Method for dispensing doses of coffee grounds

Abstract

A method of controlling dispensing of doses of coffee grounds, the machine comprising a grinding device which is configured to grind coffee beans, a conduit, having an inlet in communication with the grinding device for receiving coffee grounds, and an outlet, a closure member which is adapted to be removed between an open position for the coffee grounds to be discharged from the conduit through the outlet, and a closed position for closing the outlet, and a coffee grounds weight sensor, which is configured to generate signals representative of the weight of coffee grounds built-up in the dispensing conduit when the closure member is in the closed position.

1 . A method of method of dispensing a dose of coffee grounds from a grinding-dosing machine, the machine comprising a grinding device which is configured to grind coffee beans, a dispensing conduit, having an inlet in communication with the grinding device for receiving the coffee grounds, and an outlet, a closure member which is adapted to be removed between an open position for the coffee grounds to be discharged from the dispensing conduit through the outlet, and a closed position for closing the outlet, the method comprising:
 storing a buffer weight value and a first grinding time value associated with the buffer weight value;   placing the closure member in the closed position;   carrying out a first grinding operation, by operating the grinding device for a time equal to the first grinding time, for discharging the coffee grounds through the dispensing conduit so that the amount of the coffee grounds that build up on the closure member corresponds to the buffer weight value;   receiving input data requesting the coffee grounds dispensing, associated with a nominal weight value of the coffee grounds;   comparing the received nominal weight value input with the buffer weight value;   based on the comparison result, if the nominal weight value corresponds to the buffer weight value, placing the closure member in the open position to discharge the coffee grounds built up at the end of the first grinding operation through the outlet of the dispensing conduit;   based on the comparison result, if the nominal weight value is greater than the buffer weight value, carrying out the following steps:
 with the closure member maintained in the closed position, carrying out a second grinding operation by operating the grinding device to discharge the coffee grounds through the dispensing conduit onto the closure member; 
 stopping the grinding device when the built-up coffee is equal to the nominal weight value, or at the end of a grinding time associated with the nominal weight value, and 
 placing the closure member in the open position to discharge the coffee grounds built up at the end of the first and second grinding operations through the outlet of the dispensing conduit. 
   
     
     
         2 . The method of  claim 1 , wherein the grinding-dosing machine further comprises a retaining support for a portafilter, which is configured to support and/or mechanically connect a portafilter, wherein the outlet of the dispensing conduit is placed above and faces the retaining support, for the coffee grounds to be discharged into the portafilter when the portafilter is placed on the retaining, support and the closure member is in the open position. 
     
     
         3 . The method of  claim 1 , wherein the grinding dosing machine further comprises a weight sensor, which is configured to generate signals representative of the weight of the coffee grounds built-up in the dispensing conduit when the closure member is in the closed position, the method comprising, during the second grinding operation:
 continuously receiving measurement signals representative of the weight of the coffee grounds built up on the closure member during discharge of the coffee grounds through the dispensing conduit; and   continuously comparing the weight values of the coffee grounds, associated with the received measurement signals, with the nominal weight value of the coffee grounds, wherein the, grinding device is stopped as soon as a weight value measured by the sensor is equal to the nominal weight value.   
     
     
         4 . The method of  claim 1 , which further comprises, after receiving input data requesting the coffee grounds dispensing:
 associating a nominal grinding time value with the nominal weight value of the coffee grounds; and   calculating a second grinding, time as a difference between the nominal grinding time value and the first grinding time, wherein the second grinding operation is carried out for a time equal to the second grinding time and the grinding device is stopped at the end of the second grinding time.   
     
     
         5 . The method of  claim 1 , which comprises, after discharging the coffee grounds built up at the end of the first grinding operation or between the first and the second grinding operations, through the outlet of the dispensing conduit:
 placing the closure member in the closed position; and   carrying out a first grinding operation, by operating the grinding device for a time equal to the first grinding time, so that the amount of the coffee grounds that build up on the closure member corresponds to the buffer weight value.   
     
     
         6 . The method of  claim 1 , wherein the machine further comprises a coffee grounds weight sensor, which is configured to generate measurement signals representative of the weight of the coffee grounds built-up in the dispensing conduit when the closure member is in the closed position, the method comprising, after carrying out a first grinding operation and before receiving input data requesting the coffee grounds dispensing:
 receiving a measurement signal representative of an actual weight value of the coffee grounds built-up on the closure member at the end of the first grinding operation;   comparing the measured actual weight value with the stored buffer weight value and, based on the result of the comparison, if the measured actual weight value differs from the buffer weight value to an extent exceeding a predetermined threshold value, and calculating a mass throughput value based on the actual weight value and the first grinding time;   calculating a grinding time value based on the calculated mass throughout value to obtain the buffer coffee grounds dose value; and   storing the calculated grinding time value as the new first grinding time value for the first grinding operation.   
     
     
         7 . The method of  claim 1 , wherein the grinding-dosing machine further comprises a weight sensor, which is configured to generate signals representative of the weight of the coffee grounds built up in the dispensing conduit when the closure member is in the closed position, the weight sensor being a load cell connected to the dispensing conduit and to the closure member so that the load cell supports the dispensing conduit and the closure member in hanging relation, wherein the load cell is preferably configured to indicate a zero weight if no coffee grounds are contained in the dispensing conduit.