US3777057A

US3777057A - Cathode ray tubes

Info

Publication number: US3777057A
Application number: US00146042A
Authority: US
Inventors: K Abe
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 1970-05-22
Filing date: 1971-05-24
Publication date: 1973-12-04
Anticipated expiration: 1990-12-04
Also published as: CA930009A; DE2125412A1; FR2093565A5; GB1295574A

Abstract

An implosion-proof cathode ray tube assembly, having a reinforcing band applied around the cathode tube, includes an adhesive tape wrapped around the cathode ray tube, a first tension band tightly wound surrounding the adhesive tape, a plurality of mounting lugs engaging the outer periphery of the first tension band at predetermined spaced positions, and a second tension band tightly surrounding the mounting lugs to force them against the first tension band.

Description

I Umted States Patent 1 [111 3,777,o5'i Abe Dec. 4, 1973 CATHODE RAY TUBES 3,271,516 9/1966 Damm l78/7.8 [75} inventor: Katsuo AbeChiba ken, Mobara Shi, 3,317,172 5/1967 Ballnt l78/7.8 X

Japan Prima ExaminerHoward W. Britton A H h t T k [73] sslgnee "ac L d 0 Japan Att0rneyCraig, Antonelli and Hill [22] Filed: May 24, 1971 Appl. No.: 146,042

Foreign Application Priority Data May 22, 1970 Japan 45/43338 US. Cl. l78/7.8, l78/7.81 Int. Cl HOlj 61/50, HOlk 1/28 Field of Search 178/7.8, 7.81, 7.82,

References Cited UNITED STATES PATENTS 7/1969 Griswold l78/7.82

7 Claims, 4 Drawing Figures PATENTEMEP, 4197a 3,777,057

I N VENTOR KRTSkkO REE BY MM A/N'MJ ATTORNEYS,

PATENTEDBEE 4191s 3,777,057 SHYU 2. BF 2 INVENTOR BY m M k mm ATTORNEYS CATHODE RAY TUBES BACKGROUND OF THE INVENTION This invention relates to an implosion-proof cathode ray tube assembly, and more particularly to an implosion-proof cathode ray tube assembly having mounting lugs for mounting the tube in a television receiving set.

Amongcathode ray tubes reinforced against implosion, the so-called Shelbond (trade mark) type, Kimcode (trade mark) type and tension band type are included.

When mounting such prior art implosion-proof cathode ray tube assemblies on a television receiving set, it is necessary to add a mounting unit, such as a frame, to the implosion-proof cathode ray tube or to form mounting lugs by bending a plurality of projections provided on the reinforcing band for the implosion-proof cathode ray tube, such as a rim band or a tension band. Alternatively, after securing the reinforcing band to the cathode ray tube, lugs adapted to mount the cathode ray tube on the television set are welded to the band.

The first of these methods for mounting an implosion-proof cathode ray tube into a television receiving set requires a number of auxiliary fittings, such as set screws and springs. Further, for the purpose of preventing the deformation of the mounting frame, these auxiliary fixtures are ordinarily applied only at the time of assembling, thus complicating the assembling operation.

According to the second of these methods wherein the projections of the reinforcing band are bent to form the mounting lugs, it is difficult to precisely mount these mounting lugs at the correct position due to elongation of the band and incorrect position of the band, which occur when the band is used to secure the cathode ray tube. For this reason, it is often impossible to mount the cathode ray tube on the television receiving set.

According to the third of these methods wherein the mounting lugs are welded to the reinforcing band secured to the cathode ray tube, not only is the welding operation troublesome, but also the reliability of the welds is low. Further, the heat of welding causes damage to the cathode ray tube or a decrease in the reinforcing effect of the reinforcing band.

To eliminate these difficulties, an improved implosion-proof cathode ray tube has recently been proposed according to which the mounting lugs are clamped between the rim band and the tension band. This construction, however, requires the use of a large quantity of bonding agent, such as an epoxy resin, between the rim band and thecathode ray tube in order to firmly bond them together, therebycomplicating the assembling steps and increasing the cost of manufacturing. Utilization of the resinous binder spoils the cathode ray tube during fabrication. If the binder were not applied uniformly into the gap between the rim band and the periphery of the cathode ray tube,the implosion-proof quality of the cathode ray tube would be degraded, which is, of course, undesirable from the standpoint of mass production and safety.

SUMMARY OF THE INVENTION It is an object of this invention to provide an implosion-proof cathode ray tube assembly which can be fabricated by simplified manufacturing steps and in which a first tension band is used as the reinforcing band,'and

mounting lugs are disposed on the outside of the first tension band, which lugs are secured by a second tension band.

A further object of this invention is to provide an implosion-proof cathode ray tube assembly capable of perfectly preventing the movement or shift of the position of the mounting lugs, which is caused by the shearing force applied to the second tension band when it is tightened for the purpose of securely fixing the mounting lugs.

Another object of this invention is to provide an improved implosion-proof cathode ray tube assembly which can be secured by the reinforcing band without using a resinous binder and by which the mounting lugs can be secured without relying upon a welding operation, thus preventing spoilage of the cathode ray tube, so that the tube can be manufactured by mass production techniques.

Yet another object of this invention is to provide an implosion-proof cathode ray tube assembly utilizing first and second reinforcing bands, wherein the first band is used to reinforce the tube against implosion by the tightening force of the band, whereas the second band is used mainly to secure the mounting lugs and additionally to improve the implosionproof quality of the tube.

According to this invention, there is provided an implosion-proof cathode ray tube assembly of the class wherein a reinforcing band is applied around the cathode ray tube, and characterized in that there are provided an adhesive tape wrapped around the periphery of the panel of the cathode ray tube, a first tension band tightly surrounding the adhesive tape, a plurality of mounting lugs engaging the outer periphery of the first tension band at predetermined positions and a second tension band tightly surrounding the mounting lugs to force them against the first band.

BRIEF DESCRIPTION OF THE DRAWINGS Further objects and advantages of the invention will become apparent from the following detailed description of the invention taken in conjunction with the accompanying drawings, in which:

FIG. I shows a front elevation of one example of the novel cathode ray tube with mounting lugs;

FIG. 2 shows a partial sectional view of the cathode ray tube shown in FIG. 1, taken along line [1-1];

FIG. 3 shows a diagrammatic elevation illustrating a jig for applying the tension bands to the implosionproof cathode ray tube; and

FIG. 4 shows a sectional view taken along line IV-IV in FIG. '3.

DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIGS. 1 and 2, the cathode ray tube 1 itself has a conventional construction and comprises a rectangular deep dish-shapedpanel I1 and a funnel portion 12 abutting each other. Around the outer periphery of the panel, that is, around the deep dishshaped peripheral wall, is bonded an adhesive tape 2 of polyester, for example, which is wrapped about the periphery. A first tension band 3, for example, a steel tape, extending in the same direction as the adhesive tape 2, is tightly wrapped around the panel 11 under a tension commensurate with the physical dimension of the cathode ray tube, for example, under a tension of approximately 100 to 600 Kg.

On the outside of the first tension band 3 along the extension of the diagonals of the panel 11 are disposed four mounting lugs 4 of metal which are urged against the first tension band by a second tension band 5, whereby four mounting lugs are securely positioned at the four corners of panel 11. The mounting lugs may have any well known construction and are shown herein as lugs having an L-shaped cross-sectional configuration formed with openings 41 for mounting the cathode ray tube in a television set.

As above described, since in accordance with this invention mounting lugs 4 are firmly urged against the first tension band 3 by means of the second tension band 5 at four corners of the panel 11, any displacement of the position of the mounting lugs is not permissible during the tightening of the second tension band. For this reason, there are provided slip-prevention or anti-skid means between the engaging surfaces of the mounting lugs 4 and the first tension band 3 so as to increase the force acting therebetween beyond the frictional force between the mounting lugs 4 and the second tension band 5 on the outside. In the illustrated example, the anti-skid means comprise a plurality of projections 42 formed on the inner surfaces of the mounting lugs 4 confronting the outer surface of the first tension band 3. Alternatively, the anti-skid means may be provided by forming coarse surfaces on the outer surface of the first tension band 3 facing the mounting lugs, or forming such coarse surfaces on the inner surfaces of the mounting lugs.

Tightening of the reinforcing or tension bands can be advantageously performed by using a jig as shown in FIGS. 3 and 4. The jig 13 shown in these figures includes a vacuum suction pad 14 at its center for supporting the panel 11 of the cathode ray tube 1. The rear end of the vacuum suction pad 14 is connected to a suitable source of vacuum, not shown, and an adjustable screw 15 is provided between the bottom wall of the jig l3 and the neck of the suction pad for adjusting the vertical position thereof. A band clamp 16 is mounted on the jig to be movable toward the center of the cathode ray tube at a position corresponding to one side of the cathode ray tube fixed to the vacuum suction pad.

On the side of the cathode ray tube opposite to the band clamp 16 is provided a welder 17 for welding the end of the first or second tension band which is tightly wrapped about the cathode ray tube 1. On the remaining sides of the cathode ray tube are provided a pair of opposing guide members 18 which are movable toward the center of the cathode ray tube to maintain the position of the first tension band 3 or the second tension band 5 relative to the cathode ray tube, so as to align the respective bands. Along the extensions of the diagonals of the face plate of the tube are mounted four lug clamp members 19, each including a head 20 for holding the lug and a pneumatic piston-cylinder assembly 21 for forcing the head 20 toward the cathode ray tube.

To mount the lugs with the jig described above, a cathode ray tube 1, around which has been wrapped the adhesive tape 2 and the first tension band 3 in any well known manner, is mounted on the vacuum suction pad 14. Thereafter, pneumatic piston-cylinder assemblies 21 of the respective lug clamp members 19 are operated to force the mounting lugs 4 against the outer surface of the first tension band 3. Then the second tension band 5 is wrapped about the cathode ray tube 1, that is, around the outer periphery of the first tension band 3 on the outside of respective mounting lugs 4, during which operation the band clamp 16 is operated to hold a portion of the second tension band. After bringing the first tension band 3 into alignment with the second tension band 5 by the operation of the guide members 18, a suitable tension is applied to the opposite ends of the second tension band 5 by means of a suitable tension applicator and then these ends are welded together by the welder 17. In this manner, the mounting lugs are firmly secured to the cathode ray tube by the second tension band. Thereafter,

members

16, 18 and 19 are released and the vacuum in the vacuum suction pad is broken to obtain an implosion-proof cathode ray tube assembly, as shown in FIG. 2.

It will be clear that the adhesive tape and the first tension band can also be applied on the cathode ray tube while it is mounted on the jig. In such a case, after applying the first tension band, it is advantageous to rotate the cathode ray tube about its axis prior to the application of the second tension band so as to prevent overlapping of the joints of respective tension bands.

Although the invention has been shown and described in terms of its preferred embodiment, it will be clear that many changes and modifications may be made without departing from the true spirit and scope of the invention as defined in the appended claims.

I claim:

1. In an implosion-proof cathode ray tube assembly including a cathode ray tube, an adhesive tape wrapped around the periphery of a panel of said cathode ray tube and a first tension band tightly surrounding said adhesive tape, the improvement comprising a plurality of mounting lugs engaging the outer periphery of said first tension band at predetermined spaced positions, a second tension band tightly surrounding said mounting lugs to force them against said first tension band and anti-skid means provided between the peripheral surface of said first tension band and said mounting lugs to prevent movement of said lugs.

2. The implosion-proof cathode ray tube assembly according to claim 1, wherein said anti-skid means comprises a plurality of projections formed on said lugs in contact with said first tension band.

3. The implosion-proof cathode ray tube assembly according to claim 1, wherein said anti-skid means is formed on the inner surfaces of said mounting lugs facing said cathode ray tube.

4. The implosion-proof cathode ray tube assembly according to claim 1, wherein said anti-skid means comprises coarse surfaces formed on the inner surfaces of said mounting lugs facing said cathode ray tube.

5. The implosion-proof cathode ray tube assembly according to claim 1, wherein said anti-skid means comprises coarse surfaces formed on the outer periphery of said first tension band at least at portions thereof facing said mounting lugs.

6. The implosion-proof cathode ray tube assembly according to claim 1, wherein said lugs are positioned on the extensions ofthe diagonals of the face plate of said cathode ray tube.

7. The implosion-proof cathode ray tube assembly according to claim 1, wherein said mounting lugs have an L-shaped cross section.

Claims

6. The implosion-proof cathode ray tube assembly according to claim 1, wherein said lugs are positioned on the extensions of the diagonals of the face plate of said cathode ray tube.