Automatic calibration process for coffee grinder-doser apparatuses with weighing device and electronic grinder-doser apparatus

1. A process of calibrating an electronic grinder-doser of coffee beans, the grinder-doser being provided with an electronic weighing device directly connected to a logic control unit in which grinding times are pre-set in order to obtain a desired weight of ground coffee from the grinder-doser, the process periodically controlling a quantity of coffee actually ground and re-calculating and resetting grinding times in the logic control unit, the process comprising:

starting the process;

sampling by multiple detections;

processing by compensation calculating; and

self-adjusting the process, wherein the steps of sampling, processing and self-adjusting are automatic and carried out sequentially by the grinder-doser and managed by the logic control unit, the step of starting being carried out by an operator, the step of starting comprising:

positioning an empty container on the electronic weighing device, wherein the electronic weighing device is a load cell with a horizontal detection surface and is integrated below a dispenser corresponding to a dispensing spout;

detecting weights up to 20 grams by the electronic weighing device; and

measuring variations in the detected weight to a hundredth of a gram, the electronic weighing device being directly connected to the logic control unit so as to send and receive commands thereto and therefrom;

the step of sampling comprising:

dispensing multiple sequential samples at intervals with respect to each other according to at least one cycle of short-duration dispensing and at least one cycle of long-duration dispensing, the long-duration dispensing being longer than the short-duration dispensing; and

detecting a weight of each of the dispensings;

the step of processing comprising:

processing times of the dispensings and the weights of the dispensings according to a compensation calculation and in relation to an initial settlement time; and

recalculating values of an exact duration of the motor of the grinder-doser necessary to obtain a required grinding time for a desired dose of coffee;

the step of self-adjusting comprising:

automatically resetting parameters that regulate the required grinding time by the logic control unit according to the recalculated values.

2. The process of claim 1 , the step of starting further comprising:

starting the process from a display; and

confirming thea starting of automatic calibration procedures.

3. The process of claim 1 , the step of sampling further comprising:

detecting a tare of the empty container;

dispensing at least three samples identical to each other and having a duration of at least 0.3 seconds so as to exceed the settlement time; and

dispensing another at least three samples identical to each other having a duration of the previously dispensed at least three samples.

4. The process of claim 1 , the step of processing further comprising:

eliminating maximum values and minimum values of the processed times;

calculating average times of the dispensings;

calculating productivity at a uniform speed in accordance with the initial settlement time; and

recalculating the grinding time for the desired dose relative to the initial settlement time.

5. The process of claim 4 , the step of eliminating being two maximum and minimum short weighings and two maximum and minimum long weights, the step of calculating being a calculation of the average of remaining short weighings and long weighings at the step of elimination, the step of processing further comprising:

calculating a productivity constant (K, Ek) based on a quantity of actually ground and dispensed coffee at a uniform speed, the step of recalculating the grinding time necessary to obtain the desired weight being in accordance with:

Tr =( Pr−MPb )/ K+TPb

where

Pr=required dose weight

MPb=calculated average remaining short weight

K=productivity constant

TPb=time of short duration dispensings.

6. The process of claim 5 , wherein a time of the long-duration dispensings is twice a time of the short-duration dispensings.

7. The process of claim 6 , wherein the time of the short-duration dispensings is 0.5 seconds and the time of the long-duration dispensings is 1.0 second with a tolerance of +/−20%.

8. The process of claim 7 , wherein the short-duration dispensings is 0.5 in number and the long-duration dispensings is 5 in number.