Abstract:
Presented is a multi parameter automated luminaire comprised of a plurality of light engine modules a plurality of which by design homogenize light emitted by its light sources more fully than at least one of the light engine modules which is intentionally designed to noticeably not fully homogenize the light emitted by its light sources. In the preferred embodiment the non homogenizing light engine module also includes light modulator(s) optionally engagable to more fully homogenize the light output from that light engine module.

Description:
TECHNICAL FIELD OF THE INVENTION 
       [0001]    The present application is a continuation in part of: 15075191 US Patent Application filed 20 Mar. 2016. 
       TECHNICAL FIELD OF THE INVENTION 
       [0002]    The present invention generally relates to a method for providing a wash light luminaire, specifically to optical systems and a method relating to providing single and multiple beams from a wash luminaire. 
       BACKGROUND OF THE INVENTION 
       [0003]    Luminaires with automated and remotely controllable functionality are well known in the entertainment and architectural lighting markets. Such products are commonly used in theatres, television studios, concerts, theme parks, night clubs and other venues. A typical product will provide control over the functions of the luminaire allowing the operator to control the intensity and color of the light beam from the luminaire that is shining on the stage or in the studio. Many products also provide control over other parameters such as the position, focus, beam size, beam shape and beam pattern. In such products that contain light emitting diodes (LEDs) to produce the light output it is common to use more than one color of LEDs and to be able to adjust the intensity of each color separately such that the output, which comprises the combined mixed output of all LEDs, can be adjusted in color. For example, such a product may use red, green, blue, and white LEDs with separate intensity controls for each of the four types of LED. This allows the user to mix almost limitless combinations and to produce nearly any color they desire. 
         [0004]      FIG. 1  illustrates a typical multiparameter automated luminaire system  10 . These systems typically include a plurality of multiparameter automated luminaires  12  which typically each contain on-board a light source (not shown), light modulation devices, electric motors coupled to mechanical drives systems and control electronics (not shown). In addition to being connected to mains power either directly or through a power distribution system (not shown), each luminaire is connected is series or in parallel to data link  14  to one or more control desks  15 . The luminaire system  10  is typically controlled by an operator through the control desk  15 . 
         [0005]    Luminaires have been provided using non-LED light sources designed to produce a single narrow beam or a plurality of such beams. Such luminaires may use low etendue, HID light sources with a small arc gap in order to facilitate the production of tight, almost parallel light beams. U.S. patent application Ser. Nos. 14/042,758 and 14/042,759 provide examples of such a system. Single and multi-color LED sourced luminaires have also been produced with narrow beam capability using sophisticated collimation systems as, for example, disclosed in U.S. patent application Ser. No. 14/405,355. LEDs however are high etendue light sources by comparison with HID and it is difficult to produce multiple beam systems using LED light sources. 
         [0006]    Prior art optical systems utilizing multiple LED emitters may be unforgiving when it is desired to produce a homogeneous image with a light output capable of being blended between units to provide seamless coverage. This mode of operation is often called a Wash light as it washes the stage with light. Prior art systems will commonly utilize multiple LED light sources and attempt to blend them into a homogeneous whole. This approach is often unsuccessful because the individual differently colored LED emitters are still visible producing a multi-colored effect when viewing the light rather than the desired appearance of a single color. Other prior art systems use a secondary lens but that has the that the output lens may not then be filled completely and all the light will appear to be emitted from a portion at the centre of the output lens. This reduces the performance of the luminaire as a wash light as it is an important feature of wash luminaires that the effective light source be as large as possible in order to soften and reduce shadowing. 
         [0007]    There is a need for a method for producing and controlling a light beam or multiple light beams from an LED sourced wash light luminaire to produce controllable lighting effects from a luminaire with a wash light distribution with a large effective source and true blending output distribution. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings in which like reference numerals indicate like features and wherein: 
           [0009]      FIG. 1  illustrates a multiparameter automated luminaire lighting system; 
           [0010]      FIG. 2  illustrates the layout of embodiments of major components of a light engine of a luminaire generating a flower effect; 
           [0011]      FIG. 3  illustrates more detail of some of embodiments of the major components and layout of the light engine illustrated in  FIG. 2 ; 
           [0012]      FIG. 4  illustrates and embodiment of additional support structure for the light guide assembly; 
           [0013]      FIG. 5  illustrates an embodiment of a light guide without any supporting structure; 
           [0014]      FIG. 6  illustrates detail of an embodiment of the optical softening diffuser; 
           [0015]      FIG. 7  illustrates a luminaire including an embodiment of the light guide; 
           [0016]      FIG. 8  illustrates  FIG. 7  with the output lenses in place; 
           [0017]      FIG. 9  illustrates detail of an embodiment of the optical system with the lenses in the wide angle position; 
           [0018]      FIG. 10  illustrates detail of an embodiment of the optical system with the lenses in the narrow angle position; 
           [0019]      FIG. 11  illustrates a complete luminaire used in a lighting system illustrated in  FIG. 1 ; 
           [0020]      FIG. 12  illustrates detail of a lens of the optical system; 
           [0021]      FIG. 13  illustrates, in line drawing form, a front facing view of the design of the front face of the output lenses of an embodiment of the unique luminaire; 
           [0022]      FIG. 14  illustrates, in line drawing form, an isometric view of the design of the front face of  FIG. 13 ; 
           [0023]      FIG. 15  illustrates a rendering of the front facing view of the design of the unique output face a unique luminaire; 
           [0024]      FIG. 16  illustrates a rendering of an isometric view of the design of the output face of  FIG. 15 ; 
           [0025]      FIG. 17  illustrates a rendering front facing view of the output face of  FIG. 15  in situ on a multi parameter automated luminaire; and 
           [0026]      FIG. 18  illustrates a rendering isometric view of the output face of  FIG. 15  in situ on a multi parameter automated luminaire. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0027]    Preferred embodiments of the present invention are illustrated in the Figures, like numerals being used to refer to like and corresponding parts of the various drawings. 
         [0028]    The present invention generally relates to a method for providing special effects in wash light luminaires, specifically to a method relating to providing controllable lighting effects from a luminaire with a wash light distribution with a large effective source and true blending output distribution. 
         [0029]      FIG. 2  illustrates the layout of embodiments of major components of one light engine of a luminaire generating a flower effect. Light emitting module  20  comprises a single LED or an array of LEDs, which may include a primary optic (not shown). Light emitting module  20  may contain a single color of LEDs or may contain multiple dies, each of which may be of common or differing colors. For example, in one embodiment light emitting module  20  may comprise one each of a Red, Green, Blue and White LED. In further embodiments Light emitting module  20  may comprise a single LED chip or package while in yet further embodiments Light emitting module  20  may comprise multiple LED chips or packages either under a single primary optic or each package with its own primary optic. In some embodiments these LED die(s) may be paired with optical lens element(s) as part of the LED light-emitting module. In a further embodiment light emitting module  20  may comprise more than four colors of LEDs. For example, seven colors may be used, one each of a Red, Green, Blue, White, Amber, Cyan, and Deep Blue/UV LED die. 
         [0030]    The light output from the LEDs in light emitting module  20  enters light guide optic  22  contained within protective sleeve  24 . Light guide  22  may be a device utilizing internal reflection so as to collect, homogenize and constrain and conduct the light to exit port  23 . Light guide  22  may be a hollow tube with a reflective inner surface such that light impinging into the entry port may be reflected multiple times along the tube before leaving at the exit port  23 . Light guide  22  may be a square tube, a hexagonal tube, a heptagonal tube, an octagonal tube, a circular tube, or a tube of any other cross section. In a further embodiment light guide  22  may be a solid rod constructed of glass, transparent plastic or other optically transparent material where the reflection of the incident light beam within the rod is due to “total internal reflection” (TIR) from the interface between the material of the rod and the surrounding air. The integrating rod may be a square rod, a hexagonal rod, a heptagonal rod, an octagonal rod, a circular rod, or a rod of any other cross section. Light guide  22 , whether solid or hollow, and with any number of sides, may have entry port  21  and exit port  23  that differ in cross sectional shape. For example, a square entry port  21  and an octagonal exit port  23 . Further light guide  22  may have sides which are tapered so that the entrance aperture is smaller than the exit aperture. The advantage of such a structure is that the divergence angle of light exiting the guide  22  at exit port  23  will be smaller than the divergence angle for light entering the guide. The combination of a smaller divergence angle from a larger aperture serves to conserve the etendue of the system. Thus a tapered guide  22  may provide similar functionality to a condensing optical system. In a preferred embodiment of the light guide  22  has both a square entry port  21  and a square exit port  23 . For the desired flower reminiscent effect, it is advantageous to use shapes with opposing sides and to have the same shape cross section along the length of the guide  22 . 
         [0031]    Light guide  22  may have an aspect ratio where its length is much greater than its diameter. The greater the ratio between length and diameter, the better the resultant mixing and homogenization will be. Guide  22  may be enclosed in a tube or sleeve  24  that provides mechanical protection against damage, scratches, and dust. In the preferred embodiment light integrating tube  22  is of such a length so as to collimate and direct but deliberately provide incomplete homogenization of the light coming from individual LEDs on light emitting module  20 . This incomplete homogenization may be advantageously utilized in the remainder of the optical system. Similarly, the exit port of light guide  22  is polished, rather than being diffused or textured, to maintain the incomplete homogenization of the input light beams. In one embodiment the beams are less than 50% homogenized such that individual beams or colors from separate LEDs are still clearly visible. 
         [0032]    Light guide  22  within its protective sleeve  24  is mounted such that it may be freely rotated along its long, optical, axis through gears  32  and motor (not shown) supported by bearing  66 . Rotating light guide  22  will cause the emitted light beams from exit port  23  to also rotate around the optical axis of the system. In fact, the light beam movement and rotation will be complex, as a function of the rotation of the input port of light guide  22  across the array of LEDs in fixed light emitting module  20  and the total internal reflection within the rotating light guide. Thus the light beams exiting the light guide  22  will present a complex and dynamic pattern of moving beams. Light guide  22  may be rotated in either direction and at any speed under control of the operator. 
         [0033]    With the invention in its basic form, the light from the exit port  23  of light guide  22  will be directed towards and through lens  40  that serves to further control the angle of the emitted light beam. Lens  40  may be moved towards and away from light guide  22  in the direction along the optical axis of the system shown by line  41 . In the position where lens  40  is at its furthest separation from the exit port  23  of light guide  22  the emitted light beam will have a narrow beam angle. In the position where lens  40  is at its closest separation from the exit port  23  of guide  22  the emitted light beam will have a wide beam angle. Intermediate positions of lens  40  with respect to exit port  23  of light guide  22  will provide intermediate beam angles. Lens  40  may advantageously be configured as an achromat so as to minimize chromatic aberration of the emitted light beam or beams. The system illustrated herein utilizes a single lens element as lens  40  to provide output beam control. The invention is however not so limited, and further embodiments may contain different numbers and types of lenses or other optical systems as well known in the art. In particular, further embodiments may utilize systems where lens  40  comprises multiple elements. In further embodiments lens  40  may comprise a number of optical lens elements whose relationship to each other is not fixed, and can alter. The elements of lens  40  may be meniscus lenses, plano convex lenses, bi-convex lenses, holographic lenses, aspheric lenses, or other lenses as well known in the art. The elements of lens  40  may be constructed of glass, transparent plastic or other optically transparent material as known in the art. 
         [0034]    In a preferred embodiment lens  40  comprises a single element constructed, by the use of aspheric surfaces or otherwise, to exhibit achromatic properties such that the colors in the light beam remain homogenized and do not produce objectionable colored fringing to the light beam. 
         [0035]    With the layout as described the effect from the luminaire will be that of a complex pattern of a plurality of light beams created by the reflection of the individual beams from the LEDs in light emitting module within light guide  22 . As no diffusion or other homogenization is provided, these beams will remain in differing colors and patterns through projection lens system comprising lens  40 . As the light guide  22  is rotated, and lens  40  is moved towards and away from the exit port  23  of light guide  22 , the effect will be that of a flower or spreading pattern of beams that opens and closes as the lenses are moved. 
         [0036]    To change the luminaire into wash light mode instead of beam effect, diffuser arm  26  may be swung across the light beam proximate to exit port  23  of light guide  22 . Diffuser arm may contain a number of diffusers each of which may have different diffusion properties. In the embodiment illustrated diffuser arm  26  is fitted with first diffuser  28  and second diffuser  30 , however further embodiments may have differing numbers of diffusers. In operation diffuser arm  26  is rotated such that one of the diffusers  28  or  30  is positioned proximate to exit port  23  of light guide  22  and will serve to diffuse and homogenize the light beams emitting from exit port  23  before they pass into the remainder of the optical system. The diffuser serves to merge the light beams into a single homogenized beam and to increase the spread of the light beam. Differing strengths or properties of diffuser  28  or  30  may provide narrow or wide homogenized beams without the flower effect or for lower powered diffusers a softening of the flower effect. In this mode of operation Lens  40  will continue to control the overall size of the homogenized beam. 
         [0037]      FIG. 3  illustrates more detail of some of embodiments of the major components and layout of the light engine illustrated in  FIG. 2 . More specifically, in  FIG. 3 , exit port  23  of light guide  22  and the means for moving diffuser  28  and  30  across that exit port can more clearly be seen. Sub  FIG. 3 a    illustrates the system in beam flower effect mode where diffuser arm  26  is rotated such that neither diffuser  28  nor diffuser  30  are positioned across exit port  23 . In this position the undiffused light beam presents the flower effect. 
         [0038]    Motor  33  provides the motion for rotating light guide  22  through drive system  32 , and motor  35  provides the motion for diffuser arm  26 . Similar motors and drive systems as well known in the art provide the motion for lens  40  along the optical axis of the luminaire. Motors  33 , and  35  may be stepper motors, servo motors, linear actuators, solenoids, DC motors, or other mechanisms as well known in the art. In the embodiment shown the motors operate through gear systems. For example, motor  33  drives gear  32 . Other mechanisms for actuating the desired movement as are well known in the art are also contemplated. 
         [0039]    Sub  FIG. 3 b    illustrates the system in wash light mode where diffuser arm  26  is rotated such that diffuser  30  is positioned across exit port  23 . In this position the light beam is diffused by diffuser  30  and presents a homogenized beam without the flower effect. 
         [0040]      FIG. 4  illustrates the light guide assembly including its support structure. Sub  FIGS. 4 a , 4 b , 4 c , and 4 d    show the assembly from fully exploded ( 4   a ) through fully assembled ( 4   d ) to aid comprehension of the structure. Light guide  22  with exit port  23  is inserted into sleeve  24 . Sleeve  24  has, as parts of its structure, bearing support surfaces  64  and  68 . Bearing support surfaces  64  and  68  engage with bearing assemblies  66  and  70  respectively. This allows sleeve  24  (and thus light guide  22 ) to rotate within bearing assemblies  66  and  70 . Also attached to sleeve  24  is gear  62  which meshes with gear  32  shown in  FIG. 6  that is in turn driven by motor  33 . The assembly formed by sleeve  24 , light guide  22 , bearings  66  and  70 , and gear  62 , is supported within holder  72  such that (as shown in  FIG. 4 d   ) light guide  22  protrudes from the base of holder  72  and aligns with light emitting module  20 . This assembly also serves to maintain a small separation between entry port  21  of light guide  22  and light emitting module  20  such that light transfer from light emitting module  20  and light guide  22  is maximized but the two surfaces do not touch. 
         [0041]    It is envisaged that light guide assemblies as shown in  FIG. 4  could be used in multiples or arrays within a single luminaire. For example, an array of rotating light guide assemblies may be used where each light guide is positioned above its own light emitting module. In these embodiments a single motor may drive the rotation of multiple light drive assemblies. 
         [0042]      FIG. 5  illustrates an embodiment of a light guide  22  without its support structure. Light guide  22  contains input port  21  and exit port  23 . In the embodiment illustrated light guide  22  is tapered and has both a square entry port  21  and a square exit port  23 . 
         [0043]      FIG. 6  illustrates detail of an embodiment of the optical softening diffuser arm  26 . Diffuser arm  26  is shown in two positions in  FIG. 6 . In position A, diffuser arm  26  is positioned such that diffuser  30  is across exit port  23  (shown dashed as it is under the diffuser). Also illustrated is an optional feature of diffuser arm  26 . Diffuser  28  includes mask  29  which serves to constrain the light to a masked shape. Mask  29  is an opaque mask with a central open aperture with, in this case, a hexagonal shape. Mask  29  helps to constrain the projected beam into a more rounded, non square, shape. Mask  29  may be of any shape, not just the hexagon illustrated herein, including but not limited to circular, hexagonal, or octagonal. 
         [0044]    In position B, diffuser arm  26  is positioned such that diffuser  28  including mask  29  is across exit port  23  (shown dashed as it is under the diffuser). Diffusers  28  and  30  may offer differing amounts or types of diffusion producing different beam spreads in the output. Diffusers  28  and  30  may be patterned or molded glass, or plastic, or may be holographic diffusers or other diffuser types as well known in the art. Although two different diffusers  28  and  30  are shown here the invention is not so limited and any number of diffusers or homogenizers may be affixed and selected as part of diffuser arm  26 . 
         [0045]      FIG. 7  illustrates the layout of the optical support plate  100  of an alternative embodiment of a wash light with special effects luminaire utilizing a light engine which employs an array of light engine modules. Optical support plate  100  includes a number of LED light sources each with their own associated light guide  104 . In the illustrated embodiment 19 LED light sources arranged with a single centre LED light source having two concentric rings of 6 and 12 LED light sources around it are utilized but in practice use of any number is envisaged. For example, the outer ring may be omitted providing a system with 7 LED light sources, or an extra ring or rings may be added providing larger numbers of LED light sources. The 19 LED light sources and light guides  104  are here arranged in concentric rings but may be also arranged in other configurations. Some percentage of the LED light sources and light guides  104  may be fitted with the optical softening diffuser arm  26  system to provide a module as illustrated in  FIGS. 2 through 6 . In the embodiment illustrated a single central LED light source is fitted with the system as module  120 . In practice any number of the light guides  104  may be fitted with optical softening diffuser system  120 . However, in a preferred embodiment, the use of a single centrally mounted module  120  surrounded by LED light sources with “fully homogenizing” or at least more homogenizing light guides  104  provides a good combination of effects and standard wash light usage. Light guides  104  that are not fitted with optical softening diffuser system  120  may have the exit ports patterned, textured, or diffused or may have diffusion filters similar to  28  and  30  permanently attached to or constructed as part of the exit port of the light guide or the light guides may be otherwise designedly shaped to “fully homogenize” light such that these guides always produce a smooth, homogenized light output. In contrast, light guides  104  that are fitted with optical softening diffuser system  120  may be remotely controlled to produce either a smooth homogenized output, or a harder edged flower effect as desired by inserting or removing the diffusing filters  28  and  30  across the beam. 
         [0046]      FIG. 8  illustrates the system shown in  FIG. 7  with the optical support plate  100 , this time fitted with output lens module  130 . Output lens module  130  contains an array of lenses, equal in number to the LED light sources and associated light guides shown in  FIG. 7 . The lenses may be of differing outline shapes in order to fit together into an aesthetically pleasing design and also to minimize any space wasted in between lenses. Such gaps between lenses may reduce the output of the system, and produce undesirable visible gaps in light output when viewing the luminaire. The design presented here is similar to that of a spider&#39;s web and provides both functional purpose and aesthetic appeal. The lenses, although of differing shapes, may have substantially the same optical properties. For example, central lens  132  may be the same optical strength and provide the same optical effect as edge lens  134 . In other embodiments the lenses associated with LED light sources that are fitted with optical softening diffuser systems  120  such as the lens  132  associated with central module in  FIG. 7  may have the same or different optical properties as the lenses  134  associated with standard LED modules  104 . 
         [0047]      FIGS. 9 and 10  illustrate side elevation views of the system as shown in  FIG. 8 . In  FIG. 9  the lens module  130  containing an array of lenses  134  and  132  is positioned close to the light guides  104  and optical softening diffuser system  120  on the central light engine module. In the embodiment illustrated only the central light engine module is of the reduced homogenization type in a center position. In other embodiments this type of module can be placed in a non central location. In further embodiments there may be more than one of these types of light engine modules. While the reduced homogenizing module may include an electable diffusion module so that its light may be included in a full wash light mode, in other embodiment a full wash light mode can be achieved by a reduced homogenizing light module without a diffuser but a system that dims to dims out such light modules during a full wash light mode. This dimming may be automatically tied in operation when the user selects a full wash mode or in other embodiments it might be manual. In further embodiments all of the modules are of the reduced homogenization type and they all have selectable diffusion module(s). In some embodiments the individual light engine modules are controlled individually and in other embodiments the modules are controlled in groups. The groups may be of like like or of like geometric location in the array such as outer ring inner ring etc. These controls would may include color intensity diffusion flag if so equipped, image multiplier if so equipped, zoom lens if mechanically configured to be independently controllable (not shown in the figures). 
         [0048]    In the position of output from lenses  134  and  132  in  FIG. 9  the light output will be at a wider angle. In  FIG. 10  lens module  130  has been moved away from light guides  104  and optical softening diffuser system  120 . In this position the output from lenses  134  and  132  will be a narrow angle. Positions of lens module  130  intermediate to those positions shown in  FIGS. 9 and 10  will produce intermediate beam angles. As the lens module is moved there will be a continuously variable beam angle, or zoom, of the light beams emitted from the light guides  104 . 
         [0049]    If optical diffusers  28  and  30  are not positioned across the beam in module  120  then the lens when it is in its distant, narrow angle, position may be focused on the LED and the multiple internal reflections in light guides optically multiply the chip shape which creates a sharp distinct flower effect. If the lens is moved to the close, wide angle, position then, even without the diffuser in place, module  120  will produce a smoother wash style beam with less distinct flower effect. In either case, with diffuser  28  or  30  in place the system in module  120  will produce a smooth homogenized effect, without the flower effect. 
         [0050]    In the embodiment illustrated, the movement of lens module  130  is produced by motors  106  acting on lead screws  108 . Although a lead screw system is illustrated here, the invention is not so limited and other methods of moving the lenses such as belt systems, linear actuators, rack and pinion gears, and other methods well known in the art are envisaged. The lens module  130  is supported by guides  110  such that the motion is constrained to be back and forth along the optical axis of the luminaire. 
         [0051]    In the embodiment illustrated the entire array of lenses  134  and  132  moves together as a single module. However, in further embodiments individual lenses or groups of lenses may have their own motor drive systems and be capable of independent movement along the optical axis. In particular, any lenses associated with LED light sources that are fitted with optical softening diffuser systems  120  such as the central module in  FIG. 7  may move with the array  130 , may be fitted with independent motor control separate from that for the array  130 , or may be static with a fixed beam angle. 
         [0052]    The design of lenses  132  and  134  in lens array  130  is such that the individual homogenized beams of light from each of the light beams emitted from the light guides  104  are constrained to further overlap and mix as they leave the lens array  130  providing a smooth, contiguous light beam with a wash light distribution with a large effective source (comprising the total lens array  130 ) and true blending output distribution. 
         [0053]      FIG. 11  illustrates a complete luminaire as may be used in a lighting system such as that illustrated in  FIG. 1 . Lens array  130  is visible on the external face of the automated luminaire  100 . 
         [0054]      FIG. 12  illustrates a further embodiment(s) the output lenses  134  or  132  as may be used in the described system. As previously described, it is advantageous for such lenses to be achromatic in their behavior. In other words, they should present as little as possible difference between their optical effect on different colors of light to avoid objectionable colored fringing around the edge of light beams. In a preferred embodiment lens  134  comprises a single element constructed, by the use of aspheric surfaces or otherwise, to exhibit achromatic properties. In the embodiment illustrated in  FIG. 12 , the lens  134  does not have a smooth surface, instead there is a microstructure on the lens surface or surfaces. The lens surface or surfaces are covered with small engineered depressions similar to those on a golf ball. The depressions  140  are shown here larger than in reality for ease of illustration. In one embodiment the depressions may be 0.3 mm-0.4 mm in diameter with a depth of only 0.0001 mm. These depressions, along with the use of aspheric lens surfaces, may be used on one or both sides of lens  134  so as to provide achromatic operation of the lens. 
         [0055]    In operation of the luminaire the LED sources feeding light guides  104  and optical softening diffuser system  120  may be individually or collectively controlled as to color and intensity to provide either a coordinated wash light or an effects unit as desired. In particular, any LED sources fitted with optical softening diffuser system  120  may be controlled such that either they produce the aforementioned dynamic flower effect, or produce a smooth wash beam to match standard light guides  104 . The operator may choose to combine or mix these effects to achieve a desired result. 
         [0056]    While the disclosure has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments may be devised which do not depart from the scope of the disclosure as disclosed herein. The disclosure has been described in detail, it should be understood that various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the disclosure.