US3537159A - Apparatus for achieving custom mask to panel spacing in cathode ray tubes - Google Patents

Apparatus for achieving custom mask to panel spacing in cathode ray tubes Download PDF

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Publication number
US3537159A
US3537159A US777108A US3537159DA US3537159A US 3537159 A US3537159 A US 3537159A US 777108 A US777108 A US 777108A US 3537159D A US3537159D A US 3537159DA US 3537159 A US3537159 A US 3537159A
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Prior art keywords
mask
panel
frame
elevator
cam
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US777108A
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Stanley J Gartner
La Rue V Regelman
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GTE Sylvania Inc
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Sylvania Electric Products Inc
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Assigned to NORTH AMERICAN PHILIPS CONSUMER ELECTRONICS CORP. reassignment NORTH AMERICAN PHILIPS CONSUMER ELECTRONICS CORP. ASSIGNS ITS ENTIRE RIGHT TITLE AND INTEREST, UNDER SAID PATENTS AND APPLICATIONS, SUBJECT TO CONDITIONS AND LICENSES EXISTING AS OF JANUARY 21, 1981. (SEE DOCUMENT FOR DETAILS). Assignors: GTE PRODUCTS CORPORATION A DE CORP.
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/02—Electrodes; Screens; Mounting, supporting, spacing or insulating thereof
    • H01J29/06—Screens for shielding; Masks interposed in the electron stream
    • H01J29/07—Shadow masks for colour television tubes
    • H01J29/073—Mounting arrangements associated with shadow masks

Definitions

  • the mask frame with the aperture portion fitted thereon is oriented relative to the panel and the spacer rods therein in a manner that the aperture portion is positioned against terminal elements of the spacer rods.
  • Resiliently mounted pressure pads are applied by elevator means to seat the various portions of the mask, against the opposing spacer rods, and accordingly modify the contour of the mask therebetween.
  • bonding means are applied to provide attachment of the modified mask to its supporting frame.
  • the invention relates to cathode ray tubes and more particularly to an apparatus for achieving accurate custom spacing between the aperture mask and a panel in a color cathode ray tube of the shadow mask type.
  • the frame supporting the mask is usually oriented in a predeterminately spaced manner within the panel by bracket locating means on the mask frame mating with positioning means integral to the panel.
  • One of the problems encountered in the fabrication of screens for shadow mask tubes involves achieving accurate spacing between the aperture mask and the interior surface of the panel upon which the cathodoluminescent screen is disposed. Such spacing, which is predetermined during the mask and panel assembly procedure, facilitates subsequent photodeposition of the patterned screen on the panel.
  • the several electron beams emitted therein are influenced to cross one another at the mask apertures and impinge upon discretely related areas of the screen layer beneath without overlapping one another.
  • the spacing between the mask and the screen is varied in a planned sequential manner progressing from the center portion of the mask toward the edge areas thereof to provide the proper spacing relationship between the mask apertures and discrete areas of the display screen.
  • one of the conventional procedures comprises locating the formed mask on a bed substantially contoured to the dome shape of the mask. With the mask so positioned, the frame is adjusted thereon to achieve the desired dimensional relationship between the mask and the frame locating means, whereupon the mask is peripherally bonded to the adjusted frame.
  • Many mask-frame combinations have been fabricated in this manner. Accordingly, with the aforementioned procedure a relative generalized spacing between the shaped ice mask and the panel is substantially achieved in the maskpanel assembly.
  • Another conventional procedure consists of welding the mask to the frame and then compromising the positioning and attachment of the frame locating means thereon to arrive at the desired dimensional relationship between the mask surface and the frame locating means.
  • the undesired dimensional values of such mask to panel spacing affect the color purity of the dynamic display in the finished tube. Therefore, in order to attempt to achieve the desired mask to panel spacing, it has been a conventional procedure to utilize gauging means to match framed masks to panels. If the spacing between the mask and panel in the initial attempt at assembly does not meet the accepted tolerances, the mask is removed and positioned in a different panel and rechecked until a maskpanel combination is found that will fulfill the spacing specifications. An acceptable mask-panel combination is mated as an assembly and, as such, remains in associated relationship throughout subsequent processing into the completed tube. The aforedescribed matching procedure requires considerable time and handling, which is detrimental to efiicient manufacturing. Furthermore, accurate and uniform mask to panel spacing is not fully achieved because of the wide tolerance range necessitated by the procedure.
  • Another object is to provide an apparatus which in a repetitive manner can make cathode ray tube mask-panel assemblies wherein the spacing relationship between the aperture mask and the screen bearing portion of the panel is achieved in accordance with the interior contour of the panel.
  • the panel is positioned in a manner to receive a plurality of spacer rods having terminally formed pads which are oriented to contact discrete areas of the interior contour of the panel.
  • the mask supporting frame with the aperture mask portion fitted thereon is moved by elevator means to a position relative to the panel to enable the mask portion thereof to make contact with the shaped opposite ends of the several spacer rods positioned against the panel.
  • the pressure rods which have terminally related pressure pads thereon, are moved by elevator means to make contact with the under surface of the mask in the areas resting against the shaped end surfaces of the paneloriented spacer rods.
  • FIG. 1 is a general plan view of a conventional shadow mask type of cathode ray tube comprising a mask positioned in spaced relationship to a screen bearing panel;
  • FIG. 2 is a plan view showing the top of the apparatus
  • FIG. 3 is an elevational end view of the apparatus taken along the line 33 of FIG. 2;
  • FIG. 4 is an elevational view of the panel elevator cam arrangement taken along the line 4-4 of FIG. 3;
  • FIGS. 5, 6, and 7 are elevational side views of the apparatus taken along the line 5 of FIG. 2 illustrating several stages in the operation of the apparatus;
  • FIGS. 8, 9, and 10 are enlarged perspectives illustrating the sequential operational stages of the panel pickup elements
  • FIG. 11 is a plan view of the pressure rod actuation means taken along the line 1111 of FIG. 5;
  • FIG. 12 is an enlarged perspective view of the motion means associated with the pressure rod actuation means taken along the line 12--12 of FIG. 3;
  • FIG. 13 is a motion chart illustrating the several coordinated movements of the apparatus.
  • FIG. 1 With reference to FIG. 1 there is shown a conventional shadow mask type of color cathode ray tube 11.
  • an electron gun structure 17 Oriented Within the neck 13 of the tube envelope 15 is an electron gun structure 17.
  • This generalized structure comprises three electron beam emitters wherelfrom beams 19 are directed to converge at the aperture mask 21 which is a thin, metallic, foraminous member. After convergence, the beams pass through the aperture mask and impinge upon a patterned cathodoluminescent screen 25 therebeneath which is suitably disposed upon an interior surface 27 of the panel portion 29 of the tube.
  • the formed aperture mask 21 is suitably attached to a strengthening frame 31 which in turn, has bracket locating means 33 thereon to mate with mask positioning means, such as studs 35 integral to the panel, to form the mask-panel assembly 37.
  • the spacing between the formed foraminous portion 21 and the interior surface 27 of the panel is conventionally referred to as spacing.
  • Suchspacing is of predetermined values across the surface of the panel, such being achieved, for example, by resolving the required distance d between the frame locating means 33 and the interior surface of the panel immediately prior to the attachment of the formed aperture mask 21 to its supporting frame 31.
  • the mask panel assembly 37 is suitably joined to the funnel portion 39 of the tube enevlope along the seal line 41.
  • FIGS. 2, 3, 4, and 5 there is illustrated an apparatus 43 whereby the predetermined mask to panel spacing is discretely effected for each panel assembly.
  • the apparatus is constructed upon supporting platform 45 having a base portion 47 and associated upright and horizontal portions 49 and 51 with provisions thereon for accommodating three substantially horizontal levels of operational features. These levels are referenced as upper, intermediate and lower levels, 53, 55, and 57 respectively.
  • the upper level 53 accommodates means of transferring and positioning the panel 29.
  • the lower level 57 accommodates means for accomplishing a similar function of transferring and positioning the formed mask 21 and frame 31 elements; while 'the intermediate level 55 accommodates means on a stationary plane for effecting the final bonding procedure whereby the shaped and adjusted mask 21 is welded to its supporting frame 31.
  • Cam actuated elevator means position the first contact surfaces of a plurality of spacer rods 59 against discrete portions of the interior surface 2'7 of the panel 29.
  • FIGS. 3 and 5 represent elevational view of the apparatus 43 taken on vertical planes separated by 90 of orientation, plural elements of the apparatus that perform like functions will be referenced by like numerical designations and nomenclature to facilitate clarity of description.
  • the mask frame 31 with the formed aperture amsk 21 fitted thereon is transferred in a substantially verticalmanner by cam actuated mask-frame elevator means 61 from the lower level 57 to the intermediate level 55 so that the formed aperture mask portion is adjacent the shaped second contact or lower surfaces of the spacer rods 59.
  • a plurality of pressure rods 63 having terminal pressure pads 65 thereon are moved by cam actuated pressure rod elevator means 67 to effect contact of the pressure pads with the formed mask portion 21 seating the same against the shaped lower surfaces 60 of the spacer rods and thereby modifying the shape of the mask accordingly.
  • the pressure pads also adjust the shaped mask on the frame in preparation for bonding.
  • Movement activation means 69 such as a powered cam combination, efiects coordinated movement of the aforementioned elevator means and actuates generalized control means 71 which programs the mask-to-frame bonding means 73 accommodated on the intermediate level 55.
  • the upper level 53 of the apparatus accommodates panel translocation and positioning means in the form of a movable panel carrier 75 having a carrier platform 77 with associated panel carrier trolley means 79 to facilitate movement of the panel carrier along supporting rails 81.
  • the panel carrier platform 77 has a cut-out portion 83 which is dimensionally shaped to substantially conform to the inner dimensions of the open side of the panel 29.
  • a plurality of panel locating pins 85 are aflixed to the panel carrier platform to facilitate positioning of the panel thereon.
  • These rods which are of predetermined lengths as will be discussed later in this specification, have terminally oriented contact surfaces at each end.
  • the contact surface oriented toward the open panel is formed as a panel contact pad 91 and mounted in a swivel manner to facilitate substantially mating placement on the interior surface 27 of the panel.
  • the rod contact portion at the opposite end of the spacer rod is formed as an anvil element 93 having a surface contour 60 that substantially matches the predetermined general contour of the mask portion that will subsequently contact that area.
  • Each spacer rod 59 is slidably accommodated within its support means 89 in a resiliently tensional manner, as by spring means 95 whereof one end is attached to the anvil element 93 with the opposite end aflixed to a suitable attachment 97 on the rod support means.
  • the tensioned positioning of the rod permits the panel contact pad 91 to conform to the interior contour 27 of the panel.
  • the rod support means 89 are afiixed to the platform portion 103 of spacer rod elevator means 105.
  • the elevator platform also accommodates several actuated panel pickup elements 107, three in this instance, which have associated pickup actuation means 108, such as air cylinder reciprocators, formed to subsequently shift the pickup elements to cooperate with the frame positioning means or studs in the panel; such movement being activated by control means 71.
  • the spacer rod elevator means is formed to move in a substantially vertical manner to consummate contact of the spacer rod contact pads 91 with predetermined areas of the interior contour of the panel. Movement of the spacer rod elevator 105 is facilitated by elevator rods 109 and 111 which are slidably fitted within elevator guide elements 113 and 115 respectively.
  • the movement per se being instituted by a pair of spacer rod elevator cams 117 and 119 which are mounted on a common or conjugate cam shaft 121 having controlled rotation. While face cams are shown, O.D. cams are also applicable to the operation of the apparatus.
  • the predetermined vertical movement for elevator rod 109 is effected by a cam lever 123 having a bearing pivot 124 mounted on cam lever support 125.
  • a cam follower 126 positioned on the cam lever 123, cooperates with the slot 116 in face cam 117 to produce a vertical motion of the arm which is applied to the evelator rod 109 by pivot means 127. Since the mating cam 119 produces augmenting movement for elevator rod 111 in like manner, the operational description thereof will be omitted.
  • the lower level 57 of the apparatus accommodates mask translation and positioning means in the form of a movable mask carrier 131 having a carrier platform 133 with associated mask carrier trolley means 135 to facilitate movement of the mask carrier 131 along supporting rails 137.
  • the mask carrier platform 133 has a major cut-out portion 139 which is dimensionally shaped in accordance with the opening in the mask supporting frame 31. Additional cut-out portions 140 are made in the platform at areas beneath the several frame bracket locating means 33 to accommodate the positioning of the frame clamps 142 when they are subsequently raised and shifted to make holding contact with the frame brackets.
  • a plurality of mask locating pins 141 are mounted on the mask carrier platform to facilitate positioning of the mask frame.
  • mask-frame elevator means 61 Located beneath the frame 31 with the mask portion 21 fitted thereon, are mask-frame elevator means 61. Discretely positioned on an elevator table 145, having specific cut-outs therein, are a plurality of frame clamps 142 having associated frame clamp actuation means 147, such as for example, air cylinder reciprocators activated by control means 71. These clamps are oriented in a manner to make holding contact with the frame brackets 33 when the elevator means is raised.
  • the elevator table 145 is supported on and spaced from an elevator stage 149 by a plurality of fixed support columns 151. Vertical guidance is provided to the elevator stage by the sliding relationship of a plurality of guide blocks 152 and 153 on a plurality of elevator guide rods 155 and 157 respectively. Vertical movement is supplied to the elevator stage by a pair of mask-frame elevator cams 159 and 161, the movement of which will be described later.
  • the elevator stage 149 has a centrally oriented vertical bushing 163 formed to accommodate the sliding hollow support shaft 165 of the pressure rod elevator means 67 which is oriented in a manner to function between the elevator stage 149 and the mask-frame elevator table 145.
  • Vertical movement of the pressure rod elevator 67 is given guidance by a plurality of guide bushings 167 formed to slide on a plurality of guide columns 169.
  • Pressure rods 63 which have pressure pads 65 terminally oriented on resilient means 171, are mounted in pressure rod bearings or support means 173 which permit partial rotation of the pressure rods therein.
  • pressure rod movement means 175 is constructed to provide a partial rotative movement to the pressure rods 63 to subsequently shift the position of the pressure pads after they have cleared the frame and moved to operative locations relative to discrete areas of the mask portion.
  • the pressure rod movement means 175 comprises a plurality of eccentric rods 177, one for each of the pressure rods 63, which links the eccentric attachment 179 on each pressure rod with respective pivots 181 in the drive eccentric 183.
  • This drive is terminally afiixed to eccentric drive shaft 185 which is concentrically positioned to slide in a vertical manner within the hollow support shaft 165 during the operational sequence of the pressure rod elevator means 67.
  • each elevator has its own cam arrangement.
  • the elevator stage 149 which is an element of the mask-fame elevator means 61, is provided with vertical movement by mask-frame elevator cams 159 and 171; and the pressure rod elevator means 67 has its vertical movement supplied by pressure rod elevator cam 187. All cams are affixed to the common cam shaft 121. Since the operation of pressure rod elevator cam 187 is similar in principle to the operation of mask-frame elevator cam 159, a description of cam 187 is considered exemplary of both, wherein similar mechanical elements are denoted by prime designations of like numerical references. In referring to FIGS.
  • vertical elevator movement is effected by the elevator cam lever 189 which has a lever bearing pivot 191, 191 mounted on elevator cam lever support 193, 193'.
  • An elevator cam follower 195, 195, located on elevator cam lever 189, 189', cooperates with individual elevator cam slots formed in the faces of the respective cams 187, 159 and imparts a predetermined individual vertical movement to the rspective elevator cam linkage means 199, 199', which in turn is attached to the respective elevator support shaft 165 and elevator guide block 152.
  • the eccentric drive shaft 185 reciprocates vertically in accordance with the movement of the pressure rod elevator cam 187 and associated linkage. During this vertical movement, the eccentric drive shaft 185 is supplied with a partial-rotative movement which in turn imparts a related partial rotation to each pressure rod 63, thereby properly positioning each of the pressure pads 65 to contact with discrete areas of the mask portion 21. Such rotative movement is initiated by an arc imparting cam 201 which is oriented in cam shaft 121.
  • a cam follower cradle 203 which is mounted in a cradle pivot 205, has a cam follower 207 which moves in accordance with the configuration of cam slot 209. Motion is transferred from the cam follower cradle sequentially through a first universal coupling 211, a cam linkage rod 213 and a second universal coupling 215 to a pivot connection 217 on the bottom of eccentric drive shaft 185.
  • FIG. 12 illustrates, in phantom, the action of the cam linkage elements which impart partial rotation to the eccentric drive shaft as it moves vertically with the pressure rod elevator means 67.
  • a plurality of bonding or welding means 73 are positioned to effect the final operation of peripheral bonding the formed and adjusted mask 21 to the frame 31. While for clarity of illustration only four welding means are shown, a greater number are utilized to consummate adequate peripheral bonding.
  • the 'base portions 219 of the individual welding units are affixed to the stationary wel- 7 der platform 221 which has a large opening 223 in the center to accommodate the subsequent positioning of the mask and frame in the proper location for bonding.
  • the welding electrodes 225 are formed to have reciprocal movement actuated, for example, by air cylinder means 227, such being activated by control means 71.
  • the apparatus is powered by a motor-clutch unit 229 associated with cam shaft 121 by positive drive means 230, for example a chain-sprocket combination.
  • Power unit 229 is activated by control 71 through connective means r.
  • Switch cams afiixed to cam shaft 121 activate elements in the control 71 to institute a sequence of operations.
  • the first cam 231 controls the movement of an independent cam follower to actuate the motor-clutch switch 235 which is connected to control means 71 by connective means a.
  • the second earn 233 controls an independent cam follower which actuates the panel pick-up switch 239, connected to control 71 by connective means 0.
  • Another independent cam follower actuates the frame clamp switch 241 which is linked to control 71 by connective means g.
  • second control cam 233 closes both the panel pickup switch 239 and the frame clamp switch 241.
  • the control means 71 supplies air through tubing 1 to the three panel pickup actuation means 108, the movement of which is shown in FIGS. 8 and 9.
  • the air cylinder 108 moves a compound angled pickup element 243 along a slideway 244 from the location shown in FIG. 8 to that shown in FIG. 9.
  • the face portion of each angled pickup element 243 has a slanted guiding channel 245 formed therein. Adjacent the bottom of the channel there is a positioning hole 246 dimensioned to accommodate the panel stud 35.
  • the mask-frame elevator table 145 has raised to a height where the pins 2470f the frame clamps 142 are in a position to mate with the holes in the bracket locating means 33 on the frame 31.
  • the control 71 furnishes air through tubing m to actuation means 147 thereby consummating mating of the frame clamp pins 247 with the frame brackets 33.
  • FIG. 6 illustrates the approximate locations of the several moving elements of the apparatus when the cam shaft rotation has substantially reached
  • the spacer rod elevator platform 103 has reached its apex, and the panel contact pads 91 of the spacer rods 59 are seated on the interior surface of the panel 27.
  • four spacer rods 59 are shown, one at substantially each of the four corner areas of the panel, but it is not intended that the number of spacer rods be limited to four, as more or fewer rods can be utilized as required.
  • the panel 29 has been lifted free of the carrier platform 77 by the three panel pickup elements 243 mating with the panel studs 35, see FIG. 10.
  • the mask-frame elevator table is continuing in its upward movement and has lifted the mask frame 31 free of the mask carrier 131.
  • the pressure rod elevator 67 is still rising, and the pressure rod movement means are imparting final arouate movement to the pressure pad mounting means 171, but the pressure pads 65 have not yet contacted the mask 21.
  • FIG. 11 there is shown in phantom the initial location of the pads 65' as they moved upward past the inner edge 32 of the frame 31.
  • the approximate final positioning of the pads 65 and mounting means 171 therefore, are shown as solid line representations, as are the eccentric rods 177 and eccentric drive 183.
  • the first control cam 231 opens the motor-clutch switch 235 which stops movement of the cam combination 69.
  • cam 231 closes weld-timer switch 237 thereby actuating a multiple sequence timing device in the generalized control 71 which separately programs the mask-to-frame welding operation while the cam activated movements of the apparatus are at a standstill.
  • FIG. 7 illustrates the approximate positions of the several elements of the apparatus at substantially 180 of cam shaft rotation.
  • the panel contact pads 91 are seated on the interior contour 27 of the panel 29.
  • the pressure rod elevator cam 187 has raised the pressure rod elevator 67 to its apex, and the partial rotative movement of the pressure rods is fully effected; whereupon, the pressure pads 65 of the pressure rods 63 are seated against the mask 21 adjusting it on the frame 31 and conforming discrete areas to the contoured surface 60 of the spacer rod anvil element 93.
  • the aforementioned weld-timing device in the control means 71 programs the welding sequence and regulates the electrode 225 reciprocation by supplying air through tubing n and power through conductor s in accordance with the program schedule.
  • the spacer rods 59 are of predetermined lengths.
  • the Q spacing between the interior surface 27 of the panel and the surface 22 of the mask portion 21 is of predetermined values across the surface of the panel.
  • the desired distance d between the frame locating means 33 and the interior surface 27 of the panel is resolved.
  • the distance b between the frame locating means and the mask surface is also resolved.
  • Q d-b.
  • the specific Q" spacings are determined for the corner areas of the mask and panel relationship.
  • the distance d is the spacing between the panel stud 35 and the panel surface contacted by the panel contact pad 91
  • the control device trips a switch therein, not shown, which temporarily overrides the open motor clutch switch 235 and reactivates operation of the motor-clutch unit 229, Whereupon rotation of the cam shaft 121 is resumed beyond 180".
  • the reinitiated rotation of the cam shaft moves pressure rod elevator cam 187 to begin lowering of the pressure rod elevator 67 thereby removing the pressure pads 65 from contact with the mask.
  • the first control cam 231 closes motor-clutch switch 235 to resume control of the motor-clutch unit 229.
  • the second control cam 233 opens the panel pickup switch thereby releasing the panel pickup elements 107 and allowing the panel 29 to rest upon the spacer rods 59.
  • Mask-frame elevator cams 159, 161 begin lowering of the mask-frame elevator 61.
  • Arc imparting cam 201 begins a retrace of the rotative movement of the pressure rod movement means 175 thereby moving the pressure pads clockwise to clear the inner edge 32 of the mask frame as the pressure rod elevator 67 is lowered.
  • the second control cam 233 opens the frame clamp switch 241 which permits the welded mask-frame assembly 34 to rest upon the carrier platform 133.
  • the panel carrier 75 and the mask carrier 131 are moved from the operating locations of B, B to the loading-unloading locations of A, A respectively, whereat, the panel 29 and the welded maskframe assembly 34 are individually removed from the ap paratus, each being ready for mating as a mask-panel assembly.
  • the aforedescribed apparatus provides cathode ray tube mask-frame assemblies that are custom fabricated in accordance with the contour of the panel with which the mask-frame assembly is mated.
  • the resultant mask-panel assemblies have predetermined Q spacings between the mask portion and the interior contour of the panel that are of improved accuracy and uniformity.
  • the apparatus promotes increased manufacturing efiiciency of a degree heretofore unattained.
  • the speed of achieving mating assemblies is greatly enhanced as each mask has discrete contour portions thereof custom modified in accordance with the contour characteristics of an initially related panel.
  • An apparatus for manufacturing a cathode ray tube mask-panel assembly wherein the formed aperture mask is supported on a frame, said frame having bracket locating means thereon oriented to mate with positioning means in the panel to provide a predetermined spacing between the mask aperture portion and the interior surface of the panel, said apparatus comprising:
  • panel positioning means formed to provide orientation of said panel on said apparatus
  • each of said sensing means being formed to have a first and a second contact surface and a height therebetween to effect a predetermined spacing between the mask aperture portion and the interior surface of said panel; said height being greater than the predetermined spacing between the mask and the panel in the finished maskpanel assembly, said first contact surface being in contact with said interior surface of said panel;
  • pressure means having seating surfaces oriented rela tive to said related spacer means adapted to provide pressure against the interior surface of the said mask portion thereby seating said mask portion against said spacer sensing means to effect conformance of the mask portion area treated therebetween and provide custom spacing between said mask portion and said panel;
  • a plurality of bonding means oriented adjacent and substantially peripheral to said mask frame to provide attachment of said formed and adjusted mask portion to said supporting frame to provide a maskframe assembly wherein the custom achieved spacing relationship therebetween is maintained in the mask-panel assembly.
  • each of said spacer sensing means is in the form of a sensing area to substantially mate with the contour of a specific region of the interior surface of said panel, and wherein each of said second contact surfaces is formed as an anvil area having a contour substantially matching the predetermined general contour of the mask portion in that area.
  • An apparatus for manufacturing a cathode ray tube mask-panel assembly according to claim 2 wherein the anvil portion of said spacer sensing means provides a contact area at least equalling that of the seating surface area of said related pressure means.
  • An apparatus for manufacturing a cathode ray tube mask-panel assembly wherein the formed aperture mask is supported on a frame having bracket locating means thereon oriented to mate with positioning means in the panel to provide predetermined spacing between the mask domed aperture portion and the interior surface of the panel, said apparatus comprising:
  • panel positioning means accommodated on said supporting platform to provide orientation of said panel
  • each of said rods having a length greater than the predetermined spacing between the mask and the panel in the finished maskpanel assembly
  • spacer rod support means formed to hold said rods and permit individual movement of said rods to contact the interior surface of said panel
  • mask-frame positioning means accommodated on said supporting platform in a region beneath and spaced from said panel, said mask-frame being oriented in a manner that said domed aperture portion thereof is adjacent said spacer rods;
  • each of said pressure rods being formed in a manner to make substantially resilient contact with said mask portion in discrete areas substantially opposite said spacer rods;
  • pressure rod movement means operative to effect contact of said pressure rods with said mask portion in a manner to seat said mask portion against said spacer rod elements to provide the conformance of the mask portion areas thereto and adjust said modified mask portion on said frame;
  • mask-to-frame bonding means oriented peripheral to said frame to effect attachment of said adjusted mask to said support frame thereby providing a maskframe assembly wherein the custom achieved spacing relationship therebetween is maintained in the mask-panel assembly.
  • An apparatus for manufacturing a cathode ray tube mask-panel assembly wherein the formed aperture mask is supported on a frame having bracket locating means thereon oriented to mate with positioning means in the panel to provide a predetermined'spacing between the mask aperture portion and the interior surface of the panel, said apparatus comprising:
  • a supporting platform having base upright and horizontal portions with provisions for accommodating at least three substantially horizontal levels of operational features, said levels being referenced as upper, intermediate and lower levels respectively;
  • panel positioning means accommodated on said upper level to provide orientation of said panel in an inverted position with the open portion thereof in a downward direction;
  • each of said spacer rods having a first contact surface formed as a terminal panel contact pad at one end to make :contact with said panel and a second contact surface formed as an anvil element at the opposite end thereof to contact said mask;
  • spacer rod support means formed to hold said rods and permit substantially vertical individual movement thereof;
  • spacer rod elevator means formed to move said spacer rod support means to provide contact between said panel contact pads and the interior surface of said said panel;
  • panel pickup means positioned on said spacer rod elevator means and adapted to mate with said position- "ing means in said panel;
  • mask-frame positioning means accommodated on said lower level beneath said spacer rod elevator means, said positioning means being formed to provide 12 orientation of said frame with the formed aperture mask' portion fitted thereon, saidformed mask portion being positioned with the dome thereof facing said panel opening and said related spacer rods; mask to frame bonding means accommodated on a stationa-ry plane at said intermediate level in a manner to permit the orientation of said mask-frame in a position adjacent thereto;
  • mask-frame elevator means formed to vertically transfer said mask frame from said lower level positioning means to said intermediate level and support said frame during said bonding of said mask portion to said frame, said elevator means having frame clamps accommodated thereon adapted to mate with said frame bracket locating means;
  • each of said pressure rods having a pressure pad terminally oriented thereon in a position to contact said formed aperture mask portion;
  • pressure rod support means formed to hold and permit at least partial rotation of said pressure rods
  • pressure rod movement means formed to provide partial rotative movement to said pressure rods to position said pressure pads relative to discrete areas of said mask portion;
  • pressure rod elevator means formed to move said pressure rod support means in a substantially vertical plane to effect contact of said pressure pads with said mask portion and seat said mask portion against said spacer rod elements to provide the conformance of the mask areas thereto, and adjust said modified mask on said frame in preparation for bonding;
  • control means programmed to provide actuation of said panel pickup means, said frame clamp means, and said bonding means
  • activation means to effect coordinated movement of said spacer rod elevator means, said mask-frame elevator means, said pressure rod movement means, said pressure rod elevator means, and actuation of said control means;

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Description

NOV. 3, 1970 5, GARTNER ETAL $537,159
APPARATUS FOR ACHIEVING CUSTOM MASK TO PANEL SPACING IN CATHODE RAY TUBES Filed Nov. 19, 1968 8 Sheets-Sheet s. J. GARTNER ETAL Nov. 3, 1970 3,537,159
APPARATUS FOR ACHIEVING cuswom MASK 'I'O PANEL SPACING IN CATHODE RAY TUBES s sheets sheet a Filed Nov. 19, 1968 INVENTORQ STANLEYJ. GARTNER l-RRUE Y REGELMAN AT TOR NEY N 3, 1970 5. J. GARTNER EI' AL APPARATUS FOR ACHIEVING CUSTOM MASK TO PANEL SPACING IN CATHODE RAY TUBES Filed Nov. 19, 1968 75 B I 2? "I; 5/ Q & I, 35 I J as 35 83 4; 43 v a:
' us I I 3 CONTROL V INVENTORS srmvuzv .1. GARTNEI LARUE Y. REGELMAN 1 ATTORNEY a Sheets-811661. 8
Nov. 3, 1970 $.J.GARTNER m. 3,537,159
APPARATUS FOR ACHIEVING CUSTOM MASK T0 PANEL SPACING IN CATHODE RAY TUBES IN VENTORS f m j STANLEY .1. GARTNER LARUE v REGELMAN ATTO RNEY Nov. 3, 1970 5, J, R NER EI'AL 3,537,159
APPARATUS FOR ACHIEVING CUSTOM MASK TO PANEL SPACING IN CATHODE RAY TUBES Filed Nov. 19, 1968 8 Sheets-Sheet 5 INVENTORS .smmcv J. cmmea LARUE V. REGEL HAN gufidm w ATTOR NEY Nov. 3, 1970 s. .1. GARTNER ETAL APPARATUS FOR ACHIEVING CUSTOM MASK TO PANEL SIACING IN CATHODE RAY TUBES Filed Nov. 19, 1968 8 Sheets-Sheet 6 IN VENTOR8 STANLEY J. (mamas vuyaue v. REGELMAN BY ATTORNEY Nov. 3, 1970 5, GARTNER ETAL 3,537,159
APPARATUS FOR ACHIEVING CUSTOM MASK T0 PANEL SPACING IN CATHODE RAY TUBES Filed Nov. 19, 1968 8 Sheets-Sheet 7 hlllllm r allllllllllnmfii United States Patent U.S. Cl. 29-25.2 7 Claims ABSTRACT OF THE DISCLOSURE An apparatus for manufacturing a mask panel assembly for a shadow mask cathode ray tube wherein the contour of the formed aperture mask is modified in accordance with the contour of the related panel surface. Apparatus provides for panel positioning wherein a plurality of spacer rods are oriented at discrete locations to make contact with the interior surface of the panel. The mask frame with the aperture portion fitted thereon is oriented relative to the panel and the spacer rods therein in a manner that the aperture portion is positioned against terminal elements of the spacer rods. Resiliently mounted pressure pads are applied by elevator means to seat the various portions of the mask, against the opposing spacer rods, and accordingly modify the contour of the mask therebetween. With the mask portion so formed and adjusted on its frame to effect the desired orientation of the mask relative to the interior surface of the panel, bonding means are applied to provide attachment of the modified mask to its supporting frame.
Background of the invention The invention relates to cathode ray tubes and more particularly to an apparatus for achieving accurate custom spacing between the aperture mask and a panel in a color cathode ray tube of the shadow mask type. In a cathode ray tube employing an aperture shadow mask, the frame supporting the mask is usually oriented in a predeterminately spaced manner within the panel by bracket locating means on the mask frame mating with positioning means integral to the panel.
One of the problems encountered in the fabrication of screens for shadow mask tubes involves achieving accurate spacing between the aperture mask and the interior surface of the panel upon which the cathodoluminescent screen is disposed. Such spacing, which is predetermined during the mask and panel assembly procedure, facilitates subsequent photodeposition of the patterned screen on the panel. During the operation of the finished tube, the several electron beams emitted therein are influenced to cross one another at the mask apertures and impinge upon discretely related areas of the screen layer beneath without overlapping one another. Usually the spacing between the mask and the screen is varied in a planned sequential manner progressing from the center portion of the mask toward the edge areas thereof to provide the proper spacing relationship between the mask apertures and discrete areas of the display screen. In assembling the formed aperture portion of the mask to its strengthening frame to provide the mask-frame assembly, one of the conventional procedures comprises locating the formed mask on a bed substantially contoured to the dome shape of the mask. With the mask so positioned, the frame is adjusted thereon to achieve the desired dimensional relationship between the mask and the frame locating means, whereupon the mask is peripherally bonded to the adjusted frame. Many mask-frame combinations have been fabricated in this manner. Accordingly, with the aforementioned procedure a relative generalized spacing between the shaped ice mask and the panel is substantially achieved in the maskpanel assembly.
Another conventional procedure consists of welding the mask to the frame and then compromising the positioning and attachment of the frame locating means thereon to arrive at the desired dimensional relationship between the mask surface and the frame locating means.
Unfortunately, in the aforementioned conventional assembly procedures, the several tolerances inherent therein, such as those encountered in forming the aperture mask, attaching the mask to the frame, and manufacturing the panels, can only be considered in a generalized manner. However, it has been found that the normally accepted tolerances of the mask and panel at times assume combined values in the subsequent assembly to effect resultant mask to panel spacings which have dimensional values other than those required to achieve the desired screen quality.
In turn, the undesired dimensional values of such mask to panel spacing affect the color purity of the dynamic display in the finished tube. Therefore, in order to attempt to achieve the desired mask to panel spacing, it has been a conventional procedure to utilize gauging means to match framed masks to panels. If the spacing between the mask and panel in the initial attempt at assembly does not meet the accepted tolerances, the mask is removed and positioned in a different panel and rechecked until a maskpanel combination is found that will fulfill the spacing specifications. An acceptable mask-panel combination is mated as an assembly and, as such, remains in associated relationship throughout subsequent processing into the completed tube. The aforedescribed matching procedure requires considerable time and handling, which is detrimental to efiicient manufacturing. Furthermore, accurate and uniform mask to panel spacing is not fully achieved because of the wide tolerance range necessitated by the procedure.
Objects and summary of the invention It is an object of the invention to reduce the aforementioned difiiculties and to provide an apparatus for fabricating a color cathode ray tube mask-panel assembly wherein there is improved mask to panel spacing relationship.
Another object is to provide an apparatus which in a repetitive manner can make cathode ray tube mask-panel assemblies wherein the spacing relationship between the aperture mask and the screen bearing portion of the panel is achieved in accordance with the interior contour of the panel.
The foregoing objects are achieved in one aspect of the invention by the provision of an apparatus whereby the panel is positioned in a manner to receive a plurality of spacer rods having terminally formed pads which are oriented to contact discrete areas of the interior contour of the panel. The mask supporting frame with the aperture mask portion fitted thereon is moved by elevator means to a position relative to the panel to enable the mask portion thereof to make contact with the shaped opposite ends of the several spacer rods positioned against the panel. The pressure rods which have terminally related pressure pads thereon, are moved by elevator means to make contact with the under surface of the mask in the areas resting against the shaped end surfaces of the paneloriented spacer rods. Application of pressure to these discrete areas seats the respective mask portions against the shaped end surfaces of the spacer rods and thus modifies the mask contour making it compatible with that of the panel. The modified mask portion is then bonded to its supporting frame at a plurality of separated perimetric areas. Thus there is provided a mask-frame assembly whereof the formed mask portion is custom modified to achieve the desired spacing relationship with the interior contour of the panel.
Brief description of the drawings FIG. 1 is a general plan view of a conventional shadow mask type of cathode ray tube comprising a mask positioned in spaced relationship to a screen bearing panel;
FIG. 2 is a plan view showing the top of the apparatus;
FIG. 3 is an elevational end view of the apparatus taken along the line 33 of FIG. 2;
FIG. 4 is an elevational view of the panel elevator cam arrangement taken along the line 4-4 of FIG. 3;
FIGS. 5, 6, and 7 are elevational side views of the apparatus taken along the line 5 of FIG. 2 illustrating several stages in the operation of the apparatus;
FIGS. 8, 9, and 10 are enlarged perspectives illustrating the sequential operational stages of the panel pickup elements;
FIG. 11 is a plan view of the pressure rod actuation means taken along the line 1111 of FIG. 5;
FIG. 12 is an enlarged perspective view of the motion means associated with the pressure rod actuation means taken along the line 12--12 of FIG. 3; and
FIG. 13 is a motion chart illustrating the several coordinated movements of the apparatus.
Description of the preferred embodiment Fora better understanding of the present invention, to-
.gether with other and further objects, advantages and ca- .pabilities thereof, reference is made to the following specification and appended claims in connection with the aforedescribed drawings.
With reference to FIG. 1 there is shown a conventional shadow mask type of color cathode ray tube 11. Oriented Within the neck 13 of the tube envelope 15 is an electron gun structure 17. This generalized structure comprises three electron beam emitters wherelfrom beams 19 are directed to converge at the aperture mask 21 which is a thin, metallic, foraminous member. After convergence, the beams pass through the aperture mask and impinge upon a patterned cathodoluminescent screen 25 therebeneath which is suitably disposed upon an interior surface 27 of the panel portion 29 of the tube. The formed aperture mask 21 is suitably attached to a strengthening frame 31 which in turn, has bracket locating means 33 thereon to mate with mask positioning means, such as studs 35 integral to the panel, to form the mask-panel assembly 37. The spacing between the formed foraminous portion 21 and the interior surface 27 of the panel is conventionally referred to as spacing. Suchspacing is of predetermined values across the surface of the panel, such being achieved, for example, by resolving the required distance d between the frame locating means 33 and the interior surface of the panel immediately prior to the attachment of the formed aperture mask 21 to its supporting frame 31. As shown, the mask panel assembly 37 is suitably joined to the funnel portion 39 of the tube enevlope along the seal line 41.
In referring to the drawings illustrating the apparatus, it is to be noted that certain sections of the upright 49 and horizontal 51 frame portions have been deleted to promote clarity.
With particular reference to the FIGS. 2, 3, 4, and 5, there is illustrated an apparatus 43 whereby the predetermined mask to panel spacing is discretely effected for each panel assembly. The apparatus is constructed upon supporting platform 45 having a base portion 47 and associated upright and horizontal portions 49 and 51 with provisions thereon for accommodating three substantially horizontal levels of operational features. These levels are referenced as upper, intermediate and lower levels, 53, 55, and 57 respectively. In general the upper level 53 accommodates means of transferring and positioning the panel 29. The lower level 57 accommodates means for accomplishing a similar function of transferring and positioning the formed mask 21 and frame 31 elements; while 'the intermediate level 55 accommodates means on a stationary plane for effecting the final bonding procedure whereby the shaped and adjusted mask 21 is welded to its supporting frame 31. Cam actuated elevator means position the first contact surfaces of a plurality of spacer rods 59 against discrete portions of the interior surface 2'7 of the panel 29.
Since FIGS. 3 and 5 represent elevational view of the apparatus 43 taken on vertical planes separated by 90 of orientation, plural elements of the apparatus that perform like functions will be referenced by like numerical designations and nomenclature to facilitate clarity of description.
The mask frame 31 with the formed aperture amsk 21 fitted thereon is transferred in a substantially verticalmanner by cam actuated mask-frame elevator means 61 from the lower level 57 to the intermediate level 55 so that the formed aperture mask portion is adjacent the shaped second contact or lower surfaces of the spacer rods 59. At the same time, a plurality of pressure rods 63 having terminal pressure pads 65 thereon are moved by cam actuated pressure rod elevator means 67 to effect contact of the pressure pads with the formed mask portion 21 seating the same against the shaped lower surfaces 60 of the spacer rods and thereby modifying the shape of the mask accordingly. In addition to eifecting modification of the shape of the mask, the pressure pads also adjust the shaped mask on the frame in preparation for bonding. Movement activation means 69, such as a powered cam combination, efiects coordinated movement of the aforementioned elevator means and actuates generalized control means 71 which programs the mask-to-frame bonding means 73 accommodated on the intermediate level 55.
With reference to FIGS. 2-5 in greater detail, the upper level 53 of the apparatus accommodates panel translocation and positioning means in the form of a movable panel carrier 75 having a carrier platform 77 with associated panel carrier trolley means 79 to facilitate movement of the panel carrier along supporting rails 81. The panel carrier platform 77 has a cut-out portion 83 which is dimensionally shaped to substantially conform to the inner dimensions of the open side of the panel 29. A plurality of panel locating pins 85 are aflixed to the panel carrier platform to facilitate positioning of the panel thereon. When the carrier 75 with the panel thereon is moved into the operating position, it makes contact with the panel carrier switch 87, the function of which will be later explained.
Beneath the panel carrier, when in operating position, are a plurality of spacer sensing means or rods 59 suitably mounted in spacer rod support means 89 in a manner to permit substantially vertical individual movement of each rod. These rods, which are of predetermined lengths as will be discussed later in this specification, have terminally oriented contact surfaces at each end. The contact surface oriented toward the open panel is formed as a panel contact pad 91 and mounted in a swivel manner to facilitate substantially mating placement on the interior surface 27 of the panel. The rod contact portion at the opposite end of the spacer rod is formed as an anvil element 93 having a surface contour 60 that substantially matches the predetermined general contour of the mask portion that will subsequently contact that area. Each spacer rod 59 is slidably accommodated within its support means 89 in a resiliently tensional manner, as by spring means 95 whereof one end is attached to the anvil element 93 with the opposite end aflixed to a suitable attachment 97 on the rod support means. The tensioned positioning of the rod permits the panel contact pad 91 to conform to the interior contour 27 of the panel. Cooperating guide elements 99 and 101, on the support means and rod elements respectively, insure proper positioning of the contact suffaces.
The rod support means 89 are afiixed to the platform portion 103 of spacer rod elevator means 105. The elevator platform also accommodates several actuated panel pickup elements 107, three in this instance, which have associated pickup actuation means 108, such as air cylinder reciprocators, formed to subsequently shift the pickup elements to cooperate with the frame positioning means or studs in the panel; such movement being activated by control means 71. The spacer rod elevator means is formed to move in a substantially vertical manner to consummate contact of the spacer rod contact pads 91 with predetermined areas of the interior contour of the panel. Movement of the spacer rod elevator 105 is facilitated by elevator rods 109 and 111 which are slidably fitted within elevator guide elements 113 and 115 respectively. The movement per se being instituted by a pair of spacer rod elevator cams 117 and 119 which are mounted on a common or conjugate cam shaft 121 having controlled rotation. While face cams are shown, O.D. cams are also applicable to the operation of the apparatus. With reference to FIGS. 3 and 4, the predetermined vertical movement for elevator rod 109, for example, is effected by a cam lever 123 having a bearing pivot 124 mounted on cam lever support 125. A cam follower 126, positioned on the cam lever 123, cooperates with the slot 116 in face cam 117 to produce a vertical motion of the arm which is applied to the evelator rod 109 by pivot means 127. Since the mating cam 119 produces augmenting movement for elevator rod 111 in like manner, the operational description thereof will be omitted.
The lower level 57 of the apparatus accommodates mask translation and positioning means in the form of a movable mask carrier 131 having a carrier platform 133 with associated mask carrier trolley means 135 to facilitate movement of the mask carrier 131 along supporting rails 137. The mask carrier platform 133 has a major cut-out portion 139 which is dimensionally shaped in accordance with the opening in the mask supporting frame 31. Additional cut-out portions 140 are made in the platform at areas beneath the several frame bracket locating means 33 to accommodate the positioning of the frame clamps 142 when they are subsequently raised and shifted to make holding contact with the frame brackets. A plurality of mask locating pins 141 are mounted on the mask carrier platform to facilitate positioning of the mask frame. When the mask carrier transporting the mask frame 31 with the formed aperture portion '21 fitted thereon, is moved into the operating position, it makes contact with the mask carrier switch 143, the operation of which will be subsequently explained.
Located beneath the frame 31 with the mask portion 21 fitted thereon, are mask-frame elevator means 61. Discretely positioned on an elevator table 145, having specific cut-outs therein, are a plurality of frame clamps 142 having associated frame clamp actuation means 147, such as for example, air cylinder reciprocators activated by control means 71. These clamps are oriented in a manner to make holding contact with the frame brackets 33 when the elevator means is raised. The elevator table 145 is supported on and spaced from an elevator stage 149 by a plurality of fixed support columns 151. Vertical guidance is provided to the elevator stage by the sliding relationship of a plurality of guide blocks 152 and 153 on a plurality of elevator guide rods 155 and 157 respectively. Vertical movement is supplied to the elevator stage by a pair of mask- frame elevator cams 159 and 161, the movement of which will be described later.
The elevator stage 149 has a centrally oriented vertical bushing 163 formed to accommodate the sliding hollow support shaft 165 of the pressure rod elevator means 67 which is oriented in a manner to function between the elevator stage 149 and the mask-frame elevator table 145. Vertical movement of the pressure rod elevator 67 is given guidance by a plurality of guide bushings 167 formed to slide on a plurality of guide columns 169. Pressure rods 63, which have pressure pads 65 terminally oriented on resilient means 171, are mounted in pressure rod bearings or support means 173 which permit partial rotation of the pressure rods therein.
With reference to FIGS. 3, 5, and 11, pressure rod movement means 175 is constructed to provide a partial rotative movement to the pressure rods 63 to subsequently shift the position of the pressure pads after they have cleared the frame and moved to operative locations relative to discrete areas of the mask portion. The pressure rod movement means 175 comprises a plurality of eccentric rods 177, one for each of the pressure rods 63, which links the eccentric attachment 179 on each pressure rod with respective pivots 181 in the drive eccentric 183. This drive is terminally afiixed to eccentric drive shaft 185 which is concentrically positioned to slide in a vertical manner within the hollow support shaft 165 during the operational sequence of the pressure rod elevator means 67.
While the pressure rod elevator means 67 operates conjunctively with the mask-frame elevator means 61, each elevator has its own cam arrangement. As previously mentioned, the elevator stage 149, which is an element of the mask-fame elevator means 61, is provided with vertical movement by mask- frame elevator cams 159 and 171; and the pressure rod elevator means 67 has its vertical movement supplied by pressure rod elevator cam 187. All cams are affixed to the common cam shaft 121. Since the operation of pressure rod elevator cam 187 is similar in principle to the operation of mask-frame elevator cam 159, a description of cam 187 is considered exemplary of both, wherein similar mechanical elements are denoted by prime designations of like numerical references. In referring to FIGS. 3 and 5 in particular, vertical elevator movement is effected by the elevator cam lever 189 which has a lever bearing pivot 191, 191 mounted on elevator cam lever support 193, 193'. An elevator cam follower 195, 195, located on elevator cam lever 189, 189', cooperates with individual elevator cam slots formed in the faces of the respective cams 187, 159 and imparts a predetermined individual vertical movement to the rspective elevator cam linkage means 199, 199', which in turn is attached to the respective elevator support shaft 165 and elevator guide block 152.
To expedite describing the means for imparting predetermined arcuate movement to the pressure rods 63, reference is made to FIGS. 3, 5, 11 and 12. As aforementioned, the eccentric drive shaft 185 reciprocates vertically in accordance with the movement of the pressure rod elevator cam 187 and associated linkage. During this vertical movement, the eccentric drive shaft 185 is supplied with a partial-rotative movement which in turn imparts a related partial rotation to each pressure rod 63, thereby properly positioning each of the pressure pads 65 to contact with discrete areas of the mask portion 21. Such rotative movement is initiated by an arc imparting cam 201 which is oriented in cam shaft 121. A cam follower cradle 203, which is mounted in a cradle pivot 205, has a cam follower 207 which moves in accordance with the configuration of cam slot 209. Motion is transferred from the cam follower cradle sequentially through a first universal coupling 211, a cam linkage rod 213 and a second universal coupling 215 to a pivot connection 217 on the bottom of eccentric drive shaft 185. FIG. 12 illustrates, in phantom, the action of the cam linkage elements which impart partial rotation to the eccentric drive shaft as it moves vertically with the pressure rod elevator means 67.
On the intermediate level of the apparatus 55, a plurality of bonding or welding means 73 are positioned to effect the final operation of peripheral bonding the formed and adjusted mask 21 to the frame 31. While for clarity of illustration only four welding means are shown, a greater number are utilized to consummate adequate peripheral bonding. The 'base portions 219 of the individual welding units are affixed to the stationary wel- 7 der platform 221 which has a large opening 223 in the center to accommodate the subsequent positioning of the mask and frame in the proper location for bonding. The welding electrodes 225 are formed to have reciprocal movement actuated, for example, by air cylinder means 227, such being activated by control means 71.
The apparatus is powered by a motor-clutch unit 229 associated with cam shaft 121 by positive drive means 230, for example a chain-sprocket combination. Power unit 229 is activated by control 71 through connective means r.
Switch cams afiixed to cam shaft 121, see FIG. 3, activate elements in the control 71 to institute a sequence of operations.
For purposes of simplification, two control cams are shown in FIG. 3, a first and a second cam 231 and 233 respectively. It is noted that four independent cam programs are initiated. The first cam 231, for example, controls the movement of an independent cam follower to actuate the motor-clutch switch 235 which is connected to control means 71 by connective means a. Also controlled by the first cam 231 is another independent cam follower which actuates a weld-timer switch 237, linked to control 71 by connective means b. The second earn 233, for example, has an independent cam follower which actuates the panel pick-up switch 239, connected to control 71 by connective means 0. Another independent cam follower actuates the frame clamp switch 241 which is linked to control 71 by connective means g.
The description of the sequence of operations is facilitated by reference to FIGS. 2, 4, 5, 11, 12, and 13. With the apparatus 43 at rest, a frame 31 with the aperture mask portion 21 fitted thereon, is positioned on the mask-frame carrier 131 oriented at location A. The loaded carrier is then moved along the carrier supporting rails 137 to operating location B whereat the mask carrier switch 143 is closed. A panel is positioned on the panel carrier 75 at location A and moved along the carrier supporting rails 81 to operating location B whereupon the panel carrier switch 87 is closed. For safety purposes, switches 87 and 143 are series connected through connections j and k to the control means 71. The closing of both switches overrides, in the control, the off condition of motor-clutch switch 235 and institutes motion of the motor-clutch unit 229, whereupon cam shaft 121 begins to turn and activation of the apparatus begins.
In referring to the FIG. 13, as the cam shaft begins rotation by moving from three cam motions are initiated. Spacer rod elevator cams 117 and 119 begin to raise the spacer rod elevator platform 103; mask- frame elevator cams 159 and 161 start to raise the mask-frame elevator table 145; and the pressure rod elevator cam 187 begins to raise the pressure rod elevator means 67.
At approximately 60-70 of cam shaft rotation, second control cam 233 closes both the panel pickup switch 239 and the frame clamp switch 241. Considered separately, when the panel pick-up switch 239 is closed, the control means 71 supplies air through tubing 1 to the three panel pickup actuation means 108, the movement of which is shown in FIGS. 8 and 9. The air cylinder 108 moves a compound angled pickup element 243 along a slideway 244 from the location shown in FIG. 8 to that shown in FIG. 9. The face portion of each angled pickup element 243 has a slanted guiding channel 245 formed therein. Adjacent the bottom of the channel there is a positioning hole 246 dimensioned to accommodate the panel stud 35.
By the time the frame clamp switch 241 is closed, the mask-frame elevator table 145 has raised to a height where the pins 2470f the frame clamps 142 are in a position to mate with the holes in the bracket locating means 33 on the frame 31. At the closing of the switch, the control 71 furnishes air through tubing m to actuation means 147 thereby consummating mating of the frame clamp pins 247 with the frame brackets 33.
At substantially 70 of cam shaft rotation, a partial rotative motion of the pressure rod movement means 175 is initiated by are imparting cam 201. By this time the pressure rod elevator 67 has raised the pressure rods so that the pressure pads 65 and mounting means 171 therefor have cleared the inner edge 32 of the frame.
FIG. 6 illustrates the approximate locations of the several moving elements of the apparatus when the cam shaft rotation has substantially reached The spacer rod elevator platform 103 has reached its apex, and the panel contact pads 91 of the spacer rods 59 are seated on the interior surface of the panel 27. In this instance four spacer rods 59 are shown, one at substantially each of the four corner areas of the panel, but it is not intended that the number of spacer rods be limited to four, as more or fewer rods can be utilized as required. The panel 29 has been lifted free of the carrier platform 77 by the three panel pickup elements 243 mating with the panel studs 35, see FIG. 10.
The mask-frame elevator table is continuing in its upward movement and has lifted the mask frame 31 free of the mask carrier 131. The pressure rod elevator 67 is still rising, and the pressure rod movement means are imparting final arouate movement to the pressure pad mounting means 171, but the pressure pads 65 have not yet contacted the mask 21. With reference to FIG. 11, there is shown in phantom the initial location of the pads 65' as they moved upward past the inner edge 32 of the frame 31. The approximate final positioning of the pads 65 and mounting means 171 therefore, are shown as solid line representations, as are the eccentric rods 177 and eccentric drive 183.
At approximately 175 of cam shaft rotation, the first control cam 231 opens the motor-clutch switch 235 which stops movement of the cam combination 69. At the same time, cam 231 closes weld-timer switch 237 thereby actuating a multiple sequence timing device in the generalized control 71 which separately programs the mask-to-frame welding operation while the cam activated movements of the apparatus are at a standstill. FIG. 7 illustrates the approximate positions of the several elements of the apparatus at substantially 180 of cam shaft rotation. The panel contact pads 91 are seated on the interior contour 27 of the panel 29. The pressure rod elevator cam 187 has raised the pressure rod elevator 67 to its apex, and the partial rotative movement of the pressure rods is fully effected; whereupon, the pressure pads 65 of the pressure rods 63 are seated against the mask 21 adjusting it on the frame 31 and conforming discrete areas to the contoured surface 60 of the spacer rod anvil element 93. The aforementioned weld-timing device in the control means 71 programs the welding sequence and regulates the electrode 225 reciprocation by supplying air through tubing n and power through conductor s in accordance with the program schedule.
As mentioned earlier in this specification, the spacer rods 59 are of predetermined lengths. In referring to FIG. 1, the Q spacing between the interior surface 27 of the panel and the surface 22 of the mask portion 21 is of predetermined values across the surface of the panel. At the time the mask portion is properly formed and adjusted on its frame 31, the desired distance d between the frame locating means 33 and the interior surface 27 of the panel is resolved. At the same time the distance b between the frame locating means and the mask surface is also resolved. Thus, Q=d-b. In FIG. 7, the specific Q" spacings are determined for the corner areas of the mask and panel relationship. In this instance, the distance d is the spacing between the panel stud 35 and the panel surface contacted by the panel contact pad 91, and the distance b is the spacing between the frame bracket 33 and the adjusted and reformed mask which is seated against the contoured surface 60 of the spacer rod anvil element 93. Therefore, the Q spacing in the apparatus is: Q=db. Since, in the apparatus the panel stud 35 is separated from the frame bracket 33 by the distance factor of x, the predetermined lengths y of each spacer rod 59 is: y=x+Q.
After the welding sequence is completed, the control device trips a switch therein, not shown, which temporarily overrides the open motor clutch switch 235 and reactivates operation of the motor-clutch unit 229, Whereupon rotation of the cam shaft 121 is resumed beyond 180". The reinitiated rotation of the cam shaft moves pressure rod elevator cam 187 to begin lowering of the pressure rod elevator 67 thereby removing the pressure pads 65 from contact with the mask. The first control cam 231 closes motor-clutch switch 235 to resume control of the motor-clutch unit 229.
At approximately 2002l0 of ca-m rotation, the second control cam 233 opens the panel pickup switch thereby releasing the panel pickup elements 107 and allowing the panel 29 to rest upon the spacer rods 59. Mask- frame elevator cams 159, 161 begin lowering of the mask-frame elevator 61. Arc imparting cam 201 begins a retrace of the rotative movement of the pressure rod movement means 175 thereby moving the pressure pads clockwise to clear the inner edge 32 of the mask frame as the pressure rod elevator 67 is lowered. At approximately 280- 290 of cam rotation, the second control cam 233 opens the frame clamp switch 241 which permits the welded mask-frame assembly 34 to rest upon the carrier platform 133.
As the cam rotation approaches 360, the operational cycles of the several apparatus movements are completed, whereupon motor-clutch switch 235 is opened by the first control cam 231 to stop the motor clutch unit 229.
With the apparatus at rest, the panel carrier 75 and the mask carrier 131 are moved from the operating locations of B, B to the loading-unloading locations of A, A respectively, whereat, the panel 29 and the welded maskframe assembly 34 are individually removed from the ap paratus, each being ready for mating as a mask-panel assembly.
The aforedescribed apparatus provides cathode ray tube mask-frame assemblies that are custom fabricated in accordance with the contour of the panel with which the mask-frame assembly is mated. The resultant mask-panel assemblies have predetermined Q spacings between the mask portion and the interior contour of the panel that are of improved accuracy and uniformity. The apparatus promotes increased manufacturing efiiciency of a degree heretofore unattained. The speed of achieving mating assemblies is greatly enhanced as each mask has discrete contour portions thereof custom modified in accordance with the contour characteristics of an initially related panel.
While substantially rectangular panels and masks are shown, it is not intended that the apparatus of the invention be limited only to the fabrication thereof. In keeping with the scope of the invention, the aforedescribed and claimed apparatus can be adapted to handle related masks and panels of any shape.
While there has 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 scope of the invention as defined by the appended claims.
What is claimed is:
1. An apparatus for manufacturing a cathode ray tube mask-panel assembly wherein the formed aperture mask is supported on a frame, said frame having bracket locating means thereon oriented to mate with positioning means in the panel to provide a predetermined spacing between the mask aperture portion and the interior surface of the panel, said apparatus comprising:
panel positioning means formed to provide orientation of said panel on said apparatus;
a plurality of spacer sensing means adapted to be positioned to make contact with discrete areas of the interior contour of said panel, each of said sensing means being formed to have a first and a second contact surface and a height therebetween to effect a predetermined spacing between the mask aperture portion and the interior surface of said panel; said height being greater than the predetermined spacing between the mask and the panel in the finished maskpanel assembly, said first contact surface being in contact with said interior surface of said panel;
means for locating said mask supporting frame with said mask portion fitted thereon in a position rela tive to the interior surface of said panel to enable said mask portion to make plural contact with said second contact surfaces of said spacer sensing means, said frame being oriented relative to the frame positioning means of said said panel;
pressure means having seating surfaces oriented rela tive to said related spacer means adapted to provide pressure against the interior surface of the said mask portion thereby seating said mask portion against said spacer sensing means to effect conformance of the mask portion area treated therebetween and provide custom spacing between said mask portion and said panel; and
a plurality of bonding means oriented adjacent and substantially peripheral to said mask frame to provide attachment of said formed and adjusted mask portion to said supporting frame to provide a maskframe assembly wherein the custom achieved spacing relationship therebetween is maintained in the mask-panel assembly.
2. An apparatus for manufacturing a cathode ray tube mask-panel assembly according to claim 1 wherein said first contact surface of each of said spacer sensing means is in the form of a sensing area to substantially mate with the contour of a specific region of the interior surface of said panel, and wherein each of said second contact surfaces is formed as an anvil area having a contour substantially matching the predetermined general contour of the mask portion in that area.
3. An apparatus for manufacturing a cathode ray tube mask-panel assembly according to claim 1 wherein said seating surfaces of said pressure means substantially mate with the predetermined general contour of the mask portion in substantially the discrete areas treated.
4. An apparatus for manufacturing a cathode ray tube mask-panel assembly according to claim 2 wherein said pressure means exerts areas of seating pressure against said mask portion to substantially conform the same to the related anvil surface.
5. An apparatus for manufacturing a cathode ray tube mask-panel assembly according to claim 2 wherein the anvil portion of said spacer sensing means provides a contact area at least equalling that of the seating surface area of said related pressure means.
6. An apparatus for manufacturing a cathode ray tube mask-panel assembly wherein the formed aperture mask is supported on a frame having bracket locating means thereon oriented to mate with positioning means in the panel to provide predetermined spacing between the mask domed aperture portion and the interior surface of the panel, said apparatus comprising:
a supporting platform having provisions for accom modating the operational features of the apparatus;
panel positioning means accommodated on said supporting platform to provide orientation of said panel;
a plurality of spacer rods positioned relative to said panel to make contact with discrete areas of the interior surface of said panel, each of said rods having a length greater than the predetermined spacing between the mask and the panel in the finished maskpanel assembly;
spacer rod support means formed to hold said rods and permit individual movement of said rods to contact the interior surface of said panel;
mask-frame positioning means accommodated on said supporting platform in a region beneath and spaced from said panel, said mask-frame being oriented in a manner that said domed aperture portion thereof is adjacent said spacer rods;
a plurality of pressure rods positioned to apply pressure to discrete areas of said mask aperture portion, each of said pressure rods being formed in a manner to make substantially resilient contact with said mask portion in discrete areas substantially opposite said spacer rods;
pressure rod movement means operative to effect contact of said pressure rods with said mask portion in a manner to seat said mask portion against said spacer rod elements to provide the conformance of the mask portion areas thereto and adjust said modified mask portion on said frame; and
mask-to-frame bonding means oriented peripheral to said frame to effect attachment of said adjusted mask to said support frame thereby providing a maskframe assembly wherein the custom achieved spacing relationship therebetween is maintained in the mask-panel assembly.
7. An apparatus for manufacturing a cathode ray tube mask-panel assembly wherein the formed aperture mask is supported on a frame having bracket locating means thereon oriented to mate with positioning means in the panel to provide a predetermined'spacing between the mask aperture portion and the interior surface of the panel, said apparatus comprising:
a supporting platform having base upright and horizontal portions with provisions for accommodating at least three substantially horizontal levels of operational features, said levels being referenced as upper, intermediate and lower levels respectively;
panel positioning means accommodated on said upper level to provide orientation of said panel in an inverted position with the open portion thereof in a downward direction;
a plurality of spacer rodspositioned relative to said panel, in a manner to make contact with the interior surface thereof, each of said spacer rods having a first contact surface formed as a terminal panel contact pad at one end to make :contact with said panel and a second contact surface formed as an anvil element at the opposite end thereof to contact said mask;
spacer rod support means formed to hold said rods and permit substantially vertical individual movement thereof;
spacer rod elevator means formed to move said spacer rod support means to provide contact between said panel contact pads and the interior surface of said said panel;
panel pickup means positioned on said spacer rod elevator means and adapted to mate with said position- "ing means in said panel;
mask-frame positioning means accommodated on said lower level beneath said spacer rod elevator means, said positioning means being formed to provide 12 orientation of said frame with the formed aperture mask' portion fitted thereon, saidformed mask portion being positioned with the dome thereof facing said panel opening and said related spacer rods; mask to frame bonding means accommodated on a stationa-ry plane at said intermediate level in a manner to permit the orientation of said mask-frame in a position adjacent thereto;
mask-frame elevator means formed to vertically transfer said mask frame from said lower level positioning means to said intermediate level and support said frame during said bonding of said mask portion to said frame, said elevator means having frame clamps accommodated thereon adapted to mate with said frame bracket locating means;
a plurality of pressure rods positioned relative to and beneath said mask portion, each of said pressure rods having a pressure pad terminally oriented thereon in a position to contact said formed aperture mask portion;
pressure rod support means formed to hold and permit at least partial rotation of said pressure rods;
pressure rod movement means formed to provide partial rotative movement to said pressure rods to position said pressure pads relative to discrete areas of said mask portion; I
pressure rod elevator means formed to move said pressure rod support means in a substantially vertical plane to effect contact of said pressure pads with said mask portion and seat said mask portion against said spacer rod elements to provide the conformance of the mask areas thereto, and adjust said modified mask on said frame in preparation for bonding;
control means programmed to provide actuation of said panel pickup means, said frame clamp means, and said bonding means;
activation means to effect coordinated movement of said spacer rod elevator means, said mask-frame elevator means, said pressure rod movement means, said pressure rod elevator means, and actuation of said control means; and
power means to furnish predetermined movement to said activation means.
References Cited UNITED STATES PATENTS 2,871,087 1/1959 Knochel 2925.13 XR 3,187,404 6/1965 Fiore "1..--.. 2925.15 3,296,625 1/1967 Schrader 313285 3,309,493 3/1967 Vitale 2925.13 XR 3,335,479 8/1967 Morrell 2925.13 3,369,881 2/1968 Bennett et a1. 2925.13 XR 3,468,005 9/1969 Kautz 29--25.l5
JOHN F. CAMPBELL, Primary Examiner
US777108A 1968-11-19 1968-11-19 Apparatus for achieving custom mask to panel spacing in cathode ray tubes Expired - Lifetime US3537159A (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3701185A (en) * 1971-01-18 1972-10-31 Rca Corp Method of assembling a mask with a frame assembly for mounting in a cathode-ray tube using a remote assembly position
US4592149A (en) * 1985-04-18 1986-06-03 Rca Corporation Apparatus for verifying the acceptability of the curvature of a curved object
US5348506A (en) * 1992-04-10 1994-09-20 Sony Corporation Method of assembling a shadow mask and an apparatus for carrying out the same

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US2871087A (en) * 1956-02-10 1959-01-27 Westinghouse Electric Corp Method of assembling a color television tube
US3187404A (en) * 1962-01-11 1965-06-08 Rauland Corp Method of manufacture of color television picture tube
US3296625A (en) * 1964-06-12 1967-01-03 Rca Corp Cathode ray tube with electrode supported by strap-like springs
US3309493A (en) * 1964-02-21 1967-03-14 Sylvania Electric Prod Multiple bonding
US3369881A (en) * 1964-10-28 1968-02-20 Corning Glass Works Cathode ray tube envelopes and methods of preparing parts therefor and fabricating such envelopes
US3468005A (en) * 1966-09-20 1969-09-23 Sylvania Electric Prod Process for improving mask-screen registration in cathode ray tubes

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Publication number Priority date Publication date Assignee Title
US2871087A (en) * 1956-02-10 1959-01-27 Westinghouse Electric Corp Method of assembling a color television tube
US3187404A (en) * 1962-01-11 1965-06-08 Rauland Corp Method of manufacture of color television picture tube
US3309493A (en) * 1964-02-21 1967-03-14 Sylvania Electric Prod Multiple bonding
US3296625A (en) * 1964-06-12 1967-01-03 Rca Corp Cathode ray tube with electrode supported by strap-like springs
US3335479A (en) * 1964-06-12 1967-08-15 Rca Corp Method of fabricating and processing cathode ray tubes
US3369881A (en) * 1964-10-28 1968-02-20 Corning Glass Works Cathode ray tube envelopes and methods of preparing parts therefor and fabricating such envelopes
US3468005A (en) * 1966-09-20 1969-09-23 Sylvania Electric Prod Process for improving mask-screen registration in cathode ray tubes

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3701185A (en) * 1971-01-18 1972-10-31 Rca Corp Method of assembling a mask with a frame assembly for mounting in a cathode-ray tube using a remote assembly position
US4592149A (en) * 1985-04-18 1986-06-03 Rca Corporation Apparatus for verifying the acceptability of the curvature of a curved object
US5348506A (en) * 1992-04-10 1994-09-20 Sony Corporation Method of assembling a shadow mask and an apparatus for carrying out the same

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