Abstract:
A lamp mount system for high voltage projector lamps includes only a few parts which fit together without the need for connecting hardware. A single piece clip snaps into a single piece lamp mount and, together with the lamp form a lamp mounting assembly. The lamp mounting assembly in turn slidably engages with a single piece lamp base. The lamp mount assembly may be slideably removed when the lamp burns out.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority on U.S. Provisional Patent Application 60/818,649 filed Jul. 5, 2006, which is incorporated here by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to lamp mount system for high voltage lamps in illumination systems such as projectors. 
     2. Description of Related Art 
     An optical assembly to produce illumination for a projection system has several optical elements to accept and shape and relay the light from a lamp. Therefore the accurate positioning of the lamp with respect to these optical elements is mandatory. Because of the nature of the operation of an arc lamp, there is an issue with lifetime. This means that many illumination systems that use arc lamps will need to have the lamp replaced at least once. 
     Prior mounting systems for lamps in projection systems generally include many elements, such as springs, wire guides and connecting screws. While such systems work well for retaining the lamp, they are unnecessarily complicated to manufacture and require too much time and effort to assemble or to remove a burned out lamp and insert a new one. 
     A need remains in the art for a lamp mount system for projectors, having only a few parts which snap together without the need for connecting hardware. 
     SUMMARY 
     An object of the present invention is to provide a lamp mount system for projectors, having only a few parts which snap together without the need for connecting hardware. This is accomplished by assembling, outside the projector, a lamp mounting assembly which comprises a lamp mount piece, the lamp and a clip. The lamp is inserted between the lamp mount piece and the clip, and the lamp mount piece and the clip snap together to form the lamp mounting assembly. The lamp mounting assembly is then inserted into the projector as a unit. 
     Preferably the clip is formed using a single piece of sheet metal. Preferably the lamp mount piece is formed of a single element of injection molded plastic. 
     The lamp mount piece comprises means for accurately positioning and fixing the lamp perpendicular to the optical axis. For example the lamp mount piece could include integrated preload features which flex away as the lamp is inserted and bias inward to hold the lamp in place in the mounting assembly. 
     The lamp mount piece (which now forms part of the lamp mounting assembly), in turn engages with a lamp base which fits into the projector. Preferably the lamp base is formed of a single element of injection molded plastic. 
     Rails on the lamp mount piece slide into channels on the lamp base, and a flexing integral arm on the lamp base holds the mounting assembly in place. No further connection hardware or separate biasing elements are required. 
     In order to replace the lamp, the inventive lamp mounting assembly can be easily slid out of the projector if the integral arm is bent. 
     This results in a simple means of replacing lamps while some accuracy of alignment is maintained. 
     Another benefit of the simplified assembly is that the cost of the assembly is also reduced by using fewer parts and reducing the assembly time required. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded isometric view of the lamp mounting assembly comprising a lamp mount piece, a clip and a lamp. 
         FIG. 2  is an isometric view of the lamp mount piece of the lamp mounting assembly portion of  FIG. 1 . 
         FIG. 3  is an isometric view of the lamp mounting assembly of  FIG. 1 , shown assembled. 
         FIG. 4  is an isometric view of the lamp mounting assembly and the corresponding lamp base, shown separated, from the lamp side. 
         FIG. 4A  shows the separated elements of  FIG. 4  from the reverse angle. 
         FIG. 5  is an isometric view of the lamp mounting assembly and the corresponding lamp base, shown assembled from the lamp side (without the lamp). 
         FIG. 5A  shows the assembled elements of  FIG. 5  from the reverse angle. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The reference numbers below and their associated elements are used in the figures and specification: 
     
       
         
               
               
             
           
               
                   
               
               
                 Reference number 
                 Element 
               
               
                   
               
             
             
               
                 102 
                 Clip 
               
               
                 104 
                 Lamp 
               
               
                 106 
                 Lamp mount piece 
               
               
                 108 
                 Locking Tabs 
               
               
                 110 
                 Stirrups 
               
               
                 111 
                 Top inside edge of stirrups 
               
               
                 112 
                 Preloads 
               
               
                 113 
                 Side walls with preloads (side walls) 
               
               
                 114 
                 Protrusion 
               
               
                 115 
                 Top and bottom walls (end walls) 
               
               
                 116 
                 Lamp mounting assembly 
               
               
                 117 
                 Top and bottom clip flaps (end flaps) 
               
               
                 118 
                 Side clip flaps (side flaps) 
               
               
                 120 
                 Lamp base 
               
               
                 122 
                 Channels 
               
               
                 124 
                 Guide Rails 
               
               
                 126 
                 Locking arm 
               
               
                 128 
                 Interlock recess 
               
               
                 130 
                 Arms - protrusion 
               
               
                 132 
                 Lip 
               
               
                   
               
             
          
         
       
     
       FIG. 1  is an exploded isometric view of the lamp mounting assembly  116  of the lamp mount of the present invention. The lamp mounting assembly  116  comprises a single sheet metal lamp clip  102  which snaps onto a lamp mount piece  106  via locking tabs  108  and stirrups  110 , holding lamp  104  in place. Clip  102  includes side clip flaps  118  having locking tabs  108 , and also includes top and bottom flaps  117  without tabs (note that “top” and “bottom” as used in this description specify top and bottom in the figure described, rather than actual orientations in, for example, a projector). Lamp mount piece  106  includes side walls  113  with preload elements  112 , and also includes top and bottom walls  115  without preloads. Stirrups  110  are placed outside of preload walls  113 . The lamp mounting assembly is shown assembled in  FIG. 3 . Locking tabs  108  on clip  102  slide under and into stirrups  110  on lamp mount piece  106 . Tabs  108  are biased inward as they are inserted, and then snap open within stirrups  110  to hold the assembly together. Lamp mount piece  106  includes preload features  112  on side preload walls  113  (better shown in  FIG. 2 ) which hold the lamp  104  in place. 
       FIG. 2  is an isometric view of the lamp mount piece  106  of the lamp mounting assembly  116  of  FIG. 1 . In the preferred embodiment, lamp mount piece  106  is a single injection molded piece of plastic. Preload features  112  are molded into side walls  113  and flex away as lamp  104  is inserted. The structure of stirrups  110  is better shown in this figure, because the spaces in preload walls  113  into which clip  102  side walls  118  with tabs  108  slide are more visible. 
       FIG. 3  is an isometric view of the lamp mounting assembly  116  of  FIG. 1 , shown assembled. Tabs  108  have sprung back outward after insertion, and catch on the top inside edges  111  of stirrups  110 , preventing clip  102 , and hence lamp  104  from separating from lamp mount piece  106 . Side flaps  118  slide outside of preload walls  113  (but inside stirrups  110 ). Top and bottom flaps  117  slide outside top and bottom walls  118 . 
       FIGS. 4 ,  4 A,  5  and  5 A show how the lamp mounting assembly  116  is engaged with lamp base  120 . For clarity in these figures the lamp  104  as well as the clip  102  are not shown. In practice, the entire lamp mounting assembly  116 , comprising clip  102 , lamp  104  and lamp mount piece  106 , would be engaged with lamp base  120 .  FIG. 4  and  FIG. 4A  are isometric views of the lamp mounting assembly  116  and the lamp base  120  shown separated.  FIG. 4  is a view from the lamp side and  FIG. 4A  is a view from the opposite side (both without lamp  104 , for clarity).  FIG. 4A  is an isometric view of the lamp mounting assembly  116  and the lamp base  120  shown separated but from the other side.  FIG. 5  and  FIG. 5A  are isometric views of the lamp mounting assembly  116  and lamp base  120  shown assembled (both without lamp  104 , for clarity).  FIG. 5  is a view from the lamp side and  FIG. 5A  is a view from the opposite side. 
     Guide rails  124  slide into channels  122  (with assembly  116  in front of base  120  in  FIG. 4 ). Locking flexible arm  126  snaps over interlock tab  128  (shown in  FIG. 4A ) and holds the mounting assembly in place until arm  126  is deflected away from interlock tab  128  by pushing it away. In addition, arms  130  on lamp base  120  bracket finger protrusions  114  (shown in  FIG. 4A ) on assembly  116  when the elements are engaged (see  FIGS. 5 and 5A ) for additional stability. Arms  130  guide protrusion  114  in as it is inserted, and prevent sideways motion when assembled. Also in addition, finger protrusion  114  engages with lip  132  on lamp base  120  to create a preload. Lamp base  120  is preferably injection molded as one piece of plastic, and requires no additional hardware. 
     Lamp replacement is quick and easy and requires no tools. Locking arm  126  is pushed away from interlock tab  128 . Assembly  116  slides apart from lamp base  120 , via rails  124  sliding within channels  122 . 
     Note that the methods of supplying electricity to lamp  104  are convention and well known and are not shown here. For example, the electrical connection could be made manually, via a cord with connector. Or, the electrical connector could be built into the projector, with the lamp engaging with the connector as it slides into place. 
     Note that  FIGS. 1-5A  illustrate a particular embodiment of the invention for a specific use. For example, the aperture in lamp base  120  is smaller than the aperture in lamp mount piece  106 . This is because lamp mount piece  106  is envisioned as a universal part for use in a variety of projectors, while the particular lamp base  120  of  FIGS. 4-5A  is used in a device requiring a smaller aperture.