Packaging sealer having rotatable sealing wheels - fitted with pneumatic tyres which are independently pressurised

摘要

A packaging sealer for making three spaced seals in superimposed webs is described. Three sealing wheels are mounted on a rotatable shaft and work against opposed anvil wheels. Each sealing wheel has a pneumatic tyre. Tyre pressures are independently controlled through regulators. These are connected to piping which extends through the hollow shaft and communicates with the inflation spaces of the tyres. The device is used for heat or pressure sealing of packages used for the health or for food or anhydrous materials. Compensation can be made for slight dimensional or positional abnormalities e.g., as small as 0.001 inch for out-of-roundness, shaft deflection and the like. Sealing pressure is automatically kept uniform, which avoids defective seals.