Smoke and fire detector
US4845474A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 1, 1986 |
| Grant date | Jul 4, 1989 |
| Priority date | — |
| Expiry date | Aug 1, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K3/3468
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An ionization smoke and fire detector comprises a molded plastic housing that includes a nodal ring for supporting a vibrating plate that is part of an alarm. The alarm may be driven by piezoelectricity or by an electromechanical device. If the detector is battery powered, a portion of the housing is cut out to permit removal and insertion of a battery holder that makes contact automatically upon insertion to supply electric power to the electronic circuit of the smoke detector. One electrode of a reference chamber for the smoke detector is formed by wave-soldering an open metallized area on the printed-circuit board. Contact with the movable element of the alarm and with a high-impedance input in an integrated circuit are made through springs that are not soldered or welded. The outside of the smoke and fire detector is formed in part by a smoke-chamber cover which makes various electrical contacts with the printed-circuit board at electrical conductors that are bent around the edge of the board and wave-soldered. The smoke and fire detector is assembled without screws and all electrical connections among components are made without welding, hand soldering, or any soldering beyond…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.