Photoelectric smoke detector
First Claim
1. A photoelectric smoke detector comprising:
- a case having mounted therein a circuit board and a smoke detection chamber;
the smoke detection chamber having side walls with openings provided therein for ingress and egress of smoke particles, a top and a bottom;
a photoemitting diode being mounted in a mounting arrangement in the side wall of the smoke detection chamber so that a light beam from the photoemitting diode is transmitted across the smoke detection chamber without directly impinging upon either the top or the bottom surfaces;
said bottom of said smoke detection chamber having an opening therein with a shielding arrangement thereabout open to said chamber, said opening and shielding arrangement being entirely located between the vertical centerline of the smoke detection chamber and the mounting arrangement in the side wall of the chamber, said circuit board being mounted to overlie said bottom surface and including a photodiode detector mounted directly thereon and positioned generally in said opening so that it views into the smoke detection chamber through the opening and through said shielding arrangement, the shielding arrangement shielding the photodiode detector from incident light which may be present in the smoke detector chamber while providing for a diverging field of view of the photodiode detector, the diverging filed of view of the photodiode detector intersecting the light beam of the photoemitting diode to define a detection volume contained within the smoke detection chamber located close to the photoemitting diode and the photodiode detector and spaced from the surfaces of the smoke detection chamber to minimize the effect on the photodiode detector of light from the photoemitting diode which is reflected exterior to said detection volume.
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Accused Products
Abstract
The present invention provides for a smoke detection chamber and a photoelectric smoke detector containing the smoke detection chamber. The smoke detection chamber has side walls with openings provided therein for ingress and egress of smoke particles, a top and a bottom. A photoemitting diode is mounted in a mounting arrangement in the side wall of the smoke detection chamber to transmit a light beam across the smoke detection chamber without directly impinging upon either the top or the bottom surfaces. The bottom of the smoke detection chamber has an opening with a shielding arrangement thereabout open to the chamber located between the centerline of the smoke detection chamber and the mounting arrangement in the side wall of the chamber. A photodiode detector is positioned generally in the opening so that it views into the smoke detection chamber through the opening and shielding arrangement, the shielding arrangement shielding the photodiode detector from incident light which may be present in the smoke detector chamber while providing for a diverging field of view of the photodiode detector. The intersection of the field of view of the photodiode detector and the light beam of the photoemitting diode defines a detection volume contained within the smoke detection chamber located close to the photoemitting diode and the photodiode detector and spaced from the surfaces of the smoke detection chamber.
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Citations
24 Claims
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1. A photoelectric smoke detector comprising:
a case having mounted therein a circuit board and a smoke detection chamber;
the smoke detection chamber having side walls with openings provided therein for ingress and egress of smoke particles, a top and a bottom;
a photoemitting diode being mounted in a mounting arrangement in the side wall of the smoke detection chamber so that a light beam from the photoemitting diode is transmitted across the smoke detection chamber without directly impinging upon either the top or the bottom surfaces;
said bottom of said smoke detection chamber having an opening therein with a shielding arrangement thereabout open to said chamber, said opening and shielding arrangement being entirely located between the vertical centerline of the smoke detection chamber and the mounting arrangement in the side wall of the chamber, said circuit board being mounted to overlie said bottom surface and including a photodiode detector mounted directly thereon and positioned generally in said opening so that it views into the smoke detection chamber through the opening and through said shielding arrangement, the shielding arrangement shielding the photodiode detector from incident light which may be present in the smoke detector chamber while providing for a diverging field of view of the photodiode detector, the diverging filed of view of the photodiode detector intersecting the light beam of the photoemitting diode to define a detection volume contained within the smoke detection chamber located close to the photoemitting diode and the photodiode detector and spaced from the surfaces of the smoke detection chamber to minimize the effect on the photodiode detector of light from the photoemitting diode which is reflected exterior to said detection volume.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A smoke detection chamber for use in a photoelectric smoke detector comprising:
side walls with openings provided therein for ingress and egress of smoke particles, a top and bottom;
a mounting arrangement for a photoemitting diode located in the side wall of the smoke detection chamber so that a light beam from such photoemitting diode may be transmitted across the smoke detection chamber without directly impinging upon either the top or the bottom surfaces;
said bottom of said smoke detection chamber having an opening therein with a shielding arrangement thereabout open to said chamber for mounting of a photodiode detector so that it may view into the smoke detection chamber through the opening and through said shielding arrangement, said opening and shielding arrangement being entirely located between the vertical centerline of the smoke detection chamber and the mounting arrangement in the side wall of the chamber, the shielding arrangement being capable of shielding such photodiode detector from incident light which may be present in the smoke detector chamber while providing for a diverging field of view of such photodiode detector, the intersection of the centerlines of the mounting arrangement and the shielding arrangement defining a detection volume contained within the smoke detection chamber located close to the mounting arrangement and the shielding arrangement and spaced from the surfaces of the smoke detection chamber to minimize the impingement of light reflected exterior to said detection volume on such photodiode detector contained within the shielding arrangement.- View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. A smoke detection chamber for use in a photoelectric smoke detector comprising:
a side wall band encircling a detection volume to the interior thereof, a top and a bottom spaced from the side wall band to provide for open regions for ingress and egress of smoke particles to and from the detection volume;
a mounting arrangement for photoemitting diode located in the side wall band of the smoke detection chamber so that a light beam from such photoemitting diode may be transmitted across the smoke detection chamber without directly impinging upon either the top or bottom;
said bottom of said smoke detection chamber having an opening therein with a shielding arrangement thereabout open to said chamber for mounting of a photodiode detector so that it may view the detection volume through the opening and through said shielding arrangement, said opening and shielding arrangement being entirely located between the vertical centerline of the smoke detection chamber and the mounting arrangement in the side wall of the chamber, the shielding arrangement being capable of shielding such photodiode detector from incident light which may be present in the smoke detector chamber while providing for a diverging field of view of such photodiode detector, the intersection of the centerlines of the mounting arrangement and the shielding arrangement defining the detection volume contained within the smoke detection chamber located dose to the mounting arrangement and the shielding arrangement and spaced from the surfaces of the smoke detection chamber to minimize the impingement of light reflected exterior to said detection volume on such photodiode detector contained within the shielding arrangement.- View Dependent Claims (17, 18, 19, 20, 21, 22)
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23. A smoke detection chamber for use in a photoelectric smoke detector comprising:
side walls with openings provided therein for ingress and egress of smoke particles, a top and bottom;
a mounting arrangement for a photoemitting diode located in the side wall of the smoke defection chamber so that a light beam from such photoemitting diode may be transmitted across the smoke detection chamber without directly impinging upon either the top or the bottom surfaces;
said bottom of said smoke detection chamber having an opening therein with a shielding arrangement thereabout open to said chamber for mounting of a photodiode detector so that it may view into the smoke detection chamber through the opening and through said shielding arrangement, said opening and shielding arrangement being entirely located between the vertical centerline of the smoke detection chamber and the mounting arrangement in the side wall of the chamber, the shielding arrangement being capable of shielding such photodiode detector from incident light which may be present in the smoke detector chamber while providing for a diverging field of view of such photodiode detector, the intersection of the centerlines of the mounting arrangement and the shielding arrangement defining a detection volume contained within the smoke detection chamber located close to the mounting arrangement and the shielding arrangement and spaced from the surfaces of the smoke detection chamber to minimize the impingement of light reflected exterior to said detection volume on such photodiode detector contained within the shielding arrangement.- View Dependent Claims (24)
Specification