Typewriting machines – Key-board or key lever-actuating mechanism – Including control of key action
Patent
1980-12-01
1982-12-07
Sewell, Paul T.
Typewriting machines
Key-board or key lever-actuating mechanism
Including control of key action
400491, 4004912, 4004913, 200159R, 340365E, B41J 526
Patent
active
043624081
ABSTRACT:
A keyboard having a plurality of keys thereon, with each key being moveable from a rest position along an actuation path having a makepoint therealong, whereby completion of an electrical circuit is effected by moving a key with a predetermined force along its actuation path to its associated said makepoint. Each of the keys has means for restoring it towards its rest position. At least one of the keys is designated as a special key and it has warning means associated therewith and positioned with respect to the special key and keyboard so as to increase the force (above the predetermined force) required to actuate the special key. The increase in force provides tactile feedback to an operator of the keyboard before the special key's associated makepoint is reached to thereby warn said operator that he is about to actuate the special key. The warning means is made of resilient material, has a general, washer-like shape, and is positioned under the key cap of the special key.
REFERENCES:
patent: 3964593 (1976-06-01), Pointon
patent: 4132487 (1979-01-01), Fisher
IBM Technical Disclosure Bulletin, vol. 17 No. 1 June 1974 "Dual-Force Automatic Rekeying", J. E. Fox pp. 164-165.
Cordes Richard E.
Sears Ronald J.
Cavender J. T.
NCR Corporation
Roock Daniel J.
Sessler Jr. Albert L.
Sewell Paul T.
LandOfFree
Means for avoiding accidental actuation of a critical function k does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Means for avoiding accidental actuation of a critical function k, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Means for avoiding accidental actuation of a critical function k will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1900389