Method of tensioning a web of packaging material

A method of tensioning a web of material, pulled from a supply roll by means of web feeding rolls and guided over web processing means, between said web feeding rolls and said web processing means, comprising the steps of:

• providing a single source of driving power for both said web feeding rolls and said web processing means;
• providing a first transmission means upon a shaft, between said single source of driving power and said web feeding rolls, and between said single source of driving power and said web processing means, for driving said web feeding rolls and said web processing means at a low rate of speed;
• providing a second transmission means upon said shaft, between said single source of driving power and said web feeding rolls, and between said single source of driving power and said web processing means, for driving said web feeding rolls and said web processing means at a high rate of speed;
• providing a one-way transmission means between both said first and second transmission means and said web processing means;
• actuating said first transmission means while deactuating said second transmission means so as to drive said web feeding rolls and said web processing means at said low rate of speed so as to initially tension said web of material;
• actuating said second transmission means while deactuating said first transmission means so as to drive said web feeding rolls and said web processing means at said high rate of speed for convenying a predetermined amount of said web of material at a high rate of production speed;
• actuating said first transmission means while deactuating said second transmission means so as to drive said web feeding rolls and said web processing means at said low rate of speed in preparation for stopping said web feeding rolls and said web processing means;
• and
• deactuating said first transmission means while maintaining said second transmission means deactuated, and stopping said web feeding rolls and said transmission shaft, so as to stop driving power from being transmitted to said web feeding rolls and said web processing means yet permitting said one-way transmission means to continue to rotate said web processing means for a limited time after said stoppage of said web feeding rolls so as to retain said tension upon said web of material between said web feeding rolls and said web processing means during said stopped mode.

A method of tensioning a web of material, pulled from a supply roll by means of web feeding rolls, between said supply roll and said web feeding rolls, comprising the steps of:

• rotating said web feeding rolls for a predetermined amount of time, and at a predetermined rate of speed, so as to unroll said web of material from said supply roll;
• sensing the progressive diminishing of the outer diameter of said supply roll as said web of material is unrolled from said supply roll by said web feeding rolls during said predetermined amount of time;
• generating signals indicative of said sensed outer diameter values of said progressively diminishing supply roll;
• using a central processing unit to compare said sensed outer diameter values of said progressively diminishing supply roll with predetermined volume values previously stored within said central processing unit;
• and
• causing said central processing unit to apply braking forces to said supply roll in response to said compared values so as to progressively retard said supply roll as said outer diameter of said supply roll progressively diminishes in order that said web material is withdrawn from said supply roll under a predetermined amount of tension.

Apparatus for tensioning a web of packaging material in a form-fill-seal packaging system, comprising:

• a supply roll of said packaging material;
• tube forming means for forming said packaging material into tubular envelopes within which articles are to be packaged;
• web feeding rolls for withdrawing said web of packaging material from said supply roll and forwarding said withdrawn web of packaging material to said tube forming means;
• drive means for driving both said tube forming means and said web feeding rolls;
• first transmission means, mounted upon transmission shaft means, interposed between said drive means and both said web feeding rolls and said tube forming means for selectively actuating both said web feeding rolls and said tube forming means at a first operative rate of speed;
• second transmission means, mounted upon said transmission shaft means, interposed between said drive means and both said web feeding rolls and said tube forming means for selectively actuating both said web feeding rolls and said tube forming means at a second operative rate of speed;
• brake means operatively connectible to said web feeding rolls and said transmission shaft means for selectively permitting said web feeding rolls and said transmission shaft means to rotate in a drive mode, or for preventing rotation of said web feeding rolls and said transmission shaft means;
• and
• one-way transmission means interposed between said transmission shaft means and said tube forming means for permitting said tube forming means to continue to rotate for a predetermined time after said brake means has stopped rotation of said web feeding rolls and said transmission shaft means so as to cause said tube forming means to retain said web of packaging material, interposed between said web feeding rolls and said tube forming means, in a tensioned state.

Apparatus for tensioning a web of material, pulled from a supply roll by means of web feeding rolls and guided over web processing means, between said web feeding rolls and said web processing means, comprising:

• a supply roll of said web material;
• web processing means for using said web material in the fabrication of a product;
• web feeding rolls for withdrawing said web material from said supply roll and forwarding said withdrawn web material to said web processing means;
• drive means for driving both said web processing means and said web feeding rolls;
• first transmission means, mounted upon transmission shaft means, interposed between said drive means and both said web feeding rolls and said web processing means for selectively actuating both said web feeding rolls and said web processing means at a first operative rate of speed;
• second transmission means, mounted upon said transmission shaft means, interposed between said drive means and both said web feeding rolls and said web processing means for selectively actuating both said web feeding rolls and said web processing means at a second operative rate of speed;
• brake means operatively connectible to said web feeding rolls and said transmission shaft means for selectively permitting said web feeding rolls and said transmission shaft means to rotate in a drive mode, or for preventing rotation of said web feeding rolls and said transmission shaft means;
• and
• one-way transmission means interposed between said transmission shaft means and said web processing means for permitting said web processing means to continue to rotate for a predetermined time after said brake means has stopped rotation of said web feeding rolls and said transmission shaft means so as to cause said web processing means to retain said web of material, interposed between said web feeding rolls and said web processing means, in a tensioned state.

Apparatus for tensioning a web of material, pulled from a supply roll by means of web feeding rolls, between said supply roll and said web feeding rolls, comprising:

• a supply roll of said web material;
• web feeding rolls for withdrawing said web material from said supply roll;
• senser means for sensing the progressive diminishing of the outer diameter of said supply roll as said web of material is withdrawn from said supply roll by said web feeding rolls;
• means operatively connected to said senser means for generating signals indicative of said sensed outer diameter values of said progressively diminishing supply roll;
• central processing means operatively connected to said signal generating means for receiving said signals and comparing said sensed supply roll outer diameter value signals with predetermined volume values stored within said central processing means;
• and
• braking means operatively connected to said supply roll of said web material for progressively retarding the rotation of said supply roll, in response to signals received from said central processing means, as said outer diameter of said supply roll progressively diminishes in order that said web of material is withdrawn from said supply roll under a predetermined amount of tension.