Back to results
US 4,305,069 AGranted
Personal smoke and fire detector and warning unit
OwnerRobert B. Machen, John E. Thompsoninventors
Life of this patent
Estimating the term…
Abstract
This invention is a combination smoke and fire detection and alarm system that comprises a battery powered personal unit and an AC/DC sustaining unit. It provides audible and visual alarms and an emergency light. The personal unit plugs into the sustaining unit for battery charge and provides an additional smoke and fire detector when used in this mode.
Claims3
An improvement in a combination smoke indicator and alarm comprising a rechargeable battery-powered personal unit comprising means for a visual and an audible alarm;
- means for smoke and fire detection that combine a light emitting diode coupled with a light dependent resistor and a light activated silicon control rectifier in a smoke chimney with power and controls to activate a mechanical alarm to give a sensitive fire and smoke detection unit capable of detecting both white and black smoke;
- an AC/DC sustaining unit comprising means for smoke and fire detection by an ionization sensor, means for recharging the batteries in both the personal unit and the sustaining unit, means for a visual and a continuous audible alarm and an emergency light, wherein the improvement consists of a visual alarm of said personal unit having a cover which is spring loaded inactive and becoming visible when said visual alarm of said personal unit activates in the presence of smoke.
Dependencies are inferred from the claim text.