Patent GB-786715-A (GB)
Title: Valve bag filling machine
IPC: B65B1/18
Filed: 1956-05-16
Abstract: 786,715. Filling valve-bags. ST. REGIS PAPER CO. May 16, 1956 [May 18, 1955; April 25, 1956], No. 15212/56. Class 94(1). A machine for filling valve-bags with pulverulent material comprises a filling-nozzle surrounded by a sleeve of elastic material which may be inflated into sealing engagement with the interior of a bag valve to prevent escape of air and dust through the valve during the filling operation. In one form, Figs. 1 to 3, the nozzle 10 is connected by a flexible tube 13 to a hopper 29 containing pulverulent material and is surrounded by a rubber sleeve 17 having its ends secured by clamps 19 and 21. Pressure air is fed from a supply pipe 25 through a regulating valve 26 and pipe 27 to the hopper 29 and flows upwardly through a porous pad 28 to fluidize the pulverulent material. Air is also supplied to the sleeve 17 through a regulating valve 30, pipe 31, valve 32 and pipe 22, and to a valve 40 through a regulating valve 33 and pipe 34. The valve 40 is connected by pipes 41 to 44 to an air cylinder 16 operating jaws 14, 15 which are arranged to constrict the tube 13 to stop the flow of pulverulent material, to an aircylinder 24 operating a bag-clamping shoe 23, and to a flow-control valve 45 which is bypassed by a check-valve 47 and connected via a chamber 46 and pipe 55 to the valve 32. The valve 40 is also connected by pipes 50 and 60 respectively to a manually-operated valve 36 and a valve 38 which may be operated manually or through a lever 61 by a scale beam 62 supporting the bag chair 63. To initiate the filling of a bag, the valve 36 is operated temporarily to vent the pipe 50 and allow movement of the valve-member 51 to the left-hand position. Air then flows through the pipes 41 and 42 to operate the clamping shoe 23 and release the jaws 14, 15 so that pulverulent material flows into the bag. At the same time, the cylinder of the valve 32 is vented through the pipe 55, chamber 46 and valve 47 so that the valvemember 52 is moved to the left and air is admitted through the pipes 31 and 22 to inflate the sleeve 17. When the bag has been filled with the required weight of material, the beam 62 is depressed and operates the valve 38, whereby the pipe 60 is temporarily vented and the valve-member 51 is moved to its righthand position. Air then flows through the valve 45, chamber 46 and pipe 55 to move the valve member 52 to the right so that the sleeve 17 is vented through the port 54, the air cylinder 16 is operated to cause the jaws 14, 15 to constrict the tube 13 and stop the flow of pulverulent material and the clamping shoe 23 is released. The function of the chamber 46 and valve 45 is to delay the venting of the sleeve so that air escapes through the pores of the bag after closure of the tube 13 before the sleeve is deflated. The period of delay may be adjusted by a screw 45<SP>1</SP>. The nozzle 10 may be of circular or oval cross-section. In a second form, Fig. 7, the nozzle 110 comprises a rigid metal tube 114a having an extension 114c in the form of an inverted trough, and a flexible tubular liner 115. The tube 114a is surrounded by an inflatable sleeve 132 which is connected by a pipe 142 to a pneumatic circuit similar to that shown in Fig. 1, and is pivoted at 119 to the frame of the machine so that it may be swung from a lower position in which the liner 115 is constricted by a fixed metal tongue 116 to stop the flow of pulverulent material to an upper position in which the bag 112 to be filled is clamped between the trough 114c and a fixed shoe 129. The swinging of the nozzle is effected by a lever 120 coupled by a rod 128 to a piston 126 in an air cylinder 127 which is connected by pipes 170, 172 to a valve 145 similar to the valve 40 shown in Fig. 1. Alternatively the nozzle may be swung upwardly to the clamping position by an air cylinder and then allowed to swing downwardly under the weight of the bag at the end of the filling operation. In a modification, Fig. 14, the nozzle is fixed and a pivoted metal tongue 184 is swung upwardly by a lever 187 operated by an air cylinder 185 to constrict the flexible liner at the end of the filling operation.