Underwater light assembly with annularly flared re-entrant wall and sealing means

DETAILED DESCRIPTION Referring first to FIG.
1, a pool or spa wall 10 (typically concrete) forms a niche 11 that receives a metallic shell 12.
The latter receives an underwater light assembly generally indicated at 13, and including an underwater lens 14, face ring 15 supporting the lens, and attached to the shell, lens gasket 16 carried by the face ring, and light housing 17 carried by the face ring.
A light bulb 18 is carried in the conical housing 17, and electrical wiring to the bulb appears generally at 19.
See also U.
S.
Pat.
Nos.
4,234,819 and 4,460,944.
Referring now to FIGS.
2-6, the light assembly face ring 15 comprises a thin metallic annulus defining a central axis 20.
The ring has a front wall 21 which extends in a plane normal to axis 20; and outer cylindrical wall 22; and a wall 23 extending from the radially inner portion of wall 21 re-entrantly into the space 24 rearwardly of wall 21 and inwardly of wall 22.
Re-entrant wall 23 defines an annularly and rearwardly flared portion 23a to seat gasket 16 annularly and axially.
See the elastomer gasket U-shaped cross section in FIG.
4, with forward lip 16a annularly and pressurally seated and sealing against flared wall portion 23a.
Ring 15 also has circularly spaced tabs 26 thereon and projecting generally axially rearwardly beyond the edge 23b of the flared wall portion 23a to peripherally position the gasket, and blocking radially outward extrusion thereof when compressed axially by light housing 17.
In this regard, note the housing annular flange 17a pressed forwardly against the gasket head 16b, causing outward extrusion or pressing of the gasket wall 16c against the inner sides of the tabs 26.
At the same time, the outer flange 14a of the transparent (glass or plastic) lens 14 is squeezed between gasket lips 16a and 16d, to seal off therebetween.
The tabs, being circularly spaced, allow limited gasket bulging in the spaces between the tabs, to accomodate the gasket to the adjacent structure, for development of substantially uniform sealing pressure at flanges 17a and 14a