Apparatus for screwing a ring nut of a trigger pump on a container

A head (10) for screwing a ring nut of a trigger pump (1) on a vessel (6), the trigger pump (1) being provided with i) a body (8), ii) a driving trigger (5), iii) a dip pipe (4) extending downward from the body (8) and intended to be inserted within the vessel (6), and iv) an externally-toothed ring nut (2) free to rotate relative to the body (8) of the pump and is internally threaded (3) in correspondence with threading provided on the neck of the vessel (6), said head (10) comprising:

• a gripping unit comprised of a plurality of clamping levers (11) arranged about a longitudinal axis (10a), the clamping levers drivable between i) a first open position that allows an introduction of the trigger pump (1) between the levers, and ii) a second closed position where the clamping levers grip the ring nut (2) between the clamping levers;
• a motor drive (16) operatively connected to axially rotate the clamping levers, when the clamping levers are in the second closed position, about the longitudinal axis (10a) such that the clamping levers axially rotate the ring nut (2) in a screwing-on direction to screw the ring nut (2) onto the threading provided on the neck of the vessel (6) with the clamping levers avoiding interference with the driving trigger (5) during the rotation of the clamping levers;
• and
• an electronic apparatus (22) operatively connected to the motor and configured to detect a present position of the clamping levers relative to the trigger pump (1) to thereby define or not define interference conditions of the clamping levers (11) with the driving trigger (5),
• wherein the clamping levers (11) are shaped such that, in the second position during rotation of the clamping levers, the clamping levers have clearance over the driving trigger (5), wherein,
• the clamping levers are hinged at a pivot point (C),
• each of the clamping levers have a substantially C shape, a bottom portion of the C shape terminating with a plate (11A) and extending first downward and then upwardly to the pivot point,
• a distal end of the driving trigger (5) extends a first distance perpendicular to the longitudinal axis (10a), and
• the C shape defines an inside surface of each clamping lever such that, in the second position during rotation of the clamping levers, a closest inside surface of each clamping lever to the distal end of the driving trigger (5), has a second distance perpendicular to the longitudinal axis (10a) greater than the first distance perpendicular to the longitudinal axis (10a) such that the clamping levers each have clearance over the driving trigger (5) during the rotation of the ring nut (2) in the screwing-on direction when screwing the ring nut (2) onto the threading provided on the neck of the vessel (6).