Method and apparatus for separating the glass panel from a cathode ray tube

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.

BACKGROUND

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.

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.

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.

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.

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.

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.

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.

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

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.

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.

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.

Other objects and advantages of the present disclosure will be apparent from the following description, the accompanying drawings and the appended claims.

DETAILED DESCRIPTION

The disclosed apparatus for separating the glass panel from a cathode ray tube is shown inFIGS. 3 and 4and is generally designated10. A typical cathode ray tube12processed by the apparatus10is shown inFIG. 1. The cathode ray tube12may include a panel14, a funnel16, and an implosion band18. The panel14is made largely of glass and comprises approximately 70% of the weight of the tube12. The panel glass may contain approximately 0.005-4.0% lead. The panel14may be bonded to the funnel16by a ceramic frit20, which may be a lead oxide paste containing as much as 75-80% lead. The funnel16may comprise approximately 30% of the weight of the tube12, 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 band18is made of metal and is spaced about ¾ inches toward the panel14from the frit20.

As shown inFIG. 2, prior to treatment by the disclosed apparatus10(FIGS. 3-6) a majority of the funnel16of a CRT12may be broken away from the remainder of the tube, leaving the remainder of the funnel, the frit20, implosion band18and panel14. Also, the electron gun, shadow mask and yoke (all not shown) associated with the funnel16may be removed.

As shown inFIGS. 3,4,5and6, the apparatus10may include a trough24having side walls26,28extending upwardly from a generally flat bed30. The trough24may be elongate in shape and oriented such that product flow is in the longitudinal direction. The trough24may include a feeding end50and a discharge end52at opposite ends of the bed30. In embodiments, the trough24may include a discharge chute54that communicates with the discharge end52of the trough24. The trough24may be made of steel and attached to a base frame32by rocker arms34and coil springs36. The rocker arms may be pivotally attached to the trough24and base frame32. The base frame32also may support an eccentric drive assembly38(FIG. 5) that may include a motor40.

The support frame32may be mounted on an isolation frame42by pivot arms44. The isolation frame42may include support legs46that are mounted on a floor that may consist of a concrete pad48. The isolation frame42may act to isolate the vibratory action of the apparatus10and minimize transmission of vibration to the pad48. Actuation of the electric motor40may drive the eccentric drive assembly38to impart a reciprocating or oscillating motion to the base frame32. This motion may be in a longitudinal direction relative to the trough24, and may be transmitted to the trough through the springs36and rocker arms34.

Although the support frame32and trough24are shown oriented horizontally, or substantially horizontally, inFIGS. 3,4,5and6(i.e., substantially parallel to the floor or pad48), in other embodiments, the trough24may be inclined such that the feeding end50of the trough is elevated above the discharge end52. In embodiments, the trough24may be elevated at an angle of approximately 30° to the horizontal. This inclination may be accomplished by varying the height of the support legs46, or alternately, by varying the lengths of the springs36and support arms34. In other embodiments, the elevation may be adjusted by varying the lengths of the support arms44that connect the base frame32to the support frame42.

Although the vibrating conveyer shown inFIGS. 3-6is of the isolated-balanced type, it is within the scope of the disclosure to provide a device10that 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 unit38may be selected to cause the trough24to vibrate to impart a throw angle of between 5° and 15° to the plane of the bed30, and more particularly for a trough of between 20-24 feet in length.

In some embodiments, this throw angle may be in a direction that is uphill (i.e., toward the feeding end50), with embodiments in which the trough24is inclined downwardly from the feeding end50to the discharge end52. In embodiments where the trough may be oriented horizontally, or substantially horizontally, the throw angle may be in a direction toward the discharge end52sufficient to move CRTs22toward the discharge end by vibrating action. In some embodiments, the motor40may operate to drive the eccentric drive assembly to vibrate the trough24at between 900-100 hz. In other embodiments, the trough24may be vibrated at about 600 hz.

As shown inFIGS. 4 and 9, the trough24may include a plurality of chipping elements, generally designated56, that extend along its length from the feeding end50to the discharge end54. The chipping elements56may be in the form of plates having toothed edges58arranged in a chevron pattern. The chevron pattern may extend longitudinally of the trough24. As shown best inFIG. 4, the plates56may be shaped and arranged to form two rows of parallel plates56. In other embodiments, the plates may be shaped to form a single row in a chevron pattern having toothed edges58.

In embodiments, the plates56may be made of hardened steel or other abrasion-resistant material, and the toothed edges58may be carbide tipped. The toothed edges58are shown as having a squared shape inFIGS. 8 and 9, but in other embodiments, may have pointed, rounded, serrated or other shapes, or may be a straight edge. The plates56may be attached to the side walls26,28of the trough24, and spaced from each other such that glass particles and chunks (not shown) chipped from a CRT22may fall between the plates onto the bed30of the trough, where vibrating action of the trough and/or gravity may cause them to progress along the bed to the discharge end52and chute54.

As shown inFIGS. 8 and 10, in another embodiment10′, the trough24′ may include chipping elements56′ in the form of inverted, U-shaped channels, best shown inFIG. 8. The channels56′ may include toothed edges58′ that extend upwardly from the bed30of the trough24′. The channels56′ may be attached to the bed30by rivets, welding, screws, adhesives, combinations of the foregoing, or other well-known means. As shown inFIG. 10, the chipping elements56′ may be arranged in a chevron pattern, or in other embodiments, arranged in different patterns or orientations. It may be preferable to orient the elements56′ such that the channels are generally parallel to the inclination of the trough24′ so that glass chips falling upon the channels or bed30will flow downwardly to the discharge end of the trough24′ (similar to discharge end52inFIGS. 3 and 4) by vibrating action of the bed and/or gravity.

The operation of the apparatus10to separate the panel14from a CRT12is as follows. A CRT12of a type generally as shown inFIG. 1may be received for recycling. The bulk of the funnel16may be removed, so that the CRT may appear in the form of CRT22shown inFIG. 2, having with a jagged remnant of the glass funnel16. The CRTs22may be placed on the feeding end50such that their panels14face up and the jagged remnants of their funnels16face down. The CRTs22may be urged or allowed to progress along the trough24, either by vibrating action of the trough24and chipping elements56,56′ by gravity, or both. In embodiments in which the trough24is inclined downwardly from the feeding end50to the discharge end52, the CRTs22may move longitudinally along the trough as shown inFIG. 4.

The trough24may be vibrated by the eccentric drive assembly38, causing the chipping elements56,56′ to contact the remnants of the funnels16of the CRTs22. The pieces of the funnel16chipped away from the CRTs22by contact with the chipping elements56,56′ may drop downwardly to the bed30where they are conveyed by gravity along the trough24,24′ to the discharge end52and may fall downwardly through chute54to a collection bin or other container (not shown).

In embodiments, the chipping elements56,56′ may be actuated to impart an upward throw to the CRTs22traveling along the trough24,24′, which may cause the CRTs22to repeatedly fall downwardly upon the vibrating edges58,58′ of the chipping elements56,56′. The trough24,24′ may be sized such that the funnel16may be substantially entirely removed by chipping or other action by the time the CRTs22reach the discharge end52. The presence of the implosion band18may prevent the chipping elements56,56′ from chipping into the glass of the panel14. In embodiments, the eccentric drive assembly38may be configured to cause the chipping elements56,56′ 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 CRTs22to provide an impact with sufficient force to chip away the glass funnel16and frit20from the panel14.

When the CRT22reaches the discharge end52, it may have the appearance inFIG. 7as CRT22′. This CRT22′ may comprise a relatively intact panel14, and the implosion band18, which may be removed later. However, substantially all portions of the funnel16and frit20(FIGS. 1 and 2) have been removed by repeated contact with the chipping elements56,56′, conveyed downwardly to the discharge area52and removed from the trough24through discharge conduit54. Once the implosion band18, has been removed, the panel14is available for recycling.

In another embodiment, the CRT22may be held in a substantially fixed position by a user or a jig60(FIGS. 3 and 4) and the remnant of the funnel16brought into contact with one or more chipping elements56,56′. For example, a user or jig may hold the CRT22in position shown inFIGS. 3 and 4and bring the funnel16into contact with the chipping elements56of the trough24. The vibrating action of the chipping elements56,56′ may chip away the funnel16and frit20until only the panel14remains. Chips of the funnel16and frit20may be conveyed along the bed30to the discharge end52, or fall downward by gravity through holes (not shown) formed in the bed.

In yet another embodiment, shown best inFIG. 9, the trough24may include a transverse bar62extending between side walls26,28. The bar62may include chipping elements in the form of upwardly projecting teeth64. Teeth64may be positioned at an elevation above edges58of chipping elements56. The teeth64may have a triangular shape, as shown, or other shapes, such as rectangular, trapezoidal, parallelogram, rounded, and combinations thereof. The teeth64may be present alone on the trough24, or present in combination with chipping elements56. Teeth64also may be attached to and project upwardly from dividing wall66separating rows of chipping elements56. Teeth64may be formed of hardened steel, or other wear-resistant material, or steel layered with hardened material, such as carbide or other wear-resistant material.

As described above, the apparatus10,10′ 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.