Apparatus for forming a tube from a metal band

A device for forming a tube from a substantially planar material, said planar material having lateral edges adapted to be formed into a longitudinal joint for forming said tube, comprising:

• an inlet having a first cross section for admitting said planar material into said device;
• an outlet having a second cross section for emitting said planar material from said device;
• a channel communicating between said inlet and said outlet for forming said planar material into said tube as said planar material is drawn through said channel, said channel substantially solely engaging that surface of said planar material that forms the exterior surface of said tube, said planar material passing tangentially over substantially the entire length of said channel on only a portion of the total surface of said planar material;
• and
• means removably mounted on said inlet, said means defining a slit for receiving and centering said planar material with respect to said first cross section of said inlet and for guiding said planar material during the passage of said planar material in said channel.

An apparatus for forming a tube from a substantially planar material, comprising:

• a die for forming said tube from said planar material, said die comprising:
• an inlet having a first cross-sectional configuration for receiving said planar material;
• an outlet having a second cross-sectional configuration, said second cross-sectional configuration being smaller in area than said first cross-sectional configuration, and said second cross-sectional configuration being substantially of the same cross-sectional configuration as said tube;
• a conduit having a longitudinal axis, connecting said inlet and said outlet for passing said planar material, said planar material being formed into said tube as it passes through said conduit, said conduit comprising a substantially continuously smooth surface having a continuously decreasing cross section extending from said inlet to said outlet, said planar material being substantially solely formed by contact with said surface so as to be formed into said tube;
• and
• means removably mounted on said inlet, said means defining a slit for receiving and centering said planar material with respect to the cross section of said inlet and for guiding said planar material during the passage of said planar material in said conduit;
• means rotationally mounted adjacent said die for receiving said tube;
• means for rotating said receiving means to produce a winding of said tube upon said receiving means, said receiving means adapted for storage and transportation of said tube;
• and
• means for translating said die in a direction substantially parallel to the longitudinal axis of said receiving means to provide a substantially uniform winding of said tube upon said receiving means.

A device for forming a split tube from a flat and elongated strip, said strip having lateral edges adapted to be formed into a longitudinal joint for forming said tube, comprising:

• an inlet having a cross section for receiving said strip;
• an outlet for emitting said strip formed into said tube from said device;
• a conduit having an interior surface connecting said inlet and said outlet, said strip being formed into said tube by contact substantially and solely between only one side of said strip and said interior surface of said conduit;
• and
• means removably mounted on said inlet, said means defining a slit for receiving and centering said strip with respect to the cross section of said inlet and for guiding said strip during the progression of said strip within said conduit.