Shaftless gear device for axial shirring of synthetic tubular material

A device for axial shirring of synthetic tubular material, such as for use on an automated sausage stuffer, comprising:

• at least four shirring rolls rotatable about axes, all of which axes are located in a common plane, the shirring rolls being distributed equally angularly about a central opening adapted to receive a cylindrical mandrel, such that the periphery of the rolls all include a portion facing the mandrel and the said common plane of the axes is transverse to the axis of the mandrel,
• means including a holding member for mounting the assembly for revolving movement about the mandrel,
• each of said shirring rolls having a plurality of teeth, the outer end of each tooth including a concave arcuate groove, the curvature of which groove corresponds to the surface of the mandrel which it faces,
• the path of the grooves of the teeth of each shirring roll, as they pass closest to the mandrel, overlapping the path of the grooves of the teeth of the two adjacent shirring rolls, when viewed along the axis of the mandrel,
• a shaft for each shirring roll located at the axis of its shirring roll, each such shaft being fixedly connected to the holding member with its respective shirring roll mounted thereon via bearing means for rotation relative thereto,
• tapered gears fixed to the sides of at least some of said shirring rolls for rotation therewith about their respective shafts, and said tapered gears being coaxial with their respective shirring rolls,
• at least some of the adjacent pairs of tapered gears between adjacent shirring rolls meshing with each other to provide a driving connection from one of said shirring rolls to the adjacent shirring roll,
• and a roll drive means for rotating at least one of said shirring rolls about its axis, the driving force being conveyed to other shirring rolls via said meshing adjacent tapered gears.