| 摘要 |
<p>A plastic sheet is formed into a loop and a guide means shapes the sheet into a tube, heat welding clamps being provided to form longitudinal and transverse seals, the movement of the clamps, the forming of the loop and a brake for the sheet being precisely co-ordinated so that when the clamps are opened the brake is applied to stretch the material of the loop, the sheet being pulled towards the base under the action of the weight of the material used to fill the bag. The bags are esp. useful for packaging coins and may be attached to a coin counting machine, but may also be used for solids and liquids. The clamping jaws for heat sealing and the brake may be cam operated to co-ordinate their movements through a synchronising circuit which controls their movements and the heating cycle.</p> |
