Patent GB-724081-A (GB)
Title: Improvements in duplicating machines
IPC: B41L9/10
Filed: 1952-04-18
Abstract: 724,081. Operating clutches; escapements. FORD, R. M. April 18, 1952 [Jan. 18, 1951], No. 1368/51. Classes 80 (2) and 80 (4) [Also in Group XVI]. Operating clutches. A duplicating machine of the kind having two printing couples (see Group XVI) is provided with one-revolution clutch mechanisms the second one being adapted to be automatically coupled after the first, a manually operated clutch, has moved through a predetermined angle, each clutch being automatically disengaged after the completion of one revolution. The mechanism is shown in Figs. 13 and 14 and comprises a driving shaft 64 having a gear 65 meshing with a pair of gears 66, 67 slidable on shafts 68. 69 and carrying dog-clutch parts 76, 77 for engagement with mating parts 82, 83 secured to the shafts 68, 69. These shafts carry sprockets 70, 71 driving the printing couples through chains. Springs 80, 81 urge the clutch parts 76, 77 towards the engaging position and controlling heads 100, 88 bear against collars 103, 89 normally to hold the clutch in the uncoupled position. The head 88 is pivoted on an arm 87 keyed to a shaft 86 spring-loaded in the anti-clockwise direction and having a downwardly projecting finger 97 for momentary engagement by a finger 96 mounted on a bell-crank lever 95 and rotatable in an anticlockwise direction by a foot-pedal. Actuation of the foot-pedal displaces the head 88 from the collar and the clutch 77, 83 is coupled to cause rotation of shaft 69. The head 88 when displaced turns anticlockwise about its pivot 91 under the action of spring 92. A cam 90 formed on clutch part 83 engages the surface 98 of head 88 after completion of one revolution and returns the head to the normal uncoupling position. The second clutch 76, 82 is controlled by. the similar head 100 pivoted to one end of a lever 99 the other end of which bears on the cylindrical face of cam 90. After rotation of the shaft 69 through a prea complete revolution before the clutch is uncoupled by a cam 102 acting on the head 100. There is also provided a clutch mechanism adapted to rotate a pulley 109, Fig. 11 over which passes a cable 107 controlling the position of a traversing carriage carrying parts of the printing mechanism. The pulley 109 is freely mounted on the driving shaft 64 and carries dog clutch teeth 139 for engagement with a clutch part 140. The clutch part 140 is mounted inside a sleeve 142 being determined angle, lever 99 slips off cam 90 and is turned clockwise by a spring 101. This disengages the head 100 and the shaft 68 thereupon makes biased to the left by a spring 146 and retained by a collar 152. The sleeve 142 is slidable and rotatable in a guide 141 which carries a pin 144 projecting into an inclined slot 143 in sleeve 142. Rotation of sleeve 142 by an arm 147 allows the clutch parts to interengage, thus rotating the the pulley 109. After the completion of one revolution, a projection 150 on pulley 109 engages a pin 151 on sleeve 142 and rotates it to withdraw the clutch part 140 from engagement with the pulley. The arm 147 is rotated to clutch-coupling position (shown dotted in Fig. 12) by a lever 148 having a nose 157 which is engaged by a spring- loaded pivoted finger 156 mounted 'on a lever 155 actuated by a foot pedal. The finger is tripped past the nose 157 after completion of part of a revolution by a pin 158 mounted on a lever 159 which is displaced by the engagement between projection 150 and an extension 160 of the lever. This ensures that the arm 147 is free for rotation to normal position when the projection 150 engages pin 151. Escapements. Movement in the other direction of the carriage is controlled by an escapement mechanism allowing step by step rotation of pulley 109 and shown in Fig. 10. A ratchet wheel 110, attached to pulley 109 co-operates with an escapement lever 111 having horns 116, 117 for alternate engagement with the teeth of the ratchet wheel. The lever is manually displaced to allow the wheel to rotate through the space of one tooth pitch or automatically displaced once each revolution of the printing couples. The manual control comprises a lever on the front of the machine adapted to displace a link 119 to rotate a lever 112 having 'a spring-loaded finger 120 on the end. The finger engages part of the lever and trips it so the ratchet wheel can rotate through one tooth pitch. The automatic control comprises a member 113 slidably mounted on a pin 127 on the side wall of the machine and displaced by a manually operable lever 124 along the pin to bring a finger 122 into line with another part of the lever 111. The member 113 is oscillated by a link 128 connected to a lever rocked by a cam on the shaft of the main cylinder. By this means the ratchet is released for rotation through one tooth pitch by each revolution of the printing couples and the carriage transverses in steps across the machine. A back-stepping mechanism for moving the carriage in the other direction may be actuated by a foot pedal acting through link 134, rocker 135, link 136 and lever 132 to displace a link 131 carrying a pin 137 for engagement with the teeth of the ratchet wheel. Displacement to the right of the link 131 causes rotation through one tooth pitch of the ratchet wheel 110, the lever 111, then acting as a pawl. The pulley wheel 109 may be rotated for backward rotation as described above. Specifications 486,799, [Group XVI], 547,640, 557,886, 638,902, 643,143, 670,465 and 724,082, [all in Group XVI], are referred to.