Patent Publication Number: US-4259710-A

Title: Waterproof lamp

Description:
FIELD OF THE INVENTION 
     The invention relates to waterproof electrical lamps, for example floodlights for underwater illumination of swimming pools, fountains, and the like. More particularly, the invention relates to a lamp having a two part enclosure consisting of a housing member and a bezel ring which may hold a color filter disc. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     It is a principal object of the present invention to provide a waterproof lamp which may be produced of a material permitting simple and favorable manufacture but also permitting the reuse of remnants of the production so that the lamp may be produced economically from the points of view of raw materials and expense. An associated object is to provide an underwater lamp which is electrically secure. 
     These and other objects are attained according to the invention by providing a waterproof lamp having a bell-shaped outer housing member which is reinforced with external ribs and to which are attached receiver bushings for the passage of electrical cables and the like. An electrical lamp is held within the bell-shaped housing by a front bezel which may be mounted to the housing, for example, by screws and which has provisions for holding a color filter disc. 
     In a preferred exemplary embodiment of the invention, the electrical cable feedthrough is formed within a lateral extension of the housing in which a suitable threaded bushing is welded. 
     The threaded bushing may be metal, for example brass, and within it is placed an elastic ring. If the bushing is to be sealed with respect to the outside, a plastic bolt may be placed inside the ring and a hollow screw may be threadedly engaged with the bushing to apply pressure on the bolt and deform the elastic ring, thereby sealing the opening. 
     Preferably, the entire lamp is constructed of thermoplastic synthetic material with a very short curing time, thereby speeding the production of the various parts of the light. Furthermore, the remnants of production can be used again by being ground up and used in molding new parts. These two factors result in simple, rapid and inexpensive manufacture which imparts to the lamp a very economical construction . 
     The electrical feedthroughs to the housing are provided by welding or molding therein a threaded bushing after manufacture in a relatively simple and inexpensive manner. If the opening is to be sealed and is not used as an electrical feedthrough, a plastic bolt and an elastic sealing ring may be placed therein and clamped in place by a hollow screw. These elements provide water-tight sealing and electrical insulation with respect to the interior of the housing. 
     It is an advantageous feature of the invention that the bezel has a downwardly extending rim which overlaps a corresponding shoulder on the housing thereby enhancing the degree of sealing. The bezel is further provided with several threaded extensions into which suitable bolts are screwed that join the bezel to the housing . 
     The interior of the housing is provided with an electrical ground screw by means of which a grounded switch can be activated if water should accidentally enter the housing. 
     Still another preferred feature of the lamp according to the invention is the disposition therein of pockets in which a heavy mass can be poured so as to give the lamp a net density greater than water and causing it to sink. 
    
    
     Other features of the invention will appear from the following description of a preferred exemplary embodiment which is illustrated in the drawing. 
     DESCRIPTION OF THE DRAWING 
     FIG. 1 is a perspective view of a lamp according to the invention; 
     FIG. 2 is a view similar to that in FIG. 1 from a different angle; 
     FIG. 3 is a sectional view of the electrical feedthrough of the lamp; 
     FIG. 4 is a vertical half section through the lamp according to the invention; and 
     FIG. 5 is a partial front elevational view of a detailed construction of the lamp according to the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The lamp according to the invention has an enclosure 1 consisting of two major parts, a housing member 1a and attached thereto a releasable bezel 1b . The bezel locates and holds within the housing a floodlight or other electrical, e.g., incandescent light source 13 which is sealed by a sealing ring 11. The housing member 1a and the bezel 1b can be firmly joined together to form a single unit by means of bolts 12. The housing member 1a is enforced externally by ribs 2 which lend rigidity to the housing member 1a . The housing member 1a has extensions 3 which contain the electrical feedthroughs for the lamp, permitting the lamp to be used as a single source of illumination or in a multiple connection in which power passes from one lamp to the other. The lamp may have one, two or more extensions 3 and feedthroughs. The bezel 1b has frontal protrusions 6 in which is fashioned a groove 6a for receiving a snap ring that holds, for example, a color light filter disc. Each extension 3 has a radial opening 3a in which is molded or welded a threaded bushing 3b, preferably made of metal, for example, brass. Placed within the bushing 3b is a flexible and/or elastic disc, for example, a rubber or plastic disc 5, within which is inserted a pin or bolt 4, for example, made of plastic. Threaded within the bushing 3 is a hollow screw 9 which bears on the convex head of the bolt 4 or on a washer, not shown, placed on top of the bolt 4, thereby deforming the elastic disc 5 and causing it to seal the opening in all directions. In this manner, the feedthrough may be hermetically sealed and water is effectively prevented from entering the enclosure. 
     If the feedthrough is required for the passage of electrical cabling, the bolt 4 is removed, releasing the opening 3a to the passage of electrical wires and cables. In that case, the threaded engagement of the hollow screw 9 again causes a deformation of the elastic ring 5 causing it to seal the opening in all directions by pressing against the inside of the bushing 3b and the inserted cable 14. 
     The lower part of the bell-shaped housing member 1a has a mounting pedestal consisting of an arm 7 attached by reinforcing ribs 7b to a base plate 7a of preferably circular shape and provided with round or elongated holes 8 for mounting to a suitable surface. Preferably, the arm 7 is attached to one of the ribs 2 by a bolt and nut passing therethrough and permitting a change in the relative angular elevation of the lamp. If the mounting screws of the lamp are passed through the elongated holes 8, the lamp may be rotated to within the limit of the elongated holes. 
     As best seen in FIG. 4, a lamp or incandescent light 13 is placed within the housing member 1a and its front edge 13a lies within a ring seal 11 having a C-shaped cross section. The sealing ring 11 lies within a recess 15 of the bezel 1b . The cooperation of the bezel, the recess 15, the sealing ring 11 and the edge 13a cause the correct positioning and holding of the lamp 13 within the housing 1a . 
     The bezel has a skirt 17 which overlaps a cooperating shoulder 18 on the housing member 1a, thereby contributing to the sealing properties of the light. 
     The bezel 1b also has several protrusions 9, each of which contains a threaded sleeve 20 that is accessible from below and the threaded opening of which is parallel with the longitudinal extent of the lamp. Extending from the shoulder 18 of the housing member 1b are appropriate protrusions 21 opposite the bezel protrusions 19 so that threaded bolts may be passed through the protrusions 21 and the bezel 1b may be pulled against the housing 1a by tightening the bolts. The protrusions 21 are reinforced by reinforcing ribs 22. As best seen in FIG. 5, the region of the skirt 17 in the vicinity of the protrusions 21 is recessed, thereby preventing interference during assembly. 
     In order to increase the overall density of the lamp and cause it to be generally heavier than water, the inside of the housing is provided with walls 25 which define pockets 24 into which may be poured a plastic 26 containing lead granules. The pockets 24 lie generally directly above the threaded bushings 3b in the vicinity of the extensions 3. A lamp socket 27 may be screwed onto the lamp 13 and from it extend two electrical conductors 14a while a third ground connection 14b is connected to a grounding screw 28 which is threadedly engaged with a threaded sleeve 29, held preferably fixedly within a receiver boss 30 of the housing member 1a. 
     The waterproof lamp according the invention may be constructed in any suitable size and the details of construction may be adapted to prevailing conditions. Preferably the housing member 1a, the bezel 1b and the pedestal 7, 7a, 7b are integral members made from a synthetic material, preferably a thermoplastic synthetic material. 
     The foregoing is a description of a preferred exemplary but entirely non-limiting embodiment capable of numerous variants all within the scope and spirit of the invention.