GB1061794A - A method of and machine for printing hollow plastic articles - Google Patents

Abstract

1,061,794. Printing apparatus. J. A. SCHMALBACH A.G. May 1, 1964 [May 2, 1963], No. 18190/64. Heading B6C. In a pneumatically operated screen-stencilling apparatus for multi-colour printing on plastic bottles a bottle fed to an endless chain 4 at position 8<SP>1</SP>, Fig. 2, is printed upon in one colour at a printing station 11 prior to passing through a drying oven 12, Fig. 1. It is then carried to a second printing station 13, Fig. 1, for printing in a second colour and at a position 8<SP>11</SP> is ejected by an ejector 15 down an inclined passageway 14 from the lower end of which an advancer 17 propels it through a further drying oven 20. The chain 4 incorporates bottle containers 8 and is advanced intermittently by a reciprocable driver 26 which, immediately prior to its " drive " stroke, engages the rear surface of that container from which the printed bottle has just been ejected by the ejector 15. The driver 26 is moved by a piston 33 reciprocable in a cylinder 34, a valve actuable by other elements of the machine drive controlling air flow to the appropriate end of the cylinder through respective pipelines 35 and 35<SP>1</SP>. When the freshly inserted bottle is placed in the container 8 at the position 8<SP>1</SP>- and bottle feed may be manual or automatic-it is clamped in position by a retainer comprising a U-shaped bearer 38, a mandrel axially movable relative to the bottle axis, a bottle receptacle 43 and a pneumatically operated piston 42 connected to the receptacle 43. The bearer 38 along with the receptacle 43 and associated piston and cylinder 41, 42, is mounted on a disc 39 rotatable about a shaft 40 and the latter is mounted on an upright member 44<SP>1</SP> carried by a cross-bar 46 vertically reciprocable in guides 45 through an oscillatable lever 49 connected to the crossbar 46 through a pin-and-slot arrangement 48, 47, and pivotable about a shaft 50. A similar arrangement is provided at the printing station 13. A pneumatic system is used to operate the machine, appropriate four-way valves being associated with conduits I and II and III and IV, respectively, the operation of these valves deriving from the machine drive. The screen printing apparatus comprises a reciprocable frame 56 incorporating screens 57 the reciprocation deriving from the machine drive through a shaft 58, crank 59 and pin- and-slot connection 61, 60. Rotation of the shafts 50 and 58 are effected at the end of each forward stroke of the chain driver 26 through the actuation of an electromagnetic clutch on the engagement of a rod 64 carried by the driver with a limit switch 65. The movements of the various relevant machine parts are timed in order to provide commencement of the printing stroke of the forme 56 simultaneously with the engagement of the raised bottles at the printing stations with the undersurface of the screens 57, the bottle at each station being turned about its axis by the frictional engagement of screen and bottle. After the bottle at each printing station has been printed, and the members 44 and 44<SP>1</SP> lowered, the piston 42 of each receptacle is released allowing the bottle to be moved from the station by the chain 4.