Abstract:
A universal projector interface including a mount interface portion with a plurality of elongate arm assemblies coupled thereto. Each arm assembly is selectively rotatable and translatable relative to the mount interface, and includes a coupling portion. The coupling portion of each arm assembly is selectively shiftable between a first position in which the coupling portion is securely engaged with a projector attachment member on the projector and a second position in which the coupling portion is freely disengageable from the projector attachment member.

Description:
RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/060,968, filed Jun. 12, 2008, and entitled UNIVERSAL PROJECTOR INTERFACE WITH SUSTAINABLE ALIGNMENT, said application being hereby fully incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to mounting devices and more specifically to universal adjustable mounting devices for projectors. 
     BACKGROUND OF THE INVENTION 
     Multi-media presentations performed with video projection equipment have become very common for business and entertainment purposes. Often, the video projection equipment is a portable LCD projector that is placed on a table, cart, or stand in the room, with the image projected on a portion of the wall or a portable screen. Such impromptu arrangements, however, have a number of drawbacks. First, a considerable amount of time is often needed to position, aim, and focus the projector in advance of the presentation—time that is expended repeatedly whenever a different projector is set up. Further, it is often difficult to position a portable projector where it is not in the way of persons moving about in the room, or in the line of sight for those viewing the presentation. Moreover, the wires and cables used to connect the projector with the computer are in the open at ground level, presenting a tripping hazard and an opportunity for damage to the projector if someone comes in contact with them. 
     In view of these many drawbacks of portable projectors, mounting devices have been developed to enable mounting of a projection device from the ceiling of a presentation room. Such devices have generally been successful in alleviating some of the problems associated with a projector at ground level having exposed wires. These prior ceiling mounting devices have presented certain drawbacks, however. 
     In U.S. Pat. No. 5,490,655, a device for mounting a video/data projector from a ceiling or wall is disclosed in which struts are used to form channels for supporting the projector and to concealing cabling. The channels, however, result in a rather bulky device that may be difficult to harmonize with the aesthetic environment of a presentation room. In addition, adjustment of the projector for roll, pitch, and yaw may be time consuming and difficult due to the generally limited adjustment capability of the device. Also, the projector may be vulnerable to theft by anyone with common hand tools and access to the device during unattended hours. Other prior devices such as the low-profile LCD projector mount is disclosed in U.S. Pat. No. 6,042,068, offer a relatively more compact mount arrangement, but still offer only a limited range of projector pitch and yaw adjustment, and no roll adjustment at all. 
     A projector mount is described in U.S. Pat. No. 7,156,359, which alleviates many of the problems of prior devices. U.S. Pat. No. 7,156,359 is owned by the owners of the present invention and is hereby fully incorporated herein by reference. The disclosed mount provides independent projector roll, pitch, and yaw adjustments along with theft deterrence in the form of coded fasteners connecting each separate portion of the mount. Fine adjustment for position may be hampered, however, due to the number of separate fasteners to be loosened and tightened to enable adjustment (six for the pitch and roll adjustments), and by the tendency for the weight of the projector to pull the mount out of adjustment unless the projector is held in the desired position. Also, although the theft resistant security fasteners inhibit theft of the device, convenience of use of the projector device is compromised by the need to remove the security fasteners with a special tool in order to move the projector to a new location. 
     A further improvement of this projector mount is described in U.S. Pat. No. 7,497,412, hereby fully incorporated herein by reference. The projector mount described therein enables easy micro-adjustment of projector aim in roll, pitch, and yaw, and also enable quick disconnect of the projector from the mount. 
     A difficulty with all these mounts, however, is that projectors of different makes often employ different mounting-fastener patterns for attaching a mount to the projector. This has required a multiplicity of different projector mount models, each matched to a different projector make. 
     While universal mount interfaces, such as described in U.S. Pat. No. 7,503,536, hereby fully incorporated herein by reference, have provided a way to attach a projector to a variety of different projector makes, a persistent difficulty, even with such universal mounts, has been that projectors often have serviceable parts, such as filters and bulbs, that are located in the vicinity of the fastener locations for attaching the projector to the mount. When these parts need to be replaced or serviced, the mount must be removed from the projector to obtain access. Because the projector typically cannot be simply reattached in precisely the same position at it was before the mount was removed, the projector typically must be tediously and time-consumingly re-aimed. This re-aiming typically is performed by a professional, causing expense and delay for the projector end-users. 
     Hence, a need still exists in the industry for a projector mount easily and quickly adaptable to a multiplicity of different projector makes and that enables easy serviceability of the projector by end-users. 
     SUMMARY OF THE INVENTION 
     Embodiments of the present invention address the need for a projector mount easily and quickly adaptable to a multiplicity of different projector makes and that enables easy serviceability of the projector by end-users. According to an embodiment, a universal projector interface includes a mount interface portion with a plurality of elongate arm assemblies coupled thereto. Each arm assembly is selectively rotatable and translatable relative to the mount interface, and includes a coupling portion. The coupling portion of each arm assembly is selectively shiftable between a first position in which the coupling portion is securely engaged with a projector attachment member on the projector and a second position in which the coupling portion is freely disengageable from the projector attachment member. 
     The mount interface portion can be coupled with a projector mount that is in turn coupled with an element of a structure such as a ceiling. Each arm assembly can be rotated and translated so the coupling portion is positioned to be engagable with a separate projector attachment member on the projector. The projector can then be coupled to the universal projector interface and projector mount by engaging each projector attachment members with one of the coupling portions of the arm assemblies and shifting the coupling portion from the second position to the first position to secure the arm assembly to the projector. The projector may then be precisely aimed by making adjustments on the projector mount or the universal projector interface. Once the projector has been aimed, the projector can be easily and quickly removed from the projector mount and universal projector interface by shifting each of the coupling portions of the arm assemblies to the second position and removing the projector. Because shifting of the coupling portions does not affect any of the aiming adjustments on the projector mount or universal mount interface, the projector can be quickly and easily reattached with the need for reaiming by simply again engaging each projector attachment member with one of the coupling portions of the arm assemblies and shifting the coupling portion from the second position to the first position to secure the arm assembly to the projector. 
     According to an embodiment, a universal projector interface includes a mount interface portion adapted to receive a projector mount, at least one projector attachment member adapted to couple with a projector, and at least one arm assembly operably coupled with the mount interface portion so as to be selectively shiftable relative to the mount interface portion. The arm assembly includes a coupling portion selectively shiftable between a first position wherein the coupling portion is engaged with the at least one projector attachment member so as to prevent vertical and horizontal translation of the at least one arm assembly relative to the at least one projector attachment member, and a second position wherein the coupling portion and the at least one arm assembly is freely disengagable from the at least one projector attachment member. 
     The projector attachment member may be a fastener receivable in a fastener aperture of the projector and a selectively shiftable collar on the fastener, and the coupling portion may be a clip slidably received on an end of the at least one arm assembly. The clip may define a projection, the projection being engaged with the collar of the projector attachment member when the coupling portion is in the first position so as to inhibit threading movement of the collar on the fastener in order to prevent loosening of the engagement between the coupling portion and the projector attachment member. 
     In further embodiments, the mount interface portion may define a plurality of elongate apertures, and the at least one arm assembly may be coupled to the mount interface portion with a fastener extending through one of the elongate apertures, the fastener selectively shiftable along the elongate aperture to shift a position of the at least one arm assembly relative to the mount interface portion. The at least one arm assembly may include an elongate arm member defining a channel oriented longitudinally along the elongate arm member, the fastener being selectively shiftable along the channel to enable shifting of the position of the at least one arm assembly relative to the mount interface portion. 
     In further embodiments, the universal projector interface of claim  1 , further includes means for locking the coupling portion in the first position. The at least one arm assembly may define a first aperture and the coupling portion may define a second aperture, the first and second apertures being in registration when the coupling portion is in the first position. The means for locking may be a locking member insertable through the first aperture and the second aperture when the coupling portion is in the first position. 
     In further embodiments, a visual display system includes a projector, a projector mount, and a universal mount interface operably coupling the projector and the projector mount. The universal mount interface includes a mount interface portion operably coupled with the projector mount, at least one projector attachment member coupled with the projector, and at least one arm assembly operably coupled with the mount interface portion so as to be selectively shiftable relative to the mount interface portion. The arm assembly includes a coupling portion selectively shiftable between a first position wherein the coupling portion is engaged with the at least one projector attachment member so as to prevent vertical and horizontal translation of the at least one arm assembly relative to the at least one projector attachment member, and a second position wherein the coupling portion and the at least one arm assembly is freely disengagable from the at least one projector attachment member. 
     The projector attachment member may include a fastener receivable in a fastener aperture of the projector and a collar threaded on the fastener, and the coupling portion may include a clip slidably received on an end of the at least one arm assembly. The clip may define a projection, the projection being engaged with the collar of the projector attachment member when the coupling portion is in the first position so as to inhibit threading movement of the collar on the fastener. The mount interface portion may define a plurality of elongate apertures, and the at least one arm assembly may be coupled to the mount interface portion with a fastener extending through one of the elongate apertures, the fastener selectively shiftable along the elongate aperture to shift a position of the at least one arm assembly relative to the mount interface portion. Further, the at least one arm assembly may include an elongate arm member defining a channel oriented longitudinally along the elongate arm member, the fastener being selectively shiftable along the channel to enable shifting of the position of the at least one arm assembly relative to the mount interface portion. 
     In further embodiments, a method of installing a projector may include providing a universal projector interface with a mount interface portion adapted to receive a projector mount thereon, at least one projector attachment member adapted to couple with a projector, and at least one arm assembly operably coupled with the mount interface portion so as to be selectively shiftable relative to the mount interface portion. The arm assembly includes a coupling portion selectively shiftable between a first position wherein the coupling portion is engaged with the at least one projector attachment member so as to prevent vertical and horizontal translation of the at least one arm assembly relative to the at least one projector attachment member, and a second position wherein the coupling portion and the at least one arm assembly is freely disengagable from the at least one projector attachment member. The method further includes providing instructions with the universal projector interface instructing a user to couple the at least one projector attachment member with the projector, couple the mount interface portion with the projector mount, and couple the projector with the projector mount by shifting the coupling portion of the arm assembly to the second position, engaging the coupling portion with the projector attachment member, and shifting the coupling portion to the first position. 
     In still further embodiments, a visual display system includes a projector, a projector mount, and a universal mount interface operably coupling the projector and the projector mount. The universal mount interface includes a mount interface portion operably coupled with the projector mount, a plurality of projector attachment members coupled with the projector, and a plurality of arm assemblies operably coupled with the mount interface portion so as to be selectively shiftable relative to the mount interface portion. Each arm assembly includes a coupling portion selectively shiftable between a first position wherein the coupling portion is engaged with one of the projector attachment members so as to prevent vertical and horizontal translation of the arm assembly relative to the projector attachment member to which the arm assembly is attached, and a second position wherein the coupling portion and the arm assembly are freely disengagable from the projector attachment member. 
     Each projector attachment member may include a fastener receivable in a fastener aperture of the projector and a collar threaded on the fastener, and each coupling portion comprises a clip slidably received on an end of the arm assembly. The mount interface portion may define a plurality of elongate apertures, and each arm assembly may be coupled to the mount interface portion with a fastener extending through a separate one of the elongate apertures, the fastener selectively shiftable along the elongate aperture to shift a position of the arm assembly relative to the mount interface portion. Each arm assembly may include an elongate arm member defining a channel oriented longitudinally along the elongate arm member, the fastener being selectively shiftable along the channel to enable shifting of the position of the arm assembly relative to the mount interface portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the following drawings, in which: 
         FIG. 1  is a perspective view of a universal projector interface, according to an embodiment of the invention, supporting a projector; 
         FIG. 2  is an exploded perspective view of the universal projector interface of  FIG. 1 ; 
         FIG. 3  is an exploded perspective view of the track assemblies and interface plate of  FIG. 1 ; 
         FIG. 4  is a top plan view of the track assemblies and interface plate of  FIG. 3 ; 
         FIG. 5  is a bottom plan view of the track assemblies and interface plate of  FIG. 3 ; 
         FIG. 6   a  is a front elevation view of the track assemblies and interface plate of  FIG. 3 ; 
         FIG. 6   b  is a side elevation view of the track assemblies and interface plate of  FIG. 3 ; 
         FIG. 6   c  is a rear elevation view of the track assemblies and interface plate of  FIG. 3 ; 
         FIG. 7  is a perspective view of the interface plate of  FIG. 3 ; 
         FIG. 8   a  is a top plan view of the interface plate of  FIG. 7 ; 
         FIG. 8   b  is a front elevation view of the interface plate of  FIG. 7 ; 
         FIG. 8   c  is a side elevation view of the interface plate of  FIG. 7 ; 
         FIG. 8   d  is a perspective view of an interface plate according to an embodiment of the invention. 
         FIG. 8   e  is a top view of the interface plate of  FIG. 8   d.    
         FIG. 8   f  is a front view of the interface plate of  FIG. 8   d.    
         FIG. 8   g  is a side view of the interface plate of  FIG. 8   d.    
         FIG. 9  is a perspective view of the track assemblies of  FIG. 3 ; 
         FIG. 10  is a top plan view of the track assemblies of  FIG. 9 ; 
         FIG. 11   a  is a perspective view of one of the track assemblies of a universal projector interface according to an embodiment of the invention; 
         FIG. 11   b  is a top plan view of the track assembly of  FIG. 11   a;    
         FIG. 12  is an exploded perspective view of the track assembly of  FIG. 11   a;    
         FIG. 13  is a perspective view of the track bar of  FIG. 12 ; 
         FIG. 14   a  is a side elevation view of the track bar of  FIG. 13 ; 
         FIG. 14   b  is a top plan view of the track bar of  FIG. 13 ; 
         FIG. 14   c  is a bottom plan view of the track bar of  FIG. 13 ; 
         FIG. 15   a  is a front perspective view of the track bar of  FIG. 13 ; 
         FIG. 15   b  is a rear perspective view of the track bar of  FIG. 15   a;    
         FIG. 15   c  is a rear elevation view of the track bar of  FIG. 15   a;    
         FIG. 16   a  is a fragmentary top-rear perspective view of the track bar of  FIG. 13 ; 
         FIG. 16   b  is a fragmentary bottom-rear perspective view of the track bar of  FIG. 13 ; 
         FIG. 17   a  is an exploded front elevation view of the slide assembly of  FIG. 12 ; 
         FIG. 17   b  is an exploded perspective view of the slide assembly of  FIG. 17   a;    
         FIG. 17   c  is a side elevation view of the slide bridge of  FIG. 17   a;    
         FIG. 18  is a perspective cross-sectional view taken at section  14  of  FIG. 11   a;    
         FIG. 19  is a perspective view of the engagement bracket of  FIG. 12 ; 
         FIG. 19   a  is a top plan view of the engagement bracket of  FIG. 19 ; 
         FIG. 19   b  is a bottom plan view of the engagement bracket of  FIG. 19 ; 
         FIG. 19   c  is a side elevation view of the engagement bracket of  FIG. 19 ; 
         FIG. 19   d  is an opposing side elevation view of the engagement bracket of  FIG. 19 ; 
         FIG. 19   e  is a rear elevation view of the engagement bracket of  FIG. 19 ; 
         FIG. 19   f  is a front elevation view of the engagement bracket of  FIG. 19 ; 
         FIG. 20  is a perspective cross-sectional view taken at section  21  of  FIG. 19   a;    
         FIG. 21   a  is a fragmentary perspective view of the track bar of  FIG. 13  and of the engagement bracket of  FIG. 19 ; 
         FIG. 21   b  is a fragmentary side elevation view of the track bar and the engagement bracket of  FIG. 21   a;    
         FIG. 21   c  is a fragmentary top plan view of the track bar and the engagement bracket of  FIG. 21   a;    
         FIG. 21   d  is a fragmentary bottom plan view of the track bar and the engagement bracket of  FIG. 21   a;    
         FIG. 22   a  is a perspective view of the pull cover of  FIG. 12 ; 
         FIG. 22   b  is a top plan view of the pull cover of  FIG. 22   a;    
         FIG. 22   c  is a side elevation view of the pull cover of  FIG. 22   a;    
         FIG. 22   d  is a rear elevation view of the pull cover of  FIG. 22   a;    
         FIG. 23   a  is a perspective view of the engagement fastener and engagement collar of  FIG. 12 ; 
         FIG. 23   b  is a side elevation view of the engagement fastener and engagement collar of  FIG. 23   a;    
         FIG. 23   c  is a perspective view of the engagement fastener and engagement collar of  FIG. 23   a , depicting the engagement collar threaded to the engagement fastener; 
         FIG. 24   a  is a perspective view of the track bar with engagement collar and fastener according to an embodiment of the invention; 
         FIG. 24   b  is rear perspective view of the track bar with engagement collar and fastener of  FIG. 24   a;    
         FIG. 25   a  is a perspective view of the track bar with engagement bracket, collar and fastener according to an embodiment of the invention; 
         FIG. 25   b  is a side view of the track bar with engagement bracket, collar and fastener of  FIG. 25   a;    
         FIG. 25   c  is a side view of the track bar with engagement bracket, collar and fastener of  FIG. 25   a  with pull cover; 
         FIG. 26   a  is a perspective view of engagement bracket with collar and ring according to an embodiment of the invention; 
         FIG. 26   b  is a side view of engagement bracket with collar and ring of  FIG. 26   a;    
         FIG. 26   c  is another side view of engagement bracket with collar and ring of  FIG. 26   a;    
         FIG. 26   d  is a top view of engagement bracket with collar and ring of  FIG. 26   a;    
         FIG. 26   e  is a perspective cross-sectional view of engagement bracket with collar and ring of  FIG. 26   a;    
         FIG. 26   f  is a perspective cross-sectional view of engagement bracket with collar and ring of  FIG. 26   a;    
         FIG. 27  is a perspective cross-sectional view of track assembly  120   a  according to an embodiment of the invention; 
         FIG. 28   a  is a top view of engagement bracket, collar, and ring according to an embodiment of the present invention in a locked position; 
         FIG. 28   b  is a top view of engagement bracket, collar, and ring according to an embodiment of the present invention in an unlocked position; 
         FIG. 28   c  is a perspective view of engagement bracket, collar, and ring of  FIG. 28   b;    
         FIG. 29   a  is a perspective view of a rotating latching mechanism of a projector interface according to an embodiment of the invention; 
         FIG. 29   b   1  is a perspective view of a watch-band clasp mechanism of a projector interface according to an embodiment of the invention; 
         FIG. 29   b   2  is a partial cross-section of the watch-band clasp mechanism of  FIG. 29   b   1 ; 
         FIG. 29   c  is a perspective view of a beveled pin locking mechanism of a projector interface according to an embodiment of the invention; 
         FIG. 29   d  is a perspective view of a turning key mechanism of a projector interface according to an embodiment of the invention; 
         FIG. 30   a  is a top view of a slide latch mechanism of a projector interface according to an embodiment of the invention; 
         FIG. 30   b  is a side view of a slide latch mechanism of a projector interface according to an embodiment of the invention; 
         FIG. 31   a  is a top view of a squeeze latch mechanism of a projector interface according to an embodiment of the invention in a locked position; 
         FIG. 31   b  is a top view of a squeeze latch mechanism of a projector interface according to an embodiment of the invention in an unlocked position; 
         FIG. 32  is an exploded perspective view of a cross-pin latch mechanism of a projector interface according to an embodiment of the invention; 
         FIG. 33  is a an exploded perspective view of a spring clip latch mechanism of a projector interface according to an embodiment of the invention; 
         FIG. 34   a  is a top view of another squeeze latch mechanism of a projector interface according to an embodiment of the invention in an unlocked position; 
         FIG. 34   b  is a top view of another squeeze latch mechanism of a projector interface according to an embodiment of the invention in a locked position; 
         FIG. 35  is a side view of a rotating knob locking mechanism of a projector interface according to an embodiment of the invention in the locked position; 
         FIG. 36   a  is a top view of a pivoting latch mechanism of a projector interface according to an embodiment of the invention in a locked position; 
         FIG. 36   b  is a side elevation view of the pivoting latch mechanism of  FIG. 36   a;    
         FIG. 37  is an exploded side view of a plunger latch mechanism of a projector interface according to an embodiment of the invention; 
         FIG. 38  is a side view of a hook latch mechanism of a projector interface according to an embodiment of the invention in a locked position; 
         FIG. 39   a  is a side view of a tool-actuated latch mechanism of a projector interface according to an embodiment of the invention in an unlocked position; 
         FIG. 39   b  is a side view of a tool-actuated latch mechanism of a projector interface according to an embodiment of the invention in a locked position; 
         FIG. 40   a  is a top view of a top-pivoting latch mechanism of a projector interface according to an embodiment of the invention in a locked position; 
         FIG. 40   b  is a top view of a top-pivoting latch mechanism of a projector interface according to an embodiment of the invention in an unlocked position; 
         FIG. 40   c  is a perspective view of a top-pivoting latch mechanism of a projector interface according to an embodiment of the invention in an unlocked position; 
         FIG. 41  is an exploded perspective view of a rotating latch mechanism of a projector interface according to an embodiment of the invention; 
         FIG. 42  is a perspective view of a universal projector interface according to an alternative embodiment of the invention; 
         FIG. 43  is a perspective view of the interface of  FIG. 42  with the cover portion removed; 
         FIG. 44  is a partial exploded view of the interface of  FIG. 42 ; 
         FIG. 45  is a side elevation view of a coupling portion and projector interface member of the interface of  FIG. 42  with the coupling portion in an engaged position; 
         FIG. 46  is a top plan view of the coupling portion and projector interface member of  FIG. 45 ; 
         FIG. 47  is a side elevation view of a coupling portion and projector interface member of the interface of  FIG. 42  with the coupling portion in a disengaged position; 
         FIG. 48  is a top plan view of the coupling portion and projector interface member of  FIG. 47 ; and 
         FIG. 49  is a partial exploded view of a coupling portion and track arm of the interface of  FIG. 42 . 
     
    
    
     While the present invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The accompanying Figures depict embodiments of the mount of the present invention, and features and components thereof. Any references to front and back, right and left, top and bottom, upper and lower, and horizontal and vertical are intended for convenience of description, not to limit the present invention or its components to any one positional or spacial orientation. Any dimensions specified in the attached Figures and this specification may vary with a potential design and the intended use of an embodiment of the invention without departing from the scope of the invention. Moreover, the Figures may designate, for reference purposes, the relative directions of x-y-z coordinate axes as applied to the invention. Any reference herein to movement in an x-axis direction, a y-axis direction, or a z-axis direction, or to rotation about an x-axis, a y-axis or a z-axis, relates to these coordinate axes. The y-axis is oriented fore-and-aft in relation to the mounted device, the z-axis is vertical and the x-axis is perpendicular to the z-axis and the y-axis, and is oriented laterally from side-to-side in relation to the mounted device. For the purposes of the present application, pitch is defined as angular displacement about the x-axis, roll is defined as angular displacement about the y-axis, and yaw is defined as angular displacement about the z-axis. 
     As depicted in  FIGS. 1-2 , projector mounting system  100  generally includes projector  102 , projector interface  104 , projector mount  106 , optional security cable assembly  108 , and pipe support  110 . Projector  102  may be any of a number of known projection devices, and generally includes projector mounting surface  112 , projector mounting holes  114   a ,  114   b ,  114   c , and access door  116 . The details of projector mount  106  are fully described in U.S. Pat. No. 7,497,412, owned by the owners of the present invention, said patent hereby fully incorporated herein by reference. 
     As depicted in  FIGS. 3-6 , projector interface  104  generally includes interface plate  118 , track assemblies  120   a ,  120   b ,  120   c , and projector interface members in the form of engagement fasteners  121 . Track assemblies  120   a ,  120   b ,  120   c  are pivotally coupled to interface plate  118  with plate-track fasteners  125   a ,  125   b ,  125   c ,  125   d , as will be further described hereinbelow. Engagement fasteners  121  generally include engagement fasteners  121   a ,  121   b ,  121   c , and engagement collars  124   a ,  124   b ,  124   c . In the embodiment depicted, projector interface  104  includes three track assemblies  120   a ,  120   b ,  120   c , but in other embodiments, may include four or more track assemblies depending on available mounting holes  114 , and other projector  102  characteristics. 
     Referring now to  FIGS. 7-8 , interface plate  118  may be generally rectangular or nearly square in shape, and resembling a shallow tray. Interface plate  118  generally includes two long perimeter walls  126 ,  128 , two short perimeter walls  130 ,  132 , floor  134 , raised corners  136 ,  138 ,  140 ,  142 . Interface plate  118  further defines a generally central aperture  144  and a series of slots  146 . In alternative embodiments, interface plate  118  may include a series of circular holes, a combination of holes and slots, or may generally include openings of other shapes and sizes that are capable of receiving track assemblies  120 . 
     Long wall  126  generally includes a top surface  148 , outer surface  150 , inner surface  152 , transition portion  153 , and traverses the width of interface plate  118  along the x-axis between raised corners  136  and  138 . Similarly, long wall  128  generally includes a top surface  154 , outer surface  156 , inner surface  158 , transition portion  159 , and traverses the width of interface plate  118  between raised corners  140  and  142 . The length of wall  126  generally is equal to the length of wall  128 . 
     Short wall  130  generally includes a top surface  160 , outer surface  162 , inner surface  164 , transition portion  165 , and traverses the width of interface plate  118  along the x-axis between raised corners  136  and  142 . Similarly, short wall  132  generally includes a top surface  168 , outer surface  170 , inner surface  172 , transition portion  173 , and traverses the width of interface plate  118  between raised corners  140  and  142 . The length of wall  130  generally is equal to the length of wall  132   
     The heights along the z axis of walls  126 ,  128 ,  130 , and  132  define the depth of interface plate  118 , and in the depicted embodiment are substantially equal. In the embodiment depicted in the figures, the wall height is substantially less than either the length or width of the walls such that walls  126 ,  128 ,  130 ,  132 , with floor  134  form a shallow tray. In other embodiments, the height of walls  126 ,  128 ,  130 , and  132  may vary depending on the characteristics of projector mount  106 , whether interface plate will house assembly tools, and so on. 
     Short walls  130  and  132  traverse the length of interface plate  118  along the y axis, between corners  138  and  140 , and  136  and  142 , respectively. The height of short walls  130  and  132  are generally equal to the height of long walls  126  and  128 , such that top surfaces  148 ,  154 ,  160 , and  168  form a common plane. 
     In the depicted embodiment, walls  126 ,  128 ,  130  and  132  are generally perpendicular to floor  134 , but in other embodiments may form other than an acute angle with floor  134 . Walls  126 ,  128 ,  130 , and  132  join with floor  134  via transition portions  153 ,  159 ,  165 , and  173 , respectively. Wall transition portions  153 ,  159 ,  165 , and  173  are generally curvilinear and join the vertical portions of their respective walls with floor  134 . 
     In one embodiment, walls  126 ,  128 ,  130 , and  132  may each also define notches  174 ,  176 ,  178 , and  180 , respectively. Each notch  174 ,  176 ,  178 ,  180  is generally semi-circular, and located in a top central portion of each wall such that it bisects its respective top surface  150 ,  154 ,  160 ,  168 . Corners  136 ,  138 ,  140 , and  142  generally include respective tabs  182 ,  184 ,  186 ,  188  and corner walls  190 ,  192 ,  194 ,  196   
     Tabs  182 ,  184 ,  186 ,  188  generally include respective tab top surfaces  198 ,  200 ,  202 ,  204 , tab bottom surfaces  206 ,  208 ,  210 ,  212 , outer edges  214 ,  216 ,  218 ,  220 , and generally define respective circular tab holes  222 ,  224 ,  226 ,  228 . Tab top surfaces  206 ,  208 ,  210 ,  212  are substantially flat and generally lie in the same plane formed by the four wall top surfaces  150 ,  154 ,  160 ,  168 . Each tab outer edge  214 ,  216 ,  218 ,  220  forms a rounded corner edge or surface of interface plate  118 . 
     Corner walls  190 ,  192 ,  194 ,  196  include respective top portions  230 ,  232 ,  234 ,  236 , middle portions  238 ,  240 ,  242 ,  244 , bottom portions  246 ,  248 ,  250 ,  252 , inner surfaces  254 ,  256 ,  258 ,  260 , and outer surfaces  262 ,  264 ,  266 ,  268 . 
     Top portions  230 ,  232 ,  234 ,  236  extend from their respective tab top surfaces  198 ,  200 ,  202 ,  204  downward to their respective middle portions  238 ,  240 ,  242 ,  244  forming a generally concave structure as viewed from the center of interface plate  118 . Tab top surfaces  198 ,  200 ,  202 ,  204  may further form an S-shape or L-shape as viewed along the z axis. The exact curvature and shape of top portions  230 ,  232 ,  234 ,  236  may vary from embodiment to embodiment, but generally will form a concave, curved structure at each corner  136 ,  138 ,  140 ,  142 . 
     Middle portions  238 ,  240 ,  242 ,  244  are located adjacent top portions  230 ,  232 ,  234 ,  236  and bottom portions  246 ,  248 ,  250 ,  252  and may be substantially perpendicular to floor  134 . Middle portions  238 ,  240 ,  242 ,  244  may be curvilinear, generally forming a C shape, or L shape as viewed along the z axis. 
     Bottom portions  246 ,  248 ,  250 ,  252  are located adjacent middle portions  238 ,  240 ,  242 ,  244  and floor  134 . Bottom portions  246 ,  248 ,  250 ,  252  may be somewhat convex and generally follow the curvature of their respective middle and top portions. 
     Central aperture  144  in the depicted embodiment is a circular opening located in the center of interface plate  118 . In other embodiments, central aperture  144  may be square, rectangular, or otherwise appropriately shaped to receive pipe support  110 . The size of central aperture  144  may vary to accommodate pipe support  110  or to allow for needed ventilation for projector  102 . In the depicted embodiment, the diameter of central aperture  144  is approximately 35% of the width of interface plate  118 . 
     Central aperture  144  may be surrounded by raised lip  270 . Raised lip  270  rises upward from floor  134  in a vertical direction, and generally includes a top portion  272  and a bottom portion  274 . Top portion  272  is generally vertical with a flat top surface  276 , while bottom portion  274  may be slightly concave. In other embodiments, bottom portion  274  may be slightly convex. Top surface  276  generally lies in a plane beneath the plane formed by wall top surfaces  150 ,  154 ,  160 ,  168 , but in some embodiments may lie in the same plane as that formed by wall top surfaces  150 ,  154 ,  160 ,  168 . 
     Slots  146  defined by floor  134  of interface plate  118  may vary in quantity, shape, and distance from central aperture  144 , but are generally arcuate in shape with a length longer than a width. In the depicted embodiment, the radius of the arc of each slot  146  is substantially equal, but in other embodiments may be unequal. Further the radius of the arc formed by each slot  146  is generally longer than the radius formed by central aperture  144 , though in other embodiments not depicted, the radius of the arc formed by each slot  146  may be equal to, or smaller than the arc formed by central aperture  144 . 
     Generally, each slot  146  may be characterized as having a concentric or non-concentric arc with respect to the arc formed by central aperture  144 . For example, slots  278  and  280  form arcs that are concentric to central aperture  144 , while slots  282  and  284  form arcs that are non-concentric to central aperture  144 . 
     Each slot  146  may also be characterized as generally perpendicular or non-perpendicular to central aperture  144 . For example, slots  286 ,  288 ,  290 ,  292  may be considered generally perpendicular, while slots  270 ,  280  may be considered non-perpendicular. 
     Referring to  FIGS. 8   d - 8   g , in an alternate embodiment, projector interface  104  includes an interface plate  119  that generally define a series of circular holes  145 , rather than slots  146 . In this embodiment, interface plate  119  is substantially the same as interface plate  118 , with the exception of defining holes  145 , rather than slots  146 . As such, interface plate  119  generally includes two long perimeter walls  126 ,  128 , two short perimeter walls  130 ,  132 , floor  134 , raised corners  136 ,  138 ,  140 ,  142 , and defines a generally central aperture  144 . 
     As depicted, interface plate  119  defines multiple holes  145 . Holes  145  may be circular, and all have substantially the same diameter. In other embodiments, holes  145  may not be circular, and may be oval, square, or shaped as necessary to receive various embodiments of track assemblies  120 . Holes  145  may be distributed in a relatively random manner in interface plate  119 , or may be evenly distributed in a more uniform fashion as depicted. 
     Referring to  FIGS. 9-12 , projector interface generally includes multiple track assemblies  120 . In the depicted embodiment, projector interface  104  includes three track assemblies  120   a ,  120   b ,  120   c . In other embodiments, projector interface  104  may include four or more track assemblies  120 . Track assembly  120   a  generally includes track bar  294   a , a coupling portion in the form of engagement bracket  296   a , pull cover  298   a , and slide assembly  300   a . It will be understood that additional track assemblies  120 , including  120   b  and  120   c , will be essentially the same as track assembly  120   a , and will also generally include respective track bars  294 , engagement brackets  296 , pull covers  298  and slide assemblies  300 . 
     Referring to  FIGS. 13-16 , track bar  294   a  includes engagement end  297   a , mount end  299   a , left and right side walls  301   a ,  302   a , bottom wall  304   a , left and right top walls  306   a ,  308   a , left and right limit tabs  310   a ,  312   a , left and right upper hooks  314 ,  316 , left and right lower hooks  318 ,  320 , and left and right bottom wall tabs  322 ,  324 . Walls  301   a ,  302   a ,  304   a ,  306   a ,  308   a  generally include respective inside surfaces  326   a ,  328   a ,  330 ,  332   a ,  334   a , defining track interior space  336   a.    
     Left side wall  301   a  adjoins bottom wall  304  at the left side of track bar  294   a , at a substantially right angle; right side wall  302   a  adjoins bottom wall  304   a  at the right side of track bar  294   a , also substantially forming a right angle. As such, left side wall  301   a , bottom wall  304   a , and right side wall  302   a  form a U-shape when viewed from mount end  299   a  of track bar  294   a , as depicted in  FIG. 15   c . The portions of track bar  294   a  where side walls  301   a ,  302   a  adjoin bottom wall  304   a  may be slightly rounded as depicted. 
     Left top wall  306   a  is adjoined to, and forms a right angle with left side wall  301   a , while right top wall  308   a ; right top wall  308   a  is adjoined to, and forms a right angle with right side wall  302   a . Left top wall  306   a  extends inwardly from left side wall  301   a , lying in a plane parallel to bottom wall  304   a ; right top wall  308   a  extends inwardly from right side wall  302   a , lying in a plane parallel to bottom wall  304   a.    
     Track bar  294   a  defines a pair of rectangular mount-side apertures, left mount-end aperture  338   a  and right mount-end aperture  340   a , engagement fastener receiving hole  342   a , left engagement bracket receiving aperture  344   a , right engagement bracket receiving aperture  346   a , left and right side engagement slots  348   a ,  350   a , track slot  352   a , and cable hole  354 . 
     Left and right mount-end apertures may be generally rectangular in shape and located at a far end of mount end  299   a , near the top of their respective side walls  301   a ,  302   a . Engagement fastener receiving hole  342   a  is generally circular and is located at engagement end  297   a  of track bar  294   a , in bottom wall  304   a . Hole  342   a  is generally equidistant from side walls  301   a  and  302   a , with an inside diameter slightly larger than the outside diameter of engagement fastener  121   a , such that a portion of engagement fastener  121   a  may be inserted into hole  342   a  without resistance. Although depicted as round, hole  342   a  may be of a different shape that is adapted to accommodate, or receive, engagement fastener  121   a.    
     Left and right engagement bracket receiving apertures  344   a ,  346   a  are located at engagement end  297   a  of track bar  294   a , and may be rectangular in shape as depicted in the embodiment of the figures. In other embodiments, the shape of apertures  344   a ,  346   a  may be non-rectangular in shape so as to receive alternative embodiments of engagement bracket  296   a . Apertures  344   a ,  346   a  are may be equidistant from their respective top walls  306   a ,  308   a , and bottom wall  304   a , as depicted. The size, shape, and location of engagement brackets  344   a ,  346   a  will vary as needed in order to accommodate various embodiments and locations of engagement bracket  296   a.    
     Left engagement slot  348   a  is located at engagement end  296   a , and is defined by left side wall  301   a , upper left hook  314   a , and lower left hook  318   a ; right engagement slot  350   a  is located at engagement end  297   a , and is defined by right side wall  302   a , upper right hook  316   a , and lower right hook  320   a . A substantial portion of each engagement slot  348 ,  350  may be rectangular in shape, with respective narrowed openings at the distal engagement end  297  of track bar  294   a.    
     Track slot  352   a  is defined by left and right side top walls  306   a  and  308   a , is generally rectangular, and traverses the length of track bar  294   a . The width of track slot  352  may vary as needed to receive a portion of slide assembly  300   a , and in the depicted embodiment is approximately 30% to 40% of the width of bottom wall  304   a , and approximately the same width as left and right top walls  306   a  and  308   a.    
     Left and right cable holes  354   a  and  356   a  may be generally circular, and located near the distal end of engagement end  297   a . Each cable hole  354   a ,  356   a  may be located between, and slightly below the center of, their respective engagement bracket receiving aperture and engagement bracket receiving slot. In other embodiments, cable holes  354   a ,  356   a  may be located elsewhere, so long as insertion of a cable  108  assembly does not interfere with the functioning of track assembly  120   a . In some embodiments of track assembly  120   a , track bar  294   a  does not include cable holes  354   a ,  356   a.    
     Left and right limit tabs  310   a  and  312   a  are generally square or rectangular in shape and respectively project from left and right side walls  301   a  and  302   a  into track interior  346  toward their opposite respective side walls. Limit tabs  310   a ,  312   a  may be located as depicted adjacent to engagement end  297   a  of their respective engagement bracket receiving slots  344   a ,  346   a.    
     Left and right bottom wall tabs  322   a ,  324   a  are located in bottom wall  304   a  adjacent to engagement fastener receiving hole  342  and generally project downward and away from bottom wall  304   a . Tabs  322   a ,  324   a  may be generally square or rectangular in shape as depicted, with only a slight downward projection. In one embodiment, track bar  294   a  is made of a metal such as steel or aluminum, but in other embodiments may be made of plastic, fiberglass, or other materials of suitable strength. 
     Referring to  FIGS. 17   a - 17   c , slide assembly  300   a  of track assembly  120   a  generally includes slide bridge  358   a  and slide fastener  360   a . Slide bridge  358   a  generally includes top portion  362   a  with guide projections  364   a ,  366   a ,  368   a ,  370   a , top surface  372   a , and left and right support tabs  374   a ,  376   a . Guide projections  364   a ,  366   a ,  368   a ,  370   a  are located at the four corners of top portion  362   a  and project outward and away from top portion  362   a  at a substantially 90 degree angle. The engagement side of distal ends of guide projections  364   a ,  366   a , may define notches  378   a ,  380   a ; the engagement side of distal ends of guide projections  368   a ,  370   a , may define notches  382   a ,  384   a . As depicted, notches  382   a ,  384   a ,  386   a ,  388   a  may generally form a 45° angle with respect to each guide projection, but may form other angles in other embodiments. 
     Left and right support tabs  374   a  and  376   a  are connected to top portion  362   a , and bend downward and away from top portion  362   a . Each support tab  374   a  and  376   a  generally form an obtuse angle with top portion  362   a  such that top portion  362   a  in combination with tabs  374   a ,  376   a  form a bridge-like structure as depicted in  FIG. 17   a . Support tabs  374   a ,  376   a  generally include bottom surfaces  386   a ,  388   a.    
     Slide fastener  360   a  may be a threaded fastener such as a bolt or screw, and sized to be received by plate-track fastener  125   a . Slide fastener  360   a  generally includes shaft  390   a , threads  392   a , and knurled base  394   a . Top portion  358   a  of slide bridge  358   a  defines slide fastener hole  396 . Slide fastener hold  396  is sized such that shaft  390   a  may be inserted through hole  396  such that base  394  contacts top portion  358   a . Slide bridge  358   a  may optionally include a recess such that a bottom surface of slide fastener  396  is flush with a bottom surface of slide bridge  358 . Slide fastener  396  may fit loosely into hole  396 , may be pressed into hole  396  for a tight fit, or otherwise held in place. 
     Referring now to  FIG. 18 , this cross-sectional depiction of  FIG. 18  illustrates the position of slide assembly  300   a  in relation to track bar  294   a . Slide assembly  300   a  is slidably fit into track interior  336   a  such that slide bridge  358   a  is located entirely within track interior  336   a , with slide bridge support tab bottom surfaces  386   a ,  388   a  in contact with track bar bottom wall inside surface  330   a . Slide bridge top surface  372   a  may be in slight contact with left and right top wall inside surfaces  332   a ,  334   a . Slide fastener  360   a  projects outward and away from track bar  294   a  through track slot  352 . 
     Referring now to  FIGS. 19   a - f , engagement bracket  296   a  generally includes left wall  398   a , right wall  400   a , front wall  402   a , and floor  404   a . Each wall  398   a ,  400   a ,  402   a  is joined to floor  404   a  at a substantially 90° angle. Engagement bracket  296   a  may be steel, aluminum, or other bendable metal, as well as other formable materials including plastic, fiberglass, and composites. 
     Left wall  398   a  is generally flat and rectangular in shape and generally includes a left inner surface  406   a , left outer surface  408   a , left upper rear tab  410   a , left lower rear tab  412   a , left detent  414   a , and left front tab  416   a . Left rear tabs  410   a ,  412   a  are located at the rear, or mount side of left wall  398   a , with tabs oriented at a generally 90° angle to left wall  398   a . Left upper tab  410   a  projects inward toward right wall  400   a , while left lower tab  412   a  projects outward away from left wall  398   a . Tabs  410   a ,  412   a  are generally square, but may be rectangular, or shaped otherwise. 
     In the depicted embodiment, left detent  414   a  is located near the upper rear portion of left wall  398   a , is generally circular, and with a concave curvature that projects inward toward right wall  400   a . Left front tab  416   a  may be T-shaped as depicted, square, rectangular, or otherwise shaped, and projects inward toward right wall  400   a.    
     Left wall  398   a  defines left engagement cable hole  418   a , upper cutout  420   a , and lower cutout  422   a . Left engagement cable hole  418   a  is generally circular, similar in size to track bar  124  cable hole  354   a , and located generally towards the rear of engagement bracket  296   a . Upper cutout  420   a  may be generally square or rectangular and extending from the top of left wall  398   a  downward toward a middle portion of left wall  398   a , and located slightly forward of the center of left wall  398   a . Lower cutout  422   a  is generally rectangular in shape and extending from the bottom of left wall  398   a  upwards. The height of cutout  422   a  is generally less than the length. Lower cutout  422   a  extends horizontally along the lower portion of left wall  398   a  from approximately the center of left wall  398   a  in a rearwardly direction. 
     Right wall  400   a  is generally flat and rectangular in shape and generally includes a right inner surface  424   a , right outer surface  426   a , right upper rear tab  428   a , right lower rear tab  430   a , right detent  432   a , and right front tab  434   a . Right rear tabs  428   a ,  430   a  are located at the rear, or mount side of right wall  400   a , with tabs oriented at a generally 90° angle to right wall  400   a . Right upper rear tab  428   a  projects inward toward left wall  398   a , while right lower rear tab  430   a  projects outward away from right wall  400   a . Tabs  428   a ,  430   a  are generally square, but may be rectangular, or shaped otherwise. 
     In the depicted embodiment, right detent  432   a  is located near the upper rear portion of right wall  400   a , is generally circular, and with a concave curvature that projects inward toward left wall  398   a . Right front tab  434   a  may be T-shaped as depicted, square, rectangular, or otherwise shaped, and projects inward toward left wall  398   a.    
     Right wall  400   a  defines right engagement cable hole  436   a , upper cutout  438   a , and lower cutout  440   a . Right engagement cable hole  436   a  is generally circular, similar in size to track bar  124  cable hole  356   a , and located generally towards the rear of engagement bracket  296   a . Upper cutout  438   a  may be generally square or rectangular and extending from the top of right wall  400   a  downward toward a middle portion of right wall  400   a , and located slightly forward of the center of right wall  400   a . Lower cutout  440   a  is generally rectangular in shape and extending from the bottom of right wall  400   a  upwards. The height of cutout  440   a  is generally less than the length. Lower cutout  440   a  extends horizontally along the lower portion of right wall  400   a  from approximately the center of right wall  398   a  in a rearwardly direction. 
     Front wall  402   a  is generally flat and rectangular in shape, is connected to, and forms a 90° angle with, floor  404   a . In some embodiments front wall  402   a  may be slightly taller and wider than both side walls  398   a  and  400   a . Front wall  402   a  generally includes an outer surface  442   a , inner surface  444   a , centrally-located rectangular opening  446   a , and outwardly projecting front wall tab  448   a.    
     Front wall  402   a  together with left wall  398   a  defines a vertical slot  450   a , such that front wall  402   a  is not connected to left wall  398   a . Front wall  402   a  together with right wall  400   a  defines a vertical slot  452   a , such that front wall  402   a  is not connected to right wall  400   a . Front wall  402   a  together with floor  404   a  defines a pair of horizontal slots  454   a  and  456   a , such that front wall  402   a  is only connected to floor  404   a  along a portion of the lower portion of front wall  402   a.    
     Referring to  FIGS. 19 and 20 , floor  404   a  is generally flat and rectangular in shape, and generally includes a front portion  458   a  and rear portion  460   a . Front portion  458   a  generally includes an upper surface  462   a , projection  464   a , curved upper beveled edge  466   a , and curved lower beveled edge  468   a . In some embodiments, floor front portion  458   a  may only include a single beveled edge. Curved upper beveled edge  466   a  and curved lower beveled edge  468   a  are generally semi-circular, with edge  466  having an arc radius slightly longer than the radius of curved lower beveled edge  468   a . The angle formed between curved upper beveled edge  466   a  and floor  404   a  is slightly larger, or steeper, than the relative angle between curved lower beveled edge  468   a  and floor  404   a . Further, the distance from the left-most portion of each edge to the right-most portion is nearly equal to the distance between left wall  398   a  and right wall  400   a.    
     Rear portion  460   a  of floor  404   a  generally includes an upper surface  470   a  and curved edge  472   a . The arc of curved edge  472   a  spans from left wall  398   a  to right wall  400   a  with an arc radius that is slightly larger than either of the radii of curved beveled edges  466   a  and  468   a  of floor front portion  458   a . Rear curved edge  472   a  of rear floor portion  460   a , together with curved beveled edges  466   a ,  468   a  of floor front portion  458   a , left wall  398   a , and right wall  400   a  define engagement bracket opening  474   a.    
       FIGS. 21   a - 21   d  depict engagement bracket  296   a  assembled onto track bar  294   a  in an engaged position. Engagement bracket  296   a  slidably mounts to engagement end  297   a  of track bar  294 . Engagement bracket  296   a  upper left and right rear tabs  410   a  and  430   a  project through track bar  294   a  left and right engagement bracket receiving apertures  344   a  and  346   a , respectively. Left and right wall inside surfaces  406   a  and  424   a  of engagement bracket  296   a  locate adjacent to, and in contact with, left and right walls  301  and  302 , respectively. Detents  414   a  and  432   a  engage engagement bracket receiving apertures  344   a  and  346   a , and cable holes  418   a  and  436   a  register with engagement bracket receiving apertures  344   a  and  346   a . Engagement bracket left and right front tabs  416   a  and  434   a  extend through track bar left and right engagement slots  348   a  and  350   a , nearest the rear-most end of slots  348   a  and  350   a . As depicted, front wall  402   a  does not contact track bar  294   a.    
       FIGS. 22   a - 22   d  depict pull cover  298   a  that generally includes a left wall  476 , right wall  478 , left projection  480   a , right projection  482   a , top portion  484   a , and front portion  486   a . Left and right walls  476   a  and  478   a  are generally flat and rectangular, and extend away from front portion  486   a . Left and right walls include an outside surface each having a series of vertical striations  488  and  490 . Left and right walls define a pair of generally circular cable holes  492 ,  494 . 
     Left and right projections  480   a ,  482   a  extend outwardly away from walls  476   a  and  478   a . Rear portions of projections  480   a  and  482   a  include striations  488   a  and  490   a . Front portions of projections  480   a ,  482   a  are integral to pull cover front portion  498   a , which is generally flat and curved. Top portion  484   a  is generally flat and T-shaped, and generally includes a head  492   a  and shaft  494   a . Head  492   a  extends from left projection  480   a  to right projection  482   a , while shaft  494   a  extends rearward from head  492  between walls  476   a  and  478   b.    
     Pull cover  298   a  is adapted to fit on to engagement bracket  296   a  as depicted in the figures and discussed further below.  FIGS. 23   a - c  depict the projector interface member in the form of engagement fastener  121   a  and engagement collar  124   a . Engagement fastener  121   a  as depicted is a generally cylindrical, hollow threaded fastener that is open on both ends and generally includes a tapered base  496   a , threaded shaft  498   a , top hole  500   a , and bottom hole  502   a . The inside diameter of engagement fastener  121   a  is sized to receive fastener  123   a  (depicted in  FIG. 12 ), while the diameter of bottom hole  502   a  is sized to receive a shaft of fastener  123   a , but small enough not to allow the head of fastener  123   a  to pass through. 
     Engagement collar  124   a  generally includes an upper ring  504   a , lower ring  506   a , upper ring top surface  508   a , upper ring bottom surface  510   a , upper ring outer knurled surface  512   a , lower ring outer surface  514   a , lower ring bottom surface  516   a , and inside threads  518 . Engagement collar  124   a  is sized and threaded such that engagement collar  124   a  threads onto engagement fastener  121   a , such that collar  124  may be positioned vertically along threaded shaft  498   a  of fastener  121   a  as depicted in  FIG. 23   c . Outer knurled surface  512   a  enables a user to grip and turn engagement collar  124   a    
       FIGS. 24   a - b  depict the assembled position of engagement fastener  121   a  and engagement collar  124   a  with respect to track bar  294   a . As depicted, a portion of threaded shaft  498   a  protrudes through engagement fastener receiving hole  342   a  into track interior  336   a , while a portion of threaded shaft  498  remains below track bar bottom wall  304   a . The position of engagement collar  124   a  on threaded shaft  498   a  of engagement fastener  121   a  determines the depth of penetration of shaft  498   a  into interior space  336   a . Also as depicted upper ring top surface  508  of engagement collar  124   a  abuts bottom wall  304   a  of track bar  294   a  surrounding engagement fastener receiving hole  342   a.    
       FIGS. 25   a - c  depict engagement bracket  296   a  holding engagement fastener  121   a  and engagement collar  124   a  in an engaged position with track bar  294   a . As depicted, engagement bracket  296   a  is assembled to track bar  294   a  as described above. Also as depicted, engagement bracket  296   a  holds engagement fastener  121   a  and engagement collar  124   a  into the position relative to track bar  294   a  as described above with reference to  FIG. 24 . In particular, floor front portion  458  is received under engagement collar  124   a , while upper ring top surface  508   a  of engagement collar  124   a  abuts track bar  294   a , thereby tightly clamping to engagement collar  124   a . It will be appreciated that projection  464   a  is disposed between engagement collar  124   a  and floor front portion  458 , and that an upward biasing force will thus be exerted on engagement collar  124   a  at the point of contact with projection  464   a . This biasing force tends to increase frictional engagement between the threads of engagement collar  124   a  and threaded shaft  498   a  of engagement fastener  121   a , and thereby inhibiting undesired shifting of engagement collar  124   a  on threaded shaft  498   a.    
     Referring to  FIGS. 19 and 20 , floor  404   a  is generally flat and rectangular in shape, and generally includes a front portion  458   a  and rear portion  460   a . Front portion  458   a  generally includes an upper surface  462   a , projection  464   a , curved upper beveled edge  466   a , and curved lower beveled edge  468   a . In some embodiments, floor front portion  458  may only include a single beveled edge. Curved upper beveled edge  466   a  and curved lower beveled edge  468   a  are generally semi-circular, with edge  466  having an arc radius slightly longer than the radius of curved lower beveled edge  468   a . The angle formed between curved upper beveled edge  466   a  and floor  404   a  is slightly larger, or steeper, than the relative angle between curved lower beveled edge  468   a  and floor  404   a . Further, the distance from the left-most portion of each edge to the right-most portion is nearly equal to the distance between left wall  398   a  and right wall  400   a.    
       FIG. 25   c  depicts pull cover  298   a  positioned over engagement bracket  296   a  with engagement fastener  121   a  and engagement collar  124   a  held into track bar  294   a.    
     Referring to  FIGS. 26   a  to  26   f , the relational positions of engagement fastener  121   a , engagement collar  124   a , and engagement bracket  126   a  are depicted. 
       FIG. 26   a  is a perspective view depicting engagement collar  124   a  threaded onto engagement fastener  121   a  and protruding through engagement bracket opening  474   a  of engagement bracket  296   a . Fastener  121   a  and collar  124   a  are depicted in an engaged position as described above, such that fastener  121   a  and collar  124   a  are located in the forward side of engagement bracket opening  274   a , and in contact with floor  404 . 
       FIGS. 26   b - c  provide side views of fastener  121   a  and collar  124   a  relative to engagement bracket  296   a.    
       FIG. 26   d  provides a top view of the components as previously depicted in  FIGS. 26   a  to  26   c , while  FIGS. 26   e  and  26   f  provide cross-sectional views. 
       FIG. 27  depicts a cross section of an assembled track assembly  120   a  and its respective components. 
     Referring again to  FIGS. 1-2 , in one embodiment, projector mount  106  is the projector mount described in U.S. Pat. No. 7,497,412, previously incorporated by reference. In this embodiment, projector mount  106  includes a base assembly  520 , and a device orientation adjustment structure which includes guide assemblies  522 ,  524 , and a support structure interface in the form of support structure interface assembly  526 . In other embodiments, projector mount  106  may consist of other known projector mounts for securing and adjusting projector  102  to a pipe support  110 . 
     Projector mount  106  is operably coupled to projector interface  104  via plate-mount fastener  122   a ,  122   b ,  122   c ,  122   d . Referring to  FIG. 3 , plate-mount fastener sets  122   a ,  122   b ,  122   c ,  122   d  may each generally include an upper plate-mount fastener  122   a   1 ,  122   b   1 ,  122   c   1 ,  122   d   1 , respectively, and a lower plate-mount fastener  122   a   2 ,  122   b   2 ,  122   c   2 ,  122   d   2 , respectively. In other embodiments, plate-mount fastener sets  122  may include only a single fastener, or more than two fasteners. Further details regarding the structure, mounting, and operation of projector mount  106 , and of the manner of engagement with the plate-mount fasteners may be found in U.S. Pat. No. 7,497,412. 
     Still referring to  FIGS. 1-2 , a locking member in the form of optional cable assembly  108  includes a cable  528  and a cable lock mechanism  530 . Cable  528  may be threaded through the various cable holes associated with track assemblies  120  as described above and as depicted in  FIG. 1 . Cable lock mechanism  530  secures the ends of cable  528  together, thereby forming a continuous loop that passes through each track assembly  120 . In one embodiment, cable lock mechanism  530  may be a mechanical lock such as a key-operated padlock. In other embodiments, cable lock mechanism may be a simpler, single use device, such as the one depicted, that latches about multiple portions cable  528  to form a closed loop. Such an embodiment of cable lock mechanism  530  may require that cable  528  be cut in order to remove cable  528  from projector interface  104 . 
     In general operation and referring to  FIGS. 1-28 , projector interface  104  is mounted to projector  102 , projector mount  106  is mounted to projector interface  104 , support pipe  110  is fastened into projector mount  106 , and the entire system  100  hangs downward from a ceiling or other overhead structure. A user generally manipulates projector interface  104  and projector mount  106  to adjust the position of projector  102  such that it appropriately directs an image to an intended display surface. 
     More specifically, and referring to  FIGS. 1-2  and  12 , at initial set up, each engagement fastener  121   a ,  121   b ,  121   c  is fastened to projector  102  by inserting fasteners  123   a ,  123   b ,  123   c , into hollow engagement fasteners  121   a ,  121   b ,  121   c , respectively, and threading each fastener  123   a ,  123   b ,  123   c , into a corresponding mounting hole  114  (not shown) in projector mounting surface  112 . Each projector engagement collar  124  is threaded onto its respective engagement fastener  121 . Threading collar  124  further down on fastener  121  such that collar  124  is located relatively close to projector mounting surface  112  will cause track assembly  120  to also be relatively closer to projector mounting surface  112  as described below in further detail. 
     If projector interface  104  is pre-assembled, plate-track fasteners  125  may be loosened such that track assemblies  120  may be moved relative to interface plate  118 . Fasteners  125  in one embodiment may be loosened or tightened by hand, and in other embodiments require a tool to be inserted into fastener  125  to facilitate rotation of the fastener. In one embodiment, such a tool may be placed on to interface plate  118 , and hidden from the sight of a projector user until such time that it is needed. Because interface plate  118  forms a shallow tray, any variety of small tools may be stowed in the tray formed by interface plate  118 . 
     Referring more specifically to the arrangement depicted in  FIG. 4 , plate-track fastener  125   b  is threaded onto slide fastener  360   b , which protrudes through slot  282 . As such, track assembly  120   b  is held loosely to interface plate  118 , and may be moved along slot  282  in a direction generally indicated by arrow A, or more generally may be moved back and forth along the previously defined x-axis. Further, slide mount assembly  300   b  may be slid along track slot  352   b  allowing track bar  294   a  to be moved generally along the y-axis. Further track assembly  120   b  may be pivoted about slide fastener  360   b , such that track assembly  120   b  may be moved freely about an x-y plane, limited generally only by the length of track bar  294   a  and size and shape of slot  282 . 
     Although track assembly  120   b  is depicted as operably coupled to interface plate  118  at slot  282 , track assembly  120   b  could be moved to an alternative slot so as to move track assembly  120   b  to another slot and location relative to interface plate  118  in order to accommodate the location of projector mounting holes  114 , or to adjust the aim of projector  102 . 
     When projector interface  104  includes interface plate  119  with holes  145 , rather than slots  146 , track assemblies  120  may be moved relative to plate  119  in much the same way as described above with reference to interface plate  119 . When projector interface  104  uses interface plate  119 , slide fasteners  360  protrude through holes  145 , rather than slots  146 . In this particular embodiment, slide fasteners  360  are fixed in position relative to interface plate  119 , though track assemblies  120  may still move relative to interface plate  119  by changing the position of track bars  294  in relation to slide assemblies  300 . 
     Similarly, track assemblies  120   a  and  120   c  may be moved and adjusted in a similar manner so as to accommodate a variety of projector  102  types and projector viewing environments. As such, projector interface  104  functions as a universal projector interface that may be used with a variety of projectors  102  and projector mounts  106 . 
     In use, projector  102  is coupled to projector interface  104  by shifting engagement bracket  296   a  on track bar  294   a . With engagement bracket  296   a  pushed onto track bar  294   a  to the limit of its travel, engagement bracket opening  474   a  and engagement fastener receiving hole  342   a  are registered. The top of threaded shaft  498   a  is received through engagement fastener receiving hole  342   a  with upper ring top surface  508  of engagement collar  124   a  abutting bottom wall  304   a  of track bar  294   a  surrounding engagement fastener receiving hole  342   a . With engagement fastener  121   a  received in this fashion, engagement bracket  296   a  can be pulled outward relative to track bar  294   a . Front portion  458   a  of engagement bracket floor  404   a  is received under engagement collar  124   a , while upper ring top surface  508  of engagement collar  124   a  is urged against bottom wall  304   a  of track bar  294   a , thereby tightly clamping track bar  294   a  to engagement fastener  121   a . Each track assembly  120   a ,  120   b ,  120   c , is thereby quickly and easily secured to an engagement fastener on projector  102 . 
     In some instances, after projector mounting system  100  is set into place and properly adjusted via projector interface  104  and projector mount  106 , it may be desirable to remove projector  102 . For example, projector  102  may require replacement, servicing, or a simple bulb replacement. Most projectors  102  include an access door  116  similar to the one depicted in  FIGS. 1-2  that must be opened to replace a projector bulb, or to otherwise perform service on projector  102 . To fully open access door  116 , projector  102  must be removed from projector interface  104 . In such instances, the track assemblies can be quickly disengaged for projector removal or service simply by pushing the engagement brackets onto the track arms such that front portion  458   a  of engagement bracket floor  404   a  slides out from under engagement collar  124   a , thereby releasing the engagement fasteners. 
     In contrast, when a projector is reinstalled into a previous mounting system that does not include projector interface  104  of the present invention, the projector  102  must typically be readjusted for roll, pitch, and yaw. As noted previously, this process may be very time consuming and difficult due to the generally limited adjustment capability of the mounting system. 
     When a projector  102  is installed as part of mounting system  100  that includes projector interface  104 , however, such time-consuming readjustment procedures are eliminated. The only parts that need to be shifted in order to remove and reinstall projector  102  are the sliding engagement brackets, which interface with the engagement fasteners on the projector in nearly precisely the same orientation upon reinstallation as upon removal. In this way, the alignment positioning of the projector is maintained without further adjustment even after the projector is removed for service and reinstalled. 
       FIGS. 26-27 , depict track assembly  120   a  engaged with engagement fastener  121   a  and engagement collar  124   a . Engagement fastener  121   a  and engagement collar  124   a  are located in a forward-most position relative to engagement bracket opening  474   a . The arc radii of beveled edges  466 ,  468  are less than the radius of collar top ring collar  504   a , such that a portion of top ring bottom surface  510  rests on bracket floor front upper surface  462   a . Bracket beveled edges are in contact with a portion of collar lower ring outer surface  514   a . In this engaged position, tabs  416   a ,  434   a  are in a forward-most position in slots  348   a ,  350   a , respectively, while tabs  410   a ,  430   a  are in a forward-most position in apertures  344   a ,  346   a , respectively. 
     When track assembly  120   a  is attached to projector interface  104 , engagement fastener  121   a  is attached to projector  102 , and projector  102  is otherwise suspended in place by mounting system  100 , projector interface  104  is in the “engaged” or locked position with projector  102 . As such, projector  102  is attached to track assemblies  120 . The weight of projector  102  creates a downward force due to gravity on engagement fasteners  121  and collars  124  which are engaged with engagement brackets  296 , thereby tending to hold track assemblies  120  and projector  102  in place. 
       FIG. 28   a  is a top view of engagement bracket  296   a , engagement fastener  121   a , engagement collar  124   a , and fastener  123   a , assembled together in an engaged position such that projector interface  104  supports projector  102  in an aligned and adjusted position. 
       FIG. 28   b  is a top view of engagement bracket  296   a , engagement fastener  121   a , engagement collar  124   a , and fastener  123   a , in a disengaged position. In this position, engagement bracket  268  has been moved in a direction indicated by arrow B of  FIG. 28   a  to a disengaged position of  FIG. 28   b . As such, the position of engagement fastener  121   a  with collar  124   a  is changed such that fastener  121   a  and collar  124   a  are located towards the rear, or mount-side, of engagement bracket opening  474   a.    
     In this disengaged position, tabs  416   a ,  434   a  are in a rearward position in slots  348   a ,  350   a , respectively, while tabs  410   a ,  430   a  are in a rearward position in apertures  344   a ,  346   a , respectively. The radius of engagement bracket rear floor portion is larger than the radius of engagement collar  124   a , such that engagement fastener  121   a  with collar  124   a  attached to projector  102  may be pulled downward away from track assembly  120   a.    
     To move an engagement bracket  296  back and forth between an engaged and disengaged position as depicted in  FIG. 28 , a user may grip a pull cover  298  at cover projections  480  and  482  and pull cover  298  and attached bracket  296  in a direction of arrow B to engage, or push in a direction generally opposite to direction B to disengage. 
     As such, the position of projector interface  104  relative to projector mount  106  remains fixed, with both assemblies remaining attached to support pipe  110 . Accordingly, when projector  102  is reattached to projector interface  104 , projector  102  is placed into substantially the same position it was in prior to removal, and no projector readjustment is required. 
     In addition to the devices, systems, and methods described above, the present invention also includes a method of providing a projector interface as substantially described above and a set of instructions for using the projector interface. More specifically, the method includes the step of providing a universal projector interface  104  that includes a plate  118  with openings, operably coupled to a plurality of track assemblies  120 , and wherein the projector interface is adapted to operably couple a projector  102  to a projector mount  106 , such that after initial adjustment, projector  102  may be disconnected from, then reconnected to, projector interface  104  without readjusting the relative positions of the projector  102 , interface  104 , and interface mount  106 . The method also includes the step of providing a set of instructions that instruct a user on how to attach and detach the projector interface  104  to a projector  102  and a projector mount  106 . 
     In  FIGS. 29   a - 41  there are depicted various alternative coupling portion and corresponding projector interface member embodiments. Depicted in  FIG. 29   a  is a bayonet mount arrangement  600   a  which generally includes projector interface member  98  and bayonet portion  602 . Projector interface member  98  generally includes barrel portion  600  and threaded interface  601 . Barrel portion  600  defines horizontally opposed hooked slots  600   a ,  600   b . Threaded interface  601  is adapted to thread into threaded mounting apertures (not depicted) typically provided on a projector  102 . Bayonet portion  602  generally includes cylindrical body  603  with horizontally opposing projections  603   a ,  603   b . Projections  603   a ,  603   b , are disposed so as to correspond with hooked slots  600   a ,  600   b.    
     In use, threaded interfaces  601  are threaded into apertures of the projector  102  so that barrel portions  600  face upward. Bayonet portions  602  are rotatably attached to the bottom face of each of track assemblies  120   a ,  120   b ,  120   c . The track assemblies  120   a ,  120   b ,  120   c , are then positioned so that each bayonet portion  602  is registered with one of barrel portions  600 . Projector  102  is then coupled to universal projector interface  104  by advancing bayonet portions  602  into barrel portions  600  with projections  603   a ,  603   b , registered with hooked slots  600   a ,  600   b . Bayonet portions  602  are then rotated relative to track assemblies  120   a ,  120   b ,  120   c , to hook projections  603   a ,  603   b , into hooked slots  600   a ,  600   b . Removal is the reverse of installation. 
     Referring to  FIGS. 29   b   1  and  29   b   2 , a coupling portion in the form of a watch band-like clasp mechanism  605  may be employed to attach a projector  102  to a projector interface  104 . In this embodiment, projector interface  104  includes a track assembly  120   a ,  120   b ,  120   c , presenting end  604  with attached clamp  606 . Clamp  606  is adapted to clamp to a projector interface member in the form of dome-topped projection  608  attached to a portion  610  of projector  102 , thereby locking projector  102  to projector interface  104 . 
     Referring to the embodiment of  FIG. 29   c , coupling portions  611  are disposed on an end of each of track assemblies  120   a ,  120   b ,  120   c , and each generally includes bifurcate receiving portion  612  and sliding key  622 . Receiving portion  612  defines horizontal slot  614  separating branches  613   a ,  613   b , with transverse aperture  616  extending through both branches  613   a ,  613   b . Key  622  defines keyhole slot  624  and guide slots  625 . Spring  627  projects from end  627   a  of key  622 . Key  622  is received in slot  614  with guide posts  629  extending through guide slots  625 . Spring  627  bears on back wall  614   a  and biases key  622  outward. Projector interface member  617  generally includes domed projection  618  defining horizontal groove  618   a . Threaded portion  620  threads into an aperture (not depicted) on projector  102 . 
     In use, key  622  is pressed inward against the bias of spring  627  until large portion of keyhole slot  624  is registered with aperture  616 . Coupling portion  611  can then be engaged over projector interface member  617  such that projector interface member  617  extends through keyhole slot  624  and aperture  616 . With key  622  registered with groove  618   a , key  622  can be allowed to spring outward, biased by spring  627 . Projector interface member  617  engages in the narrower neck portion of keyhole slot  624 , thereby retaining coupling portion  611  on projector interface member  617 . Removal is the reverse of installation. 
     Referring to  FIG. 29   d , track assemblies  120   a ,  120   b ,  120   c , each include a coupling portion  626  defining a key slot  628 . Projector interface member  630  is threaded into an aperture (not depicted) on projector  102  and is adapted to fit through key slot  628 . Projector interface member  630  is inserted through slot  628 , and projector interface member  630  is rotated ¼ turn, hence locking projector  102  to projector interface  104 . Removal is the reverse of installation. 
     Referring to  FIGS. 30   a - 30   b , projector interface  104  generally includes track assembly  120   a ,  120   b ,  120   c  with end  632  defining aperture  633 , and a coupling portion in the form of post  634 , and coupling slide  635  defining guide slot  636 . A projector interface member in the form of grooved post  637  projects outward from projector  102 . Coupling slide  634  slides relative to track bar  632 , with post  634  engaging and riding in guide slot  636 . Grooved post  637  is sized to be inserted through aperture  633  of end  632 . When grooved post  637  is inserted through aperture  633  of end  632 , slide  634  may be advanced toward grooved post  637  such that bifurcate end  635  of slide  634  engages around grooved post  637  to couple into end  632  such that slide  634  engages grooved post  637 , thereby locking projector  102  to track assembly  120   a ,  120   b ,  120   c.    
     Referring to  FIGS. 31   a - 31   b , a coupling portion in the form of squeeze latch mechanism  641  is used to attach a track assembly  120   a ,  120   b ,  120   c , of projector interface  104  to a projector  102 . In this embodiment, track assembly  120   a ,  120   b ,  120   c , includes a resilient squeezable end  638  which defines an opening  640 . Force is applied to two sides of squeezable end  638  such that opening  640  opens up as depicted in  FIG. 31   b . As such, pressure may be applied to squeezable end  638  as depicted in  FIG. 31   a  to expand opening  640 . End  640  may then be placed over a projector interface member in the form of post  642  projecting from projector  102  and the pressure released, thereby attaching projector interface  104  to projector  102 . Removal is the reverse of installation. 
     Referring to  FIG. 32 , track assembly  120   a ,  120   b ,  120   c , projector interface  104  includes a coupling portion in the form of bar end  644 . End  644  defines a pair of small side apertures  646   a ,  646   b , and a larger bottom aperture  648  (not depicted). A projector interface member in the form of engagement fastener  649  defines side holes  650   a ,  650   b , and is attached to a projector  102 . End  644  is placed over fastener  649  such that fastener  649  extends through aperture  648 . Apertures  650   a ,  650   b  register with apertures  646   a ,  646   b , respectively. Pin  652  is inserted through apertures  650   a ,  650   b ,  646   a ,  646   b , thereby coupling projector interface  104  and projector  102 . 
     Referring to  FIG. 33 , in another embodiment, each track assembly  120   a ,  120   b ,  120   c , includes a coupling portion in the form of spring clip  654  adapted to receive an end portion  656  of track assembly  120   a ,  120   b ,  120   c . End portion  656  and spring  654  may be trapezoidally shaped as depicted. Spring clip  654  includes end tabs  658  and  660  that forcibly contact top surface  662 , thereby holding end  656  of track assembly  120   a ,  120   b ,  120   c , to projector  102  via spring clip  654 . 
     Referring to  FIGS. 34   a - 34   b , projector interface  104  includes a coupling portion in the form of squeeze mechanism  664  attached to an end  666  of track assembly  120   a ,  120   b ,  120   c , of projector interface  104 . As depicted in  FIG. 34   b , squeeze mechanism  664  grips a projector interface member in the form of projector post  668  when force is not applied to it. When force is applied to mechanism  664  as depicted in  FIG. 34   a , the grip on post  668  is released, allowing easy removal of projector  102  from projector interface  104 . 
     Referring to  FIG. 35 , projector interface  104  includes a track assembly  120   a ,  120   b ,  120   c , having an end  670  with a coupling portion in the form of end plate  672 , locking knob  674  with locking pin  675 , and track bar fastener  676 . Fastener  680  attaches a projector interface member in the form of engagement fastener  678  to projector  102 . Track bar fastener  676  is threaded into engagement fastener  678 . Alternatively, track bar fastener  676  is attached to engagement fastener  678  via fastener  680 . The track bar fastener attached to engagement fastener  678  is inserted up into track bar  670  via an aperture or slot (not depicted) in track bar  670 . Locking knob  674  is held in position by plate  672 , and is rotated inward such that an end  675  of locking knob  674  fits into a mating groove  682  of fastener  676 , thereby locking projector interface  104  to projector  102 . 
     Referring to  FIGS. 36   a ,  36   b , track assembly  120   a ,  120   b ,  120   c , of projector interface  104  is removably coupled to projector  102  via a coupling portion in the form of pivoting latch mechanism  683 . Mechanism  683  generally includes a bar  684  with stop  686 , pivoting mechanism  688 , pivot point  690 , a projector interface member in the form of engagement fastener  692 , and pin  694 . Engagement fastener  692  is generally attached to projector  102  in the engaged or attached position. Engagement mechanism  688  pivots about point  690 , thus defining a large opening when pivoted away from bar  684  and a small opening when closed and adjacent to stop  686 . In the closed, or engaged position, the mechanism fits over, or grips engagement fastener  692 , thereby coupling projector  102  to interface  104 . In the open, or disengaged position, bar  684  and the associated pivoting mechanism or latch may be pulled away from fastener  692 , thereby disengaging projector  102 . 
     Referring to  FIG. 37 , a coupling portion in the form of plunger latch mechanism  699  may be used to removably couple a projector  102  to a projector interface  104 . The depicted system generally includes a track assembly  120   a ,  120   b ,  120   c , presenting end  700 , plunger assembly  702  and projector  102 . Plunger assembly  702  generally includes plunger  704 , plunger sleeve  706 , and a projector interface member in the form of receiving sleeve  714 . Plunger sleeve  706  includes a large diameter upper portion  707  small diameter lower portion  709  and movable ball detents  708 . Receiving sleeve  714  generally defines radial groove  716 . Receiving sleeve  714  is set into projector  102  and adapted to receive lower portion  709  and detents  708 . With lower portion  709  inserted into receiving sleeve  714  ball detents  708  move toward and into groove  716  when plunger  704  is raised, thereby locking projector interface  104  to projector  102 . When plunger  704  is pushed in, or lowered, bar  700  may be pulled upward and away from projector  102 . 
     Referring to  FIG. 38 , a coupling portion in the form of hook latch mechanism  717  may be used to removably connect projector interface  104  to projector  102 . The depicted system includes track assembly  120   a ,  120   b ,  120   c , of projector interface  104  presenting end  718 , hook latch assembly  720 , a projector interface member in the form of engagement fastener  722 , and engagement collar  724 . Engagement fastener  722  is attached to projector  102  with engagement collar  124  threaded over it. Latch hook assembly  720  includes a hook  722  and pivot pin  724 . When a downward force is applied to end  722   a  of hook  722 , hook  722  pivots about pin  724  and disengages collar  724  from end  718 , thereby uncoupling projector  102  from projector interface  104 . 
     Referring to  FIGS. 39   a - 39   b , a coupling portion in the form of tool-actuated latch mechanism  725  may be used to removably connect track assembly  120   a ,  120   b ,  120   c , of projector interface  104  to projector  102 . The system of the depicted embodiment includes track assembly  120   a ,  120   b ,  120   c , presenting end  726 , inside fastener  730 , ridged slide bar  731 , a projector interface member in the form of engagement fastener  728 , engagement collar  729 , and tool  736 . Ridged slide bar  731  defines ridges  732  and retaining end  734 . Engagement fastener  728  is coupled to projector  102  and receives threaded collar  729 . Inside fastener  730  includes a head portion  730   a  and defines groove  736 . Fastener  730  may be integral to, or separate from, engagement fastener  728 , and is inserted into an interior space of track bar  120   a ,  120   b ,  120   c . In the locked or engaged position, end  734  is located in groove  736  such that engagement fastener  728  and projector  102  are locked to track assembly  120   a ,  120   b ,  120   c . Tool  736  is a Phillips screwdriver in one embodiment, but may be any other similarly functioning tool. Tool  736  is inserted into hole  727  and engages ridges  732  of slide  731 . The rotation of tool  736  causes slide  731  to move toward or away from groove  736 , thereby locking or unlocking projector  102 . 
     Referring to  FIGS. 40   a - c , a coupling portion in the form of pivoting latch mechanism  739  may be used to removably connect projector interface  104  to projector  102 . The system of the depicted embodiment generally includes track assembly  120   a ,  120   b ,  120   c , presenting end  740 , pivoting latch mechanism  742  and a projector interface in the form of post  744 . End  740  defines a pair of openings  746   a ,  746   b . Latch mechanism  742  includes latch  748  with top portion  752 , side portion  754 , and pivot pin  750 . Latch  748  defines curved retention space  756 . Post  744  includes a head  758  with a diameter larger than the diameter of the shaft of pin  744 , and in the locked or connected position is inserted upward and through end  740 . Latch  742  is pivoted about pin  750  so that top portion  752  contacts post  744 . Curved retaining space  756  receives the shaft of post  744 , while post head  758  remains above latch top portion  752 , thereby locking projector  102  to end  740 . To unlock projector  102  from end  740  of projector interface  104 , latch  742  is pivoted away from end  740 , disengaging latch  742  from post  744 , allowing post  744  attached to projector  102  to be removed from end  740 . 
     Referring to  FIG. 41 , a coupling portion in the form of rotating latch mechanism  759  may be used to removably connect projector interface  104  to projector  102 . The system of the depicted embodiment generally includes track assembly  120   a ,  120   b ,  120   c , of projector interface  104  presenting end  760 , rotating mechanism  762 , and a projector interface member in the form of grooved engagement fastener  764 . End  760  may be cylindrical in shape so as to match the cylindrical shape of rotating mechanism  762 . Rotating mechanism  762  is rotatably attached to end  760  and generally defines an orifice  766  sized to receive grooved engagement fastener  764 , and one or more grooves  765 . Grooved engagement fastener  764  is attached at a bottom end to projector  102 , and is removably inserted through orifice  766  into rotating mechanism  762 . Rotating  762  causes an edge portion of rotating mechanism  762  near orifice  766  to be inserted into a groove  765 , thereby locking rotating mechanism  762  and bar  760  to grooved engagement fastener  764  and projector  102 . 
     Another embodiment of a projector interface  104  according to an embodiment of the invention is depicted in  FIGS. 42-49 . In this embodiment, projector interface  104  generally includes interface assembly  800  and identical track assemblies  802 ,  804 ,  806 ,  808 . Interface assembly  800  generally includes tray  810 , cover  812 , and attachment studs  814 . Tray  810  defines a plurality of apertures  816 . 
     Track assemblies  802 ,  804 ,  806 ,  808 , generally include track bar  818  and coupling portion  820 . Track bar  818  defines upwardly facing channel  822  which slidably receives fastener  824  for coupling the track bar to tray  810  through one of apertures  816 . Coupling portion  820  generally includes slide clip  826  and grip portion  828 . Slide clip  826  is received on end  830  of track bar  818  with tabs  832  received in apertures  833  and tabs  834  received in notches  836 . Grip portion  828  is received on slide clip  826  to provide improved gripping purchase for the fingers of a user. Bottom side  838  of track bar  818  defines generally round aperture  840 . Bottom side  842  of slide clip  826  defines oblong aperture  844 . Oblong aperture  844  is generally registered with aperture  840  when slide clip  826  is received on track bar  818 . 
     Projector interface member  846  generally includes threaded barrel  848  and collar  850 , which is threaded onto barrel  848 . Barrel  848  may be coupled to projector  102  with a fastener (not depicted) as described elsewhere in this application. Barrel  848  has a diameter smaller than that of aperture  840 , and collar  850  has a diameter larger than that of aperture  840  but smaller than the least dimension of aperture  844 . 
     As depicted in  FIGS. 45-48 , track assemblies  802 ,  804 ,  806 ,  808 , may be coupled to a projector interface member  846  and an attached projector by shifting slide clip  826 . As depicted in  FIGS. 47 and 48 , with slide clip  826  pushed onto track bar  818  to the limit of its travel as defined by the interface of tabs  832  in apertures  833  and tabs  834  in notches  836 , apertures  840  and  844  are registered. The top of barrel  848  is received through aperture  840  with collar  850  abutting bottom side  838  of track arm  818 . With projector interface member  846  received in this fashion, slide clip  826  can be pulled outward as depicted in  FIGS. 45 and 46 . Rear edge  852  of aperture  844  is received under collar  850 , while the top surface of collar  850  is urged against bottom side  838  of track arm  818 . Each track assembly  802 ,  804 ,  806 ,  808 , is thereby quickly and easily secured to a projector interface member  846  on projector  102 . The track assemblies can also be quickly disengaged for projector removal or service simply by pushing the slide clips onto the track arms such that the projector interface member is released. 
     Various modifications to the invention may be apparent to one of skill in the art upon reading this disclosure. For example, persons of ordinary skill in the relevant art will recognize that the various features described for the different embodiments of the invention can be suitably combined, un-combined, and re-combined with other features, alone, or in different combinations, within the spirit of the invention. Likewise, the various features described above should all be regarded as example embodiments, rather than limitations to the scope or spirit of the invention. Therefore, the above is not contemplated to limit the scope of the present invention. 
     For purposes of interpreting the claims for the present invention, it is expressly intended that the provisions of Section 112, sixth paragraph of 35 U.S.C. are not to be invoked unless the specific terms “means for” or “step for” are recited in a claim.