GB370273A - Improvements in ink ribbon feeding mechanism for printing machines - Google Patents

Abstract

370,273. Ink - ribbon mechanism. ADDRESSOGRAPH CO., 901, West Van Buren Street, Chicago, U.S.A. July 2, 1931, No. 19144. Convention date, Dec. 15, 1930. [Class 100 (iv).] In feeding and reversing-mechanism of the kind comprising a reciprocating driving-member 34 adapted to be moved into operative relationship with either of the ribbon spools 12, 13, the position of the driving-member is determined by a pivoted member 62 arranged and adapted to move in a plane at right-angles to the driving-member. The latter is pivoted at 26 to a reciprocating bell crank 17 and is formed at one end with a pin 35 to engage ratchets 36, 37 on the spools. The other end carries a pin 27 embraced by arms 30 of a pivoted dog 28 which with the spring 31 constitutes an over-centre device. The ribbon reversal is effected by moving the pin 35 on the driving- member into engagement with the ratchet 37. For this purpose, the driving-member is formed with wings 38, 39, having cam surfaces 40, 41. Arms 47, 48 carrying ribbon-engaging rollers 50, 51 are pivotally mounted on a shaft 49 and are held in position by a spring 54. Each arm carries an adjustable screw 56, 59 extending towards the pivoted member 62 which is formed with projecting fingers 63, 64, and is arranged so that these fingers are movable into engagement with the cam surfaces 41, 40 respectively, but are normally held out of engagement by the tapering sides of a projection 66 on the member 62 which engage the flattened sides of a pin 70, mounted on a spring-held pivoted member 68. As the ribbon winds on the spool 13 the arm 47 moves inwardly until the screw 56 engages the member 62, which finally presses aside the member 68 and interposes the finger 64 in the path of the cam surface 40. As the driving-member moves outwards, the surface 40 engages the finger 64 and the driving-member pivots upwards, until the spring 31 of the over-centre device snaps it into engagement with the upper ratchet, the driving-member being meanwhile held in an upper position by a pivoted latch 78. The spools are held against inadvertent movement by spring- pressed plugs 75 which bear against the spool shafts.