| 摘要 |
<p>A method and apparatus for feeding and tensioning a strap (12) in a power strapping machine (10). The apparatus includes a strap feeding mechanism (32, 34), a strap tensioning mechanism (42, 46), a pivoting roller carriage (50) pivoted by a feeding and tensioning cam (70), a strap overflow housing (110) for receiving a strap (12) that is prevented from properly feeding into a strap application assembly by an obstruction during feeding of the strap (12), and strap stretch-out housing (121) for receiving a strap (12) that is removed from the strap application assembly or the strap overflow housing (110) during tensioning of the strap (12). The pivoting roller carriage (50) first actuates the strap feeding mechanism (32, 34) to engage a portion of a strap (12) and feed it toward the strap application assembly where the strap is formed in a loop about a package. The strap feeding and tensioning mechanism actuates a gripper that secures an end of the strap. The pivoting roller carriage (50) then actuates the strap tensioning mechanism (42, 46) to engage a portion of the strap (12) and apply a tension to the looped strap. The strap (12) will be fully retracted from the strap application assembly by the strap tensioning mechanism (42, 46) if the strap (12) is not properly engaged by the gripper, and the strap (12) will then be directed into a strap stretch-out housing (121) where it will remain until the strap feeding mechanism (32, 34) again engages a portion of the strap (12) and re-feeds it. The weight and position of the strap (12) disposed in the strap stretch-out housing (121) prevents it from withdrawing entirely from the strap feeding mechanism (32, 34) thereby ensuring that the strap feeding mechanism (32, 34) will automatically engage and re-feed the strap (12). <IMAGE></p> |
