818,582. Printing-surfaces. BLACK & ANDERSON Ltd. Sept. 19, 1955 [Sept. 22, 1954], No. 27444/54. Class 100(2) A rotary hectographic copying machine employing master sheets removably secured to a printing drum in which the drum is provided around its periphery with first, second, and third sheet-sensing clips each directed axially of the drum, the second clip being arranged to be axially movable with respect to the drum and disposed at a position which is spaced rearwardly from the first clip in relation to the direction of operative rotation of the drum and the third clip being also arranged to be axially movable with respect to the drum and disposed in a position which is spaced forwardly from the second clip in relation to the direction of operative rotation of the drum. As shown, a first clip 5, Fig. 1, is a fixed clip for carrying a heading master sheet, while a third clip 6 aligned with the clip 5 is axially movable such that a mask carried by the clip 6 may be so positioned that selected items of a movable master sheet, clamped by a second clip 7, are reproduced. The clip 6 is guided by guides 8, 8a, Fig. 6, the guide 8 being rebated to receive a lip 12 of the clip 6, while the guide 8a is secured to a plate 9 secured to the machine drum. The clip 6 is maintained closed by springs 13, Fig. 2. The clip 6 and guides 8, 8a, Fig. 6, are movable step-by-step axially of the drum. A bracket 15 secured to the clip 6 carries a ratchet plate 17 having opposed ratchet teeth 18, 19, Fig. 5A, each having a pitch equal to the width of one line of the printed matter, the teeth 18 being staggered with respect to the teeth 19 half the length of a tooth. Two pawls 20 and 21 co-operate with the teeth. The pawl 20 is rotatably mounted between collars on a shaft 23 secured to the plate 9, Fig. 1, and carrying brackets 14 and 27 secured to the plate 8a. A spring 31, Fig. 6, urges the pawl 20 into contact with the teeth 19, while a spring 28, Fig. 1, urges the rod 23 into its right-hand position. The pawl 21 is freely mounted on the shaft 23 and is urged into contact with the teeth 19. The pawls 20, 21 may be released from engagement with the teeth by rocking a plate 34 which engages tail portions of the teeth. Upon actuation of the shaft 23 to the left, the pawl 20 engages one of the teeth 19 and moves the clip 6 one tooth space to the left, the pawl 21 being lifted by movement of the plate 17, such that it falls into the next tooth. By allowing the shaft 23 to return and then repeating the stroke, the clip 6 may be moved into a position appropriate to the width of an item to be produced from a movable master sheet. Return of the clip 6 is effected by a repeated slight clockwise rotation of the shaft 23 to lift the pawls from engagement with the teeth. The shaft 23 may be manually operated by a lever 65, Fig. 8, at the front of the machine. The lever 65 rocks an arm 67, link 68 and lever 69, the lever 69 being slotted to receive a pin on a lever 61. The lever 61 is pivoted at 62 and has an operating surface 63 concentric with the drum. The lever 61 rocks a lever 53 which engages a lever 45 pivoted at 46 and engaging the lower arm 43 of a bellcrank lever having an end 41, Fig. 1, which actuates the shaft 23 to the left. The lever 53, Fig. 8, also engages a bellcrank lever having a slotted arm 51 engaging the end of crankshaft 49 attached to the shaft 23, Fig. 1. Thus, the shaft may be actuated axially or rotated by movement of the lever 65, Fig. 8, in the appropriate direction. The clip 5 is mounted between guides 78, 79, Fig. 2, in a known manner, the clip being opened by a square shaft 80 carying arms 81, 82, Fig. 1. The shaft 80 may be actuated through levers 86, 87, Fig. 8, by mechanism in the side frame of the machine, for example, by mechanism described in Specification 754,341. The clip 7, Fig. 2, for clamping the movable master sheet is slidable within guides 91, 92. The clip 7 is opened by pins 93, Fig. 9, which are actuated by levers 94 connected by a link 95. The link 95 is actuated by a nose 96 on the end of an axially displaceable shaft 97 carrying a face cam, not shown, that is actuated by a lever, not shown. To prevent axial movement of the link 95 during opening an arm 102 hooks over a fixed pin 103, the arm 102 being connected to the link 95 by a spring 106. A pin 107 on the link normally prevents the arm 102 engaging the pin 103. The clip 7 may be actuated axially of the drum by a rod 100, Fig. 1, which is connected externally of the drum to a traversing carriage preferably of the kind which comprises a rack and pawl arrangement extending parallel to the drum and externally thereof either outside or between the side frames of the machine, control means being provided for obtaining step-by-step or full travel of the clip under the control of an operator. By operation of the shaft 23, Fig. 1, the width of the items on the movable master sheet can be adjusted to 2, 3, 4 or more lines as determined by the teeth 18, 19 and pawls 20, 21, Fig. 5A.