| 摘要 |
<p>A cyclicly operable machine for providing a tensioned loop of fusible thermoplastic strapping about a loosely positioned object, wherein a hoop-mounted slip-feed carrier is caused to orbit the object in one direction while one end of the strapping is held by a gripper. In so orbiting, the carrier progressively wraps a closed loop about the object, the loop having overlapping ends which become sealed to each other by a friction-fusion operation. Such sealing accomplished by a cooperating anvil and vibrator which move into the strap path to create the seal and away from the path to allow the sealed loop to completely seize the object, after which a cutter severs the excess strapping from the object. A reverse orbiting of the carrier similarly applied a successive strap loop to the object. A strap storage and dispenser system, including a strap reel, supplies strapping to the carrier and has facilities whereby, during initial application of the loop, the relatively light tension which is applied will not unseal or dislodge the loosely positioned object and whereby, after the loop is completed, a high degree of tension becomes effective to draw the loop tight around the object immediately prior to the sealing operation. Initial movement of the carrier in either direction feeds strapping back into the storage and dispenser system during partial object wrapping, but continued motion of the carrier again withdraws such stored strapping during final wrapping. A pinch or drag roller normally inhibits withdrawal of strapping from the reel during use of the stored strapping but releases the reel to pay out strapping when the stored strapping is exhausted. Novel means are provided for actuating the vibrator, the anvil, the gripper and the cutter at appropriate points in the machine cycle.</p> |
