GB1238707A - - Google Patents

Abstract

1,238,707. Typewriters. FACIT-HALDA AB. 4 Nov., 1968 [2 Nov., 1967], No. 52249/68. Heading B6F. A tabulator mechanism for typewriters having power-operated carriages includes provision for prevention of damage thereto in the event of depression of the tabulator stop setting key 21<SP>1</SP> during carriage travel in either direction, or depression of the tabulation key during carriage return. The tabulator stop setting key 21<SP>1</SP> acts through a link 1 to pivot an arm 2 on which a stop setting member 4 is resiliently mounted. A lug 4d on the member 4 is thereby engageable with a tubulator stop 8 mounted on the carriage and acts to displace the stop from its inoperative position, as shown, wherein the curved end 11a of a spring finger 11 engages a recess 8a in the stop 8, to its operative position where the spring finger 11 engages a second recess 8b. While the tabulator stop setting key is depressed, the lug 4d therefore lies between two unactuated stops 8 and carriage travel at that time would cause undesired engagement between such a stop and the lug 4d. The stop setting member is accordingly resiliently mounted by means of a pair of pins (5, 6), Fig. 3 (not shown), and a spring (7), the upper pin (5) engaging a heart-shaped slot (4b) in the member 4, so that a sideways force on the lug 4d causes camming action between the upper pin (5) and the slot (4b), whereby the member 4 is forced downwardly out of operative position. The tabulator key acts to lift one of a plurality of denominational central stops 12 guided by a slotted plate 13. If a stop 12 is lifted during carriage return travel, damage, due to an actuated stop 8 striking the stop 12 in the wrong direction, is prevented through resilient mounting of the plate 13. Displacement of the plate 13 in the carriage return direction, i.e. to the right as shown acts through a spring-biased lever 16 to push downwardly on a link 19, whereby a bail (23, Fig. 4) is pivoted downwardly, the bail engaging a foot (12a) on the stop 12 and thereby acting to depress the stop out of operative position. On return movement of the plate 13, and hence the lever 16, the stop 12 remains in its inoperative position owing to relative sliding movement between the link 19 and the lug 16a of the lever 16.