| 摘要 |
<p>A device for controlling the sealing of wrapping formed of thermoplastic material, particularly on machines that overwrap packages, for example, cigarette packages or the like, the device being of the type that includes a wrapping line having a plurality of sealing stations, each sealing a portion of a package on the individual products, the total contact time, i.e., the sum of the individual contact times at all stations between the sealing members and the heat-sealing material on each product, being such that more or less perfect operations are achieved with the machine operating at its rated speed. Sealing contrivances connected to drives which cause them to operate with a reciprocating motion are installed at the stations, the sealing contrivances being provided with complementary heating means for sealing the wrapping onto the cigarette packages at a speed compatible with the individual operating levels, and controls are connected to means sensitive to variations in the operating speed levels of the machine for actuating the drives, so that the sealing action of part of the each sealing contrivance is either put into or out of operation to suit the individual operating speed levels detected by the means sensitive to variations therein.</p> |
