| 摘要 |
A mandrel for supporting a roll of flexible web material has a brake mounted thereto that can be selectively activated to apply a braking force to rotation of the roll of flexible material about the mandrel. The brake includes an inflatable bladder and a shoe, such that when the bladder is inflated the shoe is pushed into engagement with the core of the roll of flexible material. The mandrel is particularly well suited for use with a packaging machine in which a sheet of flexible material is indexed form the supply roll. Before the completion of an indexing cycle, the bladder may be inflated such that further advancement of the sheet of flexible material or rotation of the supply roll is countered and inhibited. This braking of the supply roll advantageously introduces tension to the sheet of flexible material without the use of a dancer roll arrangement. |
