GB639130A - Improvements in and relating to clamping device for sack filling - Google Patents

Abstract

639,130. Sack holders. IMPERIAL CHEMICAL INDUSTRIES, Ltd. Feb. 17, 1947, No. 4522. [Class 58] An apparatus for filling sacks comprises a shoot 2 having one or more recesses in its wall, one or more clamping members 6 adapted to be pressed to the wall of the shoot for a portion of its perimeter and one or more secondary members 9 arranged to press the fabric of the sack into the recess or recesses in the wall of the shoot, whereby the open end of a sack placed over the outlet of the shoot is held closely and firmly to the perimeter of the shoot. As shown the clamping members 6 each comprise a cylinder having operable therein a piston 7 connected to a rod 8 passing through the end of the cylinder adjacent to the shoot. A clamping plate 14 shaped to press the sack to the wall with felt pads is attached to the rod 8. Slidably mounted in the piston rod 8 is a plunger constituting the secondary member having a head 9 shaped to co-operate with a depression in the wall of the shoot. A spring 10 controls the relative motion between the, plunger and piston rod, compressed air is supplied to the cylinder of the clamping members through the pipes 17, 19 to move the piston rods 8 towards the shoot and hold the sack by means of the plate 14 and the head 9 in the depressions. The clamping means are released by operating the 3-way valve 18 so that pipes 17 and 20 are connected and a pressure is exerted on the backs of the pistons. The valve 18 is electrically operated and electrically interlocked with the operating device for discharging pre-determined quantities of material from weighing machines only when the clamping means has operated. The clamping and secondary members may be operated by toggle and link mechanism or electrically.