| 摘要 |
<p>1,168,117. Packaging machine. TETRA PAK A.B. 5 June, 1967 [30 June, 1966], No. 25864/67. Heading B8C. A form and fill machine of the kind that forms a tube 3 by longitudinally sealing a web 1 has a bell-shaped member 12 fitted on to the filling pipe 8 and forming a seal with the inside of the tube so that a volume of gas (31), Fig. 3 (not shown), enclosed above the surface of the filling material is used to control the level of the material. The device is particularly applicable to handling viscous material. As shown, when the material rises above a certain level, excess pressure in the enclosed volume acts on the material and causes a consequential pressure increase in pipe 9, whereupon a relay unit 10 controls a throttle valve 11 to reduce the flow. The pipe 9 may be eliminated and a throttling element controlled by the pressure in pipe 8. The bell-shaped member 12 helps prevent stress on a seam 2 formed by a welder 4. An outer sleeve, or specially shaped transverse sealing jaws may further support the tube (not detailed). The member 12 may be perforated at the point where it leaves the surface of the tube so that air entering down the filling pipe with the material does not build up excessively inside the enclosure formed by the member.</p> |
