US3730990A

US3730990A - Implosion-proof cathode-ray tube

Info

Publication number: US3730990A
Application number: US00058866A
Authority: US
Inventors: Y Miyata; N Katoh
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 1969-08-01
Filing date: 1970-07-28
Publication date: 1973-05-01
Anticipated expiration: 1990-05-01

Abstract

An implosion-proof cathode-ray tube which is provided with a reinforcing band for tightening the side walls of a joined portion what is called a mold-match portion, between a face portion and a skirt portion of a panel portion of a glass-made envelope through the so-called pad assemblies disposed on the four corners of the joined portion and each comprising a metallic fixture for a cabinet and a pad connected with the fixture, and in which a hardenable bulking agent is filled into gaps between the side walls of the joined portion or a single-side adhesive tape surrounding said side walls of the joined portion and the pads, thereby increasing the implosion-proof force and facilitating the location of the fixtures.

Description

llnite States tent 1 1 1111 3,73@,@9@ iyata et a1. 5] May 1, 1973 [54] HMPLOSION-PROOF CATHODE-RAY 3,456,076 7/1969 Griswold et a1. .......l78/7.82 TUBE 3,317,172 5/1967 Balint ..178/7.8 x 3,508,310 4 1970 ..178 7.82 x [75] Inventors! YShihik Miyata, Mobara; 3,278,682 10/1966 P21211801 a1. l78/7.8

Noritada Katoh, Kitatama-gun,

Tokyo, both of Japan Assignee: Hitachi, Ltd., Tokyo, Japan Filed: July 28, 1970 Appl. No.: 58,866

Foreign Application Priority Data Aug. 1, 1969 Japan .....44/7260 9 Field of Search ..l78/7.82, 7.8, 7.81

References Cited UNITED STATES PATENTS Primary ExaminerHoward W. Britton Attorney-Craig, Antonelli & Hill [57] ABSTRACT An implosion-proof cathode-ray tube which is provided with a reinforcing band for tightening the side walls of 21 joined portion what is called a mold-match portion, between a face portion and a skirt portion of a panel portion of a glass-made envelope through the so-called pad assemblies disposed on the four corners of the joined portion and each comprising a metallic fixture for a cabinet and a pad connected with the fixture, and in which a hardenable bulking agent is filled into gaps between the side walls of the joined portion or a single-side adhesive tape surrounding said side walls of the joined portion and the pads, thereby increasing the implosion-proof force and facilitating the location of the fixtures.

5 Claims, 3 Drawing Figures Patented May 1, 1973 INVENTORS' YosmmKO MWRTH Nomi-non KnToH BYW,O-UEMML,WA'LQQ.

ATTORNEYS IMPLOSION-FROOF CATHODE-RAY TUBE BACKGROUND OF THE INVENTION molded together and the interior thereof highly evacuated, and'that the joined portion (hereinafter called as the mold-match portion) between the face portion and the skirt portion has'the lowest mechanical strength, exhibiting therein a tendencyfor an occurrence of implosive accidents and violent scattering of glass pieces in the event of an implosive accident.

As examples of means for solving the problem, it has hitherto been known to tighten the side walls of the mold-match portion of the bulb by means ofa reinforcing band and, in order to facilitate this tightening, to-interpose between the side walls and the band a singlesid'e adhesive tape which has a bonding agent coated on a side to be joined onto the bulb. It has also been known with the intention of mounting the cathode-ray tube at a predetermined position of the cabinet, to stick a rim non-tightly surrounding the side walls of the mold-match portion to said walls by means of a bonding agent. of high adhesion and to weld metallic fixtures to the rim soas to tighten the topsides thereof with a reinforcing band.

In the former means wherein the topsides of the adhesive tape are tightened with the reinforcing band, however, those protruding portions of the side walls of the mold-match portion which appear as mold seam when the skirt portion and the face portion are molded together, only or mainly catch implosive forces,so it is unsatisfactory in that no sufficient effect of reinforcemerit is sometimes attained and that it does not serve as a mechanism for assembling the bulb to the cabinet. Although the latter means wherein the rim is stuck using adhesives, serves also as a mechanism to secure the cathode-ray tube. to the cabinet and is nearly,

satisfactory in its implosion-proof property, it is unsatisfactory in that the welding of the metallic fixtures renders it impossible to adjust the positions thereof fitly to the bulb at'assemblage and that abounding agent of high adhesion is required for sticking the, rim to the bulb.

SUMMARY OF THE INVENTION An object of the present invention is to provide an implosion-proof cathode-ray tube which is simple in the positioning thereof when it is assembled to a cabinet and which has a substantially satisfactory implosion-proof property.

According to the invention, the aforementioned object is accomplished by providing a reinforcing band for tightening the side walls of a mold-match portion between a face portion and. a skirt portion of a panel portion of a bulb through the so-called pad assemblies disposed in the four corners of the mold-match portion and each comprising-a metallic fixture for a cabinet and a pad connected with the fixture, and by filling a hardenable bulking agent into gaps between the side walls of the mold-match portion or a single-side adhesive tape surrounding said side walls of the mold-match portion and the pads of the pad assemblies.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of the invention;

FIG. 2 is a sectional view showing a part of the side wall of a mold-match portion in FIG. 1; and

FIG. 3 is a sectional view showing a part of another embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the accompanying drawings, the embodiments of the invention will be described in detail.

FIG. 1 is a perspective view showing an embodiment of the invention, while FIG. 2 is a sectional view illustrating one of the diagonal portions, i.e., four corners of the cathode-ray tube in FIG. 1. In FIGS. 1 and 2, reference numeral 1 designates a panel portion of a bulb, which consists of a face portion 11 and a skirt portion 12; 13 a joined portion of them, i.e., a moldmatch portion, which is shown by a dotted line for the sake of explanation; 2 pad assemblies each incorporating a pad 21 and a metallic fixture 22 into one; 23 a fitting bolt hole of the pad assembly; 3 a reinforcing band for exerting a compressive strain upon the side walls of the mold-match portion of the bulb through the pads 21 and for fixing the pad assemblies 2; and 4 a hardenable bulking agent for filling gaps formed between the side walls of the mold-match portion and the pads 21. Numeral 14 designates a funnel portion of the bulb, and 15 designates a sealing portion joining the panel portion 1 and funnel portion 14.

With such a construction, the metallic fixtures 22 i may be fixed, after their positions have been set and held by means of a jig, by tightening the pad assemblies from the topsides thereof with the reinforcing band 3, so the positions of the fixtures 22 may be set fitly to the bulb, and the positional precision thereof may accordingly be improved. At this time, the contact between the bulb and the pad 21 is made in extremely restricted areas, i.e., in only protruded areas in the mold-match portion 13, but since the hardenable bulking agent 4 is interposed in the gaps between the bulb and-the pad 21, an instantaneous deformation of the bulb at an implosion is stopped by the entire pads 21 through the hardenable bulking agent 4, so resulting in a strong implosion-proof property.

Now, for the hardenable bulking agent 4, which must exhibit such strong breaking force as previously mentioned and should become a hard substance after filling, there may be used epoxy resins, putty (caulking), and the like, but such substances as soft rubber are unsatisfactory. Any substances that will become hard may be employed if there is a suitable bonding agent therefor, and an adhesive force of a particularly high strength is not required in itself.

According to the invention, the momentary deformation of the bulb at an implosion is stopped only by the four corners of the side walls of the mold-match portion of the bulb,'i.e. by the pad sections, so there may apparently be given an impression that the invention is inferior in its implosion-proof property to the abovedescribed prior art wherein the whole periphery of the side walls of the mold-match portion is uniformly tightened by means of a reinforcing band. However, the tensile force due to the reinforcing band is exerted to the maximum upon the four corners, also in the prior art. Furthermore, in practice, the implosion-proof property is assured when the four corners of the side walls of the joined portion remain strongly pressed.

In order to facilitate the tightening of the reinforcing band or to prevent the position of the same from being subject to deviation, it is possible also in the present invention and as shown in FIG. 3 to mount the pads 21 after sticking a single-side adhesive tape 5 so as to surround the side walls of the mold-match portion, and to tighten the pads from the topsides thereof by means of the reinforcing band 3. It has been deduced from experiments that the tension of the reinforcing band in the invention should preferably exceed 150 kg in case of a color picture tube of the 13-inch 90-deflection type.

We claim:

I. An implosion-proof cathode-ray tube comprising a bulb, pad assemblies disposed only on the parts of the side walls of a mold-match portion between a face portion and a skirt portion of a panel portion of said bulb which correspond to the four corners of said bulb, a reinforcing band for tightening said bulb through said pad assemblies, and a hardenable bulking agent filled into gaps between said pad assemblies and said side walls of the mold-match portion.

2. An implosion-proof cathode-ray tube according to claim 1, in which said hardenable bulking agent is selected from the group consisting of epoxy resins and putty.

3. An implosion-proof cathode-ray tube according to claim 1, wherein said pad assemblies each comprise a pad plate and a metallic fixture provided with a bolt hole for assembling the bulb to a cabinet.

4. An implosion-proof cathode-ray tube according to claim 1, which further comprises a single-side adhesive tape surrounding said side walls of the mold-match portion and in which said hardenable bulking agent is filled into gaps between said pad assemblies and said singleside adhesive tape.

5. An implosion-proof cathode-ray tube according to claim 4, in which said hardenable bulking agent is selected from the group consisting of epoxy resins and putty.

Claims

1. An implosion-proof cathode-ray tube comprising a bulb, pad assemblies disposed only on the parts of the side walls of a mold-match portion between a face portion and a skirt portion of a panel portion of said bulb which correspond to the four corners of said bulb, a reinforcing band for tightening said bulb through said pad assemblies, and a hardenable bulking agent filled into gaps between said pad assemblies and said side walls of the moldmatch portion.

4. An implosion-proof cathode-ray tube according to claim 1, which further comprises a single-side adhesive tape surrounding said side walls of the mold-match portion and in which said hardenable bulking agent is filled into gaps between said pad assemblies and said single-side adhesive tape.