GB1295469A - - Google Patents

Abstract

1295469 Selective printing E HJERPE 14 Nov 1969 [14 Nov 1968] 55978/69 Heading B6F Arcuate type-bar machines.-A carriage 32, Fig. 7, axially movable along the main drive shaft 23 of the machine, supports a line printing mechanism for pivotal movement about shaft 23 (Fig. 6). The line printing mechanism, particularly for printing numerals, includes a plurality of circle-sector shaped type carriers 2 with radially movable types I. Type selecting mechanism.-The type carriers 2 are pivoted about a shaft 3 to which is keyed a setting bail 4. A hook-shaped dog member 2b pivoted to each carrier 2, embraces the rod 4a of the setting bail 4, Fig. 2. Clockwise rotation of shaft 3 and setting bail 4 causes the type carriers to rotate likewise, until each carrier is individually locked in its selected position by latches 7 engaging sets of teeth (2f, Fig. 1), whereafter the rod is allowed to continue its arcuate motion, Fig. 3. An electromagnet 39 is provided for each type carrier 2. When current flows through the electromagnet, an arm 9, pivoted at 8, is maintained in its cocked position against the bias of a spring 10 (Fig. 4), thereby preventing the latch 7 from engaging teeth 2f. As a type carrier is moved clockwise, selective de-energisation of its associated magnet 39 causes its latch 7 to engage its teeth 2f, Fig. 2. After impression, the arms 9 and latches 7 are reset by the rod 11b (Fig. 4) of a resetting bail (11) engaging the arms 9. The resetting bail (11) is pivoted about a shaft 6 by a cam (12) keyed to shaft 13. Hammer impression arrangement.-Each. type carrier 2 has an associated hammer 19 pivoted on shaft 6. All the hammers are cocked simultaneously by the rod 4b of the setting bail 4 and latched in position by a latching bail 21 (Fig. 1). A cam 24, keyed to shaft 13, pivots the latching bail 21 about the shaft 23, thereby releasing the cocked hammers 19, which are swung for impression by individual springs 20, Fig. 3. Driving mechanism.-The main drive shaft 23 completes one revolution for each printing cycle. Shaft 13 is driven directly by shaft 23 via 1 : 1 ratio gearing 25. Shaft 3 is oscillated by a crank mechanism 25, 26, 27 on shaft 13. A second crank mechanism (30, 31, Fig. 6) on shaft 13 provides the pivoting motion of the printing mechanism about the shaft 23. Electrical input and control.-A punched arcuate plate 41a, Fig. 7, mounted for angular movement with the shaft 3, is associated with a light source 42 and row of photo-cells 44. A binary signal representative of the angular position of the shaft 3, and therefore the typecarriers 2, is emmitted from the photo-cells 44, and compared in a comparator circuit (Fig. 8) with a binary signal from a core storage unit. Coincidence causes the appropriate electromagnets 39 to be de-energized, thereby latching the type carriers in their selected positions. A circuit for supressing insignificant noughts is provided.