Apparatus for forming accordion pleats in a thin-walled plastic container

Claim 1

Apparatus for forming a circumaxially extending series of axially elongated accordion pleats in and about the sidewall of a generally cylindrical thin-walled plastic container which is closed at one end and which has a reduced diameter opposite end portion with an opening extending axially therethrough, each said container also having a radially outwardly projecting annular flange at its said reduced diameter opposite end portion, said apparatus comprising a container forming station, a container gripping and transporting means having an inwardly extending plate on its bottom for successively engaging unpleated containers about the annular flanges on their said reduced diameter opposite end portions and for transporting the same to and from the container forming station, the remaining portions of each container projecting from the gripping and transporting apparatus for introduction to and removal from said forming station, and said container gripping and transporting apparatus also including air supply and discharge conduits which enter said axially extending opening in said opposite end portion of a container, and a pressurized hot air supply source being provided for connection with said air supply line for the introduction of hot air to the interior of the containers whereby to render the containers malleable at least along their sidewalls when they are delivered to the forming station, a plurality of circumaxially arranged radially movable forming blades disposed about a container introduced to the forming station, each of said blades being elongated axially along and adjacent the sidewall of a container at the forming station, and an operating means for said forming blades adapted to cyclically and in unison move the blades radially inwardly and outwardly respectively to form accordion pleats in and around the sidewall and to release a container at the forming station, said container gripping and transporting means serving successively to introduce and to remove unpleated and pleated containers from said forming station in axial movement of the containers and in timed relationship with the radial inward and outward movement of said forming blades.