Signode Corporation

Illinois Tool Works Inc.

Robert J Kobiella

Timothy B Pearson

James A Haberstroh

Mark B Renz

Nelson Cheung

A strapping machine of the type configured to feed a strapping material around a load, position, tension and seal the strapping material around the load includes a weld head having a readily removable and serviceable weld blade. The head includes a body, a blade arm biasedly mounted to the body and a carrier receivable in the blade arm and movable between an operating position and a service position. The carrier is securable in the blade arm, without tools, in the operating position and the service position. The weld blade is fixedly mounted to the carrier.

Strapping machine with pivoting weld blade

A strapping machine for positioning a strap material around an associated load and tensioning the strap material around the load includes a frame for supporting the load, a chute positioned on the frame for receiving the strap material and orienting the strap material around the load, a strap supply and a strapping head for extracting the strap from the supply, feeding the strap through the chute around the load, passing the strap from the chute around the load, retracting and tensioning the strap. The strapping head includes feed rollers and retraction rollers for feeding and retracting the strap and a winder for tensioning the strap around the load. The winder is positioned between the feed and retraction rollers and the strap supply. The winder includes a rotating head portion having a stationary element and a pivotal element. The stationary and pivotal elements each define an outer surface around which the strap material is wound and a slot therebetween for receiving the strap material. The stationary and pivotal elements each further define a gripping portion at about respective ends opposingly facing one another. The pivotal element is pivotal between an open position in which the gripping portions are spaced from one another and a closed position in which the gripping portions cooperate with one another to engage and secure the strap material therebetween. The winder rotates from a home position in which the winder is in the open position and an other than home position in which the winder is in the closed position to exert a tension in the strap.

Strapper with improved winding and cutting assembly

A novel method and apparatus are provided for making an improved welded joint between overlapping lengths of thermoplastic strap. The welded joint includes a central region and an adjacent peripheral region. The pressure on the strap joint during formation is released first in the peripheral region and subsequently in the central region. An embodiment of the apparatus for making such a joint includes an anvil, a central strap-engaging member, a peripheral strap engaging member, and a mechanism for moving the anvil sequentially to three positions. At a first position the overlapping strap lengths are pressed between the anvil and both the central and peripheral strap-engaging members. In the second position of the anvil the peripheral strap-engaging member does not press against the strap lengths while the central strap-engaging member continues to press the strap lengths against the anvil. In the third position of the anvil the anvil and strap-engaging members are sufficiently spaced apart to release all of the pressure on the strap lengths.

Method and apparatus for producing a welded joint in thermoplastic strap

A method and apparatus is provided for securing together overlapping portions of a thermoplastic strap loop around an object. The overlapping strap portions are forced together in face-to-face contact under pressure. During or before the step of forcing the strap portions together, the energy in the strap portions is increased so as to melt at least a part of the thickness of each strap portion at the interface region. One embodiment of the method also includes forming a plurality of cavities that are distributed across the width of the molten parts adjacent the ends of the molten parts and that are surrounded by the molten parts. The step of increasing the energy is then terminated, and the strap portions at the interface region subsequently solidify, to encapsulate the cavities and form the welded joint. In another, and preferred, embodiment of the invention, the pressure on the strap portions is released while the parts of the strap portions are molten (whether or not cavities are present), and the strap portions at the interface region subsequently solidify in the absence of pressure.

A method and apparatus is provided for securing together overlapping portions of a thermoplastic strap loop around an object. After the strap is fed to form the loop, the upper strap portion is restrained while pulling the strap trailing portion to tension the loop. Lengths of the upper and lower strap portions are then gripped together in face-to-face contact to hold the loop in tension. The trailing portion is severed from the loop lower strap portion, and the restraint of the upper strip portion is terminated. A heating member is extended between the upper and lower strap portions in a direction generally parallel to the strap length. The upper and lower strap portions are pressed against the heating member to melt regions of the strap. The heating member is withdrawn, and the melted regions are pressed together as the melted regions solidify to form a joint. Included in the apparatus are coacting first and second gripper means, an anvil, a cutter, and a heating member. One of the gripper means defines a strap length receiving region below at least a portion of the gripping means for accomodating the lower strap portion prior to severing the trailing portion of the strap.

Method and apparatus for heat sealing strap in a strapping machine

A machine and method are disclosed for securing a loop of thermoplastic strap around an article so that two overlapping portions of strap are bonded together. One form of an apparatus in the machine has a strap engaging weld pad with spaced-apart, parallel strap-engaging ribs for effectively making a friction-fusion weld in thin film strap. Another form of the apparatus in the machine includes a rack gear associated with a weld pad and engaged with an arc of teeth on a torsion bar for utilizing the torsional oscillation kinetic energy to reciprocate the weld pad along a linear path of motion. Another form of the apparatus in the machine includes a strap carrier chain for forming the strap in a loop about an article and the chain may include a resilient lug positioned between each pair of adjacent cross pins in the chain. Another form of the apparatus in the machine includes (1) means for reciprocating an anvil between a retracted position and an extended position below an article, (2) grippers and cutters connected with a linkage system to move the grippers and cutters between a closed position against the anvil and open position away from the anvil, and (3) carriages for moving the cutters and grippers from a retracted position to an extended position independently of the anvil. All of the forms of the apparatus may be used separately and independently of each other in various other types of strapping machines.

Article strapping method and apparatus, chain assembly for such

Anvil, gripper, and cutter assembly in a strapping machine

A joint is provided in first and second overlapping portions of a loop of thermoplastic thin film wide strap tensioned about an article. The joint comprises a plurality of fused regions at the interface of the overlapping portions. The fused regions are spaced apart across the width of the strap. Each fused region has the form of an interface layer of merged resolidified strap surface portions.

Film strap weld

Article strapping method and apparatus

An automatic strapping machine is disclosed wherein strap is fed at a high rate of speed about a package so as to form a loop which is then tensioned and sealed. The loop is formed so that the leading end of the strap is overlapped by a trailing end of the strap and the resulting overlapped strap portions are joined together so as to form a seal which is not susceptible to snagging. The distal end of the overlapping strap end portion is urged against and is moved back and forth relative to an underlying strap portion in tension at a high rate of speed so as to generate heat therebetween and to form a friction-fused joint. During joint formation the strap loop about the package is in tension, but the strap end portion overlapping the loop is relaxed, i.e., not in tension. Sealing energy generating means is adapted to engage the distal end of the overlapping strap end portion and comprises a pivotable anvil and a rotatable - oscillatable hammer adapted to receive overlapping strap regions therebetween, and an oscillating motor means for the hammer which engages the loop-over-lapping strap end portion and rubs the overlapping end portion against the underlying strap region at a rate sufficient to melt an interface region therebetween and to form a friction-fused joint when energized by the oscillating motor means.

Automatic strapping machine

A strap feeding and tensioning machine is disclosed wherein strap is fed at a high rate of speed about a package so as to form a loop which is then tensioned and subsequently can be sealed. The loop is formed so that the leading end of the strap is overlapped by a trailing end of the strap and the resulting overlapped strap portions are joined together by means of an external seal, by friction fusion, or in any other convenient manner. The feeding and tensioning mechanism comprises a rotatable winder drum equipped with a pair of arcuate feed guide means, a feed wheel rotatably mounted on the winder drum, and reversible driving means for the winder drum and the feed wheel.

Growing community of inventors

Rolling Meadows, IL, United States of America

Robert J Kobiella