Smoke detectors utilizing a hydrophilic substance

• US 5,781,291 A
• Filed: 10/22/1996
• Issued: 07/14/1998
• Est. Priority Date: 10/22/1996
• Status: Expired due to Term

• Current Assignee: Pittway Corporation (Honeywell International Inc.)
• Original Assignee: Pittway Corporation (Honeywell International Inc.)
• Inventors: Daly, Juliette C., Shoenfelder, George A., So, Bernard Y.C.
• Primary Examiner(s): Font, Frank G.
• Assistant Examiner(s): VIERRA EISENBERG, JASON D
• Application Number:
  US08/734,897
• Time in Patent Office: 630 Days
• Field of Search: 356/335-343, 340/627-634
• US Class Current: 356/338
• CPC Class Codes: G08B 17/107 for detecting light-scattering due to smoke
• CPC Class Codes: G08B 17/113 Constructional details

Abstract

A smoke detector incorporates a porous plastic material which carries a hydrophilic agent alone or in combination with a surfactant which can be sprayed or deposited onto structural elements of the detector. The detector can include a molded removable plastic element that carries a hydrophilic agent. The element can be arranged to surround a light beam injected into a sensing region of a photoelectric detector.

Claims

1. An ambient condition detector comprising:

a housing which defines a sensing region;

a source for projecting a beam of radiant energy into the region;

a sensor carried by said housing for converting scattered radiant energy incident thereon to a corresponding electrical signal wherein the housing carries an element which is selected from a class which includes a surfactant containing plastic, a surfactant coated plastic, and a porous plastic which incorporates a hydrophilic substance.

2. A detector as in claim 1 which includes a surfactant containing plastic element carried by said housing adjacent to the projected beam.

3. A detector as in claim 1 wherein the beam passes through an aperture and wherein the aperture is defined in a surfactant coated material.

4. A detector as in claim 1 wherein the beam passes through an aperture and wherein the aperture is defined in a porous plastic element which incorporates a hydrophilic substance.

5. A detector as in claim 1 wherein the housing is formed, at least in part, of a surfactant coated plastic.

6. A detector as in claim 1 wherein the beam passes through a lens and wherein the lens is formed, at least in part, of a surfactant containing material.

7. A detector as in claim 1 wherein the beam passes through a lens and wherein the lens is formed at least in part, of a surfactant coated material.

8. A detector as in claim 1 which includes a molded plastic septum coated with a surfactant.

9. A detector as in claim 1 which includes a septum molded of a porous plastic which incorporates a hydrophilic-type substance.

10. A detector as in claim 1 which includes a removable element that incorporates a hydrophilic material.

11. A detector as in claim 10 wherein the removable element is smoke transmissive.

12. A detector as in claim 11 wherein the removable element includes a cylindrical screen.

13. A detector as in claim 10 wherein the removable element includes at least a portion of the housing.

14. A smoke detector comprising:

a housing which defines an internal region;

a smoke sensor carried at least in part within the housing wherein the housing carries a hydrophilic substance.

15. A detector comprising:

a housing which defines an internal region;

an ambient condition sensor carried at least in part within the housing wherein the housing carries a hydrophilic substance.

16. A detector as in claim 15 wherein the sensor includes:

a light source and a photosensor for sensing light incident thereon.

17. A detector as in claim 16 which includes a lens located adjacent to the source wherein the lens is coated with a surfactant.

18. A detector as in claim 16 wherein the source projects a light beam into the region and wherein the housing carries an aperture through which the beam is projected and wherein the aperture extends through a plastic member which incorporates a hydrophilic substance.

19. A detector as in claim 18 wherein the plastic member is porous.

20. A detector as in claim 19 wherein the plastic member is removably carried by the housing.

21. A detector as in claim 16 which includes a focusing lens carried by the housing wherein the lens incorporates a surfactant.

22. A detector as in claim 15 wherein the housing is molded, at least in part, of a porous plastic which includes the hydrophilic substance.

23. A detector as in claim 15 which incorporates a condensation sensor.

24. A detector as in claim 23 which incorporates control circuitry carried by the housing wherein the control circuitry is coupled to the condensation sensor.