Apparatus for pulling cylindrically formed film for a bag maker-packaging machine

A film transporting mechanism for pulling a cylindrically formed bag-making material in a longitudinal direction for a bag maker-packaging machine, said film transporting mechanism comprising:

• a pair of pull-down belt units each including a pull-down belt for pulling said cylindrically formed bag-making material in said longitudinal direction;
• a pair of belt-supporting members each supporting and being attached to a corresponding one of said pull-down belt units such that said corresponding pull-down belt unit is movable as a whole relative thereto;
• a motor means for moving said pair of belt-supporting members selectably towards or away from each other in a mutually coordinated manner;
• force-applying means for applying a variable force between said bag-making material and each of said pull-down belts by changing the relative position between said each pull-down belt and said corresponding one of said belt-supporting members;
• and
• position-indicating means attached to at least one of said belt-supporting members for indicating distance between said belt-supporting members.

An apparatus for pulling a cylindrically formed bag-making material in a longitudinal direction with a pull-down belt for a bag maker-packaging machine, said apparatus comprising:

• a belt-supporting member which supports and is attached to said pull-down belt such that said pull-down belt is movable as a whole relative thereto and is movable towards or away from said cylindrically formed bag-making material being transported in said longitudinal direction;
• force-applying means for applying a variable force between said bag-making material and said pull-down belt by changing the relative position between said pull-down belt and said belt-supporting member;
• and
• position-indicating means attached to said belt-supporting member for indicating position of said belt-supporting member.

A bag maker-packaging machine for bending an elongated bag-making film into a tubular shape to form a bag and simultaneously filling said bag with a batch of articles, said bag maker-packaging machine comprising:

• a web supporting means supporting a web roll having a web of said elongated film wound around a core shaft;
• a former for forming said web into a tubular shape;
• web guiding means for guiding said web from said web roll to said former and said tubularly formed web on a longitudinal downward film path;
• a longitudinal sealer for sealing side edges of said tubularly formed web longitudinally;
• a pair of pull-down belts for causing said film to move on said downward film path;
• and
• a transverse sealer for sealing said longitudinally sealed film in a direction transverse to said film path;
• said film pulling means comprising a pair of belt-supporting members which are movable towards or away from each other in a coordinated manner, each supporting and being attached to a corresponding one of said pull-down belts such that said corresponding pull-down belt is movable as a whole relative thereto, and force-applying means for applying a variable force between said bag-making material and each of said pull-down belts by changing the relative position between said each pull-down belt and said corresponding one of said belt-supporting members, there being provided position-indicating means attached to at least one of said belt-supporting members for indicating distance between said belt-supporting members.

A bag maker-packaging machine for bending an elongated bag-making film into a tubular shape to form a bag and simultaneously filling said bag with a batch of articles, said bag maker-packaging machine comprising:

• a web supporting means supporting a web roll having a web of said elongated film wound around a core shaft;
• a former for forming said web into a tubular shape;
• web guiding means for guiding said web from said web roll to said former and said tubularly formed web on a longitudinal downward film path;
• a longitudinal sealer for sealing side edges of said tubularly formed web longitudinally;
• a pull-down belt for causing said film to move on said downward film path;
• a belt-supporting member which supports and is attached to said pull-down belt such that said pull-down belt is movable as a whole relative thereto and is movable towards or away from said cylindrically formed film being transported on said downward film path;
• force-applying means for applying a variable force between said bag-making material and said pull-down belt by changing the relative position between said pull-down belt and said belt-supporting member;
• position-indicating means attached to said belt-supporting member for indicating position of said belt-supporting member;
• and
• a transverse sealer for sealing said longitudinally sealed film in a direction transverse to said film path.

A bag maker-packaging machine comprising:

• a former for forming an elongated bag-making film into a tubular shape;
• pull-down belt units each including a pull-down belt for causing said film to move longitudinally;
• belt-supporting members, each supporting and being attached to a corresponding one of said pull-down belt units such that said corresponding pull-down belt is movable as a whole relative thereto;
• a longitudinal sealer for sealing side edges of said tubularly formed film longitudinally;
• a transverse sealer for sealing said longitudinally sealed film transversely to form a bag;
• a belt-driving means for moving said pull-down belt units as a whole from specified reference positions, which are separate from said tubularly formed film, to contact positions at which said pull-down belts are in contact with said tubularly formed film;
• a measuring means for measuring a distance by which said pull-down belt units are moved by said belt-driving means;
• and
• a control means for causing said pull-down belt units to be moved as a whole from said reference positions to said contact positions, causing said measuring means to thereby obtain a measured distance between said reference positions and said contact positions, and controlling said belt-driving means on the basis of said measured distance.

An apparatus for pulling a cylindrically formed bag-making material for a bag maker-packaging machine, said apparatus comprising:

• a pair of pull-down belt units each including a pull-down belt for pulling said bag-making material in a longitudinal direction;
• a pair of belt-supporting members which move towards or away from each other in a mutually coordinated manner, each supporting and being attached to a corresponding one of said pull-down belt units;
• spring-loaded connectors each connecting one of said pull-down belts with an associated one of said belt-supporting members such that relative position therebetween is changeable such that said corresponding pull-down belt unit is movable as a whole relative thereto;
• and
• position-indicator attached to at least one of said belt-supporting members for indicating distance between said belt-supporting members.