Apparatus for severing and feeding lightweight tubular plastic elements

A mandrel assembly adpated for use in apparatus for expanding synthetic plastic tubing from flattened to tubular condition, severing tubular elements of predetermined length from the leading end of the expanded tubing and feeding said elements toward a use station, characterized by means defining a longitudinally extending mandrel body, tubing expanding means extending longitudinally from one end of said body adapted to extend within said tubing and comprising at least two angularly related webs connected end to end and disposed substantially at right angles in medially intersecting planes, said webs having smooth edges for engaging the interior of said tubing during expansion, and a tubing feed member constructed and arranged to be closely surrounded by the expanded tubing mounted on said body for movement longitudinally along said body.

A mandrel assembly comprising a body having longitudinally spaced portions formed with cylindrical surfaces of about the same diameter, a reduced diameter stem extending rigidly between said portions, an annular collar of hard smooth plastic disposed on said stem, a feed slidably mounted on said collar, said collar having a cylindrical portion adjacent the forward body portion, compression spring means surrounding the stem within said sleeve biasing said sleeve toward the rearmost of said body portions, and tubing expanding means comprising angularly related longitudinally spaced laterally flexible webs of hard smooth synthetic plastic, one of said webs being rigidly connected at its forward end to the rearmost body portion and the other of said webs terminating rearwardly in an initial tubing spreading edge, said body portions, said sleeve and said collar portion having external surfaces of about the same diameter and the maximum lateral width of said tubing expanding means being at least equal to said diameter, and a solid body of heat insulation material fixed on the forward end of the mandrel body.

A mandrel assembly adapted for use in apparatus for expanding moving synthetic plastic tubing from flattened to tubular condition, severing tubular elements of predetermined length from the leading end of the expanded tubing and feeding said elements toward a use station, characterized by means defining a longitudinally rigid mandrel body, tubing expanding means mounted on one end of said body to extent within said tubing and comprising an integral element of hard smooth synthetic plastic fixed at one end to said body, said tubing expanding element comprising flat webs connected end to end in intersecting planes, and each web being flexible laterally of its plane, and a longitudinally slidable tubing feed member on said body constructed and arranged to be closely surrounded by the tubing expanded by said tubing expanding means.

A mandrel assembly adpated for use in apparatus foe expanding moving synthetic plastic tubing from flattened to tubular condition, severing tubular elements of predetermined length from the leading end of the expanded tubing and feeding said elements toward a use station, characterized by means defining a mandrel body, tubing expanding means mounted on one end of said body to extend within said tubing and tubing feed means constructed and arranged to be closely surrounded by the tubing expanded by said tubing expanding means mounted on said body for movement longitudinally of said assembly, said tubing expanding means comprising at least two angularly related webs disposed in intersecting planes with each web having opposed longitudinally extending smooth edges for engaging the interior of the tubing during expansion, and said tubing feed means comprising a sleeve longitudinally slidably mounted on said body and spring means on the body enclosed by said sleeve connected to bias said sleeve toward said tubing expanding means.