Patent GB-632973-A (GB)
Title: Improvements in or relating to heads for container filling machines
IPC: B65B39/00
Filed: 1947-06-25
Abstract: 632,973. Filling nozzles for powdered materials. CARTER, C. F. June 25, 1947, No. 16745. Convention date, Sept. 23, 1946. [Class 94(i)] An improved head for container-filling machines of the kind described in Specification 632,517, comprises a member having a part adapted to fit loosely inside the open top of the container, spaced from another member which fits loosely around the outside of the container, the annular opening thus formed being adapted to receive the closure means of the container and a limited portion of its side walls, means operable to form an air tight joint in the opening comprising an expandable member adapted when expanded to fill the opening, and means for expanding the last mentioned member. In the construction shown in Fig. 1 the filling head comprises a body 18 which carries by means of support members 23, a shroud 13 adapted to enclose a container 12 being filled, and a throat member 26 adapted to enter between the container flaps 16 and a limited portion of the sides of the container. The throat 26 has inwardly-sloping guides 27 in order to direct the flaps through an annular space A between the throat and the flange 24 of the shroud 13 when the container is being moved into filling position by the vertical movement of a platform 10 on which the container stands. This movement may be derived' as described in Specification 632,517. The platform 10 has an annular seal 11 which co-operates with a seal 14 carried by the cowl in order to form an air tight joint between the platform and cowl when the container is in the filling position. The annular space A opens laterally into an annular groove or channel 28a in the shroud flange 24 which contains an expandable rubber tube 28 which thus surrounds the periphery of the container at the top of its body portion. Compressed air may be applied to the tube 28 through a tube 30 in order to cause the container sides to be gripped against the throat 26. In a second construction (Figs. 3 and 4, not shown) the groove 28a is formed in the throat 26 so that the tube 28 expands against the inner periphery of the container. Alternatively a tube 28 may be provided both in the throat and the flange 24. The tube 28 may alternatively be replaced by a rubber member which is pressed against the container sides by cams. The body 18 is formed with a central circular passage leading from a hopper 17 to the container and two rectangular passages 22 connected by respective pipes 19, 20 to air-evacuating means (not shown). Screens 21 are secured to the container end of each passage 22 by means of a shoulder on the throat 26 and a shoulder formed on a member 31 secured to the lower end of the central passage. The shroud 13 is connected by a pipe 15 to air-evacuating means, and fins 13<SP>1</SP> prevent expansion of the container if the pressure inside and outside of the container are unequal. The hopper 17 may be removable and may be associated with a plurality of filling heads. In operation, air pressure is applied to the tube 28 to grip the container after it has been raised into filling position by the platform 10. Each side of the filling head via the respective passages 22 is alternately evacuated. After each evacuation the pressure is restored to atmospheric in order to clear the respective screen 21 of powder.