Gas and smoke alarm

Claim 2

A gas and smoke alarm comprising a frame, a semiconductor sensor sensitive to the presence of gas and smoke, a heater for the semiconductor sensor, a signal lamp in series with the sensor, a power source electrically connected to the sensor through the lamp, an alarm horn connected to the power source across the sensor, a reset circuit adapted to restore pre-alarm discontinuity to the horn, means for adjusting the sensitivity setting of the semiconductor sensor; said sensor, heater, lamp and horn being secured to said frame; a cover for the frame, and a heat flue defined by the cover and the frame, said heat flue opening upon at least one of said heater, lamp and semiconductor sensor so as to induce convection flow in the flue for sampling ambient atmosphere.

Claim 3

Apparatus in accordance with claim 1 further comprising a central post supported on the frame; a circuitry board secured to the post and holding said sensor, lamp and heater; and means on the post securing the cover at an interval from the frame.

Claim 4

Apparatus in accordance with claim 1 wherein said frame comprises parallel end pieces spaced from the cover, spaced central ribs parallel to the end pieces, a back panel connecting the end pieces and the ribs, and a bridge between the ribs intermediate the back panel and the cover adapted to support the central post.

Claim 5

Apparatus in accordance with claim 3 wherein the cover comprises a front panel secured to the post, and parallel spaced sides surrounding the frame and extending at least between frame end pieces.

Claim 6

Apparatus in accordance with claim 1 wherein said cover is light permeable in the area of the lamp.

Claim 7

Apparatus in accordance with claim 1 further comprising time delay means in series with said reset switch in the power circuit for the alarm horn.

Claim 8

A gas and smoke sensitive alarm for use with an exterior power source and comprising a frame adapted to mount to a wall, an alarm horn fixed to the frame, a transformer fixed to the frame, a gas and smoke sensor, a signal lamp, a voltage regulating resistor for the sensor, electrical means linking the transformer, lamp and sensor with the horn, said transformer being electrically connected to the sensor through the lamp; means for adjusting the sensitivity setting of the sensor, a reset switch electrically interposed between horn and sensor, time delay means in parallel with the reset switch responsive to the heat condition of the regulating resistor for the sensor, a printed circuit board supporting the lamp, resistor and sensor; a cover for the frame, means supporting both the circuit board and the cover from the frame, and a heat flue defined by the cover and the frame, said heat flue being open to said regulating resistor, lamp and sensor.

Claim 9

A gas and smoke sensitive alarm for use with an exterior power source and comprising a frame adapted to mount to a wall, an alarm horn fixed to the frame, a transformer fixed to the frame, a gas and smoke sensor, a signal lamp, a voltage regulating resistor for the sensor, electrical means linking the transformer, lamp and sensor with the horn, said transformer being electrically connected to the sensor through the lamp; means for adjusting the sensitivity setting of the sensor, a reset switch electrically interposed between horn and sensor, time delay means in parallel with the reset switch responsive to the heat condition of the regulating resistor for the sensor, a printed circuit board supporting the lamp, resistor and sensor; a cover for the frame, means supporting both the circuit board and the cover from the frame, and a heat flue defined by the cover and the frame, said heat flue being open to said regulating resistor, lamp and sensor.

Claim 10

Apparatus in accordance with claim 7 wherein the time delay means comprises a heat sensitive switch that is normally closed cold, and a heat transfer means in contact with the switch and intervening between the switch and said heat resistor for the sensor.

Claim 11

Apparatus in accordance with claim 8 further comprising a central post supported on the frame; a circuitry board secured to the post and holding the sensor, lamp and heater; and means on the post securing the cover at an interval from the frame.

Claim 12

Apparatus in accordance with claim 8 wherein said frame comprises parallel end pieces spaced from the cover spaced central ribs parallel to the end pieces, a back panel connecting the end pieces and the ribs, and a bridge between the ribs intermediate the back panel and the cover adapted to support the central post.

Claim 13

Apparatus in accordance with claim 8 wherein the cover comprises a front panel secured to the post, and parallel spaced sides surrounding the frame and extending at least between frame end pieces.

Claim 14

Apparatus in accordance with claim 8 wherein the cover is light permeable in the area adjacent the lamp.