Abstract: A keyboard layout for a one-handed keypad having fifteen alphabetic keys. Each key has a primary letter and a secondary letter. The primary letter is keyed by solely striking the key, while the secondary letter requires striking a secondary key first or simultaneously with the primary alphanumeric key. The layout placement minimizes finger travel and keystrokes to generate the most common letters and digraphs in the English language.

Abstract: An encoder having a special construction which includes a special tension spring which increases the life of the encoder. The tension spring has first and second "U"-shaped portions formed on one end thereof with the remaining end of the spring being secured to a frame of the encoder. The first "U"-shaped portion of the spring is positioned around a stud on a beam of the encoder, and the second "U"-shaped portion receives a portion of the beam. An actuator is used to move a hammer on the beam to an impact position, and the tension spring is used to return the beam to a home position. As the beam is moved toward the impact position, there is an increase in the area of contact between the stud and the first "U"-shaped portion to thereby minimize movement therebetween. When the spring returns to the home position, the body portion of the spring assumes an "arched" position which minimizes "bounce" of the beam in returning to the home position.

Abstract: A typewriter of the kind having an array of typebars each movable by means of a flexible tension element or string connecting the typebar to the shank of a corresponding key, is provided with improved means connecting each string to the associated key. The string has a spherical bead at one end which is trapped between the shank of the key and a part of the body of the typewriter against which the shank slides in such a manner that the bead is pushed down on depression of the key. When the key is fitted to the typewriter during assembly the bead is drawn between the shank and the said body part by the movement of the key into place in the typewriter body.