Abstract: The invention relates to an "in-chamber" gathering and clipping unit in which the gathering members are rotatable around a common hub and the clip drive punch is driven to advance clips individually from a location coaxially within the hub along a direction radially outwardly onto a bag neck gathered by the gathering members. The radius of the gathering members can be kept short and have their arcuate gathering surfaces so designed that the gathering action takes place within a 90.degree. movement of each of the gathering members, so each gathering member retracts below the hub and still leaves the gathering head narrow in width so it can be incorporated in any one of a wide range of existing vacuum chamber packaging machines.