298,569. Royal Typewriter Co., Inc., (Assignees of Handley, G. F.). Oct. 11, 1927, [Convention date]. Platen and case shift-mechanism; shift-key actions; key locks.-A shiftable platen member or type-lever segment provided with a stop for engaging stops on the framework is locked in the normal or shift position by means of latches which co-operate with the stop on the member or segment and are operated by the shift keys. The segment E shown in the Figure is provided at each side with a stop 7 co-operating with resilient adjustable stops 8, 9 on the framework A. The segment is connected by adjustable links 39 to bell-cranks 37 on a rock-shaft 32, counterbalancing-springs being connected to the bell-cranks and an adjustable member 36. Latches 17, 27, mounted on an adjustable pivot 18, co-operate with one of the stops 7 to lock the segment in the normal and depressed position respectively. The latch 17 is connected by a link 16 to a bell-crank 14 pivoted on the shiftkey lever 10, and the latch 27 is connected by a link 26 to an arm 43<a> of the shift-locking keylever 43. The bell-crank 14 is pivoted at 13 to an arm 12 of the key-lever 10 and is connected thereto by an adjustable spring 20, free movement of the bell-crank on the key-lever being limited by a pin-and-slot 22. The bell-crank is connected by an adjustable link 26 to a link 25 having a slot 29 receiving a pin 30 on an arm 31 secured to the shaft 32. There is slight lost motion between the pin and the end of the slot, and a spring 41 is arranged between the pin and a lug 42 on the link. The key-lever 43 has a pin 44 engaging a pivoted locking-member 45 which abuts on a pin 51 on the key-lever 10 and has a locking-notch 52 for engaging the pin. When the key-lever 10 is depressed, the latch 17 is released during the initial part of the stroke, the link 25 moving idly, and on completion of the stroke the shaft 32 is rocked and the segment shifted downwards. When the stops 7 engage the stops 9, the springs 20 cushions the key-lever. On release of the key-lever, the segment and associated parts are returned by the springs 35. the return of the key-lever being completed by the spring 41. When the key-lever 43 is depressed, the key-lever 10 also is depressed and is locked by the member 45, the hook 17 being released and the segment being depressed in the above-described manner, and the latch 27 being moved into engagement with the stop 7. A slight further depression of the key-lever 10, a spring 48 causes the member 45 to raise the key-lever 43 and release the latch 27, the segment and associated parts being thereupon returned by the springs 35. When an action comprising intermediate levers L pivoted on the framework and connected by links M to the type-levers D is employed, compensation for case-shift is provided by so arranging the links that they are inclined upwardly and downwardly in the normal and shift positions of the segment respectivelv. Specifications 213,068 and 224,454 are referred to.