US 12,029,342 B2
Coffee machine and relative control method
Beppino Ceotto, Silea (IT); and Giovanni Rossetto, Conegliano (IT)
Appl. No. 15/119,797
Filed by CMA MACCHINE PER CAFFE' S.r.l., Susegana (IT)
PCT Filed Feb. 18, 2015, PCT No. PCT/EP2015/053361
§ 371(c)(1), (2) Date Aug. 18, 2016,
PCT Pub. No. WO2015/124592, PCT Pub. Date Aug. 27, 2015.
Claims priority of application No. MI2014A000249 (IT), filed on Feb. 20, 2014.
Prior Publication US 2017/0049259 A1, Feb. 23, 2017
Int. Cl. A47J 31/00 (2006.01); A47J 31/36 (2006.01); A47J 31/52 (2006.01)
CPC A47J 31/002 (2013.01) [A47J 31/36 (2013.01); A47J 31/52 (2013.01); A47J 31/5255 (2018.08)] 7 Claims
OG exemplary drawing
 
1. A coffee machine comprising:
at least one hydraulic infusion circuit comprising,
a feed pump for supplying water,
a boiler hydraulically connected to the feed pump by cascade connection, and
an infusion unit that is hydraulically connected to the boiler by cascade connection and through which a flow rate of hot water can pass for execution of an infusion cycle; regulating means for regulating said flow rate of hot water;
a flow rate sensor for measuring said flow rate;
a feedback controller connected to said regulating means and to said flow rate sensor and configured to compare in real time a current value of the flow rate of the hot water, as measured by the flow rate sensor, with a corresponding reference value, and to control the regulating means so as to eliminate any deviation of said cureent value of the flow rate of the hot water passing through the infusion unit with respect to said corresponding reference value; and
a pressure sensor between said feed pump and said flow rate sensor for detecting a pressure of the hydraulic infusion circuit so as to keep the pressure of said hydraulic infusion circuit within pre-determined limits and under a pre-determined maximum limit, said pressure sensor being connected to said feedback controller,
wherein the pressure detected by the pressure sensor is utilized by the feedback controller to control the flow rate within the hydraulic infusion circuit and to limit a maximum pressure of the hydraulic infusion circuit, and
wherein the regulating means comprise a bypass circuit configured to divert at least a portion of the water provided by the feed pump upstream of the pressure sensor and the boiler, and to cause the water to be fed to the feed pump again, and
wherein the feedback controller controls the flow rate by controlling an aperture, in an inversely proportional relationship, of a first valve positioned between the bypass circuit and the pressure sensor, and of a second valve positioned within the bypass circuit.