GB615542A - An improved typewriter keyboard - Google Patents

Abstract

615,542. Typewriters. HARRISON, H. T. Jan. 8, 1946, No. 632. [Class 100(iv)] A typewriter keyboard specially for use by blind persons comprises a spaced key 2 in the centre of the first or second row, a shift bar 3a in front of the first row provided with a raised centre 3, and a backspacer bar 4, preferably moving the carriage a half-space, behind the last row. In the four-bank keyboard shown in Fig. 1, small letters are typed on pressing the shift bar; the letters in the two-bank keyboard of Fig. 2 are either capitals or small letters. As shown, the key 2 is above the level of the adjoining keys and carries the letter X, and some of the keys, shown by double circles, have rims to differentiate them from the others. The letters are so distributed on the keyboard that the fingers of the right hand have to depress at least fifty-five keys for every forty-five depressed by the left hand, and the letters of two-letter groups which occur frequently are placed symmetrically on opposite sides of the keyboard and preferably in the same row. Keys operated by the fingers of both hands are differentiated by higher levels, rims, characters which stand out, or braille signs: the keys shown as blanks carry signs such as a dash, colon or semi-colon. The part 3 has edges 5, 6 serving as finger guides.