Snap-action electric switch with fulcrum means for limited contact sliding and positive-off torque
US4121069A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 19, 1976 |
| Grant date | Oct 17, 1978 |
| Priority date | — |
| Expiry date | Aug 19, 1996 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H19/635
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electric snap-action switch is disclosed having a movable contactor with oppositely inclined camming surfaces meeting at an apex on the top thereof. The contactor is centrally biased upwardly from below and cammed downwardly from above by a laterally movable operator traversing the inclined camming surfaces such that the contactor snaps laterally against vertical stationary contacts as the apex is crossed by the operator. The invention includes fulcrum means effective to stop the downward movement of the contactor before the operator crosses the apex whereby a moment arm is formed from a fulcrum to the point of operator-contactor engagement such that further movement of the operator towards the apex effectuates a torque on the contactor to pivot the contactor about the fulcrum to positively break any welds or other frictional attachments between the contacts without relying on the stored energy of the carrier biasing means, thereby affording a switch having little possibility of failure in an "on" position. The inclined camming surfaces of the contactor may be formed with compound slopes to assure constant operator pressure prior to trip point as the contactor pivots and increas…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.