Manufacturing method and apparatus for insulating member

Information

  • Patent Grant
  • 6186851
  • Patent Number
    6,186,851
  • Date Filed
    Friday, April 30, 1999
    25 years ago
  • Date Issued
    Tuesday, February 13, 2001
    23 years ago
Abstract
This invention secures the breakdown voltage between stem pins or the like for high voltage service in a cathode ray tube. This insulator formed is of a clay-like silicone compound having a tip-throughhole and pin-throughholes or a stem base with the electric insulator mounted to the stem base: A inter-stem electric insulation device is structured by mounting either one of the electric insulator or the stem base with the electric insulator to the stem of a cathode ray tube and by pressing to fix together. This structure does not occur bubble generation caused by the electric insulator, and makes the handling easy, and furthermore, accomplish an automatic mounting of the electric insulator to a stem.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




This invention relates to an electric insulator being capable of insulating between high voltage stem pins in a cathode ray tube used for electric equipment provided with high voltage electrodes, which electric equipment particularly includes color television picture tubes and monitors of image screens and computers, and for other electrodes being subjected to a high voltage, and relates to an electric insulation device using therefor, and further relates to a method of electrical insulation using the electric insulator.




2. Description of the Related Art




The cathode ray tube described above is a typical example of electric equipment provided with high voltage electrodes. The high voltage inter-stem pin electric insulator in a cathode ray tube of the prior art and the method for producing a cathode ray tube using the insulator are described below referring to FIG.


1


and FIG.


2


.





FIG. 1

illustrates the method of electric insulation between stem pins including a high voltage stem pin of the prior art.





FIG. 1A

shows a stem base, and

FIG. 1B

shows a neck of the cathode ray tube.

FIG. 2

illustrates the neck of the cathode ray tube structured in accordance with the method of electrical insulation illustrated in FIG.


1


.

FIG. 2A

gives a view of the neck, and

FIG. 2B

gives the cross sectional view along the A—A line in FIG.


2


A.




In

FIG. 1B

, the reference number


1


designates the neck of a cathode ray tube which is installed in a color television picture tube or a monitor for an image screen or computer. The neck accepts an electron gun being mounted on a stem


2


, which is not shown, by insertion therein, and the stem


2


is provided with more than one stud electrode, stem pins


3


A,


3


B,


3


C, etc. The glass periphery of the stem


2


and the glass edge periphery of the neck


1


are welded together to integrate them. The assembled cathode is evacuated through the tip


4


of the exhaust pipe formed at the center of the stem


2


, then the tip


4


is sealed. The stem pins


3


A,


3


B,


3


C, etc. are studded along a specified pin pitch circle.




In

FIG. 1A

, the reference number


10


designates a stem base. The stem base


10


consists of a bottom disc plate


11


, a tip acceptor


12


which is formed at the center of the bottom disc plate


11


and protects the tip


4


, an acceptor for high voltage stem pin


13


in a fan-shape to receive a high voltage stem pin


3


B and act also as a part of the side wall of the tip acceptor


12


, a skirt


14


which covers the edge periphery of the neck


1


formed at the periphery of the bottom plate


11


and which prevents sagging of the paste electric insulator


5


, and more than one throughhole,


15


A,


15


B,


15


C, etc. aligning to the stem pins


3


A,


3


B,


3


B, etc. formed at the periphery of the bottom plate


11


.




A common material for the stem base


10


is a resin such as polycarbonate which has excellent insulation properties. The dielectric breakdown voltage of polycarbonate resin is 30 KV/mm.




A conventional method to electrically insulate between the stem pins


3


A,


3


B,


3


C, etc. being studded onto the stem


2


on the neck


1


of the cathode ray tube is to evacuate the cathode ray tube, to seal the tip


4


, then, as illustrated in

FIG. 1B

, to insert the nozzle of a tube


6


filled with paste electric insulator


5


between the stem pins


3


A,


3


B,


3


C, etc. of the stem


2


, and to squeeze out a small amount of the electric insulator


5


from the tube


6


using fingers


7


.




The stem base


10


shown in

FIG. 1A

is placed on the applied electric insulator


5


in a manner that the tip acceptor


13




12


accepts the tip


4


and that the acceptor for high voltage stem pin B accepts the high voltage stem pin


3


B and that each of the throughholes


15


A,


15


B,


15


C, etc. accepts a corresponding stem pin


3


A,


3


B,


3


C, etc. under a slight compression. Then, the configuration becomes the one illustrated in FIG.


2


. The structure assures the electric insulation between the stem pins,


3


A,


3


B,


3


C, etc.




As realized in the present color television picture tubes and monitors for image screens and computers, the cathode ray tubes for this equipment are requested to have high brightness and high resolution. To cope with the ever increasing demand, a high voltage is applied not only to the anode of the cathode ray tube but also to the electrode of the electron gun in the cathode ray tube. In particular, a focus electrode is unavoidably applied with a high voltage for improving the focusing characteristic.




The outside diameter of the neck


1


receiving the electron gun has an upper limit from the standpoint of saving the deflection power of the electron gun. Consequently, the area of stem


2


is limited. Since such a limited area of the stem


2


receives the stem pins


3


A,


3


B,


3


C, etc., which receive various levels of voltage, the spacing of these stem pins


3


A,


3


B,


3


C, etc. becomes close.




For example, a color cathode ray tube for monitoring a graphic display made by SONY CORP. has the pin pitch circle diameter of 15.24 mm, and the number of studded pins is


14


with the pin spacing of 3.42 mm.




Among these stem pins,


3


A,


3


B,


3


C, etc., the stem pin


3


A, for example, is called the G


1


pin which is applied with a voltage of 0 to several volts, and the stem pin


3


B is the one for focus electrode which is applied with maximum 9800 volts, and the stem pin


3


C is the one to supply voltage to the convergence electrode and is applied with 0 to 2000 volts.




Accordingly, there exists a maximum difference of 9800 volts between the stem pin


3


A and the stem pin


3


B, and a maximum of 8750 volts between the stem pin


3


B and the stem pin


3


C. For a new cathode ray tube, or if the surface of the glass stem


2


is clean, the glass dielectric breakdown voltage (the lead along the stem glass surface) between the stem pins


3


A and


3


B and between the stem pins


3


B and


3


C is not problem. However, a temperature rise or deposition of dust or dirt caused by static charge degrades the dielectric breakdown voltage during operation, or an excess voltage over the dielectric breakdown voltage is often applied to the stem pins, so the dielectric breakdown voltage is not necessarily secured during operation.




To assure the necessary dielectric breakdown voltage, conventional technology uses a paste silicone resin of a room-temperature-curing type such as KE03490 made by Shin-Etsu Chemical Co. Ltd. and SE-9168 made by Toray Dow Corning Co., Ltd. That type of resin is hereinafter referred to simply as “RTV resin”.




The RTV resin has basic electric characteristics, but it lacks flowability because of its paste property. As illustrated in

FIG. 1B

, the RTV resin


5


is squeezed out from the tube


6


between the stem pins before mounting the stem base


10


to the stem


2


, then the stem base


10


is attached. Usually, the application of RTV resin


5


is manually carried out.




However, the RTV resin raises several problems in that it likely develops bubbles during application. A solvent existing in resin foams at a temperature range of from 80 to 120° C. under the heat generated during the aging stage for activating the cathode of the electron gun, Bubbles also occur during the insertion and withdrawal of connector of an instrument employed several times for inspection in the period between application of the RTV resin and the complete curing, (normally 7 days). Bubbles interfere with the perfect functioning of the electric characteristics of the resin and degrade the dielectric breakdown voltage and, in the worst case, discharge occurs between the stem pins causing damage to the cathode ray tube.




OBJECTS AND SUMMARY OF THE INVENION




The inventors solved these problems by providing the following inventions.




1. The first invention is an electric insulator for inter-electrode insulation such as inter-stem insulation between pins for high voltage service in a cathode ray tube, which electric insulator comprises:




(1) An electric insulator comprising a clay-like silicone compound being formed to secure electrical insulation between stem pins or the like for high voltage service in a cathode ray tube.




(2) An electric insulator of (1), wherein the silicone compound has a volume resistivity ranging from 1×10


12


to 1×10


15


Ω•cm and a dielectric breakdown strength ranging from 10 to 30 KV/mm.




(3) An electric insulator of (1), wherein the clay-like insulator has a degree of plasticity giving a deformation ranging from {fraction (4/10)} to {fraction (7/10)} under a compression of 19 Kg-f.




(4) An electric insulator of (3), wherein a thickness of the formed shape is in a range of from 0.8 to 2.0 mm.




(5) An electric insulator of (1) through (4), wherein more than one throughhole are formed corresponding to at least a spacing of electrodes of electric equipment and accepting those electrodes penetrating therethrough.




(6) An electric insulator of (1) through (5), wherein throughholes corresponding to more than one stem pin including a high voltage stem pin in a cathode ray tube and to a tip an exhaust pipe of the cathode ray tube are formed.




2. The second invention is a stem base having throughholes corresponding to more than one stem pin in a cathode ray tube and to a tip of exhaust pipe of an the cathode ray tube, wherein the electric insulator is attached to the stem base while aligning these throughholes with the throughholes of the electric insulator described in (6) of 1.




3. The third invention is an inter-stem pin electric insulation device in a cathode ray tube, which comprises: a stem of a cathode ray tube; and the electric insulator described in 1 being attached to the external surface of the stem in a manner being penetrated by more than one stem pin including a high voltage stem pin which is protruding from the external surface of the stem and by a tip of an exhaust pipe of the cathode ray tube; a stem base provided with throughholes, a tip acceptor, and an acceptor for a high voltage stem pin, being placed and fixed in a manner that the stem pins penetrate the throughholes and that the stem base covers the tip at the tip acceptor and that the high voltage stem pin is isolated in the acceptor for the high voltage stem pin.




4. The fourth invention is a method for producing a cathode ray tube, which comprises: attaching an electron gun provided with more than one stem pin including a high voltage stem pin and with a stem introducing an exhaust pipe to a neck of a funnel which structures a tube body; welding the periphery of the neck edge with the periphery of the stem; forming a tip and closing it after evacuating the tube body through the exhaust pipe; attaching a clay-like electric insulator consisting of silicone compound which was formed aligning each of the throughholes for receiving the stem pins and the tip of the exhaust pipe; fitting the integrated stem base by penetrating the stem pins and the tip therethrough, and mounting and fixing the stem base to the stem.




Accordingly, an electric insulator of this invention suppresses the generation of bubbles described above or further eliminates the bubble formation, completely prevents the leak along the surface which is also described above, secures the electric insulation between high voltage stem pins or the like in a cathode ray tube, and does not damage the cathode ray tube.




Since the electric insulator of this invention is a clay-like formed shape, the work for insulating high voltage stem pins or the like from each other in a cathode ray tube is performed at a significantly improved efficiency.




In addition, the use of a stem base being attached with the electric insulator of this invention enhances the efficiency of the work for insulating high voltage stem pins or the like from each other.




Furthermore, the use of a the stem base of this invention allows a mechanical mounting of an electric insulation device between high voltage stem pins or the like instead of conventional manual work. The mechanical mounting procedure leads to an automatic operation.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

comprised of

FIGS. 1A-1B

illustrates the method of electric insulation between stem pins including a high voltage stem pin of the related art.





FIG. 1A

shows a stem base, and





FIG. 1B

shows a neck of the cathode ray tube.





FIG. 2

comprised of

FIGS. 2A-2B

illustrates the neck of a cathode ray tube structured in accordance with the method of electrical insulation shown in FIG.


1


.





FIG. 2A

gives a view of the neck, and





FIG. 2B

gives the cross sectional view along A—A line in FIG.


2


A.





FIG. 3

comprised of

FIGS. 3A-3B

shows an electric insulator of the first embodiment in the present invention.





FIG. 3A

gives a view of the electric insulator.





FIG. 3B

shows the cross sectional view along A—A line of FIG.


3


A.





FIG. 4

comprised of

FIGS. 4A

,


4


B and


4


C illustrates the procedure for attaching the electric insulator of

FIG. 3

of the second embodiment in the present invention onto the stem base.





FIG. 4A

gives a view of the electric insulator of FIG.


3


.





FIG. 4B

gives a view of the electric insulator viewing from the stem side.





FIG. 4C

is a stem base attached with an electric insulator of this invention.





FIG. 5

comprised of

FIGS. 5A

,


5


B and


5


C illustrates the structure of an electric insulation device of the present invention. The neck of a cathode ray tube which uses the electric insulator for more than one stem pin including a high voltage stem pin, is shown using the electrical insulator shown in

FIG. 1

or the stem base shown in FIG.


4


.





FIG. 5A

gives a view of the device.





FIG. 5B

shows the cross sectional view along A—A line in FIG.


5


A.





FIG. 5C

shows a cross sectional view of the stem of neck structuring the cathode ray tube.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS




An electric insulator of this invention, an electric insulation device using the electric insulator, and a method for producing a cathode ray tube using the electric insulator are described below referring to FIG.


3


through FIG.


5


.





FIG. 3

shows an electric insulator of this invention.

FIG. 3A

gives a view of the electric insulator, and

FIG. 3B

shows the cross sectional view along A—A line of FIG.


3


A.





FIG. 4

illustrates the procedure for attaching the electric insulator of

FIG. 3

onto the stem base.

FIG. 4A

gives a view of the electric insulator of FIG.


3


.

FIG. 4B

gives a view of the electric insulator viewing from the stem side.

FIG. 4C

is a stem base attached with an electric insulator of this invention.





FIG. 5

illustrates the structure of an electric insulation device of this invention of the neck of cathode ray tube in which electric insulation between several stem pins including a high voltage stem pin is effected using the electrical insulator shown in

FIG. 3

or the stem base shown in FIG.


4


.

FIG. 5A

gives a view of the device.

FIG. 5B

shows the cross sectional view along A—A line in FIG.


5


A.

FIG. 5C

shows a cross sectional view of the stem of neck structuring the cathode ray tube.




The components common to those in the figures of the related art, such as the electric device of the high voltage inter-stem pin in a cathode ray tube, have the same reference numbers with each other.




The following is the description of an electric insulator of the first embodiment in the present invention.




Referring to

FIG. 3

, the electric insulator


20


of this invention is formed to a disc having a thickness described below. The disc has a throughhole


21


for receiving a tip


4


at the center, and has throughholes


22


A,


22


B,


22


C, etc. for receiving stem pins


3


A,


3


B,


3


C, etc. including the high voltage stem pin


3


B, at an each corresponding position.




Those throughholes may be formed at a time when the electric insulator


20


is punched from a large flat electric insulator using a forming die. The punching of the throughhole


21


for the tip is preferably carried out to have a cross slit


23


at the inner periphery of the throughhole


21


. The electric insulator


20


with that type of slit


23


makes the insertion of tip


4


into the throughhole


21


easy and assures close contact of the outer periphery of the tip


4


with the inner periphery of the throughhole


21


, which ensures the electric insulation.




The electric insulator


20


is a clay-like silicone compound. An example of that type of silicon compound uses “Putty-stock SMX-5999” made by Fuji Polymer Co. Ltd. as the basic component. By mixing a plasticizer to “Putty-stock SMX-5999”, an electric insulator


20


having an adequate degree of plasticity is obtained.





FIG. 3

shows an example of the electric insulator


20


having the tip-throughhole


21


, the pin-throughholes


22


A,


22


B,


22


C, etc., and the slit


23


. An electric insulator may otherwise simply be formed by punching a silicone compound to the outside diameter, and it is pressed to the tip


4


of the neck


1


and to the stem pins


3


A,


3


B,


3


C, etc. to open these throughholes using a compression force, and then mounting it to the stem


2


. Nevertheless, an electric insulator


20


which forms the throughholes shown in

FIG. 3

in advance has an advantage that the tip


4


and the stem pins


3


A,


3


B,


3


C, etc. are easily mounted without defecting the shape of the insulator.




The inventors carried out further extensive study and invented the stem base


40


with electric insulator, which is the second invention shown in FIG.


4


C.




The stem base


40


with electric insulator is formed by attaching the electric insulator


20


shown in

FIG. 4A

(

FIG. 3

) to the stem base


30


to integrate them. The material of the stem base


30


may be a high insulation resin such as polycarbonate which is used in prior art.




As illustrated in

FIG. 4B

, the stem base


30


consists of: a tip-throughhole


32


which is opened at the center of the disc base plate


31


and which accepts the tip


4


; pin-throughholes


33


A,


33


B,


33


C, etc. including for the high voltage stem pin


3


B, which are arranged along the peripheral pitch circle on the base plate


31


and which receive stem pins


3


A,


3


B,


3


C, etc. at each corresponding position; and the tip acceptor


34


and an acceptor for high voltage stem pin


35


locating on the side not facing the stem


2


of the base plate


31


to protect the tip


4


of the neck


1


.




The stem base


30


has no skirt


14


which is seen on the stem base


10


of prior art. The skirt


14


may be formed at need. However, this invention uses a clay-like electric insulator


20


and is not the type of paste electric insulator


5


, so there is not possibility of sagging of the insulator. Therefore, no skirt


14


is required in this invention. Moreover, elimination of the skirt


14


allows an easy production of the stem base


40


with the electric insulator, which stem base


40


is described below.




The following is the third embodiment of the present invention. The stem base


40


with electric insulator is formed by attaching the electric insulator


20


shown in

FIG. 3

to the stem base


30


in advance while aligning each of the tip-throughhole


21


, pin-throughholes


22


A,


22


B,


22


C, etc. with the tip-throughhole


32


, pin-throughholes


33


A,


33


B,


33


C, etc. on the stem base


30


, respectively. In other words, the stem base


40


with electric insulation has an integrated structure of the electric insulator


20


and the stem base


30


.




When this type of stem base


40


with electric insulation is prepared in advance, the production line of cathode ray tubes at an assembly plant is shortened, and a special advantage is given in automatic mounting of the stem base


40


with electric insulation to the stem


2


as described before. Furthermore, even if the assembly is carried out manually, the workability should be significantly improved.




Accordingly, as illustrated in

FIG. 5

, the stem base


40


with electric insulation of this invention is attached to the evacuated neck


1


of a cathode ray tube under a compression force while aligning the tip-throughhole


32


with the tip-throughhole


21


on the mating electric insulator


20


and aligning each pin-throughholes


33


A,


33


B,


33


C, etc. with the pin-throughholes


22


A,


22


B,


22


C, etc. on the mating electric insulator


20


, and with the stem pins


3


A,


3


B,


3


C, etc., respectively, and while pressing down on the stem base


40


with electric insulation at the mating state to firmly contact the stem


2


. The compression force is described later. In this manner, the inter-stem insulation is performed using the electric insulation device shown in FIG.


5


A and FIG.


5


B.




Otherwise, the electric insulator


20


shown in

FIG. 3

may be directly mounted on the stem pins,


3


A,


3


B,


3


C, etc. and the tip


4


of the stem


2


, and may further accept the stem base


30


as shown in

FIG. 4B

or the stem base


10


of prior art. However, if the stem base


40


with electric insulation of this invention shown in

FIG. 2C

is used, the mounting can be performed by a robot, which means that the production line of cathode ray tubes is automated.




Either electric insulator of this invention may be used to enhance the curing by the heat of cathode aging (80-120° C.) after mounting the electric insulator to the stem


2


at room temperature as described before. Since the electric insulator of this invention has a clay-like property, the amount of included solvent is quite small compared with the paste electric insulator of the prior art. As a result, the generation of bubbles in the curing stage due to the heat is minimized, and the required breakdown voltage is secured.




The following is experimental examples of the clay-like silicone compound electric insulator of this invention.




Experimental Example 1




The clay-like silicone compound used had the following properties. The experiments were conducted with various thickness, T, of the electric insulator


20


shown in FIG.


3


B.




1. Volume resistivity: 1×10


14


Ω•cm




2. Dielectric breakdown strength: 25 KV/mm




3. Diameter of pin-throughhole: 0.97 mm




4. Degree of plasticity (Note 1): ½




5. Adhesive force (Note 2): 10 Kg•f




6. Thickness: 0.5, 0.8, 1.3, 1.8, 2.0, and 2.3 mm




The clay-like silicone compound having the above listed properties was formed in a forming die to prepare the electric insulator


20


having the diameter of 22 mm, the pin-throughhole spacing of 4 mm corresponding to the spacing of stem pins


3


A and


3


B and of stem pins


3


B and


3


C. The electric insulator


20


was mounted to the stem


2


to measure the dielectric breakdown voltage between stem pins. The result is summarized in Table 1.




The term “degree of plasticity” means that the rate of shrinking of the sample thickness determined by sandwiching the clay-like silicone compound of 10 mm square between glass plates and by applying a compression force of 10 Kg*f.




The term “adhesive force” means the adhesive force determined by sandwiching the sample between a glass plate and the stem base


30


shown in FIG.


4


B and by applying a compression force of 10 Kg•f.


















TABLE 1











Thickness of electric




0.5




0.8




1.3




1.8




2.0




2.3






insulator (mm)






Inter-pin dielectric




10




30




38




45




37




15






breakdown voltage (KV)











The figures of dielectric breakdown voltage are the average of 20 samples.













The depth, D, of the recess


2


A on the stem


2


shown in

FIG. 5C

, which recess generated during the closing stage of the cathode ray tube, was normally in a range of from 0.3 to 0.5 mm. An electric insulator


20


having the thickness of 0.5 mm had a tendency of incapable of absorbing the recess


2


A and degraded the dielectric breakdown voltage. When the thickness of the electric insulator


20


exceeds 2.0 mm, the thickness was too large and a loose mount occurred. In both cases, a preferable thickness of the electric insulator


20


was in a range of from 0.8 to 2.0 mm.




Experimental Example 2




The clay-like silicone compound used had the following properties. The experiments were conducted with various degree of plasticity of the electric insulator


20


shown in FIG.


3


.




1. Volume resistivity: same as in Experimental example 1




2. Dielectric breakdown strength: same as in Experimental Example 1




3. Diameter of pin-throughhole: same as in Experimental Example 1




4. Degree of plasticity: {fraction (2/10)}, {fraction (4/10)}, {fraction (5/10)}, {fraction (6/10)}, {fraction (8/10)}




5. Adhesive force: same as in Experimental Example 1




6. Thickness: 1.8 mm




The clay-like silicone compound having the above listed properties was formed in a forming die to prepare the electric insulator


20


having the diameter of 22 mm, and the pin-throughhole spacing of 4 mm corresponding to the spacing of stem pins


3


A and


3


B and of stem pins


3


B and


3


C. The dielectric electric insulator


20


was mounted to the stem


2


to measure the breakdown voltage between stem pins. The result is summarized in Table 2.
















TABLE 2











Degree of plasticity of electric




2/10




4/10




5/10




7/10






insulator






Inter-pin dielectric breakdown




12




35




45




40






voltage (KV)














The experimental results showed a tendency that an electric insulation having a lower degree of plasticity (excess hardness) could not absorb the recess


2


A of the stem


2


as observed in Experimental example 1, and likely left bubbles in the insulator, and degraded the breakdown voltage.




As described above, the electric insulator of this invention induces no degradation of dielectric breakdown voltage between stem pins nor fracture caused by unwelcome phenomena such as the generation of bubbles or irregular application of resin which are the disadvantages of conventional RTV resin. Consequently, the electric insulator of this invention does not suffer a discharge between pins and fully utilizes the electric characteristics inherent to silicon compound. In addition, the electric insulator of this invention can form the pin-throughholes and tip-throughhole simultaneously by punching the form in a forming die, which allows the mass-production of electric insulators which are easy to mount on stems.




Furthermore, the stem base with the electric insulator of this invention is easily handled manually, as described before, and is mounted by a mechanical means, and allows an automatic mounting. Accordingly, this invention provides various effects as described above.




The detailed description given above used a cathode ray tube as an example. This invention, however, is not limited to the cathode ray tube, and naturally deals with the electric insulation between electrodes of electric equipment such as between electrodes of a high voltage transformer actuating under a high voltage.



Claims
  • 1. A method for producing a cathode ray tube comprising; attaching an electron gun provided with more than one stem pin including a high voltage stem pin and with a stem introducing an exhaust pipe to a neck of funnel which structures a tube body; welding the periphery of the neck edge with the periphery of the stem; forming a tip and closing it after evacuating the tube body through the exhaust pipe; attaching a clay-like electric insulator consisting of silicone compound which was formed aligning each of throughholes for receiving the stem pins and the tip of exhaust pipe therethrough; fitting the integrated stem base by penetrating the stem pins and the tip, and mounting and fixing the stem base to the stem.
  • 2. A method of electrically insulating stem pins of a stem of a cathode ray tube, the method comprising:inserting said stem pins, respectively, through a first plurality of pin through-holes in an insulator, said insulator being formed from a deformable silicon compound; inserting an exhaust pipe of the cathode ray tube through a first exhaust pipe through-hole formed in said insulator for receiving said exhaust pipe; wherein, the first exhaust pipe through-hole of said insulator corresponding to said exhaust tip has a diameter less than a diameter of said exhaust tip.
  • 3. The method of claim 2, wherein said silicon compound has a volume resistivity ranging from 1×1012 to 1×1015 Ωcm.
  • 4. The method of claim 2, wherein said silicon compound has a dielectric breakdown strength between 10 and 30 KV/mm.
  • 5. The method of claim 2, wherein said insulator has a thickness from 0.8 to 2.0 mm.
  • 6. The method of claim 2 wherein said silicon compound has a degree of plasticity defined by a deformation between {fraction (4/10)} to {fraction (7/10)} under a compression of 19 Kg•f.
  • 7. The method of claim 2, further comprising disposing a stem base on said stem of said cathode ray tube over said insulator.
  • 8. The method of claim 7, wherein said stem base comprises a second plurality of pin through-holes corresponding to the stem pins of the cathode ray tube and a second exhaust pipe through-hole corresponding to said tip of the exhaust pipe of the cathode ray tube.
  • 9. The method of claim 8, wherein said disposing a stem base further comprises aligning said first and second pluralities of pin through-holes and said first and second exhaust pipe through-holes.
  • 10. The method of claim 8, wherein said disposing a stem base further comprises:inserting said stem pins through said second plurality of pin through-holes; and inserting said exhaust pipe through said second exhaust pipe through-hole.
  • 11. A method of electrically insulating stem pins of a stem of a cathode ray tube, the method comprising forming an insulator from a deformable silicon compound,wherein said forming an insulator comprising forming a first plurality of pin through-holes in said insulator for receiving the stem pins of said stem of said cathode ray tube and forming a first exhaust pipe through-hole in said insulator for receiving an exhaust pipe of said cathode ray tube; wherein, the first exhaust pipe through-hole of said insulator corresponding to said exhaust tip if formed with a diameter less than a diameter of said exhaust tip.
Priority Claims (1)
Number Date Country Kind
5-235122 Sep 1993 JP
Parent Case Info

This application is a division of Ser. No. 08/305,283 filed Sep. 12, 1994, U.S. Pat. No. 5,990,610.

US Referenced Citations (4)
Number Name Date Kind
4040707 Pisano Aug 1977
4040708 Neuber et al. Aug 1977
4155616 Crosby et al. May 1979
4155618 Regnault et al. May 1979