GB526517A - Combined intermittent and continuous feed gearing - Google Patents

Abstract

526,517. Feeding webs. WILLIAMSON. C. M. March 18, 1939. No. 8707. [Class 100 (i)] [Also in Group XX] In apparatus for feeding a strip intermittently at one part of its travel and continuously at another part, particularly for use in feeding a photographically sensitive strip past a printing position and then through developing &c. baths. the intermittent feed mechanism comprises two spur or ratchet wheels 11, 12, Fig. 2, loose upon a shaft 13 and driven continuously by gearing from a shaft 3 driven by a motor and worm gear 5. Between the wheels 11, 12 and fast to the shaft 13 is an arm 14 to which is pivoted a double ended pawl 15, Figs. 2 and 4, the ends of which co-operate respectively with the wheels 11, 12 and alternately so that the arm 14 and thus the shaft 13 receive an oscillating movement. The reversal of the pawl may be effected by the direct engagement of the pawl with a pair of stops adjustably spaced apart, but is preferably effected by means of a yoke 16, Fig. 4, pivoted on the pivot of the pawl and connected to the pawl by a spring rod 18. Fixed and adjustable stops 22, 23 are engaged by the yoke which is thereby turned until the spring rod 18 completes the reversal of the yoke and at the same time reverses the pawl. Stops 20, 21 limit the movements of the yoke. The shaft 3 drives the intermittent feed rollers through a friction clutch 34, free wheel device 32a, and sprocket wheel 32. The clutch 34 allows the shaft 3 to be given a movement rather greater than that required for the feed, the return movement of the wheel 32 being limited by the engagement of a pin 37 thereon with a pin 38 on a sprocket wheel 31 which drives the continuous feed rollers and is driven continuously by gears 30, 29 from the shaft 3. The shaft 13 also has secured to it a cam which during the rest movement of the strip actuates a plunger to hold the strip stationary in the printing position. A pin on the side of the cam also actuates a trigger to operate a lighting switch for the exposure of the strip.