| 摘要 |
1,081,107. Number printing. ENGLISH NUMBERING MACHINES Ltd. Nov. 25, 1964, No. 47833/64. Heading B6C. [Also in Division F2] In a pawl mechanism for a number printing device having a pawl 41 mounted for engagement with a toothed element 34 driven by a drive member 37, a pawl actuator 45 is arranged to be moved by camming action between the pawl actuator 45 and the drive member 37, the pawl out of contact with the toothed element in response to relative indexing movement of the toothed element and the pawl. When a manually operable actuating lever 1 of the printing device is rotated in a clockwise direction about a spindle 2 the end 4 of the actuating lever strikes a cam 5 to pivot a lever 7 in an anticlockwise direction about a spindle 12 to disengage a notched portion 15 from a spindle 14 so that the levers 16 and 22 pivot together about the spindle 24 under the action of a spring 9. During this movement a printing wheel support 29 pivots in a clockwise direction about a spindle 30 until the printing wheel 34 strikes against a platen (not shown). After the printing action has been effected, the actuating lever 1 is returned to its initial position shown in Fig. 1. For indexing purposes, the printing wheel 34 is provided with an indexing mechanism having a toothed drive transmitting member 37 rotatably mounted by manual or electromagnetic means on the spindle 2 and formed over a portion of its periphery with gear teeth 38 which co-operate with teeth 39 on the printing wheel 34. On a different portion of its periphery the toothed driving member 37 is formed with a plurality of projecting portions 40 formed with numerals corresponding to type face numerals formed on the crowns of the teeth 39 of the printing wheel 34. When the printing wheel 34 is rotated by the toothed member 37 an actuating motion is imparted to the pawl actuator 45 by a camming action between the toothing of the toothed member 37 and the detent portion 48 of the pawl actuator 45 which is rocked about a spindle 47 against the action of a spring 43 to move the pawl 41 about its pivot pin 42 so as to move the pawl 41 out of contact with the printing wheel 34 during the passage of the crown of each tooth 39 past the pawl 41 to prevent wear of the type on the crowns of the teeth 39. |
