Improvements in or relating to spacing mechanisms for the paper carriage of typewriters and like office machines

摘要

903,836. Typewriters. OPTIMA BUROMASCHINENWERK ERFURT VEB. June 9, 1960, No. 20376/60. Class 100 (4). Letter-spacing mechanism.-A letter-spacing mechanism comprises two ratchet wheels 6, 7 having teeth 6a, 7a arranged two steps apart from one another and being radially offset from one another by a distance equal to a letter-space, two check pawls or levers 15, 19 mounted on separate rockers 12, 13 and a bridge member 29 movable at each key action to alternatively move the holding check lever away from its ratchet tooth and allow the other ratchet to engage the other check lever. This arrangement allows the letter-space movement to be completed in one step. The key action draws plunger 43 to the right, Figs. 4, 5, and a pawl, either 32 or 37, Fig. 2, engages check lever 15 or 19 which disconnects from its ratchet wheel. The other ratchet wheel engages its check lever and pivots it anti-clockwise, Fig. 1, until it is arrested by either stop 12a or 13a the pivoting the pawl 32 or 37 against spring 33 or 38 until the bridge member 29 returns by release of the key action. The pawl 32 or 37 thereupon is returned against its stop 34 or 39 ready to engage the check levers 15 or 19 again.