Abstract:
A weatherproof outdoor pivoting light assembly includes a front gasket on a metallic lamp housing having spaced sealing rings for locally compressively engaging to seal the floodlight envelope and a rear gasket for sealing the power cord thereby providing a sealed cartridge for the electrical socket enabling mounting at ground and structure location.

Description:
FIELD OF THE INVENTION 
     The present invention relates to outdoor lighting apparatus, and, in particular, to weatherproofing of out door light assemblies. 
     BACKGROUND OF THE INVENTION 
     Pivoting light assemblies are commonly used for outdoor lighting where varying inclinations of the light source are desired to produce directional or aesthetic effects. One highly popular pivoting light assembly uses a line voltage floodlight, such as parabolic aluminized reflector units designated PAR 30 or PAR 38 lamps. The floodlight is connected to a surface or ground mounted brackets at a pivotal connection that allows user to direct the illumination at select inclinations. 
     The outdoor location presents severe operating conditions. Moisture in the form of rain and snow can enter the lamp housing causing electrical and potential safety problems. The prevalent entry paths are at the between the light and the housing and at the rear along the power cord port. Accordingly, use in wet locations and inclined inclination in raised positions are not recommended. Moreover, dirt and grime can enter the unit and corrode the bulb connections, making removal the lamp difficult, possibly resulting in fracture of the glass envelope. Further, receiving desired approvals for the desired outdoor uses, particularly units having metallic housings mounted on walls, from recognized sources such Underwriters Laboratories is not possible unless the unit is completely weatherproofed. 
     While various sealing arrangements have been proposed for the wide range of light assemblies, none adequately addresses the particular needs of the outdoor pivoting light assemblies using the PAR lamp configurations. For instance, U.S. Pat. Nos. 5,667,296 and 5,718,504 disclose outdoor Christmas lights having gaskets for sealing the bulbs. The gaskets have chamfered inner surfaces having substantial surface engage the bulb envelopes. While effective with smaller generally conical surfaces, the eccentricities in assembling the socket to the housing in outdoor PAR bulbs could create gaps in the sealing interface resulting in leakage and potential electrical shocks. Similar drawbacks could occur with the floodlight gasket disclosed U.S. Pat. No. 4,660,916 to Williams wherein a surface to surface contact is effected with the neck of the bulb. Moreover, during installation or removal of the bulb, substantial torque is developed at the sealing interface that can dislodge the gasket and create present or subsequent leakage paths. Additional leakage problems can occur at power cord. In plastic molded units, an effective cord seal may be obtained. For metal units, the normal clearance between the cord inlet hole and the cord can create leakage paths to the interior electrical connections, also posing potential safety risks. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention provides an improved outdoor pivoting light assembly with metallic housings using a front and rear gasket for sealing potential leakage paths. A front gasket is provided to seal between the housing and the bulb envelope. The front gasket has an interior front wall conforming to the neck of the envelope that includes a pair of axially spaced narrow sealing rings that locally compressively engage the neck to establish sealing interfaces providing primary and secondary barriers to moisture penetration. The rings offer minimal resistive torque to insertion or removal of the bulb thereby maintaining the operative position of the front gasket. Additionally, the front gasket may be provided with inwardly projecting barbs are inserted into mating holes on the housing to further maintain the front gasket in place. A rear gasket is provided to seal between the cord inlet hole and the power cord. The rear gasket is a cylindrical sleeve received over the power cord, inserted into the cord hole, and retained at grooved connection. The gaskets effect a secure sealed cartridge for light components resistant to outdoor moisture conditions allowing the light assembly to be mounted on structure surfaces at desired angles of inclination for achieving a desired lighting effect. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       The above and other advantages and features of the invention will become apparent upon reading the following description taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a perspective view of the weatherproof outdoor pivoting light assembly provided with mounting base for surface installation and provided with a sealing assembly according to an embodiment of the invention; 
         FIG. 2  is an exploded perspective view of the pivoting light assembly shown in  FIG. 1  provided with a mounting spike for ground installation; 
         FIG. 3  is a vertical cross sectional view of the base of light housing illustrating the rear sealing gasket; 
         FIG. 4  is a cross sectional view of the rear sealing gasket; 
         FIG. 5  is an enlarged perspective view of the end of the power cord; 
         FIG. 6  is a vertical cross sectional view of the front gasket and the light housing; 
         FIG. 7  is an enlarged fragmentary perspective view of the front gasket; 
         FIG. 8  is a cross sectional view of the light housing and the light source; 
         FIG. 9  is a vertically sectioned perspective view of another embodiment of the front gasket; 
         FIG. 10  is a perspective view of the front gasket of  FIG. 9 ; 
         FIG. 11  is a cross sectional view of the front gasket of  FIG. 9 ; and 
         FIG. 12  is an enlarged cross sectional view of the sealing ribs on the front gasket of  FIG. 9 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the drawings for the purpose of describing the preferred embodiment and not for limiting same,  FIG. 1  illustrates a weatherproof outdoor light assembly  10  adapted for conventional pivotal horizontal or vertical mounting at a surface bracket  12  to a surface substrate  14  by fasteners  16 . Alternatively, as shown in  FIG. 2 , the light assembly  10  may be mounted at a ground bracket or spike  18  for attachment to the ground  19 . 
     The light assembly  10  as described below is adapted for carrying a low wattage or high intensity lamp, not shown in these figures. A suitable exemplary lamp is a PAR 38 line voltage lamps, and the invention will be described with reference thereto. 
     The light assembly  10  includes a light housing  20  interchangeably adjustably connected to the brackets  12 ,  14  at a pivotal connection  22 . The housing  20  carries a front gasket  24  for engaging the light bulb and the housing to prevent ambient moisture and precipitation from frontally entering the housing interior, and a rear gasket  26  carried at the rear of the housing  20  and surrounding the light power cord  28  to prevent moisture and precipitation from rearwardly entering the housing interior, thereby providing a weatherproof unit for outdoor mounting at the angles of inclination accommodated by the pivotal connection  22 . 
     Referring to  FIG. 2 , the housing  20  is formed of a thin wall metal or plastic material and includes a peripheral side wall  30  and a base  32 , the inner surfaces of which define a frontally opening cavity  34 . As additionally shown in  FIG. 6 , a conventional porcelain socket  36  having a threaded contact sleeve  38  and a base contact  39  is operatively mounted in the cavity  34 . The housing  20  includes a support arm  40  extending from the base  32 . The arm  40  includes an end section provided with a threaded aperture and surrounded by annular band of radial teeth that mate with teeth on a corresponding band on the exposed leg  44  of the stake  18 . A screw  48 , or other suitable fastener, is threaded into the aperture and permits adjustment of the housing relative to the stake or bracket in a plurality of incremental inclinations, all in a well known manner. 
     Referring to  FIG. 3 , the support arm  40  is a thin wall extension on the rear of the housing forming a pocket  50  opening frontally into the cavity  34 . The rear wall  51  of the arm  40  includes a circular rear opening  52 . The rear gasket  26  is mounted in the opening  52 . Another opening is formed in the base  32  of the housing  20 . As described in greater detail below, a fastener  55  is inserted through a threaded hole in the socket  36  for fixedly mounting the latter in assembly. In assembly production, the socket  36  may be limitedly eccentric to the housing. Nonetheless, as described below, the front gasket  24  accommodates the eccentricity and maintains weatherproof sealing relationships. 
     Referring to  FIG. 4 , the rear gasket  26  is a one-piece elastomeric molding having an annular body  56  and a central axial bore  57 . The body  56  is provided with frustoconical ends  58 . An annular groove  59  is formed in the body having a base diameter slightly smaller than the opening on the rear wall  51  of the arm  44  and a width comparable to the thickness of the arm wall. The bore  57  has a diameter providing a light compressive fit with the power cord  28 . For assembly as shown in  FIG. 3 , the rear gasket  26  is forwardly inserted into the hole and positioned with the with rear wall opening in the groove  59 . The terminal end of the power cord  28  extends through the cord gasket  26  into the housing cavity. 
     Referring to  FIG. 5 , the power cord  28  is a conventional sheathed three wire cable. For assembly, the terminal end of the sheath  60  is removed and the insulation of the leads wires  61  stripped for enabling the electrical connection. The terminal end is inserted through the rear gasket  26  and outwardly of the housing. Thereafter, a crimp ring  62  of a deformable material is swaged at  66  onto the end of the sheath  60  to mechanically prevent withdrawal in the rear direction. Conventionally, the power cord  28  includes a ground lead and power leads extending sufficiently beyond the crimp ring  62  to allow conventional electrical connection at the socket  36 . The power leads may be riveted to the connectors of the base contact and contact sleeve of the socket. As shown in  FIG. 2 , the ground lead includes a circular end terminal  64 . After electrical connections are effected, the socket  36  is inserted into the housing cavity  34 . The fastener  55  is inserted through the hole in the boss  54  and the eyelet of the terminal  64 , and threaded into the socket, thereby fixedly mounting the socket in the housing and establishing the ground for the power cord  28 . Accordingly, the fastener prevents forward movement of the socket and the crimp ring  62  rearward movement of the power cord, whereby loading on the electrical connections and lead wires is isolated. The rear gasket  26  completely seals the support arm opening and the cord, and the fastener head seals the opening in the rear wall, thereby providing water proofing barriers against rear moisture intrusion. 
     Referring to  FIG. 6 , the forward end of the side wall  22  of the housing  20  terminates with a shallow frustoconical sleeve  70  having an outwardly turned annular flange  72 . The front gasket  24  is carried on the sleeve  70  and retained at the flange  72 . Referring additionally to  FIG. 7 , the gasket  24  is a one piece molded annular elastomeric body  74  having an inner surface defining a central axial opening. The body  24  has a cylindrical outer wall  78 , a frustoconical front wall  80  and an annular end wall  82 . The inner surface includes a frontal curved wall  84  including annular axially spaced sealing ribs  86 ,  88 , a cylindrical middle wall  90 , and a cylindrical rear wall  92  axially spaced from the middle wall  90  by an annular groove  94 . The flange  72  is received in the groove  94  with the base thereof having a compressive fit with the outer surface of the flange  72  to establish a sealing interface with the housing  20 . The width of the groove  94  is slightly wider than the thickness of the flange to accommodate limited movement in assembly. The section of the body  24  has sufficient elasticity to accommodate eccentricities between the housing  20  and the associated lamp unit. 
     Referring to  FIG. 8 , the lamp unit  100  for use in the light assembly  10  as previously mentioned preferably corresponds to a PAM 38, 150 W light. The unit  100  is characterized by an outer glass reflector envelope  102  having a rearward portion including a curved reflector end section  104  and a base  106  terminating with a threaded conductive sleeve  108  and a base contact  110 . The sleeve  106  is threaded into the socket  36  for establishing the electrical connection with the leads of the power cord in a well known manner. The curved end section  104  has a contour complementary with the front wall  84  of the gasket  24  with the sealing ribs  86 ,  88  establishing primary and secondary sealing interfaces between the gasket  24  and the lamp unit section  104  to prevent moisture intrusion in the space therebetween, and at the surfaces at the groove  94  establishing a sealing interface with the flange  72  to prevent moisture intrusion therebetween. The localized compressive engagement at the ribs is sufficient to maintain sealing contact during operation and the extremes of ambient temperatures. The limited contact area at the ribs is sufficient for sealing requirements while limiting engagement to a level permitting removal and replacement of the unit without undue or potentially damaging torque levels. 
     It will be appreciated from the foregoing that the sealing systems of the invention provide and maintain complete sealing of the housing cavity under the extremes of outdoor operation, both for surface mounting and ground mounting. The plural sealing interfaces of the light gasket with the light and the housing allows the housing to be inclined at the full range of motion at the pivot connection with any moisture or precipitation ingress prevented. Further the rear gasket  26  effectively seals the cord and the housing at other potential ingress sites. Thus the present invention may be oriented at desired by the user and not subject to the mounting and use limitations of prior units. 
     In another embodiment as shown in  FIGS. 9 through 12 , the front or bulb sealing gasket is provided with retention tabs for increasing the resistance to shifting or dislodging during installation and/or use. Therein, the front sealing gasket  120  includes a pair of diametrically opposed, radially inwardly projecting barbs  122  formed at the base  124  of the lower sleeve  126 . The barbs  122  project through diametrically opposed circular openings  128  formed in the sleeve  70  of the housing. The barbs  122  have a thickness slightly smaller than the openings. The barbs  122  each include a triangular tip  130  and a rectangular shank  132  disposed in the opening in assembly. The tip  130  includes deflectable ends  134  adjacent the shank  132 . The gasket  120  is positioned on the housing sleeve with the flange in the groove of the gasket, and the barbs  122  aligned with the openings  128 . The barbs  122  are pressed inwardly, with the ends  134  deflecting through the openings and expanding thereafter thereby locking the gasket against axial or rotational movement while effecting sealing between the bulb and the housing as described above. The front end of the gasket  120  also includes the sealing ribs  86 ,  88 . 
     Having thus described a presently preferred embodiment of the present invention, it will now be appreciated that the objects of the invention have been fully achieved, and it will be understood by those skilled in the art that many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the sprit and scope of the present invention. The disclosures and description herein are intended to be illustrative and are not in any sense limiting of the invention, which is defined solely in accordance with the following claim.