A receptacle holding unit includes a first part and a second part cooperating with the first part; a cavity for receiving a receptacle containing an ingredient for preparing a beverage by a device, the cavity being delimited by at least one of the first and second parts; and a driving device for relatively moving the second part towards the first part into a closed position and relatively apart from the first part into an open position. The driving device includes an actuator and a transmission having a helicoidal ramp arrangement cooperating with a connector member for converting a translational movement into a rotational movement or vice versa. When the actuator actuates the transmission, the first and second parts are driven together or apart. The ramp arrangement includes two ramps spaced apart and generally parallel between which the connector member relatively moves along the ramp arrangement.