Patent GB-1281217-A (GB)
Title: An improved driving and control unit for rotatable dispensers of predetermined quantities of materials
IPC: G01F11/02
Filed: 1969-08-01
Abstract: 1281217 Dispensing measured quantities AZIONARIA COSTRUZIONI MACCHINE AUTOMATICHE SpA 1 Aug 1969 [2 Aug 1968] 38717/69 Heading B8N [Also in Division F2] A dispenser for delivering measured quantities of materials comprises a rotatable body 1 containing at least one double-acting piston having piston heads 7 forming measuring chambers 9 at the ends, the piston heads being adjustably connected by a stem 8 having a gear-wheel 14 for varying chamber volume, slidably mounted and meshing with a similar wheel 15 on shaft 16 coaxial with the rotatable body 1. The pistons 7 are reciprocated by a cam through linkage, Fig. 3, the cam's movement being controlled by a hand wheel 46, Fig. 4. A gear train, operatively connected to the hand wheel 46 is provided to mesh with a planetary gear system comprising two crown wheels, 37, 44 one of which, 44 is keyed to the shaft 16, and is rotated, via the other crown wheel 37, with an angular velocity equal to that of the rotatable body 1 and in the same direction. Material to be dispensed passes from a hopper 3, Fig. 1b, into the uppermost measuring chamber 9, and the body 1 is revolved to allow material to be discharged to receiving means 4. Scrapers 10, 101 and a band 102 are provided along with a member 103 engaging the lateral surface of the body 1 and movable about the axis of the body. The body 1 is fixed to a hollow shaft 2 which is rotated intermittently by a drive shaft 26 through gears 24, 25, Fig. 4. The volume of the measuring chambers 9 is adjustable by altering the relative positions of the piston heads 7 by the threaded stem 8 which may be turned by the hand wheel 46 via gears 49, 55, 56, a shaft 57, gears 58, 43, 42, 44, shaft 16 and gear-wheels 14, 15. However, when the shaft 2, is rotating, the hand wheel gear 49 may be disconnected from the gears 55, 56, and in order that the relative positions of the pistons 7 should not be altered during rotation, a spur reduction gearing 32, 35, 36 meshing with a gear-wheel 30 secured to the shaft 2, rotates the crown wheel 37 on a fixed shaft 39 with an angular velocity equal and opposite to that of the shaft 2. The crown wheel 37 meshes with planetary gears 42 to rotate the crown wheel 44 secured to the shaft 16, with an angular velocity equal to and in the same direction as that of the shaft 2 and body 1 hence maintaining the relative positions of the pistons 7. Each piston head 7 has a roller 12, reciprocable within a slot 11, so that the pistons may be moved to receive and discharge material. The rollers 12 are moved by a projection 13a mounted on an oscillating arm 13, the amplitude of movement of which is adjustable to accommodate adjustments of piston spacing for chamber volume variation. A rotating cylinder cam 59 oscillates a shaft 71 on which the arm 13 is secured, through linkage 60, 65, 68, 70. The link 65 is slotted to receive a pin on a bell crank 66 mounted on a fixed pivot 67, the pin forming a pivot for this link. The other end of the bell crank has a pin engaging a cam groove in a disc 53. The disc 53 is turned by the hand wheel 46 which has a worm 51 meshing with a worm-wheel 52 fixed to the disc 53, thus altering the fulcrum point of the link 65 and hence the swing of the arm 13. In a second embodiment, Figs. 2a, 3b (not shown), there may be two double-acting pistons at right angles, and the separation of the second pistons heads is controlled by a worm (19) slidably mounted on the adjusting stem 8 of the first pair of pistons, meshing with a wormwheel (18) on the adjusting stem (8) of the second pair. The worm-wheel (18) is supported on an extension of a member 17 fixed to the body 1, the member 17 also having a projection (17a) engaging with a groove (14a) in the gearwheel 14 so that the gear-wheel 14 and worm (19) are maintained in position as the piston 7 and the stem 8 are moved relative to the body 1.