 is a front view of a washing-up machine on which the device to open the lid according to the invention is mounted; Fig. 2 is a side view of the washing-up machine shown in Fig. 1 with the lid in the raised position; Fig. 3 is a schematic front view of the device to open the lid according to the invention; Fig. 4 is a section of a first detail of the washing-up machine shown in Fig. 1; Figs. 5, 6 and 7 show a second detail of the device according to the invention in three different operating conditions; Figs. 8, 9 and 10 show schematically three possible feed circuits of the fluid-dynamic piston of the device according to the invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENT With reference to the attached drawings, a device 10 according to the invention is associated with the lid 11 of a washing-up machine 12, which can be a dish-washer, a pan-washer or similar; the device 10 allows the lid 11 to be moved from a first closed position, or lowered position (Fig. 1), to a second open position, or raised position (Fig. 2), with respect to a base frame 13 of the washing-up machine 12. To be more exact, the device 10 is associated with a handle 14 of the lid 11 by means of which the latter is able to be moved vertically from one said position to the other. The handle 14 is laterally hinged, by means of a bar 20, to a rear part 15 of the base frame 13, inside which the device 10 is housed. The handle 14 is able to assume a lowered or raised position respectively in the closed or open position of the lid 11. In the preferential embodiment shown here, the device 10 comprises a pair of rods 16, substantially vertical, constrained at the upper part inside holes 18 of a mating pair of fins 17 keyed onto the handle 14 inside the rear part 15. The rods 16 are attached at the lower part to pins 19 fixed in a central position on respective levers 21a, 21b. Each lever 21a, 21b is hinged at one end to the rear part 15 and at the other end it is constrained to a respective compensation spring 22 which is in turn fixed to the rear part 15 and which, when the lid 11 is in the closed position, is loaded, that is, under tension. The lever 21b is constrained at the lower part to a tubular profile 23 inside which the shaft 24 of a hydraulic piston 25 is able to slide; the cylinder 26 of the hydraulic piston 25 is constrained to the rear part 15. The tubular profile 23 is provided with a pair of longitudinal eyelets 27 arranged in a diametrically opposite position and being substantially equivalent in length to the travel of the hydraulic piston 25. Above the longitudinal eyelets 27, and in alignment therewith, the tubular profile 23 has a first pair of respective pins 28 protruding towards the outside. The shaft 24 is provided with a second pair of pins 29, each of which is aligned with a mating pin 28 and is inserted inside a respective longitudinal eyelet 27 along which it is able to move. Therefore, when in a condition of abutment against the ends of the longitudinal eyelets 27, the pins 29 define the end-of-travel positions of the shaft 24 of the hydraulic piston 25. Each pin 29 is also connected to the mating pin 28 of the tubular profile 23 by means of a respective return spring 30. The hydraulic piston 25 is fed by means of a circuit 33 provided for this purpose which can have various configurations, some examples of which are shown schematically in Figs. 8, 9 and 10. In the embodiment shown in Fig. 8, the hydraulic piston 25 is fed with water taken by a pump 34 from a tank 31 provided for this purpose and mounted on the washing-up machine 12. In this embodiment, the water discharged from the cylinder 26 is sent again to the tank 31 which is advantageously provided with filling means able to automatically restore the level of the water in the tank 31 in the event of evaporation. In the embodiment shown in Fig. 9, the circuit 33 comprises downstream of the pump 34 a first electrovalve 35 and, downstream of this, a discharge conduit 37 provided with a second electrovalve 36. In this case, when the hydraulic piston 25 is fed, the first electrovalve 35 is kept open and the second electrovalve 36 is kept closed, so that the water, taken from the tank 31, is sent inside the cylinder 26. The water is discharged by closing the first electrovalve 35 and opening the second electrovalve 36, so as to make the water flow away through the discharge conduit 37, for example to a container containing the washing water of the washing-up machine 12. In a preferential embodiment of the invention, the water discharged from the hydraulic piston 25 is sent back to the tank 31, passing through the pump 34 in the case of Fig. 8 or through the discharge conduit 37 in the case of Fig. 9, so that the same water can be re-used to subsequently feed the hydraulic piston 25. The circuit 33 is therefore of the closed type and gives a considerable saving in the feed water, at the same time preventing the entry of impurities and dirt from the source of feed. In the embodiment shown in Fig. 10, the circuit 33 is configured in a similar manner to the circuit 33 shown in Fig. 9, since it has the two electrovalves 35 and 36 and the discharge conduit 37. In this case however, it is supposed that the water supplied from the water supply has enough pressure to feed the hydraulic piston 25 and therefore the water is taken directly from the pipes of the water plant 32 by activating the electrovalves 35 and 36 in an appropriate manner and without the aid of pump means. The device 10 according to the invention functions as follows: At the end of the rinsing cycle of the washing-up machine 12, the hydraulic piston 25 is partly fed, by activating the pump 34 or the electrovalves 35 and 36 in an appropriate manner, thus causing a mating lowering of the shaft 24. During this step the lid 11 is raised slightly, allowing the steam to be discharged from inside the washing-up machine 12. After a few seconds, the hydraulic piston 25 is activated in such a manner as to take the shaft 24 to the completely lowered position (Fig. 5), causing the return springs 30 to be tensed and the lid 11 to be completely raised to the open position. This lifting operation, which can optionally be accompanied by a manual action on the handle 14 by the operator, therefore requires a minimum or nil effort on his part, and occurs gradually thanks to the compensation springs 22 and the return springs 30 which balance the weight of the lid 11. Moreover, should there be any anomalies in the functioning of the hydraulic piston 25, or a lack of water feeding said hydraulic piston 25, or a failure of electric energy, the lid 11 can easily be raised in a completely manual fashion, by using the handle 14. When the lid 11 is completely open, or raised, feed to the hydraulic piston 25 is interrupted and the return springs 30 raise the shaft 24 by means of the pins 29, until the latter abut against the upper end of the longitudinal eyelets 27 (Fig. 6). As the shaft 24 is raised, this also causes the water inside the cylinder 26 to be discharged through the discharge conduit 37. When the shaft 24 has been completely raised, the return springs 30 are released. To close the lid 11, the operator has to lower the handle 14 to take it to the position shown by a line of dashes in Figs. 2 and 4. In this step, the rotation of the bar 20 in a clock-wise direction (Fig.4) causes the rods 16 to be raised and then the levers 21a and 21b to rotate upwards (Fig. 3) and the compensation springs 22 to be tensed. The tubular profile 23, constrained to the lever 21b, is also raised, causing the return springs 30 to be tensed by means of the pins 28 (Fig. 7). On the contrary, the shaft 24 is already in its most raised position, that is, in its position of maximum extraction from the cylinder 26, and cannot follow the movement of the tubular profile 23; therefore it retains the return springs 30 at the lower part by means of the pins 29. It is therefore much easier to close the lid 11, since the operator as he lowers the handle 14 has to overcome only the resistance of the return springs 30, and not that of the water feeding the hydraulic piston 25 as he would if the shaft 24 of the latter were still in the lowered position. However, modifications and/or additions may be made to the device 10 as described heretofore, but these shall remain within the field and scope of the invention. For example the piston 25 may be fed with a different fluid other than water, such as for example oil or a mixture of water and soluble oil.

Claims: Device (10) to open the lid (11) of a washing-up machine (12), such as a dish-washer, a pan-washer or similar, wherein said lid (11) is movable vertically from a closed position to an open position and vice versa, by means of gripper means (14) which can be activated manually and is connected to a movable element (24) of a fluid-dynamic actuator (25), the device being characterized in that further elastic return means (30) are connected with the movable element (24) of said fluid-dynamic actuator (25) in order to automatically take said actuator to an inactive position when said lid (11) is in the open position. Device as in Claim 1, characterized in that as said movable element (24) moves into said inactive position it causes the feed fluid to be discharged from said fluid-dynamic actuator (25). Device as in Claim 1, characterized in that said movable element (24) in said inactive position is in a condition of maximum extraction with respect to the fixed element (26) of said fluid-dynamic actuator (25). Device as in Claim 1, characterized in that said movable element (24) is arranged coaxially inside a tubular element (23) connected at one end to said gripper means (14) and provided with constraining means (28) for said elastic return means (30). Device as in Claim 4, characterized in that said tubular element (23) is provided with at least a longitudinal eyelet (27) inside which pin means (29) of said movable element (24) are able to slide, in correspondence with which pin means (29) said elastic return means (30) are associated. Device as in Claim 4, characterized in that said tubular element (23) is associated with said gripper means (14) by means of lever means (21b) hinged to a fixed structure (15) of said washing-up machine (12). Device as in Claim 6, characterized in that said lever means (21b) are associated with at least a compensation spring (22) constrained to said fixed structure (15). Device as in Claim 7, characterized in that said compensation spring (22) is able to balance the weight of said lid (11) during the movement thereof. Device as in Claim 5, characterized in that said tubular element (23) is provided with two longitudinal eyelets (27), parallel and opposite each other, inside which respective pin means (29) of said movable element (24) are able to slide, and in that the elastic return means of said pin means (29) consist of a pair of springs (30) mounted parallel to said tubular element (23). Device as in Claim 1, characterized in that said fluid-dynamic actuator (25) is able to take said lid (11) to said open position in two steps, so that in a first step said lid (11) is slightly raised, to allow the steam to be discharged from the washing-up machine (12), and in a second step it is completely raised. Device as in Claim 1, wherein said fluid-dynamic actuator (25) is fed with water, characterized in that the circuit (33) feeding said fluid-dynamic actuator (25) comprises interception means which on activation allow to take said water from a source of supply. Device as in Claim 11, characterized in that said interception means comprise at least a pump (34). Device as in Claim 11, characterized in that said interception means comprise at least an electrovalve (35). Device as in Claim 11, characterized in that said source of supply comprises at least a water accumulation tank (31). Device as in Claim 14, characterized in that said tank (31) is associated with automatic filling means. Device as in Claims 11 and 14, characterized in that said circuit (33) is a closed circuit so that the water feeding said fluid-dynamic actuator (25), once discharged therefrom, is sent back to said tank (31). Device as in Claim 11, characterized in that said source of supply consists of a pipe of the water supply plant (32). Device as in Claim 11, characterized in that said circuit (33) comprises a discharge conduit (37) to discharge the water from said fluid-dynamic actuator (25). Device as in Claim 18, characterized in that said discharge conduit (37) is able to convey said water to an accumulation container for the washing water of said washing-up machine (12). Device as in Claims 16 and 18, characterized in that said discharge conduit (37) is connected to said tank (31). Device as in Claim 18, characterized in that said discharge conduit (37) is provided with its own interception means (36).

Inventors: ZARDINI FABIO, ZARDINI, FABIO
Applicants: DIHR SPA
Application year: 2000
Main classification: A47L15
IPC codes: A47L15