Abstract:
A fluorescent lamp lens assembly for commercial display refrigerators, the fluorescent lens assembly being generally tubular in configuration and including a length generally approximating the length of the fluorescent lamp. The fluorescent lamp is positioned into the lens assembly and held in concentric relation therein by means of a pair of end caps securing the fluorescent lamp within the tubular lens. Both of the caps allow the terminal pins of the fluorescent lamp to extend outwardly allowing the pins to connect to the lamppost of a conventional fluorescent lamp fixture. One of the ends (e.g., the top end) is provided with a removable cap allowing a spent lamp to be removed therefrom and replaced with a new one.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a regular utility application of provisional application Ser. No. 60/091,189 filed Jun. 30, 1998, from which priority is claimed. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to commercial display refrigerators having glass doors for allowing viewing of merchandise contained within the refrigerator. More particularly, this invention relates to fluorescent lights that are employed within commercial display refrigerators for illuminating the merchandise contained therein. 
     2. Description of the Background Art 
     Presently, display refrigerators are commonly used in retail stores such as grocery and convenience stores, for refrigerating merchandise such as beverages behind glass doors allowing the discriminating shopper to view the merchandise while shopping. Once the selection is made, the shopper may then open the glass door and remove the product from the refrigerator. 
     In order to minimize the shopper&#39;s viewing convenience while minimizing the tendency of the shopper to open the glass doors during the selection process, it has been desirable to fully illuminate the merchandise. In this manner, the shopper will hopefully not stand with the display door open while making the selection. Rather, the shopper will properly make the selection with the door closed and then open it when the selection is made. Hence, there has been a desire in the industry for illumination systems that fully illuminate the merchandise contained within the display refrigerator without obstructing the view thereof. 
     Presently, there exist various configurations of lighting systems for display refrigerators in which the fluorescent lamp fixture is positioned horizontally at the top or bottom of the merchandise shelving area. More recently, lighting systems have been positioned behind the mullions that support the respective glass doors. By positioning the lighting system behind the mullions, they are generally concealed from view by the shopping consumer and therefore do not otherwise hinder the presentation of the merchandise to the consumer. 
     Moreover, various lens systems, covers and reflectors have been developed for directing the light rays from the fluorescent light in a direction toward the leading edge of the display shelves so that even the merchandise in the center of the shelf midway between the mullions is fully illuminated. Such lenses and reflectors have also been designed so as to minimize the reflection of light toward the glass doors themselves that would otherwise create a distracting glare on the glass doors (i.e., a “zebra” effect) and thereby not present as pleasing of a shopping environment for the consumer. 
     U.S. Pat. Nos. 5,016,146 and 5,471,372, the disclosures of which are hereby incorporated by reference herein, illustrate various types of mullion-mounted lighting systems for display refrigerators. 
     The various configurations of lenses and reflectors employed in mullion-mounted lighting systems have achieved wide acceptance in the industry. Unfortunately, the specific designs for such lighting systems vary from manufacturer to manufacturer. Moreover, the design of such lens covers typically require that the lens be removed in its entirety in order to change the fluorescent lamp contained therein. Thus, there presently exists a need in the commercial refrigerator art for a universal lighting system that accomplishes the objects of illuminating the leading edge of the shelving while minimizing door glare, and yet being able to conveniently change the fluorescent lamp as needed when they become spent (i.e., burned out). 
     Therefore, it is an object of this invention to provide an improvement which overcomes the aforementioned inadequacies of the prior art devices and provides an improvement which is a significant contribution to the advancement of the commercial display refrigerator art. 
     Another object of this invention is to provide a universal lens assembly may that be utilized in connection with various types of lighting fixtures. 
     Another object of this invention is to provide a lens assembly that may accommodate different-diameter fluorescent lamps. 
     Another object of this invention is to provide a lens assembly that will minimize lamp breakage. 
     Another object of this invention is to provide a lens that will remain stable in cold temperatures. 
     Another object of this invention is to provide a lens that fits onto the lamp for the purpose of redirecting the light to the product and out of the customer&#39;s eyes. 
     Another object of this invention is to provide a lens/lamp assembly that also constitutes a sealed assembly that provides insulation for the lamp, thus allowing greater light output. 
     Another object of this invention is to provide a lens/fluorescent lamp assembly that mounts onto commonly available lamp holder sockets and requires no other fastening means. 
     Another object of this invention is to provide a lens assembly whereby the end cap can screw down to different heights to adapt to different lamp variations. 
     The foregoing has outlined some of the pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings. 
     SUMMARY OF THE INVENTION 
     For the purpose of summarizing this invention, this invention comprises a fluorescent lamp lens assembly for commercial display refrigerators. More particularly, the fluorescent lens assembly is generally tubular in configuration and includes a length generally approximating the length of the fluorescent lamp. The fluorescent lamp is inserted into the lens assembly and is held in concentric relation therein by means of a pair of end caps that secure the fluorescent lamp within the tubular lens. Both of the caps allow the terminal pins of the fluorescent lamp to extend outwardly allowing the pins to connect to the lamppost of a conventional fluorescent lamp fixture. One of the ends (e.g., the top end) is provided with a removable cap allowing a spent lamp to be removed therefrom and replaced with a new one. 
     The tubular lens includes specially-designed prism surfaces on the lumen thereof so as to direct the light outwardly from the sides thereof so as to illuminate the frontmost portion of the display shelves and to reduce glare on the doors. The lens assembly is capable of being used in virtually any type of fluorescent light fixture without special modifications. Thus, the lens assembly of the invention finds utility in display refrigerators of various makes and models. 
     Thus, the fluorescent lens assembly of the present invention provides a universal lens assembly that may be utilized in connection with various types of lighting fixtures with the capability to accommodate different-diameter fluorescent lamps. Further, due to the protective and insulative nature of the tubular lens, the lens assembly of the present invention also minimizes lamp breakage and provides a lens that remains stable in cold temperatures. The prism aspect of the lens assembly of the present invention redirects light from a fluorescent lamp to shelved products and away from the customer&#39;s eyes. The lens assembly of the invention mounts onto commonly available lamp holder sockets and requires no other fastening means. Lastly, the lens assembly of the present invention provides the end cap that can screw down to different heights to adapt to different lamp variations. 
     The foregoing has outlined rather broadly the more pertinent and important features of the present invention in order that the detailed description of the invention that follows may be better understood so that the present contribution to the art can be more fully appreciated. Additional features of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which: 
     FIG. 1 is a partial plan view of a typical merchandising shelf of a commercial display refrigerator illustrating the placement of the fluorescent lens assembly of the invention at the mullions thereof for illuminating the leading edge of the display shelves; 
     FIG. 2 is an exploded perspective diagram of the lens assembly of the invention illustrating the various components thereof and the manner in which they are assembled; 
     FIG. 3 is a cross-sectional view of FIG. 2 along lines  3 — 3  illustrating the prisms on the lumen of the lens that are optimally designed to direct light to the leading edge of the shelving while minimizing door glare; 
     FIG. 4 is a bottom view of a cap insert which allows use of the lens assembly of the invention with various fluorescent lamps of different diameters; 
     FIG. 5 is a cross-sectional view of FIG. 4 along lines  5 — 5 ; 
     FIG. 6 is a diagrammatic view showing the manner in which the lens assembly, through the use of the end cap insert, can be utilized in conjunction with fluorescent lamps (T-10, T-5 and T-8) of different diameters; 
     FIG. 7 is a bottom view of the bottom end cap of the invention illustrating the pin holes formed therein for receiving the terminal pins of the fluorescent lamp; 
     FIG. 8 is a cross-sectional view of FIG. 7 along lines  8 — 8 ; 
     FIG. 9 is a bottom view of the top end cap of the invention; 
     FIG. 10 is a side view of FIG. 9 illustrating the exterior threads thereof for receiving a lamp cap; 
     FIG. 11 is a bottom view of the lamp cap of the invention for threaded engagement with the top end cap of FIGS. 9 and 10; 
     FIG. 12 is a cross-sectional view of FIG. 11 along lines  12 — 12 ; 
     FIG. 13 is diagrammatic view illustrating the assembly of the various components of the invention; and 
     FIG. 14 is a diagrammatic view of the removal of a spent fluorescent lamp and the installation of a new one. 
    
    
     Similar reference characters refer to similar parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1., the lens assembly  10  of the invention is intended to be utilized primarily with mullion-mounted light fixtures  12  for commercial display refrigerators for projecting light onto the leading edge  14 L of the display shelves  14  while minimizing glare on the glass refrigerator door  16 . However, it shall be understood that the lens assembly  10  of the invention may find application in other types of refrigerators or other appliances wherein it is desirable to provide a universal lens assembly  12  for directing light while allowing the fluorescent lamps to be changed as needed. 
     More particularly, as shown in FIG. 2, the lens assembly  10  of the invention includes a tubular prism lens  18 , a top end cap  20 , a bottom end cap  22 , respective end cap inserts  24  for insertion into the end caps  20  and  22 . Finally, to facilitate the changing of the fluorescent lamp, the top end cap  20  is provided with a lamp cap  26 . 
     FIG. 3 is a cross-sectional view of the tubular prism lens  18  shown in FIG.  2 . More particularly, the tubular prism lens  18  includes a tubular wall  28  having symmetric first, second, third and fourth portions  28 A,  28 B,  28 C and  28 D, respectively, an end lens portion  28 E and a base portion  28 F. The base portion  28 F preferably does not include any prism configuration as it is intended to be positioned adjacent to the light fixture  12 . The first prism wall portion  28 A is configured so as to minimize the light along the path shown by light rays  10 A in FIG. 1 that would otherwise cause a glare on the door  16 . Prism wall portion  28 B is likewise specially configured as to minimize light that may be projected along the direction of light rays  10 B as shown in FIG.  1 . Prism walls  28 C and  28 D are each configured so as to project the light from the fluorescent lamp toward the leading edge  14 L of the shelving  14  as shown by light rays  10 C and  10 D, respectively. In this manner, proper illumination of the merchandise on the shelving  14  is achieved while minimizing door glare. 
     Referring now to FIGS. 4 and 5, the end cap insert  24  of the invention is essentially a collar which accommodates for fluorescent lamps of different diameters. The outermost diameter  30  of the end cap insert  24  is dimensioned to provide an interference fit with the end caps  20  and  22 . The inner diameter  32  of the end cap insert  24  is dimensioned to slidably fit over the desired diameter of the fluorescent lamp. In this manner, without use of the end cap insert  24 , the larger-diameter fluorescent lamp (e.g., T-10) may be used in the lens assembly  10  of the invention and upon insertion of the end cap insert  24  in the respective end caps  20  and  22 , a smaller-diameter fluorescent lamp (e.g., T-8) may be utilized (see FIG.  6 ). An inwardly-extending flange  34  is provided for convenience in alignment. 
     FIGS. 7 and 8 illustrate the bottom end cap  22  of the invention. Basically, the bottom end cap  22  comprises a flared skirt portion  35  having a peripheral cross-sectional configuration corresponding to the cross-sectional configuration of the tubular prism lens  18  so as to be loosely fitted onto the bottom end thereof. The bottom end cap  22  further includes a lamp portion  36  defined by circular side walls  36 S and bottom wall  36 B. Bottom wall  36 B is provided with two holes  36 H that are appropriately dimensioned and spaced apart from the longitudinal axis of the bottom end cap  22  so as to receive the terminal pins of the fluorescent lamp. In this manner, the end of the fluorescent lamp may be encompassed by the lamp portion  36  with its terminal pins protruding from the holes  36 H. It is noted that if smaller-diameter fluorescent lamps are desired to be used, the end cap insert  24  may be inserted into the lamp portion  36  as described hereinabove. 
     FIGS. 9 and 10 illustrate the upper end cap  20  as including a configuration substantially similar to that of the bottom end cap  22  allowing it to be slid over the other end of the tubular prism lens  18 . However, unlike the bottom end cap  22 , the lamp portion  36  of the top end cap  20  includes a thread  38  on the circular side wall  36 S. No bottom wall  36 B is provided so as to provide an end cap  20  that is open as opposed to being blinded. 
     As shown in FIGS. 11 and 12, the lens assembly  10  of the invention further includes a lamp cap  26  having an internal thread  40  for threaded engagement with the thread  38  of the top end cap  20 . The lamp cap  26  further includes an annular lip  42  of a diameter that is appreciably less than that of the diameter of the fluorescent lamp. 
     As shown in FIG. 13, assembly of the lens assembly  10  is accomplished as follows. First, the end caps  20  and  22  are positioned over the respective ends of the tubular prism lens  18 . Threaded fasteners  44  may be provided for permanent mounting of the end caps  20  and  22 . A conventional fluorescent lamp  12 L is then inserted into the top of the end cap  20  and rotated so as to align its terminal pins  12 P with the holes  36 H of the lamp portion  36  of the bottom end cap  22  and extend therethrough. The lamp cap  26  is then threaded onto the top end cap  20 . It is noted that the lip  42  thereof results in the fluorescent lamp  12 L being entrained between the top and bottom end caps  20  and  22 . The final assembly thus comprises an integrated assembly wherein the tubular prism lens  18  is secured about the fluorescent lamp  12 L without restricting the manner in which the fluorescent lamp  12 L may be installed into a conventional fluorescent lamp fixture  12 . 
     As shown in FIG. 14, the lens assembly  10  containing the fluorescent lamp  12 L facilitates the quick removal and installation of the assembly  10  from a conventional light fixture  12  without requiring any modifications or design changes to the fixture  12  itself. This allows the lens assembly  10  of the invention to be utilized with conventional light fixtures  12 . Moreover, quick and easy replacement of the fluorescent lamp  12 L can be performed as shown in FIG.  14 . 
     Now referring to FIG. 14, replacement of the fluorescent lamp  12 L contained within the lens assembly  10  of the invention is accomplished as follows. First, the lens assembly  10  of the invention is disengaged from the lamp fixture  12  by pushing it up and disengaging the bottom pins  12 P from the lamp holder  12  whereupon it is then moved downwardly to disengage the pins  12 P from the top lamp holder  12  (see Start and Step  1 ). As shown in step  2 , the lamp cap  26  is removed and the spent fluorescent lamp  12  is removed (see Step  3 ). 
     Installation of a new fluorescent lamp  12  is accomplished by inserting the new fluorescent lamp  12 L into the top end cap  20  with its bottom terminal pins  12 P aligned with holes  36 H so as to protrude therefrom (see Steps  4  and  5 ). The entire lens assembly  10  of the invention that contains the fluorescent lamp  12 L is then reinstalled into the lamp fixture  12  by inserting the top pins  12 P of the fluorescent lamp  12 L into the top lamp holder  12  (which is spring-loaded) and then aligning the bottom pins  12 P with the bottom lamp holder  12  thereby causing the fluorescent lamp  12 L and the lens assembly  10  of the invention to be secured in proper position. 
     The present disclosure includes that contained in the appended claims, as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention.