WO2005055597A1

WO2005055597A1 - Cathode ray tube comprising lugs connecting the tube to a cabinet

Info

Publication number: WO2005055597A1
Application number: PCT/EP2004/053165
Authority: WO
Inventors: Pedro Cosma; Carlo Tulli; Paolo Ginesti
Original assignee: Thomson Licensing SAS
Current assignee: Thomson Licensing SAS
Priority date: 2003-12-05
Filing date: 2004-11-30
Publication date: 2005-06-16
Anticipated expiration: 2006-06-05
Also published as: ITMI20032394A1

Abstract

The invention relates to a cathode ray tube comprising lugs to connect a tube to a cabinet. Each lug (300) has an edge contact surface (302) with the rimband surrounding the front panel of the tube. A hole (308) receives a screw for the connection with a cabinet. The part (310) of each lug which includes the hole (308) forms practically a planar surface which is shifted with respect to two end surfaces (3121, 2122) of the lug, these end surfaces being also substantially planar surfaces.

Description

CATHODE RAY TUBE COMPRISING LUGS CONNECTING THE TUBE TO A CABINET

The present invention relates to a cathode ray tube comprising lugs connecting the tube to a cabinet, such as a TV cabinet. Prior art A screen display 100 (figure 1) , such as the display of a TV set, comprises lugs 102 which are fixed to the cathode-ray tube 104, through a safety rimband 105, and to the cabinet 106 of the screen display. Such lugs 102 must maintain the tube 104 inside the cabinet when considering outward shocks on the cabinet such as drops or hits. For that purpose, the lugs present generally two different kinds of shape, namely: -A flat lug shape, as shown in figure 2a where the lug 202a has a plane shape, or -A ^λI lug shape, as shown in figure 2b where the lug 202b has a first plane part 204 attached to the rimband 205 and a second plane part 206 perpendicular to the first plane part 204.

Deficiencies of the prior art: Flat lug shape or I/ lug shape require an important volume to be lodged within the cabinet, increasing thereby the volume and the cost of producing and distributing the screen display.

Invention: The purpose of the invention is to provide a cathode ray tube with lugs having a shape which increases the clearance of the lug so that its insertion in a cabinet requires a minimal volume while maintaining the stiffness of the lugs to absorb shock energy. So the invention relates to a cathode ray tube comprising lugs to attach the tube to a cabinet, each lug comprising a surface intended to be in fixation contact with an element of the tube and a hole intended to receive a fixing element, such as a screw, for its connection with the cabinet, said cathode ray tube being characterised in that the part of each lug which includes the hole forms practically a planar surface which is shifted with respect to two end surfaces of the lug which are also practically planar surfaces. A cathode ray tube having such lugs presents the advantage that it requires a lower volume compared to a lug of the prior art. Indeed, the shifting of the surfaces, as defined herein above, gives more stiffness to each lug, allowing thereby to limit the amount of material used for its realization and to reduce consequently its volume. In an embodiment, the contact surface of each lug is an edge surface fixed to the tube through a rimband surrounding the front panel of the tube. Preferably, the contact surface of each lug is welded to the rimband. In that case, the edge surface contact of each lug may present, before the welding to the rimband, protrusions or embosses to be melted for the welding to the rimband. The lugs may be attached to the four corners of the rimband. In an embodiment, the part of each lug which comprises the hole has a partially or totally rounded shape opposite to the edge surface attached to the rimband. The end surfaces of each lug may be limited by an edge substantially perpendicular to the surface of the rimband. In an embodiment, in each lug, the area of the part which includes the hole is substantially greater than the area of each end surface. In each lug, each shoulder connecting the part of the lug including the hole to an end surface has two rectilinear parts of different directions . In an embodiment, each lug has an axis of symmetry which includes the centre of the hole. Other features and advantages of the invention will appear with the description of one of its embodiments, this description being made in connection with the drawings wherein: figure 1, already described, is a perspective view of a screen display comprising lugs according to the prior art, figures 2a and 2b, already described, are perspective views of lugs according to the prior art, figures 3a and 3b are perspective views of a lug according to the invention, and figure 4 shows a lug according to the invention which is attached to the rimband of a cathode-ray tube. Description of an e-ribodiment of the invention: Figure 3a represents a lug 300 for a TV set which comprises a cathode-ray tube within a cabinet. The lug is intended to be fixed or attached to the tube, through a contact edge surface 302 extending between two ends 304 and 306, and to the cabinet, through a hole 308 in its central part, this hole receiving a fixing element such as a screw. In this embodiment, the edge contact surface 302 is fixed to the tube through a rimband 205 as will be described with figure 4. More precisely, the contact surface is welded to the rimband. To improve such welding, the lug presents protrusions 303ι-303₄ or embosses which are melted during welding and increase the adherence of the lug to the rimband. The part 310 of the lug 300 which comprises the hole

308 forms practically a plane surface 314 (figure 3b) which is shifted with respect to the plane surface formed by the two end surfaces 312ι and 312₂. Protrusions 303χ and 303₂ are on the ends, respectively, 312_α and 312₂. Protrusions 303₃ and 303₄ are on the central surface 310. The distance, or eccentricity, between the plane surfaces 312ι and 314 provide more stiffness to the lug 300 so that this lug can use a lower amount of material to provide an equivalent stiffness compared to a prior art lug. Therefore, the surface of the lug comprising the hole can have a partially rounded shape, as shown in figure 3a, which increases the clearance of the lug inside the cabinet. In fact, as shown on figure 3a, the edge 320 of the lug which is opposite to the edge contact surface 302 has, on its periphery, the shape of an arc of circle concentric with the circular hole or opening 308. This edge 320 having the shape of an arc of circle extends mainly on the central part 310. The edges of end parts 312ι and 312₂ have main sections 330ι and 330₂ which are parallel to each other and practically perpendicular to the general direction of edge 302, and are connected to rounded edge 320 through practically rectilinear sections, 332χ and 332₂, respectively. The rounded shape of the central part is adapted to the reception of a washer cooperating with a screw of the cabinet. In this example the shoulders 334ι and 334₂ between end planes 312ι, 312₂ and the central plane part 310 extend along a line having two practically rectilinear parts, the first 336ι (for shoulder 334ι ) ends on edge surface 302 and the second 336₂ ends on edge surface 320. In the shown embodiment the lug has a plane of symmetry which includes the centre of hole 308 and is practically perpendicular to the direction of edge 302. When the lug 300 is welded to a corner of the rimband as shown on figure 4, the protrusions 303ι to 303₄ are melted and the edge surface 302, having a shape adapted to the shape of the corner of the rimband, is welded in contact with this corner of the rimband. The invention relates mainly to a cathode ray tube equipped with lugs as described herein above. It relates also to a lug for a cathode ray tube and also to a TV set or a display device having such cathode ray tube.

Claims

1. A cathode ray tube comprising lugs to attach the tube to a cabinet, each lug comprising a surface intended to be in fixation contact with an element of the tube and a hole intended to receive a fixing element, such as a screw, for its connection with the cabinet, characterised in that the part (310) of each lug which includes the hole (308) forms practically a planar surface which is shifted with respect to two end surfaces of the lug which are also practically planar surfaces.

2. A cathode ray tube according to claim 1 wherein the contact surface of each lug is an edge surface fixed to the tube through a rimband surrounding the front panel of the tube.

3. A cathode ray tube according to claim 2 wherein the contact surface of each lug is welded to the rimband.

4. A cathode ray tube according to claim 3 wherein the edge surface contact of each lug presents, before its welding to the rimband, protrusions or embosses to be melted for the welding to the rimband.

5. A cathode ray tube according to any of claims 2 to 4 wherein the lugs are attached to the four corners of the rimband.

6. A cathode ray tube according to any of claims

2 to 5 wherein the part of each lug which comprises the hole has a partially or totally rounded shape opposite to the edge surface attached to the rimband.

7. A cathode ray tube according to claim 6 wherein the end surfaces of each lug are limited each by an edge substantially perpendicular to the surface of the rimband.

8. A cathode ray tube according to any of the previous claims wherein, in each lug, the area of the part (310) which includes the hole is substantially greater than the area of each end surface (312i, 312₂) .

9. A cathode ray tube according to any of the previous claims wherein, in each lug, each shoulder (334ι) connecting the part of the lug including the hole to an end surface has two rectilinear parts (336ι, 336₂) of different directions .

10. A cathode ray tube according to any of the previous claims wherein each lug has an axis of symmetry which includes the centre of the hole.