Patent GB-720355-A (GB)
Abstract: 720,355. Feeding webs; ink-ribbon mechanism. NATIONAL CASH REGISTER CO. Nov. 3, 1952 [Nov. 10, 1951], No. 27600/52. Classes 100 (1) and 100 (4). Spacing mechanism; feeding webs.-A cash register or similar accounting machine includes printing mechanism for printing a record strip, supply and receiving rolls for the strip, a finetoothed ratchet integral with the receiving roll, a rotatable plate co-axial with the receiving roll, three feeding pawls pivotally mounted on the plate, a plate actuating mechanism, and a sensing device which senses the outer diameter of the strip on the receiving roll to limit progressively the extent of rotation of the plate as the diameter increases, one of the feeding pawls always engaging the ratchet. A detail strip 45, Fig. 2, is unwound from a supply roll 46, fed under type wheels 39 and rewound on a receiving roll 51 rotated by a ratchet 61, Fig. 5, rotated a decreasing amount at each operation of the machine. The ratchet 61 has fine teeth engaged by three similar spring-urged feed pawls 62 freely mounted by studs 63 on a plate 64 rotatable on a stud 57, and by spring-urged retaining pawls 66 mounted on studs 67. The plate 64 has a stud 69 engaging a cam 70 rotated one revolution each machine operation by a shaft 71, the plate being urged counter-clockwise by a spring 72, such that the plate 64 oscillates to effect winding of the strip 45. The periphery of the strip on the roll 51, Fig. 2, is engaged by a sensing lever 78 carried by a stud 77 which supports an arm 75, Fig. 5. The arm 75 has a cam surface 74 co-operating with a stud 73 on the plate 64 so as to restrict the spring-urged counter-clockwise movement of the plate 64 and thus control the length of the feeding stroke thereof. As the diameter of the receiving roll 51 increases the roll is thus rotated a diminishing amount at each machine operation. Hammer impression, arrangements.-A hammer 44, Figs. 2 and 4, causes the detail strip 45 and an endless ink ribbon 113 to contact the type wheels 39. The hammer 44 has arms 82 and 83, Fig. 4, rotatable on a stud 48, the arms 82 and 83 supporting a stud 85 retained in position by a spring clip 87. The stud 85 supports a slidable impression-adjusting cone 88 pressed to the right as shown in Fig. 4 by a spring 89, but adjustable along the stud by a spring clip 90 retained in one of a number of annular grooves 91. The periphery of the cone 88 co-operates with a cam 95 secured to a hub 96 free on a stud 97 carrying an arm 98 having a stud 102 engaging a vertical slot in a pitman 103, Fig. 2, reciprocated by a cam on the shaft 71. The pitman 103, thus causes through the cam 95 and cone 88, rocking of the hammer 44; the hammer may be retained in inoperative position by a slot in the arm 98 engaging the stud 85, Fig. 4. Ink-ribbon mechanism.-The ink ribbon 113, Fig. 6, is fed in an endless path around the periphery of a plate 114 readily detachable from the machine wherein it is located by studs 117 and bushes 115 engaging bushes and studs respectively mounted on the machine frame, a latch 119 locking the frame in position. The ink ribbon is guided by undercut portions of the studs 117 and bushes 115. A feeding roller 122 and pressure roller 124 feed the ribbon step-by-step by means of a ratchet 136, Fig. 2, operated by a pawl 140. A transfer roller 151, Fig. 6, may be brought into engagement with the roller 122 by rocking a finger 162 of a lever 159 into "on" position. The roller 151 transfers ink from a reservoir 157 via a felt wick 155. The supply of ink in the reservoir 157 may be renewed through a removable cap 158. Specifications 614,346 and 614,347, [both in Group XIX], are referred to.