GB395546A - Method of and apparatus for making capsules - Google Patents

Abstract

395,546. Moulding capsules. SCHERER, R. P., 19995, Briarcliffe, Detroit, Michigan. U.S.A. Oct. 7, 1932, No. 27993. Convention date, Oct. 12, 1931. [Class 87 (ii).] In a method of forming capsules, a defined portion or area of plastic covering material is positioned by pressure against opposite sides thereof and fluid or powdered filling substance deposited on said portion with simultaneous deformation thereof to produce a cavity which receives the filling material. Gelatine flows from a liquefying tank 10 to a spreader 16 which spreads it upon the central portions of webs 18, 20, which are carried around rollers to points 30, 32 where the gelatine strips are removed and carried to the capsule forming mechanism 34. The capsules leave by a shoot 36, the waste strip being drawn down by rollers 38, 40 and fed to a tank 44 for re-use. The spreader comprises a box structure seated on the rollers 62, 64, so that a coating, the thickness of which is varied by means of adjustable blades, is picked up by the webs. A coil spring 88, Fig. 2, tensions the endless webs from which the gelatine bands are stripped and pass between rolls 202, 206, which exude oil, over guide rolls 224 and between rods 228 to the injecting member 242. This comprises a triangular member shaped to correspond to the curvature of die rolls 154 and containing a heating coil 248, Fig. 5. The medicinal or other filling fluid or powder, is fed to a passage 272 bored in the member 242 this passage having two small openings 280, 282 through which the material is deposited on to the gelatine strips. These are held close to the element 242 to exclude air by means of bevelled die flanges 162 provided around the apertures 160 which are regularly spaced around die rolls 154. Each aperture carries an ejector 166 which is operated by cams 144 or 146 to eject any capsule which does not fall by gravity. A cam-operated pump ejects a measured quantity of material at regular intervals through the openings 280, 282 on each portion of the strips lying within the die flanges 162 as they pass these openings. The strips are depressed to form pockets which are sealed by the strips being pressed together by the die flanges. The leading edges of co-operating flanges are timed to engage at the same time that the rear edges pass over the openings 280, 282, so that closing begins almost immediately after the injection. A driving shaft 104, Fig. 3, carries a pinion 106 which meshes with a gear wheel 108 to drive a cam 306 which actuates a pump plunger 304 to inject fluid into the element 242 by way of the pipe 270, Fig. 2. To prevent injection into the capsules of the small quantity of air permitted to enter the injection passages 280, 282, by the gelatine strip between successive dies wiping away fluid, a projecting pin 316, Fig. 3, is positioned to give a slight stroke to the plunger prior to ths actual injection. Within the projecting sleeves 112, 114 are rotatably journalled sleeves 120, 116, the latter carrying a worm wheel 110 driven by a worm gear on the shaft 104, and the former being eccentric and carrying a handle 124. A sleeve 126 is positioned within sleeve 120, and shafts 132, 134 extend through the sleeve assemblies and carry collars 140, 142 connected by a rod 138 to prevent rotation. The shafts also carry the cams 144, 146 for actuating the ejectors 166. Rotation of the handle 124 adjusts the relative position of the die rolls 154 mounted on bosses projecting from meshing spur gears 148 on the sleeves 126, 116. These gears drive rolls 184, 186, Fig. 2, the oiler rolls 202, 206, and the pinions 332, 334 which exert a frictional drawing action on the gelatine strips.