Abstract: In order to save space and manufacturing costs a pull-off effect for the operation of a key should be achieved by using a single spring. Thus the spring must have an arc-like force vs. displacement characteristic having a maximum of force about on half-way of the key stroke. This is achieved by a meander-like shaped spring (1) of flat material having two end loops (2, 3) of equal height and one middle loop (4) of about twice this height, all these loops lying within the same plane. The mounted spring is pretensioned in two directions being perpendicular to each other and lying in said plane, the operating force being applied to the top (7) of the middle loop.

Abstract: In order to have a large flexibility of application with simultaneously a reasonable number of different piece parts for a so called transformer keyboard the key element is subdivided. A base (1) usable for all applications includes elements for the protection against rotation (14) and for fixing (13) it on a printed circuit board (6) without screws and without soldering operations, further elements to guide (18) the stem (2) and to limit its stroke. The stem receives a ferromagnetic core (4) within its guidance (21). The shape and the size of wall portions (2', 22) change in accordance with the desired raster of the keyboard wherein the key element is used. A cap (3) carrying the marking has the same shape for all stems and is connected to the stem in a detatchable manner (27, 33). Due to their small height these key elements are especially suited in applications for data terminal keyboards with an ergonomically good design.

Abstract: In order to diminish the physical troubles often occurring with the usual keyboard arrangement, the alphanumeric keyboard is subdivided into two keyfields mounted on a support having a wedge-shaped extension towards the operator which extension is used as an arm rest. The keyfields are located in planes rising from the operator side of the keyboard which planes slope downward from the middle to the outside. In addition the keyfields enclose an angle open towards the operator in order to diminish the flexion of the hand with respect to the forearm needed with the prior one-piece keyboard. On both sides of these two keyfields two further keyfields are provided for numerical keys and/or function keys, for instance for data input devices. The additional keyfields are located in planes rising from the operator side of the keyboard without sloping to the outside.

Abstract: In a contactless keyboard including for each key a transformer with a core displaceable by the key operation and including a compensation transformer common to all key the compensation transformer is so designed that with an unactuated key the signal component of the compensation transformer in the signal applied to the evaluation circuit exceeds the component of the key transformer, whereas with an actuated key the signal component of the key transformer predominates. Therefrom results a phase change of the signal applied to the evaluation circuit with the actuation of a key. The evaluation circuit compares the phase of the key output signal with that of a reference signal. For increasing the immunity from disturbance the evaluation circuit delivers an output signal (key operated or key nonoperated) only when several successive comparison operations give the same result.

Abstract: The apertures in one wall of an electrical component housing through which electrical terminals protrude are sealed with resin. The resin is applied to the housing wall at a remote area and caused to flow by capillary action along grooves to the required locations for sealing the apertures. In the case of a two part housing the parts of which join at the perimeter of the wall having the protruding terminals, the resin may also be caused to flow by capillary action into this join to seal it.

Abstract: The invention relates to a micro relay intended for use in printed circuits provided with two switching-over contacts. The contacts are arranged in the core of the coil, each of the contacts being provided with its own armature fixed on the switching-over spring, thus no motion transfer elements are needed. The contact space is hermetically sealed so that contact properties similar to those of reed relays are achieved both for the make contacts and for the break contacts.