GB1354331A - Device for transporting paper particularly for photographic printing - Google Patents

Abstract

1354331 Transport mechanism for a contact printer SODER SARL 26 Nov 1971 [17 Dec 1970] 55047/71 Heading G2A A transport mechanism for a contact or projection printer comprises a drive roller 7 which advances a given length of a web of photographic paper over a table 3 after a period of stopping, the drive roller 7 having a pinion in mesh, by means of gears 10 including a unidirectionally rotatable wheel 11, with a toothed sector 12 having a return spring 15, the rotation of the roller 7 being effected by a cam 14 acting on a roller 13 fixed to the sector, the cam being mounted on a shaft 16 rotated by a motor 19 supplied with current for the time necessary for the shaft to complete one revolution to advance the web by the given length. To advance a length of paper a solenoid 31 is momentarily energized, moving a lever 29 and withdrawing a finger 28 from a notch in a disc 27 mounted on the shaft 16. The lever also actuates a micro-switch, closing a circuit to the motor 19 which then rotates shaft 16 via a screw 18 and gear 17. As the shaft rotates, the cam 14 mounted on the shaft contacts the roller 13, moving the sector 12 anti-clockwise and driving roller 7, via gears 10, 11 to advance the paper. During the latter part of rotation of the shaft the sector returns to its initial position shown under the influence of the spring 15, roller 7 remaining stationary due to wheel 11. At the end of one revolution of the shaft the finger 28 re-engages the notch, opening the circuit to motor 19 and holding the shaft in a fixed position. To vary the length of paper advanced the position of sector 12 may be adjusted to alter the distance between cam 14 and roller 13. As the paper is advanced the table 3 is lowered by a lever 25 and rod 26 controlled by a cam 24 mounted on shaft 16.