| 摘要 |
Apparatus for forming a travelling transverse seal on a continuous flexible packaging film comprises a conveyor belt 8 over a counterpressure plate 10 capable of reciprocating to and fro in the direction of conveyor advance. A travelling seal bar 9 above the conveyor belt 10 is resiliently carried by a horizontal carrier 12 on a vertical beam 13 forming part of a driven rotating parallelogram linkage 13, 14, 15. At the bottom of the orbit of the seal bar carrier 12 the seal bar 9 is pressed into contact with flexible packaging material of a tubular structure 7 to be sealed and is then able to travel along a flat horizontal path during progressive compression and expansion of the springs 11 which mount the seal bar 9 on the carrier 12. During this flat part of the seal bar path, the contact with the flexible packaging material is long enough to effect a seal. <IMAGE> |
