Laminated gage glass assembly

Claim 2

A lens assembly for a sight glass comprising a ferrule, said ferrule having an axially extending sidewall with an outwardly extending flange at one end and an inwardly extending flange at the other end, a first lens in said ferrule having a first side adjacent said inwardly extending flange, a second lens in said ferrule having a first side adjacent said outwardly extending flange, the opposite sides of said lenses being adjacent each other, and a sheet of transparent flexible plastic material extending between said lenses, between the outer periphery of said second lens and said ferrule sidewall and extending along the outer side of said outwardly extending flange.

Claim 3

A lens assembly as set forth in claim 1, wherein said sheet is bonded to said opposite sides of said lenses.

Claim 4

A lens assembly as set forth in claim 2, wherein said sheet is also bonded to said ferrule wall and said outer side of said outwardly extending flange.

Claim 5

A lens assembly as set forth in claim 3, including a second sheet of transparent flexible plastic material bonded to said first side of said second lens and to the portion of said first sheet extending along said outwardly extending flange.

Claim 6

A lens assembly as set forth in claim 3, including a gasket between said first side of said first lens and said inwardly extending flange, and bonding material filling the space between the outer periphery of said first lens and said ferrule sidewall.

Claim 7

A sight glass comprising a first pipe flange adapted to be attached to a pressure vessel, a second pipe flange secured to said first flange and defining an opening, a lens assembly clamped between said flanges and extending through said opening, said lens assembly comprising a ferrule, said ferrule having an axially extending sidewall within said opening, said ferrule also having an integral outwardly extending flange at the inner end clamped between said pipe flanges and an integral inwardly extending flange at the other end, a first lens in said ferrule having a first side adjacent said inwardly extending flange, a second lens in said ferrule having a first side adjacent said outwardly extending flange, the opposite sides of said lenses being adjacent each other, and a sheet of transparent flexible plastic material extending between said lenses, between the outer periphery of said second lens and said ferrule sidewall and along said outwardly extending flange adjacent said first pipe flange.

Claim 8

A sight glass comprising a first pipe flange adapted to be attached to a pressure vessel, a second pipe flange secured to said first flange and defining an opening, a lens assembly clamped between said flanges and extending through said opening, said lens assembly comprising a ferrule, said ferrule having an axially extending sidewall within said opening, said ferrule also having an integral outwardly extending flange at the inner end clamped between said pipe flanges and an integral inwardly extending flange at the other end, a first lens in said ferrule having a first side adjacent said inwardly extending flange, a second lens in said ferrule having a first side adjacent said outwardly extending flange, the opposite sides of said lenses being adjacent each other, and a sheet of transparent flexible plastic material extending between said lenses, between the outer periphery of said second lens and said ferrule sidewall and along said outwardly extending flange adjacent said first pipe flange.

Claim 9

A sight glass as set forth in claim 6, wherein said flexible plastic sheet is bonded to said opposite sides of said lenses.

Claim 10

A sight glass as set forth in claim 7, wherein said flexible plastic sheet is also bonded to said ferrule wall and the outer periphery of said second lens and to said outwardly extending flange.

Claim 11

A sight glass as set forth in claim 8, including a second sheet of transparent flexible plastic material bonded to said first side of said second lens and extending completely across said first side of said second lens and across said portion of said first sheet adjacent said outwardly extending flange.

Claim 12

A sight glass as set forth in claim 8, including a gasket between said first side of said first lens and said inwardly extending flange and bonding material filling the space between the outer periphery of said first lens and said ferrule sidewall.

Claim 13

A sight glass as set forth in claim 9, including a second gasket positioned between said second sheet and said first pipe flange.

Claim 14

A lens assembly comprising a frame, said frame having an axially extending sidewall with an outwardly extending surface at one end and an inwardly extending surface at the other end, a first lens in said frame having a first side adjacent said inwardly extending surface, a second lens in said frame having a first side adjacent said outwardly extending surface, the opposite sides of said lenses being adjacent each other, and a sheet of transparent flexible plastic material extending between said lenses, between the outer periphery of said second lens and said frame sidewall and extending along the outer side of said outwardly extending surface.

Claim 15

A lens assembly comprising a frame, said frame having an axially extending sidewall with an outwardly extending surface at one end and an inwardly extending surface at the other end, a first lens in said frame having a first side adjacent said inwardly extending surface, a second lens in said frame having a first side adjacent said outwardly extending surface, the opposite sides of said lenses being adjacent each other, and a sheet of transparent flexible plastic material extending between said lenses, between the outer periphery of said second lens and said frame sidewall and extending along the outer side of said outwardly extending surface.

Claim 16

A lens assembly as set forth in claim 12, wherein said sheet is bonded to said opposite sides of said lenses.

Claim 17

A lens assembly as set forth in claim 13, wherein said sheet is also bonded to said frame sidewall and said outer side of said outwardly extending surface.

Claim 18

A lens assembly as set forth in claim 14, wherein said first side of said second lens has a reflex prism surface.

Claim 19

A lens assembly as set forth in claim 14, including a second sheet of transparent flexible plastic material bonded to said first side of said second lens and to the portion of said first sheet extending along said outwardly extending surface.

Claim 20

A lens assembly as set forth in claim 14, including a gasket between said first side of said first lens and said inwardly extending surface, and bonding material filling the space between the outer periphery of said first lens and said frame sidewall.

Claim 21

A liquid level gage comprising an elongated body defining an elongated chamber therein, an inlet and an outlet for said chamber, said body having at least one elongated face defining an opening of said chamber, and a cover secured to said body to overlie said face, said cover having an elongated recess on the inner side adjacent said face in substantial alignment with said chamber opening, said recess having a sidewall extending outwardly from said inner side, said sidewall terminating at its outer edge in an inwardly extending surface defining a cover opening extending through said cover to give visual access to said chamber, a first lens in said recess having a first side adjacent said inwardly extending surface, a second lens in said recess having a first side adjacent said chamber, the opposite sides of said lenses being adjacent each other, and a sheet of transparent flexible plastic material extending between said opposite sides of said lenses, between the outer periphery of said second lens and said recess side wall and extending along the inner side of said cover in abutting relationship with said cover and the elongated face on said body to provide a seal between said body and said cover and to provide an imperforate seal against fluid flow from said chamber through said cover opening.

Claim 22

A liquid level gage comprising an elongated body defining an elongated chamber therein, an inlet and an outlet for said chamber, said body having at least one elongated face defining an opening of said chamber, and a cover secured to said body to overlie said face, said cover having an elongated recess on the inner side adjacent said face in substantial alignment with said chamber opening, said recess having a sidewall extending outwardly from said inner side, said sidewall terminating at its outer edge in an inwardly extending surface defining a cover opening extending through said cover to give visual access to said chamber, a first lens in said recess having a first side adjacent said inwardly extending surface, a second lens in said recess having a first side adjacent said chamber, the opposite sides of said lenses being adjacent each other, and a sheet of transparent flexible plastic material extending between said opposite sides of said lenses, between the outer periphery of said second lens and said recess side wall and extending along the inner side of said cover in abutting relationship with said cover and the elongated face on said body to provide a seal between said body and said cover and to provide an imperforate seal against fluid flow from said chamber through said cover opening.

Claim 23

A liquid level gage as set forth in claim 18, wherein said sheet is bonded to said opposite sides of said lenses and to said cover.

Claim 24

A liquid level gage as set forth in claim 19, including a gasket between said first side of said first lens and said inwardly extending surface, and bonding material filling the space between the outer periphery of said first lens and said recess sidewall.

Claim 25

A liquid level gage as set forth in claim 18, wherein said first side of said second lens has a reflex prism surface.