Patent GB-1393550-A (GB)
Title: Syllabic typewriters and similar machines
IPC: B41J7/90
Filed: 1972-06-19
Abstract: 1393550 Typewriters J GREMILLET 19 June 1972 [21 June 1971] 48846/74 Divided out of 1393548 Heading B6F A syllabic typewriter, having keys which can be depressed simultaneously and keys which control simultaneously several characters belonging to groups which each correspond to a distinct printing point, comprises an escapement mechanism including an escapement wheel provided with mobile teeth 1021. Escapement mechanism. - The escapement mechanism is capable of permitting a single step displacement for word spacing, commanded by a space bar (Spac, Fig. 42, not shown), or a displacement of up to five steps for letter or syllable spacing commanded by character key depression, or a combination of the two. The space bar causes powered displacement of a rod 827, Fig. 9, to rock an anchor detent 1057, Figs. 9 and 27, which coacts with teeth 1021, Fig. 27, mounted on a rotatable drum 441. The anchor detent comprises a stop arm 1018 and a restoring arm 1019, such that when the stop arm 1018 is displaced from a tooth 1021, that tooth strikes the restoring arm 1019 to return the stop arm into engagement ment with the next tooth 1021. The teeth 1021 are however themselves displaceable by character key depression. For example depression of key K, Fig. 9, of Group I, causes powered displacement of an interposer 141 both for type bar actuation and so that a heel 692 on the interposer trips a bail 271 which, through a fork 286, rod 235, lever 1247, shaft 1241 and rod 406, displaces the tooth 1021 engaging the stop arm 1018 to permit the drum 441 to rotate until the next tooth engages the stop arm 1018. If a plurality of character keys of adjacent groups are depressed, the respective bails 271-275 act on their respective rods 406-409 (and 410, Fig. 8, not shown) so that a corresponding plurality of teeth 1021 will be displaced, the resulting escapement step being of correspondingly increased length. If one or more character keys and a space bar are simultaneously depressed, an extra escapement step is added since the restoring arm 1019 will strike the next undisplaced tooth 1021. The escapement anchor 1057 may be electromagnetically operated (Figs. 32, 33), as may the teeth 1021 (Figs. 44-46). In these instances keys may be provided (e.g. TION, Fig. 42) which correspond generally to word endings and automatically add a word space to the respective number of letter spaces, unless a neutralizing key (NEUT Spa) is depressed. The letter spacing escapement operations may be initiated by switches struck by a driven type lever where the teeth 1021 are electromagnetically displaceable.  Case shift mechanism, baskets.-The type lever basket assembly is in three portions, corresponding respectively to Group I, Group II, and Groups III to V. The Group I and Group II baskets are each independently displaceable for case shift (by keys 2eI and 2eII respectively) or all three baskets may be displaced together (key Tout 2e). Two alternative case shift mechanisms are described. In the first embodiment (Fig. 6), each basket portion can be lowered by a rotatable shaft 336 carrying a crank 345, 346, 347 for each basket portion, each crank acting on a respective connecting rod 348, 349, 350 coupled to the basket portion. Each connecting rod can be disconnected from its associated crank, according to the basket displacement required; hence for Group I case shift only (key 2eI), connecting rods 349, 350 are disconnected from cranks 346, 347. Basket displacement is caused by a cam 332 urged into engagement with power roll 771 by any case shift key depression, the cam being linked to a plate 335 fixed to shaft 336 so as to rotate the shaft 336. A third case shift position is provided by displacement of the platen 252 through a lever 678 which can be engaged with the plate 335 by pin-and-slot 352, 679 (key Tout 3e). In the second embodiment (Fig. 39), three positions of the basket portions are provided, and the control of the case shift is by electromagnets. The basket portion III-IV-V for Groups III to V is fixed to a frame 601 on which the basket portions I and II are slidably mounted. A shaft 336, equivalent to that in the first embodiment and driven similarly by a cam 332 engaging a power roll 771 and linked to a plate fixed to the shaft, can be coupled to the frame 601 by electromagnets 898, 899 laterally displacing a shaft 808 and hence coupling rods 809, 812 either to cranks 854, 855 for downward displacement or to double cranks 879, 860 for upward displacement of the frame 601. Alternatively the shaft 336 can be coupled to basket I through crank 888 and rod 885 by electromagnet 907, or to basket II through crank 839 and rod 840 by electromagnet 980 for downward displacement of either basket individually. The keys commanding the case shift operations are duplicated by foot pedals 936-939. The platen may also be displaceable to provide a fourth case shift position. Type lever guides.-The type levers of the five groups are aligned in their correct impact positions by guides which at the extreme ends of the printing region resemble standard left and right type lever guide forks (621, 622, Fig. 5) but between groups comprise thin plates (625, 630, 631, 633, 634, 635). Where two adjacent groups are displaceable with respect to one another, as between Groups I and II, two plates (such as 625, 630) separate the groups, one guiding the type levers of each group, whereas where no displacement is called for, as between Groups III and IV, a single plate (such as 634) separates the groups and guides type levers of both groups.