Patent GB-757750-A (GB)
Title: Improvements in or relating to vibratory machines for packing substances, such as explosives, into containers
IPC: B65B1/22
Filed: 1954-03-15
Abstract: 757.750. Filling blasting cartridges. HERCULES POWDER CO. March 15, 1954 [April 1, 19531. No. 7514/54. Class 9(1) [Also in Group XVII] Cartridges are filled and packed with explosive by using a reciprocating member to force the material through a passage into each cartridge while vibrating the cartridge to consolidate the explosive and shortening the effective stroke of the reciprocating member when the cartridge is sufficiently filled. Furthermore, reciprocation with the shortened stroke is continued to produce a core of explosive in the passage, the filled cartridge then being replaced by an empty cartridge and the stroke lengthened to force the core into the empty cartridge case. The machine for filling blasting cartridges comprises a platen 11 mounted on resilient supports 12 which are raised and lowered by fluid cylinders 13, a vibrator 14 fixed to the platen being actuated by a piston 15 reciprocated vertically. A hopper 38 provided with stirrers 41 has outlet nozzles 40 which enter the mouths of cartridges 37 resting on the platen 11, when the platen and a shuttle 30, Fig. 2, are raised to the filling position. Above the hopper is a reciprocable cross-head assembly 42 in which metal rods 44 are supported. Wooden tamping sticks 45 with rubber tips 46 are joined to the rods, which extend through airtight cylinders 48 and carry piston heads 49. Each rod is also engaged with an orificed cam member 56, so that as the piston 49, Fig. 3, approaches the upper limit of its stroke the rod engages a projection 58 on the cam and carries the cam upwards. A projection 59 on the cam then clears a lever 60 attached to a spring-loaded rod 61 and the lever 60 then rotates to actuate valve mechanism shutting off the flow of air to the vibrator 14 and reversing the air flow in cylinders 13 to lower the platen. When the rods are returned to the down position the lever 60 is recocked to begin the next cycle of operations. The hopper may be filled by a belt conveyer. The shuttle is then loaded with empty cases and the platen 11 raised to bring the cases into engagement with the filling nozzles 40. The stirrers 41 are rotated in synchronism with reciprocation of the crosshead assembly 42 by cranks 43 connected to a power source (not shown). On raising the platen 11, the vibrator 14 is automatically actuated and the sticks 45 are reciprocated to force explosive through the nozzles into the cases, where it is consolidated by the vibration. Air is gradually admitted to the cylinders 48 through ports 50 so that the effective stroke of the pistons 49 is gradually shortened and when the cases are filled a solid core of powder is formed in each nozzle. The formation of this core raises the piston until a port 53 is uncovered to admit air at high pressure into the cylinder 48 and force the piston 49 upwards, thereby withdrawing the tamping stick 45 and actuating the valve mechanism controlling the vibrator 14 and the cylinders 13. The platen 11 is then lowered and the powder columns break away at the nozzle rims. A cylinder 33 is then actuated to swing the shuttle 30 and filled cartridges clear of the platen, whereupon the cartridges fall into a rack 16. The shuttle is then moved by cylinder 34 to a horizontal position and empty cases inserted by an automatic feeding device (not shown). Cylinder 34 is then used to return the shuttle to the vertical position and the platen is raised to start a fresh cycle of operations, the core in the nozzles being pushed into the cases. The rack 16 is swung by cylinder 18 to a vertical position, Fig. 2, and crimping mechanism 19 is pulled downwards by a rod 20 on actuation of cylinders mounted at each end of the machine. Dies 23 fold the cases inwardly and plungers 24 complete the crimping operation. Pressure is then reversed, the crimping assembly raised and the rack 16 forced outwardly to discharge the cartridges on to a tray or moving belt. In a modification, three shuttles, each with openings for a row of cases, are pivotally mounted on a rotatable support, so that the shuttles can be brought successively to the filling and crimping positions. The shuttles may be in sections which are drawn together to hold the cases in position. The frequency of the vibrator 14 may be varied as in U.S.A. Specification 2,609,791 according to the type of powder being packed. Fig. 6 shows a pneumatic vibrator having a unidirectional power stroke. Air entering through an inlet 84 flows into a groove 76 and through a duct 79 to force the piston 70 upwardly until an exhaust port 82 is uncovered. At the completion of its stroke, the piston falls freely cushioned by the air in the lower part of the cylinder. By plugging the duct 79 and removing a plug 86 the piston stroke may be reversed.