Apparatus for maintaining detecting devices free of contaminants

Claim 1

Apparatus for maintaining the lens of a detector in use substantially free of contaminants comprising, a housing containing the lens and a detecting apparatus, lens mounting means including a lens ring integral with the housing and having a downwardly extending shoulder around its upper inner end, a seat ring secured within the lower end of the lens ring, a washer mounted on top of the seat ring within the lens ring for support of the lens thereof, a lens top connected to the lens ring in spaced relation with the external surface of the lens, said lens top having an opening therethrough onto the surface of the lens, said lens top having an inwardly and downwardly extending shoulder adjacent the external surface of the lens with a groove extending around said shoulder and facing the external surface of the lens, an arcuate sealing member mounted in the groove of the lens top shoulder and secured by the lens top in fluid tight engagement with the external surface of the lens, a cleaning fluid cavity defined by the combination of the lens ring, the lens top, the arcuate sealing member, and the external surface of the lens, and an aperture in the cleaning fluid cavity, said aperture defined by the shoulder of the lens top, the external surface of the lens, and two adjacent ends of the arcuate sealing member within the lens top shoulder.