EP 0012279 B1 19820707 - PUSH-BUTTON SWITCH, PARTICULARLY FOR KEYBOARDS OF TYPEWRITERS AND SIMILAR DEVICES
Title (en)
PUSH-BUTTON SWITCH, PARTICULARLY FOR KEYBOARDS OF TYPEWRITERS AND SIMILAR DEVICES
Publication
Application
Priority
- DE 2854096 A 19781214
- DE 7914017 U 19790515
Abstract (en)
[origin: EP0012279A1] 1. A key switch, in particular for the keyboards of typewriters and similar devices, for example, teleprinters and data stations, having a key tappet (1) which on operation of the key can be moved from the rest position into the operating position against the spring force of a helical spring (4) which is fixed between the key housing (6) and a contact surface (2a) on the key tappet (1), wherein the spring (4) forms the moving contact piece which is brought into contact with a stationary counter-contact (3) during contacting, and the key tappet (1) of which can be further moved after contacting, characterised in that the helical spring (4) has two spring sections (4a, 4b) the first (4a) of which is designed in known manner as a compression spring for the return movement of the key tappet (1) from the operating position to the rest position, and the second (4b) of which rests against the side of the contact surface (2a) of the key tappet (1) which faces away from the first spring section (4a), with a given initial tension, and that the counter-contact (3) is arranged in the range of travel of the second spiral spring section (4b) of the spring (4) which is extended above the contact surface (2a) of the key tappet (1).
IPC 1-7
IPC 8 full level
H01H 13/52 (2006.01)
CPC (source: EP)
B41J 5/08 (2013.01); H01H 13/52 (2013.01)
Designated contracting state (EPC)
CH FR GB IT NL SE
DOCDB simple family (publication)
EP 0012279 A1 19800625; EP 0012279 B1 19820707; CS 216691 B2 19821126; MX 147268 A 19821101
DOCDB simple family (application)
EP 79104773 A 19791129; CS 881579 A 19791214; MX 18046279 A 19791212