초록 ▼

A photoelectric smoke detector includes a light source and a light responsive cell and a smoke chamber therebetween all located within a generally cylindrical inner housing which is in turn concentrically located within a generally cylindrical outer housing. The inside surface of the outer housing i

A photoelectric smoke detector includes a light source and a light responsive cell and a smoke chamber therebetween all located within a generally cylindrical inner housing which is in turn concentrically located within a generally cylindrical outer housing. The inside surface of the outer housing is reflective, but the inner housing normally prevents light emitted by the light source into the smoke chamber from striking the outer housing. The inner housing contains one or more windows and is rotatable to move the windows to a position wherein light from the source can pass therethrough to the reflective surface of the outer housing and be reflected thereby back to the light responsive cell. The amount of light striking the reflective surface can be continuously adjusted between a normal condition when no light is reflected and a full test condition when a maximum quantity of light is reflected to the light responsive cell. Instead of having windows therein, the inner housing may alternatively have reflective portions thereon. The inner housing is resiliently biased to its normal condition and an actuating tool is provided for effecting rotation thereof.

대표청구항 ▼

Test means for a smoke detector device having a light source, light responsive means, and a smoke chamber therebetween, light from the light source being directed through a predetermined scattering region of the smoke chamber and reflected from smoke in the scattering region to the light responsive

Test means for a smoke detector device having a light source, light responsive means, and a smoke chamber therebetween, light from the light source being directed through a predetermined scattering region of the smoke chamber and reflected from smoke in the scattering region to the light responsive means for activating an alarm at a predetermined smoke density in the scattering region, said test means comprising: control means shiftable between a normal condition and a test condition, said control means including light reflecting means disposed outside the scattering region, said control means in the normal condition thereof maintaining said light reflecting means in non-reflective relationship with respect to the light entering the smoke chamber from the light source, said control means in the test condition thereof causing light entering the smoke chamber from the light source to intercept said light reflecting means outside the scattering region and be reflected by said light reflecting means to the light responsive means for causing the light responsive means to respond as if the predetermined smoke density were in the scattering region for actuating the alarm.