Abstract:
A lighting device is disclosed herein. The lighting device includes an optic holder designed to hold optic elements over a light emitting diode (LED). The optic holders design ensures that the LEDs dome is not damaged during the assembly of the lighting device. Open covers and closed covers are provided in order to allow or block light from the LEDs to come out of the lighting device or to block empty LED locations within the lighting device in order to provide an esthetic looking facade to the lighting device.

Description:
FIELD OF THE INVENTION 
     The present invention relates to lighting devices, more particularly, to lighting devices including optic elements and optic elements holders. 
     BACKGROUND OF THE INVENTION 
     Electrical lighting devices have been used ever since the invention of the electrical light bulb by Thomas Edison in the 19 th  century. 
     The era of semiconductors introduced a new lighting device known as a “light emitting diode” (LED) which can produce light using a very compact form factor. The latest LEDs are mounted onto printed circuit boards (PCBs) as surface mounted devices (SMDs) which do not require through holes to be drilled through the PCB. 
       FIG. 1  of the prior art is an isometric view of an SMD LED assembly  101 . The LED assembly  101  includes an LED  101   a , an LED package  101   b  and an LED dome  101   d . The LED package  101   b  has an LED package side wall  101   c , LED package longitudinal length  101   ca , LED package lateral length  101   cb  and LED assembly height  101   cc.    
     The SMD LED assembly  101  connects to the electrical circuit by means of an LED assembly cathode  101   e  and an LED assembly anode  101   f.    
       FIG. 2   a  of the prior art is a bottom view schematic illustration of an optic element  13  used to disperse the light emitted by an LED  101   a.    
     The light emitted by the LED  101   a  is placed within the optic element hole  13   a  and its light is evenly dispersed by the optic element  13 . Should the optic element  13  or the LED dome  101   d  sustain damage (scratches, deformations, pressure, etc.), the light will not disperse evenly from the lighting device or the LED will be damaged. 
     Part of the optic element  13  can have a cone shape, with a circular cross section, and with an optic element cone angle  13   b.    
       FIG. 2   b  of the prior art is a top view schematic illustration of an optic element  13  used to disperse the light emitted by the LED  101   a  upon which the section plane a-a is marked. 
       FIG. 2   c  of the prior art is a cross sectional view a-a of an optic element  13 . 
     The present illustration depicts the optic element hole  13   a  into which the LED assembly  101  is inserted. 
       FIG. 3   a  of the prior art is an exploded schematic illustration of a prior art optic holder  90 . 
     The prior art optic holder  90  is composed of a prior art optic holder body  91 , an LED assembly  101  and an optic element  13 . 
       FIG. 3   b  of the prior art is a top view schematic illustration of a prior art optic holder  90 . The present illustration shows that the prior art optic holder body longitudinal length  91   a  and the prior art optic holder body lateral length  91   b  are smaller than the LED package longitudinal length  101   ca  and the LED package lateral length  101   cb , respectively. This relation between these dimensions increases the risk that the prior art optic holder  90  would damage the LED dome  101   d  during the assembly process. 
     The current assembly process includes gluing the prior art optic holder  90  to the LED assembly  101  or to the printed circuit board (PBC) onto which it is assembled. The gluing of the prior art optic holder  90  is messy, time consuming and very inaccurate and placing it with even the slightest misalignment can cause damage to the LED assembly  101 . 
     Offset position of the LED assembly in PCB can cause the optics to be rotated and change the position of the light beam, or malfunction of the lighting device. 
     There is therefore a need for a lighting device, which has characteristics and an assembly process that minimize the risk of damage to the LED assembly. 
     SUMMARY OF THE INVENTION 
     The background art does not teach or suggest a lighting device, which has characteristics and an assembly process that minimize the risk of damage to the LED assembly. 
     The present invention overcomes these deficiencies of the background art by providing a lighting device with a new optic holder. 
     An embodiment of the present invention is described herein below in which an optic holder which is equipped with several alignment pins, which are longer than the height of the LED assemblies used on the lighting device&#39;s printed circuit board (PCB) as well as an opening which is wider than the LED assemblies used on the lighting device&#39;s PCB. 
     The long alignment pins ensures that the optic holder is kept away from the LED assembly&#39;s dome until the optic holder is mounted onto the PCB and the wide openings in the optic holder ensure that once the optic holder is mounted onto the PCB there is enough room around the LED assemblies so that the optic holder does not touch the LED assemblies in order to minimize the risk of damaging the LED dome. 
     Under the PCB is a thermal pad which is used to dissipate part of the heat generated by the LEDs mounted on the PCB, as well as to provide electrical insulation. 
     The lighting device is also equipped with several open covers and several closed covers. The user of the lighting device may choose the configuration of the open and closed covers in the lighting device, allowing or disallowing light from the LEDs to come out through the covers. 
     Furthermore, the lighting device is encased in a housing which includes several mount tracks, which enable the user to mount the lighting device at various orientations and angles. 
     Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. 
     According to the present invention there is provided a lighting device including: (a) a main assembly including: (i) at least one optic holder, wherein each one of the at least one optic holder includes: (i.i) a holder body, having a holder upper surface and a holder bottom surface, wherein the bottom surface includes at least one holder opening; (i.ii) at least one holder space wall disposed between the holder upper surface and the holder bottom surface, wherein the holder space wall contains a holder space; (i.iii) at least one holder alignment pin disposed on the bottom surface, wherein the holder alignment pin has a predefined holder alignment pin length; (i.iv) at least one holder optic guide, disposed on each one of the holder space walls, inside each one of the at least one holder spaces; (i.v) at least one holder rib disposed on the holder upper surface; (i.vi) at least one holder longitudinal rib disposed on the holder upper surface, and at least one holder lateral rib disposed on the holder upper surface; (i.vii) at least one holder screw hole formed through each one of the holder upper surfaces; and (i.viii) at least one holder pin hole, formed through each one of the holder upper surfaces, wherein each one of the at least one holder openings has a predefined opening longitudinal length, and a predefined opening lateral length, wherein each one of the at least one holder optic guide has an holder optic guide end  11   ga , wherein there is a predefined holder optic guide end angle between the holder optic guide end and the holder bottom surface; (ii) at least one printed circuit board, having a printed circuit board body, wherein the at least one printed circuit board, is securely connected to the at least optic holder, wherein each one of the at least one printed circuit board includes: (ii.i) at least one header connector securely connected to the printed circuit board body, wherein the at least one printed circuit board, has at least one printed circuit alignment pin hole formed through each one of the at least one printed circuit board body; (iii) at least one thermal pad having a thermal pad body wherein the at least one thermal pad is disposed on each one of the at least one printed circuit board; (iv) at least one open covers, having an open cover weight value, mounted on the at least one optic holder, the at least one open covers includes: (iv.i) an open cover body; (iv.ii) a cover opening formed through the open cover body; and (iv.iii) at least one open cover pin disposed on the open cover body, wherein the holder body applies force on all of the at least one open cover pins, of one of the at least one open covers; (v) at least one light emitted diode assembly having a light emitting diode assembly height, wherein the at least one light emitted diode assembly is securely connected to the at least one printed circuit board body, and wherein the at least one light emitted diode assembly includes: (v.i) a light emitted diode package having a light emitted diode package longitudinal length, and a light emitted diode package lateral length; (v.ii) a light emitted diode securely connected to the light emitted diode package; and (v.iii) a light emitted diode dome light emitted diode package, wherein each one of the holder openings has a predefined opening longitudinal length, and a predefined opening lateral length, wherein the predefined opening longitudinal length is substantially larger than the light emitted diode package longitudinal length and wherein the predefined opening lateral length is substantially larger than the light emitted diode package lateral length, wherein the at least one holder alignment pin length is substantially larger than the at least one of the light emitting diode package height; (vii) at least one optic element, mounted inside of each one of the at least one holder opening, wherein the at least one optic element has an optic element hole, and wherein the at least one optic element has an optic element cone angle, wherein the optic element cone angle is compatible with the holder optic guide end angle; and (viii) at least one main assembly screw mounted through one of the at least one holder screw hole. 
     According to the present invention there is provided the lighting device further including: (b) a housing, wherein the main assembly is located inside the housing, and wherein the housing includes: (i) a housing body; (ii) an exterior cover mounted on the housing, wherein the exterior cover is at least partially transparent to light; and (iii) at least one screws holder mounted inside the housing, wherein the at least one main assembly screw is screwed into the at least one screws holder. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein: 
         FIG. 1  of the prior art is an isometric view of an SMD LED assembly. 
         FIG. 2   a  of the prior art is a bottom view schematic illustration of an optic element used to disperse the light emitted by an LED. 
         FIG. 2   b  of the prior art is a top view schematic illustration of an optic element used to disperse the light emitted by the LED upon which the section plane a-a is marked. 
         FIG. 2   c  of the prior art is a cross sectional view a-a of an optic element. The present illustration depicts the optic element hole into which the LED assembly is inserted. 
         FIG. 3   a  of the prior art is an exploded schematic illustration of a prior art optic holder. 
         FIG. 3   b  of the prior art is a top view schematic illustration of a prior art optic holder. 
         FIG. 4  is an isometric schematic illustration of a lighting device, according to the present invention. 
         FIG. 5  is an exploded schematic illustration of a lighting device, according to the present invention. 
         FIG. 6   a  is a top view schematic illustration of a lighting device upon which section planes b-b and c-c are marked, according to the present invention. 
         FIG. 6   b  is a cross sectional view b-b of a lighting device, according to the present invention. 
         FIG. 6   c  is a cross sectional view c-c of a lighting device, according to the present invention. 
         FIG. 7  is an isometric schematic illustration of a main assembly, according to the present invention. 
         FIG. 8   a  is an isometric schematic illustration of an optic holder, according to the present invention. 
         FIG. 8   b  is a top view schematic illustration of an optic holder upon which section planes d-d and e-e are marked, according to the present invention. 
         FIG. 8   c  is a bottom view schematic illustration of an optic holder, according to the present invention. 
         FIG. 8   d  is a side view schematic illustration of an optic holder, according to the present invention. 
         FIG. 8   e  is a cross sectional view e-e of an optic holder, according to the present invention. The illustration marks detail A in a circle, which is magnified in the circle on the bottom side of the illustration. 
         FIG. 8   f  is a cross sectional view d-d of an optic holder, according to the present invention. 
         FIG. 8   g  is a bottom side isometric schematic illustration of an optic holder, according to the present invention. The illustration marks detail B in a circle, which is magnified in the circle on the bottom side of the illustration. 
         FIG. 8   h  is a bottom view schematic illustration of an open cover pin, mounted inside a holder pin hole, according to the present invention. 
         FIG. 9   a  is a top view isometric schematic illustration of a closed cover, according to the present invention. 
         FIG. 9   b  is a bottom view isometric schematic illustration of a closed cover, according to the present invention. 
         FIG. 9   c  is a top view isometric schematic illustration of an open cover, according to the present invention. 
         FIG. 9   d  is a bottom view isometric schematic illustration of an open cover, according to the present invention. 
         FIG. 9   e  is a right side view schematic illustration of a closed cover, according to the present invention. 
         FIG. 9   f  is a left side view schematic illustration of a closed cover, according to the present invention. 
         FIG. 10  is an isometric schematic illustration of two printed circuit boards connected to each other, according to the present invention. 
         FIG. 11  is an isometric schematic illustration of two thermal pads connected to each other, according to the present invention. 
         FIG. 12  is an isometric schematic illustration of housing, according to the present illustration. 
         FIG. 13  is a transverse cross sectional view of a housing body, according to the present illustration. 
         FIG. 14   a  is a front view schematic illustration of an input end cup, according to the present illustration. 
         FIG. 14   b  is a back view schematic illustration of an input end cup, according to the present illustration. 
         FIG. 14   c  is a back view isometric schematic illustration of an input end cup, according to the present illustration. 
         FIG. 14   d  is a top view schematic illustration of an input end cup, according to the present illustration. 
         FIG. 15  is an isometric schematic illustration of a screws holder, according to the present illustration. 
         FIG. 16  is a top view schematic illustration of a lighting device, according to the present invention. 
         FIG. 17  is a top view schematic illustration of an optic holder and a LED assembly, according to the present invention, upon which section plane f-f is marked. 
         FIG. 18  is a cross sectional view f-f of an optic holder, a LED assembly and a printed circuit board, according to the present invention. 
         FIG. 19  is a left-bottom view isometric schematic illustration of an optic holder, a printed circuit board and a thermal pad, according to the present invention. 
         FIG. 20  is a top view isometric schematic illustration of a part of an optic holder and of an optic element, according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     The present invention is of a lighting device. 
     The principles and operation of a lighting device according to the present invention may be better understood with reference to the drawings and the accompanying description. 
     Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. 
     Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, dimensions, methods, and examples provided herein are illustrative only and are not intended to be limiting. 
     The following list is a legend of the numbering of the application illustrations:
           1  lighting device     10  main assembly     11  optic holder     11   a  holder body     11   b  holder opening     11   ba  opening longitudinal length     11   bb  opening lateral length     11   c  holder screw hole     11   d  holder pin hole     11   e  holder upper surface     11   f  holder bottom surface     11   g  holder optic guide     11   ga  holder optic guide end     11   gb  holder optic guide end angle     11   i  holder end pin     11   j  holder end hole     11   ie  holder first end     11   je  holder second end     11   k  holder alignment pin     11   ka  holder alignment pin length     11   m  holder longitudinal rib     11   n  holder lateral rib     11   p  holder space     11   q  holder space wall     13  optic element     13   a  optic element hole     13   b  optic element cone angle     14  open cover     14   a  open cover body     14   b  cover opening     14   d  open cover pin     14   e  open cover leg     14   w  open cover weight     15  closed cover     15   a  closed cover body     15   b  cover longitudinal side wall     15   c  cover lateral side wall     15   d  closed cover pin     15   e  closed cover leg     15   w  closed cover weight     16  printed circuit board (PCB)     16   a  circuit board body     16   b  header connector     16   c  circuit boards connector     16   d  printed circuit board screw hole     16   e  printed circuit alignment pin hole     17  thermal pad     17   a  thermal pad body     17   b  thermal pad screw hole     18  main assembly screws     20  housing     21  housing body     21   a  exterior cover track     21   b  end cup screws track     21   c  screws holder track     21   d  tunnel     21   e  mount track     21   f  carrier     21   g  carrier side wall     22  exterior cover     23  input end cup     23   a  end cup front wall     23   b  end cup side wall     23   c  end cup screw hole     23   d  end cup opening     23   e  end cup partition     23   f  end cup pin     24  output end cup     25  end cup screws     26  screws holder     26   a  screws holder base rib     26   b  screws holder perpendicular rib     26   c  screws holder internal thread     90  prior art optic holder     91  prior art optic holder body     91   a  prior art optic holder body longitudinal length     91   b  prior art optic holder body lateral length     101  LED assembly     101   a  LED     101   b  LED package     101   c  LED package side wall     101   ca  LED package longitudinal length     101   cb  LED package lateral length     101   d  LED dome     101   cc  LED assembly height     101   e  LED assembly cathode     101   f  LED assembly anode   F force       

     Referring now to the drawings,  FIG. 4  is an isometric schematic illustration of a lighting device  1 , according to the present invention. 
     The lighting device  1  described in the present illustration contains four open covers  14  and four closed covers  15 . 
     The present invention allows for various combinations of open covers  14  and closed covers  15 , according to user requirements, and is not limited in any way to eight covers. 
       FIG. 5  is an exploded schematic illustration of one embodiment of a lighting device  1 , according to the present invention. 
     The present illustration shows the two main assemblies in the lighting device  1 : the main assembly  10  and the housing  20 . 
     The main assembly  10  contains several open covers  14  and closed covers  15 , thermal pads  17 , printed circuit boards  16 , optic holder  11 , optic elements  13  and several main assembly screws  18 , which hold the main assembly&#39;s  10  components together. 
     The present invention is not limited in any way to two elements as shown in the specific case of the present illustration, such as the example of two optic holders  11 , two thermal pads  17 , and two printed circuit boards  16 . 
     According to the present invention, the main assembly  10  can include, for example one optic holder  11  or more than one optic holder  11 . Likewise for other elements mentioned here. 
     According to the present invention, the main assembly  10  includes at least one LED assembly  101 , with the present illustration showing eight. 
     The housing  20  contains a housing body  21 , an exterior cover  22 , an input end cup  23 , an output end cup  24 , screws holders  26  and several end cup screws  25  which hold the housing&#39;s  20  components together. 
       FIG. 6   a  is a top view schematic illustration of a lighting device  1  upon which the section plane b-b and c-c are marked, according to the present invention. 
       FIG. 6   b  is a cross sectional view b-b of a lighting device  1 , according to the present invention. 
     The present illustration shows the section plane b-b, which crosses the lighting device  1  at the location of a main assembly screw  18 . The main assembly screw  18  is held in place by the screws holder  26 , which has corresponding screw threading to accommodate the main assembly screws  18 . The main assembly screws  18  go through and optic holder  11 , the printed circuit board  16  and the thermal pad  17 , and holds them together. 
     Above the optic holder  11  is a closed cover  15  which is used to block the light emitted by the LED  101   a  (not shown in the present illustration) located under the closed cover  15 , or to cover a place without any installed LED assembly  101  and optic element  13 , (both not shown in the present illustration). 
     In order to allow the light emitted by the LED  101   a  (not shown in the present illustration) to come out of the lighting device  1 , an open cover  14  may be used. Each LED  101   a  location may have either an open cover  14  or a closed cover  15 , according to the users&#39; needs. 
     The lighting device  1  is closed by an exterior cover  22 , which is transparent to allow light through it yet to provide mechanical protection to the main assembly&#39;s  10  components of the lighting device  1 . 
     The main assembly  10  is held within the housing body  21 , which is closed from the sides with the input end cup  23  and the output end cup  24  (both not shown in the present illustration), which are held in place by the end cup screws  25 . 
       FIG. 6   c  is a cross sectional view c-c of a lighting device  1 , according to the present invention. 
     The present illustration shows the section plane c-c, which crosses the lighting device  1  at the location of an LED assembly  101 . Above the LED assembly  101  is an optic element  13  and an open cover  14 . 
       FIG. 7  is an isometric schematic illustration of a main assembly  10 , according to the present invention. 
     The present figure shows the assembled view of the main assembly  10 . 
       FIG. 8   a  is an isometric schematic illustration of an optic holder  11 , according to the present invention. 
     The structure of the optic holder  11  ensures that the LED assembly  101  will not be damaged during the assembly of the lighting device  1 . Further details are given in the following figures. 
     The embodiment of the optic holder  11  of the present figure depicts four openings for optic elements  13 , but other configurations may be possible such as one, two, three or more openings in each optic holder. 
     Each optic holder  11  includes a holder first end  11   ie  and a holder second end  11   je.    
       FIG. 8   b  is a top view schematic illustration of an optic holder  11  upon which the section plane d-d and e-e are marked, according to the present invention. 
     The optic holder&#39;s  11  main part is the holder body  11   a  in which there are several holder openings  11   b . Between every two holder openings  11   b , there is a holder screw hole  11   e  and around each holder openings  11   b  there are four holder pin holes  11   d . A different number of holder pin holes  11   d  can be used. 
       FIG. 8   c  is a bottom view schematic illustration of an optic holder  11 , according to the present invention. 
     The bottom side of the optic holder  11  is equipped with a holder end pin  11   i  (not shown in the present illustration), and a holder end hole  11   j . In order to attach two optic holders  11 , the holder end pin  11   i  of one optic holder  11  is inserted into the holder end hole  11   j  of another optic holder  11 . 
       FIG. 8   d  is a side view schematic illustration of an optic holder  11 , according to the present invention. 
     The present illustration shows the holder upper surface  11   e , the holder bottom surface  11   f  and two holder alignment pins  11   k  (other embodiments may have more or less than two holder alignment pins  11   k ). 
       FIG. 8   e  is a cross sectional view e-e of an optic holder  11 , according to the present invention. The illustration marks detail A in a circle, which is magnified in the circle on the bottom side of the illustration. 
     Detail A illustrates the structure of the holder optic guide  11   g  used to house an optic element  13 , (not shown in the present illustration), in the optic holder  11 . The holder optic guide  11   g  has a holder optic guide end  11   ga . The angle between the holder optic guide end  11   ga  and the holder bottom surface  11   f  is the holder optic guide end angle  11   gb  and is designed to fit an optic element  13 , which also helps to prevent the infliction of scratches upon LED dome  101   d  during production of the main assembly  10 , (not shown in the present illustration). 
     In addition, detail A illustrates a holder alignment pin  11   k  and its length: holder alignment pin length  11   ka . The holder alignment pin length  11   ka  is set so that it is greater than LED assembly height  101  cc, (not shown in the present illustration, shown in  FIG. 1 ) in order to ensure that unless the holder alignment pin  11   k  is inserted into the printed circuit board alignment pin hole  16   e  (not shown in the present illustration, shown in  FIG. 10 ), the holder bottom surface  11   f  is higher than the top of the LED dome  101   d  and there cannot be any contact between them leading to damage to the LED dome  101   d.    
       FIG. 8   f  is a cross sectional view d-d of an optic holder  11 , according to the present invention. 
     In the present illustration, it is possible to see the holder body  11   a  and the holder alignment pin  11   k  which is located near the holder opening  11   b.    
       FIG. 8   g  is a bottom side isometric view schematic illustration of an optic holder  11 , according to the present invention. 
     The illustration marks detail B in a circle, which is magnified in the circle on the bottom side of the illustration. Detail B depicts the smaller details surrounding the holder opening  11   b  such as the holder lateral ribs  11   n  and holder longitudinal ribs  11   m  which are used to enhance the structural integrity of the optic holder  11 . 
     Other embodiments may use solid blocks of material rather than thin ribs for this purpose and the ribs themselves may have other shapes than the ones shown in the present illustration. The ribs may be longitudinal, lateral, diagonal, curved, etc. and the description brought here is not meant to limit the present invention. 
     Two important dimensions illustrated in detail B are the opening longitudinal length  11   ba  and the opening lateral length  11   bb  which are designed to be substantially larger than the LED package longitudinal length  101   ca  and the LED package lateral length  101   cb  so that once the optic holder  11  is mounted onto the printed circuit board  16 , there is sufficient distance between the optic holder  11  and the LED assembly  101 . 
       FIG. 8   h  is a bottom view schematic illustration of an open cover pin  14   d , mounted inside a holder pin hole  11   d , according to the present invention. 
     The present illustration shows a small segment of a holder body  11   a , around the holder pin hole  11   d.    
     The holder body  11   a  applies force F on the open cover pin  14   d . The strength of force F is sufficient to enable manual assembly, without use of any tools, of open cover  14 , (not shown in the present illustration, shown in  FIG. 9   d ), or closed cover  15  (not shown in the present illustration, shown in  FIG. 9   b ) and ensures their good attachment for all practical purposes to the optic holder  11 , (not shown in the present illustration, shown in  FIG. 8   g ). The sum of force F applied to each one of the open cover pins  14   d  of each one of the open covers  14  (not shown in the present illustration, shown in  FIG. 9   c ) is no smaller than twice the value of the open cover weight  14   w  and no larger than eight times the value of the open cover weight  14   w.    
     This also applies to the force F applied to the closed cover pins  15   d , (not shown in the present illustration, shown in  FIG. 9   d ). 
       FIG. 9   a  is a top view isometric schematic illustration of a closed cover  15 , according to the present invention. 
     The closed cover  15  has a closed cover body  15   a  which is solid and does not allow any light to pass through it. 
     An additional option according to the present invention is using a closed cover  15 , which enables filtering light. 
     LED assembly  101  and optic element  13  (both not shown in the present illustration). 
       FIG. 9   b  is a bottom view isometric schematic illustration of a closed cover  15 , according to the present invention. 
     On the bottom side of the closed cover  15  are two (or more) closed cover pins  15   d . The closed cover pins  15   d  are inserted into the holder pin hole  11   d  (not shown in the present illustration, shown in  FIG. 8   b ) and its size is so that the friction between the closed cover pins  15   d  and the walls of the holder pin hole  11   d  hold the closed cover  15  in its place. 
     In addition, there are closed cover legs  15   e  which are used to elevate the closed cover  15  from the optic holder  11  (not shown in the present illustration, shown in  FIG. 8   a ). 
       FIG. 9   c  is a top view isometric schematic illustration of an open cover  14 , according to the present invention. 
     The open cover  14  has an open cover body  14   a , which includes a cover opening  14   b . The cover opening  14   b  is used to enable light to pass through the open cover  14 . 
     The open cover  14  has an open cover weight  14   w.    
       FIG. 9   d  is a bottom view isometric schematic illustration of an open cover  14 , according to the present invention. 
     Just like the closed cover  15 , the bottom side of the open cover  14  includes two (or more) open cover pins  14   d . The open cover pins  14   d  are inserted into the holder pin hole  11   d  (not shown in the present illustration, shown in  FIG. 8   b ) and its size is so that the friction between the open cover pins  14   d  and the walls of the holder pin hole  11   d  hold the open cover  14  in its place. 
     In addition, there are open cover legs  14   e , which are used to elevate the open cover  14  from the optic holder  11  (not shown in the present illustration, shown in  FIG. 8   a ). 
       FIG. 9   e  is a right side view schematic illustration of a closed cover  15 , according to the present invention. 
     The right side view of the closed cover  15  shows the cover longitudinal side wall  15   b.    
     This view also presents open cover  14 . 
       FIG. 9   f  is a left side view schematic illustration of a closed cover  15 , according to the present invention. 
     The left side view of the closed cover  15  shows the cover lateral side wall  15   c.    
     This view also presents open cover  14 . 
     The closed cover  15  has a closed cover weight  15   w.    
       FIG. 10  is an isometric schematic illustration of two printed circuit boards  16  connected to each other, according to the present invention. 
     The circuit board  16  has a circuit board body  16   a . In order to use modular components it is preferred to have short printed circuit boards  16  which normally consist of three or four LED assemblies  101 . When longer lighting devices  1  are needed it is possible to connect several circuit boards  16  in series using several circuit boards connectors  16   c . The present illustration depicts two printed circuit boards  16  connected to each other using four circuit boards connectors  16   c.    
     The header connectors  16   b  are used to connect the lighting device  1  to an external control unit. 
     Each printed circuit board  16  is equipped with several printed circuit board screw holes  16   d  and several printed circuit board alignment pin hole  16   e . According to the number of LED assemblies  101  mounted on the printed circuit boards  16 . 
       FIG. 11  is an isometric schematic illustration of two thermal pads  17  connected to each other, according to the present invention. 
     The thermal pad  17  is designed so that its size corresponds to the size of the printed circuit board  16  as the thermal pad  17  is assembled directly under the printed circuit board  16 . The thermal pad  17  has a thermal pad body  17   a  and several thermal pad screw holes  17   b  according to the number of printed circuit board screw holes  16   d  (not shown in the present illustration, shown in  FIG. 10 ). 
     In addition, the thermal pad  17  is used to electrically isolate the printed circuit board  16 , (not shown in the present figure, shown in  FIG. 13 ), from the housing body  21 , (not shown in the present figure, shown in  FIG. 10 ), as well as to apply constant pressure on the main assembly screws  18  (not shown in the present figure, shown in  FIG. 6   b ). 
       FIG. 12  is an isometric schematic illustration of a housing  20 , according to the present illustration. 
     The present illustration shows an assembled housing  20 , absent the main assembly  10 . 
       FIG. 13  is a transverse cross sectional view of a housing body  21 , according to the present illustration. 
     The major components of the housing body  21  are the exterior cover track  21   a , end cup screws track  21   b , screws holder track  21   c , tunnel  21   d , mount track  21   e  and carrier  21   f.    
     Mount track  21   e  also serves as a cooling rib and for the purpose of attachment to infrastructure. 
       FIG. 14   a  is a front view schematic illustration of an input end cup  23 , according to the present illustration. 
     The input end cup  23  has an end cup front wall  23   a  on which the “INPUT” designation may be noted for ease of use. 
       FIG. 14   b  is a back view schematic illustration of an input end cup  23 , according to the present illustration. 
     On the back side of the input end cup  23  is the end cup partition  23   e.    
       FIG. 14   c  is a back view isometric schematic illustration of an input end cup  23 , according to the present illustration. 
     Depicted in the present illustration are the end cup front wall  23   a , end cup side wall  23   b , end cup opening  23   d , end cup partition  23   e , and end cup pins  23   f.    
       FIG. 14   d  is a top view schematic illustration of an input end cup  23 , according to the present illustration. 
     The top view of the input end cup  23  shows the end cup front wall  23   a , end cup side wall  23   b , end cup partition  23   e  and end cup pins  23   f.    
       FIG. 15  is an isometric schematic illustration of a screws holder  26 , according to the present illustration. 
     The screws holder  26  includes a screws holder base rib  26   a  which serves as the basis of the screws holder  26 . The top part of the screws holder  26  is the screws holder perpendicular rib  26   b  into which several screws holder internal thread  26   c  are formed. The number of screws holder internal thread  26   c  is the same as the number of main assembly screws  18  (not shown in the present illustration, shown in  FIG. 5 ) that are used in the assembly of the lighting device  1 . 
       FIG. 16  is a top view schematic illustration of a lighting device  1 , according to the present invention. 
     The lighting device  1  shown in the present illustration includes eight possible locations for LED assemblies  101 . Of these eight locations, two are covered with open covers  14  and two are covered with closed covers  15 . The other four locations do not have any covers and the optic holder  11  is visible at these locations. At two locations there are LED assemblies  101  mounted on the printed circuit board  16 . 
     The present invention is very versatile with regard to many other possible combinations 
       FIG. 17  is a top view schematic illustration of an optic holder  11  and a LED assembly  101 , according to the present invention, upon which section plane f-f is marked. 
     In the present illustration, the optic holder  11  has only one location for a LED assembly  101  but other embodiments may have more locations. 
     The present illustration shows that the LED assembly  101  is located in the middle of the holder opening  11   b . It is also possible to see that the opening longitudinal length  11   ba  and the opening lateral length  11   bb  are substantially larger than twice the LED package longitudinal length  101   ca  and the LED package lateral length  101   cb , respectively. These size differences contribute to the minimization of risk to the LED dome  101   d.    
       FIG. 18  is a cross sectional view f-f of an optic holder  11 , a LED assembly  101 , and a printed circuit board  16 , according to the present invention. 
     This cross-section shows that the holder body  11   a  has a holder alignment pin  11   k  that only if the holder alignment pin  11   k  is inserted into the printed circuit alignment pin hole  16   e , will the optic holder  11  be able to be mounted onto the printed circuit board  16 . The locations of the holder alignment pin  11   k  and printed circuit alignment pin hole  16   e  are designed so that the LED assembly  101  would be located in the center of the holder opening  11   b.    
     The holder alignment pin length  11   ka  is larger than the LED assembly height  101   cc , to ensure no contact between the LED assembly  101  and the holder bottom surface  11   f  at any stage prior to insertion of the holder alignment pin  11   k  into the printed circuit alignment pin hole  16   e.    
       FIG. 19  is a left-bottom view isometric schematic illustration of an optic holder  11 , a printed circuit board  16  and a thermal pad  17 , according to the present invention. 
     In the underside of the optic holder  11  it is possible to see the holder longitudinal ribs  11   m  and holder lateral ribs  11 . 
     This structure of the optic holder  11  ensures good fastening to the thermal pad  17 . 
       FIG. 20  is top view isometric schematic illustration of a part of an optic holder  11  and of an optic element  13 , according to the present invention. 
     The present illustration depicts the way the optic element  13  is inserted into the optic holder  11 . The optic element  13  is inserted into the holder space  11   p  which is designed to accommodate the optic element  13  and includes several holder optic guides  11   g  (normally, four or more) that while the optic element  13  is inserted into the holder space  11   p , ensuring that the optic element  13  slides directly into its place without touching the LED dome  101   d  thereby possibly damaging it. 
     Furthermore, the holder optic guides  11   g  provide leverage to the optic element  13  after assembly. 
     The bottom of the holder space  11   p  is the holder opening  11   b  and the holder space walls  11   q  enclose the holder space  11   p.    
     While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made.