GB610821A - Improvements in and relating to machines for and method of making filled capsules - Google Patents

Abstract

610,821. Moulding capsules. COWLEY,B. C. July 30, 1945, No. 19493. [Class 87(ii)] A capsulating machine having mechanism for moulding capsule shells from a plastic film and for progressively sealing juxtaposed edges of the shells under pressure while holding fluid therein, is characterized by means initially preforming the plastic shells prior to the introduction of the fluid (e.g., a liquid medicement, a paste or a powder) and means actuated during the sealing operation for commencing the injection of a predetermined amount of fluid into the preformed capsule, the injection being completed just prior to the completion of the final sealing thereof Fig. 1-3 show diagramatically suitable mechanism : for achieving this end . Figs. 4-9 (not shown) illustrate in greater detail a preferred form of machine. Each capsule 10, of e.g. soluble gelatin, is formed from two continuous strips of gelatin film 11 and 12, which may be made continuously by flowing melted gelatin from a heated container 14 over a casting drum 15 and oiling rolls 16 past a heater 17, having say hot water or steam but preferably electric coils 18. The two coacting die rolls 22 have mould cavities 20 surrounded by die ledges 23 to cut out the finished capsules 10. At position A air is sucked from the cavity 20 by passage 24, pipe 25 and vacuum pump 28 so that the film is drawn into hemi-spherical (or elongated) shape. This vacuum is maintained until past position B. The half shells approach each other until they contact at position B where the opposed ledges 23 seal the films 11 and 12 together and progressively shear the sealed capsule from the strips as the ledges pass the centre line of the axes of die rolls 22. An intermittent pump 30 forces a predetermined fluid charge through pipe 31 having an end 32 which is thin-walled and has an elliptically shaped orifice, Fig. 3, and is arranged to project into the capsule almost to the sealing position of the leading edges of coacting ledges 23. Just prior to final sealing (a) the trailing edge of the capsule passes the tip of end 32, as shown in Fig. 2 and (b) the vacuum is released in the two coacting mould cavities by holes 27 connected with the atmosphere. The slight elasticity of the gelatine causes the capsule to shrink slightly and expel the remaining air. Pump 33 forces air through pipe 35 and passage 34 to prevent the completed capsules sticking to the mould sides.