Packaging apparatus

Apparatus for packaging units either in flexible sheet material having registration marks constituting reference points preprinted at intervals on the web for positioning said units to be packaged, or in plain flexible sheet material free of said registration marks, said apparatus comprising means for conveying a web of said material along a path through said apparatus, means for placing said units to be packaged on said web in spaced longitudinal relation to one another, means for forming said web into a tube around the units to be packaged with the units spaced longitudinally in the tube, means for sealing the tube between said units, and mode selection means selectively actuable between a printed web mode for controlling operation of said apparatus for packaging said units in said preprinted web and a plain mode for controlling operation of said apparatus for packaging said units in said plain web, said sealing means comprising:

• a wheel rotatable on an axis;
• a series of sealing units carried by the wheel;
• each sealing unit having means for coupling it to the wheel for travel therewith and adapted for uncoupling the sealing unit from the wheel to allow the wheel to rotate while the sealing unit remains stationary;
• means for arresting the first sealing unit at a hold position and for actuating its coupling means to uncouple said sealing unit from the wheel, said arresting means being movable between an operative position in which it is engageable by said coupling means of said first sealing unit to arrest said first sealing unit and to uncouple it from the wheel, and a retracted position for release of the sealing unit to travel with the wheel, said arresting means being movable from its operative to its retracted position in response to movement of the units with the tube for sealing the latter between successive units;
• said apparatus further comprising means for generating a signal for actuating said arresting means so as to effect coupling of said first sealing unit at said hold position to said wheel in timed relation to movement of said registration marks past a reference point when said mode selection means is in its printed web mode or in timed relation to passage of a unit to be packaged past another reference point when said mode selection means is in its plain film mode;
• and
• other means for generating another signal in response to movement of said wheel a predetermined distance, this last said signal controlling operation of said unit placement means when said mode selection means is in said printed film mode to place each of said units to be packaged at a desired location on the web relative to respective registration marks or for effecting the release of the first sealing unit at said hold position when said mode selector means is in said plain film mode in the event said signal generating means fails to detect the passage of a unit past said reference point, said other means comprising means for generating a number of pulses corresponding to the wheel moving through a unit length, and means for counting said pulses and for generating said other signal upon counting a specified number of pulses corresponding to a desired movement of said wheel.