Lever-operated dispensing units for coffee machines

A dispenser unit operated by a lever, for use in an espresso machine, comprising a housing mainly extending in a vertical direction between a lower base and an upper cross member, a shaft located within said housing and freely translating along said vertical extent, said shaft having an upper end and a lower end, a first opening formed in said lower base of the housing, said lower end of the shaft extending through said opening below the base, a disk attached to the lower end of said shaft perpendicular to the vertical axis thereof, a second opening formed in the upper cross member of said housing, aligned with the upper end of said shaft which projects out of said opening, an elastic member, reacting between said disk carried by the lower end of the shaft and said upper cross member of said housing, a rod-like lever, with one free end and with the opposite end operably connected to said upper end of said shaft with a cam and a cam follower mechanism interposed therebetween, said base of the housing being equipped with coupling members located at said first opening and adapted to receive and hold a portafilter for a given dose of coffee grounds, as well as members for actuating hot water supply into said portafilter when the latter is placed against said first opening, wherein said lever is mounted so as to be able to be angularly displaced about a pivot supported by said housing with an axis perpendicular to the vertical axis of said shaft, the cam of said cam mechanism is mounted to said pivot and is able to be angularly displaced with said lever, the cam follower is connected to said upper end of said shaft, and the dispenser unit includes a DC electric motor, whose rotor is connected to said pivot, and operator-selectable members for connecting and disconnecting power supply to said motor.