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Publication numberUS3326224 A
Publication typeGrant
Publication dateJun 20, 1967
Filing dateSep 29, 1965
Priority dateSep 29, 1965
Also published asDE1564724A1, US3473942
Publication numberUS 3326224 A, US 3326224A, US-A-3326224, US3326224 A, US3326224A
InventorsJacob Gartner Stanley
Original AssigneeSylvania Electric Prod
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Coating removal device
US 3326224 A
Abstract  available in
Images(4)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

June 20, 1967 5. J. GARTNER 3,326,224

COATING REMOVAL DEVICE Filed Sept. 29, 1965 4 Sheetsheet l INVENTOR. E 5 5mm. J GART/VER ATTORNLY June 20, 1967 5, GARTNER 3,326,224

COATING REMOVAL DEVICE Filed Sept. 29, 1965 4 Sheets-Sheet 2 M3 INVENTOR.

5 STANLEY J G/IRTNER 1 B Y wi M ATTORNEY June 20, 1967 5. J. GARTNER 3,326,224

COATING REMOVAL DEVICE Filed Sept. 29, 1965 4 Sheets-Sheet Z l INVENTOR.

.57'HNLEY J G/mr/vm E5 7 BY ,aMzM

June 20, 1967 s. J. GARTNER COATING REMOVAL DEVICE 4 Sheets-Sheet 4 Filed Sept. 29, 1965 INVENTOR. STANLEY J. GARTNER ATTORNEY United States Patent 3,326,224 COATING REMGVAL DEVICE Stanley Jacob Gartner, Emporium, lPa., assignor to Sylvania Electric Products Inc., a corporation of Delaware Filed Sept. 29, 1965, Ser. No. 491,131 4 Claims. (Cl. 134--58) This invention relates to the manufacturing of cathode ray tubes and more particularly to a coating removal device for achieving improved lacquering and aluminizing of the screened panel thereof.

It is conventional practice in the art of manufacturing color television cathode ray tubes, to apply a thin film or coating of aluminum to the back of the cathodoluminescent phosphor screen, that being the screen surface normally oriented toward the electron gun in the tube and away from the viewer. This aluminum coating provides a mirror-like finish which reflects, toward the viewer, a portion of the light from the screen which would otherwis be lost within the tube. It has been found that tubes so treated exhibit improved brightness and contrast in display presentation that is not evidence in non-aluminized tubes.

In color cathode ray tube fabrication, a multi-phosphor patterned screen is usually applied on the inner surface of the substantially cup-shaped tube face panel in a manner to be suitably viewed therethrough. The formed screen is thence processed before the face panel is hermetically joined to the funnel or envelope portion of the tube. The plural cathodoluminescent phosphors, per se, are suitably disposed as multitudinous dots or discrete stripes in accordance with the several established procedures well known to the art. Prior to the application of the aluminized mirror coating, the multi-phosphor screen is precoated or overlaid with a thin film of lacquer to provide a suitable surface upon which to form the mirror. In addition, the lacquer serves as a temporary barrier to prevent the aluminum from penetrating and poisoning the phosphor crystals, thereby reducing or destroying the luminescent qualities thereof, during the aluminizing procedure. This lacquer film is subsequently removed by baking whereupon the reflective aluminum remains supported directly by the phosphor screen.

The deposition of the lacquer film, whether it be by the spray or slurry techniques, usually covers the whole of the interior of the face panel, coating not only the screen portion but also the peripheral panel skirt or sidewall area as well.

The aluminum coating is conventionally applied by a vaporization technique and usually covers the whole of the interior of the screened panel including the sidewall area. Since the lacquer is removed from the screen area by baking subsequent to aluminizing, it is important to remove all traces of lacquer from the sidewall area, peripheral to the screen, prior to aluminizing as any residual lacquer underlaying the aluminium or the substantially smooth sidewall area prevents adherence of the aluminum to glass, and results in localized blistering of the aluminum coating when said residual lacquer is volatilized from therebetween during the aforementioned subsequent panel bake-out. It is important to have tight adherence of the aluminum coating to the panel sidewall not only to prevent blisters but also to insure electrical continuity of the anode coating covering the interior surface of the tube evelope; of which, the aluminum on the panel sidewall is an integral part.

Upon drying of the disposed lacquer, prior to deposition of the aluminizing film thereover, removal of the extraneous lacquer from the inner surface of the panel sidewall is a substantially manual operation. A lint-free cloth,

moistened with a suitable solvent is utilized to expedite softening and removal of the lacquer film from the panel skirt. This operation requires manual dexterity, especially in the areas surrounding the several metallic buttons that are embedded in the sidewall of the panel, as it is desired to remove all of the extraneous lacquer up to substantially the edge of the screen. It has been found that the undesired lacquer can be manually removed with a solvent moistened cloth by exercising proper care and diligence when the film is substantially dry. Attempting to remove the wet lacquer adjacent the screen, with a solvent moistened cloth, is an extremely delicate time consuming operation as the wet lacquer tends to smear. Therefore, removal of the dried film is the better method, but it is not entirely without complications as the wiping action tends to produce a somewhat roughened edge, and, in addition, there is the aforementioned difiiculty of entirely removing all of the dried lacquer from the skirt area. Unfortunately, inadequate removal of the extraneous lacquer from the skirt area is not evidence until after consummation of the subsequent aluminizing and lacquer bake-out processing steps. It is then that the tell-tale blisters make their appearance to indicate aluminizing of inferior quality along with a resultant increase in the scrap level of the manufacturing process. Even though the blisters may be small and not ruptured, they still are undesirable as they provide a possible source of loose metallic particles within the tube. Therefore, it is highly desirable to prevent blistering and at the same time insure electrical continuity by removing all traces of the lacquer film from that portion of the face panel where it is not desired.

Accordingly, an object of the invention is to reduce the aforementioned disadvantages and to provide improved aluminizing for color cathode ray tube fabrication.

Another object is to provide an apparatus for discretely removing an extraneous portion of the lacquer film beyond the screen area of a cathode ray tube face panel to promote the formation of an unblemished film of aluminium over the whole of the interior of the screened panel.

A further object is to provide a lacquer coating removal device for removing the lacquer coating from the sidewall portion of the screened face panel.

An additional object is to improve the quality of the aluminized color cathode ray tube product and to provide improved efficiency in tube manufacturing.

The foregoing objects are achieved in one aspect of the invention by the provision of a lacquer removal apparatus whereby the applied lacquer, which forms an underlay over the screen for the subsequent aluminum coating, is removed, while still in the liquid stage, from the skirt or sidewall portion of the panel adjacent the screen area. This is accomplished by utilizing apparatus means to support and rotate the coated panel in an inverted position while at least one tracking means, with an attached nozzle thereon is oriented to perimetrically follow the inner sidewall surface. The nozzle is maintained in substantially equidistant relationship with the sidewall portion, and a substantially constant pressure stream of water issuing from the nozzle forms an impingmen-t pattern on the panel sidewall to flush away the water-insoluble lacquer material from the sidewall portion before film formation thereof materializes.

For a better understanding of the present invention, together with other and further objects, advantages, and capabilities thereof, reference is made to the following specification and appended claims in connection with the accompanying drawings in which:

FIGURE 1 is a partial cross-sectional "view of a color cathode ray tube face panel showing the cathodoluminescent screen with the lacquer coating covering the whole of the interior surface of the panel;

FIGURE 2 is another partial cross-sectional view of the same panel showing means for discretely removing the lacquer coating from the sidewall portion of the panel;

FIGURE 3 is still another partial cross-sectional view showing the panel with the lacquer removed from the sidewall portion of the panel;

FIGURE 4 is a top plan view showing details of the apparatus utilized for removing the lacquer coating from the sidewall portion of the face panel;

FIGURE 5 is a partially detailed elevational view taken along the line 55 of FIGURE 4, with portions omitted to provide clarity, illustrating certain important features of the lacquer coating removal device;

FIGURE 6 is a partially sectioned elevational enlargement of the apparatus taken along the line 6-6 of FIG- URE 4 detailing panel support means utilized prior to initiating lacquer coating removal;

FIGURE '7 is a plan view showing horizontal orientation of the panel tracking means of the apparatus;

FIGURE 8 is an enlarged exploded perspective showing features of the panel tracking means; and

FIGURE 9 is a top plan view showing adaptations for accommodating a rectangular cathode ray tube face panel in the lacquer coating removal apparatus.

In referring to the drawings, FIGURES 1, 2, and 3 show cross-sectional elevations of a cathode ray tube face panel 11 before attachment to the envelope funnel portion. Suitably embedded within the wall of skirt portion 15, and spaced therearound, are a plurality of metallic buttons 17, one of which is shown. The function of these buttons is to properly orient and support a foraminous shadow mask or grid, not shown, which is utilized for both screen formation and subsequent tube operation. The panel which may be round, elliptical, or rectangular in shape, has a substantially transparent viewing portion 13 and a sidewall or skirt portion 15 perimetrical thereto. On the inner surface of the panel a patterned cathodoluminescent screen 19, comprising a repetitive plurality of color-emitting phosphors, is suitably disposed in accordance with one of the known techniques of the art.

After the forming of the screen, the whole of the interior of the face panel 11 is rinsed with an aqueous wetting solution, not shown, containing a quantity of a selected water soluble organic solvent which lowers the surface tension of the water. This provides uniform wetting of the panel and enables the aqueous solution to more closely follow the horizontal contour of the phosphor screen. When the lacquer coating is applied to the interior of the panel, the aqueous wetting film, being contiguous upon the topography of the screen, forms a thin continuous barrier to prevent lacquer penetration of the phosphor materials comprising the screen and thereby facilitates the deposition of a uniform lacquer coating 21 thereover.

A lacquer material formulation suitable for this usage has been found to comprise a solution of acrylic resin solids dissolved in at least one organic solvent selected from the group consisting essentially of toluene and xylene with the resin solids therein ranging substantially from 4.6 to 5.0 percent by weight. A suitable plasticizer, such as dibutyl phthalate, is added thereto in an amount less than one percent based on the weight of the resin solids. The resultant lacquer solution has a viscosity substantially within the range of 3.8 to 4.4 centistokes at 25 degrees Centigrade. When toluene alone is used as the solvent, lacquer set-up progresses in approximately 45 seconds (at approximately 25 degrees centigrade) to a film formation state. Thus, if the extraneous lacquer coating, disposed on the panel sidewall, is to be removed by water flushing, such operation must be initiated within approximately 35 seconds of lacquer application. It has been found that, if desired, the time of lacquer film formation can be retarded by adding xylene to the lacquer formulation with the toluene content being decreased accordingly.

The lacquer material is applied as a coating over the whole of the interior of the panel in accordance with one of the procedures known to the art such as by slurrying or spraying. From a manufacturing consideration, it is desired that the extraneous lacquer coating be removed from the panel sidewall immediatly following lacquer coating application.

With reference to FIGURE 2, there is shown the apparatus for expeditiously removing the lacquer coating from the panel sidewall in accordance with the invention. The freshly lacquered panel 11 to be subjected to the discrete lacquer removal operation, is horizontally oriented and supported with the open face thereof in a downward position by suitable means not shown in FIGURE 2 but subsequently illustrated in FIGURES 4 and 6 and fully described later in this specification. A plurality of liquid-issuing nozzles 23, one of which is shown, are oriented in a predetermined horizontal plane in a manner to maintain a substantially equidistant relationship with the skirt or sidewall portion 15 of the panel 11. Thus, when relative rotation 25 is provided between the panel sidewall 15 and the nozzle 23, the stream of liquid 27 issuing from the nozzle impinges upon the sidewall with desired constancy in a circumferential or perimetrical sweeping motion. In this instance the stream of liquid 27 is water, free from contaminating inclusions, although the invention is not intended to be limited to such as other compatible solvents may also be utilized.

With further reference to FIGURES 2 and 7, the noz- Zle 23 has a longitudinal axis 29 extended therethrough and sequentially maintained in a pivoted manner to effect substantially right angle relationship with a progressive line 33 tangential to the inner perimeter of the sidewall 15. Thus, during the relative rotational movement of the panel sidewall and the nozzle, there is maintained therebetween both a substantially constant distance and a substantially consistent angular orientation. These factors coupled with a water supply of constant pressure that is free of cavitations and gaseous inclusions provide a stream of water 27 that is discretely nozzle formed and directed toward the inner portion of the panel sidewall 15. The pressure of the stream of water is predetermined to effect a constant substantially bulbous terminal formation of water 37 upon impingement with the sidewall. This terminal formation of water has a substantially constant area configuration in keeping with the inner con tour of the panel perimeter whether it be substantially straight or arcuate, to provide a substantially consistent pattern of impingement thereon and effect a discretely formed peripheral trimming edge of water having a vertical apex 39 oriented to substantially follow the border 41 of said lacquer coated screen.

When the perimetric contour of the panel is other than arcuate, as for example, a panel of substantially rectangular shape 43 with substantially arcuately formed corners 45, as illustrated in FIGURE 9, it is important that the pattern of water impingement and the trimming edge thereof exhibit uniformity regardless of the differential perimetric contour to prevent the trimming water from climbing the corners of the panel. This uniformity of the liquid trimming pattern is achieved by predetermining the area of water impingement according to the most acute curvature of the perimeter in conjunction with the panel tracking means 49 fully described later in this specification. Whatever the size of the water trimming configuration, the volume of the stream of water is sufiicient to completely flush the extraneous lacquer coating from the panel sidewall before the inception of lacquer film formation. Thus, as shown in FIGURE 3, the cathode ray tube face panel 11 is ready for aluminizing, wherein the cathodoluminescent screen portion is covered with a film of lacquer 21 from which the extra lacquer beyond the perimeter thereof has been water trimmed and flush removed to provide a lacquer-free sidewall surface.

In FIGURES 4, 5, and 6 there is shown mechanical means, in the form of apparatus 48, which expeditiously accomplishes the desired removal of the extraneous lacquer from the panel sidewall.

In part, this lacquer removal apparatus 48 comprises a panel accommodation stage 51, which is circular in shape with a large central opening 53 therein. This stage is horizontally positioned and adequately supported around its peripheral region between vertically oriented pairs of stage rollers 55 contacting the upper and lower surfaces thereof. At least three pairs of these rollers are utilized in substantially equispatial relationship therearound, each pair being located on a suitable bracket 57 and affixed to the top portion 59 of a horizontal base platform 61. The lateral placement of the stage is achieved and maintained by employing at least three spaced apart confining rollers 63 positioned to make circumferential contact with the circular stage. These confining rollers are mounted in a horizontal rotatable manner atop vertical holders 65 also oriented on the top of the base platform 61.

The periphery 50 of the circular stage 51 is formed to cooperate with an associated drive or motion imparting means 67. As shown, the periphery is substantially channel-shaped to receive linear motion transmission from a belt or chain-type linkage 69 which imparts desired rotation to the stage from a power transfer medium, such as a drive gear or pulley 71, for a predetermined period of time to be later explained.

The aforementioned central opening 53 in the panel accommodation stage 51 is diametrically larger than the largest dimension of the cathode ray tube face panel 11 to be positioned therein. With particular reference to FIGURES 4 and 6, the lacquer coated face panel 11 is oriented open face down within the above-mentioned central opening 53. It is temporarily held therein in proper horizontal placement by the panel edge 18 resting on the forward portions 77 of at least three spaced-apart panel rests 79. These, being pivoted means formed for vertical movement, are afiixed to the top portion 59 of the base platform 61 and extended in a plane substantially parallel therewith toward the panel accommodation stage 51 thereabove. The forward portions 77 are substantially covered with plastic sleeves, as of polyethylene material, to provide resilient cushioning for the edge of the panel.

As partially phantomed in FIGURE 6, the fulcrum or pivot 81 permits the forward portion 77 of the panel rest 79 to subsequently drop, at a predetermined time when the panel is otherwise retained by retention means to be described, to a slightly lower position in accordance with programmed actuation accorded to the rear portion 83 of the panel rest. An adjustable stop 85 in conjunction with a vertical resilient means 87, such as a helical spring, and a vertical pressure means 89, in the form of an air cylinder having a plunger 91 of restricted stroke, imparts predetermined vertical movement to the forward portion 77, the sequence of which will be later explained.

With the panel vertically pre-oriented on the panel rests 79, the retention of its horizontal position is facilitated by at least three panel retainers of two types 93 and 95, spaced apart to make external tri-point peripheral contact'with the external sidewall portion of the panel. Each of the two retainers 93, with the respective body portions 97 affixed to the panel accommodation stage 51, has a panel contact pad 99 of substantially non-resilient plastic material formed and placed to fit the panel external periphery. The third panel retainer 95, which completes the triangulated retention arrangement, is likewise affixed to the accommodation stage. This retainer is manually operated by lever 101 and has a resilient contact pad 103 as of rubber or compressible plastic. When predetermined pressure is applied by mechanical linkage from lever 101, the panel 11 is securely positioned in an undistorted manner by the three retainers. Thus, the panel and the accommodation stage are oriented with a vertical axis 104 common to both.

With the panel properly positioned and retained relative to the accommodation stage by the panel retainers 93 and 95, the panel rests 79 are dropped free from the edge of the panel to positions in a common plane therebeneath, and rotary movement is imparted to the stage by drive means 67. Coating removal means 105, quiescently positioned to be within the confines of the inverted panel on a plane substantially parallel with the top of the base platform 61 is actuated to begin the tracking portion thereof in contact with a predetermined portion of the inner sidewall surface of the revolving panel. This consistent contact relationship with the moving sidewall is made by at least one panel tracking means 49 terminally affixed to the inner end of a hollow tube 107 which is arcuately movable in a horizontal plane about pivot means 109 located on the top of base platform 61; the pivot means having height adjustment provisions 110 to effect adaptability to the apparatus. Horizontal pressure means 111 in the form of an air cylinder located on the top of base platform 61, has a horizontal plunger 113 oriented to make contact with an impact pad 115 integral to the exterior of tube 107. The plunger thrust imparts, to the lacquer removal apparatus, horizontal movement in the direction of the axis 104 and removes the panel tracking means 49 from contact with the panel sidewall 15, this being the position of the coating removal means 105 during the aforementioned quiescent state wherein panel loading and unloading is accomplished. Reciprocal movement to bring the tracking means in contact with the inner surface of the panel sidewall is imparted by horizontal resilient means 117, in the form of a tensioned spring, which has one end attached to tube 107 at connection 119 in opposition to a point of affixture 121 on base platform 61.

With reference to FIGURES 2, 4, 5, 7, and 8, the flushing liquid 27 is supplied to the nozzle 23, from a source not shown, through a flexible conduit 123, thence through the hollow tube 107 and its connecting hose 125. The inner extremity of the tube 107, distal to pivot means 109, is closed by the jointure 127 with the vertical support post 129.

Tracking means frame 131 has a slotted opening 133 to receive support post 129 which is secured therein by set screw 135. A vertical swivel pin 137, on frame 131, mates with tracking head aperture 141 to provide pivoted movement to the head 139. A limit pin 175, adjacent the swivel pin, slidably mates with an arcuate slot 173 in the base of the tracking head 139 to limit the arcuate movement thereof; the arcuate slot 173 being in spaced circumferential relationship with aperture 141. The upstanding portion 143 of the tracking head has a slotted bore 145 to accommodate placement of nozzle 23. Clamping screw 147, inserted through vertical bore 149, mates with a tapped hole, not shown, in upstanding portion 143 to secure the nozzle 23. A pair of rollers 151 and 151, having respective axes 152 and 152, are movably mounted on the tracking head on vertical pins 153 and 153' in a manner for the peripheries thereof to extend beyond the forward edge 155 of the head. Thus, the rollers make two-point mobile contact with a portion of the inner surface 16 of panel sidewall adjacent the open edge 18 thereof.

The stance of this two-point roller contact with the panel sidewall is directly related to the center distance B of the axes 152 and 152'. As previously mentioned, it is important for the distance between the nozzle 23 and the inner surface 16 of sidewall 15 to remain substantially constant during panel rotation in order to provide a con sistant terminal formation of flushing water upon impingement with the sidewall. To maintain this desired distance relationship, the axes spread or center distance B is determined by the diameter of the rollers and the inner curvature of the panel sidewall. For a round panel, as

7 shown in FIGURE 4, the stance of the two-point roller contact is not critical as the uniform curvature of the panel 11 facilitates a constant nozzle-sidewall distance relationship to effect a consistent water impingement pattern on the panel sidewall during the circumferential progression thereof. However, with a rectangular shaped panel 43, as illustrated in FIGURE 9, the stance of the two-point contact of the tracking rollers must be such as to maintain substantially the same nozzle-sidewall distance relationship at the arcuate corners 45 as on the straightaway portions 47 and 47. Such is accomplished by selecting a roller center distance that will correctly track the corners; the tracking rollers having diameters in accordance therewith. Thus, an accurate cam follower relationship is provided wherein a definite portion of the inner surface of the panel sidewall, adjacent the open edge thereof, forms a continuous enclosed cam surface which is followed by the rollers of the tracking means in a consistent manner, the rollers being held in contact therewith by the horizontal resilient means 117.

The rectangular panel 45, as shown in FIGURE 9, is held substantially at two corners by panel retainers 93' having contact pads 99' oriented to effect seated contact with the panel sidewall portions adjacent the corners of one side 44 thereof. The compression panel retainer 95 is positioned at substantially the mid-section of the opposite side 44 of the panel with the resilient contact pad 1113' making contact therewith. Predetermined pressure is exerted by lever 161 to securely orient and retain the rectangular panel 43 in an undistorted manner within the accommodation stage 51 on an axis 104 common to both the panel and the stage.

With reference to FIGURES and 6, the top of the base platform 61 has an opening 159 therein at least as large as the central opening 53 in the panel accommodation stage 51. Suitably fitted into and positioned therein is an open drainage well 161, as of stainless steel, having a drainage port 163 to facilitate disposal of the liquid flushing effluent.

As described, placement of the lacquered panel 11 on the panel rests 79 is followed by the compressional orientation and retention of the panel by the respective panel retainers 93 and 95. The operational sequence of the mechanical combination 48 is automatically governed by control center 167, designated in FIGURE 4. Details of this center are not shown or described as various known systems of control means can be utilized to initiate a desired sequence of operations. A multiple sequence timing device having provisions for automatic reset is preferred for this operation. Functioning of the mechanical combination is actuated by control switch 169 which initiates an automated program of related operations. After the panel has been properly positioned on the panel rests 79 and pressure retained by retainers 93 and 95, the several vertical pressure means 89 are simultaneously activated to retract their respective plungers 91. This retracting action permits the expansion of the vertically positioned springs 87 to simultaneously lower the forward portions 77 of the panel rests 79, thus freeing the open edge 18 of the panel from any obstructions. Activation of drive means 67 provides rotation to the circular panel accommodation stage 51 whereupon the several horizontal pressure means 111 are simultaneously activated to retract their respective plungers 113 thus permitting the horizontally oriented tension springs 117 to pull the panel tracking means 49 toward the moving panel sidewall; the tracking rollers 1'51 and 151 making contact with the inner surface 16 of the sidewall 15 in the region adjacent the open edge 18 of the panel. A stream of water 27 is thence initiated to issue from each nozzle 23 and impinge upon the moving lacquer-covered panel sidewall. The pattern of water impingement thus formed provides a consistent terminal formation of water 37 having a trimming edge 39 that efiiciently flushes away the extraneous lacquer coating from the panel sidewall, and from around the me- 8 tallic buttons 17 embedded therein, before the inceptio of lacquer film formation thereon. The relative rotation between the panel sidewall and the stream of flushing water should have uniformity and a constant rate of speed to provide the desired pattern of water impingement on the panel sidewall. The speed of rotation is related to the size of the panel and the perimetric length of the sidewall portion thereof, and should be of a rate to provide an initial flush of water to the whole of the perimetric length of the sidewall before lacquer film formation materializes. Additionally, it is important that splashing impingement and uncontrolled deformation of the peripheral trimming edge of water be strictly avoided. Upon completion of the flushing operation, there follows in sequence: cessation of the liquid flow, stoppage of the stage rotation, activation of the horizontal pressure means 111 whereupon the plunger 113 extends to move the tracking means 49 away from contact with the inner surface 16 of the panel sidewall. Subsequent activation of the vertical pressure means 89 extends the plungers 91 thereof to effect movement for repositioning the several respective panel rests '79 against the open edge 18 of the panel to again provide rest positioning for the panel when the panel retainers are subsequently released. Thus, the automatic cycle of the mechanical lacquer trimming apparatus is completed. As mentioned, the subsequent release of the horizontal panel retainers frees the panel to facilitate removal thereof from the trimming device.

If desired, auxiliary water nozzles can be oriented in a stationary manner to provide a fluid rinse for the several panel rest forward portions 77 when in their lower position during the operational cycle. Thus, the panel rests are kept free of lacquer drainage residue.

The lacquer material remaining in the panel is retained in the form of a film covering the cathodoluminescent screen area where it adheres in conformance to the topography thereof. Upon drying of the lacquer film, a thin layer of aluminum is applied over the whole of the interior of the panel, preferably by a vacuum vaporization technique well known to the art.

The aluminizing procedure is completed by a baking operation wherein the panel is subjected to a baking heat of approximately 450 degrees centigrade to decompose and volatilize the lacquer film from the screen area and remove other volatile materials that may be present.

Thus, a coating removal device is provided which expeditiously prepares lacquer coated color cathode ray tube face panels for aluminizing wherein the discrete removal of the extraneous lacquer material from the panel sidewall promotes the subsequent formation of an unblemished film of aluminum over the whole of the interior of the screened panel. This coating removal apparatus advantageously utilizes the inner perimeter of the panel sidewall as a cam surface intimately contacted by at least one follower tracking means accommodating a liquid issuing nozzle to maintain substantially equidistant relationship therebetween and facilitate the formation of a uniform pattern of liquid flushing impingement perimetrically therearound. In addition to the superior quality of the resultant aluminized tube product, the coating removal device provides improved efficiency in color cathode ray tube manufacturing heretofore unachieved.

While there has been shown and described what is at present considered the preferred embodiment of the invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention as defined by the appended claims.

What is claimed is:

1. An apparatus for discretely removing extraneous coating material from the inner surface of the sidewall portion of an interiorly coated substantially cup-shaped cathode ray tube face panel, having a screen area and a perimetrical surrounding sidewall portion, said apparatus comprising:

a base platform;

rotative support mean positioned relative to said platform for supporting said coated panel in an inverted manner above said platform;

at least one panel tracking means formed to extend above said platform within said inverted panel and being oriented therein for predetermined movement on a plane substantially parallel with the top of said platform, said tracking means being formed to provide mobile cam follower contact with said panel sidewall during relative movement therebetween;

at least one liquid issuing nozzle positioned on said tracking means in a manner to effect substantially consistent angular orientation and equidistant relationship with said inner surface of said sidewall throughout the period of said cam follower contact during said panel rotation, said nozzle being formed to provide and direct at least one stream of flushing liquid to impinge said coated sidewall in a substantially constant pattern of impingement to flush away the extraneous coating material from at least a portion of said inner sidewall surface; and

rotative motion means positioned on said base platform relative to said supporting means, said motion means being formed to impart predetermined rotative relative movement to said panel supporting means whereby said panel tracking means provides a substantially perimetrical sweeping motion of said nozzle with reference to said panel sidewall.

2. An apparatus for discretely removing extraneous lacquer material from the inner surface of the sidewall portion of an interiorly coated cathode ray tube face panel having a cathodoluminescent screen area and a perimetrical surrounding sidewall portion, said apparatus comprismg:

a base platform having a top surface with an open drainage well therein;

a circular panel accommodation stage having a central opening therein larger than said panel, said stage being horizontally positioned and peripherally supported above said platform in a manner to permit rotation of said stage about a vertical axis, said central opening of said stage being oriented over said drainage well, the periphery of said stage being formed to receive linear motion transmission to effect rotation thereof;

at least two panel retainers oriented in spaced apart relationship on said accommodation stage adjacent the central opening therein to effect compression retention against the sidewall exterior of said freshly lacquered panel positioned with the open face thereof in a downward position within said central opening, said panel having a vertical axis common with said vertical axis of said stage to facilitate conjunctive rotation of said panel and said stage;

motion means positioned on said base platform relative to the periphery of said stage to impart predetermined rotation to said stage;

at least one panel tracking means formed to extend above said platform within the confines of said inverted panel and being oriented therein for predetermined movement on a plane substantially parallel with the top of said platform to provide tracking means contact with the inner surface of said panel sidewall in a cam follower relationship during the rotation of said stage;

at least one liquid-issuing nozzle positioned on said tracking means in a manner to effect substantially consistent angular orientation and equidistant relationship with said inner surface of said moving sidewall during said cam-follower contact therewith, said nozzle being oriented to direct at least one stream of flushing liquid to impinge said lacquer coated sidewall, said nozzle being constructed to issue said stream in a manner to provide a substantially con stant pattern of impingement having a discretely formed peripheral trimming edge of liquid with the predetermined vertical apex thereof substantially following the border of said lacquer coated screen in a perimetrical sweeping motion to flush away the extraneous lacquer coating from said inner surface of said panel sidewall before lacquer filming materializes; and

control means to effect a programmed sequence of stage rotation, panel tracking actuation, and liquid flushing.

3. An apparatus for discretely removing extraneous liquid lacquer material from the inner surface of the sidewall portion of an interiorly lacquered cathode ray tube face panel having a cathodoluminescent screen area and a perimetrical surrounding sidewall portion, said apparatus comprising:

a base platform having a top surface with an open drainage well therein;

a circular panel accommodation stage having a central opening therein larger than said panel, said stage being horizontally positioned and peripherally supported above said platform in a manner to permit rotation of said stage about a vertical axis, said central opening of said stage being oriented over said drainage well, the periphery of said stage being formed to receive linear motion transmission to effect rotation thereof;

at least two panel retainers oriented in spaced apart relationship on said accommodation stage adjacent the central opening therein to effect compression retention against the sidewall exterior of said freshly lacquered panel positioned with the open face thereof in a downward position within said central opening, said panel having a vertical axis common with said vertical axis of said stage to facilitate conjunctive rotation of said panel and said stage;

motion means positioned on said base platform relative to the periphery of said stage to impart predetermined rotation to said stage;

at least one panel tracking means formed to extend above said platform within the confines of said inverted panel and being oriented therein for predetermined movement on a plane substantially parallel with the top of said platform to provide tracking means contact with the inner surface of said panel sidewall, said tracking means having a pair of tracking rollers on a swiveled tracking head to accurately track a definite portion of the inner surface of said sidewall in a consistent cam follower relationship during the rotation of said stage, said tracking head having limited arcuate movement;

at least one water-issuing nozzle positioned on said tracking head in a manner to effect substantially consistent angular orientation and equidistant relationship with said inner surface of said moving sidewall during said cam-follower contact therewith, said nozzle being oriented to direct at least one stream of flushing water to impinge said lacquer coated sidewall, said nozzle being constructeds to issue said stream in a manner to provide a substantially constant pattern of impingement having a discretely formed peripheral trimming edge of water with the predetermined vertical apex thereof substantially following the border of said lacquer coated screen in a perimetrical sweeping motion to flush away the extraneous liquid lacquer coating from said inner surface of said panel sidewall before lacquer filming materializes; and

control means to effect a programmed sequence of stage rotation, panel tracking actuation, and liquid flushing.

4. An apparatus for discretely removing extraneous liquid lacquer material from the inner surface of the sidewall portion of a freshly lacquered cathode ray tube face panel having a cathodoluminescent screen area and a peria base platform having a top surface with an open drainage well therein;

a circular panel accommodation stage having a central opening therein larger than said panel, said stage being horizontally positioned and peripherally supported above said platform in a manner to permit rotation of said stage about a vertical axis, said central opening of said stage being oriented over said mined rotation to said stage and said panel retained thereon;

at least one panel tracking means formed to extend above said platform within the confines of said inverted panel being oriented therein for predetermined movement on a plane substantially parallel with the top of said platform to provide tracking means contact with a definite portion of the inner surface of said panel sidewall adjacent the edge thereof in a camfollower relationship during the rotation of said stage; drainage well, the periphery of said stage being at least one liquid-issuing nozzle positioned on said formed to receive linear motion transmission to effect tracking means in a predetermined horizontal plane rotation thereof; in a manner to effect substantially consistent angular a plurality of spaced-apart panel rests oriented on said orientation and equidistant relationship with said base platform and extended to a plane thereabove in 15 inner surface of said moving sidewall during said a manner to provide horizontal placement and temcam-follower contact therewith, said nozzle being porary rest positioning for said panel When Said oriented to direct at least one stream of flushing liqfreshly lacquered panel is placed with the open face uid to impinge said lacquer coated sidewall, said nozthereof in a downward position within said central zle being constructed to issue said stream in a manopening, said rests being formed to provide r st S pner to provide a substantially constant pattern of im- P the p edge of Said Panel d eff t hOripingement having a discretely formed peripheral zontal positioning thereof, said rests having pivoted trimming edge of liquid ith th predetermined ortiprovisions beneath said accommodation stag to p cal apex thereof substantially following the border mit a su q n lowering of the Positions of Said of said lacquer coated screen in a perimetrical sweeprests in a mann r t be W a n from Said Panel ing motion to fiush away the extraneous lacquer coatd i accordance with predetermined progr mm ing from said inner surface of said panel sidewall actuation of said apparatus when said panel is posib f lacquer filn'ling t i li d tionally retained by subsequently applied retention ntrol means to effect a programmed sequence of ap means; paratus actuation to provide stage rotation, panel rest at least two panel retainers oriented in spaced apart relowering, panel tracking actuation, liquid flushing, lationship on aid accommodation stage adjacent the anel tracking deactivation, cessation of stage rotacentral opening therein being formed as said retenti d panel t iti i tion means to effect compression retention against the sidewall exterior of said freshly lacquered panel References Cited positioned on said panel rests, ugon colnsummlation UNITED STATES PATENTS of said compression retention sai pane rests eing actuated to drop away from said edge to said lower 1886503 11/1932 Shockey, 118318 X 2,763,564 9/1956 McKenzie et al. 118-318 X position to free said edge of all obstructions, said retained panel having a vertical axis common with 2880697 4/1959 Blandmg et 118 320 id ti l axi of said stage to facilitate conjunc- 2,907,688 10/1959 Payne 134 152 X tive rotation of said panel and said stage; motion means positioned on said base platform relative to the periphery of said stage to impart predeter- CHARLES A. WILLMUTH, Primary Examiner.

R. L. BLEUTGE, Assistant Examiner.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1886503 *Aug 5, 1930Nov 8, 1932Shockey Harry KMachine for reclaiming worn brake drums
US2763564 *Nov 25, 1953Sep 18, 1956Gen ElectricMeans and methods for processing cathode ray tube bulbs
US2880697 *Apr 19, 1957Apr 7, 1959Corning Glass WorksCoating apparatus
US2907688 *Sep 1, 1955Oct 6, 1959Philco CorpImproved washing operation for cathode ray tube manufacturing process
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3873365 *Mar 21, 1973Mar 25, 1975Gte Sylvania IncApparatus for cleaning seal edge regions of cathode ray tube panels
US5778912 *Dec 26, 1996Jul 14, 1998Samsung Display Devices Co., Ltd.Panel washing device for cathode ray tube
US7041231Jan 6, 2003May 9, 2006Triumph Brands, Inc.Method of refurbishing a transition duct for a gas turbine system
DE19638951A1 *Sep 16, 1996Mar 26, 1998Samsung Elektronische BauelemeOptimum method for inserting phosphor coating in CRT mfr.
DE19638951B4 *Sep 16, 1996Apr 20, 2006Samsung Sdi Germany GmbhVerfahren und Vorrichtung zur Optimierung der Leuchtstoffbeschichtung bei der Bildröhrenproduktion
Classifications
U.S. Classification134/58.00R, 134/152, 118/318
International ClassificationH01J29/28, H01J29/18, H01J9/227
Cooperative ClassificationH01J9/227, H01J29/28
European ClassificationH01J9/227, H01J29/28
Legal Events
DateCodeEventDescription
Aug 24, 1981ASAssignment
Owner name: NORTH AMERICAN PHILIPS CONSUMER ELECTRONICS CORP.
Free format text: ASSIGNS ITS ENTIRE RIGHT TITLE AND INTEREST, UNDER SAID PATENTS AND APPLICATIONS, SUBJECT TO CONDITIONS AND LICENSES EXISTING AS OF JANUARY 21, 1981.;ASSIGNOR:GTE PRODUCTS CORPORATION A DE CORP.;REEL/FRAME:003992/0284
Effective date: 19810708
Owner name: NORTH AMERICAN PHILIPS CONSUMER ELECTRONICS CORP.,