Signode Corporation

George A Crosby

John H Leslie

An apparatus is provided on a strapping machine frame adjacent a strap chute and adjacent a strap end gripping and sealing assembly and has a pivotably mounted strap guide arm and gripper for guiding the strap during feeding in a first, upper position and for gripping the strap when the arm moves downwardly away from the first position. A single, reversible, rotating drive motor is mounted for movement with the guide arm and powers a gear drive assembly which is engaged with the motor and movable therewith for (1) rotating feedwheels to feed the strap to form a loop when the motor is rotating in a first direction, (2) rotating the feedwheels to withdraw the strap to pretension the loop with a first predetermined tension when the motor is rotating in a second direction, and (3) rotating a high tension pinion gear when both (a) the motor is rotating in the second direction and (b) the tension in the strap exceeds the predetermined, first tension. During high tensioning, the pinion gear moves along a rack and pivots the guide arm out of the first position to a second position whereby a gripper is actuated to grip the trailing portion of the strap and pull the gripped strap, thereby drawing a higher, second tension in the loop.

Strap feeding and tensioning assembly

A method and apparatus is disclosed for binding an article with strap. A strap is encircled about the article to form a loop with the leading end segment of the strap overlapping an adjacent segment of the strap. The leading end is gripped to prevent further feeding and to subsequently restrain it against movement relative to the article while the trailing portion of the strap is retracted to draw the loop tight around the article. While holding the leading end segment of the strap and an adjacent overlapped segment against relative movement and under tension, either (1) a joint is first formed in the overlapping segments and the tension is then gradually released in the trailing portion of the strap to avoid shock loading of the joint and the machine or (2) the tension is first released only in the trailing portion of strap and the joint is then formed with tension in at least the overlapped segment adjacent the strap free end. The preferred embodiment of the apparatus is used with metal strap and forms an interlocking slit-type joint in the overlapping strap segments with a notcher jaw assembly coacting with a notcher punch, both of which also function prior to joint formation to hold the overlapping strap segments together against relative movement and to maintain tension on the overlapped segment adjacent the strap free end while tension is released in the trailing portion of strap.

Method and apparatus for binding an article with a loop of tensioned

A combination jam-clearing and torque sensing traction wheel assembly and strap feed stopping mechanism is disclosed for use in a strapping machine which feeds strap in a chute about an article to form a loop and subsequently tensions the loop tightly about the article. The strap is fed into the chute by a rotating traction wheel which is driven through a torque sensing assembly comprising a driven plate, a spring-biased driver plate, and drive motor. Feeding of the strap is intermittently stopped and started as the driver plate is forced out of engagement with the driven plate when the torque increases beyond a predetermined amount in response to increased strap feed resistance resulting from an obstruction in the chute. In one embodiment, the strap feed stopping mechanism includes a permanent strap end abutment member located just past the strap overlap region in the strapping machine. When the strap free end hits the abutment member, the driver plate is forced out of engagement with the driven plate and feeding of the strap is terminated. In another embodiment, the strap feed stopping mechanism includes a ratchet wheel and a pawl actuated by a sensor in the strap chute and which is responsive to the strap free end location in the chute when a loop is being formed. Tripping of the sensor by the strap free end actuates a mechanism to move a pawl into engagement with the ratchet wheel to prevent further strap feed rotation of the traction wheel secured thereto. Additionally, the restraint against the traction wheel rotation causes the driver plate to disengage from the traction wheel.

Growing community of inventors

Long Grove, IL, United States of America

George A Crosby