Abstract:
A cathode ray tube having an evacuated envelope including a substantially rectangular faceplate panel with a sidewall joined to a funnel and an implosion resistant band surrounding at least a portion of the sidewall and in contact therewith. The cathode ray tube is mounted in a cabinet by a plurality of mounting lugs. The mounting lugs having a base portion attached to the implosion resistant band, an adjoining portion substantially perpendicular to the base portion, and a mounting portion positioned at an angle in respect to the adjoining portion. The mounting portion having an aperture for receiving a fastner for coupling the mounting portion to the cabinet.

Description:
FIELD OF THE INVENTION 
     The invention relates to cathode ray tubes (CRTs) and, more particularly, to a mounting lug for mounting the CRT to a cabinet. 
     BACKGROUND OF THE INVENTION 
     Shown in FIG. 1 is a conventional cathode ray tube  10  (CRT) having an evacuated glass envelope  32  including a substantially rectangular faceplate panel  30  and a tubular neck  34  connected by a funnel  22 . An electron gun (not shown) is mounted within the tubular neck  34  and is designed to be used with an external magnetic deflection yoke  42  positioned in the vicinity of the funnel-to-neck junction. The faceplate panel  30  has a peripheral flange or sidewall  12  that is sealed to the funnel  22  by a glass frit  38 . 
     An implosion resistant band  14  surrounds at least a portion of the sidewall  12 . One type of implosion resistant band  14  is a shrink fit band formed from a steel strip that is joined at the ends by a weld  36 . Before assembly, the periphery of the implosion resistant band  14  is initially slightly smaller than the periphery of the faceplate panel  30 . The implosion resistant band  14  is then heated to cause it to expand to a dimension that allows it to be fitted around the sidewall  12  of the faceplate panel  30 . As the implosion resistant band  14  cools, it shrinks to contact the sidewall  12  thereby applying a compressive force to the faceplate panel  30 . Although an implosion resistant band  14  in the form of a shrinkfit band is illustrated, alternatively, the implosion resistant band  14  may be a conventional tension band having ends fixed by a crimped closure. 
     Positioned at corners of the CRT  10  are mounting lugs  16  that affix the CRT  10  within a cabinet  18  adjacent to a substantially rectangular cabinet opening  46 . As shown in FIG. 2, each of the mounting lugs  16  typically has a mounting portion  26  positioned essentially perpendicular to a base portion  28 . The base portion  28  of the mounting lug  16  is attached to a surface  70  of the implosion resistant band  14  by a weld. The mounting lug  16  may optionally be integral with or disposed between the implosion resistant band  14  and the sidewall  12  of the faceplate panel  30 . The mounting portion  26  of the mounting lug  16  is provided with an aperture  44  to effectively couple the CRT  10  to a corresponding hole  48  in the cabinet  18  with an attachment member  20  such as a bolt, screw, etc. Because the mounting portion  26  is essentially perpendicular to the sidewall  12  of the faceplate panel  30 , the CRT  10  is coupled to the cabinet  18  along a Z-axis of the CRT  10 . The Z-axis is shown by the dashed lines in FIGS. 1 and 2. 
     The cabinet  18  includes speakers  24 , as best shown in FIG.  1 . Because most speakers  24  are installed to point towards the viewer, the speakers  24  are mounted in the cabinet  18  parallel to the Z-axis of the CRT  10 . Microphonic action associated with the speakers  24  creates vibrations in the cabinet  18 . Because the speakers  18  and the mounting lugs  16  are both mounted in the cabinet  18  along the Z-axis, vibrations along the Z-axis are coupled through the cabinet  18  to the mounting lugs  16  and finally to the CRT  10 . Such microphonic vibration coupling to the CRT  10  can cause undesirable anomalies in the picture due to electron beam misregister or component shifting within the CRT  10 . It is therefore desirable to develop a mounting lug  16  that will couple a CRT  10  to a cabinet along an axis other than parallel to the Z-axis to minimize microphonic vibration coupling to the CRT  10 . 
     SUMMARY OF THE INVENTION 
     This invention relates to a cathode ray tube (CRT) having an evacuated envelope including a substantially rectangular faceplate panel with a sidewall joined to a funnel and an implosion resistant band surrounding at least a portion of the sidewall in contact therewith. The CRT is mounted in a cabinet by a plurality of mounting lugs. The mounting lugs include a base portion attached to the implosion resistant band, an adjoining portion substantially perpendicular to the base portion, and a mounting portion positioned at an angle in respect to the adjoining portion. The mounting portion has an aperture for receiving a fastner for coupling the mounting portion to the cabinet. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will now be described by way of example with reference to the accompanying figures, in which: 
     FIG. 1 is a perspective view of a CRT coupled by conventional mounting lugs to a cabinet of the prior art. 
     FIG. 2 is a perspective view of a conventional mounting lug of the prior art. 
     FIG. 3 is an enlarged partial cross-sectional view of the CRT showing the CRT coupled to the cabinet by a first embodiment of a mounting lug. 
     FIG. 4 is a perspective view of the first embodiment of the mounting lug. 
     FIG. 5 is an enlarged partial cross-sectional view of the CRT showing the CRT coupled to the cabinet by a second embodiment of the mounting lug. 
     FIG. 6 is a perspective view of the second embodiment of the mounting lug. 
     FIG. 7 is an enlarged partial cross-sectional view of the CRT showing the CRT coupled to the cabinet by a third embodiment of the mounting lug. 
     FIG. 8 is a perspective view of the third embodiment of the mounting lug. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIGS. 3 through 8 show a first, second and third embodiment of a mounting lug  116 ,  216 ,  316 , respectively. The first, second and third embodiments of the mounting lugs  116 ,  216 ,  316  will be described with reference to the cathode ray tube  10  (CRT) and the cabinet  18  of FIG.  1 . It should be understood however that the CRT  10  and the cabinet  18  is modified at the mounting area to receive each of the mounting lugs  116 ,  216 ,  316 . 
     FIGS. 3 and 4 show the first embodiment of the mounting lug  116 . The first embodiment of the mounting lug  116  has a base portion  128 , an adjoining portion  150  and a mounting portion  126 . The base portion  128  has an outer side  152  and an inner side  154  and is positioned substantially perpendicular to a first end  164  of the adjoining portion  150 . A first adjoining side  156  and a second adjoining side  158  extend from the first end  164  to a second end  166  joining the mounting portion  126 . The mounting portion  126  has a fastener engaging side  160  and a cabinet engaging side  162 . An aperture  144  extends from the outer side  160  through to the cabinet engaging side  162 . The cabinet engaging side  162  is angled toward the second adjoining side  158  such that when the mounting portion  126  is coupled to the cabinet  18 , the mounting portion  126  is positioned in an off axis plane between the Z-axis and the Y-axis of the CRT  10 . 
     Attachment of the mounting lug  116  to the cabinet  18  will now be described in greater detail with reference to FIG.  3 . Substantially at corners of the faceplate panel  30 , the inner side  154  of the base portion  128  is positioned adjacent to the surface  70  of the implosion resistant band  14  such that the second adjoining side  158  is positioned toward the cabinet opening  46  and the aperture  144  will be positioned adjacent to the corresponding hole  48  in the cabinet  18 . The base portion  128  is then attached to the surface  70  of the implosion resistant band  14  by a weld (not shown). Alternatively, the base portion  128  could be positioned under the surface  70  such that the outer side  152  engages the implosion resistant band  14 . A fastening means  20  such as a bolt, screw, etc. is inserted into the aperture  144  and is received in the cabinet  18  to couple the CRT  10  to the cabinet  18  in an off axis plane between the Z-axis and Y-axis of the CRT  10 . 
     FIGS. 5 and 6 show the second embodiment of the mounting lug  216 . The second embodiment of the mounting lug  216  has a base portion  228 , an adjoining portion  250  and a mounting portion  226 . The base portion  228  has an outer side  252  and an inner side  254  and is positioned substantially perpendicular to a first end  264  of the adjoining portion  250 . A first adjoining side  256  and a second adjoining side  258  extend from the first end  264  to a second end  266  which is positioned substantially perpendicular to the mounting portion  226 . The mounting portion  226  has a fastener engaging side  260  and a cabinet engaging side  262 . An aperture  244  extends from the fastener engaging side  260  through to the cabinet engaging side  262 . The fastener engaging side  260  is substantially parallel to the outer side  252  such that when the mounting portion  226  is coupled to the cabinet  18 , the mounting portion  226  is positioned along the Y-axis of the CRT  10 . 
     Attachment of the mounting lug  216  to the cabinet  18  will now be described in greater detail with reference to FIG.  5 . Substantially at corners of the faceplate panel  30 , the inner side  254  of the base portion  228  is positioned adjacent to the surface  70  of the implosion resistant band  14  such that the second adjoining side  258  is positioned toward the cabinet opening  46  and the aperture  244  will be positioned adjacent to the corresponding hole  48  in the cabinet  18 . The base portion  228  is then attached to the surface  70  of the implosion resistant band  14  by a weld (not shown). Alternatively, the base portion  128  could be positioned under the surface  70  such that the outer side  252  engages the implosion resistant band  14 . A fastening means  20  such as a bolt, screw, etc. is inserted into the aperture  244  and is received in the cabinet  18  to couple the CRT  10  to the cabinet  18  along the Y-axis of the CRT. 
     FIGS. 7 and 8 show the third embodiment of the mounting lug  316 . The third embodiment of the mounting lug  316  has a base portion  328 , an adjoining portion  350  and a mounting portion  326 . The base portion  328  has an outer side  352  and an inner side  354 . The adjoining portion  350  is formed of two sections  368 ,  372 . The first section  368  extends from a first end  364  substantially perpendicular to the base portion  328 . The second section  372  forms a surface that has complementary ends angled  374 ,  376 . The mounting portion  326  extends from the angled end  376  and has a fastener engaging side  360  and a cabinet engaging side  362 . The cabinet engaging side  362  is angled back toward the adjoining portion  350  such that when the mounting portion  326  is coupled to the cabinet  18 , the mounting portion  326  is positioned in an off axis plane between the Z-axis and the Y-axis of the CRT  10 . The mounting portion  326  is provided with an aperture  344  that extends from the fastener engaging side  360  through to the cabinet engaging side  362 . 
     Attachment of the mounting lug  316  to the cabinet  18  will now be described in greater detail with reference to FIG.  7 . Substantially at corners of the faceplate panel  30 , the inner side  354  of the base portion  328  is positioned adjacent to the surface  70  of the implosion resistant band  14  such that the second adjoining side  358  of the first section  368  is positioned toward the cabinet opening  46  and the aperture  344  is positioned adjacent to the corresponding hole  48  in the cabinet  18 . The base portion  328  is then attached to the surface  70  of the implosion resistant band  14  by a weld (not shown). Alternatively, the base portion  128  could be positioned under the surface  70  such that the outer side  352  engages the implosion resistant band  14 . A fastening means  20  such as a bolt, screw, etc. is inserted into the fastener engaging side  360  aperture  344  and is received in the cabinet  18  to couple the CRT  10  to the cabinet  18  in an off axis plane between the Z-axis and Y-axis of the CRT  10 . 
     Advantageously, the first, second, and third embodiments of the mounting lugs  116 ,  216 ,  316  will couple an implosion resistant CRT  10  to a cabinet  18  in a direction other than parallel to the Z-axis to minimize microphonic coupling and vibration of the CRT  10 . 
     The foregoing illustrates some of the possibilities for practicing the invention. Many other embodiments are possible within the scope and spirit of the invention. It is, therefore, intended that the foregoing description be regarded as illustrative rather than limiting, and that the scope of the invention is given by the appended claims together with their full range of equivalents.