US3339522A

US3339522A - Frit dispensing device

Info

Publication number: US3339522A
Application number: US421536A
Authority: US
Inventors: Paul C Shaffer; Kenneth E Stratton
Original assignee: Sylvania Electric Products Inc
Current assignee: GTE Sylvania Inc
Priority date: 1964-12-28
Filing date: 1964-12-28
Publication date: 1967-09-05
Anticipated expiration: 1984-09-05
Also published as: GB1102328A

Description

p 1967 P. c. SHAFFER ETAL 3,339,522

FRIQT DISPENSING DEVICE Filed Dec. 28. 1964 2 Sheets-Sheet 1 4 INVENTORS PAUL C. SHAFFER I KENNETH E, Srmrrarv Y ATTORNEY Sept. 1967 P. c. SHAFFER ETAL 3,339,522

FRIT DISPENSING DEVICE Filed Dec. 28, 1964 2 Sheets-Sheet 2 INVENTORS PAUL C. SHAFFER 1! Y KENNETH f. r/urralv ATTORN EY United States Patent Ofiice 3,339,522 FRIT DISPENSING DEVICE Paul C. Shaffer, Seneca Falls, and Kenneth E. Strattou, Waterloo, N.Y., assignors to Sylvania Electric Products Inc., a corporation of Delaware Filed Dec. 28, 1964, Ser. No. 421,536 6 Claims. (Cl. 118-6) ABSTRACT OF THE DISCLOSURE A device for dispensing frit on the sealing edge of a rotating cathode ray tube funnel portion, whereof .a cam follower, oriented relative to the dispenser in a manner to follow the moving contour of the funnel, is connected to control means for regulating the speed of the funnel rotation. As the dispenser reciprocates in accordance with the peripheral shape of the funnel, the circumferential speed of the sealing edge is regulated to insure the uniform deposition of frit material thereon. Related horizontal and vertical reciprocal movements of dispenser positioning means orients the dispenser for activation and inactivation.

This invention relates to dispensing devices and more particularly to machines adapted to apply a bead of frit material to the sealing edge of the open envelope funnel portion of a cathode ray tube prior to the sealing of a separable face panel thereto during the tube manufacturing operation.

In the manufacture of cathode ray tubes using a bulb or envelope having an open or funnel portion and a compatibly matched face panel, it is necessary in the manufacturing operation -to eflfect a hermetic seal between the funnel and panel portions which will successfully endure subsequent processing and evacuation and thereby from a vacuum tight envelope enclosure. In the present state of the art, it is conventional to apply a continuous bead of glass frit material to the sealing edge of the funnel whereupon the face panel is properly positioned and the two portions theretogether are baked at an elevated temperature for a period of time sufficient to effect the desired hermetic seal therebetween. On funnels of a round shape, the bead of frit material is applied to the sealing edge by conventional machines known to those skilled in the art. In general, these machines cradle the funnel near its sealing edge and orient and rotate the funnel with the sealing edge under a frit dispensing means to apply the desired bead of frit material thereto. In processing rectangular or other than round type cathode ray tube envelope funnels the aforementioned machine is incapable of following the contour of the sealing edge to satisfactorily dispense a uniform bead of frit centrally thereon since there is no provision for accurately maintaining the position of the dispensing means with respect to the sealing edge of the respective funnel. In current practice, the funnel is usually supported near the sealing edge in an area which has comparatively liberal manfacturing tolerances rather than in the yoke area which is more carefully dimensionally controlled. As a consequence, there is a relatively wide variation from funnel to funnel in vertical spacing between the sealing edge of the funnel and the frit dispensing means which is a factor detrimental to the quality of frit bead application. According to conventional practice, the funnel normally rotates at a constant speed which is adequate in the case of a round funnel, but in the case of a rectangular type funnel, a constant speed of rotation causes the sealing edge to pass the dispensing means at a nonuniform rate of travel which results in the application of a bead of varying proportions.

Additionally, current practices and techniques do not provide an adequate or versatile method for holding or supporting funnels so that either round or other than round types may be processed interchangeably in a continuous manufacturing operation.

Accordingly, an object of the invention is to reduce the aforementioned disadvantages and to provide improved means for applying a uniform issue of frit material to the sealing edge of a cathode ray tube funnel.

Another object of the invention is the provision of means which provides uniform application of frit material to the sealing edge of both round and other than round type cathode ray tube funnels.

.A further object is the provision of a machine which provides uniform and accurate spacing between the sealing edge of the funnel and the frit dispensing means and has versatile supporting means for variously contoured funnels.

A still further object is the provision of a machine which provides the sealing edge of the funnel with a constant rate of travel as it passes beneath the frit dispensing means.

The foregoing objects are achieved in one embodiment of the invention by the provision of a frit dispensing machine having funnel portion support means formed for conformingly holding the funnel of the cathode ray tube at substantially the external yoke area to facilitate the rotation of the funnel with the sealing edge uppermost in a horizontal position. Funnel portion insert means formed to compatibly contact the interior yoke area both aligns and firmly seats the funnel on the funnel portion support. Positioning means is provided for moving the frit dispenser means into the desired position over the sealing edge of the funnel and maintaining this position by a substantially reciprocal horizontal movement effected by an associated cam follower adapted and oriented to follow the contour of the funnel as it is caused to rotate by rotatable means mechanically connected to the funnel portion support means. The rotatable means has speed control means actuated by the reciprocal horizontal movement of the positioning means to provide a uniform rate of travel to the sealing edge of the funnel as it passes beneath the frit dispensing means.

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 .accompanyin g drawings in which:

FIGURE 1 is an elevational view showing two positions of the frit disensing machine in partial cross section, one position being in phantom;

FIGURE 2 is a top view of the positioning and dispensing means;

FIGURE 3 is a top view of the funnel portion support means;and

FIGURE 4 is an elevational view of the positioning and dispensing means showing another embodiment of the invention.

With reference to FIGURE 1, there is illustrated a frit dispensing machine 11 having frit dispensing means 15 formed to provide a uniform bead of frit material 17 to the sealing edge 19 of the funnel portion 21 of a cathode ray tube of the separable funnel and face panel variety. The funnel portion 21, having a yoke area 20 defining the transition between the flared 22 and neck 24 portions thereof, as conformingly held at the external yoke area v23: by the contoured seating portion 25 of the funnel portion support means 27; the sealing edge 19 of the funnel being uppermost in a substantially horizontal position. Funnel portion insert means 29 is compatibly formed to provide positive contact with the internal yoke area 31 thereby firmly seating the external yoke area 23 of the funnel 21 in the contoured seating portion 25 of the funnel portion support means 27. The funnel being so oriented provides optimum uniform positioning of the sealing edge 19 thereof with respect to the orifice 33 of the frit dispensing means 15.

The funnel support means 27 is mounted upon a circular base 35 having an axial support shaft 36 turnable in a bearing support 34 and adapted for rotation by linkage with the rotatable means 32. As for example, in this instance, the turnable circular base 35 is circumferentially formed to accommodate a conventional V-belt 37 driven by a reduction type electric motor 32, whereby rotation is imparted to the funnel support means 27 and the funnel 21 seated therein. While belt linkage is shown, chain, shaft, or gear drives are in like manner applicable. The frit dispensing means 15, having a reservoir portion 16, is held by the movable planar support member 38 of the positioning means 39 which is capable of providing both vertical motion and substantially reciprocal horizontal movement to the dispensing means 15. A commercially available double-stroke vertically positioned air cylinder 41 is utilized to provide the vertical movement, while the commercially available double-stroke horizontally oriented air cylinder 43 is used, in conjunction with the suspended weight 45 which is attached to the movable support member 38, to provide substantially reciprocal horizontal movement. The frit dispensing machine 11, as illustrated in FIGURE 2 and in phantom in FIGURE 1, is in the frit dispensing position with the orifice 33 of the dispensing means 15 in proper location over the sealing edge 19 of the funnel portion 21. The

air cylinders

41, 43 are both in retract positions with the weight 45 holding the cam follower means 47 positively against the inner surface 49 of the funnel 21 near its sealing edge 19. The cam follower means 47 which is either a small wheel or shoe is rigidly affixed to a supporting arm 46. This arm in turn is attached to the movable support member 38 which also holds the frit dispensing means 15. The movable planar support member 38 is carried on two horizontal side guide rods 53 by guide members 55 which are attached to the planar support member 38 and are capable of sliding horizontal movement along the guide rods 53. It is to be observed that with the horizontal air cylinder 43 in the retract position and with the weight 45 attached to the movable support member 38 by, as for example, a flexible metal chain 57 suspended over a pulley 59, that a method is provided to hold the cam follower means 47 in a positive manner against the inner surface 49 of the funnel portion 21 near the sealing edge 19. Thus, the movable support 38 is capable of controlled reciprocal horizontal movement as determined by the contour of the sealing edge 19 as the cam follower 47 moves therearound. The aforedescribed cam follower feature permits the same machine 11 to be utilized for applying a bead of frit material to both round and other than round contoured cathode ray tube funnel types in a continuous manufacturing operation as long as the sealing edge 19 is always presented to the orifice 33 of the dispensing means 15 at substantially the same vertical spacing thereunder.

In greater detail, as shown in the solid line presentation in FIGURE 1, the normal sequence of operation .begins with the loading or positioning of the funnel 21 in the funnel portion support means 27. To facilitate facile load ing, the funnel portion insert means 29 is in an elevated position consummated either manually or mechanically by sliding the insert shaft 28 upward through the bushing 30 in insert support means 26 where it is temporarily manually held or mechanically clamped by holding means 18. Dispenser positioning means 39 is shown in a raised and retracted position, accomplished in a manner to be described, to thereby spacedly remove the frit dispensing means 15 to a position where it will not interfere with the loading of the funnel 21. With the insert and dispensing means temporarily out of the way, the funnel 21 is positioned in the funnel support means 27 with the funnel external yoke area 23 placed in the contoured seating portion 25.

With reference to FIGURE 3, in addition to FIGURE 1, a section of the funnel support means 27 is shown. The removable support cap 73 has therein the semi-closed contoured seating portion 25 which is shaped to substantially conform to the external yoke area 23 of the funnel.

Other yoke shapes may be accommodated by replacing the support cap 73 with another having the desired contoured seating portion. The interchanging of the variously contoured support caps 73 is easily accomplished by the removal and replacement of four securing cap screws 79. Intermediate the support cap 73 and the two upstanding support legs 81 are two removable shim spacers 83. These are of like thickness and are utilized in achieving the proper vertical spacing between the orifice 33 of the frit dispensing means 15 and the funnel sealing edge 19 when it is necessary to bead funnels of different sizes or vertical lengths. Thus, by utilizing these paired spacers 83 of various thicknesses and support caps 73 having variously shaped seating portions 25, it is possible to provide versatility to the frit dispensing device to handle a wide variety of sizes and shapes of funnels 21.

With the funnel 21 positioned in the seating portion 25, a pair of

complementary clamps

85 and 87 are adjusted by external knobs 88 to contact and hold the neck portion 24 of the funnel in desired alignment. One of these clamps 85 is threadingly located in one of the upstanding support legs 81 to form a fixed positioner for supporting one side of the neck 24 of the funnel to promote axial alignment of the funnel 21 in the funnel support means 27. The complementary adjustable positioner 87, threadingly located in the other upstanding support leg 81, is advanced into positive contact with the neck to lock the neck 24 of the funnel 21 in position on the funnel support means 27. It is to be noted that either of the

clamps

85 or 87 may become the fixed or the adjustable positioner as desired. Each positioner is of substantially the same configuration having a substantially U-shaped termination which remains on a lateral plane for facilitating aligning contact with the neck 24. The manually adjustable movement of each positioner is facilitated by conventional threaded sleeve and insert means.

With reference to the solid and phantom positions as shown in FIGURE 1, the funnel portion insert means 29 is lowered into the funnel portion 21 to make positive contact with the internal yoke area 31 of the funnel. The insert means 29 is shaped to compatibly conform to the contour of the internal yoke area 31 to promote proper alignment and seating of the funnel 21 in the seating portion 25 of the funnel portion support means 27. Positive contacting pressure of the insert 29 with the internal yoke area 31 is promoted through the use of resilient loading in the form of an insert spring 75 or other conventional means. The horizontal air cylinder 43 is actuated by controlled air pressure through the horizontal intake 63 and the plunger 44 moved into the forward position advancing the stop plate 65 on the movable support member 38 by a length of stroke suflicient to move the cam follower means 47 to a location above and adjacent the inner surface 49 of the funnel 21. The vertical air cylinder 41 supported on the cylinder base support 67 is now actuated to retract the plunger 70 to a predetermined position thereby lowering the table support 71 with its associated vertical guide rods 72. This causes the cam follower means 47 to drop to a position adjacent to, but spaced from, the inner surface 49 of the funnel 21. The horizontal air cylnder 43 is activated to retract the plunger 44 from the stop plate 65 thereby permitting the weight 45 to pull the orifice 33 of the frit dispensing means 15 into desired central position over the sealing edge 19 and simultaneously the cam follower 47 is moved into positive contact with the inner surface 49 of the funnel adjacent the sealing edge 19 thereof. The frit dispensing machine 11 is now in readiness to begin deposition of the uniform bead 17 of frit material to the sealing edge 19 of the funnel 21.

The beading operation begins with the funnel 21 in the dispense position as illustrated in phantom in FIG- URE 1. The rotatable means 32 is started or switched into rotational operation, by conventional means not shown, causing the funnel support means 27 and the funnel 21 to rotate. Controlled air pressure is admitted to the reservoir 16 of the frit dispensing means 15 through the dispensing intake 61 from a conventional external source not shown. This causes the frit material contained therein to be extruded or issued through the orifice 33 and deposited on the rotating sealing edge 19 of the funnel in the form of a uniform bead of frit material 17 in desired location thereon. Upon completion of the dispense cycle or one complete revolution or pass of the sealing edge 19 under the orifice 33, the air pressure to the dispensing means 15 is interrupted by conventional means not shown and the rotatable mean 32 is switched off permitting the funnel support means 27 and the funnel 21 therein to become stationary. The horizontal air cylinder 43 is then automatically actuated by controlled air pressure through the horizontal intake 63 moving the plunger 44 into the forward thrust position pushing against the stop plate 65 of the movable support member 38 causing the cam follower means 47 to become disengaged from the inner surface 49 of the funnel 21. The vertical air cylinder 41 is again actuated by controlled air pressure through vertical intake 69 and the plunger 70 moved upward thereby causing the table support 71 to elevate the attached movable support member 38. This raises the orifice 33 of the frit dispensing means 15 and the associated cam follower means 47 to a position spacedly above the sealing edge 19. This vertical movement is facilitated by vertical guide rods 72 sliding in compatible sleeves 74 accommodated in base support 67. The horizontal cylinder 43 is now retracted permitting the suspended weight 45 to withdraw the movable support member 38 and the associated frit dispenser 15 a sufficient distance from the funnel 21 to permit removal of the beaded funnel 21 from the funnel support means 27. This is of course facilitated by the elevation of the insert means 29 as previously described. Thus one complete operational cycle has been consummated.

An important feature of the invention is the adaptability of the device to apply a uniform bead of frit to the sealing edge of a substantially rectangular or square envelope funnel. The aforedescribed cam follower means 47 associated with the frit dispensing means 15 enables the orifice 33 to efficiently track the sealing edge 19 of the funnel 21. When applying frit to substantially round funnels, the circumference, or sealing edge being equidistant from the center of rotation, moves at a constant speed past the orifice and a uniform bead of frit is issued thereupon. With reference to FIGURE 2, there i partially shown a substantially rectangular funnel 51 having a sealing edge 19' with points A, B, and D thereon. This funnel 51 is seated as aforedescribed in a rotational funnel portion support means, not shown in FIGURE 2 but illustrated in FIGURE 1, having a center of rotation which, when vertically extended, intersects the plane of the sealing edge at C. Line CA projected perpendicular to sealing edge AB i shorter than line CD projected perradii lengthen. Thus, with funnel 51 rotating at a constant speed, it is evident that point B of sealing edge 19' will move under orifice 33 at a rate more rapid than will point D, and point D will move a rate faster than point A. This difference in rate of travel is not desirable for uniform frit deposition therefore means have been devised to vary the rotational speed of the turnable funnel support means 27 by varying the speed of the rotatable means 32 mechanically linked thereto. As shown in FIGURES 1 and 2, speed control means 91 is substantially in the form of a rheostat ridigly attached to table support 71 and electrically connected to rotatable means 32 by a conductor 93. A rotatable wheel 95 attached to the shaft of speed control means 91 has a peripheral rubber friction rim or tire 97 affixed thereto. This friction tire is adjusted to firmly touch the friction surface 99 of the friction plate 101 which is firmly attached to movable support member 38. As the cam follower means 47 steadfastly follows the contour of the inner surface 49 of the funnel 21, it causes the movable support member 38 to have horizontal lateral motion along the side guide rods 53. This motion moves the friction plate 101 thereby imparting rotation to the wheel 95 of the speed control means 91. In this manner, movement of the rheostat varies the electrical current supplied to rotatable means 32 thereby producing a change in rotational speed of the funnel support means 27. When the horizontal motion of the movable support member 38 is in the forward direction the rotational speed of the motor 32 is increased, and when the horizontal motion of the movable support 51 is in the retract direction the rotational speed of the motor is decreased. Thus, as the rectangular funnel 51 is rotated, the speed of rotation is varied to insure a constant rate of travel of the sealing edge 19' beneath the orifice 33 to thereby provide a uniform bead of frit material 17 therearound.

While the conjunctive operation of the friction tire 97 on the friction plate 101 has been described and shown,

a geared pinion and rack may also be used to achieve positive movement of the speed control rheostat 91 if so desired.

With reference to FIGURE 4, there is shown another embodiment of the invention wherein the cam follower means 47' is attached to the movable support member 38 and adapted to be positively held against the outer surface 103 of the funnel 21 to thereby locate the orifice 33 of the dispensing means 15 directly above the sealing edge 19. Positive contact of the cam follower means 47 with the outer surface 103 is promoted by the use of a movable support spring 105 encompassing a spring guide 107. The guide is attached to the stop plate at its forward end 109 and having its opposite or retract end 111 slidably projecting through a compatibly aligned bushing 113 in the upright back support 115. Thus, the spring guide 107 has sliding movement therethrough to guide the compression and expansion of the movable support spring 105 as occasioned by the substantially reciprocal horizontal movement of the movable support member 38. The expansion of the support spring maintains the cam follower 47' in contact with the contour of the outer surface 103 of the funnel 21.

To facilitate disengagement of the cam follower 47 pendicular to sealing edge BD, and diagonal CB is longer A 43', supported by the upright front support 117, is actuated whereby its plunger 44' pushes against the stop plate 65'. This action permits the cam follower means 47 to move a suflicient distance away from the outer funnel surface 103 to permit the loading and unloading of the frit dispensing machine 11. When the device is loaded with another funnel, the plunger 44' of the horizontal air cylinder 43' is retracted thereby allowing the guide spring 107 to expand and move the cam follower means 47' into positive contact with the outer surface 103 of the funnel 21. In this embodiment, the plunger 70 of the vertical air cylinder 41 is set in the desired frit dispensing position and left in that position since there is no vertical movement necessary in the sequence of operations. The remaining cycle of operations is as previously described.

Thus, there is provided an improved frit dispensing device that successively overcomes disadvantages prevalent in the known art. This device applies a consistent issue of frit material to form a uniform bead around the sealing edge of a cathode ray tube funnel regardless of whether the sealing contour of the funnel is substantially round, square, or rectangular in shape. In so doing, the device provides the sealing edge of the funnel, regardless of shape, with a constant rate of travel as it passes beneath the orifice of the frit dispenser. In addition, the machine provides uniform and accurate spacing between the sealing edge of the funnel and orifice of the frit dispenser that is both adjustable and consistently repeatable. Other contributing features of the device in conjunction with those enumerated combine to produce a frit dispensing device that is markedly superior to any known in contemporary art.

While there have been shown and described what are at present considered the preferred embodiments 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. In the manufacture of cathode ray tubes having separable funnel and face panel portions, a device for applying a bead of frit material to the sealing edge of said funnel portion comprising the combination of:

funnel portion support means adapted for rotation and formed to hold said funnel with said sealing edge uppermost in a substantially horizontal plane;

rotatable means linked to said support means to provide rotation thereto;

dispensing means formed to provide a uniform issue of frit material; positioning means formed to hold said frit dispensing means and orient the same to a position relative to said sealing edge, said positioning means being adapted to provide substantially placement movement thereto; cam follower means afiixed to said positioning means and oriented to contact said funnel adjacent to the edge thereof in a manner to substantially follow the contour of said rotating funnel to guide said dispens ing means therealong and facilitate the application of said bead of frit material to said sealing edge, and

speed control means associated with said funnel rotatable means to vary the speed thereof and facilitate the uniform application of said frit material. 2. In the manufacture of cathode ray tubes having separable funnel and face panel portions, a device for applying a bead of frit material to the sealing edge of said funnel portion comprising the combination of:

rotatable means mechanically linked .to said support means to provide rotation thereto;

dispensing means formed to provide a uniform issue of frit material;

positioning means formed to accommodate said frit dispensing means and orient the same to a position relative to said sealing edge, said positioning means being adapted to provide substantially reciprocal horizontal movement and related vertical reciprocal movement thereto, and

cam follower means aflixed to said positioning means and oriented to contact the inner surface of said funnel adjacent to the edge thereof in a manner to substantially follow the contour of said rotating funnel to guide said dispensing means therealong and facilitate the application of said head of frit material to said sealing edge. 3. In the manufacturing of cathode ray tubes having separable funnel and face panel portions, a device for applying a bead of frit material to the Sealing edge of a round, square, or rectangular funnel portion comprising the combination of:

rotatable means mechanically linked to said support means to provide rotation thereto;

dispensing means formed to provide a uniform issue of frit material; positioning means formed to hold said frit dispensing means and orient the same to a position relative to said sealing edge, said positioning means being adapted to provide both vertical and substantially reciprocal horizontal movement thereto; cam follower means affixed to said positioning means and oriented to contact the inner surface of said funnel adjacent to the edge thereof in a manner to substantially follow the contour of said rotating funnel to guide said dispensing means therealong and facilitate the application of said bead of frit material to said sealing edge, and speed control means electrically connected to said funnel rotatable means and actuated by said reciprocal horizontal movement of said positioning means to vary the speed of said rotatable means and thereby facilitate the uniform application of said bead of frit material to said sealing edge of said funnel portion. 4. In the manufacturing of cathode ray tubes having separable funnel and face panel portions, a device for applying a bead of frit material to the sealing edge of a round, square, or rectangular funnel portion comprising the combination of:

funnel portion support means adapted for rotation and formed for holding said funnel with said sealing edge uppermost in a substantially horizontal plane;

dispensing means formed to provide a uniform issue of frit material; positioning means formed to hold said frit dispensing means and orient the same relative to said sealing edge, said positioning means being adapted to provide substantially reciprocal horizontal movement thereto; cam follower means affixed to said positioning means and oriented to contact the outer surface of said funnel adjacent to the edge thereof in a manner to substantially follow the contour of said rotating funnel to guide said dispensing means therealong and facilitate the application of said bead of frit material to said sealing edge, and speed control means electrically connected to said funnel rotatable means and actuated by said reciprocal horizontal movement of said positioning means to vary the speed of said rotatable means and thereby facilitate the uniform application of said bead of frit material to said sealing edge of said funnel portion. 5. In the manufacturing of cathode ray tubes having separable funnel and face panel portions, a device for applying a bead of frit material to the sealing edge of a round, square, or rectangular funnel portion comprising the combination of:

dispensing means formed with an orifice to provide a uniform issue of frit material; positioning means formed to hold said frit dispensing means and orient the some to a position relative to said sealing edge, said positioning means being adapted to provide both vertical and substantially reciprocal horizontal movement thereto, said positioning means having a friction plate affixed thereon;

cam follower means affixed to said positioning means and oriented to contact the inner surface of said funnel adjacent to the edge thereof in a manner to substantially follow the contour of said rotating funnel to guide said dispensing means therealong and facilitate the application of said bead of frit material to said sealing edge; and

speed control means in the form of a rheostat having a rotatable wheel with a friction rim thereon, said cotrol means being electrically connected to said funnel rotatable means to provide a uniform rate of travel to said sealing edge as it passes beneath said orifice, said speed control means being frictionally actuated by the movement of said wheel on said friction plate of said positioning means during the reciprocal horizontal movement thereof to move said rheostat and vary the speed of said rotatable means to thereby facilitate the uniform application of said bead of :frit material to said sealing edge of said funnel portion.

6. In the manufacturing of cathode ray tubes having separable funnel and face panel portion, a device for applying a bead of frit material to the sealing edge of a round, square, or rectangular funnel portion comprising the combination of:

funnel portion support means adapted to be turnable on a center of rotation and formed to hold said funnel with said sealing edge uppermost in a substantially horizontal plane;

dispensing means formed with a reservoir and an orifice to provide a uniform issue of frit material; horizontal positioning means formed to hold said frit dispensing means and horizontally orient the same to a position relative to said sealing edge, said horizontal positioning means supplying mechanically reciprocal horizontal movement thereto in a manner to move said dispensing means toward or away from said center of rotation, said horizontal positioning means having a friction plate aifixed thereon;

cam follower means affixed to said positioning means and oriented to contact the inner surface of said funnel adjacent to the edge thereof in a manner to substantially follow the contour of said rotating funnel to guide said dispensing means therealong and facilitate the application of said bead of frit material to said sealing edge;

vertical positioning means formed to accommodate said horizontal positioning means and raise and lower the same as required to orient said dispensing means relative to said sealing edge, said vertical positioning means being moved by mechanical actuation; and

speed control means in the form of a rheostat having a rotatable wheel with a friction rim thereon, said control means being electrically connnected to said funnel rotatable means to provide a uniform rate of travel to said sealing edge as it passes beneath said orifice, said speed contnol means being frictionally actuated by the movement of said wheel on said friction plate of said positioning means during the reciprocal horizontal movement thereof as. said cam follower tracks said inner surface of said funnel to move said rheostat and vary the speed of said rotatable means, said speed being increased as said sealing edge moves toward said center of rotation and decreased as said sealing edge moves away from said center of rotation to provide said uniform rate of travel to said sealing edge to thereby facilitate the uniform application of said bead of frit material to said sealing edge of said funnel portion.

References Cited UNITED STATES PATENTS 718,190 11/1954 Great Britain. 354,699 7/1961 Switzerland.

CHARLES A. WILLMUTH, Primary Examiner,

R, 1. SMITH, Assistant Examiner,

Claims

1. IN THE MANUFACTURE OF CATHODE RAY TUBES HAVING SEPARABLE FUNNEL AND FACE PANEL PORTIONS, A DEVICE FOR APPLYING A BEAD OF FRIT MATERIAL TO THE SEALING EDGE OF SAID FUNNEL PORTION COMPRISING THE COMBINATION OF: FUNNEL PORTION SUPPORT MEANS ADAPTED FOR ROTATION AND FORMED TO HOLD SAID FUNNEL WITH SAID SEALING EDGE UPPERMOST IN A SUBSTANTIALLY HORIZONTAL PLANE; ROTATABLE MEANS LINKED TO SAID SUPPORT MEANS TO PROVIDE ROTATION THERETO; DISPENSING MEANS FORMED TO RPOVIDE A UNIFORM ISSUE OF FRIT MATERIAL; POSITIONING MEANS FORMED TO HOLD SAID FRIT DISPENSING MEANS AND ORIENT THE SAME TO A POSITION RELATIVE TO SAID SEALING EDGE, SAID POSITIONING MEANS BEING ADAPTED TO PROVIDE SUBSTANTIALLY PLACEMENT MOVEMENT THERETO; CAM FOLLOWER MEANS AFFIXED TO SAID POSITIONING MEANS AND ORIENTED TO CONTACT SAID FUNNEL ADJACENT TO THE EDGE THEREOF IN A MANNER TO SUBSTANTIALLY FOLLOW THE CONTOUR OF SAID ROTATING FUNNEL TO GUIDE SAID DISPENSING MEANS THEREALONG AND FACILITATE THE APPLICATION OF SAID BEAD OF FRIT MATERIAL TO SAID SEALING EDGE, AND SPEED CONTROL MEANS ASSOCIATED WITH SAID FUNNEL ROTATABLE MEANS TO VARY THE SPEED THEREOF AND FACILITATE THE UNIFORM APPLICATION OF SAID FRIT MATERIAL.