Abstract: In a keyboard for an electronic circuit having a striker on each key formed of electronic material which is conductive or carries a conductor and which is moved downwardly towards a fixed conductor assembly to provide capacitive coupling, it is found that electrostatic charges can be generated by operation of a key which give spurious outputs. The present invention provides constructions for reducing the effects of such charges.

Abstract: The device of this invention has a housing disposed to fit over the nine keys or push-buttons, numbered 1 through 9 of a push-button array of a calculator or push-button telephone, or the like. Push-button operating means are provided with U-shaped members for receiving human digits. Three of such push-button operating means are disposed along columnar openings in the housing and are resiliently held in a position which corresponds to the second row of the three rows of push-buttons in a standard array. A push-button is movably secured to the U-shaped member and extends therethrough to a finger element. When the push-button is depressed, the finger element to which it is connected depresses the push-button in the center row of the array. When the human finger is pushed against one of the concave-shaped walls of the U-shaped member, the push-button operating means moves along the column to one of the other rows. Within the housing is a wheel which is resiliently connected to the push-button operating means.

Abstract: An electronic keyboard has a chassis with keys each utilising a parallel motion linkage to permit movement of an operating member towards an electric circuit element. The main structure of the keys and linkage may be formed as a unitary plastics moulding.

Abstract: An electronic digital calculator, the calculator being in the form of an elongated tubular body having a size and shape similar to a pen or pencil and having a plurality of input valve setting keys and function keys carried on its surface as well as illuminable "read-out", or display, screen. The value setting keys and the function keys are arranged on the surface of the tubular body such that the calculator can be used while held in one hand of the user.