Patent GB-1181839-A (GB)
Title: Improvements in and relating to Apparatus for Performing Operations on the Surfaces of Workpieces
IPC: B41F15/08
Filed: 1967-03-17
Abstract: 1,181,839. Printing apparatus. INTERNATIONAL BUSINESS MACHINES CORP. 17 March, 1967 [18 March, 1966(2)], No. 12522/67. Heading B6C. [Also in Division B8] Apparatus suitable for screen printing electrical circuits on ceramic plates S comprises a rotatable carrier 32 adapted to be indexed at a plurality of stations by a lock mechanism 30, a plurality of plate holders 33, plate loading means at a station 20 adapted to locate the upper surface of each plate in a predetermined reference plane above the respective holder 33, a vertically reciprocable support pedestal 40 associated with each holder 33 and arranged to receive plates from the loading means and to preserve their upper surfaces in the said plane during printing, and a screen printing station 24. The apparatus also includes a plate detection station (22) Fig. 1A (not shown), and a plate delivery station 26. Plate feed.-The plates S are fed to a reciprocable plunger (70) ,Figs. 5 and 6 (not shown) by means of a shoot (76) and an endless belt (77) which co-operates with an idler roller (78). The screen printing apparatus drive actuates the plunger (70) via cam means, a rod (75) and an arm (74). A photo-cell (79) shuts down the printing apparatus if the plate supply is interrupted. The plunger is raised, a plate is fed against a stop (110), suction is applied through a passage (72) in the plunger, and the plunger is then lowered. Plate holder.-The pedestal 40 is moved upwardly beyond clamping arms 50, which are opened by cam means, by an elevator (48), Fig. 5, which engages a follower (46). The plunger (70) is moved downwardly against the spring-loaded pedestal, Fig. 2-4 (not shown), until an adjustable position is reached at which the arms 50 are closed and the elevation of the pedestal 40 is locked by plungers (61). The plate is then carried on a resilient planar surface on the top of the pedestal to the station 24. Screen printing apparatus.-The screen printing apparatus, Figs. 7 and 8 (not shown), includes an inking device 115 which is mounted on flexible straps 118 and is pivoted into and out of the printing position by cam means. The device has an annular depression, part of the floor of which is formed by a printing aperture 25 provided with a mask having the design configuration mounted on a slide element 116. The plane of the bottom surface of the device 115 and the mask 116 are determined by abutments (121), (122), Fig. 7. A spider 123 is rotated by the drive of the printing apparatus and a squeegee 123a on the bottom of each arm of the spider moves the ink or paste over the aperture 25. The device 115 may be adjusted in position by screws (133). Plate delivery.-At the delivery station 26 an elevator (172), Fig. 9 (not shown), raises the pedestal 40 and a cog 153 on a belt 152 sweeps the printed plate S on to a shoot 150. A conveyer (173) then moves the plate to storage or to other processing equipment. Vacuum is applied through the hollow pedestal to hold the plate in position prior to moving it to the station 26. A photo-cell (175) causes the printing apparatus to be cut out if there is a blockage of plates on the conveyer (173).