Abstract:
An apparatus for separating a panel from a cathode ray tube may include a trough, at least one chipping element mounted in the trough; and a vibrator connected to the trough and configured such that actuation of the vibrator causes the chipping element to vibrate at a frequency and at a throw angle selected to cause the chipping element to throw a cathode ray tube placed in contact therewith upward, then move upward subsequently to contact a downwardly moving cathode ray tube with sufficient force to chip away funnel and frit therefrom. A method for separating a panel from a cathode ray tube may include contacting a funnel of the cathode ray tube with at least one chipping element, and vibrating the chipping element with sufficient force to chip at least the funnel from the cathode ray tube, leaving at least the panel.

Description:
BACKGROUND 
       [0001]    The present invention relates to methods and apparatus for separating the glass panel from a cathode ray tube, and more particularly, to methods and apparatus using a vibratory conveyer to separate the glass panel from a cathode ray tube. 
         [0002]    A typical cathode ray tube (CRT) is made largely of glass and may include a funnel or bell portion and a panel portion bonded together by a ceramic frit. The funnel portion may include such components as an electron gun and a shadow mask. Cathode ray tubes also include an implosion band—a metal band strapped around the panel portion of the cathode ray tube approximately one-quarter to three-quarters inches from the ceramic frit line. 
         [0003]    A typical cathode ray tube is made up of two types of glass, both of which are impregnated with a metal in order to reduce the emission of x-rays and other radiation from the electron gun, and with respect to the panel, to improve clarity. The panel glass makes up approximately 70% of the weight of a cathode ray tube and may contain approximately 0.05-4.0% lead in the form of lead oxide (PbO). In later model CRTs, panel glass contained barium oxide instead of lead oxide. In contrast, the funnel glass, which makes up approximately 30% of the weight of the CRT, may contain as much as 18-22% lead. The bonding ceramic frit is a lead oxide paste that may contain as much as 70-85% lead. 
         [0004]    At one time, such cathode ray tubes were used extensively in televisions, computer monitors and other video monitors, as well as for oscilloscopes and other types of electronic displays incorporated in electronic equipment. However, cathode ray tubes are no longer in demand for such products, having been replaced by screens incorporating more modern display technologies such as liquid crystal display (LCD), plasma display, and organic light emitting diode (OLED). Since the manufacture of cathode ray tubes is now all but nonexistent, there is no demand for discarded cathode ray tubes to be recycled and their components to be reused to make new cathode ray tubes. It is now necessary to dispose of the various components of a CRT in compliance with regulations regarding lead-containing waste, as well as general recycling of glass with lead content. 
         [0005]    Typically, lead content in glass products for recycling may not exceed 0.05%. Consequently, panel glass of a CRT may be recycled, but not the frit or the funnel glass. In order to recycle CRT panel glass, it is necessary to separate the low-lead content panel glass from the high-lead content funnel glass and frit portion of a CRT. Current technologies may utilize a mechanical saw to cut the panel glass from the funnel glass and frit of the cathode ray tube. Such mechanical saws may include a laser or a diamond-coated metal blade, water jet, or hot water. 
         [0006]    A disadvantage with using such mechanical saws is that the sawing process is time consuming and therefore expensive. Typically, use of such saws to separate panel glass from the frit and funnel glass of a CRT operates at a speed of from one to four tubes per minute. In addition, if the CRT is received with a broken funnel, it may be difficult to align the tube in the saw to make an accurate cut. 
         [0007]    Other types of devices have been utilized to separate the panel from the frit and funnel of a cathode ray tube. For example, vibratory screeners have been employed in which a processor separates the glass from a completely broken up cathode ray tube by lead concentration using x-rays. However, while production from such a process may be higher in terms of pounds per hour, the purity of the recovered panel may be compromised, and conversely, a significant amount of clean panel may be discarded along with broken-up funnel and frit material. 
         [0008]    Accordingly, there is a need for a process and apparatus that separates the panels of a cathode ray tube from the frit and funnel components that is accurate, and provides a relatively high production rate and low cost. 
       SUMMARY 
       [0009]    The present disclosure is directed to a method and process for recovering panel glass of a cathode ray tube by separating it from the funnel glass and frit. In one embodiment, an apparatus for separating a panel from a cathode ray tube may include a trough, at least one chipping element mounted in the trough and a vibrator connected to the trough and configured such that actuation of the vibrator causes the chipping element to vibrate at a frequency and at a throw angle selected to cause the chipping element to throw a cathode ray tube placed in contact therewith upward, then move upward subsequently to contact a downwardly moving cathode ray tube with sufficient force to chip away funnel and frit therefrom. 
         [0010]    In another embodiment, an apparatus for separating a panel from a cathode ray tube may include a trough having a feeding end and a discharge end, the trough being inclined downward from the feeding end to the discharge end, a plurality of chipping elements mounted in the trough, and a vibrator connected to the trough and configured such that actuation of the vibrator causes the chipping elements to vibrate at a frequency and at a throw angle selected to cause the at chipping elements to throw a cathode ray tube placed in contact therewith upward at an angle inclined toward the feeding end, then move upward subsequently to contact a downwardly moving cathode ray tube with sufficient force to chip away funnel and frit therefrom. 
         [0011]    In another embodiment, A method for separating a glass panel from a cathode ray tube, may include contacting a funnel of the cathode ray tube with at least one chipping element, and vibrating the chipping element with sufficient force to chip at least the funnel from the cathode ray tube, leaving at least the panel glass. In yet another embodiment, a method for separating a glass panel from funnel glass and frit of a cathode ray tube may include contacting the funnel of the cathode ray tube with at least one chipping element, vibrating the chipping element with sufficient force to chip at least the funnel from the cathode ray tube, leaving at least the panel. 
         [0012]    Other objects and advantages of the present disclosure will be apparent from the following description, the accompanying drawings and the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a side elevation of a typical cathode ray tube; 
           [0014]      FIG. 2  is a detail of the cathode ray tube of  FIG. 1 , showing the funnel portion partially broken away prior to application of the method and apparatus of the present disclosure; 
           [0015]      FIG. 3  is a side elevation of one embodiment of the disclosed apparatus for separating the glass panel from a cathode ray tube; 
           [0016]      FIG. 4  is a top plan view of the apparatus shown in  FIG. 3 ; 
           [0017]      FIG. 5  is an end elevation in section taken at line  5 - 5  of  FIG. 3 ; 
           [0018]      FIG. 6  is an elevation in section taken at line  6 - 6  of  FIG. 3 ; 
           [0019]      FIG. 7  is an elevational view of a cathode ray tube in which the frit and funnel have been removed from the panel after application of the disclosed method and apparatus; 
           [0020]      FIG. 8  is a perspective view of one embodiment of a chipping element of the disclosed apparatus; 
           [0021]      FIG. 9  is a detail top plan view of the apparatus shown in  FIGS. 3 and 4 ; and 
           [0022]      FIG. 10  is a detail top plan view of a second embodiment of the disclosed apparatus, utilizing the chipping element shown in  FIG. 8 . 
       
    
    
     DETAILED DESCRIPTION 
       [0023]    The disclosed apparatus for separating the glass panel from a cathode ray tube is shown in  FIGS. 3 and 4  and is generally designated  10 . A typical cathode ray tube  12  processed by the apparatus  10  is shown in  FIG. 1 . The cathode ray tube  12  may include a panel  14 , a funnel  16 , and an implosion band  18 . The panel  14  is made largely of glass and comprises approximately 70% of the weight of the tube  12 . The panel glass may contain approximately 0.005-4.0% lead. The panel  14  may be bonded to the funnel  16  by a ceramic frit  20 , which may be a lead oxide paste containing as much as 75-80% lead. The funnel  16  may comprise approximately 30% of the weight of the tube  12 , and contain such components as an electron gun and a shadow mask, and support a yoke of magnetic coils. The funnel glass may contain approximately 18-22% lead. The implosion band  18  is made of metal and is spaced about ¾ inches toward the panel  14  from the frit  20 . 
         [0024]    As shown in  FIG. 2 , prior to treatment by the disclosed apparatus  10  ( FIGS. 3-6 ) a majority of the funnel  16  of a CRT  12  may be broken away from the remainder of the tube, leaving the remainder of the funnel, the frit  20 , implosion band  18  and panel  14 . Also, the electron gun, shadow mask and yoke (all not shown) associated with the funnel  16  may be removed. 
         [0025]    As shown in  FIGS. 3 ,  4 ,  5  and  6 , the apparatus  10  may include a trough  24  having side walls  26 ,  28  extending upwardly from a generally flat bed  30 . The trough  24  may be elongate in shape and oriented such that product flow is in the longitudinal direction. The trough  24  may include a feeding end  50  and a discharge end  52  at opposite ends of the bed  30 . In embodiments, the trough  24  may include a discharge chute  54  that communicates with the discharge end  52  of the trough  24 . The trough  24  may be made of steel and attached to a base frame  32  by rocker arms  34  and coil springs  36 . The rocker arms may be pivotally attached to the trough  24  and base frame  32 . The base frame  32  also may support an eccentric drive assembly  38  ( FIG. 5 ) that may include a motor  40 . 
         [0026]    The support frame  32  may be mounted on an isolation frame  42  by pivot arms  44 . The isolation frame  42  may include support legs  46  that are mounted on a floor that may consist of a concrete pad  48 . The isolation frame  42  may act to isolate the vibratory action of the apparatus  10  and minimize transmission of vibration to the pad  48 . Actuation of the electric motor  40  may drive the eccentric drive assembly  38  to impart a reciprocating or oscillating motion to the base frame  32 . This motion may be in a longitudinal direction relative to the trough  24 , and may be transmitted to the trough through the springs  36  and rocker arms  34 . 
         [0027]    Although the support frame  32  and trough  24  are shown oriented horizontally, or substantially horizontally, in  FIGS. 3 ,  4 ,  5  and  6  (i.e., substantially parallel to the floor or pad  48 ), in other embodiments, the trough  24  may be inclined such that the feeding end  50  of the trough is elevated above the discharge end  52 . In embodiments, the trough  24  may be elevated at an angle of approximately 30° to the horizontal. This inclination may be accomplished by varying the height of the support legs  46 , or alternately, by varying the lengths of the springs  36  and support arms  34 . In other embodiments, the elevation may be adjusted by varying the lengths of the support arms  44  that connect the base frame  32  to the support frame  42 . 
         [0028]    Although the vibrating conveyer shown in  FIGS. 3-6  is of the isolated-balanced type, it is within the scope of the disclosure to provide a device  10  that utilizes other designs of vibrating conveyers, such as base mounted, isolated weighted base balancing, balanced, and base excited balancing in isolation vibration conveyers, as well as leaf spring-type vibrating conveyers. In embodiments, the drive unit  38  may be selected to cause the trough  24  to vibrate to impart a throw angle of between 5° and 15° to the plane of the bed  30 , and more particularly for a trough of between 20-24 feet in length. 
         [0029]    In some embodiments, this throw angle may be in a direction that is uphill (i.e., toward the feeding end  50 ), with embodiments in which the trough  24  is inclined downwardly from the feeding end  50  to the discharge end  52 . In embodiments where the trough may be oriented horizontally, or substantially horizontally, the throw angle may be in a direction toward the discharge end  52  sufficient to move CRTs  22  toward the discharge end by vibrating action. In some embodiments, the motor  40  may operate to drive the eccentric drive assembly to vibrate the trough  24  at between 900-100 hz. In other embodiments, the trough  24  may be vibrated at about 600 hz. 
         [0030]    As shown in  FIGS. 4 and 9 , the trough  24  may include a plurality of chipping elements, generally designated  56 , that extend along its length from the feeding end  50  to the discharge end  54 . The chipping elements  56  may be in the form of plates having toothed edges  58  arranged in a chevron pattern. The chevron pattern may extend longitudinally of the trough  24 . As shown best in  FIG. 4 , the plates  56  may be shaped and arranged to form two rows of parallel plates  56 . In other embodiments, the plates may be shaped to form a single row in a chevron pattern having toothed edges  58 . 
         [0031]    In embodiments, the plates  56  may be made of hardened steel or other abrasion-resistant material, and the toothed edges  58  may be carbide tipped. The toothed edges  58  are shown as having a squared shape in  FIGS. 8 and 9 , but in other embodiments, may have pointed, rounded, serrated or other shapes, or may be a straight edge. The plates  56  may be attached to the side walls  26 ,  28  of the trough  24 , and spaced from each other such that glass particles and chunks (not shown) chipped from a CRT  22  may fall between the plates onto the bed  30  of the trough, where vibrating action of the trough and/or gravity may cause them to progress along the bed to the discharge end  52  and chute  54 . 
         [0032]    As shown in  FIGS. 8 and 10 , in another embodiment  10 ′, the trough  24 ′ may include chipping elements  56 ′ in the form of inverted, U-shaped channels, best shown in  FIG. 8 . The channels  56 ′ may include toothed edges  58 ′ that extend upwardly from the bed  30  of the trough  24 ′. The channels  56 ′ may be attached to the bed  30  by rivets, welding, screws, adhesives, combinations of the foregoing, or other well-known means. As shown in  FIG. 10 , the chipping elements  56 ′ may be arranged in a chevron pattern, or in other embodiments, arranged in different patterns or orientations. It may be preferable to orient the elements  56 ′ such that the channels are generally parallel to the inclination of the trough  24 ′ so that glass chips falling upon the channels or bed  30  will flow downwardly to the discharge end of the trough  24 ′ (similar to discharge end  52  in  FIGS. 3 and 4 ) by vibrating action of the bed and/or gravity. 
         [0033]    The operation of the apparatus  10  to separate the panel  14  from a CRT  12  is as follows. A CRT  12  of a type generally as shown in  FIG. 1  may be received for recycling. The bulk of the funnel  16  may be removed, so that the CRT may appear in the form of CRT  22  shown in  FIG. 2 , having with a jagged remnant of the glass funnel  16 . The CRTs  22  may be placed on the feeding end  50  such that their panels  14  face up and the jagged remnants of their funnels  16  face down. The CRTs  22  may be urged or allowed to progress along the trough  24 , either by vibrating action of the trough  24  and chipping elements  56 ,  56 ′ by gravity, or both. In embodiments in which the trough  24  is inclined downwardly from the feeding end  50  to the discharge end  52 , the CRTs  22  may move longitudinally along the trough as shown in  FIG. 4 . 
         [0034]    The trough  24  may be vibrated by the eccentric drive assembly  38 , causing the chipping elements  56 ,  56 ′ to contact the remnants of the funnels  16  of the CRTs  22 . The pieces of the funnel  16  chipped away from the CRTs  22  by contact with the chipping elements  56 ,  56 ′ may drop downwardly to the bed  30  where they are conveyed by gravity along the trough  24 ,  24 ′ to the discharge end  52  and may fall downwardly through chute  54  to a collection bin or other container (not shown). 
         [0035]    In embodiments, the chipping elements  56 ,  56 ′ may be actuated to impart an upward throw to the CRTs  22  traveling along the trough  24 ,  24 ′, which may cause the CRTs  22  to repeatedly fall downwardly upon the vibrating edges  58 ,  58 ′ of the chipping elements  56 ,  56 ′. The trough  24 ,  24 ′ may be sized such that the funnel  16  may be substantially entirely removed by chipping or other action by the time the CRTs  22  reach the discharge end  52 . The presence of the implosion band  18  may prevent the chipping elements  56 ,  56 ′ from chipping into the glass of the panel  14 . In embodiments, the eccentric drive assembly  38  may be configured to cause the chipping elements  56 ,  56 ′ to vibrate at a frequency and at a throw angle selected to cause the chipping elements to throw the CRTs in contact with them upward, then move upward themselves subsequently to contact the now downwardly moving CRTs  22  to provide an impact with sufficient force to chip away the glass funnel  16  and frit  20  from the panel  14 . 
         [0036]    When the CRT  22  reaches the discharge end  52 , it may have the appearance in  FIG. 7  as CRT  22 ′. This CRT  22 ′ may comprise a relatively intact panel  14 , and the implosion band  18 , which may be removed later. However, substantially all portions of the funnel  16  and frit  20  ( FIGS. 1 and 2 ) have been removed by repeated contact with the chipping elements  56 ,  56 ′, conveyed downwardly to the discharge area  52  and removed from the trough  24  through discharge conduit  54 . Once the implosion band  18 , has been removed, the panel  14  is available for recycling. 
         [0037]    In another embodiment, the CRT  22  may be held in a substantially fixed position by a user or a jig  60  ( FIGS. 3 and 4 ) and the remnant of the funnel  16  brought into contact with one or more chipping elements  56 ,  56 ′. For example, a user or jig may hold the CRT  22  in position shown in  FIGS. 3 and 4  and bring the funnel  16  into contact with the chipping elements  56  of the trough  24 . The vibrating action of the chipping elements  56 ,  56 ′ may chip away the funnel  16  and frit  20  until only the panel  14  remains. Chips of the funnel  16  and frit  20  may be conveyed along the bed  30  to the discharge end  52 , or fall downward by gravity through holes (not shown) formed in the bed. 
         [0038]    In yet another embodiment, shown best in  FIG. 9 , the trough  24  may include a transverse bar  62  extending between side walls  26 ,  28 . The bar  62  may include chipping elements in the form of upwardly projecting teeth  64 . Teeth  64  may be positioned at an elevation above edges  58  of chipping elements  56 . The teeth  64  may have a triangular shape, as shown, or other shapes, such as rectangular, trapezoidal, parallelogram, rounded, and combinations thereof. The teeth  64  may be present alone on the trough  24 , or present in combination with chipping elements  56 . Teeth  64  also may be attached to and project upwardly from dividing wall  66  separating rows of chipping elements  56 . Teeth  64  may be formed of hardened steel, or other wear-resistant material, or steel layered with hardened material, such as carbide or other wear-resistant material. 
         [0039]    As described above, the apparatus  10 ,  10 ′ for chipping a funnel portion from a panel portion of a cathode ray tube may be operated continuously, and provides a higher through-put of removing the funnel portion from the panel a cathode ray tube than prior art methods and devices. While the forms of apparatus and methods disclosed herein constitute preferred embodiments of the invention, it is to be understood that modifications may be made therein without departing from the scope of the invention.