Electricity: circuit makers and breakers – Liquid contact – Time delay
Patent
1980-07-09
1981-11-24
Little, Willis
Electricity: circuit makers and breakers
Liquid contact
Time delay
H01H 312, H01H 926
Patent
active
043026486
ABSTRACT:
The invention provides a key-board switch unit used, for example, in pocketable electronic calculators comprising a base plate having at least one pair of switch electrodes and a covering pad made of an insulating rubber and provided with at least one contact member made of an electroconductive rubber and bonded on the lower surface thereof to face the electrodes coming into contact therewith when the pad is depressed. The contact member is embedded in the covering pad in such a manner that the surface of it is coplanar with the surface of the covering pad at least along the peripheries in conjunction with the covering pad and the contact member is sufficiently small so as to be confined within the area of the covering pad facing the void space formed between the base plate and the covering pad at the portion of the electrodes. The hardness relationship between the rubbery materials of the covering pad and the contact member is also of essential importance for reliable switching and durability of the switch unit.
REFERENCES:
patent: 3793649 (1974-02-01), Tarnopolsky et al.
patent: 4129758 (1978-12-01), Gilano et al.
patent: 4197439 (1980-04-01), Mecklenburg et al.
patent: 4207443 (1980-06-01), Matsuura
Matumoto Shigeru
Okamoto Takekuni
Sado Ryoichi
Little Willis
Shin-Etsu Polymer Co. Ltd.
LandOfFree
Key-board switch unit does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Key-board switch unit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Key-board switch unit will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2176222