Patent GB-836783-A (GB)
Title: Improvements in hectographic duplicating machines
IPC: B41L11/00
Filed: 1955-06-08
Abstract: 836,783. Copying documents; printing- surfaces. BLOCK & ANDERSON Ltd. (Veenmans Kantcorinstallatie Bureau Rotterdam). June 7. 1956 [June 8, 1955], No. 16486/55. Class 100(2) A rotary hectographic copying machine in which moistened copy sheets are fed between a printing drum and an impression roller comprises a clip for securing a master sheet to the drum and means for traversing the clip axially of the drum. said means including an escapement, mechanism outside the drum and operatively connected to the clip inside the drum by a member passing axially through the end of the drum and capable of axial movement while allowing rotation of the drum. There are provided a fixed heading master clip 15, Fig. 5, extending half the drum length, a clip 16, Figs. 4 and 5, carrying a movable master and axially aligned with the clip 15, and a clip 17 carrying a movable item master. The clips 15 and 17 are in three sections 'and the clip 16 in two sections. The clips 15. 16 are opened by rotation of a bar 162 carrying lifting arms 150, 160 having rollers engaging the clips, the arms being angularly staggered so that the section 15a is opened first, and the sections 15b, 15c, 16a, 16b on further rotation of the bar. The clip 17 is opened by a bar 171 carrying arms 170 staggered or otherwise, but can only be opened when the clip is in its normal position at the left end of the drum. The clip 17 is guided for opening and closing between platen 20, 21 and the assembly 17, 20, 21 is axially slidable on a fixed rod 35, being moved by a rod 31 connected outside the right end of the drum by a member 30, Fig. 2, to a sheetmetal carriage 24, Figs. 3 and 7, slidable on a ball track 25 along a fixed framework 26, and urged to the right (in Figs. 5 and 7) by springs 40, 41. The carriage is secured to a bar 46 having equally spaced spring-loaded pins 47 normally projecting at each side of the bar. For operating the carriage there are provided three pawls A, B, C, Figs. 3, 7 and 12, the pawl A being keyed to a shaft 50 and the pawls B, C being rotatable on the shaft, the pawl A being normally retracted below the pins and the pawls B, C being normally against the bar 46. as in Fig. 12 (I). On partial depressing of a plunger 64 against a spring 67, a rock lever 62 acts on a fork 61 welded to an extension 60 of the pawl B to retract the latter to the position II in Fig. 12, whereupon the pin 47a, which was being held against the pawl B by the springs 40, 41, moves against the pawl C, moving the clip half a line space of the master sheet. On release of the plunger 64. the pawl B presses in the pin 47a, which then rides over the pawl C until the next pin 47b engages the pawl B, thus completing the line space. To move the carriage over its entire length of travel to the right, the plunger 64 is depressed as far as allowed by the slot 66 and screw 65. whereby the pawl B is retracted as before, and an adjustable striker pin 76 on a bracket 75 secured to the fork 61. strikes an extension 71 of the pawl C to retract the latter, whereupon the carriage moves to the end of its stroke. To retract the carriage to the left a lever 104 is depressed to close a clutch. whereupon a driven pulley 90 rotates a drum secured to a nylon cable attached to the carriage to retract the latter, the pins riding up a tail 68 of the pawl C. When the lever 104 is depressed, a lever 107 advances a bolt 120 to move a latch 122 over the rock lever 62 and prevent manual operation of the carriage. In order to step the carriage to the right automatically one line space on each revolution. of the drum, a pedal is depressed and through, a link 58 moves a latch 57 from the path of a pawl 82 on a carrier plate 80 pivoted at 81, whereupon the pawl 82 drops into a notch 84 of a lever 55 keyed to the shaft 50. A pin 87 on the drum strikes on each revolution a lever 85 pivoted at 86 when the tail of the copy sheet has left the impression zone, whereupon the plate 80 is rocked and the pawl 82 rotates the lever 55 and advances the pawl A. The pawl A depresses the pin 47a, which thereupon passes over the pawls B and C, and after retraction of the pawl A the next pin 47b comes to rest against the pawl B, the carriage having moved through one line space. Every other pin 47 has a head 130, and on moving a lever 135, a masking plate 131 is moved to the right and thereby, by means of slots 134 and screws 133, upwards, whereupon a horizontal part of the plate 131 underlying the heads 130 raises the latter to retract every other pin 47 and double the line spacing. The clip 16 is guided for opening and closing between plates 18, 19 and the assembly 16, 18, 19 is axially slidable on a fixed rod 141, being moved by a rack rod 146 extending through the left end of the drum and driven by means of teeth 147 engaging a pinion rotatable by a knob, a series of ball cups 154 in the rod 146 being engaged by a spring-loaded ball in a snap action so as to ensure that the clip 16 is advanced in unitary steps equal to the master sheet line spacing. Specifications 682,842 and 717,492 are referred to.