System for positioning a rectangular cone for a CRT
AssigneeKoninklijke Philips Electronics N.V.
InventorPeter Antonius Johannes Jacobs
Life of this patent
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Abstract
A positioning system (20) for positioning a cone part of or for a CRT comprises a first and a second positioning means (22, 23) at positions corresponding to two corners of a side of a rectangle, and a third positioning means (21) at a position in the middle of the opposite side. The first and second means (22, 23) have a saddle-shaped contact surface, which is convex in the direction (51) from the tapered end to the wide end and concave (radius of curvature R) towards a central part of the rectangle, a contact surface of the third positioning means (21) is convex in the direction (51) from the tapered end to the wide end and convex or flat in a plane through the contact surfaces of the positioning means.
Claims4
A positioning system (20) for positioning a cone part (4) having a tapered end (4B) and a wide end (4A) for a CRT comprising three positioning means (21, 22, 23), characterized in that the system comprises a first and a second positioning means (22, 23) at positions substantially corresponding to two corners of a side of a rectangle, and a third positioning means (21) at a position substantially corresponding to the middle of a side of the rectangle opposite the above-mentioned side, the first and second means (22, 23) having a contact surface which is convex in a direction (51) from the tapered end to the wide end and concave towards a central part of the rectangle, the third positioning means (21) having a contact surface which is convex in a direction (51) from the tapered end to the wide end, and convex or flat in a plane through the contact surfaces of the positioning means (21, 22, 23).
A method of manufacturing a CRT, the method comprising a step of positioning a cone part (4) of or for a CRT in a positioning system (20), characterized in that a cone part (4) having a tapered end (4B) with a substantially rectangular cross-section and a wide end (4A), the tapered end having two corner parts (4D, 4E) and an opposite side (4E), is positioned in a positioning system (20) which comprises a first and a second positioning means (22, 23) at positions substantially corresponding to two corners of a side of a rectangle, and a third positioning means (21) at a position substantially corresponding to the middle of a side of the rectangle opposite to above-mentioned side, the first and second means (22, 23) having a saddle-shaped contact surface, of a generally convex shape in a direction (51) from the tapered end to the wide end, and a generally concave shape in a direction towards a central part of the rectangle, the third positioning means (21) having a generally convex shape in a direction (51) from the tapered end to the wide end, and a generally convex or flat shape in a plane through the contact surfaces of the positioning means (21, 22, 23), the comer parts (4D, 4E) of the cone part being positioned by the first and second positioning means (22, 23) and the opposite side (4C) being positioned by the third positioning means.
Dependencies are inferred from the claim text.