| 摘要 |
A device for controlling the sealing of thermoplastic overwraps, particularly sealing end flaps of the overwraps on packets of cigarettes. At various speed levels of the overwrapping machine the time devoted to this sealing operation is kept constant. This is achieved by providing a plurality of control cams, the number of which corresponds to the number of speed levels there are on the machine. Each control cam operates at one of the speed levels, to periodically activate and deactivate sealing contrivances which operate on the ends of the packet. |
