Abstract:
Screw-on or slip-on covers, in the form of transparent or translucent plastic sleeves for CFLs functioning as diffusers and cups for handling bulbs during installation, removal and as a safety receptacle for mercury-contaminated broken bulbs. The covers have interior surfaces contoured to the various sizes of CFL tube configurations, spiral or axially folded tubes, so that they are securely retained when screwed or slipped onto the tubes. The inventive covers may be used in any orientation, open end up, down or horizontal, so that they are equally useful for upright CFLs in lamps, horizontally oriented CFLs screwed into wall sockets, or downwardly oriented or angled CFLs screwed into horizontal or sloped ceiling fixtures. The inventive covers function as light diffusers and hide the tubes in more pleasing external shapes. Attractive sleeve colors, designs and surface textures are disclosed. Shades and shade frames may be secured to the inventive CFL covers.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This is the Regular US application corresponding to a U.S. Provisional Application Ser. No. 61/298,847, entitled Folded and Spiral-Tube Type Fluorescent Bulb Diffusion Cover and Shade Assemblies filed by the same inventor on Jan. 27, 2010, the priority of which is claimed under 35 US Code Sections 119, 120, ff. 
    
    
     FIELD 
     The application is directed to screw-on or slip-on covers, in the form of transparent or translucent plastic sleeves or cups, for folded-tube and spiral-tube type fluorescent bulbs, including CFL bulbs, which function as diffusion covers while hiding the tubes in more pleasing shapes, and at the same time serving as safety cups to assist in handling the bulbs during installation and removal, while serving as a safety receptacle for broken bulbs. A wide range of attractive sleeve colors, designs and surface textures are disclosed. Shades and shade frames may be secured to the inventive sleeves. The sleeve color can be selected to provide warmer spectral light output. 
     BACKGROUND 
     Folded and spiral-tube screw-in compact fluorescent (CFL) bulbs are in wide use today, par-ticularly as they are popular as energy-saving, nominally “green” alternatives to incandescent bulbs, since they provide equivalent light lumens at lower wattage and their service life is longer. For example, typical 13 watt fluorescent bulbs are equivalent replacements for 60 watt incandescent bulbs, and 26 watt fluorescents replace 100 watt incandescent bulbs. In addition, the fluorescent bulbs operate much cooler, and can be handled even after being ON for several hours without burning the skin. Indeed, more folded and spiral-tube type screw-in fluorescent bulbs are sold than incandescent bulbs. 
     The spiral tube CFL bulb was invented in 1976 by Edward E. Hammer, an engineer with General Electric, in response to the 1973 oil crisis, but the invention was shelved. The design was eventually copied by others. 1  It was not until 1995 that spiral CFL bulbs manufactured in China were commercially available. In 1980, Philips introduced its model SL, which was a screw-in bulb having an integral ballast. The SL bulb used a folded T4 tube, stable tri-color phosphors, and a mercury amalgam. This was the first successful screw-in replacement for an incandescent lamp. However, it was not until 1985 that the market really took off as a result of the introduction by the Osram company of the first CFL having an electronic ballast. The electronic ballast reduced the flickering and hum of the standard fluorescent tube ballasts. Today CFL bulbs fit in the same volume as standard incandescent bulbs as a result of new, high efficiency phosphors that permit more power per unit area per lumen, thereby permitting reduction in bulb size. CFLs typically radiate light in a different spectral range than that of incandescent bulbs. Improved phosphor formulations have resulted in the perceived color of soft-white CFL bulb light to be on par with standard incandescent lamps. 
     The average rated life of a CFL is between 8 and 15 times that of incandescent bulbs. CFLs typically have a rated lifespan of between 6,000 and 15,000 hours, whereas incandescent lamps are usually manufactured to have a lifespan of 750 hours or 1,000 hours. Although CFLs produce less light later in their lives than when they are new, the light output decay is exponential, with the fastest losses being soon after the lamp is first used. By the end of their lives, CFLs can be expected to produce 70-80% of their original light output, but since the response of the human eye to light is logarithmic, the CFL late-in-life 20-30% light output decline will be compensated for by the eyes. 
     For a given light output, CFLs use 20 to 33 percent less power than equivalent light-output incandescent bulbs. Since lighting accounted for approximately 9% of household electricity usage in the United States in 2001, widespread use of CFLs can save as much as 7% of total US household power, hence the phase-out of incandescent bulbs has been mandated by the government. 
     However, like all fluorescents, CFL bulb tubes contain a coating of a mercury amalgam and complex phosphors. While this coating accounts for the improved energy efficiency of CFLs, it seriously complicates their disposal, especially in cases where tubes are broken, as both are hazardous materials. Current CFLs sold are in large percentage, bare bulbs, with no means of proper pick-up, handling and disposal of broken, phosphor/mercury amalgam-coated glass shards. At best the manufacturers, distributors, sellers and government safety agencies simply rely on a warning to the consumer that they contain mercury and the consumer should take care to “properly dispose of used or broken bulbs”. Many refuse pick-up services decline to handle broken or used fluorescent bulbs, whether the standard 2′-4′ tubes, or the folded/spiral CFLs. 
     In addition, most people find the shape and folds of the folded-tube fluorescent bulbs to be unacceptable, if not downright ugly, from aesthetic and design viewpoints. Accordingly, some fluorescents are being offered that are encased or encapsulated in translucent white plastic or glass covers that mimic traditional incandescent light bulb shapes. These covers are formed secured to the metal thread base, and are spaced from the folded fluorescent tubes of the bulbs. As a result, the bases are enlarged, and do not fit in many lamp sockets. Accordingly, there remain a vast number of bare spiral and folded-tube bulbs in use that are not the preference of users and present a disposal and breakage hazard. In addition, those covers cause light loss, requiring the consumer to use higher-wattage CFLs, thereby defeating the cost savings. Indeed, in some cases users retain incandescent bulbs rather than use the spiral or folded-tube fluorescents because of light loss, design or aesthetic considerations. 
     Finally, fluorescent bulb light output is perceived as harsh, cold and giving a greenish tinge to objects illuminated. It can be particularly objectionable as not providing warmth to skin tones. 
     Accordingly, there is a need in the art for a way that permits covering of folded or spiral-tube CFL bulbs to make them safe to handle during installation, removal and clean-up when broken, are design and aesthetically acceptable, permit use of small bases in screw-in socket assemblies that have small clearance constraints, yet are inexpensive, easy to manufacture, and permit a wide range of design variations, including decorative and functional shades. 
     THE INVENTION 
     Summary 
     Including Objects and Advantages 
     The invention is directed to screw-on or slip-on covers, in the form of translucent or transparent plastic sleeves, cups or shells, for spiral-tube and folded-tube fluorescent bulbs (herein CFLs) that have a threaded base for screwing into sockets, or pin-type or bayonet-type bases. The inventive covers have interior surfaces that are contoured to the various sizes of CFL tube configurations, whether spiral or axially folded tubes, so that the sleeves or cup-shaped covers screw-onto or slip-onto the tubes with the sleeve/cup interior surface engaging the tubing so as to securely retain the cups on the CFL tubes in use. 
     The inventive sleeve and cup covers may be used in any orientation, such as open end up, down or horizontal, so that they are equally useful for upright CFLs in lamps, horizontally oriented CFLs screwed into wall sockets, or downwardly oriented or angled CFLs screwed into horizontal or sloped ceiling fixtures. 
     It is a key feature of the invention that in the cup configuration, the inventive covers serve as a receptacle for retaining broken bulb shards without coming into contact with the bare hands of the user. As such the receptacle can be disposed-of safely without skin contact of the phosphors and mercury components. In addition, the receptacle, being initially threaded onto or slipped over the spiral or folded glass bulb tubing, provides a safe way for the user to handle the bulbs during the installation or removal. Thus, should the bulb break while being screwed-into a socket, the user&#39;s hand is contacting the outer surface of the inventive cover cup form, rather than bare hands on the bulb glass as it breaks. This is a valuable safety feature, preventing cuts and skin contact with contaminants. 
     The inventive covers also provide a second primary function as light diffusers, while hiding the CFL bulb tubes in more pleasing external shapes. A wide range of attractive sleeve colors, designs, surface configurations and surface textures are disclosed. Shades and shade frames may be secured to the inventive CFL covers. The material of the inventive CFL covers may be any suitable thermosetting or thermoplastic plastic polymer or co-polymer that can be molded or machined into suitable interior and exterior configurations, the interior configuration being smooth to slidingly engage the glass tubing of the CFL without scratching or breaking the glass, and the exterior being formed into any suitable shape desired from the aesthetic and design perspective. Exemplary implementations of aesthetic shapes include: generally cylindrical; flame-tip shaped; and traditional light bulb shaped; with a wide range of body color, surface configurations, shapes, and textures. 
     The preferred plastic is transparent or translucent, to a degree that it hides the CFL tubing shape, yet permits a very high percentage of light transmission there-through, without significant dimming. The plastic may include fillers, extenders, dyes, plasticizers, and UV inhibitors to select or condition the light wavelength and lengthen the service life by preventing splitting or deterioration of the plastic. The plastic should be thermally stable at the operating temperature of the bulbs, and preferably include flame retardants or flame propagation suppressor components. In addition the plastic should have a relatively low coefficient of thermal expansion, so that the sleeves or cups do not expand under bulb service temperatures by an amount that causes them to slip off. For example, the inventive sleeve may be made from a polyolefin, polystyrene, polyvinylchloride, acrylic or polycarbonate polymer (including co-, ter-, or multi-monomer plastics). 
     The colors of the inventive sleeves may be selected to provide more pleasing tone balance. For example, a preferred embodiment, the plastic is transparent acrylic that contains a dye that softens the light and shifts the perceived wavelength to a warmer color, Bastard Amber being one of the preferred colors. Thus, the inventive sleeves function to shift the color balance of the light spectrum of the CFL bulb/sleeve combination. 
     In a first embodiment, an inventive cover is a cup (a sleeve with a closed outer end) configured for a spiral-tube CFL, the interior surface of which is configured with broad shallow threads of a size permitting the cup to be screwed-onto the spiral tube of the CFL, covering the CFL tubing down to the ceramic, plastic or metal base of the CFL. The exterior is a smooth generally cylindrical shape, and the outer end is closed and slightly domed. The intersection of the side wall with a dome end may be a crisp edge, or it may be a smooth chamfered curve. The cup depth and number of internal threads is selected so that the cup depth substantially matches the height of the glass tube spiral of the CFL and the two vertical stems leading to the CFL base. This depth provides a safety factor to protect the hands during installation or removal, and to handle a bulb that is broken in service without the need to touch the glass tubing or broken shards as they are retained in the cup. 
     The plastic is selected to be transparent (clear) or translucent and to have sufficient heat resistance that the service-warmed CFL tubing does not melt or otherwise deform the cup plastic or cause it to expand and slip off the bulb tubing. The cup plastic may have any desired color, such as crystal clear transparent, cool translucent white, or transparent or translucent colors such as Bastard Amber, ivory, party or holiday colors such as red, green, blue, yellow, orange, lavender, and the like, of any selected hue. Colored designs may be cast or painted onto the cup exterior, such as orange and black spirals for Halloween, snowflake designs and the like. 
     In a second embodiment, the cup is deeper than the height of the CFL spiral so that there is a head space between the top of the bulb and the inside face of the cup. This permits installing a metal or plastic threaded coupling tube or rod into the axial center of the cup from the outside end, and the fastening of a radially extending plastic, fabric, metal or glass shade by use of a finial nut screwed onto the projecting coupling. There are two variations of this embodiment: A) where the threaded coupling is formed integral with the exterior of the cup end; and B) where the cup end is bored and threaded to receive a standard, or provided, tubular threaded coupling as a retrofit assembly. In the B-variation of this embodiment, the coupling is threaded into the cup center hole, a keeper nut is threaded on the coupling inside the cup, a shade having a center hole or other cross-piece with a hole is placed over the exterior projecting end of the coupling and finally a finial is threaded over the projecting coupling end. 
     In a third embodiment, the cup may include key-hole or other shaped slots formed in or through the side wall of the cup, into which shade stand-off ribs may be inserted for suspending a shade from the cup exterior. Optionally, a double-ended key hole slot may be used, so that the cup is universally useful to retain a shade for a lamp mounted or ceiling mounted CFL bulb. 
     In a fourth embodiment, the cup may include an upraised external flange adjacent the open end of the outer wall face, and a separate decorative, hollow bulb-shaped cover element is slipped over the cup to engage and be retained by the flange groove. Optionally, the inside surface of the decorative bulb element may be partially silvered, which configuration is particularly useful for hanging lamps, such as dining table lamps, where the bulbs hang down, and the silvered “bottom” shields the eye, and redirects the light for diffuse ceiling lighting. 
     In a fifth embodiment, another variation of the fourth, the decorative hollow bulb shaped cover may be a “flame bulb” shape to convert otherwise ugly screw-in spiral fluorescents bulbs to the more decorative flame bulb shape. Such covers may be subtly grooved and shaded or painted to mimic flames. 
     In a sixth embodiment, the bottom, closed end of the cup may be removable, formed of a snap-in or screw-in disc which may be removed to form a true sleeve configuration, as the user determines for a particular usage. The removal permits forming a generally conical spot of brighter light to emanate from the now-open end of the sleeve, while the sides remain diffuse due to the presence of the sleeve screwed or slipped-onto the CFL tubing. 
     While the embodiments of the inventive diffuser cups and sleeves have been described in connection with spiral-tube CFLs for screw-on use, one of ordinary skill in the plastic arts will recognize that it is straightforward to configure the inner walls of the inventive cups and sleeves with grooves matching the spacing, depth and tube sizes of the folded-tube type CFL bulbs so that they can be slipped-on or snapped-onto such type of CFLs. 
     In another embodiment of the invention, the cups are provided already mounted, that is slipped onto or screwed onto the folded or spiral CFL glass tubing, as a combined assembly. A plurality of cups of different colors may be packaged together as an assortment, or a suitable color of cups may be supplied pre-assembled on CFL bulbs as a package, such as a 6-pack. In still another embodiment, a separate keeper may be snapped or glued in place over the open top of the cup after assembly on the bulb so that the cup may not be unscrewed from the bulb, that is, the inventive cup is a permanent integral part of the CFL bulb and cup assembly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is described in more detail with reference to the drawings, in which: 
         FIG. 1  is an isometric view of an inventive cover in the form of a cup showing the broad threaded-contour interior wall; 
         FIG. 1A  is an enlarged section of the rim of the cup showing the parting line and snap-together shoulders; 
         FIG. 2A  is a side elevation of the inventive cup cover of  FIG. 1 ; 
         FIG. 2B  is a section view through line  2 B- 2 B of  FIG. 2A ; 
         FIG. 3  is an end view of the open end of the cup of  FIG. 1 ; 
         FIG. 4  is an end view of the exterior closed end of the cup of  FIG. 1 ; 
         FIG. 5  is an exploded isometric showing how the inventive cup is screwed onto the spiral CFL bulb tubing; 
         FIG. 6  is a side elevation showing the inventive cup mounted on a spiral tube CFL; 
         FIG. 7  is a side elevation, partly in section showing an alternative embodiment in which the inventive cup cover has a shade mounted thereon via an integral coupling; 
         FIG. 8  is a side elevation showing a variation of the  FIG. 7  embodiment in which the coupling is retrofit on the inventive cover cup; 
         FIG. 9  is a side elevation of still another embodiment in which the cup side wall includes key holes or slots for receiving shade spoke hardware for retaining a shade on the inventive cup; 
         FIG. 10  is a side elevation partly in section showing still another embodiment of the inventive cup that can be converted to an open-ended sleeve, and may include an optional bulb-shaped outer cover element; 
         FIG. 11  is a side elevation showing another embodiment of the design cover in the form of a flame-type bulb shape; and 
         FIG. 12  is an exploded isometric view of the slip-on embodiment of the inventive cover for use with folded-tube type CFLs. 
     
    
    
     DETAILED DESCRIPTION 
     Including the Best Modes of Carrying Out the Invention 
     The following detailed description illustrates the invention by way of example, not by way of limitation of the scope, equivalents or principles of the invention. This description will clearly enable one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what is presently believed to be the best modes of carrying out the invention. 
     In this regard, the invention is illustrated in the several figures, and is of sufficient complexity that the many parts, interrelationships, and sub-combinations thereof simply cannot be fully illustrated in a single patent-type drawing. For clarity and conciseness, several of the drawings show in schematic, or omit, parts that are not essential in that drawing to a description of a particular feature, aspect or principle of the invention being disclosed. Thus, the best mode embodiment of one feature may be shown in one drawing, and the best mode of another feature will be called out in another drawing. 
     Referring to  FIGS. 1-6 , in a first embodiment, inventive cover  10  is a generally tubular sleeve  12  having an outer end  14  closed to form a cup or shell. The interior wall of the sleeve  12  is configured with broad shallow threads  16  as a negative of the CFL glass lighting tube elements, thereby being sized to permit the sleeve to be screwed-onto the spiral tube  18  of the CFL  20 , covering to the ceramic, plastic or metal base  22  of the CFL. The exterior surface  24  is a smooth generally cylindrical shape, and the outer end  14  is closed and slightly domed. The intersection of the side wall with the dome end may be a crisp edge  26 , or it may be a smooth chamfered curve. 
       FIG. 2B  is the section view of the internal threads  16  of the shell  12 ;  FIGS. 3 and 4  show the open and closed ends, respectively, while  FIG. 5  shows how the bulb is screwed into the sleeve  12 . 
       FIG. 1  also shows an optional 2-part construction, in which the cups are molded in snap-together halves along a part line  88 , shown in  FIGS. 1 ,  1 A and  2 A. The join between halves preferably have mating shoulders  90  with suitable rib and groove configuration to press fit the halves together (snap-together), the shoulders being shown in enlarged end view in  FIG. 1A . 
     As best seen in  FIG. 6 , the cup depth (or height) and number of internal threads  16  is selected so that the cup depth substantially matches the height of the spiral glass tube  18  of the CFL and the two vertical stems  28  leading to the CFL base. The user may leave a portion of the stems  28  exposed if desired, or the inventive cover may be screwed down to the base  22  as shown by the dashed line representing the open end  30  of the inventive cover cup  10 . 
     In preferred mode of use in a retrofit situation (that is a non-preassembled mode), the cup is first screwed onto the CFL spiral tubing, and then the combined assembly is screwed into the socket. Thus, the user is using the inventive cup as a holder of the bulb to screw it into the socket, which is a safety precaution, in case the bulb breaks during the installation. The cup is deep enough to retain broken bulb glass without coming into contact with the hand of the user. The user never touches the glass tubing of the CFL. Removal is the reverse operation. The inventive feature of the internal cup spirals permits changing colors of cups on selected bulbs, e.g., to provide different mood lighting, different color spectrum for different seasons, parties and special occasions. 
     In a second embodiment shown in  FIGS. 7 and 8 , the cup  10  is deeper than the height of the CFL tube spiral  18  so that there is a head space  32  between the top of the bulb and the inside face of the cup end dome wall  14 . This permits installing a metal or plastic threaded coupling tube or rod  34  into the axial center of the cup from the outside end, over which is inserted a radially extending plastic, fabric, metal or glass shade  36  by use of a finial nut  38  screwed onto the projecting coupling. 
     There are two variations of this embodiment: A) where the threaded coupling is formed integral with the exterior of the cup end as shown in  FIG. 7 ; and B) where the cup end is bored and threaded to receive a standard or provided tubular threaded coupling as a retrofit assembly, shown in  FIG. 8 . In the  FIG. 8  variation of this embodiment, the coupling  34  is threaded into a cup end center hole  40 , a keeper nut  42  is threaded on the coupling inside the cup, a shade  36  having a center hole or other cross-piece with a hole is placed over the exterior projecting end of the coupling and finally a finial  38  is threaded over the projecting coupling end. 
     These  FIGS. 7 and 8  illustrate the use of the inventive cover  10  screwed on a spiral tube CFL  20  which is threaded into a ceiling-mounted receptacle  44 . 
     In a third embodiment shown in  FIG. 9 , the inventive cover  10 , here a cup, includes key-hole or other shaped slots  46 ,  48  formed in ( 48 ) or through ( 46 ) the side wall  12  of the cup  10 , into which stand-off ribs  50  of shade  52  are inserted for supporting or suspending a shade from the cup exterior. Optionally, a double-ended key hole slot  54  may be used, so that the cup is universally useful to retain a shade for a CFL bulb mounted in a lamp  56 , or ceiling fixture  44  (see  FIG. 8 ). 
     In a fourth embodiment shown in  FIG. 10 , the inventive cover  10  includes an upraised external flange  58  adjacent the open end  30  of the outer side wall face  12 , and a separate decorative, hollow bulb-shaped cover element  60  comprising an enlarged bulb shell connected to a generally tubular open neck section, the neck being slipped over the cover  10  as shown by the arrow, so the thinned lower edge  62  of the bulb shell  60  engages and is retained by the groove  62 ′ of flange  58 . Optionally, the inside surface of the decorative bulb element may be partially silvered  64 , which configuration is particularly useful for hanging lamps, such as dining table lamps, where the bulbs hang down, and the silvered “bottom” shields the eye, and redirects the light for indirect ceiling lighting. 
     Conversely, in the embodiment where the end cap  14  is threaded and removable by unscrewing via use of the knob  70 , silvering the inside flights of the inventive sleeve  12  will result in a collimated tubular beam of light useful for task lighting. 
     In a fifth embodiment shown in  FIG. 11 , the separate decorative hollow bulb shaped shell  60  may be a “flame bulb” shape  66  to convert otherwise ugly screw-in spiral CFL bulbs to the more decorative flame bulb shape. The exterior of covers  60  may be subtly grooved and shaded or painted to mimic flames. This embodiment also illustrates a plastic or metal cross-piece keeper  82  that is press fit in diametrically opposed notches  84 , or in the alternative may be glued across the open bottom end of the cup or sleeve member  12 . 
     In a sixth embodiment shown in  FIG. 10 , the bottom, closed end  14  of the cup cover  10  may be removable, to form a true sleeve configuration, as the user determines for a particular usage. As shown, the end  14  includes threads  68  so the closure end may be selectively screwed-off by turning the raise finger ridge  70 . The removal of the end piece  14  results in a generally conical spot of brighter light to emanate from the CFL  20  through the now-open end  72  of the inventive cover, while the sides remain diffuse when lighted, due to the presence of the sleeve screwed or slipped-onto the CFL tubing. Note that removal of outer end  14  converts the cup to a tubular sleeve. 
     While the embodiments of the inventive diffuser cups and sleeves have been described in connection with spiral-tube CFLs for screw-on use, one of ordinary skill in the plastic arts will recognize that it is straightforward to configure the inner walls of the inventive cups and sleeves with grooves matching the spacing, depth and tube sizes of the folded-tube type CFL bulbs so that they can be slipped-on or snapped-onto such type of CFLs. 
     An example of this slip-on embodiment for CFLs having inverted U-shaped folded tubes  74  is illustrated in  FIG. 12 , wherein the interior surface of the tubular wall  12  inventive cover  10  is configured with shallow grooves  76 , that are oriented parallel to and spaced from the center axis of the cover and the bulb and dimensioned to conform to the shape of the tubes  74 . Grooves  76  grippingly slide over the axially parallel tubes  74  of the CFL  20  to retain the cover in place. An optional gripping rib  78  conforms to the gap  80  between the pairs of folded tubes  74 . In the alternative, an optional cross member  82  may be secured across the diameter of the open end of the sleeve  12 . This cross-member functions as a keeper, and fits in the gap  80  or  86  between the folds of tubes  74 . The gap  80  is typically wider than  86 , so the keeper  82  is dimensioned to fit whichever gap is selected. 
     Although  FIG. 12  is an example showing a pair of folded tubes, it should be understood that the same principle can be applied to CFLs having three or more folded, axially oriented tubes. In general the inventive sleeves may be configured to receivingly engage CFL bulbs having compound light emitting tube shapes, typically spiral tubes, stacked circular tubes, folded tubes of various geometries, and the like. The inventive sleeves having one closed end form cups to permit safe no-hand-contact with the glass lighting tubular components of the glass CFL lighting tubular components (e.g., the spiral or folded glass tubes themselves), herein called “hands-free” installation, removal and handling. 
     Without intending to be limiting, the following are examples of the wide range of implementations possible for the transformation of relatively ugly CFL lighting tube elements into aesthetic diffusers: The plastic may be transparent and clear or tinted with a colorant dye, or may be translucent, e.g., a milky color produced by inclusion of an opacifier in the plastic composition; special effect fillers or coating materials may be used, e.g., fine fibers for a refractive effect, reflective chips for a sparkle effect, or an iridescent or frosted coating; the interior and/or internal surfaces may be textured, e.g., frosted in various degrees or grooved, or may have surface relief in a wide variety of designs; the exterior or interior may be coated, such as with a plastic-adherent paint with various designs; fluorescent or phosphorescent compounds may be included in the plastic composition for special effects; and the like. 
     In actual tests of dye tinted plastic, the light loss is minimal, and pleasing spectral shift is obtained. Thus, colors such as pale blue, rose, yellow, amber, green, lavender, red, and bastard amber dye colorants may be incorporated in the plastic to achieve more pleasing skin tones. The exterior surface in one embodiment includes sculpted axially parallel, radially spaced grooves, semicircular in cross section, the result being to refract and diffuse the light with essentially no loss of luminosity, yet with pleasing color balance shift for mood or space lighting. 
     INDUSTRIAL APPLICABILITY 
     It is clear that the inventive CFL bulb covers of this application has wide applicability to the lighting and home decor industry, including retrofit of spiral and folded tube fluorescent bulbs with decoratively pleasing diffusers. The inventive CFL bulb covers have a clear potential of becoming adopted as the new standard for safely handling mercury and phosphors containing CFL bulbs, and as pleasing light spectrum shifting diffusers and to aesthetically de-uglify CFL bulbs. 
     It should be understood that various modifications within the scope of this invention can be made by one of ordinary skill in the art without departing from the spirit thereof and without undue experimentation. For example, the external shape  12  of the inventive covers  10  can have a wide range of designs to provide the functionalities disclosed herein. Likewise the covers may be used in either sleeve-type or cup-type configurations. As bulb design changes in the future by provision of glass light emitting tubular shapes, the inventive sleeves can be easily configured to be retainingly engaged by these new shapes. This invention is therefore to be defined by the scope of the appended claims as broadly as the prior art will permit, and in view of the specification if need be, including a full range of current and future equivalents thereof. 
     
       
         
               
             
               
               
             
           
               
                 APPENDIX A 
               
               
                   
               
               
                 Parts List 
               
               
                 Parts List (This Parts List is provided as an aid to 
               
               
                 Examination and may be canceled upon allowance) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 10 
                 Inventive cover 
               
               
                 12 
                 Tubular sleeve 
               
               
                 14 
                 Closed outer end 
               
               
                 16 
                 Interior threads 
               
               
                 18 
                 Spiral tube 
               
               
                 20 
                 CFL 
               
               
                 22 
                 Base of CFL 
               
               
                 24 
                 Exterior surface 
               
               
                 26 
                 Edge intersection of dome and wall 
               
               
                 28 
                 Stems of bulb 
               
               
                 30 
                 Open end of cup 
               
               
                 32 
                 Head space 
               
               
                 34 
                 Coupling tube or rod 
               
               
                 36 
                 Shade 
               
               
                 38 
                 Finial nut 
               
               
                 40 
                 Hole in end of cup 14 
               
               
                 42 
                 Keeper nut 
               
               
                 44 
                 Ceiling mounted receptacle 
               
               
                 46 
                 Keyhole slot - through 
               
               
                 48 
                 Keyhole slot in side wall 
               
               
                 50 
                 Stand off rib 
               
               
                 52 
                 Shade 
               
               
                 54 
                 Double-ended keyhole slot 
               
               
                 56 
                 Lamp 
               
               
                 58 
                 External flange &amp; groove 62 
               
               
                 60 
                 Hollow bulb element 
               
               
                 62 
                 Thin edge; 62′ Perimeter groove in flange 58 
               
               
                 64 
                 Partial silvering 
               
               
                 66 
                 Flame tip 
               
               
                 68 
                 Threads 
               
               
                 70 
                 Finger ridge 
               
               
                 72 
                 Open top of cover sleeve 
               
               
                 74 
                 Folded-tube type CFL 
               
               
                 76 
                 Spaced shallow grooves conform to tube shape 
               
               
                 78 
                 Gripping Rib (optional) 
               
               
                 80 
                 Gap between folded tube pairs 
               
               
                 82 
                 Cross-piece keeper 
               
               
                 84 
                 Notch for cross-piece 82 
               
               
                 86 
                 Gap between folded tubes, transverse to 80 
               
               
                 88 
                 Part Line for snap-together halves 
               
               
                 90 
                 Inter-engaging shoulders of halves 
               
               
                 92 
               
               
                 94 
               
               
                 96 
               
               
                 98 
               
               
                 100