Strap feeding and tensioning system

Claim 3

A method as set forth in claim 1 in which said tensioning step is performed by holding the strap in driven relationship with a rotating member, and wherein the tension relieving step is performed by terminating said driven relationship.

Claim 4

A method as set forth in claim 2 in which said strap is held in driven relationship with said rotating member by at least one pinch roll, and wherein the step of terminating said driven relationship is performed by moving said pinch roll away from said rotating member.

Claim 5

A strapping machine for providing a tensioned loop of strAp material about a package comprising: a strap supply source, means for feeding the strap from the supply source about a package to form a loop with the leading end of the strap disposed in overlapping relationship with the trailing end of the strap, means for holding the leading end of the strap to enable slack to be removed from the loop, means for tensioning the strap to place the strap in snug binding engagement with the package, means for gripping the overlapped strap ends to retain the loop under tension, means for relieving at least a portion of the tension in the strap between the gripping means and the supply source, means for cutting the trailing end of the strap from its supply source, said tension relieving means being operatively responsive to actuation of said cutting means, and means for joining the overlapped strap portions to secure the tensioned strap about the package.

Claim 6

A strapping machine for providing a tensioned loop of strAp material about a package comprising: a strap supply source, means for feeding the strap from the supply source about a package to form a loop with the leading end of the strap disposed in overlapping relationship with the trailing end of the strap, means for holding the leading end of the strap to enable slack to be removed from the loop, means for tensioning the strap to place the strap in snug binding engagement with the package, means for gripping the overlapped strap ends to retain the loop under tension, means for relieving at least a portion of the tension in the strap between the gripping means and the supply source, means for cutting the trailing end of the strap from its supply source, said tension relieving means being operatively responsive to actuation of said cutting means, and means for joining the overlapped strap portions to secure the tensioned strap about the package.

Claim 7

In a strapping machine for providing a tensioned loop of strap material about a package including a feed and tension mechanism having a first and second wheel about which the strap is disposed, means for driving the first wheel in one direction to feed the strap from a supply source, means for directing the strap into engagement with the periphery of the first wheel comprising a pair of rotatably mounted pinch rolls, means for guiding the leading edge of the strap about the package, means for holding the leading end of the strap, means for driving the first wheel in the other direction to take up slack, means for driving the second wheel in the other direction to draw a tension on the strap while the leading end is held, means for gripping overlapped portions of the strap to hold the strap loop under tension, cutter means positioned adjacent the gripper, the improvement comprising a strap tension relief means including a supporting and operating linkage connected to said pinch rolls and to said gripping means, a shaft rotatably supporting each of the pinch rolls and rotatably supported on a frame member adjacent the first wheel, toggle means connected to the pinch rolls for moving the pinch rolls from a first position in contact with the strap and feed wheel to a second position out of contact with the strap and feed wheel, spring means connected to said toggle means and biasing said pinch rolls toward the periphery of the feed wheel in said first and second positions, lever means coupled to the gripping means and said toggle means whereby when said gripping means moves into engagement with the overlapped strap portions the lever means acts upon the toggle means to move the pinch rolls from the first position to the second position, thereby relieving the tension within the strap between the gripping means and the supply source, cutter means acting in response to the operation of the gripping means for severance of the strap from the supply source after the pinch rolls have been moved to the second position.

Claim 8

In a strapping machine for providing a tensioned loop of strap material about a package including a feed and tension mechanism having a first and second wheel about which the strap is disposed, means for driving the first wheel in one direction to feed the strap from a supply source, means for directing the strap into engagement with the periphery of the first wheel comprising a pair of rotatably mounted pinch rolls, means for guiding the leading edge of the strap about the package, means for holding the leading end of the strap, means for driving the first wheel in the other direction to take up slack, means for driving the second wheel in the other direction to draw a tension on the strap while the leading end is held, means for gripping overlapped portions of the strap to hold the strap loop under tension, cutter means positioned adjacent the gripper, the improvement comprising a strap tension relief means including a supporting and operating linkage connected to said pinch rolls and to said gripping means, a shaft rotatably supporting each of the pinch rolls and rotatably supported on a frame member adjacent the first wheel, toggle means connected to the pinch rolls for moving the pinch rolls from a first position in contact with the strap and feed wheel to a second position out of contact with the strap and feed wheel, spring means connected to said toggle means and biasing said pinch rolls toward the periphery of the feed wheel in said first and second positions, lever means coupled to the gripping means and said toggle means whereby when said gripping means moves into engagement with the overlapped strap portions the lever means acts upon the toggle means to move the pinch rolls from the first position to the second position, thereby relieving the tension within the strap between the gripping means and the supply source, cutter means acting in response to the operation of the gripping means for severance of the strap from the supply source after the pinch rolls have been moved to the second position.

Claim 9

A strapping machine for providing a tensioned strap about a package including a feeding and tensioning mechanism having a first feed wheel, a second tension wheel, and a pair of pinch rolls rotatably supported on shafts adjacent the feed wheel and having their peripheries in contact therewith, a supply of strap material, a portion of the the strap material disposed about the feed wheel between the periphery of the pinch rolls and feed wheel, means for guiding strap about the package, means for driving the feed wheel in one direction to feed strap material through said guide means and around the package, means for driving the feed wheel and the tension wheel in the opposite direction to draw slack and tension in the strap, means for holding the leading end of the strap after it is fed about the package and during the tensioning operation, gripping means for holding the leading end of the strap in overlapped relationship with the trailing end of the strap after the leading end of the strap has been engaged by the holding means and tension has been drawn on the strap, cutter means for Severing the strap from the supply of strap material, strap tension relief means comprising a toggle linkage secured to said pinch roll shafts and constructed to move said pinch rolls from a first position in which said pinch rolls are in contact with the feed wheel and the strap disposed therebetween to a second position in which said pinch rolls are out of contact with said feed wheel and said strap, the toggle linkage including a pair of links each secured to a pinch roll shaft, spring means connected between said links for biasing the pinch rolls toward the feed wheel in said first and second positions, a pivotally mounted lever operatively associated with said toggle linkage, said lever having a cam surface thereon, an operating linkage connected to said gripping means and having a cam follower in contact with the lever cam surface, whereby when said gripping means is moved into engagement with the overlapped strap portions, the lever is moved to cause the toggle linkage to move said pinch rolls away from the feed wheel periphery and the strap disposed thereabout, thereby relieving the tension between the gripping means and the supply source.

Claim 10

A strapping machine for providing a tensioned strap about a package including a feeding and tensioning mechanism having a first feed wheel, a second tension wheel, and a pair of pinch rolls rotatably supported on shafts adjacent the feed wheel and having their peripheries in contact therewith, a supply of strap material, a portion of the the strap material disposed about the feed wheel between the periphery of the pinch rolls and feed wheel, means for guiding strap about the package, means for driving the feed wheel in one direction to feed strap material through said guide means and around the package, means for driving the feed wheel and the tension wheel in the opposite direction to draw slack and tension in the strap, means for holding the leading end of the strap after it is fed about the package and during the tensioning operation, gripping means for holding the leading end of the strap in overlapped relationship with the trailing end of the strap after the leading end of the strap has been engaged by the holding means and tension has been drawn on the strap, cutter means for Severing the strap from the supply of strap material, strap tension relief means comprising a toggle linkage secured to said pinch roll shafts and constructed to move said pinch rolls from a first position in which said pinch rolls are in contact with the feed wheel and the strap disposed therebetween to a second position in which said pinch rolls are out of contact with said feed wheel and said strap, the toggle linkage including a pair of links each secured to a pinch roll shaft, spring means connected between said links for biasing the pinch rolls toward the feed wheel in said first and second positions, a pivotally mounted lever operatively associated with said toggle linkage, said lever having a cam surface thereon, an operating linkage connected to said gripping means and having a cam follower in contact with the lever cam surface, whereby when said gripping means is moved into engagement with the overlapped strap portions, the lever is moved to cause the toggle linkage to move said pinch rolls away from the feed wheel periphery and the strap disposed thereabout, thereby relieving the tension between the gripping means and the supply source.

Claim 11

The strapping machine set forth in claim 6 wherein said operating linkage actuates said cutter means after the pinch rolls have been moved away from the periphery of the feed wheel.

Claim 12

The strapping machine set forth in claim 6 wherein the pinch roll shafts are provided with a portion offset with respect to rotational axis of the pinch rolls, the offset portions of said shafts being rotatably mounted at fixed locations.

Claim 13

The strapping machine set forth in claim 8 wherein a toggle linkage is provided for actuating said gripping means, said toggle linkage having a first link and a second link and a pivot connecting the links, said cam follower being a cam roller rotatably mounted on the toggle linkage pivot and positioned in rolling contact with the cam surface on said lever.