GB2251265A - Clip for coupling inner shield with frame of electron mask, in cathode ray tube - Google Patents

Abstract

A clip for coupling an inner shield with a frame of cathode ray tube includes a first elastic bent portion (1) forming a peaked end of the clip and bent at an angle of 60 to 90 degrees; first bent portions (2) formed by inwardly bending the extensions of the first elastic bent portion; second bent portions (3) formed by outwardly bending the extensions of the first bent portions; second elastic bent portions (4) formed by bending in the shape of U the extensions of the second bent portions: and grasping portions (5) provided in the form of downward extensions of the second elastic bent portions. <IMAGE>

Description

CLIP FOR COUPLING INNER SHIELD WITH FRAME BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION The present invention relates to a clip for coupling an inner shield with the frame of a cathode ray tube.

2. DESCRIPTION OF THE PRIOR ARTS.

A cathode ray tube, and particularly a shadow mask type cathode ray tube is provided with a frame for installing a shadow mask, and the frame is for attaching not only the shadow mask but also an inner shield for shielding the influence of the geomagnetic field.

It is impossible to form the frame and the inner shield integrally due to their structural natures, and therefore, they are separately manufactured, the coupling of them being performed in the assembling process. A clip is required for coupling the frame and the inner shield in the assembling process, ad the clip has to satisfy the following three conditions. First, the couplability of the clip has to be sufficient, and the inner shield should not be oscillated or vibrated upon receipt of external forces; second, the productivity of the clip should be good; and third, the clip should ease the coupling of the inner shield with the frame.

As shown in Figure 1, the conventional clip includes: an elasticity providing portion A having a self elasticity and formed in a V shape; a pair of shoulders S symmetrically extended in the opposite directions from the elasticity providing portion A; and a pair of handles B extended from the shoulders S. When an inner shield I is overlappingly combined with a frame F, securing holes H are let to be matched with the frame F, and then, the clips are inserted through the securing holes in such a manner that the frame and the inner shield should be coupled between the elasticity providing portions A and the shoulders S.

An example of a such a conventional clip is Japanese Patent Application Laying-opening No. Sho 55-154041, and another example is Japanese Patent Publication No. Sho 62-13787.

Figure 2 illustrates the clip of Japanese Patent Application Laying-opening No. Sho 55-154041, and according to this device, a mask frame for retaining the shadow mask and a magnetic shielder for shielding external magnetic fields are fixed together by inserting elastic supporting members into the holes formed in the mask frame and the magnetic shielder. The supporting members are constituted such that: they take a V shape; a depressed portion 21 is provided at the middle of each side in an inwardly projected manner; a leading end portion 25 is extended to a pair of bent portions 22 having an acute angle; and respective rear end portions 24 of the V shaped clip extend to another pair of bent portions 23, these bent portions 23 being disposed outwardly to the depressed portions 21, and the clip being to be applied to a color picture tube.

Another example of the prior art, i.e., Japanese Patent Application Laying-opening No. Sho 62-13787 is illustrated in Figure 3, and this device is applied to a shadow mask type color picture tube. This device is proided in the form of a V shaped spring, and includes a bent portion 31, and a pair of neck portions 32 which are engaged within the holes of a support frame and a shielding member. In the front and rear of the neck portions 32, there are provided first and second shoulders 33, 34, and the first shoulder portion 33 is formed between the bent portion 31 and the neck portions 32, while the width of the second shoulder portion 34 is larger than that of the first shoulder portion 33.

The above-described two examples of the prior art place emphasis on the two conditions among the above-mentioned three conditions. That is, they focused on the couplability of the clip and the productivity of the clip, while the workability of the clip is disregarded.

The clips of the above-described two examples take a gentle V shape, and the installing of the clip is manually carried out.

However, the portion grasped by the worker, i.e., the two end portions of the V shaped clip are sloped, and therefore, they are liable to be slipped away from the hands of the worker. If the clip is slipped from the hands of the worker upon grasping it, the clip is sprung off due to the self elasticity of the clip, hereby causing the delay of the working and loss of the component.

SUMMARY OF THE INVENTION It is the object of the present invention to provide a clip for coupling an inner shield with a frame, which is acceptable in its couplability and productivity, and is superior in its workability.

The inventor's conception lies in the face that, whereas the securing holes of the inner shield and the frame for inserting the conventional clip are rectangular, if the securing holes are formed in a circular form, and if the clip is so formed as to be fit to the circular securing holes, the workability is greatly improved.

In chieving the above object, the clip for coupling the inner shield with the frame of the cathode ray tube according to the present invention is constituted such that it forms an approximate V shape by being bent at an angle of 60 - 90 degrees, and further comprises: a pair of first bent portions which are formed by inwardly bending in the shape of V the extensions of a first elastic bent portion which is the ultimate corner tip of the clip and which endows the clip with elasticity at positions a certain distance from the first elastic bent portion; a pair of second bent portions which are formed by outwardly bending the extensions of the first bent portions at positions a certain distance from the corners of the first bent portions; a pair of second elastic bent portions which are formed by bending in the shape of U the extensions of the second bent portions at positions a certain distance from the corners of the second bent portions; and a pair of grasping portions which are provided in the form of downward extensions of the second elastic bent portions, the grasping portions being endowed with elasticity by the second elastic bent portions, and the inner shield and the frame being coupled between positions on inclines formed between the first bent portions and the second bent portions and the lower ends of the grasping portions.

BRIEF DESCRIPTION OF THE DRAWINGS The above object and other advantages of the present invention will become more apparent by describing in detail the preferred embodiment of the present invention with reference to the attached drawings in which: Figure 1 is a perspective view showing a conventional frame clip, and an example of the use thereof; Figure 2 is a sectional view showing a state of coupling between the frame and inner shield by means of the conventional clip; Figure 3 is a sectional view showing a state of the coupling between a frame and an inner shield by means of another conventional clip; Figure 4 is a perspective view showing an embodiment of the clip of the present invention; Figure 5 is a sectional view showing a state of the coupling between the frame and an inner shield by means of the clip of Figure 4;; Figures 6a is a perspective view showing another embodiment of the clip of the present invention, in which the grasping portions are modified; Figures 6b, 6c, and 6d are perspective views showing still other embodiments of the clip of the present invention, in which only parts are illustrated in an enlarged scale.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Figure 4 is a perspective view showing an embodiment of the clip of the present invention. As shown in this drawing, the clip is bent in the shape of V at an angle of 60 to 90 degrees, thereby forming a first elastic bent portion 1.

The two portions of the V shaped clip are inwardly bent in the form of V shape at a certain distance from the first elastic bent portion 1, thereby forming a pair of first bent portions 2.

At a certain distance from the first bent portions, the extensions of the first bent portions 2 are outwardly bent in the shape of V, thereby forming a pair of second bent portions 3.

The extensions of the second bent portions 3 are again bent in the shape of U at an angle of about 180 degrees at a certain distance from the second bent portions 3, thereby forming a pair of second elastic bent portions 4. The outer extensions of the second elastic bent portions 4 form grasping portions 5 for being grasped by the user, and these grasping portions 5 lie approximately on the same straight line as the portions between the first elastic bent portion 1 and the first bent portions 2.

As shown in Figure 6a, the middle points of the grasping portions 5 can be bent in the shape of V so that the grasping portions 5 should have outwardly open recesses. The leading ends of the grasping portions 5 can be formed in such a manner that they should have projected corners or depressed corners, thereby making each of them have one or two peaks as shown in Figures 6b and 6c.

If the clip of the present invention constituted as described above is inserted into the securing holes of a frame and an inner shield, then as shown in Figure 5, the edge portion of the securing hole of the frame is contacted to the inclined portions which are formed between the first bent portions 2 and the second bent portions 3, while the upper face of the inner shield is contacted with the leading ends of the grasping portions.

The coupling function of the clip of the present invention is performed not only by the elastic force of the first elastic bent portion 1, but also by the elastic forces of the second elastic bent portions 4, and therefore, the clip of the present inventions is capable of exerting stronger pressing forces in the coupled state compared with the clips of the conventional techniques. Based on a principle same as that of a wedge, as the contacting angle (the angle e of Figure 5) between the frame and the inclined portions between the first bent portions 2 and the second bent portions 3 becomes smaller, the above mentioned pressing forces become stronger.

Further, if each of the leading ends of the grasping portions 5 is not let to have a flat face, but let to have one or two peaks, then the contact between the leading ends of the grasping portions 5 and the upper face of the inner shield is made not in the form of a linear contact, but in the form of a point contact, and therefore, the probability of slipping-away of the leading ends of the grasping portions from the upper face of the inner shield is greatly reduced.

Further, if the middle of each of the grasping portions 5 is bent at a gentle angle as described above, the contact between the leading ends of the grasping portions 5 and the upper face of the inner shield is further improved, as well as giving a convenience to holding the clip by the user. That is, as described above, the angle of the peak of the clip according to the present invention is 60 to 90 degrees, and therefore, the clip of the present invention raises no apprehension that it might be slipped away from the hand of the user, while, if the middle of each of the grasping portions 5 of the clip is gently bent, then such an apprehension is further eliminated.

As described above, the conventional clips are so made as to be fit to rectangular securing holes. But the clip of the present invention is bent at an angle of 60 to 90 degrees at the peak point, and therefore, the clip of the present invention can be used not only to the circular securing holes but also the rectangular securing holes. If circular securing holes are introduced, the direction (lateral or longitudinal) requirement is eliminated, and therefore, the following additional advantages are gained in addition to the above described one.

First, a convenience is obtained in manufacturing the punch and the die for forming the securing holes on the inner shield and frame, and in repairs thereof.

Second, the contact between the clip and the edge of the circular securing hole of the frame is formed at four points as shown in Figure 4d, and therefore, any slipping of the clip is prevented.

Third, in installing the clip of the present invention into the circular securing holes, the working direction, i.e., the position of the clip relative to the securing holes does not have to be considered, and therefore, the working efficiency is improved.

Claims (3)

1. A clip for coupling an inner shield with a frame of cathode ray tube, comprising: a first elastic bent portion forming a peaked end of the clip and bent at an angle of 60 to 90 degrees, said clip being endowed with elasticity by said first elastic bent portion; a pair of first bent portions formed by inwardly bending in the shape of V the extensions of said first elastic bent portion at a certain distance from said first elastic bent portion; a pair of second bent portions formed by outwardly bending in the shape of V the extensions of said first bent portions at a certain distance from said first bent portions; a pair of second elastic bent portions formed by bending in the shape of U the extensions of said second bent portion at a certain distance from said second bent portions; and a pair of grasping portions provided in the form of downward extensions of said second elastic bent portions, the grasping portions being endowed with elasticity by said second elastic bent portions, and said inner shield and said frame being coupled between positions on inclines formed between said first bent portions and said second bent portions and the lower ends of said grasping portions.

2. The clip for coupling an inner shield with a frame of cathode ray tube as claimed in claim 1, wherein the leading ends of said grasping portions are let to have one or more peaks in an angular form or halfmoon shaped form with the peak cut off flat.

3. The clip for coupling an inner shield with a frame of cathode ray tube as claimed in any one of claims 1 and 2, wherein the middle of each of said grasping portions is bent at a gentle angle in the shape of V or deflected in a round form so as for said grasping portion to have an outwardly open recess.