Abstract:
An LED lighted sign with a light diffuser sheet with embedded diffusion particles which provides a 20%-40% increase in lighting transmittance. There is also provided a light divider assembly having partitions which serve to segregate groups of LEDs for lighting only selected segments of the light divider assembly for displaying numerical images. Alternatively, there is provided an injection molded light diffuser lens of the same material which secures to each of several light diffuser chambers which combine to display numerical images. optionally, colored LEDs may be used to create color displays. Color filters may also be overlaid the light diffusers or color pigment may be added to the diffusion material during injection molding to create color displays. A molded light divider assembly is also provided in the alternative.

Description:
CROSS REFERENCES TO CO-PENDING APPLICATIONS 
     This patent application is a continuation-in-part of Ser. No. 09/708,988 entitled “LED and Light Diffuser for a Lighted Sign” filed on Nov. 8, 2000, pending. 
    
    
     BACKGROUND OF THE INVENTION 
     FIELD OF THE INVENTION 
     The present invention is for an LED lighted sign with a light diffuser. 
     SUMMARY OF THE INVENTION 
     The general purpose of the present invention is an LED lighted sign with a light diffuser. 
     According to one embodiment of the present invention, there is provided an LED lighted sign with a light diffuser sheet with embedded diffusion particles which provides a 20%-40% increase in lighting transmittance. There is also provided a one-piece light divider assembly having partitions which serve to segregate groups of LEDs for lighting only selected segments or bars of the light divider assembly for displaying numerical images optionally, color filters or color pigment may also be added atop or to the diffuser material to provide for colored numerical displays. Alternatively, a colored display can be created by using colored LEDs. 
     According to another embodiment, there is provided a one-piece light divider assembly which is comprised of separate individual chambers, each with light diffuser lenses which are created by injection molding using the same diffuser material, as previously described. When multiple chambers of the light divider assembly are used in conjunction thereto, numerical images are displayed. 
     Yet another embodiment provides for a one-piece light divider assembly which is comprised of separate individual chambers having recesses for accommodation of individual diffuser lenses which flush mount individually in the upper region of the light divider assembly. 
     Still another embodiment provides for a one-piece light divider assembly which is comprised of separate individual chambers having recesses for accommodation of individual diffuser lenses which snappingly engage and flush mount individually in the upper region of the light divider assembly. 
     All the one-piece light divider assemblies and the separate individual chambers may be made by injection molding, casting, metal forming, welding, or other appropriate means. 
     One significant aspect and feature of the present invention is a light diffuser sheet or lens which increases the light transmittance 20%-40%, while producing a uniformly lighted segment or bar. 
     Another significant aspect and feature of the present invention is a light divider assembly which allows for selected segments or bars of the display to be illuminated. 
     Still another significant aspect and feature of the present invention is the provision of optional color pigment or color filters added atop or to the diffuser material which will change the color of the emitted light. 
     Yet another significant aspect and feature of the present invention is the provision of colored LEDs with a clear light diffuser sheet or injection molded diffuser lens of the same material which will allow the emitted light to be any color. 
     Another significant aspect and feature of the present invention is a one-piece light divider assembly having partitions which serve to segregate groups of LEDs for lighting only selected segments of the light divider assembly. 
     Another significant aspect and feature of the present invention is a light divider assembly which is comprised of separate individual chambers, each with light diffuser lenses which snappingly engage the light divider assembly. 
     Another significant aspect and feature of the present invention is a one-piece light divider assembly which is comprised of separate individual chambers having recesses for accommodation of individual diffuser lenses which flush mount individually in the upper region of the light divider assembly. 
     Another significant aspect and feature of the present invention is a one-piece light divider assembly which is comprised of separate individual chambers having recesses for accommodation of individual diffuser lenses which flush mount individually in the upper region of the light divider assembly. Each individual diffuser lens includes ramped tabs which flex the panels of the light divider assembly outwardly to gain access and to snappingly engage ramped tab receivers in the light divider assembly. 
     Having thus described embodiments of the present invention and enumerated significant aspects and features thereof, it is the principal object of the present invention to provide an LED lighted sign with a light diffuser sheet or an injection molded lens of the same material. 
     One object of the present invention is to provide a means for segregating light segments. 
     Another object of the present invention is to provide a light diffuser sheet or light diffuser lens which increases the lighting transmittance 20%-40% while producing a uniformly lighted segment or bar. 
     Yet another object of the present invention is to provide a means for easily changing the color of the display. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects of the present invention and many of the attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, in which like reference numerals designate like parts throughout the figures thereof and wherein: 
     FIG. 1 illustrates an exploded isometric view of an LED lighted sign with a light diffuser, the present invention; 
     FIG. 2 illustrates a front view of the light divider assembly and the PC board with LEDs projecting therefrom; 
     FIG. 3 illustrates a front view of the face plate; 
     FIG. 4, a first alternative embodiment, illustrates an exploded isometric view of an LED lighted sign with light diffuser lenses covering segmented geometric chambers; 
     FIG. 5 illustrates an end view of a geometric chamber with a light diffuser lens snappingly engaged thereto; 
     FIG. 6 illustrates a side view of a geometric chamber with a light diffuser lens snappingly engaged thereto; 
     FIG. 7, a second alternative embodiment, illustrates an exploded isometric view of an LED lighted sign with individual light diffuser lenses which align to segmented geometric chambers; 
     FIG. 8 illustrates a front view of the light divider assembly and PC board including LEDs of FIG. 7; 
     FIG. 9, a third alternative embodiment, illustrates an exploded isometric view of an LED lighted sign with individual light diffuser lenses having ramped tabs which align to and snappingly engage ramped tab receivers in the light divider assembly; 
     FIG. 10 illustrates an isometric view of a light diffuser lens having ramped tabs; 
     FIG. 11 illustrates a section view of the light divider assembly along line  11 — 11  of FIG. 12; and, 
     FIG. 12 illustrates a front view of the light divider assembly, several light diffuser lenses, and a printed circuit board including the LEDs of FIG.  9 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 illustrates an exploded isometric view of an LED lighted sign  10  with a light diffuser sheet  20 , the present invention. The LED lighted sign  10  comprises a PC board  12 , a light divider assembly  22 , a light diffuser sheet  20 , an optional color filter  30 , and a face plate  32 . The PC board  12  accepts any number of LEDs  18   a - 18   n  which are soldered to its upper surface. It is to be understood that the PC board  12  accepts any number of LEDs enumerated as LEDs  18   a - 18   n . The light divider assembly  22  comprises a base  26  (FIG. 2) substantially in the form of a figure eight and a plurality of partitions  23   a - 23   n  upstanding from the base  26  which along with the base  26  form seven geometric chambers  24   a - 24   g . The base  26  of light divider assembly  22  contains a plurality of apertures  34   a - 34   n  corresponding in number and orientation to the LEDs  18   a - 18   n  projecting from the PC board  12 , as shown in FIG.  2 . Light diffuser sheet  20  is aligned over the top of light divider assembly  22 . The light diffuser sheet  20  gives a 20%-40% increase in lighting transmittance. The light diffuser sheet  20  is a polymer such as, but not limited to, Acrylite® df made by Cyro Industries. Acrylite® df light diffusing molding and extrusion compounds are acrylic polymers with superior light diffusion and transmittance, resulting in higher light intensity and output ratio compared to conventional pigment-diffusion polymers. This offers increased lighting efficiency with a 20-40% increase in light transmittance versus pigmented products. The special optical properties are obtained by incorporating spherical, high molecular weight polymer beads with a different refractive index into the acrylic matrix. The difference in refractive indices changes the direction of light travel within the manufactured part. The net result is an even distribution of light exiting the part. 
     Alternatively, the Acrylite® df may be injection molded into a lens configuration which may or may not be pigmented for a color display. Acrylite® df exhibits very minimal, if any, color shift when viewed from the side and has a low contrast to its background when in the off state compared to traditional light diffusers, which have significant color shift, and reflects ambient light to the point of looking illuminated. Other light diffuser sheets with similar properties may be used without changing the purpose or scope of the invention. A technical data sheet pertaining to Acrylite® df is attached as Appendix  1  and incorporated herein by reference. An optional color filter  30 , in any desired color, can be placed over light diffuser sheet  20 . The color filter  30  is not necessary, but it is to be understood that the color filter  30  provides the capability of changing the color of the emitted light easily. Without compromising transmittance, the LED lighted sign  10  has a face plate  32  having seven geometric cutouts  36   a - 36   g  corresponding to the seven geometric chambers  24   a - 24   g  which allow light to be passed through. The face plate  32  has a rectangular lip  38  which fits about the outer perimeter of the light divider assembly  22 . The components of the LED lighted sign  10  may be assembled and secured by nuts and bolts, an appropriate adhesive, or welding. 
     FIG. 2 illustrates a front view of the light divider assembly  22  and the PC board  12  with the LEDs  18   a - 18   n  projecting therefrom, where all numerals correspond to those elements previously described. Illustrated in particular is the plurality of apertures  34   a - 34   n  in the base  26  which correspond in number and orientation to the LEDs  18   a - 18   n  shown projecting from the PC board  12 . The one-piece light divider assembly  22  has a plurality of planar partitions  23   a - 23   n  forming the seven geometric chambers  24   a - 24   g  which separate the light emitted by the sets of LEDs  18   a - 18   n , respectively, in each geometric chamber  24   a - 24   g . The light divider assembly  22  may be made by injection molding, casting, metal forming, welding, or other appropriate means. Four LEDs are depicted for each geometric chamber  24   a - 24   g , but any number of LEDs could be provided, the number provided being dependent on the size of the individual geometric chambers. The LEDs of each set are disposed in a line for forming a segment or bar of a numeric display. By lighting the LEDs in only selected geometric chambers  24   a - 24   g , a numeric display can be achieved ranging from zero to nine. The LED lighted sign  10  can be used in a scoreboard, a clock, a timer, or any other application which requires a numeric digit display. 
     FIG. 3 illustrates a front view of the face plate  32 , where all numerals correspond to those elements previously described. Illustrated in particular is the layout of the geometric cutouts  36   a - 36   g  which allow different numeric displays when the LEDs in different geometric cutouts are illuminated. 
     FIG. 4 illustrates an exploded isometric view of a LED lighted sign  110  with light diffuser lenses  120   a - 120   g  covering segmented geometric chambers  124   a - 124   g , the first alternative embodiment. The LED lighted sign  110  comprises a PC board  112 , a light divider assembly  122  comprised of a plurality of segmented geometric chambers  124   a - 124   g , a plurality of light diffuser lenses  120   a - 120   g , and a face plate  132  having a plurality of geometric cutouts  136   a - 136   g . The PC board  112  has a plurality of LEDs  118   a - 118   n  appropriately wired and secured thereto. The LEDs  118   a - 118   n  are oval in shape with varying beam spread in two directions which allows positioning of the LEDs  118   a - 118   n  to distribute the light in the most efficient manner to achieve uniform lighting of the geometric cutouts  136   a - 136   g  of face plate  132 . It is to be understood that any number of LEDs  118   a - 118   n  may be used to accommodate varying light intensity requirements. The light divider assembly  122  is comprised of seven individual geometric chambers  124   a - 124   g , each having like components. Each geometric chamber  124   a - 124   g has four protruding tabs  142   a - 142   d , as exemplified about the geometric chamber  124   a , extending outwardly from the upper lip of each of the geometric chambers  124   a - 124   g . There are also provided four flexible locking tabs  146   a - 14   d  which extend downwardly from the lower edge of each geometric chamber  124   a - 124   g  and snappingly engage in apertures  140   a - 140   f  of PC board  112 , once properly aligned and positioned over LEDs  118   a - 118   n . For purposes of brevity and clarity, only flexible locking tab  146   a  associated with geometric chamber  124   a  is specifically identified in FIG.  4 . Geometric chamber  124   a  and all of the flexible locking tabs  146   a - 146   d  will be described in detail with reference to FIGS. 5 and 6. It is to be understood that geometric chambers  124   b - 124   g  are identical to geometric chamber  124   a  in function and form. Geometric chambers  124   a - 124   g  can be made by injection molding, casting, metal forming, welding, or other appropriate means. 
     Light diffuser lenses  120   a - 120   g  are now described in detail. The light diffuser lenses  120   a - 120   g  are injection molded and are made of the same material as the light diffuser sheet  20  of the preferred embodiment. Each light diffuser lens  120   a - 120   g  incorporates four flexible tab receivers  144   a - 144   d  which extend downwardly from their edges. The flexible tab receivers  144   a - 144   d  snappingly engage protruding tabs  142   a - 142   d  and secure the light diffuser lens  120   a  to the geometric chamber  124   a . Optionally, the light diffuser lenses  120   a - 120   g  may be pigmented in the injection molding process to allow any color of light to be emitted. For purposes of brevity and clarity, only the flexible tab receivers  144   a - 144   d  associated with light diffuser lens  120   a  are specifically identified in FIG.  4 . Light diffuser lens  120   a  will be further described in detail with reference to FIGS. 5 and 6. Light diffuser lenses  120   b - 120   g  are identical to light diffuser lens  120   a  in function and form. The face plate  132  of the LED lighted sign  110  has seven geometric cutouts  136   a - 136   g  corresponding to the seven geometric chambers  124   a - 124   g  mounted to the PC board  112  which allow light to pass through and create a numeric display when select geometric chambers  124   a - 124   g  are illuminated. There is provided a rectangular lip  138  which extends downwardly from the underside perimeter of face plate  132  which fits intimately over and about the perimeter of the light divider assembly  122 . The components of the LED lighted sign  110  may be assembled and secured by nuts and bolts, screws, an appropriate adhesive, or welding. 
     FIG. 5 illustrates an end view of geometric chamber  124   a  with light diffuser lens  120   a  snappingly engaged thereto, and FIG. 6 illustrates a side view of geometric chamber  124   a  with light diffuser lens  120   a  secured thereto, where all numerals correspond to those elements previously described. With additional reference to FIG. 4, the geometric chamber  124   a  and light diffuser lens  120   a  are now described in detail. Illustrated in particular is the alignment and snapping engagement of the protruding tabs  142   a - 142   d  in conjunction with the flexible tab receivers  144   a - 144   d  and the configuration of the flexible locking tabs  146   a - 146   d  which snappingly engage apertures  140   a - 140   f  when two to three geometric chambers  124   a - 124   g  are perpendicularly aligned as illustrated in FIG.  4 . Also illustrated in particular is the light diffuser lens  120   a  which aligningly extends upwardly and is accommodated by the geometric cutouts  136   a - 136   g  where the light diffuser lens  120   a  extends up to or above the plane of face plate  132 . 
     FIG. 7 illustrates an exploded isometric view of an LED lighted sign  210  with individual light diffuser lenses  220   a - 220   g  which align to segmented geometric chambers  224   a - 224   g , the second alternative embodiment. The LED lighted sign  210  comprises a PC board  212 , a light divider assembly  222 , preferably vacuum formed or extruded polymer material or molded of foam, plastic, metal or other suitable reflective or suitably colored material, comprised of a plurality of segmented geometric chambers  224   a - 224   g , a plurality of light diffuser lenses  220   a - 220   g , a face plate  232  having a plurality of geometric cutouts  236   a - 236   g , and a color filter  230 . The PC board  212  has a plurality of LEDs  218   a - 218   n  appropriately wired and secured thereto. It is to be understood that any number of LEDs  218   a - 218   n  may be used to accommodate varying light intensity requirements. The light divider assembly  222  is comprised of seven individual geometric chambers  224   a - 224   g , each having like components. A segmented lip  238  is located along the bottom edges of the light divider assembly  222  and as such provides for alignment of the light divider assembly  222  with the edges of the PC board  212 . A recess  226   a  is located along and about the upper region of the geometric chamber  224   a  to accommodate light diffuser lens  220   a . Light diffuser lens  220   a  aligns in the recess  226   a  and is flush with the upper surface of the light divider assembly  222 . Similarly shaped recesses  226   b - 226   g  are located along and about the upper region of the geometric chambers  224   b - 224   g  to accommodate light diffuser lenses  220   b - 220   g  in a similar fashion. Geometric chambers  224   a - 224   g  of the light divider assembly  222  can be made by injection molding, casting, metal forming, welding, or other appropriate means. 
     Light diffuser lenses  220   a - 220   g  are now described in detail. The light diffuser lenses  220   a - 220   g , which are individual members, can be injection molded or otherwise formed and are made of the same material as the light diffuser sheet  20  of the preferred embodiment. Optionally, the light diffuser lenses  220   a - 220   g  may be pigmented in the injection molding process to allow any color of light to be emitted. In the alternative, a light diffuser sheet  20  of the preferred embodiment can be placed over the upper surfaces of the light divider assembly  222  in substitution for the light diffuser lenses  220   a - 220   g . The face plate  232  of the LED lighted sign  210  has seven geometric cutouts  236   a - 236   g  corresponding to the seven geometric chambers  224   a - 224   g  which mount to the PC board  212  which allow light to pass through and create a numeric display when select geometric chambers  224   a - 224   g  are illuminated. The components of the LED lighted sign  210  may be assembled and secured, depending on the materials used, by nuts and bolts, screws, an appropriate adhesive, or welding. 
     FIG. 8 illustrates a front view of the light divider assembly  222  and PC board  212  including LEDs  218   a - 218   n . Shown in particular are the recesses  226   a - 226   g  located along and about the upper regions of the geometric chambers  224   a - 224   g , respectively, for accommodation of the light diffuser lenses  220   a - 220   g . Also shown is the alignment of the LEDs  218   a - 218   n  extending upwardly from the PC  212  board into the respective geometric chambers  224   a - 224   g.    
     FIG. 9, a third alternative embodiment, illustrates an exploded isometric view of an LED lighted sign  310  with individual light diffuser lenses  320   a - 320   g  which align to segmented geometric chambers  324   a - 324   g . The LED lighted sign  310  comprises a printed circuit board  312 , a light divider assembly  322 , preferably vacuum formed or extruded polymer material or molded of foam, plastic, metal or other suitable reflective or suitably colored material, and comprised of a plurality of segmented geometric chambers  324   a - 324   g , a plurality of light diffuser lenses  320   a - 320   g  having a plurality of similarly shaped ramped tabs  325   a - 325   d  extending therefrom, as best shown in FIG. 10, a face plate  332  having a plurality of geometric cutouts  336   a - 336   g , and a color filter  330 . The printed circuit board  312  has a plurality of LEDs  318   a - 318   n  appropriately wired and secured thereto which align with the geometric chambers  324   a - 324   g , respectively. The geometric chambers  324   a - 324   g  should be of molded or vacuum formed material preferably of a suitable color, such as gray or a shade of gray. LED color and brightness, along with the diffuser, also are factored into the color selection from the color spectrum for the chamber color. It is to be understood that any number of LEDs  318   a - 318   n  may be used to accommodate varying light intensity requirements. The light divider assembly  322  is comprised of seven individual geometric chambers  324   a - 324   g , each having like components. A recess  326   a  is located along and about the upper region of the geometric chamber  324   a  to accommodate the light diffuser lens  320   a . As also shown in FIG. 10, a plurality of ramped tabs  325   a - 325   d  extend horizontally from the major edges of the light diffuser lens  320   a  as well as being located on and extending in a similar fashion from each of the remaining light diffuser lenses  320   b - 320   g . The ramped tabs  325   a - 325   d  of the light diffuser lens  320   a  snappingly engage a plurality of like ramped tab receivers  340  (FIG. 11) distributed and correspondingly located along and about the region adjacent the recess  326   a . The light diffuser lens  320   a  aligns in the recess  326   a , as shown in FIG. 12, and is flush with the upper surface of the light divider assembly  322 . Similarly shaped recesses  326   b - 326   g  having ramped tab receivers  340  are located along and about the upper region of the geometric chambers  324   b - 324   g  to accommodate light diffuser lenses  320   b - 320   g  in a similar fashion. Geometric chambers  324   a - 324   g  of the light divider assembly  322  can be made by injection molding, casting, metal forming, welding, or other appropriate means. 
     Light diffuser lenses  320   a - 320   g  are now described in detail. The light diffuser lenses  320   a - 320   g , which are individual members, can be injection molded or otherwise formed and are made of the same material as the light diffuser sheet  20  of the preferred embodiment. Optionally, the light diffuser lenses  320   a - 320   g  may be pigmented in the injection molding process to allow any color of light to be emitted. In the alternative, a light diffuser sheet  20  of the preferred embodiment can be placed over the upper surfaces of the light divider assembly  322  in substitution for the light diffuser lenses  320   a - 320   g . The face plate  332  of the LED lighted sign  310  has seven geometric cutouts  336   a - 336   g  corresponding to the seven geometric chambers  324   a - 324   g  which mount to the printed circuit board  312  which allow light to pass through and create a numeric display when select geometric chambers  324   a - 324   g  are illuminated. The components of the LED lighted sign  310  may be assembled and secured, depending on the materials used, by nuts and bolts, screws, an appropriate adhesive, or welding. 
     FIG. 10 illustrates an isometric view of a light diffuser lens  320   a . Each light diffuser lens  320   a - 320   g  preferably has four ramped tabs  325   a - 325   d  extending outwardly from the edge of the light diffuser lens, as exemplified by the light diffuser lens  320   a.    
     FIG. 11 illustrates a section view of the light divider assembly  322 , light diffuser lenses  320   a  and  320   f , along line  11 — 11  of FIG.  12 . Illustrated in particular are the ramped tab receivers  340  located along and about the portions of the recesses  326   b  and  326   f  typifying in part the location of the ramped tab receivers  340  to the recesses  326   a - 326   g.    
     FIG. 12 illustrates a front view of the light divider assembly  322  and printed circuit board  312  including LEDs  318   a - 318   n  aligned respectively in geometric chambers  324   a - 324   g . Shown in particular are the recesses  326   a - 326   g  located along and about the vertical regions of the geometric chambers  324   a - 324   g , respectively, for accommodation of the light diffuser lenses  320   a - 320   g . Light diffuser lens  320   a  in particular is shown in engagement with the geometric chamber  324   a  where snapping engagement of the ramped tabs  325   a - 325   d  with the appropriate aligned ramped tab receivers  340  has occurred. Also shown is the alignment of the LEDs  318   a - 318   n  extending upwardly from the printed circuit board  312  into the respective geometric chambers  324   a - 324   g.    
     MODE OF OPERATION 
     With reference to FIGS. 1-3, the mode of operation is now described, where all numerals correspond to those elements previously described. LEDs  18   a - 18   n  are soldered onto the upper surface of PC board  12 . Once the LEDs  18   a - 18   n  are appropriately soldered, the apertures  34   a - 34   n  of the light divider assembly  22  are positioned over and about the corresponding LEDs  18   a - 18   n  of PC board  12 . The light diffuser sheet  20  is then positioned over the light divider assembly  22 . A color filter  30  of any desired color may then be positioned over the light diffuser sheet  20 . It is to be understood that a color filter  30  is not necessary if no color display is desired. Face plate  32  is then positioned over the color filter  30  and the light diffuser sheet  20 . The rectangular lip  38  of the face plate  32  fits about the outside perimeter of the light divider assembly  22  which is suitably secured to the PC board  12 . 
     With reference to FIGS. 4-6, the mode of operation is similar to that of the preferred embodiment, with the exception that the geometric chambers  124   a - 124   g  of the light divider assembly  122  must first be aligned and configured, as illustrated, and snappingly engaged to the PC board  112 . In the first alternative embodiment, light diffuser lenses  120   a - 120   g  are substituted for the light diffuser sheet  20  and are injection molded of the same light diffusing material. 
     With reference to FIGS. 7-8, the mode of operation is similar to that of the preferred embodiment, with the exception that individual light diffuser lenses  220   a - 220   g  are substituted for the light diffuser sheet  20  and are accommodated by the recesses  226   a - 226   g  in the geometric chambers  224   a - 224   g  and are injection molded of the same light diffusing material previously described. The LEDs  218   a - 218   n  project upwardly and directly into the geometric chambers  224   a - 224   g  without passing through any other apertures. 
     With reference to FIGS. 9-12, the mode of operation is similar to that of the preferred embodiment, with the exception that individual light diffuser lenses  320   a - 320   g  are substituted for the light diffuser sheet  20  and are accommodated by the recesses  326   a - 326   g  in the geometric chambers  324   a - 324   g  and are injection molded of the same light diffusing material previously described. Also included in each of the light diffuser lenses  320   a - 320   g  are ramped tabs  325   a - 325   d  which, during installation, force the sides of the individual geometric chambers  324   a - 324   g  and outside edges of the recesses  326   a - 326   g  outwardly for snapping engagement with the ramped tab receivers  340 . The LEDs  318   a - 318   n  project upwardly and directly into the geometric chambers  324   a - 324   g  without passing through any other apertures. 
     Various modifications can be made to the present invention without departing from the apparent scope hereof.