Not sure if this is relevant?
A posser was historically a tool used for possing or mixing laundry while hand washing it. Possers come in various forms, there is usually a vertical pole with a handle bar at the top but the base can be conical, with three (or more) legs or sometimes a flat disk.
And, from world-grain.com:
Bagging equipment manufacturers can provide: dust tight bag clamps; bag transfer devices to move the filled bag from the filling spout to the closing system without opening the bag again; interlocked access points; and automatic, motorized height adjustment on conveyors and bag possers, which help settle product in the bag.
From Millsarchive.org:
Posser
Used for filling sacks. A suspended lever carries a wooden or metal ring with sack hooks at one end. Has sufficient leverage to enable the sack to be shaken manually. Steam mills had power driven-possers.
And finally, from flourmilling.co.uk:
Posser A bumping device to assist filling of sacks.
