Rotary filling apparatus

A rotary filling apparatus comprising:

• a rotatable drum body having an apex and a base, an outer circumferential wall which defines a drum periphery, and lateral walls which extend from the drum periphery into the drum body to define a plurality of spaced drum chambers, the lateral walls having aligned keyhole slots therein, positioned away from the drum periphery;
• a vessel, slidably positioned in each chamber, which extends from a base portion adjacent the keyhole slots to a head portion adjacent the drum periphery;
• a key, positioned in each keyhole slot, having a longitudinal axis and a cross-sectional area which increases from a base portion to a head portion, so that upon longitudinal displacement of the key in the keyhole slot the vessel is caused to ascend or descend in the chamber, thereby decreasing or increasing the volume of the chamber;
• and
• a cover plate, positioned adjacent the drum periphery, between the drum apex and base, for retaining product in drum chambers during rotation of the drum.