1
Theobald Schmid, Horst Widmaier, Friedrich Wolf: Keyboard for initiating switching operations or switching signals associated with respective symbols on the surfaces of the keys. Hand Widmaier Fabrik Fur Apparate Der Fernmelde und Feinwerktechnik, Baker Maxham Callan & Jester, July 23, 1985: US04531033 (18 worldwide citation)

A keyboard for initiating switching functions or switching signals. Synchronizing pins coupled to four key members at the mutually adjacent crossing between them cause actuation of contact sets upon depression of the keyboard surface above each synchronizing pin. Actuation of at least two contact se ...


2
Theobald Schmid, Horst Widmaier, Friedrich Wolf: Keyboard for initiating switching operations or switching signals associated with respective symbols on the surfaces of the keys. Hand Widmaier Fabrik fur Apparate der Fernmelde und Feinwerktechnik, Baker Maxham & Jester, March 10, 1987: US04649246 (4 worldwide citation)

A keyboard for initiating switching functions or switching signals. Synchronizing pins coupled to four key members at the mutually adjacent crossing between them cause actuation of contact sets upon depression of the keyboard surface above each synchronizing pin. Actuation of at least two contact se ...