Ionization smoke detector and alarm system
First Claim
Patent Images
1. An ionization smoke detector having a sensing chamber comprised of:
- a mounting board;
a perforated metallic shell defining an open interior space and supported at one side on the mounting board with the one side and the board in adjacent relationship;
an electrode mounted on the board and positioned within the open interior space of the metallic shell adjacent the one side in electrically insulated relationship to the metallic shell, the electrode having a surface facing away from the board and toward the side of the shell opposite the one side and defining an aperture in the middle of the surface; and
a radiation source supported from the mounting board in the aperture of the electrode for exposure within the interior space of the shell.
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Abstract
An ionization smoke detector particularly suited to residential use is disclosed. The detector is battery-operated and is connected with a non-latching, pulsating alarm circuit. The detector has a sensing chamber formed by a perforated metallic shell and an electrode within which an insulated radiation source is centrally positioned to generate an ionization current for detecting smoke or other similar aerosols. The alarm circuit provides a pulsating alarm signal when smoke levels above a predetermined value are sensed. The alarm circuit also includes a low voltage detection circuit for sounding the alarm when the end of useful battery life is approaching.
23 Citations
13 Claims
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1. An ionization smoke detector having a sensing chamber comprised of:
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a mounting board; a perforated metallic shell defining an open interior space and supported at one side on the mounting board with the one side and the board in adjacent relationship; an electrode mounted on the board and positioned within the open interior space of the metallic shell adjacent the one side in electrically insulated relationship to the metallic shell, the electrode having a surface facing away from the board and toward the side of the shell opposite the one side and defining an aperture in the middle of the surface; and a radiation source supported from the mounting board in the aperture of the electrode for exposure within the interior space of the shell. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An ionization smoke detector having a sensing chamber comprising:
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a platform; a porous shell mounted on the platform and defining an interior chamber space ventilated through the walls of the shell; an electrode mounted within the chamber space defined by the shell; a radioactive source mounted near the center of the electrode in electrically insulated relationship to the electrode; and an electrically conductive element supported by the porous shell in the chamber space at another side of the space separated from said one side. - View Dependent Claims (9, 10)
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11. A housing for an ionization smoke detector having a ventilated sensing chamber comprising:
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a base portion having a bottom and a sloped, peripheral wall containing a plurality of apertures and diverging away from the bottom; and a cover portion engaged with the base portion and having a concave outer surface disposed generally parallel to the bottom of the base portion, the cover portion also defining a central aperture circumscribed by the concave surface and exposing the ventilated sensing chamber. - View Dependent Claims (12, 13)
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Specification