with reference to the above figures , the machine for making infusions such as espresso coffee , with automatic ground coffee introduction and dregs expulsion , according to the invention , comprises a supporting structure that is generally designated by the reference numeral 1 and whereon an actuation unit 2 for the actuation of a main shaft 3 is located . the actuation unit can be of the manual type and therefore comprises an actuation crank 10 connected to a first gear 11 , which meshes with a second gear 12 , which has a greater number of teeth than the first gear 11 and is keyed on the main shaft 3 so as to make it rotate . it is of course possible to provide for a motorization system that performs the movements that can be obtained with the crank . a transmission pin wheel 13 is provided on the main shaft 3 and meshes with a pin wheel 14 having a substantially vertical axis and actuating the mixer 15 of a dosage device 16 , in which the ground coffee to be used to produce the extract is placed . an important particularity of the invention resides in the fact that a cam - based actuation unit , generally designated by the reference numeral 20 , is located on the main shaft 3 and in practice controls all the functions of the machine , allowing to perform the various operating steps in succession . the cam - and - gear actuation unit 20 interacts with a ground coffee feeding and expulsion unit , with the block that forms the extraction chamber , and with the actuation lever of the infusion plunger to achieve synchronized movement . the cam - and - gear actuation unit 20 , which is shown more clearly in fig6 and 7 , is provided with a substantially circular plate - like element 21 having a toothed portion 22 for the actuation of a ground coffee feeding and expulsion unit , generally designated by the reference numeral 30 . the toothed portion 22 interacts with a rack - like set of teeth 31 formed in the lower part of the feeding and expulsion unit 30 , which is slideable below the dosage device 16 . the feeding and expulsion unit 30 has an elongated body 35 ending , at the front , with a pusher 36 that has the purpose , as will become apparent hereinafter , of removing the pellet of used coffee dregs . the feeding unit 30 forms a coffee introduction chamber 37 that can be arranged below the dosage device 16 for the introduction of a measured amount of coffee by means of the mixer 15 . to the side of the introduction chamber 37 there is provided a hammer 38 provided with a stem 39 that ends with a tooth 40 which , during the translatory motion of the body 35 , engages an abutment of the hammer 41 so as to load the spring 42 that is arranged around the stem 39 . below the introduction chamber 37 , and so as to removably close it , there is provided a gate 45 slideable for engagement between a tooth 46 formed by the gate and a pawl 47 that engages the tooth 46 to produce the sliding of the gate with respect to the body 35 , with consequent opening of the coffee introduction chamber 37 . the gate pawl 47 is actuated by a gate cam 48 that allows to disengage the pawl from the tooth 46 when one does not wish to introduce the dose of coffee in the infusion chamber , as will become apparent hereinafter . during the translatory motion of the elongated body as shown in fig1 , the gate begins to open when the chamber 37 is arranged above the extraction chamber , which will be described hereinafter . furthermore , in order to allow full dispensing of the ground coffee , the hammer 38 is removably retained by the abutment 41 , loading the spring 42 until a release element 49 acts on the end of the stem of the hammer , disengaging the tooth 40 from the abutment 41 , consequently causing the impact against the coffee introduction chamber and the full dispensing of the coffee . the rotation of the cam unit 20 , in addition to producing the movement of the feeding and expulsion unit 30 , also causes the movement of the extraction chamber , generally designated by the reference numeral 50 , by virtue of the presence of a sector 23 arranged laterally adjacent to the plate 21 and provided with a set of teeth for the translatory motion of the extraction chamber 24 ; said set of teeth engages a rack - like set of teeth for the translatory motion of the extraction chamber 25 , which is formed on the body of the extraction chamber , which can slide since it is guided by two guiding columns , designated by the reference numeral 51 . an infusion plunger 60 can slide hermetically with respect to the inside of the extraction chamber 50 ; its stem 61 protrudes downwards from the extraction chamber 50 and engages the fork - like end 62 of an infusion plunger actuation lever 63 , which has a folded end 64 that can engage an infusion plunger retraction cam 65 formed on the portion 23 of the cam - based unit 20 , in a point that is offset with respect to the set of teeth . a sector - shaped cam 66 is provided on the cam - based unit 20 , on the opposite face of the plate - like element 21 provided with the portion 23 , and engages a pin 67 that actuates a secondary lever 68 arranged below the lever 63 to prevent its movement when the plunger is in the raised position . above the extraction chamber there is provided a fixed complementary plunger , designated by the reference numeral 70 , that has the function of compacting the coffee pellet and of forming the extraction chamber . the complementary plunger 70 forms the coffee extract dispensing duct 71 , which is controlled by a dispensing counterpressure valve , designated by the reference numeral 75 in fig1 , that is controlled by a dispensing lever 76 acting on a rod 77 , which presses on the conical pin 78 of the dispensing valve . the lever 76 can be actuated by a contoured portion of a secondary actuation shaft , designated by the reference numeral 80 , and is provided with a grip knob 81 ; the secondary shaft 80 has the purpose of synchronizing the engagement of the valve with the dispensing action of the pump and therefore with the dispensing of the coffee . the complementary plunger 70 is provided with a sealing gasket 72 that hermetically engages the extraction chamber and has a particular shape that assuredly prevents infiltrations of ground coffee . the execution of the gasket 72 is particularly important , since it allows a very low sliding friction and high resistance to clogging by ground coffee , allowing sliding with the limited applied forces that can be achieved by manual actuation . furthermore , below the extraction chamber there is provided a venting valve , generally designated by the reference numeral 90 , having a stem 91 that interacts with the tab 62a of the fork , so as to connect the extraction chamber to the discharge when it is necessary to perform the retracting descent of the infusion plunger . a similar discharge valve , shown in fig1 and designated by the reference numeral 92 , is provided at the dispensing region and has the purpose of opening , under the actuation of a cam by means of the secondary shaft 80 to allow the venting of pressure for correct movement during the opening of the chamber . moreover , there is provided a locking lever , designated by the reference numeral 95 , that is pivoted to the extraction chamber 50 and closes on a set of teeth 96 formed on the side of the complementary plunger and having the purpose of keeping the extraction chamber closed on the complementary plunger during the dispensing of the coffee . said lever , which is shown in fig1 , is actuated by a cam 97 of the closure lever that is arranged on the main shaft 3 and has the purpose of opening the lever for optional actuation after the end of the dispensing step . substantially , the secondary shaft 80 , which can be actuated manually , allows to engage the counterpressure valve 75 downstream of the extraction chamber and to synchronize the engagement of said valve with respect to pump feeding , by means of a cam acting on a lever that actuates , so as to release it , a spring element and by means of a cam acting on a switch . the shaft furthermore synchronizes , by means of another cam acting on a switch , the engagement of the pump and controls the opening of a faucet for drawing hot water . the secondary shaft 80 , turned into another position , synchronizes the engagement of the resistor of the boiler and the opening of said faucet by means of a cam acting on a switch to produce steam . the faucet is coupled to an external knob that allows to select the desired function according to the selected position . there is also provided a sector 98 that allows to visualize the various positions of the lever to allow the cyclic operating sequence . during the initial step , starting from the completed dispensing of a coffee ( fig5 ), by turning the lever 10 in one direction , first of all the extraction chamber is shifted downwards , after releasing the closure lever that held it connected to the complementary plunger 70 . when the extraction chamber is at its lowest point , shown in fig3 the infusion plunger , which is kept in the raised position for engagement below the actuation lever 63 of the secondary lever 68 that limits the translatory motion of said lever , moves the pellet of dregs so that it lies above the extraction chamber , which is instead shifted downwards by engagement between the sets of teeth 24 and 25 . by continuing the rotation of the lever 10 , the set of teeth 22 and the toothed portion 31 engage one another , with the consequent translatory motion of the body 35 of the feeding and expulsion unit causing an initial expulsion of the dregs . as the rotation of the lever continues , the translatory motion of the unit 35 also continues , said unit being arranged below the dosage device and receiving the desired amount of coffee . the subsequent rotation causes the cam 65 to engage the portion 64 of the lever and causes the pin 66 in practice to disengage the secondary lever 68 below the lever 63 , allowing further downward translatory motion thanks to the engagement of the cam 65 with the end 64 , and the infusion plunger moves into the lower part of the extraction chamber . the further translatory motion of the unit 30 causes the gate to be engaged by the pawl 47 , consequently opening it and preparing the ground coffee in the extraction chamber . if one does not wish to prepare the ground coffee , it is sufficient to act on the secondary shaft 48 , which does not allow to open the gate by turning the gate pawl 47 . after the ground coffee has been prepared in the extraction chamber , the rotation of the lever 10 is reversed , consequently causing the return of the unit 30 and the subsequent rise of the extraction chamber , which couples to the complementary plunger , performing stable securing by means of the locking lever 95 . in these conditions , the machine is ready for dispensing the coffee ; dispensing occurs by actuating the pump for delivering hot water , which is fed below the infusion plunger at a pressure that overcomes the calibrated valve 59 provided in said infusion plunger ; therefore , the water is delivered , passes at a preset pressure through the ground coffee , and is then dispensed externally by means of the dispensing duct 71 , into which the coffee extract is fed after passing through the counterpressure valve , which controls the delivery duct on the complementary plunger 70 . coffee dispensing is interrupted by turning the knob 81 into the position that selects stopping ; the knob acts on the secondary shaft 80 which , by means of a cannula provided thereon , opens the discharge valve of the duct that feeds water below the infusion plunger , discharging the residual pressure . from the above description it is thus evident that the invention achieves the intended aim and objects , and in particular the fact is stressed that a coffee dispensing machine is provided the operation whereof is achieved through mechanical couplings that constitute a great constructive simplification and allow to perform the automatic sequence of movements . furthermore , the particular embodiment used , which allows to reduce friction during movement , allows to use manual actuation with reduced actuation efforts . the invention thus conceived is susceptible of numerous modifications and variations , all of which are within the scope of the inventive concept . furthermore , all the details may be replaced with other technically equivalent elements . in practice , the materials employed , as well as the contingent shapes and dimensions , may be any according to the requirements .
a machine for making a beverage such as espresso coffee , with automatic ground coffee introduction and dregs expulsion , having a main shaft that drives , synchronously and simultaneously , through sector - shaped gears and cams controlled thereby , the movement of a ground coffee dosage and feeding device , of a used dregs expulsion unit , of a unit that forms the extraction chamber , and , through a lever , of a plunger that forms the bottom of the extraction chamber and furthermore moves , directly or indirectly , all the other elements required for operation .