| 摘要 |
A tool is provided for constricting a loop of thermoplastic strap that encircles an article and has overlapping strap segments and for sealing the segments with a friction fusion weld. A multiple drive shaft assembly is driven by a motor which can be rotated in a first direction and then in a second, opposite direction. The drive shaft assembly is engaged to a tension wheel in the first direction of rotation to constrict and tension the loop. A sensing and control means senses a predetermined loop tension level and reverses rotation of one of the drive shafts to the second direction. A mechanism responsive to the rotation of the shaft in the second direction is provided for pressing the overlapping strap segments together and for moving one of the segments relative to the other segment to effect the friction fusion weld. |
