Contraves Ag

Heinz Waser

Peter Wendel

Hans Beck

Peter Bettschart

In the stepping or indexing drive of a character drum having secured thereat a pinion, wherein there is provided an actuation plunger for rotary motion of the pinion in the one direction and another actuation plunger for rotary motion of the pinion in the other direction, there must be prevented that the character drum while rotating from one index position to the next can be stopped and remain in an intermediate position between two index positions. For this purpose, there is provided a movable locking or detent element which coacts with both actuation plungers and with inclined surfaces formed at the switch housing. This locking or detent element is brought by each individual actuation plunger, at the start of its actuating path, into a locking position for the other actuation plunger and retained in this locking position to positively prevent simultaneous actuation of both actuation plungers.

Push-button multi-position switch

The electric push-button switch comprises a housing portion and a linearly moveable push-button portion. Guide columns at the housing portion and the push-button portion attain accurate linear guiding and rotational positioning of the push-button portion. These guide columns mutually interact or interengage and are in multiple line contact with one another. This multiple line contact extends in the direction of movement of the push-button portion. The length of such line contact is variable between a rest position and an operating position of the push-button portion. This line contact is greatest when the push-button portion assumes its operating position. A contact surface of a fixed counter contact comprises a planar slide surface for resilient contact arms carried by the push-button portion. The friction arising during the forced sliding movement of the resilient contact arms over the contact surface produces self-cleaning of the contacts and damping of contact chatter movements. The contact chatter time, even when eccentrically actuating the push-button switch, can be decisively shortened by the exact guidance and damping of the movements. A snap-action, which is to be overcome when actuating the push-button switch, advantageously comprises a permanent magnetic cover plate at the housing portion and an armature plate at the push-button portion. The push-button switch can be used for single switches or for switches forming component parts of a push-button panel or switchboard having a common housing portion.

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Schlieren, Switzerland

Heinz Waser