US3919542A

US3919542A - Floodlight assembly with improved lens frame

Info

Publication number: US3919542A
Application number: US485603A
Authority: US
Inventors: William A Castic
Original assignee: North Star Lighting Inc
Current assignee: North Star Lighting Inc
Priority date: 1974-07-03
Filing date: 1974-07-03
Publication date: 1975-11-11
Anticipated expiration: 1992-11-11

Abstract

A resiliently flexible frame which may be of quadrilateral form is engaged with the edge portions of a complementary lens for closing a similarly sized opening in a cavitated lamp and reflector housing. The frame is continuous about the lens but has a split therein with confronting ends to facilitate assembly of the lens with the frame by springing the frame open to receive the lens and then securing hinge means on the frame at each side of the split to the housing whereby the ends are held against separating and the frame is maintained fixedly on the lens and the lens and the frame can be swung as a unit between open and closed positions relative to the opening and held by releasable means in the closed position with the lens and the frame closed against a sealing gasket.

Description

United States Patent 1191 Castic 5] Nov. 11, 1975 FLOODLIGHT ASSEMBLY WITH IMPROVED LENS FRAME Primary Examiner-Robert P. Greiner [75] Inventor William A Castic Elk Grove Attorney. Agent. or FirmHill. Gross. Simpson. Van village Santen, Steadman. Chiara & Simpson [73] Assignee: North Star Lighting Inc., Berwyn [57] ABSTRACT lll. A resiliently flexible frame which may be of quadrilat- Filed; July 3, 1974 eral form is engaged with the edge portions of a complementary lens for closing a similarly sized opening in PP 485603 a cavitated lamp and reflector housing The frame is continuous about the lens but has a split therein with 52 us. c1 240/4155; 350/245 Confronting ends to facilitate h' Ofthe lens 51 int. c1. F21V 17/00 the frame by springing the Open fhceh'h the 5 Field f Search 240/4151 151 152 lens and then securing hinge means on the frame at 350/245. 253 each side of the split to the housing whereby the-ends are held against separating and the frame is main- 5 References Cited tained fixedly on the lens and the lens and the frame UNITED STATES PATENTS can be swung as a unit between open and closed positions relative to the opening and held by releasable means in the closed position with the lens and the 1:731:2s4 10/1950 Andel LIL 11:11:. 350/545 x frame Closed ugamst a seahng gasket 3.2911496 12/1966 Appleton .1 240/4155 19 Claims, 5 Drawing Figures US. Patent 0 Nov. 11, 1975 FLOODLIGHT ASSEMBLY WITH IMPROVED LENS FRAME This invention relates to improvements in floodlight assemblies, and is more particularly concerned with new and improved lens frame means for such assemblies.

As generally constructed heretofore, lens frames for outdoor floodlights have customarily been made in one piece and then shaped about the edge of the lens, or have been made from sections rigidly secured together requiring retainer pieces to hold the lens in the frame. Prior constructions have also presented some difficulties with proper sealing the lamp cavity about the lens, especially where the lens frame has been made from relatively thick or large cross section material such as aluminum which must be relatively thick to provide adequate strength.

It is, accordingly, an important object of the present invention to overcome the deficiencies, inefficiencies and problems in prior floodlight lens frame structures and to provide a new and improved lens frame and a method of assembling the same.

Another object of the invention is to provide a floodlight assembly having a new and improved lens mounting frame which can be easily and efficiently assembled with the lens and which will effectively support the lens for opening and closing relative to the floodlight housmg.

A further object of the invention is to provide a new and improved floodlight lens frame structure, and method of assembling with a lens.

Still another object of the invention is to provide a new and improved resiliently flexible lens frame for floodlight and which will firmly maintain the lens in operating position.

Other objects, features and advantages of the invention will be readily apparent from the following description of a preferred embodiment thereof, taken in conjunction with the accompanying drawing although variations and modifications may be effected without departing from the spirit and scope of the novel concepts embodied in the disclosure, and in which:

FIG. 1 is a prospective view of a floodlight assembly embodying features of the invention;

FIG. 2 is an enlarged fragmental vertical sectional detail view taken substantially along the line II-II of FIG.

FIG. 3 is a more or less schematic elevational view illustrating the method of assembling the frame with the floodlight lens;

FIG. 4 is an enlarged fragmentary elevational detail view taken substantially within the area IV of FIG. 3; and

FIG. 5 is an enlarged fragmentary elevational view taken substantially in the area V of FIG. 3.

On reference to FIG. 1, a floodlight assembly embodying features of the invention includes a housing 1 1 which may be an aluminum casting cavitated to support a lamp 112 and a reflector 13 therein. A light egress opening 14 in the housing 11 is provided thereabout with a generally outwardly facing seat 15 against which is received a sealing gasket 17 desirably of substantial thickness and resilient pliability and which may be made from a suitable elastomeric material and bonded if desired to the seat 15. Arranged to be closed against the gasket 17 is a closure lens 18 which may be made from thermal and shock resistant glass and which is dimensioned to be received in a complementary lens recess 19 provided by the housing outwardly about the seat 15. In one preferred form, the opening 14 as well as the recess 19, and the lens 18 are of quadrilateral shape and elongated in a horizontal direction as shown. At its underside, the housing 11 may support lamp ballast and wiring casing 20 and a mounting yoke 21.

According to the present invention, a substantially new and improved lens mounting frame 22 is provided for supporting the lens 18 in opening and closing relation to the housing opening 14 and more particularly the recess 19. Construction and relationship of the frame 22 to the lens 18 is such that assembly of the frame with the lens can be easily and quickly effected by simply springing the frame into assembly with the lens whereafter by securing the frame hingedly to the housing 11, the frame is rigidly maintained and efficiently mounts the lens for opening and closing relative to the lamp cavity. To this end, the frame 22 is formed up from resiliently flexible sheet metal such as stainless steel shaped into generally U-channel shape to fit onto the edges of the lens 18 fairly snugly but slidably in assembling the same.

In a preferred arrangement, the frame 22 comprises one longitudinal section 23 (FIGS. 1, 2 and 3) to receive one longitudinal edge of the lens 18, two opposite side sections 24 coextensive with and to receive the opposite side edges of the lens 18, and two half sections 25 to combine in longitudinal alignment to receive the remaining longitudinal edge portion of the lens 18. When the frame is assembled on and about the lens 18, the split ends of the sections 25 confront one another at a split joint 27. In order to provide for thorough engagement of the frame 22 with and about the lens 18, all of the frame sections are constructed of generally U-channel shape provided with a flange 28 to lie against the outer face margin of the lens 18, a web 29 to engage the contiguous edge of the lens, and a flange 30 in spaced parallel relation to the flange 28 to engage with the back margin of the lens. Preferably the flange 30 is narrower than the flange 28 to facilitate assembly of the frame onto the lens 18, and also narrower than the gasket 17 so that the gasket will engage not only the frame flange 30 but also directly against the adjacent portion of the lens 18 in thorough sealing relation.

For optimum results, the frame 22 should be formed up from a single continuous strip of material so that in the finished article the web 29 is continuous for all of the

sections

23, 24 and 25 of the frame. To attain this end, the

flanges

28 and 30 are notched out at the respective corner portions of the frame on proper miter angles so that when the web 29 is bent to provide the respective corners the notched edges of the

flanges

28 and 30 will abut. Although if preferred the abutting miter edges of the

flanges

28 or 30 or both may be welded, satisfactory rigidity is attained by securing respective reinforcing plates 31 in symmetrical bridging relation over the miter joint between the adjoining areas of the flange 28 of the side sections 24 and the split sections 25 as by means of spot welding 32 (FIGS. 3 and 4). Similarly, the miter joint between the longitudinal frame section 23 and the side sections 24, in each instance, is substantially rigidly fixed by attachment in bridging relation across the joint on the flanges 28 of said sections respective reinforcing plates 33 as by means of spot welding 34. Thereby, although the frame 22 is constructed as a one piece element secured together and reinforced at the miter joints of the flange portions 28 of the respective angularly related sections of the frame, there is adequate resilient yieldability in the frame sections so that the lens 18 even though fairly closely sized to the inside dimensions between the web portions 29 of the opposite frame sections, can be eas ily assembled within the frame simply by springing the frame open to receive the lens, as permitted by the split between the sections 25, substantially as illustrated in somewhat exaggerated form in FIG. 3. In other words, the frame is spread apart by swinging the frame sections away from one another and effecting a resilient yielding of the

frame sections

23 and 24 sufficient to receive a longitudinal edge of the lens 18 within the channel of the frame section 23 and adjacent portions of the side edges of the lens in the channels of the side frame sections 24 adjacent to the junctures with the frame section 23, and the frame then permitted to spring back to its intended quadrilateral form with all edges of the lens 18 received in the channels of all of the frame sections. Since the frame is made from sheet stainless steel, 22 gauge (0.030) type 302 bright annealed stainless steel having been found satisfactory for the purpose, substantial resilient flexibility is present in the frame to facilitate the flexing action. Yet the frame is sufficiently rigid when fully mounted to provide excellent support for the lens 18. It may be pointed out that although the outer frame flange 28 is of substantial width, providing desirable rigidity in the frame and providing ample base for attachment of the corner plates, the substantially narrower inner frame flange 30 in addition to facilitating dual sealing efficiency of the gasket 17 with the frame and the lens 18, facilitates flexing and assembly of the lens 18 with the frame.

Hinged mounting of the frame 22 on the housing 11 is effected by means of respective hinges mounted on the frame sections 25 and more particularly on the flange portions 28 of such sections. In a desirable form, the hinges 35 are of the piano hinge construction comprising a hinge plate strip 37 of about the same width as the flange 38 and secured to the outer side of the flange 28 by means such as spot welding 38 at suitable spaced points therealong. Completing the hinge 35 in each instance is a complementary hinge plate 39 pivotally attached to the hinge plate 37 by means of a hinge pin 40 engaging through alternating hinge curls on the hinge strips as is customary with piano hinges. For maximum security, the hinges 35 are substantially coextensive with the frame sections between the split 27 and the corner plates 31. Attachment of the hinges 35 to the housing 11 is by means of screws 41 fastening the hinge plate 39 to a horizontal face 42 on preferably the lower portion of the housing and suitably offset outwardly relative to the seat 15 to mount the frame and lens unit for swinging into closed position within the recess 19 and against the gasket 17, with the flange 28 of the frame flush with the face 42.

For securing the frame 22 in the closing relation of the lens and frame assembly unit, means are provided on the upper frame section 23 comprising a pair of tab plates 43 (FIGS. 1, 2 and 3) secured to the outer face of the flange 28 as by means of spot welding 44 and projecting upwardly therefrom. In addition each of the corner plates 33 may be provided with an upward tab extension 45 equal to the projection of the plates 43 from the frame section 23 and serving the same purpose. Means for securing the plates 43 and the extensions 45 to the housing 11, in the closed condition of the lens and frame assembly, conveniently comprise respective screws 47 extending through respective screw holes 48 in the plates and the extensions and threaded into respective bores 49 in the housing 11 to secure the plates and extensions onto respective seat area surfaces 50 on the upper portion of the housing 1 1 and disposed in a comrn n plane with the face 42 to which the hinge plate strips 49 are secured. As a result, easy access into the cavity 14 is attained by simply removing the screws 47 and swinging the lens and frame assembly open about the pivot provided by the hinges 35. Upon closing the lens and frame assembly closure, fastening of the tab plates 43 and the tab extensions 45 will result in positive retention of the closure in the closing position and firm positive pressing of the inside margins of the lens 18 and the frame against the sealing gasket 17,

compressing the gasket against the seat 15.

In order to assist in handling the hingedly mounted lens and frame assembly closure, a handle 51 is desirably provided on the upper portion of the frame and comprises a stainless steel member suitably secured as by means of spot welding to the frame flange 28, preferably midway along the upper frame section 23.

Although the frame 22 itself may be constructed from relatively thin gauge stainless steel because due to its multiangular cross section the profile affords ample rigidity while enabling sufficient springing to facilitate assembly of the lens 18 with the frame, the various attachments to the frame may be constructed from heavier gauge material for adequate resistance to deformation in flat pieces. For example, where the frame is constructed from 22 gauge (.030) material, at least the

corner plates

31 and 33 and the handle 51 may be formed from 16 gauge (.060) material. The hinges 35 may be constructed from 16 gauge stainless steel material, although if preferred a lighter gauge may be employed. 7

It will be understood that variations and modifications may be effected without departing from the spirit and scope of the novel concepts of this invention.

I claim as my invention:

1. In a floodlight assembly including a cavitated housing supporting a lamp and reflector therein and having a light egress opening with an outwardly facing seat thereabout against which a sealing gasket is received, and a closure lens arranged to be closed against the gasket, the improvement comprising:

a resiliently flexible lens mounting frame in the form of an integral lens edge receiving channel and engaging in support relation about the lens and having a split therein with ends in confronting relation and facilitating assembly of the lens with the frame by flexing the frame open sufficiently from a substantially closed loop condition to receive the lens edgewise in the channel structure and then allowing the frame to spring back into the substantially closed loop condition to entrap the lens edgewise in the channel structure;

hinge means on the frame at each side of the split and secured to the housing whereby said ends are held against separating and the frame is maintained in the substantially closed loop condition fixedly on the lens and enabling the lens and the frame as a unit to be swung between open and closed positions relative to said opening and said gasket; and

releasable means for securing the frame in the closed position with the lens and the frame closed against the gasket. A

2. An assembly according to claim 1, wherein said housing comprises an aluminum casting, said frame comprises thin gauge stainless steel, screws securing said hin'ge means to the housing; and said releasable means comprising extensions from the frame and screws securing the extensions to the housing.

3. An assembly according to claim 1, wherein said lens, said frame, and said opening are of quadrilateral outline shape, said housing being provided with a recess about said opening complementary to and receptive of said frame therein and defined by an inner outwardly facing seat supporting the sealing gasket thereagainst for compression by engagement with said frame and the lens in sealing engagement with the gasket, said housing having a mounting surface along and outwardly from said recess, said hinge means engaging and secured to said mounting surface, attachment tab extensions from said frame on the opposite side thereof from said hinge means and providing partof said releasable means, and screws also comprising part of the releasable means and securing the tab extensions to the housing.

4. An assembly according to claim 1, wherein said releasable means comprise tabs projecting from the frame on the opposite side of the frame from said hinge means for releasable attachment to the housing.

5. An assembly according to claim 1, wherein said frame is formed from sheet metal and is of substantially U-shape cross section having an inner flange which is shorter than an outer flange, the lens being engaged between the flanges, and the shorter flange facilitating sealing engagement of the gasket along the edge of the shorter flange.

6. An assembly according to claim 1, wherein the frame is formed from sheet metal and is of generally U- shape, the frame having a plurality of angularly related sections joined at corners, and reinforcing and connecting plates permanently secured to said sections across the joints at said corners.

7. An assembly according to claim 6, wherein said plates at opposite corners of the frame have attachment tab extensions comprising part of said releasable means.

8. An assembly according to claim 1, including a handle permanently secured to and projecting outwardly on said frame on the opposite side of the frame from said hinge means.

9. In a floodlight assembly including a cavitated housing supporting a lamp and reflector therein and having a light egress opening with an outwardly facing seat thereabout against which a sealing gasket is received, and a closure lens arranged to be closed against the gasket, the improvement comprising:

a resiliently flexible lens mounting frame engaging in supporting relation about the lens and having a split therein with ends in confronting relation and facilitating assembly of the lens with the frame by springing the frame;

hinge means on the frame at each side of the split and secured to the housing whereby said ends are held against separating and the frame is maintained fixedly on the lens and enabling the lens and the frame as a unit to be swung between open and closed positions relative to said opening and said gasket;

releasable means for securing the frame in the closed position with the lens and the frame closed against 7 the gasket; and said hinge means comprising piano hinges, each having a plate strip portion secured to the frame and a hingedly connected plate strip portion for securing the hinge to the housing. 10. An assembly according to claim 9, wherein said releasable means include tabs projecting from the frame on the opposite side thereof from said hinge means and adapted to be secured to the housing by screws. i

11. A frame for supporting a lens in position to be closed against a gasket on an outwardly facing seat about a light egress opening in a cavitated housing supporting a lamp and reflector therein, the frame comprising:

a resiliently flexible lens mounting frame structure in the'form of an integral lens edge receiving channel for engaging in supporting relation about the lens and having a split in the frame with ends of the frame confronting one another at the split to facilitate assembly of the lens with the frame by springing the frame open sufficiently from a substantially closed loop condition to receive a lens edgewise in the channel and then allowing the frame to spring back into the substantially closed loop condition to entrap the lens edgewise in the channel; hinge means on the frame at each side of the split and adapted to be secured to the housing so that the ends of the frame will be held against separating and the frame thereby mounted fixedly on the lens and the lens and the frame thereby enabled to be swung as a unit between opening and closing positions relative to the opening and the gasket; and

means on the frame for releasably securing the frame in the closed position and with the lens and the frame closed against the gasket.

12. A frame according to claim 11, wherein said releasable means comprise tabs projecting from the frame on the opposite side of the frame from said hinge means for releasable attachment to the housing.

13. A frame according to claim 11, wherein said frame is formed from sheet metal and is of substantially U-shape cross section having an inner flange which is shorter than an outer flange, the lens being engageable between the flanges, and the shorter flange facilitating sealing engagement of the gasket along the edge of the shorter flange.

14. A frame according to claim 13, wherein the frame is formed from sheet metal and is of generally U- shaped, the frame having a plurality of angularly related sections joined at comers, and reinforcing and connecting plates permanently secured to said sections across the joints at said corners.

15. A frame according to claim 14, wherein said plates at opposite corners of the frame have attachment tab extensions comprising part of said releasable means.

16. A frame according to claim 15, including a handle permanently secured to and projecting outwardly on said frame on the opposite side of the frame from said hinge means.

17. A frame for supporting a lens in position to be closed against a gasket on an outwardly facing seat about a light egress opening in a cavitated housing supporting a lamp and reflector therein the fra me comprising:

a resiliently flexible lens mounting frame structure for engaging in supporting relation about the lens and having a split in the frame with ends of the frame confronting one another at the split to facilitate assembly of the lens with the frame by springing the frame;

hinge means on the frame at each side of the split and adapted to be secured to the housing so that the ends of the frame will be held against separating and the frame thereby mounting fixedly on the lens and the lens and the frame thereby enabled to be swung as a unit between opening and closing positions relative to the opening and the gasket;

means on the frame for releasably securing the frame in'the closed position and with the lens and the frame closed against the gasket;

said hinge means comprising piano hinges, each having a plate strip portion secured to the frame and a hingedly connected plate strip portion for securing the hinge to the housing.

18. A frame according to claim 17, wherein said releasable means include tabs projecting from the frame on the opposite side thereof from said hinge means and adapted to be secured to the housing by screws.

19. In a method of mounting a closure lens for the egress opening of a cavitated floodlight housing having therein a lamp and a reflector, the steps of: providing a resiliently flexible lens mounting frame in the form of an integral lens edge receiving channel structure adapted to engage supportingly about the edges of the lens and having a split with confronting ends, with hinge means on the frame at opposite sides of the split;

resiliently flexing and spreading the frame apart at the split from a substantially closed loop condition to receive the lens edgewise within the frame channel structure;

permitting the frame to spring back into substantially closed loop condition and thereby closing the frame into supporting relation about the lens;

securing the hinge means fixedly to the housing to thereby hold the frame against spreading and so that the lens and frame as a unit can be swung between open and closed positions relative to said opening; and I releasably securing the frame in the closed position against a sealing gasket mounted between the frame and the housing.

l l l

Claims

1. In a floodlight assembly including a cavitated housing supporting a lamp and reflector therein and having a light egress opening with an outwardly facing seat thereabout against which a sealing gasket is received, and a closure lens arranged to be closed against the gasket, the improvement comprising: a resiliently flexible lens mounting frame in the form of an integral lens edge receiving channel and engaging in support relation about the lens and having a split therein with ends in confronting relation and facilitating assembly of the lens with the frame by flexing the frame open sufficiently from a substantially closed loop condition to receive the lens edgewise in the channel structure and then allowing the frame to spring back into the substantially closed loop condition to entrap the lens edgewise in the channel structure; hinge means on the frame at each side of the split and secured to the housing whereby said ends are held against separating and the frame is maintained in the substantially closed loop condition fixedly on the lens and enabling the lens and the frame as a unit to be swung between open and closed positions relative to said opening and said gasket; and releasable means for securing the frame in the closed position with the lens and the frame closed against the gasket.

2. An assembly according to claim 1, wherein said housing comprises an aluminum casting, said frame comprises thin gauge stainless steel, screws securing said hinge means to the housing; and said releasable means comprising extensions from the frame and screws securing the extensions to the housing.

3. An assembly according to claim 1, wherein said lens, said frame, and said opening are of quadrilateral outline shape, said housing being provided with a recess about said opening complementary to and receptive of said frame therein and defined by an inner outwardly facing seat supporting the sealing gasket thereagainst for compression by engagement with said frame and the lens in sealing Engagement with the gasket, said housing having a mounting surface along and outwardly from said recess, said hinge means engaging and secured to said mounting surface, attachment tab extensions from said frame on the opposite side thereof from said hinge means and providing part of said releasable means, and screws also comprising part of the releasable means and securing the tab extensions to the housing.

6. An assembly according to claim 1, wherein the frame is formed from sheet metal and is of generally U-shape, the frame having a plurality of angularly related sections joined at corners, and reinforcing and connecting plates permanently secured to said sections across the joints at said corners.

9. In a floodlight assembly including a cavitated housing supporting a lamp and reflector therein and having a light egress opening with an outwardly facing seat thereabout against which a sealing gasket is received, and a closure lens arranged to be closed against the gasket, the improvement comprising: a resiliently flexible lens mounting frame engaging in supporting relation about the lens and having a split therein with ends in confronting relation and facilitating assembly of the lens with the frame by springing the frame; hinge means on the frame at each side of the split and secured to the housing whereby said ends are held against separating and the frame is maintained fixedly on the lens and enabling the lens and the frame as a unit to be swung between open and closed positions relative to said opening and said gasket; releasable means for securing the frame in the closed position with the lens and the frame closed against the gasket; and said hinge means comprising piano hinges, each having a plate strip portion secured to the frame and a hingedly connected plate strip portion for securing the hinge to the housing.

10. An assembly according to claim 9, wherein said releasable means include tabs projecting from the frame on the opposite side thereof from said hinge means and adapted to be secured to the housing by screws.

11. A frame for supporting a lens in position to be closed against a gasket on an outwardly facing seat about a light egress opening in a cavitated housing supporting a lamp and reflector therein, the frame comprising: a resiliently flexible lens mounting frame structure in the form of an integral lens edge receiving channel for engaging in supporting relation about the lens and having a split in the frame with ends of the frame confronting one another at the split to facilitate assembly of the lens with the frame by springing the frame open sufficiently from a substantially closed loop condition to receive a lens edgewise in the channel and then allowing the frame to spring back into the substantially closed loop condition to entrap the lens edgewise in the channel; hinge means on the frame at each side of the split and adapted to be secured to the housing so that the ends of the frame will be held against separating and the frame thereby mounted fixedly on the lens and the lens and the frame thereby enabled to bE swung as a unit between opening and closing positions relative to the opening and the gasket; and means on the frame for releasably securing the frame in the closed position and with the lens and the frame closed against the gasket.

14. A frame according to claim 13, wherein the frame is formed from sheet metal and is of generally U-shaped, the frame having a plurality of angularly related sections joined at corners, and reinforcing and connecting plates permanently secured to said sections across the joints at said corners.

17. A frame for supporting a lens in position to be closed against a gasket on an outwardly facing seat about a light egress opening in a cavitated housing supporting a lamp and reflector therein, the frame comprising: a resiliently flexible lens mounting frame structure for engaging in supporting relation about the lens and having a split in the frame with ends of the frame confronting one another at the split to facilitate assembly of the lens with the frame by springing the frame; hinge means on the frame at each side of the split and adapted to be secured to the housing so that the ends of the frame will be held against separating and the frame thereby mounting fixedly on the lens and the lens and the frame thereby enabled to be swung as a unit between opening and closing positions relative to the opening and the gasket; means on the frame for releasably securing the frame in the closed position and with the lens and the frame closed against the gasket; said hinge means comprising piano hinges, each having a plate strip portion secured to the frame and a hingedly connected plate strip portion for securing the hinge to the housing.

19. In a method of mounting a closure lens for the egress opening of a cavitated floodlight housing having therein a lamp and a reflector, the steps of: providing a resiliently flexible lens mounting frame in the form of an integral lens edge receiving channel structure adapted to engage supportingly about the edges of the lens and having a split with confronting ends, with hinge means on the frame at opposite sides of the split; resiliently flexing and spreading the frame apart at the split from a substantially closed loop condition to receive the lens edgewise within the frame channel structure; permitting the frame to spring back into substantially closed loop condition and thereby closing the frame into supporting relation about the lens; securing the hinge means fixedly to the housing to thereby hold the frame against spreading and so that the lens and frame as a unit can be swung between open and closed positions relative to said opening; and releasably securing the frame in the closed position against a sealing gasket mounted between the frame and the housing.