Improved dishwasher operation cycle and dishwasher carrying out said cycle

Abstract: An operation cycle for dishwashers provided with a start timer (T) includes the steps of: a) setting through the timer (T) a delay in the start of the washing cycle; b) loading the water in the tank; c) running the washing pump for some minutes; d) waiting with the water in the tank until the time of starting the washing cycle is reached; e) carrying out the washing cycle. A dishwasher provided with a start timer (T), a programmer (P) for selecting the washing cycle, a washing pump (L) and a draining pump (S), also includes means for detecting the setting of a start delay through said timer (T) and consequently activate the washing pump (L) for some minutes while deactivating the draining pump (S) until the set time of starting the washing cycle is reached.

Description: The present invention relates to dishwashing machines, and in particular to a dishwasher cycle suitable to achieve better washing results and to reduce the water consumption. It is known that several models of dishwasher include a so-called "soaking" cycle in which the machine loads water, the washing pump runs for some minutes and then the draining pump drains the water out of the tank. The soaking achieved through such a short cycle prevents the dirt from drying on the dishes, whereby it is easier to clean them when the complete cycle is performed (see, e.g., EP 0 725 181A). This cycle is therefore advisable when the load of dishes is insufficient to start the dishwasher for a complete cycle. In fact, in this case the dirty dishes will stay in the machine for some hours before being washed, until the next meal when the machine load will be completed. It is also possible that the user wishes to delay the start of the washing cycle even if the machine is fully loaded. This may be useful to prevent overlapping of operation with other domestic appliances, or to use the machine during a low fare period in case there are different fares for low and high consumption periods. In this case, the cycle start delay is set through a timer which will start the machine at the desired time. Though the soaking allows to achieve good washing results, there are two types of drawback. A first drawback is a greater water consumption since when the washing is carried out the cycle starts from the beginning regardless of the soaking cycle having been previously carried out or not. Therefore all the water consumption during the soaking cycle is an additional consumption. A second drawback stems from the fact that the soaking cycle must be programmed by the user separately from the complete washing cycle, the latter being delayed or not. In other words, if the user forgets to set the soaking cycle after loading the machine, the washing result will not be completely satisfactory. Therefore the object of the present invention is to provide an operation cycle and a dishwasher which overcome the above-mentioned drawbacks. This object is achieved by means of a cycle including the operation steps disclosed in claim 1 and of a dishwasher having the features disclosed in claim 2. The first advantage of the present cycle is to prevent any additional water consumption when the soaking cycle is carried out. The second advantage of this operation cycle is that it does not require a separate setting of the soaking cycle when the user sets a start delay for a delayed cycle. This assures a good washing result and saves the user the effort to remember the need for a double setting. These and other advantages and characteristics of the cycle and dishwasher according to the present invention will be clear to those skilled in the art from the following detailed description of an embodiment thereof, with reference to the only drawing, annexed as fig.1, wherein there is illustrated a diagram of the device of the dishwasher carrying out the cycle. With reference to said figure, there is seen that a device of the dishwasher according to the invention includes a timer T, a programmer P, a washing pump L and a draining pump S. The programmer P controls as usual the pumps L and S in order to carry out the various steps of the washing cycle, and the timer T in turn controls the activation of the programmer P when a start delay is set. Unlike prior art machines, in this case the timer T also directly controls the pumps L and S. In this way, when the timer T is activated to delay the cycle start, not only does it provide the deactivation of the programmer P until the desired time is reached but also immediately intervenes on the pumps. In particular, the washing pump L is run for some minutes in order to load the water in the tank and carry out the soaking, whereas the draining pump S is kept deactivated. Consequently, at the end of the soaking cycle the machine stops with the water in the tank, ready for the complete washing cycle at the preset time. However, since the tank is already filled with water, when the complete cycle is started there is no additional water loading but the soaking water is re-used. In this way there is achieved the object of reducing the water consumption, and the soaking is automatically carried out by the machine when a start delay is set through the timer T. It is clear that the above-described and illustrated embodiment of the device according to the invention is just an example susceptible of various modifications. In particular, instead of directly connecting the timer T to the pumps it is possible to set it so that it has the programmer P carry out the soaking cycle as soon as the start delay is set. Clearly also in this case the water is not drained out at the end of the soaking cycle and the programmer P is then deactivated until the desired time for carrying out the complete washing cycle is reached.

Claims: An operation cycle for dishwashers provided with a start timer (T), a washing pump (L) and a draining pump (S), wherein it includes the following steps: a) setting through said timer (T) a delay in the start of the washing cycle; b) loading the water in the dishwasher tank; c) running said washing pump (L) for some minutes; d) waiting with the water in the tank until the time of starting the washing cycle is reached; and e) carrying out the washing cycle. A dishwasher provided with a start timer (T), a programmer (P) for selecting the washing cycle, a washing pump (L) and a draining pump (S), wherein it includes means for detecting the setting of a start delay through said timer (T) and consequently activate said washing pump (L) for some minutes while deactivating said draining pump (S) until the set time of starting the washing cycle is reached. A dishwasher according to claim 2, characterized in that said means for detecting the setting of a start delay directly activate the washing pump (L). A dishwasher according to claim 2, characterized in that said means for detecting the setting of a start delay immediately activate the programmer (P) as soon as a start delay is set and have the programmer (P) carry out a soaking cycle without drainage of the water.

Inventors: BERTAZZONI ROBERTO, BERTAZZONI, ROBERTO
Applicants: SMEG SPA, SMEG S.P.A.
Application year: 1998
Main classification: A47L15
IPC codes: A47L15