Quiet pushbutton switch ratchet mechanism
US6621028B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 29, 2002 |
| Grant date | Sep 16, 2003 |
| Priority date | — |
| Expiry date | Oct 29, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H13/585
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A pushbutton has a body including a barrel and a plunger longitudinally movable in the barrel. A plurality of longitudinally extending teeth on the plunger engage a plurality of longitudinally extending teeth on a rotatable ratchet coaxial with the plunger. The ratchet is spring loaded against the plunger. A rotatable electrical contact cup connected to the ratchet makes or breaks contact with a fixed electrical terminal in the body. The plunger teeth each include a driving face which causes rotation of the ratchet. The driving face has an angle from a normal to the longitudinal direction of the plunger wherein the angle is at least the arctangent of the coefficient of friction between the ratchet teeth and the plunger tooth plus the arctangent of the effective coefficient of friction between electrical contacts in the switch, plus a margin of safety greater than the arctangent of the effective coefficient of friction between other parts of the switch. The angle is up to about 30 degrees.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.