Patent GB-672945-A (GB)
Title: Improvements in the packaging of powdery, granular and other fluent solid materials
Inventor: ROSE ALFRED GERMAN
IPC: B65B1/38
Filed: 1949-07-21
Abstract: 672,945. Filling-machines. ROSE BROS. (GAINSBOROUGH), Ltd. Sept. 27, 1950 [July 21, 1949], No. 19194/49. Class 94(i). [Also in Groups XVIII and XXVI].. In a filling-machine in which powder is fed from a hopper into a measuring cylinder containing a piston which determines the quantity measured and is subsequently operated to discharge the powder through a funnel into a container, there is formed between opposed surfaces of the piston and cylinder an annular chamber to which air under low pressure is admitted to minimize or prevent leakage of powder through the working clearance between the piston and cylinder. The chamber may be formed in the piston or cylinder wall or partly in the piston and partly in the cylinder wall. As shown, powder 11 flows from a supply pipe 12 into a collecting chamber 13 from which it passes into pockets 14 and cylinders 16 in a rotatable wheel 17, the pockets being provided with pivoted bases 18 which are opened at intervals by cam mechanism to allow the powder to fall through discharge chutes 21 into cartons 22 moved into position by a chain conveyer 23. The chamber 13 is arranged in an annular channel 24 in the wheel 17 and forms with the base thereof an enclosed chamber through which the pockets and cylinders pass in succession. The wheel 17 is carried by a series of pillars 26 secured to a chain wheel 27 mounted on a sleeve 28 forming part of the main driving gear. Each cylinder is provided with a piston 38 whose rod 39 is pivoted to the arm 41 of a two-armed actuating lever 41, 42 pivoted to a bracket 44 depending from an adjusting wheel 29, the latter being formed with bosses 31 slidable on the pillars 26, and supported by a thrust bearing 33 carried by a sleeve 34 in threaded engagement with a rotatable adjusting shaft 37. The levers 41, 42 are rocked to actuate the pistons by twoarmed operating levers 49, 51, the arms 49 of which carry rollers 52 engaging a stationary cam 53 secured to the sleeve 34 under the action of springs 54. The arms 42 and 51 are urged towards each other by springs 56. Each cylinder is formed with an annular chamber 57 to which air under low pressure is admitted through a flexible conduit 58 and conduits 59, 62 and 64 in the wheel 29 and a flanged member 66 from a central bore 63 in the shaft 37. A felt sealing ring 67 is arranged in a recess in each piston, the air from the chamber 57 oozing through the ring being effective to prevent leakage of powder through the clearance between the piston and cylinder without causing turbulence in the powder in the cylinder. As each pocket 14 reaches the discharge station, the piston in the preceding cylinder 16 is raised to discharge the powder on to the base of the channel 24 within the confines of the walls of a stationary guiding member 83, Fig. 2 (not shown), so that as the pocket passes the guiding member it receives the contents of the cylinder and the charge delivered to the carton is thus supplemented. Variation of the volume of powder delivered to the cartons is effected by raising or lowering the wheel 29. The cam 53 provides the maximum required stroke of the pistons, and when the apparatus is adjusted for a smaller volume, stops 46 on the piston rods engage fixed abutments 47 to prevent the pistons protruding from the upper ends of the cylinders, the necessary lost motion being provided by the spring connection between the arms 42 and 51. Specification 690,215 is referred to in the Provisional Specification.